CN114680869A

CN114680869A - Respiration rate calculation method and computer equipment

Info

Publication number: CN114680869A
Application number: CN202011639513.9A
Authority: CN
Inventors: 潘海洋; 祝荣荣
Original assignee: Resvent Medical Technology Co Ltd
Current assignee: Resvent Medical Technology Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-07-01
Anticipated expiration: 2040-12-31
Also published as: CN114680869B

Abstract

The invention provides a respiratory rate calculation method, which comprises the following steps: judging whether an oral-nasal airflow signal is acquired; when the oral-nasal airflow signals are collected, calculating a first respiratory rate according to the oral-nasal airflow signals; acquiring synchronous photoplethysmography signals synchronous with the oral and nasal airflow signals from the acquired photoplethysmography signals; acquiring a plurality of envelopes according to the synchronous photoplethysmography signals and generating corresponding first envelope frequency spectrum integral graphs; selecting at least one of a plurality of envelopes as a preferred envelope according to the oral-nasal airflow signal and a plurality of first envelope frequency spectrum integral graphs; when the oral and nasal airflow signals cannot be acquired, acquiring an optimal envelope corresponding to the photoplethysmography signals and generating a corresponding second envelope frequency spectrum integral diagram; and calculating a second respiration rate from the second envelope spectrum integral map. In addition, the invention also provides computer equipment. The technical scheme of the invention can calculate the respiratory rate by using the oronasal airflow signal and the photoplethysmography signal.

Description

Respiration rate calculation method and computer equipment

Technical Field

The invention relates to the technical field of signal processing, in particular to a respiration rate calculation method and computer equipment.

Background

When the heart periodically contracts and relaxes, blood ejected from the ventricle into the aorta propagates along the vasculature in the form of waves from the aortic root, forming a pulse wave. Currently, the most common non-invasive pulse wave detection method is photoplethysmography, which uses a photoelectric sensor to measure the change of blood volume in a blood vessel on the body surface to obtain a pulse wave. Research shows that the photoplethysmography includes abundant physiological and pathological information, such as pulse, heart rate, respiration, blood pressure, and the like. Compared with the traditional respiration detection method, the method for extracting the respiration information from the photoplethysmography has the advantages of stronger operability, stable performance, repeated and continuous use and the like, can monitor other pathological information simultaneously, is more beneficial to integration of medical equipment, and is suitable for daily monitoring in hospitals and families.

Disclosure of Invention

The invention provides a respiratory rate calculation method and computer equipment, which are used for calculating the respiratory rate by using an oronasal airflow signal and a photoplethysmography signal.

In a first aspect, an embodiment of the present invention provides a respiration rate calculation method, where the respiration rate calculation method includes:

judging whether an oral-nasal airflow signal is acquired;

when the oronasal airflow signal is acquired, calculating a first respiratory rate according to the oronasal airflow signal;

acquiring synchronous photoplethysmography signals synchronous with the oral and nasal airflow signals from the acquired photoplethysmography signals;

acquiring a plurality of envelopes according to the synchronous photoplethysmography signals and generating corresponding first envelope frequency spectrum integral graphs;

selecting at least one of the plurality of envelopes as a preferred envelope according to the oronasal airflow signal and the plurality of first envelope frequency spectrum integral graphs;

when the oral and nasal airflow signals cannot be acquired, acquiring a preferred envelope corresponding to the photoplethysmography signals and generating a corresponding second envelope frequency spectrum integral diagram; and

and calculating a second respiration rate according to the second envelope spectrum integral diagram.

In a second aspect, an embodiment of the present invention provides a computer device, which includes a processor and a memory, wherein the memory is used for storing respiration rate calculation program instructions, and the processor is used for executing the respiration rate calculation program instructions to implement the respiration rate calculation method as described above.

According to the respiratory rate calculation method and the computer equipment, when the oral-nasal airflow signals are acquired, the respiratory rate is calculated by using the oral-nasal airflow signals. Meanwhile, a plurality of envelopes are obtained according to the photoplethysmography signals synchronous with the oronasal airflow signals, and a first envelope frequency spectrum integral graph is correspondingly generated. And judging the first envelope frequency spectrum integral graph by using the respiratory rate acquired by the oral-nasal airflow signal, and selecting a corresponding envelope as an optimal envelope. When the signals of the oral and nasal airflow cannot be acquired, the optimal envelope is acquired according to the pulse wave signals of the photoplethysmography and a second envelope spectrum integral graph is correspondingly generated, so that the respiratory rate is calculated. The calculation method of the respiration rate can ensure that the respiration rate of the user can be accurately calculated by utilizing the photoplethysmography signals when the oral airflow and the nasal airflow of the user cannot be collected, and further improves the practicability of the instrument.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a flowchart of a respiration rate calculation method according to an embodiment of the present invention.

Fig. 2 is a first sub-flowchart of a respiration rate calculation method according to an embodiment of the present invention.

Fig. 3 is a second sub-flowchart of a respiration rate calculation method according to an embodiment of the present invention.

Fig. 4 is a waveform diagram of the oronasal airflow signal shown in fig. 1.

Fig. 5 is a waveform diagram of the photoplethysmographic signal shown in fig. 1.

Fig. 6 is a graph of the envelope shown in fig. 1.

FIG. 7 is a graph of the first pulse amplitude envelope spectrum shown in FIG. 1.

FIG. 8 is a graph of the first pulse wave amplitude envelope spectrum integral shown in FIG. 1.

Fig. 9 is a schematic diagram of the determination of the preferred envelope shown in fig. 1.

Fig. 10 is a schematic structural diagram of a computer device according to an embodiment of the present invention.

DESCRIPTION OF SYMBOLS IN THE DRAWINGS

Label name

10 computer device a peak envelope

11 processor B valley envelope

12 memory C peak-to-peak interval envelope

D pulse wave amplitude envelope

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances, in other words that the embodiments described are to be practiced in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and any other variation thereof, may also include other things, such as processes, methods, systems, articles, or apparatus that comprise a list of steps or elements is not necessarily limited to only those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such processes, methods, articles, or apparatus.

It should be noted that the description relating to "first", "second", etc. in the present invention is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

Please refer to fig. 1, which is a flowchart illustrating a respiration rate calculating method according to an embodiment of the present invention. The respiratory rate calculation method includes but is not limited to the application of the medical equipment such as a sleep prescreening instrument and the like which can simultaneously acquire the air flow and the pulse of the mouth and the nose of a user. In this embodiment, the respiration rate calculation method is applied to a sleep prescreening instrument (not shown), which can simultaneously collect the oronasal airflow and the pulse of the same user and correspondingly generate an oronasal airflow signal and a photoplethysmography signal. The respiration rate calculation method specifically includes the following steps.

And S102, judging whether an oral-nasal airflow signal is acquired. Specifically, the method utilizes the computer device 10 arranged on the sleep prescreening instrument to judge whether the signals of the air flow of the mouth and the nose are collected. The sleep prescreening instrument comprises an oronasal trachea and a bracelet, and when the user uses the sleep prescreening instrument, the oronasal trachea and the bracelet are worn simultaneously in the sleep process. Wherein, oronasal trachea is used for gathering user's oronasal air current, and the bracelet is used for gathering user's pulse. The mouth, nose and trachea may fall off due to the turning of the user during the sleeping process. When the oronasal trachea does not fall off, an oronasal airflow signal can be acquired; when the mouth and nose trachea falls off, the mouth and nose airflow signals cannot be collected. When the oral-nasal airflow signal is acquired, step S104 is executed. When the oronasal airflow signal cannot be acquired, step S112 is executed.

And step S104, calculating a first respiratory rate according to the oronasal airflow signal. Specifically, when an oronasal airflow signal is acquired, the method calculates a first respiratory rate from the oronasal airflow signal (as shown in FIG. 4) using computer device 10. In this embodiment, the computer device 10 first pre-processes the oronasal airflow signals. Wherein the preprocessing includes, but is not limited to, smoothing filtering. And then carrying out peak value detection on the preprocessed oral and nasal airflow signals, and acquiring a peak-to-peak interval of the oral and nasal airflow signals as a first respiratory rate.

Step S106, acquiring synchronous photoplethysmography signals synchronous with the oral and nasal airflow signals from the acquired photoplethysmography signals. Specifically, the method utilizes a computer device 10 to acquire a synchronized photoplethysmographic signal synchronized with the oronasal airflow signal. It can be understood that the bracelet does not fall off due to actions such as turning around during the sleeping process of the user. Therefore, the user can always acquire the photoplethysmography signals during the sleeping process. When the mouth and nose air pipes are not dropped off, the collected photoplethysmography signals are synchronous photoplethysmography signals synchronous with the mouth and nose airflow signals.

Step S108, a plurality of envelopes are obtained according to the synchronous photoplethysmography signals, and corresponding first envelope frequency spectrum integral graphs are generated. In particular, the method utilizes a computer device 10 to obtain several envelopes from a synchronous photoplethysmographic signal (as shown in FIG. 5). The envelope includes a peak envelope a, a valley envelope B, a peak-to-peak interval envelope C, and a pulse wave amplitude envelope D (as shown in fig. 6). In this embodiment, the computer device 10 first performs fast fourier transform on a plurality of envelopes and obtains corresponding first envelope spectrograms. The computer device 10 performs fast fourier transform on the peak envelope a, the valley envelope B, the peak-to-peak interval envelope C, and the pulse wave amplitude envelope D, and obtains a corresponding first peak envelope spectrogram, a first valley envelope spectrogram, a first peak-to-peak interval envelope spectrogram, and a first pulse wave amplitude envelope spectrogram (as shown in fig. 7). The computer device 10 further integrates the first envelope spectrogram according to a preset window width and obtains a corresponding first envelope spectrogram. The breathing may be unstable during use of the sleep prescreening device by the user. When breathing is unstable, a plurality of peaks may appear in the acquired first envelope spectrogram, which may cause interference. Therefore, the first envelope spectrogram is integrated according to the preset window width, so that the interference of other peaks can be eliminated, and the peaks in the first envelope spectrogram are unique. The computer device 10 integrates the first peak envelope spectrogram, the first valley envelope spectrogram, the first peak interval envelope spectrogram, and the first pulse wave amplitude envelope spectrogram according to a preset window width, and obtains a corresponding first peak envelope spectrum integrogram, a corresponding first valley envelope spectrum integrogram, a corresponding first peak interval envelope spectrum integrogram, and a corresponding first pulse wave amplitude envelope spectrum integrogram (as shown in fig. 8).

And step S110, selecting at least one of the plurality of envelopes as a preferred envelope according to the oral-nasal airflow signal and the plurality of first envelope frequency spectrum integral graphs. Specifically, the method uses the computer device 10 to select at least one of the peak envelope A, the valley envelope B, the peak-to-peak interval envelope C, and the pulse wave amplitude envelope D as a preferred envelope based on the oronasal airflow signal and the first envelope spectrum integral diagram. The process of how to specifically select the preferred envelope will be described in detail below.

And step S112, acquiring a preferred envelope corresponding to the photoplethysmography signal and generating a corresponding second envelope spectrum integral chart. Specifically, when the oronasal airflow signal cannot be acquired, the method acquires a preferred envelope corresponding to the photoplethysmography signal by using the computer device 10, and generates a corresponding second envelope spectrum integral diagram. It can be understood that the photoplethysmography signals collected when the oronasal trachea falls are different from the photoplethysmography signals collected when the oronasal trachea does not fall.

When the preferred envelope is one, the preferred envelope is acquired from the photoplethysmographic signal. For example, when the preferred envelope is the pulse wave amplitude envelope D, the computer device 10 only needs to obtain the pulse wave amplitude envelope D from the photoplethysmographic pulse wave signal. And performing fast Fourier transform on the preferred envelope and acquiring a second envelope spectrogram, namely a second pulse wave amplitude envelope spectrogram. And integrating the second envelope spectrogram according to a preset window width to obtain a second envelope spectrum integral image, namely a second pulse wave amplitude envelope spectrum integral image.

When the preferred envelope is greater than one, each preferred envelope is acquired separately from the photoplethysmographic signal. For example, when two envelopes, peak envelope a and peak-to-peak period envelope C, respectively, are preferred, the computer device 10 obtains the peak envelope a and the peak-to-peak period envelope C from the photoplethysmographic signal. And respectively carrying out fast Fourier transform on the preferred envelope and acquiring a second envelope spectrogram, namely a second peak envelope spectrogram and a second peak interval envelope spectrogram. And performing superposition averaging on the second envelope spectrogram. That is, when the preferred envelope is greater than one, the acquired plurality of second envelope spectrograms need to be superimposed and averaged. And finally, integrating the second envelope spectrogram after the superposition and the averaging according to a preset window width and acquiring a second envelope spectrum integral image.

And step S114, calculating a second respiration rate according to the second envelope spectrum integral graph. In particular, the method calculates a second breathing rate using the computer device 10. It can be understood that the second respiratory rate is a respiratory rate calculated from the photoplethysmography signals when the oronasal airflow signals are not acquired. In this embodiment, the computer device 10 first obtains the maximum peak value of the second spectrum and the total energy according to the second envelope spectrum integral graph, and determines whether a ratio of the maximum peak value of the second spectrum to the second total energy is greater than a preset value. And when the ratio of the second spectrum maximum peak value to the second total energy is greater than a preset value, the product of the frequency corresponding to the second spectrum maximum peak value and the unit time is a second respiration rate. In this embodiment, the unit of the frequency corresponding to the maximum peak of the second spectrum is times/second, and the unit of the respiration rate is times/minute, and the unit time is 60. That is, the product of the frequency corresponding to the maximum peak of the second spectrum and 60 is the second respiration rate.

In the above embodiment, when the oronasal airflow signals are acquired, the first breathing rate is calculated using the oronasal airflow signals. When the respiratory rate of the user cannot be calculated by collecting the oronasal airflow signals, the respiratory rate of the user can be calculated by means of the photoplethysmography signals. Firstly, an accurate first respiratory rate is obtained according to the oral-nasal airflow signal, a peak envelope, a valley envelope, a peak-to-peak interval envelope and a pulse wave amplitude envelope in the photoplethysmography signal are obtained, and the envelope corresponding to the first respiratory rate is preferably used as the preferred envelope for calculating the second respiratory rate, so that the accuracy of calculating the second respiratory rate is improved. Meanwhile, each optimized envelope can be calculated to obtain a respiration rate, and when the optimized envelope is larger than one, the second envelope spectrograms of the optimized envelopes are superposed and averaged, so that the calculated second respiration rate can be more accurate.

Referring to fig. 2 and fig. 9 in combination, fig. 2 is a first sub-flowchart of a respiration rate calculation method according to an embodiment of the present invention, and fig. 9 is a schematic diagram of determining a preferred envelope. Step S110 specifically includes the following steps.

Step S202, respectively obtaining a first spectrum maximum peak value and a first total energy according to the first envelope spectrum integral graph. Specifically, the method uses the computer device 10 to obtain a first spectrum maximum peak value and a first total energy according to the first envelope spectrum integral graph. In the present embodiment, the computer device 10 finds the maximum peak in the first envelope spectrum integral graph as the first spectrum maximum peak within the specified frequency region. Wherein the designated frequency region is 0.1-0.8 Hz. Preferably, the specified frequency region is 0.15-0.67 Hz. In this embodiment, the first maximum peak of the spectrum is the maximum peak of the first envelope spectrum integral diagram within 0.1-0.8Hz, and the first total energy is the total energy of the first envelope spectrum integral diagram within 0.1-0.8 Hz.

Step S204, a threshold range is set according to the first respiration rate. Specifically, the method utilizes the computer device 10 to set the threshold range according to the first breathing rate. For example, when the first breath rate is 15/min, i.e. 0.25/s, the set threshold value range may be 0.15-0.35/s.

Step S206, determining whether the frequency corresponding to the maximum peak of the first spectrum is within the threshold range. Specifically, the method determines, by using the computer device 10, whether the frequency corresponding to the maximum peak of the first spectrum is within the threshold range. For example, if the frequency corresponding to the maximum peak of the first peak envelope spectrum integrogram in the specified frequency region is 0.15 times/second, the frequency corresponding to the maximum peak of the first valley envelope spectrum integrogram in the specified frequency region is 0.25 times/second, the frequency corresponding to the maximum peak of the first peak interval envelope spectrum integrogram in the specified frequency region is 0.3 times/second, and the frequency corresponding to the maximum peak of the first pulse wave amplitude envelope spectrum integrogram in the specified frequency region is 0.5 times/second, the frequency corresponding to the maximum peak of the first peak envelope spectrum in the specified frequency region, the frequency corresponding to the maximum peak of the first valley envelope spectrum in the specified frequency region, the frequency of the first peak interval envelope spectrum, and the frequency corresponding to the maximum peak of the first valley envelope spectrum in the specified frequency region are 0.5 times/second, The frequencies corresponding to the maximum peaks of the first peak-to-peak interval envelope spectrum in the designated frequency region are all within the threshold range of 0.15-0.35 times/second.

Step S208, determining whether a ratio of the first spectrum maximum peak to the first total energy is greater than a predetermined value. Specifically, the method determines whether the ratio of the maximum peak of each first spectrum to the first total energy of the corresponding first envelope spectrum integral graph is greater than a preset value by using the computer device 10. In the present embodiment, the preset value is 0.4. In some possible embodiments, the preset value may be any value from 0.3 to 0.5, which is not limited herein. For example, if the ratio of the maximum peak value of the first peak envelope spectrum integral graph in the designated frequency region 0.1-0.8Hz to the total energy of the first peak value in the designated frequency region 0.1-0.8Hz is 0.6, the ratio of the maximum peak value of the first valley envelope spectrum integral graph in the designated frequency region 0.1-0.8Hz to the total energy of the first valley interval in the designated frequency region 0.1-0.8Hz is 0.3, the ratio of the maximum peak value of the first peak interval envelope spectrum integral graph in the designated frequency region 0.1-0.8Hz to the total energy of the first peak interval in the designated frequency region 0.1-0.8Hz is 0.5, and the ratio of the maximum peak value of the first pulse amplitude envelope spectrum integral graph in the designated frequency region 0.1-0.8Hz to the total energy of the first peak interval in the designated frequency region 0.1-0.8Hz is 0.45 Hz, the ratio of the maximum peak value of the first peak envelope spectrum to the total energy of the first peak value, the ratio of the maximum peak value of the first peak interval envelope spectrum to the total energy of the first peak interval envelope spectrum and the ratio of the maximum peak value of the first pulse wave amplitude envelope spectrum to the total energy of the first pulse wave amplitude are greater than a preset value of 0.4.

Step S210, when the frequency corresponding to the first spectrum maximum peak is within the threshold range and the ratio of the first spectrum maximum peak to the first total energy is greater than the preset value, determining that the envelope corresponding to the first envelope spectrum integral graph is the preferred envelope. Specifically, the method determines, by using the computer device 10, an envelope corresponding to the first envelope spectrum integral graph satisfying two conditions at the same time as the preferred envelope. For example, if the first peak envelope spectrum integrogram and the first peak interval envelope spectrum integrogram satisfy that the frequency corresponding to the maximum peak of the first spectrum is within the threshold range and the ratio of the maximum peak of the first spectrum to the first total energy is greater than the predetermined value, the peak envelope corresponding to the first peak envelope spectrum integrogram is the preferred envelope and the peak interval envelope corresponding to the first peak interval envelope spectrum integrogram is the preferred envelope.

In the above embodiment, when the frequency corresponding to the first spectrum maximum peak is within the threshold range and the ratio of the first spectrum maximum peak to the first total energy is greater than the preset value, the envelope is determined to be the preferred envelope, so that the second respiratory rate can be calculated more accurately.

Referring to fig. 3 and fig. 6 in combination, fig. 3 is a second sub-flowchart of a respiration rate calculation method according to an embodiment of the present invention, and fig. 6 is a graph of an envelope. The method for acquiring a plurality of envelopes according to the synchronous photoplethysmographic signal specifically comprises the following steps.

Step S302, pre-filtering the synchronous photoplethysmographic pulse wave signal and obtaining a peak value and a valley value. Specifically, the method pre-filters the synchronous photoplethysmographic pulse wave signal by using the computer device 10, and then obtains the peak value and the valley value by adopting a characteristic point positioning method. In this embodiment, the pre-filtering is a low-pass filtering. In some possible embodiments, the pre-filtering may be filtering in other manners.

Step S304, obtaining the peak-to-peak interval and the pulse wave amplitude according to the peak value and the valley value. Specifically, the method utilizes the computer device 10 to obtain peak-to-peak intervals, and pulse wave amplitudes from the peaks and valleys.

Step S306, respectively and sequentially carrying out cubic spline interpolation and resampling on the peak value, the valley value, the peak-peak interval and the pulse wave amplitude of the preset time period, and obtaining a peak value envelope, a valley value envelope, a peak-peak interval envelope and a pulse wave amplitude envelope. Specifically, the method uses the computer device 10 to perform cubic spline interpolation on the peak value, the valley value, the peak-to-peak interval and the pulse wave amplitude of the preset time period respectively to obtain a corresponding peak value curve, a corresponding valley value curve, a corresponding peak-to-peak interval curve and a corresponding pulse wave amplitude curve. Wherein the preset time period is 5 minutes. In some possible embodiments, the preset time period may be any value between 3 and 10 minutes, and is not limited herein. The computer device 10 then resamples the peak curve, the valley curve, the peak-to-peak interval curve, and the pulse wave amplitude curve at 4Hz to obtain a peak envelope a, a valley envelope B, a peak-to-peak interval envelope C, and a pulse wave amplitude envelope D.

In the above embodiment, when the peak envelope, the valley envelope, the peak-to-peak interval envelope, and the pulse wave amplitude envelope are obtained, the peak, the valley, the peak-to-peak interval, and the pulse wave amplitude of the preset time period are selected for calculation, so that the envelope can be obtained quickly and accurately, and a large calculation amount caused by excessive collected data is avoided.

Please refer to fig. 10, which is a schematic structural diagram of a computer device according to an embodiment of the present invention. The computer device 10 includes a processor 11, and a memory 12. In the present embodiment, the memory 12 is configured to store respiration rate calculation program instructions, and the processor 11 is configured to execute the respiration rate calculation program instructions to implement the respiration rate calculation method.

The processor 11 may be, in some embodiments, a Central Processing Unit (CPU), controller, microcontroller, microprocessor or other data Processing chip for executing the respiration rate calculation program instructions stored in the memory 12.

The memory 12 includes at least one type of readable storage medium including flash memory, hard disks, multi-media cards, card-type memory (e.g., SD or DX memory, etc.), magnetic memory, magnetic disks, optical disks, and the like. The memory 12 may in some embodiments be an internal storage unit of the computer device, for example a hard disk of the computer device. The memory 12 may also be a storage device of an external computer device in other embodiments, such as a plug-in hard disk provided on the computer device, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and so forth. Further, the memory 12 may also include both an internal storage unit and an external storage device of the computer device. The memory 12 may be used not only to store application software installed in the computer device and various kinds of data such as codes for implementing respiration rate calculation and the like, but also to temporarily store data that has been output or is to be output.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product.

The computer program product includes one or more computer instructions. The procedures or functions according to the embodiments of the invention are brought about in whole or in part when the computer program instructions are loaded and executed on a computer. The computer apparatus may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the unit is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone, or two or more units may be integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method of the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It should be noted that the above-mentioned numbers of the embodiments of the present invention are merely for description, and do not represent the merits of the embodiments. And the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, apparatus, article, or method. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, apparatus, article, or method that includes the element.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A respiration rate calculation method characterized by comprising:

judging whether an oral-nasal airflow signal is acquired;

2. The method for calculating the breathing rate according to claim 1, wherein the selecting at least one of the plurality of envelopes as a preferred envelope according to the oronasal airflow signal and the plurality of first envelope spectrograms specifically comprises:

respectively acquiring a first spectrum maximum peak value and first total energy according to the first envelope spectrum integral graph;

setting a threshold range according to the first respiration rate;

judging whether the frequency corresponding to the maximum peak value of the first frequency spectrum is within the threshold range;

judging whether the ratio of the first frequency spectrum maximum peak value to the first total energy is greater than a preset value or not;

and when the frequency corresponding to the first spectrum maximum peak value is within the threshold range and the ratio of the first spectrum maximum peak value to the first total energy is greater than the preset value, judging the envelope corresponding to the first envelope spectrum integral graph as the preferred envelope.

3. The respiration rate calculation method according to claim 2, wherein the obtaining of the first spectral maximum peak value from the first envelope spectrum integral map specifically comprises:

and searching the maximum peak value in the first envelope spectrum integral graph in a specified frequency region as the first spectrum maximum peak value.

4. The method of claim 1, wherein obtaining a plurality of envelopes from the synchronous photoplethysmography signals and generating corresponding first envelope spectrum integrals comprises:

acquiring the plurality of envelopes according to the synchronous photoplethysmographic signal;

respectively carrying out fast Fourier transform on the plurality of envelopes and acquiring corresponding first envelope spectrograms;

and integrating the first envelope spectrogram according to a preset window width and acquiring the corresponding first envelope spectrogram.

5. The method of claim 4, wherein the envelopes comprise a peak envelope, a valley envelope, a peak-to-peak interval envelope, and a pulse wave amplitude envelope, and wherein obtaining the envelopes from the synchronized photoplethysmographic signal comprises:

pre-filtering the synchronous photoplethysmography signal and acquiring a peak value and a valley value;

acquiring a peak-to-peak interval and a pulse wave amplitude according to the peak value and the valley value;

and respectively and sequentially carrying out cubic spline interpolation and resampling on the peak value, the valley value, the peak-peak interval and the pulse wave amplitude in a preset time period, and obtaining the peak value envelope, the valley value envelope, the peak-peak interval envelope and the pulse wave amplitude envelope.

6. The method of claim 1, wherein calculating a first respiratory rate from the oronasal airflow signal specifically comprises:

pre-processing the oronasal airflow signals;

and carrying out peak value detection on the preprocessed oral and nasal airflow signals, and acquiring the peak-to-peak interval of the oral and nasal airflow signals as the first respiratory rate.

7. The method of calculating a respiration rate according to claim 1, wherein, when the preferred envelopes are one, acquiring a preferred envelope corresponding to the photoplethysmographic signal and generating a corresponding second envelope spectrum integral map specifically includes:

acquiring the optimal envelope according to the photoplethysmography signals;

performing fast Fourier transform on the preferred envelope and acquiring a second envelope spectrogram;

and integrating the second envelope spectrogram according to a preset window width and acquiring the second envelope spectrogram.

8. The method of calculating a respiration rate of claim 1, wherein acquiring a preferred envelope corresponding to the photoplethysmographic signal and generating a corresponding second envelope spectrum integral map when the preferred envelope is greater than one specifically comprises:

respectively acquiring each optimized envelope according to the photoelectric volume pulse wave signal;

respectively carrying out fast Fourier transform on the preferred envelopes and acquiring a second envelope spectrogram;

performing superposition averaging on the second envelope spectrogram;

and integrating the second envelope spectrogram after the superposition and the averaging according to a preset window width and acquiring the second envelope spectrogram.

9. The respiration rate calculation method according to any one of claims 7 or 8, wherein calculating the second respiration rate from the second envelope spectrum integral map specifically comprises:

respectively acquiring a second spectrum maximum peak value and a second total energy according to the second envelope spectrum integral graph;

judging whether the ratio of the maximum peak value of the second frequency spectrum to the second total energy is greater than a preset value;

and when the ratio of the second spectrum maximum peak value to the second total energy is greater than a preset value, the product of the frequency corresponding to the second spectrum maximum peak value and the unit time is the second respiration rate.

10. A computer device comprising a processor and a memory for storing respiration rate calculation program instructions, the processor being configured to execute the respiration rate calculation program instructions to implement the respiration rate calculation method according to any one of claims 1 to 9.