EP4168083A1

EP4168083A1 - Device, method and computer program for determining conditions of a patient

Info

Publication number: EP4168083A1
Application number: EP22713252.9A
Authority: EP
Inventors: Marcus Eger; Frank Franz
Original assignee: Draegerwerk AG and Co KGaA
Current assignee: Draegerwerk AG and Co KGaA
Priority date: 2021-06-18
Filing date: 2022-02-28
Publication date: 2023-04-26
Also published as: US20240207552A1; DE102022101845A1; WO2022262887A1; DE102022101848A1

Abstract

The invention relates to a device, a method and a computer program relative to determining conditions during breathing or ventilation. Described are concepts for obtaining, acquiring or determining information. Information, for example with respect to the respiratory musculature of the patient, a resilience of a patient, a need for support in breathing and with respect to the possibilities of adequately stimulatively supporting breathing is very valuable in the treatment and therapy of living beings or patients.

Description

Apparatus, method and computer program for determining patient situations

Situations of a patient, in particular situations when ventilating a patient or supporting the ventilation or breathing of a patient require information about the patient, for example with regard to the patient's respiratory muscles, with regard to the patient's resilience, with regard to the patient's need for respiratory support and also with regard to the Possibilities of adequately stimulating the patient's breathing.

Obtaining information regarding such information with concepts for determining states of a patient in the environment of breathing and/or ventilation forms the basis for the tasks presented in the context of the following description and their solutions.

The present invention relates to a device, a method and a computer program for determining a state of a patient's respiratory muscles, in particular, but not exclusively, to a concept for determining at least one state parameter of the respiratory muscles of a patient based on an evaluation of an activation signal in response to a stimulation of the respiratory muscles.

The present invention also relates to a concept for determining a load capacity and a measure for a portion of the ventilation that is performed by the patient himself and for taking into account the load capacity and the measure when supporting the ventilation. In a further aspect, the present invention relates to a ventilation system, a device, a method and a computer program for ventilation of a patient

The present invention also relates to a concept for determining a measure of respiratory support for a patient based on target respiratory muscle activation and actual respiratory muscle activation. In a further aspect, the present invention relates to a device, a method and a computer program for a component of a ventilation system for respiratory support of a patient, a ventilation device, a stimulator, a sensor unit, methods and computer programs for a ventilation device, a stimulator and a sensor unit , a ventilation system, a method and a computer program for a ventilation system. The present invention also relates to a concept for stimulative ventilation support for a patient synchronized with a spontaneously generated respiratory muscle activity of the patient. In a further aspect, the present invention relates to a ventilation system, a device, a method and a computer program for stimulative ventilation support of a patient.

All of the above concepts and/or aspects of the invention combine in an effort to improve a patient's situation on ventilation by providing an adequate response to the patient's actual situation of workload, exercise tolerance and the patient's need for respiratory support. The provision can take the form of concepts and measures relating to the performance of automated ventilation and/or the performance of stimulations to activate the patient's respiratory effort. Automated ventilation can be carried out as mandatory ventilation, triggered mandatory ventilation, supportive ventilation.

The preservation and recovery of spontaneous breathing has long had a high priority in intensive care medicine. In the event that spontaneous breathing is not possible for the patient, lung-protective ventilation is used, which is intended to damage the lung tissue as little as possible. The protection of the respiratory muscles, especially the diaphragm, has only recently come into focus. The prior art of the present invention can be found, for example, in the following documents:

US 5,820,560 B1, US 7,021,310 B1, WO 2019 1548 34 A1, WO 2019 1548 37 A1,

WO 2019 154839 A1, WO 20200792 66 A1, WO 2020 188069 A1, DE 102019 006480 A1, US 20170252558 A1, DE102019006480 A1,

US20150366480A1, US20120103334A1, US20170252558A1,

DE 102019 007717 B3, DE 102020000014 A1, DE 102007062214 B3,

WO 2018 143844 A1, DE 102015 011 390 A1. DE 102015011 390 A1,

DE 102021 115865 A1, DE 102020 123 138 A1, DE 102007 052 897 B4. The sources listed below provide additional information on the technical, medical-technical, medical and clinical background. The list below includes an exemplary selection of papers and publications on the acquisition and processing of different measurement signals or signals in/on the human body and their use in the context of ventilation, ventilation control, as well as in the environment of ventilation with respiratory stimulation. Walker, DJ: "Prediction of the esophagus pressure by the mouth closure pressure after magnetic stimulation of the phrenic nerve", dissertation University of Freiburg: 2006.

Kahl, L. et. AI.: "Comparison of algorithms to quantify muscle fatigue in upper limb muscles based on sEMG signals", Medical Engineering & Physics: 2016. Jansen D. et. al.: “Estimation of the diaphragm neuromuscular efficiency index in mechanically ventilated critically ill patients”, Critical Care: 2018.

Liu L et. al.: "Neuroventilatory efficiency and extubation readiness in critically ill patients", Critical Care: 2012.

Cattapan, S.E. et. al: "Can diaphragmatic contractility be assessed by airway twitch pressure in mechanically ventilated patients?", Thorax: 2003.

Younes, M. et. al. "A method for monitoring and improving patient ventilator interaction," Intensive Care Med: 2007.

Blanch Lluis et. al. "Measurement of AirTrapping, Intrinsic Positive End-Expiratory Pressure, and Dynamic Hyperinflation in Mechanically Ventilated Patients", Respiratory Care: 2005. Purro A. et. al. "Static Intrinsic PEEP in COPD Patients during Spontaneous Breathing", AJRCCM: 1988.

Bernardi E. et. al. "A New Ultrasound Method for Estimating Dynamic Intrinsic Positive Airway Pressure: A Prospective Clinical Trial", AJRCCM: 2018.

Pisani L. et. al. "Noninvasive detection of positive end-expiratory pressure in COPD patients recovering from acute respiratory failure", European Respiratory Journal: 2016.

Bellani, G. et. al. "Clinical Assessment of Auto-positive End-expiratory Pressure by Diaphragmatic Electrical Activity during Pressure Support and Neurally Adjusted Ventilatory Assist", Anesthesiology: 2014.

Younes, M. "Dynamic Intrinsic PEEP (PEEPi.dyn) Is It Worth Saving?", AJRCCM: 2000. Shalaby, RE-S.: "Development of an Electromyography Detection System for the Control of Functional Electrical Stimulation in Neurological Rehabilitation", PhD thesis, 2011.

Younes, M. et. al. "A method for monitoring and improving patient ventilator interaction," Intensive Care Med (2007).

Putensen C. et. al. "Long-term effects of spontaneous breathing during ventilatory support in patients with acute lung injury", AM Journal Respir Crit Care Med 2001.

Otis, A.B. et. al.: "Mechanics of Breathing in Man", J Appl Physiol. 1950

Osuagwu, BAC et. al. "Active proportional electromyogram controlled functional electrical stimulation system", Nature 2020. Virtanen, J. et. al. "Instrumentation for the measurement of electric brain responses to transcranial magnetic stimulation", Med. Biol. Eng. Computer., 1999.

These and other documents are referred to in part for specific aspects of the invention as the description proceeds. In some cases, instead of extensive citations, references [E1] to [E38] to a table 4 included after the description of the figures are used.

In order to avoid ambiguities due to linguistic formulations, some notes on understanding and some explanations on the use of terms are given at the beginning of the application. In the description and/or the patent claims, within the scope of the present invention or

Inventions those formulations in verbal form, substantiated verbal form, which in the method, or also through configurations of a control unit in configurations of the devices, such as and in particular "determining", "high-pass filtering", "determining", "stimulating" , "a performing", "a transforming", "an outputting", "a capturing", "a setting" are used with the same meaning as formulations with nouns in a noun form, such as and in particular "a determination", "a high-pass filtering ", "a determination", "an implementation", "a transformation", "an output", "an acquisition", "an adjustment", "a stimulation". With regard to the disclosure of the invention, or inventions arise equivalent and equivalent

Meanings for the formulations with nouns, nouns, substantiated verbs and verbs, so that for features and details between the verbal form and substantiated form with regard to the revelation, reference is always made to each other, or can be referred to. In doing so, formulations with “implementation of determinations, high-pass filtering, stimulation,

Stimuli, determinations, acquisitions, inputs, outputs, transformations, etc.”, meanings of equivalent and equivalent effect are deemed to be implied. Features and details that are described within the scope of the present inventions in connection with devices and embodiments of devices, of course, also apply in connection with the methods described within the scope of this invention and their embodiments, as well as vice versa, so that with regard to the disclosure of individual aspects of the invention are always mutually referred to, or can be. Furthermore, formulations which are used to designate and assign parts, units, elements or modules in or on devices or systems can be used synonymously for one another and correspond to the technical details, such as "control unit" and "Control Module". The same applies, for example, to the term “stimulator”; a stimulator can also be referred to as a stimulation device or a device for stimulation. The same applies, for example, to the designation "respirator", a respirator can also be referred to as a respiration device or a device for respiration.

DE 102019006480 A1 [E14] describes a method that allows an estimation of shares in the work of breathing by means of electromyography of the respiratory muscles. Electromyography (EMG) is a neurological examination of living things that measures the natural electrical activity of a muscle. Electromyography (EMG) makes it possible to determine the force with which a muscle is contracted. Measurements on superficial muscles are also referred to as sEMG. Electrical impedance myography (EIM) is a non-invasive technique for assessing muscle health, using electrical impedance measurements to examine the characteristics of individual muscles or muscle groups, as well as muscle composition and their microscopic structures. Myomechanography (MMG) is a method for recording elastic, viscous and plastic qualities of muscles. The Pmus parameter represents a value derived from a measured EMG signal (electro-myogram), an sEMG signal (surface electro-myogram), an EIM signal (electro-impedance myogram) or an MMG signal (mechano-myogram ) derived quantity. The parameter Pmus indicates a pressure level which has been caused by a patient's muscular effort to breathe. The cause of the muscular effort to breathe can be initiated by the patient himself in the form of spontaneous breathing activity and/or brought about by means of an external, for example electrical, magnetic or electromagnetic stimulation. On the one hand, the muscular respiratory effort can be derived indirectly from electrical, electromagnetic or magnetic signals. Muscular respiratory effort can also be measured directly as a pressure difference compared to a reference pressure, for example by measuring the pressure on a patient's thorax. The ambient pressure can be selected as the reference pressure or a pressure level provided by a ventilator. Pressure levels typically provided by the ventilator are, for example, an inspiratory pressure level, usually referred to as inspiratory pressure or inspiration pressure Pinsp, as well as, for example, an expiratory pressure level, usually referred to as expiratory pressure or expiratory pressure Pexp, a special case The expiratory pressure level is what is known as PEEP (positive end expiratory pressure), which describes a pressure level that can be measured at the end of expiration in the patient's airways as a pressure difference compared to the ambient pressure. Both the inspiratory pressure Pinsp and the expiratory pressure Pexp are measured as a pressure difference compared to the

Ambient pressure recorded and usually specified in the unit mBar. Such a parameter Pmus can also be referred to as a respiratory muscle pressure Pmus.

In the description and/or the patent claims, the terms “muscular airway pressure”, “respiratory muscle pressure” with formulations such as “parameter Pmus”, “pressure parameter Pmus”, “pressure parameter or parameter P, Pmus, which indicates a pressure which has been caused by a patient's muscular respiratory effort", "a respiratory pressure Pmus applied by a patient's musculature" is used in an equivalent and equivalent manner, so that the term can be referred to reciprocally. The Flowmus parameter represents a quantity derived from the Pmus parameter. Higher frequencies in the Pmus waveform can provide a measure of muscle-related components, flow direction, and reversal of flow direction in airway flow. The high-pass filtering of the Pmus parameter can be used to determine the Flowmus parameter. With the term airway flow

Flow rates referred to as volumes that flow into the patient during inhalation phases, i.e. are inhaled, or flow out of the patient during exhalation phases, i.e. are exhaled. The Flowmus parameter indicates a flow quantity with a flow direction, the cause of the flow being based on a patient's muscular effort to breathe. The cause of the muscular effort to breathe can be initiated by the patient himself in the form of spontaneous breathing activity and/or brought about by means of an external, for example electrical, magnetic or electromagnetic stimulation. Such a parameter Flowmus can also be referred to as a muscular airway flow or also as a respiratory muscle flow Flowmus. Signal processing with high-pass signal filtering of the signal curve of the Pmus parameter makes it possible to determine muscle-related respiratory phase changes and times in the Flowmus parameter at which there is a reversal of the sign of the Flowmus parameter. The reversal of the sign of the Flowmus parameter indicates points in time at which a respiratory phase change between

Inhalation phases (inspiration) and exhalation phases (expiration) are given, which are based on the patient's muscular breathing efforts. In the description and/or the patent claims, the terms "muscular airway flow", "respiratory muscle flow" with formulations such as "parameter flowmus", "flow parameter flowmus", "flow parameter or parameter flow,

Flowmus, which indicates a pressure which has been caused by a patient's muscular respiratory effort", "a Flowmus produced by a patient's musculature" is used in an equivalent and equivalent manner, so that the term can be referred to reciprocally. The following list serves to clarify some of the terms used in this application:

• In the context of the present invention, an airway pressure is a pressure or a pressure level—usually and usually above the ambient pressure—in the airways, lungs, trachea of a living being.

• Under a muscular airway pressure or a respiratory muscle pressure is understood in the sense of the present invention, a respiratory pressure applied by a musculature, a proportion of the airway pressure, in particular on the basis - spontaneous or stimulated - muscular activity of the respiratory muscles and / or muscular activity of the auxiliary respiratory muscles of the living being .

For the purposes of the present invention, a respiratory flow or a respiratory gas flow is understood to mean any movement of quantities of respiratory gas as a quantity of inhaled gases to and into a living being, as well as out of and from a living being as a quantity of exhaled gases.

• Under a muscular airway flow (or a respiratory muscle flow) within the meaning of the present invention, any movement of amounts of respiratory gas as an amount of inhaled gases towards and into a living being, as well as from and from a living being as an amount of exhaled gases on the basis - spontaneous or understood - stimulated muscular activity of the respiratory muscles and / or muscular activity of the auxiliary respiratory muscles of the living being.

The terms muscular airway pressure and respiratory muscle pressure are used synonymously within the scope of the present invention. The terms muscular airway flow and respiratory muscle flow are used synonymously within the scope of the present invention.

The respiratory musculature consists of the main inspiratory muscle, the diaphragm, and the auxiliary musculature. These include the external (inspiratory acting) and internal (expiratory acting) intercostal muscles and the expiratory acting abdominal muscles. It was found that long ventilation times and excessive support of spontaneous breathing cause the diaphragm to atrophy and make time-consuming weaning necessary. On the other hand, due to increased respiratory load (obstruction,

restriction) become exhausted and damaged (fatigue). In certain situations, some patients tend to make great efforts to breathe themselves, which in turn can damage the lungs. The prior art describes how respiratory muscles can be stimulated. All muscles can be stimulated directly by activating muscle fibers or the feeding efferent nerves.

For example, the muscle fibers of the diaphragm can be stimulated directly transcutaneously. Alternatively, the phrenic nerve, which is responsible for contracting the diaphragm, can be stimulated. In both cases, the muscles are activated and contracted. The aim of these procedures is to improve weaning, to promote evacuation of secretions and possibly also to avoid ventilation or respiratory support. In contrast to ventilation or assisted spontaneous breathing, it is not necessary to administer a breathing gas. In US 20170252558A1, as well as in Cattapan, S.E. et. al: "Can diaphragmatic contractility be assessed by airway twitch pressure in mechanically ventilated patients?", Thorax: 2003; a flow and pressure sensor is used to determine the patient's work of breathing and adjust stimulation to achieve a target corridor. However, there is no information technology connection to a ventilator. Respiratory mechanics parameters must be taken from the ventilator's graphical user interface and entered manually into the separate stimulator. Furthermore, with conventional ventilators one cannot rely on the displayed values of the respiratory mechanics calculated from pneumatic signals as long as the patient is breathing strongly spontaneously. This means that the measured amount of work of breathing is only a rough estimate.

Accordingly, no method is known to date that can adequately adjust and coordinate ventilation and stimulation, particularly with regard to the work of breathing to be performed. The fact that stimulation and ventilation have to be coordinated in their basic mechanism is self-evident and known, for example from WO2019154834, WO2019154837, WO19154839, WO2020079266, US2017/0252558A1. So far, however, there is no method that measures the degree of Support and stimulation can specify, for example, depending on a therapy goal. The minute volume required for the patient as well as threshold values and limits of the machine pressure support (trigger, pressure, frequency) are usually set. The part to be paid by the patient can hardly be determined, since there has not been a sufficiently precise way to date

division of the work of breathing between the machine and the patient. A procedure in which the respiratory mechanics parameters of the ventilator used are manually transferred and then used in the stimulator is practically unaffordable: the parameters change, e.g. after the patient has been repositioned. They would therefore have to be entered repeatedly. In addition, they are very imprecise as long as only pneumatic signals were used in the ventilator to determine the parameters. Little is known about how much the patient actually performs, as this would require knowledge of the patient's contribution to the driving pressure (Pmus) or breathing gas flow (FlowMus). DE 102019 006480 describes the estimation of these respiratory work shares using electromyography of the respiratory muscles.

For procedures with "Neurally Adjusted Ventilatory Assist" (NAVA), as described e.g. in: Sinderby et al. ”ls one fixed level of assist sufficient to mechanically ventilate spontaneously breathing patients?”, Yearbook of intensive care and emergency medicine, 2007, as well as Sinderby et al.: "Neural control of mechanically ventilation in respiratory failure", Nature Medicine 1999; the electrical activity of the diaphragm (EAdi) is recorded using a modified stomach tube equipped with electrodes in order to regulate the pressure support of the ventilator proportionally to this electrical activity.

From US Pat. No. 7,021,310 B1, a special, proportionally supporting NAVA method using a signal for the electrical activity of the diaphragm is known, the special feature of which is that the electrical activity of the diaphragm required for a specific respiratory volume (the so-called neuroventilatory efficiency) is determined by means of a " closed-loop” control should be kept constant.

From US 2009 159082 AA, or DE 102007062214 B3 - on their explanations in the description of this application also expressly with regard to the disclosure of terms such as "musculature", "respiratory muscles", "muscular airway pressure",

"Respiratory muscle pressure""ParameterPmus","Pressure parameter Pmus", "Pressure parameter or parameter Pmus, which indicates a pressure which is caused by a muscular respiratory effort of a patient has been caused" a reference is to be made - there are variants of how the pressure parameter Pmus, or the "muscular airway pressure" or respiratory muscle pressure Pmus, _pmus (t) can be determined, for example. The respiratory muscle pressure p _mus (t) can be determined, for example, in the following way: a) Calculation from measured values for airway pressure, volume flow Flow(t), from which the tidal volume Vol(t) results through integration, as well as the pulmonary mechanical parameters R (resistance) and E (elastance). b) Determination by equating with the negative airway pressure -P _okkl (t) measured during an occlusion, with the pulmonary mechanical parameters R and E either also being calculated or being predetermined. c) Determination by means of an esophagus catheter, which is equipped with pressure sensors for measuring the intrathoracic pressure Pes(t). The esophageal catheter can optionally be equipped and used to measure the abdominal pressure Pabd(t). d) Determination by means of an arrangement of surface electrodes or sensors, which are arranged on the thorax and deliver electromyographic or mechanomyographic electrical signals, which, using suitable assignment rules, tables, functions or conversion parameters, for example the so-called "neuromechanical efficiency" or "neuromuscular efficiency" (NME) to the respiratory muscle pressure P _mus (t), or by means of the so-called "neuroventilatory efficiency" (NVE) can also be related to a volume V _mus (t). e) Determination by means of a gastric probe equipped with electrodes, which supply electrical signals which can be related to the respiratory muscle _{pressure Pmus} (t) by means of suitable assignment specifications, tables, functions or conversion parameters. The variants of the determination of _Pmus (t) or Pmus listed in a) to e) and the other components required for their implementation in a device, system or method, such as sensors, electrodes, surface electrodes, pressure sensors, flow sensors, Stomach tube, esophagus catheter each arise according to the variant. The respiratory activity signal u _emg (t) can be subjected to a transformation into a pressure signal p _emg (u _emg (t)) by means of a predetermined transformation rule. The transformation rule can be determined by linear or non-linear regression between U _emg (t) and P _mus (t) are determined or with other procedures, such as. B. with neural networks, machine learning, or simple scaling+. The following linear regression equation can be used as an example to determine the regression coefficients for the transformation rule sought

P _mus (t) ⁼ a ₀ + a ₁ *U _emg (t) + a2*U ² _emg (t) + a3*u ³ _emg (t) + (t) are used, with which finally a transformed p _emg (t)- Signal for further use, for example for ventilation control and/or for stimulation.

Proceeding from this, the tasks arise for which solutions and concepts are provided by the aspects of the present invention.

Proceeding from this, it is an object of the present invention to provide an improved concept for diagnostics in a therapy method.

A further object is to provide an improved concept for supporting a patient during ventilation.

A further object is to create an improved concept for respiratory support for a patient.

A further object is to create an improved concept for stimulative ventilation support for a patient.

This and other objects are solved according to the subject-matters of the dependent independent claims.

The object is achieved in particular by a device having the features of patent claim 1.

The objects are further achieved by devices with the features of patent claims 14, 27, 40.

These issues are further solved by methods having the features of claims 53, 54, 55, 56. These issues are further solved by computer programs with the features of patent claim 57.

Advantageous embodiments of the invention result from the dependent claims and are explained in more detail in the following description with partial reference to the figures.

The following designations are used below, with the following variables changing over time, as shown in Table 1 below:

The present description uses the following terms and definitions of terms: (Muscular) breathing effort: The term is used in a generic sense. It describes the patient's muscular effort to generate respiratory muscle pressure in order to achieve airway flow. If the respiratory effort is occluded, ie the airway flow is interrupted by a blockage, then there is a respiratory muscle pressure generated (which can be measured as "mouth pressure" when the airways are open), but no airway flow occurs. It is an isometric contraction of the respiratory muscles. The respiratory effort always corresponds to a physiological work, which cannot be measured directly. On the other hand, measurable physical work is only done when the contraction is not isometric, ie when an airway flow is generated.

Breathing support:

Breathing support is a ventilatory counterpart to muscular breathing effort. The ventilator supports the patient's detected (triggered) respiratory effort synchronously with a support stroke. The patient determines the breathing rhythm. It can be pressure-controlled support (airway pressure is set) or, more rarely, volume-controlled support (tidal volume is set). In all cases, the ventilator performs physical work, i.e. part of the total work of breathing to be performed is relieved of the patient.

(Mandatory) ventilation:

With mandatory ventilation, the patient does all the work of breathing. The breathing rhythm is determined by the machine. Normally, the patient is passive during mandatory ventilation, so there is no conflict between human/patient and machine. The patient's passivity is often achieved by administering sedatives and relaxants. WOB - Breathwork:

This is the physiological or physical work done for breathing and/or ventilation. In the case of isometric contraction, no physical work is performed in the sense of the equation of motion, as explained below in the further course of the description. However, other definitions of work can be used, e.g. the so-called pressure-time product (time integral).

WOBtot - Total work of breathing:

This is the entire physiological or physical work done for breathing and/or ventilation. WOBvent - machine/fan-side work of breathing:

This is the portion of the work of breathing done by the ventilator.

WOBmus - patient-side (muscular) work of breathing:

This is the portion of the work of breathing performed by the patient alone, both with and without muscle stimulation.

WOBspon - Spontaneous (patient-side) work of breathing:

This is the work of breathing done by the patient's spontaneous breathing. The muscles are not stimulated.

WOBstim - Stimulated (patient-side) work of breathing:

This is the work of breathing done by stimulating the patient's respiratory muscles.

Pdrv - Driving Pressure:

Pdrv is the sum of the pressures applied by the ventilator and the patient.

Pvent - ventilation pressure:

Pvent is the pressure applied by the ventilator.

Pmus - muscle pressure:

Pmus is the pressure exerted by the patient's muscles alone, both with and without muscle stimulation.

Pspon - Spontaneous Muscle Pressure:

Pspon is the proportion of muscle pressure that is applied spontaneously, i.e. without stimulation, by the patient.

Pstim - Stimulated Muscle Pressure:

Pstim is the proportion of muscle pressure that is exerted by the patient solely due to the stimulation of the muscles.

WOBbase or PmusBase - basic respiratory load:

The basic respiratory load can be equated with the work of breathing or the driving pressure that is necessary to overcome the resistive, elastic and possibly other resistances and a sufficient volume (e.g. that of clinical staff set minute volume) with a healthy breathing pattern. An energy-optimized pattern is preferably assumed as the breathing pattern.

The work of breathing or the driving pressure can be applied by the patient and/or the machine. The latter would be the case with (mandatory) ventilation.

respiratory load:

The respiratory load can be determined by recording the work of breathing or the driving pressure that is actually required for ventilation. The respiratory load is normally higher than the basic respiratory load because the patient's breathing rhythm is not energy-optimized, the patient is aiming for a higher volume than necessary due to hunger for air, for example, or there is asynchrony between the patient and the ventilator. In the case of respiratory support, the ventilator takes over part of the respiratory load.

Activation signal:

This is a signal that captures the neuronal activation of the muscle (whether evoked by stimulation or spontaneous respiratory effort), e.g. the (s)EMG (Surface electro-myogram), EIM (Electro-impedance-myogram), MMG (Mechanomyogram ). Alternatively, signals can also be used that are detected using innovative optical or acoustic (e.g. ultrasonic) technology. In the following, without excluding other signals, the envelope of the EMG is used as the activation signal (referred to as “EMG” for the sake of simplicity). This is not to exclude the possibility that there are different activation signals from different muscle groups (e.g. diaphragm and intercostal muscles), each of which provides its own activation signal. In the context of the stimulation of the diaphragm (e.g. by magnetic stimulation of the phrenic nerve), the diaphragm activation signal is in the foreground. Activability:

This is the ability to electrically excite (activate) the muscles, e.g. through electrical or magnetic stimulation. The activation is preferably caused by a so-called magnetic twitch stimulation, a transient stimulation impulse with high intensity, which leads to a maximum contraction of the stimulated muscle [E11]. Other stimulation patterns would also be conceivable. The activation can be detected by means of an activation signal, preferably with EMG. Effectiveness:

Efficacy is a pneumatic target (pressure or volume) that is achieved through muscular activation. The "neuromechanical efficiency" (or "neuromuscular efficiency") NME relates the generated muscle pressure [E18, E21], the "neuroventilatory efficiency" NVE the generated volume to the EMG [E22] Determining the effectiveness often requires maneuvers, e.g. occlusions or Changes in respiratory support. As explained in [E22], the values have a diagnostic meaning, e.g. in evaluating the progress of weaning from the ventilator.

Maximum attainable respiratory effort:

This corresponds to the work of breathing WOBmusMax, the volume VolMusMax or the muscle pressure PmusMax, which can be achieved through maximum exertion of the respiratory muscles. PmusMax is most likely to be measured in a standardized way. In the literature, the Plmax value is often used as a measure of the maximum muscle pressure that can be achieved, i.e. the maximum pressure generated during inspiration when the mouth is closed. Since the voluntary contraction of the diaphragm leads to unreliable results, so-called (usually magnetic) twitch stimulation, which can be carried out independently of the patient's ability to cooperate, has recently been used to trigger the contraction. Normally, the PmusMax is recorded via an esophageal pressure catheter, but the more easily measured mouth closure pressure has also proven to be meaningful [E23]. Triggering the stimulation is advantageous here [E11].

LI - Load (Load Index):

This is a measure that depends on the ratio of the work of breathing performed to the maximum work of breathing that can be achieved, whereby muscle pressure or another measure can also be used instead of "work". For muscle pressure, the load can be defined as:

LI Pmus / PmusMax LBC - Load Bearing Capacity:

This is the ability of the muscles to develop a certain force or - in the case of the respiratory muscles - pressure through contraction and thus to be able to do work. To the When quantifying the resilience, the muscle pressure/breathing work developed by the muscles is often related to the maximum muscle pressure/breathing work that can be achieved. In this way, the resilience can be determined quantitatively depending on the ratio of the basic respiratory load to the maximum respiratory effort that can be achieved. If the basic respiratory load exceeds a certain part of the maximum respiratory effort that can be achieved, the resilience for exclusive spontaneous breathing is no longer given and ventilation is mandatory.

For muscle pressure, exercise capacity can be defined as:

LBC = 1 - PmusBase / PmuxMax

Exhaustion:

This occurs after some time when the resilience of the respiratory muscles is so low that the proportion of the respiratory load provided by the patient exceeds a certain part of the maximum respiratory effort that can be achieved, e.g. 50%.

Fatigue Rank:

The degree of exhaustion is related to the exercise capacity, the respiratory effort and its duration, but cannot be calculated exclusively and directly from this. However, there are parameters that can be calculated, for example, from the electromyogram of the muscles and used as a surrogate for the degree of exhaustion [E19, E20].

The relationships between the relevant variables can also be described using formulas, some of which are presented below. The work of breathing can be calculated as the integral of the corresponding pressure over the volume, e.g. for the total work of breathing:

WOBtot = ʃ Pdrv(t) dV = ʃ Pdrv(t) Flow(t) dt

Alternatively (especially in the case of isometric loads), the pressure-time product can be used:

WOBtot ~= ʃ P drv(t) dt

The driving pressure is divided into the different parts - analogous to the work of breathing -: Pdrv = Pvent + Pmus = Pvent + Pspon + Pstim

WOBtot = WOBvent + WOBmus = WOBvent + WOBspon + WOBstim The flow or the volume can also be mathematically divided into the different parts, analogous to the work of breathing:

Flow = FlowVent + FlowMus = FlowVent + FlowSpon + FlowStim, or: Vol = VolVent + VolMus = VolVent + VolSpon + VolStim

The basic equation of motion for the breathing circle is:

Pdrv = Pvent + Pmus = R Flow + E Vol + const where R and E=1/C mean the patient's resistance and elastance (the reciprocal value of compliance) parameters of respiratory mechanics. The equation applies under the assumption that the patient's respiratory system can be described as a simple RC element. If the flow and volume (as described above) are respectively defined as the sum of the ventilator and patient proportions, the result for Pvent and Pmus is:

Pvent = R * FlowVent + E * VolVent + const, and

Pmus = R * FlowMus + E * VolMus + const. The work of breathing of the ventilator and that of the patient can be calculated as follows: WOBvent = ʃ P vent Flow dt = ʃ Pdrv FlowVent dt,

WOBmus = ʃPmus Flow dt = ʃPdrv FlowMus dt

The fact that there are two possibilities in each case is derived from the equation of motion (see above) and can be proved by inserting them into the integrals. In a simplified assumption, Pmus can be assumed to be proportional to the EMG signal:

Pmus = NME · EMG or, for example, as a linear combination of the EMG signals of two muscle groups: Pmus = NME1 · EMG1 + NME2 · EMG2 where NME, NME1 and NME2 represent the neuromechanical efficiency of the respective muscle group. This changes the equation of motion:

Pvent + Pmus = R Flow + E Vol + const to:

Pvent R Flow + E Vol + const- NME EMG DE 102007062214B3, WO 2018 143844 A, DE 102019006480A1, DE 102019006480A1, DE 102020000014 A1, for example, already set out how the NME can be determined [E17, E18, E14, E15, E16]. Stimulation-elicited activity: EMG = EMGspon + EMGstim, assuming that the amplitude of the stimulation-elicited activity is multiplicatively related to the activatability k and the amplitude of the stimulation intensity lstim ^{^} : EMGstim ^{^} = k * lstim ^{^}

The scalar relationship is applicable when measures of stimulation intensity and activation are valid for larger time ranges, e.g. whole breaths. Now, however, stimulation typically occurs as a sequence of weighted pulses spaced 20-100ms corresponding to 10-50Hz (preferably 40-50ms corresponding to 20-25Hz). Each individual impulse (twitch) triggers a single activation, but only after the entire impulse sequence does the breath-like form of the activation signal result. This means that the time course of the triggered activity EMGstim(t) differs significantly from the time course of the stimulation intensity Istim(t). The activatability can only be represented as a simple constant (or characteristic curve) for variables that are averaged over time. A kernel-based estimation is possible for the timing behavior, e.g. with the simple assumption:

EMGstim(t) = Istim(t) * k(t) where * is the convolution symbol and k(t) is the core of the modeling to be estimated

(Kernel) of activability. Equal parts (offsets) of activation in terms of tonic muscle tension are neglected here. Typically Istim(t) is a sequence of transient stimulation pulses. k(t) then corresponds to the impulse response of activation to a stimulation impulse of intensity Istim(t). There are many methods for estimating the kernel k(t), e.g

System identification, stimulus-dependent averaging (e.g. analogous to peri-stimulus time histogram) or least squares estimation method.

In the equation:

EMG = EMGspon + Istim(t) * k(t) EMGspon is assumed to be an error signal, which is minimized by adapting the kernel. Finally, the spontaneous activity EMGspon can also be determined in this way, so that all factors of the equation of motion:

Pvent(t) = R Flow(t) + E Vol(t) + const- NME [EMGspon(t) + k(t) * Istim(t)] are known. In this way, the proportions of the total work of breathing and the driving pressure can be determined and used to control ventilation and stimulation. Instead of estimating the kernel samples, a parametric estimation can also be used. In this way, the kernel could be understood as a system impulse response and its parameters identified.

The following applies to the activation of, for example, two muscle groups, if necessary by means of stimulation:

EMG = EMG1 + EMG2

= EMG1spon + EMG1stim + EMG2spon + EMG2stim and:

Pvent(t) = R * Flow(t) + E * Vol(t) + const

- NME1 * [ EMG1spon(t) + k1(t) * Istim1(t)]

- NME2 · [ EMG2spon(t) + k2(t) * Istim2(t)] With this, the proportions of the work of breathing performed by different muscle groups can be determined. The specific stimulation enables stimulation maneuvers that specifically affect certain muscle groups and lead to activation. This makes it comparatively easy to estimate the neuromechanical efficiencies and the kernels or stimulation impulse responses. Instead of using work of breathing (WOB) or muscle pressure (Pmus) as target values for the stimulation, the proportion of the flow caused by the muscles, FlowMus, could alternatively be used. In some circumstances FlowMus or its integral over time, the volume VolMus, can be advantageous (US 2017 0252558A1, [E13]). It would be advantageous that clinical staff are very familiar with the terms flow and volume, in contrast to muscle pressure or work of breathing. The division of flow or volume into patient and machine portions is a basis in exemplary embodiments. If FlowMus is available, it can be determined very easily by an integral of VolMus (as a time course), but also VTmus (muscular tidal volume performed) or MVmus (muscular minute volume). These variables can be important for respiratory diagnostics and therapy. Exemplary embodiments are based on the knowledge that a state of a patient's respiratory muscles can be characterized by stimulation and subsequent measurement of a reaction of the respiratory muscles to the stimulation. Information about the state of the respiratory muscles, for example in the form of one or more state parameters, can then be obtained from the reaction of the respiratory muscles.

Further exemplary embodiments are based on the knowledge that the degree of utilization of the patient's muscles can be derived from a resilience of the patient's respiratory muscles and the spontaneous breathing activity (the proportion of the work of breathing performed by oneself). If the resilience of the musculature is greater than what corresponds to the part that is performed by the patient, the patient's musculature can be subjected to more stress, for example through stimulation. If the self-performed part is greater than the resilience of the musculature, the patient's musculature can be relieved, for example, by increasing the degree of sedation.

By setting the actual load on the muscles, they can be spared, trained or loaded according to their condition.

Further exemplary embodiments are based on the knowledge that a patient's respiratory muscle activation can be determined and within the framework of a

Ventilation can also be specified. A measure of respiratory support for the patient can then be determined from an actual respiratory muscle activation and a target respiratory muscle activation. Other embodiments are based on the knowledge that from a

Activation signal of the respiratory muscles of a patient, a time course of the patient's own activity can be derived. Based on the course over time, an additional stimulation of the respiratory muscles can then take place in a temporal alignment. The activity of the respiratory muscles is now based on the patient's own activity and the stimulation that is timed to match. In this way, synchronous and proportional stimulative ventilation support can be provided. Embodiments provide an apparatus for determining a condition of a patient's respiratory muscles. The device includes one or more interfaces designed to acquire patient signals.

Embodiments create an apparatus for ventilating a patient. The device includes one or more interfaces for exchanging information are designed with a ventilation unit, a stimulation unit and/or a sensor unit.

Embodiments therefore create a device for a component of a ventilation system for respiratory support of a patient. The device includes one or more interfaces for communication with components of the ventilation system.

Embodiments provide a stimulator or stimulation device for stimulative ventilation support of a patient. The device includes one or more interfaces that are designed to exchange information with a ventilation unit and a sensor unit.

Embodiments create devices in configurations of ventilation systems, ventilation devices, stimulation devices (stimulators) to support a patient during ventilation based on at least one of the devices, systems, methods, computer programs or computer program products described in this description. Exemplary embodiments create methods for supporting a patient during ventilation with at least one of the devices, systems, methods, computer programs or computer program products described in this description. Exemplary embodiments can be formed by computer programs or computer program products with a program code for performing one of the methods described when the program code is executed on a computer, a processor or a programmable hardware component. Computer programs or computer program products can form parts of a medical technology system. Additional elements such as measuring devices, ventilation devices, monitoring devices,

Stimulator devices (stimulators), sensors for pressure measurement, sensors for flow rate measurement, sensors for detecting EMG signals (electromyogram), sEMG signals (surface electro-myogram), EIM signals (electro-impedance myogram) or MMG signals (mechano-myogram). The exemplary embodiments or the devices can include a control unit. Embodiments can include detecting a measure of a portion of the ventilation provided by the patient himself and determining a measure of the patient's resilience. The exemplary embodiments can include influencing the proportion of ventilation provided by the patient and assisting the patient in ventilation based on the measure of the proportion of ventilation provided by the patient and based on the measure of the patient's resilience. Embodiments may include assisting with pressure-controlled or volume-controlled ventilation. Assisting may also include stimulating the patient's respiratory muscles. Embodiments can include regulating the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. In addition, exemplary embodiments can include regulating the proportion performed by the patient himself based on a proportion of the ventilation specified as a secondary goal. Furthermore, monitoring and regulation of the patient's total tidal volume provided by the patient himself, the work of breathing performed by the patient himself, and/or an oxygenation of the patient can take place. The influencing and the supporting can be based on a breathing rhythm specified by the patient or on a breathing rhythm specified by the influencing. In exemplary embodiments, the influencing and support can be based on a breathing rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, while otherwise the support is based on a breathing rhythm specified by stimulation, provided that the patient's spontaneous activity is non-existent or harmful and in the absence of a stimulation effect, the support is based on a breathing rhythm predetermined by pneumatic ventilation.

Further embodiments may include determining an efficiency of the patient's respiratory muscles, the assisting being further based on the efficiency. In addition, the ability of the patient's respiratory muscles to be activated can be determined, with the assisting also being based on the ability to be activated. Additionally or alternatively, an exhaustion of the patient's respiratory muscles can also be determined, with the support also being based on the exhaustion. Determining the resilience can include determining a basic respiratory load and detecting a maximum possible respiratory effort by the patient. Capturing the maximum possible respiratory effort may include performing twitch stimulation. The control unit can be designed to stimulate the respiratory muscles of the patient with a stimulation signal and to detect an activation signal as a reaction to the stimulation. The control unit is also designed to determine one or more status parameters for the respiratory muscles based on the stimulation signal and the activation signal. By directly detecting the activation signal as a reaction to the stimulation, information about the state of the patient's respiratory muscles can be reliably obtained.

The control unit can also be designed to generate the stimulation signal with one or more stimulation pulses. Using of

Stimulation impulses can offer the advantage that desired reactions of the muscles can be evoked by variations in the impulse sequences and impulse intensities. The control unit can be designed to record a measure of a portion of the ventilation provided by the patient himself and to determine a measure of the patient's ability to work under pressure. The control unit is also designed to influence the portion of ventilation performed by the patient himself and to support the patient during ventilation based on the measure of the portion of ventilation performed by the patient himself and based on the measure of the patient's resilience. In this way, exemplary embodiments can enable ventilation support that is adapted to the patient's ability to bear stress and the proportion they have provided themselves. For example, the control unit can be designed to output a signal for pressure-controlled or volume-controlled ventilation to provide support. Pneumatic ventilation support is thus possible.

In addition or as an alternative, the control unit can also be designed to output a signal for stimulating the patient's respiratory muscles for support. The ventilation support can therefore also be stimulative or pneumatic and stimulative.

The measure of the work done by the patient himself can be at least one element from the group of: a muscle pressure, Pmus, absolute or relative to a total respiratory pressure, Paw, or a total driving pressure, Pdrv, - a respiratory gas flow caused by the patient's muscles , Flowmus, absolute or relative to a total respiratory gas flow, Flow, a tidal volume caused by the patient's musculature, Volmus, absolute or relative to a total tidal volume, Vol, a work of breathing performed by the patient himself, WOBmus, absolute or relative to a total work of breathing, WOB.

The control unit can be designed to record information about a time profile of an activation signal of the patient's respiratory muscles and to stimulate the respiratory muscles in temporal alignment with the activation signal for muscular respiratory support of the patient. This allows effective stimulative ventilation support to be provided. The control unit can also be designed to record information about the time profile of a portion of the respiratory work performed by the patient himself in order to record the information about the time profile of the activation signal, and to determine the activation signal for the patient's respiratory muscles based on information about the time course of the part of the work of breathing performed by the patient himself. The stimulative support can therefore be based on the part that the patient himself has provided. The control unit can also be designed to determine and take into account a lower activation threshold for the stimulation. When the respiratory muscles are stimulated above the activation threshold, the respiratory muscles can be activated, and when the respiratory muscles are stimulated below the activation threshold, activation can be at least reduced or absent. By considering the activation threshold, a better temporal alignment between intrinsic activity and stimulated muscle activity can be achieved.

In some exemplary embodiments, the stimulating can be carried out in a feed-forward manner with the activation signal from the control unit. Stimulating then increases the intrinsic activity, for example proportionally. The

Control unit also be designed to determine a stimulation effect. If the stimulation effect is known, the actual stimulative support can be fine-tuned. For example, the control unit can be designed to carry out a titration to determine the stimulation effect. As a result, a stimulation effect can be considered and checked individually and also in a timely manner. In some exemplary embodiments, the control unit can be designed to carry out the stimulating in proportion to the activation signal. In this way, for example, a relative stimulative support, which can also depend on the resilience of the patient's respiratory muscles, can be set. As information about the time course of the activation signal

The patient's respiratory muscles can, for example, contain information about at least one element from the group consisting of a muscle pressure, Pmus, a spontaneous muscle pressure, Pspon, - a respiratory gas flow caused by the patient's muscles, Flowmus, a respiratory gas flow spontaneously caused by the patient's muscles, Flowspon, a work of breathing, WOB, performed by the patient himself, a spontaneous work of breathing, WOBspon, performed by the patient himself. Embodiments may have several options for

Provide activation signal determination. In addition or as an alternative, the control unit can be designed to ventilate the patient pneumatically in parallel. Embodiments can thus also allow pneumatic respiration support in combination with stimulative support. The control unit can be designed to carry out the parallel pneumatic ventilation as proportional ventilation. A pneumatic support component can also be based on the patient's own activity. For example, the information about the time course of the activation signal of the patient's respiratory muscles can be recorded on the basis of an electromyographic signal, a signal from electro-impedance myography, a signal from a strain sensor, a signal from an ultrasonic sensor or a mechanomyographic signal. At least some of these exemplary embodiments offer the possibility of non-invasive detection of the activation signal. In further exemplary embodiments, the control unit can be designed to set an intensity of the stimulation based on a predetermined level. A simple and effective specification for the intensity can thus be made possible. For example, the predetermined level is specified via a ratio of stimulation intensity and activation signal or via a ratio of stimulation intensity and estimated respiratory effort, Pmus. The degree can thus correspond to a simple ratio or a simple relation. The degree can also be a ratio between a stimulated respiratory activity and a determine the patient's spontaneous respiratory activity. This can be used, for example, to specify that the patient's spontaneous breathing activity is supported by half, twice, etc. In some exemplary embodiments, the control unit can be designed to determine the patient's spontaneous respiratory activity based on the information about the time profile of the activation signal of the patient's respiratory muscles. This results in an effective way of determining the spontaneous breathing activity. The control unit can also be designed to generate a stimulation signal based on the ratio between the stimulated breathing activity and the spontaneous

Determine the patient's respiratory activity and an activation impulse response of the patient's muscles. An actual muscle reaction of the patient can thus be taken into account. For example, the control unit can be designed to determine the stimulation signal by inverse convolution of a desired stimulation-induced activation signal, EMGstim, with the activation impulse response. This results in a simple methodical way of determining the stimulation signal. The spontaneous respiratory activity can be determined, for example, as a respiratory muscle pressure, Pspon, generated spontaneously by the patient, and the stimulated respiratory activity as a respiratory muscle pressure, Pstim, generated by stimulation. In addition or as an alternative, the control unit can be designed to determine the spontaneous breathing activity as a breathing gas flow, Flowspon, generated spontaneously by the patient, and the stimulated breathing activity as a breathing gas flow, Flowstim, generated by stimulation. It is also possible for the control unit to be designed to measure the spontaneous breathing activity as work of breathing spontaneously generated by the patient, WOBspon, or its time derivative, dWOBspon/dt, and the stimulated

determine respiratory activity as a work of breathing produced by stimulation, WOBstim, or its time derivative, dWOBstim/dt. Exemplary embodiments can use different variants for determining the spontaneous breathing activity. In some exemplary embodiments, the control unit can be configured to track the predetermined level at a time level that is greater than or equal to a respiratory cycle of the patient. This also makes it possible to adapt the degree of support in exemplary embodiments. The control unit can be designed to stimulate the achievement of a target value, which includes a patient-side portion of a driving pressure, ΔPmus, a patient-side portion of a volume,

ΔVolmus, or a patient-side contribution to a work of breathing, AWOBmus, to settle. This allows the ventilation support to be adjusted continuously to suit the patient.

Embodiments also provide a ventilation system with a stimulation device described herein.

Another embodiment is formed by a method for stimulative ventilation support of a patient. The method includes acquiring information about a time profile of an activation signal of a patient's respiratory muscles and stimulating the respiratory muscles in temporal alignment with the activation signal for muscular ventilation support of the patient.

In further exemplary embodiments, capturing the information about the time profile of the activation signal can include capturing information about a time profile of a portion of the work of breathing performed by the patient himself and determining the activation signal for the patient's respiratory muscles based on the information about the time profile of the the patient's own share of the work of breathing. The method can also include determining and taking into account a lower activation threshold for the stimulation, with the respiratory muscles being activated when the respiratory muscles are stimulated above the activation threshold, and activation being at least reduced or absent when the respiratory muscles are stimulated below the activation threshold. The stimulating can take place in a feed-forward manner with the activation signal. Furthermore, a determination of a

stimulation effect are carried out. For example, the method can also include a titration to determine the stimulation effect. The pacing can be proportional to the activation signal. In some embodiments, the information about the time course of the activation signal of the patient's respiratory muscles can be information about at least one element from the group of a muscle pressure, Pmus, a spontaneous muscle pressure, Pspon, a respiratory gas flow caused by the patient's muscles, Flowmus, one of the Breathing gas flow spontaneously caused by the patient's musculature, Flowspon, one provided by the patient himself

Work of Breathing, WOB, and a spontaneous work of breathing performed by the patient, WOBspon. The method may include parallel pneumatic ventilation of the patient. The parallel pneumatic ventilation can preferably include proportional ventilation. The information about the time course of the activation signal of the patient's respiratory muscles can be recorded, for example, on the basis of an electromyographic signal, a signal from electro-impedance myography, a signal from a strain sensor, a signal from an ultrasound sensor or a mechanomyographic signal. The method may further include adjusting an intensity of the pacing based on a predetermined level. The predetermined level may comprise a ratio of stimulation intensity and activation signal or of stimulation intensity and estimated respiratory effort, Pmus. For example, the degree can determine a ratio between a stimulated breathing activity and a spontaneous breathing activity of the patient. At least in some exemplary embodiments, the patient's spontaneous breathing activity can be determined based on the information about the time profile of the activation signal of the patient's respiratory muscles.

In addition or as an alternative, the method can include determining a stimulation signal based on the relationship between the stimulated breathing activity and the spontaneous breathing activity of the patient and an activation impulse response of the patient's muscles. The stimulation signal can be determined, for example, by inverse convolution of a desired activation signal, EMGstim, caused by stimulation, with the activation impulse response. Alternatively, processing can also be carried out in the frequency domain, where the convolution appears as multiplication. This may require a block-by-block transformation, which can lead to delays. Spontaneous respiratory activity may include patient spontaneously generated respiratory muscle pressure, Pspon, and stimulated respiratory activity may include stimulation-induced respiratory muscle pressure, Pstim. In addition or as an alternative, the spontaneous breathing activity can include a breathing gas flow, Flowspon, generated spontaneously by the patient, and the stimulated breathing activity can include a breathing gas flow, Flowstim, generated by stimulation. Spontaneous respiratory activity may include patient spontaneously generated work of breathing, WOBspon, or its time derivative, dWOBspon/dt, and stimulated respiratory activity may include stimulation generated work of breathing, WOBstim, or its time derivative, dWOBstim/dt. In further exemplary embodiments, the predetermined degree can be tracked at a time level which is greater than or equal to a respiratory cycle of the patient. The method may further include controlling pacing to achieve a target value that includes a patient contribution to a driving pressure, ΔPmus, a patient contribution to a volume, ΔVolmus, or a patient contribution to a work of breathing, AWOBmus. The control unit can be designed to determine first information about a target respiratory muscle activation of a patient and to determine second information about an actual respiratory muscle activation of the patient. The control unit is also designed to determine a measure of respiratory support for the patient based on the first information and based on the second information. Embodiments can allow for effective respiratory support of a patient. For example, the device can include a device for measuring airway flow and airway pressure on the patient. The control unit can be designed to determine the first information and the second information based on an airway flow measurement and an airway pressure measurement. In exemplary embodiments, pneumatic variables can thus be used to determine muscle activation. The device can also additionally comprise a device for pneumatic respiratory support and the measure of respiratory support can comprise a measure of pneumatic respiratory support. Pneumatic respiratory support can thus take place in exemplary embodiments. Additionally, in at least some embodiments, the apparatus may further include means for sedating the patient based on the level of respiratory support. In exemplary embodiments, a basis for automated or partially automated sedation can thus be created. For example, measurement information about an airway flow measurement or an airway pressure measurement on the patient can be obtained via the one or more interfaces, and the control unit can be designed to determine the amount of respiratory support based on the measurement information. In this respect, it may be possible to also obtain the measurement information from other components of a ventilation system.

In further exemplary embodiments, the device can also comprise a device for sensory detection of a signal which depends on the actual respiratory muscle activation. The control unit can then be designed to determine the degree of respiratory support based on the signal detected by sensors. In this respect, signals that are detected by sensors and, in particular, also non-invasively can also be used taken into account when determining respiratory support. For example, the device for sensory detection can be designed to detect an electro-myogram, a mechano-myogram, or an electro-impedance myogram. At least some of these signals can offer the advantage that they can be detected non-invasively. The device for sensory detection can include, for example, a strain sensor, an ultrasonic sensor or an esophageal pressure sensor.

In some exemplary embodiments, the device can also have a device for stimulating the respiratory muscles of the patient based on the measure of the

include respiratory support. The breathing support can therefore be supplementary or alternatively also stimulative.

Some embodiments may enable breathing regulation. The control unit can also be designed to detect a difference between the first

To reduce information and the second information about the amount of respiratory support via a scheme. The control unit can, for example, generate a stimulation signal for the patient as a measure of the respiratory support. The first and the second information can then each comprise a measure of a patient-side stimulated or total respiratory muscle activation, a patient-side stimulated or total respiratory muscle flow or a patient-side stimulated or total respiratory muscle pressure. A spontaneous activity of the patient can thus be taken into account in exemplary embodiments. In some exemplary embodiments, the control unit can also be designed to determine and provide information about respiratory muscle activation caused by the patient's spontaneous respiratory activity, respiratory muscle flow caused by the patient's spontaneous respiratory activity or respiratory muscle pressure caused by the patient's spontaneous respiratory activity. In this respect, further consideration or processing of the patient's spontaneous activity can be made possible. The control unit can also be designed to determine the degree of respiratory support based on the information about the patient's spontaneous respiratory activity and thus also to take it into account in any regulation. In some exemplary embodiments, the measure of respiratory support can also indicate a measure of more intensive sedation of the patient if the information about the patient's spontaneous respiratory activity is a respiratory muscle activity above target respiratory muscle activation. The patient's muscles and respiratory system can thus be protected from overuse. The control unit can also be configured to estimate a stimulation impulse response of the patient based on the second information in response to the measure of respiratory support. From the

Stimulation impulse response and desired activations can then be determined corresponding stimulation excitations. The control unit can determine the estimate based on a stimulation maneuver, for example. Such a maneuver can allow for a precise estimation. The control unit can be designed to repeat the estimate regularly or continuously. Furthermore, in some exemplary embodiments, the control unit can be designed to determine a reliability for the first and the second information and to display it if the reliability falls below a predetermined threshold. This can result in more effective respiratory support as unreliable information can be acted upon accordingly.

Embodiments also provide a ventilator having an embodiment of the apparatus described herein. The functionality described for the device can then be integrated in such a ventilator.

In further exemplary embodiments, the control unit can be designed to communicate information about the degree of respiratory support to a stimulator via the one or more interfaces. In this respect, exemplary embodiments enable a corresponding interaction between the ventilator and the stimulator. A stimulator is a device that enables stimulation for respiratory support.

The measure for respiratory support can include at least one parameter from the group of: an amplitude, a ramp gradient, a stimulation duration, a start time, an end time, an actual respiratory muscle activation of the target respiratory muscle activation. In this respect, the measure can be suitable for controlling a stimulator. The one or more interfaces can be designed for real-time communication with a stimulator and/or with a sensor unit. This ensures that the components involved react quickly. For example, the one or more interfaces are designed for sample-by-sample real-time communication with a stimulator and/or with a sensor unit. In addition or as an alternative, the one or more interfaces can be designed to communicate a time profile of the measure of respiratory support with a stimulator and/or with a sensor unit. In this way, sufficient time synchronization between the components involved in ventilation support can be ensured. The time profile describes the form of the signal, eg the stimulation intensity for the stimulator, which triggers the previously known form of the stimulation intensity at the start time point. This means that sample-by-sample real-time communication is not necessary in this case. In exemplary embodiments, various implementations for the temporal

Coordination of the components conceivable. For example, the control unit can be designed to specify a clock for a stimulator via the one or more interfaces. In some exemplary embodiments, the ventilator can also have an integrated stimulator. The control unit can be designed to communicate with a stimulator via the one or more interfaces, the first and the second

to provide information. In addition or as an alternative, the control unit can be designed to coordinate ventilation maneuvers with a stimulator via the one or more interfaces. Exemplary embodiments thus allow ventilation with coordinated operation of the ventilation device and stimulator and possibly also a sensor unit.

Embodiments also provide a stimulator having an embodiment of the device described herein. The control unit can then be designed to receive the first and the second information via the one or more interfaces from a sensor unit or from a ventilator. In this respect, a stimulator with the appropriate functionality can also be integrated into a ventilation system.

In the stimulator, the control unit can be designed to receive at least one piece of information from the group of an amplitude, a ramp gradient, a stimulation duration, a start time, an end time, a time course of the target respiratory muscle activation, an airway flow via the one or more interfaces from a sensor unit , an airway pressure, a respiratory muscle pressure, a respiratory muscle work and respiratory muscle flow. A systemic interaction with a sensor unit can thus be ensured. The start or end time does not have to be an absolute time in the sense of a time, but is to be understood as an event that, for example, triggers or ends a stimulation.

The control unit can be designed to receive a clock from a sensor unit and/or a ventilator via the one or more interfaces. Adequate temporal synchronization of the components involved can thus be achieved. The stimulator can therefore follow a received clock. The control unit can be designed to specify a clock for a sensor unit and/or a ventilator via the one or more interfaces. In some exemplary embodiments, the stimulator can also provide or specify a clock for other components. The control unit can also be designed here to communicate in real time via the one or more interfaces. In this way, sufficient time synchronization of the components in the system can be achieved. The control unit can be designed accordingly in order to coordinate ventilation maneuvers with a ventilator via the one or more interfaces. As a result, a ventilation maneuver can be coordinated accordingly.

Embodiments also provide a sensor unit with an embodiment of the device described herein. The control unit can then be designed to receive information about at least one pneumatic signal from a ventilator via the one or more interfaces and to also determine the measure for respiratory support based on the information about the at least one pneumatic signal. In this respect, a pneumatic signal can also be taken into account by the sensor unit when determining the degree of respiratory support. The control unit can be designed, for example, to determine the second information based on sensor signals. The sensor signals can then be used to determine the actual respiratory muscle activation. Here, too, the control unit can be designed to communicate in real time via the one or more interfaces and thus establish sufficient time synchronization between the components of the ventilation system. The control unit can also be designed here to transmit at least one piece of information from the group of an amplitude, a ramp gradient, a Provide stimulation duration, a start time, an end time, an actual respiratory muscle activation, an airway flow, an airway pressure, a respiratory muscle pressure, a respiratory muscle work and a respiratory muscle flow as a measure of respiratory support. This can enable systemic interaction with the other components. Accordingly, the control unit can be designed to receive information about a maneuver via the one or more interfaces from a ventilator or a stimulator. This allows maneuver coordination between the components.

In some exemplary embodiments, the control unit can also be designed to receive information about blanking, measurement times to be suppressed, filtering, or suppression of stimulation artifacts via the one or more interfaces from a ventilator or a stimulator as first information or with the first information. This means that interference in sensor signals can be effectively suppressed.

Embodiments also provide a ventilator system including an embodiment of the device described herein. The ventilator system may include a ventilator as described herein. In addition or as an alternative, the ventilation system can also include a stimulator, as described herein, or a sensor unit, as described herein.

Embodiments also provide a method for a component of a ventilator system to assist a patient in breathing. The method includes determining first information about a target respiratory muscle activation of the patient, determining second information about an actual respiratory muscle activation of the patient, and determining a measure of respiratory support for the patient based on the first information and based on the second information.

In embodiments, the method may further include determining the first information and the second information based on an airway flow measurement and an airway pressure measurement. The measure of respiratory support may include a measure of pneumatic respiratory support. The method may include sedating the patient based on the level of respiratory support. Additionally, the method may include obtaining measurement information about an airway flow measurement or an airway pressure measurement on the patient and determining the level of respiratory support further based on the measurement information. There can be a sensory detection of a signal that depends on the actual respiratory muscle activation and a determination of the measure for the respiratory support based on the sensory detected signal.

The signal detected by sensors can be, for example, an electro-myogram, a mechano-myogram, or an electro-impedance myogram. The sensory signal can be detected, for example, with a strain sensor, an ultrasonic sensor or an esophageal pressure sensor. In other embodiments, the method may also include stimulating the patient's respiratory muscles based on the measure of respiratory support. A difference between the first piece of information and the second piece of information can be reduced by rules about the degree of respiratory support. Additionally or alternatively, a stimulation signal can be generated for the patient as a measure of the respiratory support. The first and second pieces of information may each include a measure of patient-paced or total respiratory muscle activation, patient-paced or total respiratory muscle flow, or patient-paced or total respiratory muscle pressure. The method can include determining and providing information about respiratory muscle activation caused by the patient's spontaneous respiratory activity, respiratory muscle flow caused by the patient's spontaneous respiratory activity, or respiratory muscle pressure caused by the patient's spontaneous respiratory activity. The method may include determining the level of respiratory support based on information about the patient's spontaneous respiratory activity. The measure of respiratory support may also indicate a measure of more intense sedation of the patient when the patient's spontaneous respiratory activity information indicates respiratory muscle activity above target respiratory muscle activation.

Additionally, estimating a patient's stimulation impulse response from the second information in response to the measure of respiratory support. The estimation can be based on a stimulation maneuver, for example. The estimation can be done regularly or continuously. The method may also include determining a reliability on each of the first and second pieces of information and indicating when the reliability falls below a predetermined threshold.

Embodiments also provide a method for a ventilator that includes any of the methods described herein. The method may include communicating information about the level of respiratory support to a stimulator. The measure of respiratory support can include at least one parameter Group of an amplitude, a ramp steepness, a stimulation duration, a start time, an actual respiratory muscle activation, an end time and the target respiratory muscle activation. In the method, communication can also take place in real time with a stimulator and/or with a sensor unit. The communication can take place, for example, on a sample basis in real time with a stimulator and/or with a sensor unit. The communication can include communicating a time profile of the measure of the respiratory support with a stimulator and/or with a sensor unit. A clock can be specified for a stimulator. The method can include specifying the first and the second information to a stimulator and/or coordinating a ventilation maneuver with a stimulator.

Embodiments also provide a method for a stimulator that includes any of the methods described herein. In this case, the first or the second information can be received by a sensor unit or by a ventilator. At least one piece of information from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an end time, an actual respiratory muscle activation, the target respiratory muscle activation, an airway flow, an airway pressure, a respiratory muscle pressure, a respiratory muscle work and a Respiratory muscle flow can be received. In addition, a clock can be received from a sensor unit and/or a ventilator. A cycle can also be specified for a sensor unit and/or a ventilator. Communication can take place in real time. This can be particularly important in the case of "blanking" (fading out artefacts/interference). By specifying the clock, the sensor unit can receive the information when stimulation is taking place, i.e. when artefacts/interference is to be expected. The method may include coordinating a ventilation maneuver with a ventilator. Embodiments also provide a method for a sensor unit using any of the methods described herein. The method may include receiving information about at least one pneumatic signal from a ventilator and determining the amount of respiratory support further based on the information about the at least one pneumatic signal. The second information can be determined based on sensor signals. That

Method may include communicating in real time. In addition, providing at least one piece of information from the group of an amplitude, a Ramp gradient, a stimulation duration, a start time, an end time, an actual respiratory muscle activation, an airway flow, an airway pressure, a respiratory muscle pressure, a respiratory muscle work and a respiratory muscle flow, as a measure for the respiratory support to a ventilator or to a stimulator. Information about a maneuver can be obtained. For example, information about blanking, measurement times to be suppressed, filtering, or suppression of stimulation artifacts can be received from a respirator or a stimulator as the first information or with the first information. In addition, exemplary embodiments create a method for a ventilation system with one of the methods described herein. The method may include a method described herein for a ventilator, a method described herein for a stimulator and/or a method described herein for a sensor unit. The control unit can be designed to detect the activation signal as an impulse response. The response to specific stimulation pulse sequences or a specific stimulation pulse sequence for a desired reaction can now be determined by means of the impulse response.

The control unit can also be designed to determine an activability of the respiratory muscles of the patient by determining the one or more status parameters. The ability to be activated can be helpful, for example, to take account of a degree of exhaustion (also "fatigue") of the respiratory muscles. For example, some of the muscle fibers cannot be recruited/activated. The degree of exhaustion correlates significantly with the lack of contraction (force/pressure generation) as a result of activation. This means that although the muscle fibers are activated, they do little.

In some exemplary embodiments, the control unit can be designed to take into account a lower activation threshold for the stimulation signal when determining the activatability, with activation of the respiratory muscles being reduced or absent when the respiratory muscles are stimulated below the activation threshold. A stimulation can then take place above the activation threshold, for example with a clear reaction of the respiratory muscles. If the activation threshold is known, the stimulation can be better synchronized with ventilation or spontaneous breathing, for example. For example, ramped waveforms are used for stimulation to increase stimulation for the

to make patients as comfortable as possible. However, if the ramp starts at 0, there may be a significant time delay before the respiratory muscles actually react given, because due to the finite ramp steepness it can take a while until the activation threshold is exceeded.

In further exemplary embodiments, the control unit can be further designed to determine a respiratory muscle pressure, Pstim, that can be generated by stimulation, a respiratory volume that can be generated by stimulation, Volstim, and/or a work of breathing of the patient that can be generated by stimulation. A stimulation effect and a stimulation intensity can thus be determined based on a desired degree of support for the stimulation. In addition or as an alternative, the control unit can be designed to also carry out a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and to also determine the one or more status parameters based on the pneumatic ventilation parameter. Taking the pneumatic ventilation parameter into account can contribute to a more reliable determination of the one or more state parameters. The diagnostic pneumatic maneuver may include, for example, occlusion, airflow limitation, omission of support for individual breaths, or variability in the patient's respiratory support. In general, a variety of diagnostic maneuvers for further determination of pneumatic parameters are conceivable in exemplary embodiments.

In some exemplary embodiments, the detection of the measure of the patient's self-contribution can be carried out on the basis of an electromyographic signal, a signal from electro-impedance myography, a mechanomyographic signal, an ultrasound signal, a signal from a strain sensor, or a signal from an esophageal pressure sensor will. At least some of these options offer the possibility of capturing the information or signals non-invasively.

In further exemplary embodiments, the control unit can be designed to output a signal for stimulating the patient's respiratory muscles in order to influence the proportion performed by the patient himself. The patient's musculature can thus be activated and trained to a certain extent, provided this is compatible with the resilience of the musculature. The control unit can also be designed to emit a signal for influencing the administration of medication in order to influence the proportion paid by the patient himself. This can prevent overloading of the muscles and also the lung tissue, especially if the degree of spontaneous activity of the patient exceeds the patient's capacity prevent muscle damage. If the driving pressure (to which muscle pressure contributes directly) and thus the tidal volume are too high, the lungs can be damaged by baro- or volutrauma and repeated opening and collapse of lung areas. Lung-protective ventilation avoids this. Exemplary embodiments can thus enable ventilation that protects the diaphragm and protects the lungs.

Various control mechanisms are conceivable in exemplary embodiments. The control unit can be designed, for example, to regulate the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. In addition or as an alternative, the control unit can be designed to regulate the portion performed by the patient himself based on a portion of the ventilation specified as a secondary goal. Efficient regulation can thus take place in exemplary embodiments. The entire respiratory volume and that provided by the patient himself can be monitored and regulated by the control unit. In addition, the control unit can be designed to regulate and monitor the work of breathing performed by the patient himself. At the same time, the patient's oxygenation can also be monitored and/or regulated by the control unit. In exemplary embodiments, comprehensive monitoring and ventilation control can be carried out in this way. The control unit can be designed to direct the influencing and the support according to a breathing rhythm specified by the patient. This means that ventilation support can be synchronous and therefore more comfortable for the patient. In further exemplary embodiments, it can also be advantageous to direct the support according to a respiratory rhythm predetermined by the influencing, for example if there is little or no intrinsic activity on the part of the patient. The control unit can therefore be designed to direct the influencing and the support according to a respiratory rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, and otherwise to direct the support according to a respiratory rhythm specified by a stimulation, provided that the patient does not spontaneously act is present or harmful and, in the absence of a stimulation effect, to direct the support to a respiratory rhythm predetermined by pneumatic ventilation. In exemplary embodiments, ventilation support can then be adjusted and synchronized based on the patient's condition. In some further exemplary embodiments, the control unit can be designed to determine an efficiency of the respiratory muscles of the patient, with the assisting also being based on the efficiency. This means that the support can also be adjusted to the efficiency of the respiratory muscles. The control unit can also be designed to determine whether the patient's respiratory muscles can be activated, with the support also being based on the ability to be activated. Accordingly, an activatability in ventilation support can then also be taken into account. In addition or as an alternative, the control unit can be designed to determine exhaustion of the patient's respiratory muscles, with the support also being based on the exhaustion, which can therefore also be taken into account. In some exemplary embodiments, the control unit can be designed to determine a basic mechanical breathing load and to determine a maximum possible breathing effort by the patient in order to determine the exercise capacity. In this way, for example, the basic load can also be taken into account in the case of a reasonable breathing effort. the

The control unit can be designed to determine the maximum possible breathing effort, for example by carrying out a twitch stimulation. This enables an effective determination of the maximum respiratory effort. In some further exemplary embodiments, the control unit can also be designed to also determine a measure of the resilience of the patient's respiratory muscles. The measure of endurance can be used to prevent overloading of the respiratory muscles. The measure of the exercise capacity can be based, for example, on a relationship between a base load, PmusBase, and a maximum attainable respiratory effort, PmusMax, of the patient, which can allow an efficient determination of the measure. The control unit can be designed to also determine a measure of the efficiency of the patient's respiratory muscles. The efficiency can, for example, help to find a balance between pneumatic and stimulative breathing support during ventilation, with the pneumatic support relieving the patient of the work of breathing and the stimulative support requiring the patient to work. The measure of the efficiency can include, for example, a ratio of a tidal volume that can be generated by stimulation and the activation signal. In addition or as an alternative, the measure of the efficiency can also include, for example, a ratio of a respiratory muscle pressure that can be generated by stimulation and the activation signal. The control unit can also be designed to output information about the one or more status parameters via the one or more interfaces. In some exemplary embodiments, the progress of therapy can be recorded in a non-invasive therapy method. For example, the efficiency of the respiratory muscles, their resilience, degree of exhaustion, etc. are monitored.

In addition, the respiratory effort to be made by the patient can be specified. For example, a volume/flow is determined from an EMG signal and WOB/Pmus/FlowMus/VolMus is then specified. The “pace generator” can also be defined depending on the patient/ventilation situation. In exemplary embodiments, the proportion of the respiratory effort for the patient can also be recorded/determined spontaneously and in a stimulated manner, for example via a ventilator. In addition, automation can take place with the aim of increasing resilience and eventually weaning. The respiratory effort to be made can be specified in relation to the maximum effort that can be achieved. In this case, a rule-based ventilation system can be provided which, for example, specifies appropriate trajectories or a therapy plan.

The statements above have been made mainly in relation to the device and also apply to the respective method steps of the method. Support can include pressure-controlled or volume-controlled ventilation. Assisting may also include stimulating the patient's respiratory muscles. The determination of the measure of the contribution made by the patient can be carried out on the basis of an electromyographic signal, a signal from electro-impedance myography, a mechanomyographic signal, an ultrasound signal, a signal from a strain sensor, or a signal from an esophageal pressure sensor. Influencing the portion performed by the patient himself can include stimulating the patient's respiratory muscles and/or influencing the administration of medication. The method can also include regulating the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. The method 20 can also include regulating the proportion performed by the patient himself based on a proportion of the ventilation specified as a secondary goal. In addition or as an alternative, the total respiratory volume and that provided by the patient himself, the work of breathing performed by the patient himself and/or oxygenation of the patient can be monitored and regulated. In some exemplary embodiments, the influencing and the supporting can be based on a patient-specified Breathing rhythm or according to a breathing rhythm predetermined by the influencing. Influencing and supporting can be based on a breathing rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, while otherwise the support is based on a breathing rhythm specified by stimulation, provided that the patient's spontaneous activity is non-existent or harmful and with In the absence of a stimulation effect, the support is based on a respiratory rhythm specified by pneumatic ventilation. In addition, in exemplary embodiments, an efficiency, an activatability and/or an exhaustion of the patient's respiratory muscles can be determined, with the support also being based on the efficiency, the activatability and/or the exhaustion. Determining the resilience can include determining a basic respiratory load and detecting a maximum possible respiratory effort by the patient. Capturing the maximum possible respiratory effort may include performing twitch stimulation. Embodiments can allow a combination of ventilation and muscle stimulation for diagnostics. For example, embodiments may provide a mechanism for an automated therapy method or system that uses a combination of respiratory muscle stimulation and ventilation. The mechanism translates the target signal required for the therapy into a corresponding control signal (e.g. the desired muscle pressure into the stimulation intensity) so that both muscle stimulation and ventilation can be controlled in relation to their effect. Embodiments can support a system that enables effective and largely automated therapy for patients. Patients may require respiratory support or mechanical ventilation for reasons such as poor gas exchange and/or impaired respiratory muscle pump function. Embodiments may further provide an automated therapy method and system that includes a combination of respiratory muscle stimulation and ventilation. In this way, an effective and largely automated therapy can be made possible for patients who need respiratory support or mechanical ventilation for reasons of inadequate gas exchange and/or a limited respiratory muscle pump function. In contrast to conventional ventilation, the system should monitor both the activity of the respiratory muscles - preferably the inspiratory

adequately monitor and control the respiratory muscles, primarily the diaphragm - as well as the gas exchange in the lungs. arise under conventional ventilation frequent damage to the lungs (also known as “ventilator induced lung injury”, VI LI) and/or diaphragm (also known as “ventilator induced diaphragm dysfunction”, VIDD). The driving pressure (sum of ventilation pressure and muscle pressure) can lead to an excessive tidal volume and thus damage the lungs. The respiratory muscles can become fatigued from overuse or atrophy from underactivity. In the latter case, lung damage also often occurs, since the necessary comprehensive positive pressure ventilation damages the lung tissue more than if the respiratory muscle pulls along with negative pressure during inspiration [E25].

In some embodiments, a measure of the work done by the patient himself, as well as a measure of respiratory muscle activation, preferably muscle pressure, may be captured using sEMG or other suitable technology. For example, the detection of the measure of the patient's own contribution, or the measure of muscle activation on the basis of an electromyographic signal, a signal from an electro-impedance myography, a mechanomyographic signal, an ultrasound signal, a signal from a strain sensor, or of a signal from an esophageal pressure sensor. Instead of muscle pressure Pmus, the proportion of the flow caused by the muscles, FlowMus, could also be recorded [E29]

In some embodiments, FlowMus may be preferred over Pmus.

Another alternative would be the work of breathing (WOB), which can be calculated from the muscle pressure Pmus or the FlowMus by integrating:

WOBmus = ʃPmus(t) Flow(t) dt = ʃP(t) FlowMus(t) dt.

For the sake of simplicity, only "muscle pressure" is mentioned below, with the other dimensions being explicitly included.

In exemplary embodiments, the measure of the work done by the patient himself can be at least one element from the group: from a muscle pressure, Pmus, absolute or relative to a total respiratory pressure, Paw, or a total driving pressure, Pdrv; a respiratory gas flow, Flowmus, caused by the musculature of the patient, absolute or relative to a total respiratory gas flow, Flow; a tidal volume, Volmus, caused by the patient's musculature, absolute or relative to a total tidal volume, Vol; and - a work of breathing performed by the patient himself, WOBmus, absolute or relative to a total work of breathing, WOB.

The relationship between Pmus and the driving pressure or airway pressure is as follows:

If Pmus = fac * Pdrv, then Pmus/fac = Pdrv Paw + Pmus or Pmus = fac/(1 - fac) * Paw.

In addition, based on this measure, a secondary therapy goal (preferably in the sense of a corridor) can be specified. For example, the control unit 14 is designed to regulate the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. The control unit 14 can then, at least in some exemplary embodiments, also be designed to regulate the proportion performed by the patient himself based on a proportion of the ventilation specified as a secondary goal, as will be explained in more detail below. For example, respiratory muscle pressure beyond spontaneous activity can be generated by means of magnetic or electrical (or other types of) stimulation of the respiratory muscles. The stimulation can be direct by activating the muscle fibers or indirectly by stimulating the feeding efferent nerves. The control unit is then designed to output a signal for stimulating the patient's respiratory muscles for support. The control unit can also be designed to emit a signal for stimulating the patient's respiratory muscles in order to influence the proportion performed by the patient himself.

In further exemplary embodiments, the muscle pressure resulting from spontaneous breathing can be reduced, if necessary by automatically administering medication (eg sedatives or relaxants). The control unit is then designed to emit a signal for influencing the dispensing of medication in order to influence the proportion paid by the patient himself. A connected ventilator can be used to ensure that the patient receives sufficient minute volume as the primary goal of therapy and that oxygenation via the FiO ₂ setting is guaranteed. The control unit is then designed to output a signal for pressure-controlled or volume-controlled ventilation to provide support. In this way, it can also be ensured that pressure support is provided if the respiratory muscle is not able to bear the load, and if spontaneous activity is insufficient and the stimulation effect is insufficient mechanical ventilation is performed. Accordingly, the control unit can be designed to monitor and regulate the total respiratory volume and the respiratory volume provided by the patient himself, the work of breathing performed by the patient himself and/or oxygenation of the patient. In contrast to previously available therapy devices, at least some exemplary embodiments of the system described here can simultaneously offer or focus on protecting the lungs and the respiratory muscles, in particular the diaphragm. Its use is expected to reduce the number of patients affected by VILI or VIDD. An important physiological reason for improving the therapy is that the diaphragm - depending on its resilience - should always be actively involved during inspiration without causing damage to the lungs (due to excessive driving pressure). The negative pressure caused by the diaphragm has a major advantage over positive pressure ventilation in terms of tissue damage [E25]

To implement a system and a method that allows ventilation and stimulation to be adjusted and coordinated, e.g. The sensor unit (e.g. sEMG amplifier) should record the activation signal and calculate the respiratory muscle pressure using pneumatic information. The stimulator (actuator unit), on the other hand, should generate a stimulation signal from the actual and target value of a target variable (e.g. muscle activation, airway flow, esophagus or muscle pressure) and, if necessary, identify the kernel or parameters of the system impulse response. The components are connected to each other via the appropriate interfaces.

In exemplary embodiments, a ventilator system includes, for example, a ventilator with the option of mechanical pressure or volume-controlled ventilation, triggered pressure support and, if necessary,

Proportional support to patient effort. The ventilator may have airway flow and pressure measurement capability and may include the devices described herein.

If no sensor unit is available, the muscle pressure signal can still be calculated. However, the calculation is less accurate when based solely on the pneumatic signals from the ventilator's sensors. The ventilator may have the ability to adjust the sedation level of the to change patients. For example, deeper sedation reduces spontaneous breathing activity. Normally, attempts are made to ventilate patients with as few sedatives or relaxants as possible. If the respiratory muscle pressure is too great and therefore the lungs and diaphragm can be damaged, it can be reduced by administering an appropriate amount of sedatives or relaxants.

In some exemplary embodiments, the ventilation system can also include an actuator unit (stimulator) for stimulating (e.g. electrically, ultrasonically or preferably magnetically) the respiratory muscles, which can also potentially include the devices described. The actuator is preferably used non-invasively on the body surface, e.g. by means of stimulation electrodes or coils. The actuator can be controlled directly by specifying a time-dependent stimulation intensity Istim(t). However, it is desirable to control the effect of the stimulation in a fine-grained manner. A measure of the activation of the muscles, the airway flow caused or preferably the muscle pressure achieved by the contraction can be considered as a target variable. This requires sensory feedback of the target variable (e.g. the read EMG, EIM, or MMG envelope curve as a measure of muscle activation, the flow signal or the calculated muscle pressure Pmus). After specifying this time-dependent target variable, the actuator then stimulates in such a way that the target value is reached, i.e. the measured (read-in) actual value matches the target value as precisely as possible. This means that the stimulation is carried out in such a way that it achieves a specific effect. The stimulation intensity is adjusted accordingly (continuously if necessary).

Muscle activation/flow/muscle pressure caused by spontaneous breathing activity is interpreted as an error signal. This error signal can be displayed on a GUI (graphical user interface), since it has therapeutic and/or diagnostic value. For example, stimulation would only take place if the specified total patient-side muscle pressure is greater than the current patient-side muscle pressure. In the other case, there would be no stimulation; if necessary, the sedation could be increased in order to reduce the error signal (the spontaneous muscle pressure). Alternatively, a volume signal could be used as a measure of respiratory muscle activation, e.g. the proportion of volume or flow caused by muscle activation (FlowMus or VolMus) [E29]

For example, the actuator unit takes into account the signal quality of the signals that are necessary for the stimulation effect. If the signal quality is insufficient (e.g. des sEMG of the respiratory muscles as a prerequisite for calculating the muscle pressure) the attending clinical staff can be made aware of this (alarm). The muscle pressure actually to be provided by the patient could then, if necessary, be automatically taken over by the ventilator as part of pressure support (fallback).

In exemplary embodiments, the ventilation system can also include a sensor unit for detecting the muscle activation signal, preferably the electromyogram of the diaphragm, using surface electrodes. The sensor unit is intended to function simultaneously with the stimulation. Therefore, in general, there is the

Necessity to avoid stimulation artefacts in the detected stimulation signal or to remove them in real time. For example, reliability measures can also be determined in order to minimize artefact influences (e.g. due to movement) on the estimation. Furthermore, the sensor unit detects the quality of the detected muscle activation signal or the calculated muscle pressure signal to counteract

To be prepared for errors and artefact influences (e.g. body movement, interference signals). Clinical staff can be notified of poor quality or the system can be switched to a fallback mode. Exemplary embodiments can create a therapy method that can be used, for example, as a non-invasive therapy method in which the breathing work to be performed by the patient (absolute or relative) is specified depending on the therapy progress (e.g. efficiency of the respiratory muscles, resilience or degree of exhaustion). The minute volume, oxygenation and/or other basic ventilation parameters are specified by the doctor/clinical staff as the primary therapy goal. In addition, the proportion or the absolute value (preferably in the sense of a corridor, e.g. a trajectory with margin) of the breathing work to be performed by the patient can now be specified as a secondary goal. This breathing work on the part of the patient is in turn divided into a spontaneous part and a part that is caused by the stimulation of the respiratory muscles - preferably the diaphragm. Furthermore, the stimulation is preferably carried out magnetically by activating the phrenic nerve in the neck.

The remaining portion of the work necessary to achieve the primary goal of therapy is performed by the ventilator. If the patient is now unable to achieve his/her therapy goal within the framework of respiratory support set in this way, the proportion of self-respiration could be increased by stimulating the inspiratory muscles. On the other hand, the patient's breathing work become larger than the specified proportion due to spontaneous breathing activity. In this case, the stimulation intensity is reduced or, if necessary, the degree of sedation or the rate of sedatives or relaxants is increased. The long-term goal is, for example, that the patient maintains his resilience as much as possible or at least regains it quickly so that he can do all the work of breathing himself. Weaning is either no longer necessary or attainable in the short term. In practice, a measure of the efficiency, activability, resilience and the degree of exhaustion is repeatedly determined and the proportion of the total work of breathing to be performed by the patient (i.e. the sum with and without stimulation) is adjusted accordingly. Accordingly, the control unit is then designed to increase the efficiency of the

determining the patient's respiratory muscles, the assisting being further based on efficiency. In addition or as an alternative, the control unit can be designed to determine whether the respiratory muscles of the patient can be activated, with the support also being based on the ability to be activated. As a further option, the control unit can be designed to detect exhaustion of the respiratory muscles of the

to determine patients, wherein the assisting is further based on the exhaustion. The ventilator does the rest of the work of breathing. For example, exhaustion can be avoided. If the diaphragm is unable to perform the required work of breathing (e.g. due to fatigue, neuronal dysfunction, obstruction, restriction or other pathology), a specifically adjusted combination of muscle stimulation and pneumatic respiratory support can help. If the patient's muscles, e.g. due to fatigue, are not able to spontaneously trigger respiratory strokes and thus enable support, mechanical ventilation is used as a fallback. The breathing rhythm and the complete work of breathing are then performed by the ventilator. At the same time, there should be light stimulation to avoid muscle atrophy, synchronized with ventilation. The synchronization of the stimulation takes into account both the beginning and the end of the breaths. The control unit can thus be designed to direct the influencing and the supporting according to a breathing rhythm specified by the patient. In addition or as an alternative, the control unit can be designed to direct the support according to a breathing rhythm predetermined by the influencing.

At least in some exemplary embodiments, the control unit can be designed to direct the influencing and the support according to a breathing rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless. Otherwise, the support is based on a breathing rhythm specified by a stimulation, provided there is no spontaneous activity on the part of the patient is present or harmful and if there is no stimulation effect, the support is based on a respiratory rhythm specified by pneumatic ventilation. It is then no longer a matter of support in the true sense of the word, but of mandatory ventilation. If the activation signal (or pneumatic signals) indicate that self-breathing begins, the patient should be switched back from mechanical ventilation to respiratory support. If the patient's muscles are able to trigger respiratory strokes or even to breathe spontaneously on their own, but the muscles are not activated due to neuronal damage, for example, then the lack of spontaneous breathing can be compensated for by stimulation. The ventilator detects these stimulated respiratory efforts and can support them if the patient is unable to do all the work of breathing on their own. In exemplary embodiments, the primary therapy goal is ensured. The following procedure defines how to ensure adequate ventilation and, if necessary, oxygenation and how to protect both the lungs (in terms of volume) and the diaphragm (in terms of the work of breathing). Volume is always monitored to ensure lung protection (VT < VTmax) and adequate ventilation (MV > MVmin). - If the tidal volume VT becomes too large, the stimulation intensity must be reduced and, if necessary, the sedation increased. - If the tidal volume VT becomes too small and at the same time the respiratory rate becomes too high, this is an indication of fatigue (rapid shallow breathing). The patient's work of breathing must be reduced (possibly by reducing the stimulation intensity) and the support increased. - If the minute volume MV is too small, the stimulation intensity or the support must be increased depending on the resilience of the muscles.

The work of breathing is always monitored in order to protect the diaphragm, i.e. to avoid atrophy (WOBmus < WOBmin) and fatigue (WOBmus > WOBmax). - If the patient's work of breathing becomes too small, there is a risk of atrophy and an increase is sought (by reducing the support provided by the ventilator and/or by increasing the stimulation intensity). - If the patient's work of breathing becomes too great, there is a risk of exhaustion/fatigue and a reduction is sought (by increasing support by the ventilator or by reducing the stimulation intensity).

If necessary, the oxygenation is monitored using SpC>2 sensors. Depending on the saturation value, the PEEP (positive end-expiratory pressure) and the F1O2 value are adjusted. This is preferably done automatically.

In exemplary embodiments, several instances can be considered as clock generators for the synchronization. For example, the following procedure determines who or which component is the “pace generator,” i.e., sets the pace of breathing. The patient is preferably the pacemaker when there is (sufficient) spontaneous activity. - Muscle activation is detected by the EMG and the ventilator. - The stimulation is used depending on the degree of resilience of the muscles, in order to increase muscle activation synchronously with spontaneous activity and increase resilience.

- Depending on the work of breathing to be performed and the resilience, ventilation is then assisted synchronously with muscle activation.

Alternatively, the stimulation unit is a pacemaker even when there is spontaneous activity, particularly when the breathing pattern is harmful to the patient. - Muscle activation is detected by the EMG and the ventilator. - The stimulation unit carries out so-called "pacing", i.e. it specifies the breathing pattern. This is preferably lung-protective and energy-optimized. - It is possible (and probable) that the patient will accept the lung-protective and energy-optimized stimulation pattern and his

Spontaneous activity synchronized with it. If this does not happen within a specified period of time, the patient's spontaneous activity pattern is used as the basis for the stimulation. - The stimulation is used depending on the degree of resilience of the muscles, in order to increase muscle activation synchronously with spontaneous activity and increase resilience.

- Depending on the work of breathing to be performed and the resilience, support from ventilation is provided synchronously with muscle activation.

The stimulation unit is preferably the clock when there is no (sufficient) spontaneous activity. This requires the stimulation to be available for an unlimited period of time. Depending on the degree of resilience of the muscles, stimulation is used in order to achieve adequate muscle activation. - The breathing pattern specified by the stimulation unit is preferably lung-protective and energy-optimized. - Muscle activation is detected by the EMG and the ventilator.

- Depending on the work of breathing to be performed and the resilience, support from ventilation is provided synchronously with muscle activation. Alternatively, or in the event that pacing is not available or the pacing effect is not achievable, the ventilator takes over the role of pacemaker. - Controlled mechanical ventilation (no support!) is carried out. - Simultaneously to ventilation, stimulation takes place depending on the current resilience of the muscles in order to achieve the desired muscle activation, in particular to avoid atrophy and increase/maintain resilience.

In one exemplary embodiment, automatic ventilation and stimulation take place, for example, in the following steps: The clinical staff initially enters a primary therapy goal, preferably via the ventilator's GUI. o For the primary therapy goal (maintenance of CO ₂ removal and oxygenation), the doctor/clinic staff preferably specifies the minute volume (MV), the PEEP and the proportion of oxygen in the respiratory air (F1O2). As an alternative to the MV, you can also do that

Tidal volume (VT) can be set in conjunction with breath rate or breath duration. Simply specifying the inspiratory pressure is not enough, as the administered volume depends on the patient's lung mechanical properties. o It is imperative that the primary goal of therapy is met. If the patient is not able to ensure adequate ventilation (CO ₂ removal) and oxygenation, the ventilator must take on this role. - The clinical staff initially enters a secondary therapy goal, preferably via the GUI of the ventilator. o The clinical staff preferably uses the GUI of the

ventilator as a secondary therapy goal, how much of the for the work required for breathing (in terms of the ventilation to be performed for CC>2 evacuation) by the patient or how much work is to be performed by the ventilator. o The proportions that occur in a ventilation situation can be determined by calculating the muscle pressure Pmus or FlowMus and can be modified and regulated by adjusting parameters (eg stimulation intensity, degree of sedation or support pressure). - The secondary therapy goal can depend on the patient's condition - depending in particular on the muscular resilience and the pulmonary mechanical

Properties, i.e. the basic respiratory load - can be adjusted manually. These parameters and the patient's current (spontaneous and stimulated) respiratory effort are available to the clinical staff numerically and/or graphically. From this it is easy to derive what burden the patient can be expected to put up with during the course of therapy. Automation can be easily implemented by repeatedly determining the maximum work of breathing that can be performed and relating the work of breathing to be performed by the patient to this. If the maximum work of breathing increases, the patient's resilience increases and the patient can gradually be required to do more work of breathing. Through this training effect comes the

Patient progressively closer to their long-term goal of being completely weaned from the ventilator until fully unaided to breathe and extubate. The procedure would be as follows: o The proportion of the work of breathing to be performed by the patient is reduced to a percentage X (e.g. 50%) of the maximum that can be performed by the patient

respiratory effort (e.g. WOBmusMax, VolMusMax or PmusMax). This means that the system tries to demand the corresponding work of breathing from the patient. o If the patient significantly exceeds the required work of breathing, then appropriate sedation should be given - particularly if

If the spontaneous activity continues, damage to the lungs or respiratory muscles would be expected. o If the patient is not able to perform the required breathing work with his muscles because his resilience is less than (100% - X) the maximum possible breathing effort, a corresponding effort is made

pressure support. o If the patient is unable to perform the required work of breathing because of his

If the patient could be able to cope with stress, but the spontaneous activity is not sufficient, a stimulation for muscle activation takes place that is synchronized with the spontaneous activity (triggered). The stimulation amplitude is regulated in such a way that the respiratory effort reaches percentage X (on average). Alternatively, this can be done using the particularly physiological proportional stimulation, in which case not only the amplitude but also the progression over time is specified. o If the patient is able to perform the required breathing work (at least in part) but is not spontaneously active (eg due to a neuronal disorder), stimulation is carried out with a specified time pattern. If the patient is only partially able to perform the work, appropriate pressure support is provided, synchronized with the stimulated muscle activity. Alternatively, the ventilator could specify a mandatory ventilation pattern with an adjusted amplitude (e.g. as part of volume-controlled ventilation). The stimulation would be synchronized with this ventilation pattern and adjusted so that the stimulated muscle activity corresponds to the percentage X. - An alternative for the automated pursuit of the secondary goal of therapy would be the incorporation into a weaning process. Instead of just adjusting the pressure support as before, the stimulation can also be adjusted with a similar rule-based scheme. Due to the additional availability of the sensor unit (preferably sEMG), the weaning process receives further indicators that can make the path to weaning safer and faster (efficiency, activatability, resilience and, if necessary, degree of exhaustion). - Another alternative is to follow a specified training or therapy plan for the pursuit of the secondary therapy goal [E32] Here, the therapy progress and the adjustment of the secondary therapy goal can be described and presented, for example by trajectories or trends, so that the clinical staff can Expectation of progress can be related to the current situation in order to control the further course of therapy. - Other aspects for automation o The mechanical properties of the lungs, in particular resistance and elastance, determine the basic respiratory load and are largely responsible for how high the total work of breathing is required, for example to achieve a specific minute volume (primary therapy goal). For this reason, the mechanical properties of the lungs are preferably estimated repeatedly (eg continuously) [E16, E17] o A measure of the patient's capacity must be known in order to determine the patient's share of the work of breathing. This is determined, for example, as a function of the quotient of the basic respiratory load and the maximum respiratory effort that can be achieved. o The maximum respiratory effort that can be achieved can be determined once or preferably (regularly if necessary) repeatedly by twitch stimulation and simultaneous recording of the mouth closure pressure or a Pmus estimate. Because of its invasiveness or the abrupt and unpleasant effect, it is desirable to perform this maneuver rather infrequently. Accordingly, the control unit can be designed to determine a basic mechanical breathing load in order to determine the exercise capacity and to determine a maximum possible breathing effort by the patient. The control unit can also be designed to determine the maximum possible breathing effort by performing a twitch stimulation. The implementation of a twitch stimulation can be used, for example, to determine the max. to be able to determine the respiratory effort o Furthermore, a measure for the current stress of the patient is determined, for example depending on the quotient of the respiratory effort made to the maximum possible respiratory effort o For automatic ventilation it is ensured that especially patients with low exercise capacity are only so heavily burdened with breathing work that the muscles do not tire. This is possible by limiting the work of breathing to be performed to a certain proportion of the maximum work of breathing that can be performed (eg 50%). The respiratory support must be adjusted accordingly.

In exemplary embodiments, both muscle stimulation and ventilation can be controlled in relation to their effect for an automatic therapy method that consists of the combination of respiratory muscle stimulation and ventilation. For this purpose, a target signal to be specified can be translated into a corresponding control signal (eg a desired muscle pressure into a stimulation intensity). Such an effect control is known for ventilation [E17], but not so far for the combination with stimulation. Something similar to an effect control for the stimulation is described in [E13], but focuses exclusively on "diaphragm work" and does not use any characterization of the controlled system (measures of effectiveness). Fractional pressure or fractional flow or volume may be preferable to a measure of work of breathing. For reasons of brevity, breathwork is used in the following, with the other measures being explicitly included and even preferred. In exemplary embodiments, the automatic therapy method can take place in the following steps:

In the first step, the clinical staff or a machine specifies the primary therapy goal, decisively the minute volume, the oxygenation and/or other basic ventilation parameters. - In the second step, the clinical staff or a machine gives the secondary

Therapy goal, i.e. the proportion of the work of breathing to be performed by the patient or the ventilator. Alternatively, the total work of breathing can also be specified, as well as the work of breathing of the patient or the ventilator. Depending on the specified work that the ventilator has to perform, the ventilator is preferably set automatically. - In the third step, the deviation from the respiratory effort demanded by the patient is determined and the patient reacts accordingly: - If this deviation is positive (patient is doing too much), then measures can be taken to reduce the respiratory drive.

For example, sedation or relaxation can be increased with medication, the CO2 partial pressure can be reduced (eg by extracorporeal methods), and the oxygen partial pressure SpÜ2 can be increased by increasing the F1O2 concentration. - If this deviation is negative (the patient is performing too little, but could perform better muscularly), the respiratory muscles are stimulated with the aim of achieving the specified work of breathing as precisely as possible. - If the deviation is negative (patient is underperforming but muscularly unable to perform), the ventilator provides appropriate pressure support to ensure adequate ventilation and avoid exhaustion. In the course of Hopefully, as the therapy progresses, at a later point in time the support will no longer be necessary and the patient will be able to fully perform the required breathing work. Embodiments also provide a method for determining a condition of a patient's respiratory muscles. The method includes stimulating the patient's respiratory muscles with a stimulation signal and detecting an activation signal in response to the stimulating. The method further includes determining one or more condition parameters for the respiratory muscles based on the stimulation signal and the activation signal. As already explained above with reference to the device, the stimulation signal can include one or more stimulation pulses. The activation signal can be detected as an impulse response. Determining the activatability can include taking into account a lower activation threshold for the stimulation signal, with activation of the respiratory muscles below the activation threshold being activated

Respiratory muscles are reduced or absent. Determining the one or more status parameters can include determining an activatability of the patient's respiratory muscles. In further exemplary embodiments, the method can also include determining a respiratory muscle pressure that can be generated by stimulation, Pstim, a respiratory volume that can be generated by stimulation, Volstim, and/or a work of breathing of the patient that can be generated by stimulation. The method may further include performing a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and determining the one or more

further comprising condition parameters based on the pneumatic ventilation parameter. The diagnostic pneumatic maneuver may include occlusion, airflow limitation, omission of single breath support, or variability in the patient's respiratory support. The method may also include determining a measure of a patient's maximum attainable respiratory effort. The measure of the patient's maximum effort to breathe can include, for example, a mouth closure pressure with maximum activation of the respiratory muscles. In some exemplary embodiments, the method can also further include determining a measure of the capacity of the patient's respiratory muscles to work under pressure. The measure of resilience can be based on a relationship between a base load, PmusBase, and a patient's maximum attainable respiratory effort, PmusMax. The method can also include determining a measure of an efficiency of the patient's respiratory muscles. The measure of the efficiency can, for example, be a ratio of a tidal volume that can be generated by stimulation and the activation signal or a ratio of a

Stimulation that can be generated respiratory muscle pressure and the activation signal include. The method may further include outputting information about the one or more status parameters. Another embodiment is a computer program with program code for performing one of the methods described herein when the program code is executed on a computer, a processor or a programmable hardware component. Further exemplary embodiments show a sensor unit and/or a stimulation device (stimulator).

Further exemplary embodiments show a ventilation device.

The following is a consolidated and clear compilation of some of the embodiments and combinations of embodiments described in this document with concepts for determining patient conditions in the area of breathing and/or ventilation as inventive, preferred and particularly preferred embodiments.

An embodiment according to the invention is formed by a device for determining a state of a patient's respiratory muscles. The device according to the invention has one or more interfaces that are designed to record patient signals. The device has a control unit that is designed to:

• Stimulating the patient's respiratory muscles with a stimulation signal,

• detecting an activation signal in response to pacing,

• Determining one or more condition parameters for the respiratory muscles based on the stimulation signal and the activation signal. In a preferred embodiment, the control unit can be designed to generate the stimulation signal with one or more stimulation pulses.

In a preferred embodiment, the control unit can be designed to detect the activation signal as an impulse response.

In a preferred embodiment, the control unit can be designed to determine an activability of the patient's respiratory muscles by determining the one or more state parameters.

In a preferred embodiment, the control unit can be designed to take into account a lower activation threshold for the stimulation signal when determining the activatability, wherein the respiratory muscles are activated when the respiratory muscles are stimulated above the activation threshold and activation occurs when the respiratory muscles are stimulated below the activation threshold is at least reduced or absent.

In a preferred embodiment, the control unit can be designed to

• a respiratory muscle pressure that can be generated by stimulation, Pstim,

• a tidal volume that can be generated by stimulation, Volstim, and/or

• to determine a patient's work of breathing that can be generated by stimulation.

In a preferred embodiment, the control unit can be designed to carry out a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and to determine the one or more status parameters based on the pneumatic ventilation parameter.

In a preferred embodiment, the diagnostic pneumatic maneuver may include occlusion, airflow limitation, omission of single breath support, or variability in the patient's respiratory support.

In a preferred embodiment, the control unit can be designed to determine a measure of the maximum respiratory effort that can be achieved by the patient. In a preferred embodiment, the measure of the patient's maximum respiratory effort can include a mouth closure pressure with maximum activation of the respiratory muscles. In a preferred embodiment, the control unit can be designed to determine a measure of the resilience of the patient's respiratory muscles and/or a measure of the efficiency of the patient's respiratory muscles.

In a preferred embodiment, the exercise tolerance measure may be based on a relationship between a baseline load, PmusBase, and a patient's maximum attainable respiratory effort, PmusMax.

In a preferred embodiment, the measure of the efficiency can include a ratio of a respiratory volume or respiratory muscle pressure that can be generated by stimulation and the activation signal.

In a preferred embodiment, the control unit can be designed to output information about the one or more status parameters via the one or more interfaces.

An embodiment according to the invention is formed by a device for ventilating a patient. The device according to the invention has one or more interfaces which are designed for the exchange of information with a ventilation unit, a stimulation unit or a sensor unit and are designed with a control unit. The control unit is designed to

• recording a measure of a portion of the ventilation performed by the patient himself,

• Determining a measure of the patient's resilience,

• influencing the patient's contribution to ventilation, and

• Assist the patient with ventilation based on a measure of the patient's contribution to ventilation and based on a measure of the patient's exercise capacity. In a preferred embodiment, the control unit can be designed to support a signal for pressure-controlled or volume-controlled ventilation, or to emit a signal to stimulate the patient's respiratory muscles.

In a preferred embodiment, the measure of the work done by the patient himself can be at least one element from the group of

• a muscle pressure, Pmus, absolute or relative to a total respiratory pressure, Paw, or a total driving pressure, Pdrv;

• a respiratory gas flow caused by the patient's muscles,

Flowmus, absolute or relative to a total respiratory gas flow, Flow;

• a respiratory volume caused by the patient's muscles,

Volmus, absolute or relative to a total tidal volume, Vol; and

• is breathing work done by the patient himself,

WOBmus, absolute or relative to a total work of breathing, WOB; include.

In a preferred embodiment, the detection of the measure of the contribution made by the patient can be based on an electromyographic signal, a signal from electro-impedance myography, a mechanomyographic signal, an ultrasound signal, a signal from a strain sensor, or a signal from an esophageal pressure sensor be performed.

In a preferred embodiment, the control unit can be designed to influence the portion made by the patient himself a signal to

Stimulate the patient's respiratory muscles or emit a signal to influence drug delivery.

In a preferred embodiment, the control unit can be designed to ventilate the patient with regard to a target specified as the primary goal

Ventilation parameters to regulate and wherein the control unit is designed to regulate the portion made by the patient himself based on a portion of the ventilation specified as a secondary goal. In a preferred embodiment, the control unit can be designed to monitor and regulate the total tidal volume and the tidal volume produced by the patient himself, in order to regulate and regulate the work of breathing produced by the patient himself and/or to monitor and regulate oxygenation of the patient.

In a preferred embodiment, the control unit can be designed to direct the influencing and the supporting (28) according to a breathing rhythm specified by the patient or according to a specified breathing rhythm.

In a preferred embodiment, the control unit can be designed to direct the influencing and the support according to a respiratory rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, and otherwise to direct the support according to a respiratory rhythm specified by a stimulation, provided a spontaneous activity of the patient is absent or harmful and, in the absence of a stimulation effect, to direct the support to a respiratory rhythm predetermined by pneumatic ventilation.

In a preferred embodiment, the control unit can be designed to determine an efficiency of the patient's respiratory muscles, the support being based on the efficiency, the control unit being designed to determine an activability of the patient's respiratory muscles, the support being based on the activatability based, and / or wherein the control unit is designed to determine an exhaustion of the patient's respiratory muscles, wherein the support is based on the exhaustion.

In a preferred embodiment, the control unit can be designed to determine a basic mechanical respiratory load and to determine a maximum possible respiratory effort of the patient in order to determine the exercise capacity.

In a preferred embodiment, the control unit can be designed to determine the maximum possible breathing effort by performing a twitch stimulation.

An embodiment according to the invention is formed by a device according to the invention for a component of a ventilation system for respiratory support of a patient, with one or more interfaces for communication with components of the ventilation system and a control unit. The control unit is designed to • Determination of a first piece of information about a target respiratory muscle activation of the patient,

• determining a second piece of information about an actual respiratory muscle activation of the patient, and · determining a measure for a respiratory support of the patient based on the first piece of information and based on the second piece of information.

A preferred embodiment may include a device for measuring airway flow and airway pressure on the patient. The control unit can be designed to determine the first information and the second information based on an airway flow measurement and an airway pressure measurement.

A preferred embodiment may include a pneumatic respiratory support device. The measure of respiratory support can include a measure of pneumatic respiratory support.

A preferred embodiment may include means for sedating the patient based on the measure of respiratory support.

A preferred embodiment can include a device for stimulating the patient's respiratory muscles based on the measure of respiratory support. In a preferred embodiment, the device can be designed to receive measurement information about an airway flow measurement or an airway pressure measurement on the patient via the one or more interfaces. In this case, the control unit can be designed to determine the measure for the respiratory support based on the measurement information.

A preferred embodiment may include means for sensing a signal dependent on actual respiratory muscle activation. In this case, the control unit can be designed to determine the degree of respiratory support based on the signal detected by sensors. In a preferred embodiment, the device for sensory detection can be designed to detect an electro-myogram, a mechano-myogram, or an electro-impedance myogram. In a preferred embodiment, the device for sensory detection can include a strain sensor, an ultrasonic sensor or an esophageal pressure sensor.

In a preferred embodiment, the control unit can be designed to reduce a difference between the first piece of information and the second piece of information about the degree of respiratory support via a regulation.

In a preferred embodiment, the first and second pieces of information may each comprise a measure of patient-stimulated or total respiratory muscle activation, patient-stimulated or total respiratory muscle flow, or patient-stimulated or total respiratory muscle pressure.

In a preferred embodiment, the control unit can be designed to determine and provide information about respiratory muscle activation caused by the patient's spontaneous breathing activity, respiratory muscle flow caused by the patient's spontaneous breathing activity or respiratory muscle pressure caused by the patient's spontaneous breathing activity.

The control unit can be designed to determine the level of respiratory support based on the information about the patient's spontaneous respiratory activity, with the level of respiratory support indicating a level of more intensive sedation of the patient if the information about the spontaneous respiratory activity of the patient is patient shows respiratory muscle activity above target respiratory muscle activation. In a preferred embodiment, the control unit can be designed to estimate a stimulation impulse response of the patient based on the second information in response to the measure for the respiratory support. In a preferred embodiment, the control unit can be designed to determine the estimate on the basis of a stimulation maneuver. In a preferred embodiment, the control unit can be designed to determine a reliability for the first and the second information and to indicate when the reliability falls below a predetermined threshold.

An embodiment according to the invention is formed by a device for stimulative ventilation support of a patient. The device according to the invention has one or more interfaces which are designed to exchange information with a ventilation unit and with a sensor unit. The device has a control unit which is designed for

• detecting information about a time profile of an activation signal of the patient's respiratory muscles;

• Stimulate the respiratory muscles in time alignment with the activation signal for muscular respiratory support of the patient.

In a preferred embodiment, the control unit can be designed to record information about a time profile of a portion of the respiratory work performed by the patient himself, and a

Determination of the activation signal for the respiratory muscles of the patient based on the information about the time course of the part of the work of breathing performed by the patient himself.

In a preferred embodiment, the control unit can be designed to determine and take into account a lower activation threshold for the stimulation, with activation of the respiratory muscles taking place when the respiratory muscles are stimulated above the activation threshold and activation being at least reduced when the respiratory muscles are stimulated below the activation threshold is or absent.

In a preferred embodiment, the control unit can be designed to carry out the stimulation in positive feedback with the activation signal and/or proportionally to the activation signal.

In a preferred embodiment, the control unit can be designed to determine a stimulation effect. In a preferred embodiment, the control unit can be designed to provide information about at least one element from the group of

• a muscle pressure, Pmus,

• a spontaneous muscle pressure, Pspon,

• a respiratory gas flow caused by the patient's muscles, Flowmus,

• a respiratory gas flow spontaneously caused by the patient's muscles, Flowspon,

• a work of breathing performed by the patient himself, WOB,

• and a spontaneous work of breathing, WOBspon, performed by the patient himself.

In a preferred embodiment, the control unit can be designed to ventilate the patient pneumatically in parallel as proportional ventilation.

In a preferred embodiment, the control unit can be designed to set an intensity of the stimulation based on a predetermined level.

In a preferred embodiment, the control unit can be designed to measure the predetermined degree via a ratio of stimulation intensity and

Activation signal or from stimulation intensity and estimated respiratory effort, Pmus, to determine the degree of a ratio between a stimulated respiratory activity and a spontaneous respiratory activity of the patient In a preferred embodiment, the control unit can be designed to the spontaneous respiratory activity of the patient based on the information about to determine the time course of the activation signal of the respiratory muscles of the patient. In a preferred embodiment, the control unit can be designed to determine a stimulation signal based on the relationship between the stimulated breathing activity and the spontaneous breathing activity of the patient and an activation impulse response of the patient's muscles. In a preferred embodiment, the control unit can be designed to generate the stimulation signal by inverse convolution of a desired stimulation elicited activation signal, EMGstim, to be determined with the activation impulse response.

In a preferred embodiment, the control unit can be designed

• to measure the spontaneous respiratory activity as a respiratory muscle pressure, Pspon, spontaneously generated by the patient

• and determine the stimulated respiratory activity as a stimulation-induced respiratory muscle pressure, Pstim,

• to describe the spontaneous respiratory activity as a respiratory gas flow spontaneously generated by the patient, Flowspon,

• and to determine the stimulated respiratory activity as a respiratory gas flow generated by stimulation, Flowstim, and/or

• to describe spontaneous breathing activity as work of breathing spontaneously generated by the patient, WOBspon,

• or its time derivative, dWOBspon/dt,

• the stimulated respiratory activity as a work of breathing produced by stimulation, WOBstim,

• or to determine its time derivative, dWOBstim/dt.

An embodiment can be formed by a ventilation system for supporting a patient during ventilation with a device according to one of the aforementioned embodiments.

An embodiment can be formed by a respirator, a stimulator, and/or a sensor unit with a device according to one of the aforementioned embodiments. A device is referred to as a stimulator which enables stimulation for respiratory support.

An embodiment according to the invention is provided by a method for determining a state of a patient's respiratory muscles,

• By stimulating the patient's respiratory muscles with a stimulation signal; · detecting an activation signal in response to the pacing; • Determining one or more status parameters for the respiratory muscles based on the stimulation signal and the activation signal. An embodiment according to the invention is provided by a method for ventilating a patient

• detecting a measure of a portion of the ventilation performed by the patient himself;

• determining a measure of the patient's ability to exercise; · Influencing the patient's own contribution to ventilation; and

• Trained to assist the patient with ventilation based on a measure of the patient's contribution to ventilation and based on a measure of the patient's endurance.

An embodiment according to the invention is provided by a method for a component of a ventilation system for respiratory support of a patient

• Determining a first piece of information about a target respiratory muscle activation of the patient;

• determining second information about an actual respiratory muscle activation of the patient; and

• determining a measure of respiratory support for the patient based on the first information and based on the second information.

An embodiment according to the invention is provided by a method for the stimulative ventilation support of a patient with: detecting information about a time course of a

Activation signal of a respiratory muscle of the patient;

• and stimulating the respiratory muscles in temporal alignment with the activation signal for muscular ventilation support of the patient. Further embodiments can be embodied as methods, in which case the individual steps of the method can be carried out with the aid of a control unit or a control module. The control unit or the control module can be designed as elements of the previously described embodiments for carrying out the method.

An embodiment is formed by a computer program with a program code for carrying out the method for determining a state of a patient's respiratory muscles, the program code being executable on a computer, a processor or a programmable hardware component.

One embodiment is formed by a computer program with a program code for carrying out the method for ventilating a patient, the program code being executable on a computer, a processor or a programmable hardware component.

These and other embodiments can be embodied according to the invention by a computer program or multiple computer programs with a program code for carrying out the method, the program code being executable on a computer, a processor or a programmable hardware component.

Some examples of devices and/or methods are explained in more detail below with reference to the enclosed figures. FIGS. 1a to 1d show block diagrams of devices for implementing concepts: a) for determining a state of a patient's respiratory muscles b) to determine a measure of a proportion of ventilation c) to determine a measure of respiratory support for a patient d) for stimulative ventilation support for a patient

FIGS. 2a to 2d show flowcharts for carrying out methods a) for determining a state of a patient's respiratory muscles; b) for ventilation with determination of a measure for a proportion of the ventilation c) for determination of a measure for respiratory support of a patient d) for stimulative respiratory support of a patient

In addition, they show:

3 shows an overview figure for the ventilation of a patient and for the detection of an electromyographic signal;

4 shows a schematic representation of a control circuit;

5 schematic representation of a regulation;

6 representations of EMG signal curves;

FIG. 7 shows an enlarged detail from FIG. 6;

FIG. 8 shows an even further enlarged detail from FIG. 6;

Figure 9 shows an average stimulation impulse response;

10 shows a schematic representation of a course of a muscle pressure;

11 shows a representation of the ability to be activated with an activation threshold.

Various examples will now be described in more detail with reference to the accompanying figures. In the figures, the thicknesses of lines, layers, and/or areas may be exaggerated for clarity. Other examples may cover modifications, equivalents, and alternatives falling within the scope of the disclosure. The same or similar reference numbers refer to the same or similar elements throughout the description of the figures, which, when compared with one another, may be implemented identically or in a modified form while providing the same or a similar function. It should be understood that when an element is referred to as being “connected” or “coupled” to another element, the elements may be connected or coupled directly, or through one or more intermediary elements. When two elements A and B are combined using an "or", it is to be understood that all possible combinations are disclosed, ie only A, only B, and A and B, unless explicitly or implicitly defined otherwise. An alternative wording for the same combinations is "at least one of A and B" or "A and/or B". The same applies, mutatis mutandis, to combinations of more than two elements.

FIGS. 1a, 1b, 1c, 1d show schematic representations of devices for realizing concepts in the context of respiration, respiration, respiratory support and stimulation. Identical elements in FIGS. 1a, 1b, 1c, 1d are denoted by the same reference numbers in FIGS. 1a, 1b, 1c, 1d.

1a shows an embodiment of a device 100, 10.

The device 10 is designed as a device for determining a state of a patient's respiratory muscles. The device 10 includes one or more interfaces 12, which are designed to acquire patient signals. The one or more interfaces are coupled to a control unit 14 . The control unit 14 is designed to stimulate the respiratory muscles of the patient with a stimulation signal and to detect an activation signal as a reaction to the stimulation. The control unit 14 is also designed to determine one or more status parameters for the respiratory muscles based on the stimulation signal and the activation signal. The figure also illustrates an exemplary embodiment of a stimulation unit (stimulator) 110 or a sensor unit 200 with a device 10. In a ventilation system 120, the device 10 can be integrated into one or more system components or also implemented separately. For example, the activatability k or k(t) can be determined as a state parameter by means of an exemplary embodiment of the device 10 .

1b shows an exemplary embodiment of a device 100, 10. The device 10 is designed as a device 10 for ventilating a patient.

The device 10 comprises one or more interfaces 12, which are designed to exchange information with a ventilation unit 120, a stimulation unit (stimulator) 110 and/or a sensor unit 200. The device 10 also includes a control unit 14 which is coupled to the one or more interfaces. The control unit 14 is designed to record a measure of a portion of the ventilation provided by the patient himself. This proportion can be recorded, for example, as the volume flow performed by the patient himself, Flowmus, as the muscle pressure performed by the patient himself, Pmus, or as the work of breathing performed by the patient himself, WOB. The control unit 14 is for determining a measure of a patient's resilience and for influencing the vom

Patients are trained to share the ventilation themselves. In addition, the control unit 14 is designed to support the patient during ventilation based on the patient's self-performing measure of ventilation and based on the patient's exercise capacity measure.

1c shows an exemplary embodiment of a device 100, 10. FIG. 1c shows a block diagram of an exemplary embodiment of a device 10 for a component 100 of a ventilation system 120 for respiratory support of a patient and block diagrams of exemplary embodiments of a ventilation system 120, a sensor unit 200 and a stimulation unit ( Stimulator) 110 with such a device 10. This figure also illustrates a device 10 for a component 100 of a ventilation system 120 for respiratory support of a patient. The device 10 includes one or more interfaces 12 for communication with components 100 of the ventilation system 120. The device 10 includes a control unit 14 which is coupled to the one or more interfaces 12 and which is designed to determine first information about a target Respiratory muscle activation of the patient, for determining second information about an actual respiratory muscle activation of the patient and for determining a measure of respiratory support for the patient based on the first information and based on the second information. Fig. 1d shows an embodiment of a device 100, 10.

The device 10, 110 is designed as a device 110 for stimulative ventilation support for a patient. The device 10 comprises one or more interfaces 12 which are designed to exchange information with a ventilation unit 120 and a sensor unit 200 . The stimulation device 110 also includes a control unit 14 which is designed to record information about a time profile of an activation signal of the patient's respiratory muscles and to stimulate the respiratory muscles in temporal alignment with the activation signal for muscular ventilation support of the patient. This figure also illustrates an exemplary embodiment of a ventilation system 120 for supporting a patient during ventilation with a device 10. In a ventilation system 120, the device 10, 110 can be integrated into one or more system components 100 or can also be implemented separately. The devices 10, 100 or components 100 according to FIGS. 1a, 1b, 1c, 1d include one or more interfaces 12 which are coupled to the control unit 14. In Figures 1a, 1b, 1c, 1d, the one or more interfaces 12 for example in the form of a machine interface or in the form of a software interface. In exemplary embodiments, the one or more interfaces 12 can be embodied as typical interface(s) for communication in networks or between network components or medical devices, eg respirators, sensor or measuring units, stimulators, etc. For example, in exemplary embodiments, these can be formed by corresponding contacts. In exemplary embodiments, it can also be embodied as separate hardware and can include a memory that at least temporarily stores the signals to be sent or the signals received. The one or more interfaces 12 can be designed to receive electrical signals, for example as a bus interface, as an optical interface, as an Ethernet interface, as a radio interface, as a fieldbus interface, etc. It can also be designed in exemplary embodiments for radio transmission and a radio -Front end and associated antennas include. Input and/or output devices such as screen, keyboard, mouse can also be connected via the one or more interfaces 12 in order to record user inputs and/or to enable outputs. In exemplary embodiments, the control unit 14 can comprise one or more arbitrary controllers, microcontrollers, network processors, processor cores such as digital signal processor cores (DSPs), programmable hardware components, etc. Exemplary embodiments are not limited to a specific type of processor core. Any number of processor cores or even a plurality of processor cores or microcontrollers are conceivable for implementing a control unit 14 . Implementations in an integrated form with other devices are also conceivable, for example in a control unit which also includes one or more other functions. In exemplary embodiments, a

Control unit 14 by a processor core, a computer processor core (CPU = Central Processing Unit), a graphics processor core (GPU = Graphics Processing Unit), an application-specific integrated circuit core (ASIC = Application-Specific Integrated Circuit), an integrated circuit (IC = Integrated Circuit), a system on chip (SOC) core, a programmable logic element, or a field programmable gate array with a microprocessor (Field Programmable Gate Array (FPGA)) as the core of the device or devices.

FIGS. 2a, 2b, 2c, 2d show schematic representations of methods for realizing concepts in the context of respiration, ventilation, respiratory support and stimulation. Identical elements in FIGS. 2a, 2b, 2c, 2d, 1a, 1b, 1c, 1d are denoted by the same reference numbers in FIGS. 2a, 2b, 2c, 2d, 1a, 1b, 1c, 1d. FIG. 2a shows an exemplary embodiment of a method 20 for determining a state of a patient's respiratory muscles. The method 20 includes stimulating 22 the respiratory muscles of the patient with a stimulation signal, detecting 24 an activation signal in response to the stimulating 22 and determining 29 one or more state parameters for the respiratory muscles based on the stimulation signal and the activation signal.

2b shows an exemplary embodiment of a method 20 for ventilating a patient. The method includes detecting 21 a measure of a portion of the ventilation provided by the patient himself and determining 25 a measure of the patient's ability to cope with stress. The method 20 also includes influencing 26 the portion of the ventilation performed by the patient himself and supporting 28 the patient during ventilation based on the measure of the portion of the ventilation performed by the patient himself and based on the measure of the patient's resilience .

2c shows an exemplary embodiment of a method 20 for a component of a ventilation system for breathing support for a patient. The method includes determining 23 first information about target respiratory muscle activation of the patient and determining 24 second information about actual respiratory muscle activation of the patient. The method 20 also includes determining 25 a measure of respiratory support for the patient based on the first information and based on the second information.

FIG. 2d shows an exemplary embodiment of a method 20 for stimulative ventilation support for a patient. The method 20 includes a detection 19 of information about a time profile of an activation signal of a respiratory musculature of the patient and a stimulation 22 of the respiratory musculature in temporal alignment with the activation signal for muscular ventilation support of the patient. For example, the portion provided by the patient corresponds to the activation signal and includes the spontaneous and/or stimulated portion.

FIG. 3 shows a schematic overview figure for the ventilation of a patient and for the detection of an electromyographic signal. 3 shows a

Ventilation device 200, which ventilates a patient 300. An electromyographic scan is performed on patient 300's respiratory muscles (diaphragm and accessory muscles). Signal 340 is detected via sensors and an original signal EMG(t) 345 is supplied to a first signal processing unit 310, which determines an envelope EMG(t) 350 from original signal 345. A further signal processing 320 then determines a profile 331 of the respiratory muscle pressure Pmus from the envelope EMG(t) 350 and from the signals [airway pressure, Paw(t), volume flow V′(t) and tidal volume V(t)] 360 supplied by the ventilation device 120 330 of the patient 300.

4 shows a schematic representation of a control circuit. The dashed block shows the patient 300 or the patient model 400 with the respiratory system 410. A block 420 models the neuromechanical efficiency (NMEspon) of the spontaneous breathing based on an electromyographic activation signal for the spontaneous breathing EMGspon(t) from the respiratory system 410 is provided. Block 420 then provides a signal Pspon(t) indicative of the muscle pressure spontaneously evoked by the patient. The stimulated muscle pressure Pstim(t) is determined by a block 430 that models the neuromechanical efficiency (NMEstim) of the stimulation based on an activation signal EMGstim(t) generated by the stimulation. The activation signal EMGstim(t) generated by the stimulation is in turn determined by block 440 (k(t)), based on a stimulation intensity Istim(t) and the activatability k(t). The total muscle pressure Pmus(t) then results from the sum of the stimulated muscle pressure Pstim(t) and the spontaneous muscle pressure Pspon(t). Block 450 specifies sedation affecting respiratory system 410 . Higher sedation results in lower spontaneous breathing activity. Block 460 represents the stimulation and sets the stimulation intensity Istim(t). The block 470 represents the pneumatic ventilation or respiratory support that the

Patient ventilated with the pressure Pvent(t). The pressure Pmus(t) generated by the patient's own muscles is then superimposed on this pressure to form the driving pressure Pdrv(t), which ultimately acts on the respiratory system 410 . The controller 480 specifies the control variables for the components sedation 450, stimulation 460 and pneumatic respiratory support 470 and determines these from the

Control difference at its input. In the present case, the control difference results from the difference between a predefined setpoint muscle pressure PmusSoll(t) and an estimated muscle pressure Pmus(t). This is calculated by an estimator 490 based on the outlet pressure of the respiratory support 470 Pvent(t), an electromyographic signal sEMG(t) recorded on the patient and the measured tidal volume flow

Flow(t) determined. In exemplary embodiments, the device can, for example, in which Respirator 470, the stimulator 460 or a sensor unit may be included. The figure illustrates a ventilation system with these components.

A therapy system consists of a respirator 470, a stimulator 460 and the possibility of setting the sedation depth 450. The patient 300, 400 is supported in his breathing with the pressure Pvent. The respiratory muscles are stimulated with the Istim intensity. The resulting flow, the support pressure and the sEMG are measured. The estimator 490 determines the muscle pressure Pmus from this. The deviation from the target value is fed to controller 480, which controls sedation 450, stimulation 460 or respiratory support 470, depending on the polarity and size of the result.

In order to enable the therapy method described, various maneuvers can be carried out in exemplary embodiments in order to calculate effectiveness measures. These measures of effectiveness then allow the ventilation and stimulation to be controlled effectively. The control unit 14 can be designed to carry out a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and to determine the one or more status parameters based on the pneumatic ventilation parameter. The diagnostic pneumatic maneuver may include, for example, occlusion, airflow limitation, omission of support for individual breaths, or variability in the patient's respiratory support.

The following maneuvers, as known, for example, from DE 102007062214B3, WO 2018 143 844A, DE 102019006480A1, DE 102019006480 A1, DE 102020000014 A1, can be carried out once, repeatedly or regularly in exemplary embodiments:

Maneuvers to determine neuromechanical efficiency (NME) in spontaneous breathing [E18, E21, E26]:

The control unit 14 can be designed to determine a measure of the efficiency of the patient's respiratory muscles. The measure of the efficiency can include, for example, a ratio of a tidal volume that can be generated by stimulation and the activation signal. The measure of the efficiency can, for example, also include a ratio of a respiratory muscle pressure that can be generated by stimulation and the activation signal. End-expiratory occlusion maneuver:

The airway flow is blocked at the end of expiration, so that the patient's subsequent respiratory effort can be recorded as "mouth pressure". The maximum amplitude, the area or other parameters over time of the mouth pressure can be used as a measure. This measure will be for the

Calculation of the NME a corresponding measure of the activation signal (EMG) set in relation. Repeated measurements, removal of outliers (outliers) and averaging of the result may be necessary, since high variability is to be expected in some cases [E21,E26]. In exemplary embodiments, the control unit can be designed to determine a measure of the maximum respiratory effort that can be achieved by the patient. For example, the measure of the maximum respiratory effort that can be achieved by the patient can include a mouth closure pressure with maximum activation of the respiratory muscles. These (rather invasive) maneuvers can be dispensed with if there is sufficient variability in spontaneous breathing and respiratory support. The variability can be created on demand, e.g. by randomly changing the pressure support or stimulation amplitude. Using estimation methods, it is then possible to calculate NME [E15]

Maneuver to determine the neuroventilatorv efficiencv NVE in spontaneous breathing [E27, E22]

The support is omitted for one breath or several breaths and the generated tidal volume VolSpon (possibly averaged over several breaths) is recorded and compared to a measure (mean value, area or similar) of the activation signal (EMGspon). - In [E28] the quotient of volume to activation is both during

support and without support are determined and the result is compared. This gives a measure of the patient's contribution to the total tidal volume. The idea behind it is reminiscent of the distribution of the proportions of the volumes in the total volume, as described in [E29], whereby in [E29] a real time signal is calculated based on the Pmus and omitting the support is not necessary. - A surrogate for the NVE can therefore be calculated without omitting the support as the quotient of VolSpon to EMGspon. Because the surrogate is determined dynamically (i.e. from the flow of the FlowSpon over time), it may differ from the static NVE by an offset and/or

Factor. The maneuver, which is not carried out so often, is then used to calibrate the surrogate, which continuously delivers current values. Maneuver to determine the activability k(t): - A so-called twitch stimulation [E21] takes place, ie a transient stimulation impulse with a high (eg 100%) intensity for a short-term maximum activation of the respiratory muscles. This should not be construed as a limitation. Other stimulation patterns are also conceivable. Ultimately, any desired stimulation pattern can be represented as a sequence of twitches that may be differently weighted. Accordingly, the control unit 14 is then designed to generate the stimulation signal with one or more stimulation pulses. The stimulation signal can, for example, comprise one or more stimulation pulses. The control unit is then designed to detect the activation signal as an impulse response. The ability to activate the patient's respiratory muscles is determined by determining the one or more status parameters.

In some exemplary embodiments, an activation threshold can be taken into account here. The control unit 14 is then designed to take into account a lower activation threshold for the stimulation signal when determining the activatability. When the respiratory muscles are stimulated above the activation threshold, the respiratory muscles are activated and when the respiratory muscles are stimulated below the activation threshold, activation is at least reduced or does not occur at all. If the activation threshold is known, the stimulation can be better synchronized with ventilation or spontaneous breathing, for example. For example, a ramped course is used for the stimulation. If such a ramp begins at 0, there can be a significant time delay, since it takes a while before the activation threshold is exceeded due to the finite ramp gradient.

Exemplary embodiments can create a system and interfaces for the combination of ventilation and muscle stimulation. In this case, exemplary embodiments can provide an architecture of a system which consists of components which communicate with one another via interfaces and are equipped with computing capacity. This system can provide effective and largely automated therapy for patients who require respiratory support or mechanical ventilation due to poor gas exchange and/or limited respiratory muscle pump function. Unlike in conventional ventilation, the system can monitor both the activity of the respiratory muscles - preferably the inspiratory respiratory muscles, primarily the diaphragm - and adequately monitor and control the gas exchange in the lungs. Conventional ventilation often causes damage to the lungs (also known as “ventilator induced lung injury”, VI LI) and/or respiratory muscles (also known as “ventilator induced diaphragm dysfunction”, VIDD). The driving pressure (sum of ventilation pressure and muscle pressure) can lead to an excessive tidal volume and thus damage the lungs. The respiratory muscles can become fatigued from overuse or atrophy from lack of activity. In the latter case, lung damage also often occurs, since the necessary comprehensive positive pressure ventilation damages the lung tissue more than if the respiratory muscle pulls along with negative pressure during inspiration [E25].

Exemplary embodiments can, for example - by means of sEMG (or another suitable technology) record a measure of the respiratory muscle activation, preferably the muscle pressure (instead of muscle pressure Pmus, the proportion of the flow caused by the muscles, FlowMus, could also be called [E29] In some embodiments FlowMus can be preferred to Pmus Another alternative would be the work of breathing (WOB), which can be calculated from the muscle pressure Pmus or the FlowMus by integration to WOBmus = integral Pmus(t) Flow(t) dt = integral P (t) · FlowMus(t) dt. For reasons of simplicity, only "muscle pressure" is mentioned in the following, with the other dimensions being explicitly included), - specify a secondary therapy goal based on this dimension (preferably in the sense of a corridor), - by means of magnetic or electrical (or other types of) stimulation of the respiratory muscles, respiratory muscle pressure is generated beyond spontaneous activity (the Stimul ation can take place directly by activating the muscle fibers or indirectly by stimulating the feeding efferent nerves), - if necessary by automatically administering medication (e.g. Sedatives or relaxants) reduce the muscle pressure caused by spontaneous breathing, ensure by means of a connected ventilator that o the patient is basically sufficient as the primary goal of therapy

minute volume and oxygenation is guaranteed via the Fi02 setting, o pressure support is provided if the respiratory muscle is not able to cope with stress, o with insufficient spontaneous activity and insufficient

Stimulating effect mechanical ventilation is performed.

In contrast to previously available therapy devices, exemplary embodiments focus on protecting the lungs as well as the respiratory muscles, in particular the diaphragm. It is to be expected that their use will reduce the number of patients affected by VI LI or VI DD. An important physiological reason for improving the therapy is that the diaphragm - depending on its resilience - should always be actively involved during inspiration without causing damage to the lungs (due to excessive driving pressure). The negative pressure caused by the diaphragm has a major advantage over positive pressure ventilation in terms of tissue damage [E25]

In exemplary embodiments, various components can be combined with one another to implement a system and a method that allows ventilation and stimulation, for example with regard to the respiratory muscle pressure to be provided, to be adequately adjusted and coordinated: a ventilator, a stimulator (actuator unit) and a sensor unit. For reasons of a powerful and clear hardware/software architecture, the "intelligence", i.e. CPU power (computing capacity) and algorithms, is preferably distributed to the components. In this way, specific calculation/estimation tasks are to be performed by the components that are most likely to be able to do this with their available signals. The sensor unit (e.g. sEMG amplifier) should record the activation signal and calculate the respiratory muscle pressure using pneumatic information accessible via an interface. The stimulator (actuator unit), on the other hand, should generate a stimulation signal from the actual and target value of a target variable (e.g. muscle activation, airway flow or muscle pressure) and, if necessary, identify the kernel or parameters of the system impulse response. As a result, the interfaces of the various components are of particular importance. All interfaces are preferably bidirectional. The interfaces do not necessarily have to be designed for a real-time requirement (response time <50ms), but only if this is necessary in the context of synchronizing activities of the communicating components. The device 10 described above can thus be implemented in a ventilator, a stimulator and/or a sensor unit. Distributed implementations are also conceivable, which then have corresponding effects on the interfaces and between the components signals/information to be exchanged. Thus, at least in some exemplary embodiments, the device 10 can comprise a device for measuring the airway flow and for measuring the airway pressure on the patient, and the control unit 14 can be designed to determine the first information and the second information based on an airway flow measurement and an airway pressure measurement. The apparatus 10 may further include a pneumatic respiratory support device and the measure of respiratory support may include a measure of pneumatic respiratory support. For example, in one exemplary embodiment, a ventilator has the option of mechanical pressure-controlled ventilation, triggered pressure support and, if necessary, support proportional to the patient's effort. The ventilator may have an airway flow and pressure measurement capability. The flow and pressure signals recorded in this way are preferably fed to the sensor unit which is connected by information technology and which calculates a muscle pressure signal or the like in conjunction with the activation signal recorded. The device 10 is then designed to receive (sensor unit) or provide (ventilator) measurement information about an airway flow measurement or an airway pressure measurement on the patient via the one or more interfaces 12 . The control unit can then be designed to also determine the measure for the respiratory support based on the measurement information. Alternatively, if a separate sensor unit is not available, these signals can be calculated by the ventilator itself. However, the calculation is less accurate when based solely on the pneumatic signals from the ventilator's sensors. In this respect, the device 10 can be implemented in a sensor unit. The device 10 can be a device for sensory detection of a signal from the actual

respiratory muscle activation. The control unit 14 can be designed to determine the measure for the respiratory support based on the sensor-detected signal. For example, the device for sensory detection is designed to detect an electro-myogram, a mechano-myogram, or an electro-impedance myogram. For example, the device for sensory detection includes a strain sensor, an ultrasonic sensor or an esophageal pressure sensor. Furthermore, the flow (or volume) signal and possibly the muscle pressure signal calculated or received by the sensor unit are fed to the connected stimulator as a target variable. The ventilator may have the ability to change the patient's sedation level. For example, deeper sedation reduces spontaneous breathing activity. Normally, attempts are made to ventilate patients with as few sedatives or relaxants as possible. In In such an embodiment, the apparatus 10 further includes means for sedating the patient based on the level of respiratory support. In exemplary embodiments, the measure of respiratory support may indicate a measure of more intense sedation of the patient when the information about the patient's spontaneous respiratory activity indicates respiratory muscle activity above the target

indicates respiratory muscle activation. If the respiratory muscle pressure is too great and therefore the lungs and diaphragm can be damaged, it can be reduced by administering an appropriate amount of sedatives or relaxants. In general, the device 10 can be integrated into the control loop, i.e. it can also be implemented as a controller. The control unit 14 can also be designed to reduce a difference between the first piece of information and the second piece of information about the degree of respiratory support via a regulation.

Accordingly, in exemplary embodiments, the device 10 may be implemented with or in a ventilator. The control unit 14 can then be designed to communicate information about the degree of respiratory support to a stimulator via the one or more interfaces 12 . The measure for the respiratory support can include at least one parameter from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an end time, an actual respiratory muscle activation and the target respiratory muscle activation. The one or more interfaces can be designed for real-time communication with a stimulator and/or with a sensor unit. Here, real-time communication means communication with a response time of <50ms. For example, the one or more interfaces are designed for sample-by-sample real-time communication with a stimulator and/or with a sensor unit. The one or more interfaces can also be designed to communicate a time profile of the measure of respiratory support with a stimulator and/or with a sensor unit. For the purpose of time synchronization or coordination, the control unit 14 can be designed to specify a clock for a stimulator via the one or more interfaces or to receive such a clock. Embodiments are also conceivable in which a stimulator is integrated into a ventilator. The control unit 14 can be designed to specify the first and the second information to a stimulator via the one or more interfaces and/or to coordinate ventilation maneuvers with a stimulator via the one or more interfaces. In some exemplary embodiments, the device 10 is implemented in or with an actuator unit (stimulator) for stimulating (eg, electrically, by ultrasound or preferably magnetically) the respiratory muscles. The control unit 14 of the device 10 can then be designed to generate a stimulation signal for the patient as a measure of the respiratory support and/or comprise a device for stimulating the respiratory muscles of the patient based on the measure of the respiratory support. The actuator is preferably used non-invasively on the body surface, for example by means of stimulation electrodes or coils. The actuator can either work independently, its stimulation can be adjusted by specifying (non-time-critical) parameters (e.g. maximum stimulation intensity) or it can be directly controlled by time-critical specification of a time-dependent stimulation intensity Istim(t) or a synchronization event (e.g. stimulation start/stop). . Preferably, the effect of the stimulation should be controlled. A measure of the activation of the muscles, the airway flow caused, or preferably the muscle pressure achieved by the contraction, can be used as a target variable. This requires sensory feedback of the target variable (e.g. the EMG, EIM or MMG envelope that has been read in as a measure of muscle activation, the flow signal, the esophagogastric, gastric or differential pressure or the calculated muscle pressure Pmus). After specifying this time-dependent target variable, the actuator then stimulates in such a way that the target value is reached, ie the measured (read-in) actual value matches the target value as precisely as possible. The use of a regulator, which is preferably integrated in the actuator unit, is a good idea here. The actuator unit is therefore able to emit a stimulation signal to the patient and to read in the specified and current target value signal via an interface. The target value of the controller can be the stimulated or the entire (patient-side)

Muscle activation, flow or muscle pressure can be selected, whereby the direct effect of the actor only influences the stimulated

muscle activation/flow/muscle pressure. The first and second information (target respiratory muscle activation, actual respiratory muscle activation) can each include a measure of patient-stimulated or total respiratory muscle activation, patient-stimulated or total respiratory muscle flow, or patient-stimulated or total respiratory muscle pressure. The muscle activation/flow/muscle pressure caused by spontaneous breathing activity is then interpreted as an error signal. The control unit 14 is then designed to receive information about a respiratory muscle activation caused by the patient's spontaneous breathing activity, a respiratory muscle flow caused by the patient's spontaneous breathing activity or a respiratory muscle flow caused by the patient's spontaneous breathing activity Determine and provide respiratory muscle pressure. This error signal is preferably determined by the actuator unit and possibly also forwarded to the connected ventilator for visualization, since it has therapeutic and/or diagnostic value. The control unit 14 is then designed to determine the measure of respiratory support based on the information about the patient's spontaneous respiratory activity. For example, stimulation is only carried out if the specified total muscle pressure on the patient side is greater than the current muscle pressure on the patient side. Otherwise there would be no stimulation. Instead, sedation could be increased via the ventilator to reduce the error signal (spontaneous muscle pressure). Alternatively, a volume signal could be used as a measure of the activation of the respiratory muscles, e.g. the proportion of volume or flow caused by muscle activation (FlowMus or VolMus) [E29] In all of these cases, the actuator unit performs an estimation task in conjunction with a control system to be solved, since the stimulation is intended to achieve a certain effect that is initially at the time of delivery of the

stimulation intensity is not yet known. By varying the stimulation intensity and "correlation" with the target value signal (e.g. the recorded muscle activation or the stimulated patient-side muscle pressure signal), a stimulation impulse response or a linear/nonlinear kernel k(t) can be determined in the sense of a system identification, which shows the time course of the stimulation intensity in translates the target variable signal. The control unit 14 is then designed, for example, to estimate a stimulation impulse response of the patient based on the second information in response to the measure for the respiratory support. The control unit 14 can also be designed to determine the estimate on the basis of a stimulation maneuver. while the

Since the impulse response can usually be parameterized (e.g. similar to specifying the P, I, D component of a PID controller or by specifying the time constant), the sampling values are specified in the kernel. The stimulation intensity can be varied using maneuvers, random changes (similar to noisy PSV, pressure support ventilation mode in which the support is randomly slightly varied) or other forms of variability. The estimation task is preferably carried out repeatedly, if necessary regularly or even continuously (sampled value for sampled value). For example, for the realization of a stimulation proportional to the respiratory effort, the estimation task and control will take place online with high real-time requirements (reaction time <50ms). The control unit 14 is then designed to repeat the estimate regularly or continuously. To adjust the stimulation amplitude, the Requirements less time critical (reaction time <5s, preferably within one breath). When estimating the stimulation effect, the actuator unit should take into account the signal quality of the signals required for the estimation. If the signal quality is insufficient (e.g. the sEMG of the respiratory muscles as a prerequisite for calculating the muscle pressure), the attending clinical staff can be made aware of this (notification or alarm). The muscle pressure actually to be provided by the patient could then, if necessary, be automatically taken over by the ventilator as part of pressure support (fallback). In this respect, the control unit 14 is designed to determine and display a reliability for the first and the second information when the reliability falls below a predetermined threshold. In accordance with the above description, the control unit 14 can be designed to receive the first and the second information via the one or more interfaces 14 from a sensor unit or from a ventilator. The control unit 14 can also be designed to receive at least one piece of information from the group of an amplitude, a ramp gradient, a stimulation duration, a start time, an end time, a time profile of the target respiratory muscle activation, an airway flow via the one or more interfaces from a sensor unit , airway pressure, respiratory muscle pressure, respiratory muscle work and respiratory muscle flow. A clock from a sensor unit and/or a ventilator can be received via the one or more interfaces 12 or this can be communicated via the one or more interfaces 12 in real time, at least in some exemplary embodiments. In some exemplary embodiments, the one or more interfaces 12 can also be Ventilation maneuvers are coordinated with a ventilator.

Embodiments also create a sensor unit with a device 10. The sensor unit is designed to detect the muscle activation signal, preferably the electromyogram of the diaphragm, using surface electrodes. Alternatively, the EIM (electro-impedance-myogram), MMG (mechano-myogram) or signals that are recorded using new optical or acoustic (eg ultrasound) technology can be used. The envelope (also known as the envelope curve) of the respective original signal is preferably used as a measure of the muscle activation. For example, the control unit 14 can be designed to send at least one piece of information from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an end time, actual respiratory muscle activation, airway flow, airway pressure, respiratory muscle pressure, respiratory muscle work and respiratory muscle flow, as a measure of respiratory support. Based on the above description, the control unit 14 can also be designed on the side of the sensor unit in order to obtain information about a maneuver from a ventilator or a stimulator via the one or more interfaces 12 . In addition, the control unit 14 can be designed to receive information about at least one pneumatic signal from a ventilator via the one or more interfaces 12 and to also determine the measure of respiratory support based on the information about the at least one pneumatic signal. the

The control unit can, for example, determine the second piece of information (actual respiratory muscle activation) based on the sensor signals. The sensor unit is intended to function simultaneously with the stimulation. Therefore, there is a general need to avoid stimulation artifacts in the captured stimulation signal (e.g. through a kind of "blanking" or filtering) or to remove them almost in real time. the

Like the actuator unit, the sensor unit is preferably equipped with its own computing unit in accordance with the desired architecture in order to process the recorded muscle activation signals, i.e. to remove artefacts, for example,

Calculate envelopes or determine trigger/cycling-off times. If pneumatic signals that are read in at the same time are available, further measures can be calculated based on the model, e.g. work of breathing, muscle pressure, asynchrony and lung mechanics as well as other diagnostic values. The sensor unit therefore preferably has a powerful computing unit, which is necessary for signal processing and in particular for the estimation tasks, as well as a bidirectional interface [E31] As already explained above, the control unit 14 can be designed to use the one or more interfaces 12 to communicate in real time. Furthermore, the sensor unit records the quality of the recorded muscle activation signal in order to be prepared for errors and artifacts (e.g. body movement, interference signals). The control unit 14 can be designed to use the one or more interfaces 12 from a

Respirator or a stimulator as the first piece of information to receive additional information about blanking, measurement times to be hidden, filtering, or suppression of stimulation artifacts. The quality of the pneumatic signals read in can also be taken into account. This allows for a robust estimation. Clinical staff can be notified of poor quality or the system can be switched to a fallback mode. Exemplary embodiments also create a ventilation system with a device 10. Various implementations and combinations of the components of the ventilation system are conceivable, some of which are explained in more detail below. In general, the ventilation system in exemplary embodiments can comprise a ventilation device, a stimulator and/or a sensor unit according to the present description.

In some exemplary embodiments, at least two of the three components (ventilator, stimulator, sensor unit) together form a system. Within the scope of this description, three possible combinations are described in more detail: For example, a ventilator and stimulator are combined. The stimulator can be integrated into the ventilator or (particularly in the case of magnetic stimulation) it can be an external device. The ventilator's Graphical User Interface (GUI) is used to enter and track the primary goal of therapy (e.g., ensuring minimal minute ventilation and oxygenation). A secondary therapy goal is also entered there (e.g. the patient's breathing effort or muscle pressure). The stimulator does not necessarily need a GUI.

However, if available, the GUI can visualize stimulation intensity and tracking of the secondary therapy goal. The ventilator provides the stimulator with the amplitude (or other parameters such as ramp steepness, stimulation duration, etc.), the times (events) for the start and stop of stimulation, or even the time course of the target variable that the stimulator should generate by adjusting the time-dependent stimulation intensity. If the ventilator is the clock generator (clock generator for the synchronization of the components involved in the ventilator system), it may be necessary for the ventilator to stimulator communication to be real-time with a guaranteed response time <50ms. This is necessary, for example, if the ventilator is

Spontaneous breathing of the patient administered triggered or mandatory breaths and the stimulator should be active during the inspiration phases. A stimulation proportional to the spontaneous respiratory effort also requires real-time capability. This is not required (or only with a long guaranteed response time <5 s) if the stimulator is the pacemaker and only the stimulation amplitude (or other parameters) need to be adjusted. If the stimulator is not a pacemaker, the stimulator is preferentially used for each breath to be stimulated signals in real time when the breath starts, when it ends and what the amplitude is for the target size. Furthermore, additional parameters that describe the shape of the stimulation stroke (eg ramp gradient) can be transmitted. The amplitude can be a scalar value or a time series that describes the course of the target variable, as would be necessary with proportional real-time stimulation. The stimulator is capable of reacting to the signals in real time within <50ms and stimulating accordingly. The airway flow (or more or less equivalently, the volume) or the muscle pressure Pmus (or FlowMus, WOB) estimated by the ventilator can be used as a target variable. The stimulator thus receives an actual value and a target value from the ventilator for the target variable and tries to change the actual value through the stimulation as part of a control that takes place within the stimulator so that it is as close as possible to the target value. If the target variable is not a scalar value but a time profile, then the control can record the mean value or other statistical measures of the actual value and control the stimulation in such a way that the specified setpoint value is reached as well as possible. Maneuvers may be necessary to identify the controlled system (that is, the system between the stimulation intensity and the activation signal), eg the omission of support strokes or mandatory strokes of the ventilator as well as a variation of the stimulation. The ventilation maneuvers are requested, for example, by the stimulator from the ventilator, which then—depending on the therapy situation—carries out the maneuvers. Actual and target values are provided, for example, by the ventilator (e.g. flow or volume, possibly Pmus). In another embodiment, the stimulator and sensor unit are combined. The stimulator can also be used without a ventilator. It is assumed that ventilation is not mandatory and that the primary goal of therapy is therefore no longer applicable. The secondary therapy goal can be set via the GUI of the stimulator. The sensor unit preferably supplies the stimulator with the activation signal as a target variable, either as an amplitude, as times (events) for the start and stop of the stimulation, or even as a time course that the stimulator should generate by adjusting the time-dependent stimulation intensity. It would also be conceivable for the sensor unit to provide the airway flow and pressure signals and, if applicable, the calculated muscle pressure Pmus (or WOB, FlowMus). This would possibly require additional sensors. If the sensor unit is the clock generator, it is required that the communication from the sensor unit to the stimulator is real-time with a guaranteed response time <50ms. This is necessary, for example, if the stimulation is should be synchronized with the timing of the activation signal or the start/stop events, e.g. in the case of stimulation proportional to the spontaneous respiratory effort. Real-time is not required (or only with a long guaranteed response time <5s) when the stimulator is the pacemaker and only the stimulation amplitude (or other parameters) need to be adjusted. If the stimulator is not the clock generator, the stimulator is preferably signaled in real time for each breath to be supported by stimulation, when the breath begins and when it ends, what amplitude the target size is and, if necessary, the time course is transmitted (details as in the above embodiment with the combination of ventilator and stimulator). The stimulator thus receives an actual value for the target variable from the sensor unit. Of the

Set point is set by the stimulator as a consequence of the secondary goal of therapy. As part of a regulation that takes place within the stimulator, the stimulator tries to change the actual value through the stimulation in such a way that it is as close as possible to the desired value. In this configuration, no ventilation maneuvers can be used to regulate the stimulation intensity. Stimulation maneuvers are possible, e.g. the stimulation can take place at the same time as or at a later time than the spontaneous breathing activity. The evaluation of the activation signal then makes it possible to determine the proportion of the activation that took place as a result of the stimulation. This must be taken into account when controlling, because the spontaneous part of the activation can be interpreted as an error signal. The actual value is specified, for example, by the sensor unit and the target value by the stimulator (activation signal).

In a further exemplary embodiment, the ventilator, stimulator and sensor unit are combined. The configuration corresponds to the description above. However, the muscle pressure (Pmus) or a similar measure (eg WOB, FlowMus), which is calculated from the pneumatic signals and the signals provided by the sensor unit, can be used as the target variable. The calculation required for this preferably takes place in the sensor unit, which receives the required pneumatic signals from the ventilator. The target variable can be represented in its actual value by parameters (amplitude, slope, etc.) or as a time curve. As above (example with the combination of ventilator and stimulator), the stimulator receives an actual value (scalar or as a time curve) and a target value for the target variable from the ventilator in parallel and tries to achieve the actual value through the stimulation as part of a regulation that takes place within the stimulator changed so that it is as close as possible to the setpoint. Alternatively, the actual value can also be supplied directly by the sensor unit. If the ventilator or sensor unit is the clock generator, it is necessary for the ventilator or sensor unit to communicate with the stimulator in real time with a guaranteed response time <50ms. This is necessary, for example, if the ventilator administers breaths that are triggered by the patient's spontaneous breathing or if the stimulator is to be active during the inspiration phases. A stimulation proportional to the spontaneous respiratory effort also requires real-time capability. This is not required (or only with a long guaranteed response time <5s) if the stimulator is the pacemaker and only the stimulation amplitude (or other parameters) need to be adjusted. For more details, see the combined ventilator and stimulator embodiment above. The muscle pressure Pmus (or FlowMus, WOB) estimated by the sensor unit preferably comes into consideration as a target variable. The stimulator thus receives an actual value and a target value for the target variable from the ventilator or the sensor unit in parallel and, within the framework of a control that takes place within the stimulator, tries to change the actual value through the stimulation so that it is as close as possible to the target value. If the target variable is not a scalar value but a time profile, then the control can record the mean value or other statistical measures of the actual value and control the stimulation in such a way that the specified setpoint value is reached as well as possible. Maneuvers may be necessary to identify the controlled system (that is, the system between the stimulation intensity and the activation signal), eg the omission of support strokes or mandatory strokes of the ventilator as well as a variation of the stimulation.

The ventilation maneuvers are requested by the stimulator from the ventilator, which then - depending on the therapy situation - carries out the manoeuvres. In the opposite direction, stimulation maneuvers are requested by the ventilator (or the sensor unit) from the stimulator. The actual value is specified by the ventilator (possibly sensor unit) and the target value by the ventilator (Pmus).

Exemplary embodiments can enable such a therapy method. The system described above, consisting of a combination of at least two devices (ventilator, stimulator, sensor unit) connected by interfaces, is suitable for automating a therapy method. The interfaces can - but do not always have to - meet real-time requirements. The therapy method is preferably non-invasive. Depending on the progress of the therapy (e.g. efficiency of the respiratory muscles, resilience or degree of exhaustion), the work of breathing to be performed by the patient (absolute or relatively) specified. The physician specifies the minute volume, oxygenation and/or another fundamental parameter of ventilation as the primary therapy goal. In addition, the proportion or the absolute value (preferably in the sense of a corridor, for example a trajectory with a margin) of the work of breathing to be performed by the patient can now also be specified as a secondary goal. This breathing work on the part of the patient is in turn divided into a spontaneous part and a part that is caused by the stimulation of the respiratory muscles - preferably the diaphragm. Furthermore, the stimulation is preferably carried out magnetically by activating the phrenic nerve in the neck. The remainder of the work required to achieve the primary goal of therapy is

ventilator performed. If the patient is now unable to achieve his/her therapy goal within the framework of respiratory support set in this way, the proportion of self-respiration could be increased by stimulating the inspiratory muscles. On the other hand, the patient's work of breathing can become greater than the specified proportion due to spontaneous breathing activity. In this case, the stimulation intensity is reduced or, if necessary, the degree of sedation or the rate of sedatives or relaxants is increased. The long-term goal is for the patient to maintain their resilience as far as possible or at least regain it quickly so that they can do all the work of breathing themselves. Weaning is either no longer necessary or attainable in the short term. In practice, a measure of the efficiency, activability, resilience and the degree of exhaustion is repeatedly determined and the proportion of the total work of breathing to be performed by the patient (i.e. the sum with and without stimulation) is adjusted accordingly. The ventilator does the rest of the work of breathing. This can be automated, for example a therapy system can be used for this purpose. For example, exhaustion can be avoided. When the diaphragm is unable to perform the required work of breathing (e.g. due to fatigue, neural dysfunction, obstruction, restriction or other pathology), a specifically adjusted combination of muscle stimulation and pneumatic respiratory support can help. If the patient's muscles, eg due to fatigue, are not able to spontaneously trigger respiratory strokes and thus enable support, the system switches to mechanical ventilation as a fallback. The breathing rhythm and the complete work of breathing are then performed by the ventilator. At the same time, there should be light stimulation to avoid muscle atrophy, synchronized with ventilation. The synchronization of the stimulation takes into account both the beginning and the end of the breaths. If, judging from the activation signal (or pneumatic signals), self-respiration sets in, the patient should switch back to mechanical ventilation change respiratory support. If the patient's muscles are able to trigger respiratory strokes or even to breathe spontaneously on their own, but the muscles are not activated due to neuronal damage, for example, then the lack of spontaneous breathing can be compensated for by stimulation. The ventilator detects these stimulated respiratory efforts and can support them if the patient is unable to do all the work of breathing on their own.

Embodiments provide a ventilation system and its components, for example a ventilator, a stimulator and/or a sensor unit. In exemplary embodiments, stimulation can then take place with the aim of muscle activation (estimator/controller). Corresponding measures for the muscle activation can be determined: EMG, flow/volume, Pmus/FlowMus, WOB, etc. Exemplary embodiments can define and provide the corresponding interfaces as well as the information and signals to be transmitted for this.

In exemplary embodiments, various combinations of components of a ventilation system can occur, such as combinations of ventilation device and stimulator, with the actual and setpoint values being specified by the ventilation device (flow/volume, possibly Pmus/FlowMus). Another possible combination is the stimulator and sensor unit. Here the actual value is specified by the sensor unit and the target value by the stimulator (activation signal). In the case of a combination of ventilator, stimulator and sensor unit, the actual value is specified by the ventilator (possibly sensor unit) and the setpoint value by the ventilator (Pmus/FlowMus).

In the above description, the various configurations of the exemplary embodiments have been described mainly in terms of the device. The method can be designed according to the device. The method can thus include determining the first information and the second information based on an airway flow measurement and an airway pressure measurement. The measure of respiratory support may include a measure of pneumatic respiratory support. In at least some embodiments, the patient may also be sedated based on the level of respiratory support. Measurement information about an airway flow measurement or an airway pressure measurement on the patient can be obtained, the amount of respiratory support can also be determined based on the measurement information. The method may further include sensing a signal that is dependent on actual respiratory muscle activation and determining the amount of respiratory support based on the sensed signal. The sensored signal may include an electro-myogram, a mechano-myogram, or an electro-impedance myogram. In addition, the sensory signal can be detected using a strain sensor, an ultrasonic sensor or an esophageal pressure sensor. Additionally or alternatively, the patient's respiratory muscles may be stimulated based on the level of respiratory support. In this respect, a difference between the first piece of information and the second piece of information can also be reduced by rules relating to the degree of respiratory support.

In some embodiments, the method may include generating a stimulation signal to the patient as a measure of respiratory support. The first and second pieces of information may each include a measure of patient-paced or total respiratory muscle activation, patient-paced or total respiratory muscle flow, or patient-paced or total respiratory muscle pressure. In addition, information about respiratory muscle activation caused by the patient's spontaneous breathing activity, respiratory muscle flow caused by the patient's spontaneous breathing activity or respiratory muscle pressure caused by the patient's spontaneous breathing activity can be determined and provided. The level of respiratory support can be determined based on information about the patient's spontaneous respiratory activity. The respiratory support measure may indicate a measure of more intense sedation of the patient when the patient's spontaneous respiratory activity information indicates respiratory muscle activity above the target respiratory muscle activation. A stimulation impulse response of the patient may also be estimated from the second information in response to the measure of respiratory support. For example, the estimation can be based on a stimulation maneuver, possibly also regularly or continuously. Furthermore, in some exemplary embodiments, a reliability can be determined for the first and the second information and it can be indicated if the reliability falls below a predetermined threshold.

Embodiments also provide a method for a ventilator comprising one of the methods. In this way, communication of information about the Measure of respiratory support can be done using a stimulator. The measure for the respiratory support can include at least one parameter from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an actual respiratory muscle activation, an end time and the target respiratory muscle activation. Communicating can be done in real time with a stimulator and/or with a sensor unit. For example, the communication takes place sample-by-sample in real time with a stimulator and/or with a sensor unit. The communication can include communicating a time profile of the measure of the respiratory support with a stimulator and/or with a sensor unit. At least in some exemplary embodiments, the method can also include specifying a pace to a stimulator. By sample means that the communication is based on the sequence of samples, i.e. sample-by-sample. The first and the second information can be given to a stimulator and/or a ventilation maneuver can be coordinated with a stimulator.

Embodiments also provide a method for a stimulator comprising any of the methods. In this case, the first or the second information can be received by a sensor unit or by a ventilator. In addition, at least one piece of information from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an end time, an actual respiratory muscle activation, the target respiratory muscle activation, an airway flow, an airway pressure, a respiratory muscle pressure, a respiratory muscle work and a respiratory muscle flow can be received. In some embodiments, a clock can also be received from a sensor unit and/or a ventilator. In addition or as an alternative, the cycle can be specified to a sensor unit and/or a ventilator. Communication can take place in real time. Ventilation maneuvers can be coordinated with a ventilator.

Embodiments also provide a method for a sensor unit with a method. The method may include receiving information about at least one pneumatic signal from a ventilator and determining the level of respiratory support further based on the information about the at least one pneumatic signal. The second piece of information can, for example be determined based on sensor signals. Here too, at least in some exemplary embodiments, communication can take place in real time. In addition, information can be provided to a ventilator or to a stimulator, for example at least one piece of information from the group of an amplitude, a ramp gradient, a stimulation duration, a start time, an end time, an actual respiratory muscle activation, an airway flow, an airway pressure, respiratory muscle pressure, respiratory muscle work and respiratory muscle flow, as a measure of respiratory support. In this way, information about a maneuver can also be obtained. The method can also include receiving information about blanking, measurement times to be masked out, filtering, or suppression of stimulation artifacts from a ventilator or a stimulator as or with the first piece of information.

Embodiments also provide a method for a ventilation system with a method as described herein. A method for a ventilator, a method for a stimulator and/or a method for a sensor unit can be included.

Embodiments may allow for muscle stimulation proportional to respiratory effort. In analogy to proportional ventilation, the respiratory muscles can also be stimulated proportionally to the patient's spontaneous breathing. According to exemplary embodiments, information about a time course of an activation signal of the respiratory muscles of the patient is recorded. At least in some exemplary embodiments, this information and a factor alpha or k ^{^} −1 can be used for stimulation. The contribution made by the patient is also important, for example, when there is an overarching regulation of the degree of positive feedback alpha. At least in some exemplary embodiments, alpha can also be selected simply, for example 0.5. Then, in addition to spontaneous patient activity, another half would come from stimulation. The control unit 14 can record the information about the time course of the activation signal

Record information about a time course of a proportion of the work of breathing performed by the patient himself. The activation signal for the patient's respiratory muscles can be determined on the basis of the information about the time course of the portion of the work of breathing performed by the patient himself. The control unit 14 can be designed to a lower

To determine activation threshold (Istimoffs) for stimulating and to take into account, with a stimulation of the respiratory muscles above the Activation threshold activation of the respiratory muscles takes place and activation is at least reduced or absent when the respiratory muscles are stimulated below the activation threshold. This is explained in more detail below in further figures. For example, the control unit is also designed to carry out the stimulation 24 in positive feedback with the activation signal. With this particularly physiological type of stimulation, positive feedback is used, ie the spontaneous effort to breathe is synchronously supported by stimulation. The support is not provided by the machine relieving the patient of the work of breathing (as is the case with respiratory support from a ventilator), but by inducing additional muscle activation, which leads to an increased contraction of the patient's respiratory muscles.

Even if the term "work of breathing" is used, it does not only mean the physical work here, but - depending on the context - the pressure applied or the volume achieved. Whenever pressure is applied and volume is thereby achieved, work of breathing is also done. Only with isometric contraction (i.e., when the volume does not change) is no physical work done. This case occurs with occlusions that are not considered here.

The following versions are possible in exemplary embodiments: The level of positive feedback is set absolutely by an adjuster that links the intensity of the stimulation to the amplitude of the activation or a measure of the respiratory effort. The stimulation effect is unpredictable, so titration is necessary when setting. The control unit 14 is then designed to determine a stimulation effect. The control unit 14 can also be designed to carry out a titration to determine the stimulation effect. - The level of positive feedback is set relatively, e.g. by specifying a percentage. This means that the stimulation effect is related to a reference (activation signal or respiratory effort) and can therefore be predicted. The control unit 14 is then designed to carry out the stimulation in proportion to the activation signal. - Muscle stimulation is performed in parallel with respiratory support, which is preferably proportional ventilation. While proportional ventilation provides mechanical support for the work of breathing, muscle stimulation leads to increased activation.

This increases the patient's muscular contribution to the work of breathing. The control unit 14 is then designed to monitor the patient be ventilated pneumatically in parallel. Parallel pneumatic ventilation is carried out as proportional ventilation. - The level of positive feedback is set taking into account an overarching goal. This is preferably the determination of the patient and machine parts of the work of breathing. the

Control unit 14 is then designed, for example, to set an intensity of the stimulation based on a predetermined level.

The stimulation of the respiratory muscles can be proportional to a measure of respiratory effort. Several variants are conceivable. The control unit 14 can be designed to provide information about the time course of the

Activation signal of the patient's respiratory muscles Information about at least one element from the group of - a muscle pressure, Pmus, - a spontaneous muscle pressure, Pspon, - a respiratory gas flow caused by the patient's muscles, Flowmus, - a respiratory gas flow caused spontaneously by the patient's muscles, Flowspon, - a work of breathing performed by the patient himself, WOB, and a spontaneous work of breathing performed by the patient himself, WOBspon. These quantities are equivalent insofar as information about the patient's own activity can be obtained from all of them.

In the context of neurological rehabilitation, the electrical stimulation of the skeletal muscles that is dependent on an activation signal is known, as well as the stimulation that is proportional to it [E35, E36]. Magnetic stimulation is more difficult to control than electrical stimulation because very high currents (> 1000A) flow in the stimulation coils. which have to be fed with a high frequency (pulse spacing 20 to 100ms, preferably 40 to 50ms). Both sensing respiratory muscle activation and stimulation is more difficult than skeletal muscle because of anatomy, unconscious control, and the central function of breathing. In some exemplary embodiments, the control unit 14 is designed to record the information about the time course of the activation signal of the patient's respiratory muscles on the basis of an electromyographic signal, a signal from an electro-impedance myography, a signal from a strain sensor, a signal from an ultrasonic sensor or a mechanomyographic signal. The connection between the pneumatic ventilation signals, the muscular activation (EMG) and the muscle stimulation can be described by the following equation of motion:

Pvent(t) = R Flow(t) + E Vol(t) + const - NME ( EMGspon(t) + EMGstim(t) ) where is assumed for the muscle pressure

Pmus(t) = NME ( EMGspon(t) + EMGstim(t) ) and for the stimulation-induced activation signal EMGstim(t) = k(t) * Istim(t)

(the character is a folding symbol).

option A

In some exemplary embodiments, the degree of positive feedback is set in absolute terms by an adjuster (via a parameter a or b, respectively) that adjusts the intensity of the stimulation with the amplitude of the activation

Istim(t) = a EMG(t) or a measure of respiratory effort,

Istim(t) = b * Pmus(t).

The control unit 14 is then designed to determine the predetermined degree via a ratio of stimulation intensity and activation signal or of stimulation intensity and estimated respiratory effort, Pmus.

The stimulation effect, i.e. which activation or which muscle pressure it generates, is not predictable in this way. A titration is therefore necessary for the appropriate setting of the factor. This means that initially with small stimulation intensities and then with adjusted rather small incremental changes, the stimulation intensity with which the desired activation or muscle pressure can be achieved is "tried out". The activation signal EMG(t) is measured, the muscle pressure Pmus(t) is estimated [E16]

Variant B

In some embodiments of respiratory effort proportional stimulation, a relative adjustment is made because it is related to the activation signal. The coupling is:

EMGstim(t) = α * EMGspon(t). This requirement means that the activation factor a caused by stimulation should be times as large as the activation by spontaneous breathing. The degree then corresponds to a ratio between a stimulated breathing activity and a spontaneous breathing activity of the patient. Because:

EMG(t) = EMGspon(t) + EMGstim(t) results in:

EMGstim(t) = α / (1 + α) EMG(t), where for the sake of simplicity α / (1 + α) = β can be set. EMGstim(t) = β * EMG(t).

The positive feedback can therefore be determined via the factor a based on the spontaneous activity or via the factor β based on the overall activity. The latter is easier to implement since the spontaneous part of the activation does not have to be determined first. In order to obtain the curve of the stimulation intensity, an expansion is necessary, which can be solved, for example, in matrix notation by inverting the Toeplitz matrix K [E 29] The representation of the time curve of the stimulation intensity as a vector T _stim is equivalent to the sampling of the time signal Istim(t) at discrete points in time: t = t _k = k · Δt.

As a result, the EMG signal is weighted and filtered with K ^-1 and used for stimulation. The activation signal EMG(t) and the (inverted) activatability k(t) are therefore necessary for the stimulation. The latter describes the activation response of the muscle to a stimulation impulse in the sense of a weight function. The control unit 14 can accordingly be designed to determine the patient's spontaneous respiratory activity based on the information about the time course of the activation signal of the patient's respiratory muscles. That

The stimulation signal can be determined based on the relationship between the stimulated breathing activity and the patient's spontaneous breathing activity and an activation impulse response of the patient's muscles. The control unit 14 can also be designed to generate the stimulation signal by inverse convolution of a desired one caused by the stimulation

Activation signal, EMGstim, to be determined with the activation impulse response. Variant C

This third variant in exemplary embodiments is similar to variant B, but relates to the muscle pressure signal. The positive feedback is Pstim(t) = α · Pspon(t).

This requirement means that the muscle pressure caused by stimulation, factor a, should be times as great as the muscle pressure caused by spontaneous breathing. The control unit 14 is designed here to monitor the spontaneous respiratory activity as a respiratory muscle pressure, Pspon, spontaneously generated by the patient and the stimulated

determine respiratory activity as a respiratory muscle pressure, Pstim, produced by stimulation. Because:

Pmus(t) = Pspon(t) + Pstim(t), we get:

Pstim(t) = β Pmus(t) and taking into account the effectiveness measures NMEstim EMGstim(t) = β NME EMG(t).

If the measure of effectiveness under stimulation does not differ from that under spontaneous breathing, the result is identical to variant B. Otherwise, the following applies: In addition to the activation signal EMG(t), the (inverted) activability k(t) and the effectiveness measures NME and NMEstim are required for the stimulation.

Variant D

This variant refers to the volume produced by the muscular effort. The control unit 14 is designed here to determine the spontaneous breathing activity as a breathing gas flow, Flowspon, generated spontaneously by the patient, and the stimulated breathing activity as a breathing gas flow, Flowstim, generated by stimulation. The coupling is:

FlowStim(t) = α x FlowSpon(t). Here, no integral quantities such as volume are used, but rather its derivative (the flow), since the proportional support is carried out in real time - and not breath by breath. Now the flow caused by the muscles can be calculated from the muscle pressure:

FlowStim(t) = Pstim(t) * DT1(t) and

FlowSpon(t) = Pspon(t) * DT1(t), where DT1(t) represents the DT1 transmission element (first-order delay element) described in [E29], which is characterized by the lung mechanical properties of the patient. This results in:

Pstim(t) = α · Pspon(t), so that the result of this variant does not differ from variant C.

Variant E

This variant refers to the muscular work of breathing. The control unit 14 is designed here to record the spontaneous breathing activity as work of breathing spontaneously generated by the patient, WOBspon, or its time derivative, dWOBspon/dt, and the stimulated breathing activity as work of breathing produced by stimulation, WOBstim, or its time derivative, dWOBstim/ dt, to determine. The positive feedback is: dWOBStim(t)/dt α · dWOBSpon(t)/dt. As with variant D is here wg. the real-time requirement uses the derivative. This is equivalent to:

P _stim (t)Flow(t) = α P _spon (t) Flow(t) and since Flow(t) occurs on both sides of the equation, the result does not differ from variant C.

Variant F

In this variant, which builds on one of the previous variants (A to E), the degree of feed-forward to a coarser time level is regulated in such a way that an overarching goal is achieved (e.g. not at the sample level, but rather breath-by-breath or even over a minute or more). the Control unit 14 is then configured to track the predetermined level at a time level that is greater than or equal to a breathing cycle of the patient.

FIG. 5 shows regulation in an exemplary embodiment using a schematic diagram to illustrate a variant. The variant shown is described based on variant F (FIG. 4). Identical elements in FIGS. 4, 5 and 11 are denoted in FIGS. 4, 5 and 11 with the same reference numbers. A stimulation signal Istim(t) is supplied to the patient 300 or the patient model 400, which via the activability k(t) 502 leads to an EMG signal EMGstim(t) based on the stimulation. An EMG signal EMGspon(t) spontaneously generated by the respiratory system 504 is superimposed on this and leads to the EMG overall signal EMG(t). This is in turn converted into a muscle pressure Pmus(t) and/or a muscle volume flow Fmus(t) via the NME in block 506 . There are two feedback loops. The EMG timing signal EMG(t) is fed back sample-by-sample to generate the stimulation signal Istim(t) at block 510 proportionally thereto. It should be noted that this is an amplitude-modulated pulse sequence with a fixed pulse interval. The degree of positive feedback is largely determined by β. This is determined by a second feedback depending on the deviation of the muscle pressure Pmus from the desired value _PmuS set at a coarser time level in block 512 (multiplication of the control difference by 1/Pmus). For this purpose, in block 514 an averaging of Pmus(t) takes place.

Two other exemplary embodiments are shown as alternatives, with the feedback being determined as a function of the deviation in the volume Vmus(t) performed by the muscles or the work of breathing WOBmus(t). The muscular volume Vmus(t) can also be calculated directly from the EMG multiplied by NVE. As shown in this figure, the signal Fmus(t)/Flow(t) can be generated from Pmus(t) via the DT 1 element 522 (first-order delay element), from which the volume Vmus can be determined by integration in block 524 . In block 526 (multiplication of the control difference by 1/Vmus), β can then in turn _be determined from the difference between Vmus and Vmus setpoint. Alternatively, the product of Pmus(t) and Flow(t) can also be integrated via block 532 to form WOBmus(t). From the difference between WOBmus and WOBmus target β can then _be determined in block 534 (multiplication of the control difference by 1/WOBmus). In variant F, the degree of positive feedback is regulated at a coarser time level in such a way that an overarching goal is achieved. Apart from the amplitude (which depends on the degree of the positive feedback is determined directly), the time course of the stimulation does not change, however, the proportionality remains the same. The goal to be pursued is preferably the determination of the patient's share of the driving pressure (1), of the volume achieved (2) and/or of the work of breathing (3), specifically at a coarser time level. The control unit 14 is designed, for example, to stimulate the achievement of a target value, which includes a proportion of the driving pressure on the part of the patient,

ΔPmus, a patient portion of a volume, ΔVolmus, or a patient portion of a work of breathing, AWOBmus. The procedure could be implemented in a sequence of steps (1) to (3) similar to the automatic setting of the proportionality factor in proportional ventilation [E37],

(1) In order to regulate the positive feedback, feedback of the deviation of the target variable from the setpoint is necessary, as described in [E29]. The following applies to the control deviation when considering the muscle pressure:

The control deviation is to be considered as an integral variable (i.e. not at sample level) that is determined over one or more breaths, e.g. by averaging, median formation or area calculation. Alternatively, the controller fed by the control deviation carries out this calculation. The controller translates the control deviation into the manipulated variable, namely the degree of positive feedback to be set. Since the control deviation should be brought to zero by the stimulation, the following applies to the consideration of the muscle pressure:

ΔP _mus = P _stim and therefore with the equation from variant C (which also applies integrally - i.e. on a coarser time level)

Pstim = β Pmus = _ΔPmus .

Solving for β gives

(2) When considering the muscular volume generated, the deviation is: ΔVol _mus — Vol _muSsoN Vol _mus .

It can be equated with the stimulation effect:

ΔVol _mus = / _stim K NVE = EMG _stim NVE.

Because of the proportionality:

EMGstim = β EMG, the result is:

(3) The following applies to the control deviation of the work of breathing: It can be equated with the stimulation effect:

AWOB _mus = / _stim - K - NME Vol = P _stim Vol

Because of the proportionality: Pstim = β Pmus and because of: WOB _mus = P _mus Vol the result is:

In all three cases, the positive feedback can be set based on the control deviation and setpoint. A comparison of the equations from variant A and B gives the correspondences: a = K ^-1 β, and because P us(t) = NME · EMG(t), so that the adjustment of the positive feedback for all variants A to E, F (Figure 4) is possible. 6 shows EMG signal curves based on test person recordings.

The abscissas (x-axes) 1 are plotted as time axes with a scaling in [ms] in an upper representation 600 and a lower representation 601 . In the upper illustration 600, the signal "intercost.stm" is shown on the left as ordinate (y-axis) 2 and the signal "Costmar.org" is shown on the right as ordinate (y-axis) 3. shown. In the lower illustration 601, the signal "Costmar.ecgr" is shown on the left as the ordinate (y-axis) 4 and the signal "Costmar.em" is shown on the right as the ordinate (y-axis) 5. The rectangular areas 602 (“intercost.stim”) in the upper illustration 600 designate the time ranges in which stimulation took place (each approximately 4.5 seconds, but not proportional to the respiratory effort). A signal “costmar.org” 604 in μV is shown in the lower representation 601 . The signal “costmar.org” 604 is an original EMG signal derived from the costal margin using two electrodes. The signal "costmar.ecgr" 606 differs from the original EMG signal 604 in that the ECG and stimulation artifacts and the offset have been removed. The signal "costmar.env" 608 is the envelope of the signal "costmar.ecgr" 606, formed as a mean (root mean square) over a time interval of 250 ms and is a measure of diaphragm activation.

FIG. 7 shows an enlarged detail 666 from the recording from FIG. The abscissas (x-axes) 1 are plotted as time axes with a scaling in [ms] in an upper representation 700 and a lower representation 701 . In the upper representation 700 the signal "intercost.stm" is shown on the left as ordinate (y axis) 2 and the signal "Costmar.org" is shown on the right as ordinate (y axis) 3 . In the lower illustration 701, the signal “Costmar.ecgr” is shown on the left as the ordinate (y axis) 4 and the signal “Costmar.em” is shown on the right as the ordinate (y axis) 5. Identical elements in FIGS. 6 and 7 are identified in FIGS. 6 and 7 with the same reference numbers. The vertical gray lines 702 in the top plot 700 are the timing of the pacing pulses. As can be seen from the shape of the envelope signal 608 (costmar.env), stimulation was carried out with a ramped intensity profile. The signal 606 again shows the profile (costmar.ecgr) which has been cleaned of artefacts and offset, and the signal 608 shows the associated envelope (costmar.env).

FIG. 8 shows an even further enlarged section 777 from FIGS. 6 and 7, which includes a number of stimulation pulses 802. FIG. The abscissa (x-axis) 1 is shown in a representation 800 as a time axis with a scaling in [ms]. Like elements in Figures 6, 7 and 8 are given the same reference numerals in Figures 6, 7 and 8. In the representation 800 the signal “intercost.stm” is shown on the left as ordinate (y axis) 2 and the signal “Costmar.org” is shown on the right as ordinate (y axis) 3 . In the representation 800 are the original EMG Signal 604 and the times of the stimulation pulses 802 in a manner analogous to that shown in the upper illustration 700 according to FIG. Approximately 20-30ms after each stimulation pulse 802, the original signal 604 costmar.org shows patterns of activity (stimulation responses).

Figure 9 shows an average stimulation impulse response over time. The abscissa (x-axis) 1 is shown as a time axis. Like elements in Figures 6, 7, 8 and 9 are given the same reference numerals in Figures 6, 7, 8 and 9. The ordinate (y-axis) shows 6 stimulation responses "costmar.avg" 904 (mean original signal costmar in pV after stimulation) of the original EMG signal 604 "costmar.org" (Figures 6 , 7, 8). The averaging was carried out in relation to the stimulus time and includes two stimulation pulse intervals. The times of the stimulation pulses are indicated by the vertical dashed lines 902 . These lines are coincident with corresponding stimulation artifacts. A number of effectiveness measures and maneuvers, as used in exemplary embodiments, are explained below. Measures of effectiveness are required for the positive feedback and its regulation, which can be determined using maneuvers as described in [E29]. Essentially, this is a twitch stimulation and, if necessary, an end-expiratory occlusion to be carried out simultaneously to determine the activability k(t) and the neuromechanical efficiency NME. An offset determination can be carried out as follows. For stimulation is the maximum stimulation intensity to be determined, which just does not lead to muscle activation. This offset is to be subtracted from the original stimulation signal:

The original stimulation signal can also be referred to as a "raw stimulation signal". Only then is stimulation proportional to the respiratory effort possible while avoiding strong non-linear distortion. The offset determination can take place automatically. For this purpose, a stimulation with varied stimulation intensities is carried out, for example a stimulation sequence in the form of a ramp or with randomly distributed amplitudes. The activation generated is then plotted against the associated stimulation intensity, for example as a peak of the stimulation response. In some embodiments, artifact removal/suppression may occur. The removal or at least the reduction of the stimulation artifacts in real time may be necessary, since otherwise the positive feedback Runaways (outliers, uncontrolled oscillating of the signals due to the positive feedback of the stimulation artifacts). Further details on removing artefacts can be found in [E36, E38] A kind of blanking ("gating") is often carried out in which the stimulation artefacts are cut out before the subsequent filter stages in order to avoid disruptive impulse responses and to lose as little signal power as possible. Artifact reduction is also possible at the signal processing level, for example by means of ICA (independent component analysis) or wavelet transformation. Embodiments may provide stimulation intensity proportional to the patient's respiratory effort. The offset (maximum stimulation intensity without activation) can be automatically titrated and/or maneuvers can be carried out, for example to determine effectiveness measures and the ability to be activated. In this case, use can be made of positive feedback. Simultaneous stimulation and detection of muscle activation can occur, with real-time removal of stimulation artifacts. In some exemplary embodiments, the stimulation intensity can be set absolutely. In some embodiments, a relative adjustment can also be made, so that the clinical staff only has to indicate the degree of feedforward. In exemplary embodiments, an overarching goal can be specified (patient-side proportion of the driving pressure, the volume or the work of breathing) and thus an automatic setting of the positive feedback can be achieved. Normally, the phrenic nerve is stimulated with the aim of activating the diaphragm. To determine the ability to be activated, the time course k(t) of the activation signal is recorded (by EMG). In order to obtain a reliable weight function (kernel, impulse response), it is advisable to repeat the maneuver and average the time course accordingly (Peri-Stimulus-Time-Histogram, PSTH). The temporal response of muscle activation (EMG) to a sequence of stimulation pulses can now be predicted by convolution with k(t). The possibly varied intensity of the stimulation pulses must be taken into account. In principle, the portion (offset) that does not lead to activation must be subtracted from the stimulation intensity. Activation only takes place when the minimum activation threshold is exceeded. According to this, linearity and the validity of the superposition principle can (but need not necessarily) be assumed. In general, the control unit can be designed to generate a respiratory muscle pressure, Pstim, that can be generated by stimulation

To determine tidal volume, Volstim, and/or a work of breathing of the patient that can be generated by stimulation. Maneuver for determining the neuromechanical efficiency (NME) with stimulation: This maneuver can be carried out analogously to determining the neuromechanical efficiency (NME) with spontaneous breathing, with complete breaths being stimulated instead of spontaneous breathing. It is therefore a maneuver combination: a breath stimulation and at the same time an end-expiratory occlusion. - Breath stimulation:

A sequence of intensity-weighted twitch maneuvers is performed, resulting in a sequence of stimulation pulses that has an effect similar to that of a spontaneous breath. I.e. the duration of the sequence and, if necessary, the form is adapted to a spontaneous breath [D18] The intensity of the individual pulses is usually significantly lower than the 100% intensity of a twitch pulse. - End-expiratory occlusion maneuver, determination of the neuromechanical efficiency (NME) in spontaneous breathing

- These (rather invasive) maneuvers can be dispensed with if the breath stimulation produces a clear activation that is separable from spontaneous breathing. As with spontaneous breathing, it is then possible to use estimation methods to calculate NMEstim [E15].

Maneuver to determine the neuroventilatorv efficiencv NVE with stimulation: - The support is omitted for one or more stimulated breaths and the generated tidal volume VolStim (possibly averaged over several breaths) is recorded and converted to a measure (mean value, area or similar) of the Activation signal (EMGstim) set in relation. - This requires a combination of two maneuvers, Breath Stimulation (see above) and the omission of support in a scenario where breath support is normally provided. - As with the determination of the neuroventilator efficiency in spontaneous breathing, a surrogate for the NVE can also be calculated and used without omitting the support as the quotient of VolStim to EMGstim.

Maneuver to determine the stimulative mechanical efficiencv SME(t) - There is a twitch stimulation as for the determination of k(t) or SVE(t) and at the same time an occlusion [E21] The time course of the mouth closure pressure (mouth pressure) is recorded and averaged over several repetitions of the double maneuver, if necessary. - The temporal response of mouth closure pressure (corresponding to Pmus in open airways) to a sequence of stimulation pulses is now predictable by convolution with SME(t).

- Alternatively, instead of using a double maneuver, k(t) and NMEstim can be determined one after the other and the stimulative mechanical efficiency can be calculated

SME(t) = k(t) NMEstim - At maximum stimulation intensity, the amplitude of the mouth closure pressure corresponds to PmusMax, which is a measure of the maximum respiratory effort that can be achieved [E11, E23]

Maneuver to determine the stimulative ventilatory efficiency SVE(t) - This involves twitch stimulation as for the determination of k(t) or SME(t) and at the same time the volume produced is recorded without the support of a ventilator. In the literature, only pressure, not volume, is usually recorded for twitch stimulation. If necessary, the volume is averaged over several repetitions of the maneuver. - The temporal response of the delivered volume to a sequence of stimulation pulses can now be predicted by convolution with SVE(t).

- Alternatively, k(t) and NVestim can be determined one after the other and the stimulative fan efficiency can be calculated

SVE(t) = k(t) * NVEstim

Maneuvers for determining the load capacity LBC: The control unit can be designed to also determine a measure of the load capacity of the patient's respiratory muscles. For example, the exercise tolerance measure may be based on a relationship between a baseline load, PmusBase, and a patient's maximum attainable respiratory effort, PmusMax. - The resilience relates the basic load (ie the muscular effort required due to the possibly restricted respiratory mechanics) to the maximum possible respiratory effort. It is calculated in the context of this description LBC = 1 - PmusBase / PmusMax where PmusBase corresponds to a measure (mean value, amplitude, area, etc.) of the muscle pressure that is necessary to achieve sufficient volume with an optimal breathing pattern (see primary therapy goal). This value can be calculated with known respiratory mechanics parameters [E30] - A measure of the maximum respiratory effort that can be achieved is the mouth closure pressure at maximum activation, which corresponds to the maneuver used to determine SME(t). Accordingly, PmusMax is a measure (mean value, amplitude, area, etc.) of this time signal SME(t).

In contrast to previously available therapy devices, in exemplary embodiments the system simultaneously focuses on protecting the lungs and the respiratory muscles, in particular the diaphragm. It can be expected that its use will reduce the number of patients affected by VI LI or VI DD. An important physiological reason for improving the therapy is that the diaphragm - depending on its resilience - should always be actively involved during inspiration without causing damage to the lungs (due to excessive driving pressure). In terms of tissue damage, the negative pressure caused by the diaphragm has a major advantage over positive pressure ventilation [E25] for the realization of a system and a procedure that allows ventilation and stimulation, for example, with a view to the to be performed To adjust and coordinate respiratory muscle pressure adequately, various components are preferably combined with one another: a ventilator 470, a stimulator 460 (actuator unit) (FIG. 4) and a sensor unit 200 (FIGS. 1a, 1b, 1c, 1d). The sensor unit (e.g. sEMG amplifier) should record the activation signal and calculate the respiratory muscle pressure using pneumatic information. The stimulator 460 (FIG. 4) (actuator unit), on the other hand, should generate a stimulation signal from the actual and desired value of a target variable (eg muscle activation, airway flow, esophagus or muscle pressure) and identify the kernel or parameters of the system impulse response for this. The components are connected to each other via appropriate interfaces. Accordingly, the control unit can also be designed to output information about the one or more status parameters via the one or more interfaces 12 . For example, the ventilator 470 has the option of mechanical pressure or volume-controlled ventilation, triggered pressure support and, if necessary, proportional support of the patient's effort. The 470 ventilator has the ability to measure airway flow and pressure. if If no sensor unit is available, the muscle pressure signal can be calculated. However, the calculation is less accurate when based solely on the pneumatic signals from the ventilator's sensors. The ventilator 470 may have the ability to change the patient's level of sedation. For example, deeper sedation reduces spontaneous breathing activity. Normally, attempts are made to ventilate patients with as few sedatives or relaxants as possible. If the respiratory muscle pressure is too great and therefore the lungs and diaphragm can be damaged, it can be reduced by administering an appropriate amount of sedatives or relaxants. The actuator unit 460 (stimulator) (FIG. 4) is used to stimulate (eg electrically, by ultrasound or preferably magnetically) the respiratory muscles. The actuator is preferably used non-invasively on the body surface, for example by means of stimulation electrodes or coils. The actuator can be controlled directly by specifying a time-dependent stimulation intensity Istim(t). However, it is desirable to be able to control the effect of the stimulation with fine granularity. A measure of the activation of the muscles, the airway flow caused, or preferably the muscle pressure achieved by the contraction, can be used as a target variable.

This requires sensory feedback of the target variable (e.g. the read EMG, EIM, or MMG envelope curve as a measure of muscle activation, the flow signal or the calculated muscle pressure Pmus). After specifying this time-dependent target variable, the actuator 460 (FIG. 4) then stimulates in such a way that the target value is reached, i.e. that the measured (read-in) actual value matches the target value as precisely as possible. That is, the stimulation is done in a way that achieves a specific effect. The stimulation intensity is adjusted accordingly (continuously if necessary). The muscle activation/flow/muscle pressure caused by spontaneous breathing activity is interpreted as an error signal. This error signal should be able to be displayed on a GUI since it has therapeutic and/or diagnostic value. For example, stimulation would only take place if the specified total patient-side muscle pressure is greater than the current patient-side muscle pressure. In the other case, there would be no stimulation; if necessary, the sedation could be increased in order to reduce the error signal (the spontaneous muscle pressure).

Alternatively, a volume signal could be used as a measure of respiratory muscle activation, e.g. the proportion of volume or flow caused by muscle activation [E29]

The actuator unit 460 (FIG. 4) takes into account the signal quality of the signals that are necessary for the stimulation effect. If the signal quality is insufficient (e.g. des sEMG of the respiratory muscles as a prerequisite for calculating the muscle pressure) the attending clinical staff can be made aware of this (alarm). The muscle pressure actually to be provided by the patient could then, if necessary, be automatically taken over by the ventilator as part of pressure support (fallback).

A sensor unit can be used to detect a muscle activation signal, preferably an electromyogram of the diaphragm using surface electrodes. The sensor unit is intended to function simultaneously with the stimulation. Therefore i. In general, the need to avoid stimulation artifacts in the captured stimulation signal or to remove them in real time. Furthermore, the sensor unit records the quality of the recorded muscle activation signal or the calculated muscle pressure signal in order to be prepared for errors and artefact influences (e.g. body movement, interference signals). Clinical staff can be notified of poor quality or the system can be switched to a fallback mode.

For example, the following definitions of effectiveness measures can be used:

For effect-controlled ventilation based on an activity signal (such as EMG), a corresponding measure of effectiveness is required, e.g

"neuromechanical efficiency" (NME), which relates the produced muscle pressure [E18] or the "neuroventilatory efficiency" (NVE), which relates the produced volume to the EMG [E27] If an activity signal is available, it can be determined using the effectiveness measures of the dem Muscle pressure (Pmus) or volume (VolMus) corresponding to the activity signal can be determined (estimated). Conversely, this also creates a standard for the allocation of parts of the work of breathing, the muscle pressure or the volume caused by the muscles. In addition to the muscular proportions, the proportions of the ventilator can also be specified, for example the level of support pressure. With regard to the assignment of proportions, both muscle pressure and volume can be produced by spontaneous activity (which can be dampened by the administration of sedatives/relaxants) or by stimulated activity of the respiratory muscles. The measures of effectiveness are preferably identical in both cases. However, depending on the anatomy and pathology, the measures of effectiveness may differ, so that two separate measures must then be determined, eg NMEspon and NMEstim or NVespon and NVestim. In order to enable a measure for the stimulation analogous to ventilation, there is also a measure for the neuronal activation of the musculature required by the stimulation. The activatability k describes the muscle activation depending on the stimulation, e.g. its time course, so that the activation signal (preferably EMG) can be calculated from the stimulation signal:

EMGstim(t) = Istim(t) * k(t).

With the help of e.g. the NME, the time course of the muscle pressure caused by the stimulation can be predicted:

Pstim(t) = EMGstim(t) * NMEstim = Istim(t) * k(t) * NMEstim.

In the same way, the time course of the volume produced by the stimulation can be predicted using NVE:

VolStim(t) = EMGstim(t) * NVestim = Istim(t) * k(t) * NVestim.

The activatability and the measure of effectiveness can be summarized: SME(t) = k(t) * NMEstim, and

SVE(t) = k(t) * NVEstim.

The measures "stimulative mechanical efficiency" (SME) and "stimulative ventilatory efficiency" (SVE) are also measures of effectiveness. However, they do not use the EMG as a neuronal activation signal, but rather the muscle pressure or volume achieved by the stimulation. Unlike the NME or NVE, SME(t) and SVE(t) are potentially time-dependent signals (e.g. kernels) to be convolved with the time course of stimulation intensity. The determination of the effectiveness measures can be necessary for ventilation and stimulation related to their effect in some exemplary embodiments and represents a characterization of the

It relates the respective control signal to the intended effect, so that the deviation from the expected setpoint is less than if, without knowing the controlled system, a simple algorithm or controller is used to reach the setpoint by changing the control signal in some way (see e.g. [E13]). In the stimulation, normally not only a scalar factor or a characteristic has to be considered, but a time-dependent kernel, which corresponds to the impulse response of the controlled system. In addition, the stimulation is typically delivered as a sequence of weighted pulses spaced 20 to 100 ms apart (preferably 40 to 50 ms). Each impulse triggers a single activation (twitch), but only after the entire impulse sequence does the breath-like form of the activation signal result. The maneuvers listed in Table 2 below can be used to determine the appropriate measures of effectiveness (see also above):

Table 2 shows an overview of the maneuvers and their combination as well as the values that can be determined from them. The "^" sign indicates that the sizes are determined by estimation, eg using regression or a Kalman filter. The suffixes "stim" and "spon" denote the reference to stimulation and spontaneous breathing, respectively. If a suffix is missing, then the reference is the combination of both scenarios or cannot be clearly assigned. If it is to be expected that the dimensions will not differ, the suffixes can be omitted. The invasiveness of the maneuvers, i.e. the degree of stress for the patient, varies. Depending on the degree of stress, maneuvers may be carried out more or less frequently. The following is an example of the level of exertion and acceptable frequency: - Twitch stimulation: high, 1/d - End-expiratory occlusion: medium, 24/d - Breath stimulation: medium, 24/d - Omission of respiratory support: low, 240/d - Variability of respiratory support: none, unlimited

Depending on the device configuration, the maneuvers are performed by the ventilator 470 or the stimulator 460 (FIG. 4). However, they can be requested by the other device. For example, when the stimulator 460 (Figure 4) wants to determine the SME(t), it requests the ventilator 470 to perform an end-expiratory occlusion maneuver. On the other hand, if the ventilator 470 (FIG. 4) or the connected sensor unit 200 (FIGS. 1a, 1b, 1c, 1d) wants to determine Pmus and/or NME, it may request a breath from the stimulator 460 (FIG. 4). stimulation to increase the variability of the signals and to make the parameter estimation (e.g. using regression or Kalman filter) more reliable. A measure of the signal quality is preferably to be determined for each of the measured measures. The frequency of the maneuvers should preferably be automatically adapted to the signal quality of the measured values of the recorded dimensions [E15] If, for example, the VolSpon is unreliable while the support is omitted, this maneuver can be repeated and the measured values can be averaged - until sufficient reliability is achieved . On the other hand, the limits of frequency depend on the degree of

load to be taken into account. So if a maneuver cannot be repeated for the time being because of these limits, the measure determined is given the attribute of a low signal quality and can no longer be used for certain purposes (e.g. displaying diagnostic information) or can only be used to a limited extent. For the application of the effectiveness measures, these are used at least in some

inverted in the exemplary embodiments, because the specification of the proportions of the respiratory work to be performed/muscle pressure/volume requires the target variable (e.g. when specifying the target value). Scalar measures of effectiveness can also be viewed as factors. For example, if the target variable is specified, the control signal can be calculated very easily using the reciprocal of the factor, e.g. as follows:

Pmus = NME x EMG the possibility of specifying the Pmus for the associated EMG:

EMG = Pmus / NME to be generated by spontaneous breathing or by stimulation. Pmus and EMG can represent sampled time signals, or (integral) values per breath.

The specification of the support pressure of the ventilator is easily possible because of : ʃ Pmus(t) dt = ʃ Pvent(t) dt a2 / b2 with: ʃPmus dt = a2 ʃPdrv dt, ʃPvent dt = b2 ʃPdrv dt, if the calculation is not based on Sample level is performed, but integral measures are applied. This can be considered a preferred approach. ʃ EMG(t) dt =ʃ Pvent(t) dt · a2 / b2 / NME.

The muscle activation to be requested from the patient (i.e. the EMG signal) is thus derived from the specification of the support pressure and the required proportions of the driving pressure (a2 and b2). Another embodiment is the specification of the muscular volume to be achieved:

VolMus = NVE * EMG.

After forming the reciprocal value, the EMG associated with the VolMus specification results in:

EMG = VolMus / NVE.

If the volume is a tidal volume, the flow and EMG must be integrated over the breath. If it is a minute volume, then the integration takes place over a minute, for example. The application of the effectiveness measures to the stimulation is somewhat more difficult if not only integral values per breath are used, but a high time resolution is required. The timing of the stimulation intensity should now be inferred from the EMG signal to be requested. As described above, if the kernel k(t) is known, an estimate of the EMG signal generated by stimulation results in:

EMGstim(t) = Istim(t) * k(t), but the equation cannot be solved by reciprocal Istim(t) (The "*" character is the convolution symbol). This requires deconvolution (inverse convolution, deconvolution, deconvolution), for example the use of a Wiener filter. The convolution operation can also be represented in matrix notation: where the components of the vectors represent samples of the respective time series. K is the Toeplitz matrix associated with kernel k(t). The equation according to Istim can be solved by inverting the matrix K: and with Istim(t) one obtains an estimate of the time course of the stimulation as the cause of the EMG signal assumed (or required) to be known. However, if only integral values per breath are used (ie Istim describes the scalar stimulation amplitude for the breath and EMGstim describes a similar measure like amplitude, area or similar of the activation signal), then the equations simplify to:

EMGstim = Istim · k and Istim = EMGstim / k, so that a reciprocal value formation is sufficient instead of a matrix inversion.

Target variables can be specified accordingly in exemplary embodiments. In the present case, the muscle pressure produced is referred to as Pmus and the volume or flow as VolMus or FlowMus. These quantities are related to the work of breathing as follows:

WOB = WOBvent + WOBmus ,

WOBmus = ʃ P mus(t) Flow(t) dt = ʃ P (t) FlowMus(t) dt , WOBvent = ʃ P vent(t) Flow(t) dt = ʃ P (t) FlowVent( t) dt , Pdrv = Pvent + Pmus ,

Flow = FlowVent + FlowMus ,

Vol = VolVent + VolMus .

For example, if the patient is doing a fraction of the total work of breathing:

WOBmus = a1 * WOB and accordingly the ventilator:

WOBvent = b1 · WOB, then the patient and the ventilator share the entire work of breathing in the ratio a1:b1. This division is similar (but usually not identical) to the contributions to the driving pressure Pdrv or to the flow - using an integral measure, e.g. the area integral for the pressure: ʃ P mus dt = a2 ʃ P drv dt, ʃ Pvent dt = b2 ʃ P drv dt, and accordingly for the flow: ʃ FlowMus dt = a3 j Flow dt, ʃ FlowVent dt = b3 J Flow dt, so that it can be written in a simplified way:

VolMus = a3 Vol,

VolVent = b3 Vol.

The respective sum of the weights preferably results in ai + bi = 1, e.g. a1 + b1 = 1. In this sense, the ai*100 and bi*100 represent percentages. Instead of the area integral, for example, a quadratic norm or a similar integral measure can be used. The patient and ventilator contributions do not relate to individual samples, but to intervals, such as respiratory phases (inspiration or expiration) or whole or multiple breaths. As already noted, the weights ai and bi can differ in each case. For example, a patient who mathematically takes on a larger part of the work of breathing (WOBmus) may only take on a smaller part of the flow (FlowMus) if the pressure in the time window of the muscular flow is high but in the time window of the flow provided by the ventilator is low. However, these cases are only of a theoretical nature. The proportions of the flow or volume or the pressures may be more intuitive to understand than proportionate measures of the work of breathing, since the monitoring and determination of the volume (e.g. minute volume MV or tidal volume VT) or the support pressure is of great clinical importance.

At least some embodiments may enable effect-controlled ventilation and stimulation. For the effect-controlled therapy must im The degree of respiratory effort can be determined and adjusted (in the sense of a control or regulation) in connection with the secondary therapy goal. The patient's respiratory effort (as work of breathing, muscle pressure, or flow or volume induced by the respiratory muscles), whether induced by spontaneous activity, stimulation, or both, is determined as follows:

In the equation of motion:

Pvent(t) + Pmus(t) = R Flow(t) + E Vol(t) + const the muscle pressure Pmus(t) is replaced by the assumption: Pmus(t) = NME EMG(t), so that in the estimation equation:

Pvent(t) = R Flow(t) + E Vol(t) + const - NME EMG(t) + epsilon e.g. by means of regression or Kalman filtering by minimizing the error epsilon the factors R, E and NME can be determined can. The constant can be neglected in the consideration. Since NME is now known, the muscle pressure can be calculated as: Pmus(t) = NME EMG(t), but also as:

Pmus1(t) = R Flow(t) + E Vol(t) + const - Pvent(t), or as a weighted combination, where the difference lies only in the allocation of the estimation error epsilon. The first variant is used below, without this being understood as a restriction. The proportions based on spontaneous breathing and stimulation result in:

Pstim(t) = k(t) * Istim(t) and Pspon(t) = Pmus(t) - Pstim(t) = Pmus(t) - k(t) * Istim(t).

The work of breathing corresponding to the muscle pressure Pmus(t) results in: and accordingly for the shares: and

The airway flow triggered by muscle pressure is calculated according to [E29] in the frequency range as follows:

FlowMus = s/E * Pmus / (1 + R/E * s) , which corresponds to applying a DT1 transfer element to Pmus(t). The filtering of Pmus(t) can easily be described and implemented in the time domain by appropriate differential or (more suitable for the implementation) difference equations. The volume produced by the muscle pressure is identical to the time integral of the flow: usually over one or more breaths if necessary. The proportions related to spontaneous breathing and stimulation require the calculation of FlowSpon(t) and FlowStim(t) as a result of DT1 filtering of the corresponding known pressure signals Pspon(t) and Pstim(t), i.e.: and

In order to be able to adjust (regulate) the patient's respiratory effort, the control deviation is determined, and the proportion of the muscle pressure WOBmus, the work of breathing WOBmus or the volume VolMus is specified - either directly by the clinical user or by an automatic therapy system. The deviation of the actual value (see above) from the specified target value is determined. The setpoint and the actual value are each either a scalar value (preferably a value per breath) or a high temporal resolution signal (often represented as a vector), as is necessary for real-time control, for example in proportional support or stimulation. In the following, scalar quantities are assumed, without this being the same as a restriction. The following applies to the deviation in muscle pressure: EMG being a parameter of the EMG signal (eg amplitude or area). The same applies to breathing work: WOBmus is the value of the integral ʃ P _mus (t)Flow(t)dt, preferably over one breath. The same applies to the muscular volume:

In the next step, a control signal is generated from the control deviation. If the control deviation is positive (patient is not doing enough), the respiratory muscles are stimulated. If the muscle pressure is specified, the stimulation takes place with the intensity:

I _stim — ΔP _mus SME ^-1 If the volume to be achieved by muscles is specified, the following applies:

I _stim — ΔVol _{mus '} SVE ^-1 and given the muscular work of breathing: in the event that the stimulation intensity is sufficiently constant in the breath under consideration. The work of breathing done by stimulation can be represented as:

With constant stimulation amplitude over one breath: so that after l _stim one can switch to: If the pacing amplitude is not constant in the breath, it will soften

Result slightly different from the true value. However, this hardly plays a role in the regulation. If the control deviation is negative (patient is doing too much), a Δbreath support. The support pressure (“above PEEP”) when the muscle pressure is specified is:

Event = — ΔP _mus

If the muscular volume to be achieved is specified, the following applies:

Event = — Δ _Volmus E

If you look at the time of the maximum muscular volume produced, the restoring force (recoil) caused by the volume corresponds to this value. However, if one considers integral variables (eg mean values over the inspiration duration), then the result deviates from the value, but this hardly plays a role in the control. To get a more accurate result, the equation of motion: Pmus(t) = R FlowMus(t) + E VolMus(t) + const would have to be integrated over the time domain (preferably the inspiration duration). The result then shows dependencies on the course of the volume increase VolMus(t) and the time constant tau=R/E. If the muscular work of breathing is specified, this results in: as long as Pmus(t) is sufficiently constant during inspiration. If the course of the signal Pmus(t) deviates significantly from a constant value, the integral would have to be used for a more precise calculation:

WOB _mus = ʃ P _mus (t)Flow(t)dt can be calculated and resolved according to a measure (e.g. mean value) of Pmus(t). This calculation is not trivial and normally not necessary, since the above approximation is sufficient within the framework of the control. If the control deviation is permanently very large (the patient is doing far too much), self-respiration must be dampened by administering sedatives or relaxants to protect the patient. This is preferably done through the intervention of the clinical staff. Automation would be possible, but would require an assessment of the sedation effect. If the activatability k(t) changes as a result, appropriate maneuvers would have to be carried out in order to redetermine it. Automatic ventilation and pacing require the following steps in one embodiment:

Specification of the primary therapy goal: o preferably minute volume (MV) or tidal volume (VT) and respiratory rate (f); - Determination of the respiratory-mechanical parameters: o primarily Resistance (R) and Elastance (E); o Mandatory ventilation in sedated patients or o Ensuring sufficient variability in the support during spontaneous breathing (e.g. through Noisy PSV (from “pressure support ventilation”, pressure-supporting ventilation mode in which the support is randomly slightly varied)) and estimation of the parameters, e.g regression or Kalman filter; - Calculation of the optimal respiratory rate [E30]; - Determination of the respiratory base load (PmusBase) depending on the primary

therapy goal; - Determination of the ability to be activated and the maximum respiratory muscle effort PmusMax that can be achieved by twitch stimulation and end-expiratory occlusion; - Determination of effectiveness measures; - Determination of the load capacity LBC; - Specification of the secondary therapy goal: o manually by the clinical user. the basic respiratory load,

Exercise capacity, patient effort, etc. are displayed on the ventilator's GUI (Graphical User Interface). Based on this, the clinical user can assess what burden he can expect from the patient. Accordingly, the part to be performed by the patient (breathing work, muscle pressure or muscular volume) must be specified via the GUI; o automatically by a therapy system. The proportion of the patient's respiratory effort is reduced to a percentage X (e.g. 50%) of the patient's maximum respiratory effort (e.g.

WOBmusMax, VolMusMax or PmusMax). The therapy system tries to demand the corresponding work of breathing from the patient; - The control deviation is determined; - Based on the control deviation, an adjustment of the

suggested respiratory support or stimulation intensity or Done automatically. Sedatives or relaxants are preferably administered through the intervention of clinical staff.

Exemplary embodiments can support the diagnostics in particular. The specific values or characteristics of - activatability, - measures of effectiveness, - resilience, - maximum possible respiratory effort, - spontaneous respiratory effort, - respiratory effort induced by stimulation have diagnostic relevance and help the clinical staff to assess the patient situation and the progress of therapy. The measurements can be displayed graphically on the GUI of the ventilator and, if applicable, the stimulator, e.g. over time, as a bar chart, trend chart or 2-dimensional plot (e.g. Pmus vs. Vol). Appropriate signal quality measures should be taken into account - if available. For example, an unreliable signal would be poorly contrasted or not displayed at all. Scalar dimensions can, for example, be displayed in tables or in so-called P-boxes. Depending on the relevance for the patient and the clinical staff, information, alarms or instructions can be issued.

Accordingly, exemplary embodiments can include certain maneuvers for determining - activatability (characteristic that describes the ability to activate the muscles through stimulation), - efficiency (target variable that is achieved through muscular activation, e.g. NME or NVE), and/or - resilience ( depending on the ratio of the basic respiratory load to the maximum respiratory effort that can be achieved).

Various types of maneuvers that occur in exemplary embodiments are, for example - twitch stimulation, - breath stimulation, - end-expiratory occlusion,

- omission of ventilatory support for individual breathing cycles, - other forms of variability of ventilatory support and possibly stimulation.

The control unit can be designed to carry out these maneuvers.

Graphic representation of the characteristics (activatability, efficiency, resilience) for the diagnostics can occur in the exemplary embodiment. In exemplary embodiments, the characteristics can be used to automate ventilation and stimulation.

FIG. 10 shows a schematic representation 1000 of muscle activation (y-axis, ordinate) as a function of the stimulation intensity lstimr _a (x-axis, abscissa) in an exemplary embodiment with an activation threshold. Various measuring points 1001 of the generated activation are plotted against the associated stimulation intensity. The dependency of the activation on the stimulation intensity can be quantified by means of regression or other methods. The dependency of the activation on the stimulation intensity can be quantified by means of regression or other methods. In particular, the intensity lstim _offs 500 (activation threshold) can be determined at which the characteristic bends. At the intensity lstim _offs 500, the characteristic bends upwards, ie from this intensity 500 the respiratory muscles are activated.

FIG. 11 shows a schematic representation of a time profile of a muscle pressure 331, 540, Pmus 330. The abscissa (x-axis) 1 is designed as a time axis. Identical elements in FIGS. 5 and 11 are denoted in FIGS. 5 and 11 with the same reference numbers. The curve 510 shows the maximum muscle pressure PmusMax that can be produced and the dashed curve 520 shows 50% of this maximum muscle pressure PmusMax. The curve 530 shows the basic respiratory load PmusBase and the curve 540 the muscle pressure Pmus, which is made up of a spontaneous component 550 and a stimulated component 560 . PmusBase 530 is the base load, ie the muscle pressure that is necessary to achieve a sufficient minute volume with an optimal breathing rhythm. PmusMax 510 is the maximum muscle pressure that the patient can apply. 50% PmusMax 520 is the default value of respiratory effort to be demanded from the patient. Pmus 540 is the actual respiratory effort made by the patient. This temporarily exceeds the 50% PmusMax line 520, which in the example leads to exhaustion (point 570) and the need for respiratory support (area 580) after a short time. The load capacity 590 LBC = 1 - PmusBase / PmuxMax is the (relative) distance between the base load 530 and the maximum respiratory effort that can be achieved 510. It is very small in the interval marked with dashed lines (600, base load higher than 50% mark 520, imminent exhaustion) and explains the fatigue.

The attempt is made to keep the Pmus 540 near the 50% PmusMax line 520 for automation. If Pmus is smaller, then it is stimulated (560). If Pmus is greater (especially if the basic load increases), respiratory support is provided, in this example with the support pressure 610. There is a reserve 620 between the actual Pmus and the maximum muscle pressure PmusMax that can be achieved.

Overventilation - either due to excessive support pressure or excessive stimulation intensity - can manifest itself as periodic breathing. The sEMG of the respiratory muscles shows a periodic modulation with a time constant of the order of one minute or more. The periodic respiration is also reflected in the flow and respiratory muscle pressure signal. For example, after increasing the support pressure Paw, the EMG signal drops to a low value, only to periodically rise and fall again and again (apnea). If periodic breathing is detected, support pressure and/or

stimulation intensity can be reduced as a test. If the intensity of the periodic breathing decreases, overventilation was obviously present. If not, the support pressure/stimulation intensity will be reset to the previous value. The synchronization of the stimulation takes into account both the beginning and the end of the breaths. For example, a protective or energy-optimized timing of the ventilation pattern could be transferred directly to the stimulation signal [E30,

E33, E34] This also makes sense when there is no mechanical ventilation but only support. The pattern of the stimulation intensity is chosen in a way that protects the lungs and is energy-optimized, as long as possible spontaneous activity is synchronized with it. It is possible and also probable that the patient agrees to a lung-protective and energy-optimized stimulation pattern and synchronizes his spontaneous activity with it. If this does not happen within a specified period of time, the patient's spontaneous activity pattern is used as the basis for the stimulation.

The aspects and features described together with one or more of the previously detailed examples and figures can also be combined with one or more of the other examples to replace a same feature of the other example or to add the feature to the other example to introduce Examples can still be a computer program with a

be or relate to program code for performing one or more of the above methods if the computer program runs on a computer or processor is running. Steps, operations, or processes of various methods described above may be performed by programmed computers or processors. Examples can also

program storage devices, e.g. digital data storage media that is machine, processor, or computer readable and that encodes machine, processor, or computer executable programs of instructions. The instructions perform or cause performance of some or all of the steps of the methods described above. The program storage devices may e.g. B. digital memory, magnetic storage media such as magnetic disks and magnetic tapes,

include or be hard disk drives or optically readable digital data storage media. Other examples may also include computers, processors, or controllers programmed to perform the steps of the methods described above, or (Field) Programmable Logic Arrays ((F)PLAs) or (Field) Programmable Gate Arrays ((F)PGA = (Field) Programmable Gate Arrays) programmed to perform the steps of the methods described above. The description and drawings represent only the principles of the disclosure. Furthermore, all examples provided herein are generally expressly intended to be for illustrative purposes only to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor(s) to advance the art. All statements herein regarding principles, aspects, and examples of disclosure, and specific examples thereof, include their equivalents. A functional block referred to as "means for..." performing a particular function may refer to circuitry configured to perform a particular function.

Thus, a "means for something" can be implemented as a "means designed for or suitable for something", e.g. B. a component or a circuit designed for or suitable for the respective task. Functions of various elements shown in the figures, including each functional block labeled "means", "means for providing a signal", "means for generating a signal", etc., may take the form of dedicated hardware, e.g. B "a signal provider", "a signal processing unit", "a processor", "a controller", etc., and implemented as hardware capable of executing software in conjunction with associated software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some or all of which may be shared. However is The term "processor" or "controller" is far from limited to hardware capable of running only software, but may include digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC). circuit), Field Programmable Gate Array (FPGA), Read Only Memory (ROM) for storing software, Random Access Memory (RAM) and non-volatile memory devices (storage). Other hardware, conventional and/or custom, may also be included. For example, a block diagram may represent a high level circuit diagram that implements the principles of the disclosure. Similarly, a flowchart, flowchart, state transition diagram, pseudocode, and the like may represent various processes, operations, or steps, embodied, for example, substantially on a computer-readable medium and so executed by a computer or processor, whether or not one Computer or processor is explicitly shown. Methods disclosed in the specification or claims may be implemented by a device having means for performing each of the respective steps of those methods. It should be understood that the disclosure of a plurality of steps, processes, operations or functions disclosed in the specification or claims should not be construed as being in the particular order unless otherwise expressly or implicitly stated, e.g. B. for technical reasons. Therefore, the disclosure of multiple steps or functions is not limited to a specific order, unless those steps or functions are not interchangeable for technical reasons. Further, in some examples, a single step, function, process, or operation may include and/or be broken into multiple sub-steps, functions, processes, or operations. Such sub-steps may be included and form part of the disclosure of that sub-step unless explicitly excluded. Furthermore, the following claims are hereby incorporated into the Detailed Description, where each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it should be noted that although a dependent claim in the claims may relate to a particular combination with one or more other claims, other examples also include a combination of the dependent claim and the subject-matter of each other dependent or independent claim. Such combinations are explicitly suggested here, provided that no indication is given that a particular combination is not intended. Furthermore, features of a claim are also intended to be included for any other independent claim, even if that claim is not made directly dependent on the independent claim.

A large number of the various embodiments described above in this document and their possible combinations are compiled in an overview below. These different embodiments and their possible combinations provide a basis for further inventive, preferred and also particularly preferred embodiments and independent and/or subordinate patent claims based on these embodiments, as well as subclaims based on advantageous embodiments. Further and preferred embodiments of the invention relating to a concept for determining a state of a patient's respiratory muscles, in particular a concept for determining at least one state parameter of the respiratory muscles of a patient based on an evaluation of an activation signal as a reaction to stimulation of the respiratory muscles, are described in more detail below. A basic embodiment shows a device for determining a state of a patient's respiratory muscles with one or more interfaces designed to detect patient signals and a control unit designed to - stimulate the patient's respiratory muscles with a stimulation signal, - detect an activation signal in response to the stimulation and - determining one or more condition parameters for the respiratory muscles based on the stimulation signal and the activation signal.

In a preferred embodiment based on the embodiment described above, the control unit can be designed to generate the stimulation signal with one or more stimulation pulses.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to detect the activation signal as an impulse response. In a preferred embodiment based on at least one of the previously described embodiments, the control unit can be designed to determine an activability of the patient's respiratory muscles by determining the one or more state parameters.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to take into account a lower activation threshold for the stimulation signal when determining the activatability, wherein the respiratory muscles are activated when the respiratory muscles are stimulated above the activation threshold and the respiratory muscles are activated when there is a stimulation of the respiratory muscles below the activation threshold, activation is at least reduced or absent.

In a preferred embodiment based on at least one of the previously described embodiments, the control unit can be designed to determine a respiratory muscle pressure that can be generated by stimulation, P _stim , a respiratory volume that can be generated by stimulation, Volstim, and/or a patient's work of breathing that can be generated by stimulation. In a preferred embodiment based on at least one of the embodiments described above, the control unit can also be designed to carry out a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and to determine the one or more status parameters based on the pneumatic ventilation parameter.

In a preferred embodiment based on at least one of the previously described embodiments, the pneumatic diagnostic maneuver may include occlusion, airflow limitation, omission of single breath support, or variability in the patient's respiratory support.

In a preferred embodiment based on at least one of the previously described embodiments, the control unit can be designed to also determine a measure of a maximum respiratory effort that can be achieved by the patient. In a preferred embodiment based on at least one of the previously described embodiments, the measure of the patient's maximum respiratory effort can include a mouth closure pressure with maximum activation of the respiratory muscles.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to also determine a measure of the resilience of the patient's respiratory muscles. In a preferred embodiment based on at least one of the above-described embodiments, the exercise tolerance measure may be based on a relationship between a base load, Pmus _Base , and a maximum attainable respiratory effort, Pmus _Max , of the patient. In a preferred embodiment based on at least one of the embodiments described above, the control unit can also be designed to determine a measure of the efficiency of the patient's respiratory muscles.

In a preferred embodiment based on at least one of the embodiments described above, the measure of efficiency can include a ratio of a tidal volume that can be generated by stimulation and the activation signal.

In a preferred embodiment based on at least one of the embodiments described above, the measure of the efficiency can include a ratio of a respiratory muscle pressure that can be generated by stimulation and the activation signal.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed

Output information about the one or more state parameters on the one or more interfaces.

A basic embodiment shows a method for determining a state of a patient's respiratory muscles with - stimulating the patient's respiratory muscles with a stimulation signal, - detecting an activation signal as a reaction to the stimulation, - determining one or more state parameters for the respiratory muscles based on the stimulation signal and the activation signal.

In a preferred embodiment based on the basic embodiment, the stimulation signal may comprise one or more stimulation pulses.

In a preferred embodiment based on at least one of the embodiments described above, the activation signal can be detected as an impulse response.

In a preferred embodiment based on at least one of the embodiments described above, determining the activatability can include taking into account a lower activation threshold for the stimulation signal, activation of the respiratory muscles being reduced or absent when the respiratory muscles are stimulated below the activation threshold.

A preferred embodiment based on at least one of the previously described embodiments can include determining the one or more state parameters determining an activability of the respiratory muscles of the patient.

A preferred embodiment based on at least one of the previously described embodiments can - include determining a respiratory muscle pressure P _stim that can be generated by stimulation, - include determining a tidal volume Volstim that can be generated by stimulation, - include determining a patient's work of breathing that can be generated by stimulation.

A preferred embodiment based on at least one of the previously described embodiments may include performing a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and determining the one or more state parameters based on the pneumatic ventilation parameter. In a preferred embodiment, based on at least one of the embodiments described above, the pneumatic diagnostic maneuver may include occlusion, air flow limitation, omission of support for individual breaths, or variability in the patient's respiratory support.

A preferred embodiment based on at least one of the previously described embodiments can include determining a measure of a maximum respiratory effort that can be achieved by the patient. In a preferred embodiment based on at least one of the previously described embodiments, the measure of the patient's maximum respiratory effort can include a mouth closure pressure with maximum activation of the respiratory muscles. A preferred embodiment based on at least one of the above-described embodiments can include determining a measure of the patient's respiratory musculature resilience.

In a preferred embodiment based on at least one of the embodiments described above, the measure of the exercise capacity can be based on a relationship between a base load P _musBase and a maximum respiratory effort P _{musMax that} the patient can achieve.

A preferred embodiment based on at least one of the previously described embodiments can include determining a measure of an efficiency of the patient's respiratory muscles.

A preferred embodiment based on at least one of the previously described embodiments can include outputting information about the one or more status parameters. A basic embodiment may include a computer program with program code for performing at least one of the embodiments described above. The program code can advantageously be executed on a computer, a processor or a programmable hardware component.

Further and preferred embodiments of the invention relating to a ventilation system, a device, a method and a computer program for ventilating a patient with a concept for determining a load capacity and a measure of a portion of the ventilation provided by the patient himself and for taking into account the load capacity and of the degree of ventilation support. A basic embodiment shows a device for ventilating a patient with one or more interfaces, which is designed to exchange information with a ventilation unit, a stimulation unit or a sensor unit and has a control module which is designed to: Percentage of ventilation, - determining a measure of a patient's resilience, - influencing the patient's self-performed proportion of ventilation, - assisting the patient with ventilation based on the measure of the patient's self-performed proportion of ventilation and based on the measure of the patient's resilience.

In a preferred embodiment based on the embodiment described above, the control unit can be designed to output a signal for pressure-controlled or volume-controlled ventilation for support.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to output a signal for stimulating the respiratory muscles of the patient for support.

In a preferred embodiment based on at least one of the previously described embodiments, the measure of the work done by the patient himself can be at least one element from the group of: - a muscle pressure P _mus absolute or relative to a total respiratory pressure P _a , - a total driving pressure P _drv , - a respiratory gas flow Flow _mus absolute or relative to a total respiratory gas flow Flow caused by the patient’s musculature, - a tidal volume Vol _mus absolute or relative to a total tidal volume Vol, caused by the patient’s musculature, - a respiratory effort WOB _mus absolute or relative performed by the patient to include a total breath work WOB.

In a preferred embodiment, based on at least one of the embodiments described above, the detection of the measure of the patient's own share on the basis of - an electromyographic signal, - a signal from an electro-impedance myography, - a mechanomyographic signal, - a Ultrasound signal, - a signal from a strain sensor, - a signal from an esophageal pressure sensor. In a preferred embodiment based on at least one of the previously described embodiments, the control module can be designed to output a signal for stimulating the patient's respiratory muscles in order to influence the proportion performed by the patient himself. In a preferred embodiment based on at least one of the above-described embodiments, the control module can be designed to output a signal for influencing the administration of medication in order to influence the proportion paid by the patient himself. In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to regulate the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to to regulate the portion provided by the patient based on a portion of the ventilation specified as a secondary goal.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to monitor and regulate the total respiratory volume and the respiratory volume provided by the patient himself.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to regulate and monitor the work of breathing performed by the patient himself.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to monitor and regulate oxygenation of the patient.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to direct the influencing and the support according to a breathing rhythm specified by the patient.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to direct the support according to a respiratory rhythm predetermined by the influencing.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to influence and support a respiratory rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, and otherwise to support it by stimulation set breathing rhythm, if a spontaneous activity of the patient does not exist or is harmful and to set the support in the absence of a stimulation effect according to a breathing rhythm predetermined by pneumatic ventilation.

In a preferred embodiment based on at least one of the embodiments described above, the control module can be designed to a - to determine the efficiency of the patient's respiratory muscles, the assisting being further based on the efficiency.

In a preferred embodiment based on at least one of the previously described embodiments, the control module can be designed to determine the ability of the patient's respiratory muscles to be activated, with the assisting also being based on the ability to be activated.

In a preferred embodiment based on at least one of the previously described embodiments, the control module can be configured to determine exhaustion of the patient's respiratory muscles, with the assisting also being based on the exhaustion.

In a preferred embodiment based on at least one of the previously described embodiments, the control module can be designed to determine a basic respiratory load for determining the exercise capacity and to determine a maximum possible respiratory effort of the patient.

In a preferred embodiment based on at least one of the previously described embodiments, the control module can be designed to determine the maximum possible breathing effort by performing a twitch stimulation.

In preferred embodiments, a ventilation system for assisting a patient in ventilation can be designed or formed with a device based on at least one of the previously described embodiments.

A basic embodiment shows a method for ventilating a patient with: - detecting a measure of a portion of the ventilation provided by the patient himself, - determining a measure of the patient's resilience, - influencing the portion of the ventilation provided by the patient himself, - Assist the patient in ventilation based on the measure of the patient's contribution to the ventilation ventilation and based on the patient's exercise tolerance measure.

In a preferred embodiment based on the embodiment described above, the assisting may include pressure-controlled or volume-controlled ventilation.

In a preferred embodiment based on at least one of the embodiments described above, the assisting can include stimulating the respiratory muscles of the patient.

In a preferred embodiment based on at least one of the previously described embodiments, the measure of the work done by the patient himself can be at least one element from the group of: - a muscle pressure P _mus absolute or relative to a total respiratory pressure P _a , - a total driving pressure P _drv , - a respiratory gas flow Flow _mus caused by the patient's musculature in absolute terms or relative to a total respiratory gas flow Flow, - a tidal volume Vol _mus caused by the musculature of the patient in absolute terms or relative to a total respiratory volume Vol, - a work of breathing performed by the patient WOB _mus absolute or relative to a total work of breathing WOB. A preferred embodiment based on at least one of the previously described embodiments can detect the measure of the patient's own contribution on the basis of: - an electromyographic signal, - a signal from an electro-impedance myography, - a mechanomyographic signal, - a Ultrasound signal, - a signal from a strain sensor, - a signal from an esophageal pressure sensor. In a preferred embodiment based on at least one of the previously described embodiments, influencing the portion performed by the patient himself can include stimulating the patient's respiratory muscles. A preferred embodiment based on at least one of the embodiments described above can also include regulating the ventilation of the patient with regard to a ventilation parameter specified as the primary goal. A preferred embodiment based on at least one of the above-described embodiments can also include regulating the proportion performed by the patient himself based on a proportion of the ventilation specified as a secondary goal. A preferred embodiment based on at least one of the embodiments described above can also include monitoring and regulating the patient's total tidal volume and the patient's own tidal volume. A preferred embodiment based on at least one of the embodiments described above can also include monitoring and regulating the work of breathing performed by the patient himself.

A preferred embodiment based on at least one of the previously described embodiments may further comprise monitoring and controlling the patient's oxygenation.

In a preferred embodiment based on at least one of the embodiments described above, the influencing and the supporting can be based on a breathing rhythm specified by the patient.

In a preferred embodiment based on at least one of the previously described embodiments, the support can be based on a breathing rhythm that is predetermined by the influencing. In a preferred embodiment based on at least one of the embodiments described above, the support can be based on a breathing rhythm specified by the patient, provided that the patient's spontaneous activity is present and harmless, otherwise the support is based on a breathing rhythm specified by a stimulation if spontaneous activity by the patient is absent or harmful, with the support being based on a breathing rhythm specified by pneumatic ventilation if there is no stimulation effect.

A preferred embodiment based on at least one of the above-described embodiments may include determining an efficiency of the patient's respiratory muscles, the assisting being further based on the efficiency.

A preferred embodiment based on at least one of the previously described embodiments may further include determining an activatability of the patient's respiratory muscles, wherein the assisting is also based on the activatability.

A preferred embodiment based on at least one of the above-described embodiments may further include determining a fatigue of the patient's respiratory muscles, wherein the assisting is further based on the fatigue.

In a preferred embodiment based on at least one of the previously described embodiments, the determination of the exercise capacity can include a determination of a basic respiratory load and a detection of a maximum possible respiratory effort of the patient.

In a preferred embodiment based on at least one of the embodiments described above, the detection of the maximum possible respiratory effort can include performing a twitch stimulation.

A basic embodiment may include a computer program with program code for performing at least one of the embodiments described above. The program code can advantageously be executed on a computer, a processor or a programmable hardware component. Further and preferred embodiments of the invention relating to a device, a method and a computer program for a component of a ventilation system for respiratory support of a patient are described below with regard to a concept for determining a measure of respiratory support for a patient based on a target respiratory muscle activation and an actual - Respiratory muscle activation described in more detail. Further aspects relating to a ventilator, a stimulator, a sensor unit and aspects relating to various methods and computer programs for a ventilator, a stimulator and a sensor unit, a ventilation system, a method and a computer program for a ventilation system are also described. A basic embodiment shows a device for a component of a ventilation system for respiratory support of a patient with one or more interfaces for communication with components of the ventilation system and with a control unit that is designed to - determine a first piece of information about a target respiratory muscle activation

patient, - determining second information about actual respiratory muscle activation of the patient, - determining a measure for respiratory support for the patient based on the first information and based on the second information.

In a preferred embodiment based on the embodiment described above, the device comprises a device for measuring the airway flow and for measuring the airway pressure on the patient. The control unit can be designed to determine the first piece of information and the second piece of information based on an airway flow measurement and an airway pressure measurement.

In a preferred embodiment based on at least one of the embodiments described above, the device can also comprise a device for pneumatic respiratory support. In this case, the measure of the respiratory support can include a measure of the pneumatic respiratory support.

In a preferred embodiment based on at least one of the embodiments described above, the device may further comprise means for sedating the patient based on the level of respiratory support. In a preferred embodiment based on at least one of the embodiments described above, the device can be designed to receive measurement information about an airway flow measurement or an airway pressure measurement on the patient via the one or more interfaces. In this preferred embodiment, the control unit can be designed to also determine the measure for the respiratory support based on the measurement information.

In a preferred embodiment based on at least one of the embodiments described above, the device can also include a device for sensory detection of a signal that depends on the actual respiratory muscle activation. In this preferred embodiment, the control unit can be designed to determine the degree of respiratory support based on the signal detected by sensors. In a preferred embodiment based on at least one of the embodiments described above, the device for sensory detection can be designed to detect an electro-myogram, a mechano-myogram or an electro-impedance myogram. In a preferred embodiment based on at least one of the embodiments described above, the device for sensory detection can include a strain sensor, an ultrasonic sensor or an esophageal pressure sensor. In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to reduce a difference between the first piece of information and the second piece of information about the degree of respiratory support via a regulation. In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to generate a stimulation signal for the patient as a measure of the respiratory support.

In a preferred embodiment based on at least one of the embodiments described above, the device can further comprise a device for stimulating the respiratory muscles of the patient based on the measure of respiratory support. In a preferred embodiment based on at least one of the above-described embodiments, the first and second pieces of information may each comprise a measure of patient-side paced or total respiratory muscle activation, patient-side paced or total respiratory muscle flow, or patient-side paced or total respiratory muscle pressure.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to determine information about respiratory muscle activation caused by the patient's spontaneous respiratory activity, respiratory muscle flow caused by the patient's spontaneous respiratory activity or respiratory muscle pressure caused by the patient's spontaneous respiratory activity and to provide. In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to determine the measure of respiratory support based on the information about the patient's spontaneous respiratory activity. In a preferred embodiment based on at least one of the embodiments described above, the measure of respiratory support may indicate a measure of more intense sedation of the patient when the information about the patient's spontaneous respiratory activity indicates respiratory muscle activity above the target respiratory muscle activation.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to carry out an estimate for a stimulation impulse response of the patient based on the second information in response to the measure for the respiratory support.

In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to determine the estimate on the basis of a stimulation maneuver. In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to repeat the estimation regularly or continuously. In a preferred embodiment based on at least one of the embodiments described above, the control unit can be designed to determine and display a reliability for the first and the second information when the reliability falls below a predetermined threshold value. A particularly preferred embodiment based on at least one of the embodiments described above can be designed as a ventilator.

In a preferred embodiment of the ventilator based on the embodiment described above, the control unit can be designed to communicate information about the measure of respiratory support to a stimulator via the one or more interfaces.

In a preferred embodiment of the ventilator based on at least one of the embodiments described above, the measure for respiratory support can be at least one parameter from the group of: - an amplitude, - a ramp steepness, - a stimulation duration, - a start time, - an end time, - an actual -respiratory muscle activation, - include target respiratory muscle activation.

In a preferred embodiment of the ventilator based on at least one of the embodiments described above, the one or more interfaces for real-time communication with a stimulator and/or with a sensor unit can be designed. In a preferred embodiment of the ventilator based on at least one of the embodiments described above, the one or more interfaces can - for real-time communication with a stimulator and/or with a sensor unit, - for communication of a time profile of the measure of respiratory support with a stimulator and/or be formed with a sensor unit. The real-time communication via the one or more interfaces can preferably be designed as a sample-by-sample real-time communication, sample-by-sample means that the communication is based on the sequence of sampled values, ie sample-by-sample.

In a preferred embodiment of the ventilator based on at least one of the above-described embodiments, the control unit can be designed to set a rhythm for a stimulator via the one or more interfaces.

In a particularly preferred embodiment of the ventilator based on at least one of the embodiments described above, the ventilator can have an integrated stimulator.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to receive the first and the second information via the one or more interfaces from a sensor unit or from a ventilator.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to receive at least one piece of information from the group of - an amplitude, - a ramp steepness, - a stimulation duration, - a starting time via the one or more interfaces from a sensor unit , - an end time, - a time course of the target respiratory muscle activation, - an airway flow, - an airway pressure, - an inspiratory muscle pressure, - an inspiratory muscle work, - an inspiratory muscle flow.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to receive a clock pulse from a sensor unit and/or a ventilator via the one or more interfaces.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to specify a clock for a sensor unit and/or a ventilator via the one or more interfaces.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to communicate in real time via the one or more interfaces.

In a preferred embodiment of the stimulator based on the embodiment described above, the control unit can be designed to coordinate ventilation maneuvers with a ventilator via the one or more interfaces.

A particularly preferred embodiment based on at least one of the embodiments described above can be designed as a sensor unit.

In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to receive information about at least one pneumatic signal from a ventilator via the one or more interfaces and to calculate the measure of respiratory support based on the information about the to determine at least one pneumatic signal. In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to determine the second information based on sensor signals. In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to communicate in real time via the one or more interfaces.

In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to transmit at least one piece of information from the group of - an amplitude - a ramp gradient - a stimulation duration - via the one or more interfaces to a ventilator or a stimulator a start time, - an end time, - an actual respiratory muscle activation, - an airway flow, - an airway pressure, - a respiratory muscle pressure, - a respiratory muscle work, - a respiratory muscle flow, as a measure of respiratory support.

In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to receive information about a maneuver via the one or more interfaces from a ventilator or a stimulator.

In a preferred embodiment of the sensor unit based on the embodiment described above, the control unit can be designed to receive information via the one or more interfaces from a ventilator or a stimulator as first information about - blanking, - measurement times to be suppressed, - filtering, - Receive suppression of stimulation artifacts.

A particularly preferred embodiment based on at least one of the embodiments described above can be designed as a ventilation system.

In a preferred embodiment of the ventilation system based on at least one of the embodiments described above, the ventilation system can also include a stimulator.

In a preferred embodiment of the ventilation system based on at least one of the embodiments described above, the ventilation system can also include a sensor unit.

A basic embodiment shows a method for a component of a ventilation system for respiratory support of a patient with - determining a first piece of information about a target respiratory muscle activation of the patient, - determining a second piece of information about an actual respiratory muscle activation

patient, - determining a measure of respiratory support for the patient based on the first information and based on the second information.

A preferred embodiment of the method based on the embodiment described above can include determining the first information and the second information based on an airway flow measurement and an airway pressure measurement.

In a preferred embodiment of the method based on at least one of the embodiments described above, the measure of respiratory support can comprise a measure of pneumatic respiratory support. A preferred embodiment of the method based on at least one of the embodiments described above may include sedating the patient based on the level of respiratory support. A preferred embodiment of the method based on at least one of the previously described embodiments may include obtaining measurement information about an airway flow measurement or an airway pressure measurement on the patient and determining the amount of respiratory support based on the measurement information.

A preferred embodiment of the method based on at least one of the embodiments described above can include a sensory detection of a signal that depends on the actual respiratory muscle activation, and a

determining the measure of respiratory support based on the sensored signal.

In a preferred embodiment of the method based on the embodiment described above, the sensor-detected signal can be an electrical

myogram, a mechano-myogram, or an electroimpedance myogram.

In a preferred embodiment of the method based on at least one of the embodiments described above, the sensory signal can be detected using a strain sensor, an ultrasonic sensor or an esophageal pressure sensor.

A preferred embodiment of the method based on at least one of the embodiments described above may include stimulating the patient's respiratory muscles based on the measure of respiratory support.

A preferred embodiment of the method based on at least one of the above-described embodiments may include reducing a difference between the first information and the second information by rules about the level of respiratory support.

A preferred embodiment of the method based on at least one of the embodiments described above can include generating a stimulation signal for the patient as a measure of respiratory support.

In a preferred embodiment of the method based on at least one of the embodiments described above, the first and the second information each comprise a measure of patient-paced or total respiratory muscle activation, patient-paced or total respiratory muscle flow, or patient-paced or total respiratory muscle pressure.

A preferred embodiment of the method based on at least one of the embodiments described above can include determining and providing information about respiratory muscle activation caused by the patient's spontaneous respiratory activity, respiratory muscle flow caused by the patient's spontaneous respiratory activity or respiratory muscle pressure caused by the patient's spontaneous respiratory activity.

In a preferred embodiment of the method based on at least one of the embodiments described above, the measure of respiratory support may indicate a measure of more intensive sedation of the patient if the information about the patient's spontaneous respiratory activity indicates respiratory muscle activity above the target respiratory muscle activation.

A preferred embodiment of the method based on at least one of the embodiments described above can estimate a

patient stimulation impulse response from the second information in response to the level of respiratory support.

In a preferred embodiment of the method based on at least one of the embodiments described above, the estimation can also be based on a stimulation maneuver.

In a preferred embodiment of the method based on at least one of the embodiments described above, the estimation can take place regularly or continuously.

A preferred embodiment of the method based on at least one of the above-described embodiments can include a determination - or an output and/or a display - of further information, for example reliable, in addition to the first and second information, if the reliability falls below one predetermined threshold falls. A preferred embodiment of the method based on at least one of the embodiments described above may include a method for a ventilator. A preferred embodiment of the method based on the embodiment described above may include communicating information about the level of respiratory support to a stimulator.

In a preferred embodiment of the method based on the embodiment described above, the measure for the respiratory support can include at least one parameter from the group of an amplitude, a ramp steepness, a stimulation duration, a start time, an actual respiratory muscle activation, an end time and the target respiratory muscle activation. In a preferred embodiment of the method based on at least one of the embodiments described above, the communication with a stimulator and/or with a sensor unit can take place in real time.

In a preferred embodiment of the method based on at least one of the embodiments described above, the communication can take place "sample-by-sample", i.e. sample-by-sample oriented on the sequence of samples, in real time with a stimulator and/or with a sensor unit.

In a preferred embodiment of the method based on at least one of the embodiments described above, the communication can be a

communicating a time history of the measure of respiratory support with a stimulator and/or with a sensor unit.

In a preferred embodiment of the method based on at least one of the embodiments described above, the communication can include specifying a clock to a stimulator.

A preferred embodiment of the method based on at least one of the embodiments described above can include specifying the first and the second information to a stimulator and/or coordinating a ventilation maneuver with a stimulator. A preferred embodiment of the method based on at least one of the embodiments described above may comprise a method for a stimulator. A preferred embodiment of the method based on at least one of the embodiments described above can include receiving the first or the second information from a sensor unit or from a ventilator. A preferred embodiment of the method based on at least one of the previously described embodiments can receive from a sensor unit at least one item of information from the group of - an amplitude, - a ramp gradient, - a stimulation duration, - a start time, - an end time, - an actual respiratory muscle activation, - the target respiratory muscle activation, - an airway flow, - an airway pressure, - a respiratory muscle pressure, - a respiratory muscle work - a respiratory muscle flow.

A preferred embodiment of the method based on at least one of the embodiments described above can include specifying a cycle to a sensor unit and/or a ventilator.

A preferred embodiment of the method based on at least one of the embodiments described above may include communicating in real time. A preferred embodiment of the method based on at least one of the embodiments described above can include a coordination of a ventilation maneuver with a ventilator. A preferred embodiment of the method based on at least one of the embodiments described above can include a method for a sensor unit.

A preferred embodiment of the method based on at least one of the previously described embodiments may include receiving information about at least one pneumatic signal from a ventilator and determining the level of respiratory support based on the information about the at least one pneumatic signal.

A preferred embodiment of the method based on at least one of the embodiments described above can include determining the second information based on sensor signals.

A preferred embodiment of the method based on at least one of the embodiments described above may include communicating in real time. A preferred embodiment of the method based on at least one of the previously described embodiments can provide a ventilator or a stimulator with at least one item of information from the group of an amplitude, a ramp gradient, a stimulation duration, a start time, an end time, an actual respiratory muscle activation, an airway flow, an airway pressure, a respiratory muscle pressure, a

respiratory muscle work and respiratory muscle flow as a measure of respiratory support.

A preferred embodiment of the method based on at least one of the embodiments described above may include obtaining information about a maneuver.

In a preferred embodiment of the method based on at least one of the previously described embodiments, receiving from a ventilator or a stimulator can, as first information, contain information about - blanking, - measurement times to be suppressed, - filtering, - suppression of stimulation artifacts. A preferred embodiment of the method based on at least one of the embodiments described above can include a method for - a ventilation system, - a ventilation device, - a stimulator, - a sensor unit.

A basic embodiment may include a computer program with program code for performing at least one of the embodiments described above. The program code can advantageously be executed on a computer, a processor or a programmable hardware component.

Further and preferred embodiments of the stimulation device of the invention relating to a ventilation system, a device, a method and a computer program for stimulative ventilation support of a patient, in particular a concept for stimulative ventilation support of a patient synchronized to a spontaneously generated respiratory muscle activity of the patient, are described below. A basic embodiment of the stimulation device shows a stimulation device for stimulative

Ventilation support for a patient with one or more interfaces for communication, with components of the ventilation system and with a control unit that is designed to record information about a time profile of an activation signal of the patient's respiratory muscles.

In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the control unit can be designed to record the information about the time profile of the activation signal - recording information about a time profile of a portion of the respiratory effort performed by the patient himself, - Determining the activation signal for the patient's respiratory muscles based on the information about the time profile of the portion of the respiratory work performed by the patient himself.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to determine and take into account a lower activation threshold for the stimulation. In this preferred embodiment of the stimulation device, activation of the respiratory muscles can take place when the respiratory muscles are stimulated above the activation threshold and activation of the respiratory muscles is at least reduced or omitted when the respiratory muscles are stimulated below the activation threshold.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to carry out the stimulation in a positive feedback with the activation signal.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to determine a stimulation effect.

In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the control unit can be designed to carry out a titration to determine the stimulation effect.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to carry out the stimulation proportionally to the activation signal. In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed as information about the time course of the activation signal of the respiratory muscles of the patient information about at least one element from the group of - a muscle pressure P _mus , - a spontaneous muscle pressure P _spon , - a respiratory gas flow Flow _mus caused by the patient's muscles, - a respiratory gas flow FlOW _spon caused spontaneously by the patient's muscles, - a work of breathing WOB performed by the patient himself, - a spontaneous work of breathing WOB _spon performed by the patient himself to determine. In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to ventilate the patient pneumatically in parallel. In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the control unit can be designed to carry out the parallel pneumatic ventilation as proportional ventilation. In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to record the information about the time profile of the activation signal of the patient's respiratory muscles on the basis of an electromyographic signal, a signal from an electrical impedance -perform myography, a signal from a strain sensor, a signal from an ultrasonic sensor or a mechanomyographic signal.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of

Stimulating device, the control unit can be designed, an intensity of the Adjust pacing based on a predetermined level.

In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the control unit can be designed to determine the predetermined degree via a ratio of stimulation intensity and activation signal or of stimulation intensity and estimated respiratory effort _Pmus .

In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the degree can be defined as a ratio between a stimulated breathing activity and a spontaneous breathing activity of the patient.

In a preferred embodiment of the stimulation device based on the embodiment of the stimulation device described above, the

Control unit be designed to determine the patient's spontaneous respiratory activity based on the information about the time course of the activation signal of the respiratory muscles of the patient. In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments of the stimulation device, the control unit can be designed to determine a stimulation signal based on the relationship between the stimulated breathing activity and the spontaneous breathing activity of the patient and an activation impulse response of the patient's muscles.

In a preferred embodiment of the stimulation device based on at least one of the embodiments described above, the control unit can be designed to determine the stimulation signal by inverse convolution of a desired activation signal EMG _stim caused by stimulation with the activation impulse response.

In a preferred embodiment of the stimulation device based on at least one of the previously described embodiments, the control unit can be designed to determine the spontaneous respiratory activity as a respiratory muscle pressure P _spon generated spontaneously by the patient and the stimulated respiratory activity as a respiratory muscle pressure P _stim generated by stimulation. In a preferred embodiment of the stimulation device based on at least one of the embodiments described above, the control unit can be designed to determine the spontaneous respiratory activity as a respiratory gas flow Flow _spon generated spontaneously by the patient and the stimulated respiratory activity as a respiratory gas flow Flow _stim generated by stimulation.

In a preferred embodiment of the stimulation device based on at least one of the above-described embodiments, the control unit can be embodied - the spontaneous breathing activity as a work of breathing spontaneously generated by the patient

WOBspon - or its time derivative dWOB _spon /dt - and the stimulated respiratory activity as a work of breathing produced by stimulation WOBstim - or its time derivative dWOB _stim /dt.

In a preferred embodiment of the stimulation device based on at least one of the embodiments described above, the control unit can be designed to track the predetermined level at a time level that is greater than or equal to a respiratory cycle of the patient.

In a preferred embodiment of the stimulation device based on at least one of the embodiments described above, the control unit can be designed to stimulate to achieve a target value which - a patient-side portion of a driving pressure ΔP _mus , - a patient-side portion of a volume ΔVol _mus , - includes a patient-side part of a breathing work ΔWOB _mus to regulate.

An embodiment based on at least one of the previously described embodiments of the stimulation device shows a ventilation system with a stimulation device for stimulative ventilation support of a patient.

A basic embodiment of the stimulation device shows a method for stimulative ventilation support for a patient - a detection of information about a time course of an activation signal of a respiratory musculature of the patient and - a stimulation of the respiratory musculature in temporal alignment to the activation signal for muscular ventilation support of the patient.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the embodiments described above, the acquisition of the information about the time profile of the activation signal can - a capture of information about a time profile of a portion of the respiratory work performed by the patient himself and - a determination of the activation signal for the respiratory muscles of the patient based on the information about the time course of the portion of the respiratory effort performed by the patient himself.

A preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the embodiments described above can include determining and taking into account a lower activation threshold for the stimulation, wherein - when the respiratory muscles are stimulated above the activation threshold, the respiratory muscles are activated and - at a stimulation of the respiratory muscles below the activation threshold activation is at least reduced or absent.

In a preferred embodiment of the method for the stimulative ventilation support of a patient based on at least one of the previously described embodiments, the stimulation can take place in a positive coupling with the activation signal.

A preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the previously described embodiments can include determining a stimulation effect. A preferred embodiment of the method for stimulative ventilation support of a patient based on the embodiment described above can include a titration to determine the stimulation effect.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the previously described embodiments, the stimulation can take place proportionally to the activation signal.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the embodiments described above, the information about the time course of the activation signal of the respiratory muscles of the patient information about at least one element from the group of - a muscle pressure P _mus , - a spontaneous muscle pressure P _spon , - a respiratory gas flow Flow _mus caused by the patient's musculature, - a respiratory gas flow Flow _spon caused spontaneously by the patient's musculature, - a respiratory effort WOB performed by the patient himself, - a spontaneous respiratory effort WOB _spon performed by the patient himself. A preferred embodiment of the method for stimulative

Ventilation support of a patient based on at least one of the previously described embodiments can include parallel pneumatic ventilation of the patient. In a preferred embodiment of the method for stimulative

Ventilation support of a patient based on at least one of the previously described embodiments can include the parallel pneumatic ventilation a proportional ventilation. In a preferred embodiment of the method for stimulative

Ventilation support of a patient based on at least one of the embodiments described above, the acquisition of information about the time course of the activation signal of the patient's respiratory muscles on the basis of - an electromyographic signal, - a signal from electro-impedance myography, - a signal from a strain sensor, - a signal from an ultrasonic sensor, - a mechanomyographic signal. A preferred embodiment of the method for stimulative

Assisting a patient's ventilation based on at least one of the above-described embodiments may include adjusting an intensity of the pacing based on a predetermined level. In a preferred embodiment of the method for stimulative

Ventilation support of a patient based on the embodiment described above, the predetermined level can comprise a ratio of stimulation intensity and activation signal or of stimulation intensity and estimated respiratory effort P _mus .

In a preferred embodiment of the method for stimulative ventilation support of a patient based on the embodiment described above, the degree can determine a ratio between a stimulated breathing activity and a spontaneous breathing activity of the patient.

A preferred embodiment of the method for stimulative ventilation support of a patient based on the embodiment described above can include determining the spontaneous breathing activity of the patient based on the information about the time profile of the activation signal of the patient's respiratory muscles.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the embodiments described above, determining a stimulation signal based on the ratio between the stimulated breathing activity and the spontaneous breathing activity of the patient and an activation impulse response of the patient's muscles can include. A preferred embodiment of the method for stimulative ventilation support of a patient based on the embodiment described above can include determining the stimulation signal by inverse convolution of a desired activation signal EMGstim caused by stimulation with the activation impulse response.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the embodiments described above, the spontaneous breathing activity can be one of

patient's spontaneously generated respiratory muscle pressure P _spon and the stimulated respiratory activity comprise a respiratory muscle pressure P _stim generated by stimulation.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the previously described embodiments

• Spontaneous respiratory activity, a respiratory gas flow Flow _spon generated spontaneously by the patient and · Stimulated respiratory activity, a respiratory gas flow generated by stimulation

include FlOWstim.

• Spontaneous breathing activity, a work of breathing spontaneously generated by the patient

WOB's _P on

• or their time derivative dWOB _spon /dt and

• the stimulated breathing activity is a work of breathing produced by WOBstim stimulation

• or their time derivative include dWOB _stim /dt. A preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the previously described embodiments can include tracking the predetermined degree on a time level that is greater than or equal to a respiratory cycle of the patient.

In a preferred embodiment of the method for stimulative ventilation support of a patient based on at least one of the previously described embodiments, the stimulation can be regulated to achieve a target value

• a patient-side share in a driving pressure AP _mus ,

• a patient-side portion of a volume ΔVol _mus ,

• or include a patient-side portion of a _breathwork AWOB.

A basic embodiment can comprise a computer program with a program code for carrying out at least one of the previously described embodiments of the stimulation device. The program code can advantageously be executed on a computer, a processor or a programmable hardware component.

Table 3 below includes the abbreviations and designations used in the context of this invention, combined with brief explanations in each case.

Table 3

Table 4 below lists all of the patent documents and publications cited in this description with the publication number or a short title of the publication. The full titles can be found in the statements on the prior art in the introduction to the description. In the description, the reference numbers [E1] to [E38] listed in Table 4 are sometimes used instead of extensive citations. reference number list

1 abscissa, (x-axis), time axis

2 ordinate (y-axis), (Signal Intercost.stm)

3 ordinate (y-axis), (Costmar.org)

4 ordinate (y-axis), (Costmar.ecgr)

5 ordinate (y-axis), (Costmar.em)

6 ordinate (y-axis), (Costmar.avg)

10 device

12 interfaces, interface

14 control unit

19 Acquiring information about a course of an activation signal

20 procedures

21 Capture a measure of a contribution to ventilation

22 Stimulating the respiratory muscles

23 Determination of a first piece of information about a target respiratory muscle activation

24 Determination of a first piece of information about an actual respiratory muscle activation

25 Determining a measure of respiratory support

28 Assisting the patient during ventilation

29 Determination of condition parameters for the respiratory muscles

100 device, component

110 stimulation unit (stimulator), stimulation unit, stimulation device

120 ventilation system, ventilation unit, ventilation device, respirator

200 sensor unit

300 patient, living creature

310 first signal processing

320 further signal processing

330 respiratory muscle pressure Pmus

331 Temporal progression of the respiratory muscle pressure Pmus

340 electromyographic signal

345 original signal EMG(t) (raw signal)

350 envelope EMG(t)

360 signals of airway pressure, Paw(t), volume flow V'(t) and tidal volume V(t)

400 patient model

410 respiratory system

420 Neuromechanical Efficiency spontaneously 430 neuromechanical efficiency stimulative 440 activatability k 450 sedation

460 stimulation device stimulator, device for stimulation 470 ventilator, pneumatic breathing assistance

480 controller 490 estimator 500 activation threshold 502 activatability k(t) 504 respiratory system

506 Neuromechanical efficiency 510 Determination of stimulation intensity

512 weighting muscle pressure difference

514 averaging 522 first-order delay element

524 integration

526 weighting volume difference 532 integration

534 Muscle work difference weighting 540 Muscle pressure Pmus

600 upper representation Figure 6

601 lower representation Figure 6

602 stimulation 604 EMG signal 606 EMG signal, adjusted for artefacts and offset

608 envelope

666 enlarged detail from Figure 6 in Figure 7

700 upper representation Figure 7

701 lower representation Figure 7 702 stimulation

777 enlarged detail from Figure 7 in Figure 8 801 upper representation Figure 8

801 lower representation Figure 8

802 stimulation 901 representation figure 9

902 stimulation 904 EMG signal 1000 representation Figure 10

1001 measuring points

1100 representation Figure 11

Claims

patent claims

First device (10) for determining a state of a patient's respiratory muscles, with one or more interfaces (12) which are designed for detecting patient signals and with a control unit (14) which is designed for

• stimulating the patient's respiratory muscles with a stimulation signal, · detecting an activation signal in response to the stimulating,

• Determining one or more condition parameters for the respiratory muscles based on the stimulation signal and the activation signal.

2. The device (10) according to claim 1, wherein the control unit (14) is designed to generate the stimulation signal with one or more stimulation pulses.

3. The device (10) according to any one of claims 1 or 2, wherein the control unit (14) is designed to detect the activation signal as an impulse response.

4. The device (10) according to any one of claims 1 to 3, wherein the control unit (14) is designed to determine an activability of the patient's respiratory muscles by determining the one or more state parameters.

5. The device (10) according to claim 4, wherein the control unit (14) is designed to take into account a lower activation threshold for the stimulation signal when determining the activatability, wherein the respiratory muscles are activated when the respiratory muscles are stimulated above the activation threshold and activation is at least reduced or absent when the respiratory muscles are stimulated below the activation threshold.

6. The device (10) according to claim 5, wherein the control unit (14) is designed to • a respiratory muscle pressure that can be generated by stimulation, Pstim,

• a tidal volume that can be generated by stimulation, Volstim, and/or

7. The device (10) according to any one of claims 1 to 6, wherein the control unit (14) is designed to also perform a pneumatic diagnostic maneuver to determine a pneumatic ventilation parameter and the one or more state parameters based on the pneumatic

determine ventilation parameters.

The device (10) according to claim 7, wherein the pneumatic diagnostic maneuver · an occlusion,

• an airflow limitation,

• missing breath support or

• involves variability in the patient's respiratory support.

9. The device (10) according to any one of claims 1 to 8, wherein the control unit (14) is designed to also determine a measure of a maximum attainable respiratory effort of the patient.

10. The device (10) according to claim 9, wherein the measure of the patient's maximum respiratory effort comprises a mouth closure pressure at maximum activation of the respiratory muscles.

11. The device (10) according to any one of claims 1 to 10, wherein the control unit (14) is designed to determine a measure of the resilience of the patient's respiratory muscles and/or a measure of the efficiency of the patient's respiratory muscles.

12. The device (10) according to claim 11, wherein the measure of the exercise capacity is based on a relationship between a base load, PmusBase, and a maximum attainable respiratory effort, PmusMax, of the patient, and/or wherein the measure of the efficiency is a ratio of a respiratory volume or respiratory muscle pressure that can be generated by stimulation and the activation signal.

13. The device (10) according to any one of claims 1 to 12, wherein the control unit (14) is designed to output information about the one or more status parameters via the one or more interfaces.

14. Device (10) for ventilating a patient, having one or more interfaces (12) which are designed to exchange information with a ventilator unit, a stimulation unit or a sensor unit; and with a control unit (14) which is designed for

• Determining a measure of the patient's resilience,

• influencing the patient's contribution to ventilation, and

• Assist the patient with ventilation based on a measure of the patient's contribution to ventilation and based on a measure of the patient's exercise capacity.

15. The device (10) according to claim 14, wherein the control unit (14) is designed to output a signal for pressure-controlled or volume-controlled ventilation for support, or a signal for stimulating the patient's respiratory muscles.

16. The device (10) according to any one of claims 14 or 15, wherein the measure of the work done by the patient himself at least one element from the group of - a muscle pressure, Pmus, absolute or relative to a total respiratory pressure, Paw, or a total driving pressure, Pdrv; - A respiratory gas flow, Flowmus, caused by the patient's musculature, absolutely or relative to a total respiratory gas flow, Flow; - a respiratory volume caused by the patient's muscles,

Volmus, absolute or relative to a total tidal volume, Vol; and - a patient's own work of breathing, WOBmus, absolute or relative to a total work of breathing, WOB; includes.

The apparatus (10) of any one of claims 13 to 16, wherein detecting the self-contribution measure is based on an electromyographic signal, an electro-impedance myographic signal, a mechanomyographic signal, an ultrasound signal , a signal from a strain gauge, or a

Signal of an esophageal pressure sensor is performed.

18. The device (10) according to any one of claims 14 to 17, wherein the control unit (14) is designed to influence the contribution made by the patient himself a signal for stimulating the

Outputting the patient's respiratory muscles or a signal for influencing a drug administration.

19. The device (10) according to any one of claims 14 to 18, wherein the control unit (14) is designed to regulate the ventilation of the patient with regard to a ventilation parameter specified as the primary goal and wherein the control unit (14) is designed to regulate the patient's own share based on a share of the ventilation specified as a secondary goal.

20. The device (10) according to any one of claims 14 to 19, wherein the control unit (14) is designed to monitor and regulate the total respiratory volume and the respiratory volume provided by the patient himself, in order to regulate the respiratory work performed by the patient himself and and/or to monitor and regulate oxygenation of the patient.

21. The device (10) according to one of claims 14 to 20, wherein the control unit (14) is designed to direct the influencing and the supporting (28) according to a breathing rhythm specified by the patient or according to a specified breathing rhythm.

22. The device (10) according to one of claims 14 to 21, wherein the control unit (14) is designed to direct the influencing and the support according to a breathing rhythm specified by the patient if the patient's spontaneous activity is present and harmless, and otherwise to To direct support according to a breathing rhythm specified by stimulation, provided that spontaneous activity on the part of the patient does not exist or is harmful, and to direct support according to a breathing rhythm specified by pneumatic ventilation if there is no stimulation effect.

23. The device (10) according to any one of claims 14 to 22, wherein the control unit (14) is designed to determine an efficiency of the respiratory muscles of the patient, wherein the supporting is based on the efficiency, wherein the control unit (14) is designed to determine an activability of the patient's respiratory muscles, the support being based on the activatability, and/or the control unit (14) being designed to determine exhaustion of the patient's respiratory muscles, the support being based on the exhaustion.

24. The device (10) according to any one of claims 14 to 23, wherein the control unit (14) is designed to determine a respiratory mechanical base load to determine the resilience and to determine a maximum possible respiratory effort of the patient.

25. The device (10) according to claim 24, wherein the control unit (14) is designed to determine the maximum possible respiratory effort by performing a twitch stimulation.

26. A ventilation system (120) for supporting a patient during ventilation with a device (10) according to any one of claims 1 to 25.

27. Device (10) for a component (100) of a ventilation system (120) for respiratory support of a patient, with one or more interfaces (12) for communication with components (100) of the ventilation system; and a control unit (14) that is designed to determine first information about a target respiratory muscle activation of the patient,

• determining second information about an actual respiratory muscle activation of the patient, and

• determining a measure of patient respiratory support based on the first information and based on the second

Information.

28. The device (10) according to claim 27, which comprises a device for airway flow measurement and airway pressure measurement on the patient and wherein the

Control unit (14) is designed to determine the first information and the second information based on an airway flow measurement and an airway pressure measurement.

29. The device (10) according to any one of claims 27 or 28, comprising means for pneumatic respiratory support and wherein the measure of respiratory support comprises a measure of pneumatic respiratory support, comprising means for sedating the patient based on the measure of the comprises respiratory support, and/or which comprises a device for stimulating the patient's respiratory muscles based on the level of respiratory support.

30. The device (10) according to any one of claims 27 to 29, which is designed to use the one or more interfaces (12) measurement information about an airway flow measurement or a

Airway pressure measurement on the patient to obtain, and wherein the control unit (14) is adapted to determine the amount of respiratory support based on the measurement information.

31. The device (10) according to any one of claims 27 to 30, which comprises a device for sensory detection of a signal which depends on the actual respiratory muscle activation, and wherein the control unit (14) is designed to determine the measure of respiratory support based on the signal detected by sensors.

32. The device (10) according to claim 31, wherein the device for sensory detection is designed to record an electro-myogram

to detect a mechano-myogram, or an electroimpedance myogram, and/or wherein the device for sensory detection comprises a strain sensor, an ultrasonic sensor or an esophageal pressure sensor.

33. The device (10) according to any one of claims 27 to 32, wherein the control unit (14) is designed to reduce a difference between the first piece of information and the second piece of information about the degree of respiratory support via a regulation.

34. The device (10) according to any one of claims 27 to 33, wherein the first and the second information each comprise a measure of a patient-side stimulated or total respiratory muscle activation, a patient-side stimulated or total respiratory muscle flow or a patient-side stimulated or total respiratory muscle pressure.

35. The device (10) according to claim 27 to 34, wherein the control unit (14) is designed to receive information about a respiratory muscle activation caused by the patient's spontaneous breathing activity, a respiratory muscle activation caused by the patient's spontaneous breathing activity

to determine and provide respiratory muscle flow or respiratory muscle pressure caused by the patient's spontaneous respiratory activity, the control unit (14) being designed to determine the measure of respiratory support based on the information about the spontaneous respiratory activity of the patient, the measure of respiratory support being a indicates a measure of more intense sedation of the patient when the patient's spontaneous respiratory activity information indicates respiratory muscle activity above the target respiratory muscle activation.

36. The device (10) according to any one of claims 27 to 35, wherein the control unit (14) is designed to based on the second information in response to the measure of respiratory support to estimate a patient's stimulation impulse response.

37. The device (10) according to claim 36, wherein the control unit (14) is configured to determine the estimation on the basis of a stimulation maneuver.

38. The device (10) according to any one of claims 27 to 37, wherein the control unit (14) is designed to determine a reliability for the first and the second information and to indicate when the reliability falls below a predetermined threshold.

39. Respirator (470), stimulator (460), and/or sensor unit with a device (10) according to one of claims 27 to 38.

40. Device (10) for stimulative ventilation support of a patient, with one or more interfaces (12) which are designed to exchange information with a ventilation unit and a sensor unit and a control unit (14) which is designed for

41. The device (10) according to claim 40, wherein the control unit (14) is designed to detect the information about the time profile of the activation signal

detecting information about a time profile of a portion of the breathing work performed by the patient himself, and determining the activation signal for the patient's respiratory muscles based on the information about the time profile of the portion of the breathing work performed by the patient himself.

42. The device (10) according to one of claims 40 or 41, wherein the control unit (14) is designed to determine and take into account a lower activation threshold for the stimulation activation of the respiratory muscles occurs when the respiratory muscles are stimulated above the activation threshold, and activation is at least reduced or absent when the respiratory muscles are stimulated below the activation threshold.

43. The device (10) according to any one of claims 40 to 42, wherein the control unit (14) is designed to carry out the stimulation in a positive feedback with the activation signal and/or proportionally to the activation signal.

44. The device (10) according to any one of claims 40 to 43, wherein the control unit (14) is designed to determine a stimulation effect.

45. The device (10) according to any one of claims 40 to 44, wherein the control unit (14) is designed to, as information about the time course of the activation signal of the patient's respiratory muscles, information about at least one element from the group of

• a muscle pressure, Pmus,

• a spontaneous muscle pressure, Pspon,

• a respiratory gas flow caused by the patient's muscles, Flowmus,

• a work of breathing performed by the patient himself, WOB,

46. The device (10) according to any one of claims 40 to 45, wherein the control unit (14) is designed to ventilate the patient pneumatically in parallel as proportional ventilation.

47. The device (10) according to any one of claims 40 to 46, wherein the control unit (14) is designed to measure an intensity of the Adjust pacing based on a predetermined level.

48. The device (10) according to claim 47, wherein the control unit (14) is designed to the predetermined degree via a ratio of stimulation intensity and activation signal or off

stimulation intensity and estimated respiratory effort, Pmus.

49. The device (10) according to claim 48, wherein the degree defines a ratio between a stimulated respiratory activity and a spontaneous respiratory activity of the patient and wherein the control unit (14) is designed to monitor the patient's spontaneous respiratory activity based on the information about the temporal To determine the course of the activation signal of the respiratory muscles of the patient.

50. The device (10) according to claim 49, wherein the control unit (14) is designed to determine a stimulation signal based on the relationship between the stimulated respiratory activity and the spontaneous respiratory activity of the patient and an activation impulse response of the patient's muscles.

51. The device (10) according to claim 50, wherein the control unit (14) is designed to determine the stimulation signal by inverse convolution of a desired stimulation-induced activation signal, EMGstim, with the activation impulse response.

52. The device (10) according to any one of claims 49 to 51, wherein the control unit (14) is designed

• Spontaneous respiratory activity as a respiratory muscle pressure, Pspon, produced spontaneously by the patient and stimulated respiratory activity as one produced by stimulation

respiratory muscle pressure, Pstim, to determine

• and to determine the stimulated respiratory activity as a respiratory gas flow generated by stimulation, Flowstim, and/or • to describe spontaneous breathing activity as work of breathing spontaneously generated by the patient, WOBspon,

• or their time derivative, dWOBspon/dt,

• and the stimulated respiratory activity as a stimulation-induced work of breathing, WOBstim,

• or to determine its time derivative, dWOBstim/dt.

53. Method (20) for determining a state of a patient's respiratory muscles, with

• Stimulating the patient's respiratory muscles with a stimulation signal;

• detecting an activation signal in response to the pacing;

54. Method (20) for ventilating a patient, with

• determining a measure of the patient's ability to exercise;

• Influencing the patient's own contribution to ventilation; and

55. Method (20)) for a component (100) of a ventilation system for respiratory support of a patient, with

56. Method (20) for stimulative ventilation support of a patient,

• with acquisition of information about a time course of an activation signal of a respiratory musculature of the patient; and

• stimulate the respiratory muscles in time alignment with the activation signal to support the patient's muscular ventilation.

57. Computer program with a program code for carrying out one of

A method (20) according to any one of claims 53 to 56.