Heart rhythm detection device and physiological detection device

Abstract

A heart rhythm detection device includes a detection unit for detecting the emitted light after a single multi-color light source irradiates the subcutaneous tissue to output a plurality of light detection signals related to a plurality of wavelengths. The heart rhythm detection device also includes a processor for eliminating motion noise using the plurality of light detection signals related to the plurality of wavelengths to obtain a clean heart rhythm signal.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 201910292687.3, application date April 12, 2019, and name “Heart rhythm detection device and its operation method, physiological detection device”. Technical Field

[0002] The present invention relates to a physiological detection, and more particularly to a heart rhythm detection device and an operation method thereof that uses multi-wavelength light to eliminate motion noise generated by muscle motion. Background Art

[0003] Traditionally, heart rhythm detection can be performed by analyzing ECG, but ECG detection requires the use of two electrodes, which is inconvenient in operation. Therefore, in recent years, the use of optical methods for heart rhythm detection has emerged. Optical heart rhythm detectors can be used in portable and wearable electronic devices.

[0004] It is known that optical physiological detection is affected by the relative movement between the detection device and the skin surface. In particular, when the optical detection device is applied to a wearable device, users prefer to use it to detect changes in heart rate during exercise, so there is a situation where the detection accuracy is reduced due to the influence of noise.

[0005] One known denoising method is to operate an optical physiological detection device in conjunction with an accelerometer, and use the detection results of the accelerometer to denoise the detection results of the optical physiological detection device to improve detection accuracy. However, this denoising method cannot eliminate the noise generated by a single muscle movement, such as when the user's arm is not waving but only the wrist or fingers are moving. As a result, the accelerometer cannot generate a usable detection result for denoising.

[0006] In addition, the current physiological detection field does not mention the influence of the noise generated by the above-mentioned simple muscle movement on the detection results, nor does it involve how to eliminate this motion noise (motion artifact).

[0007] In view of this, there is a need to provide a physiological detection device that can eliminate the motion noise generated by the muscle movement under the detected skin area to improve the detection accuracy. Summary of the invention

[0008] The present invention provides a heart rhythm detection device and an operation method thereof, which performs vector operation on a predetermined intensity distribution of polychromatic light and a current multi-detection signal of the polychromatic light to eliminate motion noise in the detected photoplethysmographic waveform (PPG) signal.

[0009] The present invention also provides a physiological detection device with high detection efficiency and low energy consumption.

[0010] The present invention provides a heart rhythm detection device, comprising at least one light source, a light detector and a processor. Each of the at least one light source is used to emit multi-wavelength light to illuminate the skin surface of a user. The light detector comprises a detection unit for detecting the emitted light of the skin surface and outputting a plurality of light detection signals related to different color lights of the multi-wavelength light. The processor is used to perform vector operations on the plurality of light detection signals and the pre-stored intensity distribution of the different color lights to eliminate motion noise.

[0011] The present invention also provides a physiological detection device, comprising a white light source, a molded structure and a pixel array. The white light source emits white light with a color temperature of 2800K to 3200K. The molded structure is formed on the white light source to limit the emission angle of the white light to between 60 degrees and 80 degrees. The pixel array is covered with a filter layer with a wavelength of 570 nanometers to 610 nanometers to filter the white light.

[0012] In an embodiment of the present invention, the light detector is used to detect the light reflected and scattered by the subcutaneous tissue illuminated by the multi-wavelength light source. The multi-wavelength light source can be a white light emitting diode or a white light laser diode. The multi-wavelength light source can also be formed by a plurality of light emitting diode crystals or a plurality of laser diode crystals emitting light of different wavelengths, and the distance between different crystals is preferably less than 2000 microns, so that the emitted light passes through substantially the same muscle fibers or muscle bundles. The different crystals are, for example, formed on the same substrate.

[0013] In the embodiment of the present invention, it is preferred to use a single pixel array to operate with respect to a multi-wavelength light source. The distance between pixels of the single pixel array is preferably less than 2000 microns, so as to receive the emitted light from substantially the same muscle fiber or muscle bundle.

[0014] In the embodiment of the present invention, when the multi-wavelength light source is a white light source, the pixel array of the light detector can be covered with a multi-color filter layer to achieve the purpose of detecting different colors of light. When the multi-wavelength light source is formed by a plurality of crystal grains of different colors of light, the pixel array of the light detector is not covered with a filter layer of different colors of light, and the purpose of detecting different colors of light can also be achieved by lighting up the crystal grains of different colors of light in a time-sharing manner.

[0015] In the embodiment of the present invention, at least two wavelengths of light are used, and the wavelength difference between different wavelengths of light is preferably greater than 25 nanometers to achieve a good denoising effect. However, when only two wavelengths of light are used, the larger the wavelength difference, the better, for example, preferably greater than 50 nanometers.

[0016] In order to make the above and other purposes, features and advantages of the present invention more obvious, the following will be described in detail with reference to the accompanying drawings. In addition, in the description of the present invention, the same components are represented by the same symbols, which are hereby described together. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a block diagram of a heart rhythm detection device according to an embodiment of the present invention;

[0018] Figure 2A is a schematic diagram of configuring a light source and a light detector in a cardiac rhythm device according to an embodiment of the present invention;

[0019] Figure 2B is a schematic diagram of a light source and a light detector configured in a cardiac rhythm device according to another embodiment of the present invention;

[0020] Figure 3A is a flow chart of an operating method of a heart rhythm detection device according to an embodiment of the present invention;

[0021] Figure 3B is a schematic diagram of multiple light detection signals detected by the heart rhythm detection device according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of data after vector operation generated by a heart rhythm detection device according to an embodiment of the present invention; and

[0023] Figure 5 Schematic diagram of a white light source and a molded structure thereon of a physiological detection device according to an embodiment of the present invention.

[0024] Description of Reference Numerals

[0025] 100 Heart rhythm detection device

[0026] 11 Multi-wavelength light source

[0027] 13 Photodetector

[0028] 15 Processor

[0029] λ 1 , 2 …λ M Light wavelength

[0030] PPG 1 、PPG 2 …PPG M Light detection signal

[0031] S skin DETAILED DESCRIPTION

[0032] The physiological detection device of the embodiment of the present invention is used, for example, to detect a photoplethysmographic (PPG) signal, calculate the heart rate based on the PPG signal, and analyze the user's state reflected by the heart rate waveform. In addition to eliminating the noise generated by the relative movement between the device and the measured skin surface, the physiological detection device of the present invention can also eliminate the movement noise of the muscle fibers or muscle bundles under the measured skin surface (even if there is no relative movement between the device and the measured skin surface), such as caused by typing, moving the wrist, and opening and closing the palm.

[0033] Please refer to Figure 1 , which is a block diagram of a heart rhythm detection device 100 according to an embodiment of the present invention. The heart rhythm detection device 100 includes at least one multi-wavelength light source 11, a light detector 13, and a processor 15; wherein the light detector 13 and the processor 15 are, for example, formed in the same detection chip, but not limited thereto. In a non-limiting embodiment, the multi-wavelength light source 11, the light detector 13, and the processor 15 are formed in the same packaging structure and built into a wearable or portable electronic device, such as a watch, a mobile phone, etc.

[0034] The multi-wavelength light source 11 includes, for example, a light emitting diode or a laser diode, etc. The light detector 13 includes, for example, a CCD image sensor or a CMOS image sensor, etc. The processor 15 includes, for example, a digital signal processor (DSP), a microcontroller unit (MCU), a graphics processing unit (GPU), a central processing unit (CPU), or an application-specific integrated circuit (ASIC), etc.

[0035] Each of the at least one multi-wavelength light source 11 is used to emit multi-wavelength light (eg Figure 1 Display wavelength λ 1 , 2 …λ M ) illuminates the user's skin surface S; wherein the skin surface S is determined according to the configuration position of the heart rhythm detection device 100, such as the forearm, upper arm, etc., and there is no specific limitation. The wavelength range of the multi-wavelength light depends on the number of wavelengths required to be used. For example, the more the number of detection signals related to different color lights required for calculating the heart rhythm (examples are given below), the wider the wavelength range is used. Figure 1 As shown, although the penetration depths of different colored lights are different, they still pass through part of the same tissue area. For example, the wavelength spacing of the different colored lights is preferably at least 25 nanometers, so that there is sufficient difference between the detection signals.

[0036] The light detector 13 includes a detection unit (eg Figure 2A The single pixel array 131 of the display is used to output a plurality of light detection signals related to the different colored lights of the multi-wavelengths; wherein the light detection signals are called PPG signals, for example Figure 1 Display light detection signal PPG 1、PPG 2 …PPG M Since body tissues have different absorption rates for different colors of light, different light detection signals have different intensities. Figure 3B shown.

[0037] Please also refer to Figure 2A and Figure 2B , which is a schematic diagram of configuring a light source and a light detector in a heart rhythm detection device according to an embodiment of the present invention.

[0038] In a non-limiting embodiment, the multi-wavelength light source 11 is a white light source. The single pixel array 131 includes a plurality of pixel regions, for example Figure 2A Display pixel area A λ1 To A λM The plurality of pixel regions A λ1 To A λM By forming different color filter layers (relative to λ 1 To M ), so that the plurality of pixel regions A of the single pixel array 131 λ1 To A λM Output multiple light detection signals related to the different color lights (for example Figure 1 PPG 1 、PPG 2 …PPG M ). For example, pixel area A λ1 Output PPG 1 , pixel area A λ2 Output PPG 2 , and so on.

[0039] Each pixel area A λ1 To A λM In one non-limiting embodiment, each pixel region has substantially the same area and thus has the same number of pixels, but the invention is not limited thereto. When a pixel region includes multiple pixels, a hardware circuit or software code can be used to add the light detection signals of the multiple pixels and output the sum of the light detection signals as Figure 1 The light detection signal PPG 1 、PPG 2 …PPG M .

[0040] It must be pointed out that although Figure 2AFour white light sources 111-114 are arranged on the display substrate 10, but they are for increasing the probability that the light detector 13 can detect the noise of muscle movement. The heart rhythm detection device 100 of the present invention is for eliminating the noise of tiny muscle movements under the detected skin surface, and the muscle bundles that move are determined according to the user's actions, such as finger movement. In some cases, the emission light of the multi-wavelength light sources 111 and 113 arranged on two opposite sides of the pixel array 131 of the light detector 13 in the first direction can enable the pixel array 131 to detect the motion noise, while the emission light of the multi-wavelength light sources 112 and 114 arranged on two opposite sides of the pixel array 131 of the light detector 13 in the second direction cannot enable the pixel array 131 to detect the motion noise, or vice versa, or the emission light of all white light sources 111 to 114 can enable the pixel array 131 to detect the motion noise.

[0041] In more detail, as long as the tissue through which the light emitted by a white light source passes moves, the pixel array 131 can detect motion noise. Therefore, a single white light source can be used, and it is not limited to configuring multiple multi-wavelength light sources. It is also possible to configure multiple white light sources around the pixel array 131 to increase the detection probability. In addition, since the tissue range of the same muscle fibers or muscle bundles is very small, the pixel area A λ1 To A λM The interval Dr between two regions is preferably less than 2000 microns, such as 1500, 1200, 1000, 800 or 600 microns, to effectively eliminate motion noise. λ1 To A λM When the emitted light of different muscle fibers or muscle bundles is detected, the denoising effect will be reduced. Therefore, the area spacing Dr is not just a simple numerical selection, but has its physical meaning.

[0042] In another non-limiting embodiment, the pixel array 131' of the light detector 13 is not divided into a plurality of pixel areas for detecting different color lights. Figure 2B As shown. Multiple light detection signals related to different colored lights are detected by the multi-wavelength light source emitting different colored lights in time. For example, the multi-wavelength light source 11 may include a single crystal grain, and the wavelength of the light emitted by it is changed by controlling its driving parameters (such as driving voltage or current) or controlling the variable color filter covering the single crystal grain. Alternatively, the multi-wavelength light source 11 includes multiple light-emitting crystal grains (such as Figure 2B Display as L λ1 To L λM ) is used to emit the multi-wavelength light.

[0043] As mentioned above, in order to detect the emitted light of substantially the same muscle fiber or muscle bundle, the plurality of light emitting crystal particles L in each multi-wavelength light source 11 are λ1 To L λM The grain spacing d L Preferably, the distance is less than 2000 microns. For example, multiple light-emitting crystals are packaged in the same molding and located on the same substrate layer, so that the emitted light of the multiple light-emitting crystals passes through roughly the same muscle fibers or muscle bundles, which can effectively eliminate the tiny motion noise. L It is not just a simple numerical choice, but has physical meaning. Figure 2B The plurality of light emitting crystals may be disposed on only one side, two sides, or around the pixel array 131 ′ in a single direction.

[0044] The processor 15 is used to perform vector operations on the multiple current light detection signals (obtained in the working mode) and the pre-stored intensity distribution or ratio of the different color lights (obtained in the registration mode) to eliminate motion noise; wherein the pre-stored intensity distribution or ratio of the different color lights is when the user is stationary (so that the muscles under the tested skin do not move), using a single pixel array 131 or 131' to detect multiple light detection signals PPG related to the different color lights 1 、PPG 2 …PPG M That is, the heart rhythm detection device 100 also has a storage (including volatile and / or non-volatile storage) for storing the intensity distribution or ratio and the algorithm and parameters required for operation.

[0045] Please refer to Figure 3A and 3B As shown, Figure 3A is a flow chart of the operation method of the heart rhythm detection device according to an embodiment of the present invention, which is applicable to Figure 1 -3 heart rhythm detection device 100; Figure 3B are multiple light detection signals PPG detected by the heart rhythm detection device of the embodiment of the present invention 1 、PPG 2 …PPG M (corresponding to wavelength λ 1 To M ). The operation method of this embodiment includes the following steps: entering a registration mode (step S31); establishing registration data in the registration mode (step S32); entering a working mode (step S33); in the working mode, performing vector operation on the sampled data and the registration data (step S34); and calculating the heart rhythm according to the data after the vector operation (step S35).

[0046] As mentioned above, the registration mode refers to, for example, a detection mode when the user is stationary, for example Figure 3B During the stationary period. For example, when the user executes the APP or presses a button on the heart rhythm detection device 100, the heart rhythm detection device 100 enters the registration mode. At this time, the body part of the user wearing the heart rhythm detection device 100 is preferably completely still to record the registration data related to different color lights, which represents the intensity distribution or ratio of the light detection signal related to different color lights in the absence of motion noise.

[0047] In the operation method of this embodiment, the working mode refers to the mode in which the user wears the heart rhythm detection device 100 to measure the heart rhythm in daily life, for example Figure 3B The working mode can also be entered by the user executing an APP or pressing a button. If the light detection signals related to different color lights with motion noise detected in the working mode are projected back to the pre-stored intensity distribution or ratio, the motion noise can be eliminated.

[0048] Please also refer to Figure 1 and Figure 3A-3B , Figure 3A The details are described below using an example. The processor includes, for example, a normalization unit, a filtering unit, and an intensity calculation unit.

[0049] Steps S31-S32: In the registration mode, the processor 15 controls the multi-wavelength light source 11 to illuminate the first skin surface of the user. At this time, the pixel array 131 or 131' of the light detector 13 detects the emitted light of the first skin surface to generate a plurality of first light detection signals related to different color lights, for example Figure 3B PPG shown 1 、PPG 2 …PPG M The light detector 13 can obtain multiple sampling data related to different color lights at a fixed or adjustable sampling frequency (examples are given below). The processor 15 uses the multiple sampling data related to different color lights to calculate and store registration data, which reflects the intensity distribution or ratio of different color lights.

[0050] For example, the processor 15 continuously receives a plurality of first light detection signals PPG associated with different color lights from the light detector 13. 1 、PPG 2 …PPG M In the present invention, each of the plurality of light detection signals detected by the light detector 13 is referred to as a channel, and each channel is associated with one of the plurality of different color lights. The processor 15 processes the plurality of first light detection signals PPG during each sampling period. 1 、PPG 2 …PPG MEach channel samples a predetermined number (for example, L here) of sampling points at different time points as a piece of sampling data. It can be understood that the optical wavelength range covered by each channel here is not a single wavelength, but a predetermined optical wavelength range, such as multiple wavelengths within the half-width (FWHM) range.

[0051] For example, the L sampling points of the M channels acquired by the processor 15 during one sampling period can be represented by an M×L matrix as a segment of sampling data. As time passes, the processor 15 acquires an M×L matrix during each sampling period, and the first light detection signals PPG associated with the different color lights are processed during the registration time. 1 、PPG 2 …PPG M Each channel samples multiple sections of sampling data (ie, the registration time includes multiple sampling periods) to obtain multiple M×L sampling matrices.

[0052] Next, the normalization unit of the processor 15 normalizes each of the multiple sampling data (i.e., multiple M×L sampling matrices) of the multiple first light detection signals. For example, the normalization method is to eliminate the DC component of each sampling value.

[0053] After normalization, the processor 15 may select to filter each segment of the normalized sampled data. For example, the filter unit of the processor 15 uses a 0.5 Hz to 3.5 Hz bandpass digital filter to filter each segment of the normalized sampled values.

[0054] Next, the strength calculation unit of the processor 15 calculates the average of the standard deviations of the multiple sampling data (e.g., 20 sampling data per second, 600 sampling data in 30 seconds, but not limited to this) of each channel within the registration time (predetermined time, such as 30 seconds, but not limited to this). First, the processor 15 calculates the standard deviation of each sampling data in the registration time. Next, the processor 15 calculates the average of multiple standard deviations of the multiple sampling data of each channel.

[0055] The processor 15 may finally obtain the intensity distribution of the average value of each channel (for example, PPG1 to PPG8 here) as the registration data related to the different color lights.

[0056] The processor, for example, further includes a vector operation unit operating in a working mode.

[0057] Steps S33-S34: In the working mode, the processor 15 controls the multi-wavelength light source 11 to illuminate the second skin surface of the user; wherein the second skin surface may be the same as or different from the first skin surface in the registration mode. At this time, the pixel array 131 or 131' of the light detector 13 detects the emitted light of the second skin surface to generate a plurality of second light detection signals related to different color lights, for example Figure 3B PPG shown 1 、PPG 2 …PPG M It must be noted that the pixel array 131 or 131 ′ of the photodetector 13 acquires a plurality of first light detection signals in the same manner as that of acquiring a plurality of second light detection signals, but only in different modes (or different stages or different times).

[0058] The processor 15 also processes the plurality of second light detection signals PPG during each sampling period. 1 、PPG 2 …PPG M Each channel samples a predetermined number (for example, L here) of sampling points at different time points as a segment of sampling data. For example, the processor 15 can also obtain an M×L sampling matrix during each sampling period; wherein, the method in which the processor 15 obtains the M×L sampling matrix has been described above, and thus will not be repeated here.

[0059] The normalization unit of the processor 15 then processes the plurality of second light detection signals PPG 1 、PPG 2 …PPG M Each segment of sampled data (i.e., each M×L sampling matrix) is normalized, and the filter unit of the processor 15 filters each segment of the normalized sampled data; wherein, the normalization and filtering methods have been described above, so they are not repeated here. It must be noted that the filter unit of the present invention is configured to increase the calculation accuracy, and the filter unit is not necessarily implemented.

[0060] Then, the vector operation unit of the processor 15 converts each segment of the sampling data (eg, R M×L ) performs vector operation with the registered data to eliminate motion noise. For example, P represents the data after vector operation. In the working mode, the processor 15 can output a set of heart rhythm data P every time a sampling period passes, for example Figure 4 P1, P2, P3, ..., which has eliminated motion noise. Figure 4 The display processor 15 outputs a plurality of vector operated data P at continuous times (expressed as n=0, 1, 2, ...). The number of data in each data group P is the same as the number of samples L taken by the processor 15 in each sampling period.

[0061] In the present invention, the processor 15 samples multiple segments of sampled data (ie, multiple M×L matrices) to establish registration data in the registration mode, but samples one segment of sampled data (ie, one M×L matrix) per sampling period in the working mode to perform vector operations with the registration data.

[0062] It can be understood that the number of channels M of the plurality of first light detection signals and the plurality of second light detection signals is the same, so as to facilitate vector operations. In a non-limiting embodiment, in the registration mode, the processor 15 can use a larger number of channels (for example, but not limited to, 8 channels corresponding to 8 colors of 430 nanometers, 460 nanometers, 490 nanometers, 515 nanometers, 560 nanometers, 615 nanometers, 660 nanometers and 695 nanometers) to establish registration data, and use a smaller number of channels (for example, but not limited to, 3 channels corresponding to 3 colors of 430 nanometers, 560 nanometers and 695 nanometers) in the working mode. When the processor 15 reads the registration data from the storage 17, it only needs to read the required data. For example, in the working mode, when the result of one group of channels is incorrect (for example, the noise is still too high), another group of channels can be changed to use, and the number of channels used can be increased, decreased or maintained. In other embodiments, the channels used can be selected according to the ratio of the AC to DC components of the PPG signal in the multiple channels (called PI value), wherein the higher the PI value, the better the tissue response to the emitted light. For example, use the channel with the highest PI value and the channel with the lowest PI value to perform denoising.

[0063] Finally, in the working mode, the processor 15 calculates the heart rhythm in the time domain or frequency domain using the vector operated data P. For example, the processor 15 calculates the heart rhythm based on the time difference between two adjacent peaks or other corresponding turning points in the operated data P, or converts the operated data P into the frequency domain and then calculates the heart rhythm based on it.

[0064] In a non-limiting embodiment, since the sampling frequency (or frame rate) of the light detector 13 is higher than the heart rate, in order to increase the signal strength, the processor 15 may first perform a superposition operation on the data P after the vector operation within a predetermined number or a predetermined time (for example, P1+P2+P3+…, each segment is added), and then calculate the heart rate with the sum of the superposition data.

[0065] It must be noted that although the above operation method is described by dividing the operation of the processor 15 into multiple functional blocks, the actions performed by each functional block can be considered to be performed by the processor 15 using software code and / or hardware code.

[0066] As mentioned above, the registered data is free of motion noise (e.g. Figure 3B During the static period), the intensity distribution or ratio of the light detection signal related to each color light. In actual use and when the user is in action (for example Figure 3BDuring the activity period of the second light detection signal, the sampling matrix R M×L The data intensity in the sample matrix R is affected by noise and deviates from the pre-stored intensity distribution or ratio. The vector operation of the present invention is to make the sampling matrix R M×L The intensity associated with different colors of light is projected onto a pre-stored intensity distribution or ratio to eliminate motion noise.

[0067] In a non-limiting embodiment, the heart rhythm detection device of the present invention may further include a display (not shown) for displaying the value and / or waveform of the heart rhythm.

[0068] It must be pointed out that the above Figure 3A The operation method is only one implementation of the heart rhythm detection device 100 applicable to the embodiment of the present invention, and is not intended to limit the present invention. The heart rhythm detection device 100 may also use other algorithms to eliminate noise, as long as the light detector 13 detects the output light of substantially the same muscle fiber or muscle bundle, for example, performing a subtraction operation on multiple light detection signals related to different color lights to eliminate motion noise.

[0069] It is to be understood that the values ​​in the above embodiments, such as the wavelength of light, the number of light sources, the number of samples, the number of channels, etc., are merely examples and are not intended to limit the present invention.

[0070] Since it is known to those skilled in the art that white light sources are not efficient, the physiological detection system does not use white light sources. At the same time, according to the characteristics of the luminescent material, it is difficult for a light emitting diode that emits yellow light at 570 nanometers to 620 nanometers to achieve high luminous efficiency (i.e., high energy consumption). Therefore, although the response of the PPG signal (i.e., the aforementioned PI value) is better than that of green light within the range of 570 nanometers to 620 nanometers, the luminous efficiency of the green light source is better, so the PI value is sacrificed and a green light source with better luminous efficiency is selected to avoid using a yellow light source and consuming too much electrical energy. In order to simultaneously improve the PI value and save energy (i.e., high luminous efficiency), in one embodiment of the present invention, a white light source with a color temperature between 2800K and 3200K is selected as the light source, and a filter layer of 570 nanometers to 620 nanometers is formed on the pixel array of the light detector to filter the white light emitted by the white light source, thereby achieving the purpose of high PI value and low energy consumption at the same time. For example, under the premise of achieving the same PI value, the luminous efficiency of using white light emitting diodes with a color temperature between 2800K and 3200K is about three times that of using green light emitting diodes or yellow light emitting diodes, which is a significant improvement.

[0071] In addition, the current purpose of using white light emitting diodes is to be used for space lighting, which requires a wide light emitting angle, so there is no optical structure formed on them to limit their light emitting angle. Figure 5As shown, in order to further optimize the detection efficiency, the present invention forms a plastic or glass molding structure 71 on the white light LED to cover the grain 73 on the base layer 75 to limit the light emitting angle θ of the white light LED to between 60 and 80 degrees, thereby improving the system efficiency.

[0072] In summary, the conventional physiological detection device can only eliminate the noise caused by intense exercise, but cannot eliminate the noise caused by small muscle movements (such as movements that cannot be detected by accelerometers). Therefore, the present invention further provides a heart rhythm detection device ( Figure 1 , 2A -2B) and its operation method ( Figure 3A ), which uses a single pixel array to detect the reflected and scattered light of the tissue under the skin surface illuminated by a multi-wavelength light source to generate multiple light detection signals related to light of different wavelengths, and uses light detection signals of different wavelengths to cancel motion noise from each other, such as performing subtraction or vector projection operations, based on the fact that muscle movement has the same interference on the light detection signals of each wavelength, to obtain a clean heart rhythm waveform. A clean heart rhythm waveform can be used to obtain a more accurate heart rhythm.

[0073] Although the present invention has been disclosed through the above examples, they are not intended to limit the present invention. Any person skilled in the art with ordinary knowledge in the art to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the appended claims.

Claims

1. A heart rhythm detection device, comprising: At least one light source, each of the at least one light source is used to emit multi-wavelength light to illuminate the user's skin surface; A light detector, the light detector comprising a detection unit, the detection unit being used to detect the emitted light from the skin surface and output a plurality of light detection signals related to different color lights of the multi-wavelength light; and A processor is used to perform vector operations on the multiple light detection signals and the pre-stored intensity distributions of the different color lights to eliminate motion noise.

2. The heart rhythm detection device according to claim 1, wherein Each of the at least one light source is a white light source, and The detection unit is a single pixel array including a plurality of pixel areas, each of which is respectively provided with a filter layer of one of the different color lights, so that the plurality of pixel areas of the single pixel array output the plurality of light detection signals related to the different color lights. 3 . The heart rhythm detection device according to claim 2 , wherein the region pitch of the plurality of pixel regions is less than 2000 microns.

4. The heart rhythm detection device according to claim 1, wherein the wavelength interval between the different colored lights is at least 25 nanometers.

5. The heart rhythm detection device according to claim 1, wherein The light source comprises a plurality of crystal chips for emitting the multi-wavelength light, and The grain spacing of the plurality of grains is less than 2000 micrometers.

6. The heart rhythm detection device according to claim 1, wherein the pre-stored intensity distribution of the different colored lights is a plurality of intensities of the plurality of light detection signals associated with the different colored lights acquired and stored by the detection unit when the user is stationary.

7. The heart rhythm detection device according to claim 1, wherein the number of channels of the plurality of light detection signals is the same as the number of channels of the pre-stored intensity distribution of the different color lights. 8 . The heart rhythm detection device according to claim 1 , comprising two multi-wavelength light sources disposed on two opposite sides of the light detector in the first direction.

9. The heart rhythm detection device according to claim 1, comprising four multi-wavelength light sources, wherein Two multi-wavelength light sources are disposed on two opposite sides of the light detector in the first direction, and The remaining two multi-wavelength light sources are disposed at two opposite sides of the light detector in the second direction.

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