A method, system and related devices for physiological feature detection

Abstract

The application discloses a physiological characteristic detection method, system and related device, which is used for realizing low-power consumption and high-precision physiological characteristic parameter detection in a limited physical packaging space. The method comprises the following steps: controlling at least two different wavelength light sources to be lit at different time points in a sampling period according to a preset timing sequence to form a plurality of light emitting periods; setting a reference time slot in the sampling period, and controlling all light sources to be turned off in the reference time slot; collecting corresponding photoelectric signals in each light emitting period through the same photoelectric detector, and collecting a reference signal corresponding to an environmental reference in the reference time slot; separating the photoelectric signals according to the corresponding relationship between the sampling time of the photoelectric signals and the light emitting period in the preset timing sequence, and obtaining initial photoelectric signals corresponding to different light emitting wavelengths respectively; calibrating the initial photoelectric signals by using the reference signal, and extracting physiological characteristic parameters of a target object based on the calibrated effective photoelectric signals.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a method, system and related device for detecting physiological characteristics. Background Technology

[0002] Photoplethysmography (PPG) is a detection technique that obtains physiological parameters by emitting light of a specific wavelength and detecting changes in the reflected light from human tissue. It is widely used in monitoring indicators such as heart rate and blood oxygen saturation. In existing technologies, multi-wavelength PPG detection schemes typically use multiple light sources to emit light signals of different wavelengths, and set up corresponding photodetectors for each wavelength to collect the signals. The photoelectric signals of each wavelength are collected separately and then input to independent transimpedance amplifiers and analog-to-digital converters for parallel processing.

[0003] However, this multi-channel parallel acquisition and processing method has design limitations in micro-sized wearable devices. The physical packaging space of micro-sized wearable devices is limited, and the simultaneous amplification and analog-to-digital conversion of multiple signal links leads to high overall power consumption during system operation, limiting the device's battery life. At the same time, if signals of different wavelengths are received by detectors at different locations, the optical path and the sampled tissue area will not be completely consistent, thus introducing baseline errors and affecting the accuracy of physiological characteristic parameters calculated based on the ratio of multi-wavelength signals. Summary of the Invention

[0004] This application provides a method, system, and related apparatus for detecting physiological features, enabling low-power and high-precision detection of physiological feature parameters within a limited physical packaging space.

[0005] The first aspect of this application provides a method for detecting physiological characteristics, including:

[0006] At least two different wavelength light sources are lit in a time-sharing manner within the sampling period according to a preset timing control, so as to form multiple light emission periods; A reference time slot is set within the sampling period, and all the light sources are controlled to be turned off within the reference time slot. The photoelectric signals are collected in each of the light emission periods using the same photodetector, and a reference signal corresponding to the environmental reference is collected in the reference time slot. Based on the correspondence between the sampling time of the photoelectric signal and the emission period in the preset time sequence, the photoelectric signal is separated to obtain initial photoelectric signals corresponding to different emission wavelengths; The initial photoelectric signal is calibrated using the reference signal, and the physiological characteristic parameters of the target object are extracted based on the calibrated effective photoelectric signal.

[0007] Optionally, the step of controlling at least two different wavelengths of light sources to be lit in a time-division manner within the sampling period according to a preset timing sequence to form multiple light emission periods includes: Within the sampling period, effective driving levels are output to at least two different wavelength light sources according to a preset timing sequence to form multiple light emission periods; An invalid level is output between two adjacent valid drive levels to form a protection interval, the duration of which is not less than the light response tail decay time of the previous light source.

[0008] Optionally, calibrating the initial photoelectric signal using the reference signal includes: The DC bias component in the reference signal is extracted as a background reference to characterize ambient light interference and dark current of the photodetector. The difference between the sampled amplitude of the initial photoelectric signal and the background reference is calculated to obtain the calibrated effective photoelectric signal.

[0009] Optionally, the light source includes a green light source, a red light source, and an infrared light source; The extraction of physiological feature parameters of the target object based on the calibrated effective photoelectric signal includes at least one of the following: Based on the periodic variation characteristics of the effective photoelectric signal corresponding to the green light source, the heart rate parameters are calculated; Based on the amplitude ratio of the effective photoelectric signal corresponding to the red light source and the effective photoelectric signal corresponding to the infrared light source, the blood oxygen saturation parameter is calculated jointly. Based on the effective photoelectric signal corresponding to the infrared light source, venous return characteristic parameters are extracted.

[0010] Optionally, the step of jointly calculating the blood oxygen saturation parameter based on the amplitude ratio of the effective photoelectric signal corresponding to the red light source and the effective photoelectric signal corresponding to the infrared light source includes: The first AC component and the first DC component of the effective photoelectric signal corresponding to the red light source, and the second AC component and the second DC component of the effective photoelectric signal corresponding to the infrared light source are extracted respectively. Calculate the first normalized ratio of the first AC component to the first DC component, and calculate the second normalized ratio of the second AC component to the second DC component; Based on the quotient of the first normalized ratio and the second normalized ratio, a preset parameter mapping table is matched to obtain the blood oxygen saturation parameter.

[0011] Optionally, the method further includes: Real-time acquisition of the activity scene status of the target object, including daily monitoring status, sleep monitoring status and exercise monitoring status; When the current activity scene is in the daily monitoring state, the red light source and the infrared light source are turned off in the preset time sequence, and the green light source is configured to emit light during a specific period at a first sampling frequency. When the current activity scene state is the sleep monitoring state, the green light source is configured to emit light during the first sampling frequency in the preset time sequence, and the red light source and the infrared light source are configured to emit light during the second sampling frequency. When the current activity scene state is the motion monitoring state, the red light source and the infrared light source are turned off in the preset time sequence, and the green light source is configured to emit light during a period of time at a third sampling frequency, wherein the third sampling frequency is greater than the first sampling frequency.

[0012] Optionally, the method further includes: Acquire the signal quality characteristics of the photoelectric signals acquired in real time; The target sampling rate and target duration are adjusted according to the signal quality characteristics, and the preset timing is dynamically updated according to the target sampling rate and the target duration.

[0013] A second aspect of this application provides a system for detecting physiological characteristics, comprising: The first control unit is used to control at least two different wavelength light sources to light up in a time-sharing manner within the sampling period according to a preset timing sequence, so as to form multiple light-emitting periods; The second control unit is used to set a reference time slot during the sampling period and control all the light sources to turn off during the reference time slot. The acquisition unit is used to acquire corresponding photoelectric signals in each of the light emission periods using the same photodetector, and to acquire a reference signal corresponding to the environmental reference in the reference time slot. The acquisition unit is used to separate the photoelectric signal according to the correspondence between the sampling time of the photoelectric signal and the emission period on the preset time sequence, and acquire the initial photoelectric signals corresponding to different emission wavelengths respectively; The extraction unit is used to calibrate the initial photoelectric signal using the reference signal, and extract the physiological characteristic parameters of the target object based on the calibrated effective photoelectric signal.

[0014] A third aspect of this application provides a device for detecting physiological characteristics, the device comprising: Processor, memory, input / output units, and bus; The processor is connected to the memory, the input / output unit, and the bus; The memory stores a program, which the processor invokes to execute the first aspect and any optional method of physiological feature detection in the first aspect.

[0015] The fourth aspect of this application provides a wearable device that stores a program that performs the first aspect and any optional method of physiological feature detection in the first aspect.

[0016] As can be seen from the above technical solutions, this application has the following advantages: By illuminating at least two different wavelength light sources at preset times within a sampling period, and setting a reference time slot within the same sampling period to acquire environmental baseline signals, a single photodetector synchronously acquires corresponding photoelectric signals during each emission period and acquires baseline signals in the reference time slot, achieving the acquisition of signals of different wavelengths at the same detection location. The photoelectric signals are separated according to the correspondence between sampling time and emission period, and calibrated using the reference signal to obtain effective photoelectric signals, reflecting the blood flow and light absorption changes of the target object at various wavelengths. Finally, physiological characteristic parameters are extracted based on the calibrated effective photoelectric signals, enabling continuous measurement of multi-wavelength PPG signals.

[0017] Since all wavelength signals are acquired by the same photodetector at a fixed location, the amplitude of the photoelectric signal, after calibration, can accurately reflect the actual light absorption variation characteristics of the same tissue site, reducing the baseline error introduced by multi-channel discrete acquisition. At the same time, using only a single photodetector can also reduce device power consumption, achieving low-power and high-precision detection of physiological characteristic parameters within a limited physical packaging space. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic flowchart of an embodiment of the physiological characteristic detection method provided in this application; Figure 2 A schematic flowchart of an embodiment of the method for detecting physiological characteristics provided in this application, regarding the protective interval; Figure 3 A schematic flowchart of an embodiment of the method for detecting physiological characteristics provided in this application, which calibrates the initial photoelectric signal; Figure 4A schematic flowchart of an embodiment of the method for extracting physiological feature parameters of a target object in the physiological feature detection method provided in this application; Figure 5 A schematic flowchart of an embodiment of the physiological feature detection method provided in this application, which adaptively adjusts the light source driving timing and sampling frequency based on the target object's activity scene state; Figure 6 A schematic flowchart of an embodiment of the physiological feature detection method provided in this application, which dynamically adjusts a preset timing sequence based on signal quality; Figure 7 A schematic diagram of an embodiment of the physiological feature detection system provided in this application; Figure 8 A schematic diagram of an embodiment of the physiological characteristic detection device provided in this application. Detailed Implementation

[0020] This application provides a method, system, and related apparatus for detecting physiological features, enabling low-power and high-precision detection of physiological feature parameters within a limited physical packaging space.

[0021] It should be noted that the physiological characteristic detection method provided in this application can be applied to various wearable devices, such as smart rings, smartwatches, smart bracelets, smart headbands, and smart headphones. It is particularly suitable for micro-sized wearable devices with limited internal physical packaging space and stringent requirements for battery life, such as smart rings. For ease of explanation, this application uses a processor or controller built into the device as an example for illustration.

[0022] Please see Figure 1 , Figure 1 An embodiment of the physiological characteristic detection method provided in this application includes: S101. Control at least two different wavelength light sources to light up at different times within the sampling period according to a preset timing sequence, so as to form multiple light-emitting periods; In this embodiment, to obtain multi-dimensional physiological characteristic parameters, the device is equipped with at least two light sources emitting different spectral characteristics. The microcontroller, according to a preset timing sequence, sequentially drives each light source in a time-division multiplexing manner within a single sampling period, ensuring that each light source occupies an independent emission period on the time axis, with no overlap between emission periods, thus completing the time-division lighting operation. The sampling period refers to the basic time span required for the device to complete one complete photoelectric signal cycle acquisition, and the preset timing sequence is a time allocation sequence pre-configured by the device's microcontroller in the underlying hardware. In practical applications, emission periods matching the number of light sources are divided within a single sampling period. Each emission period is arranged sequentially in a preset fixed order within the sampling period, and the duration of each emission period can be adjusted according to detection requirements, preferably configured to be between fifty and two hundred microseconds.

[0023] S102. Set a reference time slot within the sampling period and control all light sources to turn off within the reference time slot; To eliminate the impact of ambient light interference and the dark current of the photodetector itself on the accuracy of subsequent photoelectric signal acquisition, a reference time slot can be synchronously set within a single sampling period, in addition to setting emission periods that match the number of light sources. This reference time slot serves as an independent time interval within the sampling period, not overlapping with any emission periods. Its placement can be rationally set according to the timing plan of the sampling period, typically at the end of all emission periods, but can also be adjusted between emission periods according to actual timing requirements. When entering the reference time slot, the microcontroller controls all light sources to be completely turned off, generating no light signal output.

[0024] The reference time slot refers to the time interval used to collect environmental reference signals. Its core function is to provide a basic reference for the subsequent calibration of photoelectric signals. The duration of the reference time slot needs to meet the stable acquisition requirements of ambient light and the dark current signal of the photodetector. It is usually consistent with the duration of a single emission period, or adaptively adjusted according to the actual calibration accuracy requirements, to ensure that the acquired reference signal can truly reflect the current level of ambient light interference and the influence of the dark current of the photodetector itself.

[0025] S103. Collect the corresponding photoelectric signals in each emission period using the same photodetector, and collect the reference signal corresponding to the environmental reference in the reference time slot. In this embodiment, to save hardware layout space and simplify circuit structure, the device is equipped with only one photodetector. This photodetector is a broadband response device capable of receiving light signals emitted by light sources of different wavelengths. Its response range should cover the emission wavelengths of all light sources, converting the incident light signal into a corresponding electrical signal to complete the photoelectric conversion process.

[0026] Specifically, during each emission period, the corresponding wavelength of the light source is illuminated. The emitted light signal is incident on the human detection site, reflected or transmitted through human tissue, and fed back to the photodetector. The photodetector performs photoelectric conversion on the feedback light signal, generating a photoelectric signal corresponding to that wavelength. The signal amplitude is related to changes in human physiological characteristics. When entering the reference time slot, all light sources are turned off. At this time, the photodetector only collects the ambient light signal in the current environment and the dark current signal generated during its own operation. The two are superimposed to form a reference signal corresponding to the environmental benchmark. Throughout the acquisition process, the photodetector remains operational, maintaining strict synchronization with the driving sequence of the light sources through a preset timing sequence. This ensures accurate acquisition of the corresponding signal during the corresponding time period, avoids crosstalk between signals from different time periods, and guarantees the accuracy and integrity of the acquired photoelectric signal and reference signal.

[0027] S104. Based on the correspondence between the sampling time of the photoelectric signal and the emission period in the preset time sequence, the photoelectric signal is separated to obtain the initial photoelectric signals corresponding to different emission wavelengths. After signal acquisition for each time period, since there is a fixed correspondence between the sampling time of each photoelectric signal and the corresponding emission period on the time axis, the microcontroller performs timing matching and differentiation on the continuously acquired photoelectric signals based on this timing correspondence. That is, using a preset timing sequence as a benchmark, the photoelectric signals acquired at each sampling time are aggregated into the emission wavelength channel that matches its sampling time, thereby achieving the orderly separation of multi-wavelength mixed photoelectric signals. The signals obtained after separation are the initial photoelectric signals corresponding to different emission wavelengths. After timing matching and separation, each initial photoelectric signal retains the physiological characteristic information of the corresponding wavelength light signal after being acted upon by human tissue; the signals are independent of each other and do not interfere with each other.

[0028] S105. The initial photoelectric signal is calibrated using a reference signal, and the physiological characteristic parameters of the target object are extracted based on the calibrated effective photoelectric signal.

[0029] Because the initial photoelectric signal is inevitably superimposed with ambient light interference and the dark current of the photodetector itself during the acquisition process, direct use for physiological feature parameter extraction would lead to a decrease in measurement accuracy. Therefore, it is necessary to calibrate the initial photoelectric signal using a reference signal acquired within a reference time slot. By eliminating the superposition interference of ambient light and dark current on the initial photoelectric signal through the reference signal, the signal obtained after this calibration process becomes the effective photoelectric signal. The effective photoelectric signal can accurately reflect the changes in the light signal emitted by the light source after being acted upon by human tissue. Based on the calibrated effective photoelectric signal and combined with the physiological characteristics of light signals at different wavelengths, the microcontroller extracts the physiological feature parameters of the target object. Different wavelengths of effective photoelectric signals are used to extract different physiological feature parameters; the specific use is not limited here.

[0030] In practical applications, the hardware structure required for the physiological characteristic detection method provided in this embodiment can be built based on a photoelectric sensor module. This module integrates a drive control circuit, a signal acquisition and processing circuit, a light-emitting package, and a single photoelectric receiver on a substrate. The light-emitting package integrates at least three light-emitting elements of different wavelengths. Each light-emitting element forms a common anode electrical connection architecture through shared and independent pins. Each wavelength of light-emitting element corresponds to an independent drive channel, which is independently controlled by the drive control circuit to meet the hardware control requirements of time-division lighting. The photoelectric receiver is electrically connected to the signal acquisition and processing circuit, enabling synchronous photoelectric conversion and signal sampling output within the light-emitting period and reference time slot. The drive control circuit and the signal acquisition and processing circuit are time-synchronously coupled, sharing the same clock reference, ensuring strict alignment between the on / off timing of the light-emitting elements and the sampling timing of the photoelectric receiver, achieving timing matching between the photoelectric signal and the emission wavelength.

[0031] In this embodiment, at least two different wavelength light sources are illuminated in a time-division manner according to a preset timing sequence within the sampling period. A reference time slot is set within the same sampling period to collect environmental reference signals. The same photodetector synchronously collects corresponding photoelectric signals during each emission period and acquires baseline signals in the reference time slot, achieving the acquisition of signals of different wavelengths at the same detection location. The photoelectric signals are separated according to the correspondence between sampling time and emission period, and calibrated using the reference signal to obtain effective photoelectric signals, reflecting the blood flow and light absorption changes of the target object at various wavelengths. Finally, physiological characteristic parameters are extracted based on the calibrated effective photoelectric signals, enabling continuous measurement of multi-wavelength PPG signals.

[0032] Since all wavelength signals are acquired by the same photodetector at a fixed location, the amplitude of the photoelectric signal, after calibration, can accurately reflect the actual light absorption variation characteristics of the same tissue site, reducing the baseline error introduced by multi-channel discrete acquisition. At the same time, using only a single photodetector can also reduce device power consumption, achieving low-power and high-precision detection of physiological characteristic parameters within a limited physical packaging space.

[0033] Please see Figure 2 According to some embodiments of the present invention, in step S101, at least two different wavelength light sources are controlled to light up in a time-division manner within the sampling period according to a preset timing sequence, so as to form multiple light emission periods, including but not limited to the following: S201. During the sampling period, effective driving levels are output to at least two different wavelength light sources according to a preset timing sequence to form multiple light emission periods; S202. An invalid level is output between two adjacent valid drive levels to form a protection interval. The duration of the invalid level is not less than the light response tail decay time of the previous light source.

[0034] In this embodiment, the microcontroller generates corresponding drive level signals according to a preset timing sequence and outputs these signals to the drive circuits of each light source to control its operating state. Within a single sampling period, the microcontroller sequentially outputs valid drive levels to at least two different wavelength light sources according to the preset timing sequence. Upon receiving a valid drive level, the light source enters a lit-up state. The operating time periods corresponding to different wavelength light sources constitute multiple independent light-emitting periods. To avoid superposition and crosstalk between adjacent wavelength light sources in the time domain, the microcontroller outputs an invalid level between two adjacent valid drive levels. This invalid level controls the previous light source to turn off and the next light source to temporarily not start, thus forming a protective interval between adjacent light-emitting periods. The duration of this protective interval is determined by the light response tail attenuation characteristics of the light source. The duration of the protective interval is set to be no less than the light response tail attenuation time of the previous light source after it is turned off, for example, 10-30 microseconds. This ensures that the residual light signal output by the previous light source completely attenuates before starting the next light source, thereby reducing mutual interference between different wavelength light signals and ensuring the purity of subsequent photoelectric signal acquisition.

[0035] Please see Figure 3 According to some embodiments of the present invention, in step S105, the initial photoelectric signal is calibrated using a reference signal, including but not limited to the following: S301. Extract the DC bias component from the reference signal as a background reference to characterize ambient light interference and dark current of the photodetector. S302. Perform a difference calculation between the sampled amplitude of the initial photoelectric signal and the background reference to obtain the calibrated effective photoelectric signal.

[0036] In this embodiment, all light sources are turned off within the reference time slot. At this time, the reference signal acquired by the photodetector does not contain alternating components caused by physiological changes; it consists only of the photocurrent generated by ambient light and the dark current generated by the photodetector itself. These two types of interference signals have stable amplitudes within a short time, manifesting as a DC bias component in the reference signal. Therefore, this DC bias component can be directly used as a background reference characterizing ambient light interference and the photodetector's dark current. The microcontroller performs numerical calculations on the sampled amplitude of the initial photoelectric signal and this background reference. The initial photoelectric signal also contains ambient light interference components and the photodetector's dark current components under the same environmental conditions. By removing the constant interference components corresponding to the background reference, fixed deviations unrelated to physiological characteristics can be eliminated, ensuring that the processed signal retains only the effective fluctuation components caused by changes in blood flow and light absorption in human tissue. This achieves calibration of the initial photoelectric signal, resulting in an effective photoelectric signal that truly reflects physiological changes.

[0037] Please see Figure 4 According to some embodiments of the present invention, the light source specifically employs three devices with different wavelengths: a green light source, a red light source, and an infrared light source. The green light source has an emission wavelength of 530 nm and a working drive current of 5 mA; the red light source has an emission wavelength of 660 nm and a working drive current of 3 mA; and the infrared light source has an emission wavelength of 940 nm and a working drive current of 5 mA. The drive current parameters of the three light sources are reasonably set according to the detection requirements of each wavelength of light signal to ensure that the light signal can effectively penetrate the tissue of the human body detection site, while also taking into account the power consumption control of the device.

[0038] In step S105, which involves extracting physiological feature parameters of the target object based on the calibrated effective photoelectric signal, the microcontroller performs the corresponding parameter extraction operation according to the different physiological response characteristics of the three wavelengths of effective photoelectric signals. Specifically, at least one of the following extraction processes can be implemented: S401. Calculate heart rate parameters based on the periodic variation characteristics of the effective photoelectric signal of the corresponding green light source; When the microcontroller executes S401, it calculates heart rate parameters based on the effective photoelectric signal of the corresponding green light source. Because green light is highly sensitive to absorption by hemoglobin in human blood, when the human heart beats periodically, blood flow velocity and blood volume change periodically, causing periodic fluctuations in the intensity of the green light signal after reflection or transmission through human tissue. This fluctuation is synchronously reflected in the effective photoelectric signal of the corresponding green light source, manifesting as periodic changes in signal amplitude. By identifying the periodic variation characteristics of this effective photoelectric signal, the microcontroller calculates the signal fluctuation period and converts it into the heart rate parameters of the target object, achieving accurate heart rate detection.

[0039] S402. Based on the amplitude ratio of the effective photoelectric signal of the corresponding red light source and the effective photoelectric signal of the corresponding infrared light source, the blood oxygen saturation parameter is calculated jointly. When the microcontroller executes S402, it combines the effective photoelectric signals from the corresponding red light source and the corresponding infrared light source, and calculates the blood oxygen saturation parameter by analyzing the amplitude ratio between the two. The core principle is that there is a significant difference in the absorption coefficients of oxyhemoglobin and deoxyhemoglobin in human blood for red and infrared light. Oxyhemoglobin absorbs red light weakly and infrared light strongly, while deoxyhemoglobin does the opposite. This absorption difference is directly reflected in the amplitude changes of the two effective photoelectric signals. By analyzing and calculating the amplitude ratio between the two effective photoelectric signals, and combining this with the intrinsic correlation between light absorption and blood oxygen saturation, the microcontroller can jointly calculate the blood oxygen saturation parameter of the target object.

[0040] According to some embodiments of the present invention, when calculating blood oxygen saturation parameters based on the combined effective photoelectric signals from red and infrared light sources, the microcontroller performs component decomposition processing on the two calibrated effective photoelectric signals. The microcontroller separates a first AC component characterizing blood flow pulsation changes and a first DC component characterizing average light intensity from the effective photoelectric signal from the corresponding red light source, and simultaneously separates a second AC component and a second DC component from the effective photoelectric signal from the corresponding infrared light source. Based on this, the microcontroller performs a ratio calculation between the first AC component and the first DC component to obtain a first normalized ratio for the red light channel, and performs a ratio calculation between the second AC component and the second DC component to obtain a second normalized ratio for the infrared channel. Subsequently, the microcontroller calculates the quotient between the first and second normalized ratios, matches this quotient with a preset parameter mapping table within the device, and directly determines the blood oxygen saturation value corresponding to the current quotient through a table lookup, thus completing the acquisition of the blood oxygen saturation parameter.

[0041] S403. Extract venous return characteristic parameters based on the effective photoelectric signal of the corresponding infrared light source.

[0042] When the microcontroller executes S403, it extracts venous return characteristic parameters based on the effective photoelectric signal of the corresponding infrared light source. Because infrared light has a strong penetration depth in human tissue, reaching 3-5mm, it can penetrate the superficial skin tissue and detect changes in blood volume in deep veins. Changes in venous return directly cause corresponding fluctuations in venous blood volume, which are synchronously reflected in the effective photoelectric signal of the infrared light source. The microcontroller performs feature analysis on this effective photoelectric signal, extracts signal features related to changes in venous blood volume, and then extracts the venous return characteristic parameters of the target object, thus realizing the detection of the venous return status.

[0043] Please see Figure 5 According to some embodiments of the present invention, in order to adapt to the detection requirements of different usage scenarios of the target object and achieve a dynamic balance between signal detection accuracy and device power consumption, the present invention also includes a method for adaptively adjusting the light source driving timing and sampling frequency based on the activity scene state of the target object. This method includes, but is not limited to, the following: S501. Real-time acquisition of the activity scene status of the target object, including daily monitoring status, sleep monitoring status and motion monitoring status; S502. When the current activity scenario is in the daily monitoring state, turn off the red light source and infrared light source in the preset time sequence, and configure the green light source to emit light during the first sampling frequency. S503. When the current activity scenario is in sleep monitoring mode, the green light source is configured to emit light during the first sampling frequency in the preset time sequence, and the red light source and infrared light source are configured to emit light during the second sampling frequency. S504. When the current activity scene is in motion monitoring state, turn off the red light source and infrared light source in the preset timing, and configure the green light source to emit light during the third sampling frequency, which is greater than the first sampling frequency.

[0044] In this embodiment, the microcontroller acquires the activity scene status of the target object in real time. The activity scene status is divided into three categories: daily monitoring status, sleep monitoring status, and motion monitoring status. The device can identify and determine the scene status through data collected by the built-in sensing unit or user settings. When the microcontroller determines that the current activity scene status is daily monitoring status, it adjusts the preset timing configuration parameters, turns off the drive output of the red light source and infrared light source, and configures the emission period of the green light source at the first sampling frequency, retaining only the basic heart rate detection function, so that the device operates in the lowest power consumption mode. When the microcontroller determines that the current activity scene status is sleep monitoring status, it configures the emission period of the green light source at the first sampling frequency, and configures the emission periods of the red light source and infrared light source at the second sampling frequency, simultaneously realizing the detection of multiple parameters such as heart rate, blood oxygen saturation, and venous return, meeting the full-dimensional physiological monitoring needs in the sleep scene. When the microcontroller determines that the current activity scene is in motion monitoring mode, it shuts down the drive outputs of the red and infrared light sources and configures the green light source's emission period at a third sampling frequency. This third sampling frequency is higher than the first sampling frequency. By increasing the sampling frequency of the green light signal, motion artifacts are suppressed from interfering with the detection results, ensuring the stability and accuracy of heart rate detection in motion scenarios. In some specific embodiments, the first sampling frequency can be set to 25Hz, the second sampling frequency to 50Hz, and the third sampling frequency to 100Hz.

[0045] In addition, the device supports a user-triggered blood oxygen saturation detection mode. The microcontroller can automatically switch the light source drive timing and time slot configuration by combining motion signals collected by the accelerometer and user-input control commands. When the microcontroller receives a user-triggered blood oxygen detection command, it turns on the red and infrared light sources and configures their sampling frequency to the third sampling frequency, while simultaneously maintaining the normal operation of the green light source to achieve rapid detection of high-precision blood oxygen saturation parameters. The microcontroller manages the timing of this detection state, and after 30 seconds of continuous detection, it automatically turns off the drive output of the red and infrared light sources, restoring the timing configuration state before the detection command was triggered, thereby reducing unnecessary power consumption. Throughout the scene switching and blood oxygen detection process, the microcontroller reads the motion data output by the accelerometer in real time and combines it with user commands to complete the adaptive switching of the timing configuration, ensuring the stability of the detection process and the controllability of the device's power consumption.

[0046] Please see Figure 6 According to some embodiments of the present invention, in order to improve the adaptability of photoelectric signal acquisition, ensure the effectiveness of physiological feature detection results, and optimize device operating power consumption, the present invention also includes a processing procedure for dynamically adjusting a preset timing based on signal quality. This processing procedure includes, but is not limited to, the following: S601. Acquire the signal quality characteristics of the real-time acquired photoelectric signals; S602. Adjust the target sampling rate and target duration for the corresponding emission period according to the signal quality characteristics, and dynamically update the preset timing according to the target sampling rate and target duration.

[0047] In this embodiment, the microcontroller acquires real-time photoelectric signals and analyzes them to obtain the corresponding signal quality characteristics. These characteristics characterize the degree of interference and the proportion of valid data in the current photoelectric signal, serving as a basis for adjusting timing parameters. Based on the analyzed signal quality characteristics, the microcontroller determines the target sampling rate and target duration for each emission period. It then adaptively adjusts the sampling frequency and duration parameters according to the signal quality. Subsequently, based on the determined target sampling rate and target duration, the microcontroller updates the internally pre-configured timing parameters in real time, completing the dynamic adjustment of the preset timing. This ensures that the light source driving timing is adapted to the current signal acquisition environment, achieving reasonable power consumption control while guaranteeing signal acquisition quality.

[0048] The following provides a detailed description of the physiological characteristic detection system provided in this application. Please refer to [link / reference]. Figure 7 , Figure 7 Another embodiment of the physiological characteristic detection system provided in this application, the system includes: The first control unit 701 is used to control at least two different wavelength light sources to light up in a time-sharing manner within the sampling period according to a preset timing sequence, so as to form multiple light-emitting periods; The second control unit 702 is used to set a reference time slot within the sampling period and control all light sources to turn off within the reference time slot; The acquisition unit 703 is used to acquire corresponding photoelectric signals in each emission period using the same photodetector, and to acquire reference signals corresponding to the environmental reference in the reference time slot. The acquisition unit 704 is used to separate the photoelectric signal according to the correspondence between the sampling time of the photoelectric signal and the emission period in a preset time sequence, and acquire the initial photoelectric signals corresponding to different emission wavelengths respectively. The extraction unit 705 is used to calibrate the initial photoelectric signal using a reference signal and extract the physiological characteristic parameters of the target object based on the calibrated effective photoelectric signal.

[0049] In this embodiment, the functions of each unit are the same as described above. Figures 1 to 6 The steps in the method embodiments shown correspond to those in the examples, and will not be repeated here.

[0050] This application also provides a device for detecting physiological characteristics; please refer to [link to relevant documentation]. Figure 8 , Figure 8 One embodiment of the physiological characteristic detection device provided in this application includes: Processor 801, memory 802, input / output unit 803, bus 804; The processor 801 is connected to the memory 802, the input / output unit 803, and the bus 804; The memory 802 stores a program, and the processor 801 calls the program to execute any of the above-mentioned methods for detecting physiological characteristics.

[0051] This application also relates to a wearable device that performs any of the above-described methods for detecting physiological characteristics.

[0052] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0053] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0054] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0055] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0056] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for detecting physiological characteristics, characterized in that, The method includes: At least two different wavelength light sources are lit in a time-sharing manner within the sampling period according to a preset timing control, so as to form multiple light emission periods; A reference time slot is set within the sampling period, and all the light sources are controlled to be turned off within the reference time slot. The photoelectric signals are collected in each of the light emission periods using the same photodetector, and a reference signal corresponding to the environmental reference is collected in the reference time slot. Based on the correspondence between the sampling time of the photoelectric signal and the emission period in the preset time sequence, the photoelectric signal is separated to obtain initial photoelectric signals corresponding to different emission wavelengths; The initial photoelectric signal is calibrated using the reference signal, and the physiological characteristic parameters of the target object are extracted based on the calibrated effective photoelectric signal.

2. The method according to claim 1, characterized in that, The method of controlling at least two different wavelength light sources to light up at different times within a sampling period according to a preset timing sequence to form multiple light-emitting periods includes: Within the sampling period, effective driving levels are output to at least two different wavelength light sources according to a preset timing sequence to form multiple light emission periods; An invalid level is output between two adjacent valid drive levels to form a protection interval, the duration of which is not less than the light response tail decay time of the previous light source.

3. The method according to claim 1, characterized in that, The calibration of the initial photoelectric signal using the reference signal includes: The DC bias component in the reference signal is extracted as a background reference to characterize ambient light interference and dark current of the photodetector. The difference between the sampled amplitude of the initial photoelectric signal and the background reference is calculated to obtain the calibrated effective photoelectric signal.

4. The method according to claim 1, characterized in that, The light source includes a green light source, a red light source, and an infrared light source; The extraction of physiological feature parameters of the target object based on the calibrated effective photoelectric signal includes at least one of the following: Based on the periodic variation characteristics of the effective photoelectric signal corresponding to the green light source, the heart rate parameters are calculated; Based on the amplitude ratio of the effective photoelectric signal corresponding to the red light source and the effective photoelectric signal corresponding to the infrared light source, the blood oxygen saturation parameter is calculated jointly. Based on the effective photoelectric signal corresponding to the infrared light source, venous return characteristic parameters are extracted.

5. The method according to claim 4, characterized in that, The calculation of blood oxygen saturation parameters based on the amplitude ratio of the effective photoelectric signal corresponding to the red light source and the effective photoelectric signal corresponding to the infrared light source includes: The first AC component and the first DC component of the effective photoelectric signal corresponding to the red light source, and the second AC component and the second DC component of the effective photoelectric signal corresponding to the infrared light source are extracted respectively. Calculate the first normalized ratio of the first AC component to the first DC component, and calculate the second normalized ratio of the second AC component to the second DC component; Based on the quotient of the first normalized ratio and the second normalized ratio, a preset parameter mapping table is matched to obtain the blood oxygen saturation parameter.

6. The method according to claim 4, characterized in that, The method further includes: Real-time acquisition of the activity scene status of the target object, including daily monitoring status, sleep monitoring status and exercise monitoring status; When the current activity scene is in the daily monitoring state, the red light source and the infrared light source are turned off in the preset time sequence, and the green light source is configured to emit light during a specific period at a first sampling frequency. When the current activity scene state is the sleep monitoring state, the green light source is configured to emit light during the first sampling frequency in the preset time sequence, and the red light source and the infrared light source are configured to emit light during the second sampling frequency. When the current activity scene state is the motion monitoring state, the red light source and the infrared light source are turned off in the preset time sequence, and the green light source is configured to emit light during a period of time at a third sampling frequency, wherein the third sampling frequency is greater than the first sampling frequency.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: Acquire the signal quality characteristics of the photoelectric signals acquired in real time; The target sampling rate and target duration are adjusted according to the signal quality characteristics, and the preset timing is dynamically updated according to the target sampling rate and the target duration.

8. A system for detecting physiological characteristics, characterized in that, The system includes: The first control unit is used to control at least two different wavelength light sources to light up in a time-sharing manner within the sampling period according to a preset timing sequence, so as to form multiple light-emitting periods; The second control unit is used to set a reference time slot during the sampling period and control all the light sources to turn off during the reference time slot. The acquisition unit is used to acquire corresponding photoelectric signals in each of the light emission periods using the same photodetector, and to acquire a reference signal corresponding to the environmental reference in the reference time slot. The acquisition unit is used to separate the photoelectric signal according to the correspondence between the sampling time of the photoelectric signal and the emission period on the preset time sequence, and acquire the initial photoelectric signals corresponding to different emission wavelengths respectively; The extraction unit is used to calibrate the initial photoelectric signal using the reference signal, and extract the physiological characteristic parameters of the target object based on the calibrated effective photoelectric signal.

9. A device for detecting physiological characteristics, characterized in that, The device includes: Processor, memory, input / output units, and bus; The processor is connected to the memory, the input / output unit, and the bus; The memory stores a program, which the processor invokes to perform the method as described in any one of claims 1 to 7.

10. A wearable device, characterized in that, The wearable device performs the method as described in any one of claims 1 to 7.

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