CN108784675A - Electronic device and method capable of eliminating or avoiding offset interference and accurately measuring physiological characteristics - Google Patents

Abstract

A method for measuring physiological characteristics includes: using at least one light emitting unit to emit at least one light, the at least one light including a first light component corresponding to a first wavelength and a second light component corresponding to a second wavelength, the first wavelength being different from the second wavelength; using an image sensing circuit to sense and generate at least one physiological characteristic measurement signal in response to the at least one light; performing an offset correction operation on the at least one physiological characteristic measurement signal to generate at least one corrected physiological characteristic measurement signal; and calculating the at least one corrected physiological characteristic measurement signal to estimate a physiological characteristic result.

Description

An electronic device capable of eliminating or avoiding offset interference to accurately measure physiological characteristics and methods

technical field

The invention relates to a mechanism for measuring physiological characteristics, in particular to an electronic device and method for measuring physiological characteristics.

Background technique

In general, traditional photoplethysmography (PPG) sensing technology uses multiple wavelengths to detect heartbeat signals, but is highly susceptible to interference from motion artifacts, the optical sensing system itself, and/or external noise These interferences can easily lead to offset effects in the estimation of the PPG signal, resulting in heartbeat detection errors. Even if the traditional technology directly takes two PPG signals of different wavelengths for ratio processing, it can slightly reduce the interference of some noises, but it still cannot Solve the action artifacts of DC offset caused by light reflection, the interference of the optical sensing system itself and/or external noise.

Contents of the invention

Therefore, one of the objectives of the present invention is to provide an electronic device and method for measuring physiological characteristics to solve the problems encountered in the prior art.

According to an embodiment of the present invention, an electronic device for measuring physiological characteristics is disclosed. The electronic device includes an image sensing circuit, at least one light emitting unit and a processing circuit, at least one light emitting unit is used to emit at least one light, the at least one light includes a first light component corresponding to a first wavelength and corresponding to A second light component at a second wavelength, the first wavelength being different from the second wavelength. The image sensing circuit can sense and generate at least one physiological characteristic measurement signal in response to the at least one light. The processing circuit is coupled to the image sensing circuit, and is used for performing an offset correction operation on the at least one physiological characteristic measurement signal to generate at least one corrected physiological characteristic measurement signal, and the at least one corrected physiological characteristic measurement signal The physiological characteristic measurement signal is calculated to obtain a physiological characteristic result through estimation.

According to an embodiment of the present invention, a method for measuring physiological characteristics is also disclosed. The method includes: using at least one light emitting unit to emit at least one light, the at least one light includes a first light component corresponding to a first wavelength and a second light component corresponding to a second wavelength, the first light A wavelength is different from the second wavelength; an image sensing circuit is used to sense and generate at least one physiological characteristic measurement signal in response to the at least one light; an offset correction operation is performed on the at least one physiological characteristic measurement signal, to generate at least one corrected physiological characteristic measurement signal; and perform calculation on the at least one corrected physiological characteristic measurement signal to estimate and obtain a physiological characteristic result.

According to the embodiment of the present invention, the main advantage is that it can solve the problems of traditional technologies, improve the ability of the photoplethysmography sensor to resist motion artifacts, increase the accuracy of heartbeat detection, and can be adjusted for multi-wavelength offsets to improve heartbeat Detection is affected by motion artifacts, for example, by taking two photoplethysmographic signals of different wavelengths, removing the DC offset effect of motion noise, and then comparing the two different wavelength signals after removing the DC offset Processing or motion noise subtraction techniques can effectively improve the impact of motion artifacts.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative effort.

FIG. 1 is a schematic diagram of an electronic device 100 for measuring physiological characteristics according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of an FFT spectrum of an example of a test result signal of an offset correction performed by the electronic device of FIG. 1 .

FIG. 3 is a schematic diagram of another example of the FFT spectrum of the test result signal of the electronic device in FIG. 1 performing offset correction.

FIG. 4 is a schematic flow diagram of the operation flow of the processing circuit shown in FIG. 1 .

Explanation of reference numbers:

label name label name 100 electronic device 120 processing circuit 105 Image sensing circuit 1201 Offset Determining Unit 110 light unit 1202 Motion Noise Correction Unit 115 light source controller 1203 Physiological Characteristic Estimation Unit

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that if there is a directional indication (such as up, down, left, right, front, back...) in the embodiment of the present invention, the directional indication is only used to explain the position in a certain posture (as shown in the accompanying drawing). If the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions involving "first", "second" and so on in the embodiments of the present invention, the descriptions of "first", "second" and so on are only for descriptive purposes, and should not be interpreted as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , nor within the scope of protection required by the present invention.

The spirit of the present invention is to reduce or avoid the influence of motion artifacts, optical sensing system itself and/or external noise on the estimation of photoplethysmography signals. Motion artifacts are mainly caused by the movement of the user. And cause inaccurate sensing of physiological characteristics. For example, when a user wears a wrist-type electronic device that can detect physiological characteristics on his wrist, a slight typing action of the user is enough to affect the wrist-type electronic device and cause physiological problems. The sensing of features is inaccurate. The offset caused by the optical sensing system itself is mainly due to the slight differences in the assembly of each optical sensing device, which leads to inaccurate sensing of physiological features. In addition, the external noise is one of the reasons One is the external noise sensed by the sensor when light enters the skin and is reflected to enter the sensor, this external noise will also lead to inaccurate sensing of physiological characteristics. The following electronic device and corresponding method of the present invention can reduce or avoid the influence of motion artifacts, the optical sensing system itself and/or external noise on the estimation of the photoplethysmography signal, especially reduce or avoid the influence on the The influence of the DC offset caused by the estimation of the photoplethysmographic signal, by estimating and correcting the offset of at least one photoplethysmographic signal, so that the subsequent use of the corrected photoplethysmographic signal to estimate the physiological characteristics (such as heartbeat) frequency, etc.) to obtain more accurate physiological feature sensing results without interference from motion artifacts, the optical sensing system itself, and/or external noise. Embodiments of the present invention will be described in detail below.

Please refer to FIG. 1 , which is a schematic diagram of an electronic device 100 for measuring physiological characteristics according to an embodiment of the present invention. The electronic device 100 includes an image sensing circuit 105 (such as an image sensor array), at least one light emitting unit 110, a light source controller 115, and a processing circuit 120, and may be a portable electronic device or a wearable electronic device in practice. For devices (such as smart watches or bracelets, etc.), the processing circuit 120 includes an offset determination unit 1201 , an action noise correction unit 1202 and a physiological feature estimation unit 1203 .

The light source controller 115, such as a light emitting diode controller, is used to control the at least one light emitting unit 110. The at least one light emitting unit 110, such as a light emitting diode, is used to emit at least one light to the surface of the user's human skin of the electronic device 100, so that the user The red blood cell components of human blood absorb the emitted light, and reflect and image on the image sensing circuit 105 due to the different absorption rates of different light rays, so as to obtain photoplethysmography (PPG) signals of different light rays, and estimate and calculate accordingly The results of the user's physiological characteristics (such as heartbeat frequency, etc.). In practice, the at least one light emitting unit 110 includes, for example, a white light emitting diode unit or a plurality of light emitting diode units corresponding to different wavelengths of light (for example, red light and green light emitting diode units, which are not limited to this application), and the white light emits The light emitted by the diode unit includes light components with multiple light wavelengths, and the multiple light-emitting diode units with different wavelengths are used to independently emit light components with different light wavelengths to the surface of human skin at different time points; the above Possible implementations of the at least one light emitting unit 110 all fall within the scope of this application.

The image sensing circuit 105 is used to sense light components with different light wavelengths to generate different photoplethysmographic signals. The test circuit 105 will adopt a color filter array (Color Filter Array, CFA) 1051, the color filter array 1051 includes a plurality of color channels (color channels) corresponding to different light wavelengths, respectively filter out the color channels with different light wavelengths For example, the light components of red wavelength, green wavelength, and blue wavelength are respectively filtered out, and the image sensing circuit 105 then forms images to generate different light volumes according to the light components of red wavelength, green wavelength, and blue wavelength. Tracing signal. In addition, if the light-emitting unit 110 actually includes a plurality of light-emitting diode units corresponding to different light wavelengths (for example, red light with a first wavelength and green light with a second wavelength), then the corresponding image sensing circuit 105 does not need to use color light. The filter array, the image sensing circuit 105 can generate the photoplethysmography signal of the red light wavelength according to the imaging result signal of the light generated by the red light emitting diode after being absorbed by the blood of the user's body at the first time point, and at the first time point At the second time point, the photoplethysmography signal of the green wavelength is generated according to the result signal of the light generated by the green light-emitting diode after being absorbed by the user's blood, so that different wavelengths of light components can be generated respectively. The photoplethysmography signal; therefore, due to the different design of the light emitting unit 110, the color filter array 1051 is optional (optional), not limited by the present invention.

The photoplethysmographic signal measured above can be used to estimate physiological characteristics, which is the physiological characteristic measurement signal described in the present invention. It should be noted that each of the aforementioned photoplethysmographic signals may or may not be offset, so after generating the aforementioned physiological characteristic measurement signals, in order to reduce or avoid motion artifacts, the optical sensing system itself and/or external noise For the offset effect caused by the estimation of the photoplethysmography signal, the processing circuit 120 receives the above-mentioned at least one physiological characteristic measurement signal and corrects the offset of the above-mentioned at least one physiological characteristic measurement signal to generate a corrected physiological characteristic measurement signal, and then estimate a physiological characteristic result (such as the user's heartbeat frequency) according to the corrected physiological characteristic measurement signal. The operation of the processing circuit 120 is described in detail below.

In practice, the processing circuit 120 includes an offset determination unit 1201, an action noise correction unit 1202, and a physiological characteristic estimation unit 1203. For a physiological characteristic measurement signal (ie, a PPG signal), the offset determination unit 1201 For generating or estimating an offset correction amount of the PPG signal, the motion noise correction unit 1202 is used for correcting the offset of the PPG signal according to the offset correction amount, generating a corrected PPG signal, and then estimating physiological characteristics Unit 1203 estimates, for example, the user's heartbeat frequency according to the corrected PPG signal. The above operations can be realized by using software, hardware or a combination of software and hardware, that is, the above-mentioned processing circuit 120 and its units 1201 to 1203 can be realized by using software or hardware or a combination of software and hardware. In terms of software implementation, the units 1201 to 1203 As a software unit included in a specific program code, the processing circuit 120 is, for example, a processor and configured to execute the specific program code to perform the above-mentioned offset correction operation and physiological characteristic estimation operation. If it is realized by hardware, the above units can be realized by using different circuit components; the realization of the above software/hardware combination all belongs to the scope of the present invention.

The operation of the offset determining unit 1201 for generating or estimating an offset correction of a PPG signal is as follows. The processing circuit 120 receives, for example, three PPG signals, such as PPG signals respectively corresponding to the red wavelength channel, the green wavelength channel and the blue wavelength channel (RGB channels, that is, different light components). In this embodiment, in order to accurately estimate the DC bias The processing circuit 120 can use two PPG signals respectively corresponding to two different wavelength channels (for example, PPG signals of red wavelength and green wavelength, or PPG signals of blue wavelength and green wavelength) to perform physiological characteristic estimation Therefore, only two PPG signals need to perform offset correction operations, and it is not necessary to perform offset correction operations on all PPG signals; however, this is not a limitation of the present invention, and other embodiments can also perform offset correction operations on a single PPG signal or all PPG signals PPG signal is offset corrected.

For example, to correct the DC offset caused by the process variation or the gain value of individual pixels, the processing circuit 120 first captures a completely black background image, and at this time the corresponding sensing value of the individual pixels can be regarded as The DC offset, that is, the processing circuit 120 controls the electronic device 100 to be in an environment where the ambient light is blocked, and then measures a PPG signal when the ambient light is blocked, and estimates the DC offset of the PPG signal in a completely dark environment , as the offset correction amount for correcting the DC offset, based on which the DC offset caused by the process variation or the gain value of individual pixels is corrected.

For correcting the DC offset of the motion artifact, it is performed when the ambient light is not shielded, for example, the motion artifact of a specific frequency is applied, and the electronic device 100 is placed on the user's skin and the motion artifact of a specific frequency or interference is applied. In this way, the offset determining unit 1201 can generate a plurality of different PPG test result signals corresponding to the red wavelength by gradually applying or adjusting a plurality of different DC offset test quantities to a color channel corresponding to the red wavelength, from From these different PPG test result signals, a DC offset correction value of the PPG signal with a red wavelength is inversely estimated, and the motion noise correction unit 1202 can use the DC offset correction value to perform an operation on the PPG signal with a red wavelength. An offset correction, similarly, the offset determination unit 1201 can generate multiple different PPGs corresponding to the green wavelength by gradually applying or adjusting multiple different DC offset test quantities to a color channel corresponding to the green wavelength The test result signal, from these different PPG test result signals, inversely estimates a DC offset correction amount of the PPG signal of the green wavelength, and uses the DC offset correction amount to execute the PPG signal of the green wavelength - Deskew.

When applying or adjusting different DC offset test values above, these different DC offset test values can be generated by a fixed step size, or these different DC offset test values can be generated by dynamically adjusting the step size test volume. Wherein, taking the fixed step size as an example, the adjustment range can be selected from half of the negative value of the initial DC offset R_DC of the red light wavelength caused by the optical sensing system itself to 1/2 of the positive value of the initial DC offset Half, that is, -R_DC/2 to R_DC/2, and one-twentieth of the adjustment range (that is, R_DC/20) is used as a fixed step to perform test adjustment of the DC offset. Similarly, the test adjustment of the green light wavelength and the blue light wavelength is also the same as the above operation, and will not be repeated here. It should be noted that the above illustrations are only for readers to understand the embodiments of the present invention more easily, and are not intended to limit the present invention.

In addition, the frequency spectrum of the Fourier transform function of multiple test result signals of one or more color channels can also be counted and analyzed, and the offset determination unit 1201 can use a Fourier transform function (such as a fast Fourier transform FFT) to convert each test result signal Converting the frequency spectrum from the time domain to the frequency domain, generating a specific critical value based on a maximum energy value and a ratio of one spectrum of each test result signal, and based on the frequency of each test result signal exceeding the specific critical value The number of a local extremum of the component is reversely estimated from a plurality of different DC offsets corresponding to a plurality of different test result signals to estimate a DC offset correction value of a PPG signal with a specific light wavelength. When the number of local extreme values of a specific test result signal is less than a specific number, the offset determining unit 1201 selects a DC offset corresponding to the specific test result signal as the DC offset correction value.

Referring to FIG. 2 , it is a schematic diagram of time-frequency analysis of an example FFT spectrum of the test result signal of the offset correction performed by the electronic device of FIG. 1 . As shown in Figure 2, the X-axis represents time, the Y-axis represents the energy intensity value of the FFT spectrum (representing the signal energy intensity of a certain frequency), and the horizontal dotted line represents a specific threshold TH, which is first detected by the offset determining unit 1201 The maximum energy value of the frequency spectrum of the test result signal is located at point A, and TH is calculated by using the energy value corresponding to point A and a ratio (for example, 1/4), that is, the value of TH is the energy value corresponding to point A divided by 4 , and then comparing the number of local extremums of the frequency components exceeding the specific critical value TH in the test result signal, it can be detected that the number of local extremas is 2. If the specific number is set to 4, then the The number of local extremums of the test result signal of this time is 2 and less than a specific number of 4, so the offset determination unit 1201 can select the DC offset corresponding to the test result signal used this time as the DC offset correction amount.

Referring to FIG. 3 , it is a schematic diagram of time-frequency analysis of another example of the FFT spectrum of the test result signal of the offset correction performed by the electronic device of FIG. 1 . As shown in Figure 3, the X-axis represents time, the Y-axis represents the energy intensity value of the FFT spectrum (representing the signal energy intensity of a certain frequency), and the horizontal dotted line represents a specific threshold TH, which is detected by the offset determination unit 1201 first. The maximum energy value of the frequency spectrum of the test result signal is located at point A', and TH is calculated by using the energy value corresponding to point A' and a ratio (for example, 1/4), that is, the value of TH is the energy corresponding to point A' The value is divided by 4, and then compared with the number of local extremums of the frequency components exceeding the specific critical value TH in the test result signal, the number of local extrema can be detected to be 8, if the specific number is set to 4 , then the number of local extreme values of the test result signal this time is 8 and greater than the specific number 4, so the offset determination unit 1201 will not select the DC offset corresponding to the test result signal used this time as The DC offset correction amount.

When a test result signal is converted from the time domain to the frequency domain, the frequency of the maximum energy value of the frequency spectrum of the test result signal usually represents the estimated physiological characteristics (ie heartbeat frequency). In an ideal situation without DC offset interference, the The maximum energy value will be several times the energy intensity value of other frequency components, so a ratio (such as 1/4) is used to distinguish the frequency of the maximum energy value from other frequency components of energy intensity, and in fact a The setting of a specific number determines whether the current test result signal is more or less affected by the DC offset. The number of values is 2, and the offset determination unit 1201 can determine that the test result signal is less affected by the DC offset, if no other test result signal is better than the test result signal, then the corresponding test result signal can be selected The DC offset is used as the DC offset correction amount. Conversely, in the test result signal shown in Figure 3, the number of local extremums of the frequency components exceeding the specific critical value TH is 8, which is greater than the specific number 4, and the offset determination unit 1201 can determine the test result signal It is greatly affected by the DC offset, so the DC offset corresponding to the test result signal is not selected as the DC offset correction amount. Accordingly, the offset determination unit 1201 can determine the quality of different test result signals to determine the final DC offset correction.

It should be noted that when the offset determination unit 1201 performs spectrum analysis, it can only take energy intensity values within the normal heartbeat frequency range for statistical analysis, such as the range from frequency f1 to frequency f2 shown in FIG. 2 . However, this is not a limitation of this case.

When the offset determination unit 1201 finally determines the correction amount of the DC offset, the motion noise correction unit 1202 adjusts according to the correction amount to reduce or eliminate the DC offset of the PPG signal corresponding to a wavelength of light, and then The physiological feature estimation unit 1203 estimates the heartbeat frequency based on the corrected PPG signals of two different light wavelengths. In practice, the physiological feature estimation unit 1203 can independently perform a Chromaticity space conversion, take the corresponding chromaticity values of the two PPG signals, calculate a ratio of the two sets of chromaticity signals, and then convert the ratio to the frequency domain to determine the heartbeat frequency. For example, in one embodiment, if the offset determination unit 1201 respectively determines the two offset correction amounts of the physiological characteristic measurement signal of the color channels of the red wavelength and the green wavelength, the motion noise correction unit 1202 uses the red wavelength The two offset correction amounts of the green wavelength and the green wavelength are used to reduce or eliminate the DC offset of the PPG signal of the red wavelength and the green wavelength, and the physiological characteristic estimation unit 1203 uses the corrected red wavelength and the green wavelength The two PPG signals are respectively converted into chromaticity space, and the corresponding chromaticity values of the two PPG signals are taken, the ratio of the two sets of chromaticity signals is calculated, and then the ratio is converted to the frequency domain to determine the heartbeat frequency. The above operations are also applicable to the PPG signals of the blue wavelength and the green wavelength.

In order for readers to easily understand the operation of the present invention, the operation flow steps of the processing circuit 120 of the above-mentioned electronic device 100 are described in FIG. 4 to help readers understand. If substantially the same result can be achieved, it is not necessary to follow the sequence of steps in the process shown in Figure 4, and the steps shown in Figure 4 do not have to be performed continuously, that is, other steps can also be inserted therein:

Step 405: start;

Step 410: Make the electronic device 100 in an environment that shields ambient light;

Step 415: Measure the DC offset of the PPG signal in total darkness as a preliminary offset correction value;

Step 420A: applying and adjusting a plurality of different DC offset test quantities step by step to color channels corresponding to two different light wavelengths to generate a plurality of different PPG test result signals corresponding to different light wavelengths;

Step 425A: From different PPG test result signals, inversely estimate the DC offset correction amounts of different light wavelengths;

Step 420B: Generate a specific critical value according to a maximum energy value and a ratio of a frequency spectrum of each PPG test result signal;

Step 425B: Comparing the number of a local extremum of the frequency component exceeding the specific critical value in each test result signal, inversely estimating a DC offset correction amount;

Step 430: Determine the final offset correction amount of the two different light wavelengths, and correct the PPG signals of the two different light wavelengths;

Step 435: Perform chromaticity space conversion on the calibrated PPG signals of two different light wavelengths, and obtain corresponding chromaticity signal values of the two PPG signals; and

Step 440: Calculate a ratio of the two sets of chrominance signals, and then transform the ratio into frequency domain to determine the heartbeat frequency of the user.

Furthermore, in practice, the above-mentioned PPG signal includes a matrix value. When calculating the offset correction amount, it can be calculated by adding the sensing pixel values in a single pixel unit size (pixel-based). Calculated by adding the values of multiple pixel rows in units of a single pixel row size (column-based) or by adding the values of the entire frame in units of the entire frame size (frame-based) For calculation, all similar implementation changes are consistent with the spirit of the present invention.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (18)

1. An electronic device for measuring physiological characteristics, comprising: At least one light-emitting unit for emitting at least one light, the at least one light includes a first light component corresponding to a first wavelength and a second light component corresponding to a second wavelength, the first wavelength is different from the second wavelength; An image sensing circuit capable of sensing and generating at least one physiological characteristic measurement signal in response to the at least one light; and A processing circuit, coupled to the image sensing circuit, for performing an offset correction operation on the at least one physiological characteristic measurement signal to generate at least one corrected physiological characteristic measurement signal, and correcting the at least one physiological characteristic measurement signal The subsequent physiological characteristic measurement signal is calculated to estimate a physiological characteristic result. 2. The electronic device as described in claim 1, wherein the processing circuit estimates at least one DC offset correction amount of the at least one light component, and according to the at least one DC offset correction amount, the at least one physiological A DC offset correction operation is performed on the characteristic measurement signal. 3. The electronic device as described in item 2 of the scope of patent application, wherein the at least one physiological characteristic measurement signal includes a first physiological characteristic measurement signal corresponding to the first light component and a signal corresponding to the second light component A second physiological characteristic measurement signal, the processing circuit includes: a determination unit, used for estimating a first DC offset correction amount corresponding to the first light component and estimating a second DC offset correction amount corresponding to the second light component; A calibration unit, configured to perform the DC offset on the first physiological characteristic measurement signal and the second physiological characteristic measurement signal according to the first DC offset correction amount and the second DC offset correction amount respectively a calibration operation to generate the calibrated first physiological characteristic measurement signal and the calibrated second physiological characteristic measurement signal; and An estimation unit is used for calculating and estimating the physiological characteristic result according to the corrected first physiological characteristic measurement signal and the corrected second physiological characteristic measurement signal. 4. The electronic device as described in item 3 of the scope of patent application, wherein the estimation unit performs a chromaticity space conversion, and respectively measures the corrected first physiological characteristic measurement signal and the corrected second physiological characteristic measurement signal The signal is converted into a first chrominance signal and a second chrominance signal, and a ratio of the first chrominance signal to the second chrominance signal is calculated, and the ratio is converted to a frequency domain to calculate the Physiological Characterization Results. 5. The electronic device as described in claim 2, wherein the processing circuit measures a DC offset when the ambient light is shielded as a preliminary DC offset correction value used in the offset correction operation. 6. The electronic device as described in item 5 of the scope of patent application, wherein the processing circuit generates multiple different The different test result signals are used to inversely estimate the DC offset correction amount from the different test result signals, and use the DC offset correction amount to perform the offset correction operation on the at least one physiological characteristic measurement signal. 7. The electronic device as described in item 6 of the scope of the patent application, wherein when the processing circuit gradually applies the multiple different DC offset test values to the color channel, the different DC offsets are generated through a fixed step size Offset test quantities, or generate these different DC offset test quantities by dynamically adjusting the step size. 8. The electronic device as described in item 6 of the scope of patent application, wherein the processing circuit generates a specific critical value according to a maximum energy value and a ratio of a frequency spectrum of each test result signal, and according to each test result The number of local extremums of the frequency components in the result signal exceeding the specific critical value, from the different DC offsets corresponding to the different test result signals, the DC offset correction amount is estimated by inverse estimation , wherein when the number of local extreme values of a specific test result signal is less than a specific number, the processing circuit selects a DC offset corresponding to the specific test result signal as the DC offset correction value. 9. The electronic device as described in item 1 of the scope of the patent application, wherein the at least one physiological characteristic measurement signal includes a numerical matrix, and the processing circuit can use pixel units (pixels) as units, pixel rows (columns) The value of the numerical matrix is calculated in unit or frame, so as to calculate an offset correction amount used in the offset correction operation. 10. A method of measuring physiological characteristics, comprising: At least one light emitting unit is used to emit at least one light, the at least one light includes a first light component corresponding to a first wavelength and a second light component corresponding to a second wavelength, the first wavelength is different from the second wavelength; using an image sensing circuit to sense and generate at least one physiological characteristic measurement signal in response to the at least one light; performing an offset correction operation on the at least one physiological characteristic measurement signal to generate at least one corrected physiological characteristic measurement signal; and Calculation is performed on the at least one corrected physiological characteristic measurement signal to estimate a physiological characteristic result. 11. The method as described in claim 10, wherein the step of performing the offset correction operation comprises: estimating at least one DC offset correction amount of the at least one light component, and based on the at least one DC offset correction amount , performing a DC offset correction operation on the at least one physiological characteristic measurement signal. 12. The method described in claim 11, wherein the at least one physiological characteristic measurement signal includes a first physiological characteristic measurement signal corresponding to the first light component and a signal corresponding to the second light component A second physiological characteristic measurement signal, the method further includes: estimating a first DC offset correction amount corresponding to the first light component and estimating a second DC offset correction amount corresponding to the second light component; performing the DC offset correction operation on the first physiological characteristic measurement signal and the second physiological characteristic measurement signal according to the first DC offset correction amount and the second DC offset correction amount respectively, to generate the correction the subsequent first physiological characteristic measurement signal and the corrected second physiological characteristic measurement signal; and The physiological characteristic result is calculated and estimated according to the corrected first physiological characteristic measurement signal and the corrected second physiological characteristic measurement signal. 13. The method described in item 12 of the scope of patent application, wherein the step of calculating and estimating the result of the physiological characteristic includes: performing a chromaticity space conversion, respectively converting the corrected first physiological characteristic measurement signal and the corrected second physiological characteristic measurement signal into a first chrominance signal and a second chrominance signal; calculating a ratio of the first chrominance signal to the second chrominance signal; and The ratio is transformed into a frequency domain to calculate the physiological characteristic result. 14. The method according to claim 11, wherein the step of estimating the at least one DC offset correction of the at least one light component comprises: measuring a DC offset as the offset correction when ambient light is blocked One of the preliminary DC offset corrections used by the operation. 15. The method as described in claim 14, wherein the step of estimating the at least one DC offset correction amount of the at least one light component further comprises: A plurality of different test result signals are generated by gradually applying a plurality of different DC offset test quantities to at least one color channel corresponding to the at least one light component; and From the different test result signals, the DC offset correction amount is inversely estimated. 16. The method as described in item 15 of the scope of the patent application, wherein the step of gradually applying a plurality of different DC offset test values includes: generating these different DC offset test values through a fixed step size, or by dynamically adjusting The step size is used to generate these different DC offset test values. 17. The method as described in item 15 of the scope of patent application, wherein the step of inversely estimating the DC offset correction amount from the different test result signals includes; generating a specific critical value according to a maximum energy value and a ratio of a frequency spectrum of each test result signal; and According to the number of local extremums of the frequency components exceeding the specific critical value in each test result signal, the different DC offsets corresponding to the different test result signals are reversely estimated to estimate the DC offset correction amount; Wherein when the number of local extreme values of a specific test result signal is less than a specific number, a DC offset corresponding to the specific test result signal is selected as the DC offset correction value. 18. The method as described in item 10 of the scope of patent application, wherein the at least one physiological characteristic measurement signal includes a numerical matrix, and the processing circuit can use the unit of pixel unit, the unit of pixel row or the unit of picture frame Calculate the values of the numerical matrix to calculate an offset correction amount used in the offset correction operation.