CN115297916A

CN115297916A - Respiration monitoring device and method

Info

Publication number: CN115297916A
Application number: CN202080098474.8A
Authority: CN
Inventors: 邹心茹; 刘京雷; 周小勇
Original assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Current assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Priority date: 2020-03-23
Filing date: 2020-03-23
Publication date: 2022-11-04
Also published as: WO2021189197A1

Abstract

A respiratory monitoring device and method, comprising: acquiring a pressure (200) of the patient during ventilation, the pressure reflecting pressures acting on different sites of the respiratory system of the patient during ventilation; acquiring a gas flow rate (100) of a patient during ventilation; energy applied to the patient's respiratory system during mechanical ventilation is calculated from the acquired pressure and gas flow rate (300). The pressure and the gas flow rate of a patient can be monitored in the ventilation process through the respiration monitoring device, and the energy acted on a respiratory system of the patient by mechanical ventilation can be obtained according to the pressure and the gas flow rate of the patient, so that the lung injury can be evaluated more accurately, truly and in real time, further, information such as numerical values of the energy can be analyzed, and subsequent work such as alarming and disease condition judgment can be carried out.

Description

Respiration monitoring device and method

Technical Field

The invention relates to a respiration monitoring device and a respiration monitoring method.

Background

Human respiration means that gas is inhaled and exhaled periodically and rhythmically, oxygen is absorbed and carbon dioxide is discharged, and thus gas exchange is achieved. When some patients cannot breathe spontaneously, the patients can be helped to finish breathing through mechanical ventilation; for example, in the case of a patient who is not breathing spontaneously, respiratory support may be provided to the patient, typically by an external device such as a ventilator or the like. It can be seen that mechanical ventilation is a ventilation mode that utilizes mechanical means to replace, control or modify the spontaneous respiratory motion of a patient. Mechanical ventilation, however, is also prone to patient lung injury when applied (VILI). In order to reduce lung injury caused by mechanical ventilation, researchers and technicians have proposed many ventilation strategies to reduce lung injury. Currently widely accepted are lung protection strategies (LPVS) centered on small tidal volumes, low end-inspiratory alveolar positive pressure, optimal end-expiratory positive pressure, and permissive carbonation. A description of a lung protective ventilation strategy or a strategy for reducing lung injury follows.

Some strategies for reducing lung injury are preferably directed at low tidal volumes, but the lungs are completely inflated, high tidal volumes are not the main cause of harm, and the mortality caused by Acute Respiratory Distress Syndrome (ARDS) when ventilated with low tidal volumes is not reduced, because ARDS patients have different sizes and distributions of collapsed alveolar regions due to different types, causes, and lesion involvement ranges, resulting in lung heterogeneity that causes lung compliance and restorable alveolar volumes to vary from patient to patient, and the actual tidal volumes required by different patients to vary, so that tidal volumes alone are not sufficient as an indicator for the assessment of lung injury.

There are therefore also some strategies for reducing lung injury that use low tidal volume in combination with optimal Positive End Expiratory Pressure (PEEP), but this also has the risk of over-inflation of the alveoli in the gravity-independent region and tidal collapse and re-expansion of the alveoli in the gravity-dependent region, which still leads to a higher incidence of ventilator-related lung injury.

In addition, some lung injury reduction strategies have been implemented by combining low tidal volume with plateau pressure limitation, but studies and practice have shown that patients with many collapsed alveoli have fewer normally ventilated alveoli and significantly higher over-inflation, and thus lung injury may still occur in these patients.

Disclosure of Invention

The invention mainly provides a respiration monitoring device and a method aiming at the problem of reducing lung injury.

According to a first aspect, there is provided in an embodiment a method of respiratory monitoring comprising:

acquiring the pressure of the patient during ventilation, wherein the pressure reflects the pressure acting on different sites of the respiratory system of the patient during ventilation;

acquiring the gas flow rate of a patient in the ventilation process;

the energy applied to the patient's respiratory system during mechanical ventilation is calculated from the acquired pressure and gas flow rate.

In one embodiment, the pressure at the different sites comprises one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, intragastric pressure, transpulmonary pressure, and transphrenic pressure.

In one embodiment, the respiration monitoring method further comprises: the transpulmonary pressure is corrected by airway and esophageal pressures at zero and non-zero positive end expiratory pressure.

In one embodiment, the respiration monitoring method further comprises: the transpulmonary pressure is corrected by lung compliance and chest wall compliance.

In one embodiment, the respiration monitoring method further comprises: the transphrenic pressure is corrected by esophageal and gastric pressures at zero and non-zero positive end expiratory pressure.

In one embodiment, the gas flow rate comprises at least an inspiratory flow rate.

In one embodiment, the calculating the energy applied to the respiratory system of the patient during mechanical ventilation based on the acquired pressure and gas flow rate comprises:

the pressure and gas flow rate are integrated to obtain the energy acting on the patient's respiratory system during mechanical ventilation.

In one embodiment, the integrating the pressure and the gas flow rate includes:

integrating the pressure and the gas flow rate within a preset unit time; alternatively, the first and second electrodes may be,

the pressure and gas flow rate are integrated over a breath cycle.

In one embodiment, the respiration monitoring method further comprises: displaying the energy of the mechanical ventilation acting on the respiratory system of the patient.

In one embodiment, the displaying the energy applied to the respiratory system of the patient by the mechanical ventilation comprises: displaying a real-time value of the energy applied to the patient's respiratory system by the mechanical ventilation and/or displaying a change in the energy applied to the patient's respiratory system by the mechanical ventilation over time.

In one embodiment, the respiration monitoring method further comprises: an alarm is generated based on the energy applied to the patient's respiratory system by the mechanical ventilation.

In one embodiment, the alerting based on energy applied to the respiratory system of the patient by the mechanical ventilation comprises:

when the energy of the mechanical ventilation acting on the respiratory system of the patient is judged to exceed a first threshold value, alarming; and/or the presence of a gas in the gas,

and when the energy of the mechanical ventilation acting on the respiratory system of the patient is judged to be lower than the second threshold value, alarming.

In one embodiment, the respiration monitoring method further comprises: the condition of the patient is judged according to the energy of the mechanical ventilation acting on the respiratory system of the patient.

In one embodiment, the determining the condition of the patient based on the energy applied to the respiratory system of the patient by the mechanical ventilation comprises:

the patient condition is determined based on the real-time value and/or trend of change of the energy applied to the patient's respiratory system by the mechanical ventilation.

According to a second aspect, an embodiment provides a respiration monitoring apparatus comprising:

a pressure sensor for acquiring the pressure of the patient during ventilation, wherein the pressure reflects the pressure acting on different sites of the respiratory system of the patient during ventilation;

the flow sensor is used for acquiring the gas flow rate of a patient in the ventilation process;

a processor for acquiring the pressure of the patient during ventilation and the flow rate of gas during ventilation of the patient, and calculating the energy acting on the respiratory system of the patient during mechanical ventilation from the acquired pressure and flow rate of gas.

In one embodiment, the pressure at the different sites includes one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, intragastric pressure, transpulmonary pressure, and transphrenic pressure.

In one embodiment, the processor corrects the transpulmonary pressure by airway pressure and esophageal pressure at zero and non-zero positive end expiratory pressure.

In one embodiment, the processor corrects the transpulmonary pressure by lung compliance and chest wall compliance.

In one embodiment, the processor corrects the trans-phrenic pressure by esophageal and gastric pressures at zero and non-zero positive end expiratory pressure.

In one embodiment, the processor integrates the pressure and gas flow rate to derive the energy applied to the patient's respiratory system during mechanical ventilation.

In one embodiment, the processor integrates the pressure and gas flow rate over a predetermined unit of time; alternatively, the processor integrates the pressure and gas flow rate over a single breath cycle.

In one embodiment, the respiratory monitoring device further comprises a display for displaying the energy of the mechanical ventilation acting on the respiratory system of the patient.

In one embodiment, the display displays a real-time value of the energy applied to the patient's respiratory system by the mechanical ventilation and/or displays a change in the energy applied to the patient's respiratory system by the mechanical ventilation over time.

In one embodiment, the processor also alerts based on energy applied to the patient's respiratory system based on the mechanical ventilation.

In one embodiment, the processor alarms when it is determined that the energy applied to the patient's respiratory system by mechanical ventilation exceeds a first threshold.

In one embodiment, the processor alarms when it is determined that the energy applied to the patient's respiratory system by mechanical ventilation is below a second threshold.

In one embodiment, the processor further determines the patient condition based on the energy applied to the patient's respiratory system by the mechanical ventilation.

In one embodiment, the processor determines the patient condition based on a real-time value and/or trend of change of energy applied to the patient's respiratory system by the mechanical ventilation.

In one embodiment, the respiratory monitoring device comprises a patient monitor, a patient monitor module, or a medical ventilator.

According to a third aspect, an embodiment provides a computer readable storage medium comprising a program executable by a processor to implement a method as described in any of the embodiments herein.

Drawings

FIG. 1 is a schematic diagram of a respiratory monitoring device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a respiratory monitoring device according to another embodiment of the present application;

FIG. 3 is a schematic diagram of a respiratory monitoring device according to yet another embodiment of the present application;

FIG. 4 is a schematic diagram of a respiratory monitoring device according to yet another embodiment of the present application;

FIG. 5 is a flow chart of a respiration monitoring method of an embodiment of the present application;

FIG. 6 is a flow chart of a respiration monitoring method of another embodiment of the present application;

FIG. 7 is a flow chart of a respiration monitoring method of yet another embodiment of the present application;

fig. 8 is a flow chart of a respiration monitoring method according to yet another embodiment of the present application.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments have been given like element numbers associated therewith. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in this specification in order not to obscure the core of the present application with unnecessary detail, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the description of the methods may be transposed or transposed in order, as will be apparent to a person skilled in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" as used herein includes both direct and indirect connections (couplings), unless otherwise specified.

The lung injury VILI is a combination of various types of injuries and is caused by excessive dynamic strain and energy load, so that the lung injury can be evaluated more accurately, truly and in real time by calculating the energy acting on the respiratory system of a patient in the mechanical ventilation process.

In some embodiments of the present invention, a respiration monitoring device is disclosed, and referring to fig. 1, the respiration monitoring device may include a pressure sensor 10, a flow sensor 30, and a processor 50. The respiration monitoring device of the present invention may be used in a variety of applications, for example, the respiration monitoring device of the present invention may be a patient monitor or patient monitoring module in some embodiments, and may be a medical ventilator, such as a ventilator or an anesthesia machine, in some embodiments, as described separately below.

The respiratory monitoring device may be a patient monitor in some embodiments.

Referring to fig. 2, in some embodiments, the respiration monitoring device may have a separate housing, and a sensor interface area may be provided on a panel of the housing, wherein the sensor interface area may integrate a plurality of sensor interfaces for connecting with external physiological parameter sensor accessories 111, and in some embodiments, may also be used for connecting with the pressure sensor 10 and the flow sensor 30. One or more of a small IXD display area, a display 70, input interface circuitry 122, and alarm circuitry 120 (e.g., an LED alarm area), etc., may also be included on the housing panel. The respiration monitoring device is provided with an external communication interface 119 and a power interface 116 which are used for communicating with a medical equipment host machine such as a patient monitor, a breathing machine, an anesthesia machine and the like and getting electricity from the medical equipment host machine. The respiration monitoring device can also support an external parameter insertion module, a plug-in type monitor host can be formed by inserting the parameter insertion module and is used as a part of the monitor, the host can also be connected with the respiration monitoring device through a cable, and the external parameter insertion module is used as an external accessory of the monitor. The internal circuit of the respiration monitoring device is arranged in the housing and can include a signal acquisition circuit 112 and a front end signal processing circuit 113 corresponding to one or more physiological parameters, the signal acquisition circuit 112 can be selected from an electrocardio circuit, a respiration circuit, a body temperature circuit, a blood oxygen circuit, a noninvasive blood pressure circuit, an invasive blood pressure circuit and the like, the signal acquisition circuits 112 are respectively electrically connected with corresponding sensor interfaces and are used for being electrically connected to sensor accessories 111 corresponding to different physiological parameters, the output end of the signal acquisition circuit is coupled to the front end signal processing circuit 113, the communication port of the front end signal processing circuit 113 is coupled to the processor 50, and the processor 50 is electrically connected with an external communication interface 119 and a power supply interface 116. The sensor accessory 111 and the signal acquisition circuit 112 corresponding to various physiological parameters can adopt a common circuit in the prior art, the front-end signal processing circuit 113 performs sampling and analog-to-digital conversion of the output signal of the signal acquisition circuit 112, and outputs a control signal to control the measurement process of the physiological signal, and the parameters include but are not limited to: electrocardio, respiration, body temperature, blood oxygen, noninvasive blood pressure and invasive blood pressure parameters. The front-end signal processing circuit 113 may be implemented by a single chip microcomputer or other semiconductor devices, for example, a mixed signal single chip microcomputer such as LPC2136 of philips corporation or adic 7021 of ADI, or an ASIC or FPGA. The front-end signal processing circuit 113 may be powered by an isolated power supply, and the sampled data may be sent to the processor 50 through an isolated communication interface after being simply processed and packed, for example, the front-end signal processing circuit 113 may be coupled to the processor 50 through an isolated power supply interface 114 and a communication interface 115. The reason that the front-end signal processing circuit 113 is powered by the isolation power supply is that the DC/DC power supply isolated by the transformer plays a role in isolating a patient from power supply equipment, and the main purpose is as follows: 1. isolating the patient, and floating the application part through an isolation transformer to ensure that the leakage current of the patient is small enough; 2. the voltage or energy when defibrillation or electrotome is applied is prevented from influencing board cards and devices of intermediate circuits such as a main control board and the like (the creepage distance and the electric clearance are used for ensuring). Of course, the front-end signal processing circuit 113 may also be directly connected to the processor 50 through a cable. The processor 50 is used for calculating physiological parameters and transmitting the calculation results and waveforms of the parameters to a host (such as a host with a display, a PC, a central station, etc.) through the external communication interface 119; the processor 50 may be directly connected to the external communication interface 119 through a cable for communication, and directly connected to the power interface 116 through a cable for power supply; the respiration monitoring device may further include a power supply and battery management circuit 117, where the power supply and battery management circuit 117 takes power from the host computer through a power interface 116, and supplies the processed power to the processor 50, such as rectification, filtering, and the like; the power supply and battery management circuitry 117 may also monitor, manage and power protect the power drawn from the host through the power interface 116. The external communication interface 119 may be one or a combination of an Ethernet (Ethernet), a Token Ring (Token Ring), a Token Bus (Token Bus), and a local area network interface (lan interface) configured by a backbone Fiber Distributed Data Interface (FDDI) as these three networks, one or a combination of wireless interfaces such as infrared, bluetooth, wifi, WMTS communication, or one or a combination of wired data connection interfaces such as RS232 and USB. The external communication interface 119 may also be one or a combination of a wireless data transmission interface and a wired data transmission interface. The host computer can be any computer equipment of a host computer, a computer and the like of the monitor, and the monitoring equipment can be formed by installing matched software. The host machine can also be communication equipment such as a mobile phone, and the respiration monitoring device sends data to the mobile phone supporting Bluetooth communication through the Bluetooth interface to realize remote transmission of the data. After the processor 50 completes the calculation of the physiological parameter, it can also determine whether the physiological parameter is abnormal, and if so, it can alarm through the alarm circuit 120. The memory 118 may store intermediate and final data for the monitor as well as program instructions or code for execution by the processor 50 or the like. If the monitor has a function of blood pressure measurement, a pump valve driving circuit 121 may be further included, and the pump valve driving circuit 121 is used for performing inflation or deflation operations under the control of the processor 50.

The above are some illustrations of the respiratory monitoring device being a patient monitor.

In some embodiments, the respiration monitoring device may also be a ventilator, which is an artificial mechanical ventilator used to assist or control the spontaneous respiratory movement of the patient, so as to achieve the function of gas exchange in the lungs, reduce the consumption of the human body, and facilitate the recovery of the respiratory function. Referring to fig. 3, in some embodiments, the respiration monitoring device may further include a respiration interface 211, a gas source interface 212, a respiration circuit, a respiration assistance device, and a display 70.

The breathing circuit selectively communicates the gas supply interface 212 with the patient's breathing system. In some embodiments, the breathing circuit includes an expiratory limb 213a and an inspiratory limb 213b, and the expiratory limb 213a is coupled between the respiratory interface 211 and the exhaust port 213c for conducting exhaled gas from the patient to the exhaust port 213c. The exhaust port 213c may be opened to the external environment or may be a gas recovery device dedicated to the passage. The gas source interface 212 is used for connecting with a gas source (not shown in the drawings) for providing gas, which may be oxygen, air, etc.; in some embodiments, the gas source may be a compressed gas cylinder or a central gas supply source, the breathing machine is supplied with gas through the gas source interface 212, the gas supply type includes oxygen O2, air, and the like, and the gas source interface 212 may include conventional components such as a pressure gauge, a pressure regulator, a flow meter, a pressure reducing valve, and an air-oxygen ratio regulation and protection device, which are respectively used for controlling the flow rates of various gases (such as oxygen and air). The inspiration limb 213b is coupled between the breathing interface 211 and the gas source interface 212 for providing oxygen or air to the patient, such as gas input from the gas source interface 212, into the inspiration limb 213b and then through the breathing interface 211 into the patient's lungs. The breathing interface 211 is used for connecting the patient to the breathing circuit, and can introduce the gas transmitted from the inspiration branch 213b into the patient, and can also introduce the gas expired by the patient into the exhaust port 213c through the expiration branch 213 a; the respiratory interface 211 may be a nasal cannula or a face mask for wearing over the mouth and nose, as the case may be. The breathing assistance device is connected with the gas source interface 212 and the breathing circuit, and is used for controlling the gas provided by the external gas source to be delivered to the patient through the breathing circuit; in some embodiments, the breathing assistance apparatus may include an exhalation controller 214a and an inhalation controller 214b, wherein the exhalation controller 214a is disposed on the exhalation branch 213a and is used for turning on the exhalation branch 213a or turning off the exhalation branch 213a according to a control command, or controlling the flow rate or pressure of the gas exhaled by the patient. In particular implementations, exhalation controller 214a may include one or more of an exhalation valve, a one-way valve, a flow controller, a PEEP valve, etc. that enable control of flow or pressure. The suction controller 214b is provided on the suction branch 213b, and is configured to turn on the suction branch 213b or turn off the suction branch 213b, or control the flow rate or pressure of the output gas, according to a control command. In particular implementations, inhalation controller 214b may include one or more of an exhalation valve, a one-way valve, or a flow controller, among other devices that enable control of flow or pressure.

The memory 215 may be used to store data or programs, such as data acquired by a sensor, data generated by a processor via calculations, or image frames generated by a processor, which may be 2D or 3D images, or the memory 215 may store a graphical user interface, one or more default image display settings, programming instructions for a processor. The memory 215 may be a tangible and non-transitory computer readable medium, such as flash memory, RAM, ROM, EEPROM, and the like.

In some embodiments, processor 50 is configured to execute instructions or programs to control the breathing assistance apparatus, gas source interface 212, and/or various control valves in the breathing circuit, or to process received data to generate desired calculations or determinations, or to generate visual data or graphics and output the visual data or graphics to display 70.

While the above is some description of the respiratory monitoring device as a ventilator, it should be noted that fig. 3 is only an example of a ventilator and is not intended to limit the structure of a ventilator to this configuration.

In some embodiments, the respiration monitoring device may also be an anesthesia machine that is primarily used to provide anesthesia gas to the respiratory system of a patient via a ventilator and to control the amount of anesthesia gas inhaled. Referring to fig. 4, the respiration monitoring device of some embodiments may further include a respiration interface 311, a gas source interface 312, a respiration assistance device 320, an anesthetic output device 330, a respiration circuit, a memory 350, and a display 70.

The gas source interface 312 is adapted to be connected to a gas source (not shown) for providing gas. The gas may be oxygen, nitrous oxide (laughing gas), air, or the like. In some embodiments, the gas source may be a compressed gas cylinder or a central gas source, and the gas source interface 312 supplies gas to the anesthesia apparatus, wherein the gas supply may be oxygen O2, laughing gas N2O, air, or the like. The gas source interface 312 may include conventional components such as a pressure gauge, a pressure regulator, a flow meter, a pressure reducing valve, and an N2O-O2 proportional control protection device, which are respectively used for controlling the flow of various gases (such as oxygen, laughing gas, and air). The gas input from the gas source interface 312 enters the breathing circuit and forms a mixed gas with the original gas in the breathing circuit.

The breathing assistance device 320 is used to provide power for the patient's involuntary breathing to maintain an airway patency. The breathing assistance apparatus 320 in some embodiments is coupled to a gas source interface 312 and a breathing circuit through which gas provided by an external gas source is controlled to be delivered to a patient. In some embodiments, the breathing assistance device 320 mixes the fresh gas input from the gas source 312 with the gas exhaled by the patient in the breathing circuit and the anesthetic drug output from the anesthetic output device 330, and outputs the mixture to the breathing interface 311 through the inhalation branch 340b, so as to drive the patient to inhale, and receive the gas exhaled by the patient through the exhalation branch 340 a. In a particular embodiment, the breathing assistance apparatus 320 generally includes a mechanospheral module having a flow conduit in communication with the breathing circuit. In the anesthesia maintenance stage in the operation process or in the state that the patient does not recover spontaneous respiration, the mechanical control ventilation module is adopted to provide the breathing power for the patient. In some embodiments, the breathing assistance apparatus 320 further includes a manual ventilation module, and the airflow conduit of the manual ventilation module is in communication with the breathing circuit. During the induction phase prior to intubating the patient during the procedure, it is often necessary to use a manual ventilation module to provide respiratory assistance to the patient. When the breathing assistance apparatus 320 includes both a mechanical or manual ventilation module and a manual ventilation module, the mechanical or manual ventilation mode may be switched by a mechanical or manual switch (e.g., a three-way valve) to communicate the mechanical or manual ventilation module with the breathing circuit to control the breathing of the patient. It will be appreciated by those skilled in the art that only a mechanical ventilation module or a manual ventilation module may be included in the anesthesia machine, depending on the particular needs.

The anesthetic output device 330 is used to provide anesthetic drugs, which are typically mixed in a gaseous form into the fresh air introduced by the air source interface 312 and delivered together into the breathing circuit. In one embodiment, the anesthetic output device 330 is implemented as an anesthetic volatilization canister. The anesthetic is usually in a liquid state and is stored in the anesthetic volatilization tank, optionally, the anesthetic volatilization tank may comprise a heating device for heating the anesthetic to volatilize the anesthetic, so as to generate anesthetic vapor, the anesthetic output device 330 is communicated with the pipeline of the air source interface 312, and the anesthetic vapor is mixed with fresh air introduced by the air source interface 312 and then is conveyed to the breathing circuit together.

In some embodiments, the breathing circuit may include an inhalation branch 340b, an exhalation branch 340a, and a soda lime tank 340c, the inhalation branch 340b and the exhalation branch 340a are communicated to form a closed circuit, and the soda lime tank 340c is disposed on a pipeline of the exhalation branch 340 a. The mixture of fresh air introduced from the air source interface 312 is inputted from the inlet of the inhalation branch 340b and is provided to the patient through the breathing interface 311 disposed at the outlet of the inhalation branch 340 b. The respiratory interface 311 may be a mask, a nasal cannula, or an endotracheal tube. In the preferred embodiment, the inspiratory leg 340b is provided with a one-way valve that opens during the inspiratory phase and closes during the expiratory phase. Expiratory limb 340a is also provided with a one-way valve which closes during the inspiratory phase and opens during the expiratory phase. The inlet of the expiration branch 340a is communicated with the breathing interface 311, when the patient exhales, the exhaled gas enters the soda lime tank 340c through the expiration branch 340a, carbon dioxide in the exhaled gas is filtered by substances in the soda lime tank 340c, and the gas after carbon dioxide filtering is recycled into the inspiration branch 340 b.

The memory 350 may be used to store data or programs, such as data acquired by various sensors, data computationally generated by a processor, or image frames generated by a processor, which may be 2D or 3D images, or the memory 350 may store a graphical user interface, one or more default image display settings, programming instructions for a processor. The memory 350 may be a tangible and non-transitory computer readable medium, such as flash memory, RAM, ROM, EEPROM, and the like.

The processor 50 is configured to execute instructions or programs to control the breathing assistance device 320, the gas source interface 310, and/or various control valves in the breathing circuit, or to process received data to generate desired calculations or determinations, or to generate visual data or graphics, and to output the visual data or graphics to the display 70 for display.

While the above is a description of the respiration monitoring apparatus as an anesthesia machine, it should be noted that the above fig. 4 is only an example of an anesthesia machine, and is not intended to limit the anesthesia machine to such a configuration.

The following is a description of how the respiratory monitoring device calculates and uses the energy applied to the patient's respiratory system during mechanical ventilation.

The flow sensor 30 is used to acquire the gas flow rate of the patient during ventilation. In some embodiments, the flow rate of gas during ventilation of the patient includes at least an inspiratory flow rate of the patient. In some embodiments, the flow sensor 30 may be a patient-side flow sensor, such as a flow sensor disposed at the patient interface, and the flow rate of gas is the flow rate of gas collected by the flow sensor during inspiration. In some embodiments, the flow sensors 30 are multiple in number, including an inspiratory flow sensor and an expiratory flow sensor disposed at the mechanical ventilation end, such as an inspiratory flow sensor disposed in the inspiratory branch 213b and an expiratory flow sensor disposed in the expiratory branch 213a for a ventilator, and an inspiratory flow sensor disposed in the inspiratory branch 340b and an expiratory flow sensor disposed in the expiratory branch 340a for an anesthesia machine; the gas flow rate is the difference in flow rates acquired by the inspiratory flow sensor and the expiratory flow sensor during inspiration. In some embodiments, the flow sensor 30 may also be a Ypiece flow sensor, which measures the flow rate into and out of the patient as the gas flow rate directly. Of course, the energy applied to the patient's respiratory system during mechanical ventilation may be calculated taking into account the gas flow rate during the entire breath, including during inspiration and during expiration.

The number of pressure sensors 10 is one or more in some embodiments. Pressure sensor 10 is used to acquire patient pressure during ventilation, which reflects the pressure applied to various points in the patient's respiratory system during ventilation, such as one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, and gastric pressure.

In some embodiments, the pressure sensor 10 may be a catheter-type pressure sensor or a fiber optic pressure sensor, or the like, that can be used to acquire pressure to a site in the patient's respiratory system by extending the pressure sensor into the site. For example, stretch into patient's air flue with pressure sensor then can gather the air flue and press, stretch into the esophagus with pressure sensor then can gather the esophagus and press, stretch into the stomach with pressure sensor then can gather the intragastric pressure, stretch into tracheal inside carina department with pressure sensor, then can gather carina pressure, stretch into the stomach with pressure sensor then can gather intragastric pressure, stretch into the thorax through wounding incision etc. then can gather intrathoracic pressure with pressure sensor. Of course, esophageal pressure may also be used as an approximate alternative to intrathoracic pressure. Some embodiments may also replace or calculate the pressure at some other location in the respiratory system by the pressure at some other location, as described below by way of a few examples.

In some embodiments, carina pressure may be used in place of intra-pulmonary pressure. In some embodiments, esophageal pressure may be used instead of intrathoracic pressure. In some embodiments, intragastric pressure may be used in place of intraabdominal pressure.

In some embodiments, processor 50 may calculate the intrapulmonary pressure based on the airway pressure. For example, in some embodiments, processor 50 performs the calculation of the intrapulmonary pressure from the airway pressure, respiratory resistance, and gas flow rates described above. In one specific example, this can be calculated by the following formula:

Plung(t)＝Paw(t)-Raw*Flow(t)；

wherein Plung (t) refers to the change in intra-pulmonary pressure as a function of time t, or real-time intra-pulmonary pressure; paw (t) refers to the change in airway pressure as a function of time tOr real-time airway pressure; flow (t) is a function of the patient's gas Flow rate during ventilation over time t, or is the patient's real-time gas Flow rate during ventilation; PEEP is end-expiratory positive airway pressure, which may be cmH ₂ O; raw is respiratory resistance.

In some embodiments, processor 50 may calculate the transpulmonary pressure by subtracting either the esophageal pressure or the intrathoracic pressure from either the intra-pulmonary pressure or the airway pressure. Transpulmonary pressure is obtained, for example, by subtracting esophageal pressure from airway pressure. In some embodiments, the processor 50 may also correct for cross-lung pressure, as described in more detail below.

In some embodiments, processor 50 also corrects for transpulmonary pressure by airway and esophageal pressure values in the state where positive end expiratory pressure is zero and non-zero; specifically, the processor 50 obtains the airway pressure Paw in a state where the positive end-expiratory pressure is non-zero _PEEP And esophageal pressure Pes _PEEP And acquiring the airway pressure Paw under the condition that the positive end expiratory pressure is zero _ZEEP And esophageal pressure Pes _ZEEP (ii) a The processor 50 adds (Paw) the transpulmonary pressure _PEEP -Paw _ZEEP ) And subtract (Pes) _PEEP -Pes _ZEEP ) Obtaining the corrected transpulmonary pressure.

In some embodiments, processor 50 also corrects the cross-lung pressure value by lung compliance and chest wall compliance; specifically, the processor 50 acquires the lung compliance mount and the chest wall compliance Ccw; it should be noted that there are various methods for the processor 50 to obtain the lung compliance mount and the chest wall compliance Ccw, for example, the processor 50 may obtain the chest wall compliance Ccw by the following formula:

wherein TV is tidal volume, pesI is end-inspiratory esophageal pressure, PEEP _es End-tidal esophageal pressure;

then can pass throughThe total compliance C is calculated by the following formula _state ：

Wherein TV is tidal volume, pplt is plateau pressure, PEEP is positive end-expiratory airway pressure; the total compliance C is obtained through calculation _state And chest wall compliance Ccw, the lung compliance mount can be calculated by solving the following equation:

after obtaining the lung compliance mount and the chest wall compliance Ccw, the processor 50 may calculate an error compensation value by the following equation:

wherein Δ Ptrans _erro For error compensation, ptrans is the transpulmonary pressure value, and Plung is the intrapulmonary pressure value;

the processor 50 subtracts the error compensation value from the transpulmonary pressure to obtain a corrected transpulmonary pressure.

In some embodiments, processor 50 may calculate the trans-diaphragmatic pressure by subtracting either intra-abdominal pressure or intra-gastric pressure from either intra-thoracic pressure or intra-esophageal pressure. Transphrenic pressure is obtained, for example, by subtracting intra-gastric pressure from esophageal pressure. It should be noted that in some embodiments, the intra-abdominal pressure may be collected by inserting the pressure sensor through a wound incision or the like into the abdomen. In some embodiments, the processor 50 may also correct for trans-phrenic pressure. For example, the processor 50 obtains the esophageal pressure Pes in a state that the positive end expiratory pressure is non-zero _PEEP And stomach interior pressure Psto _PEEP And obtaining the esophagus in a state where the positive end-expiratory pressure is zeroPressure Pes _ZEEP And stomach interior pressure Psto _ZEEP (ii) a The processor 50 will add (Pes) to the trans-phrenic pressure _PEEP -Pes _ZEEP ) And subtract (Psto) _PEEP -Psto _ZEEP ) And obtaining the corrected trans-phrenic pressure.

The above are some of the descriptions of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, and intragastric pressure, intraabdominal pressure, transpulmonary pressure, and transphrenic pressure.

In the present invention, the processor 50 receives signals from the pressure sensor 30 and the flow sensor 10 and calculates the energy applied to the patient's respiratory system during mechanical ventilation based on the collected pressure and gas flow rate. In some embodiments, processor 50 integrates the collected pressure and gas flow rate to derive the energy applied to the patient's respiratory system during mechanical ventilation. In some embodiments, processor 50 integrates the acquired pressure and gas flow rate over a preset unit of time, such as 1 minute, to obtain the energy of the mechanical ventilation acting on the patient's respiratory system. In some embodiments, processor 50 may integrate the acquired pressure and gas flow rate over a respiratory cycle to obtain the energy of the mechanical ventilation acting on the patient's respiratory system. Alternatively, the processor 50 may integrate the acquired pressure and gas flow rate over a respiratory cycle and multiply the respiratory rate to obtain the energy of the mechanical ventilation applied to the patient's respiratory system. In this context, integrating the pressure and gas flow rate acquired during a respiratory cycle, and multiplying by the respiratory rate for a simple statistical cycle, also belongs to the way of integrating the acquired pressure and gas flow rate during a respiratory cycle. The calculation of the energy applied by the mechanical ventilation to the respiratory system of a patient is further described below in connection with the pressures at different points in the respiratory system.

In some embodiments, processor 50 calculates the energy of the mechanical ventilation acting on the patient's respiratory system based on the airway pressure and the gas flow rate. For example, the energy of mechanical ventilation acting on the respiratory system of a patient is obtained by integrating the airway pressure and the gas flow rate, and the formula is as follows:

wherein Energy _rs Mechanical ventilation, which is integrated from airway pressure and gas Flow rate for a single cycle, imparts energy to the patient's respiratory system, tinsp is the inspiratory time of each respiratory cycle, paw is airway pressure, and Flow is gas Flow rate. Of course, the calculated energy in combination with the respiration rate for a single cycle can also be converted into the amount per minute, and the formula is as follows:

wherein the airway pressure Paw is expressed in cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power of mechanical ventilation applied to respiratory system of patient from integral of airway pressure and gas flow rate _rs Has the unit of J/min, due to 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Of course, it is also possible to directly add energy of all cycles in 1 minute to obtain energy per minute.

In some embodiments, the energy applied to the respiratory system of the patient by the mechanical ventilation may be calculated based on the airway pressure and the gas flow rate, and the potential energy generated by the tidal volume portion formed by the positive end-expiratory pressure may be considered, and the energy of the tidal volume portion is generally a fixed value and does not vary with the mechanical ventilation, and may be omitted because additional positive end-expiratory pressure delivery is required. When this part of the potential energy is considered, the above formula becomes:

and (3) obtaining the energy per minute after unit conversion by combining the respiration rate:

PEEP of these two formulae _Volume The tidal volume caused by the positive end-expiratory pressure is L, and specifically is the volume exhaled when the positive end-expiratory pressure drop is 0; PEEP is positive end-expiratory pressure.

Calculating the energy of the mechanical ventilation acting on the respiratory system of the patient from the airway pressure and the gas flow rate may represent the energy of the mechanical ventilation acting on the entire respiratory system of the patient, e.g. the total energy acting on the trachea, chest wall, lungs, etc. of the patient.

In some embodiments, the processor 50 calculates the energy applied to the respiratory system of the patient by the mechanical ventilation according to the intra-pulmonary pressure and the gas flow rate, it should be noted that the intra-pulmonary pressure can be acquired by the pressure sensor 10, or can be estimated through the gas pressure channel, etc., which has been described in detail above and will not be described herein again. In some examples, the integration of the intra-pulmonary pressure and the gas flow rate results in the energy of the mechanical ventilation applied to the patient's respiratory system, and the formula is as follows:

wherein Energy _lung The mechanical ventilation integrated from the intra-pulmonary pressure and the gas Flow rate for a single cycle exerts energy on the patient's respiratory system, tinsp is the inspiratory time of each respiratory cycle, plung is the intra-pulmonary pressure, and Flow is the gas Flow rate. Of course, the calculated energy of a single cycle may be converted into energy per minute in combination with the respiration rate, and the formula is as follows:

wherein the unit of the pulmonary pressure Plung is cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of minutes; power, the energy of mechanical ventilation effected on the respiratory system of a patient, obtained by integration of the intrapulmonary pressure and the gas flow rate _lung The unit of (b) may be J/min, since 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Of course, the energy per second or hour may be calculated according to specific needs, and in this case, the corresponding unit is J/s or J/h. Correspondingly, the coefficient 0.098 in the above formula corresponds to other values converted by the unit.

In some embodiments, the energy of mechanical ventilation applied to the respiratory system of the patient is calculated based on the intra-pulmonary pressure and the gas flow rate, and the potential energy generated by the tidal volume fraction of the end-tidal intra-pulmonary pressure is also considered, and is generally a fixed value and does not vary with the mechanical ventilation, and therefore is often omitted. When this portion of the potential energy is considered, the above equation becomes:

PlungE in these two equations _Volume The tidal volume caused by the end-expiratory intrapulmonary pressure is L, and specifically the expired volume when the pressure drop in the end-expiratory lung is 0; plougE is the end-expiratory lung pressure.

Calculating the energy of the mechanical ventilation acting on the respiratory system of the patient from the intra-pulmonary pressure and the gas flow rate may represent the energy of the mechanical ventilation acting on the lungs and chest wall in the respiratory system of the patient.

In some embodiments, the processor 50 calculates the energy of the mechanical ventilation applied to the patient's respiratory system based on the transpulmonary pressure and the gas flow rate values. For example, integrating the transpulmonary pressure and the gas flow rate to obtain the energy of the mechanical ventilation acting on the respiratory system of the patient, the formula is as follows:

wherein Energy _tr Energy applied to the patient's respiratory system by mechanical ventilation integrated from transpulmonary pressure and gas flow rate for a single cycle; tinsp is the inspiratory time of each respiratory cycle, ptrans is the transpulmonary pressure, and Flow is the gas Flow rate. Of course, the energy calculated in a single cycle may be converted into energy per minute in combination with the respiration rate, and the formula is as follows

Wherein the unit of transpulmonary pressure Ptrans is cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power of mechanical ventilation acting on respiratory system of patient obtained by integrating transpulmonary pressure and gas flow rate _tr Has the unit of J/min, due to 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Also, the unit and the coefficient may be set as needed.

In some embodiments, the energy applied to the respiratory system of the patient by the mechanical ventilation is calculated based on the transpulmonary pressure and the gas flow rate, and the potential energy generated by the tidal volume fraction generated by the end-tidal transpulmonary pressure is also considered, and is usually a fixed value and does not vary with the mechanical ventilation, so that it can be omitted. When this portion of the potential energy is considered, the above equation becomes:

the unit conversion is carried out in combination with the respiration rate into energy per minute:

PtansE in these two formulae _volume The unit of tidal volume caused by the exhalation transpulmonary pressure is L, and specifically the volume exhaled when the end-exhalation transpulmonary pressure is reduced to 0; ptransE is the end-tidal transpulmonary pressure.

The energy of the mechanical ventilation acting on the patient's respiratory system is calculated from the cross-lung pressure and the gas flow rate and may represent the energy of the mechanical ventilation acting on the lungs in the patient's respiratory system.

In some embodiments, processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system from the trans-phrenic pressure and the gas flow rate values. For example, the energy of mechanical ventilation acting on the respiratory system of a patient is obtained by performing integral operation on the trans-diaphragmatic pressure and the gas flow rate, and the formula is as follows:

wherein Energy _di Energy acting on the patient's respiratory system by mechanical ventilation integrated from the trans-phrenic pressure and the gas flow rate for a single cycle; tinsp is the inspiratory time of each respiratory cycle, pdi is the trans-phrenic pressure, and Flow is the gas Flow rate. Of course, the energy calculated in a single cycle can be converted into energy per minute in combination with the respiration rate, and the formulaAs follows

Wherein the unit of the transpulmonary pressure Pdi is cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power, the energy of mechanical ventilation effected on the patient's respiratory system, obtained from the integral of the trans-diaphragmatic pressure and the gas flow rate _di Has the unit of J/min, due to 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Also, the unit and the coefficient may be set as needed.

In some embodiments, when calculating the energy applied to the respiratory system of the patient by the mechanical ventilation based on the trans-phrenic pressure and the gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory trans-phrenic pressure may be considered, and the energy is generally a fixed value and does not vary with the mechanical ventilation, so that it may be omitted. When this part of the potential energy is considered, the above formula becomes:

pdi E in these two equations _volume The unit of tidal volume caused by expiratory trans-diaphragmatic pressure is L, and specifically the volume exhaled when the end-expiratory trans-diaphragmatic pressure drop is 0; pdIE is the end-tidal trans-diaphragm pressure.

Calculating the energy of mechanical ventilation acting on the patient's respiratory system from the trans-diaphragmatic pressure and the gas flow rate may represent the energy of mechanical ventilation acting on the diaphragm in the patient's respiratory system.

The above is some of the description of calculating the energy of mechanical ventilation acting on the respiratory system of a patient.

The processor 50 calculates the energy of mechanical ventilation applied to the patient's respiratory system for a number of post-uses, as described in more detail below.

Some studies show that too high energy of mechanical ventilation acting on the respiratory system of a patient has a significant clinical correlation with lung injury, and particularly, some clinics show that when the energy of mechanical ventilation acting on the whole respiratory system of the patient is more than 25J/min, or the energy of mechanical ventilation acting on the lung in the respiratory system of the patient is more than 12J/min or 13J/min, and the like, the lung injury is caused significantly; some clinics have shown that mechanical ventilation significantly increases patient mortality when the energy applied to the patient's entire respiratory system is greater than 17J/min.

Thus, in some embodiments, the display 70 displays the calculated energy of the mechanical ventilation acting on the respiratory system of the patient, for example, displays a real-time value of the energy of the mechanical ventilation acting on the respiratory system of the patient and/or displays a change of the energy of the mechanical ventilation acting on the respiratory system of the patient over time, for example, may display a trend graph, a trend chart, or the like of the change of the energy of the mechanical ventilation acting on the respiratory system of the patient. An observer, such as a doctor or the like, can evaluate and judge the current degree and condition of lung damage based on the displayed energy of mechanical ventilation acting on the patient's respiratory system.

In some embodiments, processor 50 may alarm based on the energy applied to the patient's respiratory system by mechanical ventilation. The processor 50 alarms, for example, when it determines that the energy applied to the patient's respiratory system by mechanical ventilation exceeds a first threshold; and/or processor 50 may alarm when the energy applied to the patient's respiratory system by mechanical ventilation is determined to be below a second threshold. The manner in which the processor 50 alerts may be varied, for example, the processor 50 may control the display 70 to display an alert message. The first threshold and the second threshold may be set by a user in some embodiments.

In some embodiments, the processor 50 may determine the patient condition based on the energy applied to the patient's respiratory system by the mechanical ventilation. In some embodiments, processor 50 determines the patient condition based on a real-time value and/or trend of change of the energy applied to the patient's respiratory system by the mechanical ventilation. For example, in the case that the ventilation parameters are not changed, when it is determined that the variation trend of the energy applied to the respiratory system of the patient by the mechanical ventilation in the preset time period is decreased, the processor 50 determines that the condition of the patient is improving, and generates corresponding prompt information; and/or, under the condition that the ventilation parameters are not changed, when the change trend of the energy of the mechanical ventilation acting on the respiratory system of the patient in the preset time period is judged to be increased, the processor 50 judges that the state of the patient is deteriorated and generates corresponding prompt information. It should be noted that the ventilation parameters refer to parameters of mechanical ventilation performed by the control device, especially when the respiration monitoring device is a ventilator or an anesthesia machine, and typically include parameters such as tidal volume, inspiratory flow rate, driving pressure, positive end expiratory pressure, and expiratory ratio.

The foregoing are some illustrations of the respiratory monitoring device disclosed herein. In some embodiments of the invention, a respiration monitoring method is also disclosed.

FIG. 5 is a flow chart of a respiration monitoring method according to some embodiments of the invention, the method comprising the steps of:

step 100, acquiring the gas flow rate of the patient during the ventilation process.

The gas flow rate includes at least the inspiratory flow rate of the patient, and of course, may also include the flow rate during inspiration and during expiration by the patient. The gas flow rate can be acquired by the flow sensor 30.

Step 200, acquiring a pressure of a patient during ventilation.

The pressure reflects the pressure applied to various points in the patient's respiratory system during ventilation, such as one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, and gastric pressure. The various pressures described above can be acquired by the pressure sensor 10.

In some embodiments, the pressure sensor 10 may be a catheter-type pressure sensor or a fiber optic pressure sensor, or the like, that can be used to measure pressure to a corresponding site in the patient's respiratory system by extending the pressure sensor into the corresponding site. For example, stretch into patient's air flue with pressure sensor then can gather the air flue and press, stretch into the esophagus with pressure sensor then can gather the esophagus and press, stretch into the stomach with pressure sensor then can gather the intragastric pressure, stretch into tracheal inside carina department with pressure sensor, then can gather carina pressure, stretch into the stomach with pressure sensor then can gather intragastric pressure, stretch into the thorax through wounding incision etc. then can gather intrathoracic pressure with pressure sensor. Some embodiments may also replace or calculate the pressure at some other location in the respiratory system by the pressure at some other location, as described below by way of a few examples.

In some embodiments, step 200 may calculate the intrapulmonary pressure based on the airway pressure. For example, in some embodiments, step 200 performs the calculation of the intra-pulmonary pressure from the airway pressure, respiratory system resistance, and gas flow rates described above. In one specific example, this can be calculated by the following formula:

Plung(t)＝Paw(t)-Raw*Flow(t)；

wherein Plung (t) refers to the change in pulmonary pressure as a function of time t, or real-time pulmonary pressure; paw (t) refers to the function of airway pressure as a function of time t, or real-time airway pressure; flow (t) is a function of the patient's gas Flow rate during ventilation over time t, or is the patient's real-time gas Flow rate during ventilation; raw is respiratory resistance.

In some embodiments, step 200 may calculate the transpulmonary pressure by subtracting either the esophageal pressure or the intrathoracic pressure from either the intra-pulmonary pressure or the airway pressure. Transpulmonary pressure is obtained, for example, by subtracting esophageal pressure from airway pressure.

In some embodiments, step 200 may calculate the trans-diaphragmatic pressure by subtracting either intra-abdominal pressure or intra-gastric pressure from either intra-thoracic pressure or intra-esophageal pressure. Transphrenic pressure is obtained, for example, by subtracting intra-gastric pressure from esophageal pressure. It should be noted that in some embodiments, the intra-abdominal pressure may be collected by inserting the pressure sensor through a wound incision or the like into the abdomen.

Some embodiments may correct the pressure before using the acquired pressure of the patient in the calculation, for example, fig. 6 is an example, and the pressure may be corrected by introducing step 210, in order to make the energy applied to the respiratory system of the patient more accurate during the mechanical ventilation calculation.

Step 210, correcting the acquired pressure of the patient. Step 210 may be to correct for transpulmonary pressure, transphrenic pressure, etc., as described in more detail below.

For example, after the transpulmonary pressure of the patient is obtained in step 200, the transpulmonary pressure is corrected. The manner of correcting the transpulmonary pressure will be described in detail below by way of example.

In some embodiments, step 210 corrects for transpulmonary pressure by airway and esophageal pressure values at zero and non-zero positive end expiratory pressure; specifically, step 210 acquires the airway pressure Paw in a state where the positive end-expiratory pressure is non-zero _PEEP And esophageal pressure Pes _PEEP And acquiring the airway pressure Paw under the condition that the positive end expiratory pressure is zero _ZEEP And esophageal pressure Pes _ZEEP (ii) a Step 210 adds (Paw) to the transpulmonary pressure _PEEP -Paw _ZEEP ) And subtract (Pes) _PEEP -Pes _ZEEP ) Obtaining the corrected transpulmonary pressure.

In some embodiments, step 210 further corrects the cross-lung pressure value by lung compliance and chest wall compliance; specifically, step 210 obtains lung compliance mount and chest wall compliance Ccw; it should be noted that there are various methods for obtaining the lung compliance mount and the chest wall compliance Ccw in step 210, for example, the chest wall compliance Ccw can be obtained in step 210 by the following formula:

the total compliance C can then be calculated by the following equation _state ：

Wherein TV is tidal volume, plat is plateau pressure, PEEP is positive end-expiratory airway pressure; the total compliance C is obtained through calculation _state And chest wall compliance Ccw, the lung compliance mount can be calculated by solving the following equation:

step 210 subtracts the error compensation value from the transpulmonary pressure to obtain a corrected transpulmonary pressure.

For another example, after the trans-phrenic pressure of the patient is acquired in step 200, the trans-phrenic pressure is corrected. The following examples will specifically explain the manner of correcting the trans-phrenic pressure.

Step 210 acquires the esophageal pressure Pes in the state that the positive end expiratory pressure is non-zero _PEEP And gastric intrapressor Psto _PEEP And obtaining positive end-expiratory pressure ofEsophageal pressure Pes at zero state _ZEEP And stomach interior pressure Psto _ZEEP (ii) a Step 210 adds (Pes) to the trans-phrenic pressure _PEEP -Pes _ZEEP ) And subtract (Psto) _PEEP -Psto _ZEEP ) And obtaining the corrected trans-phrenic pressure.

In some embodiments, step 210 may be omitted, i.e., the acquired patient pressure is not corrected, for example, fig. 5 is an example without step 210, and fig. 6 is an example with step 210.

And step 300, calculating the energy acting on the respiratory system of the patient during the mechanical ventilation process according to the acquired pressure and the acquired gas flow rate.

In some embodiments, step 300 integrates the collected pressure and gas flow rate over a preset unit of time, such as 1 minute, to obtain the energy of mechanical ventilation applied to the patient's respiratory system. In some embodiments, step 300 integrates the acquired pressure and gas flow rate over a respiratory cycle and multiplies the respiratory rate to obtain the energy of the mechanical ventilation acting on the patient's respiratory system. Of course, step 300 may also integrate the collected pressure and gas flow rate over a respiratory cycle to obtain the energy of the mechanical ventilation acting on the patient's respiratory system. The calculation of the energy applied by the mechanical ventilation to the respiratory system of a patient will be further described below in connection with the pressures at different points in the respiratory system.

In some embodiments, step 300 calculates the energy of the mechanical ventilation acting on the respiratory system of the patient according to the airway pressure and the gas flow rate, and in particular, step 300 integrates the airway pressure and the gas flow rate to obtain the energy of the mechanical ventilation acting on the respiratory system of the patient, where the formula is as follows:

wherein Energy _rs The energy applied to the respiratory system of a patient by mechanical ventilation obtained by integrating the airway pressure and the gas flow rate for a single cycle, tinsp being per cycleInspiratory time of each respiratory cycle, paw is airway pressure and Flow is gas Flow rate. Of course, the calculated energy in combination with the respiration rate for a single cycle can also be converted into the amount per minute, and the formula is as follows:

wherein the airway pressure Paw is expressed in cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power of mechanical ventilation applied to respiratory system of patient obtained by integrating airway pressure and gas flow rate _rs Has the unit of J/min, due to 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Of course, it is also possible to directly add energy of all cycles in 1 minute to obtain energy per minute.

In some embodiments, the energy applied to the respiratory system of the patient by the mechanical ventilation is calculated based on the airway pressure and the gas flow rate, and the potential energy generated by the tidal volume fraction generated by the positive end-expiratory pressure is also considered, and the potential energy is generally a fixed value and does not change with the mechanical ventilation, and is often omitted because additional positive end-expiratory pressure release is required. When this part of the potential energy is considered, the above formula becomes:

and (4) performing unit conversion by combining the respiration rate to obtain energy per minute:

PEEP of these two formulae _Volume The tidal volume caused by the positive end-expiratory pressure is L, and specifically the volume exhaled when the positive end-expiratory pressure drop is 0; PEEP is positive end-expiratory pressure.

In some embodiments, step 300 calculates the energy applied to the respiratory system of the patient by the mechanical ventilation according to the lung pressure and the gas flow rate, where it is noted that the lung pressure may be acquired by the pressure sensor 10, or may be estimated through the air pressure channel, etc., which has been described in detail above and will not be described herein again. In some examples, the integration of the intra-pulmonary pressure and the gas flow rate is used to obtain the energy of the mechanical ventilation applied to the respiratory system of the patient, and the formula is as follows:

wherein the unit of the pulmonary pressure Plung is cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power, the energy of mechanical ventilation effected on the respiratory system of a patient, obtained by integration of the intrapulmonary pressure and the gas flow rate _lung Can be made ofIs J/min, since 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Of course, the energy per second or hour may be calculated according to specific needs, and in this case, the corresponding unit is J/s or J/h. Correspondingly, the coefficient 0.098 in the above formula corresponds to other values converted by the unit.

In some embodiments, the energy applied to the respiratory system of the patient by the mechanical ventilation may be calculated based on the intra-pulmonary pressure and the gas flow rate, taking into account the potential energy generated by the portion of tidal volume resulting from the end-expiratory intra-pulmonary pressure, which is generally a fixed value and does not vary with the mechanical ventilation, and therefore may often be omitted. When this portion of the potential energy is considered, the above equation becomes:

PlungE in these two equations _Volume The tidal volume caused by the end-expiratory intrapulmonary pressure is expressed in L, and specifically, the volume expired when the pressure drop in the end-expiratory lung is 0; plougE is the end-expiratory pulmonary pressure.

In some embodiments, step 300 calculates the energy of the mechanical ventilation acting on the patient's respiratory system from the cross-lung pressure and the gas flow rate values. For example, the energy of the mechanical ventilation acting on the respiratory system of the patient is obtained by integrating the transpulmonary pressure and the gas flow rate, and the formula is as follows:

In some embodiments, the energy applied to the respiratory system of the patient by the mechanical ventilation is calculated based on the transpulmonary pressure and the gas flow rate, and the potential energy generated by the tidal volume fraction generated by the end-tidal transpulmonary pressure is also considered, and is usually a fixed value and does not vary with the mechanical ventilation, so that it can be omitted. When this part of the potential energy is considered, the above formula becomes:

unit conversion to energy per minute in conjunction with respiration rate:

PtansE in these two formulae _volume The unit of tidal volume caused by the expiratory transpulmonary pressure is L, and specifically the volume expired when the end expiratory transpulmonary pressure is reduced to 0; ptransE is the end-tidal transpulmonary pressure.

The energy of the mechanical ventilation acting on the patient's respiratory system, calculated from the cross-lung pressure and the gas flow rate, may represent the energy of the mechanical ventilation acting on the lungs in the patient's respiratory system.

In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system from the trans-phrenic pressure and gas flow rate values. For example, the energy of mechanical ventilation acting on the respiratory system of a patient is obtained by performing integral operation on the trans-diaphragmatic pressure and the gas flow rate, and the formula is as follows:

wherein Energy _di Energy acting on the patient's respiratory system by mechanical ventilation integrated from the trans-phrenic pressure and the gas flow rate for a single cycle; tinsp is the inspiratory time of each respiratory cycle, pdi is the trans-phrenic pressure, and Flow is the gas Flow rate. Of course, the energy calculated in a single cycle may be converted into energy per minute in combination with the respiration rate, and the formula is as follows

Wherein the unit of transpulmonary pressure Pdi is cmH ₂ O; the unit of the gas Flow rate Flow is L/min; the inspiration time Tinsp for each respiratory cycle is in units of s; RR is the respiratory rate in units of per minute; power, the energy of mechanical ventilation effected on the patient's respiratory system, obtained from the integral of the trans-diaphragmatic pressure and the gas flow rate _di Unit of (2)J/min, due to 1cmH ₂ O1L/min =0.098J/min, so there is a factor of 0.098 in the above formula. Also, the unit and the coefficient may be set as needed.

unit conversion to energy per minute in conjunction with respiration rate:

pdi E in these two equations _volume The tidal volume caused by the expiratory trans-diaphragm pressure is L, and specifically the expired volume when the end-expiratory trans-diaphragm pressure drop is 0; pdiE is the end-tidal trans-diaphragm pressure.

Calculating the energy of the mechanical ventilation acting on the respiratory system of the patient according to the trans-diaphragmatic pressure and the gas flow rate can represent the energy of the mechanical ventilation acting on the diaphragm muscle in the respiratory system of the patient.

After calculating the energy of the mechanical ventilation applied to the respiratory system of the patient in step 300, there are a number of subsequent applications depending on the energy, and therefore referring to fig. 7, in some embodiments, the respiration monitoring method may further include step 310 of applying the energy of the mechanical ventilation applied to the respiratory system of the patient.

Step 310 utilizes the energy of the mechanical ventilation applied to the patient's respiratory system, which may be displayed, used to alarm and indicate the patient's condition, etc. Thus, referring to fig. 8, in some embodiments, step 310 may include one or more of steps 311 through 313, as described in more detail below.

Step 311, displaying the energy of the mechanical ventilation acting on the respiratory system of the patient.

In some embodiments, step 311 displays the calculated energy of the mechanical ventilation acting on the respiratory system of the patient, for example, displays a real-time value of the energy of the mechanical ventilation acting on the respiratory system of the patient and/or displays a time variation of the energy of the mechanical ventilation acting on the respiratory system of the patient, for example, may display a trend graph, a trend table, and the like of the time variation of the energy of the mechanical ventilation acting on the respiratory system of the patient. An observer, such as a physician, can evaluate and determine the current degree and condition of lung injury based on the displayed energy of mechanical ventilation acting on the patient's respiratory system.

An alarm is generated based on the energy applied to the patient's respiratory system by the mechanical ventilation, step 312.

In some embodiments, step 312 may alert based on the energy applied to the patient's respiratory system by mechanical ventilation. Step 312 provides an alarm, for example, when it is determined that the energy applied to the patient's respiratory system by mechanical ventilation exceeds a first threshold; and/or, when it is determined that the energy applied to the patient's respiratory system by mechanical ventilation is below a second threshold, an alarm is generated at step 312.

The manner in which the alarm is generated at step 312 can be varied, for example, step 312 can control the display of an alarm message. The first threshold and the second threshold may be set by a user in some embodiments.

313, determining the condition of the patient based on the energy applied to the respiratory system of the patient by the mechanical ventilation.

In some embodiments, step 313 may determine the patient condition based on the energy applied to the patient's respiratory system by mechanical ventilation. In some embodiments, step 313 determines the condition of the patient based on the real-time value and/or trend of the energy applied to the patient's respiratory system by the mechanical ventilation.

For example, under the condition that the ventilation parameters are not changed, when it is determined that the variation trend of the energy applied to the respiratory system of the patient by the mechanical ventilation in the preset time period is decreased, step 313 determines that the condition of the patient is improved, and generates corresponding prompt information; and/or, under the condition that the ventilation parameters are not changed, when the trend of the change of the energy of the mechanical ventilation acting on the respiratory system of the patient in the preset time period is judged to be increased, the step 313 judges that the illness state of the patient is worsened, and generates corresponding prompt information. The ventilation parameters refer to parameters for mechanical ventilation by the control device, particularly when the respiration monitoring device is a ventilator or an anesthesia machine, and typically include parameters such as tidal volume, inspiratory flow rate, driving pressure, end-expiratory positive pressure, and expiratory ratio.

As described above, one or more of the steps 311 to 313 may be selectively performed by the user according to the actual condition of the patient.

By the respiration monitoring device and the respiration monitoring method, the pressure and the gas flow rate of the patient can be monitored in the ventilation process, and the energy acted on different parts of the respiratory system of the patient by mechanical ventilation can be obtained according to different types of pressure and gas flow rate of the patient, so that the lung injury can be evaluated accurately, truly and in real time, and further, information such as the numerical value of the energy can be analyzed for subsequent work such as alarming and disease condition judgment.

Reference is made herein to various exemplary embodiments. However, those skilled in the art will recognize that changes and modifications may be made to the exemplary embodiments without departing from the scope hereof. For example, the various operational steps, as well as the components used to perform the operational steps, may be implemented in differing ways depending upon the particular application or consideration of any number of cost functions associated with operation of the system (e.g., one or more steps may be deleted, modified or incorporated into other steps).

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. Additionally, as will be appreciated by one skilled in the art, the principles herein may be reflected in a computer program product on a computer readable storage medium, which is pre-loaded with computer readable program code. Any tangible, non-transitory computer-readable storage medium may be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-to-ROM, DVD, blu Ray disc, etc.), flash memory, and/or the like. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including means for implementing the function specified. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified.

While the principles herein have been illustrated in various embodiments, many modifications of structure, arrangement, proportions, elements, materials, and components and otherwise, used in the practice of the disclosure, which are particularly adapted to specific environments and operative requirements, may be employed without departing from the principles and scope of the present disclosure. The above modifications and other changes or modifications are intended to be included within the scope of this document.

The foregoing detailed description has been described with reference to various embodiments. However, one skilled in the art will recognize that various modifications and changes may be made without departing from the scope of the present disclosure. Accordingly, the disclosure is to be considered in all respects as illustrative and not restrictive, and all such modifications are intended to be included within the scope thereof. Also, advantages, other advantages, and solutions to problems have been described above with regard to various embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any element(s) to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, system, article, or apparatus. Furthermore, the term "coupled," and any other variation thereof, as used herein, refers to a physical connection, an electrical connection, a magnetic connection, an optical connection, a communicative connection, a functional connection, and/or any other connection.

Those skilled in the art will recognize that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. Accordingly, the scope of the invention should be determined only by the following claims.

Claims

Further comprising: displaying the energy of the mechanical ventilation acting on the respiratory system of the patient.
The respiration monitoring method of claim 9, wherein the displaying the energy of the mechanical ventilation acting on the respiratory system of the patient comprises: displaying a real-time value of the energy applied to the patient's respiratory system by the mechanical ventilation and/or displaying a change in the energy applied to the patient's respiratory system by the mechanical ventilation over time.
The respiratory monitoring method of any one of claims 1 to 8, further comprising: an alarm is generated based on the energy applied to the patient's respiratory system by the mechanical ventilation.
The respiratory monitoring method of claim 11, wherein the alerting based on the energy applied to the respiratory system of the patient by the mechanical ventilation comprises:

when the energy of the mechanical ventilation acting on the respiratory system of the patient is judged to exceed a first threshold value, alarming; and/or the presence of a gas in the atmosphere,

and when the energy of the mechanical ventilation acting on the respiratory system of the patient is judged to be lower than the second threshold value, alarming.
The respiration monitoring method of any one of claims 1-8, further comprising: the condition of the patient is judged according to the energy of the mechanical ventilation acting on the respiratory system of the patient.
The respiratory monitoring method of claim 13, wherein determining the patient condition based on the energy of the mechanical ventilation acting on the patient's respiratory system comprises:

the patient condition is determined based on the real-time value and/or trend of change of the energy applied to the patient's respiratory system by the mechanical ventilation.
A respiratory monitoring device, comprising:

a pressure sensor for acquiring the pressure of the patient during the ventilation process, wherein the pressure reflects the pressure acting on different sites of the respiratory system of the patient during the ventilation process;

the flow sensor is used for acquiring the gas flow rate of a patient in the ventilation process;

a processor for acquiring the pressure of the patient during ventilation and the flow rate of gas during ventilation of the patient, and calculating the energy acting on the respiratory system of the patient during mechanical ventilation from the acquired pressure and flow rate of gas.
The respiratory monitoring device of claim 15, wherein the pressures at the different sites include one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, intragastric pressure, transpulmonary pressure, and transphrenic pressure.
The respiratory monitoring device of claim 15, wherein the gas flow rate comprises at least an inspiratory flow rate.
The respiratory monitoring device of any one of claims 15 to 17, wherein the processor integrates the pressure and gas flow rate to derive the energy applied to the patient's respiratory system during mechanical ventilation.
The respiratory monitoring device of claim 18, further comprising a display for displaying the energy applied to the patient's respiratory system by the mechanical ventilation.
The respiratory monitoring device of any one of claims 15 to 17, wherein the processor further alarms and/or determines a patient condition based on energy applied to the patient's respiratory system by mechanical ventilation.
The respiratory monitoring device of claim 15, wherein the respiratory monitoring device comprises a patient monitor, a patient monitoring module, or a medical ventilator.
A computer-readable storage medium, characterized by comprising a program executable by a processor to implement the method of any one of claims 1 to 14.