Method and device for performing ventilation monitoring on patient

Abstract

A method and apparatus for performing ventilation monitoring on a patient may include: acquiring pressure (200) of the patient during ventilation, the pressure reflecting pressure acting on different sites of a respiratory system of the patient during ventilation; acquiring a gas flow rate of the patient during ventilation (100); calculating energy acting on the respiratory system of the patient in the mechanical ventilation process according to the acquired pressure and gas flow rate (300); acquiring ventilation parameters (400); a contribution of the ventilation parameter to energy acting on the respiratory system of the patient during mechanical ventilation is determined (500).

Description

[0001] This application is a divisional application of the following parent case:

[0002] The parent application was filed on March 23, 2020, with the Chinese application number 202080098485.6 (international application number PCT / CN2020 / 080701) and the title "A method and apparatus for monitoring ventilation in patients". Technical Field

[0003] This invention relates to a method and apparatus for monitoring ventilation in patients. Background Technology

[0004] Human respiration refers to the periodic and rhythmic inhalation and exhalation of gases, absorbing oxygen and expelling carbon dioxide, thereby achieving gas exchange. When some patients are unable to breathe spontaneously, mechanical ventilation can assist them in completing their breathing. For example, in cases where patients cannot breathe spontaneously, external devices such as ventilators can typically provide respiratory support. Mechanical ventilation is a ventilation method that uses mechanical devices to replace, control, or assist a patient's spontaneous breathing movements. However, mechanical ventilation can also easily cause ventilator-induced lung injury (VILI). Typically, inappropriate settings of related mechanical devices, such as ventilators, during mechanical ventilation can cause lung injury. Therefore, how to control, adjust, and set the parameters of related mechanical devices to avoid lung injury caused by mechanical ventilation, and even to improve lung-related parameters, is a problem that engineers have been researching continuously. Summary of the Invention

[0005] This invention mainly provides a method and apparatus for monitoring ventilation in patients.

[0006] According to the first aspect, one embodiment provides a method for monitoring ventilation in a patient, comprising:

[0007] Acquire the pressure of the patient during ventilation, the pressure reflecting the pressure acting on different sites of the patient's respiratory system during ventilation;

[0008] Obtain the gas flow rate of the patient during ventilation;

[0009] The energy acting on the patient's respiratory system during mechanical ventilation is calculated based on the obtained pressure and gas flow rate.

[0010] Obtain ventilation parameters;

[0011] Determine the contribution of ventilation parameters to the energy exerted on the patient's respiratory system during mechanical ventilation.

[0012] In one embodiment, the ventilation parameters include ventilation control parameters and / or respiratory system-related parameters; the ventilation control parameters include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio; and the respiratory system-related parameters include one or more of respiratory system compliance and respiratory system resistance.

[0013] In one embodiment, the method for monitoring ventilation in a patient further includes displaying the contribution of each ventilation parameter.

[0014] In one embodiment, the contribution of each ventilation parameter is displayed using one or more of the following methods: text, numbers, characters, tables, graphs, or icons.

[0015] In one embodiment, the method for monitoring patient ventilation further includes: guiding mechanical ventilation based on the contribution.

[0016] In one embodiment, guiding mechanical ventilation based on the contribution includes:

[0017] When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds the first threshold, the ventilation parameters are reduced based on the contribution ranking, or the ventilation parameters are controlled to be reduced based on the contribution ranking.

[0018] In one embodiment, guiding mechanical ventilation based on the contribution includes:

[0019] When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below the second threshold, the ventilation parameters are increased based on the contribution ranking, or the ventilation parameters are increased based on the contribution ranking.

[0020] In one embodiment, guiding mechanical ventilation based on the contribution includes:

[0021] Based on the ventilation control parameter setting command, estimate and output the energy of the set mechanical ventilation acting on the patient's respiratory system.

[0022] In one embodiment, guiding mechanical ventilation based on the contribution level further includes:

[0023] The alarm is triggered based on the estimated energy exerted by mechanical ventilation on the patient's respiratory system.

[0024] In one embodiment, guiding mechanical ventilation based on the contribution includes:

[0025] Whether to issue an alarm is determined based on the contribution of each respiratory system-related parameter.

[0026] According to a second aspect, one embodiment provides a device for monitoring ventilation in a patient, comprising:

[0027] A pressure sensor collects the patient's pressure during ventilation, which reflects the pressure acting on different sites of the patient's respiratory system during ventilation.

[0028] A flow sensor collects the gas flow rate during ventilation.

[0029] The processor is used to acquire the patient's pressure and gas flow rate during ventilation, and to calculate the energy acting on the patient's respiratory system during mechanical ventilation based on the acquired pressure and gas flow rate; the processor also acquires ventilation parameters and determines the contribution of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

[0030] In one embodiment, the ventilation parameters include ventilation control parameters and / or respiratory system-related parameters; the ventilation control parameters include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio; and the respiratory system-related parameters include one or more of respiratory system compliance and respiratory system resistance.

[0031] In one embodiment, the device for monitoring the ventilation of the patient further includes a display for showing the contribution of each ventilation parameter.

[0032] In one embodiment, the processor also guides mechanical ventilation based on the contribution level.

[0033] In one embodiment, the processor guiding mechanical ventilation based on the contribution includes:

[0034] When the processor determines that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a first threshold, it prompts the processor to reduce the ventilation parameters based on contribution ranking, or controls the reduction of ventilation parameters based on contribution ranking; and / or,

[0035] When the processor determines that the energy exerted by mechanical ventilation on the patient's respiratory system is below a second threshold, it prompts the increase of ventilation parameters based on the contribution ranking, or controls the increase of ventilation parameters based on the contribution ranking.

[0036] In one embodiment, the processor guiding mechanical ventilation based on the contribution includes:

[0037] Based on the ventilation control parameter setting commands, the processor estimates and outputs the energy of the set mechanical ventilation applied to the patient's respiratory system.

[0038] In one embodiment, the processor guiding mechanical ventilation based on the contribution includes:

[0039] The alarm is triggered based on the estimated energy exerted by mechanical ventilation on the patient's respiratory system.

[0040] In one embodiment, the processor guiding mechanical ventilation based on the contribution includes:

[0041] The processor determines whether to issue an alarm based on the contribution of each respiratory system-related parameter.

[0042] In one embodiment, the device for monitoring the patient's ventilation is a patient monitor, a patient monitoring module, or a medical ventilation device.

[0043] According to a third aspect, one embodiment provides a computer-readable storage medium including a program that can be executed by a processor to implement the methods described in any of the embodiments herein. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of a device for monitoring the ventilation of a patient according to one embodiment.

[0045] Figure 2 This is a schematic diagram of a device for monitoring patient ventilation according to another embodiment;

[0046] Figure 3 This is a schematic diagram of a device for monitoring patient ventilation according to another embodiment;

[0047] Figure 4 This is a schematic diagram of a device for monitoring patient ventilation according to another embodiment;

[0048] Figure 5 This is a schematic diagram of the static pressure-volume curve of a respiratory system according to one embodiment;

[0049] Figure 6 This is a schematic diagram of the static pressure-volume curve of a respiratory system according to another embodiment;

[0050] Figures 7(a) and 7(b) are schematic diagrams showing two different ways of displaying contribution.

[0051] Figure 8 A flowchart illustrating a method for monitoring a patient's ventilation according to one embodiment;

[0052] Figure 9 A flowchart of a method for monitoring a patient's ventilation, according to another embodiment;

[0053] Figure 10 A flowchart of a method for monitoring ventilation in a patient according to another embodiment;

[0054] Figure 11 This is a flowchart illustrating a method for monitoring ventilation in a patient, according to yet another embodiment. Detailed Implementation

[0055] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0056] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0057] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0058] Some embodiments of the present invention disclose a device for monitoring the ventilation of a patient; please refer to [reference needed]. Figure 1 The device for monitoring patient ventilation may include a pressure sensor 10, a flow sensor 30, and a processor 50. The device for monitoring patient ventilation of the present invention can be applied to various situations. For example, in some embodiments, the device for monitoring patient ventilation of the present invention may be a patient monitor or a patient monitoring module, and in other embodiments, it may be a medical ventilation device, such as a ventilator or anesthesia machine, which will be described below.

[0059] In some embodiments, the device for monitoring the ventilation of a patient may be a patient monitor.

[0060] Please refer to Figure 2In some embodiments, the device for monitoring patient ventilation may have a separate housing. The housing panel may have a sensor interface area, which may integrate multiple sensor interfaces for connection to various external physiological parameter sensor accessories 111. In some embodiments, it may also be used to connect to pressure sensor 10 and flow sensor 30. The housing panel may also include one or more of the following: a small LCD display area, a display 70, an input interface circuit 122, and an alarm circuit 120 (such as an LED alarm area). The device for monitoring patient ventilation has an external communication interface 119 and a power interface 116 for communicating with and drawing power from medical device hosts such as patient monitors, ventilators, and anesthesia machines. The device for monitoring patient ventilation may also support external parameter modules. These modules can be inserted to form a plug-in monitor host, serving as part of the monitor, or connected to the host via a cable, with the external parameter module serving as an external accessory for the monitor. The internal circuitry of the device for monitoring patient ventilation is housed within a casing. It may include one or more signal acquisition circuits 112 and front-end signal processing circuits 113 corresponding to different physiological parameters. The signal acquisition circuits 112 can be selected from ECG circuits, respiratory circuits, body temperature circuits, blood oxygenation circuits, non-invasive blood pressure circuits, and invasive blood pressure circuits, etc. These signal acquisition circuits 112 are electrically connected to corresponding sensor interfaces for electrical connection to sensor accessories 111 corresponding to different physiological parameters. Their output terminals are 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. The processor 50 is electrically connected to an external communication interface 119 and a power interface 116. The sensor accessories 111 and signal acquisition circuits 112 corresponding to various physiological parameters can employ general-purpose circuits from the prior art. The front-end signal processing circuit 113 samples and converts the output signals of the signal acquisition circuits 112 to analog-to-digital conversion, and outputs control signals to control the measurement process of physiological signals. These parameters include, but are not limited to, ECG, respiration, body temperature, blood oxygenation, non-invasive blood pressure, and invasive blood pressure parameters. The front-end signal processing circuit 113 can be implemented using a microcontroller or other semiconductor devices, such as the PHLIPS LPC2136 or ADI ADuC7021 mixed-signal microcontrollers, or it can be implemented using an ASIC or FPGA. The front-end signal processing circuit 113 can be powered by an isolated power supply. After simple processing and packaging, the sampled data is sent to the processor 50 through an isolated communication interface. For example, the front-end signal processing circuit 113 can be coupled to the processor 50 through the isolated power supply interface 114 and the communication interface 115.The front-end signal processing circuit 113 is powered by an isolated power supply. This transformer-isolated DC / DC power supply isolates the patient from the power supply equipment. The main purposes are: 1. Isolating the patient by grounding the application section via the isolation transformer, ensuring sufficiently low leakage current; 2. Preventing voltage or energy from affecting the main control board and other intermediate circuit boards and components during defibrillation or electrosurgical applications (ensuring this through creepage distance and clearance). Alternatively, the front-end signal processing circuit 113 can also be directly connected to the processor 50 via a cable. The processor 50 is used to calculate physiological parameters and send the calculation results and waveforms to the host (such as a host with a display, PC, central station, etc.) through the external communication interface 119. The processor 50 can be directly connected to the external communication interface 119 for communication and directly connected to the power interface 116 for power supply through a cable. The device for monitoring the ventilation of patients may also include a power and battery management circuit 117, which draws power from the host through the power interface 116 and supplies it to the processor 50 after processing, such as rectification and filtering. The power and battery management circuit 117 can also monitor, manage and protect the power obtained from the host through the power interface 116. The external communication interface 119 can be one or a combination of Ethernet, Token Ring, Token Bus, and Fiber Distributed Data Interface (FDDI) as the backbone of these three networks; it can also be one or a combination of wireless interfaces such as infrared, Bluetooth, Wi-Fi, and WMTS communication; or it can be one or a combination of wired data connection interfaces such as RS232 and USB. The external communication interface 119 can also be one or a combination of wireless and wired data transmission interfaces. The host can be any computer device such as the monitor's host or a computer; with the appropriate software installed, it can form a monitoring device. The host can also be a communication device, such as a mobile phone. The device for monitoring the patient's ventilation can send data to a Bluetooth-enabled mobile phone via the Bluetooth interface, achieving remote data transmission. After the processor 50 completes the calculation of physiological parameters, it can also determine whether the physiological parameters are abnormal. If abnormal, an alarm can be triggered through the alarm circuit 120. The memory 118 can store the intermediate and final data of the monitor, as well as program instructions or code for execution by the processor 50, etc. If the monitor has a blood pressure measurement function, it may also include a pump valve drive circuit 121, which is used to perform inflation or deflation operations under the control of the processor 50.

[0061] The above is some explanation of the device used to monitor patient ventilation as a patient monitor.

[0062] In some embodiments, the device for monitoring patient ventilation may also be a ventilator. A ventilator is an artificial mechanical ventilation device used to assist or control a patient's spontaneous breathing movements to achieve gas exchange in the lungs, reduce the body's energy expenditure, and facilitate the recovery of respiratory function. Please refer to... Figure 3 In some embodiments, the device for monitoring patient ventilation may also include a breathing interface 211, a gas source interface 212, a breathing circuit, a breathing assist device, and a display 70.

[0063] The breathing circuit selectively connects the gas source interface 212 to the patient's respiratory system. In some embodiments, the breathing circuit includes an expiratory branch 213a and an inspiratory branch 213b. The expiratory branch 213a connects the breathing interface 211 and the exhaust port 213c, and is used to guide the patient's exhaled air to the exhaust port 213c. The exhaust port 213c can lead to the external environment or into a dedicated gas recovery device. The gas source interface 212 is used to connect to a gas source (not shown in the figure) to provide gas, which can typically be oxygen or air. In some embodiments, the gas source can be a compressed gas cylinder or a central gas supply source, which supplies gas to the ventilator through the gas source interface 212. The types of gas supplied include oxygen (O2) and air. The gas source interface 212 can include conventional components such as a pressure gauge, pressure regulator, flow meter, pressure reducing valve, and air-oxygen ratio control and protection device, which are used to control the flow rate of various gases (e.g., oxygen and air). Inspiratory branch 213b connects the breathing interface 211 and the gas source interface 212 to provide oxygen or air to the patient. For example, gas input from the gas source interface 212 enters the inspiratory branch 213b and then enters the patient's lungs through the breathing interface 211. The breathing interface 211 is used to connect the patient to the breathing circuit. In addition to introducing the gas transmitted from the inspiratory branch 213b to the patient, it can also introduce the patient's exhaled gas through the expiratory branch 213a to the exhaust port 213c. Depending on the situation, the breathing interface 211 can be a nasal cannula or a mask worn over the mouth and nose. The respiratory assist device is connected to the gas source interface 212 and the breathing circuit, controlling the delivery of gas supplied by an external gas source to the patient through the breathing circuit. In some embodiments, the respiratory assist device may include an expiratory controller 214a and an inspiratory controller 214b. The expiratory controller 214a is disposed on the expiratory branch 213a and is used to connect or disconnect the expiratory branch 213a according to control commands, or to control the flow rate or pressure of the patient's exhaled gas. In specific implementations, the expiratory controller 214a may include one or more devices capable of controlling flow rate or pressure, such as an expiratory valve, a one-way valve, a flow controller, or a PEEP valve. The inspiratory controller 214b is disposed on the inspiratory branch 213b and is used to connect or disconnect the inspiratory branch 213b according to control commands, or to control the flow rate or pressure of the output gas. In specific implementations, the inspiratory controller 214b may include one or more devices capable of controlling flow rate or pressure, such as an expiratory valve, a one-way valve, or a flow controller.

[0064] Memory 215 can be used to store data or programs, such as data acquired by sensors, data generated by the processor, or image frames generated by the processor, which can be 2D or 3D images. Alternatively, memory 215 can store a graphical user interface, one or more default image display settings, or programming instructions for the processor. Memory 215 can be a tangible and non-transitory computer-readable medium, such as flash memory, RAM, ROM, EEPROM, etc.

[0065] In some embodiments, the processor 50 is used to execute instructions or programs to control various control valves in the breathing assist device, the air source interface 212 and / or the breathing circuit, or to process the received data to generate the required calculation or judgment results, or to generate visualization data or graphics and output the visualization data or graphics to the display 70 for display.

[0066] The above describes the device used for monitoring patient ventilation as a ventilator. It should be noted that... Figure 3 This is just one example of a ventilator, and it is not meant to limit ventilators to having only this kind of structure.

[0067] In some embodiments, the device for monitoring patient ventilation can also be an anesthesia machine, which is primarily used to provide anesthetic gas, deliver the anesthetic gas to the patient's respiratory system via a respirator, and control the amount of anesthetic gas inhaled. Please refer to... Figure 4 In some embodiments, the device for monitoring patient ventilation may also include a breathing interface 311, a gas source interface 312, a breathing assist device 320, an anesthetic delivery device 330, a breathing circuit, a memory 350, and a display 70.

[0068] Gas source interface 312 is used to connect to a gas source (not shown in the figure) to provide gas. This gas can typically be oxygen, nitrous oxide (laughing gas), or air. In some embodiments, the gas source can be a compressed gas cylinder or a central gas supply source, supplying gas to the anesthesia machine through gas source interface 312. The supplied gas types include oxygen (O2), nitrous oxide (N2O), and air. Gas source interface 312 may include conventional components such as a pressure gauge, pressure regulator, flow meter, pressure reducing valve, and N2O-O2 proportional control protection device, used to control the flow rate of various gases (e.g., oxygen, nitrous oxide, and air). The gas input through gas source interface 312 enters the breathing circuit and mixes with the existing gas in the breathing circuit to form a gas mixture.

[0069] The respiratory assist device 320 is used to power the patient's involuntary breathing and maintain airway patency. In some embodiments, the respiratory assist device 320 is connected to the gas source interface 312 and the breathing circuit, controlling the delivery of gas supplied by an external gas source to the patient through the breathing circuit. In some specific embodiments, the respiratory assist device 320 mixes fresh gas input from the gas source interface 312 with gas exhaled by the patient in the breathing circuit and anesthetic drugs output from the anesthetic drug output device 330, and outputs the mixture through the inspiratory branch 340b to the breathing interface 311 to drive the patient's inhalation, and receives the patient's exhaled gas through the expiratory branch 340a. In specific embodiments, the respiratory assist device 320 typically includes a mechanical ventilation module, the airflow channel of which is connected to the breathing circuit. During the anesthesia maintenance phase of the operation or when the patient has not resumed spontaneous breathing, the mechanical ventilation module provides the patient with the power for breathing. In some embodiments, the respiratory assist device 320 also includes a manual ventilation module, the airflow channel of which is connected to the breathing circuit. During the induction phase before intubation in surgery, a manual ventilation module is typically used to assist the patient's breathing. When the respiratory assist device 320 includes both a mechanical ventilation module and a manual ventilation module, the mechanical or manual ventilation mode can be switched via a mechanical or manual switch (e.g., a three-way valve) to connect the mechanical or manual ventilation module to the breathing circuit, thereby controlling the patient's breathing. Those skilled in the art should understand that, depending on specific needs, the anesthesia machine may include only a mechanical ventilation module or a manual ventilation module.

[0070] The anesthetic delivery device 330 is used to provide anesthetic drugs. Typically, the anesthetic drug is mixed in gaseous form with fresh air introduced through the gas source interface 312 and delivered together into the breathing circuit. In one specific embodiment, the anesthetic delivery device 330 is implemented using an anesthetic vaporizer. The anesthetic drug is typically in liquid form and stored in the vaporizer. Optionally, the vaporizer may include a heating device for heating the anesthetic drug to volatilize it, generating anesthetic vapor. The anesthetic delivery device 330 is connected to the gas source interface 312 via a conduit. The anesthetic vapor mixes with the fresh air introduced through the gas source interface 312 and is then delivered together into the breathing circuit.

[0071] In some embodiments, the breathing circuit may include an inspiratory branch 340b, an expiratory branch 340a, and a soda lime canister 340c. The inspiratory branch 340b and expiratory branch 340a are connected to form a closed loop, and the soda lime canister 340c is disposed on the tubing of the expiratory branch 340a. A mixture of fresh air and gas introduced by the air supply interface 312 is input through the inlet of the inspiratory branch 340b and provided to the patient through a breathing interface 311 located at the outlet of the inspiratory branch 340b. The breathing interface 311 may be a face mask, a nasal cannula, or an endotracheal tube. In a preferred embodiment, a one-way valve is provided on the inspiratory branch 340b, which opens during the inspiratory phase and closes during the expiratory phase. A one-way valve is also provided on the expiratory branch 340a, which closes during the inspiratory phase and opens during the expiratory phase. The inlet of the expiratory branch 340a is connected to the breathing interface 311. When the patient exhales, the exhaled gas enters the soda lime container 340c through the expiratory branch 340a. The carbon dioxide in the exhaled gas is filtered out by the substance in the soda lime container 340c. The gas after the carbon dioxide is filtered out is then recirculated into the inspiratory branch 340b.

[0072] The memory 350 can be used to store data or programs, such as data collected by various sensors, data generated by the processor, or image frames generated by the processor. These image frames can be 2D or 3D images. Alternatively, the memory 350 can store a graphical user interface, one or more default image display settings, or programming instructions for the processor. The memory 350 can be a tangible and non-transitory computer-readable medium, such as flash memory, RAM, ROM, EEPROM, etc.

[0073] The processor 50 is used to execute instructions or programs to control the breathing assist device 320, the air source interface 310 and / or various control valves in the breathing circuit, or to process the received data to generate the required calculation or judgment results, or to generate visual data or graphics and output the visual data or graphics to the display 70 for display.

[0074] The above describes the device used for monitoring patient ventilation as an anesthesia machine. It should be noted that... Figure 4 This is just one example of an anesthesia machine, and it is not intended to limit anesthesia machines to only having this kind of structure.

[0075] VILI (Vibration-Induced Lung Injury) is a combination of various types of injury caused by excessive dynamic strain and energy load. In some embodiments, lung injury can be evaluated more accurately, realistically, and in real time by calculating the energy acting on the patient's respiratory system during mechanical ventilation. The following explains how the ventilation monitoring device described in this article calculates the energy acting on the patient's respiratory system during mechanical ventilation.

[0076] The flow sensor 30 is used to collect the gas flow rate of the patient during ventilation. In some embodiments, the gas flow rate of the patient during ventilation may refer to the patient's inspiratory flow rate. In some embodiments, the flow sensor 30 may be a flow sensor located at the patient end, such as a flow sensor located at the patient interface, and the gas flow rate is the gas flow rate collected by the flow sensor during inspiration. In some embodiments, there are multiple flow sensors 30, including an inspiratory flow sensor and an expiratory flow sensor located at the mechanical ventilation end. For example, for a ventilator, it may be an inspiratory flow sensor located in the inspiratory branch 213b and an expiratory flow sensor located in the expiratory branch 213a; for an anesthesia machine, it may be an inspiratory flow sensor located in the inspiratory branch 340b and an expiratory flow sensor located in the expiratory branch 340a; the gas flow rate is the difference between the flow rates collected 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 gas flow rate by directly measuring the inflow and outflow velocities at the patient end. Of course, the energy acting on the patient's respiratory system during mechanical ventilation can be calculated using the gas flow rate throughout the entire respiratory period, including the gas flow rates during inspiration and expiration.

[0077] In some embodiments, the number of pressure sensors 10 is one or more. The pressure sensors 10 are used to acquire the pressure of the patient during ventilation, the pressure reflecting the pressure acting on different sites of the patient's respiratory system during ventilation—such as one or more of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, and intragastric pressure.

[0078] In some embodiments, the pressure sensor 10 can be a catheter-type pressure sensor or a fiber optic pressure sensor, etc. By inserting the pressure sensor into a corresponding site in the patient's respiratory system, the pressure at that site can be measured. For example, inserting the pressure sensor into the patient's airway can measure airway pressure, inserting it into the esophagus can measure esophageal pressure, inserting it into the stomach can measure intragastric pressure, inserting it into the carina inside the trachea can measure carina pressure, inserting it into the stomach can measure intragastric pressure, and inserting it into the pleural cavity through an incision can measure intrapleural pressure. In some embodiments, the pressure at some sites in the respiratory system can be used to replace or calculate the pressure at other sites, as illustrated by the following examples.

[0079] In some embodiments, carina pressure may be used instead of intrapulmonary pressure. In some embodiments, esophageal pressure may be used instead of intrathoracic pressure. In some embodiments, gastric pressure may be used instead of intra-abdominal pressure.

[0080] In some embodiments, processor 50 can calculate intrapulmonary pressure based on airway pressure. For example, in some embodiments, processor 50 calculates intrapulmonary pressure using airway pressure, respiratory system resistance, and the aforementioned gas flow rate. In a specific example, it can be calculated using the following formula:

[0081] Plung(t)=Paw(t)-Raw*Flow(t);

[0082] Where Plung(t) is a function of intrapulmonary pressure changing with time t, or real-time intrapulmonary pressure; Paw(t) is a function of airway pressure changing with time t, or real-time airway pressure; Flow(t) is a function of gas flow rate during ventilation changing with time t, or real-time gas flow rate during ventilation; and Raw is respiratory system resistance.

[0083] In some embodiments, the processor 50 can calculate the transpulmonary pressure by subtracting either the esophageal pressure or the intrathoracic pressure from either the intrapulmonary pressure or the airway pressure. For example, the transpulmonary pressure can be obtained by subtracting the esophageal pressure from the airway pressure. In some embodiments, the processor 50 can also correct the transpulmonary pressure, as described in detail below.

[0084] In some embodiments, the processor 50 further corrects the transpulmonary pressure by measuring airway pressure and esophageal pressure values ​​in states where the positive end-expiratory pressure (PEEP) is zero and non-zero; specifically, the processor 50 acquires the airway pressure Paw in a state where the PEEP is non-zero. PEEP and esophageal pressure Pes PEEP And obtain the airway pressure Paw when the positive end-expiratory pressure is zero. ZEEP and esophageal pressure Pes ZEEP Processor 50 will add transpulmonary pressure (Paw) PEEP -Paw ZEEP ) and subtract (Pes PEEP -Pes ZEEP The corrected transpulmonary pressure was obtained.

[0085] In some embodiments, the processor 50 further corrects the transpulmonary pressure values ​​using lung compliance and chest wall compliance; specifically, the processor 50 obtains lung compliance Clung and chest wall compliance Ccw; it should be noted that the processor 50 can obtain lung compliance Clung and chest wall compliance Ccw in various ways, for example, the processor 50 can obtain chest wall compliance Ccw using the following formula:

[0086]

[0087] TV represents tidal volume, PesI represents end-inspiratory esophageal pressure, and PEEP represents... es End-tidal esophageal pressure;

[0088] The overall compliance C can then be calculated using the following formula. state :

[0089]

[0090] Where TV is tidal volume, Pplat is plateau pressure, PEEP is positive end-expiratory airway pressure; the total compliance C is calculated as follows: state In the case of chest wall compliance (Ccw), lung compliance (Clung) can be calculated by solving the following equation:

[0091]

[0092] After obtaining lung compliance Clung and chest wall compliance Ccw, processor 50 can calculate the error compensation value using the following formula:

[0093]

[0094] Where ΔPtrans erro The error compensation value is Ptrans, which is the transpulmonary pressure value, and Plung is the intrapulmonary pressure value.

[0095] The processor 50 subtracts the error compensation value from the transpulmonary pressure to obtain the corrected transpulmonary pressure.

[0096] In some embodiments, the processor 50 can calculate the transdiaphragmatic pressure by subtracting either the intra-abdominal pressure or the intragastric pressure from either the intrathoracic pressure or the esophageal pressure. For example, the transdiaphragmatic pressure can be obtained by subtracting the intragastric pressure from the esophageal pressure. It should be noted that in some embodiments, the intra-abdominal pressure can be acquired by inserting a pressure sensor into the abdomen through an incision. In some embodiments, the processor 50 can also correct the transdiaphragmatic pressure. For example, the processor 50 acquires the esophageal pressure Pes when the positive end-expiratory pressure is non-zero. PEEP Psto (intragastric pressure) PEEP And to obtain the esophageal pressure Pes when the positive end-expiratory pressure is zero. ZEEP Psto (intragastric pressure) ZEEP Processor 50 will add (Pes) to the transdiaphragm pressure. PEEP -Pes ZEEP ) and subtract (Psto) PEEP -Psto ZEEP The corrected transdiaphragmatic pressure is obtained.

[0097] The above is an explanation of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, intragastric pressure, intra-abdominal pressure, transpulmonary pressure, and transdiaphragmatic pressure.

[0098] In this invention, the processor 50 receives signals from the pressure sensor 30 and the flow sensor 10, and calculates the energy acting on the patient's respiratory system during mechanical ventilation based on the collected pressure and gas flow rate. In some embodiments, the processor 50 integrates the collected pressure and gas flow rate to obtain the energy acting on the patient's respiratory system during mechanical ventilation. In some embodiments, the processor 50 integrates the collected pressure and gas flow rate over a preset unit time—for example, 1 minute—to obtain the energy of mechanical ventilation acting on the patient's respiratory system. In some embodiments, the processor 50 integrates the collected pressure and gas flow rate over one respiratory cycle and multiplies it by the respiratory rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system. The following explanation, using pressure at different points on the respiratory system, further illustrates how to calculate the energy of mechanical ventilation acting on the patient's respiratory system.

[0099] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on airway pressure and gas flow rate. For example, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the airway pressure and gas flow rate, as shown in the following formula:

[0100]

[0101] Energy rs Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating airway pressure and gas flow rate per respiratory cycle. Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to per minute by combining the respiratory rate, as shown in the following formula:

[0102]

[0103] Where airway pressure (Paw) is measured in cmH2O; gas flow rate (Flow) is measured in L / min; inspiratory time (Tinsp) per respiratory cycle is measured in seconds; respiratory rate (RR) is measured in minutes; and power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating airway pressure and gas flow rate. rs The unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Alternatively, you can directly sum the Energyrs from all cycles within one minute to obtain the energy per minute.

[0104] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on airway pressure and gas flow rate, the potential energy generated by the tidal volume portion of positive end-expiratory pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, and it can often be omitted because additional positive end-expiratory pressure release is required. When this potential energy is considered, the above formula becomes:

[0105]

[0106] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0107]

[0108] In these two formulas, PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0109] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on airway pressure and gas flow rate. This can represent the energy exerted by mechanical ventilation on the patient's entire respiratory system, such as the total energy exerted on the patient's trachea, chest wall, and lungs.

[0110] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the intrapulmonary pressure and gas flow rate. It should be noted that the intrapulmonary pressure can be acquired by the pressure sensor 10 or estimated through methods such as air pressure channels, as described in detail above and will not be repeated here. In some examples, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the intrapulmonary pressure and gas flow rate, as shown in the following formula:

[0111]

[0112] Energy lung Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating intrapulmonary pressure and gas flow rate per respiratory cycle. Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to energy per minute by combining the respiratory rate, as shown in the following formula:

[0113]

[0114] Where Plung (intrapulmonary pressure) is measured in cmH2O; Flow (gas flow rate) is measured in L / min; Tinsp (inspiratory time per respiratory cycle) is measured in seconds; RR (respiratory rate) is measured in minutes; and Power (energy exerted by mechanical ventilation on the patient's respiratory system) is calculated by integrating Plung and Flow. lung The unit can be J / min. Since 1cmH2O * 1L / min = 0.098J / min, the formula above contains a coefficient of 0.098. Of course, depending on the specific needs, energy per second or per hour can be calculated, in which case the corresponding unit would be J / s or J / h. Correspondingly, the coefficient 0.098 in the above formula represents other values ​​converted from the unit.

[0115] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on intrapulmonary pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory intrapulmonary pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0116]

[0117] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0118]

[0119] In these two formulas, PlungE Volume Tidal volume is the volume of air exhaled when the intrapulmonary pressure drops to 0 at the end of exhalation, measured in liters (L). PlungE is the intrapulmonary pressure at the end of exhalation.

[0120] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on intrapulmonary pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the lungs and chest wall of the patient's respiratory system.

[0121] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the transpulmonary pressure and gas flow rate values. For example, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the transpulmonary pressure and gas flow rate, as shown in the following formula:

[0122]

[0123] Energy trTinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating transpulmonary pressure and gas flow rate per respiratory cycle; Tinsp is the inspiratory time of each respiratory cycle, Ptrans is the transpulmonary pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to energy per minute by combining the respiratory rate, as shown in the following formula.

[0124]

[0125] Where transpulmonary pressure Ptrans is measured in cmH2O; gas flow rate is measured in L / min; inspiratory time Tinsp per respiratory cycle is measured in seconds; RR is the respiratory rate, measured in minutes; and Power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating transpulmonary pressure and gas flow rate. tr The unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Similarly, the unit and coefficient can be set as needed.

[0126] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on transpulmonary pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory transpulmonary pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0127]

[0128] Convert the energy per minute based on the respiratory rate:

[0129]

[0130] In these two formulas, PtansE volume PtransE is the tidal volume caused by the transpulmonary pressure at the end of expiration, measured in liters (L). Specifically, it is the volume exhaled when the transpulmonary pressure at the end of expiration drops to 0. PtransE is the transpulmonary pressure at the end of expiration.

[0131] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on transpulmonary pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the lungs of the patient's respiratory system.

[0132] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate values. For example, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the transdiaphragmatic pressure and gas flow rate, as shown in the following formula:

[0133]

[0134] Energy di Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, obtained by integrating the transdiaphragmatic pressure and gas flow rate in a single respiratory cycle; Tinsp is the inspiratory time of each respiratory cycle, Pdi is the transdiaphragmatic pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be combined with the respiratory rate to convert it to energy per minute, as shown in the following formula.

[0135]

[0136] The unit of transpulmonary pressure Pdi is cmH2O; the unit of gas flow rate is L / min; the unit of inspiratory time Tinsp per respiratory cycle is s; RR is the respiratory rate, in minutes; and Power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating transdiaphragmatic pressure and gas flow rate. di The unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Similarly, the unit and coefficient can be set as needed.

[0137] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on transdiaphragmatic pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory transdiaphragmatic pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0138]

[0139] Convert the energy per minute based on the respiratory rate:

[0140]

[0141] In these two formulas, PdiE volume Tidal volume is the volume of air exhaled when the transdiaphragmatic pressure drops to 0 at the end of exhalation, measured in liters (L). PdiE is the transdiaphragmatic pressure at the end of exhalation.

[0142] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on the transdiaphragmatic pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the diaphragm in the patient's respiratory system.

[0143] The above is an explanation of how mechanical ventilation affects the patient's respiratory system.

[0144] VILI (Vibration-Induced Lung Injury) is a combination of various types of injury. Generally, VILI can include one or more of barotrauma, volumetric injury, atelectasis, and tissue injury. As mentioned above, the energy acting on the patient's respiratory system during mechanical ventilation can accurately, realistically, and in real time evaluate lung injury. However, this provides a relatively comprehensive description of lung injury. In reality, the role of each ventilation parameter during mechanical ventilation is important. Each ventilation parameter affects the contribution of various parts of the energy acting on the patient's respiratory system during mechanical ventilation to the potential for injury. Therefore, in some embodiments, the ventilation monitoring device described herein also determines the contribution of ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation, which will be explained in detail below.

[0145] In some embodiments, the processor 50 acquires ventilation parameters and determines the contribution of these parameters to the energy exerted on the patient's respiratory system during mechanical ventilation. In some embodiments, the ventilation parameters include ventilation control parameters and / or respiratory system-related parameters.

[0146] In some embodiments, ventilation control parameters may include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio. When determining the contribution of a ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation, the contribution can be determined by changing the value of the ventilation parameter and observing the changes in the energy acting on the patient's respiratory system during mechanical ventilation.

[0147] Contribution can be reflected in different ways:

[0148] 1. Monitoring values ​​of the mechanical energy generated by ventilation parameters, such as the mechanical energy PowerR generated by respiratory resistance;

[0149] 2. The proportion of mechanical energy generated by ventilation parameters, that is, the proportion of mechanical energy generated by each ventilation parameter in the total mechanical energy, such as the proportion of mechanical energy generated by respiratory resistance in the total mechanical energy: PowerR / Powerrs;

[0150] 3. The rate of change of mechanical energy generated by ventilation parameters, such as the ratio of the percentage increase in the corresponding ventilation parameter to the percentage increase in the corresponding mechanical energy.

[0151] Specifically, when determining the contribution of any ventilation control parameter, other ventilation control parameters can be kept constant. Then, the relationship between the ventilation control parameter whose contribution needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be established. For example, by changing the ventilation control parameter whose contribution needs to be determined by a fixed amount, the corresponding change in energy acting on the patient's respiratory system during mechanical ventilation can be obtained. Then, through fitting—for example, linear fitting or exponential fitting—the relationship between the ventilation control parameter whose contribution needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be obtained, thereby determining the contribution of that ventilation control parameter. Of course, it is also possible to control the change of a ventilation control parameter without changing it by a fixed amount. Taking volume-based mechanical ventilation as an example, the ventilation control parameters involved in this mode typically include tidal volume, gas flow rate, positive end-expiratory pressure (PEEP), respiratory rate, and respiratory ratio. To calculate the contribution of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation, the gas flow rate, PEEP, respiratory rate, and respiratory ratio can be kept and set to fixed values. Then, the tidal volume value can be changed, for example, by increasing the tidal volume by a fixed percentage X% each time—e.g., 2%. Then, the corresponding percentage increase Y% in the energy acting on the patient's respiratory system during mechanical ventilation can be obtained—for example, Y1%, Y2%, ..., Yn%. A fitting relationship between X and Y can then be obtained. For example, let's assume K = Y / X; then the contribution of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation is K. For example, the following table shows the changes in ventilation parameters and the energy acting on the patient's respiratory system during mechanical ventilation, as shown in Table 1 below. In the table, Power represents the energy exerted on the patient's respiratory system during mechanical ventilation; TV represents tidal volume; Rate represents respiratory rate; I represents inspiratory time; and E represents expiratory time. It can be seen that the ratio of I to E in the table is 1 / 2. Raw represents respiratory system resistance; Crs represents respiratory system compliance; and PEEP represents positive end-expiratory airway pressure. The change from state 1 to state 2 is due to the change in ventilation parameters. TV increases from 500 to 1000, a 100% increase. Correspondingly, Power increases from 5.82 to 17.4, an approximately 200% increase. If a linear fit is performed, the rate of change of TV, or its contribution, is 2. The change from state 1 to state 3 is due to the change in ventilation parameters. Rate increases from 12 to 24, a 100% increase. Correspondingly, Power increases from 5.82 to 14.46, an approximately 150% increase. If a linear fit is performed, the rate of change of Rate, or its contribution, is 1.5.

[0152] parameter unit State 1 State 2 State 3 POWER J / min 5.82 17.4 14.46 TV mL 500 1000 500 Rate bpm 12 12 24 I 1 1 1 E 2 2 2 Raw cmH2O / L / s 8 8 8 Crs mL / cmH2O 100 100 100 PEEP cmH2O 5 5 5

[0153] Table 1

[0154] Understandably, when gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio are kept or set to fixed values, these fixed values ​​will affect the contribution of tidal volume. For example, if the gas flow rate is set to two different fixed values, the contribution of tidal volume will generally be different when calculated separately. Nevertheless, the order of the contribution of these ventilation control parameters to the energy acting on the patient's respiratory system during mechanical ventilation is generally fixed.

[0155] In some embodiments, respiratory system-related parameters may include one or more of the patient's respiratory system compliance and respiratory system resistance. The contribution of respiratory system compliance to the energy acting on the patient's respiratory system during mechanical ventilation can be expressed as the proportion of the work done to overcome respiratory system compliance to the energy acting on the patient's respiratory system during mechanical ventilation; similarly, the contribution of respiratory system resistance to the energy acting on the patient's respiratory system during mechanical ventilation can be expressed as the proportion of the work done to overcome respiratory system resistance to the energy acting on the patient's respiratory system during mechanical ventilation. This is explained in detail below. Please refer to... Figure 5 The figure shows the static pressure-volume curve (PV curve) of the respiratory system, which reflects the mechanical state of the patient's respiratory system. The horizontal axis of the figure represents airway pressure (Paw). In some other examples, the horizontal axis can also represent intrapulmonary pressure (Plung), transpulmonary pressure (Ptrans), or transdiaphragmatic pressure (Pdi), etc.

[0156] Let's take airway pressure (Paw) on the horizontal axis as an example. In the diagram, A represents the kinetic energy component, indicating the amount of work done to overcome respiratory system resistance. B, C, and D represent the potential energy component, which is related to respiratory system compliance. Specifically, A and B are dynamically changing, doing work as tidal volume and driving pressure change. C and D are statically constant. When the driving pressure changes above the positive end-expiratory pressure (PEEP), the tidal volume and pressure related to PEEP do not do work, but there is elastic potential energy, which is part of the energy acting on the patient's respiratory system during mechanical ventilation.

[0157] In one example, the potential energy components related to respiratory system compliance in the diagram, namely B, C, and D, can be calculated using the following formula:

[0158]

[0159] Energy C To characterize the energy related to respiratory system compliance in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate; PEEP VolumeTidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0160] In some examples, the potential energy related to respiratory system compliance can be further divided into the potential energy related to dynamic respiratory system compliance and the potential energy related to static respiratory system compliance. Specifically, the work done to overcome the dynamic compliance of the respiratory system, i.e., the potential energy components of B and C in the figure, is:

[0161]

[0162] Energy Cdyn To characterize the energy associated with respiratory system dynamic compliance in a single cycle—that is, the work done to overcome respiratory system dynamic compliance—Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0163] The work done to overcome the static compliance of the respiratory system, which is the potential energy component at point D in the diagram, is as follows:

[0164]

[0165] Energy Cstat To characterize the energy associated with respiratory system static compliance in a single cycle—that is, the work done to overcome respiratory system static compliance—PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0166] In one example, the work done to overcome the resistance of the respiratory system, i.e., the kinetic energy A, can be calculated using the following formula:

[0167]

[0168] Energy R To characterize the work done in a single cycle to overcome respiratory resistance, Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0169] Of course, the energy calculated from a single cycle can also be converted into a per-minute amount by combining it with the breathing rate. Below is a discussion of the energy mentioned above. C Energy Cdyn Energy Cstat and Energy R Each of these will be explained separately.

[0170] Energy related to respiratory compliance in a single cycle C The conversion is as follows:

[0171]

[0172] Energy associated with respiratory system dynamic compliance in a single cycle Cdyn The conversion is as follows:

[0173]

[0174] Energy associated with respiratory system static compliance in a single cycle Cstat The conversion is as follows:

[0175]

[0176] Energy is the work done in a single cycle to overcome respiratory resistance. R The conversion is as follows:

[0177]

[0178] In the above formulas, the units for airway pressure (Paw) and intrapulmonary pressure (Plung) are both cmH2O; the unit for gas flow rate (Flow) is L / min; the unit for inspiratory time (Tinsp) per respiratory cycle is s; RR is the respiratory rate, in units of per minute; and Power is the energy per minute related to respiratory system compliance. C Energy per minute related to respiratory system dynamic compliance. Cdyn Energy per minute per cycle related to respiratory system static compliance. Cstat and the work done per minute to overcome respiratory resistance. R The units are all J / min. Since 1cmH2O*1L / min=0.098J / min, there is a coefficient of 0.098 in the above formula.

[0179] Of course, you can also directly use the Energy from all cycles within 1 minute. C The energy per minute is accumulated to obtain the power. C Directly convert all cycles of Energy within 1 minute Cdyn The energy per minute is accumulated to obtain the power. Cdyn Directly convert all cycles of Energy within 1 minute Cstat The energy per minute is accumulated to obtain the power. Cstat Directly convert all cycles of Energy within 1 minute R The energy per minute is accumulated to obtain the power.R .

[0180] The above calculation uses an integral method to determine the contribution of respiratory system-related parameters to the energy exerted on the patient's respiratory system during mechanical ventilation. In some embodiments, a formula method can also be used to calculate the contribution of respiratory system-related parameters to the energy exerted on the patient's respiratory system during mechanical ventilation.

[0181] Figure 6 and Figure 5 Similarly, it is also a static pressure-volume curve (PV curve) of the respiratory system. Let's take... Figure 6 Taking airway pressure (Paw) as an example, the energy acting on the patient's respiratory system during mechanical ventilation is:

[0182]

[0183] Energy rs To characterize the energy acting on the patient's respiratory system during a single ventilation cycle, TV represents tidal volume, CRS represents respiratory system compliance, RR represents respiratory rate, I:E represents the ratio of inspiratory time to expiratory time (i.e., respiratory ratio), Raw represents respiratory system resistance, and PEEP represents positive end-expiratory airway pressure. Alternatively, the energy acting on the patient's respiratory system during a single mechanical ventilation cycle can also be expressed as Energy. rs The formula for converting respiratory rate to volume per minute is as follows:

[0184]

[0185] The amount of power per minute rs The units are J / min; respiratory rate (RR) is measured in minutes; tidal volume (TV) is measured in liters (L); respiratory system compliance (Crs) is measured in ml / cmH2O; respiratory system resistance (Raw) is measured in cmH2O / L / s; and positive end-expiratory airway pressure (PEEP) is measured in cmH2O.

[0186] When calculating the energy acting on the patient's respiratory system during ventilation, the potential energy generated by the tidal volume portion of positive end-expiratory pressure (PEEP) can generally be considered. This portion of energy is usually a fixed value and does not change with mechanical ventilation. Furthermore, because additional PEEP release is required, it can often be omitted. When this potential energy is considered, the formula above becomes:

[0187]

[0188] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0189]

[0190] In these two formulas, PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0191] The contribution of respiratory system-related parameters is calculated below. Let's consider the energy acting on the patient's respiratory system in a single cycle during mechanical ventilation as... Energy per minute For example, the following equation holds true according to the respiratory mechanics equation:

[0192]

[0193] Flow*Raw=(Ppeak-P plat );

[0194] Where Pplat is the plateau pressure, Tinsp is the inspiratory time of each respiratory cycle, Flow is the gas flow rate, and Ppeak is the peak pressure shown in the figure; therefore, it can be deduced that:

[0195]

[0196] Therefore, the work done to overcome the resistance of the respiratory system is:

[0197]

[0198] The work done to overcome the dynamic compliance of the respiratory system is:

[0199] Energy Cdyn =TV*PEEP;

[0200] The work done to overcome the static compliance of the respiratory system is:

[0201]

[0202] The work done to overcome respiratory system compliance is equal to the work done to overcome dynamic respiratory system compliance plus the work done to overcome static respiratory system compliance.

[0203] Furthermore, the contribution of respiratory system compliance can be represented by calculating the ratio of the work done to overcome respiratory system compliance to the energy exerted on the patient's respiratory system during mechanical ventilation; similarly, the contribution of respiratory system resistance can be represented by calculating the ratio of the work done to overcome respiratory system resistance to the energy exerted on the patient's respiratory system during mechanical ventilation.

[0204] The above explains the contribution of ventilation parameters—including ventilation control parameters and / or respiratory system-related parameters—to the energy exerted on the patient's respiratory system during mechanical ventilation. Once the contribution of ventilation parameters to the energy exerted on the patient's respiratory system during mechanical ventilation is determined, there are several ways to utilize this contribution, which are explained below.

[0205] In some embodiments, the display 70 can display the contribution of each ventilation parameter in one or more ways, such as text, numbers, characters, tables, graphs, or icons. For example, the display 70 can display the name of each ventilation parameter and its corresponding contribution value. In some specific embodiments, the display 70 can display the name of each ventilation parameter and its corresponding contribution value in descending or ascending order of contribution, so that medical staff can easily understand the contribution of each parameter to the energy acting on the patient's respiratory system during mechanical ventilation. For example, in one example of mechanical ventilation in volume mode, display 70 can show the contribution of ventilation control parameters involved in this mode, such as tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio. As another example, in one example of mechanical ventilation in pressure mode, display 70 can show the contribution of ventilation control parameters involved in this mode, such as tidal volume, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio. Of course, in some examples, regardless of whether it is in volume mode or pressure mode, display 70 can also show the contribution of respiratory system-related parameters such as patient respiratory compliance and respiratory resistance. Therefore, in some examples, display 70 can display the name of each ventilation control parameter and its corresponding contribution value. Of course, in some examples, display 70 can display the name of each ventilation control parameter and its corresponding contribution ranking. In some examples, the display 70 can graphically display the contribution of each ventilation control parameter; in others, it can display the name of each respiratory system-related parameter and its corresponding contribution value; in still others, it can display the percentage of contribution of each respiratory system-related parameter; and in yet another example, it can graphically display the contribution of each respiratory system-related parameter. Of course, the display 70 can also display changes in the contribution of each ventilation parameter using symbols or icons such as rising, falling, or parallel lines. Furthermore, the contribution value can be represented in various ways, such as monitored values, percentages, or rates of change. For example, displaying the contribution value of respiratory system compliance could show the actual monitored value, percentage, or rate of change of the energy exerted on the patient's respiratory system during mechanical ventilation by the work done to overcome respiratory system compliance. Similarly, displaying the contribution value of respiratory system resistance could show the actual monitored value, percentage, or rate of change of the energy exerted on the patient's respiratory system during mechanical ventilation by the work done to overcome respiratory system resistance.

[0206] Table 2 below is an example.

[0207] parameter unit normal patients ARDS COPD TV mL 500 500 500 Rate bpm 12 12 12 I 1 1 1 E 2 2 2 Raw cmH2O / L / s 5 20 20 Crs mL / cmH2O 50 20 100 PEEP cmH2O 3 3 3 Power J / min 5.59 12.64 6.76 <![CDATA[Power C ]]> J / min 4.70 9.11 3.23 <![CDATA[Power R ]]> J / min 0.88 3.53 3.53 <![CDATA[Power C %]]> 84％ 72％ 48％ <![CDATA[Power R %]]> 16％ 28％ 52％

[0208] Table 2

[0209] In the table, TV represents tidal volume, Rate represents respiratory rate, I represents inspiratory time, and E represents expiratory time. Note that the ratio of I to E in the table is 1 / 2. Raw represents respiratory resistance, CRS represents respiratory compliance, PEEP represents positive end-expiratory airway pressure, and Power represents the energy exerted on the patient's respiratory system during mechanical ventilation. C Power represents the work done to overcome respiratory system compliance. R Power represents the work done to overcome respiratory resistance. C % represents the percentage of work done to overcome respiratory system compliance, i.e., Power C The ratio of power to power; Power R % represents the percentage of work done to overcome respiratory resistance, i.e., Power R The ratio of Power; it can be seen that the Power of normal patients, patients with acute respiratory distress syndrome (ARDS), and patients with chronic obstructive pulmonary disease are different. C % and Power R The percentages are all different; in other words, Power C % and Power R % can provide some information about the patient's illness; different patient types have different power levels. C % are different, their power R % are also different.

[0210] Therefore, in some embodiments, in addition to displaying the names of ventilation parameters and their corresponding numerical contributions as mentioned above, the contribution of each ventilation parameter can also be displayed graphically—for example, in a bar chart, pie chart, or graph. The table above graphically displays the contribution of respiratory system resistance (e.g., the work done to overcome respiratory system resistance and its percentage in the table) and the contribution of respiratory system compliance (e.g., the work done to overcome respiratory system compliance and its percentage in the table). Figures 7(a) and 7(b) are examples of displaying the contribution of respiratory system resistance and respiratory system compliance of normal patients in the table using bar charts and pie charts.

[0211] In some embodiments, the processor 50 can guide mechanical ventilation based on the contribution of ventilation parameters. This is described in detail below.

[0212] In some embodiments, when it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a first threshold, the processor 50 can prompt a reduction in ventilation parameters based on their contribution ranking, or control the reduction of ventilation parameters based on their contribution ranking. Specifically, the processor 50 can prompt a priority reduction of the ventilation parameter with the highest contribution among the ventilation control parameters, or control a priority reduction of the ventilation parameter with the highest contribution among the ventilation control parameters. When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a relatively safe threshold, the ventilation parameter with the highest contribution among the ventilation control parameters can be manually or automatically reduced first, allowing the energy exerted by mechanical ventilation on the patient's respiratory system to be reduced to a safe range relatively quickly.

[0213] In some embodiments, when it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below a second threshold, the processor 50 can prompt an increase in ventilation parameters based on their contribution ranking, or control the increase of ventilation parameters based on their contribution ranking. Specifically, the processor 50 can prompt an increase in the ventilation parameter with the lowest contribution among the ventilation control parameters, or control the increase in the ventilation parameter with the lowest contribution among the ventilation control parameters. When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below a relatively safe threshold, the ventilation parameter with the lowest contribution can be increased manually or automatically. This allows the energy exerted by mechanical ventilation on the patient's respiratory system to enter a safe range relatively smoothly and safely, preventing the energy exerted by mechanical ventilation on the patient's respiratory system from suddenly exceeding the limit and causing other problems.

[0214] In some embodiments, based on the ventilation control parameter setting command, the processor 50 estimates and outputs the energy of the set mechanical ventilation acting on the patient's respiratory system. Specifically, the estimated energy of the mechanical ventilation acting on the patient's respiratory system can be displayed on the display 70 for medical personnel to view and make decisions. In some embodiments, the processor 50 can also determine whether to issue an alarm based on the estimated energy of the mechanical ventilation acting on the patient's respiratory system; for example, the processor 50 issues an alarm when the estimated energy of the mechanical ventilation acting on the patient's respiratory system exceeds a first threshold or is less than a second threshold.

[0215] Some studies have shown a significant clinical correlation between excessive energy exerted by mechanical ventilation on the patient's respiratory system and lung injury. Specifically, some clinical studies have indicated that when the energy exerted by mechanical ventilation on the patient's entire respiratory system exceeds 25 J / min, or when the energy exerted by mechanical ventilation on the lungs exceeds 12 J / min or 13 J / min, it significantly causes lung injury. Other clinical studies have shown that when the energy exerted by mechanical ventilation on the patient's entire respiratory system exceeds 17 J / min, it significantly increases patient mortality. Therefore, the aforementioned first and second thresholds can be set based on clinical data and the patient's specific condition.

[0216] In some embodiments, the processor 50 can determine whether to issue an alarm based on the contribution of various respiratory system-related parameters. For example, the processor 50 issues different alarms based on the proportion of respiratory system resistance's contribution, i.e., the range in which the work done to overcome respiratory system resistance accounts for the energy acting on the patient's respiratory system during mechanical ventilation. Similarly, the processor 50 issues different alarms based on the proportion of respiratory system compliance's contribution, i.e., the range in which the work done to overcome respiratory system compliance accounts for the energy acting on the patient's respiratory system during mechanical ventilation. The specific alarm to trigger within a given percentage range can be determined and set by those skilled in the art based on clinical data. For example, if the contribution of respiratory compliance is between 80% and 85%, no alarm is triggered, and the patient is currently normal; if the contribution of respiratory compliance is between 70% and 75%, an alarm is triggered indicating that the patient currently has acute respiratory distress syndrome (ARDS); if the contribution of respiratory compliance is between 40% and 50%, an alarm is triggered indicating that the patient currently has chronic obstructive pulmonary disease (COPD); or, if the contribution of respiratory compliance is outside the 80% to 85% range, an alarm is triggered, and vice versa.

[0217] The above describes the apparatus for monitoring patient ventilation in some embodiments of this application. In some embodiments of the present invention, a method for monitoring patient ventilation is also disclosed.

[0218] Figure 8 This is a flowchart of a method for monitoring ventilation in a patient according to some embodiments of the present invention, the method comprising the following steps:

[0219] Step 100: Obtain the gas flow rate of the patient during ventilation.

[0220] The gas flow rate can refer to the patient's inspiratory flow rate, or it can refer to the flow rate during the patient's inhalation and exhalation. This gas flow rate can be acquired using the flow sensor 30.

[0221] Step 200: Obtain the patient's pressure during ventilation.

[0222] The pressure reflects the pressure acting on different sites of the patient's respiratory system during ventilation—such as one or more of the following: airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, and intragastric pressure. These pressures can be acquired by pressure sensor 10.

[0223] In some embodiments, the pressure sensor 10 can be a catheter-type pressure sensor or a fiber optic pressure sensor, etc. By inserting the pressure sensor into a corresponding site in the patient's respiratory system, the pressure at that site can be measured. For example, inserting the pressure sensor into the patient's airway can measure airway pressure, inserting it into the esophagus can measure esophageal pressure, inserting it into the stomach can measure intragastric pressure, inserting it into the carina inside the trachea can measure carina pressure, inserting it into the stomach can measure intragastric pressure, and inserting it into the pleural cavity through an incision can measure intrapleural pressure. In some embodiments, the pressure at some sites in the respiratory system can be used to replace or calculate the pressure at other sites, as illustrated by the following examples.

[0224] In some embodiments, carina pressure may be used instead of intrapulmonary pressure. In some embodiments, esophageal pressure may be used instead of intrathoracic pressure. In some embodiments, gastric pressure may be used instead of intra-abdominal pressure.

[0225] In some embodiments, step 200 may calculate intrapulmonary pressure based on airway pressure. For example, in some embodiments, step 200 calculates intrapulmonary pressure using airway pressure, respiratory system resistance, and the aforementioned gas flow rate. In a specific example, it can be calculated using the following formula:

[0226] Plung(t)=Paw(t)-Raw*Flow(t);

[0227] Where Plung(t) is a function of intrapulmonary pressure changing with time t, or real-time intrapulmonary pressure; Paw(t) is a function of airway pressure changing with time t, or real-time airway pressure; Flow(t) is a function of gas flow rate during ventilation changing with time t, or real-time gas flow rate during ventilation; and Raw is respiratory system resistance.

[0228] In some embodiments, step 200 can calculate the transpulmonary pressure by subtracting either the esophageal pressure or the intrathoracic pressure from either the intrapulmonary pressure or the airway pressure. For example, the transpulmonary pressure can be obtained by subtracting the esophageal pressure from the airway pressure.

[0229] In some embodiments, step 200 can calculate the transdiaphragmatic pressure by subtracting either the intra-abdominal pressure or the intragastric pressure from either the intrathoracic pressure or the esophageal pressure. For example, the transdiaphragmatic pressure can be obtained by subtracting the intragastric pressure from the esophageal pressure. It should be noted that in some embodiments, the intra-abdominal pressure can be collected by inserting a pressure sensor into the abdomen through an incision or other opening.

[0230] In some embodiments, to make the energy acting on the patient's respiratory system during mechanical ventilation more accurate, the pressure can be corrected before using the acquired patient pressure in the calculation, for example... Figure 9 One example is the pressure correction achieved by introducing step 210.

[0231] Step 210 involves correcting the obtained patient pressure. Step 210 may involve correcting for transpulmonary pressure or transdiaphragmatic pressure, as explained below.

[0232] For example, after obtaining the patient's transpulmonary pressure in step 200, the transpulmonary pressure is corrected. Several examples of methods for correcting transpulmonary pressure are given below.

[0233] In some embodiments, step 210 corrects the transpulmonary pressure by measuring airway pressure and esophageal pressure values ​​in states where the positive end-expiratory pressure (PEEP) is zero and non-zero; specifically, step 210 acquires the airway pressure Paw in a state where the PEEP is non-zero. PEEP and esophageal pressure Pes PEEP And obtain the airway pressure Paw when the positive end-expiratory pressure is zero. ZEEP and esophageal pressure Pes ZEEP Step 210 adds transpulmonary pressure (Paw) PEEP -Paw ZEEP ) and subtract (Pes PEEP -Pes ZEEP The corrected transpulmonary pressure was obtained.

[0234] In some embodiments, step 210 further corrects the transpulmonary pressure value using lung compliance and chest wall compliance; specifically, step 210 obtains lung compliance Clung and chest wall compliance Ccw; it should be noted that there are various methods for obtaining lung compliance Clung and chest wall compliance Ccw in step 210, for example, step 210 can obtain chest wall compliance Ccw using the following formula:

[0235]

[0236] TV represents tidal volume, PesI represents end-inspiratory esophageal pressure, and PEEP represents... es End-tidal esophageal pressure;

[0237] The overall compliance C can then be calculated using the following formula. state :

[0238]

[0239] Where TV is tidal volume, Pplat is plateau pressure, PEEP is positive end-expiratory airway pressure; the total compliance C is calculated as follows: stateIn the case of chest wall compliance (Ccw), lung compliance (Clung) can be calculated by solving the following equation:

[0240]

[0241] After obtaining lung compliance Clung and chest wall compliance Ccw, processor 50 can calculate the error compensation value using the following formula:

[0242]

[0243] Where ΔPtrans erro The error compensation value is Ptrans, which is the transpulmonary pressure value, and Plung is the intrapulmonary pressure value.

[0244] Step 210 subtracts the error compensation value from the transpulmonary pressure to obtain the corrected transpulmonary pressure.

[0245] For example, after obtaining the patient's transdiaphragmatic pressure in step 200, the transdiaphragmatic pressure is corrected. The following example illustrates the specific method for correcting transdiaphragmatic pressure.

[0246] Step 210: Obtain the esophageal pressure Pes when the positive end-expiratory pressure is non-zero. PEEP Psto (intragastric pressure) PEEP And to obtain the esophageal pressure Pes when the positive end-expiratory pressure is zero. ZEEP Psto (intragastric pressure) ZEEP Step 210 adds the transdiaphragmatic pressure (Pes) PEEP -Pes ZEEP ) and subtract (Psto) PEEP -Psto ZEEP The corrected transdiaphragmatic pressure is obtained.

[0247] In some embodiments, step 210 can be omitted, that is, the obtained patient pressure is not corrected, for example, as described above. Figure 8 This excludes the example of step 210, as mentioned above. Figure 9 This includes examples such as step 210.

[0248] Step 300: Calculate the energy acting on the patient's respiratory system during mechanical ventilation based on the obtained pressure and gas flow rate.

[0249] In some embodiments, step 300 integrates the collected pressure and gas flow rate over a preset unit time—e.g., 1 minute—to obtain the energy of mechanical ventilation acting on the patient's respiratory system. In some embodiments, step 300 integrates the collected pressure and gas flow rate over one respiratory cycle and multiplies it by the respiratory rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system. The following explanation of how to calculate the energy of mechanical ventilation acting on the patient's respiratory system is further illustrated by considering pressure at different locations within the respiratory system.

[0250] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on airway pressure and gas flow rate. Specifically, step 300 integrates the airway pressure and gas flow rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system, as shown in the following formula:

[0251]

[0252] Energy rs Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating airway pressure and gas flow rate per respiratory cycle. Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to per minute by combining the respiratory rate, as shown in the following formula:

[0253]

[0254] Where airway pressure (Paw) is measured in cmH2O; gas flow rate (Flow) is measured in L / min; inspiratory time (Tinsp) per respiratory cycle is measured in seconds; respiratory rate (RR) is measured in minutes; and power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating airway pressure and gas flow rate. rs The unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Alternatively, you can directly sum the Energyrs from all cycles within one minute to obtain the energy per minute.

[0255] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on airway pressure and gas flow rate, the potential energy generated by the tidal volume portion of positive end-expiratory pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, and it can often be omitted because additional positive end-expiratory pressure release is required. When this potential energy is considered, the above formula becomes:

[0256]

[0257] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0258]

[0259] In these two formulas, PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0260] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on airway pressure and gas flow rate. This can represent the energy exerted by mechanical ventilation on the patient's entire respiratory system, such as the total energy exerted on the patient's trachea, chest wall, and lungs.

[0261] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the intrapulmonary pressure and gas flow rate. It should be noted that the intrapulmonary pressure can be collected by the pressure sensor 10 or estimated through methods such as air pressure channels, as described in detail above and will not be repeated here. In some examples, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the intrapulmonary pressure and gas flow rate, as shown in the following formula:

[0262]

[0263] Energy lung Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating intrapulmonary pressure and gas flow rate per respiratory cycle. Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to energy per minute by combining the respiratory rate, as shown in the following formula:

[0264]

[0265] Where Plung (intrapulmonary pressure) is measured in cmH2O; Flow (gas flow rate) is measured in L / min; Tinsp (inspiratory time per respiratory cycle) is measured in seconds; RR (respiratory rate) is measured in minutes; and Power (energy exerted by mechanical ventilation on the patient's respiratory system) is calculated by integrating Plung and Flow. lung The unit can be J / min. Since 1cmH2O * 1L / min = 0.098J / min, the formula above contains a coefficient of 0.098. Of course, depending on the specific needs, energy per second or per hour can be calculated, in which case the corresponding unit would be J / s or J / h. Correspondingly, the coefficient 0.098 in the above formula represents other values ​​converted from the unit.

[0266] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on intrapulmonary pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory intrapulmonary pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0267]

[0268] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0269]

[0270] In these two formulas, PlungE Volume Tidal volume is the volume of air exhaled when the intrapulmonary pressure drops to 0 at the end of exhalation, measured in liters (L). PlungE is the intrapulmonary pressure at the end of exhalation.

[0271] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on intrapulmonary pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the lungs and chest wall of the patient's respiratory system.

[0272] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the transpulmonary pressure and gas flow rate values. For example, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the transpulmonary pressure and gas flow rate, as shown in the following formula:

[0273]

[0274] Energy tr Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, calculated by integrating transpulmonary pressure and gas flow rate per respiratory cycle; Tinsp is the inspiratory time of each respiratory cycle, Ptrans is the transpulmonary pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be converted to energy per minute by combining the respiratory rate, as shown in the following formula.

[0275]

[0276] Where transpulmonary pressure Ptrans is measured in cmH2O; gas flow rate is measured in L / min; inspiratory time Tinsp per respiratory cycle is measured in seconds; RR is the respiratory rate, measured in minutes; and Power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating transpulmonary pressure and gas flow rate. tr The unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Similarly, the unit and coefficient can be set as needed.

[0277] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on transpulmonary pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory transpulmonary pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0278]

[0279] Convert the energy per minute based on the respiratory rate:

[0280]

[0281] In these two formulas, PtansE volume PtransE is the tidal volume caused by the transpulmonary pressure at the end of expiration, measured in liters (L). Specifically, it is the volume exhaled when the transpulmonary pressure at the end of expiration drops to 0. PtransE is the transpulmonary pressure at the end of expiration.

[0282] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on transpulmonary pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the lungs of the patient's respiratory system.

[0283] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate values. For example, the energy of mechanical ventilation acting on the patient's respiratory system is obtained by integrating the transdiaphragmatic pressure and gas flow rate, as shown in the following formula:

[0284]

[0285] Energy di Tinsp is the energy exerted on the patient's respiratory system by mechanical ventilation, obtained by integrating the transdiaphragmatic pressure and gas flow rate in a single respiratory cycle; Tinsp is the inspiratory time of each respiratory cycle, Pdi is the transdiaphragmatic pressure, and Flow is the gas flow rate. Alternatively, the energy calculated per cycle can be combined with the respiratory rate to convert it to energy per minute, as shown in the following formula.

[0286]

[0287] The unit of transpulmonary pressure Pdi is cmH2O; the unit of gas flow rate is L / min; the unit of inspiratory time Tinsp per respiratory cycle is s; RR is the respiratory rate, in minutes; and Power is the energy exerted by mechanical ventilation on the patient's respiratory system, obtained by integrating transdiaphragmatic pressure and gas flow rate. diThe unit is J / min. Since 1cmH2O*1L / min=0.098J / min, the formula above contains a coefficient of 0.098. Similarly, the unit and coefficient can be set as needed.

[0288] In some embodiments, when calculating the energy of mechanical ventilation on the patient's respiratory system based on transdiaphragmatic pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by the end-expiratory transdiaphragmatic pressure can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When this portion of potential energy is considered, the above formula becomes:

[0289] Convert the energy per minute based on the respiratory rate:

[0290]

[0291] In these two formulas, PdiE volume Tidal volume is the volume of air exhaled when the transdiaphragmatic pressure drops to 0 at the end of exhalation, measured in liters (L). PdiE is the transdiaphragmatic pressure at the end of exhalation.

[0292] The energy exerted by mechanical ventilation on the patient's respiratory system can be calculated based on the transdiaphragmatic pressure and gas flow rate, which can represent the energy exerted by mechanical ventilation on the diaphragm in the patient's respiratory system.

[0293] Step 400: Obtain ventilation parameters. In some embodiments, ventilation parameters include ventilation control parameters and / or respiratory system-related parameters. In some embodiments, ventilation control parameters may include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio. Typically, in volume-mode mechanical ventilation, the ventilation control parameters involved include tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio; in pressure-mode mechanical ventilation, the ventilation control parameters involved include the contribution of tidal volume, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio. In some embodiments, respiratory system-related parameters may include one or more of patient respiratory system compliance and respiratory system resistance.

[0294] Step 500: Determine the contribution of ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation. The following explains how step 50 determines the contribution of ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

[0295] As described above, in some embodiments, ventilation control parameters may include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio. When determining the contribution of any ventilation control parameter, other ventilation control parameters can be kept constant. Then, the relationship between the ventilation control parameter whose contribution needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be determined. For example, by changing the ventilation control parameter whose contribution needs to be determined by a fixed amount, the corresponding change in energy acting on the patient's respiratory system during mechanical ventilation can be obtained. Then, through fitting—for example, linear fitting or exponential fitting—the relationship between the ventilation control parameter whose contribution needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be obtained, thereby determining the contribution of that ventilation control parameter. Taking mechanical ventilation in volume mode as an example, the ventilation control parameters involved in this mode typically include tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio. To calculate the contribution of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation, the gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio can be kept and set to fixed values. Then, the value of tidal volume can be changed, for example, by increasing the tidal volume by a fixed percentage X% each time—for example, 2%. Then, the corresponding percentage increase in energy acting on the patient's respiratory system during mechanical ventilation—for example, Y1%, Y2%, ..., Yn%—can be obtained sequentially. Then, the relationship between X and Y can be obtained by fitting. For example, let's assume K = Y / X, then the contribution of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation is K. Taking Table 1 above as an example, the change from state 1 to state 2 is due to the change in ventilation parameter TV from 500 to 1000, which is an increase of 100%. Correspondingly, power increases from 5.82 to 17.4, which is an increase of approximately 200%. If linear fitting is performed, the rate of change of TV, or the contribution value, is 2. The change from state 1 to state 3 is due to the change in ventilation parameter Rate from 12 to 24, which is an increase of 100%. Correspondingly, power increases from 5.82 to 14.46, which is an increase of approximately 150%. If linear fitting is performed, the rate of change of Rate, or the contribution value, is 1.5. Understandably, when gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio are kept or set to fixed values, these fixed values ​​will affect the contribution of tidal volume. For example, if the gas flow rate is set to two different fixed values, the contribution of tidal volume will generally be different when calculated separately. Nevertheless, the order of the contribution of these ventilation control parameters to the energy acting on the patient's respiratory system during mechanical ventilation is generally fixed.

[0296] As described above, in some embodiments, respiratory system-related parameters may include one or more of the patient's respiratory system compliance and respiratory system resistance. The contribution of respiratory system compliance to the energy acting on the patient's respiratory system during mechanical ventilation can be expressed as the proportion of the work done to overcome respiratory system compliance to the energy acting on the patient's respiratory system during mechanical ventilation; similarly, the contribution of respiratory system resistance to the energy acting on the patient's respiratory system during mechanical ventilation can be expressed as the proportion of the work done to overcome respiratory system resistance to the energy acting on the patient's respiratory system during mechanical ventilation. This will be explained in detail below. Please refer to the above text. Figure 5 The figure shows the static pressure-volume curve (PV curve) of the respiratory system, which reflects the mechanical state of the patient's respiratory system. The horizontal axis of the figure represents airway pressure (Paw). In some other examples, the horizontal axis can also represent intrapulmonary pressure (Plung), transpulmonary pressure (Ptrans), or transdiaphragmatic pressure (Pdi), etc.

[0297] Let's take airway pressure (Paw) on the horizontal axis as an example. In the diagram, A represents the kinetic energy component, indicating the amount of work done to overcome respiratory system resistance. B, C, and D represent the potential energy component, which is related to respiratory system compliance. Specifically, A and B are dynamically changing, doing work as tidal volume and driving pressure change. C and D are statically constant. When the driving pressure changes above the positive end-expiratory pressure (PEEP), the tidal volume and pressure related to PEEP do not do work, but there is elastic potential energy, which is part of the energy acting on the patient's respiratory system during mechanical ventilation.

[0298] In one example, the potential energy components related to respiratory system compliance in the diagram, namely B, C, and D, can be calculated using the following formula:

[0299]

[0300] Energy C To characterize the energy related to respiratory system compliance in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate; PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0301] In some examples, the potential energy related to respiratory system compliance can be further divided into the potential energy related to dynamic respiratory system compliance and the potential energy related to static respiratory system compliance. Specifically, the work done to overcome the dynamic compliance of the respiratory system, i.e., the potential energy components of B and C in the figure, is:

[0302]

[0303] Energy Cdyn To characterize the energy associated with respiratory system dynamic compliance in a single cycle—that is, the work done to overcome respiratory system dynamic compliance—Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0304] The work done to overcome the static compliance of the respiratory system, which is the potential energy component at point D in the diagram, is as follows:

[0305]

[0306] Energy Cstat To characterize the energy associated with respiratory system static compliance in a single cycle—that is, the work done to overcome respiratory system static compliance—PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0307] In one example, the work done to overcome the resistance of the respiratory system, i.e., the kinetic energy A, can be calculated using the following formula:

[0308]

[0309] Energy R To characterize the work done in a single cycle to overcome respiratory resistance, Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0310] Of course, the energy calculated from a single cycle can also be converted into a per-minute amount by combining it with the breathing rate. Below is a discussion of the energy mentioned above. C Energy Cdyn Energy Cstat and Energy R Each of these will be explained separately.

[0311] Energy related to respiratory compliance in a single cycle C The conversion is as follows:

[0312]

[0313] Energy associated with respiratory system dynamic compliance in a single cycle Cdyn The conversion is as follows:

[0314]

[0315] Energy associated with respiratory system static compliance in a single cycle Cstat The conversion is as follows:

[0316]

[0317] Energy is the work done in a single cycle to overcome respiratory resistance. R The conversion is as follows:

[0318]

[0319] In the above formulas, the units for airway pressure (Paw) and intrapulmonary pressure (Plung) are both cmH2O; the unit for gas flow rate (Flow) is L / min; the unit for inspiratory time (Tinsp) per respiratory cycle is s; RR is the respiratory rate, in units of per minute; and Power is the energy per minute related to respiratory system compliance. C Energy per minute related to respiratory system dynamic compliance. Cdyn Energy per minute per cycle related to respiratory system static compliance. Cstat and the work done per minute to overcome respiratory resistance. R The units are all J / min. Since 1cmH2O*1L / min=0.098J / min, there is a coefficient of 0.098 in the above formula.

[0320] Of course, you can also directly use the Energy from all cycles within 1 minute. C The energy per minute is accumulated to obtain the power. C Directly convert all cycles of Energy within 1 minute Cdyn The energy per minute is accumulated to obtain the power. Cdyn Directly convert all cycles of Energy within 1 minute Cstat The energy per minute is accumulated to obtain the power. Cstat Directly convert all cycles of Energy within 1 minute R The energy per minute is accumulated to obtain the power. R .

[0321] The above calculation uses an integral method to determine the contribution of respiratory system-related parameters to the energy exerted on the patient's respiratory system during mechanical ventilation. In some embodiments, a formula method can also be used to calculate the contribution of respiratory system-related parameters to the energy exerted on the patient's respiratory system during mechanical ventilation.

[0322] Figure 6 and Figure 5Similarly, it is also a static pressure-volume curve (PV curve) of the respiratory system. Let's take... Figure 6 Taking airway pressure (Paw) as an example, the energy acting on the patient's respiratory system during mechanical ventilation is:

[0323]

[0324] Energy rs To characterize the energy acting on the patient's respiratory system during a single ventilation cycle, TV represents tidal volume, CRS represents respiratory system compliance, RR represents respiratory rate, I:E represents the ratio of inspiratory time to expiratory time (i.e., respiratory ratio), Raw represents respiratory system resistance, and PEEP represents positive end-expiratory airway pressure. Alternatively, the energy acting on the patient's respiratory system during a single mechanical ventilation cycle can also be expressed as Energy. rs The formula for converting respiratory rate to volume per minute is as follows:

[0325]

[0326] The amount of power per minute rs The units are J / min; respiratory rate (RR) is measured in minutes; tidal volume (TV) is measured in liters (L); respiratory system compliance (Crs) is measured in ml / cmH2O; respiratory system resistance (Raw) is measured in cmH2O / L / s; and positive end-expiratory airway pressure (PEEP) is measured in cmH2O.

[0327] When calculating the energy acting on the patient's respiratory system during ventilation, the potential energy generated by the tidal volume portion of positive end-expiratory pressure (PEEP) can generally be considered. This portion of energy is usually a fixed value and does not change with mechanical ventilation. Furthermore, because additional PEEP release is required, it can often be omitted. When this potential energy is considered, the formula above becomes:

[0328]

[0329] After converting the unit based on the respiratory rate, the energy per minute is obtained:

[0330]

[0331] In these two formulas, PEEP Volume Tidal volume is the volume of air exhaled when the positive end-expiratory pressure (PEEP) drops to 0.

[0332] The contribution of respiratory system-related parameters is calculated below. Let's consider the energy acting on the patient's respiratory system in a single cycle during mechanical ventilation as... Energy per minute For example, the following equation holds true according to the respiratory mechanics equation:

[0333]

[0334] Flow*Raw=(Ppeak-P plat );

[0335] Where Pplat is the plateau pressure, Tinsp is the inspiratory time of each respiratory cycle, Flow is the gas flow rate, and Ppeak is the peak pressure shown in the figure; therefore, it can be deduced that:

[0336]

[0338] Therefore, the work done to overcome the resistance of the respiratory system is:

[0339]

[0340] The work done to overcome the dynamic compliance of the respiratory system is:

[0341] Energy Cdyn =TV*PEEP;

[0342] The work done to overcome the static compliance of the respiratory system is:

[0343]

[0344] The work done to overcome respiratory system compliance is equal to the work done to overcome dynamic respiratory system compliance plus the work done to overcome static respiratory system compliance.

[0345] Furthermore, the contribution of respiratory system compliance can be represented by calculating the ratio of the work done to overcome respiratory system compliance to the energy exerted on the patient's respiratory system during mechanical ventilation; similarly, the contribution of respiratory system resistance can be represented by calculating the ratio of the work done to overcome respiratory system resistance to the energy exerted on the patient's respiratory system during mechanical ventilation.

[0346] The above explains the contribution of ventilation parameters—including ventilation control parameters and / or respiratory system-related parameters—to the energy exerted on the patient's respiratory system during mechanical ventilation. Once the contribution of ventilation parameters to the energy exerted on the patient's respiratory system during mechanical ventilation is determined, there are several ways to utilize this contribution, which will be explained in detail below.

[0347] Please refer to Figure 10In some embodiments, the method for monitoring patient ventilation may further include step 600, displaying the contribution of each ventilation parameter using one or more methods such as text, numbers, characters, tables, graphs, or icons. For example, step 600 displays the name of each ventilation parameter and its corresponding contribution value. In some specific embodiments, step 600 may display the name of each ventilation parameter and its corresponding contribution value in descending or ascending order of contribution, thus allowing medical staff to easily understand the contribution of each parameter to the energy acting on the patient's respiratory system during mechanical ventilation. For example, in one example of mechanical ventilation in volume mode, step 600 may display the contribution of ventilation control parameters involved in this mode, such as tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio; as another example, in one example of mechanical ventilation in pressure mode, step 600 may display the contribution of ventilation control parameters involved in this mode, such as tidal volume, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio; of course, in some examples, whether in volume mode or pressure mode, step 600 may also display the contribution of respiratory system-related parameters such as patient respiratory compliance and respiratory resistance. Therefore, in some examples, step 600 can display the name of each ventilation control parameter and its corresponding contribution value; in some examples, step 600 displays the name of each ventilation control parameter and its corresponding contribution ranking. In some examples, step 600 can graphically display the contribution of each ventilation control parameter; in others, it can display the name of each respiratory system-related parameter and its corresponding contribution value; in still others, it can display the percentage of contribution of each respiratory system-related parameter; and in yet another example, it can graphically display the contribution of each respiratory system-related parameter. Therefore, the contribution value can be represented in various ways, such as monitored values, percentages, or rates of change. For example, displaying the contribution value of respiratory system compliance could show the actual monitored value, percentage, or rate of change of the energy exerted on the patient's respiratory system during mechanical ventilation by the work done to overcome respiratory system compliance. Similarly, displaying the contribution value of respiratory system resistance could show the actual monitored value, percentage, or rate of change of the energy exerted on the patient's respiratory system during mechanical ventilation by the work done to overcome respiratory system resistance. In some embodiments, the contribution of ventilation parameters can be displayed not only by showing the names of the ventilation parameters and their corresponding numerical contributions, as mentioned above, but also graphically—for example, in the form of bar charts, pie charts, or graphs. Table 2 and Figure 7 above are examples; other methods are as described above and will not be repeated here.

[0348] Please refer to Figure 11In some embodiments, the method for monitoring patient ventilation may further include step 700, which guides mechanical ventilation based on the contribution of ventilation parameters. The following explains how step 700 guides mechanical ventilation based on the contribution of ventilation parameters.

[0349] In some embodiments, when it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a first threshold, step 700 prompts a reduction in ventilation parameters based on contribution ranking, or controls the reduction of ventilation parameters based on contribution ranking. Specifically, it may prompt a priority reduction of the ventilation parameter with the highest contribution among the ventilation control parameters, or control a priority reduction of the ventilation parameter with the highest contribution among the ventilation control parameters. When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a relatively safe threshold, manually or automatically prioritizing a reduction of the ventilation parameter with the highest contribution among the ventilation control parameters can quickly reduce the energy exerted by mechanical ventilation on the patient's respiratory system to a safe range. In some embodiments, when it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below a second threshold, step 700 prompts an increase in ventilation parameters based on contribution ranking, or controls an increase in ventilation parameters based on contribution ranking. Specifically, it may prompt a priority increase of the ventilation parameter with the lowest contribution among the ventilation control parameters, or control a priority increase of the ventilation parameter with the lowest contribution among the ventilation control parameters. When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below a relatively safe threshold, manually or automatically increasing the ventilation parameter with the smallest contribution among the ventilation control parameters can ensure that the energy exerted by mechanical ventilation on the patient's respiratory system enters a relatively stable and safe range, preventing the energy exerted by mechanical ventilation on the patient's respiratory system from exceeding the limit and causing other problems.

[0350] In some embodiments, based on the ventilation control parameter setting command, step 700 estimates and outputs the energy of the set mechanical ventilation acting on the patient's respiratory system. Specifically, the estimated energy of the mechanical ventilation acting on the patient's respiratory system can be displayed for medical personnel to view and make decisions. In some embodiments, step 700 can also determine whether to issue an alarm based on the estimated energy of the mechanical ventilation acting on the patient's respiratory system; for example, when the estimated energy of the mechanical ventilation acting on the patient's respiratory system exceeds a first threshold or is less than a second threshold, step 700 issues an alarm.

[0351] Some studies have shown a significant clinical correlation between excessive energy exerted by mechanical ventilation on the patient's respiratory system and lung injury. Specifically, some clinical studies have indicated that when the energy exerted by mechanical ventilation on the patient's entire respiratory system exceeds 25 J / min, or when the energy exerted by mechanical ventilation on the lungs exceeds 12 J / min or 13 J / min, it significantly causes lung injury. Other clinical studies have shown that when the energy exerted by mechanical ventilation on the patient's entire respiratory system exceeds 17 J / min, it significantly increases patient mortality. Therefore, the aforementioned first and second thresholds can be set based on clinical data and the patient's specific condition.

[0352] In some embodiments, step 700 can determine whether to issue an alarm based on the proportion of contribution of each respiratory system-related parameter. For example, step 700 issues different alarms based on the proportion of contribution of respiratory system resistance, that is, when the work done to overcome respiratory system resistance accounts for different ranges of the energy acting on the patient's respiratory system during mechanical ventilation; similarly, step 700 issues different alarms based on the proportion of contribution of respiratory system compliance, that is, when the work done to overcome respiratory system compliance accounts for different ranges of the energy acting on the patient's respiratory system during mechanical ventilation. The specific alarm to trigger within a given percentage range can be determined and set by those skilled in the art based on clinical data. For example, if the contribution of respiratory compliance is between 80% and 85%, no alarm is triggered, and the patient is currently normal; if the contribution of respiratory compliance is between 70% and 75%, an alarm is triggered indicating that the patient currently has acute respiratory distress syndrome (ARDS); if the contribution of respiratory compliance is between 40% and 50%, an alarm is triggered indicating that the patient currently has chronic obstructive pulmonary disease (COPD); or, if the contribution of respiratory compliance is outside the 80% to 85% range, an alarm is triggered, and vice versa.

[0353] This document describes various exemplary embodiments with reference to them. However, those skilled in the art will recognize that changes and modifications can be made to the exemplary embodiments without departing from the scope of this document. For example, various operational steps and components for performing operational steps can be implemented in different ways depending on the specific application or considering any number of cost functions associated with the operation of the system (e.g., one or more steps can be deleted, modified, or combined with other steps).

[0354] In the above embodiments, implementation can be achieved, in whole or in part, by software, hardware, firmware, or any combination thereof. Furthermore, as those skilled in the art will understand, the principles herein can be reflected in a computer program product on a computer-readable storage medium 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-ROMs, DVDs, Blu-ray discs, etc.), flash memory, and / or the like. These computer program instructions can be loaded onto a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to form a machine, such that instructions executing on the computer or other programmable data processing apparatus can generate means for implementing a specified function. These computer program instructions can also be stored in a computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to operate in a particular manner, such that instructions stored in the computer-readable storage medium can form an article of manufacture including means for implementing the specified function. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to perform a series of operational steps on the computer or other programmable apparatus to produce a computer-implemented process, such that instructions executing on the computer or other programmable apparatus can provide steps for implementing the specified function.

[0355] While the principles herein have been illustrated in various embodiments, numerous modifications to the structure, arrangement, proportions, elements, materials, and components, particularly suited to specific environmental and operational requirements, may be used without departing from the principles and scope of this disclosure. These modifications and other alterations or alterations will be included within the scope of this document.

[0356] The foregoing specific descriptions have been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of this disclosure. Therefore, considerations for this disclosure are to be illustrative rather than restrictive, and all such modifications are to be included within its scope. Similarly, advantages, other advantages, and solutions to problems with respect to various embodiments have been described above. However, benefits, advantages, solutions to problems, and any elements that produce these, or make them more explicit, should not be construed as critical, essential, or necessary. The term “comprising” and any other variations thereof as used herein are non-exclusive inclusion, meaning that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed or not part of the process, method, system, article, or apparatus. Furthermore, the term “coupled” and any other variations thereof as used herein refer to physical connections, electrical connections, magnetic connections, optical connections, communication connections, functional connections, and / or any other connections.

[0357] Those skilled in the art will recognize that many changes can be made to the details of the above embodiments without departing from the basic principles of the invention. Therefore, the scope of the invention should be determined only by the following claims.

Claims

1. A method for monitoring ventilation in patients, characterized in that, include: Acquire the patient's pressure during ventilation, the pressure reflecting the pressure acting on the patient's respiratory system during ventilation; Obtain the gas flow rate of the patient during ventilation; The energy acting on the patient's respiratory system during mechanical ventilation is calculated based on the obtained pressure and gas flow rate. Obtain ventilation parameters during mechanical ventilation; Determine the contribution of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

2. The method as described in claim 1, characterized in that, The ventilation parameters mentioned above can affect the energy applied to the patient's respiratory system during mechanical ventilation.

3. The method as described in claim 1 or 2, characterized in that, The ventilation parameters during mechanical ventilation include ventilation control parameters and / or respiratory system-related parameters; the ventilation control parameters include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio; and the respiratory system-related parameters include one or more of respiratory system compliance and respiratory system resistance.

4. The method as described in claim 1, characterized in that, Determining the contribution of the ventilation parameters during mechanical ventilation to the energy acting on the patient's respiratory system during mechanical ventilation includes at least one of the following: The contribution of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by monitoring the mechanical energy generated by the ventilation parameters. The contribution of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by measuring the proportion of mechanical energy generated by the ventilation parameter. The contribution of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by measuring the rate of change of mechanical energy generated by the ventilation parameter.

5. The method according to any one of claims 1 to 4, characterized in that, Also includes: This displays the contribution of each ventilation parameter.

6. The method as described in claim 5, characterized in that, The contribution of each ventilation parameter can be displayed using one or more of the following methods: text, numbers, characters, tables, graphs, or icons.

7. The method according to any one of claims 1 to 6, characterized in that, Also includes: Mechanical ventilation is guided based on the stated contribution.

8. The method as described in claim 7, characterized in that, The method of guiding mechanical ventilation based on the contribution includes: When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds the first threshold, the ventilation parameters are reduced based on the contribution ranking, or the ventilation parameters are controlled to be reduced based on the contribution ranking.

9. The method as described in claim 7, characterized in that, The method of guiding mechanical ventilation based on the contribution includes: When it is determined that the energy exerted by mechanical ventilation on the patient's respiratory system is below the second threshold, the ventilation parameters are increased based on the contribution ranking, or the ventilation parameters are increased based on the contribution ranking.

10. The method as described in claim 7, characterized in that, The method of guiding mechanical ventilation based on the contribution includes: Based on the ventilation control parameter setting command, estimate and output the energy of the set mechanical ventilation acting on the patient's respiratory system.

11. The method as described in claim 10, characterized in that, The method of guiding mechanical ventilation based on the contribution level also includes: The alarm is triggered based on the estimated energy exerted by mechanical ventilation on the patient's respiratory system.

12. The method as described in claim 7, characterized in that, The method of guiding mechanical ventilation based on the contribution includes: Whether to issue an alarm is determined based on the contribution of each respiratory system-related parameter.

13. The method as described in claim 1, characterized in that, The pressure reflects the pressure acting on different sites of the patient's respiratory system during ventilation; or, the pressure reflects the pressure acting on one or more sites of the patient's respiratory system during ventilation.

14. A device for monitoring ventilation in patients, characterized in that, include: A pressure sensor collects the patient's pressure during ventilation, the pressure reflecting the pressure acting on the patient's respiratory system during ventilation; A flow sensor collects the gas flow rate during ventilation. The processor is configured to acquire the patient's pressure and gas flow rate during ventilation, and calculate the energy acting on the patient's respiratory system during mechanical ventilation based on the acquired pressure and gas flow rate; the processor also acquires ventilation parameters during mechanical ventilation and determines the contribution of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

15. The method as described in claim 14, characterized in that, The ventilation parameters mentioned above can affect the energy applied to the patient's respiratory system during mechanical ventilation.

16. The apparatus as claimed in claim 14 or 15, characterized in that, The ventilation parameters include ventilation control parameters and / or respiratory system-related parameters; the ventilation control parameters include one or more of tidal volume, gas flow rate, driving pressure, positive end-expiratory pressure, respiratory rate, and respiratory ratio; and the respiratory system-related parameters include one or more of respiratory system compliance and respiratory system resistance.

17. The method as described in claim 14, characterized in that, The processor determines the contribution of the ventilation parameters during mechanical ventilation to the energy acting on the patient's respiratory system during mechanical ventilation, including at least one of the following: The contribution of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by monitoring the mechanical energy generated by the ventilation parameters. The contribution of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by measuring the proportion of mechanical energy generated by the ventilation parameter. The contribution of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation is obtained by measuring the rate of change of mechanical energy generated by the ventilation parameter.

18. The apparatus as claimed in any one of claims 14 to 17, characterized in that, It also includes a display showing the contribution of each ventilation parameter.

19. The apparatus as claimed in any one of claims 14 to 17, characterized in that, The processor also guides mechanical ventilation based on the contribution level.

20. The apparatus as claimed in claim 19, characterized in that, The processor guides mechanical ventilation based on the contribution level, including: When the processor determines that the energy exerted by mechanical ventilation on the patient's respiratory system exceeds a first threshold, it prompts to prioritize reducing the ventilation parameter that contributes the most to the ventilation control parameters, or controls to prioritize reducing the ventilation parameter that contributes the most to the ventilation control parameters; and / or, When the processor determines that the energy exerted by mechanical ventilation on the patient's respiratory system is below a second threshold, it prompts to prioritize increasing the ventilation parameter with the lowest contribution among the ventilation control parameters, or controls to prioritize increasing the ventilation parameter with the lowest contribution among the ventilation control parameters; and / or, Based on the ventilation control parameter setting command, the processor estimates and outputs the energy of the set mechanical ventilation acting on the patient's respiratory system; and / or, Based on the estimated energy exerted by mechanical ventilation on the patient's respiratory system, the processor determines whether to issue an alarm; and / or, The processor determines whether to issue an alarm based on the contribution of each respiratory system-related parameter.

21. The method as described in claim 14, characterized in that, The pressure reflects the pressure acting on different sites of the patient's respiratory system during ventilation; or, the pressure reflects the pressure acting on one or more sites of the patient's respiratory system during ventilation.

22. The apparatus as claimed in claim 14, characterized in that, The device is a patient monitor, a patient monitoring module, or a medical ventilation device.

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