Light modulation method, device, equipment and storage medium for photoplethysmography

Abstract

This invention provides a dimming method, apparatus, device, and storage medium for photoplethysmography. The method includes: if the current induced current is not within the dimming trigger range, acquiring historical induced currents and their corresponding LED driving currents; determining the LED driving current for the first dimming and performing the first dimming; if the induced current for the first dimming is not within the dimming convergence range, or if the induced current for the first dimming is within the dimming convergence range but the first preset dimming count is greater than 1, determining the LED driving current for the second dimming and performing the second dimming; if the induced current for the first dimming and the induced current for the second dimming do not meet the dimming stop condition, continuously determining the LED driving current for the next dimming and performing dimming again, until the induced current for dimming meets the dimming stop condition, and then stopping the dimming. This method can improve dimming efficiency.

Description

Technical Field

[0001] This invention relates to the field of dimming technology, and in particular to a dimming method, apparatus, device, and storage medium for photoplethysmography. Background Technology

[0002] The method of measuring heart rate and blood oxygen saturation by measuring the intensity of light reflected from blood vessels in accordance with the pulse is called PPG (Photoplethysmography). During the measurement, an LED (Light-Emitting Diode) emits light of a certain intensity onto the human body. A small portion of this light penetrates the skin and tissues to reach the blood vessels, where the blood reflects / scatters this small portion of the light back to a photodetector outside the tissues. Because the light emitted by the LED passes through human tissue twice—once reflected / scattered by the blood back to the photodetector—the energy loss is very large. This results in a very weak portion of the light intensity related to pulse pulsation received by the photodetector, making pulse pulsation measurement very difficult and easily affected by various noises. Therefore, the light intensity received by the photodetector must reach a certain level. However, the photoelectric coupling coefficient between the LED and the photodetector is affected by various environmental conditions. To keep the current received by the photodetector within a relatively ideal range, the LED's driving current needs to be adjusted, i.e., dimming is required. Existing dimming solutions require many dimming cycles, take a long time, and have low dimming efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a dimming method, apparatus, device and storage medium for photoplethysmography, so as to solve the technical problem of low dimming efficiency in the dimming schemes of the prior art.

[0004] The technical solution of the present invention is as follows: a dimming method for photoplethysmography is provided, comprising:

[0005] Obtain the current induced current of the photodetector. If the current induced current is not within the dimming trigger range, obtain the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current.

[0006] The LED driving current for the first dimming is determined based on the historical induced current and the LED driving current. The first dimming is performed based on the first dimming LED driving current, and the induced current for the first dimming is obtained.

[0007] If the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming number is greater than 1, then the LED driving current for the second dimming is determined based on the induced current of the first dimming and the LED driving current of the first dimming, the second dimming is performed based on the LED driving current of the second dimming, and the induced current of the second dimming is obtained.

[0008] If the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, the LED driving current for the next dimming is continuously determined based on the induced current of the previous dimming and the LED driving current of the previous dimming, and dimming is performed again based on the LED driving current of the next dimming, until the induced current of dimming meets the dimming stop condition, and dimming stops; wherein, the dimming stop condition is that the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range.

[0009] Further, determining the LED drive current for the first dimming based on the historical induced current and the LED drive current includes:

[0010] The LED driving current for the first dimming is determined based on the historical induced current, the LED driving current, and the convergence target current.

[0011] Further, determining the LED driving current for the first dimming based on the historical induced current, the LED driving current, and the convergence target current includes:

[0012] Multiply the LED driving current and the convergence target current and divide by the historical induced current to obtain the LED driving current for the first dimming.

[0013] Further, determining the LED driving current for the second dimming based on the induced current of the first dimming and the LED driving current of the first dimming includes:

[0014] The convergence target current is subtracted from the induced current of the first dimming, and then multiplied by the LED driving current of the first dimming. The result of the multiplication is divided by the induced current of the first dimming, and then added to the LED driving current of the first dimming to obtain the LED driving current of the second dimming.

[0015] Furthermore, the LED driving current for the next dimming is determined based on the induced current and the LED driving current from the previous dimming, including:

[0016] The convergence target current is subtracted from the induced current of the previous dimming, and then multiplied by the LED driving current of the previous dimming. The result of the multiplication is divided by the induced current of the previous dimming, and then added to the LED driving current of the previous dimming to obtain the LED driving current of the next dimming.

[0017] Furthermore, the dimming method for photoplethysmography further includes: determining whether the induced current of the first dimming is within the dimming convergence range; if so, and when the first preset dimming count is 1, then stopping the dimming.

[0018] Furthermore, the dimming method for photoplethysmography further includes: counting the total number of dimming cycles; if the total number of dimming cycles reaches a second preset number of dimming cycles, then dimming is stopped.

[0019] Another technical solution of the present invention is as follows: a dimming device for photoplethysmography is also provided, including a current data acquisition module, a first dimming module, a second dimming module and a third dimming module;

[0020] The current data acquisition module is used to acquire the current induced current of the photodetector. If the current induced current is not within the dimming convergence range, the module acquires the historical induced current of the photodetector within the dimming convergence range and the LED driving current corresponding to the historical induced current.

[0021] The first dimming module is used to determine the LED driving current for the first dimming based on the historical induced current and the LED driving current, perform the first dimming based on the first dimming LED driving current, and obtain the induced current for the first dimming.

[0022] The second dimming module is configured to determine the LED driving current for the second dimming based on the induced current of the first dimming and the LED driving current of the first dimming if the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming number is greater than 1, and perform the second dimming based on the LED driving current of the second dimming, and obtain the induced current of the second dimming.

[0023] The third dimming module is configured to, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, continuously determine the LED driving current for the next dimming based on the induced current of the previous dimming and the LED driving current of the previous dimming, and perform dimming again based on the LED driving current of the next dimming, until the induced current of dimming meets the dimming stop condition, and then stop dimming; wherein, the dimming stop condition is that the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range.

[0024] Another technical solution of the present invention is as follows: an electronic device is also provided, including a memory and a processor. The memory stores a computer program that can be executed by the processor. When the processor executes the computer program, it implements the dimming method for photoplethysmography as described in any of the above technical solutions.

[0025] Another technical solution of the present invention is as follows: a computer-readable storage medium is also provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the dimming method for photoplethysmography as described in any of the above technical solutions.

[0026] The beneficial effects of this invention are as follows: The current induced current of the photodetector is obtained; if the current induced current is not within the dimming trigger range, the historical induced current of the photodetector and the corresponding LED driving current are obtained; the LED driving current for the first dimming is determined based on the historical induced current and the LED driving current; the first dimming is performed based on the first dimming LED driving current, and the induced current for the first dimming is obtained; if the induced current for the first dimming is not within the dimming convergence range, or if the induced current for the first dimming is within the dimming convergence range but the first preset dimming count is greater than 1, then the LED driving current for the first dimming is determined based on the historical induced current and the corresponding LED driving current. The LED driving current for the second dimming is determined by the D driving current. Second dimming is performed based on this second LED driving current, and the induced current for the second dimming is obtained. If the induced current for the first dimming and the induced current for the second dimming do not meet the dimming stop condition, the LED driving current for the next dimming is continuously determined based on the induced current for the previous dimming and the LED driving current for the previous dimming. Dimming is then performed again based on the induced current for the next dimming, until the induced current for dimming meets the dimming stop condition, at which point dimming stops. The dimming stop condition is that the induced current for dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range. This technical solution can improve dimming efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of a dimming method for photoplethysmography provided in an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the dimming device for photoplethysmography provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] Figure 1 This is a schematic flowchart of a dimming method for photoplethysmography according to an embodiment of the present invention. It should be noted that, if substantially the same result is achieved, the dimming method for photoplethysmography of the present invention does not necessarily require further elaboration. Figure 1 The illustrated process sequence is limited. For example... Figure 1 As shown, the dimming method for photoplethysmography mainly includes the following steps:

[0033] S101, obtain the current induced current of the photodetector. If the current induced current is not within the dimming trigger range, obtain the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current.

[0034] In one specific embodiment, when measuring heart rate and / or blood oxygen saturation using photoplethysmography, the photodetector needs to continuously receive induced current and obtain the current induced current of the photodetector. If the current induced current is within the dimming trigger range, dimming is not required. If the current induced current is not within the dimming trigger range, dimming is required. In this case, it is necessary to obtain the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current.

[0035] S102, determine the LED driving current for the first dimming based on the historical induced current and the LED driving current, perform the first dimming based on the first dimming LED driving current, and obtain the induced current for the first dimming.

[0036] In some embodiments, the dimming method for photoplethysmography further includes: determining whether the induced current of the first dimming is within the dimming convergence range; if so, and when the first preset dimming count is 1, then stopping the dimming.

[0037] In one specific embodiment, the LED driving current for the first dimming is determined based on the historical induced current and the LED driving current. The first dimming is then performed based on this LED driving current. If the induced current for the first dimming is within the dimming convergence range and the first preset dimming count is 1, dimming is successful, and dimming stops. If the induced current for the first dimming is within the dimming convergence range and the first preset dimming count is greater than 1, dimming continues until the induced current for the consecutive first preset dimming counts is within the dimming convergence range, at which point dimming stops. The dimming convergence range can be determined based on actual conditions. For example, in a typical application, the dimming convergence range can be 1μA to 3μA. This provides a high signal-to-noise ratio, a relatively low LED driving current, and a moderate total power consumption. The dimming trigger range can be greater than the dimming convergence range, while the dimming convergence range is within the dimming trigger range. For example, the dimming trigger range can be 0.8μA to 3.2μA.

[0038] In some embodiments, determining the LED drive current for the first dimming based on the historical induced current and the LED drive current includes:

[0039] The LED driving current for the first dimming is determined based on the historical induced current, the LED driving current, and the convergence target current.

[0040] In one specific embodiment, the convergence target current (current value) can be determined according to the actual situation. Specifically, the convergence target current is within the dimming convergence range, for example, the convergence target current is I. g Then the dimming convergence range can be [I g- Z,I g +Z], where Z can be a preset current value. If the target current for convergence is 2μA, then the dimming convergence range can be [1μA, 3μA], and the preset current value Z can be 1μA.

[0041] In some embodiments, determining the LED drive current for the first dimming based on the historical induced current, the LED drive current, and the convergence target current includes:

[0042] Multiply the LED driving current and the convergence target current and divide by the historical induced current to obtain the LED driving current for the first dimming.

[0043] In one specific embodiment, without loss of generality, the LED driving current corresponding to the historical induced current is I. a0 The convergence target current is I g The historical induced current is I b0 The LED drive current I during the first dimming is... a1 =I a0* Ig / I b0 The LED drive current obtained using the above method can be used for the first dimming.

[0044] S103, if the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming number is greater than 1, then the LED driving current for the second dimming is determined based on the induced current of the first dimming and the LED driving current of the first dimming, the second dimming is performed based on the LED driving current of the second dimming, and the induced current of the second dimming is obtained.

[0045] In some embodiments, determining the LED driving current for the second dimming based on the induced current of the first dimming and the LED driving current of the first dimming includes:

[0046] The convergence target current is subtracted from the induced current of the first dimming, and then multiplied by the LED driving current of the first dimming. The result of the multiplication is divided by the induced current of the first dimming, and then added to the LED driving current of the first dimming to obtain the LED driving current of the second dimming.

[0047] In one specific embodiment, the first preset dimming count can be 1, indicating that the induced current of a certain dimming is within the dimming convergence range, thus dimming is successful and ends. The first preset dimming count can also be greater than 1, indicating that the induced current of multiple consecutive dimmings is within the dimming convergence range, thus dimming is successful and ends. The number of consecutive dimmings is the first preset dimming count. If the LED driving current for the first dimming is I... a1 The induced current for the first dimming is I. b1 Then the LED drive current I for the second dimming a2 =I a1* (I g -I b1 ) / I b1+ I a1 The LED driving current obtained using the above method can be used for the second dimming.

[0048] S104, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, then the LED driving current for the next dimming is continuously determined based on the induced current of the previous dimming and the LED driving current of the previous dimming, and dimming is performed again based on the LED driving current of the next dimming, until the induced current of dimming meets the dimming stop condition, and dimming stops; wherein, the dimming stop condition is that the induced current of dimming for the first preset dimming number of consecutive dimming cycles is within the dimming convergence range.

[0049] In some embodiments, determining the LED drive current for the next dimming based on the induced current of the previous dimming and the LED drive current of the previous dimming includes:

[0050] The convergence target current is subtracted from the induced current of the previous dimming, and then multiplied by the LED driving current of the previous dimming. The result of the multiplication is divided by the induced current of the previous dimming, and then added to the LED driving current of the previous dimming to obtain the LED driving current of the next dimming.

[0051] In this embodiment of the invention, by subtracting the induced current of the previous dimming from the convergence target current, multiplying it by the LED driving current of the previous dimming, dividing the result by the induced current of the previous dimming, and adding it to the LED driving current of the previous dimming, the accuracy of the LED driving current for the next dimming can be improved. This allows for achieving the dimming target with fewer dimming cycles, thereby improving dimming efficiency.

[0052] In one specific embodiment, without loss of generality, if the LED drive current of the last dimming was I... am The induced current of the last dimming was I. bm Then the LED drive current I for the next dimming an =I am* (I g -I bm ) / I bm+ I am The LED drive current obtained using the above method can be used for the next dimming cycle. Here, "previous dimming" and "next dimming" are relative concepts; for example, if the fourth dimming cycle is the previous dimming cycle, then the fifth dimming cycle is the next dimming cycle.

[0053] In one specific embodiment, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, there can be four situations: 1) neither the induced current of the first dimming nor the induced current of the second dimming is within the dimming convergence range; 2) the induced current of the first dimming is within the dimming convergence range, neither the induced current of the second dimming is within the dimming convergence range, and the first preset dimming count is greater than 1; 3) the induced current of the first dimming is not within the dimming convergence range, both the induced current of the second dimming are within the dimming convergence range, and the first preset dimming count is greater than 1; 4) the induced current of the first dimming is within the dimming convergence range, both the induced current of the second dimming are within the dimming convergence range, and the first preset dimming count is greater than 2. In any of these situations, dimming needs to continue.

[0054] In one specific embodiment, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, the LED driving current for the next dimming is continuously determined based on the induced current of the previous dimming and the LED driving current of the previous dimming, and dimming is performed again based on the LED driving current of the next dimming, until the induced current of dimming meets the dimming stop condition, that is, the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range, and dimming stops, where the first preset number of dimming cycles is greater than or equal to 1.

[0055] In some embodiments, the dimming method for photoplethysmography further includes: counting the total number of dimming cycles; if the total number of dimming cycles reaches a second preset number of dimming cycles, then dimming is stopped.

[0056] In one specific embodiment, the second preset dimming count needs to be greater than or equal to the first preset dimming count. If dimming is still unsuccessful after the second preset dimming count, the dimming process ends, and a dimming failure flag is generated for query processing.

[0057] This invention provides a dimming method for photoplethysmography. The method involves acquiring the current induced current of a photodetector. If the current induced current is outside the dimming trigger range, the method acquires the historical induced current of the photodetector and the corresponding LED driving current. Based on the historical induced current and the LED driving current, a first dimming LED driving current is determined. First dimming is performed based on the first dimming LED driving current, and the induced current for the first dimming is acquired. If the induced current for the first dimming is outside the dimming convergence range, or if the induced current for the first dimming is within the dimming convergence range but the first preset dimming count is greater than 1, then the method proceeds based on the induced current for the first dimming and the corresponding LED driving current. The induced current is used to determine the LED driving current for the second dimming. The second dimming is then performed based on this induced current, and the resulting current is obtained. If the induced current from the first dimming and the second dimming do not meet the dimming stop condition, the next dimming LED driving current is continuously determined based on the previous dimming induced current and the previous dimming LED driving current. Dimming is then performed again based on the next dimming LED driving current until the dimming induced current meets the dimming stop condition, at which point dimming stops. The dimming stop condition is that the dimming induced current for a first preset dimming number of consecutive dimming cycles falls within the dimming convergence range. This improves dimming efficiency and accuracy, and the higher the first preset dimming number, the higher the dimming accuracy.

[0058] Based on the above-described dimming method for photoplethysmography, this invention provides a dimming device for photoplethysmography, the schematic diagram of which is shown below. Figure 2 As shown, the dimming device 20 for photoplethysmography includes a current data acquisition module 21, a first dimming module 22, a second dimming module 23, and a third dimming module 24.

[0059] The current data acquisition module 21 is used to acquire the current induced current of the photodetector. If the current induced current is not within the dimming trigger range, the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current are acquired.

[0060] The first dimming module 22 is used to determine the LED driving current for the first dimming based on the historical induced current and the LED driving current, perform the first dimming based on the first dimming LED driving current, and obtain the induced current for the first dimming.

[0061] The second dimming module 23 is configured to determine the LED driving current for the second dimming based on the induced current of the first dimming and the LED driving current of the first dimming if the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming number is greater than 1, and perform the second dimming based on the LED driving current of the second dimming, and obtain the induced current of the second dimming.

[0062] The third dimming module 24 is configured to, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, continuously determine the LED driving current for the next dimming based on the induced current of the previous dimming and the LED driving current of the previous dimming, and perform dimming again based on the LED driving current of the next dimming, until the induced current of dimming meets the dimming stop condition and dimming stops; wherein, the dimming stop condition is that the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range.

[0063] For further details regarding the implementation of the above-mentioned technical solution by each module in the dimming device for photoplethysmography, please refer to the description of the dimming method for photoplethysmography provided in the above-mentioned embodiments of the invention, which will not be repeated here.

[0064] Based on the above-described dimming method for photoplethysmography, this invention also provides an electronic device, the schematic diagram of which is shown below. Figure 3As shown, the device 30 includes a processor 31 and a memory 32 coupled to the processor 31. The memory 32 stores a computer program that, when executed by the processor 31, causes the processor 31 to perform the steps of the dimming method for photoplethysmography in the above embodiments.

[0065] For further details regarding the implementation of the above-mentioned technical solution by the processor 31 in the dimming device 30 for photoplethysmography, please refer to the description in the dimming method for photoplethysmography provided in the above-mentioned embodiments of the invention, which will not be repeated here.

[0066] The processor 31 can also be called a CPU (Central Processing Unit). The processor 31 may be an integrated circuit chip with signal processing capabilities. The processor 31 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 31 can be any conventional processor.

[0067] This invention also provides a computer-readable storage medium storing a readable computer program. The computer program 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 this 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.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed apparatus 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 through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0069] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A dimming method for photoplethysmography, characterized in that, include: Obtain the current induced current of the photodetector. If the current induced current is not within the dimming trigger range, obtain the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current. Multiply the LED driving current and the convergence target current and divide by the historical induced current to obtain the LED driving current for the first dimming. Perform the first dimming based on the LED driving current for the first dimming and obtain the induced current for the first dimming. If the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming number is greater than 1, then the convergence target current minus the induced current of the first dimming is multiplied by the LED driving current of the first dimming, the result of the multiplication is divided by the induced current of the first dimming, and then the LED driving current of the first dimming is added to obtain the LED driving current of the second dimming. The second dimming is performed according to the LED driving current of the second dimming, and the induced current of the second dimming is obtained. If the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, then the convergence target current is continuously subtracted from the induced current of the previous dimming and multiplied by the LED driving current of the previous dimming. The result of the multiplication is divided by the induced current of the previous dimming and added to the LED driving current of the previous dimming to obtain the LED driving current of the next dimming. Dimming is then performed again based on the LED driving current of the next dimming until the induced current of dimming meets the dimming stop condition, at which point dimming stops. The dimming stop condition is that the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range.

2. The dimming method for photoplethysmography as described in claim 1, characterized in that, The dimming method for photoplethysmography further includes: determining whether the induced current of the first dimming is within the dimming convergence range; if so, and when the first preset dimming count is 1, then stopping the dimming.

3. The dimming method for photoplethysmography as described in claim 1, characterized in that, The dimming method for photoplethysmography further includes: counting the total number of dimming cycles; if the total number of dimming cycles reaches a second preset dimming cycle, then dimming is stopped.

4. A dimming device for photoplethysmography, characterized in that, It includes a current data acquisition module, a first dimming module, a second dimming module, and a third dimming module; The current data acquisition module is used to acquire the current induced current of the photodetector. If the current induced current is not within the dimming trigger range, the historical induced current of the photodetector and the LED driving current corresponding to the historical induced current are acquired. The first dimming module is used to multiply the LED driving current and the convergence target current and divide by the historical induced current to obtain the LED driving current for the first dimming, perform the first dimming based on the LED driving current for the first dimming, and obtain the induced current for the first dimming. The second dimming module is configured to, if the induced current of the first dimming is not within the dimming convergence range, or if the induced current of the first dimming is within the dimming convergence range but the first preset dimming count is greater than 1, then subtract the induced current of the first dimming from the convergence target current, multiply it by the LED driving current of the first dimming, divide the result of the multiplication by the induced current of the first dimming, add the LED driving current of the first dimming, obtain the LED driving current of the second dimming, perform the second dimming based on the LED driving current of the second dimming, and obtain the induced current of the second dimming; The third dimming module is configured to, if the induced current of the first dimming and the induced current of the second dimming do not meet the dimming stop condition, continuously subtract the induced current of the previous dimming from the convergence target current, multiply it by the LED driving current of the previous dimming, divide the result of the multiplication by the induced current of the previous dimming, and add the LED driving current of the previous dimming to obtain the LED driving current of the next dimming. Dimming is then performed again based on the LED driving current of the next dimming until the induced current of dimming meets the dimming stop condition, at which point dimming stops. The dimming stop condition is that the induced current of dimming for a first preset number of consecutive dimming cycles is within the dimming convergence range.

5. An electronic device, comprising a memory and a processor, wherein the memory stores a computer program executable by the processor, characterized in that, When the processor executes the computer program, it implements the dimming method for photoplethysmography as described in any one of claims 1 to 3.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the dimming method for photoplethysmography as described in any one of claims 1 to 3.

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