A method and device for ventilating and monitoring a patient

Abstract

A method and apparatus for ventilatory monitoring of a patient may include: obtaining the pressure of the patient during ventilation (200), the pressure reflecting the pressures acting on different sites of the patient's respiratory system during ventilation; obtaining the gas flow rate of the patient during ventilation (100); calculating the energy acting on the patient's respiratory system during mechanical ventilation based on the obtained pressure and gas flow rate (300); obtaining ventilation parameters (400); and determining the contribution degree of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation (500).

Description

Technical Field

[0001] The present invention relates to a method and a device for ventilatory monitoring of a patient. Background Art

[0002] Human respiration refers to the periodic and rhythmic inhalation and exhalation of gases, absorbing oxygen and discharging carbon dioxide, thereby achieving gas exchange. When some patients are unable to breathe spontaneously, mechanical ventilation can be used to assist the patients to complete breathing. For example, in the case where a patient has no spontaneous breathing, usually an external device such as a ventilator can be used to provide respiratory support to the patient. It can be seen that mechanical ventilation is a ventilation mode that uses a mechanical device to replace, control, or assist the patient's spontaneous breathing movement. However, mechanical ventilation is also likely to cause ventilator-induced lung injury (VILI) to the patient. Typically, during the mechanical ventilation process, inappropriate settings of related mechanical devices such as ventilators can cause lung injury to the patient. Therefore, how to control, adjust, and set the parameters of related mechanical devices to avoid mechanical ventilation causing lung injury to the patient, and even improve the patient's lung-related parameters, is an issue that technicians have been researching. Summary of the Invention

[0003] The present invention mainly provides a method and a device for ventilatory monitoring of a patient.

[0004] According to a first aspect, in one embodiment, a method for ventilatory monitoring of a patient is provided, including:

[0005] Obtaining the pressure of the patient during ventilation, where the pressure reflects the pressures acting on different sites of the patient's respiratory system during ventilation;

[0006] Obtaining the gas flow rate of the patient during ventilation;

[0007] Calculating the energy acting on the patient's respiratory system during mechanical ventilation according to the obtained pressure and gas flow rate;

[0008] Obtaining ventilation parameters;

[0009] Determining the contribution degree of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

[0010] 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.

[0011] In one embodiment, the method for ventilatory monitoring of a patient further includes: displaying the contribution degrees of each ventilatory parameter.

[0012] In one embodiment, the contribution degrees of each ventilatory parameter are displayed in one or more of the ways of text, numbers, characters, tables, graphs or icons.

[0013] In one embodiment, the method for ventilatory monitoring of a patient further includes: guiding mechanical ventilation according to the contribution degrees.

[0014] In one embodiment, the guiding of mechanical ventilation according to the contribution degrees includes:

[0015] When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds a first threshold, prompting to reduce the ventilatory parameter according to the contribution degree ranking, or controlling to reduce the ventilatory parameter according to the contribution degree ranking.

[0016] In one embodiment, the guiding of mechanical ventilation according to the contribution degrees includes:

[0017] When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than a second threshold, prompting to increase the ventilatory parameter according to the contribution degree ranking, or controlling to increase the ventilatory parameter according to the contribution degree ranking.

[0018] In one embodiment, the guiding of mechanical ventilation according to the contribution degrees includes:

[0019] Estimating and outputting the energy of the set mechanical ventilation acting on the patient's respiratory system according to the setting command of the ventilation control parameter.

[0020] In one embodiment, the guiding of mechanical ventilation according to the contribution degrees further includes:

[0021] Judging whether to give an alarm according to the estimated energy of the mechanical ventilation acting on the patient's respiratory system.

[0022] In one embodiment, the guiding of mechanical ventilation according to the contribution degrees includes:

[0023] Judging whether to give an alarm according to the contribution degrees of each respiratory system-related parameter.

[0024] According to a second aspect, in one embodiment, a device for ventilatory monitoring of a patient is provided, including:

[0025] A pressure sensor, which collects the pressure of the patient during ventilation, and the pressure reflects the pressures acting on different sites of the patient's respiratory system during ventilation;

[0026] A flow sensor, which collects the gas flow rate of the patient during ventilation;

[0027] A processor for obtaining the pressure of a patient during ventilation and the gas flow rate of the patient during ventilation, and calculating the energy acting on the patient's respiratory system during mechanical ventilation based on the obtained pressure and gas flow rate; the processor also obtains ventilation parameters and determines the contribution degree of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

[0028] 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.

[0029] In one embodiment, the device for ventilating and monitoring a patient further includes a display for displaying the contribution degree of each ventilation parameter.

[0030] In one embodiment, the processor also guides mechanical ventilation according to the contribution degree.

[0031] In one embodiment, the processor guiding mechanical ventilation according to the contribution degree includes:

[0032] When it is determined that the energy acting on the patient's respiratory system during mechanical ventilation exceeds a first threshold, the processor prompts to reduce the ventilation parameters according to the contribution degree ranking, or controls to reduce the ventilation parameters according to the contribution degree ranking; and / or,

[0033] When it is determined that the energy acting on the patient's respiratory system during mechanical ventilation is lower than a second threshold, the processor prompts to increase the ventilation parameters according to the contribution degree ranking, or controls to increase the ventilation parameters according to the contribution degree ranking.

[0034] In one embodiment, the processor guiding mechanical ventilation according to the contribution degree includes:

[0035] According to the setting command of the ventilation control parameters, the processor estimates and outputs the energy acting on the patient's respiratory system after the setting.

[0036] In one embodiment, the processor guiding mechanical ventilation according to the contribution degree includes:

[0037] According to the estimated energy acting on the patient's respiratory system during mechanical ventilation, it is determined whether to give an alarm.

[0038] In one embodiment, the processor guiding mechanical ventilation according to the contribution degree includes:

[0039] According to the contribution degree of each respiratory system-related parameter, the processor determines whether to give an alarm.

[0040] In one embodiment, the device for ventilatory monitoring of a patient is a patient monitor, a patient monitoring module, or a medical ventilator.

[0041] According to a third aspect, an embodiment provides a computer-readable storage medium including a program that can be executed by a processor to implement the method described in any one of the embodiments herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 FIG. 9 is a schematic structural diagram of a device for ventilatory monitoring of a patient according to an embodiment;

[0043] Figure 2 FIG. 13 is a schematic structural diagram of a device for ventilatory monitoring of a patient according to another embodiment;

[0044] Figure 3 FIG. 17 is a schematic structural diagram of a device for ventilatory monitoring of a patient according to still another embodiment;

[0045] Figure 4 FIG. 21 is a schematic structural diagram of a device for ventilatory monitoring of a patient according to yet another embodiment;

[0046] Figure 5 FIG. 25 is a schematic diagram of a static pressure-volume curve of the respiratory system according to an embodiment;

[0047] Figure 6 FIG. 29 is a schematic diagram of a static pressure-volume curve of the respiratory system according to another embodiment;

[0048] FIGS. 7(a) and 7(b) are schematic diagrams showing contribution degrees;

[0049] Figure 8 FIG. 36 is a flowchart of a method for ventilatory monitoring of a patient according to an embodiment;

[0050] Figure 9 FIG. 40 is a flowchart of a method for ventilatory monitoring of a patient according to another embodiment;

[0051] Figure 10 FIG. 44 is a flowchart of a method for ventilatory monitoring of a patient according to still another embodiment;

[0052] Figure 11 FIG. 48 is a flowchart of a method for ventilatory monitoring of a patient according to yet another embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The present invention will be further described in detail below in conjunction with the accompanying drawings through specific embodiments. Similar elements in different embodiments are denoted by related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid inundating the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0054] In addition, 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 also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment, and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0055] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described, and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0056] Some embodiments of the present invention disclose a device for ventilatory monitoring of a patient. Please refer to Figure 1 , the device for ventilatory monitoring of a patient may include a pressure sensor 10, a flow sensor 30, and a processor 50. The device for ventilatory monitoring of a patient according to the present invention can be applied to various occasions. For example, in some embodiments, the device for ventilatory monitoring of a patient according to the present invention can be a patient monitor or a patient monitoring module, etc. In some embodiments, it can be a medical ventilatory device, such as a ventilator and an anesthesia machine, etc. The following will be described separately.

[0057] In some embodiments, the device for ventilatory monitoring of a patient can be a patient monitor.

[0058] Please refer to Figure 2, in some embodiments, the device for ventilatory monitoring of a patient may have an independent housing, and a sensor interface area may be provided on the housing panel. The sensor interface area may integrate multiple sensor interfaces for connecting to various external physiological parameter sensor accessories 111, and in some embodiments, it may also be connected to a pressure sensor 10 and a flow sensor 30. The housing panel may also include one or more of a small IXD display area, a display 70, an input interface circuit 122, and an alarm circuit 120 (such as an LED alarm area). The device for ventilatory monitoring of a patient has an external communication interface 119 and a power supply interface 116 for communicating with a host of medical devices such as a patient monitor, a ventilator, and an anesthetic machine and obtaining power from the host of medical devices. The device for ventilatory monitoring of a patient may also support an externally pluggable parameter module. It can form a plug-in monitor host by inserting the parameter module and serve as a part of the monitor, or it can be connected to the host through a cable, with the externally pluggable parameter module being an external accessory of the monitor. The internal circuit of the device for ventilatory monitoring of a patient is placed inside the housing and may include one or more signal acquisition circuits 112 corresponding to physiological parameters and a front-end signal processing circuit 113. The signal acquisition circuits 112 may be selected from an electrocardiogram circuit, a respiration circuit, a body temperature circuit, a blood oxygen circuit, a non-invasive blood pressure circuit, an invasive blood pressure circuit, etc. These signal acquisition circuits 112 are respectively electrically connected to the corresponding sensor interfaces for being electrically connected to sensor accessories 111 corresponding to different physiological parameters, and their output ends are coupled to the front-end signal processing circuit 113. The communication port of the front-end signal processing circuit 113 is coupled to a processor 50, and the processor 50 is electrically connected to the external communication interface 119 and the power supply interface 116. The sensor accessories 111 and the signal acquisition circuits 112 corresponding to various physiological parameters may adopt general circuits in the prior art. The front-end signal processing circuit 113 completes sampling and analog-to-digital conversion of the output signals of the signal acquisition circuits 112 and outputs control signals to control the measurement process of physiological signals. These parameters include but are not limited to: electrocardiogram, respiration, body temperature, blood oxygen, non-invasive blood pressure, and invasive blood pressure parameters. The front-end signal processing circuit 113 may be implemented using a single-chip microcomputer or other semiconductor devices. For example, an LPC2136 of NXP Semiconductors or a mixed-signal single-chip microcomputer such as the ADuC7021 of Analog Devices may be selected, or it may also be implemented using an ASIC or an FPGA. The front-end signal processing circuit 113 may be powered by an isolated power supply. After the sampled data is simply processed and packed, it is sent to the processor 50 through an isolated communication interface. For example, the front-end signal processing circuit 113 may be coupled to the processor 50 through an isolated power supply interface 114 and a communication interface 115.The reason why the front-end signal processing circuit 113 is powered by an isolated power supply is that the DC / DC power supply isolated by a transformer plays a role in isolating the patient from the power supply device. The main purposes are as follows: 1. Isolate the patient. Through the isolation transformer, the application part is floating-grounded, making the patient leakage current small enough; 2. Prevent the voltage or energy during defibrillation or electrosurgical applications from affecting the circuit boards and components of the intermediate circuit such as the main control board (ensured by creepage distance and clearance). Of course, the front-end signal processing circuit 113 can also be directly connected to the processor 50 through a cable. The processor 50 is used to complete the calculation of physiological parameters and send the calculation results and waveforms of the parameters to the host (such as a host with a display, a PC, a central station, etc.) through the external communication interface 119; among them, the processor 50 can be directly connected to the external communication interface 119 through a cable for communication, and directly connected to the power interface 116 through a cable for power supply; the device for ventilatory monitoring of the patient may further include a power supply and battery management circuit 117. The power supply and battery management circuit 117 takes power from the host through the power interface 116 and supplies it to the processor 50 after processing, such as rectification and filtering, etc.; the power supply and battery management circuit 117 can also monitor, manage, and provide power protection for the power obtained from the host through the power interface 116. The external communication interface 119 can be one or a combination of local area network interfaces composed of Ethernet, Token Ring, Token Bus, and the Fiber Distributed Data Interface (FDDI) which is the backbone network of these three networks, and can also be one or a combination of wireless interfaces such as infrared, Bluetooth, wifi, WMTS communication, etc., or can also be one or a combination of wired data connection interfaces such as RS232, USB, etc. The external communication interface 119 can also be a combination of a wireless data transmission interface and a wired data transmission interface. The host can be any computer device such as the host of a patient monitor, a computer, etc. By installing the matching software, a monitoring device can be formed. The host can also be a communication device, such as a mobile phone. The device for ventilatory monitoring of the patient sends data to a mobile phone supporting Bluetooth communication through the Bluetooth interface to achieve remote data transmission. After the processor 50 completes the calculation of physiological parameters, it can also judge whether the physiological parameters are abnormal. If abnormal, an alarm can be given through the alarm circuit 120. The memory 118 can store the intermediate and final data of the patient monitor, as well as the program instructions or codes to be executed by the processor 50, etc. If the patient monitor has the function of blood pressure measurement, it may further include a pump valve drive circuit 121. The pump valve drive circuit 121 is used to perform inflation or deflation operations under the control of the processor 50.

[0059] The above are some descriptions of the device for ventilatory monitoring of the patient being a patient monitor.

[0060] In some embodiments, the device for ventilatory monitoring of a patient may also be a ventilator, which is an artificial mechanical ventilation device used to assist or control the patient's spontaneous breathing movement to achieve the function of gas exchange in the lungs, reduce the body's consumption, and facilitate the recovery of respiratory function. Please refer to Figure 3 , in some embodiments, the device for ventilatory monitoring of a patient may further include a respiratory interface 211, a gas source interface 212, a breathing circuit, a breathing assistance device, and a display 70.

[0061] The breathing circuit selectively connects the gas source interface 212 and the patient's respiratory system. In some embodiments, the breathing circuit includes an exhalation branch 213a and an inhalation branch 213b. The exhalation branch 213a is connected between the breathing interface 211 and the exhaust port 213c, and is used to conduct the gas exhaled by the patient to the exhaust port 213c. The exhaust port 213c can lead to the external environment or a dedicated gas recovery device. The gas source interface 212 is used to connect to a gas source (not shown in the figure), and the gas source is used to provide gas, which can generally be oxygen, air, etc.; in some embodiments, the gas source can be a compressed gas cylinder or a central gas supply source, and supply gas to the ventilator through the gas source interface 212. The types of supplied gas include oxygen O2, air, etc. The gas source interface 212 can include conventional components such as a pressure gauge, a pressure regulator, a flow meter, a pressure reducing valve, and an air-oxygen ratio control and protection device, which are respectively used to control the flow rates of various gases (such as oxygen and air). The inhalation branch 213b is connected between the breathing interface 211 and the gas source interface 212, and is used to provide oxygen or air for the patient. For example, the gas input from the gas source interface 212 enters the inhalation 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 by the inhalation branch 213b into the patient, it can also introduce the gas exhaled by the patient into the exhaust port 213c through the exhalation branch 213a; depending on the situation, the breathing interface 211 can be a nasal cannula or a mask for wearing on the mouth and nose. The breathing assistance device is connected to the gas source interface 212 and the breathing circuit, and controls the gas provided by the external gas source to be delivered to the patient through the breathing circuit; in some embodiments, the breathing assistance device can include an exhalation controller 214a and an inhalation controller 214b. The exhalation controller 214a is arranged on the exhalation branch 213a, and is used to connect or disconnect the exhalation branch 213a according to a control instruction, or control the flow rate or pressure of the gas exhaled by the patient. Specifically, the exhalation controller 214a can include one or more of devices capable of realizing flow or pressure control, such as an exhalation valve, a one-way valve, a flow controller, a PEEP valve, etc. The inhalation controller 214b is arranged on the inhalation branch 213b, and is used to connect or disconnect the inhalation branch 213b according to a control instruction, or control the flow rate or pressure of the output gas. Specifically, the inhalation controller 214b can include one or more of devices capable of realizing flow or pressure control, such as an exhalation valve, a one-way valve, or a flow controller, etc.

[0062] The memory 215 can be used to store data or programs, such as data collected by sensors, data generated by the processor through calculations, or image frames generated by the processor. The image frames can be 2D or 3D images. Or the memory 215 can store a graphical user interface, one or more default image display settings, and programming instructions for the processor. The memory 215 can be a tangible and non-transitory computer-readable medium, such as flash memory, RAM, ROM, EEPROM, etc.

[0063] In some embodiments, the processor 50 is used to execute instructions or programs to control various control valves in the breathing assistance device, the gas 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 visual data or graphics, and output the visual data or graphics to the display 70 for display.

[0064] The above are some descriptions of the ventilator as a device for ventilating and monitoring patients. It should be noted that Figure 3 this is only an example of a ventilator, and it is not used to limit that the ventilator can only have such a structure.

[0065] In some embodiments, the device for ventilating and monitoring patients can also be an anesthesia machine, which is mainly used to provide anesthetic gas, send the anesthetic gas to the respiratory system of the patient through a breathing apparatus, and control the inhaled amount of the anesthetic gas. Please refer to Figure 4 , in some embodiments, the device for ventilating and monitoring patients may further include a breathing interface 311, a gas source interface 312, a breathing assistance device 320, an anesthetic output device 330, a breathing circuit, a memory 350, and a display 70.

[0066] The gas source interface 312 is used to connect to a gas source (not shown in the figure), and the gas source is used to provide gas. The gas can generally be oxygen, nitrous oxide (laughing gas), or air, etc. In some embodiments, the gas source can be a compressed gas cylinder or a central gas supply source, and supply gas to the anesthesia machine through the gas source interface 312. The types of supplied gas include oxygen O2, nitrous oxide N2O, air, etc. The gas source interface 312 can include conventional components such as a pressure gauge, a pressure regulator, a flow meter, a pressure reducing valve, and an N2O-O2 ratio control and protection device, which are respectively used to control the flow rates of various gases (such as oxygen, nitrous oxide, and air). The gas input through the gas source interface 312 enters the breathing circuit and forms a mixed gas with the gas originally in the breathing circuit.

[0067] The respiratory assistance device 320 is used to power the involuntary breathing of a patient and maintain the patency of the airway. In some embodiments, the respiratory assistance device 320 is connected to the gas source interface 312 and the breathing circuit, and controls the delivery of the gas provided by the external gas source to the patient through the breathing circuit. In some specific embodiments, the respiratory assistance device 320 mixes the fresh gas input from the gas source interface 312, the gas exhaled by the patient in the breathing circuit, and the anesthetic drug output by the anesthetic drug output device 330, and then outputs the mixture to the breathing interface 311 through the inhalation branch 340b to drive the patient to inhale, and receives the gas exhaled by the patient through the exhalation branch 340a. In a specific embodiment, the respiratory assistance device 320 generally includes a mechanical ventilation module, and the air flow pipeline of the mechanical ventilation module is communicated with the breathing circuit. During the anesthesia maintenance stage of the operation or when the patient has not recovered spontaneous breathing, the mechanical ventilation module is used to provide the power for the patient's breathing. In some embodiments, the respiratory assistance device 320 further includes a manual ventilation module, and the air flow pipeline of the manual ventilation module is communicated with the breathing circuit. During the induction stage before intubating the patient during the operation, it is usually necessary to use the manual ventilation module to assist the patient's breathing. When the respiratory assistance device 320 includes both a mechanical ventilation module and a manual ventilation module, the mechanical or manual ventilation mode can be switched through a mechanical or manual switch (such as a three-way valve) so as to communicate the mechanical ventilation module or the manual ventilation module with the breathing circuit, thereby controlling the patient's breathing. Those skilled in the art should understand that, according to specific needs, the anesthetic machine may only include a mechanical ventilation module or a manual ventilation module.

[0068] The anesthetic drug output device 330 is used to provide anesthetic drugs. Usually, the anesthetic drugs are mixed in the form of gas into the fresh air introduced by the gas source interface 312 and are delivered to the breathing circuit together. In a specific embodiment, the anesthetic drug output device 330 is implemented by an anesthetic vaporizer. The anesthetic drug is usually in liquid form and is stored in the anesthetic vaporizer. Optionally, the anesthetic vaporizer may include a heating device for heating the anesthetic drug to volatilize it and generate anesthetic vapor. The anesthetic drug output device 330 is communicated with the pipeline of the gas source interface 312, and the anesthetic vapor is mixed with the fresh air introduced by the gas source interface 312 and then is delivered to the breathing circuit together.

[0069] In some embodiments, the breathing circuit may include an inhalation branch 340b, an exhalation branch 340a, and a soda lime canister 340c. The inhalation branch 340b and the exhalation branch 340a are connected to form a closed loop, and the soda lime canister 340c is disposed on the pipeline of the exhalation branch 340a. The mixed gas of fresh air introduced by the gas source interface 312 is input from the inlet of the inhalation branch 340b and provided to the patient through the breathing interface 311 disposed at the outlet of the inhalation 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 disposed on the inhalation branch 340b, and the one-way valve is opened during inhalation and closed during exhalation. A one-way valve is also disposed on the exhalation branch 340a, and the one-way valve is closed during inhalation and opened during exhalation. The inlet of the exhalation branch 340a is communicated with the breathing interface 311. When the patient exhales, the exhaled gas enters the soda lime canister 340c through the exhalation branch 340a, and the carbon dioxide in the exhaled gas is filtered by the substance in the soda lime canister 340c. The gas after filtering carbon dioxide is recycled into the inhalation branch 340b.

[0070] The memory 350 can be used to store data or programs, such as the data collected by each sensor, the data generated by the processor through calculation, or the image frames generated by the processor. The 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, and programming instructions for the processor. The memory 350 can be a tangible and non-transitory computer-readable medium, such as a flash memory, a RAM, a ROM, an EEPROM, etc.

[0071] The processor 50 is used to execute instructions or programs, control various control valves in the breathing assistance device 320, the gas source interface 310, and / or the breathing circuit, or process the received data to generate the required calculation or judgment results, or generate visual data or graphics, and output the visual data or graphics to the display 70 for display.

[0072] The above is some descriptions of the device for ventilating and monitoring the patient, which is an anesthesia machine. It should be noted that the above Figure 4 is just an example of an anesthesia machine, which does not limit the structure of the anesthesia machine to be only like this.

[0073] Ventilator-induced lung injury (VILI) is a combination of multiple types of injuries caused by excessive dynamic strain and energy load. In some embodiments, by calculating the energy acting on the patient's respiratory system during mechanical ventilation, the lung injury can be evaluated more accurately, truly, and in real time. The following describes how the device for ventilating and monitoring the patient in this article calculates the energy acting on the patient's respiratory system during mechanical ventilation.

[0074] 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 inspiratory flow rate of the patient. In some embodiments, the flow sensor 30 may be a flow sensor disposed at the patient end, such as a flow sensor disposed at the patient interface, and the gas flow rate is the gas flow rate collected by the flow sensor during inspiration. In some embodiments, the number of the flow sensors 30 is multiple, including an inspiratory flow sensor and an expiratory flow sensor disposed at the mechanical ventilation end. For example, for a ventilator, it may be an inspiratory flow sensor disposed in the inspiratory branch 213b and an expiratory flow sensor disposed in the expiratory branch 213a. For an anesthesia machine, it may be an inspiratory flow sensor disposed in the inspiratory branch 340b and an expiratory flow sensor disposed 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 Y-piece flow sensor, and the gas flow rate is directly measured by the flow rates flowing into and out of the patient end. Of course, the energy acting on the patient's respiratory system during mechanical ventilation can be considered to be calculated using the gas flow rate during the entire breathing period, including the gas flow rate during inspiration and expiration.

[0075] In some embodiments, the number of the pressure sensors 10 is one or more. The pressure sensor 10 is used to collect the pressure of the patient during ventilation, and the pressure reflects 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 gastric pressure.

[0076] In some embodiments, the pressure sensor 10 may be a catheter-type pressure sensor or a fiber-optic pressure sensor, etc. By inserting the pressure sensor into the corresponding site of the patient's respiratory system, the pressure at the corresponding site can be measured. For example, by inserting the pressure sensor into the patient's airway, the airway pressure can be collected; by inserting the pressure sensor into the esophagus, the esophageal pressure can be collected; by inserting the pressure sensor into the stomach, the gastric pressure can be collected; by inserting the pressure sensor into the carina inside the trachea, the carina pressure can be collected; by inserting the pressure sensor into the stomach, the gastric pressure can be collected; by inserting the pressure sensor into the thoracic cavity through an incision, etc., the intrathoracic pressure can be collected. In some embodiments, the pressure at some sites in the respiratory system can also be used to replace or calculate the pressure at other some sites. The following will be illustrated by several examples.

[0077] In some embodiments, the carina pressure can be used to replace the intrapulmonary pressure. In some embodiments, the esophageal pressure can be used to replace the intrathoracic pressure. In some embodiments, the gastric pressure can be used to replace the intra-abdominal pressure.

[0078] In some embodiments, the processor 50 may calculate the intrapulmonary pressure based on the airway pressure. For example, in some embodiments, the processor 50 calculates the intrapulmonary pressure through the airway pressure, the respiratory system resistance, and the gas flow rate described above. In a specific example, it can be calculated by the following formula:

[0079] Plung(t) = Paw(t) - Raw * Flow(t);

[0080] Where Plung(t) refers to the function of the intrapulmonary pressure changing with time t, or the real-time intrapulmonary pressure; Paw(t) refers to the function of the airway pressure changing with time t, or the real-time airway pressure; Flow(t) is the function of the gas flow rate changing with time t during the patient's ventilation, or the real-time gas flow rate of the patient during ventilation; Raw is the respiratory system resistance.

[0081] In some embodiments, the processor 50 may calculate the transpulmonary pressure by subtracting any one of the esophageal pressure or the intrathoracic pressure from any one of the intrapulmonary pressure or the airway pressure. For example, the transpulmonary pressure is obtained by subtracting the esophageal pressure from the airway pressure. In some embodiments, the processor 50 may also correct the transpulmonary pressure, which will be specifically described below.

[0082] In some embodiments, the processor 50 also corrects the transpulmonary pressure by using the airway pressure values and esophageal pressure values in the states where the positive end-expiratory pressure is zero and non-zero; specifically, the processor 50 obtains the airway pressure Paw PEEP and the esophageal pressure Pes PEEP in the state where the positive end-expiratory pressure is non-zero, and obtains the airway pressure Paw ZEEP and the esophageal pressure Pes ZEEP in the state where the positive end-expiratory pressure is zero; the processor 50 adds (Paw PEEP -Paw ZEEP ) to the transpulmonary pressure and subtracts (Pes PEEP -Pes ZEEP ) to obtain the corrected transpulmonary pressure.

[0083] In some embodiments, the processor 50 also corrects the transpulmonary pressure value by using the lung compliance and chest wall compliance; specifically, the processor 50 obtains the lung compliance Clung and the chest wall compliance Ccw; it should be noted that there are various methods for the processor 50 to obtain the lung compliance Clung and the chest wall compliance Ccw. For example, the processor 50 can obtain the chest wall compliance Ccw through the following formula:

[0084]

[0085] Where TV is the tidal volume, PesI is the end-inspiratory esophageal pressure, and PEEP es is the end-expiratory esophageal pressure;

[0086] The total compliance C can then be calculated using the following formula state :

[0087]

[0088] where TV is the tidal volume, Pplat is the plateau pressure, and PEEP is the positive end-expiratory pressure; after calculating the total compliance C state and the chest wall compliance Ccw, the lung compliance Clung can be calculated by solving the following equation:

[0089]

[0090] After obtaining the lung compliance Clung and the chest wall compliance Ccw, the processor 50 can calculate the error compensation value using the following formula:

[0091]

[0092] where ΔPtrans erro is the error compensation value, Ptrans is the transpulmonary pressure value, and Plung is the intrapulmonary pressure value;

[0093] The processor 50 subtracts the error compensation value from the transpulmonary pressure to obtain the corrected transpulmonary pressure.

[0094] 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 pressure sensor can be inserted into the abdomen through an incision or the like to collect the intra-abdominal pressure. In some embodiments, the processor 50 can also correct the transdiaphragmatic pressure. For example, the processor 50 obtains the esophageal pressure Pes PEEP and the intragastric pressure Psto PEEP in a state where the positive end-expiratory pressure is non-zero, and obtains the esophageal pressure Pes ZEEP and the intragastric pressure Psto ZEEP in a state where the positive end-expiratory pressure is zero; the processor 50 adds (Pes PEEP - Pes ZEEP ) to the transdiaphragmatic pressure and subtracts (Psto PEEP - Psto ZEEP ) to obtain the corrected transdiaphragmatic pressure.

[0095] The above is some descriptions of airway pressure, intrathoracic pressure, carina pressure, intrapulmonary pressure, esophageal pressure, intragastric pressure, intra-abdominal pressure, transpulmonary pressure, and transdiaphragmatic pressure.

[0096] In the present invention, the processor 50 receives the 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 according to the collected pressure and gas flow rate. In some embodiments, the processor 50 performs an integration operation on 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 within 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 within 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 further illustrates how to calculate the energy of mechanical ventilation acting on the patient's respiratory system in combination with the pressures at different sites of the respiratory system.

[0097] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system according to the airway pressure and gas flow rate. For example, integrating the airway pressure and gas flow rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system, the formula is as follows:

[0098]

[0099] where Energy rs is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the airway pressure and gas flow rate in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, and Flow is the gas flow rate. Of course, the energy calculated in a single cycle can also be converted into the amount per minute in combination with the respiratory rate, and the formula is as follows:

[0100]

[0101] where the unit of the airway pressure Paw is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power rs of mechanical ventilation acting on the patient's respiratory system obtained by integrating the airway pressure and gas flow rate has the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Of course, the Energyrs within all cycles in 1 minute can also be directly accumulated to obtain the energy per minute.

[0102] In some embodiments, when calculating the energy of mechanical ventilation acting on the patient's respiratory system based on airway pressure and gas flow rate, the potential energy generated by the tidal volume portion formed by positive end-expiratory pressure (PEEP) can also be considered. This portion of energy is generally a fixed value and does not change with mechanical ventilation. Also, because additional PEEP release is required, it can often be omitted. When considering this portion of potential energy, the above formula becomes:

[0103]

[0104] After unit conversion in combination with the respiratory rate, the energy per minute is obtained:

[0105]

[0106] In these two formulas, PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0107] Calculating the energy of mechanical ventilation acting on the patient's respiratory system based on airway pressure and gas flow rate can represent the energy of mechanical ventilation acting on the entire respiratory system of the patient, such as the total energy acting on the patient's trachea, chest wall, lungs, etc.

[0108] 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 value. It should be noted that the intrapulmonary pressure can be collected by the pressure sensor 10 or estimated through the airway pressure, etc., which has been described in detail above and will not be elaborated here. In some examples, the intrapulmonary pressure and gas flow rate are integrated to obtain the energy of mechanical ventilation acting on the patient's respiratory system, and the formula is as follows:

[0109]

[0110] where Energy lung is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the intrapulmonary pressure and gas flow rate 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. Of course, the energy calculated in a single cycle can also be converted into the energy per minute in combination with the respiratory rate, and the formula is as follows:

[0111]

[0112] where the unit of the intrapulmonary pressure Plung is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power lung acted on the patient's respiratory system by mechanical ventilation obtained by integrating the intrapulmonary pressure and the gas flow rate can be in J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Of course, the energy per second or per hour can be calculated according to specific needs. At this time, the corresponding unit is J / s or J / h. Correspondingly, the coefficient 0.098 in the above formula corresponds to other values according to unit conversion.

[0113] In some embodiments, when calculating the energy acted on the patient's respiratory system by mechanical ventilation according to the intrapulmonary pressure and the gas flow rate, the potential energy generated by the tidal volume part formed by the end-expiratory intrapulmonary pressure can also be considered. This part of the energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0114]

[0115] After unit conversion in combination with the respiratory rate, the energy per minute is obtained:

[0116]

[0117] In these two formulas, PlungE Volume is the tidal volume caused by the end-expiratory intrapulmonary pressure, with the unit of L, specifically the volume exhaled when the end-expiratory intrapulmonary pressure drops to 0; PlungE is the end-expiratory intrapulmonary pressure.

[0118] Calculating the energy acted on the patient's respiratory system by mechanical ventilation according to the intrapulmonary pressure and the gas flow rate can represent the energy acted on the lungs and chest wall in the patient's respiratory system by mechanical ventilation.

[0119] In some embodiments, the processor 50 calculates the energy acted on the patient's respiratory system by mechanical ventilation according to the transpulmonary pressure and the gas flow rate value. For example, integrating the transpulmonary pressure and the gas flow rate to obtain the energy acted on the patient's respiratory system, and the formula is as follows:

[0120]

[0121] where Energy trThe energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transpulmonary pressure and gas flow rate for a single cycle; Tinsp is the inspiratory time of each respiratory cycle, Ptrans is the transpulmonary pressure, and Flow is the gas flow rate. Of course, the energy calculated for a single cycle can also be converted into the energy per minute by combining with the respiratory rate, and the formula is as follows

[0122]

[0123] Among them, the unit of the transpulmonary pressure Ptrans is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, and the unit is per minute; the energy Power of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transpulmonary pressure and gas flow rate tr is in J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Similarly, the units and coefficients can be set as needed.

[0124] In some embodiments, when calculating the energy of mechanical ventilation acting on the patient's respiratory system according to the transpulmonary pressure and gas flow rate, the potential energy generated by the tidal volume part formed by the end-expiratory transpulmonary pressure can also be considered. This part of the energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0125]

[0126] Combined with the respiratory rate for unit conversion into the energy per minute:

[0127]

[0128] In these two formulas, PtansE volume is the tidal volume caused by the expiratory transpulmonary pressure, and the unit is L, specifically the volume exhaled when the end-expiratory transpulmonary pressure drops to 0; PtransE is the end-expiratory transpulmonary pressure.

[0129] Calculating the energy of mechanical ventilation acting on the patient's respiratory system according to the transpulmonary pressure and gas flow rate can represent the energy of mechanical ventilation acting on the lungs in the patient's respiratory system.

[0130] In some embodiments, the processor 50 calculates the energy of mechanical ventilation acting on the patient's respiratory system according to the transdiaphragmatic pressure and gas flow rate values. For example, integrating the transdiaphragmatic pressure and gas flow rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system, and the formula is as follows:

[0131]

[0132] Among them, Energy di is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transdiaphragmatic pressure and gas flow rate in a single cycle; Tinsp is the inspiratory time of each respiratory cycle, Pdi is the transdiaphragmatic pressure, and Flow is the gas flow rate. Of course, the energy calculated in a single cycle can also be converted into the energy per minute by combining with the respiratory rate, and the formula is as follows

[0133]

[0134] where the unit of the transpulmonary pressure Pdi is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transdiaphragmatic pressure and gas flow rate di has the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Similarly, the units and coefficients can be set as needed.

[0135] In some embodiments, when calculating the energy of mechanical ventilation acting on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate, the potential energy generated by the tidal volume part formed by the end-expiratory transdiaphragmatic pressure can also be considered. This part of the energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0136]

[0137] Combined with the respiratory rate for unit conversion into the energy per minute:

[0138]

[0139] In these two formulas, PdiE volume is the tidal volume caused by the expiratory transdiaphragmatic pressure, with the unit of L, specifically the volume exhaled when the end-expiratory transdiaphragmatic pressure drops to 0; PdiE is the end-expiratory transdiaphragmatic pressure.

[0140] Calculating the energy of mechanical ventilation acting on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate can represent the energy of mechanical ventilation acting on the diaphragm in the patient's respiratory system.

[0141] The above is some explanations about calculating the energy of mechanical ventilation acting on the patient's respiratory system.

[0142] Ventilator-induced lung injury (VILI) is a combination of multiple types of injuries. Generally, VILI can include one or more of barotrauma, volutrauma, atelectrauma, and tissue injury, etc. As described above, the energy acting on the patient's respiratory system during mechanical ventilation can accurately, truly, and real-time evaluate lung injury. However, this provides a relatively comprehensive description of lung injury. In fact, the effects of each ventilation parameter during mechanical ventilation are very important. Each ventilation parameter affects the contribution of each part of the energy acting on the patient's respiratory system during mechanical ventilation that may cause harm. Therefore, in some embodiments, the device for ventilating and monitoring the patient in this article also determines the contribution degree of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation. The following is a specific description.

[0143] In some embodiments, the processor 50 obtains the ventilation parameter and determines the contribution degree of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation. In some embodiments, the ventilation parameter includes a ventilation control parameter and / or a respiratory system-related parameter.

[0144] In some embodiments, the ventilation control parameter 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 degree of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation, the contribution degree of the ventilation parameter to the energy acting on the patient's respiratory system during mechanical ventilation can be determined by changing the value of the ventilation parameter and observing the change in the energy acting on the patient's respiratory system during mechanical ventilation.

[0145] The contribution degree can be reflected in different ways:

[0146] 1. The monitored value of the mechanical energy generated by the ventilation parameter, such as the mechanical energy PowerR generated by respiratory resistance;

[0147] 2. The proportion of the mechanical energy generated by the ventilation parameter, that is, the proportion of the mechanical energy generated by each ventilation parameter in the total mechanical energy. For example, the proportion of the mechanical energy generated by respiratory resistance in the total mechanical energy is PowerR / Powerrs;

[0148] 3. The change rate of the mechanical energy generated by the ventilation parameter, such as the ratio of the growth percentage of the corresponding ventilation parameter to the growth percentage of the corresponding mechanical energy.

[0149] Specifically, when determining the contribution degree of any ventilation control parameter, other ventilation control parameters can be kept unchanged, and then the variation relationship between the ventilation control parameter whose contribution degree needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be determined. For example, when the ventilation control parameter whose contribution degree needs to be determined changes by a fixed amount each time, obtain how much the energy acting on the patient's respiratory system during mechanical ventilation changes accordingly, and then through fitting - such as linear fitting or exponential fitting, etc. - to obtain the relationship between the ventilation control parameter whose contribution degree needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation, so as to determine the contribution degree of this ventilation control parameter. Of course, when controlling the change of a certain ventilation control parameter, it is also possible not to change by a fixed amount. Taking mechanical ventilation in volume mode as an example, the ventilation control parameters involved in this mode usually include tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio. To calculate the contribution degree 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 as fixed values, and then the value of tidal volume is changed. For example, each time the tidal volume is increased by a fixed percentage X% - such as 2%, and then obtain the percentage Y% by which the energy acting on the patient's respiratory system during mechanical ventilation increases accordingly - such as obtaining Y1%, Y2%,..., Yn% in sequence, and then perform fitting to obtain the relationship between X and Y. For example, assume that K = Y / X without loss of generality, then the contribution degree of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation is K. For example, the following is a table showing the changes in ventilation parameters and the energy acting on the patient's respiratory system during mechanical ventilation, that is, Table 1 below. In the table, Power represents the energy acting on the patient's respiratory system during mechanical ventilation, TV represents tidal volume, Rate represents respiratory rate, I represents inspiratory time, E represents expiratory time, and it can be seen that I:E is 1 / 2 in the table; Raw represents respiratory system resistance, Crs represents respiratory system compliance, and PEEP represents positive end-expiratory pressure. Changing from state 1 to state 2 is because TV in the ventilation parameters changes from 500 to 1000, that is, it increases by 100%, and correspondingly, Power increases from 5.82 to 17.4, increasing by approximately 200%. If linear fitting is performed, the change rate or the value of the contribution degree of TV is 2; changing from state 1 to state 3 is because Rate in the ventilation parameters changes from 12 to 24, that is, it increases by 100%, and correspondingly, Power increases from 5.82 to 14.46, increasing by approximately 150%. If linear fitting is performed, the change rate or the value of the contribution degree of Rate is 1.5.

[0150] Parameter Unit Status 1 Status 2 Status 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

[0151] Table 1

[0152] Understandably, when the gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio are maintained and set to fixed values, these fixed values will affect the contribution value of tidal volume. For example, when the gas flow rate takes two different fixed values, the contribution values of tidal volume are calculated respectively, and generally, the obtained contribution values of tidal volume are different. However, generally, the magnitude ranking of the contribution of these ventilation control parameters to the energy acting on the patient's respiratory system during mechanical ventilation remains fixed.

[0153] In some embodiments, the 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 in 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 in the energy acting on the patient's respiratory system during mechanical ventilation. The following is a specific description. Please refer to Figure 5 , is the static pressure-volume curve (P-V curve) of the respiratory system, which can reflect the mechanical state of the patient's respiratory system. In the figure, the abscissa is the airway pressure Paw. In some other examples, the abscissa can also be the intrapulmonary pressure Plung, the transpulmonary pressure Ptrans, or the transdiaphragmatic pressure Pdi, etc.

[0154] Taking the abscissa as the airway pressure Paw as an example, in the figure, A is the kinetic energy part, representing the magnitude of the work done to overcome the respiratory system resistance. B, C, and D in the figure are the potential energy parts, related to the respiratory system compliance. Specifically, A and B are dynamically changing, and they do work as the tidal volume and driving pressure change; C and D are static and unchanged. When the driving pressure changes above the positive end-expiratory pressure PEEP, the tidal volume and pressure related to the positive end-expiratory pressure PEEP do not do work, but there will be elastic potential energy, which is part of the energy acting on the patient's respiratory system during mechanical ventilation.

[0155] In an example, the potential energy parts related to the respiratory system compliance in the figure, namely B, C, and D, can be calculated by the following formula:

[0156]

[0157] where Energy C represents the energy related to the respiratory system compliance in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, Flow is the gas flow rate; PEEP VolumeThe tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically refers to the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0158] In some examples, the potential energy part related to the respiratory system compliance can be further divided into the potential energy part related to the dynamic compliance of the respiratory system and the potential energy part related to the static compliance of the respiratory system. Specifically, the work done to overcome the dynamic compliance of the respiratory system in the figure, that is, the potential energy parts of B and C in the figure, is:

[0159]

[0160] where Energy Cdyn represents the energy related to the dynamic compliance of the respiratory system in a single cycle - that is, the work done to overcome the dynamic compliance of the respiratory system. Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0161] The work done to overcome the static compliance of the respiratory system in the figure, that is, the potential energy part of D in the figure, is:

[0162]

[0163] where Energy Cstat represents the energy related to the static compliance of the respiratory system in a single cycle - that is, the work done to overcome the static compliance of the respiratory system. PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically refers to the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0164] In one example, the work done to overcome the resistance of the respiratory system in the figure, that is, the kinetic energy part A, can be calculated by the following formula:

[0165]

[0166] where Energy R represents the work done to overcome the resistance of the respiratory system in a single cycle. 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.

[0167] Of course, the energy calculated in a single cycle can also be converted into a per-minute quantity by combining with the respiratory rate. Below, the energy Energy C 、Energy Cdyn 、Energy Cstat and Energy R will be described separately.

[0168] Energy related to respiratory system compliance in a single cycle C is converted as follows:

[0169]

[0170] Energy related to dynamic respiratory system compliance in a single cycle Cdyn is converted as follows:

[0171]

[0172] Energy related to static respiratory system compliance in a single cycle Cstat is converted as follows:

[0173]

[0174] Work done to overcome respiratory system resistance in a single cycle R is converted as follows:

[0175]

[0176] In the above formulas, the units of airway pressure Paw and intrapulmonary pressure Plung are both cmH2O; the unit of gas flow rate Flow is L / min; the unit of inspiratory time Tinsp in each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power related to respiratory system compliance per minute C , the energy Power related to dynamic respiratory system compliance per minute Cdyn , the energy Power related to static respiratory system compliance per minute for a single cycle Cstat and the work done to overcome respiratory system resistance per minute R are all in the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formulas.

[0177] Of course, it is also possible to directly accumulate all the Energy C in one minute to obtain the energy Power C ; directly accumulate all the Energy Cdyn in one minute to obtain the energy Power Cdyn ; directly accumulate all the Energy Cstat in one minute to obtain the energy Power Cstat ; directly accumulate all the Energy R in one minute to obtain the energy PowerR 。

[0178] The above calculates the contribution of respiratory system-related parameters to the energy acting on the patient's respiratory system during mechanical ventilation through the integration method. In some embodiments, the contribution of respiratory system-related parameters to the energy acting on the patient's respiratory system during mechanical ventilation can also be calculated through the formula method.

[0179] Figure 6 and Figure 5 is also the static pressure-volume curve (P-V curve) of the respiratory system. Let's take, for example, Figure 6 where the abscissa is the airway pressure Paw. The energy acting on the patient's respiratory system during mechanical ventilation is:

[0180]

[0181] where Energy rs represents the energy acting on the patient's respiratory system during a single cycle of ventilation. TV is the tidal volume, Crs is the respiratory system compliance, RR is the respiratory rate, I:E is the ratio of the inspiratory time to the expiratory time, i.e., the respiratory ratio; Raw is the respiratory system resistance, and PEEP represents the positive end-expiratory pressure. The energy Energy acting on the patient's respiratory system during a single cycle of mechanical ventilation can also be rs converted into a per-minute quantity in combination with the respiratory rate. The formula is as follows:

[0182]

[0183] where the per-minute quantity Power rs has the unit of J / min; the respiratory rate RR has the unit of per minute; the tidal volume TV has the unit of L; the respiratory system compliance Crs has the unit of ml / cmH2O; the respiratory system resistance Raw has the unit of cmH2O / L / s; and the positive end-expiratory pressure PEEP has the unit of cmH2O.

[0184] Generally, when calculating the energy acting on the patient's respiratory system during ventilation, the potential energy generated by the tidal volume part formed by the positive end-expiratory pressure can also be considered. This part of the energy is generally a fixed value and does not change with mechanical ventilation. And because the positive end-expiratory pressure release needs to be carried out additionally, it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0185]

[0186] After unit conversion in combination with the respiratory rate, the energy per minute is obtained:

[0187]

[0188] In these two formulas, PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L. Specifically, it is the volume exhaled when the positive end-expiratory pressure drops to 0.

[0189] Next, calculate the contribution degrees of the relevant parameters of the respiratory system. Let's take the energy of a single cycle acting on the patient's respiratory system during mechanical ventilation as The energy per minute is as an example. From the respiratory mechanics equation, the following equation holds:

[0190]

[0191]

[0192] Flow*Raw = (Ppeak - P plat );

[0193] 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:

[0194]

[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 the compliance of the respiratory system is equal to the sum of the work done to overcome the dynamic compliance of the respiratory system and the work done to overcome the static compliance of the respiratory system.

[0203] Further, the ratio of the work done to overcome the respiratory system compliance to the energy acting on the patient's respiratory system during mechanical ventilation can be calculated to represent the contribution degree of the respiratory system compliance; similarly, the ratio of the work done to overcome the respiratory system resistance to the energy acting on the patient's respiratory system during mechanical ventilation can be calculated to represent the contribution degree of the respiratory system resistance.

[0204] The above are some explanations of the contribution degrees of ventilation parameters - including ventilation control parameters and / or respiratory system-related parameters - to the energy acting on the patient's respiratory system during mechanical ventilation. After determining the contribution degrees of ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation, there are various ways to utilize this contribution degree, which will be described below.

[0205] In some embodiments, the display 70 may display the contribution degrees of each ventilation parameter in one or more ways such as text, numbers, characters, tables, graphs, or icons. For example, the display 70 may display the names of each ventilation parameter and the corresponding numerical values of the contribution degrees. In some specific embodiments, the display 70 may display the names of each ventilation parameter and the corresponding numerical values of the contribution degrees in descending or ascending order of the contribution degrees, so that medical staff can very conveniently understand the magnitudes of the contribution degrees of each parameter to the energy acting on the patient's respiratory system during mechanical ventilation. For example, in an example of mechanical ventilation in volume mode, the display 70 may display the contribution degrees of the ventilation control parameters involved in this mode, such as tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio; for another example, in an example of mechanical ventilation in pressure mode, the display 70 may display the contribution degrees of the 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, the display 70 may also display the contribution degrees of respiratory system-related parameters such as the compliance and resistance of the patient's respiratory system. Therefore, in some examples, the display 70 can display the names of each ventilation control parameter and the corresponding numerical values of the contribution degrees. Of course, in some examples, the display 70 may display the names of each ventilation control parameter and the corresponding rankings of the contribution degrees. In some other examples, the display 70 can display the contribution degrees of each ventilation control parameter in a graphical manner; in some other examples, the display 70 can display the names of each respiratory system-related parameter and the corresponding numerical values of the contribution degrees; in some other examples, the display 70 can display the proportion of the contribution degrees of each respiratory system-related parameter; in some other examples, the display 70 can display the contribution degrees of each respiratory system-related parameter in a graphical manner. Of course, the display 70 can also display the changes in the contribution degrees corresponding to each ventilation parameter by means of symbols or icons such as upward, downward, or parallel lines. And the numerical values of the contribution degrees can be reflected in various ways, such as monitored values, percentages, or rates of change, etc. Taking the compliance of the respiratory system as an example, the numerical value of its contribution degree can be the actual monitored value, the percentage occupied, or the rate of change, etc., of the work done to overcome the compliance of the respiratory system in the energy acting on the patient's respiratory system during mechanical ventilation. Similarly, the numerical value of the contribution degree of the respiratory system resistance can be the actual monitored value, the percentage occupied, or the rate of change, etc., of the work done to overcome the respiratory system resistance in the energy acting on the patient's respiratory system during mechanical ventilation. Table 2 below is an example.

[0206] Parameter Unit Normal patient 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

[0207] <![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. It can be seen that the I:E in the table is 1 / 2; Raw represents respiratory system resistance, Crs represents respiratory system compliance, and PEEP represents positive end-expiratory pressure; Power represents the energy acting on the patient's respiratory system during mechanical ventilation, and Power C represents the work done to overcome respiratory system compliance, and Power R represents the work done to overcome respiratory system resistance; Power C % represents the proportion of the work done to overcome respiratory system compliance, that is, the ratio of Power C to Power; Power R % represents the proportion of the work done to overcome respiratory system resistance, that is, the ratio of Power R to Power; It can be seen that for normal patients, patients with acute respiratory distress syndrome (ARDS), and patients with chronic obstructive pulmonary disease, their Power C % and Power R % are all different. In other words, Power C % and Power R % can give some information about the patient's illness. For different patient types, their Power C % is different, and their Power R % is also different.

[0210] Therefore, in some embodiments, the way to display the contribution degree of ventilation parameters, in addition to displaying the names of ventilation parameters and their corresponding contribution degree values mentioned above, can also be to display the contribution degree of each ventilation parameter in a graphical way - such as a bar chart, a pie chart, or a graph, etc. The above table shows the contribution degree of respiratory system resistance (such as the work done to overcome respiratory system resistance and its proportion in the table) and the contribution degree of respiratory system compliance (such as the work done to overcome respiratory system compliance and its proportion in the table) in the form of a graph. Figures 7(a) and 7(b) are examples of showing the contribution degree of respiratory system resistance and the contribution degree of respiratory system compliance of normal patients in the table in the form of a bar chart and a pie chart.

[0211] In some embodiments, the processor 50 can guide mechanical ventilation according to the contribution degree of ventilation parameters. The following is a specific description.

[0212] In some embodiments, when it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds a first threshold, the processor 50 may prompt to reduce the ventilation parameters according to the contribution degree ranking, or control to reduce the ventilation parameters according to the contribution degree ranking. Specifically, the processor 50 may prompt to preferentially reduce the ventilation parameter with the largest contribution degree in the ventilation control parameters, or control to preferentially reduce the ventilation parameter with the largest contribution degree in the ventilation control parameters. When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds a relatively safe threshold, at this time, the ventilation parameter with the largest contribution degree in the ventilation control parameters can be manually or automatically preferentially reduced, so that the energy of mechanical ventilation acting on the patient's respiratory system can be quickly reduced to a safe range.

[0213] In some embodiments, when it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than a second threshold, the processor 50 may prompt to increase the ventilation parameters according to the contribution degree ranking, or control to increase the ventilation parameters according to the contribution degree ranking. Specifically, the processor 50 may prompt to preferentially increase the ventilation parameter with the smallest contribution degree in the ventilation control parameters, or control to preferentially increase the ventilation parameter with the smallest contribution degree in the ventilation control parameters. When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than a relatively safe threshold, at this time, the ventilation parameter with the smallest contribution degree in the ventilation control parameters can be manually or automatically preferentially increased, so that the energy of mechanical ventilation acting on the patient's respiratory system can enter the safe range more smoothly and safely, and will not suddenly cause the energy of mechanical ventilation acting on the patient's respiratory system to exceed the standard, resulting in other problems.

[0214] In some embodiments, according to the setting command of the ventilation control parameters, the processor 50 estimates and outputs the energy of the mechanical ventilation acting on the patient's respiratory system after setting. Specifically, the estimated energy of the mechanical ventilation acting on the patient's respiratory system can be displayed on the display 70 for medical staff to view and thus make decisions. In some embodiments, the processor 50 may also determine whether to give an alarm according to 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 the first threshold or is less than the second threshold, the processor 50 gives an alarm.

[0215] Some studies have shown that there is a significant clinical correlation between excessive energy of mechanical ventilation acting on the patient's respiratory system and lung injury. Specifically, some clinical studies have shown that when the energy of mechanical ventilation acting on the entire respiratory system of the patient is greater than 25 J / min, or the energy of mechanical ventilation acting on the lungs in the patient's respiratory system is greater than 12 J / min or 13 J / min, etc., it will significantly cause lung injury; some clinical studies have shown that when the energy of mechanical ventilation acting on the entire respiratory system of the patient is greater than 17 J / min, the patient's mortality rate increases significantly. Therefore, the above-mentioned first threshold and second threshold can be set according to clinical data and the specific situation of the patient.

[0216] In some embodiments, the processor 50 is capable of determining whether to give an alarm according to the contribution degrees of various respiratory system-related parameters. For example, the processor 50 gives different alarms according to the proportion of the contribution degree of the respiratory system resistance, that is, when the work done to overcome the respiratory system resistance accounts for the energy acting on the patient's respiratory system during mechanical ventilation in different ranges. Similarly, the processor 50 gives different alarms according to the proportion of the contribution degree of the respiratory system compliance, that is, when the work done to overcome the respiratory system compliance accounts for the energy acting on the patient's respiratory system during mechanical ventilation in different ranges. As for what kind of alarm to give for specific proportion ranges, those skilled in the art can determine and set it according to clinical data. For example, when the proportion of the contribution degree of the respiratory system compliance is between 80% and 85%, no alarm is given and the current situation is normal; when the proportion of the contribution degree of the respiratory system compliance is between 70% and 75%, an alarm is given that the patient currently has acute respiratory distress syndrome (ARDS); when the proportion of the contribution degree of the respiratory system compliance is between 40% and 50%, an alarm is given that the patient currently has chronic obstructive pulmonary disease; or, when the proportion of the contribution degree of the respiratory system compliance is outside the range of 80% to 85%, an alarm is given, and vice versa, no alarm is given.

[0217] The above is the description of the device for ventilatory monitoring of a patient in some embodiments of the present application. In some embodiments of the present invention, a method for ventilatory monitoring of a patient is also disclosed.

[0218] Figure 8 is a flowchart of the method for ventilatory monitoring of a patient in some embodiments of the present invention, and the method includes the following steps:

[0219] Step 100, obtaining the gas flow rate of the patient during ventilation.

[0220] The gas flow rate may refer to the inspiratory flow rate of the patient, or may refer to the flow rates during the patient's inhalation and exhalation periods. The above gas flow rate can be collected and obtained by the flow sensor 30.

[0221] Step 200, obtaining the pressure of the patient during ventilation.

[0222] The pressure reflects the pressures 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 gastric pressure. The above various pressures can be obtained by the pressure sensor 10.

[0223] In some embodiments, the pressure sensor 10 may be a catheter-type pressure sensor, an optical fiber-type pressure sensor, etc. By inserting the pressure sensor into the corresponding site of the patient's respiratory system, the pressure at the corresponding site can be measured. For example, by inserting the pressure sensor into the patient's airway, the airway pressure can be collected; by inserting the pressure sensor into the esophagus, the esophageal pressure can be collected; by inserting the pressure sensor into the stomach, the intragastric pressure can be collected; by inserting the pressure sensor into the carina inside the trachea, the carina pressure can be collected; by inserting the pressure sensor into the stomach, the intragastric pressure can be collected; by inserting the pressure sensor through an incision or the like into the thoracic cavity, the intrathoracic pressure can be collected. In some embodiments, the pressure at some sites in the respiratory system can also be used to replace or calculate the pressure at other sites. Several examples are given below to illustrate this.

[0224] In some embodiments, the carina pressure can be used to replace the intrapulmonary pressure. In some embodiments, the esophageal pressure can be used to replace the intrathoracic pressure. In some embodiments, the intragastric pressure can be used to replace the intra-abdominal pressure.

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

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

[0227] Where Plung(t) refers to the function of the intrapulmonary pressure changing with time t, or the real-time intrapulmonary pressure; Paw(t) refers to the function of the airway pressure changing with time t, or the real-time airway pressure; Flow(t) is the function of the gas flow rate changing with time t during the patient's ventilation, or the real-time gas flow rate of the patient during ventilation; Raw is the respiratory system resistance.

[0228] In some embodiments, step 200 may 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 may 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 the pressure sensor through an incision or the like into the abdomen.

[0230] In some embodiments, in order to make the energy acting on the patient's respiratory system during mechanical ventilation calculated later more accurate, the pressure of the patient obtained can be corrected before being used for calculation. For example Figure 9 is an example, where step 210 is introduced to correct the pressure.

[0231] Step 210 corrects the pressure of the patient obtained. Step 210 can correct the transpulmonary pressure, transdiaphragmatic pressure, etc., which will be specifically described below.

[0232] For example, after obtaining the patient's transpulmonary pressure in step 200, the transpulmonary pressure is corrected. Several examples of the correction method for the transpulmonary pressure will be specifically described below.

[0233] In some embodiments, step 210 corrects the transpulmonary pressure by using the airway pressure value and esophageal pressure value in the states where the positive end-expiratory pressure is zero and non-zero; specifically, step 210 obtains the airway pressure Paw PEEP and esophageal pressure Pes PEEP in the state where the positive end-expiratory pressure is non-zero, and obtains the airway pressure Paw ZEEP and esophageal pressure Pes ZEEP in the state where the positive end-expiratory pressure is zero; step 210 adds (Paw PEEP - Paw ZEEP ) to the transpulmonary pressure and subtracts (Pes PEEP - Pes ZEEP ) to obtain the corrected transpulmonary pressure.

[0234] In some embodiments, step 210 also corrects the transpulmonary pressure value by 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 step 210 to obtain lung compliance Clung and chest wall compliance Ccw. For example, step 210 can obtain chest wall compliance Ccw through the following formula:

[0235]

[0236] where TV is the tidal volume, PesI is the end-inspiratory esophageal pressure, and PEEP es is the end-expiratory esophageal pressure;

[0237] Then the total compliance C state can be calculated through the following formula:

[0238]

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

[0240]

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

[0242]

[0243] where ΔPtrans erro is the error compensation value, Ptrans 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 another example, after obtaining the transdiaphragmatic pressure of the patient in step 200, the transdiaphragmatic pressure is corrected. The following example specifically illustrates the correction method of the transdiaphragmatic pressure.

[0246] Step 210 obtains the esophageal pressure Pes PEEP and the intragastric pressure Psto PEEP in the state where the positive end-expiratory pressure is non-zero, and obtains the esophageal pressure Pes ZEEP and the intragastric pressure Psto ZEEP in the state where the positive end-expiratory pressure is zero; step 210 adds (Pes PEEP - Pes ZEEP ) to the transdiaphragmatic pressure and subtracts (Psto PEEP - Psto ZEEP ) to obtain the corrected transdiaphragmatic pressure.

[0247] In some embodiments, step 210 can also be omitted, that is, the pressure of the obtained patient is not corrected. For example, the above Figure 8 is an example that does not include step 210, and the above Figure 9 is an example that includes step 210.

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

[0249] In some embodiments, in step 300, the collected pressure and gas flow rate are integrated over a preset unit time, such as 1 minute, to obtain the energy of mechanical ventilation acting on the patient's respiratory system. In some embodiments, in step 300, the collected pressure and gas flow rate are integrated over a respiratory cycle and multiplied by the respiratory rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system. The following further illustrates how to calculate the energy of mechanical ventilation acting on the patient's respiratory system in combination with the pressures at different sites of the respiratory system.

[0250] In some embodiments, in step 300, the energy of mechanical ventilation acting on the patient's respiratory system is calculated based on the airway pressure and gas flow rate. Specifically, in step 300, the airway pressure and gas flow rate are integrated to obtain the energy of mechanical ventilation acting on the patient's respiratory system. The formula is as follows:

[0251]

[0252] where Energy rs is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the airway pressure and gas flow rate in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Paw is the airway pressure, and Flow is the gas flow rate. Of course, the energy calculated in a single cycle can also be converted into the amount per minute in combination with the respiratory rate. The formula is as follows:

[0253]

[0254] where the unit of the airway pressure Paw is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power rs of mechanical ventilation acting on the patient's respiratory system obtained by integrating the airway pressure and gas flow rate has the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Of course, the Energys of all cycles within 1 minute can also be directly accumulated to obtain the energy per minute.

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

[0256]

[0257] The energy per minute obtained after unit conversion in combination with the respiratory rate:

[0258]

[0259] In these two formulas, PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0260] Calculating the energy of mechanical ventilation acting on the patient's respiratory system based on airway pressure and gas flow rate can represent the energy of mechanical ventilation acting on the entire respiratory system of the patient, such as the total energy acting on the patient's trachea, chest wall, lungs, etc.

[0261] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system according to the intrapulmonary pressure and gas flow rate value. It should be noted that the intrapulmonary pressure can be obtained by the pressure sensor 10 or estimated through the airway pressure, etc., which has been described in detail above and will not be elaborated here. In some examples, the intrapulmonary pressure and gas flow rate are integrated to obtain the energy of mechanical ventilation acting on the patient's respiratory system, and the formula is as follows:

[0262]

[0263] where Energy lung is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the intrapulmonary pressure and gas flow rate 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. Of course, the energy calculated in a single cycle can also be converted into the energy per minute in combination with the respiratory rate, and the formula is as follows:

[0264]

[0265] where the unit of the intrapulmonary pressure Plung is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power of mechanical ventilation acting on the patient's respiratory system obtained by integrating the intrapulmonary pressure and gas flow rate lung can have the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Of course, the energy per second or per hour can be calculated according to specific needs. At this time, the corresponding unit is J / s or J / h. Correspondingly, the coefficient 0.098 in the above formula corresponds to other values according to unit conversion.

[0266] In some embodiments, when calculating the energy of mechanical ventilation acting on the patient's respiratory system based on the 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 part of the energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0267]

[0268] After unit conversion in combination with the respiratory rate, the energy per minute is obtained:

[0269]

[0270] In these two formulas, PlungE Volume is the tidal volume caused by the end-expiratory intrapulmonary pressure, with the unit of L, specifically the volume exhaled when the end-expiratory intrapulmonary pressure drops to 0; PlungE is the end-expiratory intrapulmonary pressure.

[0271] Calculating the energy of mechanical ventilation acting on the patient's respiratory system based on the intrapulmonary pressure and gas flow rate can represent the energy of mechanical ventilation acting on the lungs and chest wall in the patient's respiratory system.

[0272] In some embodiments, step 300 calculates the energy of mechanical ventilation acting on the patient's respiratory system according to the transpulmonary pressure and gas flow rate values. For example, integrating the transpulmonary pressure and gas flow rate to obtain the energy of mechanical ventilation acting on the patient's respiratory system, and the formula is as follows:

[0273]

[0274] where Energy tr is the energy of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transpulmonary pressure and gas flow rate in a single cycle; Tinsp is the inspiratory time of each respiratory cycle, Ptrans is the transpulmonary pressure, and Flow is the gas flow rate. Of course, the energy calculated in a single cycle can also be converted into the energy per minute in combination with the respiratory rate, and the formula is as follows

[0275]

[0276] where the unit of the transpulmonary pressure Ptrans is cmH2O; the unit of the gas flow rate Flow is L / min; the unit of the inspiratory time Tinsp of each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power of mechanical ventilation acting on the patient's respiratory system obtained by integrating the transpulmonary pressure and gas flow rate tr has the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formula. Similarly, the units and coefficients can be set as needed.

[0277] In some embodiments, when calculating the energy exerted by mechanical ventilation on the patient's respiratory system based on the 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 considering this portion of potential energy, the above formula becomes:

[0278]

[0279] Perform unit conversion to energy per minute in combination with the respiratory rate:

[0280]

[0281] In these two formulas, PtansE volume is the tidal volume caused by the transpulmonary pressure during exhalation, with the unit of L, specifically the volume exhaled when the end-expiratory transpulmonary pressure drops to 0; PtransE is the end-expiratory transpulmonary pressure.

[0282] Calculating the energy exerted by mechanical ventilation on the patient's respiratory system based on the transpulmonary pressure and gas flow rate can represent the energy exerted by mechanical ventilation on the lungs in the patient's respiratory system.

[0283] In some embodiments, step 300 calculates the energy exerted by mechanical ventilation on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate values. For example, integrating the transdiaphragmatic pressure and gas flow rate to obtain the energy exerted by mechanical ventilation on the patient's respiratory system, and the formula is as follows:

[0284]

[0285] where Energy di is the energy exerted by mechanical ventilation on the patient's respiratory system obtained by integrating the transdiaphragmatic pressure and gas flow rate in a single cycle; Tinsp is the inspiratory time of each respiratory cycle, Pdi is the transdiaphragmatic pressure, and Flow is the gas flow rate. Of course, the energy calculated in a single cycle can also be converted to energy per minute in combination with the respiratory rate, and the formula is as follows

[0286]

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

[0288] In some embodiments, when calculating the energy exerted by mechanical ventilation on the patient's respiratory system based on the 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 part of the energy is generally a fixed value and does not change with mechanical ventilation, so it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0289]

[0290] Perform unit conversion to energy per minute in combination with the respiratory rate:

[0291]

[0292] In these two formulas, PdiE volume is the tidal volume caused by the expiratory transdiaphragmatic pressure, with the unit of L, specifically the volume exhaled when the end-expiratory transdiaphragmatic pressure drops to 0; PdiE is the end-expiratory transdiaphragmatic pressure.

[0293] Calculating the energy exerted by mechanical ventilation on the patient's respiratory system based on the transdiaphragmatic pressure and gas flow rate can represent the energy exerted by mechanical ventilation on the diaphragm in the patient's respiratory system.

[0294] Step 400, obtain ventilation parameters. In some embodiments, the ventilation parameters include ventilation control parameters and / or respiratory system-related parameters. In some embodiments, the 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. Generally, in volume-controlled mechanical ventilation, the ventilation control parameters involved include tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio. In pressure-controlled mechanical ventilation, the ventilation control parameters involved include tidal volume, driving pressure, positive end-expiratory pressure, respiratory rate, and the contribution degree of the respiratory ratio. In some embodiments, the respiratory system-related parameters may include one or more of the patient's respiratory system compliance and respiratory system resistance.

[0295] Step 500, determine the contribution degree of the ventilation parameters to the energy exerted on the patient's respiratory system during mechanical ventilation. The following explains how to determine the contribution degree of the ventilation parameters to the energy exerted on the patient's respiratory system during mechanical ventilation in step 50.

[0296] As described above, in some embodiments, the 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 degree of any ventilation control parameter, other ventilation control parameters can be kept unchanged, and then the variation relationship between the ventilation control parameter whose contribution degree needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation can be determined. For example, when the ventilation control parameter whose contribution degree needs to be determined changes by a fixed amount each time, obtain how much the energy acting on the patient's respiratory system during mechanical ventilation changes accordingly, and then obtain the relationship between the ventilation control parameter whose contribution degree needs to be determined and the energy acting on the patient's respiratory system during mechanical ventilation through fitting, such as linear fitting or exponential fitting, etc., so as to determine the contribution degree of this ventilation control parameter. Taking mechanical ventilation in volume mode as an example, the ventilation control parameters involved in this mode usually include tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio. To calculate the contribution degree 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 as fixed values, and then the value of tidal volume is changed. For example, each time the tidal volume is increased by a fixed percentage X% - such as 2%, and then obtain the percentage Y% by which the energy acting on the patient's respiratory system during the corresponding mechanical ventilation increases - such as obtaining Y1%, Y2%,..., Yn% in sequence, and then perform fitting to obtain the relationship between X and Y. For example, assume K = Y / X without loss of generality, then the contribution degree of tidal volume to the energy acting on the patient's respiratory system during mechanical ventilation is K. Still taking Table 1 in the above text as an example, from state 1 to state 2, it is because in the ventilation parameters, TV changes from 500 to 1000, that is, it increases by 100%, and correspondingly, Power increases from 5.82 to 17.4, an increase of approximately 200%. If linear fitting is performed, the change rate or the value of the contribution degree of TV is 2; from state 1 to state 3, it is because in the ventilation parameters, Rate changes from 12 to 24, that is, it increases by 100%, and correspondingly, Power increases from 5.82 to 14.46, an increase of approximately 150%. If linear fitting is performed, the change rate or the value of the contribution degree of Rate is 1.5. It can be understood that when the gas flow rate, positive end-expiratory pressure, respiratory rate, and respiratory ratio are kept and set as fixed values, these fixed values will affect the value of the contribution degree of tidal volume. For example, when the gas flow rate takes two different fixed values, calculate the contribution degree of tidal volume respectively, and generally the values of the contribution degree of tidal volume obtained are different. Nevertheless, generally speaking, the magnitude ranking of the contribution degrees of these ventilation control parameters to the energy acting on the patient's respiratory system during mechanical ventilation is fixed and unchanged.

[0297] As described above, in some embodiments, the respiratory system related parameters may include one or more of the patient's respiratory system compliance and respiratory system resistance. The contribution degree of the 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 the respiratory system compliance in the energy acting on the patient's respiratory system during mechanical ventilation; similarly, the contribution degree of the 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 the respiratory system resistance in the energy acting on the patient's respiratory system during mechanical ventilation. The following is a specific description. Please refer to the above text. Figure 5 , is the static pressure-volume curve (P-V curve) of the respiratory system, which can reflect the mechanical state of the patient's respiratory system. The abscissa shown in the figure is the airway pressure Paw. In some other examples, the abscissa can also be the intrapulmonary pressure Plung, the transpulmonary pressure Ptrans or the transdiaphragmatic pressure Pdi, etc.

[0298] Taking the abscissa as the airway pressure Paw as an example, A in the figure is the kinetic energy part, representing the magnitude of the work done to overcome the respiratory system resistance. B, C, and D in the figure are the potential energy parts, which are related to the respiratory system compliance. Specifically, A and B are dynamically changing, and they will do work as the tidal volume and driving pressure change; C and D are statically unchanged. When the driving pressure changes above the positive end-expiratory pressure PEEP, the tidal volume and pressure related to the positive end-expiratory pressure PEEP do not do work during expiration, but there will be elastic potential energy, which is part of the energy acting on the patient's respiratory system during mechanical ventilation.

[0299] In one example, the potential energy parts related to the respiratory system compliance in the figure, namely B, C, and D, can be calculated by the following formula:

[0300]

[0301] where Energy C represents the energy related to the respiratory system compliance in a single cycle, Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, Flow is the gas flow rate; PEEP Volume is the tidal volume caused by the positive end-expiratory pressure, with the unit of L, specifically the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0302] In some examples, the potential energy parts related to the respiratory system compliance can be further divided into the potential energy parts related to the dynamic respiratory system compliance and the potential energy parts related to the static respiratory system compliance. Specifically, the work done to overcome the dynamic respiratory system compliance in the figure, that is, the potential energy parts of B and C in the figure, is:

[0303]

[0304] Among them, Energy Cdyn represents the energy related to the dynamic compliance of the respiratory system in a single cycle - that is, the work done to overcome the dynamic compliance of the respiratory system. Tinsp is the inspiratory time of each respiratory cycle, Plung is the intrapulmonary pressure, and Flow is the gas flow rate.

[0305] The work done to overcome the static compliance of the respiratory system in the figure, that is, the potential energy part of D in the figure, is:

[0306]

[0307] Among them, Energy Cstat represents the energy related to the static compliance of the respiratory system in a single cycle - that is, the work done to overcome the static compliance of the respiratory system, and PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically the volume exhaled when the positive end-expiratory pressure drops to 0; PEEP is the positive end-expiratory pressure.

[0308] In one example, the work done to overcome the resistance of the respiratory system in the figure, that is, the kinetic energy part A, can be calculated by the following formula:

[0309]

[0310] Among them, Energy R represents the work done to overcome the resistance of the respiratory system in a single cycle. 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.

[0311] Of course, the energy calculated in a single cycle can also be converted into a per-minute quantity by combining with the respiratory rate. The following will explain the above-mentioned energy Energy C 、Energy Cdyn 、Energy Cstat and Energy R 、respectively.

[0312] The energy Energy related to the compliance of the respiratory system in a single cycle C is converted as follows:

[0313]

[0314] The energy Energy related to the dynamic compliance of the respiratory system in a single cycle Cdyn is converted as follows:

[0315]

[0316] Energy related to the static compliance of the respiratory system in a single cycle Cstat is converted as follows:

[0317]

[0318] Work done to overcome the resistance of the respiratory system in a single cycle Energy R is converted as follows:

[0319]

[0320] In the above formulas, the units of airway pressure Paw and intrapulmonary pressure Plung are both cmH2O; the unit of gas flow rate Flow is L / min; the unit of inspiratory time Tinsp for each respiratory cycle is s; RR is the respiratory rate, with the unit of per minute; the energy Power related to the compliance of the respiratory system per minute C , the energy Power related to the dynamic compliance of the respiratory system per minute Cdyn , the energy Power related to the static compliance of the respiratory system in a single cycle per minute Cstat and the work done to overcome the resistance of the respiratory system per minute Power R are all in the unit of J / min. Since 1 cmH2O * 1 L / min = 0.098 J / min, there is a coefficient of 0.098 in the above formulas.

[0321] Of course, it is also possible to directly accumulate all the Energies C in one minute to obtain the energy Power per minute C ; directly accumulate all the Energies Cdyn in one minute to obtain the energy Power per minute Cdyn ; directly accumulate all the Energies Cstat in one minute to obtain the energy Power per minute Cstat ; directly accumulate all the Energies R in one minute to obtain the energy Power per minute R .

[0322] The above calculates the contribution of respiratory system-related parameters to the energy acting on the patient's respiratory system during mechanical ventilation through the integration method. In some embodiments, the contribution of respiratory system-related parameters to the energy acting on the patient's respiratory system during mechanical ventilation can also be calculated through the formula method.

[0323] Figure 6 and Figure 5Similarly, it is also the static pressure-volume curve (P-V curve) of the respiratory system. For example, take the abscissa as the airway pressure Paw in Figure 6 During mechanical ventilation, the energy acting on the patient's respiratory system is:

[0324]

[0325] where Energy rs represents the energy acting on the patient's respiratory system during a single cycle of ventilation. TV is the tidal volume, Crs is the respiratory system compliance, RR is the respiratory rate, I:E is the ratio of inspiratory time to expiratory time, i.e., the respiratory ratio; Raw is the respiratory system resistance, and PEEP represents positive end-expiratory pressure. The energy Energy acting on the patient's respiratory system during a single cycle of mechanical ventilation can also be rs converted into a per-minute quantity by combining with the respiratory rate. The formula is as follows:

[0326]

[0327] where the per-minute quantity Power rs has the unit of J / min; the respiratory rate RR has the unit of per minute; the tidal volume TV has the unit of L; the respiratory system compliance Crs has the unit of ml / cmH2O; the respiratory system resistance Raw has the unit of cmH2O / L / s; and the positive end-expiratory pressure PEEP has the unit of cmH2O.

[0328] Generally, when calculating the energy acting on the patient's respiratory system during ventilation, the potential energy generated by the tidal volume part formed by positive end-expiratory pressure can also be considered. This part of the energy is generally a fixed value and does not change with mechanical ventilation. And because positive end-expiratory pressure release is required additionally, it can often be omitted. When considering this part of the potential energy, the above formula becomes:

[0329]

[0330] After unit conversion by combining with the respiratory rate, the per-minute energy is obtained:

[0331]

[0332] In these two formulas, PEEP Volume is the tidal volume caused by positive end-expiratory pressure, with the unit of L, specifically the volume exhaled when the positive end-expiratory pressure drops to 0.

[0333] Next, calculate the contribution degrees of the relevant parameters of the respiratory system. For example, take the energy of a single cycle acting on the patient's respiratory system during mechanical ventilation as The per-minute energy is For example, according to the respiratory mechanics equation, the following equation holds:

[0334]

[0335]

[0336] Flow*Raw=(Ppeak - P plat );

[0337] 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; thus, it can be derived that:

[0338]

[0339]

[0340] Therefore, the work done to overcome the resistance of the respiratory system is:

[0341]

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

[0343] Energy Cdyn = TV * PEEP;

[0344] The work done to overcome the static compliance of the respiratory system is:

[0345]

[0346] The work done to overcome the compliance of the respiratory system is equal to the work done to overcome the dynamic compliance of the respiratory system plus the work done to overcome the static compliance of the respiratory system.

[0347] Furthermore, the ratio of the work done to overcome the compliance of the respiratory system to the energy acting on the patient's respiratory system during mechanical ventilation can be calculated to represent the contribution degree of respiratory system compliance; similarly, the ratio of the work done to overcome the resistance of the respiratory system to the energy acting on the patient's respiratory system during mechanical ventilation can be calculated to represent the contribution degree of respiratory system resistance.

[0348] The above is some explanations of the contribution degree of ventilation parameters - including ventilation control parameters and / or respiratory system-related parameters - to the energy acting on the patient's respiratory system during mechanical ventilation. After determining the contribution degree of ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation, there are various ways to utilize this contribution degree, which will be described below.

[0349] Please refer to Figure 10, the method for ventilatory monitoring in some embodiments may further include step 600 of displaying the contribution degrees of the respective ventilatory parameters in one or more ways such as text, numbers, characters, tables, graphs or icons. For example, step 600 displays the names of the respective ventilatory parameters and the numerical values of their corresponding contribution degrees. In some specific embodiments, step 600 may display the names of the respective ventilatory parameters and the numerical values of their corresponding contribution degrees in the order from largest to smallest or from smallest to largest in terms of the contribution degree, so that medical staff can very conveniently understand the magnitudes of the contribution degrees of the respective parameters to the energy acting on the patient's respiratory system during mechanical ventilation. For example, in an example of mechanical ventilation in volume mode, step 600 may display the contribution degrees of the ventilatory control parameters involved in this mode such as tidal volume, gas flow rate, positive end-expiratory pressure, respiratory rate and respiratory ratio; for another example, in an example of mechanical ventilation in pressure mode, step 600 may display the contribution degrees of the ventilatory 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 degrees of the respiratory system-related parameters such as the compliance and resistance of the patient's respiratory system. Therefore, in some examples, step 600 can display the names of the respective ventilatory control parameters and the numerical values of their corresponding contribution degrees; in some examples, step 600 displays the names of the respective ventilatory control parameters and their corresponding rankings in terms of the contribution degree. In still other examples, step 600 can display the contribution degrees of the respective ventilatory control parameters in a graphical manner; in still other examples, step 600 can display the names of the respective respiratory system-related parameters and the numerical values of their corresponding contribution degrees; in still other examples, step 600 can display the proportion of the contribution degrees of the respective respiratory system-related parameters; in still other examples, step 600 can display the contribution degrees of the respective respiratory system-related parameters in a graphical manner. Therefore, the numerical values of the contribution degree can be reflected in various ways, such as monitoring values, percentages or rates of change, etc. Taking the compliance of the respiratory system as an example, the numerical value of its contribution degree can be the actual monitoring value, the percentage or the rate of change of the work done to overcome the compliance of the respiratory system in the energy acting on the patient's respiratory system during mechanical ventilation. Similarly, for the contribution degree of the respiratory system resistance, the numerical value can be the actual monitoring value, the percentage or the rate of change of the work done to overcome the respiratory system resistance in the energy acting on the patient's respiratory system during mechanical ventilation. In some embodiments, the way of displaying the contribution degree of the ventilatory parameter, in addition to displaying the name of the ventilatory parameter and the numerical value of its corresponding contribution degree mentioned above, can also be to display the contribution degrees of the respective ventilatory parameters in a graphical manner - such as a bar chart, a pie chart or a graph, etc. Table 2 and Figure 7 in the above text are examples, and other ways are as described above and will not be elaborated here.

[0350] Please refer to Figure 11, the method for ventilatory monitoring in some embodiments may further include step 700, which can guide mechanical ventilation according to the contribution degree of ventilation parameters. The following describes how step 700 guides mechanical ventilation according to the contribution degree of ventilation parameters.

[0351] In some embodiments, when it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds the first threshold, step 700 prompts to reduce the ventilation parameters according to the contribution degree ranking, or controls to reduce the ventilation parameters according to the contribution degree ranking. Specifically, it can prompt to preferentially reduce the ventilation parameter with the largest contribution degree in the ventilation control parameters, or control to preferentially reduce the ventilation parameter with the largest contribution degree in the ventilation control parameters. When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds a relatively safe threshold, at this time, manually or automatically preferentially reducing the ventilation parameter with the largest contribution degree in the ventilation control parameters can make the energy of mechanical ventilation acting on the patient's respiratory system quickly reduced to the safe range. In some embodiments, when it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than the second threshold, step 700 can prompt to increase the ventilation parameters according to the contribution degree ranking, or control to increase the ventilation parameters according to the contribution degree ranking. Specifically, it can prompt to preferentially increase the ventilation parameter with the smallest contribution degree in the ventilation control parameters, or control to preferentially increase the ventilation parameter with the smallest contribution degree in the ventilation control parameters. When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than a relatively safe threshold, at this time, manually or automatically preferentially increasing the ventilation parameter with the smallest contribution degree in the ventilation control parameters can make the energy of mechanical ventilation acting on the patient's respiratory system smoothly and safely enter the safe range, and will not suddenly make the energy of mechanical ventilation acting on the patient's respiratory system exceed the standard, resulting in other problems.

[0352] In some embodiments, according to the setting command of the ventilation control parameters, step 700 estimates and outputs the energy of the mechanical ventilation acting on the patient's respiratory system after setting. Specifically, the estimated energy of the mechanical ventilation acting on the patient's respiratory system can be displayed for medical staff to view and thus make decisions. In some embodiments, step 700 can also determine whether to give an alarm according to 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 the first threshold or is less than the second threshold, step 700 gives an alarm.

[0353] Some studies have shown that excessive energy of mechanical ventilation acting on the patient's respiratory system has a significant clinical correlation with lung injury. Specifically, some clinical studies have shown that when the energy of mechanical ventilation acting on the patient's entire respiratory system is greater than 25 J / min, or the energy of mechanical ventilation acting on the lungs in the patient's respiratory system is greater than 12 J / min or 13 J / min, etc., lung injury will be significantly caused; some clinical studies have shown that when the energy of mechanical ventilation acting on the patient's entire respiratory system is greater than 17 J / min, the patient's mortality rate will increase significantly. Therefore, the above-mentioned first threshold and second threshold can be set according to clinical data and the specific situation of the patient.

[0354] In some embodiments, step 700 can determine whether to give an alarm according to the proportion of the contribution of each respiratory system-related parameter. For example, step 700 gives different alarms according to the proportion of the contribution of respiratory system resistance, that is, when the work done to overcome the respiratory system resistance accounts for the energy of mechanical ventilation acting on the patient's respiratory system in different ranges; similarly, step 700 gives different alarms according to the proportion of the contribution of respiratory system compliance, that is, when the work done to overcome the respiratory system compliance accounts for the energy of mechanical ventilation acting on the patient's respiratory system in different ranges. As for what kind of alarm to give for specific proportion ranges, those skilled in the art can determine and set it according to clinical data. For example, when the proportion of the contribution of respiratory system compliance is between 80% and 85%, no alarm is given and the current situation is normal; when the proportion of the contribution of respiratory system compliance is between 70% and 75%, an alarm is given that the patient currently has acute respiratory distress syndrome (ARDS); when the proportion of the contribution of respiratory system compliance is between 40% and 50%, an alarm is given that the patient currently has chronic obstructive pulmonary disease; or when the proportion of the contribution of respiratory system compliance is outside the range of 80% to 85%, an alarm is given, and vice versa, no alarm is given.

[0355] This document is described with reference to various exemplary embodiments. 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 operating steps and the components used to perform the operating steps can be implemented in different ways according to a 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 into other steps).

[0356] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. Additionally, as understood by those skilled in the art, the principles herein can be reflected in a computer program product on a computer-readable storage medium, which is preloaded with computer-readable program code. Any tangible, non-transitory computer-readable storage medium can be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-ROMs, DVDs, Blu-ray discs, etc.), flash memories, and / or the like. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing devices to form a machine, such that the instructions executed on the computer or other programmable data processing devices can generate a device for implementing the specified functions. These computer program instructions can also be stored in a computer-readable memory, which can direct the computer or other programmable data processing devices to operate in a specific manner, so that the instructions stored in the computer-readable memory can form a manufactured article, including an implementation device for implementing the specified functions. The computer program instructions can also be loaded onto a computer or other programmable data processing devices, thereby performing a series of operation steps on the computer or other programmable devices to generate a computer-implemented process, such that the instructions executed on the computer or other programmable devices can provide steps for implementing the specified functions.

[0357] Although the principles herein have been shown in various embodiments, many modifications of the structures, arrangements, proportions, elements, materials, and components, which are particularly applicable to specific environments and operational requirements, can be used without departing from the principles and scope of this disclosure. The above modifications and other changes or corrections will be included within the scope of this disclosure.

[0358] The foregoing detailed description has 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, the consideration of this disclosure will be in an illustrative rather than a restrictive sense, and all such modifications will be included within its scope. Similarly, the advantages of the various embodiments, other advantages, and solutions to problems have been described above. However, the benefits, advantages, solutions to problems, and any elements that can produce these, or solutions that make them more explicit, should not be construed as critical, essential, or necessary. As used herein, the term "comprising" and any other variants thereof are non-exclusive inclusions, such that a process, method, article, or device that includes a list of elements not only includes these elements, but also includes other elements not expressly listed or not belonging to the process, method, system, article, or device. Additionally, as used herein, the term "coupled" and any other variants thereof refer to physical connection, electrical connection, magnetic connection, optical connection, communication connection, functional connection, and / or any other connection.

[0359] Those skilled in the art will recognize that many changes may be made to the details of the above-described embodiments without departing from the basic principles of the present invention. Accordingly, the scope of the present invention should be determined solely by the following claims.

Claims

1. A method for ventilatory monitoring of a patient, characterized in that, Comprising: Obtaining the pressure of the patient during ventilation, the pressure reflecting the pressures acting on different sites of the patient's respiratory system during ventilation; Obtaining the gas flow rate of the patient during ventilation; Calculating the energy acting on the patient's respiratory system during mechanical ventilation according to the obtained pressure and gas flow rate; Obtaining ventilation parameters, the ventilation parameters including one or more of ventilation control parameters and / or respiratory system related parameters; Determining the contribution degree of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

2. The method according to claim 1, wherein 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.

3. The method according to claim 2, characterized in that Further comprising: Displaying the contribution degree of each ventilation parameter.

4. The method according to claim 3, wherein Displaying the contribution degree of each ventilation parameter in one or more ways of text, numbers, characters, tables, graphs, or icons.

5. The method according to any one of claims 1 to 4, characterized in that Further comprising: Guiding mechanical ventilation according to the contribution degree.

6. The method according to claim 5, characterized in that, The guiding mechanical ventilation according to the contribution degree includes: When it is judged that the energy acting on the patient's respiratory system during mechanical ventilation exceeds a first threshold, prompting to reduce the ventilation parameters according to the contribution degree ranking, or controlling to reduce the ventilation parameters according to the contribution degree ranking.

7. The method according to claim 5, characterized in that The guiding mechanical ventilation according to the contribution degree includes: When it is judged that the energy acting on the patient's respiratory system during mechanical ventilation is lower than a second threshold, prompting to increase the ventilation parameters according to the contribution degree ranking, or controlling to increase the ventilation parameters according to the contribution degree ranking.

8. The method according to claim 5, wherein The guiding mechanical ventilation according to the contribution degree includes: Estimating and outputting the energy acting on the patient's respiratory system after the mechanical ventilation is set according to the setting command of the ventilation control parameters.

9. The method according to claim 8, wherein The guiding mechanical ventilation according to the contribution degree further includes: Judging whether to give an alarm according to the estimated energy acting on the patient's respiratory system during mechanical ventilation.

10. The method according to claim 5, characterized in that The guiding mechanical ventilation according to the contribution degree includes: Judging whether to give an alarm according to the contribution degree of each respiratory system related parameter.

11. A device for ventilatory monitoring of a patient, characterized in that, Comprising: A pressure sensor for collecting the pressure of the patient during ventilation, the pressure reflecting the pressures acting on different sites of the patient's respiratory system during ventilation; A flow sensor for collecting the gas flow rate of the patient during ventilation; A processor for obtaining the pressure of the patient during ventilation and the gas flow rate of the patient during ventilation, and calculating the energy acting on the patient's respiratory system during mechanical ventilation according to the obtained pressure and gas flow rate; the processor also obtains ventilation parameters, the ventilation parameters including one or more of ventilation control parameters and / or respiratory system related parameters, and determines the contribution degree of the ventilation parameters to the energy acting on the patient's respiratory system during mechanical ventilation.

12. The device according to claim 11, wherein 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.

13. The device according to claim 11, characterized in that, Further comprising a display for displaying the contribution degree of each ventilation parameter.

14. The device according to any one of claims 11 to 13, characterized in that The processor also guides mechanical ventilation according to the contribution degree.

15. The device according to claim 14, characterized in that, The processor guiding mechanical ventilation according to the contribution degree includes: When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system exceeds a first threshold, the processor prompts to preferentially reduce the ventilation parameter with the largest contribution among the ventilation control parameters, or controls to preferentially reduce the ventilation parameter with the largest contribution among the ventilation control parameters; and / or, When it is determined that the energy of mechanical ventilation acting on the patient's respiratory system is lower than a second threshold, the processor prompts to preferentially increase the ventilation parameter with the smallest contribution among the ventilation control parameters, or controls to preferentially increase the ventilation parameter with the smallest contribution among the ventilation control parameters.

16. The device according to claim 14, wherein The processor guiding mechanical ventilation according to the contribution degree includes: According to the setting command of the ventilation control parameter, the processor estimates and outputs the energy of the set mechanical ventilation acting on the patient's respiratory system.

17. The device according to claim 16, characterized in that, The processor guiding mechanical ventilation according to the contribution degree further includes: According to the estimated energy of mechanical ventilation acting on the patient's respiratory system, the processor determines whether to give an alarm.

18. The device according to claim 14, wherein, The processor guiding mechanical ventilation according to the contribution degree includes: According to the contribution degrees of the relevant parameters of each respiratory system, the processor determines whether to give an alarm.

19. The device according to claim 11, wherein The device is a patient monitor, a patient monitoring module or a medical ventilation device.

20. A computer-readable storage medium, characterized in that, It includes a program that can be executed by a processor to implement the method according to any one of claims 1 to 10.

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