WO2021092814A1

WO2021092814A1 - Biological feature detection method, biological feature detection apparatus, biological feature detection system and computer storage medium

Info

Publication number: WO2021092814A1
Application number: PCT/CN2019/118195
Authority: WO
Inventors: 李仕柏
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-11-13
Filing date: 2019-11-13
Publication date: 2021-05-20
Also published as: CN111132610A; CN111132610B

Abstract

Disclosed are a biological feature detection method, a biological feature detection apparatus, a biological feature detection system and a computer storage medium. The biological feature detection method comprises: controlling a first light source to emit a first optical signal to an object to be tested, and sampling a first electrical signal formed after the first optical signal passes through the object to be tested and is subjected to photoelectric conversion (101); controlling a second light source to emit a second optical signal to the object to be tested, and sampling a second electrical signal formed after the second optical signal passes through the object to be tested and is subjected to photoelectric conversion, wherein the first optical signal is different from the second optical signal (102); synthesizing the first electrical signal and a white noise signal to obtain a motion reference signal, wherein the amplitude of the white noise signal is lower than the amplitude of the first electrical signal (103); and carrying out interference removal processing on the second electrical signal by means of the motion reference signal to obtain a valid electrical signal of a biological feature of the object to be tested (104). By means of the biological feature detection method, the influence of an interference signal on a test is reduced, and the accuracy of an optical test is improved.

Description

Biometric detection method, biometric detection device, system and computer storage medium

Technical field

The embodiments of the present application relate to the field of electronic technology, and in particular to biometric detection methods, biometric detection devices, systems, and computer storage media.

Background technique

The use of light signals for detection is widely used in various fields. For example, in the medical field, light signals can be used to detect heart rate. Take PPG (English: Photoplethysmograph, Photoplethysmograph) as an example. PPG transmits light signals to human tissues and receives For the returned optical signal, because the blood volume changes with the heartbeat, the electrical signal intensity of the electrical signal converted by the returned optical signal is different. The human body's heart rate can be determined by the change of the electrical signal intensity. However, during the detection process, the human tissue at the detection location or the slight movement of the sensor will cause interference to the detection, because too many interference signals lead to inaccurate heart rate detection.

Summary of the invention

In view of this, one of the technical problems solved by the embodiments of the present application is to provide a biometric detection method, biometric detection device, system, and computer storage medium to overcome the use of light signals to detect the object under test in the prior art. At that time, the defect of inaccurate detection is caused by the influence of interference signal.

In the first aspect, an embodiment of the present application provides a biometric detection method, including:

Controlling the first light source to emit a first light signal to the object to be detected; sampling the first electrical signal formed by the first light signal after passing through the object to be detected and being photoelectrically converted; controlling the second light source to emit a second light signal to the object to be detected; Sampling the second electrical signal after the second optical signal passes through the object to be detected and is photoelectrically converted; the first optical signal is different from the second optical signal; the first electrical signal and the white noise signal are synthesized to obtain the motion reference signal, white The amplitude of the noise signal is lower than the amplitude of the first electrical signal; the second electrical signal is used for interference removal processing using the motion reference signal to obtain the effective electrical signal of the biological characteristics of the object to be detected.

Optionally, in an embodiment of the present application, the absorption rate of the first light signal by the object to be detected is greater than the absorption rate of the second light signal by the object to be detected.

Optionally, in an embodiment of the present application, the first optical signal is red light, and the second optical signal is green light;

Controlling the first light source to emit a first light signal to the object to be detected, sampling the first electrical signal formed after the first light signal passes through the object to be detected and photoelectrically converted, includes: controlling the first light source to emit red light to the object to be detected, Sampling the first electrical signal formed after the red light passes through the object to be detected and is photoelectrically converted;

Controlling the second light source to emit a second light signal to the object to be detected, sampling the second electrical signal formed after the second light signal passes through the object to be detected and photoelectrically converted, includes: controlling the second light source to emit green light to the object to be detected, Sampling the second electrical signal formed after the green light passes through the object to be detected and is photoelectrically converted.

Optionally, in an embodiment of the present application, using the motion reference signal to perform de-interference processing on the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected includes:

Use the preset algorithm model to simulate the motion reference signal to obtain the simulated interference signal;

Using the analog interference signal to perform de-interference processing on the second electrical signal to obtain an effective electrical signal of the biological feature of the object to be detected.

Optionally, in an embodiment of the present application, using a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal includes:

The preset algorithm model is used to adjust the amplitude of the motion reference signal to obtain an analog interference signal, and the difference between the amplitude of the analog interference signal and the amplitude of the second electrical signal is within a preset range.

Calculate the amplitude parameter in the preset algorithm model according to the motion reference signal and the second electrical signal; input the amplitude parameter and the motion reference signal into the preset algorithm model to obtain a model interference signal.

The least square method model is used to simulate the motion reference signal to obtain the simulated interference signal, and the preset algorithm model includes the least square method model.

Optionally, in an embodiment of the present application, using the analog interference signal to perform interference removal processing on the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected includes:

The analog interference signal is subtracted from the second electrical signal to obtain the effective electrical signal of the biological characteristic of the object to be detected.

Optionally, in an embodiment of the present application, there are at least two first light sources, and controlling the first light source to emit the first light signal to the object to be detected includes: controlling the at least two first light sources to simultaneously emit the first light signal to the object to be detected A light signal;

And/or, there are at least two second light sources, and controlling the second light source to emit the second light signal to the object to be detected includes: controlling the at least two second light sources to simultaneously emit the second light signal to the object to be detected.

In a second aspect, an embodiment of the present application provides a biological feature detection device, including: a control module, a sampling module, and a signal processing module;

The control module is used to control the first light source to emit the first light signal to the object to be detected;

The sampling module is used to sample the first electrical signal formed after the first optical signal passes through the object to be detected and is photoelectrically converted;

The control module is also used to control the second light source to emit a second light signal to the object to be detected;

The sampling module is also used to sample the second electrical signal formed after the second optical signal passes through the object to be detected and is photoelectrically converted; the first optical signal is different from the second optical signal;

The signal processing module is used to synthesize the first electrical signal and the white noise signal to obtain a motion reference signal, the amplitude of the white noise signal is lower than the amplitude of the first electrical signal; the motion reference signal is used to de-interference the second electrical signal The effective electrical signal of the biological characteristics of the object to be detected is obtained by processing.

Optionally, in an embodiment of the present application, the first light signal is red light, and the second light signal is green light; the control module is also specifically configured to control the first light source to emit red light to the object to be detected; the sampling module , Is also specifically used to sample the first electrical signal formed after the red light passes through the object to be detected and is photoelectrically converted;

The control module is also specifically configured to control the second light source to emit green light to the object to be detected; the sampling module is also specifically configured to sample the second electrical signal formed after the green light passes through the object to be detected and is photoelectrically converted.

Optionally, in an embodiment of the present application, the signal processing module is further specifically configured to use a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal; use the analog interference signal to perform interference removal processing on the second electrical signal Obtain the effective electrical signal of the biological characteristics of the object to be detected.

Optionally, in an embodiment of the present application, the signal processing module is further specifically configured to use a preset algorithm model to adjust the amplitude of the motion reference signal to obtain an analog interference signal, and the amplitude of the analog interference signal is compared with the second electrical signal. The difference in signal amplitude is within a preset range.

Optionally, in an embodiment of the present application, the signal processing module is further specifically configured to calculate the amplitude parameter in the preset algorithm model according to the motion reference signal and the second electrical signal; input the amplitude parameter and the motion reference signal The preset algorithm model obtains the model interference signal.

Optionally, in an embodiment of the present application, the signal processing module is further specifically configured to use the least squares model to simulate the motion reference signal to obtain the simulated interference signal, and the preset algorithm model includes the least squares model.

Optionally, in an embodiment of the present application, the signal processing module is further specifically configured to subtract the analog interference signal from the second electrical signal to obtain the effective electrical signal of the biological characteristic of the object to be detected.

Optionally, in an embodiment of the present application, there are at least two first light sources, and the control module is further specifically configured to control the first light source to emit the first light signal to the object to be detected, including: controlling at least two first light sources Simultaneously emit the first light signal to the object to be detected;

And/or, there are at least two second light sources, and the control module is further specifically configured to control the second light source to emit the second light signal to the object to be detected, including: controlling the at least two second light sources to simultaneously emit the second light to the object to be detected signal.

Optionally, in an embodiment of the present application, the biometric detection device further includes a photoelectric conversion module; the photoelectric conversion module is configured to perform photoelectric conversion on the first light signal and the second light signal passing through the object to be detected.

Optionally, in an embodiment of the present application, the photodiodes in the photoelectric conversion module are evenly distributed on a circle with the first light source as the center and the first preset distance as the radius.

In a third aspect, an embodiment of the present application provides a biometric detection system, including: a first light source, a second light source, and a biometric detection device. The biometric detection device is the second aspect or any one of the embodiments of the second aspect. The described biological feature detection device, the first light source is used to emit a first light signal, the second light source is used to emit a second light signal, the first light source is electrically connected to the biological feature detection device, and the second light source is electrically connected to the biological feature detection device .

Optionally, in an embodiment of the present application, the photodiodes in the biometric detection device are symmetrically distributed around the first light source; the light emitting center of the second light source coincides with the light emitting center of the first light source.

Optionally, in an embodiment of the present application, there are at least two first light sources, and the at least two first light sources are evenly distributed on a circle with the second light source as the center and the second preset distance as the radius.

In a fourth aspect, an embodiment of the present application provides a computer storage medium with a program stored on the computer storage medium. When the processor executes the program stored on the computer storage medium, it implements the first aspect or any one of the embodiments of the first aspect. The biometric detection method described in.

The biological feature detection method, control chip, device, and computer storage medium provided by the embodiments of the application control the first light source to emit the first light signal to the object to be detected; the sampled first light signal is formed after passing through the object to be detected and photoelectrically converted Control the second light source to emit a second light signal to the object to be detected; sample the second electrical signal formed after the second light signal passes through the object to be detected and is photoelectrically converted; the first light signal and the second light Signals are different. The first electrical signal is added to the white noise signal to simulate the motion reference signal contained in the second electrical signal, that is, the interference signal. The object to be detected can be obtained by using the motion reference signal to remove interference from the second electrical signal. The effective electrical signal of the biological characteristics reduces the influence of interference signals on detection and improves the accuracy of optical detection.

Description of the drawings

Hereinafter, some specific embodiments of the embodiments of the present application will be described in detail in an exemplary but not restrictive manner with reference to the accompanying drawings. The same reference numerals in the drawings indicate the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the attached picture:

FIG. 1 is a flowchart of a method for detecting biometrics according to an embodiment of this application;

2 is a schematic diagram of a photodiode distribution effect provided by an embodiment of the application;

3 is a schematic diagram of a photodiode distribution effect provided by an embodiment of the application;

4 is a schematic diagram of a light source distribution effect provided by an embodiment of the application;

FIG. 5 is a schematic structural diagram of a biological feature detection device provided by an embodiment of the application;

Fig. 6 is a schematic structural diagram of a biometric detection system provided by an embodiment of the application.

Detailed ways

The implementation of any technical solution of the embodiments of the present application does not necessarily need to achieve all the above advantages at the same time.

In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the description The embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art should fall within the protection scope of the embodiments of the present application.

The specific implementation of the embodiments of the present application will be further described below in conjunction with the drawings of the embodiments of the present application.

Example one,

Fig. 1 is a flowchart of a biometric detection method provided by an embodiment of the application; as shown in Fig. 1, the biometric detection method includes the following steps:

Step 101: Control the first light source to emit a first light signal to the object to be detected, and sample the first electrical signal formed after the first light signal passes through the object to be detected and is photoelectrically converted.

It should be noted that the first light signal may be absorbed by the object to be detected. Of course, during the detection process, the first light signal may be completely absorbed by the object to be detected, or it may be only partly absorbed by the object to be detected. This application does not deal with this. limit. In this application, the optical signal refers to a light wave, and the first light signal may be a light wave, for example, a red light wave, a blue light wave, and the like. The object to be detected is the object to be detected. For example, in the medical field, the object to be detected can be a blood vessel, and the object around the object to be detected can be tissue around the blood vessel. When the object to be detected is detected, the object to be detected and the surrounding area of the object to be detected All objects will reflect the light signal, so it will produce interference signals. The first electrical signal may be an analog signal or a digital signal.

After the first optical signal passes through the object to be detected and is photoelectrically converted, the electrical signals formed can be all sampled, that is, the electrical signal formed after photoelectric conversion is used as the first electrical signal, or the electrical signal formed after photoelectric conversion can be preset The frequency is sampled to obtain the first electrical signal, which is not limited in this application.

Optionally, in an embodiment of the present application, there are at least two first light sources, and controlling the first light source to emit the first light signal to the object to be detected includes: controlling the at least two first light sources to simultaneously emit the first light signal to the object to be detected A light signal.

Here, a specific example is cited to illustrate how to collect the first electrical signal. Optionally, in an embodiment of the present application, the first electrical signal is obtained by using the first optical signal to detect objects around the object to be detected, including:

The first light source is controlled to emit the first light signal to the object to be detected, and the object to be detected absorbs the first light signal; the photodiode array is controlled to receive the signal reflected by the object around the object to be detected, and perform photoelectric conversion, and perform photoelectric conversion on the signal after photoelectric conversion. The first electrical signal is sampled, and the photodiodes (English: Photo Diode, PD) in the photodiode array are symmetrically distributed around the first light source. The first light source may be a light emitting diode (English: Light Emitting Diode, LED). It should be noted that the object to be detected can absorb the first light signal, but it may absorb part of the first light signal, or it may absorb all of it. For example, the part of the first light signal that hits the object to be detected is completely absorbed, and the light hits the object to be detected. The part of the object surrounding the detection object is reflected back, converted into an electrical signal by the photodiode, and then sampled to obtain the first electrical signal; another example, if the part of the first light signal irradiated by the object to be detected is partially absorbed, it is to be detected The object reflects a part of the first light signal. Because it is partially absorbed, the intensity of the light signal reflected by the object to be detected is weak. Objects around the object to be detected reflect the first light signal, and the light reflected back by the surrounding objects The signal strength is strong, and the two optical signals are photoelectrically converted to obtain an electrical signal, and then sampling is performed to obtain a second electrical signal.

Optionally, in an embodiment of the present application, the photodiodes in the photodiode array are evenly distributed on a circle with the first light source as the center and the first preset distance as the radius.

For example, FIG. 2 is a schematic diagram of a photodiode distribution effect provided by an embodiment of the application. As shown in FIG. 2, in FIG. 2, the first light source is located in the center position, and the four photodiodes are respectively arranged on the upper, lower, left, and right sides of the first light source. The distances from the four photodiodes to the first light source are all equal. Of course, FIG. 2 is just an example, and it can also be symmetrical distribution of 2 photodiodes, or symmetrical distribution of 6 diodes and 8 diodes, which is not limited in this application. Of course, preferably, the number of diodes is an even number. When the photodiodes are symmetrically distributed around the first light source, PD1 and PD2 are symmetrical. Therefore, the first light signal emitted by the first light source has basically the same influence on PD1 and PD2, which also ensures that PD1 receives after reflection from surrounding objects The path of the optical signal and the optical signal received by PD2 are as consistent as possible to reduce the error of the optical signal received between the two PDs.

As another example, as shown in FIG. 3, FIG. 3 is a schematic diagram of a photodiode distribution effect provided by an embodiment of the application. In FIG. 3, the photodiodes are arranged at equal intervals around the first light source, and the distance between each photodiode and the first light source The distances are all equal. Taking Figure 3 as an example, the distance between each photodiode and the first light source is R (that is, the first preset distance). The photodiodes are distributed on a circle with the first light source as the center and R as the radius. The adjacent photodiodes are The distance between them is equal. In Fig. 3, the number of photodiodes is 5, and Fig. 3 is only an exemplary illustration. The number of photodiodes may be odd or even, which is not limited in this application.

Step 102: Control the second light source to emit a second light signal to the object to be detected; sample the second electrical signal formed after the second light signal passes through the object to be detected and is photoelectrically converted.

The first optical signal is different from the second optical signal. It should be noted that there may be no sequence between step 101 and step 102, and step 102 can be performed before step 101 or after step 101. Optionally, in an embodiment of the present application, the absorption rate of the first light signal by the object to be detected is greater than the absorption rate of the second light signal by the object to be detected.

The second electrical signal is obtained by detecting the object to be detected, but it also contains the electrical signal converted by the light signal reflected by the surrounding objects. The first electrical signal is processed and the motion reference signal is obtained to simulate the second electrical signal. The interference signal of the second electrical signal is processed to remove interference.

Optionally, in an embodiment of the present application, sampling the second electrical signal formed after the second light signal passes through the object to be detected and is photoelectrically converted includes: controlling the photodiode array to receive reflections from the object to be detected and surrounding objects And perform photoelectric conversion, and sample the photoelectric conversion signal to obtain the second electrical signal.

Optionally, in an embodiment of the present application, there are at least two second light sources, and controlling the second light source to emit the second light signal to the object to be detected includes: controlling the at least two second light sources to simultaneously emit the second light signal to the object to be detected Two optical signals.

The second light source may be an LED light source. When the light emitting center of the second light source coincides with the light emitting center of the first light source, when each photodiode detects the first light signal and detects the second light signal, it can ensure that the two light signals are in the same condition as the photodiode , The path is consistent, to ensure that the interference signals in the two optical signals are as close as possible, and to improve the accuracy of the interference signal estimation.

Optionally, in an embodiment of the present application, the number of the first light sources may be multiple, and the multiple first light sources are evenly distributed on a circle with the second light source as the center and the second predetermined distance as the radius.

Referring to FIG. 4, FIG. 4 is a schematic diagram of a light source distribution effect provided by an embodiment of the application. The number of the first light source can be an odd number or an even number, which is not limited in this application. When there is only one first light source, The distance between the first light source and the second light source is as small as possible. When the number of the first light source is greater than or equal to 2, the first light source surrounds the second light source, and the distance from each first light source to the second light source is the same , The distance from each first light source to the second light source is less than the preset distance. The first light source and the second light source are arranged as close as possible to further ensure that the signals of the two light sources received by each PD have a better correlation. Of course, this is only an exemplary description, which does not mean that the application is limited to this.

Optionally, in an embodiment of the present application, the first light signal is red light, and the second light signal is green light; the first light source is controlled to emit the first light signal to the object to be detected, and the first light signal is sampled and passed through the object to be detected. The first electrical signal formed after the object is detected and photoelectrically converted includes: controlling the first light source to emit red light to the object to be detected, and sampling the first electrical signal formed after the red light passes through the object to be detected and is photoelectrically converted;

Here, the present solution is further described by taking an example of detecting the heart rate of the human body by using a light signal. Here, the object to be measured is a blood vessel, and the surrounding object is the tissue around the blood vessel. Optionally, the first light source can be controlled to emit the first light signal to the blood vessel; the photodiode array can be controlled to receive the signal reflected by the tissue around the blood vessel and photoelectrically converted to obtain the first electrical signal; the second light source can be controlled to emit the second light to the blood vessel Signal, the light emitting center of the second light source coincides with the light emitting center of the first light source; controlling the photodiode array to receive the signal reflected by the blood vessel and the tissue around the blood vessel, and perform photoelectric conversion to obtain the second electrical signal;

The second light signal can be green light. After the second light signal is irradiated to the blood vessels of the human body, the blood volume of the human body changes with the change of the heartbeat, and the intensity of the reflected light signal will also change. The photoelectric sensor will reflect the light signal When converted into the second electrical signal, the intensity of the second electrical signal will also change, but the tissues around the blood vessel also reflect the second light signal back and convert it into an electrical signal.

The first light signal can be red light. Because blood is red, the part of the first light signal irradiated to the blood vessel will be absorbed to a large extent, and the part irradiated to the tissue around the blood vessel will be reflected back. The first electrical signal obtained after the signal is converted by the photoelectric sensor mainly shows the change of the first light signal with the movement of the tissue around the blood vessel. By processing the first electrical signal, the interference in the second electrical signal can be simulated signal.

Step 103: Synthesize the first electrical signal and the white noise signal to obtain a motion reference signal.

Step 103 is executed after step 101. Step 103 and step 102 are in no order. They can be executed before step 102 or after step 102.

The amplitude of the white noise signal is lower than the amplitude of the first electrical signal. White noise is used to cover out the signal about the object to be detected in the first electrical signal. The first electrical signal is obtained by detecting the surrounding objects in order to simulate an interference signal. However, the surrounding objects and the object to be detected The objects are together. Therefore, the first electrical signal also contains the part about the object to be detected. However, because the object to be detected absorbs the first light signal, the signal about the object to be detected is very weak, so white noise is added. This part of the signal can be overwritten, so that the motion reference signal only retains the signals of the surrounding objects. The white noise signal may be a random signal or a preset signal, which is not limited in this application.

Optionally, in an embodiment of the present application, the color of the first light signal is similar to the color of the object to be detected. Preferably, the color of the first light signal is the same as the color of the object to be detected. Exemplarily, if the absolute value of the difference between the color of the first light signal and the color of the object to be detected is within the preset difference interval, it can be determined that the color of the first light signal is different from the color of the object to be detected. The colors of the detected objects are similar. Of course, this is only an exemplary description, which does not mean that the application is limited to this. When the color of the first light signal is the same or similar to the color of the object to be detected, the signal emitted by the first light signal to the surrounding surface of the object will be reflected back, while the signal emitted by the first light signal to the surface of the object to be detected will be reflected back. It will be absorbed by the object to be detected, and a small part of it will return. In this way, the part of the object to be detected in the first light signal will be very weak, and white noise signal is added to further cover the signal about the object to be detected, so that it can be very large. The interference signal is simulated to a certain extent.

Step 104: Perform de-interference processing on the second electrical signal by using the motion reference signal to obtain an effective electrical signal of the biological feature of the object to be detected.

Using a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal; using the analog interference signal to perform de-interference processing on the second electrical signal to obtain an effective electrical signal of the biological characteristics of the object to be detected.

Specifically, in an embodiment of the present application, using a preset algorithm model to simulate a motion reference signal to obtain an analog interference signal includes:

When the difference between the amplitude of the analog interference signal and the amplitude of the second electrical signal is within the preset range, it indicates that the amplitude of the analog interference signal is very close to the amplitude of the interference signal in the second electrical signal, and the second electrical signal is used By subtracting the analog interference signal, the effective electrical signal of the biological characteristics of the object to be detected can be obtained for the object to be detected. It should be noted that in the present application, the amplitude of the electrical signal may indicate the strength of the electrical signal, and may be the level value, voltage value, etc. of the electrical signal, which is not limited in the present application.

For example, the first sampling point may be determined in the motion reference signal, and the second sampling point may be determined in the position corresponding to the time sequence of the first sampling point in the second electrical signal; multiple first sampling points may be determined in the motion reference signal and the second electrical signal. A sampling point and a second sampling point form the first sampling point set and the second sampling point set, and the amplitude in the preset algorithm model is calculated according to the sampling points corresponding to the time sequence in the first sampling point set and the second sampling point set Parameters; input the amplitude parameter and the motion reference signal into the preset algorithm model to obtain the simulated interference signal.

For example, the time length of the motion reference signal and the second electrical signal are both 5 seconds, and a sampling point is determined every second. In the motion reference signal, the first second, second second, third second, fourth second, and fifth second are determined. The 5 points of the second are regarded as the 5 first sampling points, and the 5 points of the 1st, 2nd, 3rd, 4th and 5th seconds in the second electrical signal are regarded as the 5 second sampling points. , The first sampling point set contains the signal amplitudes of 5 first sampling points, the second sampling point set contains the signal amplitudes of 5 second sampling points, and the signal amplitudes of the 5 first sampling points and the 5th The signal amplitude and amplitude parameters of the two sampling points are input into a preset algorithm model to obtain an analog interference signal.

The biological feature detection method provided by the embodiment of the application controls the first light source to emit a first light signal to the object to be detected; sampling the first electrical signal formed after the first light signal passes through the object to be detected and is photoelectrically converted; control The second light source emits a second optical signal to the object to be detected; the second electrical signal is formed by sampling the second optical signal after passing through the object to be detected and being photoelectrically converted; the first optical signal is different from the second optical signal, and the second optical signal is An electrical signal is added to a white noise signal to simulate the motion reference signal contained in the second electrical signal, that is, an interference signal. After the motion reference signal is used to de-interference the second electrical signal, the effective biological characteristics of the object to be detected can be obtained. The electrical signal reduces the influence of interference signals on detection and improves the accuracy of optical detection.

Embodiment two

Based on the biometric detection method described in the first embodiment, this embodiment combines steps 101-104 in the first embodiment to use light signals to detect the human heart rate as an example to describe the biometric detection method provided in the first embodiment of the present application in detail.

In this embodiment, the first light source is a first LED, and the second light source is a second LED. PPG1 is used to represent the first electrical signal, and PPG2 is used to represent the second electrical signal.

In each sampling period, the first LED is lit to collect data once to obtain the electrical signal PPG1, and then the second LED is lit to collect data once, and the electrical signals PPG2 are obtained. The length of time for obtaining the electrical signals PPG1 and PPG2 is the same. It should be noted that the operation on the signal in this embodiment refers to the operation on the signal amplitude (that is, the amplitude of the electrical signal).

According to formula 1, a certain proportion of white noise signal is added to PPG1 to obtain the motion reference signal, and formula 1 is as follows:

PPG1′=PPG1+Ne (Formula 1);

Among them, PPG1' represents a motion reference signal, Ne represents a white noise signal, and PPG1 represents a first electrical signal.

According to Formula 2 and Formula 3, the least square method is used to determine the analog interference signal. Formula 2 and Formula 3 are as follows:

Ne′=C*PPG1′ (Formula 2);

e=∑(PPG2-C*PPG1′) ² (Formula 3);

Among them, C represents the amplitude parameter, and Ne' represents the analog interference signal. When e takes the minimum value, the value of C is obtained, and then substituted into Equation 2, the analog interference signal can be determined. Specifically, the first sampling point set may be determined in the motion reference signal, and the second sampling point set may be determined in the second electrical signal. The first embodiment of how to determine the two sampling point sets has been described in detail and will not be repeated here. The signal amplitude of the sampling point in the first sampling point set and the signal amplitude of the sampling point in the second sampling point set are input into formula 3, and the value of C when e takes the minimum value is obtained. Of course, this is only an exemplary description, which does not mean that the application is limited to this.

According to formula 4, the effective electrical signal of the biological characteristics of the object to be detected after the motion interference is eliminated, formula 4 is as follows:

PPG2'=PPG2-Ne' (Formula 4);

Among them, PPG2' represents the effective electrical signal of the biological characteristics of the object to be detected.

The human heart rate can be determined according to the change of the signal amplitude in the effective electrical signal of the biological characteristics of the object to be detected.

Embodiment three

Based on the biological feature detection method described in the first embodiment, an embodiment of the present application provides a biological feature detection device for executing the biological feature detection method described in the first embodiment. As shown in FIG. 5, the biological feature detection The device 50 includes: a control module 501, a sampling module 502, and a signal processing module 503;

The control module 501 is configured to control the first light source to emit a first light signal to the object to be detected;

The sampling module 502 is configured to sample the first electrical signal formed after the first optical signal passes through the object to be detected and is photoelectrically converted;

The control module 501 is also used to control the second light source to emit a second light signal to the object to be detected;

The sampling module 502 is also used to sample a second electrical signal formed after the second optical signal passes through the object to be detected and is photoelectrically converted; the first optical signal is different from the second optical signal;

The signal processing module 503 is used to synthesize the first electrical signal and the white noise signal to obtain a motion reference signal. The amplitude of the white noise signal is lower than the amplitude of the first electrical signal; the motion reference signal is used to remove the second electrical signal. The interference processing obtains the effective electrical signal of the biological characteristics of the object to be detected.

Optionally, in an embodiment of the present application, the first light signal is red light, and the second light signal is green light; the control module 501 is also specifically configured to control the first light source to emit red light to the object to be detected; sampling The module 502 also specifically uses the first electrical signal formed after the sampled red light passes through the object to be detected and is photoelectrically converted;

The control module 501 is also specifically configured to control the second light source to emit green light to the object to be detected; the sampling module 502 is also specifically configured to sample the second electrical signal formed after the green light passes through the object to be detected and is photoelectrically converted.

Optionally, in an embodiment of the present application, the signal processing module 503 is further specifically configured to use a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal; use the analog interference signal to de-interference the second electrical signal The effective electrical signal of the biological characteristics of the object to be detected is obtained by processing.

Optionally, in an embodiment of the present application, the signal processing module 503 is further specifically configured to use a preset algorithm model to adjust the amplitude of the motion reference signal to obtain an analog interference signal, and the amplitude of the analog interference signal is equal to the second The difference in the amplitude of the electrical signal is within a preset range.

Optionally, in an embodiment of the present application, the signal processing module 503 is further specifically configured to calculate the amplitude parameter in the preset algorithm model according to the motion reference signal and the second electrical signal; Input the preset algorithm model to obtain the model interference signal.

Optionally, in an embodiment of the present application, the signal processing module 503 is further specifically configured to use the least squares model to simulate the motion reference signal to obtain the simulated interference signal, and the preset algorithm model includes the least squares model.

Optionally, in an embodiment of the present application, the signal processing module 503 is further specifically configured to subtract the analog interference signal from the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected.

Optionally, in an embodiment of the present application, there are at least two first light sources, and the control module 501 is further specifically configured to control the first light source to emit the first light signal to the object to be detected, including: controlling at least two first light sources. The light source simultaneously emits the first light signal to the object to be detected;

And/or, there are at least two second light sources, and the control module 501 is further specifically configured to control the second light source to emit the second light signal to the object to be detected, including: controlling at least two second light sources to simultaneously emit the second light signal to the object to be detected Light signal.

Optionally, in an embodiment of the present application, the biometric detection device 50 further includes a photoelectric conversion module 504; the photoelectric conversion module 504 is used to perform photoelectric conversion on the first light signal and the second light signal passing through the object to be detected .

Optionally, in an embodiment of the present application, the photodiodes in the photoelectric conversion module 504 are evenly distributed on a circle with the first light source as the center and the first preset distance as the radius.

For example, the photoelectric conversion module 504 may be a photodiode array, and the photodiode array includes at least one photodiode.

Optionally, in an embodiment of the present application, the biometric detection device 50 further includes an analog-to-digital conversion module 505; the analog-to-digital conversion module 505 is configured to perform analog-to-digital conversion processing on the first electrical signal and the second electrical signal. For example, the analog-to-digital conversion module 505 may include one or more analog-to-digital converters, one analog-to-digital converter corresponds to one photodiode, or one analog-to-digital converter corresponds to multiple photodiodes, which is not limited in this application. .

It should be noted that the biometric detection device provided in the embodiment of the present application may be a detection chip, and when the detection chip executes the stored program, the method described in the first or second embodiment is implemented.

Embodiment four

Based on the biometric detection method described in the first embodiment above and the biometric detection device described in the third embodiment above, an embodiment of the present application provides a biometric detection system for executing the method described in the first embodiment, such as As shown in FIG. 6, the biological feature detection system 60 includes: a biological feature detection device 601, a first light source 602, and a second light source 603. The biological feature detection device 601 is the biological feature detection device described in the third embodiment; the first light source 602 is used to emit a first light signal, the second light source 603 is used to emit a second light signal, the first light source 602 is electrically connected to the biometric detection device 601, and the second light source 603 is electrically connected to the biometric detection device 601.

Optionally, in an embodiment of the present application, the photodiodes in the biometric detection device 601 are symmetrically distributed around the first light source 602, and the light emitting center of the second light source 603 coincides with the light emitting center of the first light source 602.

Optionally, in an embodiment of the present application, there are at least two first light sources 602, and the at least two first light sources 602 are on a circle with the second light source 603 as the center and the second preset distance as the radius. Evenly distributed.

The biometric detection device provided by the embodiment of the present application controls the first light source to emit a first light signal to the object to be detected; sampling the first electrical signal formed after the first light signal passes through the object to be detected and is photoelectrically converted; control The second light source emits a second optical signal to the object to be detected; the second electrical signal is formed by sampling the second optical signal after passing through the object to be detected and being photoelectrically converted; the first optical signal is different from the second optical signal, and the second optical signal is An electrical signal is added to a white noise signal to simulate the motion reference signal contained in the second electrical signal, that is, an interference signal. After the motion reference signal is used to de-interference the second electrical signal, the effective biological characteristics of the object to be detected can be obtained. The electrical signal reduces the influence of interference signals on detection and improves the accuracy of optical detection.

Embodiment five

Based on the biometric detection method described in the first embodiment, an embodiment of the present application provides a computer storage medium with a program stored on the computer storage medium. When the processor executes the program stored on the computer storage medium, the implementation is as in the first embodiment. Or the method described in Example 2.

So far, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order shown or sequential order in order to achieve the desired result. In certain embodiments, multitasking and parallel processing may be advantageous.

In the 1990s, the improvement of a technology can be clearly distinguished between hardware improvements (for example, improvements in circuit structures such as diodes, transistors, switches, etc.) or software improvements (improvements in method flow). However, with the development of technology, the improvement of many methods and processes of today can be regarded as a direct improvement of the hardware circuit structure. Designers almost always get the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be realized by the hardware entity module. For example, a programmable logic device (Programmable Logic Device, PLD) (for example, a Field Programmable Gate Array (Field Programmable Gate Array, FPGA)) is such an integrated circuit whose logic function is determined by the user's programming of the device. It is programmed by the designer to "integrate" a digital system on a PLD, without requiring the chip manufacturer to design and manufacture a dedicated integrated circuit chip. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly realized by using "logic compiler" software, which is similar to the software compiler used in program development and writing, but before compilation The original code must also be written in a specific programming language, which is called Hardware Description Language (HDL), and there is not only one type of HDL, but many types, such as ABEL (Advanced Boolean Expression Language) , AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description), etc., currently most commonly used It is VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog. It should also be clear to those skilled in the art that just a little bit of logic programming of the method flow in the above-mentioned hardware description languages and programming into an integrated circuit can obtain the hardware circuit that implements the logic method flow.

The control chip can be implemented in any suitable manner. For example, the control chip can take the form of a micro-control chip or a control chip and a computer-readable medium storing computer-readable program codes (such as software or firmware) that can be executed by the (micro)control chip. , Logic gates, switches, application specific integrated circuits (ASICs), programmable logic control chips and embedded micro-control chips. Examples of control chips include but are not limited to the following micro-control chips: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicon Labs C8051F320, the memory control chip can also be implemented as part of the memory control logic. Those skilled in the art also know that, in addition to implementing the control chip in a purely computer-readable program code manner, it is entirely possible to program the method steps to make the control chip use logic gates, switches, application specific integrated circuits, programmable logic control chips and embedded The same function can be realized in the form of a micro-control chip. Therefore, such a control chip can be regarded as a hardware component, and the devices included in it for realizing various functions can also be regarded as a structure within the hardware component. Or even, the device for realizing various functions can be regarded as both a software module for realizing the method and a structure within a hardware component.

For the convenience of description, when describing the above device, the functions are divided into various units and described separately. Of course, when implementing this application, the functions of each unit can be implemented in the same one or more software and/or hardware.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, devices, or computer program products. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, devices, and computer program products according to embodiments of this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the control chip of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing equipment to generate a machine, so that the instructions executed by the control chip of the computer or other programmable data processing equipment are generated for use. It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

In a typical configuration, the computing device includes one or more control chips (CPU), input/output interfaces, network interfaces, and memory.

The memory may include non-permanent memory in a computer readable medium, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media include permanent and non-permanent, removable and non-removable media, and information storage can be realized by any method or technology. 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, 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 can be used to store information that can be accessed by computing devices. According to the definition in this article, computer-readable media does not include transitory media, such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or equipment including a series of elements includes not only those elements, but also Other elements that are not explicitly listed, or they also include elements inherent to such processes, methods, commodities, or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, commodity, or equipment that includes the element.

Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for related parts, please refer to the part of the description of the method embodiment.

The foregoing descriptions are only examples of the present application, and are not used to limit the present application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims

A method for detecting biological characteristics, which is characterized in that it comprises:

Controlling the first light source to emit a first light signal to the object to be detected;

Sampling the first electrical signal formed after the first optical signal passes through the object to be detected and is photoelectrically converted;

Controlling the second light source to emit a second light signal to the object to be detected;

Sampling a second electrical signal formed after the second optical signal passes through the object to be detected and is photoelectrically converted; the first optical signal is different from the second optical signal;

Synthesizing the first electrical signal and the white noise signal to obtain a motion reference signal, where the amplitude of the white noise signal is lower than the amplitude of the first electrical signal;

Using the motion reference signal to perform interference removal processing on the second electrical signal to obtain an effective electrical signal of the biological feature of the object to be detected.
The biological feature detection method according to claim 1, wherein the absorption rate of the first light signal by the object to be detected is greater than the absorption rate of the second light signal by the object to be detected.
The biological feature detection method according to claim 1 or 2, wherein the first light signal is red light, and the second light signal is green light;

Controlling the first light source to emit a first light signal to the object to be detected, and sampling the first electrical signal formed after the first light signal passes through the object to be detected and photoelectrically converted includes: controlling the first light source to transmit the first light signal to the object to be detected. The detection object emits the red light, and the first electrical signal formed after the red light passes through the object to be detected and is photoelectrically converted is sampled;

Controlling the second light source to emit a second light signal to the object to be detected, sampling the second electrical signal formed after the second light signal passes through the object to be detected and being photoelectrically converted, includes: controlling the second light source to transmit the second light signal to the object to be detected. The detection object emits the green light, and the second electrical signal formed after the green light passes through the object to be detected and is photoelectrically converted is sampled.
The biometric detection method according to claim 1 or 2, characterized in that, using the motion reference signal to perform de-interference processing on the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected comprises:

Using a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal;

Using the analog interference signal to perform de-interference processing on the second electrical signal to obtain an effective electrical signal of the biological feature of the object to be detected.
The biometric detection method according to claim 4, characterized in that, using a preset algorithm model to simulate the motion reference signal to obtain a simulated interference signal, comprising:

Using the preset algorithm model to adjust the amplitude of the motion reference signal to obtain the analog interference signal, and the difference between the amplitude of the analog interference signal and the amplitude of the second electrical signal is within a preset range .
The biometric detection method according to claim 5, characterized in that, using a preset algorithm model to simulate the motion reference signal to obtain a simulated interference signal, comprising:

Calculate the amplitude parameter in the preset algorithm model according to the motion reference signal and the second electrical signal; input the amplitude parameter and the motion reference signal into the preset algorithm model to obtain the model interference signal.
The biometric detection method according to claim 4, characterized in that, using a preset algorithm model to simulate the motion reference signal to obtain a simulated interference signal, comprising:

The motion reference signal is simulated by using a least squares model to obtain the simulated interference signal, and the preset algorithm model includes the least squares model.
4. The biological feature detection method according to claim 4, wherein the use of the analog interference signal to perform interference removal processing on the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected comprises:

Subtracting the analog interference signal from the second electrical signal to obtain an effective electrical signal of the biological feature of the object to be detected.
The biometric detection method according to claim 1 or 2, wherein there are at least two first light sources, and controlling the first light sources to emit the first light signal to the object to be detected includes: controlling at least two first light sources Simultaneously emit the first light signal to the object to be detected;

And/or, there are at least two second light sources, and controlling the second light sources to emit second light signals to the object to be detected includes: controlling the at least two second light sources to simultaneously emit the second light signals to the object to be detected.
A biological feature detection device, which is characterized by comprising: a control module, a sampling module, and a signal processing module;

The control module is used to control the first light source to emit the first light signal to the object to be detected;

The sampling module is configured to sample the first electrical signal formed after the first optical signal passes through the object to be detected and is photoelectrically converted;

The control module is also used to control the second light source to emit a second light signal to the object to be detected;

The sampling module is also used to sample a second electrical signal formed after the second optical signal passes through the object to be detected and is photoelectrically converted; the wavelength of the first optical signal is different from the wavelength of the second optical signal ；

The signal processing module is configured to synthesize the first electrical signal and the white noise signal to obtain a motion reference signal, and the amplitude of the white noise signal is lower than the amplitude of the first electrical signal; using the motion The reference signal performs interference removal processing on the second electrical signal to obtain an effective electrical signal of the biological feature of the object to be detected.
The biometric detection device according to claim 10, wherein the absorption rate of the first optical signal by the object to be detected is greater than the absorption rate of the second optical signal by the object to be detected.
The biological feature detection device according to claim 10 or 11, wherein the first light signal is red light, and the second light signal is green light;

The control module is further specifically configured to control the first light source to emit the red light to the object to be detected;

The sampling module is also specifically configured to sample the first electrical signal formed after the red light passes through the object to be detected and is photoelectrically converted;

The control module is further specifically configured to control the second light source to emit the green light to the object to be detected;

The sampling module is also specifically configured to sample the second electrical signal formed after the green light passes through the object to be detected and is photoelectrically converted.
The biometric detection device according to claim 10 or 11, wherein:

The signal processing module is further specifically configured to use a preset algorithm model to simulate the motion reference signal to obtain an analog interference signal; use the analog interference signal to perform interference removal processing on the second electrical signal to obtain the to-be-detected The effective electrical signal of the biological characteristics of the object.
The biometric detection device according to claim 13, wherein:

The signal processing module is further specifically configured to use the preset algorithm model to adjust the amplitude of the motion reference signal to obtain the analog interference signal, and the amplitude of the analog interference signal and the second electrical signal The difference in amplitude is within the preset range.
The biometric detection device according to claim 14, wherein:

The signal processing module is further specifically configured to calculate the amplitude parameter in the preset algorithm model according to the motion reference signal and the second electrical signal; input the amplitude parameter and the motion reference signal into the office The preset algorithm model obtains the model interference signal.
The biometric detection device according to claim 13, wherein:

The signal processing module is further specifically configured to use a least squares method model to simulate the motion reference signal to obtain the simulated interference signal, and the preset algorithm model includes the least squares method model.
The biometric detection device according to claim 13, wherein:

The signal processing module is further specifically configured to subtract the analog interference signal from the second electrical signal to obtain the effective electrical signal of the biological feature of the object to be detected.
The biometric detection device according to claim 10 or 11, wherein:

There are at least two first light sources, and the control module is further specifically configured to control the first light source to emit the first light signal to the object to be detected, including: controlling the at least two first light sources to simultaneously emit the first light to the object to be detected signal;

And/or, there are at least two second light sources, and the control module is further specifically configured to control the second light source to emit the second light signal to the object to be detected, including: controlling the at least two second light sources to simultaneously transmit the second light signal to the object to be detected The second optical signal is emitted.
The biological feature detection device according to claim 10 or 11, wherein the biological feature detection device further comprises a photoelectric conversion module;

The photoelectric conversion module is configured to perform photoelectric conversion on the first light signal and the second light signal passing through the object to be detected.
The biological feature detection device according to claim 19, wherein the photodiodes in the photoelectric conversion module are evenly distributed on a circle centered on the first light source and a radius of the first preset distance.
A biological feature detection system, comprising: a first light source, a second light source, and the biological feature detection device according to any one of claims 10-20, and the first light source is used to emit a first light signal The second light source is used to emit a second light signal, the first light source is electrically connected to the biological feature detection device, and the second light source is electrically connected to the biological feature detection device.
The biometric detection system according to claim 21, wherein:

The photodiodes in the biometric detection device are symmetrically distributed around the first light source; the light-emitting center of the second light source coincides with the light-emitting center of the first light source.
The biometric detection system according to claim 21, wherein:

There are at least two first light sources, and at least two of the first light sources are evenly distributed on a circle with the second light source as the center and the second preset distance as the radius.
A computer storage medium, characterized in that a program is stored on the computer storage medium, and when the processor executes the program stored on the computer storage medium, the biological feature according to any one of claims 1-9 is realized Detection method.