An adaptive variability ventilation method and system and ventilator

Abstract

The application provides a self-adaptive variability ventilation method and system and a breathing machine. The method comprises the following steps: attaching a set minute ventilation variability to a set target minute ventilation; calculating a user optimal ventilation frequency and a user optimal tidal volume; adjusting a driving pressure of a ventilation system based on a difference AV between a user actual tidal volume and the user optimal tidal volume, so as to reduce a difference AV between the optimal ventilation frequency and the actual tidal volume; adjusting a ventilation frequency of the ventilation system based on a difference Af between a user actual breathing frequency and the user optimal ventilation frequency, so as to reduce a difference Af between the user optimal ventilation frequency and the user actual breathing frequency. The application attaches the user's breathing variability to the variability ventilation system, simulates the tidal volume variability degree for the user, and adjusts the output tidal volume and the ventilation frequency of the ventilation system, so that the work of the user's breathing is minimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a self-adaptive variability ventilation method and system and a ventilator comprising the self-adaptive variability ventilation system. BACKGROUND

[0002] Mechanical ventilation is usually used to provide breathing support for people who cannot rely on their own breathing, and ASV, i.e. adaptive support ventilation, is an intelligent closed-loop ventilation mode in which the machine provides breathing ventilation support for the user according to the minute ventilation volume preset by the user. However, this mode only provides fixed tidal volume and breathing frequency support after the ventilation is stable, and there is a certain variability in the real spontaneous breathing, and sighs will intermittently appear, and the tidal volume, breathing frequency and inspiratory flow rate fluctuate within a certain range. The existing technology has a single gas delivery mode and cannot adapt to the changes in tidal volume and breathing frequency. SUMMARY

[0003] The present application aims to overcome the problem that the existing ventilation system cannot adapt to the changes in tidal volume and breathing frequency, and thus provides a self-adaptive variability ventilation method and system and a ventilator comprising the self-adaptive variability ventilation system.

[0004] To solve the above technical problems, the self-adaptive variability ventilation method provided by the technical solution of the present application relates to a ventilation system, which comprises:

[0005] appending a set minute ventilation variability to a set target minute ventilation;

[0006] calculating a user optimal ventilation frequency and a user optimal tidal volume based on the appended target minute ventilation and user parameters;

[0007] adjusting the driving pressure of the ventilation system based on the difference ΔV between the user actual tidal volume and the user optimal tidal volume to reduce the difference ΔV between the optimal ventilation frequency and the actual tidal volume, and adjusting the ventilation frequency of the ventilation system based on the difference Δf between the user actual breathing frequency and the user optimal ventilation frequency to reduce the difference Δf between the user optimal ventilation frequency and the user actual breathing frequency;

[0008] continuously adjusting the driving pressure and the ventilation frequency of the ventilation system until the difference ΔV between the user optimal tidal volume and the user actual tidal volume is less than a first preset threshold and the difference Δf between the user optimal ventilation frequency and the user actual breathing frequency is less than a second preset threshold.

[0009] As an improvement of the above method, the step of appending the set minute ventilation variability to the set target minute ventilation specifically comprises:

[0010] MVT=MV+dMV×a

[0011] wherein MVT is the target minute ventilation after addition, MV is the target minute ventilation set, dMV is the minute ventilation variation set, and a is a Gaussian coefficient conforming to normal distribution, wherein a≠0.

[0012] As an improvement of the above method, the user actual tidal volume is obtained by the following method:

[0013] Monitoring the user actual inhalation tidal volume Vti and the user actual exhalation tidal volume Vte;

[0014] The user actual tidal volume Vt is calculated by the user actual inhalation tidal volume Vti and the user actual exhalation tidal volume Vte:

[0015] Vt=(Vti+Vte) / 2

[0016] The user actual breathing frequency f is obtained by monitoring.

[0017] As an improvement of the above method, the user optimal ventilation frequency and the user optimal tidal volume are calculated based on the target minute ventilation after addition and the user parameters, including the following steps:

[0018] The user optimal ventilation frequency fb is calculated based on the target minute ventilation after addition MVT, the user respiratory constant RC e and the user weight W:

[0019]

[0020] wherein m is a first constant, 1≤m≤100, n is a second constant, 2≤n≤5, and a is a Gaussian coefficient conforming to normal distribution, wherein a≠0;

[0021] The user optimal tidal volume VTb is calculated by the user optimal ventilation frequency fb and the target minute ventilation after addition MVT:

[0022] VTb=MVT / fb.

[0023] As an improvement of the above method, the driving pressure of the ventilation system is adjusted based on the difference ΔV between the user actual tidal volume and the user optimal tidal volume, specifically including:

[0024] The difference ΔV between the user actual tidal volume Vt and the user optimal tidal volume VTb is calculated:

[0025] ΔV=Vt-VTb;

[0026] The driving pressure P of the adjusted ventilation system is calculated by the ventilation frequency Ppre of the ventilation system in the last breathing cycle and the difference AV between the actual tidal volume of the user and the optimal tidal volume of the user:

[0027] P = Ppre - k1 x AV

[0028] wherein k1 is a third constant, 0.01 ≤ k1 ≤ 1;

[0029] The ventilation system outputs the driving pressure P.

[0030] As an improvement of the above method, the ventilation frequency of the ventilation system is adjusted based on the difference Af between the actual breathing frequency of the user and the optimal ventilation frequency of the user, and specifically comprises:

[0031] The difference Af between the actual breathing frequency f of the user and the optimal ventilation frequency fb of the user is calculated:

[0032] Af = f - fb

[0033] The adjusted ventilation frequency F of the ventilation system is calculated by the ventilation frequency Fpre of the ventilation system in the last breathing cycle and the difference Af between the actual breathing frequency of the user and the optimal ventilation frequency of the user:

[0034] F = Fpre - k2 x Af

[0035] wherein k2 is a fourth constant, 0.1 ≤ k2 ≤ 1;

[0036] The ventilation system ventilates based on the adjusted ventilation frequency F.

[0037] To achieve another object of the present application, the present application provides an adaptive variability ventilation system, comprising: a ventilation module and a control module; wherein,

[0038] The control module is configured to: append a set minute ventilation variability to a set target minute ventilation; calculate the optimal ventilation frequency of the user and the optimal tidal volume of the user based on the appended target minute ventilation and user parameters; adjust the driving pressure of the ventilation module based on the difference AV between the actual tidal volume of the user and the optimal tidal volume of the user, so as to reduce the difference AV between the optimal ventilation frequency and the actual tidal volume; adjust the ventilation frequency of the ventilation module based on the difference Af between the actual breathing frequency of the user and the optimal ventilation frequency of the user, so as to reduce the difference Af between the optimal ventilation frequency of the user and the actual breathing frequency of the user; and continuously adjust the driving pressure and the ventilation frequency of the ventilation module until the difference AV between the optimal tidal volume of the user and the actual tidal volume of the user is less than a first preset threshold and the difference Af between the optimal ventilation frequency of the user and the actual breathing frequency of the user is less than a second preset threshold.

[0039] The ventilation module works based on the adjusted driving pressure and ventilation frequency.

[0040] To achieve another object of the present application, the present application further provides a breathing machine comprising the adaptive variability ventilation system.

[0041] Compared with the prior art, the present application has the advantage of solving the problem that the conventional fixed parameter ventilation mode does not conform to the respiratory variability of the physiological state. The present application improves the ASV ventilation mode, and the basic principle is to add the respiratory variability of the user to the variability ventilation system, simulate the tidal volume variability, and adjust the output tidal volume and ventilation frequency of the ventilation system, so that the work of the user's respiration is minimized. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A flowchart of an adaptive variability ventilation method provided by the present application is shown. DETAILED DESCRIPTION

[0043] The technical solutions provided by the present application are further illustrated below in combination with embodiments.

[0044] Embodiment 1

[0045] The present embodiment provides an adaptive variability ventilation method, as shown in Figure 1 The method comprises the following steps:

[0046] The set minute ventilation variability is added to the set target minute ventilation;

[0047] Based on the added target minute ventilation and the user parameters, the optimal ventilation frequency of the user and the optimal tidal volume of the user are calculated;

[0048] Based on the difference ΔV between the actual tidal volume of the user and the optimal tidal volume of the user, the driving pressure of the ventilation system is adjusted to reduce the difference ΔV between the optimal ventilation frequency and the actual tidal volume; based on the difference Δf between the actual respiratory frequency of the user and the optimal ventilation frequency of the user, the ventilation frequency of the ventilation system is adjusted to reduce the difference Δf between the optimal ventilation frequency of the user and the actual respiratory frequency of the user;

[0049] The driving pressure and the ventilation frequency of the ventilation system are continuously adjusted until the difference ΔV between the optimal tidal volume of the user and the actual tidal volume of the user is less than a first preset threshold and the difference Δf between the optimal ventilation frequency of the user and the actual respiratory frequency of the user is less than a second preset threshold.

[0050] The adaptive variability ventilation method specifically comprises:

[0051] 1. Obtain the user input parameters, and the parameters include: target minute ventilation MV and minute ventilation variability dMV.

[0052] 2. Generating a Gaussian coefficient a (a≠0) subject to normal distribution, adding the set minute ventilation variability to the set target minute ventilation; then the added target minute ventilation MVT is:

[0053] MVT=MV+dMV×a

[0054] Therefore, the added target minute ventilation MVT is the minute ventilation of the user added with a certain variability.

[0055] 3. Real-time monitoring the actual tidal volume Vt of the user by the flow sensor:

[0056] Vt=(Vti+Vte) / 2;

[0057] Wherein, Vti is the inhaled tidal volume of the user monitored, and Vte is the exhaled tidal volume of the user monitored.

[0058] 4. Real-time monitoring the actual breathing frequency f of the user.

[0059] 5. Calculating the optimal ventilation frequency fb of the user based on the user parameters:

[0060]

[0061] V D =n*W

[0062] Wherein, the user parameters include: the user exhalation constant RC e and the user weight W. m is the first constant, n is the second constant, m takes the value of 1-100, and n takes the value of 2-5.

[0063] 6. Calculating the optimal tidal volume VTb of the user:

[0064] VTb=MVT / fb

[0065] 7. Getting the difference ΔV between the actual tidal volume and the optimal tidal volume, ΔV=Vt-VTb, and getting the difference Δf between the actual breathing frequency and the optimal ventilation frequency:

[0066] Δf=f-fb

[0067] 8. Adjusting the driving pressure P of the current breathing cycle of the ventilation system to make the actual tidal volume close to the optimal tidal volume:

[0068] P=Ppre-k1×ΔV

[0069] Wherein, Ppre is the driving pressure of the last breathing cycle of the ventilation system, and k1 is the third constant, taking the value of 0.01-1.

[0070] 9、Meanwhile, the actual respiratory frequency is made to approach the optimal ventilation frequency by adjusting the ventilation frequency F of the ventilation system in the current respiratory cycle:

[0071] F = Fpre - k2 x Af

[0072] Wherein, Fpre is the ventilation frequency of the last respiratory cycle of the ventilation system, k2 is a fourth constant, and the value is 0.1-1.

[0073] 10、The above steps 3, 4, 8, 9 are repeated in turn until the user enters a stable optimal respiratory state, that is, AV is less than the first preset threshold and Af is less than the second preset threshold, and in the embodiment, the first preset threshold can be 30 and the second preset threshold can be 1. After running for a period of time (such as 1 hour) according to this state, return to step 2 again and execute in turn, and enter a new round of adaptive ventilation.

[0074] Embodiment 2

[0075] The embodiment provides an adaptive variability ventilation system, comprising: a ventilation module and a control module; wherein,

[0076] The control module is configured to append a set minute ventilation variability to a set target minute ventilation; calculate a user optimal ventilation frequency and a user optimal tidal volume based on the appended target minute ventilation and user parameters; adjust the driving pressure of the ventilation module based on the difference AV between the user actual tidal volume and the user optimal tidal volume, so as to reduce the difference AV between the optimal ventilation frequency and the actual tidal volume; adjust the ventilation frequency of the ventilation module based on the difference Af between the user actual respiratory frequency and the user optimal ventilation frequency, so as to reduce the difference Af between the user optimal ventilation frequency and the user actual respiratory frequency; and continuously adjust the driving pressure and the ventilation frequency of the ventilation module until the difference AV between the user optimal tidal volume and the user actual tidal volume is less than a first preset threshold and the difference Af between the user optimal ventilation frequency and the user actual respiratory frequency is less than a second preset threshold.

[0077] The ventilation module works based on the adjusted driving pressure and ventilation frequency.

[0078] Embodiment 3

[0079] The embodiment provides a breathing machine, comprising the adaptive variability ventilation system provided in embodiment 2.

[0080] The present application solves the problem that the conventional fixed parameter ventilation mode does not conform to the respiratory variability of the physiological state. The present application improves the ASV ventilation mode, and the basic principle is to append the respiratory variability of the user to the variability ventilation system, simulate the tidal volume variability degree, and adjust the output tidal volume and ventilation frequency of the ventilation system, so that the work of the user's respiration is minimized.

[0081] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit. Although the present application is explained in detail with reference to the embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. An adaptive variable ventilation system, comprising: The ventilation module is characterized in that it further includes a control module; wherein, The control module is configured to: add a set minute ventilation variability to a set target minute ventilation; calculate the user's optimal ventilation frequency and optimal tidal volume based on the added target minute ventilation and user parameters; adjust the driving pressure of the ventilation module based on the difference ΔV between the user's actual tidal volume and the user's optimal tidal volume to reduce the difference ΔV between the optimal ventilation frequency and the actual tidal volume; adjust the ventilation frequency of the ventilation module based on the difference Δf between the user's actual respiratory rate and the user's optimal ventilation rate to reduce the difference Δf between the user's optimal ventilation rate and the user's actual respiratory rate; and continuously adjust the driving pressure and ventilation frequency of the ventilation module until the difference ΔV between the user's optimal tidal volume and the user's actual tidal volume is less than a first preset threshold and the difference Δf between the user's optimal ventilation frequency and the user's actual respiratory rate is less than a second preset threshold. The ventilation module operates based on the adjusted driving pressure and ventilation frequency. The process by which the control module adds the set minute ventilation variability to the set target minute ventilation includes: MVT = MV + dMV × a Where MVT is the target minute ventilation after the addition, MV is the set target minute ventilation, dMV is the set minute ventilation variability, and a is the Gaussian coefficient that conforms to a normal distribution, where a≠0; The process by which the control module calculates the optimal ventilation frequency and optimal tidal volume for the user based on the additional target minute ventilation and user parameters includes: Based on the added target minute ventilation (MVT) and user respiratory constant (RC) e Given the user's weight W, calculate the user's optimal ventilation frequency fb: Where f is the user's actual respiratory rate, m is the first constant, 1≤m≤100, n is the second constant, 2≤n≤5, and a is the Gaussian coefficient that conforms to a normal distribution, where a≠0; Calculate the user's optimal tidal volume VTb using the user's optimal ventilation frequency fb and the additional target minute ventilation MVT: VTb = MVT / fb The process by which the control module adjusts the ventilation rate of the ventilation module based on the difference Δf between the user's actual respiratory rate and the user's optimal ventilation rate includes: Calculate the difference Δf between the user's actual respiratory rate f and the user's optimal ventilatory rate fb: Δf=f-fb The adjusted ventilation rate F is calculated using the ventilation rate Fpre of the ventilation system in the previous respiratory cycle and the difference Δf between the user's actual respiratory rate and the user's optimal ventilation rate. F=Fpre-k2×Δf Where k2 is the fourth constant, 0.1≤k2≤1; The ventilation system ventilates based on an adjusted ventilation frequency F.

2. The adaptive variable ventilation system according to claim 1, characterized in that, The user's actual tidal volume was obtained through the following method: Monitor the user's actual inspiratory tidal volume Vti and the user's actual expiratory tidal volume Vte; The user's actual tidal volume Vt is calculated using the user's actual inspiratory tidal volume Vti and the user's actual expiratory tidal volume Vte. Vt=(Vti+Vte) / 2 The user's actual respiratory rate f is obtained through monitoring.

3. The adaptive variable ventilation system according to claim 1, characterized in that, The process by which the control module adjusts the driving pressure of the ventilation module based on the difference ΔV between the user's actual tidal volume and the user's optimal tidal volume includes: Calculate the difference ΔV between the user's actual tidal volume Vt and the user's optimal tidal volume VTb: ΔV = Vt - VTb; The driving pressure P of the regulated ventilation system is calculated using the ventilation rate Ppre of the previous respiratory cycle and the difference ΔV between the user's actual tidal volume and the user's optimal tidal volume. P=Ppre-k1×ΔV Where k1 is the third constant, 0.01≤k1≤1; The ventilation system outputs driving pressure P.

4. A ventilator, characterized in that, Including the adaptive variable ventilation system as described in claim 1.

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