Intelligent pressure release method of breathing machine and breathing machine

Abstract

The invention discloses an intelligent pressure release method of a breathing machine, which modifies a target value of output pressure when the breathing machine calibrates expiration start, and the target value of the output pressure is determined according to expiration flow. In the pressure release process, the pressure target is dynamically adjusted according to the expiration requirement of the user, and the requirements of different users and different use scenes can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of ventilators, and in particular to an intelligent pressure release method of a ventilator and a ventilator. Background Art

[0002] Ventilators can help control and regulate the user's normal physiological breathing, increase lung ventilation, improve respiratory function, and reduce respiratory consumption. In addition to their clinical applications, there are now various types of home ventilators.

[0003] With the continuous expansion of the clinical cognition of respiratory medicine, supported by the great progress of high-performance electromechanical and electronic devices, the comfort of using home ventilators has greatly improved. However, after the user wears the ventilator, it is still different from natural breathing. Intelligent pressure release is a technology applied to home ventilators to improve the user's comfort. The purpose of intelligent pressure release technology is to improve the user's comfort, and the method is to control the ventilator to achieve the expected therapeutic effect while making the user's breathing closer to the natural breathing of the human body.

[0004] Some existing ventilators have begun to apply intelligent pressure release algorithms, such as softPAP, EPR, Flex, Reslex, etc. However, in existing ventilator products, the pressure release algorithms used mostly use a fixed pressure waveform as the goal to reduce the ventilator output pressure during exhalation, and most of them start to adjust after the ventilator airflow has changed from positive to negative, such as Figure 1 As shown, it often lags behind the actual start of exhalation. Summary of the invention

[0005] In view of some or all of the problems in the prior art, the first aspect of the present invention provides an intelligent pressure release method for a ventilator, comprising:

[0006] When the ventilator calibrates the start of exhalation, the target value of the output pressure is modified, wherein the target value of the output pressure is determined according to the exhalation flow rate.

[0007] Furthermore, the target value of the output pressure is modified according to the following formula:

[0008] Pressure set,new =Pressure set +C*min(0,Flow pat ),

[0009] Among them, Pressure set,new is the target value of the modified output pressure, Pressure set is the initial output pressure, C is the set value, and Flow pat The amount of airflow entering the user's lungs.

[0010] Furthermore, the value of C is determined according to the amplitude of pressure to be released, wherein the larger the value of C is, the greater the amplitude of pressure release is.

[0011] Furthermore, the value of C is 0 to 3.

[0012] Further, the ventilator calibrates the start of exhalation including:

[0013] The air flow rate at the user end is determined. If the air flow rate is less than the first preset value and the rate of decrease of the air flow rate increases, the start of exhalation is marked.

[0014] Furthermore, the first preset value is equal to the maximum airflow K in a steady state. q times, where K q The value of is not greater than 1.

[0015] Furthermore, the K q The value of is 0.85.

[0016] Furthermore, the ventilator calibration of the start of exhalation also includes:

[0017] If the airflow rate is not less than the preset value, and / or the rate of decrease of the airflow rate does not increase, the mask pressure of the ventilator is measured; if the mask pressure is greater than a second preset value and the mask pressure rises faster, the start of exhalation is calibrated.

[0018] Furthermore, the second preset value is equal to the maximum mask pressure in a stable state.

[0019] Furthermore, the intelligent pressure release method further comprises:

[0020] When the exhaled airflow at the user end is less than a preset value, the pressure target is adjusted to the original output pressure.

[0021] Based on the intelligent pressure release method as described above, a second aspect of the present invention provides a ventilator, which includes a control module, and the control module adjusts the airflow of the ventilator according to the intelligent pressure release method as described above.

[0022] The present invention provides an intelligent pressure release method for a ventilator. During the pressure release process, the pressure target is dynamically adjusted according to the user's exhalation needs to meet the needs of different users and different usage scenarios. The method determines the exhalation needs in advance and sets the timing of pre-pressure release to coordinate more smoothly with the natural breathing of the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To further illustrate the above and other advantages and features of various embodiments of the present invention, a more specific description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings only depict typical embodiments of the present invention and are therefore not to be considered as limiting the scope thereof. In the accompanying drawings, for clarity, identical or corresponding parts will be represented by identical or similar reference numerals.

[0024] Figure 1 A schematic diagram showing the relationship between the output pressure of a ventilator and the flow rate of a ventilator in the prior art;

[0025] Figure 2 A schematic flow chart showing an intelligent pressure release method for a ventilator according to an embodiment of the present invention; and

[0026] Figure 3 A schematic diagram showing the relationship between the output pressure and the flow rate of a ventilator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that various embodiments can be implemented without one or more specific details or with other replacement and / or additional methods, materials or components. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid blurring the inventive point of the present invention. Similarly, for the purpose of explanation, specific quantities, materials and configurations are set forth to provide a comprehensive understanding of embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn in correct proportions.

[0028] In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in this specification does not necessarily all refer to the same embodiment.

[0029] It should be noted that the embodiments of the present invention describe the process steps in a specific order, but this is only for the purpose of illustrating the specific embodiment, rather than limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the adjustment of the process.

[0030] For a ventilator equipped with an intelligent pressure release function, the control of the pressure waveform in the CPAP mode is not a simple constant pressure or a regular square wave, but a pressure release at the beginning of the expiratory phase to simulate the natural exhalation of the human body, and a pressure release at the end of the inspiratory phase to simulate the pressure drop caused by the diffusion of gas in the lungs when the inhalation is paused during the natural breathing of the human body. However, in existing ventilator products, the pressure release algorithms used are all aimed at reducing the output pressure of the ventilator during exhalation with a fixed pressure waveform as the target, and the adaptability is poor. In addition, the pressure release of existing ventilators only starts after the ventilator airflow has changed from positive to negative, and often lags behind the actual start of exhalation. In view of the above problems, in order to better simulate the natural exhalation of the human body, the present invention provides an intelligent pressure release method for a ventilator. During the pressure release process, the pressure target is dynamically adjusted according to the user's exhalation needs to meet the needs of different users and different usage scenarios. At the same time, the exhalation needs are judged in advance, and the timing of the pre-pressure release is more smooth in coordination with the natural breathing of the person.

[0031] The technical solution of the present invention is further described below in conjunction with the accompanying drawings of the embodiments.

[0032] Figure 2 A schematic flow chart of an intelligent pressure release method for a ventilator according to an embodiment of the present invention is shown. Figure 2 As shown, an intelligent pressure release method for a ventilator includes:

[0033] First, in step 201, the start of exhalation is calibrated. As mentioned above, the present invention dynamically adjusts the pressure target when exhalation starts, so it is necessary to first monitor the need for the start of exhalation during the inhalation cycle, that is, to calibrate the start of exhalation. The determination of the start of exhalation is usually to determine the node where the ventilator flow changes from positive to negative. In one embodiment of the present invention, the user's air flow (Q pat ) is used as the main method and the mask pressure (mask) is used as the auxiliary method to determine whether exhalation has started. Specifically, in one embodiment of the present invention, Figure 3 As shown, for flow and pressure, the change in their absolute value and the first-order derivative, that is, the rate of change, is used to determine. pat ) The determination includes: detecting the airflow at the user end, and comparing it with a first preset value, and detecting the rate of change of the airflow at the user end. If the current airflow Q2 is less than the first preset value, and the rate of decrease of the airflow increases, then the exhalation starts. The first preset value is equal to the maximum airflow Q2 in a stable state. max K q times, where K q The value of K is not greater than 1. q The value of K can be customized by the user. In one embodiment of the present invention, qThe value of is 0.85. The airflow rate reduction increase means that the first-order derivative dQ2 / dt of the user airflow is less than the preset threshold value Q d , indicating that the exhalation demand increases, that is, indicating that exhalation begins. In one embodiment of the present invention, if the airflow rate based on the user (Q pat ) can be further judged based on the mask pressure (mask), including: detecting the mask pressure of the ventilator and comparing it with the second preset value, and detecting the rate of change of the mask pressure of the ventilator. If the current pressure P2 is less than the second preset value and the pressure rise rate increases, the start of exhalation is marked. The second preset value is equal to the maximum mask pressure P under steady state. max The increase in the pressure rise rate means that the first-order derivative dP2 / dt of the mask pressure is greater than the preset threshold value P d , indicating an increase in the need for exhalation, which means that exhalation has begun;

[0034] Next, in step 202, pressure is released. When the ventilator calibrates the start of exhalation, the pressure target is modified and pressure release is performed, wherein the target value of the output pressure is determined according to the exhalation flow rate. In one embodiment of the present invention, the target value of the output pressure of the ventilator, or the required pressure release amount, is determined by the pressure release setting and the exhalation flow rate of the user. In one embodiment of the present invention, the target value of the output pressure is modified according to the following formula:

[0035] Pressure set,new =Pressure set +C*min(0,Flow pat ),

[0036] Among them, Pressure set，new is the target value of the modified output pressure, Pressure set is the initial output pressure, C is the set value, and Flow patIt is the size of the airflow entering the user's lungs. The initial output pressure is set by the user. In one embodiment of the present invention, the ventilator is built with multiple initial output pressures, corresponding to different scenarios and needs. The user can select the gear according to actual needs, or customize the output pressure value. The value of C is determined according to the pressure amplitude to be released, wherein the larger the value of C, the greater the amplitude of pressure release. The value of C can be customized by the user. The higher the setting value C and the larger the exhalation flow, the greater the pressure relief. In one embodiment of the present invention, the value of C is 0 to 3. Specifically, for example, four options such as 0, 1, 2, and 3 can be preset in the setting menu of the ventilator, and the user can choose to set according to needs, wherein 0 means turning off automatic pressure release, 1 to 3 correspond to the size of pressure release, and 3 is the maximum. The size of the airflow entering the user's lungs can be calculated based on the output flow and leakage flow of the ventilator, wherein the leakage flow includes pipeline leakage flow and leakage flow around the mask. In one embodiment of the present invention, the leakage flow rate of the next cycle can be determined according to the inelastic leakage coefficient K1, the elastic leakage coefficient K2 of the current cycle and the airway pressure of the next cycle, and then the leakage flow of the ventilator is calculated, and finally the size of the airflow entering the user's lungs is calculated; and

[0037] Finally, in step 203, the pressure release is terminated. The pressure release can be terminated after the user's exhalation demand ends, that is, when the exhalation airflow at the user end is less than the preset value, the pressure target is adjusted to the original output pressure. In one embodiment of the present invention, the pressure release is terminated when the airflow entering the user's lungs is less than the preset value, so that the target pressure returns to the original output pressure.

[0038] like Figure 3 As shown, based on the intelligent pressure release method as described above, the ventilator flow waveform finally obtained is closer to natural breathing. It should be understood that in the embodiment of the present invention, the pressure release amount of the ventilator can be controlled by the opening of a throttling element such as a control valve and / or a switch element, which will not be described in detail here.

[0039] Based on the intelligent pressure release method as described above, the present invention further provides a ventilator, which includes a detection module and a control module, wherein the detection module is used to detect the output airflow, user-end pressure, etc. of the ventilator in real time, so as to collect data to calibrate the start of exhalation, and / or determine the output pressure target, etc., and the control module adjusts the airflow of the ventilator according to the intelligent pressure release method as described above based on the detection data of the detection module. Wherein, the detection module includes a pressure sensor element and a flow sensor element, and the pressure sensor element and the flow sensor element are arranged at the output port of the ventilator and / or the user mask. The control module includes a control unit and a throttling element and / or a switching element such as a control valve, and the control unit is used to calibrate the start of exhalation, and / or determine the output pressure target, and control the opening of the throttling element and / or the switching element according to the output pressure target.

[0040] The present invention provides an intelligent pressure release method for a ventilator. During the pressure release process, the pressure target is dynamically adjusted according to the user's exhalation needs to meet the needs of different users and different usage scenarios. The method determines the exhalation needs in advance and sets the timing of pre-pressure release to coordinate more smoothly with the natural breathing of the human body.

[0041] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only and not as limitations. It is obvious to those skilled in the relevant art that various combinations, modifications and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should only be defined according to the attached claims and their equivalents.

Claims

1. An intelligent pressure release method for a ventilator, characterized in that: Includes steps: Perform ventilator calibration; Determine expiratory flow; as well as When exhalation begins, a target value of the output pressure is modified, wherein the target value of the output pressure is determined according to the exhalation flow rate.

2. The intelligent pressure release method according to claim 1, characterized in that: Modify the target value of the output pressure according to the following formula: Pressure set,new =Pressure set +C*min(0,Flow pat ), Among them, Pressure set,new is the target value of the modified output pressure, Pressure set is the initial output pressure, C is the set value, and Flow pat The amount of airflow entering the user's lungs.

3. The intelligent pressure release method according to claim 2, characterized in that: The value of C is determined according to the amplitude of pressure to be released, wherein the larger the value of C is, the greater the amplitude of pressure release is.

4. The intelligent pressure release method according to claim 2, characterized in that: The value of C is 0 to 3.

5. The intelligent pressure release method according to claim 1, characterized in that: The ventilator calibration exhalation start comprises the steps of: The air flow rate at the user end is determined. If the air flow rate is less than the first preset value and the rate of decrease of the air flow rate increases, the start of exhalation is marked.

6. The intelligent pressure release method according to claim 5, characterized in that: The first preset value is equal to the maximum airflow K in a steady state. q times, where K q The value of is not greater than 1.

7. The intelligent pressure release method according to claim 6, characterized in that: The K q The value of is 0.

85.

8. The intelligent pressure release method according to claim 5, characterized in that: The ventilator calibration of the start of exhalation also includes the steps of: If the airflow rate is not less than a preset value, and / or the rate of decrease of the airflow rate does not increase, the mask pressure of the ventilator is measured; if the mask pressure is greater than a second preset value and the mask pressure rises faster, the start of exhalation is calibrated, wherein the second preset value is equal to the maximum mask pressure under steady state.

9. The intelligent pressure release method according to claim 1, characterized in that: Also includes the steps: When the exhaled airflow at the user end is less than a preset value, the pressure target is adjusted to the original output pressure.

10. A ventilator, characterized in that: It comprises a control module, which is configured to adjust the airflow of the ventilator according to the intelligent pressure release method according to any one of claims 1 to 9.

Images