Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes operated by electrical means
  • A61M16/022—Control means therefor
  • A61M16/024—Control means therefor including calculation means, e.g. using a processor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0057—Pumps therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0051—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes with alarm devices
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0057—Pumps therefor
  • A61M16/0066—Blowers or centrifugal pumps
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/20—Valves specially adapted to medical respiratory devices
  • A61M16/201—Controlled valves
  • A61M16/202—Controlled valves electrically actuated
  • A61M16/203—Proportional
  • A61M16/204—Proportional used for inhalation control
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/20—Valves specially adapted to medical respiratory devices
  • A61M16/201—Controlled valves
  • A61M16/202—Controlled valves electrically actuated
  • A61M16/203—Proportional
  • A61M16/205—Proportional used for exhalation control
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
  • A61M2016/0027—Accessories therefor, e.g. sensors, vibrators, negative pressure pressure meter
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
  • A61M2016/003—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/332—Force measuring means
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/3331—Pressure; Flow
  • A61M2205/3334—Measuring or controlling the flow rate

Definitions

• Ventilation device with automated detection of a flow sensor error taking into account spontaneous breathing
• the present invention relates to a ventilation device for the artificial respiration of a patient with
• a ventilation duct arrangement extending between the respiratory gas source and a patient-side, proximal end
• a valve assembly comprising an inspiratory valve and an expiratory valve
• a flow sensor arrangement for the quantitative detection of a gas flow in the ventilation line arrangement, comprising a distal flow sensor located farther from the patient end of the ventilation line arrangement and a proximal flow sensor located closer to the patient end of the ventilation line arrangement, a pressure sensor arrangement for quantitatively detecting a gas pressure of gas flowing in the ventilation line arrangement,
• control device which is at least adapted
• the product "SERVO-U" from Maquet is known on the market.
• This known ventilator uses a distal flow sensor inside a ventilator. The distal end of a breathing tube arrangement of the ventilation line arrangement is connected to the ventilator. Furthermore, the known ventilator uses tion a proximal flow sensor in the form of a hot wire anemometer in a Y-connector.
• the Y-connector connects on its side facing the respiratory gas source side a pair of tubes from an inspiratory breathing tube and a separately formed from the inspiratory breathing tube expiratory breathing tube with a patient on the side facing the breathing tube arranged, leading to the patient's respiratory line.
• the manual for this known ventilator indicates that the outputs of internal pressure and flow sensors are compared with the measurement result of the proximal sensor in the Y-connector and the proximal sensor is deactivated if there is a significant difference between the values used for comparison Deviation is detected.
• the ventilator "SERVO-U” is not generic because its controller is not configured to control the operation of the pressure varying assembly based on measurement signals from the proximal flow sensor.
• ventilator devices of the applicant which are commercially available and marketed under the names “Hamilton-S1", “Hamilton-G1” and “Hamilton-C3” are known as generic respiration devices. These are able to operate according to the respiratory mode “Adaptive Pressure Ventilation (APV)” known from the Applicant's house, in which the control device, in dependence on the measurement signal of the proximal flow sensor, that is dependent on the detected proximal flow of the respiratory gas, the pressure of the respiratory gas changed in the ventilation line arrangement so that the gas volume administered to the patient reaches or retains a predetermined target value or target range.
• AVG Adaptive Pressure Ventilation
• PC-CMVa and PC-IMV each after Chatburn
• PRVC pressure-regulated olume control
• the control devices of the generic ventilator devices compare values of a ventilation gas volume determined from measured signals of the distal and the proximal flow sensor and then close to a fault of the proximal flow sensor when the proximal ventilation gas volume determined on the basis of measurement signals of the proximal flow sensor and the distal determined by measurement signals of the distal flow sensor Distinguish ventilation gas volume in a different than expected or permissible for the prevailing operating state or permissible manner.
• the expected or permissible difference of the ventilation gas volumes depending on the operating state can be taken into account by threshold characteristic values or characteristic maps in which at least one difference threshold value for error detection is stored in a data memory of the control device, in particular as a function of other operating parameters.
• a disadvantage of the known generic respiratory apparatus and the error detection based thereon, which is based solely on the measurement signals of the flow sensors, is that situations may occur during the ventilation of patients despite the present functionality of the measurement technique on the ventilator, which conditions the measurement signals of the distal and proximal flow sensors - influence that a comparison of the same or a comparison of the values determined therefrom without further measures leads to a false-positive error detection.
• the respiratory gas flow value or the respiration gas volume value determined by the distal flow sensor is always greater in magnitude than the corresponding flow value detected by the proximal flow sensor and / or the volume value determined therefrom.
• This is due in part to elasticities in the portion of the breathing duct arrangement located between the distal and proximal flow sensors.
• a portion of the gas flow detected by the distal flow sensor serves to stretch the elastic portions of the breathing duct assembly and does not reach the proximal flow sensor.
• This is due to another part of leaks in the expiratory valve, due to which a proportion of the total ventilation gas flow as a cross flow in a short circuit flow from the inspiratory valve to the expiratory valve, without reaching the patient and without the proximal flow sensor.
• the proportion of gas flow lost as a cross-flow for the ventilation of a patient is detected by the distal, but not by the proximal flow sensor.
• the distal flow sensor which is usually unaffected by fluid, still senses the correct flow of respiratory gas, so due to incorrect detection by the proximal flow sensor, the sensed flow values of both sensors and those from the flow readings - usually through integration over time Approximate volume values in amount.
• the proximal ventilation gas volume is controlled by changing the ventilation gas pressure
• an increase in the detected proximal ventilation gas flow and consequently in the ventilation gas volume determined therefrom results in a control Lowering the ventilation gas pressure in order to reduce the proximal flow value detected as increased or / and the volume value ascertained from this as elevated again to its original desired level.
• the control device thus keeps constant the proximal ventilation gas volume determined from the detected proximal ventilation gas flow by reducing the ventilation gas pressure.
• a respiration device of the type mentioned in the introduction in which the control device is designed to close in response to measurement signals from the proximal flow sensor and the distal flow sensor to an error candidate of the proximal flow sensor and only after a delay after detection of the error candidate to close a fault of the proximal flow sensor, wherein the control means is adapted to discard the error candidate, if during a Verifi- z istsphase, which begins with or after the detection of the error candidate, at least one of a degree of spontaneous breathing activity of the patient considering discard criterion for Discarding the error candidate is met.
• the previously identified error candidate may be discarded so that the proximal flow sensor is still judged to be correct and the control means no further action triggers, but continues to operate the ventilator according to the selected mode.
• the distal inspiratory ventilation gas flow measured on the internal flow sensor and the distal inspiratory ventilation gas volume determined therefrom decrease, so that the difference in magnitude between the ventilation gas flows measured by the distal flow sensor and the proximal flow sensor and / or the respectively determined ventilation gas volumes decreases.
• the at least one discard criterion takes into account spontaneous breathing of the patient connected to the ventilation device.
• the at least one discard criterion may be dependent on a number of active breaths triggered by the patient, or may take into account such a number.
• the term "number" also includes a proportion of active breaths in a total number of breaths.
• the discard criterion may be a predetermined discard criterion, ie it may be pre-stored in the controller or in a data store cooperating with the controller and, if necessary, read from the data store.
• the discard criterion is determined as a function of operating parameters of the respiration device as well as of patient data or patient parameters during the operation of the respiration device.
• the use of a predetermined discard criterion is preferred.
• such a rejection criterion should also be considered to be predetermined, which is determined by the control device individually depending on set operating parameters of the respiration device and / or adjusted patient data for the selected operation and / or the patient to be ventilated, however after its determination, it is stored in a data memory and ready for further use during the ventilation operation. What has been said about the predeterminedness of the discard criterion also applies to the predetermination of all other parameters mentioned in this application.
• the verification phase is predetermined in terms of onset and duration, but it should not be excluded that individually for a recognized error candidate depending on the aforementioned possible parameters: operating parameters of the respiratory device and / or condition parameters of the patient ( Patient data) is determined.
• the verification phase may be a period of time.
• the verification phase is a number of breaths.
• a breath is an inspiratory process and an expiration process comprehensive respiration process of a patient, which temporally between the triggering times (in the art also referred to as "trigger times") of two directly aufeinan- subsequent inspiratory procedures, and which is periodically repeated to ventilate a patient.
• the verification phase may begin a predetermined delay period or a predetermined delay number of breaths after recognition of an error candidate.
• the verification phase begins with the recognition of the error candidate.
• the verification phase preferably begins immediately either with the recognition of the candidate error or with a triggering of the breath immediately following the breath in which the candidate error was detected.
• the accuracy with which a once recognized error candidate is discarded again can be further increased by the fact that the control device is designed to reject the error candidate if at least one discard criterion is met at the end of the verification phase. Then a false positives rejection of the error candidate due to accidental and only a short fulfillment of a discard criterion can be prevented.
• the control device preferably uses not only a discard criterion but a plurality of discard criteria. In this case, the control device can be configured to discard the error candidate only if more than one rejection criterion is fulfilled during the verification phase and / or is fulfilled at the end of the verification phase.
• the discarding criterion taking into account at least one spontaneous breathing may include:
• a number of active breaths of the patient triggered by the patient ventilated with the ventilator during the verification phase exceed an active breath lift threshold.
• spontaneous breathing and “active breathing stroke” are synonymous in the present application in that both terms designate a respiratory stroke triggered by the patient.
• the control device of the respiratory device can be signal-transmission-coupled to a further data processing device and receive information about active breathing strokes of the patient from the further data processing device.
• the control device is preferably as independent as possible of further data processing devices and therefore configured to recognize an active breath.
• numerous methods are known from the prior art to automatically distinguish active breaths of mandatory breaths and thus to detect active breaths even during artificial respiration.
• the respiration device can use different sensors, or be signal-coupled with different sensors in order to detect an active breath from the data transmitted by the sensors and optionally by interposed control or evaluation devices of the sensors to the control device and their evaluation.
• Assisted Spontaneous Breathing or "Assisted Spontaneous Breathing”
• ASB Assisted Spontaneous Breathing
• the control device is particularly preferably configured to detect a time duration detection value which represents a time duration between the triggering of a detection breath and the triggering of the breath lift immediately following the detection breath as the breath lift duration of the detection breath.
• the control device is further configured to compare the time duration detection value with an operation time duration value which represents a time duration between the respective mandatory triggering of two immediately successive mandatory breaths triggered by the ventilation device. This latter period of time is a mandatory breath lift duration.
• the control means is adapted to detect the detection breath on the basis of the time duration comparison result as an active breath.
• acquisition breath refers only to that breath for which the control device is to recognize whether it is an active or a mandatory breath.
• the controller may determine whether the detection breath is an active or mandatory breath, without going beyond the sensors already present on the ventilator additional sensors are necessary. Since the active respiratory effort triggered by the patient can only be triggered by the patient if the breath has not already been triggered by the ventilator, a breath taken immediately before an active breath usually has a shorter breath duration than the mandatory breath duration set on the ventilator. Instead of the breath lift duration, the respiratory rate proportional to the reciprocal of the breath lift duration can be used. This also represents the breath lift duration of a breath.
• the controller may detect a breath as an active breath when it is configured to detect a time duration detection value that includes a time period between the initiation of a sense breath and the initiation of the breath immediately following the sense breath Breath lift duration of the acquisition breath.
• the control device is further configured to compare the detection value with a time duration comparison value, which represents a mean value of breath lift averages over a plurality of breaths.
• the controller is configured to detect the acquisition breath based on the time duration comparison result as an active breath.
• the acquisition breathing stroke follows the majority of breaths over whose respiratory lifetimes an average value is formed.
• the acquisition breath can also be part of the plurality of breaths over whose durations the average is formed.
• the detection breath is then the last in time of the plurality of breaths.
• any kind of averaging can be used.
• an arithmetic mean is formed. This may or may not be weighted.
• the most accurate, less error-prone detection of active breaths can take place in that the time duration comparison value represents a moving average of respiratory lift durations over a predetermined number of breath strokes following one another until the acquisition breath.
• the acquisition breath can follow the last breath of the moving average a plurality of breaths or may be part of the plurality of breaths. Preferably, it is the last in time of the plurality of breaths.
• the moving average is preferably an arithmetic mean that may be weighted but not weighted.
• a moving average, or even an average of respiratory rates is formed over a number of five to ten breaths, most preferably eight breaths.
• the breaths used for averaging respiratory periods follow one another directly in time.
• the control device of the ventilation device can detect an active breath lift even without reference to the pressure values of the ventilation gas pressure of respiratory gas flowing in the ventilation line arrangement, which are present anyway by the pressure sensor arrangement. This is technically based on the fact that, as a rule, a higher respiratory gas flow is detected in a first active breath than in a mandatory breath, as the activity of the patient is added to the mandatory ventilation. As a result, in the pressure control considered here to achieve a desired flow or a desired tidal volume, the respiratory gas pressure lowered the subsequent breath.
• the controller of the ventilator may also detect a sensing breath as an active breath by detecting the gas pressure of gas flowing in the breathing conduit and comparing a sensed gas pressure during a sense breath with the sensed gas pressure during a previous breath, wherein the control means is adapted to detect the detection breath on the basis of the pressure comparison result as an active breath.
• the detected gas pressure is a pressure of an inspiratory breathing gas.
• the preceding breath is preferably a breath that precedes the acquisition breath, and it should not be ruled out that at least one additional breath is located between the previous breath and the acquisition breath.
• the controller of the ventilator is preferably configured to perform both a duration comparison and a pressure comparison, the detection breath then being more active based on both the time duration comparison result and the pressure comparison result Breath of breath is detected or not.
• the controller of the ventilator may be configured to detect at least a value of an esophageal pressure and / or a pleural pressure of the patient during a detection breath and to detect the detection breath as the active breath on the basis of the at least one sensed pressure value the sensor assemblies initially mentioned as part of the respiratory device require further sensors.
• the pleural pressure is often referred to as "interpleural pressure".
• the spontaneous breathing shown by the patient during artificial respiration is typically only relevant to false-positive error detection if there are enough active breathing strokes during the verification phase appeared. Therefore, the active breath lift threshold, which is exceeded as a discard criterion, may be at least 39% of the total number of breaths in the verification phase as a predetermined active breath lift threshold.
• the active breath lift threshold may be individually determined during artificial ventilation of the patient or even during the verification phase based on ventilator operating data and / or patient data, or may be stored as a predetermined threshold in a memory.
• the active breath lift threshold is a predetermined threshold.
• the active breath lift threshold value can be extended in one
• the preferred embodiment of the ventilator is preferably at least 45%, more preferably at least 50%, of the total number of breaths in the verification phase.
• the controller may be configured to, if the number of active breaths determined during the predetermined verification phase is greater than zero and less than the predetermined active breath lift threshold, increase the verification phase by one Extend additional verification phase.
• the additional verification phase can be determined on the basis of individually present operating or / and patient data or can be used to determine a predetermined amount.
• sentence verification phase which is stored in a cooperating with the controller data storage.
• the duration of the extended verification phase is then the duration of the original verification phase plus the duration of the additional verification phase.
• the control device applies the same at least one throw-away criterion as in the original verification phase, ie. H. only the verification phase is extended, an adaptation of the at least one discard criterion does not take place with the extension of the verification phase.
• the discard criterion described above taking account of spontaneous respiration of the patient, may be the only discard criterion whose fulfillment leads to the rejection of the error candidate and thus to the assessment of a possibly critical operating state of the respiratory device, in particular of the proximal flow sensor, as non-defective ,
• the accuracy of the detection of a fault of the respiratory device, in particular of the proximal flow sensor can be further increased by the fact that the at least one discarding criterion additionally comprises:
• an absolute volume difference which indicates a difference between the distal gas volume determined by means of the distal flow sensor and the proximal gas volume determined by the proximal flow sensor during the same breath stroke, lies within a volume difference acceptance range, and / or
• an absolute value of pressure difference which indicates a difference between the gas pressures detected by the pressure sensor arrangement during different breaths, lies within a pressure-difference-value-permissible range.
• one or both of the admissibility ranges may be stored in a predetermined manner in a data memory interacting with the control device, or may be stored in a predetermined manner. be determined individually depending on operating and / or patient data at the time of detection of the error candidate.
• the error candidate is usually recognized by the fact that the volume difference in terms of volume is outside of a volume difference acceptance range, and / or that the magnitude difference in pressure value is outside a range of pressure difference values. In this respect, it can also serve as a discard criterion that the fulfilled condition for recognizing an error candidate ceases to exist during the verification phase or is no longer present at least at the end of the verification phase.
• the control device is preferably designed such that it discards the error candidate immediately if, during the verification phase-which includes the above-mentioned extended verification phase-one or both of the difference values lie within the respectively assigned difference-value acceptance range, and the error candidate is discarded only then, if, at the end of the verification phase - including the extended verification phase - the total number of breaths is above the active breath lift threshold.
• the control device of the respiratory device proposed in the present application is specifically designed to control the operation of the pressure change arrangement on the basis of measurement signals of the proximal flow sensor such that, in the prescribed mandatory ventilator operation, it changes the pressure change arrangement for changing the gas pressure of the in the inspiratory breathing gas flowing in accordance with the measurement signal of the proximal flow sensor controls such that a gas volume value determined on the basis of the gas flow value detected by the proximal flow sensor is within a predetermined volume value range, preferably substantially constant.
• the gas volume value can be determined, for example, from the measurement signal of the proximal flow sensor representing a gas flow by means of integration over time.
• a proximal flow sensor can be used, which works according to any physical working principle, as long as it is only able to measure the ventilation gas flow at the location of its arrangement.
• the proximal flow sensor may comprise a hot wire anemometer.
• the proximal flow sensor is preferably a differential pressure sensor, the pressure sensor arrangement detecting at least one of the gas pressures detected at the differential pressure sensor as the gas pressure of gas flowing in the ventilation line arrangement, and the control device using this detected gas pressure for determining a fault candidate of the proximal flow sensor. This is because the proximal flow sensor can also be used for pressure detection of respiratory gas pressure in the ventilation line arrangement.
• the control device of the ventilation device is preferably designed to carry out a control intervention on the ventilation device when it concludes an error in the proximal flow sensor.
• a control action may be the output of an error message, including an alarm. This can also take place far away from the site of the ventilation device, for example by radio signals at a location in which nursing staff are present or ready.
• the control device may be configured to continue the artificial respiration of the patient with operating parameters after detection of the error, which were used at a predetermined time or in a predetermined period of time prior to detection of the error candidate.
• an auxiliary ventilator can only be maintained for a short time. However, it may thus be possible to ventilate the patient with more accurate operating parameters than based on those currently affected by the faulty practice. be supplied with flow sensor. With the simultaneous output of an error message or an alarm, the time for such an emergency operation is limited.
• FIG. 1 shows an embodiment of a ventilation device according to the invention
• FIG. 2 shows roughly schematic curves of the volume of ventilation gas introduced into a patient lung and the respiratory gas pressure in the ventilation line arrangement as functions of the time in purely mandatory ventilation
• FIG. 3 shows roughly schematic curves of the respiratory gas volume, the respiratory gas pressure and an esophageal pressure as a function of time during assisted spontaneous respiration
• FIG. 4 shows an exemplary clinical curve of the respiratory frequency of the patient, the distal ventilation gas volume, the proximal ventilation gas volume and the respiratory gas pressure, plotted over time, with the error candidate detected, but rejected, FIG.
• Figure 5 is a diagram of the same parameters as in Figure 4, plotted on the
• FIG. 6 is a third rough schematic diagram with the parameters of Figure 5 with detection of an error candidate and detection of an error thereof.
• an embodiment of a ventilation device according to the invention is designated generally by 10.
• the respiratory device 10 serves in the illustrated example for the artificial respiration of a human patient 12.
• the ventilation device 10 according to the invention can be accommodated as a mobile respiratory device 10 on a rollable frame 13.
• the respiratory device 10 has a housing 14, in which - a pressure change arrangement 16 and a control device 18 can be accommodated, which is not visible from outside because of the opaque housing material.
• the pressure change arrangement 16 is constructed in a manner known per se and has a respiratory gas source 15 in the form of a pump, a compressor or a blower, which are each load-controllable and therefore not only the introduction of breathing gas in the respiratory device, but also the change of pressure serve the introduced respiratory gas.
• the respiratory gas source 15 gas source 15
• the pressure variation arrangement 16 may comprise the gas source 15 and optionally additionally, or in the case of a pressurized gas supply as the gas source alternatively, a reducing valve and the like.
• the respiratory device 10 in a conventional manner, an inspiratory valve 20 and an expiratory valve 22 on.
• the control device 18 is usually realized as a computer or microprocessor. It comprises a memory device, not shown in FIG. 1, in order to be able to store and, if necessary, call up data necessary for the operation of the respiration device 10.
• the memory device can also be located outside of the housing 14 during network operation and connected to the control device 18 by means of a data transmission connection.
• the data transmission connection may be formed by a cable or a radio link.
• the memory device is preferably integrated into the control device 18 or at least received in the same housing 14 as this.
• the respiration device 10 has a data input 24, which is represented in the example shown in FIG. 1 by a keyboard.
• the control device 18 can receive data via various data inputs, for example via a network line, a radio link or via sensor connections 26, which are discussed in greater detail below.
• the respiratory device 10 may include an output device 28, in the example shown a screen.
• the patient 12 is connected to the respiratory device 10, more precisely to the pressure change arrangement 16 in the housing 14, via a ventilation line arrangement 30.
• the patient 12 is intubated for this purpose.
• the ventilation line arrangement 30, via which fresh respiratory gas can be conducted from the gas source 15 and the pressure change arrangement 16 into the lungs of the patient 12, has an inspiratory tube 32 outside the housing 14.
• the inspiratory tube 32 may be interrupted and have a first partial inspiratory tube 34 and a second partial inspiratory tube 36, between which a conditioning device 38 for targeted moistening and possibly also temperature control of the fresh respiratory gas supplied to the patient 12 may be provided.
• the conditioning device 38 can be connected to an external fluid reservoir 40, via which water for humidification or else a medicament, for example for inflammation inhibition or for enlargement of the respiratory tract, can be supplied to the respiratory gas.
• a medicament for example for inflammation inhibition or for enlargement of the respiratory tract.
• volatile anesthetics controlled in this way the respiratory device 10 are delivered to the patient 12.
• the conditioning device 38 ensures that the fresh respiratory gas is supplied to the patient 12 with a predetermined moisture content, optionally with the addition of a medicament aerosol, and at a predetermined temperature.
• the ventilation line arrangement 30 has, in addition to the already mentioned inspiration valve 20, the expiration valve 22 and further an expiration tube 42 via which metabolized respiratory gas is blown out of the lungs of the patient 12 into the atmosphere.
• the inspiratory tube 32 is coupled to the inspiration valve 20, the expiratory tube 42 to the expiratory valve 22. Only one of the two valves is opened at the same time for the passage of a gas flow.
• the actuation control of the valves 20 and 22 is likewise effected by the control device 18.
• the exhalation valve 22 is initially closed for the duration of the inspiration phase, and the inspiration valve 20 is opened so that fresh respiratory gas can be conducted from the housing 14 to the patient 12.
• a flow of the fresh respiratory gas is effected by targeted pressure increase of the respiratory gas by the pressure change arrangement 16. Due to the increase in pressure, the fresh respiratory gas flows into the lungs of the patient 12 and expands there the body area close to the lungs, ie in particular the thorax, against the individual elasticity of the body parts close to the lungs. As a result, the gas pressure inside the lung of the patient 12 also increases.
• the inspiration valve 20 is closed and the expiratory valve 22 is opened. It begins the expiratory phase. Due to the elevated gas pressure until the end of the inspiratory phase of the respiratory gas located in the lungs of the patient 12, this flows into the atmosphere after opening the expiration valve 22, whereby the gas pressure in the lungs of the patient 12 decreases as the flow duration progresses.
• the gas pressure in the lung 12 reaches a positive end-expiratory volume set on the respirator 10 toric pressure, so a slightly higher pressure than the atmospheric pressure
• the expiratory phase is terminated with the closing of the expiratory valve 22 and it is followed by another ventilation cycle.
• the inspiration phase the patient 12 is supplied with the so-called respiratory tidal volume, ie the respiratory gas volume per breath.
• the ventilation device 10, in particular the control device 18, is designed to repeatedly update or determine respiratory operating parameters that characterize the ventilation mode of the respiratory device 10 during the ventilation operation to ensure that the ventilation mode optimally optimizes the ventilation mode at any time each to be ventilated patient 12 is tuned.
• the determination of one or more ventilation operating parameters with the ventilation frequency, so that for each ventilation cycle current and thus optimally adapted to the patient 12 ventilation operating parameters can be provided.
• the respiratory device 10 is connected in terms of data transmission with one or more sensors which monitor the condition of the patient and / or the operation of the respiration device.
• One of these sensors is a proximal flow sensor 44, which detects the respiratory gas flow prevailing there in the ventilation line arrangement 30 in a Y-connector 45.
• the flow sensor 44 may be coupled to the data inputs 26 of the control device 18 by means of a sensor line arrangement 46.
• the sensor lead 46 may or may not include electrical signal transmission lines. It can also have hose lines which transmit the prevailing in the flow direction on both sides of the flow sensor 44 gas pressure to the data inputs 26, where these pressure sensors 27th be quantified.
• the flow sensor 44 is shown here as a differential pressure flow sensor 44. Although the flow sensor 44 is preferably a flow sensor operating according to the differential pressure principle, it can also be a flow sensor operating according to another physical operating principle.
• a further flow sensor 48 is provided, which is referred to as a distal flow sensor 48 due to its greater distance from the patient 12 - compared with the proximal flow sensor 44.
• the measurement signals of the pressure sensors 27 can be used to carry out a particularly advantageous mode of operation, which are known in the art as "Adaptive Pressure Ventilation" or short APV.
• Adaptive Pressure Ventilation or short APV.
• the ventilation gas volume determined from the ventilation gas flow measured by the proximal flow sensor 44 is changed by the pressure change arrangement 16 by changing the pressure of the ventilation gas in the ventilation line arrangement 30 such that the ventilation gas volume determined by means of the proximal flow sensor 44 corresponds to a predetermined desired value or is located in a predetermined setpoint range.
• the desired value or desired value range can be predetermined by the attending physician via the input device or can be calculated from the patient data accessible to the control device 18.
• a change in the ventilation gas volume ascertained by means of the proximal flow sensor 44 thus generally leads to a change in the pressure of the ventilation gas in the ventilation line arrangement 30.
• the proximal flow sensor 44 in contrast to the distal flow sensor 48, is also generally capable of sensing the flow of expiratory breathing gas through the expiratory tube 42.
• the proper functioning of the flow sensors 44 and 48 is essential to the proper operation of the respirator 10, and thus to the health of the patient 12. It has been shown in operation that the proximal flow sensor 48, in particular, is at greater risk of faults than the distal flow sensor 48 because of its proximity to the patient 12.
• the proximal flow sensor 44, through which expiratory breathing gas also flows, is stronger than the distal flow sensor 48, for example moisture contained in the breathing gas. This applies all the more if, as in the present example of FIG. 1, the distal flow sensor 48 is arranged in the direction of inspiration upstream of the conditioning device 38 and thus substantially only dry inspiratory breathing gas flows through it.
• the control device 18 of the respiratory device 10 is designed to monitor the operation of the flow sensor arrangement formed by the proximal flow sensor 44 and the distal flow sensor 48 in order to be able to detect a malfunction of the flow sensor arrangement in good time.
• the distal flow sensor 48 measures a relatively larger ventilation gas flow, resulting in a larger volume of ventilation gas determined therefrom, than the proximal flow sensor 44, since the distal flow sensor 48 is located closer to the respiratory gas source 15 than the proximal flow sensor 44 and thus less subject to less gas flow error influences ,
• Such an influence is, for example, the elasticity of the ventilation line arrangement 30, in particular of the inspiratory tube 32. If inspiratory breathing gas is introduced, which must be under system pressure in relation to the surrounding atmosphere, the introduced inspiratory breathing gas works against the elasticity of the inspiration tube 32 and stretches this. In the enlarged by this expansion volume of the inspiratory tube 32 respiratory gas is received, which although has flowed through the distal flow meter 48, but no longer reaches the patient 12 and the lying directly in front of him proximal flow sensor 44.
• the exhalation valve 22 does not close off hermetically tight in many cases, so that in the inspiration phase, a transverse flow in flow-mechanical short circuit between inspiratory valve 20 and expiratory valve 22 is formed.
• this cross-flow ventilation gas flows through the distal flow sensor 48, but neither the proximal flow sensor 44, nor the patient 12 reaches, but previously in the Y-connector 45 flows directly from the inspiratory tube 32 into the expiratory tube 42.
• the level of the flux detection and, associated therewith, the volume determination by means of the distal flow sensor 48 is higher in magnitude than the level of the flow detection and, associated therewith, the volume determination by means of the proximal flow sensor 44.
• proximal flow sensor 44 An excessively liquid contaminated and therefore erroneously detecting proximal flow sensor 44 will not self-regenerate and must be replaced with a faultless fluid-unloaded sensor to further ensure proper ventilation of the patient 12.
• a similar effect ie, increased proximal flow and, as a consequence, increased proximal ventilation gas volume, may also occur due to causes other than excessive fluid loading of the proximal flow sensor 44.
• spontaneous breathing occurring during artificial respiration may also be the difference in value between the distal ventilation gas flow measured by the distal flow sensor 48 and the distal ventilation gas volume determined therefrom and the proximal ventilation gas flow measured by the proximal flow sensor 44 and the proximal ventilation gas volume determined therefrom relative to the difference value for purely mandatory breathing change.
• FIG. 2 shows-merely roughly schematically for purposes of illustration-in an upper diagram the ventilation gas volume supplied to the artificially ventilated patient 12 as a function of time, wherein the curve of the ventilation gas volume is designated by reference numeral 50 as a function of time.
• a target specification of the tidal volume is shown by the horizontal dashed line 52.
• FIG. 1 shows four temporally successive breath strokes. Below the ventilation gas volume as a function of time, the ventilation gas pressure as a function of time in the curve 54 is shown with the same time scale and also only roughly schematically.
• a predetermined by the controller 18 of the pressure variation assembly 16 maximum control pressure is designated by reference numeral 56. In the purely mandatory artificial respiration shown in FIG. 2, it is constant over the illustrated four breaths. For reasons known per se, the control device 18 controls the pressure change arrangement 16 in such a way that the respiratory gas pressure in the ventilation line arrangement does not fall below the positive end-expiratory pressure "PEEP".
• PEEP positive end-expiratory pressure
• the tidal volume supplied to the patient corresponds to the desired tidal volume Vsoii.
• the tidal volume according to the rough-schematic curve 50 has been determined with the proximal flow sensor 44. Then, if in a breath If the ventilation gas volume supplied to the patient does not sufficiently correspond to the predefined setpoint volume Vsoii, an increased or reduced control pressure p s is preset by the control device 18 for the subsequent breath stroke so as to keep the volume of ventilation gas supplied to the patient 12 as constant as possible for each breath ,
• a respiratory stroke lasts from the time at which the curve 50 of the ventilation gas volume changes as a function of time from its baseline to higher values.
• the phase of increasing volume values corresponds to an inspiratory phase
• the phase of decreasing volume values corresponds to an expiratory phase.
• FIG. 3 shows the same data curves as in FIG. 2, but with spontaneous respiration occurring.
• the same graphs and sizes as in FIG. 2 are given the same reference numerals in FIG. 3, but increased by the number 10.
• FIG. 3 shows five respiratory strokes which follow each other directly in time or the respiratory gas volumes belonging to these breaths as a function of time and the respiratory gas pressures in the ventilation line arrangement 30 as a function of time.
• the first breath in Figure 3 is a mandatory breath. It corresponds to the first breath in Figure 2 with the exception of his shorter breath duration explained in more detail below.
• the second breath is an active breath which has been triggered by the patient. Since the patient 12 in addition to the him on the ventilation Vor- Direction 10 supplied ventilation gas sucks self-contained breathing gas, it receives in the second breath a total of a larger volume of respiratory gas as provided by the control device 18 of the respiratory device 10. The control device 18 therefore lowers the control pressure p s of the respiratory gas for the subsequent third breath to return the volume of ventilation gas supplied to the patient during a breath to its desired value Vsoii (see target curve 62 in FIG. 3) ). Since the third breath of Figure 3 is an active breath, the return of the patient 12 supplied ventilation gas volume to the predetermined target level succeeds.
• the breath lift duration T2 of the second breath is shorter than the predetermined breath lift duration of a mandatory breath.
• the same also applies to the respiratory stroke duration T1 of the first breath, although this does not occur as clearly in FIG. 3 as for the second breath.
• the fourth breath is again a purely mandatory breath, which is performed with the already applicable for the third breath control pressure p tax, which has led to the desired delivery of the desired ventilation gas volume for the third breath. Since spontaneous breathing of the patient does not occur in the fourth breath, however, the maximum pressure p tax of the respiratory gas during the inspiration phase is too low to supply the target ventilation gas volume Vsoii to the patient. Accordingly, the ventilation gas volume supplied to the patient 12 in the fourth breath is too low, whereupon the control device 18 controls the pressure change arrangement 16 for the provision of a higher maximum ventilation gas pressure p control for the subsequent fifth breath.
• the ventilation durations Ti, T2 and T3 are of different lengths due to the spontaneous breathing in the breaths 2 and 3.
• a purely mandatory breath, which immediately precedes an active breath is usually shortened in time compared to a purely mandatory breath, which is followed by another purely mandatory breath.
• An active breath in the pressure control shown to achieve A target tidal volume immediately following a purely mandatory respiratory stroke generally has too low a tidal volume or a smaller tidal volume than that provided by the control device 18.
• the control device 18 can detect individual breaths as active breaths of the patient 12 without additional sensors alone from the existing breath sensors 44 and 48 and the existing pressure sensors 27.
• an active breathing stroke can be detected by detecting the muscle pressure in the thorax region or the esophageal pressure. While in purely mandatory breaths no or no significant muscle or esophageal pressures occur, the curve 68 in Figure 3 in the active breathing strokes 2 and 3 a significant US, Esophageal pressure, for its detection, however, a further sensor is necessary, which is otherwise not needed for the respiratory device 10.
• Detection of active breaths plays a role in avoiding false-positive error messages on the respiratory device 10, as will be explained below.
• FIG. 4 shows a first diagram in which the respiratory rate is plotted as respiratory strokes per minute with the graph 70, the distal ventilation gas volume, ie the temporal integral of the respiratory gas flow measured by the distal flow sensor 48 with the curve 72 in milliliters, is the beat - Gas pressure in centimeters water column as a curve 74 and finally the proximal ventilation gas volume, ie the temporal integral of the measured by the proximal flow sensor 44 ventilation gas flow, as curve 76 is again plotted in milliliters.
• the difference in magnitude between the distal and the proximal breathing gas volume is known, or a volume difference acceptance range is defined for this difference in magnitude.
• a volume difference acceptance range is defined for this difference in magnitude.
• the difference in volume between the distal and the proximal ventilation gas volume is in this admissibility range, there is no reason to assume that the respiration device malfunctions, in particular the proximal flow sensor 44.
• the difference in magnitude between the distal and the proximal ventilation gas volume leaves the assigned admissibility range, this could be due to a functional impairment of the proximal flow sensor 44, so that when said volume difference value leaves the assigned admissibility range, the control device 18 fails - Candidate flag sets and thus detects an error candidate. This is done in Figure 4, for example, at the time ti.
• the control device 18 With the recognition of the error candidate at time ti, the control device begins a verification phase, which preferably continues over exactly 50 breaths. It ends at the time t.sub.2 in FIG. 4. In addition, it stores the respiratory gas pressure prevailing at the time t.sub.i of the recognition of the error candidate, designated as "p.sub.i" in FIG. This value pi is the basis of a discard criterion which will be discussed below in connection with Figure 5 in more detail.
• the control device 18 begins to examine occurring breaths as to whether they are active or mandatory breaths. For this purpose it uses the signal evaluation set forth in connection with FIG. For the ventilation procedure of FIG. 4, the control device 18 determines that the gray-shaded area 78 shows active breaths continuously. Since at the end of the verification phase at time t.2 more than 50% of the 50 breaths of the verification phase were active breaths, a discard criterion is met and the controller 18 rejects the candidate error detected at time ti and does not perform any based on recognition of the error candidate through further control interventions.
• control device 18 in the event that more than half of the breaths were active breaths during the verification phase, which initially as a potentially critical reduction in the difference between distal and proximal breathing gas volume has its cause in the spontaneous breathing of the patient 12 and not in a fault or damage of the proximal flow sensor 44.
• FIG. 5 shows a diagram of another but comparable ventilation process.
• the same value curves as in FIG. 4 are provided with the same reference numerals in FIG. 5, but increased by the number 10.
• an absolute difference between the distal and the proximal ventilation gas volumes is outside a permissible range so that the controller 18, which detects the leaving of the permissive area, begins a verification phase.
• the at the beginning of the verification phase ie at the time ti of detecting an error candidate prevailing ventilation gas pressure, measured by a pressure sensor connected to the proximal flow sensor 44, stored in a data memory.
• FIG. 6 shows a diagram of a further ventilation situation similar to those of FIGS. 4 and 5. Identical value curves as in FIG. 5 are denoted by the same reference numerals, but increased by the number 10.
• a candidate for an error of the proximal flow sensor 44 is recognized by the control device 18, since the distal and the proximal ones are detected
• the amount of ventilation gas volume is approaching such an amount that its difference value lies outside of a predetermined admissibility range.
• the control device 18 starts the predetermined verification phase at the time t.sub.i, in which the control device 18 checks whether predetermined invalidation criteria exist or occur which result in rejection of the error candidate.
• the additional verification phase is shorter than in the case illustrated in FIG. 5, which may be due, for example, to deviating patient data.
• control device 18 Since no discard criterion has also occurred up to the end of the extended verification phase at time t3, control device 18 detects an error from the error candidate detected at time ti at time t.3 and performs a control intervention, for example by the control unit issuing an alarm, connected with a specific error message, triggers.

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• 2017
  • 2017-10-06 DE DE102017217858.2A patent/DE102017217858A1/de not_active Withdrawn
• 2018
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