Test circuit and method and electronic equipment

Abstract

The invention provides a test circuit, a test method and electronic equipment. The test circuit is small in size, low in cost, beneficial to miniaturization design of the electronic equipment and beneficial to cost reduction of the electronic equipment. The test circuit comprises a light emitting assembly used for emitting at least two optical signals, and the at least two optical signals comprise a first optical signal and a second optical signal; the first optical signal and the second optical signal are different in wavelength; and the proximity light sensor is used for collecting a first light reference signal and a second light reference signal which are reflected and / or scattered by the human body, and the first light reference signal and the second light reference signal are used for calculating the characteristic value of the human body.

Description

Testing circuit and method, electronic equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on October 16, 2023, with application number 202311344325.7 and application name “Test Circuits and Methods, Electronic Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of electronic technology, and in particular to a test circuit and method, and electronic equipment. Background Art

[0003] At present, with the development of terminal technology, terminal devices have become a part of people's work and life. In order to meet the needs of users for their own health management, many terminal devices can support the user's human vital sign parameter monitoring function. For example, users can use wearable devices such as smart watches to measure human body characteristics such as heart rate, respiratory rate, blood pressure or blood oxygen. Typically, terminal devices can be configured with a photoplethysmograph (PPG) module for measuring human body characteristics. However, existing PPG modules have the problem of occupying a large space.

[0004] Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a test circuit and method, and an electronic device. The test circuit of the present application is small in size and low in cost, which is conducive to the miniaturization design of electronic equipment and helps reduce the cost of electronic equipment.

[0006] In a first aspect, an embodiment of the present application provides a test circuit, which includes: a light-emitting component for emitting at least two optical signals, the at least two optical signals including a first optical signal and a second optical signal; the first optical signal and the second optical signal have different wavelengths; and a proximity light sensor for collecting a first optical reference signal and a second optical reference signal reflected and / or scattered by a human body, the first optical reference signal and the second optical reference signal being used to calculate a human body characteristic value.

[0007] By replacing the existing PPG module with a light-emitting component and a proximity light sensor, the test circuit provided in the embodiments of the present application can reduce costs by utilizing the proximity light sensor to detect PPG signals, due to its widespread application and low price. Furthermore, because the proximity light sensor integrates a structure for collecting and processing light signals, the test circuit capable of measuring PPG signals in the embodiments of the present application is smaller than the PPG module in the prior art.

[0008] Exemplarily, the at least two optical signals may further include a first optical signal, a second optical signal, and a third optical signal, or the at least two optical signals may include a first optical signal, a second optical signal, a third optical signal, and a fourth optical signal, or the at least two optical signals may include a first optical signal, a second optical signal, a third optical signal, a fourth optical signal, and a fifth optical signal, etc., that is, the test circuit can not only calculate blood oxygen saturation, heart rate, etc. based on signals of two different optical bands (such as the first optical signal and the second optical signal), but can also couple optical signals of other bands to determine the PPG signal, so as to calculate human vital sign parameters such as blood pressure, blood sugar, perfusion index, pulse variability index, carbon monoxide hemoglobin, glycated hemoglobin and other blood indicators based on the PPG signal.

[0009] Illustratively, the first optical reference signal reflected and / or scattered by the human body may be the first optical reference signal reflected by the human body, the first optical reference signal scattered by the human body, or the first optical reference signal reflected and scattered by the human body.

[0010] According to a first aspect, a proximity light sensor includes: an acquisition unit for acquiring a first light reference signal and a second light reference signal, and converting the first light reference signal and the second light reference signal into electrical signals, respectively, wherein the electrical signals are analog signals; an analog-to-digital converter connected to the acquisition unit, for converting the analog signal into a digital signal, and the digital signal is used to calculate a human body characteristic value.

[0011] The above is a specific structure of a proximity light sensor. The simple internal structure of the proximity light sensor makes the proximity light sensor relatively small. Of course, the structure of the proximity light sensor is not limited to this. Any proximity light sensor that can collect the first and second optical reference signals and calculate human body characteristic values ​​based on the collected signals is within the scope of protection of this application.

[0012] According to the first aspect, or any implementation of the first aspect above, the light-emitting component includes a first light-emitting unit and a second light-emitting unit, the collection unit includes a first photosensitive device and a second photosensitive device, the first light-emitting unit is used to emit a first light signal, the first photosensitive device is used to collect a first optical reference signal, the second light-emitting unit is used to emit a second light signal, and the second photosensitive device is used to collect a second optical reference signal.

[0013] In other words, different photosensors respond to light signals of different wavelengths (i.e., they can convert light signals of different wavelengths into electrical signals), so that the light signals do not affect each other, thereby improving detection accuracy.

[0014] Exemplarily, the number of photosensors in the collection unit can correspond one-to-one to the number of light-emitting units. For example, the light-emitting assembly includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit, and the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit respectively emit a first light signal, a second light signal, and a third light signal. Accordingly, the collection unit includes a first photosensor, a second photosensor, and a third photosensor, where the first photosensor is used to collect a first optical reference signal, the second photosensor is used to collect a second optical reference signal, and the third photosensor is used to collect a third optical reference signal reflected and / or scattered by the human body.

[0015] According to the first aspect, or any implementation of the first aspect, the proximity light sensor includes a first light emitting unit or a second light emitting unit.

[0016] That is, the emitting light source inside the proximity light sensor is used as one of the light-emitting units. In this way, the number of light-emitting units required to be provided in the light-emitting assembly can be reduced, further reducing the volume of the test circuit.

[0017] According to the first aspect, or any implementation of the first aspect above, it also includes a processing unit, which is connected to the analog-to-digital converter and is used to obtain the integral value of the light intensity of the first light reference signal in the first time period and the light intensity of the second light reference signal in the second time period based on the digital signal, and the integral value is used to calculate the human body characteristic value.

[0018] Exemplarily, the proximity light sensor includes a processing unit, that is, the processing unit can be provided in the proximity light sensor. In this way, there is no need to provide an external processing unit, further reducing the volume of the test circuit.

[0019] For example, the processing unit can also be an external processing unit, that is, a device with specific processing functions in the electronic device, such as a processor. By utilizing the device with processing functions in the electronic device to process the digital signal, the need for a separate processing unit is eliminated, further reducing the size and cost of the test circuit.

[0020] According to the first aspect, or any implementation of the first aspect above, the light-emitting component emits the first optical signal and the second optical signal according to a duty cycle. This allows for obtaining multiple sets of the first optical reference signal and the second optical reference signal, and for calculating human body feature values ​​based on the multiple sets of the first optical reference signal and the second optical reference signal.

[0021] For example, the processing unit of the proximity light sensor may drive the light-emitting component to emit the first light signal and the second light signal according to the working cycle; or a device with specific processing functions in the electronic device, such as a processor, may drive the light-emitting component to emit the first light signal and the second light signal according to the working cycle.

[0022] According to the first aspect, or any implementation of the first aspect above, the working cycle includes at least a first stage and a second stage; the first stage and the second stage each include at least one pulse period, the pulse period including a light-emitting stage operating in a first level state and a non-light-emitting stage operating in a second level state; the light-emitting component is configured to emit a first light signal during the light-emitting stage of the first stage, and to emit a second light signal during the light-emitting stage of the second stage; the proximity light sensor is configured to collect a third light signal during the light-emitting stage of the first stage, and to collect a fourth light signal during the non-light-emitting stage of the first stage; the proximity light sensor is configured to collect a fifth light signal during the light-emitting stage of the second stage, and to collect a sixth light signal during the non-light-emitting stage of the second stage; the processing unit is configured to obtain an integral value of the light intensity of the first optical reference signal based on the third light signal and the fourth light signal; and is configured to obtain an integral value of the light intensity of the second optical reference signal based on the fifth light signal and the sixth light signal; the first time period is the first stage, and the second time period is the second stage; the third light signal is determined based on ambient light and reflection and / or scattering of the first light signal, the fourth light signal is determined based on ambient light, the fifth light signal is determined based on reflection and / or scattering of the ambient light and the second light signal, and the sixth light signal is determined based on ambient light.

[0023] The test circuit not only detects light reflected and / or scattered by the first optical signal and the second optical signal, but also detects ambient light. In this way, interference from external ambient light can be reduced, background noise can be filtered out, and detection accuracy can be improved.

[0024] Exemplarily, the first optical reference signal includes both the first optical signal and the signal of the ambient light reflected and / or scattered by the human body during the luminous stage of the first stage, and the signal of the ambient light reflected and / or scattered by the human body during the non-luminous stage of the first stage.

[0025] Exemplarily, the second optical reference signal includes both the second optical signal and the signal of the ambient light reflected and / or scattered by the human body during the light-emitting stage of the second stage, and the signal of the ambient light reflected and / or scattered by the human body during the non-light-emitting stage of the second stage.

[0026] Exemplarily, the first level is, for example, a high level, and the second level is, for example, a low level.

[0027] Exemplarily, the third optical signal is determined based on the reflection and / or scattering of the ambient light and the first optical signal. The third optical signal may be determined based on the reflection of the ambient light and the first optical signal, or may be determined based on the scattering of the ambient light and the first optical signal, or may be determined based on the reflection and scattering of the ambient light and the first optical signal.

[0028] Exemplarily, the fifth optical signal is determined based on the reflection and / or scattering of the ambient light and the second optical signal. The fifth optical signal may be determined based on the reflection of the ambient light and the second optical signal, or may be determined based on the scattering of the ambient light and the second optical signal, or may be determined based on the reflection and scattering of the ambient light and the second optical signal.

[0029] According to the first aspect, or any implementation of the first aspect above, the acquisition unit includes a first photosensor and a second photosensor, the first photosensor and the analog-to-digital converter form a first acquisition channel, and the second photosensor and the analog-to-digital converter form a second acquisition channel; the first acquisition channel is used to collect the third light signal during the light-emitting phase of the first stage and the fourth light signal during the non-light-emitting phase of the first stage; the second acquisition channel is used to collect the fifth light signal during the light-emitting phase of the second stage and the sixth light signal during the non-light-emitting phase of the second stage.

[0030] Since the analog-to-digital converter is shared, the third optical signal and the fourth optical signal, as well as the fifth optical signal and the sixth optical signal are collected in a time-sharing manner through the first collection channel and the second collection channel, thereby avoiding mutual influence between different optical signals.

[0031] According to the first aspect, or any implementation of the first aspect above, the first stage and the second stage both include N pulse periods, where N≥2, and N is a positive integer.

[0032] That is, a single pulse (light signal) emission period is divided into several pulse periods, shortening the pulse time. Without affecting the sensitivity, the influence of the flickering light source can be reduced and the anti-interference ability can be improved.

[0033] According to the first aspect, or any implementation of the first aspect above, a working cycle includes at least one pulse cycle, and the pulse cycle includes a light-emitting phase operating in a first level state and a non-light-emitting phase operating in a second level state; the light-emitting component is used to emit a first light signal and a second light signal in the light-emitting phase; the proximity light sensor is used to collect a seventh light signal and an eighth light signal in the light-emitting phase, and to collect a ninth light signal and a tenth light signal in the non-light-emitting phase; the processing unit is used to obtain an integral value of the light intensity of the first optical reference signal based on the seventh light signal and the ninth light signal; and is also used to obtain an integral value of the light intensity of the second optical reference signal based on the eighth light signal and the tenth light signal; the first time period and the second time period are the same time period, and the first time period is one working cycle; the seventh light signal is determined based on ambient light and reflection and / or scattering of the first light signal, the eighth light signal is determined based on reflection and / or scattering of the ambient light and the second light signal, the ninth light signal is determined based on ambient light, and the tenth light signal is determined based on ambient light.

[0034] The test circuit not only detects light reflected and / or scattered by the first and second optical signals, but also detects ambient light. This reduces interference from ambient light, filters out background noise, and improves detection accuracy. Furthermore, when the proximity light sensor includes multiple analog-to-digital converters, the proximity light sensor can simultaneously collect the seventh and eighth optical signals during the light-emitting phase, and simultaneously collect the ninth and tenth optical signals during the non-light-emitting phase, collecting optical signals of different wavelengths at the same time. Compared to collecting optical signals of different wavelengths in a time-sharing manner (i.e., at different times), since vital sign parameters are determined based on optical signals of different wavelengths, the optical signals of different wavelengths obtained in a time-sharing manner result in a certain time difference in the user's vital signs, which cannot better reflect the true vital signs. In this solution, optical signals of different wavelengths can be obtained at the same time, i.e., they can reflect the user's vital signs at the same time, better follow the user's physiological change data, and more realistically reflect the vital signs. On this basis, more time can be reserved for the analog-to-digital converter to process the optical signals, which can increase the detection integration time and achieve better sensitivity.

[0035] Exemplarily, the first optical reference signal includes both the first optical signal and the signal of ambient light reflected and / or scattered by the human body in the light-emitting phase, and the signal of ambient light reflected and / or scattered by the human body in the non-light-emitting phase.

[0036] Exemplarily, the second optical reference signal includes both the second optical signal and the signal of ambient light reflected and / or scattered by the human body in the light-emitting phase, and the signal of ambient light reflected and / or scattered by the human body in the non-light-emitting phase.

[0037] Exemplarily, the first level is, for example, a high level, and the second level is, for example, a low level.

[0038] Exemplarily, the seventh optical signal is determined based on the reflection and / or scattering of the ambient light and the first optical signal. The seventh optical signal may be determined based on the reflection of the ambient light and the first optical signal, or may be determined based on the scattering of the ambient light and the first optical signal, or may be determined based on the reflection and scattering of the ambient light and the first optical signal.

[0039] Exemplarily, the eighth optical signal is determined based on the reflection and / or scattering of the ambient light and the second optical signal. The eighth optical signal may be determined based on the reflection of the ambient light and the second optical signal, or may be determined based on the scattering of the ambient light and the second optical signal, or may be determined based on the reflection and scattering of the ambient light and the second optical signal.

[0040] According to the first aspect, or any implementation of the first aspect above, the acquisition unit includes a first photosensor and a second photosensor, and the analog-to-digital converter includes a first analog-to-digital converter and a second analog-to-digital converter; the first photosensor and the first analog-to-digital converter form a first acquisition channel, and the second photosensor and the second analog-to-digital converter form a second acquisition channel; the first acquisition channel is used to collect the seventh light signal in the light-emitting phase and the ninth light signal in the non-light-emitting phase; the second acquisition channel is used to collect the eighth light signal in the light-emitting phase and the tenth light signal in the non-light-emitting phase.

[0041] Since there are multiple analog-to-digital converters, the seventh optical signal and the eighth optical signal can be collected simultaneously through the first acquisition channel and the second acquisition channel in the light-emitting phase, and the ninth optical signal and the tenth optical signal can be collected simultaneously in the non-light-emitting phase, thereby avoiding mutual influence between different optical signals.

[0042] According to the first aspect, or any implementation of the first aspect above, the working cycle includes N pulse cycles, where N≥2 and N is a positive integer.

[0043] That is, a single pulse (light signal) emission period is divided into several pulse periods, shortening the pulse time. Without affecting the sensitivity, the influence of the flickering light source can be reduced and the anti-interference ability can be improved.

[0044] According to the first aspect, or any implementation of the first aspect above, the first optical signal includes a red light signal, and the second optical signal includes an infrared light signal.

[0045] This is beneficial for calculating the blood oxygen saturation.

[0046] Of course, this does not constitute a limitation of the present application, and those skilled in the art may make choices based on actual circumstances. Optionally, the first optical signal may include, for example, a green light signal, and the second optical signal may include, for example, a blue light signal; or, the first optical signal may include, for example, a red light signal, and the second optical signal may include, for example, a green light signal; or, the first optical signal may include, for example, a green light signal, and the second optical signal may include, for example, an infrared light signal.

[0047] Of course, optical signals of other wavelength bands can also be coupled to realize different functions, and are not limited to optical signals of two wavelength bands.

[0048] In a second aspect, an embodiment of the present application provides an electronic device, which includes: a test circuit corresponding to the above-mentioned first aspect and any one of the implementation methods of the first aspect.

[0049] The second aspect and any implementation of the second aspect correspond to the first aspect and any implementation of the first aspect, respectively. The technical effects corresponding to the second aspect and any implementation of the second aspect can be referred to the technical effects corresponding to the first aspect and any implementation of the first aspect, and will not be repeated here.

[0050] According to a second aspect, the electronic device further includes a display screen, which is reused as a light-emitting component.

[0051] Directly using the display screen in the electronic device as a light-emitting component eliminates the need to set up a separate light-emitting component, thereby reducing costs, further reducing the test circuit's occupancy of the electronic device, and freeing up more space for setting up other structures.

[0052] According to the second aspect, or any implementation of the first aspect, the display screen includes a display area and a non-display area surrounding the display area, and the proximity light sensor is located in the non-display area.

[0053] During detection, the user's finger needs to cover the proximity light sensor and part of the display area of ​​the display to facilitate user detection.

[0054] Of course, the position of the proximity light sensor is not limited to this. Optionally, the proximity light sensor can also be set at a position such as below the display screen.

[0055] According to the second aspect, or any implementation of the first aspect above, the electronic device includes a display screen and a flash light arranged on opposite sides of the electronic device, the proximity light sensor and the flash light are arranged on the same side of the electronic device, the flash light is multiplexed into a light-emitting component, and the light signal emitted by the flash light consists of at least a first light signal and a second light signal.

[0056] Directly utilizing the flashlight in the electronic device as the light-emitting component eliminates the need to separately provide a light-emitting component, thereby reducing costs, further reducing the test circuit's occupation of the electronic device, and freeing up more space for arranging other structures.

[0057] The proximity sensor is placed near the flash. During detection, the user's finger needs to cover the proximity sensor and the flash.

[0058] In a third aspect, an embodiment of the present application provides a testing method, which is applied to an electronic device, wherein the electronic device includes multiple working cycles, the working cycle includes at least one pulse cycle, and the pulse cycle includes a light-emitting phase working in a first level state and a non-light-emitting phase working in a second level state; the testing method includes: in the light-emitting phase, emitting a first light signal and a second light signal, and collecting a seventh light signal and an eighth light signal, the first light signal and the second light signal having different wavelengths, the seventh light signal being determined based on the ambient light and the reflection and / or scattering of the first light signal, and the eighth light signal being determined based on the reflection and / or scattering of the ambient light and the second light signal; in the non-light-emitting phase, collecting a ninth light signal and a tenth light signal, the ninth light signal being determined by the ambient light, and the tenth light signal being determined by the ambient light; obtaining an integral value of the light intensity of the first optical reference signal based on the seventh light signal and the ninth light signal, and obtaining an integral value of the light intensity of the second optical reference signal based on the eighth light signal and the tenth light signal.

[0059] The light-emitting component can emit at least two optical signals simultaneously. The electronic device collects and processes the seventh optical signal and the ninth optical signal to obtain the integral value of the light intensity of the first optical reference signal. At the same time, the electronic device collects and processes the eighth optical signal and the tenth optical signal to obtain the integral value of the light intensity of the second optical reference signal. That is, at the same time, optical signals of different wavelengths are obtained. Compared with optical signals of different wavelengths obtained in time-sharing (i.e., at different times), since vital sign parameters are determined based on optical signals of different wavelengths, the optical signals of different wavelengths obtained in time-sharing result in a certain time difference in the user's vital signs, which cannot better reflect the true vital signs. In this solution, optical signals of different wavelengths can be obtained at the same time, that is, they can reflect the user's vital signs at the same time, better follow the user's physiological change data, and can more realistically reflect the vital signs. On this basis, since there is no need to collect optical signals of different wavelengths in time-sharing, more time can be reserved for optical signal processing, and a longer integration time can be reserved, thereby obtaining better sensitivity.

[0060] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising: a memory and a processor, the memory and the processor being coupled; the memory stores program instructions, and when the program instructions are executed by the processor, the electronic device executes the test method described in the third aspect.

[0061] The fourth aspect corresponds to the third aspect. The technical effects corresponding to the fourth aspect can be referred to the technical effects corresponding to the third aspect, which will not be repeated here.

[0062] Exemplarily, the electronic device includes a mobile phone, a tablet computer, or a wearable electronic device.

[0063] Of course, this does not constitute a limitation of the present application, and those skilled in the art may make choices based on actual circumstances. Optionally, the electronic device may also include medical equipment, laptop computers, smart home devices, personal digital assistants (PDAs), car computers, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is a graph showing the absorption spectra of different types of hemoglobin;

[0065] FIG2 is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

[0066] FIG3 is a cross-sectional view of the electronic device shown in FIG2 along the line AA';

[0067] FIG4 is a diagram showing the working principle of a proximity light sensor;

[0068] FIG5 is a schematic diagram of one application scenario of an electronic device provided in an embodiment of the present application;

[0069] FIG6 is a circuit diagram of a test circuit provided in an embodiment of the present application;

[0070] FIG7 is a top view of a proximity light sensor provided in an embodiment of the present application;

[0071] FIG8 is an example of a test circuit provided in an embodiment of the present application;

[0072] FIG9 is a timing diagram of time-sharing driving of a test circuit provided in an embodiment of the present application;

[0073] FIG10 is a comparison diagram of the operating timing of the light-emitting component and the operating timing of the flashing light source in the embodiment of the present application;

[0074] FIG11 is another timing diagram of the time-sharing drive of the test circuit provided in an embodiment of the present application;

[0075] FIG12 is a circuit diagram of another test circuit provided in an embodiment of the present application;

[0076] FIG13 is an example of a proximity light sensor provided in an embodiment of the present application;

[0077] FIG14 is a timing diagram of simultaneous driving of a test circuit provided in an embodiment of the present application;

[0078] FIG15 is another timing diagram of simultaneous driving of the test circuit provided in an embodiment of the present application

[0079] FIG16 is an interface diagram of the blood oxygen and heart rate test results obtained based on the test circuit provided in an embodiment of the present application;

[0080] FIG17 is an oxygen reduction monitoring diagram obtained based on the test circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0081] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0082] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0083] In the description and claims of the embodiments of this application, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first target object" and "second target object" are used to distinguish different objects, rather than to describe a specific order of objects.

[0084] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0085] In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. For example, "multiple processing units" means two or more processing units; "multiple systems" means two or more systems.

[0086] When light passes through skin tissue and then reflects back to the detection structure, it experiences a certain amount of attenuation. Light absorption by muscle, bone, veins, and other connective tissues remains essentially constant (assuming the measurement site doesn't move significantly). However, blood is different. Due to the flow of blood in arteries, its absorption naturally varies. Figure 1 shows the absorption spectra of different types of hemoglobin. As can be seen from Figure 1, the absorption rates of Hb (deoxyhemoglobin) and HbO2 (oxyhemoglobin) in human blood vary across different wavelengths. For example, at 700 nanometers, the absorption rate of Hb (deoxyhemoglobin) is higher than that of HbO2 (oxyhemoglobin), while at 900 nanometers, the absorption rate of HbO2 (oxyhemoglobin) is higher than that of Hb (deoxyhemoglobin).

[0087] When light is converted into electrical signals, the resulting signal can be divided into alternating current (AC) and direct current (DC) signals, precisely because arterial absorption varies while absorption by other tissues remains largely unchanged. Extracting the AC signal reveals the characteristics of blood flow. This technology is called photoplethysmography (PPG).

[0088] PPG modules are often used in smart wearable devices. Based on photoplethysmography (PPG) technology, PPG modules detect a user's heart rate, blood oxygen saturation, and other human characteristics. PPG modules primarily consist of an analog front end (AFE), a light-emitting diode (LED) light source, and a photodetector (PD). The detection principle is as follows: A light signal is emitted by the LED. After it reaches the skin, some of the light signal is absorbed by human tissue (including blood), while some is scattered and reflected. A portion of the scattered and reflected light signal is received by the PD and converted into an electrical signal. The scattered and reflected light signal exhibits regular changes with the pulsation of the human pulse. The AFE detects changes in the pulse wave based on the changes in the electrical signal detected by the PD, and can then determine heart rate, blood oxygen saturation, and other data based on these changes in the pulse wave.

[0089] Specifically, when the PPG module is operating, the AFE drives the LED to time-share light signals of different wavelengths. Once the light signals reach the skin, some are absorbed by tissue (including blood), while others are scattered and reflected. Some of these scattered and reflected light signals are received by the PD and converted into electrical signals. The AFE then amplifies and processes the electrical signals from the PD to generate PPG signals of different wavelengths.

[0090] The blood oxygen saturation (SPO2) is calculated using multiple PPG signals of different wavelengths (such as red light and infrared light). The empirical formula for calculating blood oxygen saturation is: SPO2 = a × R + b

[0091] Wherein, R = PI(RED) / PI(IR), PI(RED) is the ratio of the AC signal to the DC signal separated from the red light PPG signal, PI(IR) is the ratio of the AC signal to the DC signal separated from the infrared light PPG signal, a and b are fitting coefficients. The blood oxygen saturation SPO2 can be measured using a medical oximeter and the R value can be obtained. Then, a and b can be obtained by fitting according to the data fitting method.

[0092] The PD, LED and AFE devices in the existing PPG module are all independent structures. The independent setting of the PD, LED and AFE devices will cause the PPG module to be larger in size and occupy a larger space in the electronic device. This is not conducive to the miniaturization design of electronic devices using the PPG module.

[0093] Furthermore, the existing solution of integrating the PD, LED, and AFE into a single PPG module results in a high cost due to the integration process, which hinders the cost reduction of electronic devices using the PPG module. Furthermore, because the PD of the PPG module can only collect light signals of different wavelengths in a time-sharing manner, the collected red light signal and infrared light signal are delayed compared to the other. This means that the red light signal and infrared light signal are not obtained simultaneously, resulting in poor tracking of physiological change data and low accuracy of the calculated blood oxygen saturation value.

[0094] To solve the above technical problems, the embodiments of the present application provide a test circuit, which can be applied to electronic devices. Electronic devices include but are not limited to smart wearable devices (such as smart watches, smart bracelets, or smart eye masks that can support human health monitoring), mobile phones, tablet computers, laptops, medical devices, smart home appliances, etc. For ease of understanding, the following example uses the test circuit applied to a mobile phone as an example for illustrative purposes.

[0095] 2 and 3 , FIG2 is a schematic structural diagram of an electronic device provided in an embodiment of the present application, and FIG3 is a cross-sectional view of the electronic device shown in FIG2 along the AA′ direction. The electronic device 100 includes a display module 10 , a back cover (also called a battery cover) 20 and a middle frame 30 .

[0096] The display module 10 includes a stacked cover plate and a display screen. The cover plate protects the display screen. The display screen may include a liquid crystal display (LCD), an organic light emitting diode (OLED) display screen, or an LED display screen. The LED display screen may include a micro-LED display screen or a mini-LED display screen. The present embodiment does not limit the type of display screen.

[0097] Exemplarily, the display screen 12 includes a display area and a non-display area surrounding the display area. The display area is provided with a plurality of sub-pixels for emitting light, and the non-display area is provided with a driving circuit for driving the sub-pixels in the display area to emit light.

[0098] The material of the back cover 20 may include opaque materials such as plastic, plain leather, and fiberglass; or may include translucent materials such as glass. The present embodiment of the application does not limit the material of the back cover 20.

[0099] The middle frame 30 includes an annular appearance member 31 and a support member (not shown) located within the annular appearance member 31 and between the display module 10 and the back cover 20. The back cover 20 and the middle frame 30 can be an integrated structure or separate structures, which is not limited in this embodiment of the application.

[0100] The cover, back cover (also known as the battery cover) 20, and annular exterior member 31 enclose a housing cavity, which houses a printed circuit board (PCB) 40 and functional components 50. The functional components 50 include a first functional component and a second functional component. The first functional component can be located on and electrically connected to the PCB 40, while the second functional component may not be located on the PCB 40 but is electrically connected to it. The first functional component may include components such as a processor 51, a test circuit 52, and a display driver chip (a chip used to drive the display screen). The second functional component may include components such as a camera 53 and a flash 54. The display screen and flash 54 are located on opposite sides of the phone, with the camera 53 and flash 54 located on the same side of the electronic device. Alternatively, the functional component 50 may include only the first functional component or only the second functional component. The components are electrically connected via the PCB 40, enabling signal transmission and interaction. The support member may support some of the structures within the housing cavity.

[0101] The test circuit 52 includes a light-emitting component 521 and a proximity light sensor 522, etc. The PPG signal is tested through the test circuit 52, and then the user's heart rate, respiratory rate, blood oxygen, blood pressure, blood sugar, perfusion index, pulse variability index, carbon monoxide hemoglobin, glycosylated hemoglobin and other blood indicators and other human vital sign parameters are determined based on the PPG signal.

[0102] The proximity light sensor 522 is commonly used in electronic devices (such as mobile phones, smart wearable devices, tablets, etc.) to detect whether there is an object near the electronic device 100, as well as the distance of the object. For example, the electronic device 100 can use the proximity light sensor to detect that the user holds the electronic device 100 close to the ear to talk, so as to automatically turn off the screen to save power. See Figure 4, which is a diagram of the working principle of the proximity light sensor. As shown in Figure 4, the working principle of the proximity light sensor is that an emitting light source, such as an infrared light source, emits infrared light. Among them, the infrared light source can be an infrared LED, an infrared vertical cavity surface emitting laser (VCSEL), etc. At the same time, an infrared light detector is used to receive the infrared light reflected back from the approaching object, and the intensity of the reflected infrared light is integrated. The integral value is defined as proximity data (PDATA), and the proximity distance of the external object can be sensed based on the size of PDATA. In order to prevent part of the infrared light emitted by the infrared light source from being reflected or diffracted by internal structural parts or directly reaching the infrared light detector from the outside, black isolation foam can be added between the infrared light detector and the infrared light source to avoid light crosstalk and improve the signal-to-noise ratio.

[0103] The proximity light sensor 522 is widely used and inexpensive. Therefore, the test circuit 52 provided in the embodiment of the present application utilizes the proximity light sensor to detect PPG signals, thereby reducing costs. Furthermore, because the proximity light sensor 522 integrates a structure for collecting and processing light signals (the specific structure and operation will be described below), the test circuit 52 in the embodiment of the present application is smaller than conventional PPG modules.

[0104] It will be appreciated that, to detect the proximity of external objects, existing proximity light sensors typically only have one light source, and the light signal emitted by this light source is of a single wavelength. This light source can be integrated into the proximity light sensor or provided independently. Because determining human vital sign parameters requires light signals of at least two different wavelengths, the test circuit 52 in this embodiment of the present application can include a separate light-emitting unit in addition to the proximity light sensor 522. When the test circuit 52 requires the proximity light sensor 522's light source to emit light signals for PPG signal detection, the light-emitting unit and the proximity light sensor 522's light source are collectively referred to as a light-emitting assembly 521, and the light-emitting unit and the proximity light sensor 522's light source emit light signals of at least two different wavelengths. When the test circuit 52 does not require the proximity light sensor 522's light source to emit light signals for PPG signal detection, at least two light-emitting units are required to form the light-emitting assembly 521, so that the light-emitting assembly 521 emits light signals of at least two different wavelengths.

[0105] It should be understood that FIG2 and FIG3 and the related figures below only schematically illustrate some components included in the electronic device 100. The actual electronic device 100 may have more or fewer components than shown in the figures, or some components may be combined or separated, or the components may be arranged differently. The components shown in the figures may be implemented in hardware, software, or a combination of software and hardware.

[0106] It should be noted that in FIG2 , the mobile phone 100 is in the shape of a rectangular flat plate. In other optional embodiments, the shape of the electronic device may also be a square flat plate, a circular flat plate, an oval flat plate, etc. Of course, the electronic device may also be a foldable electronic device, etc.

[0107] Continuing to refer to Figures 2 and 3, the back cover 20 includes a light-transmitting portion 21, through which the light signal emitted by the light-emitting component 521 can be emitted. Referring to Figure 5, Figure 5 is one of the application scenario diagrams of an electronic device provided by an embodiment of the present application. When a user touches the light-transmitting portion 21 with a fingertip, the light signal emitted by the light-emitting component 521 is emitted through the light-transmitting portion 21 and irradiates the user's fingertip. The light signal passes through the skin tissue of the fingertip and is then reflected to the proximity light sensor 522. The proximity light sensor 522 converts the light into an electrical signal and determines a PPG signal based on the electrical signal.

[0108] The specific structure and working principle of the test circuit provided in the embodiment of the present application are described in detail below. Among them, the specific structure and working principle of the test circuit provided in the embodiment of the present application are described in detail using two situations: a proximity light sensor cooperates with a light-emitting component to realize the PPG test function in a time-sharing manner; and a proximity light sensor cooperates with a light-emitting component to realize the PPG test function simultaneously.

[0109] First, the specific structure and working principle of the test circuit provided in the embodiment of the present application are described in detail by using a proximity light sensor and a light-emitting component to realize the PPG test function in a time-sharing manner.

[0110] Referring to FIG6 , FIG6 is a circuit diagram of a test circuit provided in an embodiment of the present application. As shown in FIG6 , the test circuit 52 includes: a light-emitting component 521 and a proximity light sensor 522. The light-emitting component 521 includes at least a first light-emitting unit 5211 and a second light-emitting unit 5212. The first light-emitting unit 5211 and the second light-emitting unit 5212 are, for example, devices that can emit light, such as LED lamps. The first light-emitting unit 5211 can emit a first light signal, and the second light-emitting unit 5212 can emit a second light signal. The first light signal can be a red light signal, and the second light signal can be an infrared light signal; alternatively, the first light signal can be an infrared light signal, and the second light signal can be a green light signal, and so on. The wavelength range of red light can be 610.0nm to 699.9.0nm, the wavelength range of infrared light can be 700.0nm to 1100.0nm, and the wavelength range of green light can be 510.0nm to 549.9nm. For example, the first light signal is a red light signal having a wavelength of 690 nm, and the second light signal is an infrared light signal having a wavelength of 940 nm. Referring to FIG1 , when the wavelengths of the red light signal are 690 nm and the infrared light signal are 940 nm, the absorption rates of Hb (deoxyhemoglobin) and HbO2 (oxyhemoglobin) in human blood at 690 nm and 940 nm are different, with the absorption rate difference being the largest. This facilitates the calculation of blood oxygen saturation.

[0111] It should be noted that the wavelength range of red light, the wavelength range of infrared light, and the wavelength range of green light are merely examples and do not constitute a limitation to the present application.

[0112] Referring to FIG. 7 , FIG. 7 is a top view of a proximity light sensor provided in an embodiment of the present application. As shown in FIG. 6 and FIG. 7 , the proximity light sensor 522 includes a collection unit 5221 and an analog-to-digital converter 5222. The collection unit 5221 includes multiple photosensitive devices. FIG. 7 illustrates an example in which the collection unit 5221 includes six photosensitive devices. Exemplarily, the photosensitive devices may include devices such as photodetectors that can convert light into electrical signals. The multiple photosensitive devices include at least a first photosensitive device 52211 and a second photosensitive device 52212. Different photosensitive devices correspond to light signals of different wavelengths, i.e., different photosensitive devices respond to light signals of different wavelengths (convert light signals into electrical signals). In FIG. 7 , graphics filled with different patterns represent different photosensitive devices to reflect that different photosensitive devices respond to light signals of different wavelengths. For example, the first photosensitive device 52211 responds to the first light signal, and the second photosensitive device 52212 responds to the second light signal. The first photosensor 52211 and the second photosensor 52212 are both electrically connected to the analog-to-digital converter 5222. The first photosensor 52211 and the analog-to-digital converter 5222, as well as the second photosensor 52212 and the analog-to-digital converter 5222, form two acquisition channels, for example, a first acquisition channel and a second acquisition channel.

[0113] Optionally, the proximity light sensor 522 includes a processing unit 5223, which is electrically connected to the analog-to-digital converter 5222, the first light-emitting unit 5211, and the second light-emitting unit 5212, respectively. The processing unit 5223 is used to send a drive signal to the first light-emitting unit 5211 and the second light-emitting unit 5212 to drive the first light-emitting unit 5211 and the second light-emitting unit 5212 to emit light. The processing unit 5223 is also used to process the digital signal output by the analog-to-digital converter 5222. Of course, the first light-emitting unit 5211 and the second light-emitting unit 5212 can also be driven to emit light and the digital signal output by the analog-to-digital converter 5222 can be processed by a processing unit with driving capability, such as the processor 51 within the electronic device 100, which is not limited to this embodiment of the present application. In this way, there is no need to separately set up a structure for driving the first light-emitting unit 5211 and the second light-emitting unit 5212 to emit light and a structure for processing data.

[0114] It should be noted that, in the embodiment of the present application, a processing unit 5223 is provided in the proximity light sensor 522, and the processing unit 5223 drives the first light-emitting unit 5211 and the second light-emitting unit 5212 to emit light, and the first light signal emitted by the first light-emitting unit 5211 is a red light signal, and the second light signal emitted by the second light-emitting unit 5212 is an infrared light signal.

[0115] Referring to FIG8 , FIG8 is an example of a test circuit provided in an embodiment of the present application. As shown in FIG8 , the test circuit 52 includes a light-emitting component 521 and a proximity light sensor 522. The light-emitting component 521 includes a first light-emitting unit 5211 and a second light-emitting unit 5212. The first light-emitting unit 5211 is an external light LED, and the second light-emitting unit 5212 is an infrared light LED. The proximity light sensor 522 includes a processing unit 5223, a switch 5224, a first resistor R1, an acquisition unit (not shown in FIG7 ), and an analog-to-digital converter (not shown in FIG7 ). The processing unit 5223 includes a first pin 1, a second pin 2, a third pin 3, a fourth pin 4, a fifth pin 5, a sixth pin 6, a seventh pin 7, an eighth pin 8, and a ninth pin 9. The third pin 3 is electrically connected to the anode of the infrared LED and the anode of the red LED. The sixth pin 6 and the seventh pin 7 are electrically connected to the cathode of the infrared LED and the cathode of the red LED, respectively. The first pin 1 can receive a 3.3V voltage to power the infrared LED and the red LED through the third pin 3. The fourth pin 4 and the fifth pin 5 are I2C communication pins. The eighth pin 8 and the ninth pin 9 are both grounded. The second pin 2 is electrically connected to the switch 5224. When the switch 5224 is turned on, a 1.8V voltage is transmitted to the second pin 2 through the switch 5224 to power the processing unit 5223, ensuring its normal operation. In some embodiments, the first pin 1 is provided with a first resistor R1, which can be coupled with other components to implement functions such as filtering.

[0116] It should be noted that FIG8 is only an example of a light-emitting component and a proximity light sensor, and does not constitute a limitation on the present application. Those skilled in the art can select a proximity light sensor and a light-emitting component according to actual conditions.

[0117] Referring to Figure 9, Figure 9 is a timing diagram of the time-sharing drive of the test circuit provided in an embodiment of the present application. As shown in Figure 9, the test circuit 52 includes multiple working cycles T0, each working cycle T0 includes at least a first stage T1 and a second stage T2, the first stage T1 corresponds to the acquisition and processing process of the first optical signal, and the second stage T2 corresponds to the acquisition and processing process of the second optical signal. In Figure 9, the solid line represents the timing of the acquisition and processing of the first optical signal, and the dotted line represents the timing of the acquisition and processing of the second optical signal. The first stage T1 and the second stage T2 each include at least one pulse period, and the pulse period includes a light-emitting stage T01 operating in a first level (such as a high level) state and a non-light-emitting stage T02 operating in a second level (such as a low level) state. Since the first photosensor 52211 and the second photosensor 52212 share the analog-to-digital converter 5222, the first acquisition channel formed by the first photosensor 52211 and the analog-to-digital converter 5222 and the second acquisition channel formed by the second photosensor 52212 and the analog-to-digital converter 5222 need to collect and process the first light signal emitted by the first light-emitting unit 5211 and the second light signal emitted by the second light-emitting unit 5212 in a time-sharing manner (i.e., in two different time periods of the first stage T1 and the second stage T2) to distinguish the first light signal from the second light signal.

[0118] The specific testing method is as follows: during the light-emitting stage T01 of the first stage T1, the processing unit 5223 transmits a first driving signal to the first light-emitting unit 5211. The first light-emitting unit 5211 emits a red light signal (also referred to as a first light signal) based on the first driving signal. After the red light signal is emitted through the light-transmitting portion 21, it is reflected and / or scattered when it irradiates the skin tissue of the user's fingertip. The first photosensor 52211 collects ambient light and light reflected and / or scattered by the red light signal (collectively referred to as a third light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The analog-to-digital converter 5222 converts the analog signal into a digital signal. The processing unit 5223 processes the digital signal, such as by performing calibration, filtering, integration (accumulating signal strength over a period of time), and other processing to obtain a light signal integral value D1. That is, the first acquisition channel, formed by the first photosensor 52211 and the analog-to-digital converter 5222, collects ambient light and light reflected and / or scattered by the red light signal, converts the light signals into digital signals, and the processing unit 5223 processes the digital signals to obtain an integral value D1. During the non-light-emitting phase T02 of the first phase T1, the processing unit 5223 transmits a second drive signal to the first light-emitting unit 5211, causing the first light-emitting unit 5211 to not emit light. The first photosensor 52211 only collects ambient light (also known as the fourth light signal) and converts the light signal into an electrical signal, where the electrical signal is an analog signal. The analog-to-digital converter 5222 converts the analog signal into a digital signal, and the processing unit 5223 processes the digital signal, such as by performing calibration, filtering, and integration (accumulating signal strength over a period of time), to obtain an optical signal integral value D2. In other words, the first acquisition channel, comprised of the first photosensor 52211 and the analog-to-digital converter 5222, only collects ambient light, converting the optical signal into a digital signal. The processing unit 5223 then processes this digital signal to obtain an integral value D2. After a pulse cycle in the first phase T1, the processing unit 5223 calculates the difference between the integral values ​​D1 and D2 to obtain the integral value of the light intensity of the first optical reference signal (containing only the first optical signal component) to eliminate interference from the DC component of ambient light. This integral value of the light intensity of the first optical reference signal is then transmitted to the processor 51.

[0119] It should be noted that the reflection and / or scattering in the embodiments of the present application may be only reflection, only scattering, or both reflection and scattering may occur.

[0120] During the light-emitting phase T01 of the second phase T2, the processing unit 5223 transmits a first drive signal to the second light-emitting unit 5212. The second light-emitting unit 5212 emits an infrared light signal (also referred to as a second light signal) based on the first drive signal. After the infrared light signal is emitted through the light-transmitting portion 21, it is reflected and / or scattered when it irradiates the skin tissue of the user's fingertip. The second photosensor 52212 collects ambient light and light reflected and / or scattered by the infrared light signal (collectively referred to as the fifth light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The analog-to-digital converter 5222 converts the analog signal into a digital signal. The processing unit 5223 processes the digital signal, such as by performing calibration, filtering, integration (accumulating signal strength over a period of time), and other processing to obtain an integral value D3 of the light signal. In other words, the second collection channel formed by the second photosensor 52212 and the analog-to-digital converter 5222 collects ambient light and light reflected and / or scattered by the infrared light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D3. During the non-light-emitting phase T02 of the second phase T2, the processing unit 5223 transmits a second drive signal to the second light-emitting unit 5212, causing the second light-emitting unit 5212 to remain silent. The second photosensor 52212 collects only ambient light (also known as the sixth light signal) and converts the light signal into an electrical signal, which is an analog signal. The analog-to-digital converter 5222 converts the analog signal into a digital signal, and the processing unit 5223 processes the digital signal, such as by calibration, filtering, and integration (accumulating signal intensity over a period of time), to obtain an integrated value D4 of the light signal. In other words, the second light-emitting unit 52212 and the analog-to-digital converter 5222 form the second collection channel, collecting only ambient light, converting the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integrated value D4. After a pulse cycle in the second phase T2, the proximity light sensor 522 calculates the difference between the integrated value D3 and the integrated value D4 to obtain the integrated value of the light intensity of the second optical reference signal (containing only the second optical signal component) to eliminate interference from the DC component of the ambient light. The integrated value of the light intensity of the second optical reference signal is then sent to processor 51 .

[0121] Because the test circuit includes multiple operating cycles T0, the processor 51 obtains the integrated value of the light intensity of the first optical reference signal over a period of time through the above method. That is, the multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of the multiple first optical reference signals. The integrated values ​​of the light intensity of the multiple first optical reference signals can form a curve that represents the intensity of the red light signal (i.e., the red light PPG signal), as shown by arrow ② in Figure 15. Figure 15 will be described in detail below and will not be repeated here. In addition, the processor 51 obtains the integrated value of the light intensity of the second optical reference signal over a period of time. That is, the multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of the multiple second optical reference signals. The integrated values ​​of the light intensity of the multiple second optical reference signals can form a curve that represents the intensity of the infrared light signal (i.e., the infrared light PPG signal), as shown by arrow ① in Figure 15. The processor 51 can separate the red light AC signal and the direct current DC signal based on the red light PPG signal and the infrared light PPG signal, and separate the infrared light AC signal and the direct current DC signal to obtain the ratio PI(RED) of the red light AC signal and the direct current DC signal, and the ratio PI(IR) of the infrared light AC signal and the direct current DC signal, and determine the R value based on PI(RED) and PI(IR), and then determine human body characteristics such as heart rate and blood oxygen saturation.

[0122] It should be noted here that the test circuit can not only calculate blood oxygen saturation, heart rate, etc. based on signals of two different optical bands (such as the first optical signal and the second optical signal), but can also couple optical signals of other bands, such as determining the PPG signal based on optical signals of three (correspondingly, the acquisition unit 5221 includes three photosensors), four (correspondingly, the acquisition unit 5221 includes four photosensors), five (correspondingly, the acquisition unit 5221 includes five photosensors) or six (correspondingly, the acquisition unit 5221 includes six photosensors) optical bands, so as to calculate human vital sign parameters such as blood pressure, blood sugar, perfusion index, pulse variability index, carbon monoxide hemoglobin, glycated hemoglobin and other blood indicators based on the PPG signal.

[0123] In actual applications, there may be other flickering light sources outside the electronic device 100. Since a flickering light source is a light source that switches between bright and dim states at a specific frequency, this may cause the difference between the integral value D1 and the integral value D2 to differ from the actual difference, causing the integral of the light intensity of the first optical reference signal to fluctuate (appear to be a maximum or minimum value), and even causing the proximity light sensor 522 to malfunction. Alternatively, the difference between the integral value D3 and the integral value D4 may differ from the actual difference, causing the integral of the light intensity of the second optical reference signal to fluctuate (appear to be a maximum or minimum value), and even causing the proximity light sensor 522 to malfunction. Alternatively, the difference between the integral value D1 and the integral value D2 may differ from the actual difference, and the difference between the integral value D3 and the integral value D4 may differ from the actual difference, causing the integral value of the light intensity of the first optical reference signal and the integral value of the light intensity of the second optical reference signal to fluctuate (appear to be a maximum or minimum value), and even causing the proximity light sensor 522 to malfunction.

[0124] For example, refer to Figure 10, which is a comparison diagram of the working timing of the light-emitting component and the working timing of the flashing light source in the embodiment of the present application. As shown in Figure 10, in the light-emitting stage T01 of the first stage T1, the first acquisition channel composed of the first photosensor 52211 and the analog-to-digital converter 5222, for example, still collects ambient light and light reflected and / or scattered by the red light signal (collectively referred to as the third light signal), so its integral value D1 remains unchanged. In the non-light-emitting stage T02 of the first stage T1, the first acquisition channel composed of the first photosensor 52211 and the analog-to-digital converter 5222 not only collects ambient light, but also collects external flashing light sources, so the integral value D2 will become larger. After the end of a pulse cycle of the first stage T1, the difference between the integral value D1 and the integral value D2 calculated by the processing unit 5223 is less than the actual value.

[0125] In order to isolate the interference of external flickering light sources, refer to Figure 11, which is another timing diagram of the time-sharing drive of the test circuit provided in an embodiment of the present application. In Figure 11, the solid line represents the timing of the acquisition and processing of the first light signal, and the dotted line represents the timing of the acquisition and processing of the second light signal. As shown in Figure 11, the first stage T1 and the second stage T2 of each working cycle T0 both include N pulse periods, N ≥ 2, and N is a positive integer. In other words, the single pulse period in Figure 9 is divided into several pulse periods. Among them, Figure 11 is explained by taking the example that the first stage T1 and the second stage T2 of each working cycle T0 both include two pulse periods.

[0126] This is because, when a pulse cycle is long, external flickering light sources may affect each pulse cycle, i.e., the integrated value of the light intensity of each first optical reference signal may differ from the actual value; or the integrated value of the light intensity of each second optical reference signal may differ from the actual value; or, the integrated value of the light intensity of each first optical reference signal and the integrated value of the light intensity of each second optical reference signal may differ from the actual value, thereby affecting the PPG test results. When the first stage T1 and the second stage T2 of each working cycle T0 both include N pulse cycles, the external flickering light source may only affect a portion of the pulse cycles. For example, when one or more pulse cycles (pulse cycles after the pulse time is shortened) are located in the dark area of ​​the external flickering light source, these one or more pulse cycles will not be affected. In other words, the external flickering light source may only affect the integrated value of the light intensity of a portion of the first optical reference signal; or, it may only affect the integrated value of the light intensity of a portion of the second optical reference signal; or, it may affect the integrated value of the light intensity of a portion of the first optical reference signal and the integrated value of the light intensity of a portion of the second optical reference signal. This reduces the impact of the flickering light source and improves the anti-interference capability.

[0127] The above details the time-sharing implementation of PPG testing using a proximity light sensor in conjunction with a light-emitting component. As can be seen, using a light-emitting component and proximity light sensor instead of an existing PPG module to implement PPG detection reduces the cost of the test circuit and the size of the electronic device it occupies. Furthermore, each operating cycle T0 of the test circuit is configured to include multiple pulse periods in both the first phase T1 and the second phase T2, improving bandpass matching and ensuring better anti-interference characteristics.

[0128] Next, the specific structure and working principle of the test circuit provided in the embodiment of the present application are described in detail by using a proximity light sensor and a light-emitting component to realize the PPG test function.

[0129] Referring to Figure 12, Figure 12 is a circuit diagram of another test circuit provided in an embodiment of the present application. As shown in Figure 12, unlike the above, the proximity light sensor 522 includes at least two analog-to-digital converters 5222, including a first analog-to-digital converter 52221 and a second analog-to-digital converter 52222. The first photosensor 52211 is electrically connected to the first analog-to-digital converter 52221, and the second photosensor 52212 is electrically connected to the second analog-to-digital converter 52222. The first photosensor 52211 and the first analog-to-digital converter 52221, as well as the second photosensor 52212 and the second analog-to-digital converter 52222, form two acquisition channels, for example, a first acquisition channel and a second acquisition channel.

[0130] For example, see Figure 13, which shows an example of a proximity light sensor provided in an embodiment of the present application. As shown in Figure 13, the proximity light sensor 522 includes a processing unit 5223, an acquisition unit 5221, and five analog-to-digital converters 5222. The acquisition unit 5221 includes a first photosensor 52211, a second photosensor 52212, a third photosensor 52213, a fourth photosensor 52214, and a fifth photosensor 52215. The first photosensor 52211 can convert infrared light signals into electrical signals, the second photosensor 52212 can convert red light signals into electrical signals, the third photosensor 52213 can convert green light signals into electrical signals, the fourth photosensor 52214 can convert blue light signals into electrical signals, and the fifth photosensor 52215 can convert violet light signals into electrical signals. In Figure 13, the graphics filled with different patterns represent different photosensors, reflecting that different photosensors respond to light signals in different wavelength bands. The five analog-to-digital converters include a first analog-to-digital converter 52221, a second analog-to-digital converter 52222, a third analog-to-digital converter 52223, a fourth analog-to-digital converter 52224, and a fifth analog-to-digital converter 52225. The first analog-to-digital converter 52221 is electrically connected to the first photosensor 52211 to convert the electrical signal converted by the first photosensor 52211 into a digital signal. The second analog-to-digital converter 52222 is electrically connected to the second photosensor 52212 to convert the electrical signal converted by the second photosensor 52212 into a digital signal. The third analog-to-digital converter 52223 is electrically connected to the third photosensor 52213 to convert the electrical signal converted by the third photosensor 52213 into a digital signal. The fourth analog-to-digital converter 52224 is electrically connected to the fourth photosensor 52214 to convert the electrical signal converted by the fourth photosensor 52214 into a digital signal. The fifth analog-to-digital converter 52225 is electrically connected to the fifth photosensor 52215 to convert the electrical signal converted by the fifth photosensor 52215 into a digital signal.

[0131] The following content is explained using the example of a proximity light sensor 522 including two photosensors and two analog-to-digital converters 5222. Referring to Figure 14, Figure 14 is a timing diagram of simultaneous driving of a test circuit provided in an embodiment of the present application. As shown in Figure 14, the test circuit 52 includes a plurality of working cycles T0, each working cycle T0 includes at least one pulse period, and the pulse period includes a light-emitting stage T01 operating in a first level (such as a high level) state and a non-light-emitting stage T02 operating in a second level (such as a low level) state. In Figure 13, the solid line represents the timing of the acquisition and processing of the first light signal, and the dotted line represents the timing of the acquisition and processing of the second light signal. Since the first photosensor 52211 and the second photosensor 52212 correspond to different analog-to-digital converters 5222 respectively, the first acquisition channel formed by the first photosensor 52211 and the analog-to-digital converter 5222 and the second acquisition channel formed by the second photosensor 52212 and the analog-to-digital converter 5222 can simultaneously (i.e., both in the light-emitting stage T01) collect and process the first light signal emitted by the first light-emitting unit 5211 and the second light signal emitted by the second light-emitting unit 5212, that is, different acquisition channels can simultaneously collect light signals of different bands, thereby realizing the simultaneous collection and processing of light signals of different bands.

[0132] The specific testing method is as follows: During the light-emitting phase T01, the processing unit 5223 transmits a first driving signal to the first light-emitting unit 5211 and the second light-emitting unit 5212, respectively. The first light-emitting unit 5211 emits a red light signal (also referred to as the first light signal) based on the first driving signal, and the second light-emitting unit 5212 emits an infrared light signal (also referred to as the second light signal) based on the first driving signal. After the red light signal and the infrared light signal are emitted through the light-transmitting portion 21, they are reflected and / or scattered when irradiated by the skin tissue of the user's fingertip. The first photosensor 52211 collects ambient light and light reflected and / or scattered by the red light signal (collectively referred to as the seventh light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The first analog-to-digital converter 52221 converts the analog signal into a digital signal. The processing unit 5223 processes the digital signal, such as by performing calibration, filtering, integration (accumulating signal intensities over a period of time), and other processing to obtain a light signal integral value D5. The second photosensor 52212 collects light reflected and / or scattered by ambient light and the infrared light signal (collectively referred to as the eighth light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The second analog-to-digital converter 52222 converts the analog signal into a digital signal, and the processing unit 5223 processes the digital signal, such as by performing calibration, filtering, and integration (accumulating signal strength over a period of time), to obtain an optical signal integral value D6. In other words, the first collection channel formed by the first photosensor 52211 and the first analog-to-digital converter 52221 collects light reflected and / or scattered by ambient light and the infrared light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D5. Simultaneously, the second collection channel formed by the second photosensor 52212 and the second analog-to-digital converter 52222 collects light reflected and / or scattered by ambient light and the infrared light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D6.

[0133] During the non-light-emitting phase T02, the processing unit 5223 transmits a second drive signal to the first light-emitting unit 5211 and the second light-emitting unit 5212, respectively. The first light-emitting unit 5211 and the second light-emitting unit 5212 do not emit light. The first photosensitive device 52211 only collects ambient light (also known as the ninth light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The first analog-to-digital converter 52221 converts the analog signal into a digital signal. The processing unit 5223 processes the digital signal, such as by performing calibration, filtering, integration (accumulating the signal intensity over a period of time), etc., to obtain a light signal integral value D7. The second photosensitive device 52212 only collects ambient light (also known as the tenth light signal) and converts the light signal into an electrical signal, wherein the electrical signal is an analog signal. The second analog-to-digital converter 52222 converts the analog signal into a digital signal. The processing unit 5223 processes the digital signal, such as by performing calibration, filtering, integration (accumulating the signal intensity over a period of time), etc., to obtain a light signal integral value D8. That is, the first acquisition channel formed by the first photosensor 52211 and the first analog-to-digital converter 52221 only collects ambient light, converts the optical signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D7. Simultaneously, the second acquisition channel formed by the second photosensor 52212 and the second analog-to-digital converter 52222 only collects ambient light, converts the optical signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D8. After a pulse cycle, the processing unit 5223 calculates the difference between the integral values ​​D5 and D7 to obtain the integral value of the light intensity of the first optical reference signal (containing only the first optical signal component). Furthermore, the processing unit 5223 calculates the difference between the integral values ​​D6 and D8 to obtain the integral value of the light intensity of the second optical reference signal (containing only the second optical signal component), thereby eliminating interference from the DC component of ambient light. The integral values ​​of the first and second optical reference signals are then sent to the processor 51.

[0134] Because the test circuit includes multiple operating cycles T0, the processor 51 obtains the integrated value of the light intensity of the first optical reference signal over a period of time through the above method. That is, multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of multiple first optical reference signals. The integrated values ​​of the light intensity of multiple first optical reference signals can form a curve, which represents the intensity of the red light signal (i.e., the red light PPG signal). In addition, the processor 51 obtains the integrated value of the light intensity of the second optical reference signal over a period of time. That is, multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of multiple second optical reference signals. The integrated values ​​of the light intensity of multiple second optical reference signals can form a curve, which represents the intensity of the infrared light signal (i.e., the infrared light PPG signal). The processor 51 can separate the red light AC signal and the direct current DC signal based on the red light PPG signal and the infrared light PPG signal, and separate the infrared light AC signal and the direct current DC signal to obtain the ratio PI(RED) of the red light AC signal and the direct current DC signal, and the ratio PI(IR) of the infrared light AC signal and the direct current DC signal, and determine the R value based on PI(RED) and PI(IR), and then determine human body characteristics such as heart rate and blood oxygen saturation.

[0135] It should be noted here that the test circuit can not only calculate blood oxygen saturation, heart rate, etc. based on signals of two different optical bands (such as the first optical signal and the second optical signal), but can also couple optical signals of other bands, such as determining the PPG signal based on optical signals of three (correspondingly, the acquisition unit 5221 includes three photosensors, and the number of analog-to-digital converters 5222 is at least three), four (correspondingly, the acquisition unit 5221 includes four photosensors, and the number of analog-to-digital converters 5222 is at least four), five (correspondingly, the acquisition unit 5221 includes five photosensors, and the number of analog-to-digital converters 5222 is at least five) or six (correspondingly, the acquisition unit 5221 includes six photosensors, and the number of analog-to-digital converters 5222 is at least six) optical bands, so as to calculate human vital sign parameters such as the content of blood indicators such as blood pressure, blood sugar, perfusion index, pulse variability index, carbon monoxide hemoglobin, and glycated hemoglobin based on the PPG signal.

[0136] Similarly, in order to isolate the interference of external flickering light sources, refer to Figure 15. Figure 15 is another timing diagram of the simultaneous drive of the test circuit provided in the embodiment of the present application. In Figure 15, the solid line represents the timing of the acquisition and processing of the first light signal, and the dotted line represents the timing of the acquisition and processing of the second light signal. As shown in Figure 15, each working cycle T0 includes N pulse periods, N≥2, and N is a positive integer. In other words, the single pulse period in Figure 14 is divided into several pulse periods. Among them, Figure 15 is explained by taking the example that each working cycle T0 includes two pulse periods. The specific principle of reducing the influence of the flickering light source and improving the anti-interference ability by having each working cycle T0 include N pulse periods is similar to the above content. Please refer to the above content for details and will not be repeated here.

[0137] The above describes in detail how a proximity light sensor and a light-emitting component can simultaneously implement a PPG test function. As can be seen from the above, PPG detection is achieved by replacing the existing PPG module with a light-emitting component and a proximity light sensor. The proximity light sensor is equipped with multiple analog-to-digital converters. The multiple photosensors correspond to the multiple analog-to-digital converters to form different acquisition channels. These acquisition channels can simultaneously acquire and process optical signals of different wavelengths. Because the integral value of the light intensity of the first optical reference signal and the integral value of the light intensity of the second optical reference signal measured at the same time are compared to the integral value of the light intensity of different wavelengths obtained at different times, the time-sharing (i.e., different moments) optical signals of different wavelengths result in a certain time difference in the user's vital signs. This solution, however, can obtain optical signals of different wavelengths at the same moment, reflecting the user's vital signs at the same moment. This solution provides better tracking of the user's physiological change data and more realistically reflects the vital signs. Furthermore, more time can be reserved for the analog-to-digital converter to process the optical signals, resulting in a longer detection integration time and improved sensitivity.

[0138] In this case (simultaneously collecting and processing light signals of different wavelength bands), the light emitting component can use a wide-spectrum light source, which is a light source whose emitted light signal is composed of at least two light signals of different wavelengths. The wavelength range of the wide-spectrum light source is relatively wide, for example, 380-780nm. Exemplarily, the wide-spectrum light source is white light, for example, and the light signal emitted by the wide-spectrum light source is composed of seven colors of light: red, orange, yellow, green, blue, indigo, and violet. Among them, red light can be used as the above-mentioned first light signal, and green light can be used as the above-mentioned second light signal. That is to say, when the wide-spectrum light source emits white light, the first collection channel can only collect and process the red light in the white light, and the second collection channel can only collect and process the green light in the white light.

[0139] When a broad-spectrum light source is used as the light-emitting component, there is no need to set up different light-emitting units, only one light source is needed, which reduces the cost of the test circuit and the occupied area of ​​the PCB 40 in the electronic device.

[0140] Furthermore, considering that the light emitted by the display screen 12 may be composed of light of multiple different wavelength bands, for example, the light emitted by the display screen 12 is white light, to further reduce the cost of the test circuit and reduce the space occupied by the PCB 40 in the electronic device, the display screen used by the electronic device for display is reused as the light-emitting component 521.

[0141] In this case, the proximity light sensor 522 can be set in the non-display area of ​​the display screen 12, or below the display screen 12. During detection, the user's finger only needs to cover the proximity light sensor 522 and part of the display area of ​​the display screen 12.

[0142] It is understandable that when the display screen is multiplexed into the light-emitting component 521, the display driver chip can control the display screen to emit a light signal of a first preset color, wherein the light signal of the first preset color can be composed of light of at least two different wavelength bands.

[0143] Exemplarily, in the light-emitting stage T01, the display screen 12 can emit a light signal of a first preset color according to the driving signal sent by the display driver chip. The light signal of the first preset color can be a white light signal, and the white light signal includes a first light signal and a second light signal, wherein the first light signal is, for example, a red light signal and the second light signal is, for example, a green light signal. When the light signal emitted by the display screen 12 is irradiated by the skin tissue of the user's fingertip, it is reflected and / or scattered. The first acquisition channel formed by the first photosensor 52211 and the first analog-to-digital converter 52221 collects ambient light and light reflected and / or scattered by the red light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D5. The second acquisition channel formed by the second photosensor 52212 and the second analog-to-digital converter 52222 collects ambient light and light reflected and / or scattered by the green light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D7.

[0144] During the non-luminous phase T02, the display screen remains silent under the control of the display driver chip. The first acquisition channel, formed by the first photosensor 52211 and the first analog-to-digital converter 52221, only collects ambient light and converts the optical signal into a digital signal. The processing unit 5223 processes this digital signal to obtain an integral value D6. The second acquisition channel, formed by the second photosensor 52212 and the second analog-to-digital converter 52222, only collects ambient light and converts the optical signal into a digital signal. The processing unit 5223 processes this digital signal to obtain an integral value D8. After a pulse cycle, the processing unit 5223 calculates the difference between integral values ​​D5 and D7 to obtain the integral value of the intensity of the first optical reference signal (containing only the first optical signal component). Furthermore, the processing unit 5223 calculates the difference between integral values ​​D6 and D8 to obtain the integral value of the light intensity of the second optical reference signal (containing only the second optical signal component) to eliminate interference from the DC component of ambient light. The integral values ​​of the first and second optical reference signals are then sent to the processor 51 for processing.

[0145] The above is an explanation based on the display driver chip controlling the display screen to emit a light signal of a first preset color, wherein the light signal of the first preset color can be composed of at least two light components of different wavelengths. In other optional embodiments of the present application, the display driver chip can also control the display screen to only send a first light signal (such as a red light signal) and a second light signal (such as a green light signal) at different moments. The specific process of calculating the human body characteristic value based on the first light signal and the second light signal can refer to the above content (corresponding to the structure of Figure 6 and the content of the timing of Figure 9), which will not be repeated here. Of course, the light-emitting component that emits a wide-spectrum light source is not limited to the display screen 12. For example, the light-emitting component can also be a flash 54, wherein the flash 54 emits a light signal of a second preset color, and the light signal of the second preset color can be composed of at least two light components of different wavelengths, and the light signal of the second preset color is, for example, white light. That is, the flash 54 not only has a fill light effect, but can also be multiplexed as a light-emitting component.

[0146] In this case, the proximity light sensor 522 and the flash light 54 can be arranged on the same side of the mobile phone, and the proximity light sensor 522 and the flash light 54 are arranged adjacent to each other. During detection, the user's finger only needs to cover the proximity light sensor 522 and the flash light 54.

[0147] Exemplarily, in the light-emitting stage T01, the flashlight 54 can emit a light signal of a second preset color according to a driving signal sent by the processing unit 5223 or the processor 51. The light signal of the second preset color can be a white light signal, and the white light signal includes a first light signal and a second light signal, wherein the first light signal is, for example, a red light signal and the second light signal is, for example, a green light signal. When the light signal emitted by the flashlight 54 is irradiated by the skin tissue of the user's fingertip, it is reflected and / or scattered. The first photosensor 52211 and the first analog-to-digital converter 52221 collect ambient light and light reflected and / or scattered by the red light signal, convert the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D5. The second collection channel formed by the second photosensor 52212 and the second analog-to-digital converter 52222 collects ambient light and light reflected and / or scattered by the green light signal, converts the light signal into a digital signal, and the processing unit 5223 processes the digital signal to obtain an integral value D7.

[0148] During the non-lighting phase T02, the flashlight 54 does not emit light. The first acquisition channel formed by the first photosensor 52211 and the first analog-to-digital converter 52221 only collects ambient light and converts the light signal into a digital signal. The processing unit 5223 processes this digital signal to obtain an integral value D6. The second photosensor 52212 and the second analog-to-digital converter 52222 only collect ambient light and convert the light signal into a digital signal. The processing unit 5223 processes this digital signal to obtain an integral value D8. After a pulse cycle, the proximity light sensor 522 calculates the difference between the integral value D5 and the integral value D7 to obtain the integral value of the light intensity of the first optical reference signal (containing only the first optical signal component). Furthermore, the difference between the integral value D6 and the integral value D8 is calculated to obtain the integral value of the light intensity of the second optical reference signal (containing only the second optical signal component), thereby eliminating interference from the DC component of the ambient light. The integral values ​​of the light intensity of the first and second optical reference signals are then sent to the processor 51 for processing.

[0149] It should be noted that the above description is based on an example in which a proximity light sensor includes multiple acquisition channels, and the multiple acquisition channels can simultaneously acquire and process light signals of different bands, but it does not constitute a limitation of the present application. As long as the sensor can form multiple acquisition channels and the multiple acquisition channels can simultaneously acquire and process light signals of different bands, it is within the protection scope of the present application.

[0150] In summary, by replacing the existing PPG module with a light-emitting component and a proximity light sensor, the cost of the test circuit can be reduced because the proximity light sensor is widely used and inexpensive; and because the proximity light sensor is internally integrated with an acquisition unit, an analog-to-digital converter, and a processing unit, the volume of the test circuit is smaller, reducing the volume occupied by the test circuit in the electronic device. In addition, the test circuit not only detects the light reflected and / or scattered by the first light signal and the second light signal, but also detects the ambient light. In this way, the interference of the external ambient light can be reduced, the background noise can be filtered out, and the detection accuracy can be improved. In addition, the photoelectric sensor of the embodiment of the present application may include multiple photosensors and multiple analog-to-digital converters, and the multiple photosensors and the multiple analog-to-digital converters respectively form different acquisition channels. Therefore, different acquisition channels can respectively and simultaneously acquire light signals of different wavelengths, and the tracking of physiological change data is better. In this way, when calculating blood oxygen saturation, heart rate, etc. based on the PPG signal, the detection accuracy can be further improved. In addition, the test circuit can not only calculate blood oxygen saturation, heart rate, etc. based on signals of two different optical bands (such as the first optical signal and the second optical signal), but can also couple optical signals of other bands. For example, the PPG signal can be determined based on optical signals of three, four, five or six optical bands to calculate human vital sign parameters such as blood pressure, blood sugar, perfusion index, pulse variability index, carbon monoxide hemoglobin, glycated hemoglobin and other blood indicators.

[0151] In addition, a blood oxygen heart rate test was performed on the test circuit provided in the embodiment of the present application, wherein the test was performed with the first light signal being a red light signal and the second light signal being an infrared light signal. In conjunction with Figure 5, when the user's finger touches the light-transmitting portion 21 of the back cover 20 and remains still and quiet, the infrared light signal and the red light signal emitted by the light-emitting component 521 are emitted through the light-transmitting portion 21 and irradiated to the user's fingertips. The infrared light signal and the red light signal pass through the skin tissue of the fingertips and then reflect to the proximity light sensor 522. The proximity light sensor 522 converts the light into an electrical signal and derives a stable infrared light PPG signal and a red light PPG signal based on the electrical signal, as shown in Figure 16. Figure 16 is an interface diagram of the blood oxygen heart rate test results obtained based on the test circuit provided in the embodiment of the present application. In Figure 16, arrow ① indicates the infrared signal and arrow ② indicates the red light PPG signal. It can be seen from the interface that the infrared light PPG signal and the red light PPG signal obtained by testing the test circuit provided in the embodiment of the present application show that the heart rate status is 85BPM and the blood oxygen status is 95%. The blood oxygen and heart rate test accuracy is basically consistent with the blood oxygen clip, that is, the electronic device 100 using the test circuit provided in the embodiment of the present application can replace medical equipment and detect the user's health status in real time with low cost and high detection accuracy.

[0152] In addition, the test circuit provided in the embodiment of the present application was tested for oxygen reduction and oxygen increase monitoring. For example, three electronic devices using the test circuit of the present application were tested, and each electronic device was tested for six simulated oxygen reduction and oxygen increase tests on six people. In addition, six simulated oxygen reduction and oxygen increase tests were performed using a medical blood oximeter. The comparison chart of oxygen reduction and oxygen increase monitoring shown in Figure 17 was obtained. Figure 17 only shows the comparison chart of oxygen reduction and oxygen increase test data for one person using the electronic device using the test circuit provided in the embodiment of the present application and the medical blood oximeter. The pattern is the same for other people, so the comparison charts of oxygen reduction and oxygen increase test data for other people are not shown. In Figure 17, arrow ③ indicates the oxygen reduction and oxygen increase test data curve obtained by the electronic device using the test circuit of the present application, and arrow ④ indicates the oxygen reduction and oxygen increase test data curve obtained by the medical blood oximeter. In Figure 17, the horizontal axis represents the sampling point, that is, one point is recorded every preset time, such as one point every 10 seconds, and the vertical axis represents the blood oxygen value. Through testing, it can be concluded that the oxygen reduction and oxygen increase test data curve obtained based on the test circuit provided in the embodiment of the present application and the oxygen reduction and oxygen increase test data curve obtained based on the blood oxygen clamp have basically the same trend. And the oxygen reduction and oxygen increase test data obtained based on the test circuit provided in the embodiment of the present application can be used to calculate the root mean square error (RMSE) value, as shown in Table 1. For the three electronic devices, the oxygen reduction and oxygen increase test data of 6 people corresponding to each electronic device (a total of 18 groups of root mean square errors) are averaged. The average value of the root mean square error is, for example, 2.42%, which meets the FDA medical standard (the standard value RMSE is 3.5%).

[0153] Table 1

[0154] In addition, an embodiment of the present application provides an electronic device, which also includes: a memory and a processor, the memory and the processor are coupled; the memory stores program instructions, and when the program instructions are executed by the processor, the electronic device executes the above-mentioned related steps to implement the test method in the above-mentioned embodiment.

[0155] Exemplarily, when the proximity light sensor 522 includes a processing unit 5223, the processing unit 5223 sends the integrated value of the light intensity of the first light reference signal and the integrated value of the light intensity of the second light reference signal to the processor. The processor obtains the integrated value of the light intensity of the first light reference signal over a period of time, i.e., the integrated values ​​of the light intensity of the multiple first light reference signals corresponding to multiple operating cycles T0 over a period of time, and can store the integrated values ​​of the light intensity of the multiple first light reference signals in a memory. The integrated values ​​of the light intensity of the multiple first light reference signals can form a curve. This curve can represent the intensity of the red light signal (i.e., the red light PPG signal). Furthermore, the processor obtains the integrated value of the light intensity of the second light reference signal over a period of time, i.e., the integrated values ​​of the light intensity of the multiple second light reference signals corresponding to multiple operating cycles T0 over a period of time, and can store the integrated values ​​of the light intensity of the multiple second light reference signals in the memory. The integrated values ​​of the light intensity of the multiple second light reference signals can form a curve. This curve can represent the intensity of the infrared light signal (i.e., the infrared light PPG signal). The processor can separate the red light AC signal and the direct current DC signal, and separate the infrared light AC signal and the direct current DC signal based on the red light PPG signal and the infrared light PPG signal stored in the memory to obtain the ratio PI(RED) of the red light AC signal and the direct current DC signal, and the ratio PI(IR) of the infrared light AC signal and the direct current DC signal, and determine the R value based on PI(RED) and PI(IR), and then determine human body characteristics such as heart rate and blood oxygen saturation.

[0156] Exemplarily, when the processing unit 5223 is a processor for specific processing functions in an electronic device, that is, the processor is the processing unit 5223, the processor directly obtains the integrated value of the light intensity of the first light reference signal over a period of time. That is, multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of multiple first light reference signals, and the integrated values ​​of the light intensity of the multiple first light reference signals can be stored in a memory. The integrated values ​​of the light intensity of the multiple first light reference signals can form a curve, which can represent the intensity of the red light signal (i.e., the red light PPG signal). Furthermore, the processor directly obtains the integrated value of the light intensity of the second light reference signal over a period of time. That is, multiple operating cycles T0 over a period of time correspond to the integrated values ​​of the light intensity of multiple second light reference signals, and the processor can store the integrated values ​​of the light intensity of the multiple first light reference signals in a memory. The integrated values ​​of the light intensity of the multiple second light reference signals can form a curve, which can represent the intensity of the infrared light signal (i.e., the infrared light PPG signal). The processor can separate the red light AC signal and the direct current DC signal, and separate the infrared light AC signal and the direct current DC signal based on the red light PPG signal and the infrared light PPG signal stored in the memory to obtain the ratio PI(RED) of the red light AC signal and the direct current DC signal, and the ratio PI(IR) of the infrared light AC signal and the direct current DC signal, and determine the R value based on PI(RED) and PI(IR), and then determine human body characteristics such as heart rate and blood oxygen saturation.

[0157] In addition, an embodiment of the present application further provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the above-mentioned related steps to implement the testing method in the above-mentioned embodiment.

[0158] This embodiment further provides a computer program product. When the computer program product is run on an electronic device, the electronic device is caused to execute the above-mentioned related steps to implement the testing method in the above-mentioned embodiment.

[0159] In addition, an embodiment of the present application also provides a chip (which may also be a component or module), which may include one or more processing circuits and one or more transceiver pins; wherein the transceiver pins and the processing circuit communicate with each other through an internal connection path, and the processing circuit executes the above-mentioned related method steps to implement the test method in the above-mentioned embodiment to control the receiving pin to receive the signal, so as to control the transmitting pin to transmit the signal.

[0160] In addition, it can be seen from the above description that the electronic device, computer-readable storage medium, computer program product or chip provided in the embodiments of the present application are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0161] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A test circuit, characterized in that: include: A light emitting component, configured to emit at least two optical signals, wherein the at least two optical signals include a first optical signal and a second optical signal; The first optical signal and the second optical signal have different wavelengths; as well as, The proximity light sensor is used to collect a first light reference signal and a second light reference signal reflected and / or scattered by a human body, wherein the first light reference signal and the second light reference signal are used to calculate a human body feature value.

2. The test circuit according to claim 1, characterized in that: The proximity light sensor comprises: a collection unit, configured to collect the first optical reference signal and the second optical reference signal, and convert the first optical reference signal and the second optical reference signal into electrical signals, respectively, wherein the electrical signals are analog signals; An analog-to-digital converter is connected to the acquisition unit and is used to convert the analog signal into a digital signal, and the digital signal is used to calculate the human body characteristic value.

3. The test circuit according to claim 2, characterized in that: The light-emitting component includes a first light-emitting unit and a second light-emitting unit, and the collection unit includes a first photosensitive device and a second photosensitive device. The first light-emitting unit is used to emit the first light signal, and the first photosensitive device is used to collect the first light reference signal. The second light-emitting unit is used to emit the second light signal, and the second photosensitive device is used to collect the second light reference signal.

4. The test circuit according to claim 3, characterized in that: The proximity light sensor includes the first light emitting unit or the second light emitting unit.

5. The test circuit according to any one of claims 2 to 4, characterized in that: It also includes a processing unit, which is connected to the analog-to-digital converter and is used to obtain the integral value of the light intensity of the first light reference signal in the first time period and the light intensity of the second light reference signal in the second time period according to the digital signal, and the integral value is used to calculate the human body characteristic value.

6. The test circuit according to claim 5, characterized in that: The light emitting component emits the first optical signal and the second optical signal according to a working cycle.

7. The test circuit according to claim 6, characterized in that: The working cycle includes at least a first stage and a second stage; the first stage and the second stage each include at least one pulse cycle, and the pulse cycle includes a light-emitting stage working in a first level state and a non-light-emitting stage working in a second level state; The light emitting component is used to emit the first light signal in the light emitting phase of the first phase, and to emit the second light signal in the light emitting phase of the second phase; The proximity light sensor is used to collect a third light signal in the light-emitting stage of the first stage, and to collect a fourth light signal in the non-light-emitting stage of the first stage; and is also used to collect a fifth light signal in the light-emitting stage of the second stage, and to collect a sixth light signal in the non-light-emitting stage of the second stage; The processing unit is used to obtain an integrated value of the light intensity of the first optical reference signal according to the third optical signal and the fourth optical signal; is also used to obtain an integral value of the light intensity of the second optical reference signal according to the fifth optical signal and the sixth optical signal; The first time period is the first stage, and the second time period is the second stage; The third optical signal is determined based on ambient light and reflection and / or scattering of the first optical signal, the fourth optical signal is determined based on the ambient light, the fifth optical signal is determined based on ambient light and reflection and / or scattering of the second optical signal, and the sixth optical signal is determined based on the ambient light.

8. The test circuit according to claim 7, characterized in that: The acquisition unit comprises a first photosensitive device and a second photosensitive device, the first photosensitive device and the analog-to-digital converter form a first acquisition channel, and the second photosensitive device and the analog-to-digital converter form a second acquisition channel; The first acquisition channel is used to acquire the third optical signal in the light-emitting phase of the first phase, and to acquire the fourth optical signal in the non-light-emitting phase of the first phase; The second collection channel is used to collect the fifth optical signal in the light-emitting stage of the second stage, and to collect the sixth optical signal in the non-light-emitting stage of the second stage.

9. The test circuit according to claim 7 or 8, characterized in that: The first stage and the second stage both include N pulse cycles, where N≥2 and N is a positive integer.

10. The test circuit according to claim 5, characterized in that: The working cycle includes at least one pulse cycle, and the pulse cycle includes a light-emitting phase working in a first level state and a non-light-emitting phase working in a second level state; The light emitting component is used to emit the first light signal and the second light signal during the light emitting phase; The proximity light sensor is used to collect the seventh light signal and the eighth light signal in the light emitting stage, and collect the ninth light signal and the tenth light signal in the non-light emitting stage; The processing unit is used to obtain an integrated value of the light intensity of the first optical reference signal according to the seventh optical signal and the ninth optical signal; is also used to obtain an integrated value of the light intensity of the second optical reference signal according to the eighth optical signal and the tenth optical signal; The first time period and the second time period are the same time period, and the first time period is one working cycle; The seventh optical signal is determined based on ambient light and reflection and / or scattering of the first optical signal, the eighth optical signal is determined based on ambient light and reflection and / or scattering of the second optical signal, the ninth optical signal is determined based on ambient light, and the tenth optical signal is determined based on ambient light.

11. The test circuit according to claim 10, characterized in that: The acquisition unit includes a first photosensitive device and a second photosensitive device, and the analog-to-digital converter includes a first analog-to-digital converter and a second analog-to-digital converter; the first photosensitive device and the first analog-to-digital converter form a first acquisition channel, and the second photosensitive device and the second analog-to-digital converter form a second acquisition channel; The first acquisition channel is used to acquire the seventh light signal in the light-emitting phase and to acquire the ninth light signal in the non-light-emitting phase; The second collection channel is used to collect the eighth light signal in the light-emitting stage and to collect the tenth light signal in the non-light-emitting stage.

12. The test circuit according to claim 10 or 11, characterized in that: The working cycle includes N pulse cycles, wherein N≥2, and N is a positive integer.

13. The test circuit according to any one of claims 1 to 12, characterized in that: The first light signal includes a red light signal, and the second light signal includes an infrared light signal.

14. The test circuit according to any one of claims 5 to 13, characterized in that: The proximity light sensor includes the processing unit.

15. An electronic device, characterized in that: The test circuit comprises the test circuit described in any one of claims 1 to 14.

16. The electronic device according to claim 15, characterized in that: It also includes a display screen, which is reused as the light-emitting component.

17. The electronic device according to claim 16, characterized in that: The display screen includes a display area and a non-display area surrounding the display area, and the proximity light sensor is located in the non-display area.

18. The electronic device according to claim 15, characterized in that: It includes a display screen and a flashlight arranged on opposite sides of the electronic device, the proximity light sensor and the flashlight are arranged on the same side of the electronic device, the flashlight is multiplexed as the light-emitting component, and the light signal emitted by the flashlight is composed of at least the first light signal and the second light signal.

19. A testing method, characterized in that: Applied to an electronic device, the electronic device comprises a plurality of working cycles, the working cycle comprises at least one pulse cycle, the pulse cycle comprises a light emitting phase operating in a first level state and a non-light emitting phase operating in a second level state; The method comprises: In the light emitting stage, a first light signal and a second light signal are emitted, and a seventh light signal and an eighth light signal are collected, wherein the first light signal and the second light signal have different wavelengths, the seventh light signal is determined according to ambient light and reflection and / or scattering of the first light signal, and the eighth light signal is determined according to ambient light and reflection and / or scattering of the second light signal; In the non-light-emitting stage, a ninth light signal and a tenth light signal are collected, wherein the ninth light signal is determined by the ambient light, and the tenth light signal is determined by the ambient light; An integral value of the light intensity of a first optical reference signal is obtained according to the seventh optical signal and the ninth optical signal, and an integral value of the light intensity of a second optical reference signal is obtained according to the eighth optical signal and the tenth optical signal.

20. An electronic device, characterized in that: It includes: a memory and a processor, the memory and the processor are coupled; the memory stores program instructions, and when the program instructions are executed by the processor, the electronic device executes the test method as described in claim 19.

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