Ultrasonic finger heart rate measuring and calculating method and apparatus, electronic device and storage medium

Abstract

The present application provides an ultrasonic finger heart rate measuring and calculating method and device, an electronic device, and a storage medium. The ultrasonic finger heart rate measuring and calculating method comprises: when a screen is pressed by a finger, acquiring a correspondence function between an echo signal and a flight time, and determining a target flight time according to the correspondence function, the flight time being the time from an ultrasonic signal being emitted to being received; emitting an ultrasonic signal to the finger, and based on the target flight time, receiving a current echo frame returned by the finger and carrying fingerprint information of the finger; determining a time domain sampling signal based on an inter-frame difference between the current echo frame and a reference frame; and calculating a heart rate value based on the time domain sampling signal. By means of the described steps, heart rate measuring and calculating can be achieved via a finger based on an ultrasonic fingerprint apparatus.

Description

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

[0001] This application claims priority to the Chinese invention patent application with application date of September 27, 2023, application number "202311286849.5", and patent name "Ultrasonic finger heart rate measurement method, device, electronic device and storage medium", all contents of which are hereby incorporated by reference. Technical Field

[0002] The embodiments of the present invention relate to the technical field of ultrasonic signal processing, and in particular to an ultrasonic finger heart rate measurement method, device, electronic device and storage medium. Background Art

[0003] With the rapid development of the electronic equipment industry, the demand for biometric technology is increasing in various fields. Fingerprint recognition is one of the most important identification methods. Mature fingerprint collection solutions include optical and capacitive methods. In recent years, ultrasonic fingerprint technology has become a new development direction for fingerprint technology.

[0004] In optical fingerprint chips, heart rate can be measured using photoplethysmography. However, ultrasonic fingerprint chips use acoustic wave technology and cannot use optical principles to measure heart rate signals. Therefore, a new method is needed to measure the human heart rate signal while simultaneously performing ultrasonic fingerprint recognition.

[0005] Summary of the Invention

[0006] In view of this, embodiments of the present invention provide an ultrasonic finger heart rate measurement method, device, electronic device, and storage medium to at least partially solve the above-mentioned problems.

[0007] According to a first aspect of an embodiment of the present invention, there is provided a method for measuring an ultrasonic finger heart rate, which is applied to an ultrasonic fingerprint device. The ultrasonic fingerprint device is arranged under the cover of an electronic device to realize under-screen ultrasonic fingerprint recognition, comprising: when a finger presses the screen, obtaining a correspondence function between an echo signal and a flight time, and determining a target flight time according to the correspondence function, wherein the flight time is the time elapsed from the emission to the reception of an ultrasonic signal; 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 flight time; 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.

[0008] In another implementation of the present invention, determining the target flight time based on the correspondence function includes: determining the peak value of the correspondence function based on the correspondence function; determining the target flight time based on the peak value of the correspondence function, and the target flight time is the flight time corresponding to the maximum echo signal.

[0009] In another implementation of the present invention, the method further includes: calculating an inter-frame difference between the current echo frame and a previous echo frame; if the difference satisfies an inter-frame difference threshold, using the current echo frame as a reference frame.

[0010] In another implementation of the present invention, if the difference satisfies the inter-frame difference threshold, the current echo frame is used as a reference frame, including: calculating the continuous count value of the current echo frame that satisfies the inter-frame difference threshold; when the continuous count value satisfies the count threshold, any current echo frame that satisfies the inter-frame difference threshold corresponding to the continuous count value is used as a reference frame.

[0011] In another implementation of the present invention, the time domain sampling signal is determined based on the inter-frame difference between the current echo frame and the reference frame, including: calculating the reference difference between the current echo frame and the reference frame, and 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.

[0012] In another implementation of the present invention, the taking the reference difference as the time domain sampling data of the current echo frame includes: when the reference difference meets a reference difference threshold, taking the reference difference as the time domain sampling data of the current echo frame.

[0013] In another implementation of the present invention, calculating the heart rate value based on the time domain sampling signal includes: filtering the time domain sampling signal to obtain a filtered time domain sampling signal; and calculating the heart rate value based on the filtered time domain sampling signal.

[0014] According to a second aspect of an embodiment of the present invention, an ultrasonic finger heart rate measurement device is provided, comprising: a flight time determination module, configured to obtain a correspondence function between an echo signal and a flight time when a finger presses the screen, and determine a target flight time based on the correspondence function, wherein the flight time is the time elapsed from the transmission to the reception of an ultrasonic signal; 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 based on the target flight time; 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.

[0015] According to a third aspect of an embodiment 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, and the executable instruction enables the processor to perform an operation corresponding to the method described in the first aspect.

[0016] According to a fourth aspect of an embodiment of the present invention, a computer storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the method according to the first aspect is implemented.

[0017] In the embodiment of the present invention, the ultrasonic echo signal generated when a finger presses the screen is used to simultaneously measure the human heart rate during fingerprint recognition. This allows the ultrasonic fingerprint device to add heart rate detection functionality without increasing hardware costs, and simultaneously adds heart rate detection functionality to various portable electronic devices that use the ultrasonic fingerprint device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] FIG1 is a flowchart of a method for measuring finger heart rate using ultrasound according to an embodiment of the present invention.

[0020] FIG2 is a schematic diagram showing the principle of fingerprint recognition by an electronic device having an ultrasonic fingerprint device according to an embodiment of the present invention.

[0021] FIG3 is a flow chart showing steps for determining a target flight time according to an embodiment of the present invention.

[0022] FIG4 is a flow chart showing steps for determining a reference frame according to an embodiment of the present invention.

[0023] FIG5 is a flowchart illustrating steps of converting a current echo frame received according to a target flight time into a time domain sampling signal according to an embodiment of the present invention.

[0024] FIG6 is a flow chart showing steps for obtaining a heart rate value based on a time domain sampling signal according to an embodiment of the present invention.

[0025] FIG7 is a waveform diagram of a time-domain sampling signal according to an embodiment of the present invention.

[0026] FIG8 is a flowchart showing the steps of calculating heart rate according to an embodiment of the present invention.

[0027] FIG9 is a functional structure diagram of an ultrasonic finger heart rate measurement device according to an embodiment of the present invention.

[0028] FIG10 is a schematic diagram of the hardware framework structure of an ultrasonic finger heart rate measurement system according to an embodiment of the present invention.

[0029] FIG11 is a schematic structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order 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 detailedly described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0031] 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 rather than to describe a specific order. The terms "include" and "comprising" used in the specification and claims of this disclosure indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0032] It should also be understood that the terminology used in this disclosure is for the purpose of describing specific embodiments only and is not intended to limit the disclosure. As used in this disclosure and the claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should be further understood that the term "and / or" as used in this disclosure and the claims refers to any and all possible combinations of one or more of the associated listed items, including and including these combinations.

[0033] The human finger structure is primarily composed of phalanges, tendons, muscles, nerves, and blood vessels. The blood vessels in the fingers contract and relax regularly with the heart rate, causing regular changes in these tissues. This method transmits ultrasound waves into the finger, receives the reflected signal, and analyzes the reflected signal image to extract the regular tissue changes and calculate the heart rate.

[0034] Principle: Because different parts of the finger structure reflect different acoustic signals, the phalanges have the strongest acoustic signals. To collect better finger tissue echoes, the ultrasound's time-of-flight (TFL) needs to be adjusted to a value near the phalanges, which maximizes the ultrasound echo.

[0035] An ultrasonic fingerprint device can be an ultrasonic chip, specifically an array of pixels with an MxN resolution. Each pixel can independently emit and receive ultrasonic waves. When the chip is operating, each pixel begins generating ultrasonic waves through an ultrasonic transducer. After a certain period of acoustic wave transmission, defined as the fly time, the ultrasonic transducer at the pixel begins receiving the ultrasonic echo and converting the acoustic wave signal into an electrical signal. The MxN image captured by the ultrasonic chip is the acoustic echo image, also known as an echo frame.

[0036] Finger tissue relaxes and contracts regularly with the heartbeat. These muscle changes cause regular variations in the transmission medium after the ultrasonic signal reaches the finger. This, in turn, affects the phase of the sound echo. The ultrasonic chip maintains a fixed frame rate of n and an integration time of t, integrating the finger at a fixed frame rate over the same flight time. The echoes with phase variations are captured as a single image, or echo frame. By analyzing successive frames of the ultrasonic echo signal and calculating the regular echo variations between frames, the heart rate in the finger can be extracted.

[0037] Figure 1 shows an exemplary process of an ultrasonic finger heart rate measurement method according to an embodiment of the present invention. The ultrasonic finger heart rate measurement method of this embodiment is applied to an ultrasonic fingerprint device, which is disposed under the cover of an electronic device to implement under-screen ultrasonic fingerprint recognition, and includes:

[0038] S210: When a finger presses the screen, a correspondence function between the echo signal and the flight time is obtained, and a target flight time is determined according to the correspondence function, wherein the flight time is the time elapsed from the transmission to the reception of the ultrasonic signal.

[0039] It should be noted that, as shown in Figure 2, ultrasonic heart rate measurement requires transmitting the ultrasonic signal to the phalanges of the fingers to obtain a strong echo signal. For example, the ultrasonic wave generated by the ultrasonic transducer penetrates the cover plate and enters the finger. After reaching the phalanges, a strong echo signal is reflected back to the ultrasonic transducer. To adapt to different fingers, it is necessary to measure and determine the appropriate flight time (target flight time) after the finger is pressed, so that the measured echo signal is the strongest echo signal near the phalanges.

[0040] The process for determining the target flight time is shown in Figure 3. The process begins (S2101); determines whether a finger is pressing the screen (S2102); when the finger is pressing the screen, the ultrasonic fingerprint device captures an echo frame of an image, starting with flight time T1 (S2103); continues image capture with T3 as the step time (S2104); determines whether the flight time is still within the T1-T2 interval (S2105); and selects the peak value of the echo signal within the T1-T2 interval as the target flight time for measuring the heart rate of the current finger (S2106). The T1-T2 interval can be an manually determined empirical value.

[0041] S220: Transmitting an ultrasonic signal to the finger, and receiving a current echo frame returned by the finger and carrying fingerprint information of the finger according to the target flight time.

[0042] S230: Determine a time domain sampling signal according to an inter-frame difference between the current echo frame and a reference frame.

[0043] S240: Calculate the heart rate value according to the time domain sampling signal.

[0044] In the embodiment of the present invention, the ultrasonic echo signal generated when a finger presses the screen is used to simultaneously measure the human heart rate during fingerprint recognition. This allows the ultrasonic fingerprint device to add heart rate detection functionality without increasing hardware costs, and simultaneously adds heart rate detection functionality to various portable electronic devices that use the ultrasonic fingerprint device.

[0045] In a possible implementation, 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, and the target flight time is the flight time corresponding to the maximum echo signal.

[0046] In a possible implementation, the method further includes: calculating an inter-frame difference between the current echo frame and a previous echo frame;

[0047] If the difference meets the inter-frame difference threshold, the current echo frame is used as a reference frame.

[0048] In one possible implementation, if the difference satisfies the inter-frame difference threshold, the current echo frame is used as a reference frame, including: calculating the continuous count value of the current echo frame that satisfies the inter-frame difference threshold; when the continuous count value satisfies the count threshold, any current echo frame that satisfies the inter-frame difference threshold corresponding to the continuous count value is used as a reference frame.

[0049] It should be noted that in order to extract the regular heart rate signal between echo frames, it is necessary to select a stable echo frame as the reference frame. The finger tissue changes fastest at the moment of cardiac contraction, and the finger tissue tends to be stable during cardiac diastole. The stable frame is used as the reference frame.

[0050] By calculating the difference between each corresponding pixel in the current echo frame and the previous echo frame, the difference between the two frames can be determined and quantified. The time point of the current echo frame where the continuous count value meets the count threshold TH3 is selected as the time point of diastole. The image obtained by averaging the current echo frames where the count value meets the count threshold TH3 is used as the reference frame. After the reference frame is determined, the time domain sampling signal of the images acquired will be calculated based on this reference frame. Since images are acquired continuously, each acquired frame is judged to determine whether it meets the reference frame conditions. If the reference frame conditions are met, the reference frame needs to be re-determined.

[0051] Specifically, the process of obtaining the reference frame is shown in Figure 4. The process starts (S41); the current echo frame is acquired (S42); the pixel points corresponding to the image of the current echo frame and the previous echo frame are calculated and the absolute value of the difference is taken as the inter-frame difference (S43); it is determined whether the ratio of the inter-frame difference less than the inter-frame interpolation threshold TH1 is less than the ratio threshold TH2 (S44); if the ratio is less than the ratio 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 ratio is greater than or equal to the ratio 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 count threshold TH3 (S46); if the continuous count value is less than the count threshold TH3, the count value is reset to zero (S47), and the process returns to step S42; if the continuous count value is greater than or equal to the count threshold TH3, any current echo frame that meets the inter-frame difference threshold corresponding to the continuous count value is used as the reference frame (Base) (S48).

[0052] 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 the reference difference between the current echo frame and the reference frame, and 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.

[0053] It should be noted that step S220 and step S230 can be processed in parallel. The echo frames in step S220 are continuously received at fixed intervals, and the determination of the time domain sampling signal in step S230 can be performed once every 1 second.

[0054] In a possible implementation, taking the reference difference as the time domain sampling data of the current echo frame includes: when the reference difference meets a reference difference threshold, taking the reference difference as the time domain sampling data of the current echo frame.

[0055] 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 sampled data in the time domain. The specific conversion method is shown in Figure 5. The process starts (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. Because the echo frame phase changes can be positive or negative, the absolute value of the difference needs to be taken. The absolute value of all the differences is then averaged. If the average value is greater than the reference difference threshold TH4, the average value is used as the sampled data in the time domain for the current echo frame (S54).

[0056] In a possible implementation, as shown in FIG6 , the step S240 includes: step S2401 , filtering the time domain sampling signal to obtain a filtered time domain sampling signal; and step S2402 , calculating the heart rate value according to the filtered time domain sampling signal.

[0057] It should be noted that the time domain sampling signal can be used to calculate the heart rate in seconds, that is, once per second. The time domain sampling signal is shown in FIG7 .

[0058] Specifically, the heart rate calculation process is shown in Figure 8. The process starts (S81); a smooth filter curve is calculated for the time domain sampling signal (original signal), and the filter window is the minimum heart rate period. The smooth filter curve is used as the DC component of the signal (S82); the DC curve after smooth filtering is subtracted from the original signal curve to obtain an AC signal curve containing heart rate information (S83); the AC curve is Fourier transformed and bandpass filtered, and f is obtained. min <f<f max , where f min and f max Represent the minimum frequency (e.g., 0.6) and the maximum frequency (e.g., 4) of the heart rate respectively. After filtering, inverse transformation is performed to obtain a filtered curve (S84). Autocorrelation calculation is performed on the filtered curve to obtain an autocorrelation curve (S85). The peak or trough of the autocorrelation curve is determined (S86). The heart rate value is calculated (S87). The heart rate calculation formula is: where f sample is the sampling rate of the ultrasound chip image, which is the reciprocal of the fixed interval time T for each frame image acquisition. N is the average value of the peak or trough intervals.

[0059] Preferably, an autocorrelation calculation is performed on the filtered time domain sampling signal to obtain an autocorrelation signal; and the heart rate value is calculated based on the autocorrelation signal.

[0060] Figure 9 is a schematic block diagram of an ultrasonic finger heart rate measurement device according to another embodiment of the present invention. The solution of the embodiment of the present invention can be applied to electronic devices, including but not limited to: terminal devices with communication functions or electronic devices with interactive behavior capabilities.

[0061] The ultrasonic finger heart rate measurement device of this embodiment includes: a flight time determination module, which is used to obtain a correspondence function between the echo signal and the flight time when the finger presses the screen, and determine the target flight time based on the correspondence function, wherein the flight time is the time elapsed from the transmission to the reception of the ultrasonic signal; an ultrasonic transceiver module, which is used to transmit the 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; a sampling signal processing module, which is used to determine the time domain sampling signal based on the inter-frame difference between the current echo frame and the reference frame; and a heart rate value calculation module, which is used to calculate the heart rate value based on the time domain sampling signal.

[0062] In other examples, the flight time determination module is specifically configured to: determine a peak value of the correspondence function according to the correspondence function; and determine a target flight time according to the peak value of the correspondence function.

[0063] 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 a reference frame.

[0064] In other examples, the sampling signal processing module is specifically used to: calculate the continuous count value of the current echo frame that meets the inter-frame difference threshold; when the continuous count value meets the count threshold, use any current echo frame that meets the inter-frame difference threshold corresponding to the continuous count value as a reference frame.

[0065] In other examples, the sampling signal processing module is specifically used to: calculate a reference difference between the current echo frame and the reference frame, and use the reference difference as time domain sampling data of the current echo frame; and determine a time domain sampling signal based on the time domain sampling data.

[0066] In other examples, the sampling signal processing module is specifically configured to: when the reference difference value satisfies a reference difference value threshold, use the reference difference value as the time domain sampling data of the current echo frame.

[0067] In other examples, the heart rate value calculation module is specifically used to: filter the time domain sampling signal to obtain a filtered time domain sampling signal; and calculate the heart rate value according to the filtered time domain sampling signal.

[0068] Specifically, as shown in Figure 10, the ultrasonic finger heart rate measurement device may include: a pixel array control transducer with an MxN resolution, a control module, an ADC module, and an SPI bus. Under the control of the control module, the signal generation module generates a drive voltage to drive the transducer to transmit an ultrasonic signal. After transmitting the ultrasonic signal, the control module waits for the flight time to expire, at which point the transducer switches to acoustic wave reception mode. The transducer converts the received acoustic wave signal into an electrical signal, which the ADC then converts into a digital signal and transmits to the processing module via the SPI bus.

[0069] As shown in FIG11 , the ultrasonic fingerprint device is arranged under the cover of the electronic device to realize under-screen ultrasonic fingerprint recognition. The cover can be made of glass, plastic or other materials.

[0070] 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. Ordinary technicians in the relevant technical field 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 scope of patent protection 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 entities, or by products with certain functions.

[0071] For the convenience of description, the above device is described as being divided into various units according to their functions. Of course, when implementing the present invention, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0072] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0074] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0075] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0076] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory. Memory may include non-permanent storage in a computer-readable medium, 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 a computer-readable medium.

[0077] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules 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 technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0078] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0079] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] The present invention may be described in the general context of computer-executable instructions, such as program modules, executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media, including storage devices.

[0081] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

Claims

1. An ultrasonic finger heart rate measurement method is applied to an ultrasonic fingerprint device, wherein the ultrasonic fingerprint device is arranged under a cover of an electronic device to realize under-screen ultrasonic fingerprint recognition, comprising: When the finger presses the screen, a correspondence function between the echo signal and the flight time is obtained, and a target flight time is determined according to the correspondence function, wherein the flight time is the time from when the ultrasonic signal is emitted to when it is received; Transmitting an ultrasonic signal to the finger, and receiving a current echo frame carrying fingerprint information of the finger returned by the finger according to the target flight time; Determine a time domain sampling signal according to an inter-frame difference between the current echo frame and a reference frame; The heart rate value is calculated according to the time domain sampling signal.

2. The method according to claim 1, wherein: Determining the target flight time according to the corresponding relationship function includes: Determining a peak value of the correspondence function according to the correspondence function; The target flight time is determined according to the peak value of the corresponding relationship function, and the target flight time is the flight time corresponding to obtaining the maximum echo signal.

3. The method according to claim 2, wherein: The method further comprises: Calculating 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 a reference frame.

4. The method according to claim 3, wherein: If the difference satisfies an inter-frame difference threshold, taking the current echo frame as a reference frame comprises: Calculating the continuous count value of the current echo frame that meets the inter-frame difference threshold; When the continuous count value satisfies the count threshold, any current echo frame corresponding to the continuous count value and satisfying the inter-frame difference threshold is used as a reference frame.

5. The method according to claim 4, wherein: Determining the time domain sampling signal according to 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, and using the reference difference as time domain sampling data of the current echo frame; A time domain sampling signal is determined according to the time domain sampling data.

6. The method according to claim 5, wherein: The step of using the reference difference as time domain sampling data of the current echo frame includes: When the reference difference value meets the reference difference value threshold, the reference difference value is used as the time domain sampling data of the current echo frame.

7. The method according to claim 6, wherein: Calculating the heart rate value according to the time domain sampling signal includes: Filtering the time domain sampling signal to obtain a filtered time domain sampling signal; The heart rate value is calculated according to the filtered time domain sampling signal.

8. An ultrasonic finger heart rate measuring device, comprising: A flight time determination module, used to obtain a correspondence function between the echo signal and the flight time when the finger presses the screen, and determine the target flight time according to the correspondence function, wherein the flight time is the time from the emission to the reception of the ultrasonic signal; An ultrasonic transceiver module, used for 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 flight time; A sampling signal processing module, used for determining a time domain sampling signal according to an inter-frame difference between the current echo frame and the reference frame; The heart rate value calculation module is used to calculate the heart rate value according to the time domain sampling signal.

9. An electronic device, 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, and the executable instruction enables the processor to perform an operation corresponding to the method according to any one of claims 1 to 7.

10. A computer storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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