CN113440118A

CN113440118A - Method and device for acquiring PPG signal, terminal equipment and storage medium

Info

Publication number: CN113440118A
Application number: CN202010227848.3A
Authority: CN
Inventors: 熊浩; 李靖; 李玥
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-28
Also published as: WO2021190377A1

Abstract

The application is applicable to the technical field of medical detection, and provides a method, a device, terminal equipment and a storage medium for acquiring PPG signals. The method comprises the following steps: acquiring a photoplethysmography (PPG) signal acquired by a wearable device, wherein the wearable device is worn on a specified part of a user body; if the acquired PPG signal does not accord with a preset condition, adjusting a pressure value between the wearable device and the designated part, and acquiring the PPG signal acquired by the wearable device again after the pressure value is adjusted until the acquired PPG signal accords with the preset condition. This application can judge whether this PPG signal accords with the preset condition after acquireing the PPG signal, if not conform to then show the signal quality unsatisfactory of this PPG signal, wears the pressure value between the position through adjustment wearable equipment and human body this moment, can make this wearable equipment stabilize and wear on the human body to improve the quality of the PPG signal that obtains, and then improve blood oxygen detection's accuracy.

Description

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

Technical Field

The present application belongs to the technical field of medical detection, and in particular, to a method, an apparatus, a terminal device, and a storage medium for acquiring a PPG signal.

Background

Oxygen required in the metabolism process of a human body enters the blood of the human body mainly through a respiratory system, is combined with deoxyhemoglobin of red blood cells in the blood to obtain oxyhemoglobin, and then is conveyed to histiocytes of all parts of the human body. An important indicator of blood oxygen detection is the blood oxygen saturation, which is the percentage of the volume of oxygenated hemoglobin bound by oxygen in the blood to the total available hemoglobin volume, i.e., the concentration of blood oxygen in the blood.

Currently, blood oxygen detection generally adopts dual-wavelength spectroscopy, and the method mainly comprises the following steps: irradiating red light and infrared light into human tissues; receiving red light photoplethysmography (PPG) signals and infrared PPG signals generated after red light and infrared light pass through human tissues by a photoelectric sensor; decomposing the red PPG signal and the infrared PPG signal into corresponding direct current signals and alternating current signals; and finally, substituting the characteristics of the obtained direct current signal and alternating current signal into a set blood oxygen concentration calculation formula to calculate the blood oxygen concentration.

Obviously, the accuracy of the above blood oxygen detection method depends greatly on the quality of the obtained PPG signal, i.e. it is required to obtain a stable and reliable PPG signal. However, when a user wears a blood oxygen detection device (for example, wearable devices such as a bracelet with a blood oxygen detection function or a watch), due to the fact that the device is worn unstably, the obtained PPG signal is unstable, and the accuracy of blood oxygen detection is reduced.

Disclosure of Invention

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

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

acquiring a photoplethysmography (PPG) signal acquired by a wearable device, wherein the wearable device is worn on a specified part of a user body;

if the acquired PPG signal does not accord with a preset condition, adjusting a pressure value between the wearable device and the designated part, and acquiring the PPG signal acquired by the wearable device again after the pressure value is adjusted until the acquired PPG signal accords with the preset condition.

After the PPG signal is acquired, whether the PPG signal meets a preset condition or not is judged, if yes, the PPG signal is stable and reliable and meets the signal quality requirement of blood oxygen detection, and the PPG signal can be output at the moment to execute a subsequent blood oxygen detection process; if the measured values do not meet the requirement, the signal quality of the PPG signal is indicated to be not satisfactory, and the wearable device can be stably worn on the human body by adjusting the pressure value between the wearable device (blood oxygen detection device) and the wearing part of the human body, so that the quality of the obtained PPG signal is effectively improved, and the accuracy of blood oxygen detection is improved.

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

determining a user account currently logged in by the wearable device;

searching for a target pressure value associated with the user account;

and if the target pressure value is found, adjusting the pressure value between the wearable equipment and the specified part to be the target pressure value.

Before acquiring the PPG signal, determining a user account where the wearable device is currently logged in, searching a target pressure value associated with the user account, and adjusting a pressure value between the wearable device and the designated part to be the target pressure value. Through setting up like this, can adjust the pressure value that wearable equipment wore in advance to a more reasonable numerical value to improve the probability that obtains high-quality PPG signal, reduce in the follow-up operation because many times, the repetitious pressure adjustment process that the unsatisfactory results in of PPG signal quality.

Still further, after acquiring the photoplethysmography PPG signal acquired by the wearable device, the method may further include:

if the acquired PPG signal meets the preset condition, detecting and recording a pressure value between the wearable device and the specified part;

associating the recorded pressure values with the user account.

In the secondary blood oxygen detection, if the acquired PPG signal meets the preset condition, that is, the PPG signal is more stable and reliable, and meets the signal quality requirement of blood oxygen detection, the pressure value between the wearable device and the designated part can be detected and recorded at the moment, and then the recorded pressure value is associated with 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 may be determined by:

matching the PPG signal with a pre-stored standard signal to obtain a matching degree, wherein the standard signal is the PPG signal which is associated with the user and has a signal characteristic meeting a preset requirement;

if the matching degree is larger than or equal to a preset threshold value, determining that the PPG signal meets the preset condition;

and if the matching degree is smaller than the preset threshold value, determining that the PPG signal does not meet the preset condition.

For a certain user a, if a high-quality PPG signal with stable and distinct signal characteristics is obtained in a previous certain blood oxygen detection, the PPG information obtained in the certain blood oxygen detection may be stored as a standard PPG signal associated with the user a. Then, when the user a performs blood oxygen detection again, the currently detected PPG signal may be matched with a pre-stored standard PPG signal, and if the matching degree exceeds a certain preset threshold (for example, 90%), it is determined that the quality of the currently detected PPG signal meets the requirement, that is, the quality meets the preset condition.

intercepting a target signal with a preset length from the PPG signal;

detecting peaks and troughs of the target signal;

and determining whether the PPG signal meets the preset condition or not according to the characteristics of the wave crest and the characteristics of the wave trough.

First, a target signal of a preset length may be intercepted from the PPG signal, for example, a 20 second signal segment. Then, detecting each peak and each trough of the target signal, and determining whether the PPG signal meets the preset condition according to the characteristics of the peaks and the troughs. For example, whether the number of peaks and troughs meets the requirement, whether the peak characteristics of the peaks and troughs are obvious, and the like.

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

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

if the number of the peaks is smaller than a preset threshold value, or the number of the troughs is smaller than a preset threshold value, determining that the PPG signal does not meet the preset condition;

or

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

if the amplitude difference exceeds a preset threshold value, determining 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 the adjacent peak;

and if the variance of the amplitude of each peak exceeds a preset threshold, or the variance of the peak width of each peak exceeds a preset threshold, or the variance of the peak distance between each peak and an adjacent peak exceeds a preset threshold, determining that the PPG signal does not meet the preset condition.

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

detecting a pressure value between the wearable device and the designated location;

if the pressure value between the wearable device and the designated part does not fall into a preset pressure range interval, adjusting the tightness of the wearable device worn at the designated part until the pressure value between the wearable device and the designated part falls into the pressure range interval.

Before acquiring a PPG signal, detecting a pressure value between a wearable device and a designated part of a user body, and if the pressure value between the wearable device and the designated part does not fall into a preset pressure range interval, adjusting the tightness of the wearable device worn at the designated part until the pressure value between the wearable device and the designated part falls into the pressure range interval. Through setting up like this, can adjust the pressure value that wearable equipment wore in advance to a more reasonable numerical value to improve the probability that obtains high-quality PPG signal, reduce in the follow-up operation because many times, the repetitious pressure adjustment process that the unsatisfactory results in of PPG signal quality.

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

the signal acquisition module is used for acquiring a photoplethysmography (PPG) signal acquired by a wearable device, wherein the wearable device is worn on a specified part of a user body;

and the pressure adjusting module is used for adjusting the pressure value between the wearable device and the designated part if the acquired PPG signal does not accord with a preset condition, and reacquiring the PPG signal acquired by the wearable device after the pressure value is adjusted until the acquired PPG signal accords with the preset condition.

In a third aspect, an embodiment of the present application provides a terminal device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the method for acquiring a PPG signal as set forth in the first aspect of the embodiment of the present application is implemented.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the method for acquiring a PPG signal as set forth in the first aspect of the embodiment of the present application is implemented.

In a fifth aspect, an embodiment of the present application provides a computer program product, which when run on a terminal device, causes the terminal device to perform the method for acquiring a PPG signal according to any one of the above first aspects.

Compared with the prior art, the embodiment of the application has the advantages that: can improve the quality of PPG signal acquisition, and then improve blood oxygen detection's accuracy, it is convenient to implement moreover, has stronger practicality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

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

fig. 2 is a flowchart of a method for acquiring a PPG signal according to an embodiment of the present application;

fig. 3 is a flowchart of another method for acquiring 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 system diagram of an application of the method for acquiring a PPG signal according to an embodiment of the present application in an actual scene;

FIG. 6 is a schematic flow chart of the operation of the system of FIG. 5;

FIG. 7 is another schematic flow diagram of the operation of the system of FIG. 5;

fig. 8 is a schematic diagram of PPG signals respectively obtained when the wearable device is worn too tightly, too loosely and in 3 suitable cases on the user's wrist;

fig. 9 is a block diagram of an apparatus for acquiring a PPG signal according to an embodiment of the present disclosure;

fig. 10 is a schematic diagram of a terminal device according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular device structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

The terminology used in the following examples is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise. It should also be understood that in the embodiments of the present application, "one or more" means one, two, or more than two; "and/or" describes the association relationship of the associated objects, indicating that three relationships may exist; for example, a and/or B, may represent: a alone, both A and B, and B alone, where A, B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

The method for acquiring the PPG signal provided in the embodiment of the application may be applied to a mobile phone, a tablet computer, a wearable device, a vehicle-mounted device, an Augmented Reality (AR)/Virtual Reality (VR) device, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a Personal Digital Assistant (PDA), and other terminal devices or servers, and the embodiment of the application does not limit the specific types of the terminal devices and the servers.

For example, the terminal device may be a Station (ST) in a WLAN, which may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with Wireless communication capability, a computing device or other processing device connected to a Wireless modem, a vehicle-mounted device, a vehicle-mounted networking terminal, a computer, a laptop, a handheld communication device, a handheld computing device, a satellite Wireless device, a Wireless modem card, a television set-top box (STB), a Customer Premises Equipment (CPE), and/or other devices for communicating on a Wireless device and a next generation communication device, such as a Mobile terminal in a 5G Network or a Public Land Mobile Network (future evolved, PLMN) mobile terminals in the network, etc.

By way of example and not limitation, when the terminal device is a wearable device, the wearable device may also be a generic term for intelligently designing daily wearing by applying wearable technology, developing wearable devices, such as glasses, gloves, watches, bracelets, clothing, shoes, and the like. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable intelligent device has the advantages that the generalized wearable intelligent device is complete in function and large in size, can realize complete or partial functions without depending on a smart phone, such as a smart watch or smart glasses, and only is concentrated on a certain application function, and needs to be matched with other devices such as the smart phone for use, such as various smart bracelets for monitoring physical signs, smart jewelry and the like.

Taking the terminal device as a wearable device as an example. Fig. 1 is a block diagram illustrating a partial structure of a wearable device provided in an embodiment of the present application. Referring to fig. 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, a wireless fidelity (WiFi) module 107, a processor 108, a power supply 109, a light source 110, and a photodetector 111. Those skilled in the art will appreciate that the wearable device structure shown in fig. 1 does not constitute a limitation of the wearable device, and may include more or fewer components than those shown, or some components in combination, or a different arrangement of components.

The following describes each component of the wearable device in detail with reference to fig. 1:

the RF circuit 101 may be used for receiving and transmitting signals during information transmission and reception or during a call, and in particular, for receiving downlink information of a base station and then processing the received downlink information to the processor 108; in addition, the data for designing uplink is transmitted to the base station. Typically, the RF circuitry 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 circuitry 101 may also communicate with networks and other devices via wireless communications. The wireless communication may use any communication standard or protocol, including but not limited to Global System for Mobile communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE)), e-mail, Short Messaging Service (SMS), and the like.

The memory 102 may be used to store software programs and modules, and 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 program storage area and a data storage area, wherein the program storage area may store an operating device, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phone book, etc.) created according to the use of the wearable device, and the like. Further, the memory 102 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The input unit 103 may be used to receive input 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 referred to as a touch screen, may collect touch operations by a user (e.g., operations by a user on or near the touch panel 1031 using any suitable object or accessory such as a finger, a stylus, etc.) and drive corresponding connection devices according to a preset program. Alternatively, the touch panel 1031 may include two parts, a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, sends the touch point coordinates to the processor 108, and can receive and execute commands sent by the processor 108. In addition, the touch panel 1031 may be implemented by various types such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. The input unit 103 may include other input devices 1032 in addition to the touch panel 1031. In particular, other input devices 1032 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a track ball, a mouse, a joystick, or the like.

The display unit 104 may be used to display information input by or provided to the user and various menus of the wearable device. The Display unit 104 may include a Display panel 1041, and optionally, the Display panel 1041 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like. Further, the touch panel 1031 may cover the display panel 1041, and when the touch panel 1031 detects a touch operation on or near the touch panel 1031, the touch operation is transmitted to the processor 108 to determine the type of the touch event, and then the processor 108 provides a corresponding visual output on the display panel 1041 according to the type of the touch event. Although in fig. 1, the touch panel 1031 and the display panel 1041 are two separate components to implement the input and output functions of the wearable device, in some embodiments, the touch panel 1031 and the display panel 1041 may be integrated to implement the input and output functions of the wearable device.

The wearable device further comprises at least one pressure sensor 105, which may be used to detect the pressure the wearable device is wearing on the person, but may also comprise other types of sensors, such as light sensors, motion sensors, etc. Specifically, the light sensor may include an ambient light sensor that may adjust the brightness of the display panel 1041 according to the brightness of ambient light, and a proximity sensor that may turn off the display panel 1041 and/or the backlight when the wearable device is moved to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in each direction (generally, three axes), detect the magnitude and direction of gravity when stationary, and can be used for applications (such as horizontal and vertical screen switching, related games, magnetometer attitude calibration) for recognizing wearable device attitude, and related functions (such as pedometer and tapping) for vibration recognition; as for other sensors such as a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which can be further configured on the wearable device, detailed description is omitted here.

Audio circuitry 106, speaker 1061, microphone 1062 may provide an audio interface between the user and the wearable device. The audio circuit 106 may transmit the electrical signal converted from the received audio data to the speaker 1061, and convert the electrical signal into a sound signal for output by the speaker 1061; on the other hand, the microphone 1062 converts the collected sound signals into electrical signals, which are received by the audio circuit 106 and converted into audio data, which are processed by the audio data output processor 108, and then passed through the RF circuit 101 to be sent to, for example, another wearable device, or output to the memory 102 for further processing.

WiFi belongs to short-range wireless transmission technology, and the wearable device can help the user send and receive e-mails, browse web pages, access streaming media and the like through the WiFi module 107, and provides wireless broadband internet access for the user. Although fig. 1 shows the WiFi module 107, it is understood that it does not belong to the essential constitution of the wearable device, and can be omitted entirely as needed within the scope not changing the essence of the invention.

The processor 108 is a control center of the wearable device, connects various parts of the entire wearable device by various interfaces and lines, and performs various functions of the wearable device and processes data by running or executing software programs and/or modules stored in the memory 102 and calling up data stored in the memory 102, thereby performing overall monitoring of the wearable device. Alternatively, processor 108 may include one or more processing units; preferably, the processor 108 may integrate an application processor, which primarily handles operating devices, user interfaces, applications, etc., and a modem processor, which primarily handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 108.

The wearable device also includes a power supply 109 (e.g., a battery) for powering the various components, which may preferably be logically connected to the processor 108 via a power management device, such that the power management device may perform functions of managing charging, discharging, and power consumption.

The wearable device further comprises a light source 110, and specifically, the light source 110 may include an infrared light source and a red light source, which may respectively emit infrared light and red light, and the infrared light and the red light may pass through the wrist and other parts of the user, and may generate corresponding PPG signals, which may be used for blood oxygen detection.

The wearable device further comprises a photodetector 111 for collecting red PPG signals and infrared PPG signals generated by red light or infrared light passing through the wrist or the like of the user.

In addition, although not shown, the wearable device further includes a wearing component for wearing the wearable device on the user, specifically, the wearing component may be a watch strap, a watch buckle, or the like. In addition, the wearing part also comprises a pressure adjusting device which can adjust the pressure of the appointed part of the user wearing the wearable device.

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

201. acquiring a photoplethysmography (PPG) signal acquired by wearable equipment;

the execution subject of the embodiment of the present application may be a wearable device with blood oxygen detection function, such as a smart watch, a smart bracelet, and the like. 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, where the PPG signal detection module may include components such as a red light source, an infrared light source, and a photoelectric sensor. Firstly, the wearable device is worn on a specified part of the body of a user, such as a wrist, a neck and the like, and the heart rate of the user can be detected; then, a photoplethysmography signal (PPG signal) is acquired by the PPG signal detection module, specifically, a light source is controlled to emit light (infrared, red light, etc.) to the designated region, so as to generate a corresponding PPG signal, and then the PPG signal is acquired by the photosensor.

202. Judging whether the acquired PPG signal meets a preset condition or not;

after the PPG signal is acquired, whether the PPG signal meets a preset condition is judged. The preset conditions are quality conditions on the PPG signal preset to meet the accuracy requirement of blood oxygen detection, such as whether the number of peaks and troughs of the PPG signal meets the requirement, whether the characteristics of the respective peaks and troughs are obvious, and the like. Specifically, the PPG signal may be evaluated by using a signal quality evaluation module, and whether the PPG signal meets the signal quality requirement is determined by detecting features of the PPG signal, such as peak amplitude, cycle, peak distance, and peak number.

Specifically, whether the acquired PPG signal meets the preset condition may be determined by the following steps:

(1) matching the PPG signal with a pre-stored standard signal to obtain a matching degree, wherein the standard signal is the PPG signal which is associated with the user and has a signal characteristic meeting a preset requirement;

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

(3) and if the matching degree is smaller than the preset threshold value, determining that the PPG signal does not meet the preset condition.

(1) intercepting a target signal with a preset length from the PPG signal;

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

(3) and determining whether the PPG signal meets the preset condition or not according to the characteristics of the wave crest and the characteristics of the wave trough.

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

the first method is as follows:

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

(2) and if the number of the wave crests is smaller than a preset threshold value, or the number of the wave troughs is smaller than a preset threshold value, determining that the PPG signal does not meet the preset condition.

Generally speaking, a high-quality PPG signal should have a distinct periodic pulse wave signal characteristic, that is, a certain number of peaks and troughs should be provided in the signal. Therefore, whether the quality of the PPG signal meets the requirements can be determined by counting the number of peaks and the number of troughs: if the number of the wave crests or the wave troughs is too small, determining that the PPG signal does not meet the preset condition; and if the number of the peaks or the troughs is enough, determining that the PPG signal meets the preset condition.

The second method comprises the following steps:

(1) calculating the amplitude difference of any two adjacent wave crests in the target signal;

(2) and if the amplitude difference exceeds a preset threshold value, determining that the PPG signal does not meet the preset condition.

Consider another way that a high quality PPG signal, with the amplitude of each pulse wave, should be approximately the same. Therefore, it can be determined whether the quality of the PPG signal meets the requirements by calculating the amplitude difference of any two adjacent peaks in the target signal: if the amplitude difference exceeds a set threshold value, determining that the PPG signal does not meet the preset condition; and if the amplitude difference does not exceed a set threshold value, determining that the PPG signal meets the preset condition. It should be understood that there may be a plurality of amplitude differences, such as the amplitude difference between a and B and the amplitude difference between B and C for the peak a, the peak B and the peak C, and that all amplitude differences may be used or a certain number of amplitude differences may be selected in the determination.

The third method comprises the following steps:

(1) 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 the adjacent peak;

(2) and if the variance of the amplitude of each peak exceeds a preset threshold, or the variance of the peak width of each peak exceeds a preset threshold, or the variance of the peak distance between each peak and an adjacent peak exceeds a preset threshold, determining that the PPG signal does not meet the preset condition.

A high quality PPG signal having an amplitude, a peak width (peak width) and a peak distance (peak distance) between adjacent peaks of the respective pulse wave should be approximately the same, i.e. the variance of the amplitude of the respective peak, the variance of the peak width of the respective peak and the variance of the peak distance between the respective peak and the adjacent peak are small. Thus, it may be determined whether the quality of the PPG signal is satisfactory by calculating the variance of the amplitudes of the individual peaks, the variance of the peak widths of the individual peaks, and the variance of the peak distances between the individual peaks and adjacent peaks in the target signal: if the variances do not exceed the set threshold, determining that the PPG signal meets the preset condition; and if more than one of the variances exceeds a set threshold value, determining that the PPG signal does not meet the preset condition.

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

203. Adjusting a pressure value between the wearable device and the designated site;

the obtained PPG signal does not meet the preset condition, which indicates that the quality of the PPG signal is low, and the detection of blood oxygen cannot be completed by directly adopting the PPG signal at the moment. The reason for this problem is probably that the tightness of the wearable device worn by the user is not appropriate, for example, the arm is pressed by the user who wears the wearable device too tightly (the pressure value is too large), so that the blood flow perfusion is not normal, the local blood flow is reduced, and the PPG signal is abnormal; too loose a fit (too small a pressure value) results in weak and insignificant signal characteristics of the detected PPG signal. Thus, the quality of the obtained PPG signal may be adjusted and improved by adjusting the pressure value between the wearable device and the designated site. The specific operation mode may be that the pressure value between the wearable device and the designated portion is adjusted 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, the step 201 is executed again, that is, the PPG signal obtained under the current pressure condition is acquired again, then the quality of the acquired PPG signal is evaluated, if the quality meets the requirement, the step 204 is executed, if the quality does not meet the requirement, the pressure value between the wearable device and the designated part is adjusted again, and the above steps are repeated until the high-quality PPG signal meeting the requirement is obtained.

204. The subsequent blood oxygen detection operation steps are executed.

The acquired PPG signal meets the preset condition, which shows that the PPG signal is stable and reliable, and meets the signal quality requirement of blood oxygen detection, and at the moment, the PPG signal can be output to execute the subsequent blood oxygen detection process.

Fig. 3 shows a flowchart of another method for acquiring a PPG signal provided in the present application, which includes:

301. determining a user account currently logged in by the wearable device;

in this embodiment of the application, a user can log in his or her user account in the wearable device, and wear the wearable device on a designated part of his or her body, such as a wrist, a neck, or other parts where the heart rate of the user can be detected. Before the wearable device acquires the PPG signal, the current logged user account is determined to search the historical blood oxygen detection record of the user, a more reasonable initial pressure recommendation value of the user can be obtained through the historical blood oxygen detection record, and a more proper pressure value of the wearable device worn on the user can be obtained.

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

after determining a user account to which the wearable device is currently logged in, looking up a target pressure value associated with the user account. If the user account has performed the blood oxygen detection before, the pressure value of the wearable device worn by the user in the previous effective blood oxygen detection of a certain time can be recorded as a target pressure value, and the target pressure value is associated with the user account and stored in a certain pressure reference value database. Upon secondary blood oxygenation detection, the wearable device may look up from the database whether there is a target pressure value associated with the currently logged-in user account.

303. Judging whether the target pressure value is found;

determining whether a target pressure value associated with the user account can be found, if the target pressure value is found, executing step 304, and if the target pressure value is not found, directly executing step 305, or adjusting a pressure value between the wearable device and the designated portion to be near a default recommended pressure value, and then executing step 305.

304. Adjusting a pressure value between the wearable device and the designated part to be the target pressure value;

and after the target pressure value is found, adjusting the pressure value between the wearable device and the specified part to be the target pressure value, and acquiring a corresponding PPG signal on the basis. It should be understood that, the target pressure value may be used as the center of the range interval, a pressure range interval which floats up and down may be constructed, and the pressure value between the wearable device and the designated portion may be adjusted to fall within the pressure range interval. In addition, if the target pressure value is not found, a preset default pressure value may be used as the center of the pressure range.

305. Acquiring a photoplethysmography (PPG) signal acquired by the wearable device;

306. judging whether the acquired PPG signal meets a preset condition or not;

if the preset condition is met, go to step 308; if the predetermined condition is not met, go to step 307.

307. Adjusting a pressure value between the wearable device and the designated site;

and if the PPG signal does not meet the preset condition, adjusting the pressure value between the wearable device and the designated part, and returning to execute step 305 after the pressure value is adjusted.

308. The subsequent blood oxygen detection operation steps are executed.

The detailed description of

steps

305 and 308 can refer to the related description of

steps

201 and 204 in the previous embodiment.

Further, in step 308, the method may further include:

(1) if the acquired PPG signal meets the preset condition, detecting and recording a pressure value between the wearable device and the specified part;

(2) associating the recorded pressure values with the user account.

In the secondary blood oxygen detection, if the acquired PPG signal meets the preset condition, that is, the PPG signal is more stable and reliable, and meets the signal quality requirement of blood oxygen detection, the pressure value between the wearable device and the designated part can be detected and recorded at the moment, and then the recorded pressure value is associated with the user account and stored in the pressure reference value database. For a user account associated with a target pressure value, the target pressure value may be updated with the currently detected and recorded pressure value. For user accounts that are not associated with a target pressure value, the currently detected and recorded pressure value may be employed as the associated target pressure value.

Before the PPG signal is acquired, a user account where the wearable device is currently logged in is determined, a target pressure value associated with the user account is searched, and a pressure value between the wearable device and the designated part is adjusted to be the target pressure value. Through setting up like this, can adjust the pressure value that wearable equipment wore in advance to a more reasonable numerical value to improve the probability that obtains high-quality PPG signal, reduce in the follow-up operation because many times, the repetitious pressure adjustment process that the unsatisfactory results in of PPG signal quality.

Fig. 4 shows a flowchart of another method for acquiring a PPG signal provided herein, which includes:

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

after a user wears a wearable device for blood oxygen detection, a pressure value between the wearable device and a designated part of the user's body is detected. For example, for wearable devices such as a watch, a bracelet, etc., then 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 into a preset pressure range interval, adjusting the tightness of the wearable device worn at the designated part until the pressure value between the wearable device and the designated part falls into the pressure range interval;

if the pressure value between the wearable device and the designated part does not fall into the preset pressure range interval, the current wearing tightness of the wearable device is not proper, and at the moment, the tightness of the wearable device worn at the designated part can be adjusted until the pressure value between the wearable device and the designated part falls into 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 one: wearable equipment wears the part and is the watchband, the length of watchband is flexible under the drive of motor, the adjustment wearable equipment wear in the elasticity of appointed position department includes:

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

(2) under the driving of the rotation of the motor, the length of the watchband is controlled to stretch, so that the tightness of the wearable device worn on the designated position is adjusted.

When the wearing pressure of wearable equipment needs to be increased, a control instruction can be sent to the motor, the motor is controlled to rotate, the length of the wearing part of the watchband is driven to shrink, and the wearing tightness is improved, so that the wearing pressure is increased. When the wearing pressure needs to be reduced, a control instruction can be sent to the motor, the motor is controlled to rotate reversely, the length of the wearing part of the watchband is driven to extend, the wearing tightness is reduced, and therefore the wearing pressure is reduced.

Example two: wearable equipment wear the part and be hollow watchband, watchband internally mounted has the gasbag, the gasbag is realized filling the gassing under the effect of air pump, the adjustment wearable equipment wear in the elasticity of appointed position department can include:

and sending a control instruction to the air pump to control the air pump to perform inflation and deflation operation on the air bag, so that the tightness of the wearable device worn at the specified position is adjusted.

When the wearing pressure of the wearable device needs to be increased, a control instruction can be sent to the air pump, the air pump is controlled to inflate the air bag, the watchband is made to expand, and therefore the wearing pressure is increased. When the wearing pressure needs to be reduced, a control instruction can be sent to the air pump, the air pump is controlled to deflate the air bag, the watchband is contracted, and therefore the wearing pressure is reduced.

403. Acquiring a photoplethysmography (PPG) signal acquired by the wearable device;

404. judging whether the acquired PPG signal meets a preset condition or not;

if the PPG signal meets the predetermined condition, go to step 406; if the predetermined condition is not met, go to step 405.

405. Adjusting a pressure value between the wearable device and the designated site;

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

406. The subsequent blood oxygen detection operation steps are executed.

The detailed description of

steps

403 and 406 can refer to the related description of

steps

201 and 204.

Before the PPG signal is obtained, a pressure value between the wearable device and a designated part of the body of a user is detected, and if the pressure value between the wearable device and the designated part does not fall into a preset pressure range interval, the tightness of the wearable device worn at the designated part is adjusted until the pressure value between the wearable device and the designated part falls into the pressure range interval. Through setting up like this, can adjust the pressure value that wearable equipment wore in advance to a more reasonable numerical value to improve the probability that obtains high-quality PPG signal, reduce in the follow-up operation because many times, the repetitious pressure adjustment process that the unsatisfactory results in of PPG signal quality.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

For ease of understanding, the method for acquiring PPG signals proposed in the present application is described below in several practical application scenarios.

Fig. 5 is a schematic system diagram of an application of the method for acquiring a PPG signal in an actual scene according to the embodiment of the present application.

In fig. 5, the wearable device for blood oxygen detection includes 4 functional modules, such as a pressure detection module, a PPG detection module (including a red light source, an infrared light source, a photodetector, etc.), a pressure adjustment module, and a signal quality evaluation module. The pressure detection module is used for detecting the pressure of the wearable device worn on the wrist and other parts of the user in real time and is realized by adopting a pressure sensor; the PPG detection module is used for detecting and collecting PPG signals generated after red light and infrared light pass through the wrist; the signal quality evaluation module is used for evaluating whether the quality of the currently acquired PPG signal meets the requirement, if not, the pressure of the wearable device worn on the wrist and other parts is adjusted through the pressure adjustment module, the PPG signal under the current pressure condition is acquired again after the pressure adjustment, the signal quality evaluation module continues to evaluate the quality of the newly acquired PPG signal, and the process is repeated until the PPG signal with the signal quality meeting the requirement is obtained for subsequent blood oxygen calculation. Specifically, the pressure adjustment module can be used for adjusting the pressure, such as using a whole inflatable/deflatable watchband, using a part inflatable/deflatable watchband, using a length-adjustable watchband, and so on.

FIG. 6 is a schematic flow chart illustrating the operation of the system of FIG. 5, wherein the user initiates the blood oxygen detection process after wearing the wearable device; then, the pressure of the designated parts such as the wrist of the user is detected, and whether the pressure is in a preset pressure range interval is judged; if not, starting the pressure adjusting module to adjust the pressure of the wearable device worn on the wrist and other parts until the pressure is within the pressure range interval; after the pressure is continuously and stably in the pressure range interval, starting a PPG signal quality evaluation module, acquiring a PPG signal acquired under the current pressure condition for evaluation, and judging whether the PPG signal meets the quality condition; if the quality condition is met, the blood oxygen value can be calculated by adopting the PPG signal, and the result of blood oxygen detection is finally obtained; if the quality condition is not met, the pressure adjusting module is continuously started to adjust the pressure of the wearable device worn on the wrist and other parts, the PPG signal acquired after the pressure adjustment is acquired again for evaluation, and the steps are repeated until the PPG signal meeting the quality condition is obtained.

Fig. 7 is another schematic flow chart of the operating principle of the system shown in fig. 5, in which after the user wears the wearable device, the blood oxygen detection process is started, the best detected pressure value (i.e., the target pressure value) in the historical blood oxygen detection process of the user is searched from the pre-constructed pressure reference database, and if the target pressure value exists in the database, the target pressure value is extracted as the central threshold value of the pressure range interval; if the target pressure value does not exist in the database, a default pressure value of the system is adopted as a central threshold value of the pressure range interval. Next, detecting the pressure of the designated part such as the wrist of the user, and determining whether the pressure is within the pressure range interval, the subsequent processing flow is basically the same as the flow shown in fig. 6, and the only difference is that after collecting the PPG signal meeting the quality condition, the pressure of the part such as the wrist worn by the current wearable device is detected and recorded in the pressure reference database, and is taken as a new target pressure value bound with the user. By adopting the mode, after the user uses the wearable device for a period of time, the optimal measurement pressure value matched with the user can be automatically called and adjusted according to the historical pressure adjustment value of the user, and the rapid and intelligent blood oxygen measurement of accurately matching the individual characteristics of the user and the use habit is realized.

Fig. 8 is a schematic diagram of PPG signals respectively obtained when the wearable device is worn on the wrist of the user under 3 cases of over-tightness, over-looseness and suitability. In fig. 8, the abscissa of each PPG signal image and the real-time pressure image is time. In fig. 8, the upper left side is the PPG signal image obtained when the patient is worn too tightly, and the upper right side is the real-time pressure image detected when the patient is worn too tightly, it can be seen that the detected real-time pressure is obviously higher than the recommended standard pressure, which results in a relatively sharp PPG signal, which is an abnormal condition. The left lower part of fig. 8 is the PPG signal image obtained and the real-time pressure image detected when the wearing is too loose, and it can be seen that the detected real-time pressure is significantly lower than the recommended standard pressure, which results in a very weak PPG signal, which is also an abnormal condition. By adopting the pressure self-adjusting mode provided by the application, the pressure of the wearable device worn by the user can be adjusted to be close to the proper standard pressure, the finally obtained PPG signal image and the detected real-time pressure image are shown in the lower right of the graph 8, it can be seen that the detected real-time pressure is close to the standard pressure, the obtained PPG signal has obvious characteristics, and the quality meets the requirements.

Corresponding to the method for acquiring a PPG signal described in the above embodiments, fig. 9 shows a block diagram of a device for acquiring a PPG signal provided in an embodiment of the present application, and for convenience of illustration, only the parts related to the embodiment of the present application are shown.

Referring to fig. 9, the apparatus includes:

a signal acquisition module 501, configured to acquire a photoplethysmography (PPG) signal acquired by a wearable device, where the wearable device is worn on a specified part of a user's body;

a pressure adjusting module 502, configured to adjust a pressure value between the wearable device and the designated part if the obtained PPG signal does not meet a preset condition, and reacquire the PPG signal acquired by the wearable device after the pressure value is adjusted until the obtained PPG signal meets the preset condition.

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

the user account determination module is used for determining a user account currently logged in by the wearable device;

a target pressure value searching module for searching a target pressure value associated with the user account;

and the pressure adjusting module is used for adjusting the pressure value between the wearable device and the specified part to be the target pressure value if the target pressure value is found.

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

the pressure value recording module is used for detecting and recording a current pressure value between the wearable device and the specified part if the acquired PPG signal meets the preset condition;

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

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

the signal matching module is used for matching the PPG signal with a pre-stored standard signal to obtain a matching degree, wherein the standard signal is the PPG signal which is associated with the user and has a signal characteristic meeting a preset requirement;

the first signal evaluation module is used for determining that the PPG signal meets the preset condition if the matching degree is greater than or equal to a preset threshold;

and the second signal evaluation module is used for determining that the PPG signal does not meet the preset condition if the matching degree is smaller than the preset threshold.

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

the signal interception module is used for intercepting a target signal with a preset length from the PPG signal;

the signal characteristic detection module is used for detecting the wave crest and the wave trough of the target signal;

and the third signal evaluation module is used for determining whether the PPG signal meets the preset condition or not according to the characteristics of the wave crests and the characteristics of the wave troughs.

Still further, the third signal evaluation module may include:

the number counting unit is used for counting the number of the wave crests and the number of the wave troughs;

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

the amplitude difference calculating unit is used for calculating the amplitude difference of any two adjacent wave crests 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;

a variance calculating unit for calculating a variance of the amplitude of each peak, a variance of the peak width of each peak, and a variance of the peak distance between each peak and an adjacent peak in the target signal, respectively;

and the third signal evaluation unit is used for determining that the PPG signal does not meet the preset condition if the variance of the amplitude of each peak exceeds a preset threshold, or the variance of the peak width of each peak exceeds a preset threshold, or the variance of the peak distance between each peak and an adjacent peak exceeds a preset threshold.

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

the pressure detection module is used for detecting a pressure value between the wearable device and the designated part;

and the tightness adjusting module is used for adjusting the tightness of the appointed part of the wearable equipment if the pressure value between the wearable equipment and the appointed part does not fall into a preset pressure range interval, until the pressure value between the wearable equipment and the appointed part falls into the pressure range interval.

An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the computer program implements the steps of the methods for acquiring a PPG signal as proposed in the present application.

An embodiment of the present application further provides a computer program product, which, when running on a terminal device, enables the terminal device to execute the steps of the methods for acquiring a PPG signal provided in the present application.

Fig. 10 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 10, the terminal device 6 of this embodiment includes: at least one processor 60 (only one shown in fig. 10), a memory 61, and a computer program 62 stored in said memory 61 and executable on said at least one processor 60, said processor 60 implementing the steps in any of the above described method embodiments of acquiring PPG signals when executing said computer program 62.

The terminal device 6 may be a mobile phone, a wearable device, a desktop computer, a notebook, a palm computer, a cloud server, or other computing devices. The terminal device may include, but is not limited to, a processor 60, a memory 61. Those skilled in the art will appreciate that fig. 10 is merely an example of the terminal device 6, and does not constitute a limitation to the terminal device 6, and may include more or less components than those shown, or combine some components, or different components, such as an input/output device, a network access device, and the like.

The Processor 60 may be a Central Processing Unit (CPU), and the Processor 60 may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 61 may in some embodiments be an internal storage unit of the terminal device 6, such as a hard disk or a memory of the terminal device 6. The memory 61 may also be an external storage device of the terminal device 6 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, which are equipped on the terminal device 6. Further, the memory 61 may also include both an internal storage unit and an external storage device of the terminal device 6. The memory 61 is used for storing operating means, applications, bootloaders (bootloaders), data and other programs, such as program codes of the computer programs. The memory 61 may also be used to temporarily store data that has been output or is to be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the above-mentioned apparatus may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, and for example, the division of the modules or units is only one logical functional division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another device, 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 physically, or two or more units are 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, all or part of the processes in the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium and can implement the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or apparatus capable of carrying computer program code to a terminal device, recording medium, computer Memory, Read-Only Memory (ROM), Random-Access Memory (RAM), electrical carrier wave signals, telecommunications signals, and software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc. In certain jurisdictions, computer-readable media may not be an electrical carrier signal or a telecommunications signal in accordance with legislative and patent practice.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A method of acquiring a PPG signal, comprising:

2. The method of acquiring a PPG signal of claim 1, further comprising, prior to acquiring the photoplethysmographic PPG signal acquired by the wearable device:

determining a user account currently logged in by the wearable device;

searching for a target pressure value associated with the user account;

3. The method of acquiring a PPG signal according to claim 2, further comprising, after acquiring the photoplethysmographic PPG signal acquired by the wearable device:

associating the recorded pressure values with the user account.

4. The method of acquiring a PPG signal according to claim 1, wherein whether the PPG signal acquired meets the preset condition is determined by:

5. The method of acquiring a PPG signal according to claim 1, wherein whether the PPG signal acquired meets the preset condition is determined by:

intercepting a target signal with a preset length from the PPG signal;

detecting peaks and troughs of the target signal;

6. The method of acquiring a PPG signal according to claim 5, wherein said determining whether the PPG signal meets the preset condition based on the characteristics of the peaks and the characteristics of the valleys comprises:

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

or

7. The method of acquiring a PPG signal according to any of claims 1 to 6, further comprising, prior to acquiring the photoplethysmographic PPG signal acquired by the wearable device:

8. An apparatus for acquiring a PPG signal, comprising:

9. Terminal device comprising a memory, a processor and a computer program stored in said memory and executable on said processor, characterized in that said processor, when executing said computer program, implements the steps of the method of acquiring PPG signals according to any of claims 1 to 7.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method of acquiring a PPG signal according to any of claims 1 to 7.