Respiration rate detection method and device applied to oxygen therapy instrument

Abstract

The invention provides a respiratory rate detection method and device applied to an oxygen therapy instrument, and relates to the technical field of medical instruments. The method comprises the steps that a target flow signal set of a target oxygen therapy instrument is acquired, and target flow signals in the target flow signal set are standardized; 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 value in a preset frequency range of the target amplitude-frequency signal, and determining a corresponding first target respiratory frequency range according to a first target respiratory rate range of the target oxygen therapy instrument; determining whether the target user accesses a target oxygen therapy instrument according to the first target frequency and the first target respiratory frequency range; and when whether the target user accesses the target oxygen therapy instrument or not is not determined, baseline drift detection, interference detection and frequency doubling detection are sequentially performed on the target amplitude-frequency signal, and a second target respiration rate is determined and output according to a detection result. The false detection probability can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a respiratory rate detection method and device applied to oxygen therapy equipment. Background Art

[0002] Nasal high-flow humidified oxygen therapy is an oxygen therapy method that directly delivers a certain oxygen concentration of air-oxygen mixed with high-flow gas to the patient through a nasal catheter without the need for sealing. This gas has the characteristics of high flow, accurate oxygen concentration and heated humidification.

[0003] Respiratory rate is a very important physiological parameter in respiratory therapy products. If the nasal high-flow humidified oxygen therapy device can effectively monitor the respiratory rate, combined with the blood oxygen saturation SpO2 and the inspired oxygen concentration FiO2, it can provide respiratory oxygenation index monitoring. The oxygenation index refers to a goal in respiratory therapy. It is an important index that organs and tissues can get enough 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, nasal high-flow humidified oxygen therapy devices generally do not have respiratory rate monitoring functions and do not have oxygenation index monitoring functions; in addition, the algorithms in related technologies have a high probability of false detection. Summary of the invention

[0004] The purpose of the present invention is to provide a respiratory rate detection method and device for oxygen therapy equipment to address the deficiencies in the above-mentioned prior art, so as to eliminate baseline drift, interference, and frequency doubling in the flow signal and reduce the probability of false detection.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a respiratory rate detection method for an oxygen therapy device, comprising: obtaining a target flow signal set of a target oxygen therapy device, and standardizing the target flow signals 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 within a preset frequency range of the target amplitude-frequency signal, and determining a corresponding first target respiratory frequency range according to the first target respiratory 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 is connected to the target oxygen therapy device according to 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, performing baseline drift detection, interference detection, and frequency doubling detection on the target amplitude-frequency signal in sequence, and determining and outputting a second target respiratory rate according to the detection results.

[0007] In one embodiment, before the target flow signals in the target flow signal set are standardized, the method further includes: band-pass filtering the target flow signals in the target flow signal set to obtain a target frequency band; the target frequency band includes 0.01 to 3 Hz.

[0008] In one embodiment, determining whether the target user is connected to the target oxygen therapy device based on the first target frequency and the first target respiratory frequency range includes: 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 is not connected to the target oxygen therapy device; otherwise, determining whether the target user is connected to the target oxygen therapy device.

[0009] In one embodiment, the baseline drift detection, interference detection and frequency multiplication 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, determining the second target frequency corresponding to the second target amplitude peak in the first target respiratory frequency range; determining whether the target amplitude valley value within the 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, and when the target amplitude valley value is greater than 1 / 2 of the second target amplitude peak, determining that there is baseline drift in the target flow signal; otherwise, determining that there is no baseline drift in the target flow signal, outputting the second target respiratory frequency and the 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 within the range of the first target respiratory frequency, determining that there is no baseline drift in the target flow signal, and outputting the third target respiratory frequency and the 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.

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

[0011] In one embodiment, the baseline drift detection, interference detection and frequency doubling detection of the target amplitude-frequency signal include: respectively determining whether the number of fourth target amplitude peaks within the range of the lower limit of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency, which are greater than the third preset respiratory wave amplitude threshold, and the second target respiratory frequency and the third target respiratory frequency are integer multiples of the 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, determining that frequency doubling exists in the target flow signal; otherwise, determining that frequency doubling does not exist in the target flow signal, and outputting the fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0012] In one embodiment, determining and outputting the second target respiratory rate based on the detection results includes: when there is no baseline drift, interference and frequency doubling in the target flow signal, determining the fifth target respiratory frequency based on the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency, and determining the second target respiratory rate based on the fifth target respiratory frequency.

[0013] In one embodiment, determining the fifth target respiratory frequency based on the second target respiratory frequency, the third target respiratory frequency, and the fourth target respiratory frequency includes: 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 one embodiment, determining the second target respiratory rate according to the fifth target respiratory rate includes: determining the second target respiratory rate according to the fifth target respiratory rate based on a preset formula; the preset formula is as follows:

[0015] RR=60*Freq

[0016] Among them, Freq represents the fifth target respiratory frequency; RR represents the second target respiratory rate.

[0017] In a second aspect, an embodiment of the present application further provides a respiratory rate detection device for an oxygen therapy device, comprising: an acquisition module, configured to acquire a target flow signal set of a target oxygen therapy device, and standardize the target flow signals 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 within 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 device; the preset frequency range is [0, Fs / 2], where Fs represents the sampling frequency of the target flow signal; a second determination module, configured to determine whether a target user is connected to the target oxygen therapy device according to 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, baseline drift detection, interference detection and frequency doubling detection are performed on the target amplitude-frequency signal in sequence, and a second target respiratory rate is determined and output according to the detection results.

[0018] In one implementation, the acquisition module is configured to: perform bandpass filtering on the target flow signal in the target flow signal set to obtain a target frequency band; the target frequency band includes 0.01 to 3 Hz.

[0019] In one embodiment, 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, 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.

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

[0021] In one embodiment, the second determination 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, and 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 the number of third target amplitude peaks within the first target respiratory frequency range that are greater than the second preset respiratory wave amplitude threshold is greater than a first preset number, and when the number of the third target amplitude peaks is greater than the first preset number, determine that interference exists in the target flow signal; otherwise, determine that there is no interference in the target flow signal.

[0022] In one embodiment, the second determination module is configured to: respectively determine whether the number of fourth target amplitude peaks greater than the third preset respiratory wave amplitude threshold within the range of the lower limit value of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency, and the second target respiratory frequency and the third target respiratory frequency are integer multiples of the 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 doubling in the target flow signal; otherwise, determine that there is no frequency doubling in the target flow signal, and output the fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0023] In one embodiment, the second determination module is configured to: when there is no baseline drift, interference and frequency doubling in the target flow signal, determine the fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency, and determine the second target respiratory rate according to the fifth target respiratory frequency.

[0024] In one implementation, the second determination module is configured to: determine a 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 one embodiment, the second determination 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] Among them, Freq represents the fifth target respiratory frequency; RR represents the second target respiratory rate.

[0028] In a third aspect, an embodiment of the present application provides a computer device, comprising: a processor, a storage medium and a bus, wherein the storage medium stores program instructions executable by the processor, and when the computer device is running, the processor communicates with the storage medium through the bus, and the processor executes the program instructions to perform 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, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any one of the above methods are performed.

[0030] The beneficial effects of the present application are: without adding a pressure sensor and without increasing additional costs, the respiratory rate detection algorithm of the present application is logically rigorous, fully considering the complex situations that may arise during use, and has strong anti-interference capabilities, which greatly reduces the probability of false detection in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0032] Figure 1A flow chart of a respiratory rate detection method applied to an oxygen therapy device provided in an embodiment of the present application;

[0033] Figure 2 A flow chart of a respiratory rate detection method applied to an oxygen therapy device provided in an embodiment of the present application;

[0034] Figure 3 A flow chart of a respiratory rate detection method applied to an oxygen therapy device provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the structure of a respiratory rate detection device applied to an oxygen therapy device provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0038] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work 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. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0040] In addition, the terms "first", "second", etc. in the description, claims, and above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

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

[0042] Figure 1 It is a schematic flow chart of a respiratory rate detection method applied to an oxygen therapy device provided by an embodiment of the present application; as Figure 1 shown, the method includes:

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

[0044] Among them, the target oxygen therapy device is the oxygen therapy device used to collect the target flow signal set; the target flow signal set includes several recent target flow signals.

[0045] Standardization means first calculating the average value of several target flow signals in the target flow signal set, and then subtracting the average value from each target flow signal. Specifically, assuming that the target flow signal set includes N target flow signals, where N = 2 n , the sampling frequency is Fs, and further, the storage duration of the target flow signal is T = N / Fs, and the target flow signal is updated once at each time t (t < T). According to the following formula (1), calculate the mean value FlowMean of the N target flow signals in the target flow signal set:

[0046]

[0047] Among them, i represents the number of target flow signals.

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

[0049] Among them, the Fourier transform is a tool for converting a time-domain signal into a frequency-domain signal for frequency analysis. Its computational complexity is high and it 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 and is particularly suitable for frequency domain analysis of large-scale discrete signals. It 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 within the frequency range of [0, Fs], and the frequency difference between two adjacent points is ΔFs=Fs / N.

[0052] Step 130: determine a first target frequency corresponding to a first target amplitude peak within 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 device.

[0053] 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 may be recorded as PeakAmp1, and the first target frequency may be recorded as F1.

[0055] The unit of target respiratory rate is Hz, which refers to the number of times per second. The target respiratory rate is generally expressed as times / min, 1min=60s, so the target respiratory rate 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], then the corresponding first target respiratory rate range is [0.05Hz, 1.67Hz]. Specifically, the minimum target respiratory rate is 3 times / min, then its corresponding target respiratory rate = 3 / 60 = 0.05Hz; the maximum target respiratory rate is 100 times / min, then its corresponding target respiratory rate = 100 / 60 = 1.67Hz.

[0056] Step 140: determine whether the 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 is connected to the target oxygen therapy device, perform baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal in sequence, and determine and output the second target respiratory rate based on the detection results.

[0057] Among them, by comparing the first target frequency with the effective range of the respiratory frequency (the first target respiratory frequency range), it is determined whether the target user is connected to the target oxygen therapy device. When the target user is not connected to the target oxygen therapy device, no further detection is required; when the target user is connected to the target oxygen therapy device, it is necessary to eliminate the baseline drift, interference and frequency doubling in the target flow signal respectively. Specifically, the "determining whether the target user is connected to the target oxygen therapy device according to the first target frequency and the first target respiratory frequency range" in the above step 140 can further include the following steps:

[0058] 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, determine that the target user is not connected to the target oxygen therapy device; otherwise, it is not determined whether the target user is connected to the target oxygen therapy device.

[0059] Among them, when the first target frequency is greater than the upper limit value of the first target respiratory frequency range, it means that the target flow signal exceeds the effective range of the respiratory frequency (the first target respiratory frequency range), then the target user is not connected to the target oxygen therapy device, and no further testing is required; otherwise, it means that the target user is connected to the target oxygen therapy device.

[0060] When it is uncertain whether the target user is connected to the target oxygen therapy device, it is necessary to eliminate the baseline drift, interference and frequency doubling in the target flow signal to determine the target user's access to the target oxygen therapy device. Specifically, Figure 2 The flowchart of the respiratory rate detection method applied to oxygen therapy equipment provided in the embodiment of the present application is as follows. Figure 2 As shown, the baseline drift detection in the above step 140 may further include the following steps 210 to 240:

[0061] Step 210: 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 value in the first target respiratory frequency range.

[0062] The second target amplitude peak is the amplitude peak within the first target respiratory frequency range, and the second target frequency is the frequency corresponding to the second target amplitude peak. The second target amplitude peak is recorded as PeakAmp2, and the second target frequency is recorded as F2.

[0063] Step 220, determine whether the lower limit value of the first target respiratory frequency range and the target amplitude valley value within the second target frequency interval are greater than 1 / 2 of the second target amplitude peak value. When the target amplitude valley value is greater than 1 / 2 of the second target amplitude peak value, determine that there is baseline drift in the target flow signal.

[0064] The target amplitude valley value is the amplitude valley value within the interval between the lower limit of the first target respiratory frequency range and the second target frequency range, that is, the amplitude valley value within the interval (0.05, F2). The target amplitude valley value is recorded as MinAmp.

[0065] In this step, 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 accuracy of the algorithm and reduce the probability of false detection, 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 wave amplitude value are output.

[0067] The second target respiratory frequency is equal to the second target frequency; and the first target respiratory wave amplitude value is equal to the second target amplitude peak value.

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

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

[0071] Step 240: 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 wave amplitude value.

[0072] The third target respiratory frequency is equal to the first target frequency; and the second target respiratory wave amplitude value is equal to the first target amplitude peak value.

[0073] The above describes the case where 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 where the first target frequency is less than the lower limit value of the first target respiratory frequency range, and this step describes the case where the first target frequency is within the first target respiratory frequency range.

[0074] The third target respiratory frequency, that is, the respiratory frequency output when the first target frequency is within the range of the first target respiratory frequency and the target amplitude-frequency signal does not have a baseline drift.

[0075] The second target respiratory wave amplitude value is, that is, the respiratory wave 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 a baseline drift.

[0076] In this step, that is, there is no baseline drift in the target flow signal, at this time, the algorithm accuracy can be improved to a certain extent, the probability of false detection can be reduced, and the third target respiratory frequency and the second target respiratory wave amplitude value can be output; the third target respiratory frequency Freq3 = F1, the second target respiratory wave amplitude value Amp2 = PeakAmp1.

[0077] Figure 3 The flowchart of the respiratory rate detection method applied to oxygen therapy equipment provided in the embodiment of the present application is as follows. Figure 3 As shown, the interference detection in the above step 140 may further include the following steps 310 and 320:

[0078] Step 310: 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 value. 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, determine that the target user is not connected to the target oxygen therapy device.

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

[0080] In this step, 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, it means that the first target respiratory wave amplitude value or the second target respiratory wave amplitude is too low, then the target user is not connected to the target oxygen therapy device, and no further detection is required.

[0081] Step 320, 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. 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.

[0082] The second preset respiratory wave amplitude threshold 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 AmpThr2=Amp?*K2, wherein K2<1.

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

[0084] Generally, the first preset number is ≥ 4. If the number of the third target amplitude peaks is greater than the first preset number, it means that it is difficult to identify the respiratory wave from both the time domain angle and the frequency domain angle. At this time, in order to improve the accuracy of the algorithm and reduce the probability of false detection, the respiratory rate is not calculated.

[0085] The frequency doubling detection in step 140 may further include the following steps:

[0086] Determine respectively whether the number of fourth target amplitude peaks greater than the third preset respiratory wave amplitude threshold within the range of the lower limit value of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency, and the second target respiratory frequency and the third target respiratory frequency are integer multiples of the corresponding fourth target frequency, is greater than or equal to the second preset number; when the number of fourth target amplitude peaks is greater than or equal to the second preset number, determine that there is frequency doubling in the target flow signal; otherwise, determine that there is no frequency doubling in the target flow signal, and output the fourth target respiratory frequency.

[0087] Among them, the fourth target respiratory frequency is equal to the fourth target frequency.

[0088] The third preset respiratory wave amplitude threshold 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 AmpThr2=Amp?*K3, wherein K3<1.

[0089] The fourth target amplitude peak, that is, the amplitude peak value within the range of the lower limit value of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency is greater than the third preset respiratory wave amplitude threshold, and the second target respiratory frequency and the third target respiratory frequency are integer multiples of the corresponding fourth target frequency.

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

[0091] The following is an example to explain the process of determining and outputting the second target respiratory rate according to the detection result in the above embodiment. Specifically, the above step 140 may further include the following steps:

[0092] When there is no baseline drift, interference and frequency doubling 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] Among them, the fifth target respiratory rate is the final respiratory rate.

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

[0095] The latest value among 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] Among them, baseline drift detection, interference detection, and frequency doubling detection are performed in sequence. The respiratory frequency (second target respiratory frequency, third target respiratory frequency, fourth target respiratory frequency) output during each detection process will be updated in real time. Therefore, the final fifth target respiratory frequency is the updated respiratory frequency output at the end of the frequency doubling detection.

[0097] The following is an example to explain the process of determining the second target respiratory rate according to the fifth target respiratory rate in the above embodiment. Specifically, the above step 140 may further include the following steps:

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

[0099] RR=60*Freq

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

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

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

[0103] Among them, the target frequency band includes 0.01~3Hz.

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

[0105] The respiratory rate detection method applied to oxygen therapy equipment provided in the embodiment of the present application first obtains a target flow signal set of the target oxygen therapy equipment, and standardizes the target flow signals in the target flow signal set; secondly, performs Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal; thirdly, determines a first target frequency corresponding to a first target amplitude peak within a preset frequency range of the target amplitude-frequency signal, and determines a corresponding first target respiratory frequency range according to the first target respiratory rate range of the target oxygen therapy equipment; the preset frequency range is [0, Fs / 2], and Fs represents the sampling frequency of the target flow signal; finally, determines whether the target user is connected to the target oxygen therapy equipment according to 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 equipment, performs baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal in turn, and determines and outputs a second target respiratory rate according to the detection results. In this way, the monitoring of respiratory rate, an important physiological parameter, is achieved without adding a pressure sensor and without increasing additional costs. The respiratory rate detection algorithm of the present application has rigorous logic, fully considers the complex situations that may arise during use, has strong anti-interference ability, and greatly reduces the probability of false detection in related technologies.

[0106] After introducing the respiratory rate detection method applied to oxygen therapy equipment according to the exemplary embodiment of the present disclosure, next, reference is made to Figure 4 A respiratory rate detection device 400 applied to an oxygen therapy device according to an exemplary embodiment of the present disclosure will be described.

[0107] refer to Figure 4 , a respiratory rate detection device 400 applied to an oxygen therapy device, comprising: an acquisition module 410, configured to acquire a target flow signal set of a target oxygen therapy device, and to standardize the target flow signal in the target flow signal set; a processing module 420, configured to perform Fourier transform on the standardized target flow signal 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 within 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 device; the preset frequency range is [0, Fs / 2], where Fs represents a sampling frequency of the target flow signal; a second determination module 440, configured to determine whether a target user is connected to a target oxygen therapy device according to 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, baseline drift detection, interference detection, and frequency doubling detection are sequentially performed on the target amplitude-frequency signal, and a second target respiratory rate is determined and output according to the detection results.

[0108] In one implementation, the acquisition module 410 is configured to: perform bandpass filtering on the target flow signal in the target flow signal set to obtain a target frequency band; the target frequency band includes 0.01 to 3 Hz.

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

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

[0111] In one embodiment, the second determination module 440 is configured to: respectively determine whether the first target respiratory wave amplitude value and the second target respiratory wave amplitude value are less than the first preset respiratory wave amplitude threshold, and 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 the number of third target amplitude peaks within the first target respiratory frequency range that are greater than the second preset respiratory wave amplitude threshold is greater than the first preset number, and 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 one embodiment, the second determination module 440 is configured to: respectively determine the lower limit value of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency within the interval greater than the third preset respiratory wave amplitude threshold, and the number of fourth target amplitude peaks whose second target respiratory frequency and the third target respiratory frequency are integer multiples of the corresponding fourth target frequency, whether it is greater than or equal to the second preset number; when the number of fourth target amplitude peaks is greater than or equal to the second preset number, determine that there is frequency doubling in the target flow signal; otherwise, determine that there is no frequency doubling in the target flow signal, and output the fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

[0113] In one embodiment, the second determination module 440 is configured to: when there is no baseline drift, interference and frequency doubling in the target flow signal, determine the fifth target respiratory frequency based on the second target respiratory frequency, the third target respiratory frequency and the fourth target respiratory frequency, and determine the second target respiratory rate based on the fifth target respiratory frequency.

[0114] In one implementation, the second determination 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 one embodiment, the second determination 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] Among them, Freq represents the fifth target respiratory frequency; RR represents the second target respiratory rate.

[0118] The above-mentioned device is used to execute the method provided by the aforementioned embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

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

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

[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 via the bus 503. The processor 501 executes the program instructions to perform the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0123] Optionally, the present invention also provides a program product, such as a computer-readable storage medium, comprising a program, which is used to execute the above method embodiment when executed by a processor.

[0124] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0125] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0126] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0127] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to perform some steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, abbreviated: ROM), random access memory (English: Random Access Memory, abbreviated: RAM), disk or optical disk and other media that can store program codes.

[0128] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A respiratory rate detection method applied to oxygen therapy equipment, characterized in that: include: Acquire a target flow signal set of a target oxygen therapy device, and standardize the target flow signals in the target flow signal set; Performing Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal; Determine a first target frequency corresponding to a first target amplitude peak within 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 device; the preset frequency range is [0, Fs / 2], where Fs represents a sampling frequency of the target flow signal; Determine whether the target user is connected to the target oxygen therapy device based on the first target frequency and the first target breathing frequency range; when it is uncertain whether the target user is connected to the target oxygen therapy device, perform baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal in sequence, and determine and output the second target breathing rate based on the detection results.

2. The method according to claim 1, characterized in that Before the target flow signal in the target flow signal set is standardized, the method further includes: The target flow signal in the target flow signal set is band-pass filtered to obtain a target frequency band; the target frequency band includes 0.01 to 3 Hz.

3. The method according to claim 1, characterized in that: The determining whether the target user is connected to the target oxygen therapy device according to the first target frequency and the first target respiratory frequency range includes: 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, determine that the target user is not connected to the target oxygen therapy device; otherwise, it is not determined whether the target user is connected to the target oxygen therapy device.

4. The method according to claim 1, characterized in that The performing of baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal comprises: When the first target frequency is less than a lower limit of the first target respiratory frequency range, determining a second target frequency corresponding to a second target amplitude peak value in the first target respiratory frequency range; Determine whether the lower limit value of the first target respiratory frequency range and the target amplitude valley value within the second target frequency interval are greater than 1 / 2 of the second target amplitude peak value, and when the target amplitude valley value is greater than 1 / 2 of the second target amplitude peak value, determine that there is baseline drift in the target flow signal; On the contrary, it is determined that there is no baseline drift in the target flow signal, and a second target respiratory frequency and a 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 a third target respiratory frequency and a second target respiratory wave amplitude value are output; the third target respiratory frequency is equal to the first target frequency; and 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 performing of baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal comprises: respectively determining whether a first target respiratory wave amplitude value and a second target respiratory wave amplitude value are less than a first preset respiratory wave amplitude threshold, and 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, determining that the target user is not connected to the target oxygen therapy device; Determine whether the number of third target amplitude peaks within the first target respiratory frequency range that are greater than the second preset respiratory wave amplitude threshold is greater than the first preset number; when the number of the third target amplitude peaks is greater than the first preset number, determine that interference exists in the target flow signal; otherwise, determine that no interference exists in the target flow signal.

6. The method according to claim 1, characterized in that The performing of baseline drift detection, interference detection and frequency doubling detection on the target amplitude-frequency signal comprises: Determine respectively whether the number of fourth target amplitude peaks greater than the third preset respiratory wave amplitude threshold within the range of the lower limit value of the first target respiratory frequency range and the second target respiratory frequency and the third target respiratory frequency, and the second target respiratory frequency and the third target respiratory frequency are integer multiples of the corresponding fourth target frequency, is greater than or equal to the 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 doubling in the target flow signal; otherwise, determine that there is no frequency doubling in the target flow signal, and output the fourth target respiratory frequency; the fourth target respiratory frequency is equal to the fourth target frequency.

7. The method according to claim 1, characterized in that The step of determining and outputting the second target respiratory rate according to the detection result includes: When there is no baseline drift, interference and frequency doubling 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.

8. The method according to claim 7, characterized in that Determining the fifth target respiratory frequency according to the second target respiratory frequency, the third target respiratory frequency, and the fourth target respiratory frequency includes: The latest value among the second target respiratory frequency, the third target respiratory frequency, and the fourth target respiratory frequency is determined as the fifth target respiratory frequency.

9. The method according to claim 7, characterized in that: The determining the second target respiratory rate according to the fifth target respiratory frequency comprises: Based on a preset formula, the second target respiratory rate is determined according to the fifth target respiratory frequency; the preset formula is as follows: RR=60*Freq Among them, Freq represents the fifth target respiratory frequency; RR represents the second target respiratory rate.

10. A respiratory rate detection device used in oxygen therapy equipment, characterized in that: include: an acquisition module, configured to acquire a target flow signal set of a target oxygen therapy device, and standardize the target flow signals in the target flow signal set; A processing module is configured to perform Fourier transform on the standardized target flow signal to obtain a target amplitude-frequency signal; A first determination module is configured to determine a first target frequency corresponding to a first target amplitude peak within 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 device; the preset frequency range is [0, Fs / 2], and Fs represents a sampling frequency of the target flow signal; A second determination module is configured to determine whether a target user is connected to the target oxygen therapy device according to 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, baseline drift detection, interference detection and frequency doubling detection are performed on the target amplitude-frequency signal in sequence, and a second target respiratory rate is determined and output according to the detection results.

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