A method for detecting air leakage of a mask

Abstract

The present invention discloses a method for detecting air leakage of a mask, comprising the following steps: collecting the vibration acceleration of the edge of the mask, calculating acceleration derivative data according to the vibration acceleration, wherein the acceleration derivative data includes acceleration mean square error, acceleration frequency or acceleration smoothing filter value. Judging whether the mask is leaking is based on the acceleration mean square error, acceleration frequency and acceleration smoothing filter value, and when the mask is judged to be leaking according to two or more acceleration derivative data, the mask is finally judged to be leaking. This method can detect whether the mask is leaking, and timely notify medical staff when leaking, so that the medical staff can adjust the mask, thereby enabling the patient to obtain a better treatment effect, and also avoiding the medical staff from being exposed to treatment gas such as laughing gas, thereby protecting the health of the medical staff. It also reduces the waste of treatment gas.

Description

Technical Field

[0001] The invention relates to a method for detecting air leakage of a mask, and in particular to a method for detecting air leakage of a mask by utilizing acceleration. Background Art

[0002] Masks are often used for treatment during medical treatment. Existing respiratory mask devices generally detect whether the mask device has leaks by comparing the patient's inhaled gas flow rate and the patient's exhaled gas flow rate. However, in existing devices such as nitrous oxide analgesics, gas is supplied according to the total nitrous oxide flow rate and nitrous oxide concentration. This nitrous oxide supply device cannot detect whether the patient has completely received all the gas supplied by the device. If the mask leaks, the nitrous oxide device cannot detect whether it leaks based on the gas flow rate. If the mask of the nitrous oxide supply device leaks, the patient's treatment effect will be weakened, and oxygen and nitrous oxide resources will be wasted. At the same time, the leaked nitrous oxide will also pollute the indoor air, exposing medical staff to nitrous oxide and damaging their health. Summary of the invention

[0003] In order to solve the problem of detecting air leakage of a mask in a laughing gas device, the present application provides a method for detecting air leakage of a mask.

[0004] A method for detecting air leakage from a mask, comprising the following steps:

[0005] The vibration acceleration of the edge of the mask within a period of time is collected, acceleration-derived data is calculated according to the vibration acceleration, and whether the mask is leaking is determined according to the relationship between the acceleration-derived data and set parameters.

[0006] Furthermore, the acceleration derived data includes: one or more of acceleration mean square error, acceleration frequency or acceleration smoothing filter value.

[0007] Further, whether the mask is leaking is determined based on the acceleration mean square error, the acceleration frequency and the smoothed filter value of the acceleration. When the mask is leaking based on two or more acceleration-derived data, it is finally determined that the mask is leaking.

[0008] Furthermore, acceleration-derived data is calculated according to the vibration acceleration, and whether the mask is leaking is determined according to the relationship between the acceleration-derived data and set parameters, specifically including: high-pass filtering the vibration acceleration to obtain filtered data, calculating the mean square error of the filtered data, and determining that the mask is leaking if the mean square error exceeds a set threshold.

[0009] Furthermore, acceleration-derived data is calculated according to the vibration acceleration, and whether the mask is leaking is determined according to the relationship between the acceleration-derived data and set parameters, specifically including: calculating the frequency of the vibration acceleration using Fourier transform, and accumulating the values ​​of the frequency in a first range of frequencies and a second range of frequencies, wherein the first range of frequencies is lower than the second range of frequencies, and if the value of the first range of frequencies is lower than the value of the second range of frequencies, then it is determined that the mask is leaking.

[0010] Furthermore, acceleration-derived data is calculated according to the vibration acceleration, and whether the mask is leaking is determined according to the relationship between the acceleration-derived data and set parameters, specifically including: smoothing filtering the vibration acceleration to obtain a smoothing filter value, calculating the mean difference between the smoothing filter value and the average value of the smoothing filter value, and if the number of zero points in the mean difference exceeds a set threshold, it is determined that the mask is leaking.

[0011] Furthermore, the sampling frequency of collecting the vibration acceleration of the mask edge is greater than or equal to 500 Hz.

[0012] The present invention also discloses a mask, comprising: an acceleration unit, a main control unit and a power supply, wherein the acceleration unit is connected to the main control unit and is located at the edge of the mask; the acceleration unit collects vibration acceleration of the edge of the mask, the main control unit calculates acceleration-derived data according to the vibration acceleration, and determines whether the mask is leaking according to the acceleration-derived data.

[0013] Furthermore, the main control unit includes a computing module and a communication module, the computing module is connected to the communication module, and the communication module is connected to the host.

[0014] The invention also discloses a laughing gas supply device, which comprises the above-mentioned mask and a main machine.

[0015] The beneficial effects of the present invention are:

[0016] This method uses the principle that the vibration frequency of the mask will become faster when there is a leak, collects the vibration acceleration of the edge of the mask, and processes the acceleration data through filtering, Fourier transform, etc. to form acceleration derivative data, and then judges whether the mask is leaking based on the acceleration derivative data. This method can detect whether the mask is leaking, and when there is a leak, the medical staff can be notified in time, so that the medical staff can adjust the mask, so that the patient can get a better treatment effect, and also avoid the medical staff from being exposed to treatment gases such as laughing gas, protecting the health of the medical staff. It also reduces the waste of treatment gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a method for detecting mask leakage in a preferred embodiment;

[0019] Figure 2 It is a schematic diagram of the components of the mask. DETAILED DESCRIPTION

[0020] In order to make the purpose, features, and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0022] In the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] Example 1

[0024] This embodiment provides a method for detecting mask leakage, which specifically includes:

[0025] The vibration acceleration Acc[t] of the mask edge over a period of time is collected, acceleration derivative data is calculated based on the vibration acceleration, and whether the mask is leaking is determined based on the relationship between the acceleration derivative data and the set parameters.

[0026] The acceleration derived data in this embodiment is the acceleration mean square error, and the setting parameter is the mean square error threshold. The specific judgment method is:

[0027] S1, collect the vibration acceleration of the edge of the mask, and the sampled vibration acceleration is Acc[t].

[0028] S2, high-pass filter the vibration acceleration to obtain the filtered data Acc[f], and calculate the mean square error std_f of the filtered data:

[0029] mean is the mean of Acc[f].

[0030] Among them, the high-pass filter adopts IIR2-order Butterworth high-pass filter. The purpose of high-pass filtering is to remove the influence of the patient's breathing and body swing. The patient's breathing frequency is generally very low, between 10Hz-20Hz, while the vibration frequency of the mask during air leakage is very high, which can reach hundreds of hertz. In this embodiment, a high-pass cutoff frequency of 60Hz is adopted.

[0031] S3, judging whether the mask is leaking, if the mean square error exceeds the threshold, the mask is judged to be leaking. If the mask is not leaking, the value of the mean square error std_f is small, if the mask is leaking, the value of the mean square error std_f will be significantly larger, if the value of the mean square error std_f exceeds the threshold THstd_f, the mask may be leaking. The value of THstd_f can be set by analysis of experimental and clinical data.

[0032] Example 2

[0033] This embodiment provides a method for detecting mask leakage, which specifically includes:

[0034] The vibration acceleration Acc[t] of the mask edge over a period of time is collected, acceleration derivative data is calculated based on the vibration acceleration, and whether the mask is leaking is determined based on the relationship between the acceleration derivative data and the set parameters.

[0035] The acceleration derived data in this embodiment is the acceleration frequency, and the setting parameter is the numerical ratio of the first and second range frequencies. The specific determination method is:

[0036] The frequency Acc[fft] of the vibration acceleration Acc[t] is calculated using Fourier transform, and the value fft_sum1 of the frequency Acc[fft] between the first range of frequencies 5 Hz-40 Hz and the value fft_sum2 of the frequency Acc[fft] between the second range of frequencies 100 Hz-250 Hz are accumulated. If the value fft_sum1 of the first range of frequencies is lower than the value fft_sum2 of the second range of frequencies, it is determined that the mask is leaking.

[0037] If the mask is not leaking, the main vibration energy will be concentrated between 5Hz-40Hz, and fft_sum1 will be greater than fft_sum2; if the mask is leaking, the main vibration energy will be concentrated between 100Hz-250Hz, and fft_sum1 will be less than fft_sum2.

[0038] Example 3

[0039] This embodiment provides a method for detecting mask leakage, which specifically includes:

[0040] The vibration acceleration Acc[t] of the mask edge over a period of time is collected, acceleration derivative data is calculated based on the vibration acceleration, and whether the mask is leaking is determined based on the relationship between the acceleration derivative data and the set parameters.

[0041] The acceleration derived data in this embodiment is the smoothed filter value of the acceleration, and the setting parameter is the threshold value of the number of zero crossing points. The specific judgment method is:

[0042] The vibration acceleration Acc[t] is smoothed and filtered according to the smoothing filter function to obtain the smoothing filter value Acc[maf]. The smoothing filter value is subtracted from the average value of the smoothing filter value to obtain the mean difference. If the number of zero points in the mean difference exceeds the threshold, it is determined that the mask is leaking. The smoothing filter function is as follows:

[0043] M is the order of the smoothing filter function, and in this embodiment, the order is selected to be 10.

[0044] Subtract the mean value of Acc[maf] from Acc[maf] to obtain the mean difference Acc[m], and count the number of zero-crossing points in Acc[m]. If the mask is not leaking, the contraction of the mask is regular and the number of zero-crossing points is small. If the mask is leaking, the vibration of the mask will bring a large number of zero-crossing values. Therefore, if the number of zero-crossing points exceeds the threshold THzero, the mask may be leaking. In this embodiment, the number of THzero is selected to be 20, and THzero can be set through the analysis of experimental and clinical data.

[0045] Example 4

[0046] This embodiment provides a method for detecting mask leakage, which specifically includes:

[0047] The vibration acceleration Acc[t] of the mask edge over a period of time is collected, acceleration derivative data is calculated based on the vibration acceleration, and whether the mask is leaking is determined based on the relationship between the acceleration derivative data and the set parameters.

[0048] like Figure 1 As shown, the acceleration derived data in this embodiment includes acceleration mean square error, acceleration frequency or acceleration smoothing filter value. Whether the mask is leaking is judged according to the acceleration mean square error, acceleration frequency and acceleration smoothing filter value. When the mask is judged to be leaking according to two or more acceleration derived data, it is finally judged that the mask is leaking.

[0049] (1) Judging based on the mean square error of acceleration, including:

[0050] Perform high-pass filtering on the vibration acceleration to obtain the filtered data Acc[f], and calculate the mean square error std_f of the filtered data:

[0051] mean is the mean of Acc[f].

[0052] If the mask is not leaking, the value of the mean square error std_f is small. If the mask is leaking, the value of the mean square error std_f will be significantly larger. If the value of the mean square error std_f exceeds the threshold THstd_f, the mask may be leaking. The value of THstd_f can be set through analysis of experimental and clinical data.

[0053] If the value of the mean square error std_f exceeds the threshold value THstd_f, the judgment result is recorded as 1; if the value of std_f does not exceed the threshold value THstd_f, the judgment result is recorded as 0.

[0054] (2) Judging based on the acceleration frequency, including:

[0055] The frequency Acc[fft] of the vibration acceleration Acc[t] is calculated using Fourier transform, and the value fft_sum1 of the frequency Acc[fft] between the first range of frequencies 5 Hz-40 Hz and the value fft_sum2 of the frequency Acc[fft] between the second range of frequencies 100 Hz-250 Hz are accumulated. If the value fft_sum1 of the first range of frequencies is lower than the value fft_sum2 of the second range of frequencies, it is determined that the mask is leaking.

[0056] If the value of fft_sum1 is less than the value of fft_sum2, the judgment result is recorded as 1. If the value of fft_sum1 is greater than the value of fft_sum2, the judgment result is recorded as 0.

[0057] (3) Making a judgment based on the smoothing filter value of the acceleration, specifically including:

[0058] The vibration acceleration Acc[t] is smoothed and filtered according to the smoothing filter function to obtain the smoothing filter value Acc[maf]. The smoothing filter value is subtracted from the average value of the smoothing filter value to obtain the mean difference. If the number of zero points in the mean difference exceeds the threshold, it is determined that the mask is leaking. The smoothing filter function is as follows:

[0059] M is the order of the smoothing filter function, and in this embodiment, the order is selected to be 10.

[0060] Subtract the mean value of Acc[maf] from Acc[maf] to obtain the mean difference Acc[m], and count the number of zero-crossing points in Acc[m]. If the mask is not leaking, the contraction of the mask is regular and the number of zero-crossing points is small. If the mask is leaking, the vibration of the mask will bring a large number of zero-crossing values. Therefore, if the number of zero-crossing points exceeds the threshold THzero, the mask may be leaking. In this embodiment, the number of THzero is selected to be 20, and THzero can be set through the analysis of experimental and clinical data.

[0061] If the value of the mean difference Acc[m] exceeds the threshold value THzero, the judgment result is recorded as 1; if the value of the mean difference Acc[m] does not exceed the threshold value THzero, the judgment result is recorded as 0.

[0062] Add the judgment results of (1), (2) and (3) above. If the sum is greater than or equal to 2, it means that at least two of the three methods above determine that the mask is leaking at this time, and the final result is that the mask is leaking.

[0063] This embodiment combines multiple calculation detection methods, which can avoid misjudgment when there is only one detection method, improve the accuracy of leakage judgment, and do not add the workload of manual inspection for misjudgment to medical staff, thereby helping medical staff to better treat and provide patients with a more accurate supply of nitrous oxide.

[0064] The sampling frequency of collecting the vibration acceleration Acc[t] of the mask edge in the above-mentioned embodiments 1-4 is 500 Hz.

[0065] Example 5

[0066] A mask, such as Figure 2 As shown, the method for implementing any one of the above embodiments 1-4 includes:

[0067] An acceleration unit, a main control unit and a power supply, wherein the acceleration unit is connected to the main control unit and is located at the edge of the mask.

[0068] The acceleration unit collects vibration acceleration data of the edge of the mask, and the main control unit calculates acceleration derivative data based on the vibration acceleration data, and determines whether the mask is leaking based on the acceleration derivative data. The main control unit includes a calculation module and a communication module, the calculation module is connected to the communication module, and the communication module is connected to the host, and the result is sent to the host, and the host can display or alarm in time to notify medical staff that the mask is leaking.

[0069] Among them, the main control unit is a low-power Bluetooth main control chip, model nRF52832, the acceleration unit is an acceleration chip, model BMA280, and the power supply is a battery, model CR2032.

[0070] Example 6

[0071] A laughing gas supply device comprises the mask, a main unit, laughing gas supply equipment and oxygen supply equipment described in the fifth embodiment.

[0072] The nitrous oxide supply device and the oxygen supply device are both connected to the mask, through which oxygen and nitrous oxide are supplied to the patient. The mask is connected to the host, and when the mask detects a leak, this information is sent to the host. After the medical staff knows that the mask is leaking through the host, they adjust the patient's mask.

[0073] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0074] The units may or may not be physically separated, and the components displayed as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0075] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0076] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting air leakage in a mask, characterized in that: The following steps are involved: Collecting the vibration acceleration of the edge of the mask over a period of time, calculating acceleration derivative data according to the vibration acceleration, and judging whether the mask is leaking according to the relationship between the acceleration derivative data and the set parameters, specifically includes the following steps: Performing high-pass filtering on the vibration acceleration to obtain filtered data, calculating the mean square error of the filtered data, and determining that the mask is leaking if the mean square error exceeds a set threshold; Or, the frequency of the vibration acceleration is calculated by Fourier transform, and the values ​​of the frequency in a first range of frequencies and a second range of frequencies are accumulated, the first range of frequencies is lower than the second range of frequencies, and if the value of the first range of frequencies is lower than the value of the second range of frequencies, it is determined that the mask is leaking; Or, the vibration acceleration is smoothed and filtered to obtain a smoothed filter value, and a mean difference between the smoothed filter value and an average value of the smoothed filter value is calculated. If the number of zero points in the mean difference exceeds a set threshold, it is determined that the mask is leaking.

2. The method for detecting mask leakage according to claim 1, characterized in that: The acceleration derived data includes one or more of: acceleration mean square error, acceleration frequency or acceleration smoothing filter value.

3. The method for detecting mask leakage according to claim 2, characterized in that: Whether the mask is leaking is determined based on the acceleration mean square error, the acceleration frequency and the smoothed filter value of the acceleration. When the mask is judged to be leaking based on two or more acceleration-derived data, it is finally determined that the mask is leaking.

4. The method for detecting mask leakage according to claim 1, characterized in that: The sampling frequency of collecting the vibration acceleration of the mask edge is greater than or equal to 500 Hz.

5. A mask, used to implement the method for detecting mask leakage according to any one of claims 1 to 3, characterized in that: include: An acceleration unit, a main control unit and a power supply, wherein the acceleration unit is connected to the main control unit and is located at the edge of the mask; The acceleration unit collects the vibration acceleration of the edge of the mask, the main control unit calculates acceleration-derived data according to the vibration acceleration, and determines whether the mask is leaking according to the acceleration-derived data.

6. The mask according to claim 5, characterized in that The main control unit includes a computing module and a communication module, the computing module is connected to the communication module, and the communication module is connected to the host.

7. A laughing gas supply device, characterized in that: It comprises the mask and the host as described in any one of claims 5 or 6.

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