WO2021190377A1

WO2021190377A1 - Ppg signal obtaining method and apparatus, terminal device, and storage medium

Info

Publication number: WO2021190377A1
Application number: PCT/CN2021/081307
Authority: WO
Inventors: 熊浩; 李靖; 李玥
Original assignee: 华为技术有限公司
Priority date: 2020-03-27
Filing date: 2021-03-17
Publication date: 2021-09-30
Also published as: CN113440118A

Abstract

A photoplethysmograph (PPG) signal obtaining method and apparatus, a terminal device, and a storage medium, applicable to the technical field of medical measurement. The method comprises: obtaining a PPG signal acquired by a wearable device (201, 305, 403), wherein the wearable device is worn at a designated part of a user body; and if the obtained PPG signal does not meet a preset condition, adjusting the pressure value between the wearable device and the designated part (203, 307, 405), and obtaining, after adjusting the pressure value, a new PPG signal acquired by the wearable device, until the obtained PPG signal meets the preset condition. After a PPG signal is obtained, whether the PPG signal meets a preset condition would be determined, and if not, it indicates that the signal quality of the PPG signal does not meet requirements; at that time, the wearable device can be firmly worn on the human body by adjusting the pressure value between the wearable device and the wearing part of the human body, thereby improving the quality of an obtained PPG signal and further improving the accuracy of blood oxygen measurement.

Description

Method, device, terminal equipment and storage medium for acquiring PPG signal

This application claims the priority of a Chinese patent application filed with the State Intellectual Property Office on March 27, 2020, the application number is 202010227848.3, and the application name is "Methods, devices, terminal equipment and storage media for obtaining PPG signals", and its entire contents Incorporated in this application by reference.

Technical field

This application belongs to the technical field of medical detection, and in particular relates to a method, a device, a terminal device, and a storage medium for obtaining PPG signals.

Background technique

The oxygen required in the process of human metabolism enters the human blood mainly through the respiratory system, combines with the deoxyhemoglobin of the red blood cells in the blood to obtain oxygenated hemoglobin, and then transports it to the tissue cells of various parts of the human body. An important indicator of blood oxygen detection is blood oxygen saturation, which refers to the percentage of the volume of oxygenated hemoglobin in the blood that is bound by oxygen to the total volume of hemoglobin that can be bound, that is, the concentration of blood oxygen in the blood.

At present, blood oxygen detection usually adopts dual-wavelength spectroscopy, which mainly includes: irradiating red light and infrared light into human tissues; using photoelectric sensors to receive red light and infrared light through human tissues to produce red light photoplethysmography (PhotoPlethysmoGraph , PPG) signal and infrared PPG signal; decompose the red light PPG signal and infrared PPG signal into the corresponding DC signal and AC signal; finally, use the characteristics of the obtained DC signal and AC signal to substitute into the set blood oxygen concentration calculation The formula can calculate the blood oxygen concentration.

Obviously, the accuracy of the above blood oxygen detection method is very dependent on the quality of the obtained PPG signal, that is, it is required to obtain a stable and reliable PPG signal. However, when the user is wearing a blood oxygen detection device (such as a wristband with blood oxygen detection function or a wearable device such as a watch), due to the unstable wearing of the device and other reasons, the obtained PPG signal will be unstable, which will lead to the blood oxygen detection. The accuracy drops.

Summary of the invention

In view of this, the embodiments of the present application provide a method, a device, a terminal device, and a storage medium for acquiring a PPG signal, which can improve the quality of PPG signal acquisition, thereby improving the accuracy of blood oxygen detection.

In the first aspect, an embodiment of the present application provides a method for acquiring a PPG signal, including:

Acquiring a photoplethysmography PPG signal collected by a wearable device, wherein the wearable device is worn on a designated part of the user's body;

If the acquired PPG signal does not meet the preset condition, adjust the pressure value between the wearable device and the designated part, and reacquire the PPG signal collected by the wearable device after the pressure value is adjusted, Until the acquired PPG signal meets the preset condition.

After acquiring the PPG signal, the embodiment of the application will determine whether the PPG signal meets the preset conditions. If it meets the preset conditions, it indicates that the PPG signal is relatively stable and reliable and meets the signal quality requirements for blood oxygen detection. At this time, the PPG signal can be output. Perform the subsequent blood oxygen detection process; if it does not meet the requirements, it indicates that the signal quality of the PPG signal does not meet the requirements. At this time, by adjusting the pressure value between the wearable device (blood oxygen detection device) and the body wearing part, the wearable can be made The device is steadily worn on the human body, thereby effectively improving the quality of the PPG signal obtained, thereby improving the accuracy of blood oxygen detection.

In a possible implementation of the first aspect, before acquiring the photoplethysmography PPG signal collected by the wearable device, it may further include:

Determining the user account currently logged in to the wearable device;

Looking up the target pressure value associated with the user account;

If the target pressure value is found, the pressure value between the wearable device and the designated part is adjusted to the target pressure value.

Before acquiring the PPG signal, first determine the user account currently logged in to the wearable device, find the target pressure value associated with the user account, and adjust the pressure value between the wearable device and the designated part to the target pressure value. Through this setting, the pressure value worn by the wearable device can be adjusted to a more reasonable value in advance, thereby increasing the probability of obtaining high-quality PPG signals, and reducing multiple and repetitive pressures caused by unqualified PPG signal quality in subsequent operations Adjustment process.

Furthermore, after obtaining the photoplethysmography PPG signal collected by the wearable device, it may also include:

If the acquired PPG signal meets the preset condition, detect and record the current pressure value between the wearable device and the designated part;

Associating the recorded pressure value with the user account.

In the current blood oxygen test, if the acquired PPG signal meets the preset condition, that is, the PPG signal is relatively stable and reliable, and meets the signal quality requirements of the blood oxygen test. At this time, the current wearable device and the wearable device can be detected and recorded. The pressure value between the designated parts is then associated with the recorded pressure value and the user account and stored in the pressure reference value database.

In a possible implementation manner of the first aspect, whether the acquired PPG signal meets the preset condition can be determined by the following steps:

Matching the PPG signal with a pre-stored standard signal to obtain a matching degree, where the standard signal is a PPG signal that is associated with the user and whose signal characteristics meet a preset requirement;

If the matching degree is greater than or equal to a preset threshold, determining that the PPG signal meets the preset condition;

If the matching degree is less than the preset threshold, it is determined that the PPG signal does not meet the preset condition.

For a user A, if in a previous blood oxygen test, a relatively stable and high-quality PPG signal with obvious signal characteristics is obtained, the PPG information obtained from the blood oxygen test can be stored. As a standard PPG signal associated with this user A. Later, when user A performs blood oxygen detection again, he can match the currently detected PPG signal with the pre-stored standard PPG signal. If the matching degree exceeds a certain preset threshold (for example, 90%), the currently detected PPG signal is considered The quality of the PPG signal meets the requirements, that is, meets the preset conditions.

Intercepting a target signal of a preset length from the PPG signal;

Detecting the peaks and troughs of the target signal;

According to the characteristics of the wave peaks and the characteristics of the wave valleys, it is determined whether the PPG signal meets the preset condition.

First, a target signal of a preset length can be intercepted from the PPG signal, for example, a signal segment of 20 seconds can be intercepted. Then, each wave peak and wave trough of the target signal is detected, and according to the characteristics of the wave peak and wave trough, it is determined whether the PPG signal meets the preset condition. For example, whether the number of crests and troughs meet the requirements, and whether the peak characteristics of crests and troughs are obvious.

Further, the determining whether the PPG signal meets the preset condition according to the characteristics of the peaks and the characteristics of the valleys may include:

Counting the number of wave crests and the number of wave troughs;

If the number of wave crests is less than a preset threshold, or the number of wave troughs is less than a preset threshold, it is determined that the PPG signal does not meet the preset condition;

or

Calculating the amplitude difference of any two adjacent peaks in the target signal;

If the amplitude difference exceeds a preset threshold, it is determined that the PPG signal does not meet the preset condition;

or

Respectively calculating the variance of the amplitude of each peak in the target signal, the variance of the peak width of each peak, and the variance of the peak distance between each peak and adjacent peaks;

If the variance of the amplitude of each wave crest exceeds a preset threshold, or the variance of the peak width of each wave crest exceeds the preset threshold, or the variance of the peak distance between each wave crest and adjacent wave crests exceeds the preset threshold, It is determined that the PPG signal does not meet the preset condition.

Generally speaking, a high-quality PPG signal should have obvious periodic pulse wave signal characteristics, that is, the signal should have a certain number of peaks and valleys; moreover, the amplitude of each pulse wave should be approximately the same ; In addition, the amplitude, peak width (peak width) of each pulse wave and the peak distance (peak distance) between adjacent peaks should be approximately the same, that is, the variance of the amplitude of each peak, the peak of each peak The wide variance and the variance of the peak distance between each peak and adjacent peaks are small. Therefore, these signal characteristics can be used to determine whether the acquired PPG signal meets the preset quality conditions.

Detecting the pressure value between the wearable device and the designated part;

If the pressure value between the wearable device and the designated part does not fall within the preset pressure range interval, adjust the tightness of the wearable device at the designated part until the wearable device The pressure value between and the designated part falls within the pressure range interval.

Before acquiring the PPG signal, detect the pressure value between the wearable device and the specified part of the user's body. If the pressure value between the wearable device and the specified part does not fall within the preset pressure range interval, adjust the pressure value. The tightness of the wearable device worn on the designated part until the pressure value between the wearable device and the designated part falls within the pressure range interval. Through this setting, the pressure value worn by the wearable device can be adjusted to a more reasonable value in advance, thereby increasing the probability of obtaining high-quality PPG signals, and reducing multiple and repetitive pressures caused by unqualified PPG signal quality in subsequent operations Adjustment process.

In the second aspect, an embodiment of the present application provides an apparatus for acquiring a PPG signal, including:

A signal acquisition module for acquiring photoplethysmography PPG signals collected by a wearable device, wherein the wearable device is worn on a designated part of the user's body;

The pressure adjustment module is configured to adjust the pressure value between the wearable device and the designated part if the acquired PPG signal does not meet the preset condition, and obtain the wearable again after the pressure value is adjusted The PPG signal collected by the device until the acquired PPG signal meets the preset condition.

In the third aspect, an embodiment of the present application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, The method for acquiring the PPG signal as proposed in the first aspect of the embodiments of the present application is implemented.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements what is proposed in the first aspect of the embodiment of the present application. Method of obtaining PPG signal.

In a fifth aspect, the embodiments of the present application provide a computer program product, which when the computer program product runs on a terminal device, causes the terminal device to execute the method for acquiring a PPG signal as described in any one of the above-mentioned first aspects.

Compared with the prior art, the embodiment of the present application has the beneficial effects that the quality of PPG signal acquisition can be improved, thereby improving the accuracy of blood oxygen detection, and the implementation is convenient and has strong practicability.

Description of the drawings

FIG. 1 is a schematic diagram of the hardware structure of a wearable device to which the method for acquiring a PPG signal provided by an embodiment of the present application is applicable;

FIG. 2 is a flowchart of a method for acquiring a PPG signal provided by an embodiment of the present application;

FIG. 3 is a flowchart of another method for obtaining a PPG signal according to an embodiment of the present application;

FIG. 4 is a flowchart of another method for acquiring a PPG signal according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a system in which the method for acquiring PPG signals proposed in an embodiment of the present application is applied in an actual scenario;

Fig. 6 is a schematic flow chart of the working principle of the system shown in Fig. 5;

Fig. 7 is another schematic flow chart of the working principle of the system shown in Fig. 5;

FIG. 8 is a schematic diagram of PPG signals obtained when the wearable device is worn on the user's wrist too tightly, too loosely, and appropriately;

FIG. 9 is a structural diagram of a device for acquiring a PPG signal provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a terminal device provided by an embodiment of the present application.

Detailed ways

In the following description, for the purpose of illustration rather than limitation, specific details such as a specific device structure and technology are proposed for a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known devices, circuits, and methods are omitted to avoid unnecessary details from obstructing the description of this application.

The terms used in the following embodiments are only for the purpose of describing specific embodiments, and are not intended to limit the application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also This includes expressions such as "one or more" unless the context clearly indicates to the contrary. It should also be understood that in the embodiments of the present application, "one or more" refers to one, two or more than two; "and/or" describes the association relationship of the associated objects, indicating that there may be three relationships; for example, A and/or B can mean the situation where A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the associated objects before and after are in an "or" relationship.

The method for obtaining PPG signals provided by the embodiments of this application can be applied to mobile phones, tablet computers, wearable devices, in-vehicle devices, augmented reality (AR)/virtual reality (VR) devices, notebook computers, and super mobiles. On terminal devices or servers such as ultra-mobile personal computers (UMPC), netbooks, and personal digital assistants (PDAs), the embodiments of this application do not impose any restrictions on the specific types of terminal devices and servers.

For example, the terminal device may be a station (STAION, ST) in a WLAN, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, Personal Digital Assistant (PDA) devices, handheld devices with wireless communication functions, computing devices or other processing devices connected to wireless modems, in-vehicle devices, car networking terminals, computers, laptop computers, handheld communication devices , Handheld computing equipment, satellite wireless equipment, wireless modem cards, TV set top boxes (STB), customer premise equipment (customer premise equipment, CPE), and/or other equipment used to communicate on wireless devices and download A first-generation communication device, for example, a mobile terminal in a 5G network or a mobile terminal in a public land mobile network (PLMN) network that will evolve in the future.

As an example and not a limitation, when the terminal device is a wearable device, the wearable device can also be a general term for applying wearable technology to intelligently design daily wear and develop wearable devices, such as glasses, gloves, Watches, bracelets, clothing and shoes, etc. A wearable device is a portable device that is directly worn on the body or integrated into the user's clothes or accessories. Wearable devices are not only a kind of hardware device, but also realize powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include full-featured, large-sized, complete or partial functions that can be implemented without relying on smart phones, such as smart watches or smart glasses, and only focus on a certain type of application function, and need to be used in conjunction with other devices such as smart phones. , Such as all kinds of smart bracelets and smart jewelry for physical sign monitoring.

Take the terminal device as a wearable device as an example. FIG. 1 shows a block diagram of a part of the structure of a wearable device provided by an embodiment of the present application. 1, the wearable device includes: a radio frequency (RF) circuit 101, a memory 102, an input unit 103, a display unit 104, a pressure sensor 105, an audio circuit 106, and a wireless fidelity (WiFi) module 107 , Processor 108, power supply 109, light source 110 and photodetector 111 and other components. Those skilled in the art can understand that the structure of the wearable device shown in FIG. 1 does not constitute a limitation on the wearable device, and may include more or fewer components than shown in the figure, or a combination of certain components, or different components Layout.

The following describes the components of the wearable device in detail with reference to Figure 1:

The RF circuit 101 can be used for receiving and sending signals during the process of sending and receiving information or talking. In particular, after receiving the downlink information of the base station, it is processed by the processor 108; in addition, the designed uplink data is sent to the base station. Generally, the RF circuit includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier (LNA), a duplexer, and the like. In addition, the RF circuit 101 can also communicate with the network and other devices through wireless communication. The above-mentioned wireless communication can use any communication standard or protocol, including but not limited to Global System of Mobile Communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (Code Division) Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE)), Email, Short Messaging Service (SMS), etc.

The memory 102 may be used to store software programs and modules. The processor 108 executes various functional applications and data processing of the wearable device by running the software programs and modules stored in the memory 102. The memory 102 may mainly include a storage program area and a storage data area. The storage program area may store an operating device, an application program required by at least one function (such as a sound playback function, an image playback function, etc.), etc.; Data created by the use of wearable devices (such as audio data, phone book, etc.), etc. In addition, the memory 102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

The input unit 103 can be used to receive inputted numeric or character information, and generate key signal inputs related to user settings and function control of the wearable device. Specifically, the input unit 103 may include a touch panel 1031 and other input devices 1032. The touch panel 1031, also called a touch screen, can collect user touch operations on or near it (for example, the user uses any suitable objects or accessories such as fingers, stylus, etc.) on the touch panel 1031 or near the touch panel 1031. Operation), and drive the corresponding connection device according to the preset program. Optionally, the touch panel 1031 may include two parts: a touch detection device and a touch controller. Among them, the touch detection device detects the user's touch position, detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts it into contact coordinates, and then sends it To the processor 108, and can receive commands sent by the processor 108 and execute them. In addition, the touch panel 1031 can be implemented in multiple types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel 1031, the input unit 103 may also include other input devices 1032. Specifically, the other input device 1032 may include, but is not limited to, one or more of a physical keyboard, function keys (such as volume control buttons, switch buttons, etc.), trackball, mouse, and joystick.

The display unit 104 may be used to display information input by the user or information provided to the user and various menus of the wearable device. The display unit 104 may include a display panel 1041. Optionally, the display panel 1041 may be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), etc. Further, the touch panel 1031 can cover the display panel 1041. When the touch panel 1031 detects a touch operation on or near it, it transmits it to the processor 108 to determine the type of the touch event, and then the processor 108 responds to the touch event. The type provides corresponding visual output on the display panel 1041. Although in FIG. 1, the touch panel 1031 and the display panel 1041 are used as two independent components to realize the input and input functions of the wearable device, but in some embodiments, the touch panel 1031 and the display panel 1041 can be combined. Integrate to realize the input and output functions of wearable devices.

The wearable device also includes at least one pressure sensor 105, which can be used to detect the pressure of the wearable device worn on the human body. In addition, it can also include other types of sensors, such as light sensors, motion sensors, and the like. Specifically, the light sensor may include an ambient light sensor and a proximity sensor. The ambient light sensor can adjust the brightness of the display panel 1041 according to the brightness of the ambient light, and the proximity sensor can close the display panel 1041 when the wearable device is moved to the ear. And/or backlight. As a kind of motion sensor, the accelerometer sensor can detect the magnitude of acceleration in various directions (usually three axes), and can detect the magnitude and direction of gravity when stationary, and can be used for applications that recognize the posture of wearable devices (such as horizontal and vertical screen switching) , Related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer, percussion), etc.; as for wearable devices, gyroscopes, barometers, hygrometers, thermometers, infrared sensors and other sensors can also be configured, I won't repeat them here.

The audio circuit 106, the speaker 1061, and the microphone 1062 can provide an audio interface between the user and the wearable device. The audio circuit 106 can transmit the electric signal after the conversion of the received audio data to the speaker 1061, which is converted into a sound signal by the speaker 1061 for output; on the other hand, the microphone 1062 converts the collected sound signal into an electric signal, and the audio circuit 106 After being received, it is converted into audio data, and then processed by the audio data output processor 108, and then sent to, for example, another wearable device through the RF circuit 101, or the audio data is output to the memory 102 for further processing.

WiFi is a short-range wireless transmission technology. Wearable devices can help users send and receive emails, browse web pages, and access streaming media through the WiFi module 107. It provides users with wireless broadband Internet access. Although FIG. 1 shows the WiFi module 107, it is understandable that it is not a necessary component of a wearable device, and can be omitted as needed without changing the essence of the invention.

The processor 108 is the control center of the wearable device. It uses various interfaces and lines to connect the various parts of the entire wearable device, runs or executes the software programs and/or modules stored in the memory 102, and calls and stores them in the memory 102. Perform various functions of the wearable device and process the data, so as to monitor the wearable device as a whole. Optionally, the processor 108 may include one or more processing units; preferably, the processor 108 may integrate an application processor and a modem processor, where the application processor mainly processes operating devices, user interfaces, application programs, etc. , The modem processor mainly deals with wireless communication. It can be understood that the above-mentioned modem processor may not be integrated into the processor 108.

The wearable device also includes a power supply 109 (such as a battery) for supplying power to various components. Preferably, the power supply can be logically connected to the processor 108 through a power management device, so that functions such as charging, discharging, and power consumption management can be managed by the power management device. .

The wearable device also includes a light source 110. Specifically, the light source 110 may include an infrared light source and a red light source, which can respectively emit infrared light and red light. The infrared light and red light can pass through the user's wrist and other parts to generate corresponding PPG signals. , Can be used for blood oxygen detection.

The wearable device also includes a photodetector 111, which is used to collect the red light PPG signal and the infrared PPG signal generated after the red light or infrared light passes through the user's wrist and other parts.

In addition, although not shown, the wearable device also includes a wearing component for wearing the wearable device on the user. Specifically, the wearing component may be a watchband, a buckle, or the like. In addition, the wearing part also includes a pressure adjusting device, which can adjust the pressure of the wearable device worn on a designated part of the user's body.

Fig. 2 shows a flow chart of a method for acquiring a PPG signal provided by an embodiment of the present application, including:

201. Obtain a photoplethysmography PPG signal collected by a wearable device;

The execution subject of the embodiment of the present application may be a wearable device with a blood oxygen detection function, such as a smart watch, a smart bracelet, and so on. The wearable device may include functional modules such as a pressure detection module, a PPG signal detection module, a pressure adjustment module, and a signal quality evaluation module. The PPG signal detection module may include components such as a red light source, an infrared light source, and a photoelectric sensor. First, wear the wearable device on a designated part of the user's body, such as the wrist, neck, and other parts that can detect the user's heart rate; then, collect the photoplethysmography signal (PPG signal) through the PPG signal detection module, specifically to control the light source The emitted light (infrared, red light, etc.) is irradiated to the designated part to generate a corresponding PPG signal, and then the PPG signal is collected by the photoelectric sensor.

202. Determine whether the acquired PPG signal meets a preset condition.

After the PPG signal is acquired, it is determined whether the PPG signal meets the preset condition. The preset conditions here are the PPG signal quality conditions preset to meet the accuracy requirements of blood oxygen detection, such as whether the number of peaks and troughs of the PPG signal meet the requirements, and whether the characteristics of each peak and trough are obvious. Specifically, a signal quality evaluation module can be used to evaluate the PPG signal, by detecting the peak amplitude, period, peak distance, and peak number of the PPG signal, and then judging whether the PPG signal meets the signal quality requirements based on these characteristics.

Specifically, whether the acquired PPG signal meets the preset condition can be determined through the following steps:

(1) Matching the PPG signal with a pre-stored standard signal to obtain a degree of matching, where the standard signal is a PPG signal that is associated with the user and whose signal characteristics meet preset requirements;

(2) If the matching degree is greater than or equal to a preset threshold, determining that the PPG signal meets the preset condition;

(3) If the matching degree is less than the preset threshold, it is determined that the PPG signal does not meet the preset condition.

(1) Intercept a target signal of a preset length from the PPG signal;

(2) Detect the peaks and troughs of the target signal;

(3) Determine whether the PPG signal meets the preset condition according to the characteristics of the wave crests and the characteristics of the wave troughs.

Further, the determining whether the PPG signal meets the preset condition according to the characteristics of the peak and the characteristics of the valley may include the following multiple methods:

method one:

(1) Count the number of wave crests and the number of wave troughs;

(2) If the number of wave crests is less than a preset threshold, or the number of wave troughs is less than a preset threshold, it is determined that the PPG signal does not meet the preset condition.

Generally speaking, a high-quality PPG signal should have obvious periodic pulse wave signal characteristics, that is, the signal should have a certain number of peaks and troughs. Therefore, the quality of the PPG signal can be determined by counting the number of crests and troughs to determine whether the quality of the PPG signal meets the requirements: if the number of crests or troughs is too small, it is determined that the PPG signal does not meet the preset conditions; if the number of crests or troughs If enough, it is determined that the PPG signal meets the preset condition.

Way two:

(1) Calculate the amplitude difference of any two adjacent peaks in the target signal;

(2) If the amplitude difference exceeds a preset threshold, it is determined that the PPG signal does not meet the preset condition.

Consider another way. A high-quality PPG signal should have approximately the same amplitude of each pulse wave. Therefore, it is possible to determine whether the quality of the PPG signal meets the requirements by calculating the amplitude difference between any two adjacent peaks in the target signal: if the amplitude difference exceeds the set threshold, it is determined that the PPG signal does not meet the requirements. A preset condition; if the amplitude difference does not exceed a set threshold, it is determined that the PPG signal meets the preset condition. It should be understood that there can be multiple amplitude differences here. For example, for peak A, peak B, and peak C, the amplitude difference includes the amplitude difference between A and B, and the amplitude difference between B and C. When determining , All amplitude differences can be used, or a certain number of amplitude differences can be selected from them.

Way three:

(1) Calculate the variance of the amplitude of each peak in the target signal, the variance of the peak width of each peak, and the variance of the peak distance between each peak and adjacent peaks;

(2) If the variance of the amplitude of each wave peak exceeds the preset threshold, or the variance of the peak width of each wave exceeds the preset threshold, or the variance of the peak distance between each wave peak and adjacent wave peaks exceeds the preset threshold. If a threshold is set, it is determined that the PPG signal does not meet the preset condition.

For a high-quality PPG signal, the amplitude, peak width (peak width) of each pulse wave and the peak distance (peak distance) between adjacent peaks should be approximately the same, that is, the variance of the amplitude of each peak, each The variance of the peak width of the wave crest and the variance of the peak distance between each wave crest and adjacent wave crests are both small. Therefore, it is possible to determine whether the quality of the PPG signal meets the requirements by calculating the variance of the amplitude of each peak in the target signal, the variance of the peak width of each peak, and the variance of the peak distance between each peak and adjacent peaks: If none of these variances exceeds the set threshold, it is determined that the PPG signal meets the preset condition; if more than one of these variances exceeds the set threshold, it is determined that the PPG signal does not meet the preset condition.

If the acquired PPG signal meets the preset condition, step 204 is executed; if the acquired PPG signal does not meet the preset condition, step 203 is executed.

203. Adjust the pressure value between the wearable device and the designated part;

The acquired PPG signal does not meet the preset condition, which indicates that the quality of the PPG signal is low. At this time, the PPG signal cannot be directly used to complete blood oxygen detection. The reason for this problem is probably due to the improper tightness of the wearable device worn by the user. For example, wearing too tightly (excessive pressure) will compress the arm, causing abnormal blood perfusion, causing local blood flow to decrease, and then leading to The PPG signal is abnormal; wearing too loose (the pressure value is too small) will cause the detected PPG signal to be very weak and the signal characteristic is not obvious. Therefore, the quality of the obtained PPG signal can be adjusted and improved by adjusting the pressure value between the wearable device and the designated part. The specific operation method may be to adjust the pressure value between the wearable device and the designated part to a certain suitable pressure range interval, and the pressure range interval may be preset according to an empirical value. After the pressure value is adjusted, return to step 201, that is, reacquire the PPG signal obtained under the current pressure condition, and then evaluate the quality of the reacquired PPG signal. If the quality meets the requirements, proceed to step 204, if the quality is still not If the requirements are met, the pressure value between the wearable device and the designated part is adjusted again, and so on, until a high-quality PPG signal that meets the requirements is obtained.

204. Perform subsequent blood oxygen detection operation steps.

The acquired PPG signal meets the preset conditions, indicating that the PPG signal is relatively stable and reliable, and meets the signal quality requirements for blood oxygen detection. At this time, the PPG signal can be output to execute the subsequent blood oxygen detection process.

Fig. 3 shows a flowchart of another method for obtaining PPG signals provided by the present application, including:

301. Determine the user account currently logged in to the wearable device;

In this embodiment of the application, the user can log in to his user account in the wearable device, and wear the wearable device on a designated part of his body, such as a wrist, neck, and other parts that can detect the user's heart rate. Before the wearable device obtains the PPG signal, it will first determine the user account currently logged in to find the user’s historical blood oxygen test record. Through the historical blood oxygen test record, a relatively reasonable initial pressure recommendation value for the user can be obtained. That is, a suitable pressure value for the wearable device to be worn on the user.

302. Search for a target pressure value associated with the user account.

After determining the user account currently logged in to the wearable device, the target pressure value associated with the user account is searched. If the user account has performed a blood oxygen test before, you can record the pressure value of the user wearing a wearable device in a previous effective blood oxygen test as the target pressure value, which is associated with the user account and stored in a certain pressure Reference value database. During the current blood oxygen test, the wearable device can find from the database whether there is a target pressure value associated with the currently logged-in user account.

303. Judge whether the target pressure value is found;

It is judged whether the target pressure value associated with the user account can be found. If the target pressure value is found, step 304 is executed. If the target pressure value is not found, step 305 can be directly executed, or the user account can be adjusted. The pressure value between the wearable device and the designated part is close to a default recommended pressure value, and then step 305 is executed.

304. Adjust the pressure value between the wearable device and the designated part to the target pressure value;

After finding the target pressure value, adjust the pressure value between the wearable device and the designated part to the target pressure value, and then obtain the corresponding PPG signal on this basis. It should be understood that it is also possible to use the target pressure value as the center of the range interval to construct a floating pressure range interval, and adjust the pressure value between the wearable device and the designated part to fall within the pressure range interval. . In addition, if the target pressure value is not found, a preset default pressure value can also be used as the center of the pressure range interval.

305. Acquire the photoplethysmography PPG signal collected by the wearable device;

306. Determine whether the acquired PPG signal meets a preset condition.

If the preset condition is met, step 308 is executed; if the preset condition is not met, step 307 is executed.

307. Adjust the pressure value between the wearable device and the designated part;

If the PPG signal does not meet the preset condition, adjust the pressure value between the wearable device and the designated part at this time, and return to step 305 after the pressure value is adjusted.

308. Perform subsequent blood oxygen detection operation steps.

For specific descriptions of steps 305-308, please refer to the relevant descriptions of steps 201-204 in the previous embodiment.

Further, in step 308, it may also include:

(1) If the acquired PPG signal meets the preset condition, detect and record the current pressure value between the wearable device and the designated part;

(2) Associating the recorded pressure value with the user account.

In the current blood oxygen test, if the acquired PPG signal meets the preset condition, that is, the PPG signal is relatively stable and reliable, and meets the signal quality requirements of the blood oxygen test. At this time, the current wearable device and the wearable device can be detected and recorded. The pressure value between the designated parts is then associated with the recorded pressure value and the user account and stored in the pressure reference value database. For user accounts that have been associated with a target pressure value, the target pressure value can be updated with the currently detected and recorded pressure value. For user accounts that are not associated with the target pressure value, the currently detected and recorded pressure value can be used as the associated target pressure value.

Before acquiring the PPG signal, this embodiment of the application will determine the user account currently logged in to the wearable device, find the target pressure value associated with the user account, and adjust the pressure value between the wearable device and the designated part to the target Pressure value. Through this setting, the pressure value worn by the wearable device can be adjusted to a more reasonable value in advance, thereby increasing the probability of obtaining high-quality PPG signals, and reducing multiple and repetitive pressures caused by unqualified PPG signal quality in subsequent operations Adjustment process.

Fig. 4 shows a flowchart of another method for obtaining PPG signals provided by the present application, including:

401. Detect the pressure value between the wearable device and a designated part of the user's body;

After the user wears the wearable device for blood oxygen detection, the pressure value between the wearable device and a designated part of the user's body is detected. For example, for wearable devices such as watches and bracelets, the pressure value between the watch, bracelet and the user's wrist is detected.

402. If the pressure value between the wearable device and the designated part does not fall within the preset pressure range interval, adjust the tightness of the wearable device at the designated part until the wearable device is worn at the designated part. The pressure value between the wearable device and the designated part falls within the pressure range interval;

If the pressure value between the wearable device and the designated part does not fall within the preset pressure range interval, it indicates that the tightness of the wearable device currently worn is not appropriate. At this time, the wearable device can be adjusted to be worn on the designated part Until the pressure value between the wearable device and the designated part falls within the pressure range interval. It should be noted that, in the embodiments of the present application, the specific form of pressure adjustment is not limited, and only two examples are listed below.

Example 1: The wearing part of the wearable device is a watchband, and the length of the watchband is stretched and contracted under the drive of a motor. The adjusting the tightness of the wearable device at the designated position includes:

(1) Send a control command to the motor to start the motor to rotate;

(2) Driven by the rotation of the motor, the length of the watchband is controlled to expand and contract, so as to adjust the tightness of the wearable device at the designated position.

When it is necessary to increase the wearing pressure of the wearable device, a control command can be sent to the motor to control the motor to rotate, and drive the length of the wearing part of the watchband to shrink, increase the wearing tightness, thereby increasing the wearing pressure. When it is necessary to reduce the wearing pressure, a control command can be sent to the motor to control the motor to rotate in the opposite direction to drive the length of the wearing part of the watchband to extend, reduce the wearing tightness, and thereby reduce the wearing pressure.

Example 2: The wearing part of the wearable device is a hollow watchband, and an airbag is installed inside the watchband. The airbag is inflated and deflated under the action of an air pump. The tightness at the specified position can include:

Sending a control instruction to the air pump to control the air pump to perform inflation and deflation operations on the airbag, so as to adjust the tightness of the wearable device worn at the designated location.

When the wearing pressure of the wearable device needs to be increased, a control command can be sent to the air pump, and the air pump can be controlled to inflate the airbag to expand the strap, thereby increasing the wearing pressure. When it is necessary to reduce the wearing pressure, a control command can be sent to the air pump, and the air pump can be controlled to deflate the airbag to contract the watchband, thereby reducing the wearing pressure.

403. Acquire a photoplethysmography PPG signal collected by the wearable device;

404. Determine whether the acquired PPG signal meets a preset condition.

If the PPG signal meets the preset condition, step 406 is executed; if the PPG signal does not meet the preset condition, step 405 is executed.

405. Adjust the pressure value between the wearable device and the designated part.

Adjust the pressure value between the wearable device and the designated part, and return to step 403 after the pressure value is adjusted.

406. Perform subsequent blood oxygen detection operation steps.

For detailed descriptions of steps 403-406, please refer to the relevant descriptions of steps 201-204.

The embodiment of this application detects the pressure value between the wearable device and the designated part of the user's body before acquiring the PPG signal, if the pressure value between the wearable device and the designated part does not fall within the preset pressure range interval , Adjust the tightness of the wearable device worn on the designated part until the pressure value between the wearable device and the designated part falls within the pressure range interval. Through this setting, the pressure value worn by the wearable device can be adjusted to a more reasonable value in advance, thereby increasing the probability of obtaining high-quality PPG signals, and reducing multiple and repetitive pressures caused by unqualified PPG signal quality in subsequent operations Adjustment process.

It should be understood that the size of the sequence number of each step in the foregoing embodiment does not mean the order of execution. The execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

For ease of understanding, the method for acquiring PPG signals proposed in this application will be explained in several practical application scenarios below.

Fig. 5 is a schematic diagram of a system applied in an actual scenario of the method for acquiring a PPG signal proposed in an embodiment of the present application.

In Figure 5, the wearable device for blood oxygen detection includes four functions: pressure detection module, PPG detection module (including red light source, infrared light source, photodetector, etc.), pressure adjustment module, and signal quality evaluation module. Module. Among them, the pressure detection module is used to detect the pressure of the wearable device on the user's wrist and other parts in real time, using a pressure sensor; the PPG detection module is used to detect and collect the PPG signal generated by the red and infrared light passing through the wrist; signal quality The evaluation module is used to evaluate whether the quality of the currently collected PPG signal meets the requirements. If it does not meet the requirements, the pressure adjustment module is used to adjust the pressure of the wearable device on the wrist and other parts. After the pressure is adjusted, the current For the PPG signal under pressure, the signal quality evaluation module continues to evaluate the quality of the re-acquired PPG signal, and repeats this until the PPG signal with the signal quality meeting the requirements is obtained for subsequent blood oxygen calculation. Specifically, the pressure adjustment method for the pressure adjustment module is optional, such as adopting an overall inflatable and deflating watchband, a partially inflatable and deflating watchband, and a stretchable length watchband, and so on.

Figure 6 is a schematic flow chart of the working principle of the system shown in Figure 5. After the user wears the wearable device, he starts the blood oxygen detection process; then the pressure on the user's wrist and other designated parts is detected to determine whether the pressure is at a preset level If not, start the pressure adjustment module to adjust the pressure of the wearable device on the wrist and other parts until the pressure is within the pressure range; wait until the pressure is continuously and stably in the pressure range After that, start the PPG signal quality evaluation module to obtain the PPG signal collected under the current pressure condition for evaluation, and judge whether the PPG signal meets the quality conditions; if it meets the quality conditions, the PPG signal can be used to calculate the blood oxygen value, and finally the blood The result of the oxygen test; if the quality conditions are not met, continue to start the pressure adjustment module, adjust the pressure of the wearable device on the wrist and other parts, and then re-acquire the PPG signal collected after the pressure adjustment for evaluation, and repeat until Obtain the PPG signal that meets the quality conditions.

Figure 7 is another flow diagram of the working principle of the system shown in Figure 5. After the user wears the wearable device, he starts the blood oxygen detection process, and searches the user's historical blood oxygen detection process from the pre-built pressure reference database The best detected pressure value (ie target pressure value). If the target pressure value exists in the database, the target pressure value is extracted as the central threshold of the pressure range interval; if the target pressure value does not exist in the database, it is used The default pressure value of the system is used as the central threshold of the pressure range interval. Next, detect the pressure on the user's wrist and other designated parts to determine whether the pressure is within the pressure range. The subsequent processing flow is basically the same as that shown in Figure 6, with the only difference being that when the PPG signal that meets the quality conditions is collected After that, the pressure of the current wearable device worn on the wrist and other parts will be detected and recorded in the pressure reference database as the new target pressure value bound to the user. In this way, after the user uses the wearable device for a period of time, it can automatically call and adjust to the best measured pressure value that matches the user according to the user's historical pressure adjustment value, so as to accurately match the user's individual characteristics and usage habits. , Intelligent blood oxygen measurement.

FIG. 8 is a schematic diagram of PPG signals obtained when the wearable device is worn on the user's wrist too tightly, too loosely, and appropriately. In Fig. 8, the abscissas of each PPG signal image and real-time pressure image are all time. The upper left of Figure 8 is the PPG signal image obtained when wearing too tightly, and the upper right is the real-time pressure image detected when wearing too tightly. It can be seen that the detected real-time pressure is significantly higher than the recommended standard pressure. As a result, the acquired PPG signal is relatively sharp, which is an abnormal condition. The bottom left of Figure 8 shows the PPG signal image and the detected real-time pressure image obtained when wearing too loosely. It can be seen that the detected real-time pressure is significantly lower than the recommended standard pressure, resulting in a very weak PPG signal. , This is also an abnormal situation. Using the pressure self-adjustment method proposed in this application, the pressure of the user wearing the wearable device can be adjusted to near the appropriate standard pressure, and the finally obtained PPG signal image and the detected real-time pressure image are shown in the lower right of Figure 8. You can see The detected real-time pressure is close to the standard pressure, and the acquired PPG signal has obvious characteristics and the quality meets the requirements.

Corresponding to the method for obtaining PPG signals described in the above embodiments, FIG. 9 shows a structural block diagram of the apparatus for obtaining PPG signals provided by an embodiment of the present application. For ease of description, only the information related to the embodiment of the present application is shown part.

Referring to Figure 9, the device includes:

The signal acquisition module 501 is configured to acquire a photoplethysmography PPG signal collected by a wearable device, where the wearable device is worn on a designated part of the user's body;

The pressure adjustment module 502 is configured to adjust the pressure value between the wearable device and the designated part if the acquired PPG signal does not meet the preset condition, and re-acquire the pressure value after the pressure value is adjusted. The PPG signal collected by the wearable device until the acquired PPG signal meets the preset condition.

Further, the apparatus for acquiring the PPG signal may further include:

The user account determination module is used to determine the user account currently logged in to the wearable device;

The target pressure value search module is used to search for the target pressure value associated with the user account;

The pressure adjustment module is configured to adjust the pressure value between the wearable device and the designated part to the target pressure value if the target pressure value is found.

Further, the apparatus for acquiring the PPG signal may further include:

A pressure value recording module, configured to detect and record the current pressure value between the wearable device and the designated part if the acquired PPG signal meets the preset condition;

The pressure value association module is used for associating the recorded pressure value with the user account.

Further, the apparatus for acquiring the PPG signal may further include:

A signal matching module, configured to match the PPG signal with a pre-stored standard signal to obtain a matching degree, where the standard signal is a PPG signal that is associated with the user and whose signal characteristics meet a preset requirement;

A first signal evaluation module, configured to determine that the PPG signal meets the preset condition if the matching degree is greater than or equal to a preset threshold;

The second signal evaluation module is configured to determine that the PPG signal does not meet the preset condition if the matching degree is less than the preset threshold.

Further, the apparatus for acquiring the PPG signal may further include:

A signal interception module for intercepting a target signal of a preset length from the PPG signal;

A signal feature detection module for detecting the peaks and troughs of the target signal;

The third signal evaluation module is configured to determine whether the PPG signal meets the preset condition according to the characteristics of the wave crests and the characteristics of the wave troughs.

Furthermore, the third signal evaluation module may include:

A quantity statistical unit for counting the number of wave crests and the number of wave troughs;

A first signal evaluation unit, configured to determine that the PPG signal does not meet the preset condition if the number of wave crests is less than a preset threshold, or the number of wave troughs is less than a preset threshold;

An amplitude difference calculation unit, configured to calculate the amplitude difference of any two adjacent peaks in the target signal;

A second signal evaluation unit, configured to determine that the PPG signal does not meet the preset condition if the amplitude difference exceeds a preset threshold;

The variance calculation unit is configured to calculate the variance of the amplitude of each peak in the target signal, the variance of the peak width of each peak, and the variance of the peak distance between each peak and adjacent peaks;

The third signal evaluation unit is configured to: if the variance of the amplitude of each wave crest exceeds a preset threshold, or the variance of the peak width of each wave crest exceeds the preset threshold, or the peak between each wave crest and adjacent wave crests If the variance of the distance exceeds a preset threshold, it is determined that the PPG signal does not meet the preset condition.

Further, the apparatus for acquiring the PPG signal may further include:

A pressure detection module for detecting the pressure value between the wearable device and the designated part;

The tightness adjustment module is configured to adjust the tightness of the wearable device at the specified position if the pressure value between the wearable device and the designated part does not fall within a preset pressure range interval , Until the pressure value between the wearable device and the designated part falls within the pressure range interval.

The embodiment of the present application also provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of each method for obtaining PPG signals as proposed in the present application. .

The embodiments of the present application also provide a computer program product, which when the computer program product runs on a terminal device, causes the terminal device to execute the steps of each method for acquiring a PPG signal proposed in this application.

FIG. 10 is a schematic structural diagram of a terminal device provided by an embodiment of this application. As shown in FIG. 10, the terminal device 6 of this embodiment includes: at least one processor 60 (only one is shown in FIG. A computer program 62 running on the processor 60, when the processor 60 executes the computer program 62, the steps in any of the above-mentioned method embodiments for acquiring a PPG signal are implemented.

The terminal device 6 may be a computing device such as a mobile phone, a wearable device, a desktop computer, a notebook, a palmtop computer, and a cloud server. The terminal device may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art can understand that FIG. 10 is only an example of the terminal device 6 and does not constitute a limitation on the terminal device 6. It may include more or less components than shown in the figure, or a combination of certain components, or different components. , For example, can also include input and output devices, network access devices, and so on.

The so-called processor 60 may be a central processing unit (Central Processing Unit, CPU), and the processor 60 may also be other general-purpose processors, digital signal processors (Digital Signal Processors, DSPs), and application specific integrated circuits (Application Specific Integrated Circuits). , ASIC), ready-made programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.

The memory 61 may be an internal storage unit of the terminal device 6 in some embodiments, such as a hard disk or a memory of the terminal device 6. In other embodiments, the memory 61 may also be an external storage device of the terminal device 6, such as a plug-in hard disk equipped on the terminal device 6, a smart media card (SMC), a secure digital (Secure Digital, SD) card, Flash Card, etc. Further, the memory 61 may also include both an internal storage unit of the terminal device 6 and an external storage device. The memory 61 is used to store an operating device, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory 61 can also be used to temporarily store data that has been output or will be output.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the division of the above functional units and modules is used as an example. In practical applications, the above functions can be allocated to different functional units and modules as needed. Module completion, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist alone physically, or two or more units can be integrated into one unit. The above-mentioned integrated units can be hardware-based Formal realization can also be realized in the form of a software functional unit. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the present application. For the specific working process of the units and modules in the above-mentioned device, reference may be made to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail or recorded in an embodiment, reference may be made to related descriptions of other embodiments.

A person of ordinary skill in the art may realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

In the embodiments provided in this application, it should be understood that the disclosed device and method may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be divided. It can be combined or integrated into another device, or some features can be omitted or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the implementation of all or part of the processes in the above-mentioned embodiment methods in the present application can be accomplished by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by the processor, the steps of the foregoing method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate forms. The computer-readable medium may at least include: any entity or device capable of carrying computer program code to a terminal device, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), and a random access memory (RAM, Random Access Memory), electric carrier signal, telecommunications signal and software distribution medium. For example, U disk, mobile hard disk, floppy disk or CD-ROM, etc. In some jurisdictions, according to legislation and patent practices, computer-readable media cannot be electrical carrier signals and telecommunication signals.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that it can still implement the foregoing The technical solutions recorded in the examples are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be included in Within the scope of protection of this application.

Claims

A method for obtaining a PPG signal, characterized in that it comprises:

Acquiring a photoplethysmography PPG signal collected by a wearable device, wherein the wearable device is worn on a designated part of the user's body;

If the acquired PPG signal does not meet the preset condition, adjust the pressure value between the wearable device and the designated part, and reacquire the PPG signal collected by the wearable device after the pressure value is adjusted, Until the acquired PPG signal meets the preset condition.
The method for obtaining PPG signals according to claim 1, wherein before obtaining the PPG signals of photoplethysmography collected by the wearable device, the method further comprises:

Determining the user account currently logged in to the wearable device;

Looking up the target pressure value associated with the user account;

If the target pressure value is found, the pressure value between the wearable device and the designated part is adjusted to the target pressure value.
The method for obtaining PPG signals according to claim 2, wherein after obtaining the PPG signals of photoplethysmography collected by the wearable device, the method further comprises:

If the acquired PPG signal meets the preset condition, detect and record the current pressure value between the wearable device and the designated part;

Associating the recorded pressure value with the user account.
The method for acquiring a PPG signal according to claim 1, wherein whether the acquired PPG signal meets the preset condition is determined by the following steps:

Matching the PPG signal with a pre-stored standard signal to obtain a matching degree, where the standard signal is a PPG signal that is associated with the user and whose signal characteristics meet a preset requirement;

If the matching degree is greater than or equal to a preset threshold, determining that the PPG signal meets the preset condition;

If the matching degree is less than the preset threshold, it is determined that the PPG signal does not meet the preset condition.
The method for acquiring a PPG signal according to claim 1, wherein whether the acquired PPG signal meets the preset condition is determined by the following steps:

Intercepting a target signal of a preset length from the PPG signal;

Detecting the peaks and troughs of the target signal;

According to the characteristics of the wave peaks and the characteristics of the wave valleys, it is determined whether the PPG signal meets the preset condition.
5. The method for obtaining a PPG signal according to claim 5, wherein the determining whether the PPG signal meets the preset condition according to the characteristics of the peak and the characteristics of the valley comprises:

Counting the number of wave crests and the number of wave troughs;

If the number of wave crests is less than a preset threshold, or the number of wave troughs is less than a preset threshold, it is determined that the PPG signal does not meet the preset condition;

or

Calculating the amplitude difference of any two adjacent peaks in the target signal;

If the amplitude difference exceeds a preset threshold, it is determined that the PPG signal does not meet the preset condition;

or

Respectively calculating the variance of the amplitude of each peak in the target signal, the variance of the peak width of each peak, and the variance of the peak distance between each peak and adjacent peaks;

If the variance of the amplitude of each wave crest exceeds a preset threshold, or the variance of the peak width of each wave crest exceeds the preset threshold, or the variance of the peak distance between each wave crest and adjacent wave crests exceeds the preset threshold, It is determined that the PPG signal does not meet the preset condition.
The method for obtaining PPG signals according to any one of claims 1 to 6, characterized in that, before obtaining the photoplethysmography PPG signals collected by the wearable device, the method further comprises:

Detecting the pressure value between the wearable device and the designated part;

If the pressure value between the wearable device and the designated part does not fall within the preset pressure range interval, adjust the tightness of the wearable device at the designated part until the wearable device The pressure value between and the designated part falls within the pressure range interval.
A device for acquiring a PPG signal, characterized in that it comprises:

A signal acquisition module for acquiring photoplethysmography PPG signals collected by a wearable device, wherein the wearable device is worn on a designated part of the user's body;

The pressure adjustment module is configured to adjust the pressure value between the wearable device and the designated part if the acquired PPG signal does not meet a preset condition, and reacquire the wearable after the pressure value is adjusted The PPG signal collected by the device until the acquired PPG signal meets the preset condition.
A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the computer program as claimed in claims 1 to 7. Steps of any of the methods for obtaining PPG signals.
A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the PPG signal acquisition according to any one of claims 1 to 7 Method steps.