Method, device and equipment for timing control of LED supply voltage and storage medium

Abstract

The application discloses a kind of LED power supply voltage timing control method, device, equipment and storage medium.The method comprises: determining multiple LED time slots in PPG measurement period;According to the specific wavelength corresponding to each LED time slot and the preset driving current, the target power supply voltage of each LED time slot is determined;According to the target power supply voltage of each LED time slot, the execution sequence of each LED time slot in PPG measurement period is determined;According to the execution sequence, the PPG measurement of each LED time slot is sequentially executed, and after the PPG measurement of current LED time slot ends, the adjustable power supply voltage for each LED time slot is adjusted to the power supply voltage corresponding to next LED time slot, until the PPG measurement of each LED time slot in PPG measurement period is completed.The application effectively reduces the power consumption of LED power supply voltage.

Description

Technical Field

[0001] This invention relates to the field of wearable device technology, and specifically to a method, apparatus, device, and storage medium for timing control of LED power supply voltage. Background Technology

[0002] Photoplethysmography (PPG) is a commonly used method in smart wearable devices for measuring physiological parameters such as heart rate and blood oxygenation. Its principle is based on the difference in absorption of specific wavelengths of light by blood and surrounding tissues, as well as the periodic changes in arterial blood volume caused by heartbeats. Specifically, LEDs in the device emit light of specific wavelengths, commonly green, red, and infrared light. When light penetrates static tissues such as skin, muscles, and bones, the absorption of light by these tissues remains relatively constant; however, the absorption of light by blood, especially arterial blood, changes with heartbeats: during systole, the heart pumps blood, increasing arterial blood volume and enhancing light absorption, resulting in a decrease in the light intensity received by the photodetector; during diastole, the heart fills, decreasing arterial blood volume and weakening light absorption, resulting in an increase in the light intensity received by the photodetector. The photodetector converts the received light intensity changes into electrical signals, which are then amplified and filtered to extract the pulse wave signal synchronized with the heartbeat.

[0003] In PPG measurement systems, LEDs require high supply voltages to ensure sufficient power supply rejection ratio (PSRR) even at maximum drive current, thus guaranteeing system measurement performance. Different wavelengths of LEDs require different forward voltages, and not all LED time slots operate at maximum drive current. However, current common power supply methods simply provide a fixed maximum voltage to meet power requirements in all situations. This results in significant voltage redundancy when driving LEDs of other wavelengths or when LEDs operate at lower drive currents, leading to unnecessary power consumption and shortening the battery life of wearable devices.

[0004] Therefore, how to reduce the power consumption of the LED power supply voltage while ensuring PPG measurement performance is an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides a method, apparatus, device, and storage medium for timing control of LED power supply voltage, in order to solve the technical problem of reducing the power consumption of LED power supply voltage while ensuring PPG measurement performance.

[0006] In a first aspect, the present invention provides a timing control method for LED power supply voltage, the method comprising: Multiple LED time slots are determined within the PPG measurement period, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current; The target power supply voltage for each LED time slot is determined based on the specific wavelength and preset drive current corresponding to each LED time slot. Based on the target power supply voltage of each LED time slot, determine the execution sequence of each LED time slot within the PPG measurement cycle; According to the execution sequence, PPG measurements for each LED time slot are performed sequentially. After the PPG measurement of the current LED time slot is completed, the adjustable power supply voltage for each LED time slot is adjusted to the power supply voltage corresponding to the next LED time slot until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

[0007] Optionally, after determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, and before sequentially performing PPG measurements on each LED time slot according to the execution sequence, the method further includes: Before the first LED time slot in the PPG measurement cycle is executed, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the first LED time slot.

[0008] Optionally, determining multiple LED time slots within the PPG measurement period, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current, includes: The multiple LED time slots within the PPG measurement cycle include at least three LED time slots, wherein the at least three LED time slots correspond to green LED, red LED and infrared LED respectively, and the preset driving current corresponding to each LED time slot is different.

[0009] Optionally, determining the target supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot includes: The minimum voltage margin corresponding to the LED time slot is determined based on the preset driving current corresponding to the LED time slot; The forward conduction voltage corresponding to the LED time slot is determined based on the specific wavelength and preset driving current corresponding to the LED time slot; The target power supply voltage for the LED time slot is determined by summing the minimum voltage margin, forward conduction voltage, and preset voltage margin corresponding to the LED time slot.

[0010] Optionally, the step of sequentially performing PPG measurements for each LED time slot according to the execution sequence, and adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the next LED time slot after the PPG measurement of the current LED time slot is completed, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed, includes: Drive the LED corresponding to the current LED time slot to emit light of a specific wavelength; The light signal is received after the light of the specific wavelength is reflected by the tissue being tested, and the light signal is converted into an electrical signal to generate the PPG signal of the current LED time slot; After generating the PPG signal for the current LED time slot, stop driving the LED corresponding to the current LED time slot; The adjustable power supply voltage is adjusted to the power supply voltage corresponding to the next LED time slot, and the PPG measurement of the next LED time slot is performed until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

[0011] Optionally, before executing the first LED time slot within the PPG measurement cycle, adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the first LED time slot includes: After each LED time slot in the current PPG measurement cycle is completed, stop driving the LEDs corresponding to each LED time slot in the current PPG measurement cycle, and keep the adjustable power supply voltage for each LED time slot unchanged. Before the first LED time slot of the next PPG measurement cycle is executed, the adjustable supply voltage is adjusted to the supply voltage corresponding to the first LED time slot of the next PPG measurement cycle.

[0012] Optionally, after determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, before adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the first LED time slot, the method further includes: Real-time detection of the change amplitude of LED driving current corresponding to each LED time slot; When the change in the LED driving current corresponding to any LED time slot exceeds a preset threshold, the adjustable power supply voltage is set to a preset safe power supply voltage. The preset safe power supply voltage is higher than the target power supply voltage for any LED time slot within the PPG measurement cycle.

[0013] In a second aspect, the present invention provides a timing control system for LED power supply voltage, comprising: The first determining module is used to determine multiple LED time slots within the PPG measurement cycle, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current; The second determining module is used to determine the target power supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot. The third determining module is used to determine the execution sequence of each LED time slot within the PPG measurement cycle based on the target power supply voltage of each LED time slot; The adjustment module is used to sequentially perform PPG measurements for each LED time slot according to the execution sequence, and after the PPG measurement of the current LED time slot is completed, adjust the adjustable power supply voltage for each LED time slot to the power supply voltage corresponding to the next LED time slot, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

[0014] Thirdly, the present invention provides a timing control device for LED power supply voltage, comprising a memory and a processor, wherein: The memory is used to store computer programs; The processor is used to read the program in the memory and execute the steps of the timing control method for LED power supply voltage as provided in the first aspect above.

[0015] Fourthly, the present invention provides a computer-readable storage medium having a readable computer program stored thereon, which, when executed by a processor, implements the steps of the timing control method for LED power supply voltage provided in the first aspect above.

[0016] Compared with the prior art, the timing control method, apparatus, device, and storage medium for LED power supply voltage provided by the present invention have the following beneficial effects: This invention pre-calculates the target supply voltage actually required for each LED time slot and determines the execution sequence of each LED time slot based on the target supply voltage. This allows the adjustable supply voltage to be adjusted according to the execution sequence within the same PPG measurement cycle, reducing boost adjustment operations between adjacent LED time slots in the execution sequence. While ensuring PPG measurement performance, this reduces the power consumption of the LED supply voltage and effectively extends the battery life of wearable devices. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and not all embodiments. For those skilled in the art, other drawings obtained from these drawings without creative effort are all within the scope of protection of this application.

[0018] Figure 1 A flowchart of a timing control method for LED power supply voltage provided in an embodiment of the present invention.

[0019] Figure 2 The LED power supply voltage timing diagram is provided for an embodiment of the present invention.

[0020] Figure 3This is a structural block diagram of a wearable device PPG measurement system provided in an embodiment of the present invention.

[0021] Figure 4 This invention provides a timing control system for LED power supply voltage.

[0022] Figure 5 This is a schematic diagram of the structure of a timing control device for LED power supply voltage provided in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] To make the description of this disclosure more detailed and complete, illustrative descriptions of embodiments and specific examples of the present invention are provided below; however, these are not the only forms of implementing or utilizing the specific embodiments of the present invention. The embodiments cover features of multiple specific embodiments and the methods, steps, and their order for constructing and operating these specific embodiments. However, other specific embodiments may also be used to achieve the same or equivalent functions and step sequences. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in sequences other than those illustrated or described herein.

[0027] In the description of the embodiments of the present invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The word "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more. Other quantifiers should be understood similarly. The preferred embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0028] Example 1 like Figure 1 The flowchart described above illustrates a timing control method for LED power supply voltage provided in an embodiment of the present invention, which includes the following steps.

[0029] S10: Determine multiple LED time slots within the PPG measurement cycle, wherein each LED time slot corresponds to a specific wavelength LED and a preset driving current. Specifically, in this embodiment of the invention, the PPG measurement cycle refers to the time period required to complete one full physiological parameter acquisition. Multiple independent LED time slots are divided within a measurement cycle, and only one specific wavelength LED is lit in each time slot, driven to emit light by a preset driving current. Different wavelengths of light have different penetration depths into human tissues and different blood absorption characteristics. It is necessary to obtain multi-dimensional physiological signals by lighting LEDs of different wavelengths at different times, while avoiding mutual interference between different wavelengths of light.

[0030] S20: Determine the target supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot. Specifically, in this embodiment of the invention, for each LED time slot, the target supply voltage required for normal LED operation under that time slot is calculated by combining its corresponding LED wavelength and driving current parameters. This can accurately match the actual power supply requirements of each LED time slot, avoid unnecessary power consumption waste caused by using a uniform high-voltage power supply, and ensure that the LED can emit light stably, meeting the illuminance requirements of PPG measurement.

[0031] S30: Determine the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot. Specifically, in this embodiment of the invention, the execution order of all LED time slots is rearranged according to the target supply voltage of each time slot calculated in step S20, so that the number of boost adjustments or the boost amplitude between adjacent LED time slots in the execution sequence is reduced. Boost-type DC-DC converters commonly used in wearable devices have asymmetrical voltage adjustment speeds. The buck process is achieved by releasing the output capacitor charge, resulting in extremely fast response speed, while the boost process requires repeated energy storage and charging through inductors, resulting in slower response speed. Optimizing the execution sequence arrangement using the target supply voltage can reduce boost operations throughout the measurement cycle, thereby avoiding the hardware limitation of slow boost speed. In one embodiment of the invention, each LED time slot can be sorted from high to low according to the target supply voltage to determine the execution sequence of the LED time slots. The supply voltage corresponding to each LED time slot in the execution sequence is sequentially decreased, so that the supply voltage decreases sequentially throughout the measurement cycle without needing to rise, thereby avoiding the hardware limitation of slow boost speed. This invention solves the problem of short time slot intervals and slow voltage adjustment speed. It can ensure the stable establishment of power supply voltage without extending the time slot interval, and does not affect the sampling frequency and real-time performance of PPG measurement.

[0032] S40: PPG measurements for each LED time slot are executed sequentially according to the execution sequence. After the PPG measurement of the current LED time slot is completed, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the next LED time slot, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed. Specifically, in this embodiment of the invention, the measurement of each LED time slot is started sequentially according to the execution sequence generated in step S30. After the PPG signal acquisition of the current time slot is completed, the adjustable supply voltage is immediately adjusted to the target voltage corresponding to the next time slot. This achieves dynamic adjustment of the supply voltage, ensuring that each LED time slot operates at a voltage close to its minimum requirement, reducing the overall power consumption of the LED driving system and effectively extending the battery life of the wearable device.

[0033] As an optional implementation, after determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, and before sequentially performing PPG measurements on each LED time slot according to the execution sequence, the method further includes: S401: Before the execution of the first LED time slot within the PPG measurement cycle, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the first LED time slot. Specifically, in this embodiment of the invention, the boost DC-DC converter used to power the LEDs in the wearable device has an inherent asymmetric characteristic in voltage adjustment speed. The buck process can be completed by quickly releasing excess charge on the output capacitor through the internal synchronous rectifier, and the response time is usually fast. However, the boost process requires repeated energy storage through the inductor to charge the output capacitor, resulting in a longer response time. If the boost is performed only when the first LED time slot begins, the voltage will not be stable at the start of the measurement, causing fluctuations in LED brightness, which in turn will distort the acquired PPG signal. Alternatively, the time slot interval may need to be extended to wait for the voltage to stabilize, thereby reducing the sampling frequency of the PPG measurement. This invention shifts the longest-consuming boost process to the idle time before the start of the measurement cycle, without occupying effective measurement time. This ensures that the supply voltage is stable at the start of the first LED time slot, ensuring the accuracy and signal quality of the PPG measurement, without reducing the system's sampling frequency.

[0034] As an optional implementation, determining multiple LED time slots within the PPG measurement period, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current, includes: S11: The multiple LED time slots within the PPG measurement cycle include at least three LED time slots, wherein the at least three LED time slots correspond to green LEDs, red LEDs, and infrared LEDs, respectively, and the preset driving currents corresponding to each LED time slot are different. Specifically, in this embodiment of the invention, the PPG measurement system of wearable devices typically needs to simultaneously detect multiple physiological parameters such as heart rate and blood oxygen saturation. A single-wavelength LED can only provide single-dimensional light absorption information and cannot meet the needs of multi-parameter measurement. When the light source is emitted, the penetration depth of light of different wavelengths to human tissues and the absorption characteristics of blood components vary significantly: 520-560nm green light is most sensitive to changes in capillary blood in the skin surface and can clearly capture changes in blood volume caused by heartbeats, making it the optimal wavelength for measuring heart rate; 660nm red light and 880-940nm infrared light have significantly different absorption coefficients for oxyhemoglobin and deoxyhemoglobin, and blood oxygen saturation can be accurately calculated by calculating the absorption ratio of the two wavelengths. By combining three wavelengths, high-quality heart rate and blood oxygenation signals can be acquired simultaneously, ensuring the accuracy and reliability of the measurement results.

[0035] As an optional implementation, determining the target supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot includes: S21: Determine the minimum voltage margin corresponding to the LED time slot based on the preset driving current corresponding to the LED time slot. Specifically, in this embodiment of the invention, the LED driver, as a constant current output device, needs to maintain a minimum voltage difference between its input and output to ensure normal constant current regulation function. This minimum voltage difference is the minimum voltage margin. Furthermore, this voltage margin is positively correlated with the driving current; the larger the driving current, the greater the on-state voltage drop and line loss of the power devices inside the driver, and the higher the required minimum voltage margin. This invention can dynamically adjust the voltage margin according to the actual operating current, avoiding unnecessary power consumption waste caused by using a fixed large margin, while ensuring that the LED driver can operate in the normal regulation range and output a stable driving current under any current.

[0036] S22: Determine the forward conduction voltage corresponding to the LED time slot based on the specific wavelength and preset driving current. Specifically, in this embodiment of the invention, the forward conduction voltage of the LED is mainly determined by its semiconductor material, with green LEDs exhibiting the highest forward conduction voltage, followed by red LEDs, and infrared LEDs the lowest. Furthermore, the forward conduction voltage of the LED increases non-linearly with the increase of the driving current; therefore, it must be corrected based on the actual driving current to obtain an accurate value. This invention can accurately obtain the forward conduction voltage of each LED under actual operating conditions, providing accurate basic data for the subsequent calculation of the target power supply voltage.

[0037] S23: The sum of the minimum voltage margin, forward conduction voltage, and preset voltage margin corresponding to the LED time slot is determined as the target supply voltage for the LED time slot. Specifically, in this embodiment of the invention, the preset voltage margin is used to compensate for various uncertainties that may occur during system operation, including battery voltage fluctuations, LED and driver parameter drift caused by temperature changes, and device parameter dispersion during mass production, ensuring that the supply voltage can meet the minimum requirements of the LED and driver under all possible operating conditions.

[0038] As an alternative implementation method, please refer to Figure 2 , Figure 2 The LED power supply voltage timing diagram provided for the embodiments of the present invention is as follows: Figure 2As shown, in this embodiment, each PPG measurement cycle includes four LED time slots, corresponding to four working states: green light 20mA, red light 40mA, infrared light 40mA, and infrared light 6mA. After the sorting calculation in step S30, the target supply voltages corresponding to the above four LED time slots are 3.9V, 3.6V, 2.9V, and 2.8V, respectively. Therefore, the execution sequence generated according to the voltage from high to low is green light 20mA, red light 40mA, infrared light 40mA, and infrared light 6mA. Before the start of the first PPG measurement cycle, the timing and amplitude control module controls the programmable DC-DC converter to pre-boost the supply voltage from 0V to 3.9V and keep it stable. Then, the PPG measurement of the four LED time slots is executed sequentially according to the generated execution sequence, with time slot 0 driving... The green LED emits light with a current of 20mA, while the supply voltage remains constant at 3.9V. After the green LED turns off in time slot 0, the supply voltage is immediately adjusted down to 3.6V, then the red LED is driven to emit light with a current of 40mA. After the red LED turns off in time slot 1, the supply voltage is immediately adjusted down to 2.9V, then the infrared LED is driven to emit light with a current of 40mA. After the infrared LED turns off in time slot 2, the supply voltage is immediately adjusted down to 2.8V, then the infrared LED is driven to emit light with a current of 6mA. After the first PPG measurement cycle ends, all LEDs are stopped from being driven, and the supply voltage is maintained at 2.8V. Before the start of the second PPG measurement cycle, the supply voltage is pre-boosted from 2.8V to 3.9V, and the above measurement process is repeated. This embodiment determines the execution sequence based on the target supply voltage of each LED time slot, ensuring that the supply voltage corresponding to each LED time slot in the execution sequence decreases sequentially. Within the same PPG measurement cycle, the supply voltage only needs to decrease sequentially, without needing to increase, reducing the time delay and power consumption waste caused by boosting operations.

[0039] As an optional implementation, the step of sequentially performing PPG measurements for each LED time slot according to the execution sequence, and adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the next LED time slot after the PPG measurement of the current LED time slot is completed, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed, includes: S41: Drive the LED corresponding to the current LED time slot to emit light of a specific wavelength. Specifically, in this embodiment of the invention, when entering a certain LED time slot, the LED of the corresponding wavelength is driven to light up according to the driving current preset for that time slot, so that it emits a light beam of a specific wavelength with stable intensity and illuminates the surface of the human tissue being measured. PPG measurement is an active optical detection technology based on changes in photoplethysmography (PPG), which requires the LED to provide incident light of a specific wavelength as a signal source; only when the wavelength and intensity of the incident light remain constant can it be ensured that the change in the intensity of the reflected light is only caused by fluctuations in the blood volume of human tissue, thereby accurately reflecting the heartbeat and blood oxygenation status.

[0040] S42: Receive the light signal reflected by the tissue under test after the light of the specific wavelength is received, and convert the light signal into an electrical signal to generate the PPG signal of the current LED time slot. Specifically, in this embodiment of the invention, a photodetector corresponding to the LED is used to receive the light signal reflected back from human skin, blood, and tissue, and the intensity change of the light signal is linearly converted into a voltage or current signal, which is then amplified and filtered to generate a digitized PPG signal.

[0041] S43: After generating the PPG signal for the current LED time slot, stop driving the LED corresponding to the current LED time slot. Specifically, in this embodiment of the invention, after all PPG signal sampling points of the current LED time slot have been collected and a complete PPG signal has been generated, the driving current of the current LED is immediately cut off, causing it to stop emitting light. PPG signal acquisition is only performed within a specific time period of each time slot. Continuing to light up the LED after the signal acquisition is completed will not generate any useful information and will only cause unnecessary power consumption. At the same time, timely extinguishing of the current LED can prevent stray light generated by it from entering the measurement process of the next LED time slot, prevent optical crosstalk between different wavelengths of light, and ensure the purity of the PPG signal in each time slot.

[0042] S44: Adjust the adjustable supply voltage to the supply voltage corresponding to the next LED time slot, and perform PPG measurement for the next LED time slot until the PPG measurement of each LED time slot within the PPG measurement cycle is completed. Specifically, in this embodiment of the invention, after the current LED is turned off, the adjustable supply voltage is immediately adjusted to the target supply voltage corresponding to the next LED time slot in the execution sequence, and then the measurement process for the next LED time slot is started. The above steps are repeated until the measurement of all LED time slots within this measurement cycle is completed.

[0043] As an optional implementation, the step of adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the first LED time slot before the execution of the first LED time slot in the PPG measurement cycle includes: S4011: After the execution of each LED time slot in the current PPG measurement cycle is completed, the driving of the LEDs corresponding to each LED time slot in the current PPG measurement cycle is stopped, and the adjustable supply voltage for each LED time slot is kept constant. Specifically, in this embodiment of the invention, after all LED time slots in the current PPG measurement cycle are completed, that is, after the PPG signal sampling of each wavelength LED is completed in sequence according to the execution sequence, the driving of all LEDs corresponding to each LED time slot in this measurement cycle is stopped. At this time, all LEDs are in an off state, and there is no longer any LED current consumption in the system. At the same time, the adjustable supply voltage for each LED time slot is kept constant, that is, the voltage is kept at the voltage level corresponding to the completion of the last LED time slot in the current measurement cycle. During this stage, the system enters a low-power sleep state. Since all LEDs are turned off, no driving current flows out, and maintaining the current voltage will not generate additional power waste.

[0044] S4012: Before the execution of the first LED time slot in the next PPG measurement cycle, the adjustable supply voltage is adjusted to the supply voltage corresponding to the first LED time slot of the next PPG measurement cycle. Specifically, in the preferred method of sorting by target supply voltage from high to low adopted in this embodiment, since the first LED time slot corresponds to the LED with the highest target supply voltage in the sorting, it is necessary to increase the supply voltage from the lower level at the end of the previous cycle to the highest level required in this cycle. This boost operation makes full use of the idle time period between two measurement cycles and does not occupy the time slot switching time within the measurement cycle, thereby ensuring that the supply voltage is stable and in place when the first LED time slot starts to execute, providing a reliable power supply guarantee for subsequent PPG signal sampling.

[0045] As an optional implementation, after determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, before adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the first LED time slot, the method further includes: The variation amplitude of the LED driving current corresponding to each LED time slot is detected in real time. Specifically, in this embodiment of the invention, the variation amplitude of the LED driving current is the degree of deviation of the LED driving current from its preset driving current value. In practical applications, when wearable devices perform hardware dimming or software dimming operations, the LED driving current may change significantly, for example, to dynamically adjust the LED brightness to adapt to the wrist transmittance of users with different skin tones or ambient light interference. Such large fluctuations in current will cause changes in the actual target supply voltage required for each LED time slot, and continuing to dynamically adjust the voltage according to the original sequence may lead to the risk of insufficient power supply.

[0046] When the change in LED driving current corresponding to any LED time slot exceeds a preset threshold, the adjustable supply voltage is set to a preset safe supply voltage. This preset safe supply voltage is higher than the target supply voltage for any LED time slot within the PPG measurement cycle. Specifically, in this embodiment, during real-time detection, when the change in LED driving current corresponding to any LED time slot exceeds a preset threshold, it indicates that the current fluctuation has reached a level that may affect the accuracy of the supply voltage requirement. At this time, the adjustable supply voltage is set to a preset safe supply voltage. This preset safe supply voltage is higher than the maximum value among the target supply voltages corresponding to all LED time slots under their respective preset driving currents within this PPG measurement cycle; that is, this safe supply voltage can cover the power supply requirements of any LED time slot within this cycle. After setting the safe supply voltage, each LED time slot within this PPG measurement cycle performs PPG measurement under this fixed safe voltage, and no further voltage downward adjustment is performed. When special operations such as dimming are completed and the LED driving current stabilizes, the system returns to normal measurement mode and re-executes the dynamic power supply strategy of sorting by voltage from high to low and adjusting the voltage downwards sequentially.

[0047] To further verify the power consumption optimization effect of the LED power supply voltage timing control method of the present invention, this embodiment provides comparative test data of the power supply strategy of the present invention and the traditional fixed 5V power supply strategy. The test conditions are as follows: the battery input voltage is 3.8V and the conversion efficiency of the programmable DC-DC converter is 85%.

[0048] Table 1 presents a comparison of the overall power consumption of the power supply strategy of this invention and the traditional fixed 5V power supply strategy during the PPG measurement period.

[0049] Table 1 The calculation formula for battery current measurement in this invention is shown in formula (1): (1) in Battery current, LED driving current, Provide the power supply voltage for the LED. Battery voltage, This refers to the conversion efficiency of the DC-DC converter.

[0050] It can be seen from formula (1) that the LED driving current Battery voltage and conversion efficiency With the battery current remaining constant With LED power supply voltage Proportional, therefore reduce LED supply voltage It can directly and proportionally reduce battery current consumption.

[0051] Taking the operation of a green LED under a 20mA drive current as an example, in the traditional fixed 5V power supply scheme, the LED power supply voltage is fixed at 5V, and the current drawn from the battery is 30.96mA. However, when using the intelligent power supply scheme of this invention, according to the actual needs of the green LED under a 20mA drive current, the power supply voltage is reduced to 3.9V, and the current drawn from the battery is 24.15mA. The power saving rate under this condition is 22%. The above calculation results show that a 22% power saving can be achieved only under the 20mA condition of green LED. In practical applications, the power saving rate will be different for LEDs of different wavelengths and under different drive currents.

[0052] As shown in Table 1 above, during a complete PPG measurement cycle, the total power consumption using the traditional method is 13653.25 mA.us, while the total power consumption using the method of this invention is 9042.73 mA.us, achieving a comprehensive power saving rate of 34%. This invention achieves a timing design where the LED time slots are sorted from high to low power supply voltage, ensuring that the power supply voltage only decreases sequentially within the same measurement cycle without needing to increase. This provides each LED time slot with the minimum power supply voltage that perfectly meets its requirements, effectively saving power consumption during PPG measurement, directly extending the device's single-charge battery life, and improving the user experience.

[0053] In the embodiments of this invention, please refer to Figure 3 , Figure 3This is a structural block diagram of a wearable device PPG measurement system provided in an embodiment of the present invention. The system mainly includes a battery, a timing and amplitude control module, a programmable DC-DC converter, an LED driver, green LEDs, red LEDs, infrared LEDs, a photodetector, an analog-to-digital converter, and a PPG signal processing module. The battery is electrically connected to the timing and amplitude control module, the programmable DC-DC converter, the LED driver, and the analog-to-digital converter, providing power to the entire system. The typical input voltage range is 3.8V-4.2V. The timing and amplitude control module is the core control unit of the system. Its first output terminal is connected to the control input terminal of the programmable DC-DC converter to adjust the output voltage of the programmable DC-DC converter. Its second output terminal is connected to the control input terminal of the LED driver to control the LED driver to light up LEDs of different wavelengths in a time-division multiplexing manner. The module adjusts the driving current. All steps of the LED power supply voltage timing control method described above are executed by this module. The output of the programmable DC-DC converter is connected to the anode of the green LED, red LED, and infrared LED respectively, providing an adjustable power supply voltage for each LED. The output of the LED driver is connected to the cathode of the green LED, red LED, and infrared LED respectively, providing constant current drive for each LED. The output of the photodetector is connected to the input of the analog-to-digital converter to receive the light signal reflected by human tissue and convert it into an analog electrical signal. The output of the analog-to-digital converter is connected to the input of the PPG signal processing module to convert the analog electrical signal into a digital signal. The output of the PPG signal processing module is connected to the input of the timing and amplitude control module to feed back the processed PPG signal to the timing and amplitude control module, realizing closed-loop control.

[0054] This invention pre-calculates the target supply voltage actually required for each LED time slot and determines the execution sequence of each LED time slot based on the target supply voltage. This allows the adjustable supply voltage to be adjusted according to the execution sequence within the same PPG measurement cycle, reducing boost adjustment operations between adjacent LED time slots in the execution sequence. While ensuring PPG measurement performance, this reduces the power consumption of the LED supply voltage and effectively extends the battery life of wearable devices.

[0055] Example 2 Based on the above-described timing control method for LED power supply voltage, this embodiment of the invention provides a timing control system for LED power supply voltage, such as... Figure 4 As shown in Figure 4, the timing control system for the LED power supply voltage includes: The first determining module 41 is used to determine multiple LED time slots within the PPG measurement cycle, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current; The second determining module 42 is used to determine the target power supply voltage of each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot. The third determining module 43 is used to determine the execution sequence of each LED time slot within the PPG measurement cycle based on the target power supply voltage of each LED time slot. The adjustment module 44 is used to sequentially perform PPG measurements for each LED time slot according to the execution sequence, and after the PPG measurement of the current LED time slot is completed, adjust the adjustable power supply voltage for each LED time slot to the power supply voltage corresponding to the next LED time slot, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

[0056] For further details regarding the implementation of the above technical solution by each module in the timing control system for LED power supply voltage, please refer to the description in the timing control method for LED power supply voltage provided in the above embodiments of the invention, which will not be repeated here.

[0057] Example 3 Based on the timing control method of the LED power supply voltage mentioned above, such as Figure 5 The diagram shows a schematic of a timing control device for LED power supply voltage provided in an embodiment of the present invention. The device includes a processor 51 and a memory 52 coupled to the processor 51. The memory 52 stores a computer program. When the computer program is executed by the processor 51, the processor 51 performs the steps of the timing control method for LED power supply voltage described in the above embodiment.

[0058] For further details regarding the implementation of the above technical solution by the processor 51 in the timing control device for the LED power supply voltage, please refer to the description in the timing control method for the LED power supply voltage provided in the above embodiments of the invention, which will not be repeated here.

[0059] The processor 51 can also be called a CPU (Central Processing Unit). The processor 51 may be an integrated circuit chip with signal processing capabilities. The processor 51 can also be a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor, or the processor 51 can be any conventional processor.

[0060] Example 4 like Figure 6 The diagram illustrates the structure of a computer-readable storage medium provided in this embodiment of the invention. The storage medium stores a readable computer program 61. This computer program 61 can be stored in the storage medium as a software product and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in various embodiments of the invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic disks or optical disks, ROM (Read-Only Memory), RAM (Random Access Memory), or terminal devices such as computers, servers, mobile phones, and tablets.

[0061] 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 modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules 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 indirect coupling or communication connection through some interfaces, apparatuses, or modules, and may be electrical, mechanical, or other forms.

[0062] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0063] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0064] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0065] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0066] The technical solutions provided in this application have been described in detail above. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

[0067] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0069] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0070] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A timing control method for LED power supply voltage, characterized in that, Applications in wearable devices include: Multiple LED time slots are determined within the PPG measurement period, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current; The target power supply voltage for each LED time slot is determined based on the specific wavelength and preset drive current corresponding to each LED time slot. Based on the target power supply voltage of each LED time slot, determine the execution sequence of each LED time slot within the PPG measurement cycle; According to the execution sequence, PPG measurements for each LED time slot are performed sequentially. After the PPG measurement of the current LED time slot is completed, the adjustable power supply voltage for each LED time slot is adjusted to the power supply voltage corresponding to the next LED time slot until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

2. The timing control method for LED power supply voltage according to claim 1, characterized in that, After determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, and before sequentially performing PPG measurements for each LED time slot according to the execution sequence, the method further includes: Before the first LED time slot in the PPG measurement cycle is executed, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the first LED time slot.

3. The timing control method for LED power supply voltage according to claim 1, characterized in that, The determination of multiple LED time slots within the PPG measurement period, wherein each LED time slot corresponds to a specific wavelength LED and a preset driving current, includes: The multiple LED time slots within the PPG measurement cycle include at least three LED time slots, wherein the at least three LED time slots correspond to green LED, red LED and infrared LED respectively, and the preset driving current corresponding to each LED time slot is different.

4. The timing control method for LED power supply voltage according to claim 1, characterized in that, The step of determining the target supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot includes: The minimum voltage margin corresponding to the LED time slot is determined based on the preset driving current corresponding to the LED time slot; The forward conduction voltage corresponding to the LED time slot is determined based on the specific wavelength and preset driving current corresponding to the LED time slot; The target power supply voltage for the LED time slot is determined by summing the minimum voltage margin, forward conduction voltage, and preset voltage margin corresponding to the LED time slot.

5. The timing control method for LED power supply voltage according to claim 1, characterized in that, The step of sequentially performing PPG measurements for each LED time slot according to the execution sequence, and adjusting the adjustable supply voltage for each LED time slot to the supply voltage corresponding to the next LED time slot after the PPG measurement of the current LED time slot is completed, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed, includes: Drive the LED corresponding to the current LED time slot to emit light of a specific wavelength; The light signal is received after the light of the specific wavelength is reflected by the tissue being tested, and the light signal is converted into an electrical signal to generate the PPG signal of the current LED time slot; After generating the PPG signal for the current LED time slot, stop driving the LED corresponding to the current LED time slot; The adjustable power supply voltage is adjusted to the power supply voltage corresponding to the next LED time slot, and the PPG measurement of the next LED time slot is performed until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

6. The timing control method for LED power supply voltage according to claim 2, characterized in that, Before the execution of the first LED time slot within the PPG measurement cycle, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the first LED time slot, including: After each LED time slot in the current PPG measurement cycle is completed, stop driving the LEDs corresponding to each LED time slot in the current PPG measurement cycle, and keep the adjustable power supply voltage for each LED time slot unchanged. Before the first LED time slot of the next PPG measurement cycle is executed, the adjustable supply voltage is adjusted to the supply voltage corresponding to the first LED time slot of the next PPG measurement cycle.

7. The timing control method for LED power supply voltage according to claim 6, characterized in that, After determining the execution sequence of each LED time slot within the PPG measurement cycle based on the target supply voltage of each LED time slot, the adjustable supply voltage for each LED time slot is adjusted to the supply voltage corresponding to the first LED time slot. The method further includes: Real-time detection of the change amplitude of LED driving current corresponding to each LED time slot; When the change in the LED driving current corresponding to any LED time slot exceeds a preset threshold, the adjustable power supply voltage is set to a preset safe power supply voltage. The preset safe power supply voltage is higher than the target power supply voltage for any LED time slot within the PPG measurement cycle.

8. A timing control system for LED power supply voltage, characterized in that, include: The first determining module is used to determine multiple LED time slots within the PPG measurement cycle, wherein each LED time slot corresponds to an LED of a specific wavelength and a preset driving current; The second determining module is used to determine the target power supply voltage for each LED time slot based on the specific wavelength and preset driving current corresponding to each LED time slot. The third determining module is used to determine the execution sequence of each LED time slot within the PPG measurement cycle based on the target power supply voltage of each LED time slot; The adjustment module is used to sequentially perform PPG measurements for each LED time slot according to the execution sequence, and after the PPG measurement of the current LED time slot is completed, adjust the adjustable power supply voltage for each LED time slot to the power supply voltage corresponding to the next LED time slot, until the PPG measurement of each LED time slot within the PPG measurement cycle is completed.

9. A timing control device for LED power supply voltage, characterized in that, Includes memory and processor, wherein: The memory is used to store computer programs; The processor is used to read the computer program in the memory and execute the steps of the timing control method for LED power supply voltage as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a readable computer program that, when executed by a processor, implements the steps of the timing control method for LED power supply voltage as described in any one of claims 1-7.

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