Method and system for self-adaptively adjusting pressure rise time and breathing machine

Abstract

The invention relates to the technical field of medical instruments, in particular to a method and system for adaptively adjusting pressure rise time and a breathing machine. The method comprises the following steps: acquiring a maximum air duct pressure value Pmax of an inspiration phase and a stable pressure value Ptable of an inspiration last stage, and calculating a pressure overrun amount Po; counting a pressure overrun proportion Ro based on the pressure overrun amount Po, comparing the pressure overrun proportion Ro with a preset threshold value, and increasing or reducing the pressure rise time according to a comparison result; acquiring a negative pressure signal P0.1 value generated within a period of time before the user actively inhales in the initial stage of inhalation; counting an absolute driving ratio Rda based on the P0.1 value, comparing the absolute driving ratio Rda with a preset threshold value, and increasing or reducing the pressure rise time according to a comparison result; and counting a relative driving ratio Rdr based on the P0.1 value, comparing the relative driving ratio Rdr with a preset threshold value, and increasing or reducing the pressure rise time according to a comparison result. The device has the advantages of being high in man-machine synchronism, high in ventilation comfort, high in adaptability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a method, system and ventilator for adaptively regulating pressure rise time. Background Art

[0002] Mechanical ventilation is a vital life support method widely used in intensive care units. Pressure-controlled ventilation (PCV) and pressure-support ventilation (PSV) are two commonly used ventilation modes. In both modes, the establishment of airway pressure depends on the setting of pressure rise time (Tslope).

[0003] Pressure rise time refers to the time it takes for the ventilator to increase from baseline pressure to the set pressure at the beginning of the inspiratory phase. This parameter directly affects the distribution of inspiratory flow and the airflow sensation during early inspiration. It is a key factor influencing patient-ventilator synchronization, respiratory comfort, and mechanical work.

[0004] In practical applications, the pressure rise time should be set neither too slowly nor too quickly. First, under normal circumstances, the inhaled gas flow rate is highest at the beginning of inspiration and gradually decreases towards the end. A too slow pressure rise can result in insufficient initial airflow, resulting in delayed ventilatory support and the user experiencing additional inhalation effort, which increases the work of breathing and causes discomfort. Studies have shown that appropriately shortening the Tslope helps improve airflow response, reduce respiratory burden, and enhance ventilation efficiency. However, there is currently inconsistent literature regarding the minimum Tslope value. Some studies suggest a range of 0.1 to 0.2 seconds, while others suggest a value as low as 20 ms to 0. If the initial pressure rise rate is slow, the inhaled gas flow rate will be low, which will affect the final tidal volume. On the other hand, a too rapid pressure rise can also be problematic, potentially leading to excessively high initial inhalation flow rates, causing an excessive sense of airflow surge, compromising comfort, and even inducing active respiratory depression, which in turn affects ventilation stability and efficacy.

[0005] Most current mainstream ventilators use a fixed Tslope setting, which remains constant throughout ventilation and cannot adapt to the user's changing respiratory capacity. This static setting mechanism is subject to lag and mismatch, making it difficult to balance timely airflow delivery with comfortable airflow intensity, and can easily lead to patient-machine asynchrony. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned problems of the prior art, thereby providing a method, system and ventilator for adaptively adjusting pressure rise time.

[0007] To solve the above technical problems, the technical solution of the present invention provides a method for adaptively adjusting pressure rise time, comprising:

[0008] Obtain the maximum airway pressure value Pmax during the inspiratory phase and the stable pressure value Pstable at the end of inspiration, and calculate the pressure excess Po. Based on the pressure excess Po, calculate the pressure excess ratio Ro, compare the pressure excess ratio Ro with a preset threshold, and increase or decrease the pressure rise time based on the comparison result.

[0009] Obtain the negative pressure signal P0.1 value generated during the period before the user actively inhales at the beginning of the inhalation phase; calculate the absolute drive ratio Rda based on the P0.1 value, compare the absolute drive ratio Rda with a preset threshold, and increase or decrease the pressure rise time based on the comparison result;

[0010] The relative drive ratio Rdr is calculated based on the P0.1 value, and the relative drive ratio Rdr is compared with a preset threshold value. The pressure rise time is increased or decreased according to the comparison result.

[0011] As an improvement to the above method, the period of time is 100 ms.

[0012] As an improvement to the above method, calculating the pressure excess ratio Ro based on the pressure excess quantity Po, comparing the pressure excess ratio Ro with a preset threshold, and increasing or decreasing the pressure rise time according to the comparison result specifically includes:

[0013] In the first preset statistical time period, the ratio of the pressure excess Po greater than the first threshold k1 is counted as the pressure excess ratio Ro;

[0014] When the pressure overlimit ratio Ro is greater than the second preset threshold value T1 and lasts for the second preset time period, it is considered that the pressure rise time is too short, and the current pressure rise time is automatically increased by the first step s1 to improve comfort;

[0015] When the pressure over-limit ratio Ro is lower than the third preset threshold value T2 and lasts for the third preset time period, the pressure rise time is automatically reduced by the second step amount s2 to improve the inhalation response speed; wherein,

[0016] The first preset statistical time period is 1 to 10 minutes, and the first threshold k1 is 0.05 to 0.4; the second preset threshold T1 is 0.6 to 1, the second preset time period is 5 to 30 minutes, the first step s1 is 0.05 to 0.2s, the third preset threshold T2 is 0.1 to 0.4, the third preset time period is 5 to 30 minutes, and the second step s2 is 0.05 to 0.2s.

[0017] As an improvement to the above method, the absolute drive ratio Rda is calculated based on the P0.1 value, the absolute drive ratio Rda is compared with a preset threshold, and the pressure rise time is increased or decreased according to the comparison result, specifically including:

[0018] Counting the proportion of P0.1 values less than the fourth preset threshold k2 within the fourth preset time period as the absolute driving ratio Rda;

[0019] When the absolute drive ratio Rda is greater than a fifth preset threshold value T3 and lasts for a fifth preset time period, the pressure rise time is automatically reduced by a third step amount s3 to reduce the user's inhalation burden;

[0020] When the absolute driving ratio Rda is less than the sixth preset threshold value T4 and lasts for the sixth preset time period, the pressure rise time is automatically increased by a fourth step amount s4 to alleviate the airflow impact.

[0021] As an improvement to the above method, the fourth preset time period is 10 to 30 minutes, the fourth preset threshold k2 is -3 to -4 cmH2O, the fifth preset time period is 5 to 20 minutes, the fifth preset threshold T3 is 0.6 to 1, the third step amount s3 is 0.05 to 0.2 s, the sixth preset time period is 5 to 20 minutes, the sixth preset threshold T4 is 0.1 to 0.4, and the fourth step amount s4 is 0.05 to 0.2 s.

[0022] As an improvement to the above method, the relative drive ratio Rdr is calculated based on the P0.1 value, the relative drive ratio Rdr is compared with a preset threshold, and the pressure rise time is increased or decreased according to the comparison result, specifically including:

[0023] In the seventh preset time period, the ratio of the number of P0.1 values less than the seventh preset value k3 to the number of P0.1 values greater than the eighth preset value k4 is counted;

[0024] When the relative drive ratio Rdr value is greater than a ninth preset value T5 and lasts for an eighth preset time period, the pressure rise time is automatically reduced by a fifth step amount s5 to enhance support;

[0025] When the relative driving ratio Rdr is lower than the tenth preset value T6 and lasts for a ninth preset period of time, the pressure rise time is automatically increased by a sixth step amount s6 to improve comfort.

[0026] As an improvement to the above method, the seventh preset time period is 10 to 30 minutes, the seventh preset value k3 is -4 to -5 cmH2O, the eighth preset value k4 is -3 to -4 cmH2O, the eighth preset time period is 5 to 20 minutes, the ninth preset value T5 is 1 to 5, the fifth step amount s5 is 0.05 to 0.2 s, the ninth preset time period is 5 to 20 minutes, the tenth preset value T6 is 0.1 to 1, and the sixth step amount s6 is 0.05 to 0.2 s.

[0027] As an improvement to the above method, the maximum increase amount Lu is set to 0 to 0.1 s, and the minimum decrease amount Ll is set to 1 to 10 s.

[0028] To achieve another object of the present invention, the present invention further provides a system for adaptively adjusting pressure rise time, comprising:

[0029] The first acquisition module is used to obtain the maximum airway pressure value Pmax of the inspiratory phase and the stable pressure value Pstable at the end of inspiration, and calculate the pressure limit Po;

[0030] The second acquisition module is used to obtain the negative pressure signal P0.1 value generated in a period of time before the user actively inhales at the initial stage of inhalation;

[0031] The first regulating module is configured to calculate a pressure excess ratio Ro based on the pressure excess quantity Po, compare the pressure excess ratio Ro with a preset threshold, and increase or decrease the pressure rise time according to the comparison result;

[0032] a second regulating module, configured to calculate an absolute driving ratio Rda based on the P0.1 value, compare the absolute driving ratio Rda with a preset threshold, and increase or decrease the pressure rise time according to the comparison result; and

[0033] The third regulating module is configured to calculate a relative driving ratio Rdr based on the P0.1 value, compare the relative driving ratio Rdr with a preset threshold, and increase or decrease the pressure rise time according to the comparison result.

[0034] To achieve another object of the present invention, the present invention also provides a ventilator that executes the above-mentioned method of adaptively adjusting pressure rise time.

[0035] Compared with the prior art, the advantage of the present invention is that the present invention provides a method, system and ventilator for adaptively adjusting the pressure rise time, which has the advantages of strong human-machine synchronization, high ventilation comfort and strong adaptability. By real-time monitoring of airway pressure changes and the user's respiratory drive signal during inhalation, the pressure rise time is automatically analyzed and adjusted, so that it can dynamically match individual needs under different respiratory states, significantly improving the individualization level of respiratory support. The present invention integrates the multi-parameter judgment mechanism of pressure feedback and drive signal, which can take into account both rapid response and airflow comfort, reduce pressure overshoot and inhalation burden, and is suitable for a variety of ventilation modes and user states. In addition, the present invention also sets an adjustment range to ensure that the adjustment process is safe and stable, and avoid discomfort or system risks caused by excessive adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of the method for adaptively adjusting pressure rise time provided in Example 1. DETAILED DESCRIPTION

[0037] The technical solution provided by the present invention is further illustrated below with reference to embodiments.

[0038] Example 1

[0039] This embodiment provides a method for adaptively adjusting the pressure rise time (Tslope), which aims to dynamically optimize the pressure rise time setting based on pressure feedback information during ventilation and the user's respiratory drive ability, thereby improving human-machine synchronization and ventilation comfort. The specific implementation method is as follows:

[0040] 1. Calculate the pressure excess limit Po:

[0041] In each inspiratory cycle, the maximum airway pressure value Pmax of the inspiratory phase and the stable pressure value Pstable at the end of inspiration are obtained. The pressure excess Po is calculated as follows:

[0042]

[0043] This parameter reflects whether there is overshoot during the pressure rise process.

[0044] 2. Statistical pressure excess ratio Ro:

[0045] The pressure overlimit ratio Ro is calculated as the percentage of times the pressure exceeds the limit value Po greater than the first threshold value k1 within the first preset statistical time period. The first preset statistical time period is 1 to 10 minutes, and the first threshold value k1 is 0.05 to 0.4. This parameter reflects the frequency of over-pressurization.

[0046] 3. Automatically reduce or increase the pressure rise time according to the pressure overlimit ratio Ro:

[0047] If the pressure overlimit ratio Ro exceeds the second preset threshold value T1 and persists for the second preset time period, the pressure rise time is considered too short and the current pressure rise time is automatically increased by the first step increment s1 to improve comfort. The second preset threshold value T1 ranges from 0.6 to 1, the second preset time period ranges from 5 to 30 minutes, and the first step increment s1 ranges from 0.05 to 0.2 seconds.

[0048] When the pressure overlimit ratio Ro falls below the third preset threshold T2 and persists for a third preset time period, the pressure rise time is automatically reduced by a second step amount s2 to improve the inhalation response speed. The third preset threshold T2 ranges from 0.1 to 0.4, the third preset time period ranges from 5 to 30 minutes, and the second step amount s2 ranges from 0.05 to 0.2 seconds.

[0049] 4. Calculate the absolute driving ratio Rda:

[0050] Obtain the P0.1 value, which represents the negative pressure signal generated by the user's active inhalation during the initial inhalation phase (the first 100 milliseconds). Count the percentage of P0.1 values within a fourth preset time period that are less than a fourth preset threshold value k2, and use this as the absolute drive ratio Rda. The fourth preset time period ranges from 10 to 30 minutes, and the fourth preset threshold value k2 ranges from -3 to -4 cmH2O. This parameter indicates whether the user's inspiratory driving force is insufficient.

[0051] 5. Automatically reduce or increase the pressure rise time according to the absolute drive ratio Rda:

[0052] When the absolute drive ratio Rda exceeds the fifth preset threshold value T3 and persists for the fifth preset time period, the pressure rise time is automatically reduced by a third step amount s3 to reduce the user's inhalation burden. The fifth preset time period is 5 to 20 minutes, the fifth preset threshold value T3 is 0.6 to 1, and the third step amount s3 is 0.05 to 0.2 seconds.

[0053] When the absolute drive ratio Rda is less than the sixth preset threshold value T4 and persists for the sixth preset time period, the pressure rise time is automatically increased by a fourth step amount s4 to mitigate the airflow shock. The sixth preset time period is 5 to 20 minutes, the sixth preset threshold value T4 is 0.1 to 0.4, and the fourth step amount s4 is 0.05 to 0.2 seconds.

[0054] 6. Calculate the relative driving ratio Rdr:

[0055] During a seventh preset time period, the ratio of P0.1 values less than a seventh preset value k3 to P0.1 values greater than an eighth preset value k4 is counted. The seventh preset time period is 10 to 30 minutes, the seventh preset value k3 is -4 to -5 cmH2O, and the eighth preset value k4 is -3 to -4 cmH2O.

[0056] 7. Automatically reduce or increase the pressure rise time according to the relative drive ratio Rdr value:

[0057] When the relative drive ratio Rdr exceeds the ninth preset value T5 and persists for the eighth preset time period, the pressure rise time is automatically reduced by the fifth step s5 to enhance support. The eighth preset time period is 5 to 20 minutes, the ninth preset value T5 is 1 to 5, and the fifth step s5 is 0.05 to 0.2 seconds.

[0058] When the relative drive ratio Rdr is lower than the tenth preset value T6 for a ninth preset period, the pressure rise time is automatically increased by the sixth step s6 to improve comfort. The ninth preset period is 5 to 20 minutes, the tenth preset value T6 is 0.1 to 1, and the sixth step s6 is 0.05 to 0.2 seconds.

[0059] 8. Set the pressure rise time adjustment range:

[0060] To ensure safety, automatic adjustment of the pressure rise time must be performed within a limited range, with a maximum increase Lu and a minimum decrease Ll set. The maximum increase Lu is 0 to 0.1s, and the minimum decrease Ll is 1 to 10s to prevent excessive changes in the pressure rise time from causing system instability or reduced comfort.

[0061] Through this method, the system can analyze pressure trends and the user's active inhalation intention in real time, automatically optimizing pressure rise time and achieving precise human-machine synchronization. This dynamic adjustment mechanism based on feedback parameters significantly outperforms traditional static settings and has promising clinical application prospects.

[0062] Example 2

[0063] This embodiment provides a system for adaptively adjusting pressure rise time, comprising:

[0064] The first acquisition module is used to obtain the maximum airway pressure value Pmax of the inspiratory phase and the stable pressure value Pstable at the end of inspiration, and calculate the pressure limit Po;

[0065] The second acquisition module is used to obtain the negative pressure signal P0.1 value generated in a period of time before the user actively inhales at the initial stage of inhalation;

[0066] The first regulating module is configured to calculate a pressure excess ratio Ro based on the pressure excess quantity Po, compare the pressure excess ratio Ro with a preset threshold, and increase or decrease the pressure rise time according to the comparison result;

[0067] a second regulating module, configured to calculate an absolute driving ratio Rda based on the P0.1 value, compare the absolute driving ratio Rda with a preset threshold, and increase or decrease the pressure rise time according to the comparison result; and

[0068] The third regulating module is configured to calculate a relative driving ratio Rdr based on the P0.1 value, compare the relative driving ratio Rdr with a preset threshold, and increase or decrease the pressure rise time according to the comparison result.

[0069] Example 3

[0070] This embodiment provides a ventilator that implements the method for adaptively adjusting the pressure rise time provided in Example 1.

[0071] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A method for adaptively adjusting pressure rise time, comprising: Obtain the maximum airway pressure value Pmax during the inspiratory phase and the stable pressure value Pstable at the end of inspiration, and calculate the pressure excess Po; Based on the pressure excess Po, the pressure excess ratio Ro is calculated, the pressure excess ratio Ro is compared with a preset threshold, and the pressure rise time is increased or decreased according to the comparison result; Obtain the negative pressure signal P0.1 value generated during the period before the user actively inhales at the beginning of the inhalation phase; calculate the absolute drive ratio Rda based on the P0.1 value, compare the absolute drive ratio Rda with a preset threshold, and increase or decrease the pressure rise time based on the comparison result; The relative drive ratio Rdr is calculated based on the P0.1 value, and the relative drive ratio Rdr is compared with a preset threshold value. The pressure rise time is increased or decreased according to the comparison result.

2. The method for adaptively adjusting pressure rise time according to claim 1, characterized in that: The period of time is 100ms.

3. The method for adaptively adjusting pressure rise time according to claim 1, characterized in that: The calculating of the pressure excess ratio Ro based on the pressure excess quantity Po, comparing the pressure excess ratio Ro with a preset threshold, and increasing or decreasing the pressure rise time according to the comparison result specifically includes: In the first preset statistical time period, the ratio of the pressure excess Po greater than the first threshold k1 is counted as the pressure excess ratio Ro; When the pressure overlimit ratio Ro is greater than the second preset threshold value T1 and lasts for the second preset time period, it is considered that the pressure rise time is too short, and the current pressure rise time is automatically increased by the first step s1 to improve comfort; When the pressure over-limit ratio Ro is lower than the third preset threshold value T2 and lasts for the third preset time period, the pressure rise time is automatically reduced by the second step amount s2 to improve the inhalation response speed; wherein, The first preset statistical time period is 1 to 10 minutes, and the first threshold k1 is 0.05 to 0.4; the second preset threshold T1 is 0.6 to 1, the second preset time period is 5 to 30 minutes, the first step s1 is 0.05 to 0.2s, the third preset threshold T2 is 0.1 to 0.4, the third preset time period is 5 to 30 minutes, and the second step s2 is 0.05 to 0.2s.

4. The method for adaptively adjusting pressure rise time according to claim 1, characterized in that: The method of calculating the absolute drive ratio Rda based on the P0.1 value, comparing the absolute drive ratio Rda with a preset threshold, and increasing or decreasing the pressure rise time according to the comparison result specifically includes: Counting the proportion of P0.1 values less than the fourth preset threshold k2 within the fourth preset time period as the absolute driving ratio Rda; When the absolute drive ratio Rda is greater than a fifth preset threshold value T3 and lasts for a fifth preset time period, the pressure rise time is automatically reduced by a third step amount s3 to reduce the user's inhalation burden; When the absolute driving ratio Rda is less than the sixth preset threshold value T4 and lasts for the sixth preset time period, the pressure rise time is automatically increased by a fourth step amount s4 to alleviate the airflow impact.

5. The method for adaptively adjusting pressure rise time according to claim 4, characterized in that: The fourth preset time period is 10 to 30 minutes, the fourth preset threshold k2 is -3 to -4 cmH2O, the fifth preset time period is 5 to 20 minutes, the fifth preset threshold T3 is 0.6 to 1, the third step amount s3 is 0.05 to 0.2 s, the sixth preset time period is 5 to 20 minutes, the sixth preset threshold T4 is 0.1 to 0.4, and the fourth step amount s4 is 0.05 to 0.2 s.

6. The method for adaptively adjusting pressure rise time according to claim 1, characterized in that: The method of calculating the relative drive ratio Rdr based on the P0.1 value, comparing the relative drive ratio Rdr with a preset threshold, and increasing or decreasing the pressure rise time according to the comparison result specifically includes: In the seventh preset time period, the ratio of the number of P0.1 values less than the seventh preset value k3 to the number of P0.1 values greater than the eighth preset value k4 is counted; When the relative drive ratio Rdr value is greater than a ninth preset value T5 and lasts for an eighth preset time period, the pressure rise time is automatically reduced by a fifth step amount s5 to enhance support; When the relative driving ratio Rdr is lower than the tenth preset value T6 and lasts for a ninth preset period of time, the pressure rise time is automatically increased by a sixth step amount s6 to improve comfort.

7. The method for adaptively adjusting pressure rise time according to claim 6, characterized in that: The seventh preset time period is 10 to 30 minutes, the seventh preset value k3 is -4 to -5 cmH2O, the eighth preset value k4 is -3 to -4 cmH2O, the eighth preset time period is 5 to 20 minutes, the ninth preset value T5 is 1 to 5, the fifth step s5 is 0.05 to 0.2 s, the ninth preset time period is 5 to 20 minutes, the tenth preset value T6 is 0.1 to 1, and the sixth step s6 is 0.05 to 0.2 s.

8. The method for adaptively adjusting pressure rise time according to claim 1, characterized in that: The maximum increase amount Lu of the increase is 0 to 0.1s, and the minimum decrease amount Ll of the decrease is 1 to 10s.

9. A system for adaptively adjusting pressure rise time, comprising: The first acquisition module is used to obtain the maximum airway pressure value Pmax of the inspiratory phase and the stable pressure value Pstable at the end of inspiration, and calculate the pressure limit Po; The second acquisition module is used to obtain the negative pressure signal P0.1 value generated in a period of time before the user actively inhales at the initial stage of inhalation; The first regulating module is configured to calculate a pressure excess ratio Ro based on the pressure excess quantity Po, compare the pressure excess ratio Ro with a preset threshold, and increase or decrease the pressure rise time according to the comparison result; The second adjustment module is used to calculate the absolute drive ratio Rda based on the P0.1 value, compare the absolute drive ratio Rda with a preset threshold, and increase or decrease the pressure rise time according to the comparison result; and The third regulating module is configured to calculate a relative driving ratio Rdr based on the P0.1 value, compare the relative driving ratio Rdr with a preset threshold, and increase or decrease the pressure rise time according to the comparison result.

10. A ventilator, characterized in that: Execute the method for adaptively adjusting pressure rise time as described in any one of claims 1-8.

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