Respiration rate detection method and device applied to oxygen therapy apparatus

Abstract

The application provides a respiration rate detection method and device applied to oxygen therapy equipment, and relates to the technical field of medical equipment. The method comprises the following steps: obtaining a target flow signal set of a target oxygen therapy equipment, and standardizing target flow signals in the target flow signal set; performing Fourier transform on the standardized target flow signals to obtain a target amplitude-frequency signal; determining a first target frequency corresponding to a first target amplitude peak in a preset frequency range of the target amplitude-frequency signal, and determining a corresponding first target respiration frequency range according to a first target respiration rate range of the target oxygen therapy equipment; determining whether a target user accesses the target oxygen therapy equipment according to the first target frequency and the first target respiration frequency range; when it is not determined whether the target user accesses the target oxygen therapy equipment, performing baseline drift detection, interference detection and frequency multiplication detection on the target amplitude-frequency signal in sequence, and determining a second target respiration rate and outputting according to the detection result. The application can reduce the false detection probability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a respiration rate detection method and device applied to oxygen therapy devices. BACKGROUND

[0002] The nasal high flow humidified oxygen therapy instrument is an oxygen therapy method that directly delivers air-oxygen mixed high flow gas with a certain oxygen concentration to a patient through a non-sealed nasal plug catheter. Such gas has the characteristics of high flow, accurate oxygen concentration, and humidification.

[0003] Respiration rate is a very important physiological parameter in respiratory therapy products. If the nasal high flow humidified oxygen therapy instrument can effectively monitor the respiration rate, combined with the blood oxygen saturation SpO2 and the inhaled oxygen concentration FiO2, the respiratory oxygenation index monitoring can be provided. The oxygenation index is a target in respiratory therapy, which is an important index for organs and tissues to obtain sufficient oxygen for oxygenation and energy. Clinically, the oxygenation index can reflect the actual ventilation function of lung tissue to a certain extent, and can be used to assist in judging the severity of the disease and evaluating the clinical treatment effect. At present, the nasal high flow humidified oxygen therapy instrument generally has no respiration rate monitoring function and does not have oxygenation index monitoring function. In addition, the algorithm in the related art has a high false detection probability. SUMMARY

[0004] The present application aims to provide a respiration rate detection method and device applied to oxygen therapy devices to eliminate baseline drift, interference, and frequency multiplication in the flow signal and reduce the false detection probability.

[0005] To achieve the above-mentioned purpose, the technical solutions adopted by the embodiments of the present application are as follows:

[0006] In a first aspect, the embodiments of the present application provide a respiration rate detection method applied to an oxygen therapy device, comprising: obtaining a target flow signal set of a target oxygen therapy device, and standardizing a target flow signal in the target flow signal set; performing Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal; determining a first target frequency corresponding to a first target amplitude peak in a preset frequency range of the target amplitude-frequency signal, and determining a corresponding first target respiration frequency range according to a first target respiration rate range of the target oxygen therapy device; the preset frequency range is [0, Fs / 2], and Fs represents the sampling frequency of the target flow signal; determining whether a target user accesses the target oxygen therapy device according to the first target frequency and the first target respiration frequency range; when it is not determined whether the target user accesses the target oxygen therapy device, performing baseline drift detection, interference detection, and frequency multiplication detection on the target amplitude-frequency signal in turn, and determining a second target respiration rate and outputting according to the detection result.

[0007] In an implementation, before the standardization of the target flow signals in the set of target flow signals, the method further comprises: band-pass filtering the target flow signals in the set of target flow signals to obtain target frequency bands; and the target frequency bands include 0.01-3 Hz.

[0008] In an implementation, the determining whether the target user accesses the target oxygen therapy device according to the first target frequency and the first target respiratory frequency range comprises: determining whether the first target frequency is greater than an upper limit value of the first target respiratory frequency range; when the first target frequency is greater than the upper limit value of the first target respiratory frequency range, determining that the target user does not access the target oxygen therapy device; otherwise, not determining whether the target user accesses the target oxygen therapy device.

[0009] In an implementation, the baseline drift detection, interference detection and frequency doubling detection of the target amplitude-frequency signal comprises: when the first target frequency is less than a lower limit value of the first target respiratory frequency range, determining a second target frequency corresponding to a second target amplitude peak in the first target respiratory frequency range; determining whether a target amplitude valley in an interval between the lower limit value of the first target respiratory frequency range and the second target frequency is greater than 1 / 2 of the second target amplitude peak; when the target amplitude valley is greater than the 1 / 2 of the second target amplitude peak, determining that there is a baseline drift in the target flow signal; otherwise, determining that there is no baseline drift in the target flow signal, and outputting a second target respiratory frequency and a first target respiratory amplitude value; the second target respiratory frequency is equal to the second target frequency; and the first target respiratory amplitude value is equal to the second target amplitude peak; when the first target frequency is in the first target respiratory frequency range, determining that there is no baseline drift in the target flow signal, and outputting a third target respiratory frequency and a second target respiratory amplitude value; the third target respiratory frequency is equal to the first target frequency; and the second target respiratory amplitude value is equal to the first target amplitude peak.

[0010] In an embodiment, the baseline drift detection, the interference detection and the frequency multiplication detection on the target amplitude-frequency signal comprises: determining whether the first target respiratory wave amplitude value and the second target respiratory wave amplitude value are less than a first preset respiratory wave amplitude threshold value respectively, and determining that the target user is not connected to the target oxygen therapy device when the first target respiratory wave amplitude value or the second target respiratory wave amplitude value is less than the first preset respiratory wave amplitude threshold value; determining whether the number of third target amplitude peaks greater than a second preset respiratory wave amplitude threshold value in the first target respiratory frequency range is greater than a first preset number, and determining that there is interference in the target flow signal when the number of the third target amplitude peaks is greater than the first preset number; otherwise, determining that there is no interference in the target flow signal.

[0011] In an embodiment, the baseline drift detection, the interference detection and the frequency multiplication detection on the target amplitude-frequency signal comprises: determining whether the lower limit value of the first target respiratory frequency range and the number of fourth target amplitude peaks greater than a third preset respiratory wave amplitude threshold value in the second target respiratory frequency range and the third target respiratory frequency range, and the second target respiratory frequency and the third target respiratory frequency being integer multiples of a corresponding fourth target frequency, are greater than or equal to a second preset number respectively, and determining that there is frequency multiplication in the target flow signal when the number of the fourth target amplitude peaks is greater than or equal to the second preset number; otherwise, determining that there is no frequency multiplication in the target flow signal, and outputting a fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0012] In an embodiment, the determining the second target respiratory rate according to the detection result comprises: determining a fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency when there is no baseline drift, interference and frequency multiplication in the target flow signal, and determining the second target respiratory rate according to the fifth target respiratory frequency.

[0013] In an embodiment, the determining the fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency comprises: determining the latest value of the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency as the fifth target respiratory frequency.

[0014] In an embodiment, the determining the second target respiratory rate according to the fifth target respiratory frequency comprises: determining the second target respiratory rate according to the fifth target respiratory frequency based on a preset formula; the preset formula is as follows:

[0015] RR = 60* Freq

[0016] wherein Freq represents the fifth target respiratory frequency; and RR represents the second target respiratory rate.

[0017] In a second aspect, the embodiments of the present application also provide a respiratory rate detection device applied to an oxygen therapy apparatus, comprising: an acquisition module configured to acquire a target flow signal set of a target oxygen therapy apparatus, and to standardize a target flow signal in the target flow signal set; a processing module configured to perform Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal; a first determination module configured to determine a first target frequency corresponding to a first target amplitude peak in a preset frequency range of the target amplitude-frequency signal, and to determine a corresponding first target respiratory frequency range according to a first target respiratory rate range of the target oxygen therapy apparatus; the preset frequency range is [0, Fs / 2], and Fs represents a sampling frequency of the target flow signal; a second determination module configured to determine whether a target user accesses the target oxygen therapy apparatus according to the first target frequency and the first target respiratory frequency range; when it is not determined whether the target user accesses the target oxygen therapy apparatus, performing baseline drift detection, interference detection and frequency multiplication detection on the target amplitude-frequency signal in sequence, and determining a second target respiratory rate and outputting according to a detection result.

[0018] In an implementation, the acquisition module is configured to perform band-pass filtering on the target flow signal in the target flow signal set to obtain a target frequency band; and the target frequency band comprises 0.01-3 Hz.

[0019] In an implementation, the second determination module is configured to determine whether the first target frequency is greater than an upper limit value of the first target respiratory frequency range; when the first target frequency is greater than the upper limit value of the first target respiratory frequency range, it is determined that the target user does not access the target oxygen therapy apparatus; otherwise, it is not determined whether the target user accesses the target oxygen therapy apparatus.

[0020] In an embodiment, the second determining module is configured to: when the first target frequency is less than the lower limit of the first target respiratory frequency range, determine a second target frequency corresponding to a second target amplitude peak in the first target respiratory frequency range; determine whether a target amplitude valley in the interval of the lower limit of the first target respiratory frequency range and the second target frequency is greater than 1 / 2 of the second target amplitude peak, when the target amplitude valley is greater than the 1 / 2 of the second target amplitude peak, determine that there is baseline drift in the target flow signal; otherwise, determine that there is no baseline drift in the target flow signal, output a second target respiratory frequency and a first target respiratory wave amplitude value; the second target respiratory frequency is equal to the second target frequency; the first target respiratory wave amplitude value is equal to the second target amplitude peak; when the first target frequency is in the first target respiratory frequency range, determine that there is no baseline drift in the target flow signal, output a third target respiratory frequency and a second target respiratory wave amplitude value; the third target respiratory frequency is equal to the first target frequency; the second target respiratory wave amplitude value is equal to the first target amplitude peak.

[0021] In an embodiment, the second determining module is configured to: respectively determine whether the first target respiratory wave amplitude value and the second target respiratory wave amplitude value are less than a first preset respiratory wave amplitude threshold, when the first target respiratory wave amplitude value or the second target respiratory wave amplitude value is less than the first preset respiratory wave amplitude threshold, determine that the target user is not connected to the target oxygen therapy device; determine whether a number of third target amplitude peaks greater than a second preset respiratory wave amplitude threshold in the first target respiratory frequency range is greater than a first preset number, when the number of the third target amplitude peaks is greater than the first preset number, determine that there is interference in the target flow signal; otherwise, determine that there is no interference in the target flow signal.

[0022] In an embodiment, the second determining module is configured to: respectively determine whether a number of fourth target amplitude peaks greater than a third preset respiratory wave amplitude threshold in the interval of the lower limit of the first target respiratory frequency range and a second target respiratory frequency, a third target respiratory frequency, and the second target respiratory frequency and the third target respiratory frequency being integer multiples of a corresponding fourth target frequency, is greater than or equal to a second preset number, when the number of the fourth target amplitude peaks is greater than or equal to the second preset number, determine that there is frequency multiplication in the target flow signal; otherwise, determine that there is no frequency multiplication in the target flow signal, output a fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0023] In an implementation form, the second determining module is configured to determine a fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency when there is no baseline drift, interference and frequency multiplication in the target flow signal, and determine the second target respiratory rate according to the fifth target respiratory frequency.

[0024] In an implementation form, the second determining module is configured to determine the latest value among the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency as the fifth target respiratory frequency.

[0025] In an implementation form, the second determining module is configured to determine the second target respiratory rate according to the fifth target respiratory frequency based on a preset formula; the preset formula is as follows:

[0026] RR = 60 * Freq

[0027] wherein, Freq represents the fifth target respiratory frequency; and RR represents the second target respiratory rate.

[0028] In a third aspect, an embodiment of the present application provides a computer device, including a processor, a storage medium and a bus, the storage medium stores program instructions executable by the processor, when the computer device is running, the processor and the storage medium communicate through the bus, and the processor executes the program instructions to execute the steps of any one of the above methods.

[0029] In a fourth aspect, an embodiment of the present application provides a non-volatile computer readable storage medium, the storage medium stores a computer program, and the computer program is executed by the processor to execute the steps of any one of the above methods.

[0030] The present application has the beneficial effects that: without adding a pressure sensor and increasing additional costs, the monitoring of the important physiological parameter of respiratory rate is realized, the respiratory rate detection algorithm of the present application is logically rigorous, the complex situations that may occur in use are fully considered, the anti-interference ability is strong, and the false detection probability in the related art is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0032] Figure 1A flowchart of a respiration rate detection method applied to oxygen therapy equipment provided by an embodiment of the present application is shown in the figure.

[0033] Figure 2 A flowchart of a respiration rate detection method applied to oxygen therapy equipment provided by an embodiment of the present application is shown in the figure.

[0034] Figure 3 A flowchart of a respiration rate detection method applied to oxygen therapy equipment provided by an embodiment of the present application is shown in the figure.

[0035] Figure 4 A structural diagram of a respiration rate detection device applied to oxygen therapy equipment provided by an embodiment of the present application is shown in the figure.

[0036] Figure 5 A structural diagram of a computer device provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application.

[0038] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts are within the scope of protection of the present application.

[0039] In the description of the present application, it should be noted that if the terms "upper", "lower", etc. indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0040] Moreover, the terms "first", "second", and the like, in the description and in the claims of the present application, as well as above-mentioned drawings, are used to distinguish similar objects and are not necessarily used to describe a specific sequential or chronological order. It is to be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the present application described herein can be carried out in other than the order shown or described herein. Furthermore, the terms "comprise" and "have", and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a list of steps or units is not necessarily limited to those steps or units that are clearly listed, but can include other steps or units that are not clearly listed or inherent to such processes, methods, products, or apparatuses.

[0041] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0042] Figure 1 A flowchart of a respiration rate detection method applied to oxygen therapy equipment provided by an embodiment of the present application is shown in FIG. 1. As shown in the figure, the method comprises the following steps. Figure 1

[0043] Step 110: Obtain a target flow signal set of a target oxygen therapy equipment, and standardize target flow signals in the target flow signal set.

[0044] The target oxygen therapy equipment is an oxygen therapy equipment used to collect the target flow signal set. The target flow signal set includes a plurality of target flow signals.

[0045] The standardization is to first calculate the average value of the plurality of target flow signals in the target flow signal set, and then subtract the average value from each target flow signal. Specifically, it is assumed that the target flow signal set includes N target flow signals, where N = 2 n , the sampling frequency is Fs, and then the storage duration of the target flow signal is T = N / Fs, the target flow signal is updated once every time t (t < T), and the average value FlowMean of the N target flow signals in the target flow signal set is calculated according to the following formula (1):

[0046]

[0047] Where i represents the number of target flow signals.

[0048] Step 120: Perform Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal.

[0049] The Fourier transform is a tool for converting time domain signals into frequency domain signals, which is used for frequency analysis and has high computational complexity, and is suitable for theoretical analysis of small-scale data or continuous signals.​

[0050] In actual operation, in order to improve the calculation speed, this step can also use fast Fourier transform. Fast Fourier transform is an efficient algorithm of Fourier transform, which greatly improves the calculation speed, especially suitable for frequency domain analysis of large-scale discrete signals, and is widely used in various signal processing fields, especially in audio, image and communication systems.

[0051] The target amplitude-frequency signal represents the flow amplitude of each frequency point in the [0, Fs] frequency range, and the frequency difference between adjacent points is ΔFs = Fs / N.

[0052] Step 130, determine the first target frequency corresponding to the first target amplitude peak value in the preset frequency range of the target amplitude-frequency signal, and determine the corresponding first target respiratory frequency range according to the first target respiratory rate range of the target oxygen therapy device.

[0053] Wherein, the preset frequency range is [0, Fs / 2], and Fs represents the sampling frequency of the target flow signal.

[0054] The first target amplitude peak value can be denoted as PeakAmp1, and the first target frequency can be denoted as F1.

[0055] The unit of target respiratory frequency is Hz, which refers to the measurement of the number of occurrences per second. The target respiratory rate is generally expressed as times / min, 1 min = 60 s, so the target respiratory frequency here = target respiratory rate / 60; For example: the first target respiratory rate range of the target oxygen therapy device is [3 times / min, 100 times / min], and the corresponding first target respiratory frequency range is [0.05 Hz, 1.67 Hz]. Specifically, the minimum target respiratory rate is 3 times / min, and the corresponding target respiratory frequency is 3 / 60 = 0.05 Hz; the maximum target respiratory rate is 100 times / min, and the corresponding target respiratory frequency is 100 / 60 = 1.67 Hz.

[0056] Step 140, determine whether the target user accesses the target oxygen therapy device according to the first target frequency and the first target respiratory frequency range; when it is not determined whether the target user accesses the target oxygen therapy device, the target amplitude-frequency signal is sequentially subjected to baseline drift detection, interference detection and frequency doubling detection, and the second target respiratory rate is determined and output according to the detection result.

[0057] The target user is determined to access the target oxygen therapy device by comparing the first target frequency with an effective range of the respiratory frequency (a first target respiratory frequency range). When the target user does not access the target oxygen therapy device, no further detection is required. When the target user accesses the target oxygen therapy device, the baseline drift, interference and frequency multiplication in the target flow signal need to be excluded respectively. Specifically, the step 140 of determining whether the target user accesses the target oxygen therapy device according to the first target frequency and the first target respiratory frequency range can further include the following steps:

[0058] It is determined whether the first target frequency is greater than an upper limit value of the first target respiratory frequency range. When the first target frequency is greater than the upper limit value of the first target respiratory frequency range, it is determined that the target user does not access the target oxygen therapy device. Otherwise, it is not determined whether the target user accesses the target oxygen therapy device.

[0059] When the first target frequency is greater than the upper limit value of the first target respiratory frequency range, it indicates that the target flow signal exceeds the effective range of the respiratory frequency (the first target respiratory frequency range), and then the target user does not access the target oxygen therapy device, and no further detection is required. Otherwise, it indicates that the target user accesses the target oxygen therapy device.

[0060] When it is not determined whether the target user accesses the target oxygen therapy device, the baseline drift, interference and frequency multiplication in the target flow signal need to be excluded respectively to determine the access of the target user to the target oxygen therapy device. Specifically, Figure 2 The flowchart of the respiratory rate detection method applied to the oxygen therapy device provided by the embodiment of the present application is shown in FIG. 2. Figure 2 As shown in FIG. 2, the baseline drift detection in the step 140 can further include the following steps 210 to 240.

[0061] In step 210, when the first target frequency is less than a lower limit value of the first target respiratory frequency range, a second target frequency corresponding to a second target amplitude peak value in the first target respiratory frequency range is determined.

[0062] The second target amplitude peak value is an amplitude peak value in the first target respiratory frequency range, and the second target frequency is a frequency corresponding to the second target amplitude peak value. The second target amplitude peak value is denoted as PeakAmp2, and the second target frequency is denoted as F2.

[0063] In step 220, it is determined whether a target amplitude valley value in an interval between the lower limit value of the first target respiratory frequency range and the second target frequency is greater than 1 / 2 the second target amplitude peak value. When the target amplitude valley value is greater than 1 / 2 the second target amplitude peak value, it is determined that the baseline drift exists in the target flow signal.

[0064] Wherein, the target amplitude valley value, i.e. the lower limit value of the first target respiratory frequency range and the amplitude valley value in the second target frequency interval; i.e. the amplitude valley value in the (0.05, F2) interval. The target amplitude valley value is denoted as MinAmp.

[0065] This step, i.e. when MinAmp>1 / 2PeakAmp2, it is determined that there is a baseline drift in the target flow signal, at this time, in order to improve the algorithm accuracy and reduce the false detection probability, the respiratory rate is not calculated.

[0066] Step 230, on the contrary, it is determined that there is no baseline drift in the target flow signal, and the second target respiratory frequency and the first target respiratory amplitude value are output.

[0067] Wherein, the second target respiratory frequency is equal to the second target frequency; the first target respiratory amplitude value is equal to the second target amplitude peak value.

[0068] The second target respiratory frequency, i.e. the respiratory frequency output when the first target frequency is less than the lower limit value of the first target respiratory frequency range and there is no baseline drift in the target flow signal.

[0069] The first target respiratory amplitude value, i.e. the respiratory amplitude value output when the first target frequency is less than the lower limit value of the first target respiratory frequency range and there is no baseline drift in the target flow signal.

[0070] This step, i.e. there is no baseline drift in the target flow signal, at this time, the algorithm accuracy can be improved to a certain extent and the false detection probability is reduced, and the second target respiratory frequency and the first target respiratory amplitude value are output; the second target respiratory frequency Freq2=F2 and the first target respiratory amplitude value Amp1=PeakAmp2.

[0071] Step 240, when the first target frequency is within the first target respiratory frequency range, it is determined that there is no baseline drift in the target flow signal, and the third target respiratory frequency and the second target respiratory amplitude value are output.

[0072] Wherein, the third target respiratory frequency is equal to the first target frequency; the second target respiratory amplitude value is equal to the first target amplitude peak value.

[0073] The above describes the case that the first target frequency is greater than the upper limit value of the first target respiratory frequency range, steps 210 to 230 describe the case that the first target frequency is less than the lower limit value of the first target respiratory frequency range, and this step describes the case that the first target frequency is within the first target respiratory frequency range.

[0074] The third target respiratory frequency, i.e. the respiratory frequency output when the first target frequency is within the first target respiratory frequency range and the target amplitude frequency signal has no baseline drift.

[0075] The second target respiratory amplitude value is a respiratory amplitude value output when the first target frequency is within the first target respiratory frequency range and the target amplitude-frequency signal does not have baseline drift.

[0076] In this step, when the target flow signal does not have baseline drift, the algorithm accuracy can be improved to a certain extent, the false detection probability can be reduced, and the third target respiratory frequency and the second target respiratory amplitude value are output; the third target respiratory frequency Freq3=F1, and the second target respiratory amplitude value Amp2=PeakAmp1.

[0077] Figure 3 A flowchart of a respiratory rate detection method applied to an oxygen therapy device provided in an embodiment of the present application is shown in FIG. 1. As shown in FIG. 1, the interference detection in step 140 can further include steps 310 and 320. Figure 3

[0078] In step 310, it is determined whether the first target respiratory amplitude value and the second target respiratory amplitude value are less than a first preset respiratory amplitude threshold value. When the first target respiratory amplitude value or the second target respiratory amplitude value is less than the first preset respiratory amplitude threshold value, it is determined that the target user is not connected to the target oxygen therapy device.

[0079] The first preset respiratory amplitude threshold value is determined according to the mean value of the target flow signals in the target flow signal set. Specifically, the first preset respiratory amplitude threshold value AmpThr1=FlowMean*K1, where K1<1.

[0080] In this step, when the first target respiratory amplitude value or the second target respiratory amplitude value is less than the first preset respiratory amplitude threshold value, it is indicated that the first target respiratory amplitude value or the second target respiratory amplitude value is too low, and then the target user is not connected to the target oxygen therapy device. At this time, no further detection is needed.

[0081] In step 320, it is determined whether the number of third target amplitude peaks greater than a second preset respiratory amplitude threshold value in the first target respiratory frequency range is greater than a first preset number. When the number of third target amplitude peaks is greater than the first preset number, it is determined that the target flow signal has interference; otherwise, it is determined that the target flow signal does not have interference.

[0082] The second preset respiratory amplitude threshold value is determined according to the first target respiratory amplitude value and the second target respiratory amplitude value. Specifically, the second preset respiratory amplitude threshold value AmpThr2=Amp1*K2, where K2<1.

[0083] ​The third target amplitude peak value is an amplitude peak value greater than the second preset respiratory wave amplitude threshold value in the first target respiratory frequency range. The third target amplitude peak value is an amplitude peak value close to the main amplitude peak value in the first target respiratory frequency range.

[0084] In general, the first preset number is greater than or equal to 4. If the number of the third target amplitude peak value is greater than the first preset number, it indicates that the time domain angle and the frequency domain angle are difficult to identify the respiratory wave. At this time, in order to improve the accuracy of the algorithm and reduce the false detection probability, the respiratory rate is not calculated.

[0085] The frequency multiplication detection in the step 140 can further include the following steps:

[0086] The number of the fourth target amplitude peak value greater than the third preset respiratory wave amplitude threshold value in the first target respiratory frequency range, the second target respiratory frequency, and the third target respiratory frequency interval, and the second target respiratory frequency and the third target respiratory frequency being integer multiples of the corresponding fourth target frequency, is determined whether it is greater than or equal to the second preset number. When the number of the fourth target amplitude peak value is greater than or equal to the second preset number, it is determined that the target flow signal contains frequency multiplication; otherwise, it is determined that the target flow signal does not contain frequency multiplication, and the fourth target respiratory frequency is output.

[0087] The fourth target respiratory frequency is equal to the fourth target frequency.

[0088] The third preset respiratory wave amplitude threshold value is determined according to the first target respiratory wave amplitude value and the second target respiratory wave amplitude value. Specifically, the second preset respiratory wave amplitude threshold value AmpThr2=Amp?*K3, where K3<1.

[0089] The fourth target amplitude peak value is an amplitude peak value greater than the third preset respiratory wave amplitude threshold value in the first target respiratory frequency range, the second target respiratory frequency, and the third target respiratory frequency interval, and the second target respiratory frequency and the third target respiratory frequency being integer multiples of the corresponding fourth target frequency.

[0090] In general, the second preset number is 2. If the number of the fourth target amplitude peak value is greater than or equal to the second preset number, it is determined that the target flow signal contains frequency multiplication. At this time, in order to improve the accuracy of the algorithm and reduce the false detection probability, the respiratory rate is not calculated.

[0091] The process of determining the second target respiratory rate according to the detection result and outputting in the above embodiment will be explained by examples as follows. Specifically, the step 140 can further include the following steps:

[0092] When the baseline drift, the interference and the frequency multiplication do not exist in the target flow signal, the fifth target respiratory frequency is determined according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency, and the second target respiratory rate is determined according to the fifth target respiratory frequency.

[0093] The fifth target respiratory frequency is the final respiratory frequency.

[0094] Specifically, the fifth target respiratory frequency can be determined according to the following steps:

[0095] The latest value in the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency is determined as the fifth target respiratory frequency.

[0096] The baseline drift detection, the interference detection and the frequency multiplication detection are sequentially performed, and the respiratory frequency (the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency) output in each detection process is updated in real time, so that the final fifth target respiratory frequency is the updated respiratory frequency output at the end of the frequency multiplication detection.

[0097] The process of determining the second target respiratory rate according to the fifth target respiratory frequency in the above embodiment will be further explained by examples as follows. Specifically, the step 140 can further include the following steps:

[0098] The second target respiratory rate is determined according to the fifth target respiratory frequency based on a preset formula; the preset formula is as follows:

[0099] RR = 60 * Freq

[0100] Wherein, Freq represents the fifth target respiratory frequency; and RR represents the second target respiratory rate.

[0101] In actual operation, there is interference between low frequency and high frequency in the flow signal. In order to improve the accuracy of the algorithm and reduce the false detection probability, the target flow signal can be preprocessed. Specifically, before the step 110, the method for detecting respiratory rate applied to oxygen therapy equipment provided in the embodiment of the application can further include the following steps:

[0102] The target flow signal in the target flow signal set is subjected to band-pass filtering to obtain a target frequency band.

[0103] The target frequency band includes 0.01-3Hz.

[0104] This step can be realized by a band-pass filter, which is a device that allows waves of a specific frequency band to pass through while shielding other frequency bands. For example, an RLC oscillation circuit is an analog band-pass filter.

[0105] The method for detecting respiratory rate applied to oxygen therapy apparatus provided by the embodiment of the present application first acquires a target flow signal set of a target oxygen therapy apparatus, and normalizes a target flow signal in the target flow signal set. Secondly, the target flow signal after normalization is subjected to Fourier transform to obtain a target amplitude-frequency signal. Thirdly, a first target frequency corresponding to a first target amplitude peak in a preset frequency range of the target amplitude-frequency signal is determined, and a corresponding first target respiratory frequency range is determined according to a first target respiratory rate range of the target oxygen therapy apparatus. The preset frequency range is [0, Fs / 2], and Fs represents a sampling frequency of the target flow signal. Finally, whether a target user accesses the target oxygen therapy apparatus is determined according to the first target frequency and the first target respiratory frequency range. When it is not determined whether the target user accesses the target oxygen therapy apparatus, the target amplitude-frequency signal is subjected to baseline drift detection, interference detection and frequency multiplication detection in sequence, and a second target respiratory rate is determined and output according to a detection result. In this way, the monitoring of the important physiological parameter of respiratory rate is realized without the need of adding a pressure sensor and increasing additional costs, and the respiratory rate detection algorithm of the present application has rigorous logic, fully considers possible complex situations in use, has strong anti-interference ability, and greatly reduces the false detection probability in related technologies.

[0106] After introducing the method for detecting respiratory rate applied to oxygen therapy apparatus of the exemplary embodiments of the present disclosure, next, with reference to Figure 4 The method for detecting respiratory rate applied to oxygen therapy apparatus of the exemplary embodiments of the present disclosure is described.

[0107] With reference to Figure 4 The device for detecting respiratory rate applied to oxygen therapy apparatus 400 comprises: an acquisition module 410 configured to acquire a target flow signal set of a target oxygen therapy apparatus, and normalize a target flow signal in the target flow signal set; a processing module 420 configured to subject the target flow signal after normalization to Fourier transform to obtain a target amplitude-frequency signal; a first determination module 430 configured to determine a first target frequency corresponding to a first target amplitude peak in a preset frequency range of the target amplitude-frequency signal, and determine a corresponding first target respiratory frequency range according to a first target respiratory rate range of the target oxygen therapy apparatus; the preset frequency range is [0, Fs / 2], and Fs represents a sampling frequency of the target flow signal; a second determination module 440 configured to determine whether a target user accesses the target oxygen therapy apparatus according to the first target frequency and the first target respiratory frequency range; when it is not determined whether the target user accesses the target oxygen therapy apparatus, the target amplitude-frequency signal is subjected to baseline drift detection, interference detection and frequency multiplication detection in sequence, and a second target respiratory rate is determined and output according to a detection result.

[0108] In an embodiment, the acquisition module 410 is configured to: band-pass filter the target flow signal in the target flow signal set to obtain a target frequency band; and the target frequency band comprises 0.01-3 Hz.

[0109] In an embodiment, the second determination module 440 is configured to: determine whether the first target frequency is greater than an upper limit of the first target respiratory frequency range; when the first target frequency is greater than the upper limit of the first target respiratory frequency range, determine that the target user is not connected to the target oxygen therapy device; otherwise, determine whether the target user is connected to the target oxygen therapy device.

[0110] In an embodiment, the second determination module 440 is configured to: when the first target frequency is less than a lower limit of the first target respiratory frequency range, determine a second target frequency corresponding to a second target amplitude peak in the first target respiratory frequency range; determine whether a target amplitude valley in an interval between the lower limit of the first target respiratory frequency range and the second target frequency is greater than 1 / 2 of the second target amplitude peak; when the target amplitude valley is greater than 1 / 2 of the second target amplitude peak, determine that there is baseline drift in the target flow signal; otherwise, determine that there is no baseline drift in the target flow signal, and output a second target respiratory frequency and a first target respiratory amplitude value; the second target respiratory frequency is equal to the second target frequency; and the first target respiratory amplitude value is equal to the second target amplitude peak; when the first target frequency is within the first target respiratory frequency range, determine that there is no baseline drift in the target flow signal, and output a third target respiratory frequency and a second target respiratory amplitude value; the third target respiratory frequency is equal to the first target frequency; and the second target respiratory amplitude value is equal to the first target amplitude peak.

[0111] In an embodiment, the second determination module 440 is configured to: respectively determine whether the first target respiratory amplitude value and the second target respiratory amplitude value are less than a first preset respiratory amplitude threshold; when the first target respiratory amplitude value or the second target respiratory amplitude value is less than the first preset respiratory amplitude threshold, determine that the target user is not connected to the target oxygen therapy device; determine whether a number of third target amplitude peaks greater than a second preset respiratory amplitude threshold in the first target respiratory frequency range is greater than a first preset number; when the number of third target amplitude peaks is greater than the first preset number, determine that there is interference in the target flow signal; otherwise, determine that there is no interference in the target flow signal.

[0112] In an embodiment, the second determining module 440 is configured to determine whether the number of the fourth target amplitude peaks, which are greater than the third preset respiratory wave amplitude threshold, in the first target respiratory frequency range and the second target respiratory frequency range, respectively, is greater than or equal to a second preset number, and when the number of the fourth target amplitude peaks is greater than or equal to the second preset number, determine that the target flow signal contains the frequency multiplication; otherwise, determine that the target flow signal does not contain the frequency multiplication, and output the fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0113] In an embodiment, the second determining module 440 is configured to determine a fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency when the target flow signal does not contain the baseline drift, the interference and the frequency multiplication, and determine the second target respiratory rate according to the fifth target respiratory frequency.

[0114] In an embodiment, the second determining module 440 is configured to determine the latest value among the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency as the fifth target respiratory frequency.

[0115] In an embodiment, the second determining module 440 is configured to determine the second target respiratory rate according to the fifth target respiratory frequency based on a preset formula; the preset formula is as follows:

[0116] RR = 60 * Freq

[0117] wherein, Freq represents the fifth target respiratory frequency; and RR represents the second target respiratory rate.

[0118] The above device is used to execute the method provided by the foregoing embodiments, and has similar implementation principles and technical effects, which will not be described here.

[0119] The above modules can be one or more integrated circuits configured to implement the above methods, for example, one or more application specific integrated circuits (ASICs), or one or more microprocessors, or one or more field programmable gate arrays (FPGAs), etc. For another example, when a certain module above is implemented in the form of a processing element scheduling code, the processing element can be a general purpose processor, such as a central processing unit (CPU) or other processor that can invoke program code. For another example, the modules can be integrated together to implement a system-on-a-chip (SOC).

[0120] Figure 5 A schematic diagram of a computer device provided by an embodiment of the present application is provided. The device can be integrated into a terminal device or a chip of a terminal device. The terminal device can be a computing device with a data processing function.

[0121] The device includes a processor 501, a storage medium 502, and a bus 503.

[0122] The storage medium 502 stores program instructions executable by the processor 501. When the computer device 500 is running, the processor 501 communicates with the storage medium 502 through the bus 503. The processor 501 executes the program instructions to perform the above method embodiments. The specific implementation and technical effects are similar, and will not be repeated here.

[0123] Optionally, the present application also provides a program product, for example, a computer readable storage medium, including a program. When the program is executed by a processor, the program is used to execute the above method embodiments.

[0124] In several embodiments provided by the present application, it should be understood that the disclosed apparatus and method can be implemented in other manners. For example, the described apparatus embodiments are merely schematic. The division of the units is merely a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0125] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0126] In addition, each functional unit in each embodiment of the application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of hardware plus software functional unit.

[0127] The integrated unit realized in the form of software functional unit can be stored in a computer readable storage medium. The software functional unit stored in a storage medium includes a plurality of instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) execute part of the steps of the method described in each embodiment of the application. And the foregoing storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, for short: ROM), random access memory (English: Random Access Memory, for short: RAM), magnetic disk or optical disk and various program code storage media.

[0128] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for detecting respiratory rate in oxygen therapy devices, characterized in that, include: Acquire the target flow rate signal set of the target oxygen therapy device, and standardize the target flow rate signals in the target flow rate signal set; The standardized target flow signal is subjected to a Fourier transform to obtain the target amplitude-frequency signal; A first target frequency corresponding to the first target amplitude peak value within a preset frequency range of the target amplitude-frequency signal is determined, and a corresponding first target respiratory frequency range is determined based on the first target respiratory rate range of the target oxygen therapy device; the preset frequency range is [0, Fs / 2], where Fs represents the sampling frequency of the target flow signal; The target user is determined to be connected to the target oxygen therapy device based on the first target frequency and the first target respiratory frequency range; when it is uncertain whether the target user is connected to the target oxygen therapy device, the target amplitude frequency signal is sequentially subjected to baseline drift detection, interference detection and harmonic detection, and the second target respiratory rate is determined and output based on the detection results.

2. The method according to claim 1, characterized in that, Before standardizing the target flow signals in the target flow signal set, the method further includes: The target flow signals in the target flow signal set are bandpass filtered to obtain the target frequency band; the target frequency band includes 0.01 to 3 Hz.

3. The method according to claim 1, characterized in that, The step of determining whether a target user should connect to the target oxygen therapy device based on the first target frequency and the first target respiratory frequency range includes: Determine whether the first target frequency is greater than the upper limit of the first target respiratory frequency range. If the first target frequency is greater than the upper limit of the first target respiratory frequency range, determine that the target user has not connected to the target oxygen therapy device; otherwise, determine whether the target user has connected to the target oxygen therapy device.

4. The method according to claim 1, characterized in that, The baseline drift detection, interference detection, and harmonic detection of the target amplitude-frequency signal include: When the first target frequency is less than the lower limit of the first target respiratory frequency range, the second target frequency corresponding to the peak value of the second target amplitude in the first target respiratory frequency range is determined; Determine whether the lower limit of the first target respiratory rate range and the target amplitude trough within the second target frequency range are greater than 1 / 2 of the second target amplitude peak value. If the target amplitude trough is greater than 1 / 2 of the second target amplitude peak value, it is determined that there is baseline drift in the target flow signal. Conversely, if it is determined that there is no baseline drift in the target flow signal, the second target respiratory frequency and the first target respiratory wave amplitude value are output; the second target respiratory frequency is equal to the second target frequency; the first target respiratory wave amplitude value is equal to the second target amplitude peak value; When the first target frequency is within the range of the first target respiratory frequency, it is determined that there is no baseline drift in the target flow signal, and the third target respiratory frequency and the second target respiratory wave amplitude value are output; the third target respiratory frequency is equal to the first target frequency; the second target respiratory wave amplitude value is equal to the first target amplitude peak value.

5. The method according to claim 1, characterized in that, The baseline drift detection, interference detection, and harmonic detection of the target amplitude-frequency signal include: The amplitude values ​​of the first target respiratory wave and the second target respiratory wave are determined to be less than the first preset respiratory wave amplitude threshold. When the amplitude value of the first target respiratory wave or the amplitude value of the second target respiratory wave is less than the first preset respiratory wave amplitude threshold, it is determined that the target user has not connected to the target oxygen therapy device. Determine whether the number of third target amplitude peaks greater than the second preset respiratory wave amplitude threshold within the first target respiratory frequency range is greater than the first preset number. If the number of third target amplitude peaks is greater than the first preset number, determine that there is interference in the target flow signal; otherwise, determine that there is no interference in the target flow signal.

6. The method according to claim 1, characterized in that, The baseline drift detection, interference detection, and harmonic detection of the target amplitude-frequency signal include: The lower limit of the first target respiratory frequency range and the number of fourth target amplitude peaks within the second and third target respiratory frequency ranges that are greater than a third preset respiratory wave amplitude threshold, and where the second and third target respiratory frequencies are integer multiples of the corresponding fourth target frequencies, are determined to be greater than or equal to a second preset number. If the number of fourth target amplitude peaks is greater than or equal to the second preset number, it is determined that a frequency harmonic exists in the target flow signal; otherwise, it is determined that a frequency harmonic does not exist in the target flow signal, and the fourth target respiratory frequency is output. The fourth target respiratory frequency is equal to the fourth target frequency.

7. The method according to claim 1, characterized in that, The process of determining and outputting the second target respiratory rate based on the detection results includes: When there is no baseline drift, interference, or frequency doubling in the target flow signal, the fifth target breathing frequency is determined based on the second target breathing frequency, the third target breathing frequency, and the fourth target breathing frequency, and the second target breathing rate is determined based on the fifth target breathing frequency.

8. The method according to claim 7, characterized in that, The determination of the fifth target respiratory rate based on the second, third, and fourth target respiratory rates includes: The latest value among the second target respiratory rate, the third target respiratory rate, and the fourth target respiratory rate is determined as the fifth target respiratory rate.

9. The method according to claim 7, characterized in that, Determining the second target respiratory rate based on the fifth target respiratory rate includes: The second target respiratory rate is determined based on a preset formula, according to the fifth target respiratory rate; the preset formula is as follows: RR = 60 * Freq Here, Freq represents the fifth target respiratory rate; RR represents the second target respiratory rate.

10. A respiratory rate detection device for use in oxygen therapy equipment, characterized in that, include: The acquisition module is configured to acquire a set of target flow signals from the target oxygen therapy device and to standardize the target flow signals in the set of target flow signals. The processing module is configured to perform a Fourier transform on the standardized target flow signal to obtain the target amplitude-frequency signal; The first determining module is configured to determine a first target frequency corresponding to the first target amplitude peak within a preset frequency range of the target amplitude-frequency signal, and to determine a corresponding first target respiratory frequency range based on the first target respiratory rate range of the target oxygen therapy device; the preset frequency range is [0, Fs / 2], where Fs represents the sampling frequency of the target flow signal; The second determining module is configured to determine whether a target user is connected to the target oxygen therapy device based on the first target frequency and the first target respiratory frequency range. When it is uncertain whether the target user has connected to the target oxygen therapy device, the target amplitude-frequency signal is sequentially subjected to baseline drift detection, interference detection, and octave detection, and the second target respiratory rate is determined and output based on the detection results.

Images