Ultrasonic finger heart rate measurement method and device, electronic equipment and storage medium

Abstract

Embodiments of the present application provide an ultrasonic finger heart rate measurement method, device, electronic equipment and storage medium. The ultrasonic finger heart rate measurement method comprises: acquiring a corresponding relationship function of an echo signal and a time of flight when a finger presses the screen, and determining a target time of flight according to the corresponding relationship function, wherein the time of flight is the time experienced by an ultrasonic wave signal from emission to reception; emitting an ultrasonic wave signal to the finger, receiving a current echo frame carrying fingerprint information of the finger returned by the finger according to the target time of flight; determining a time domain sampling signal according to the interframe difference between the current echo frame and a reference frame; and calculating a heart rate value according to the time domain sampling signal. Through the above steps, heart rate measurement can be realized through a finger on the basis of an ultrasonic fingerprint device.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic signal processing technology, and in particular to an ultrasonic finger heart rate measurement method, device, electronic device and storage medium. Background Technology

[0002] With the rapid development of the electronic equipment industry, the demand for biometric technology is increasing in various fields. Fingerprint recognition, as one of the most important identification methods, has mature fingerprint acquisition solutions including optical and capacitive methods. In recent years, ultrasonic fingerprint technology has emerged as a new direction for fingerprint development.

[0003] In optical fingerprint chips, heart rate can be measured using photoplethysmography. However, ultrasonic fingerprint chips use acoustic technology, which cannot measure heart rate signals using optical principles. A new method is needed to measure a person's heart rate signal simultaneously with ultrasonic fingerprint recognition. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an ultrasonic finger heart rate measurement method, apparatus, electronic device, and storage medium to at least partially solve the above-mentioned problems.

[0005] According to a first aspect of the present invention, an ultrasonic finger heart rate measurement method is provided, applied to an ultrasonic fingerprint device, the ultrasonic fingerprint device being disposed under the cover of an electronic device to realize under-screen ultrasonic fingerprint recognition, comprising: when a finger presses the screen, acquiring a correspondence function between echo signals and time of flight, and determining a target time of flight according to the correspondence function, wherein the time of flight is the time taken for the ultrasonic signal to be transmitted from emission to reception; transmitting an ultrasonic signal to the finger, and receiving a current echo frame carrying the fingerprint information of the finger returned by the finger according to the target time of flight; determining a time-domain sampling signal according to the inter-frame difference between the current echo frame and a reference frame; and calculating a heart rate value according to the time-domain sampling signal.

[0006] In another implementation of the present invention, determining the target flight time according to the correspondence function includes: determining the peak value of the correspondence function according to the correspondence function; determining the target flight time according to the peak value of the correspondence function, wherein the target flight time is the flight time corresponding to obtaining the maximum echo signal.

[0007] In another implementation of the present invention, the method further includes: calculating the inter-frame difference between the current echo frame and the previous echo frame; if the difference satisfies the inter-frame difference threshold, then the current echo frame is used as a reference frame.

[0008] In another implementation of the present invention, the step of using the current echo frame as a reference frame if the difference satisfies the inter-frame difference threshold includes: calculating the continuous count value of the current echo frame that satisfies the inter-frame difference threshold; when the continuous count value satisfies the counting threshold, using any current echo frame that satisfies the inter-frame difference threshold corresponding to the continuous count value as a reference frame.

[0009] In another implementation of the present invention, determining the time-domain sampling signal based on the inter-frame difference between the current echo frame and the reference frame includes: calculating a reference difference between the current echo frame and the reference frame, using the reference difference as the time-domain sampling data of the current echo frame; and determining the time-domain sampling signal based on the time-domain sampling data.

[0010] In another implementation of the present invention, the step of using the reference difference as the temporal sampling data of the current echo frame includes: when the reference difference meets the reference difference threshold, using the reference difference as the temporal sampling data of the current echo frame.

[0011] In another implementation of the present invention, the step of calculating the heart rate value based on the time-domain sampled signal includes: filtering the time-domain sampled signal to obtain a filtered time-domain sampled signal; and calculating the heart rate value based on the filtered time-domain sampled signal.

[0012] According to a second aspect of the present invention, an ultrasonic finger heart rate measurement device is provided, comprising: a time-of-flight determination module, configured to acquire a correspondence function between echo signals and time of flight when a finger presses the screen, and determine a target time of flight based on the correspondence function, wherein the time of flight is the time elapsed from the transmission of an ultrasonic signal to its reception; an ultrasonic transceiver module, configured to transmit an ultrasonic signal to the finger and receive a current echo frame carrying fingerprint information of the finger returned by the finger according to the target time of flight; a sampling signal processing module, configured to determine a time-domain sampling signal based on the inter-frame difference between the current echo frame and a reference frame; and a heart rate value calculation module, configured to calculate a heart rate value based on the time-domain sampling signal.

[0013] According to a third aspect of the present invention, an electronic device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, which causes the processor to perform an operation corresponding to the method described in the first aspect.

[0014] According to a fourth aspect of the present invention, a computer storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0015] In this embodiment of the invention, the ultrasonic echo signal obtained when a finger presses the screen is used to calculate the human heart rate simultaneously with fingerprint recognition. This allows the ultrasonic fingerprint device to add heart rate detection functionality without increasing hardware costs, and simultaneously enhances the heart rate detection capabilities of various portable electronic devices using this ultrasonic fingerprint device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 This is a flowchart of the steps of an ultrasonic finger heart rate measurement method according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram illustrating the principle of fingerprint recognition in an electronic device with an ultrasonic fingerprinting device according to an embodiment of the present invention.

[0019] Figure 3 This is a flowchart illustrating the steps for determining the target flight time according to an embodiment of the present invention.

[0020] Figure 4 This is a flowchart illustrating the steps for determining a reference frame according to an embodiment of the present invention.

[0021] Figure 5 This is a flowchart illustrating the steps of converting the current echo frame received according to the target flight time into a time-domain sampled signal, according to an embodiment of the present invention.

[0022] Figure 6 This is a flowchart illustrating the steps of obtaining a heart rate value from a time-domain sampled signal according to an embodiment of the present invention.

[0023] Figure 7 This is a waveform diagram of a time-domain sampled signal according to an embodiment of the present invention.

[0024] Figure 8 This is a flowchart illustrating the steps of heart rate calculation according to an embodiment of the present invention.

[0025] Figure 9 This is a functional structural diagram of an ultrasonic finger heart rate measuring device according to an embodiment of the present invention.

[0026] Figure 10 This is a schematic diagram of the hardware framework of an ultrasonic finger heart rate measurement system according to an embodiment of the present invention.

[0027] Figure 11 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0029] It should be understood that the terms "first," "second," and "third," etc., in the claims, specification, and drawings of this disclosure are used to distinguish different objects, not to describe a specific order. The terms "comprising" and "including" as used in the specification and claims of this disclosure indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets thereof.

[0030] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure. As used in this disclosure and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this disclosure and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0031] The human finger structure is mainly composed of phalanges, tendons, muscles, nerves, and blood vessels. The blood vessels in the finger contract and dilate rhythmically with the heart rate, causing regular changes in the blood vessels, muscles, and other tissues. This invention uses ultrasound waves emitted into the inside of the finger to receive the reflected signals. By analyzing the reflected signal images, regular tissue changes are extracted, and the heart rate is calculated.

[0032] Explanation of the working principle: Because different parts of the finger structure have different reflectivities for sound waves, the phalanges are the most sensitive to sound waves. To acquire better echoes from the finger tissue, the flight time of the ultrasound waves needs to be adjusted to a value near the phalanges, resulting in the strongest ultrasound echoes.

[0033] An ultrasonic fingerprint device can be an ultrasonic chip, which is an array of pixels with a resolution of M*N. Each pixel can individually emit and receive ultrasonic waves. When the chip is working, each pixel starts to generate ultrasonic waves through an ultrasonic transducer. After the generation is completed, a sound wave transmission time is defined as the fly time. Then, the ultrasonic transducer of the pixel starts to receive the ultrasonic echo and converts the sound wave signal into an electrical signal. The M*N image acquired by the ultrasonic chip is the echo image of the sound, also known as the echo frame.

[0034] The tissues of the fingers expand and contract rhythmically with the heartbeat. These muscle movements cause a regular change in the transmission medium of the ultrasound signal as it reaches the finger. This, in turn, affects the phase of the sound echo. The ultrasound chip maintains a frame rate of n and an integration time of t. Integrating the same number of frames at a fixed frame rate over the finger for the same fly time, the echoes with phase changes are captured as a single frame, known as an echo frame. By analyzing consecutive frames of the ultrasound echo signal and calculating the regular echo changes between them, the heart rate in the finger can be extracted.

[0035] Figure 1 An exemplary flow diagram of an ultrasonic finger heart rate measurement method according to an embodiment of the present invention is shown. This ultrasonic finger heart rate measurement method is applied to an ultrasonic fingerprint device, which is disposed under the cover of an electronic device to achieve under-display ultrasonic fingerprint recognition, including:

[0036] S210: When a finger presses the screen, the correspondence function between the echo signal and the flight time is obtained, and the target flight time is determined according to the correspondence function, wherein the flight time is the time taken for the ultrasonic signal to be transmitted from emission to reception.

[0037] When necessary, such as Figure 2 As shown, ultrasound heart rate measurement requires transmitting ultrasound signals to the phalanges of the fingers to obtain a strong echo signal. For example, ultrasound waves generated by an ultrasound transducer penetrate the cover plate and enter the finger, where a strong echo signal is reflected back to the transducer after reaching the phalanges. To accommodate different fingers, it is necessary to measure and determine an appropriate fly time, i.e., a target fly time, after the finger is pressed down, so that the measured echo signal is the strongest echo signal near the phalanges.

[0038] The process for determining the target flight time, such as Figure 3As shown. The process begins (S2101); it is determined whether a finger is pressing the screen (S2102); when a finger presses the screen, the ultrasonic fingerprint device acquires an echo frame of an image with a flight time T1 as the starting point (S2103); image acquisition continues with a step time of T3 (S2104); it is determined whether the flight time is still within the T1-T2 interval (S2105); the peak value of the echo signal within the T1-T2 interval is selected as the target flight time used when measuring the heart rate of the current finger (S2106). The T1-T2 interval can be a manually determined empirical value.

[0039] S220: Emit an ultrasonic signal to the finger, and receive the current echo frame carrying the fingerprint information of the finger returned by the finger according to the target flight time.

[0040] S230: Determine the time-domain sampling signal based on the inter-frame difference between the current echo frame and the reference frame.

[0041] S240: Calculate the heart rate value based on the time-domain sampled signal.

[0042] In this embodiment of the invention, the ultrasonic echo signal obtained when a finger presses the screen is used to calculate the human heart rate simultaneously with fingerprint recognition. This allows the ultrasonic fingerprint device to add heart rate detection functionality without increasing hardware costs, and simultaneously enhances the heart rate detection capabilities of various portable electronic devices using this ultrasonic fingerprint device.

[0043] In one possible implementation, determining the target flight time based on the correspondence function includes: determining the peak value of the correspondence function based on the correspondence function; and determining the target flight time based on the peak value of the correspondence function, wherein the target flight time is the flight time corresponding to obtaining the maximum echo signal.

[0044] In one possible implementation, the method further includes: calculating the inter-frame difference between the current echo frame and the previous echo frame;

[0045] If the difference satisfies the inter-frame difference threshold, then the current echo frame is used as the reference frame.

[0046] In one possible implementation, the step of using the current echo frame as a reference frame if the difference satisfies the inter-frame difference threshold includes: calculating a continuous count value of the current echo frame that satisfies the inter-frame difference threshold; and when the continuous count value satisfies the counting threshold, using any current echo frame that satisfies the inter-frame difference threshold corresponding to the continuous count value as a reference frame.

[0047] It should be noted that in order to extract regular heart rate signals between echo frames, stable echo frames need to be selected as reference frames. The changes in finger tissue are fastest during the moment of heart contraction, and the finger tissue tends to be stable during heart diastole. Frames at the stable time are used as reference frames.

[0048] The difference between two frames can be determined by calculating the difference between each corresponding pixel in the current echo frame and the previous echo frame. This difference is quantified, and the time point of the current echo frame where the continuous count value meets the counting threshold TH3 is selected as the diastolic time point. The average of the current echo frames where the count value meets the counting threshold TH3 is used as the reference frame. After the reference frame is determined, all acquired images will be calculated using this reference frame as the benchmark. Since images are continuously acquired, it is determined whether the reference frame condition is met after each acquired frame. If the reference frame condition is met, a new reference frame needs to be determined.

[0049] Specifically, the process for obtaining the reference frame is as follows: Figure 4 As shown. The process begins (S41); the current echo frame is acquired (S42); the difference between the corresponding pixels of the current echo frame and the previous echo frame is calculated, and the absolute value of the difference is taken as the inter-frame difference (S43); it is determined whether the proportion of the inter-frame difference that is less than the inter-frame interpolation threshold TH1 is less than the proportion threshold TH2 (S44); if the proportion is less than the proportion threshold TH2, the reference frame determination condition is not met, and the process returns to step S42 to continue acquiring the next echo frame; if the proportion is greater than or equal to the proportion threshold TH2, the continuous count value of the current echo frame that meets the inter-frame difference threshold is calculated (S46); it is determined whether the continuous count value is greater than or equal to the counting threshold TH3 (S46); if the continuous count value is less than the counting threshold TH3, the count value is set to zero (S47), and the process returns to step S42; if the continuous count value is greater than or equal to the counting threshold TH3, any current echo frame that meets the inter-frame difference threshold corresponding to the continuous count value is taken as the reference frame (Base) (S48).

[0050] In one possible implementation, determining the time-domain sampling signal based on the inter-frame difference between the current echo frame and the reference frame includes: calculating a reference difference between the current echo frame and the reference frame, using the reference difference as the time-domain sampling data of the current echo frame; and determining the time-domain sampling signal based on the time-domain sampling data.

[0051] It should be noted that steps S220 and S230 can be processed in parallel. The echo frames in step S220 will be continuously received at fixed intervals, and the determination of the time-domain sampling signal in step S230 can be performed once every 1 second.

[0052] In one possible implementation, using the reference difference as the temporal sampling data of the current echo frame includes: when the reference difference meets a reference difference threshold, using the reference difference as the temporal sampling data of the current echo frame.

[0053] It should be noted that in order to extract the heart rate in the time domain, each echo frame needs to be converted into a sample data point in the time domain. The specific conversion method is as follows: Figure 5 As shown. The process begins (S51); the current echo frame is acquired (S52); the reference frame is updated (S53); the difference between each pixel corresponding to the current echo frame and the reference frame is calculated. Since the phase change of the echo frame can be positive or negative, the absolute value of the difference needs to be taken. Then, the absolute values ​​of all differences are averaged. If the average value is greater than the reference difference threshold TH4, the average value is used as the sampling data of the current echo frame in the time domain (S54).

[0054] In one possible implementation, such as Figure 6 As shown, step S240 includes: step S2401, filtering the time-domain sampled signal to obtain a filtered time-domain sampled signal; step S2402, calculating the heart rate value based on the filtered time-domain sampled signal.

[0055] It should be noted that the time-domain sampled signal can be used for heart rate calculation in seconds, that is, calculated once per second. The time-domain sampled signal is as follows: Figure 7 As shown.

[0056] Specifically, the heart rate calculation process is as follows: Figure 8 As shown. The process begins (S81); a smoothed filter curve is calculated for the time-domain sampled signal (original signal), with the filtering window being the minimum heart rate cycle. This smoothed filter curve serves as the DC component of the signal (S82); the smoothed DC curve is subtracted from the original signal curve to obtain the AC signal curve containing heart rate information (S83); a Fourier transform is performed on the AC curve, followed by bandpass filtering, and f is taken as the signal component. min <f<f max , where f min and f max Let S1 represent the minimum and maximum heart rate frequencies (e.g., 0.6 and 4, respectively). After filtering, an inverse transform is performed to obtain the filtered curve (S84). Autocorrelation is calculated on the filtered curve to obtain the autocorrelation curve (S85). The peaks and troughs of the autocorrelation curve are determined (S86). The heart rate value is calculated (S87) using the following formula: Where f sample The sampling rate of the ultrasound chip images is the reciprocal of the fixed interval T between each frame of image acquisition. N is the average value of the peak or trough interval.

[0057] Preferably, the filtered time-domain sampled signal is subjected to autocorrelation calculation to obtain an autocorrelation signal; the heart rate value is calculated based on the autocorrelation signal.

[0058] Figure 9 This is a schematic block diagram of an ultrasonic finger heart rate measuring device according to another embodiment of the present invention. The solutions of this embodiment can be applied to electronic devices, including but not limited to: terminal devices with communication functions or electronic devices with interactive capabilities.

[0059] The ultrasonic finger heart rate measurement device of this embodiment includes: a time-of-flight determination module, used to acquire a correspondence function between echo signals and time of flight when a finger presses the screen, and determine a target time of flight based on the correspondence function, wherein the time of flight is the time taken for the ultrasonic signal to travel from transmission to reception; an ultrasonic transceiver module, used to transmit ultrasonic signals to the finger and receive a current echo frame carrying the fingerprint information of the finger returned by the finger according to the target time of flight; a sampling signal processing module, used to determine a time-domain sampling signal based on the inter-frame difference between the current echo frame and a reference frame; and a heart rate value calculation module, used to calculate a heart rate value based on the time-domain sampling signal.

[0060] In other examples, the flight time determination module is specifically used to: determine the peak value of the correspondence function based on the correspondence function; and determine the target flight time based on the peak value of the correspondence function.

[0061] In other examples, the sampling signal processing module is specifically used to: calculate the inter-frame difference between the current echo frame and the previous echo frame, and use the current echo frame that meets the inter-frame difference threshold as the reference frame.

[0062] In other examples, the sampling signal processing module is specifically used to: calculate the continuous count value of the current echo frame that satisfies the inter-frame difference threshold; when the continuous count value satisfies the counting threshold, take any current echo frame that satisfies the inter-frame difference threshold corresponding to the continuous count value as a reference frame.

[0063] In other examples, the sampling signal processing module is specifically used to: calculate the reference difference between the current echo frame and the reference frame, use the reference difference as the time-domain sampling data of the current echo frame, and determine the time-domain sampling signal based on the time-domain sampling data.

[0064] In other examples, the sampling signal processing module is specifically used to: when the reference difference meets the reference difference threshold, use the reference difference as the temporal sampling data of the current echo frame.

[0065] In other examples, the heart rate calculation module is specifically used to: filter the time-domain sampled signal to obtain a filtered time-domain sampled signal; and calculate the heart rate value based on the filtered time-domain sampled signal.

[0066] Specifically, such as Figure 10 As shown, the ultrasonic finger heart rate measuring device may include: a transducer with an M*N resolution pixel array, a control module, an ADC module, and an SPI bus. The signal generation module, under the control of the control module, generates a driving voltage to drive the transducer to emit ultrasonic signals. After emitting the ultrasonic signal, and waiting for the flight time to end, the control module controls the transducer to switch to acoustic wave receiving mode. The transducer converts the received acoustic wave signal into an electrical signal, the ADC converts the electrical signal into a digital signal, and sends it to the processing module via SPI.

[0067] like Figure 11 As shown, the ultrasonic fingerprint device is located under the cover of the electronic device to achieve under-display ultrasonic fingerprint recognition. The cover can be made of materials such as glass or plastic.

[0068] The above embodiments are only used to illustrate the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present invention, and the patent protection scope of the embodiments of the present invention should be defined by the claims. The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions.

[0069] For ease of description, the above apparatus is described by dividing it into various functional units. Of course, in implementing this invention, the functions of each unit can be implemented in one or more software and / or hardware components.

[0070] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0071] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0072] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0073] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0074] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, a network interface, and memory. Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0075] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0076] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0077] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0078] This invention can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific transactions or implement specific abstract data types. This invention can also be practiced in distributed computing environments where transactions are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0079] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

Claims

1. An ultrasonic finger heart rate measurement method, applied to an ultrasonic fingerprint device, wherein the ultrasonic fingerprint device is disposed under the cover of an electronic device to achieve under-display ultrasonic fingerprint recognition, comprising: When a finger presses the screen, the correspondence function between the echo signal and the flight time is obtained, and the target flight time is determined according to the correspondence function, wherein the flight time is the time taken for the ultrasonic signal to be transmitted from emission to reception; An ultrasonic signal is emitted to the finger, and the current echo frame carrying the fingerprint information of the finger is received from the finger according to the target time of flight. The time-domain sampling signal is determined based on the inter-frame difference between the current echo frame and the reference frame; Calculate the heart rate value based on the time-domain sampled signal; The step of determining the target flight time based on the correspondence function includes: determining the peak value of the correspondence function based on the correspondence function; and determining the target flight time based on the peak value of the correspondence function, wherein the target flight time is the flight time corresponding to obtaining the maximum echo signal. The method further includes: calculating the inter-frame difference between the current echo frame and the previous echo frame; if the difference meets the inter-frame difference threshold, then the current echo frame is used as a reference frame.

2. The method according to claim 1, wherein, If the difference satisfies the inter-frame difference threshold, then the current echo frame is used as the reference frame, including: Calculate the consecutive count value of the current echo frame that satisfies the inter-frame difference threshold; When the continuous count value meets the counting threshold, any current echo frame that meets the inter-frame difference threshold corresponding to the continuous count value is used as the reference frame.

3. The method according to claim 2, wherein, Determining the time-domain sampled signal based on the inter-frame difference between the current echo frame and the reference frame includes: Calculate the reference difference between the current echo frame and the reference frame, and use the reference difference as the temporal sampling data of the current echo frame; The time-domain sampling signal is determined based on the time-domain sampling data.

4. The method according to claim 3, wherein, The step of using the reference difference as the temporal sampling data of the current echo frame includes: When the reference difference meets the reference difference threshold, the reference difference is used as the temporal sampling data of the current echo frame.

5. The method according to claim 4, wherein, The step of calculating the heart rate value based on the time-domain sampled signal includes: The time-domain sampled signal is filtered to obtain the filtered time-domain sampled signal; The heart rate value is calculated based on the filtered time-domain sampled signal.

6. An ultrasonic finger heart rate measuring device, comprising: The flight time determination module is used to acquire the correspondence function between the echo signal and the flight time when a finger presses the screen, and to determine the target flight time according to the correspondence function, wherein the flight time is the time taken for the ultrasonic signal to be transmitted from emission to reception; An ultrasonic transceiver module is used to transmit ultrasonic signals to the finger and receive the current echo frame carrying the fingerprint information of the finger returned by the finger according to the target time of flight. The sampling signal processing module is used to determine the time-domain sampling signal based on the inter-frame difference between the current echo frame and the reference frame; The heart rate calculation module is used to calculate the heart rate value based on the time-domain sampled signal; The flight time determination module is further configured to: determine the peak value of the correspondence function based on the correspondence function; and determine the target flight time based on the peak value of the correspondence function, wherein the target flight time is the flight time corresponding to obtaining the maximum echo signal; The sampling signal processing module is also used to calculate the inter-frame difference between the current echo frame and the previous echo frame; if the difference meets the inter-frame difference threshold, the current echo frame is used as the reference frame.

7. An electronic device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the method as described in any one of claims 1-5.

8. A computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of claims 1-5.

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