Method and device for measuring respiratory impedance, computer equipment and storage medium
Through the filtering algorithm, the oscillating breathing signal is split and the degree of discrete index of the exhalation and inspiration process is calculated, which solves the problem of inaccurate calculation results caused by data instability in pulse oscillation technology, and achieves higher respiratory impedance measurement accuracy.
Patent Information
- Application Number
- CN202310786188.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-29
- Publication Date
- 2024-12-31
AI Technical Summary
The existing pulse oscillation technology is inaccurate in the data when measuring respiratory impedance.
The filtering algorithm is used to split the oscillating breathing signal into a breathing signal and an oscillating feedback signal, and the degree of dispersion index during the exhalation and inspiration process is calculated based on these signals, and a process with a lower degree of dispersion is selected to calculate the respiratory impedance.
Improve the accuracy of respiratory impedance measurement to ensure the smoothness and accuracy of measurement results.
Smart Images
Figure CN119214632A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of respiratory disease diagnosis, and in particular to a method, device, computer equipment and storage medium for measuring respiratory impedance. Background Art
[0002] Impulse oscillometry (IOS) is a non-invasive, non-force-dependent method for measuring mechanical properties of the respiratory system, such as airway resistance. The inspection principle is based on forced impulse oscillometry (FOT), which is to apply an oscillation wave (pressure signal) to the respiratory system during natural calm breathing, and measure the corresponding flow changes generated by the respiratory system under the oscillating pressure signal. The ratio of oscillation pressure to flow is the impedance of the respiratory system. In 1956, FOT was first used to measure respiratory impedance. With the continuous improvement of technology, oscillation technologies such as single-frequency sinusoidal signals, multi-frequency signals, pseudo-random signals, and rectangular pulse signals have been developed. Among them, the FOT measurement using rectangular pulse signals and Fourier transformation into sinusoidal signals of different frequencies is the IOS inspection.
[0003] During the IOS measurement of airway resistance, the subject only needs to breathe calmly, without exerting force or making shallow and rapid breathing movements. The instrument has a simple structure and does not require a bulky body scanning box. Therefore, it is suitable for a wide range of people, especially for subjects who are unable to complete traditional lung function tests such as spirometry, such as the elderly, children and critically ill patients. It also provides a wealth of respiratory physiological indicators (viscous resistance, elastic resistance and inertial resistance), which can more deeply understand the functional changes of respiratory diseases and has good application prospects.
[0004] Although pulse oscillation technology has advantages such as comfortable measurement process and simple calculation principle, the pulse oscillation equipment is relatively complex and the respiratory impedance measurement process involves the processing of multiple signals. The instability of data during the measurement process will lead to inaccurate subsequent measurement results. Summary of the invention
[0005] The purpose of the embodiments of the present application is to propose a method, device, computer equipment and storage medium for measuring respiratory impedance, which are used to solve the technical problem that when the existing pulse oscillation technology is used to measure respiratory impedance, the subsequent measurement results are not accurate enough due to the instability of data during the measurement process.
[0006] In order to solve the above technical problems, the first aspect of the embodiment of the present application provides a method for measuring respiratory impedance, which adopts the following technical solution: Acquire the oscillatory respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject; Demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal by using a filtering algorithm; Splitting the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal; Determining a first index and a second index, wherein the first index and the second index are used to indicate the discrete degree of relevant data during the exhalation process and the inhalation process of the subject respectively; According to the difference between the first index and the second index, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
[0007] In some possible implementations of the first aspect, before the step of determining the first indicator and the second indicator, the method for measuring respiratory impedance further includes: Calculating a first impedance value during each exhalation and a second impedance value during each inhalation according to the first oscillation feedback signal and the second oscillation feedback signal respectively; Calculating the first index according to all the first impedance values; The second index is calculated according to all the second impedance values.
[0008] In some possible implementations of the first aspect, before the step of determining the first indicator and the second indicator, the method for measuring respiratory impedance further includes: Splitting the respiratory signal into an exhalation signal during exhalation and an inhalation signal during inhalation; Determining the first index according to each exhalation waveform data in the exhalation signal; The second index is determined according to each inhalation waveform data in the inhalation signal.
[0009] In some possible implementations of the first aspect, before the step of obtaining an oscillating respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject, the method for measuring the respiratory impedance further includes: Acquire an oscillation wave signal output by the pulse oscillation device when the device is unloaded; Sampling the oscillation wave signal; Determine a first ratio of sampling points whose amplitudes are within a first preset amplitude range to all sampling points; Whether the pulse oscillation device operates normally is determined according to the size of the first ratio, and fault prompt information is generated when it is determined that the operation is abnormal.
[0010] In some possible implementations of the first aspect, after the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first indicator and the second indicator, the method for measuring respiratory impedance further includes: Sampling the respiratory signal; Determine a second ratio of sampling points whose amplitudes are within a second preset amplitude range to all sampling points; The signal quality of the respiration signal is evaluated according to the second ratio.
[0011] In some possible implementations of the first aspect, after the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first indicator and the second indicator, the method for measuring respiratory impedance further includes: Determine the period difference between each adjacent respiratory waveform and the correlation coefficient between each adjacent respiratory waveform in the respiratory signal; The stability of the subject's breathing process is evaluated based on the period difference and the correlation coefficient.
[0012] In some possible implementations of the first aspect, after the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first indicator and the second indicator, the method for measuring respiratory impedance further includes: The signal quality of the oscillation feedback signal is evaluated according to the amplitude and period of each waveform in the oscillation feedback signal.
[0013] In order to solve the above technical problems, the second aspect of the embodiment of the present application provides a respiratory impedance measurement device, which adopts the following technical solution: An acquisition module, used for acquiring an oscillating respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject; A filtering module, used for demodulating the oscillation breathing signal into a breathing signal and an oscillation feedback signal by using a filtering algorithm; a processing module, configured to split the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal; A calculation module is used to determine a first indicator and a second indicator, wherein the first indicator and the second indicator are respectively used to indicate the discreteness of relevant data during the exhalation process and the inhalation process of the subject; according to the difference between the first indicator and the second indicator, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
[0014] In order to solve the above technical problems, the third aspect of the embodiment of the present application further provides a computer device, which adopts the following technical solution, including: A memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for measuring respiratory impedance as described in the first aspect and any possible implementation manner are implemented.
[0015] In order to solve the above technical problems, the fourth aspect of the embodiment of the present application further provides a computer-readable storage medium, which adopts the following technical solution: The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the method for measuring respiratory impedance as described in the first aspect and any possible implementation manner are implemented.
[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: In the measurement method of respiratory impedance, when the pulse oscillation device is used to measure the respiratory impedance of the subject, after the oscillating respiratory signal in the main air path is obtained, the filtering algorithm can be used to split the oscillating respiratory signal into a respiratory signal and an oscillating feedback signal. Afterwards, the oscillating feedback signal is split into a first oscillating feedback signal during exhalation and a second oscillating feedback signal during inhalation according to the respiratory signal, and a first index and a second index are determined. Among them, the first index and the second index are respectively used to indicate the discreteness of the relevant data during the exhalation process and the inhalation process of the subject within a set time. Finally, according to the difference between the first index and the second index, the oscillating feedback signal corresponding to the process with a lower degree of discreteness is selected to calculate the respiratory impedance of the subject. Among them, the low degree of discreteness of the relevant data indicates that the stability of the measurement process or the measurement result is better. Therefore, compared with the existing pulse oscillation technology for measuring respiratory impedance, when the data corresponding to the process with a low degree of discreteness is selected in the embodiment of the present application to calculate the respiratory impedance, the calculation result can have better accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the scheme in the present application, a brief introduction is given below to the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 A flowchart of an embodiment of a method for measuring respiratory impedance according to the present application; Figure 2 is a schematic diagram of an embodiment of a respiratory impedance measuring device 200 according to the present application; Figure 3It is a structural diagram of an embodiment of a computer device according to the present application. Implementation
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.
[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.
[0022] like Figure 1 , a flow chart of an embodiment of a method for measuring respiratory impedance according to the present application is shown, wherein the method for measuring respiratory impedance comprises the following steps: Step 110, obtaining an oscillating respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject.
[0023] In this embodiment, the method for measuring respiratory impedance can be run on a pulse oscillation device or other electronic devices connected to the pulse oscillation device. The pulse oscillation device is provided with a flow sensor. When the pulse oscillation device is used to measure the respiratory impedance of the subject, the oscillating respiratory signal in the main airway within a set time length can be detected by the flow sensor. The oscillating respiratory signal can be represented as a flow-time image in a rectangular coordinate system.
[0024] Specifically, the pulse oscillation device has a main air circuit, one end of which has a breathing port for the subject, and the other end is connected to the outside air. The main air circuit is also connected to an oscillating wave air circuit, and a flow sensor is also provided in the main air circuit near the breathing port of the subject. When the pulse oscillation device is used to measure the respiratory impedance of the subject, the subject is connected to the breathing port of the subject and breathes calmly with the outside air through the main air circuit. At this time, the oscillating wave air circuit outputs an oscillating wave (pressure signal) of a specific frequency to the main air circuit through an oscillation pump or a speaker. The specific frequency can be a single frequency or multiple frequencies, and the specific frequency can be in the range of 5Hz-35Hz. The oscillating wave can be superimposed with the subject's breathing wave and enter the airway and lungs with the subject's breathing, and will be absorbed and reflected in the airway and lung tissue due to various types of respiratory impedance. At this time, a certain sampling time can be set, and the oscillating respiratory signal of the oscillating respiratory wave in the main air circuit is detected by the flow sensor, and then the respiratory impedance can be measured by analyzing the relevant characteristics of the oscillating respiratory signal.
[0025] Step 120: Demodulate the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm.
[0026] In this embodiment, after being collected and converted, the oscillating breathing signal can be represented as a fluctuation signal of flow rate changing with time, and the oscillating breathing signal contains a relatively high-frequency oscillating feedback signal and a relatively low-frequency breathing signal. At this time, according to the difference in the frequencies of the two signals, a filtering algorithm can be used to demodulate the oscillating breathing signal, thereby obtaining the two separate signals.
[0027] Among them, the breathing signal is used to represent the breathing process of the subject, and the oscillation feedback signal can represent the feedback signal obtained after the initial oscillation wave passes through the respiratory impedance system composed of the subject's airway and lungs.
[0028] It should be noted that the above-mentioned filtering algorithm can be a low-pass filtering algorithm or a high-pass filtering algorithm. Among them, one possible way is to design a low-pass filtering algorithm, the frequency threshold of the low-pass filtering is between the frequency of the breathing signal and the frequency of the oscillation feedback signal, after the oscillation breathing signal is input, the relatively high-frequency oscillation feedback signal is filtered out, thereby obtaining a relatively low-frequency breathing signal. Afterwards, the breathing signal is subtracted from the oscillation wave signal, thereby obtaining a relatively high-frequency oscillation feedback signal. In another possible way, the filtering algorithm can also adopt a high-pass filtering algorithm, whose frequency threshold is between the frequency of the breathing signal and the frequency of the oscillation feedback signal, and the low-frequency component can be first filtered out to obtain the oscillation feedback signal, and then the oscillation feedback signal is subtracted from the oscillation wave signal to obtain the breathing signal.
[0029] Step 130 : splitting the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal.
[0030] In this embodiment, the breathing signal and the oscillation feedback signal can be represented as a flow-time fluctuation image in a rectangular coordinate system, and the point where the flow is 0 in the fluctuation image of the breathing signal is the switching point of the exhalation and inhalation process. After obtaining the breathing signal, the moment of each switching point of the exhalation and inhalation process can be recorded, and the oscillation feedback signal can be correspondingly split and intercepted to obtain a first oscillation feedback signal in the exhalation process and a second oscillation feedback signal in the inhalation process.
[0031] Step 140, determining a first index and a second index, wherein the first index and the second index are used to indicate the discreteness of relevant data during the exhalation process and the inhalation process of the subject within a set time period, respectively.
[0032] In this embodiment, after the respiratory signal and the oscillation feedback signal are split according to the respiratory process, the exhalation process and the inhalation process can be analyzed respectively. The analysis process may involve one or more related data, such as waveform data analysis of the exhalation process and the inhalation process, stability analysis of the respiratory impedance measured during each exhalation and each inhalation during the exhalation process, and airflow pressure analysis during each exhalation and each inhalation during the exhalation process. The waveform data may include waveform similarity, period stability, amplitude stability, etc. Since the exhalation process and the inhalation process have different characteristics, and the stability of the exhalation process and the inhalation process and the discrete degree of related data may be different, after splitting into the exhalation process and the inhalation process, refined analysis can be achieved, so as to select process data with stronger reliability as much as possible for measurement, so that the measurement result of the respiratory impedance is more accurate.
[0033] Furthermore, through the analysis of the relevant data, the degree of dispersion of the relevant data can be determined, and a first index representing the degree of dispersion of the relevant data during exhalation and a second index representing the degree of dispersion of the relevant data during inhalation of the subject can be determined respectively. The degree of dispersion can be represented by a statistical relevant data index, such as one or more of the standard deviation, variance and range.
[0034] Step 150: According to the difference between the first index and the second index, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
[0035] In this embodiment, after calculating the difference between the first index and the second index, the oscillation feedback signal corresponding to the process with a lower degree of discreteness can be further selected to calculate the respiratory impedance of the subject. The degree of discreteness of the relevant data can characterize the stability of the measurement process or measurement results of the subject during exhalation and inhalation. The lower the degree of discreteness, the better the stability, and the more accurate the subsequent measurement results are.
[0036] In one implementation, a first threshold may be set during selection, and the difference may be compared with the first threshold so that the oscillation feedback signal corresponding to the process with a lower degree of discreteness may be selected to calculate the respiratory impedance of the subject.
[0037] Specifically, when the absolute value of the difference is within the first threshold, the first oscillation feedback signal and the second oscillation feedback signal are selected as input signals to calculate the respiratory impedance of the subject, that is, the respiratory impedance of the subject can be calculated with the overall oscillation feedback signal, or the respiratory impedance in each exhalation and each inhalation can be calculated separately, and the average value of all calculation results can be taken as the final respiratory impedance calculation result. When the first index is greater than the second index, and the absolute value of the difference is greater than the first threshold, the first oscillation feedback signal is selected to calculate the respiratory impedance of the subject. When specifically calculating, it can be that after calculating the respiratory impedance value of each exhalation process, all calculation results are averaged, and the average value is used as the final respiratory impedance calculation result. When the first index is less than the second index, and the absolute value of the difference is greater than the first threshold, the second oscillation feedback signal is selected to calculate the respiratory impedance of the subject. When specifically calculating, it can be that after calculating the respiratory impedance value of each inhalation process, all calculation results are averaged, and the average value is used as the final respiratory impedance calculation result.
[0038] In another implementation, the first index and the second index may be directly compared, and only the oscillation feedback signal of the process corresponding to the smaller value is used to calculate the final respiratory impedance.
[0039] It should be noted that the specific algorithm used in the above-mentioned calculation of respiratory impedance using the oscillation feedback signal is consistent with the existing algorithm for measuring respiratory impedance using a pulse oscillation device, and the details will not be repeated here.
[0040] Compared with the prior art, the embodiments of the present application have the following beneficial effects: In the measurement method of respiratory impedance, when the pulse oscillation device is obtained to measure the respiratory impedance of the subject, after the oscillating respiratory signal output within the set time length, the filtering algorithm can be used to split the oscillating respiratory signal into a respiratory signal and an oscillating feedback signal. Afterwards, the oscillating feedback signal is split into a first oscillating feedback signal during exhalation and a second oscillating feedback signal during inhalation according to the respiratory signal, and the first index and the second index are determined. Among them, the first index and the second index are respectively used to indicate the discreteness of the relevant data during the exhalation process and the inhalation process of the subject within the set time length. Finally, according to the difference between the first index and the second index, the oscillating feedback signal corresponding to the process with a lower degree of discreteness is selected to calculate the respiratory impedance of the subject. Among them, the low degree of discreteness of the relevant data indicates that the stability of the measurement process or the measurement result is better. Therefore, compared with the existing pulse oscillation technology for measuring respiratory impedance, when the data corresponding to the process with a low degree of discreteness is selected in the embodiment of the present application to calculate the respiratory impedance, the calculation result can have better accuracy.
[0041] In some optional implementations of this embodiment, after step 130 and before step 140, the method for measuring respiratory impedance may further include: Calculating a first impedance value during each exhalation and a second impedance value during each inhalation according to the first oscillation feedback signal and the second oscillation feedback signal respectively; Calculating a first index according to all first impedance values; The second index is calculated according to all the second impedance values.
[0042] Specifically, the relevant data may be respiratory impedance values calculated for the exhalation process and the inhalation process, respectively. Among them, the first impedance value at each exhalation and the second impedance value at each inhalation may be calculated according to the first oscillation feedback signal and the second oscillation feedback signal, respectively, and then the first index and the second index may be calculated according to all the first impedance values and the second impedance values, respectively. Specifically, the first index and the second index here may be the range or the standard deviation, and the first index and the second index may respectively characterize the stability of the respiratory impedance measurement results of the exhalation process and the inhalation process, and the better the stability, the better the consistency of the measurement results.
[0043] In some optional implementations of this embodiment, after step 130 and before step 140, the method for measuring respiratory impedance may further include: Splitting the respiratory signal into an exhalation signal during exhalation and an inhalation signal during inhalation; Determining the first index according to each exhalation waveform data in the exhalation signal; The second index is determined according to each inhalation waveform data in the inhalation signal.
[0044] Specifically, the relevant data may be waveform data during the exhalation process and the inhalation process, and the waveform data may be one of the similarity, period difference or amplitude difference between two adjacent waveforms. After obtaining the respiratory signal, the respiratory signal may be split into an exhalation signal and an inhalation signal according to the switching time point of the exhalation and inhalation processes. Afterwards, the first index is calculated based on each exhalation waveform data in the exhalation signal, and the second index is calculated based on each inhalation waveform data in the inhalation signal. Specifically, the first index and the second index here can be used to characterize the stability of the exhalation process and the inhalation process of the subject during the detection process, respectively. The stability of the respiratory process can indicate the stability of the data acquisition environment. The better the stability of the data acquisition environment, the higher the quality of the subsequent collected data, which can make the subsequent measurement results more accurate.
[0045] In one possible calculation method, for example, the waveform data may be the similarity of adjacent waveforms, and the similarity may be characterized by a correlation coefficient, and the specific correlation coefficient may be calculated using a covariance formula. After respectively calculating the correlation coefficients between every two adjacent expiratory waveforms and every two adjacent inspiratory waveforms during exhalation and inhalation, the standard deviation, variance or range of all correlation coefficients may be further calculated for the entire expiratory signal, and the calculation result may be used as the first indicator. The standard deviation, variance or range of all correlation coefficients may be further calculated for the entire inspiratory signal, and the calculation result may be used as the second indicator. In other possible calculation methods, the waveform data may also be the period difference of adjacent waveforms or the amplitude difference of adjacent waveforms. The first indicator and the second indicator may be calculated using, for example, the standard deviation, variance or range, and the specific details will not be repeated here.
[0046] In some optional implementations of this embodiment, before step 110, the respiratory impedance measurement method may further include: Obtain the oscillation wave signal output by the pulse oscillation device when it is unloaded; Sampling the oscillating wave signal; Determine a first ratio of sampling points whose amplitudes are within a first preset amplitude range to all sampling points; Whether the pulse oscillation device operates normally is determined according to the size of the first ratio, and fault prompt information is generated when it is determined that the operation is abnormal.
[0047] In this embodiment, when performing measurements, the output power of the pulse oscillation device may be too small or too large due to a malfunction of the oscillation pump or speaker, causing the generated oscillation wave signal to be too weak or too strong, thus affecting subsequent measurement results. Therefore, before performing respiratory impedance measurement, it is necessary to perform a self-check on the pulse oscillation device to improve the quality of subsequent signal acquisition, thereby improving the accuracy of the subsequent measurement process.
[0048] Specifically, before the subject is measured, the pulse oscillation device can be run at no load, and the flow sensor in the main gas path can measure the oscillation wave signal output by the pulse oscillation device when it is no load. The oscillation wave signal can be expressed as a fluctuation image of the flow over time in a rectangular coordinate system. After that, a certain sampling rate can be set to sample the oscillation wave signal, determine the amplitude of the signal at each sampling point, and calculate the first ratio of the sampling points with amplitudes within the first preset amplitude range to all sampling points. Finally, determine whether the pulse oscillation device is operating normally based on the size of the first ratio.
[0049] In a possible calculation method, the first preset amplitude range has an upper limit and a lower limit, and the proportion of sampling points with amplitudes between the lower limit and the upper limit needs to be counted as a first ratio. When the first ratio is greater than or equal to a set threshold, it can be considered that the power output by the oscillation pump or speaker in this state is normal, the pulse oscillation device operates normally, and the subject is instructed to continue to perform subsequent measurement operations; when the first ratio is less than the set threshold, it is considered that the pulse oscillation device operates abnormally, and a fault prompt message can be generated at this time to instruct the subject to check the device and re-measure.
[0050] In a possible calculation method, the first preset amplitude range has an upper limit and a lower limit, and the first ratio specifically includes the proportion of sampling points above the lower limit and the proportion of sampling points above the upper limit of the region. When both ratios are within the corresponding preset thresholds, it is determined that the device is operating normally, otherwise it is considered that the pulse oscillation device is operating abnormally. At this time, a fault prompt message can be generated to instruct the subject to check the device and re-measure. For example, the lower limit and the upper limit can be considered as weak signals and saturated signals, respectively. It can be set that the proportion of weak signal sampling points must be less than 10%, and the proportion of saturated signal sampling points must be less than 60%. Under this condition, it can be considered that the device is operating normally, otherwise it can be considered that the machine is not operating normally, and reasonable and correct data acquisition functions cannot be guaranteed. When it is judged that the machine is not operating normally, a corresponding pop-up reminder (such as "signal acquisition abnormality") can be displayed on the software interface at this time, so that the operator and subsequent machine maintenance personnel can make timely and reasonable adjustments.
[0051] In some optional implementations of this embodiment, after step 120 and before step 140, the respiratory impedance measurement method may further include: Sampling the breathing signal; Determine a second ratio of sampling points whose amplitudes are within a second preset amplitude range to all sampling points; The signal quality of the respiration signal is evaluated according to the second ratio.
[0052] In this embodiment, during the measurement process, there may be reasons such as a failure in the collector or excessive tension of the subject, resulting in low quality of the user's breathing signal, such as weak signal strength. Before calculating the respiratory impedance, the signal quality of the user's breathing signal can also be judged and controlled, thereby improving the accuracy of the subsequent measurement process.
[0053] Specifically, the respiratory signal can be sampled to determine the amplitude corresponding to the signal at each sampling point, and the second ratio of the sampling points with amplitudes within the second preset amplitude range to all the sampling points can be counted. When the second ratio is greater than or equal to the set second threshold, the respiratory signal is determined to be a valid signal, and the subsequent measurement process is continued. When the second ratio is less than the second threshold, the respiratory signal is determined to be too weak, and a fault prompt message is generated, which can indicate re-measurement or prompt the device to be checked.
[0054] It should be noted that the second preset amplitude range and the second threshold value can be set in advance, may be different for different types of subjects, and can be specifically set according to the respiratory system conditions of the subjects.
[0055] In some optional implementations of this embodiment, after step 120 and before step 140, the respiratory impedance measurement method may further include: Determine the period difference between each adjacent respiratory waveform and the correlation coefficient between each adjacent respiratory waveform in the respiratory signal; The stability of the subject's breathing process is evaluated based on the period difference and the correlation coefficient.
[0056] In this embodiment, during the measurement process, there may be a failure in the collector or the subject may be too nervous, which may cause unstable breathing. Before calculating the respiratory impedance, in addition to evaluating the quality of the respiratory signal, the stability of the user's respiratory signal can also be judged and controlled, thereby improving the accuracy of the subsequent measurement process.
[0057] Specifically, after acquiring the respiratory signal, the period difference between each two adjacent respiratory waveforms and the correlation coefficient between each two respiratory waveforms in the respiratory signal can be calculated in sequence. The period difference can represent the frequency difference between two adjacent respiratory processes, and the correlation coefficient can represent the stability between the two respiratory processes. After that, the variance of each period difference in the respiratory signal can be further calculated, which can also be the standard deviation or range, etc., as well as the average correlation coefficient between two adjacent respiratory waveforms in the respiratory signal.
[0058] Furthermore, when the variance calculated above is less than or equal to the set third threshold, and the average correlation coefficient is greater than or equal to the set fourth threshold, it can be determined that the subject's breathing process is relatively stable, and then the subsequent measurement process is performed. When the variance is greater than the third threshold, or the average correlation coefficient is less than the fourth threshold, it is considered that the subject's breathing process is not stable enough. At this time, a fault prompt message can be generated to prompt whether to retest.
[0059] In some optional implementations of this embodiment, after step 120 and before step 140, the respiratory impedance measurement method may further include: The signal quality of the oscillation feedback signal is evaluated according to the amplitude and period of each waveform in the oscillation feedback signal.
[0060] In this embodiment, the oscillation feedback signal is used as the input signal for impedance calculation. Since it may be affected by various factors during the measurement process, the quality of the split oscillation feedback signal is poor, which affects the subsequent measurement process. Therefore, before the subsequent impedance calculation, the signal quality of the oscillation feedback signal can also be evaluated.
[0061] Specifically, after obtaining the oscillation feedback signal, the amplitude data and period data of each waveform in the oscillation feedback signal can be determined, and then the data discreteness can be calculated for all the amplitude data in the oscillation feedback signal and the period difference between every two adjacent waveforms. The discreteness can be expressed by calculations such as variance, standard deviation or range. Afterwards, the signal quality is determined according to the data discreteness. The lower the discreteness, the better the signal quality, and the higher the discreteness, the worse the signal quality. For example, the discreteness is calculated by variance. When the variance of all amplitude data is less than the set fifth threshold value, and the variance of the period difference between adjacent waveforms is less than the set sixth threshold value, the signal quality is determined to be good. Otherwise, the signal quality is determined to be poor. When it is determined that the signal quality is poor, a fault prompt message can be generated to instruct the device to be checked.
[0062] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the aforementioned storage medium can be a non-volatile storage medium such as a disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).
[0063] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.
[0064] Further references Figure 2 , as a response to the above Figure 1 In order to realize the method shown in the figure, the present application provides a schematic diagram of an embodiment of a respiratory impedance measurement device 200, which is similar to Figure 1 Corresponding to the method embodiment shown, the device can be specifically applied to various electronic devices.
[0065] like Figure 2 As shown, the respiratory impedance measuring device 200 described in this embodiment includes: The acquisition module 210 is used to obtain the oscillation breathing signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject; A filtering module 220, configured to demodulate the oscillation breathing signal into a breathing signal and an oscillation feedback signal by using a filtering algorithm; A signal processing module 230, configured to split the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal; The calculation module 240 is used to determine a first indicator and a second indicator, wherein the first indicator and the second indicator are respectively used to indicate the discreteness of the relevant data during the exhalation process and the inhalation process of the subject; according to the difference between the first indicator and the second indicator, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
[0066] Compared with the prior art, the embodiments of the present application have the following beneficial effects: In the measuring device 200 of the respiratory impedance, when the pulse oscillation device is obtained to measure the respiratory impedance of the subject, after the oscillating respiratory signal output within the set time length, the filtering algorithm can be used to split the oscillating respiratory signal into a respiratory signal and an oscillating feedback signal. Afterwards, the oscillating feedback signal is split into a first oscillating feedback signal during the exhalation process and a second oscillating feedback signal during the inhalation process according to the respiratory signal, and the first index and the second index are determined. Among them, the first index and the second index are respectively used to indicate the discreteness of the relevant data during the exhalation process and the inhalation process of the subject within the set time length. Finally, according to the difference between the first index and the second index, the oscillating feedback signal corresponding to the process with a lower degree of discreteness is selected to calculate the respiratory impedance of the subject. Among them, the low degree of discreteness of the relevant data indicates that the stability of the measurement process or the measurement result is better. Therefore, compared with the existing pulse oscillation technology for measuring respiratory impedance, when the data corresponding to the process with a low degree of discreteness is selected in the embodiment of the present application to calculate the respiratory impedance, the calculation result can have better accuracy.
[0067] In some optional implementations of this embodiment, The signal processing module 230 is further used to calculate a first impedance value during each exhalation and a second impedance value during each inhalation according to the first oscillation feedback signal and the second oscillation feedback signal respectively; The calculation module 240 is further configured to calculate the first index according to all the first impedance values; and calculate the second index according to all the second impedance values.
[0068] In some optional implementations of this embodiment, the signal processing module 230 is further used to split the respiratory signal into an exhalation signal during the exhalation process and an inhalation signal during the inhalation process; The calculation module 240 is further configured to determine the first index according to each exhalation waveform data in the exhalation signal; and determine the second index according to each inhalation waveform data in the inhalation signal.
[0069] In some optional implementations of this embodiment, the respiratory impedance measurement device 200 further includes a first judgment module, wherein: The acquisition module 210 is also used to obtain the oscillation wave signal output by the pulse oscillation device when it is unloaded; The signal processing module 230 is further used to sample the oscillation wave signal; The calculation module 240 is further used to determine a first ratio of the sampling points whose amplitudes are within a first preset amplitude range to all the sampling points; The first judgment module is used to determine whether the pulse oscillation device operates normally according to the size of the first ratio, and generate fault prompt information when it is determined that the operation is abnormal.
[0070] In some optional implementations of this embodiment, the respiratory impedance measurement device 200 further includes a second judgment module, wherein: The signal processing module 230 is further used to sample the breathing signal; The calculation module 240 is further used to determine a second ratio of the sampling points whose amplitudes are within the second preset amplitude range to all the sampling points; The second judgment module is used to evaluate the signal quality of the respiratory signal according to the second ratio.
[0071] In some optional implementations of this embodiment, the respiratory impedance measurement device 200 further includes a third judgment module, wherein: The calculation module 240 is further used to determine the period difference between each adjacent respiratory waveform and the correlation coefficient between each adjacent respiratory waveform in the respiratory signal; The third judgment module is used to evaluate the stability of the subject's breathing process according to the period difference and the correlation coefficient.
[0072] In some optional implementations of this embodiment, the respiratory impedance measurement device 200 further includes a fourth judgment module, wherein: The fourth judgment module is used to evaluate the signal quality of the oscillation feedback signal according to the amplitude and period of each waveform in the oscillation feedback signal.
[0073] To solve the above technical problems, the present application also provides a computer device. Figure 3 , Figure 3 This is a basic structural block diagram of the computer device in this embodiment.
[0074] The computer device 300 includes a memory 310, a processor 320, and a network interface 330 that are interconnected and communicated through a system bus. It should be noted that the figure only shows a computer device 300 having components 310-330, but it should be understood that it is not required to implement all the components shown, and more or fewer components can be implemented instead. Among them, those skilled in the art can understand that the computer device here is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (Application Specific Integrated Circuit, ASIC), programmable gate arrays (Field-Programmable Gate Array, FPGA), digital processors (Digital Signal Processor, DSP), embedded devices, etc.
[0075] The computer device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The computer device may interact with the subject through a keyboard, a mouse, a remote control, a touch pad, or a voice control device.
[0076] The memory 310 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (for example, SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 310 can be an internal storage unit of the computer device 300, such as a hard disk or memory of the computer device 300. In other embodiments, the memory 310 can also be an external storage device of the computer device 300, such as a plug-in hard disk equipped on the computer device 300, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card, etc. Of course, the memory 310 can also include both the internal storage unit of the computer device 300 and its external storage device. In this embodiment, the memory 310 is generally used to store the operating system and various application software installed in the computer device 300, such as the program code of the respiratory impedance measurement method, etc. In addition, the memory 310 can also be used to temporarily store various data that have been output or will be output.
[0077] The processor 320 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor 320 is generally used to control the overall operation of the computer device 300. In this embodiment, the processor 320 is used to run the program code stored in the memory 310 or process data, such as running the program code of the respiratory impedance measurement method.
[0078] The network interface 330 may include a wireless network interface or a wired network interface. The network interface 330 is generally used to establish a communication connection between the computer device 300 and other electronic devices.
[0079] The present application also provides another embodiment, that is, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a respiratory impedance measurement method program, and the respiratory impedance measurement method program can be executed by at least one processor, so that the at least one processor performs the above Figure 1 and Figure 1 The steps of the method for measuring respiratory impedance in any possible implementation manner.
[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.
[0081] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.
Claims
1. A method for measuring respiratory impedance, characterized in that: The steps include: Acquire the oscillatory respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject; Demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal by using a filtering algorithm; Splitting the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal; Determining a first index and a second index, wherein the first index and the second index are used to indicate the discrete degree of relevant data during the exhalation process and the inhalation process of the subject respectively; According to the difference between the first index and the second index, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
2. The method for measuring respiratory impedance according to claim 1, characterized in that: Before the step of determining the first index and the second index, the method for measuring respiratory impedance further includes: Calculating a first impedance value during each exhalation and a second impedance value during each inhalation according to the first oscillation feedback signal and the second oscillation feedback signal respectively; Calculating the first index according to all the first impedance values; The second index is calculated according to all the second impedance values.
3. The method for measuring respiratory impedance according to claim 1, characterized in that: Before the step of determining the first index and the second index, the method for measuring respiratory impedance further includes: Splitting the respiratory signal into an exhalation signal during exhalation and an inhalation signal during inhalation; Determining the first index according to each exhalation waveform data in the exhalation signal; The second index is determined according to each inhalation waveform data in the inhalation signal.
4. The method for measuring respiratory impedance according to any one of claims 1 to 3, characterized in that: Before the step of obtaining the oscillating respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject, the respiratory impedance measurement method further includes: Acquire an oscillation wave signal output by the pulse oscillation device when the device is unloaded; Sampling the oscillation wave signal; Determine a first ratio of sampling points whose amplitudes are within a first preset amplitude range to all sampling points; Whether the pulse oscillation device operates normally is determined according to the size of the first ratio, and fault prompt information is generated when it is determined that the operation is abnormal.
5. The method for measuring respiratory impedance according to any one of claims 1 to 3, characterized in that: After the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first index and the second index, the method for measuring respiratory impedance further includes: Sampling the respiratory signal; Determine a second ratio of sampling points whose amplitudes are within a second preset amplitude range to all sampling points; The signal quality of the respiration signal is evaluated according to the second ratio.
6. The method for measuring respiratory impedance according to any one of claims 1 to 3, characterized in that: After the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first index and the second index, the method for measuring respiratory impedance further includes: Determine the period difference between each adjacent respiratory waveform and the correlation coefficient between each adjacent respiratory waveform in the respiratory signal; The stability of the subject's breathing process is evaluated based on the period difference and the correlation coefficient.
7. The method for measuring respiratory impedance according to any one of claims 1 to 3, characterized in that: After the step of demodulating the oscillating breathing signal into a breathing signal and an oscillating feedback signal using a filtering algorithm and before the step of determining the first index and the second index, the method for measuring respiratory impedance further includes: The signal quality of the oscillation feedback signal is evaluated according to the amplitude and period of each waveform in the oscillation feedback signal.
8. A respiratory impedance measuring device, characterized in that: include: An acquisition module, used for acquiring an oscillating respiratory signal in the main gas path when the pulse oscillation device measures the respiratory impedance of the subject; A filtering module, used for demodulating the oscillation breathing signal into a breathing signal and an oscillation feedback signal by using a filtering algorithm; a processing module, configured to split the oscillation feedback signal into a first oscillation feedback signal during exhalation and a second oscillation feedback signal during inhalation according to the breathing signal; A calculation module is used to determine a first indicator and a second indicator, wherein the first indicator and the second indicator are respectively used to indicate the discreteness of relevant data during the exhalation process and the inhalation process of the subject; according to the difference between the first indicator and the second indicator, the oscillation feedback signal corresponding to the process with a lower discreteness is selected to calculate the respiratory impedance of the subject.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method for measuring respiratory impedance according to any one of claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for measuring respiratory impedance according to any one of claims 1 to 7 are implemented.