Signal acquisition device, signal acquisition method, electronic equipment, computer storage medium and computer program product

Abstract

The embodiment of the invention discloses a signal acquisition device, a signal acquisition method, electronic equipment, a computer storage medium and a computer program product, the device comprises a light barrier, a signal acquisition device and N laser devices, the light barrier comprises a first window and K second windows, the signal acquisition device is arranged in the first window, and the N laser devices are arranged in the second window. The N laser devices are arranged in the K second windows; each laser device in the N laser devices is used for generating a coherent light source, and the signal acquisition device is used for acquiring a photoplethysmography (PPG) signal and / or a speckle plethysmography (SPG) signal. Since the light source generated by the laser device is the coherent light source, the coherent light source can be utilized to detect the speckle interference pattern of the blood vessel of the human body, and then the SPG signal is acquired according to the speckle interference pattern to reflect the blood flow in the blood vessel of the human body. And the accuracy of signal acquisition is improved.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a signal acquisition device, a signal acquisition method, an electronic device, a computer storage medium, and a computer program product. Background Art

[0002] Currently, users can measure body indicators such as heart rate and blood oxygen through electronic wearable devices (such as watches, bracelets, mobile monitoring devices, etc.), so that users can monitor and evaluate their own health conditions based on the measurement results.

[0003] In the related art, electronic wearable devices generally collect photoplethysmography signals to determine the user's heart rate, blood oxygen and other indicators. However, the accuracy of the photoplethysmography signals collected by the electronic wearable devices provided in the related art is low. Summary of the invention

[0004] The present application provides a signal acquisition device, a signal acquisition method, an electronic device, a computer storage medium and a computer program product, aiming to improve the accuracy of signal acquisition.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions: In a first aspect, an embodiment of the present application provides a signal acquisition device, which includes: a light baffle, a signal acquisition device and N laser devices, the light baffle including a first window and K second windows, the signal acquisition device is arranged in the first window, and the N laser devices are arranged in the K second windows; each of the N laser devices is used to generate a coherent light source; the signal acquisition device is used to collect a photoplethysmography (PPG) signal and / or a speckle volume plethysmography (SPG) signal; the PPG signal is obtained based on the coherent light source generated by each laser device; the SPG signal is obtained based on the coherent light source generated by each laser device; wherein N is an integer greater than or equal to 2, and K is an integer greater than or equal to 1.

[0006] Among them, since the light source generated by the laser device is a coherent light source, the coherent light source can be used to detect the speckle interference pattern of the human blood vessels, and then the SPG signal is obtained according to the speckle interference pattern to reflect the blood flow in the human blood vessels. Compared with the related art in which the PPG signal is detected to indirectly reflect the blood flow, the embodiment of the present application can more directly reflect the blood flow by detecting the SPG signal, thereby improving the accuracy of signal acquisition.

[0007] In a possible implementation, the shortest distance between each laser device and the signal acquisition device is equal, and the wavelength of the coherent light source generated by each laser device is different. Among them, by setting a signal acquisition device for collecting photoelectric signals and N laser light sources that generate coherent light sources of different wavelengths, the principle that coherent light sources of different wavelengths enter the human skin at different depths is used to collect photoelectric signals including blood flow characteristics in blood vessels at different depths in the human skin. The accuracy of the photoelectric signal can be improved, and the accuracy of the evaluation results of physiological characteristics such as blood pressure, vascular elasticity, and pulse conduction velocity can be further improved.

[0008] In a possible implementation, the shortest distances between each laser device and the signal acquisition device are not equal, and the wavelengths of the coherent light sources generated by each laser device are the same. Among them, the embodiment of the present application utilizes the propagation characteristics of the banana-shaped optical path, and by setting the shortest distances between each laser device and the signal acquisition device to be different, the light of different coherent light sources is controlled to pass through different skin depths, so as to collect the blood flow characteristics of blood vessels at different depths, which can improve the accuracy of the photoelectric signal.

[0009] In a possible implementation, when N is greater than or equal to 3, the N laser devices include P first laser devices and Q second laser devices; the wavelength of the first coherent light source generated by each first laser device is different, and the shortest distance between each first laser device and the signal acquisition device is equal; the wavelength of the second coherent light source generated by each second laser device is different from the wavelength of the Y first coherent light sources; wherein the sum of P and Q is equal to N, P is an integer greater than or equal to 1, Q is an integer greater than or equal to 1, Y is an integer less than or equal to P, and Y is greater than zero. The embodiment of the present application combines the principle that coherent light sources of different wavelengths are incident on human skin at different depths and the propagation characteristics of the banana-shaped optical path, and obtains information of blood vessels at different depths by mixing and setting first laser devices with different wavelengths and the same distance, and second laser devices with the same wavelength as the first laser device and the shortest distance different from the first laser device, so as to improve the accuracy of the photoelectric signal, and further improve the accuracy of the measurement of physiological characteristics such as blood pressure, vascular elasticity, and pulse conduction velocity.

[0010] In a possible implementation, when K is greater than or equal to 2, the shortest distance between each of the K second windows and the first window is equal; and the P laser devices are arranged in the K second windows.

[0011] In a possible implementation, the signal acquisition device includes a plurality of acquisition units, and the plurality of acquisition units are arranged in a symmetrical array. Ensuring that the light from each coherent light source can reach the signal acquisition device with the same intensity is conducive to improving the sensitivity and accuracy of the signal acquisition device, and at the same time can reduce the noise interference caused by the optical path difference, thereby improving the signal-to-noise ratio and stability of signal acquisition.

[0012] In a possible implementation, the signal acquisition device is a photodiode array device. The photodiode array device provided in the embodiment of the present application has the ability to photoelectrically respond to ultraviolet light, visible light, and near infrared light.

[0013] In a possible implementation, it also includes a printed circuit board, the light shielding plate is arranged on the printed circuit board, the signal acquisition device is arranged on the printed circuit board through a first window, and N laser devices are arranged on the first surface of the printed circuit board through K second windows.

[0014] In a possible implementation, a protective plate is further included, and the protective plate is arranged at the positions of the first window and the K second windows on the first surface of the light shielding plate, and the second surface of the light shielding plate is in contact with the first surface of the printed circuit board. By arranging a transparent protective plate on the window, on the one hand, dust, water droplets and other media can be prevented from falling into the interior of the window, and electronic components can be prevented from being contaminated or damaged; on the other hand, the light of the laser device or the light after exiting the skin can be effectively transmitted without serious attenuation, and will not cause further light scattering effect.

[0015] In a second aspect, an embodiment of the present application provides a signal acquisition method, which is applied to the signal acquisition device described in the first aspect, including: controlling each laser device to close in sequence according to a preset time interval; and collecting photoplethysmography (PPG) signals and / or speckle plethysmography (SPG) signals in sequence according to the closing order of each laser device.

[0016] In a possible implementation, the method further includes: acquiring multiple PPG signals based on corresponding coherent light sources, performing noise reduction processing on each PPG signal to obtain multiple processed PPG signals, and acquiring parameters corresponding to each processed PPG signal based on the multiple processed PPG signals.

[0017] In a possible implementation, it also includes: acquiring multiple SPG signals based on corresponding coherent light sources, performing noise reduction processing on each SPG signal to obtain multiple processed SPG signals, performing feature extraction on the multiple processed SPG signals, and acquiring blood flow characteristics corresponding to each processed SPG signal.

[0018] In a third aspect, an embodiment of the present application provides a signal acquisition method, which is applied to the signal acquisition device of the first aspect, including: controlling the closing of each laser device in sequence according to the order of each acquisition frame in the acquisition time of the photoplethysmographic signal; and collecting the photoplethysmographic PPG signal and / or the speckle volume plethysmography SPG signal corresponding to each acquisition frame.

[0019] In a possible implementation, the method further includes: acquiring multiple PPG signals based on corresponding coherent light sources, performing noise reduction processing on each PPG signal to obtain multiple processed PPG signals, and acquiring parameters corresponding to each processed PPG signal based on the multiple processed PPG signals.

[0020] In a possible implementation, it also includes: acquiring multiple SPG signals based on corresponding coherent light sources, performing noise reduction processing on each SPG signal to obtain multiple processed SPG signals, performing feature extraction on the multiple processed SPG signals, and acquiring blood flow characteristics corresponding to each processed SPG signal.

[0021] In a fourth aspect, an embodiment of the present application provides an electronic device, wherein the electronic device includes the signal acquisition device as described in the first aspect.

[0022] In a fifth aspect, an embodiment of the present application provides an electronic device, comprising: a processor and a memory; the processor is connected to the memory; wherein one or more computer programs are stored in the memory, and the one or more computer programs include instructions; when the instructions are executed by the processor, the electronic device executes the signal acquisition method of the second aspect or the third aspect.

[0023] In a sixth aspect, an embodiment of the present application provides a computer storage medium, comprising computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the signal acquisition method described in the second aspect or the third aspect.

[0024] In a seventh aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a computer, the computer executes the signal acquisition method described in the second aspect or the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a A schematic diagram of Young's double-slit interference provided for related technologies; Figure 1b A schematic diagram of a Young's double-slit interference result provided for related technologies; Figure 1c A schematic diagram of a coherent light source entering the skin surface provided for related technologies; Figure 1d A schematic diagram of a speckle interference pattern provided for related technology; Figure 1e A schematic diagram of a speckle interference pattern provided for related technology; Figure 2 A schematic diagram of a coherent light source of different wavelengths incident on the skin provided in an embodiment of the present application; Figure 3A schematic diagram of the structure of a signal acquisition device provided in an embodiment of the present application; Figure 4 A side schematic diagram of a signal acquisition device provided in an embodiment of the present application; Figure 5 A side schematic diagram of another signal acquisition device provided in an embodiment of the present application; Figure 6 A schematic diagram of the depth of a coherent light source of different wavelengths incident on the skin provided in an embodiment of the present application; Figure 7 A structural schematic diagram of another signal acquisition device is provided for an embodiment of the present application; Figure 8 A schematic diagram of an optical path provided in an embodiment of the present application; Fig. 9 A structural schematic diagram of another signal acquisition device is provided for an embodiment of the present application; Fig.10 A schematic diagram of the depth of a coherent light source with different spacing incident on the skin provided in an embodiment of the present application; Fig.11 A structural schematic diagram of another signal acquisition device is provided for the embodiment of the present application; Fig.12 A schematic diagram of the depth of another coherent light source with different spacing incident on the skin provided in an embodiment of the present application; Fig.13a A schematic diagram of an arrangement of laser devices provided in an embodiment of the present application; Fig.13b A schematic diagram of another arrangement of laser devices provided in an embodiment of the present application; Fig.13c A schematic diagram of another arrangement of laser devices provided in an embodiment of the present application; Fig.13d A schematic diagram of another arrangement of laser devices provided in an embodiment of the present application; Fig.13e A schematic diagram of another arrangement of laser devices provided in an embodiment of the present application; Fig.14a A schematic diagram of an arrangement of a second window provided in an embodiment of the present application; Fig.14b A schematic diagram of another arrangement of second windows provided in an embodiment of the present application; Fig.14c A schematic diagram of another arrangement of the second windows provided in an embodiment of the present application; Fig.15 A schematic diagram of a signal acquisition method provided in an embodiment of the present application; Fig.16A schematic diagram of another signal acquisition method provided in an embodiment of the present application; Fig.17 A schematic diagram of the waveforms of a PPG signal and an SPG signal provided in an embodiment of the present application; Fig.18 A schematic diagram of a waveform of an SPG signal of two blood vessels at different depths provided in an embodiment of the present application; Fig.19 A schematic diagram of a processing flow after signal acquisition provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the description of the following embodiments clear and concise, the terms that may appear in the following embodiments are first briefly introduced: Photoplethysmography (PPG) is a physiological signal that is used to characterize the change in blood volume in the blood vessels within the measured tissue. PPG signals can be used for, but are not limited to, heart rate monitoring, blood oxygen saturation detection (referred to as blood oxygen detection), blood pressure monitoring, cardiovascular health assessment (such as arterial compliance, arterial aging, etc.), and so on.

[0027] Speckle plethysmography (SPG) is a physiological signal. Electrocardiogram (ECG) is a graph that records the electrical activity of the heart. The ECG machine can capture the weak electrical signals generated by the heart during contraction and relaxation, and convert these signals into waveforms. These waveforms mainly include P waves, QRS complexes, and T waves, which represent the electrical activity of the atria and ventricles, respectively. The P wave represents the potential change of atrial muscle depolarization, the QRS complex represents the potential change of ventricular muscle depolarization, and the T wave represents the potential change during ventricular rapid repolarization.

[0028] Laser light source is an electric light source that uses excited particles to emit light under stimulated radiation. Laser light source is a coherent light source. Since laser light source has strong optical coherence, it can be applied to many scientific and technological fields, such as laser technology, optical fiber communication, optical imaging, etc. A typical laser interference experiment is Young's double-slit interference experiment. Figure 1a As shown, a laser light source is emitted from point a of S1, and the laser light source is divided into two beams by two slits (respectively b and c) on S2. The light from the two slits continues to propagate along the direction of light propagation, and forms a superposition in space, and forms bright and dark light spots on the receiving plate S3 (as shown in Figure 1). Figure 1b This phenomenon is called interference of light.

[0029] It should be noted that when the light emitted by the laser light source is reflected by a rough surface or penetrates a rough material (such as human skin), the light will form countless random scattered sub-lights. These scattered sub-lights are superimposed on each other during the propagation process, forming randomly and irregularly distributed bright and dark spots in space. The interference pattern can be clearly distinguished by the receiver or imaging system. This interference pattern is usually called a speckle interference pattern. Figure 1c As shown in FIG. 1 , when the light from the laser light source enters the skin, due to the disturbance of the hemoglobin in the blood vessels, the interference pattern will no longer be in a fixed state, but will form a dynamic interference pattern according to the disturbance of the hemoglobin. As an example, combined with Figure 1d and Figure 1e As shown in the figure, if the laser light source is irradiated on the skin at the wrist, after the laser light source passes through the skin surface and enters the skin, it will form randomly and irregularly distributed bright and dark spots in space due to the disturbance of hemoglobin in the blood vessels (such as Figure 1d The speckle interference pattern can be clearly distinguished by the receiver or imaging system (such as Figure 1e as shown).

[0030] An electronic wearable device refers to an electronic device that has signal collection capability and can be worn by a user, such as a watch, a bracelet, a portable detector, a patch-type detection device, etc., which is not specifically limited here. In the following embodiments, the electronic wearable device can be exemplified by taking a watch as an example.

[0031] The human skin structure is usually composed of three parts: epidermis, dermis and subcutaneous tissue. Arterial blood vessels with strong blood flow are divided into capillaries, arterioles and aorta. In the measurement of some human physiological characteristics, such as human blood pressure, which has a direct relationship with cardiac output and blood flow velocity, the characteristics of vascular structure, distribution, elasticity, etc. have a greater correlation.

[0032] Blood flow characteristics refer to the blood flow velocity, blood flow direction, blood flow velocity difference between blood vessels at different depths, and other characteristics of the blood in the human body's blood vessels.

[0033] The absorption coefficient is a physical quantity that describes the ability of a medium to absorb light. In the embodiment of the present application, the absorption coefficient is a physical quantity that describes the ability of human skin (such as the skin on the wrist) to absorb light (light from a laser light source). The absorption coefficient is usually used to quantify the phenomenon that the intensity of light decays with the propagation distance (penetration depth) when light propagates in a medium. The magnitude of the absorption coefficient directly reflects the ability of the medium to absorb light. The larger the value, the stronger the absorption of light by the medium.

[0034] The scattering coefficient is a parameter that describes the intensity characteristics of scattered light generated by the interaction between light waves and optical media. In the embodiment of the present application, the scattering parameter is a parameter that describes the intensity characteristics of scattered light generated by the interaction between light (light from a laser light source) and human skin (such as the skin on the wrist).

[0035] The optical path refers to the path that light travels through space, including the path after refraction and reflection during light propagation.

[0036] Optical fiber is a thin and long fiber used to transmit optical signals, usually composed of a core layer and a cladding layer. The core layer has a higher refractive index for light than the cladding layer, so that the light is totally reflected at the interface between the core layer and the cladding, and thus transmitted along the optical fiber. Optical fiber can transmit light of different wavelengths, and due to the dispersion effect of light, the transmission speed of light of different wavelengths in the optical fiber may be slightly different.

[0037] A waveguide is a structure used to guide and transmit light waves. Waveguides are often used to control the propagation path and direction of light. Waveguides can be designed to support the transmission of light in a specific wavelength range and achieve precise control of light transmission characteristics by adjusting their structure and materials.

[0038] In the related technology, taking watches as an example of electronic wearable devices, watches generally use the PPG photoelectric sensor at the bottom of the watch to emit light through the LED into the skin of the user's wrist. After the light penetrates the skin, the photodiode in the PPG photoelectric sensor detects the PPG signal. The PPG signal includes the pulsation information of the blood vessels at the user's wrist. By identifying and processing the pulsation information, the user's heart rate, blood oxygen and other indicators can be measured.

[0039] On the one hand, the PPG signal acquisition process is easily interfered by many factors, such as ambient light, skin color, subcutaneous fat thickness, and motion artifacts. These factors may cause changes in the absorption and reflection characteristics of light when penetrating skin tissue, resulting in low accuracy of the PPG signal.

[0040] On the other hand, the PPG photoelectric sensor in the watch collects PPG signals based on the change in optical absorption caused by the change in the volume of blood in the blood vessels. The volume in the blood vessels is an indirect reflection of blood flow. Compared with the detection of the volume in the blood vessels, the distribution of arteries in the skin varies significantly among people, so directly detecting the blood flow characteristics will be more direct and accurate. However, the electronic wearable devices provided in the related arteries are difficult to detect blood flow characteristics, resulting in low accuracy of the collected PPG signals.

[0041] It can be seen from this that the accuracy of the PPG signal collected by the electronic wearable device provided in the related art is low.

[0042] In order to solve the above technical problems, the inventors found in the study of PPG signals that the propagation characteristics of light of different wavelengths in human skin are quite different, as shown in Table 1 below, taking the optical parameters of blood substances in the dermis as an example: Table 1: Optical parameters of blood substances in the dermis

[0043] As shown in Table 1, the propagation distances of light of different wavelengths in the skin have typical differences. In the wavelength range from 300nm to 1000nm, as the wavelength of light increases, the absorption coefficient and scattering coefficient of light in the skin gradually decrease. Among them, short-wavelength light has a short propagation distance, and long-wavelength light has a long propagation distance, that is, the optical path of short-wavelength light propagating in the skin will be shorter than the optical path of long-wavelength light. Therefore, when long-wavelength light enters the human skin, the long-wavelength light can penetrate the deeper blood vessels of the skin and carry the blood flow characteristics of the deep layers, while short-wavelength light can carry the blood flow characteristics of the shallow blood vessels.

[0044] Further research found that the depth of ultraviolet light entering the skin is less than 0.3mm, the depth of blue light entering the skin is about 0.3~0.6mm, the depth of green light entering the skin is about 0.6~1mm, and the depth of red light and infrared light entering the skin can reach more than 3mm. Figure 2 As shown, according to the typical structure diagram of human skin, it can be seen that the wavelength bands of blue light, green light, and red light / infrared can effectively transmit blood to the skin depths of capillaries, arterioles, and aorta respectively. Therefore, the embodiment of the present application can utilize the combination of light of different wavelengths to obtain the blood flow characteristics of different blood vessel layers respectively.

[0045] Based on the above research findings, see Figure 3 The embodiment of the present application provides a signal acquisition device, which may include: a printed circuit board 31, a light baffle 32, a signal acquisition device 33 and N laser devices 34, where N is an integer greater than or equal to 2. The light baffle 32 is arranged on the printed circuit board 31, the signal acquisition device 33 is arranged on the printed circuit board 31 through a first window A on the light baffle 32, and the N laser devices 34 are arranged on the printed circuit board 31 through a second window B on the light baffle 32. The wavelengths of the coherent light sources corresponding to the respective laser devices 34 are different, and the shortest distances between the respective laser devices 34 and the signal acquisition device 33 are the same.

[0046] It should be noted that the embodiment of the present application is described by taking two laser devices as an example, and the number of laser devices may be N, where N is an integer greater than or equal to 2, and is not specifically limited here.

[0047] Printed Circuit Board (PCB) refers to a substrate made of insulating material, with one or more layers of conductive film (usually copper foil) on the PCB board, which is used to assemble electronic components and realize circuit connection. In a possible implementation, the insulating material can be epoxy resin, glass fiber, glass fiber reinforced plastic, etc., and the conductive material can be copper foil.

[0048] A light baffle refers to a fixed plate or an adjustable plate disposed on a PCB (the first surface of the PCB) to block or control the propagation path of light. A light baffle helps reduce external interference and improve light quality.

[0049] The light shielding plate is generally provided with N windows according to the design requirements. The windows can be understood as through holes on the light shielding plate. The windows are used to place electronic components on the PCB, such as Figure 4 As shown, the signal acquisition device 33 is arranged on the PCB board 31 through the first window A on the light shielding plate 32, and N laser devices 34 are arranged on the PCB board 31 through the second window B on the light shielding plate 32. The light of the laser device 34 can be incident into the skin through the second window B, and the light after emitting from the skin is received by the signal acquisition device 33 arranged in the first window A. In the embodiment of the present application, the N laser devices 34 are arranged in the same second window.

[0050] In a possible implementation, the N laser devices 34 can be symmetrical based on the straight line where the center of the signal acquisition device 33 is located. The straight line where the center of the signal acquisition device is located refers to the line between the center of the signal acquisition device and the center of the second window. The N laser devices are bilaterally symmetrical based on the line. Figure 4 As shown, Figure 4 It is shown that two laser devices are arranged on the second window B, and the two laser devices are symmetrical based on the line between the center of the signal acquisition device and the center of the second window to ensure that the optical paths formed between the two coherent light sources and the signal acquisition device remain the same.

[0051] It should be understood that since a light baffle is designed between the first window and the second window, it can prevent the light that has not entered the skin from directly entering the collection surface of the signal acquisition device, thereby preventing the signal acquisition device from generating serious noise after receiving the directly entered light and obliterating the effective photoelectric signal.

[0052] It should be noted that, in the embodiment, in a possible implementation, a transparent protective plate 50 (such as Figure 5As shown). A protective plate refers to a transparent plate used to protect electronic components in the window. Among them, the material of the protective plate can be transparent optical plastic or glass. The size of the protective plate can be consistent with the size of the light baffle, and the size of the protective plate can also be set according to the size of the first window and the size of the second window respectively. The protective plate can also be consistent with the size of the PCB board, which is not specifically limited here. In addition, the protective plate can also be provided on the outer shell, and the protective plate is spliced ​​at the position corresponding to the window on the outer shell. The embodiment of the present application exemplarily shows a schematic diagram in which the size of the protective plate is consistent with the light baffle. By providing a transparent protective plate on the window, on the one hand, dust, water droplets and other media can be prevented from falling into the interior of the window, thereby preventing electronic components from being contaminated or damaged; on the other hand, the light of the laser device or the light after emitting the skin can be effectively transmitted without serious attenuation, and will not cause further light scattering effect.

[0053] The signal acquisition device refers to a device for collecting light (optical signal) emitted from the skin and for converting the optical signal into an electrical signal. The signal acquisition device may include a plurality of acquisition units, and the plurality of acquisition units are arranged in a symmetrical and neatly arranged array, such as a circular array, a linear array, and the like.

[0054] In one possible implementation, the signal acquisition device may be a photodiode (PD) array device, which is a semiconductor photoelectric device consisting of N photodiode units, each of which can independently convert the received optical signal into an electrical signal. The working principle of the PD array device is that when light is irradiated to the surface of the photodiode array, photons are absorbed by the semiconductor material, exciting electrons to transition to the conduction band to form electron-hole pairs. These electron-hole pairs separate under the action of the electric field to form a photocurrent (optical signal). By measuring and amplifying these photocurrents, an electrical signal corresponding to the optical signal can be obtained. Among them, the PD array device provided in the embodiment of the present application has the ability to have a photoelectric response to the ultraviolet band, the visible light band, and the near-infrared light band.

[0055] It should be noted that in the embodiment of the present application, the multiple photodiode units in the PD array device are in the form of a symmetrical, neatly arranged array. The array of the PD array device can be a circular array, a linear array, etc., and the array form of the multiple photodiode units of the PD array device is not specifically limited here.

[0056] Laser devices are devices that generate coherent light sources (also called laser light sources). Laser devices use the principle of stimulated emission to amplify and oscillate electromagnetic waves, thereby outputting laser beams with specific wavelengths, coherence, monochromaticity and high brightness.

[0057] In the embodiment of the present application, each laser device can generate a corresponding coherent light source. For example, the signal acquisition device includes laser device 1 to laser device n, then laser device 1 to laser device n can generate n coherent light sources. In the embodiment of the present application, an example is given by taking the signal acquisition device including two laser devices as an example.

[0058] It should be noted that, in some possible implementations, a laser device can generate two non-interfering coherent light sources with different wavelengths, and the signal acquisition device may include one or more laser devices. Therefore, the type, category and quantity of the laser device are not limited in the embodiments of the present application.

[0059] It should be noted that, since the wavelengths of the coherent light sources generated by the various laser devices are different, in the embodiment of the present application, by setting the shortest distances between the various laser devices and the signal acquisition device to be equal, and arranging the centers of the various laser devices and the signal acquisition device symmetrically, the optical paths between the various laser devices and the signal acquisition device can be made equal, such as Figure 3 As shown, Figure 3 The exemplary display signal acquisition device includes two laser devices, and the shortest distance between each of the two laser devices and the signal acquisition device is represented by L and distinguished by numbers, that is, L1 = L2. Ensuring that the light from each coherent light source can reach the signal acquisition device with the same intensity is conducive to improving the sensitivity and accuracy of the signal acquisition device, while reducing the noise interference caused by the optical path difference, thereby improving the signal-to-noise ratio and stability of signal acquisition.

[0060] In a possible implementation, the light emitted by the coherent light source may also pass through an optical fiber, a waveguide, or a special optical design so that light of different wavelengths (light of the coherent light source) is emitted from the same second window to obtain the same optical path.

[0061] Among them, on the basis that each coherent light source is generated based on an independent laser device and the shortest distance between each laser device and the signal acquisition device is the same, the spacing between each laser device needs to be close, and the distance between the edges of two adjacent laser devices is no more than 0.2mm, so as to ensure that the optical paths formed between the two coherent light sources and the signal acquisition device remain the same. In addition, since there are obvious optical differences in different skin parts of the same person, in order to avoid differences in the optical properties of various points on the skin causing differences in the light propagation path, the spacing between each laser device needs to be close, so that the light propagation path has the same absorption and scattering properties, and there will be no obvious differences.

[0062] In one possible implementation, the distance between the edge of the photoelectric response area of ​​the laser device and the signal acquisition device is not less than 2 mm to avoid the signal acquisition device receiving more invalid optical signals from the shallow skin due to the close distance between the laser device and the signal acquisition device, thereby ensuring the signal-to-noise ratio of the optical signal.

[0063] In a possible implementation, the wavelengths of the coherent light sources in the embodiments of the present application are different, so different wavelength ranges can be divided into each coherent light source according to the number of coherent light sources. For example, assuming that two coherent light sources are included (a first coherent light source and a second coherent light source), the wavelength range of the first coherent light source is between 600 and 1100 nm (between the red light and infrared light bands), and the wavelength range of the second coherent light source is between 500 and 600 nm (between the yellow light and green light bands); the wavelength range of the first coherent light source can also be between 600 and 1100 nm, and the wavelength range of the second coherent light source can be between 350 and 500 nm (between the ultraviolet light and blue light bands); the wavelength range of the first coherent light source can also be between 500 and 600 nm, and the wavelength range of the second coherent light source can be between 350 and 500 nm (between the ultraviolet light and blue light bands).

[0064] Among them, by setting coherent light sources of different wavelengths, the coherent light sources of different wavelengths can reach blood vessels at different depths after entering the skin, while ensuring that the blood flow characteristics carried by each coherent light source have obvious distinction. In some possible implementations, the upper limit of the wavelength range of the coherent light source can be 2500nm, which is not specifically limited here, and the wavelength range of the coherent light source can be determined according to actual needs.

[0065] The signal acquisition device provided in the embodiment of the present application includes a printed circuit board, a light shield, a signal acquisition device and N laser devices. The light shield is arranged on the printed circuit board, the signal acquisition device is arranged on the printed circuit board through a first window on the light shield, and the N laser devices are arranged on the printed circuit board through a second window on the light shield. Among them, the wavelength of the coherent light source corresponding to each laser device is different, the shortest distance between each laser device and the signal acquisition device is the same, and each laser device is symmetrical with the center of the signal acquisition device.

[0066] Among them, by setting up a signal acquisition device for collecting photoelectric signals and N laser light sources that generate coherent light sources of different wavelengths, the principle that coherent light sources of different wavelengths are incident on human skin at different depths is utilized to facilitate the collection of photoelectric signals including blood flow characteristics in blood vessels at different depths in human skin.

[0067] As an example, Figure 6As shown in the figure, human skin can be divided into the epidermis, capillary layer, arteriolar layer, aortic layer and subcutaneous tissue layer. Assuming that the wavelength of the coherent light source is between 350 and 500 nm, the light of the coherent light source can be emitted from the epidermis to the capillary layer (such as Figure 6 Assuming that the wavelength of the coherent light source is between 500 and 600 nm, the light of the coherent light source can be emitted through the epidermis and capillary layer into the arteriolar layer (such as Figure 6 Assuming that the wavelength of the coherent light source is between 600 and 1100 nm, the light of the coherent light source can be emitted into the aorta layer through the epidermis, capillary layer and arteriolar layer (as shown in K2). Figure 6 Assuming that the wavelength of the coherent light source is above 1100nm, the light of the coherent light source can penetrate into the subcutaneous tissue layer through the epidermis, capillary layer, arteriolar layer and aorta layer (such as K3). Figure 6 K4 shown), thereby obtaining the blood flow characteristics of the blood vessels in the subcutaneous tissue layer.

[0068] It should be understood that the electronic wearable devices provided in the related art mainly collect the blood flow characteristics of the human body based on the PPG sensor. However, the PPG signal is a photoelectric signal collected based on the change in optical absorption caused by the change in the volume of blood in the blood vessels, which makes it difficult to effectively detect and extract information about the blood flow characteristics.

[0069] The signal acquisition device provided in the embodiment of the present application can not only directly measure the blood flow characteristics, but also obtain the blood flow characteristics at different depths of the skin based on the design of a multi-wavelength light source or a multi-optical path. It has a direct effect on indicators such as the peripheral resistance of blood vessels in the skin and vascular elasticity, and can improve the accuracy of the evaluation results.

[0070] Among them, the embodiment of the present application can collect PPG signals and / or SPG signals, which can further improve the accuracy of subsequent evaluation results of various different indicators based on photoelectric signals.

[0071] As an example, when the heart's beat output is the same, the blood flow rate in the skin is directly related to the peripheral resistance of the blood vessels. The greater the peripheral resistance, the greater the squeezing force of the blood on the blood vessels. Combining the changes in blood vessel volume measured by PPG and the blood flow rate measured by SPG, the vascular elasticity index can be measured.

[0072] As another example, during the diffusion of blood from the aorta to the arterioles and capillaries, the change in the aortic blood flow velocity is affected by the vascular resistance of the arterioles, and the change in the arteriolar blood flow velocity is affected by the peripheral resistance of the capillaries. Therefore, by collecting the SPG signal to obtain the difference in blood flow velocity in several blood vessels, the peripheral resistance to which the blood vessels are subjected can be directly characterized. For example, the blood pressure characteristic of the human body is the lateral pressure of the blood flowing in the blood vessels on the blood vessel walls, and the factors affecting blood pressure include peripheral vascular resistance multiplied by cardiac output, and blood pressure = cardiac output × vascular resistance. That is, the embodiment of the present application can accurately characterize the cardiac output based on the blood flow velocity difference, and can also accurately characterize the peripheral resistance based on the blood flow velocity difference in blood vessels of different depths, and more accurately measure the blood pressure index.

[0073] In this way, the accuracy of the photoelectric signal can be improved, and the accuracy of the evaluation results of physiological characteristics such as blood pressure, vascular elasticity, and pulse conduction velocity can be further improved.

[0074] At the same time, since the PPG signal is based on the optical absorption characteristics of skin tissue, blood and other substances, individual differences in skin optical properties, measurement location, skin surface quality, hair, pigment and other factors will have a greater impact on the PPG signal. For example, the typical waveform characteristics of PPG, such as PPG waveform shape, main peak size, peak coordinates, etc., will affect the accuracy of health characteristics such as blood pressure detection by simply using PPG signal characteristics.

[0075] Therefore, the photoelectric signal collected by the embodiment of the present application integrates the blood flow characteristics in the blood vessels at multiple depths, so that the accuracy of the photoelectric signal is improved. In addition, since the SPG signal is not easily affected by the difference in the optical properties of the skin during the collection process, the problem of low accuracy of the photoelectric signal caused by the changes in the absorption and reflection characteristics of the light when penetrating the skin tissue due to factors such as ambient light, skin color, subcutaneous fat thickness, and motion artifacts in the electronic wearable device in the related art during the photoelectric signal collection process is avoided.

[0076] Based on the above Figure 3 The exemplary signal acquisition device includes two laser devices. In another possible implementation, the Figure 7As shown, the signal acquisition device may include three laser devices, that is, the signal acquisition device includes a printed circuit board 31, a light shielding plate 32, a signal acquisition device 33 and three laser devices 34. The light shielding plate 32 is arranged on the printed circuit board 31, the signal acquisition device 33 is arranged on the printed circuit board 31 through a first window A on the light shielding plate 32, and the three laser devices 34 are arranged on the printed circuit board 31 through a second window B on the light shielding plate 32. The three laser devices 34 each correspond to a different wavelength of a coherent light source, and each of the three laser devices 34 has the same shortest distance from the signal acquisition device 33 (e.g. Figure 7 As shown, L1=L2=L3), the three laser devices 34 are symmetrical with the center of the signal acquisition device 33.

[0077] In the embodiment of the present application, the wavelengths of the three coherent light sources need to have obvious distinction. Therefore, in one possible implementation, the wavelength range of the first coherent light source is between 600 and 1100 nm, the wavelength range of the second coherent light source is between 500 and 600 nm, and the wavelength range of the third coherent light source is between 350 and 500 nm, so that the three coherent light sources can be respectively incident on the aorta, arterioles and capillaries in the skin to collect the blood flow characteristics in the three blood vessels.

[0078] It should be noted that the above Figure 7 Three laser devices are used as an example for illustrative explanation. In other possible implementations, four, five, ten or more laser devices can be designed, and the wavelengths of the coherent light sources corresponding to the various laser devices are different, so that the coherent light sources of different wavelengths can be incident on the skin at different depths, respectively, so as to collect the blood flow characteristics at different depths, which is beneficial to the subsequent measurement and analysis of the blood flow conditions in the skin based on the collected photoelectric signals.

[0079] Based on the signal acquisition device provided in the above embodiment, the inventors found in further research that in addition to the different depths at which light of different wavelengths can be incident into the skin, the spacing (shortest distance) between the laser device and the signal acquisition device will also affect the proportion of optical signals detected by the signal acquisition device at different depths of the skin.

[0080] like Figure 8 As shown, Figure 8 Three coherent light sources with different shortest distances from the signal acquisition device are shown, namely coherent light source 1, coherent light source 2 and coherent light source 3. When the light from coherent light source 1, coherent light source 2 and coherent light source 3 enters the skin, the skin will form body scattering in the light path, thereby changing the light propagation path. That is, the optical path of the light from the coherent light source to the signal acquisition device will form a roughly curved propagation path in the human tissue, which can be called a banana-shaped optical path.

[0081] Further integration Figure 8 As shown, the light of the coherent light source 1, which is relatively close to the signal acquisition device, is scattered by the tissue after entering the skin, and the light that passes through the shallower skin tissue will be received by the signal acquisition device. As the distance between the coherent light source and the signal acquisition device increases, the light of the coherent light source can penetrate deeper skin tissue and be received by the signal acquisition device after passing through the banana-shaped optical path. That is, the greater the distance between the coherent light source and the signal acquisition device, the deeper its light penetrates the skin, but correspondingly, more light energy is absorbed by the skin tissue.

[0082] Therefore, based on the above research findings, combined with Fig. 9 As shown, the embodiment of the present application provides another signal acquisition device, which may include: a printed circuit board 31, a light baffle 32, a signal acquisition device 33 and N laser devices 34. The light baffle 32 is arranged on the printed circuit board 31, the signal acquisition device 33 is arranged on the printed circuit board 31 through a first window A on the light baffle 32, and the N laser devices 34 are arranged on the printed circuit board 31 through a second window B on the light baffle 32. Among them, the wavelength of the coherent light source corresponding to each laser device 34 is the same, and the shortest distance between each laser device 34 and the signal acquisition device 33 is different.

[0083] It should be noted that Fig. 9 The signal acquisition device includes two laser devices as an example for illustrative description, but the specific number of laser devices is not limited.

[0084] As an example, combining Fig.10 As shown, the spacing (shortest distance) between the first coherent light source and the signal acquisition device is L1, and the spacing between the second coherent light source and the signal acquisition device is L2. Among them, L1 is different from L2, and L1 < L2. After the light of the first coherent light source is incident on the skin, the light will be quickly scattered along the direction of the light path, and the light received by the signal acquisition device forms a banana-shaped light path K1. The photoelectric signal collected by the signal acquisition device includes the blood flow characteristics of the capillary layer. After the light of the second coherent light source is incident on the skin, the light received by the signal acquisition device forms a banana-shaped light path K2, and the photoelectric signal collected by the signal acquisition device includes the blood flow characteristics of the blood vessels in the arteriolar layer. It can be seen that the spacing between the coherent light source (which can also be understood as a laser device) and the signal acquisition device is positively correlated with the depth of the coherent light source incident on the skin. The larger the spacing, the deeper the depth of the light incident on the skin.

[0085] In one possible implementation, the spacing range between the first coherent light source and the signal acquisition device can be L1 < 0.6 mm, and the spacing range between the second coherent light source and the signal acquisition device can be 0.6 mm < L2 less than < 2.5 mm. Then, the first coherent light source can be used to collect the blood flow characteristics of the blood vessels in the capillary layer, and the second coherent light source can be used to collect the blood flow characteristics of the blood vessels in the arteriolar layer.

[0086] In another possible implementation, the spacing range between the first coherent light source and the signal acquisition device can be L1 < 0.6 mm, and the spacing range between the second coherent light source and the signal acquisition device can be L2 > 3 mm. Then, the first coherent light source can be used to collect the blood flow characteristics of the blood vessels in the capillary layer, and the second coherent light source can be used to collect the blood flow characteristics of the blood vessels in the aortic layer.

[0087] In another possible implementation, the spacing range between the first coherent light source and the signal acquisition device can be 0.6mm<L1<2.5mm, and the spacing range between the second coherent light source and the signal acquisition device can be L2>3mm. Then, the first coherent light source can be used to collect the blood flow characteristics of the blood vessels in the arteriolar layer, and the second coherent light source can be used to collect the blood flow characteristics of the blood vessels in the aortic layer.

[0088] It should be understood that the embodiments of the present application utilize the propagation characteristics of the banana-shaped optical path and control the light from different coherent light sources to pass through different skin depths by setting different shortest distances between each laser device and the signal acquisition device, so as to collect the blood flow characteristics of blood vessels at different depths. This can improve the accuracy of the photoelectric signal and further improve the accuracy of the measurement of physiological characteristics such as blood pressure, vascular elasticity, and pulse conduction velocity.

[0089] At the same time, the photoelectric signal collected by the embodiment of the present application integrates the blood flow characteristics in blood vessels at multiple depths, so that the accuracy of the photoelectric signal is improved, and the problem of low accuracy of the photoelectric signal is avoided, which is caused by factors such as ambient light, skin color, subcutaneous fat thickness and motion artifacts during the photoelectric signal collection process of electronic wearable devices in related technologies, due to changes in the absorption and reflection characteristics of light when penetrating skin tissue.

[0090] Based on the signal acquisition device provided in the above embodiment, combined with Fig.11As shown, in a possible implementation, the signal acquisition device may include a printed circuit board 31, a light shield 32, a signal acquisition device 33, and three laser devices 34. The light shield 32 is disposed on the printed circuit board 31. The signal acquisition device 33 is disposed on the printed circuit board 31 through a first window A on the light shield 32. The three laser devices 34 are disposed on the printed circuit board 31 through a second window B on the light shield 32. Among them, the wavelengths of the coherent light sources respectively corresponding to the three laser devices 34 are the same, and the shortest distances between the three laser devices 34 and the signal acquisition device 33 are different (such as Fig.11 the L1 < L2 < L3 shown), and the three laser devices 34 are centrosymmetric with respect to the signal acquisition device 33.

[0091] In a possible implementation, the spacing range from the first coherent light source to the signal acquisition device may be L1 < 0.6 mm, the spacing range from the second coherent light source to the signal acquisition device may be 0.6 mm < L2 < 2.5 mm, and the spacing range from the third coherent light source to the signal acquisition device may be L3 > 3 mm. Then, the first coherent light source is used to acquire the blood flow characteristics in the blood vessels of the capillary layer, the second coherent light source is used to acquire the blood flow characteristics of the blood vessels in the arteriole layer, and the third coherent light source is used to acquire the blood flow characteristics of the blood vessels in the aorta layer and the subcutaneous tissue.

[0092] As an example, in combination with Fig.12 shown, after the light of the first coherent light source enters the skin, the light will be rapidly scattered along the optical path traveling direction, and the light received by the signal acquisition device forms a banana-shaped optical path K1. The optoelectronic signal acquired by the signal acquisition device includes the blood flow characteristics of the capillary layer. After the light of the second coherent light source enters the skin, the light received by the signal acquisition device forms a banana-shaped optical path K2. The optoelectronic signal acquired by the signal acquisition device includes the blood flow characteristics of the blood vessels in the arteriole layer. After the light of the third coherent light source enters the skin, the light will be rapidly scattered along the optical path traveling direction, and the light received by the signal acquisition device forms a banana-shaped optical path K3. The optoelectronic signal acquired by the signal acquisition device includes the blood flow characteristics of the large artery layer and the subcutaneous tissue layer. It can be seen that the spacing between the coherent light source (which can also be understood as a laser device) and the signal acquisition device is positively correlated with the depth of the coherent light source incident on the skin. The larger the spacing, the deeper the depth of the light incident on the skin.

[0093] In this way, the embodiment of the present application utilizes the propagation characteristics of the banana-shaped optical path and controls the light from different coherent light sources to pass through different skin depths by setting different shortest distances between each laser device and the signal acquisition device, so as to collect the blood flow characteristics of blood vessels at different depths. This can improve the accuracy of the photoelectric signal and further improve the accuracy of the measurement of physiological characteristics such as blood pressure, vascular elasticity, and pulse conduction velocity.

[0094] Based on the signal acquisition device provided in the above embodiments, see Fig.13a The embodiment of the present application further provides a signal acquisition device, which may include a printed circuit board 31, a light shielding plate 32, a signal acquisition device 33 and a plurality of laser devices 34. The light shielding plate 32 is arranged on the printed circuit board 31, the signal acquisition device 33 is arranged on the printed circuit board 31 through a first window A on the light shielding plate 32, and the plurality of laser devices 34 are arranged on the printed circuit board 31 through a second window B on the light shielding plate 32. Among them, the plurality of laser devices 34 are arranged in a matrix form, the number of rows and columns of the matrix is ​​the same, the wavelengths of the coherent light sources generated by the laser devices 34 in the same row are the same, the wavelengths of the coherent light sources generated by the laser devices 34 in the same column are different, the shortest distances between the laser devices 34 in the same row and the signal acquisition device are different, and the shortest distances between the laser devices 34 in the same column and the signal acquisition device are the same.

[0095] It should be noted that in the embodiment of the present application, the plurality of laser devices are not limited to being arranged in a matrix form. Fig.13b As shown, multiple laser devices can also be arranged in an "H" shape; for example, in combination Fig.13c As shown, multiple laser devices can be arranged in a "pin" shape; for example, combined Fig.13d As shown, multiple laser devices can be arranged in a "mouth" shape; for example, combined with Fig.13e As shown, a plurality of laser devices may be arranged in a "z" shape, which is not limited here.

[0096] It should be understood that in the embodiment of the present application, multiple laser devices can be arranged in the form of a matrix, and coherent light sources with the same wavelength can be arranged from near to far according to the shortest distance from the signal acquisition device, and coherent light sources with different wavelengths can be arranged at equal distances from the signal acquisition device, so as to obtain richer and more detailed blood flow characteristics at different depths of the skin, further improving the accuracy and reliability of photoelectric signal acquisition.

[0097] Based on the signal acquisition device provided in the above embodiment, in a possible implementation manner, the positional relationship between the first window and the N second windows can be implemented in a variety of ways, see Figure 14a to Figure 14cThe signal acquisition device provided in the embodiment of the present application may be the signal acquisition device described in any of the above embodiments. The signal acquisition device provided in the embodiment of the present application may include a first window and N second windows, wherein the N second windows may be arranged as follows: Figure 14a to Figure 14c In the manner shown, each second window is arranged with the first window as the center, and the shortest distances between each second window and the first window are the same.

[0098] Each second window may include laser devices with the same wavelength and different shortest distances, and / or laser devices with different wavelengths and the same shortest distance, which is not specifically limited here. The shortest distance is the shortest distance between the laser device and the signal acquisition device. Fig.14a It is exemplarily shown that each second window includes laser devices with the same wavelength and different shortest distances, Fig.14b It is exemplarily shown that each second window includes laser devices with different wavelengths and the same shortest distance, Fig.14c It is exemplarily shown that a part of the plurality of second windows includes laser devices with the same wavelength and different shortest distances, and another part includes laser devices with the same wavelength and different shortest distances.

[0099] Based on the signal acquisition device provided in the above embodiment, combined with Fig.15 As shown, an embodiment of the present application provides a signal acquisition method, which is applied to the signal acquisition device described in any of the above embodiments. The method may include: Step 11: Control each laser device to close in sequence at a preset time interval to generate a corresponding coherent light source.

[0100] It should be understood that when the laser device is closed, a corresponding coherent light source will be generated, and the light of the coherent light source will be emitted into the skin.

[0101] The preset time interval refers to the time interval for closing each laser device, such as 10 seconds, 20 seconds, 25 seconds, etc., which is not specifically limited here.

[0102] Step 12: Collect photoelectric signals in sequence according to the closing order of each laser device.

[0103] Among them, the signal of the coherent light source corresponding to each laser device can be collected according to the collection time to obtain multiple photoelectric signals.

[0104] The preset time interval refers to the closing time interval between two laser devices, for example, 2 seconds, 3 seconds, etc.

[0105] The acquisition time refers to the time for collecting the photoelectric signal, and the acquisition time may be less than or equal to the time indicated by the preset time interval. For example, if the preset time interval is 2 seconds, the acquisition time may be 1 second. As a preferred implementation, the acquisition time may be less than the time indicated by the preset time interval to avoid inaccurate photoelectric signals caused by instability of the coherent light source at the initial moment.

[0106] As an example, each coherent light source is turned on in sequence, and the photoelectric signal is collected according to the collection time. The obtained photoelectric signal is S(k, m, n), where k represents the serial number of the coherent light source, m represents the serial number of the sampled signal frame, and n represents the serial number of each collection unit in the signal collection device. After the photoelectric signal corresponding to each coherent light source is collected, the next coherent light source is turned on and the photoelectric signal of the next cycle is collected. Fig.15 As shown, S(1, 2, 2) indicates that the serial number of the coherent light source is 1, the serial number of the sampled signal frame is 2, and the acquisition unit in the acquisition device is 2.

[0107] It should be understood that, since the signal acquisition device includes a plurality of acquisition units, the PPG signal and the SPG signal can be calculated respectively by the following formula (1) and formula (2): ;Formula (1) in, It represents the average value of the photoelectric signals collected by multiple collection units. It represents the sum of the photoelectric signals of the mth frame collected by 1 to n collection units, where n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 2.

[0108] ;Formula (2) in, Represents the standard deviation of the photoelectric signal.

[0109] Based on the signal acquisition method provided in the above embodiment, combined with Fig.16 As shown, an embodiment of the present application provides another signal acquisition method, which can be applied to the signal acquisition device described in any of the above embodiments. The method may include: Step 21: According to the order of each acquisition frame in the acquisition time, control each laser device to close in turn.

[0110] It should be understood that the acquisition time includes multiple acquisition frames, and each laser device is closed in sequence according to the order of the multiple acquisition frames. For example, the acquisition time includes n acquisition frames, and the signal acquisition device includes k laser devices, n is an integer greater than or equal to 2, and k is an integer greater than or equal to 1. When performing an action on each of the n acquisition frames, the 1st, 2nd, ..., kth acquisition devices are closed in sequence; if n is greater than k, the cycle is closed (1, 2, ..., k, 1, 2, ..., k-4, ...); if n is less than or equal to k, the k laser devices are closed in sequence until the n=kth laser device.

[0111] Step 22: Collect the photocapacitive signal corresponding to each acquisition frame through the signal acquisition device.

[0112] It should be understood that the embodiments of the present application can be applied to signal acquisition devices with high sampling rates, so that different coherent light sources can maintain the same test conditions as much as possible when collecting each frame of photoelectric signals, so as to reduce changes in human physiological parameters caused by changes in the human body itself and the external environment, and ensure the accuracy of the collected photoelectric signals.

[0113] Based on the signal acquisition method provided in the above embodiment, further combined Fig.17 As shown, Fig.17 A schematic diagram of the PPG signal and SPG signal collected based on any of the above signal collection methods is shown, combined with Fig.17 As shown, Fig.17 The horizontal axis represents time, and the vertical axis represents the blood flow velocity at different times (referred to as blood flow velocity). The higher the peak value, the faster the maximum blood flow velocity. Fig.17 It can be seen that the waveform of the collected SPG signal is similar to that of the collected PPG signal, but in certain time periods, the degree of change of the SPG signal is more prominent than that of the PPG signal, such as Fig.17 In the time period T, the SPG signal fluctuates more frequently within T than the PPG signal within T, which indicates that the SPG signal can capture more subtle changes in the blood. Compared with the PPG signal, the collected SPG signal is more accurate and reliable.

[0114] By using a variety of coherent light sources, the blood flow velocity V and velocity difference δV in blood vessels at different depths can be measured respectively, such as Fig.18 As shown, Fig.18 A in FIG. 1 is the waveform of blood flow velocity represented by SPG signal 1. Fig.18 B in FIG. 1 is the waveform of the blood flow velocity represented by SPG signal 2. The peak of SPG signal 1 is higher than that of SPG signal 2. The blood vessel depths collected by SPG signal 1 and SPG signal 2 are different. Fig.18It can be seen that there is a difference in the blood flow velocity in blood vessels at different depths, which is δV.

[0115] The blood flow velocity is closely related to the peripheral resistance, vascular elasticity, and physiological structure of the human body. By collecting SPG signals, the measurement accuracy of physiological characteristics such as blood pressure, vascular hardness, and pulse conduction velocity can be further improved.

[0116] In addition, since temperature changes have a significant impact on the blood perfusion and flow rate of each layer of human skin, and due to the body's own protection mechanism, the fluidity of the surface blood will be reduced in low-temperature scenes to avoid excessive heat loss. The PPG signal in the related art is difficult to accurately collect the changes in the surface blood vessels in low-temperature scenes, and the embodiment of the present application collects the blood flow characteristics of blood vessels at different depths through multiple coherent light sources, which can solve the problem of inaccurate collected signals caused by the reduced fluidity of the surface blood vessels in low-temperature scenes, and improve the accuracy of signal collection.

[0117] Based on the signal acquisition method provided in the above embodiment, after acquiring the photoelectric signal, the photoelectric signal can be further processed. In a possible implementation, Fig.19 As shown, taking three-channel acquisition as an example (i.e. including three laser devices), the photoelectric signals of the three channels are acquired through the signal acquisition device of any of the above embodiments. The photoelectric signals of the three channels can be blood information of the aorta, arterioles and capillaries respectively, and the acquisition process can be the signal acquisition method described in any of the above embodiments. Among them, in order to obtain stable and effective photoelectric signals, the acquisition time of the photoelectric signals collected in the embodiment of the present application can be greater than or equal to 30 seconds, and the signal sampling frame rate can be greater than or equal to 100 frames. After the acquisition of the digital signals is completed, the original signals of PPG and SPG can be parsed out respectively, which are PPG1, PPG2, PPG3, SPG1, SPG2, SPG 3 respectively.

[0118] After obtaining the three-channel PPG signal and SPG signal, you can process them according to the following process: Step 1: Preprocess the PPG signal and the SPG signal to obtain the processed PPG signal and the SPG signal.

[0119] Preprocessing refers to the processing of PPG signals and SPG signals, such as timestamp alignment, noise reduction, etc.

[0120] Timestamp alignment processing means aligning original signals with different timestamps to a unified time interval for subsequent analysis and processing. For example, the PPG original signals (PPG1, PPG2, PPG3) of the three channels are timestamp aligned; the SPG original signals (SPG1, SPG2, SPG3) of the three channels are timestamp aligned. In the embodiment of the present application, the timestamp alignment processing is an optional processing step, and the signal can also be directly subjected to noise reduction processing.

[0121] Noise reduction processing means reducing or eliminating unnecessary noise in the photoelectric signal, thereby improving the quality of the photoelectric signal. Since human physiological signals such as PPG signals and SPG signals are also affected by noise, noise reduction processing of photoelectric signals can extract more accurate feature information and provide an accurate basis for subsequent indicator evaluation.

[0122] Among them, the noise reduction processing can be achieved by filtering method, joint independent component analysis (JICA) method, wavelet transform method, blind source separation technology, Kalman filtering, principal component analysis (PCA), independent component analysis (ICA) and other technologies, without specific limitation here.

[0123] Step 3: Extract features of the processed PPG signal to obtain the parameters of the PPG signal.

[0124] Feature extraction processing refers to the process of extracting information or features useful for specific indicators from the processed PPG signal. As an example, the data features such as the PPG waveform peak value, valley value, replay wave peak value, descending isthmus amplitude, and pulse wave ascending branch slope of the three signals PPG1, PPG2, and PPG3 can be extracted from the processed PPG signal. In addition, since the propagation of the pulse wave in the blood vessels at different skin depths is delayed during the flow of blood from the artery to the capillary, the pulse wave peak phase delay δt12 between PPG1 and PPG2, the pulse wave peak phase delay δt13 between PPG1 and PPG3, and the pulse wave peak phase delay δt23 between PPG2 and PPG3 can also be extracted based on the processed PPG signal. Among them, the phase delay value is related to the diffusion rate of blood.

[0125] Step 4: Extract features of the processed SPG signal to obtain blood flow features corresponding to the SPG signal.

[0126] It should be understood that, since the SPG signal can directly characterize the blood flow velocity, the maximum value of the blood flow velocity of the blood vessels at each skin depth can be directly extracted according to the SPG signal as the blood flow feature. At the same time, according to the peak values ​​of the SPG signals of the three channels, the blood flow velocity difference feature can be further extracted, such as the blood flow velocity difference δt12 between SPG1 and SPG2, the blood flow velocity difference δt13 between SPG1 and SPG3, and the blood flow velocity difference δt23 between SPG2 and SPG3. The blood flow velocity difference can characterize the peripheral resistance of the blood vessels.

[0127] It should be understood that since the peak waveform of the SPG signal is sharper, compared with the PPG signal, a more accurate peak-to-peak interval value δT can be extracted to represent the pulsation period. At the same time, the SPG signal collected by the embodiment of the present application can provide more effective and necessary signal features. By sending these signal features into the algorithm calculation model, characteristic indicators such as heart rate, blood oxygen, PWV, cardiac output, peripheral vascular resistance, and vascular elasticity can be further calculated to improve the accuracy and reliability of the calculation of various indicators.

[0128] It should be noted that in the embodiment of the present application, the photoelectric signal collected by the signal acquisition device can be understood as the original photoelectric signal, for example, the collected PPG signal is the PPG original signal, and the collected SPG signal is the SPG original signal. The original signal processed by preprocessing can be understood as the processed photoelectric signal, for example, the PPG original signal is processed by preprocessing to obtain the processed PPG signal; the SPG original signal is processed by preprocessing to obtain the processed SPG signal. The features obtained after feature extraction of the processed photoelectric signal can continue to be represented in the form of a signal, for example, the parameters extracted from the processed PPG signal can be understood as a PPG signal, and the PPG signal is output.

[0129] It should also be noted that in the embodiments of the present application, only the PPG signal or the SPG signal may be collected, or the PPG signal and the SPG signal may be collected simultaneously, or the PPG signal may be collected first and then the SPG signal, or the SPG signal may be collected first and then the PPG signal, which is not specifically limited here. Furthermore, only the collected PPG signal may be processed, or only the collected SPG signal may be processed, or both the PPG signal and the SPG signal may be processed, which is not specifically limited here.

[0130] An embodiment of the present application also provides an electronic device, which includes one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the terminal to execute the aforementioned signal acquisition method.

[0131] It should be noted that the units / modules mentioned in the various device embodiments of the present application are all logical units / modules. Physically, a logical unit / module can be a physical unit / module, or a part of a physical unit / module, or can be implemented as a combination of multiple physical units / modules. The physical implementation method of these logical units / modules themselves is not the most important. The combination of functions implemented by these logical units / modules is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.

[0132] An embodiment of the present application also provides another electronic device, which includes a signal acquisition device as described in any of the above embodiments, for collecting a user's PPG signal or SPG signal.

[0133] It should be noted that the number of laser devices in the above-mentioned embodiments and drawings is only for illustrative purposes, and each embodiment or drawing does not limit the specific number of laser devices, nor can each embodiment or drawing be used as a basis for limiting the scope of protection of the present application.

[0134] The terms "first", "second", "third", etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to limit a specific order.

[0135] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0136] The technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment. The aforementioned storage medium includes: flash memory, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk, etc., various media that can store program codes.

[0137] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A signal acquisition device, characterized in that: include: A light shield, a signal collection device and N laser devices, wherein N is an integer greater than or equal to 2; the light shield comprises a first window and K second windows, wherein K is an integer greater than or equal to 1; the signal collection device is arranged in the first window, and the N laser devices are arranged in the K second windows; each of the N laser devices is used to generate a coherent light source; The signal acquisition device is used to collect photoplethysmography (PPG) signals and / or speckle plethysmography (SPG) signals; the PPG signal is obtained based on the coherent light source generated by each laser device; and the SPG signal is obtained based on the coherent light source generated by each laser device.

2. The signal acquisition device according to claim 1, characterized in that: The shortest distances between each of the laser devices and the signal acquisition device are equal, and the wavelengths of the coherent light sources generated by each of the laser devices are different.

3. The signal acquisition device according to claim 1, characterized in that: The shortest distances between each of the laser devices and the signal acquisition device are not equal, and the wavelengths of the coherent light sources generated by each of the laser devices are the same.

4. The signal acquisition device according to claim 1, characterized in that: When N is greater than or equal to 3, the N laser devices include P first laser devices and Q second laser devices; wherein the sum of P and Q is equal to N, P is an integer greater than or equal to 1, and Q is an integer greater than or equal to 1; The wavelengths of the first coherent light sources generated by the first laser devices are different, and the shortest distances between the first laser devices and the signal acquisition device are equal; The wavelength of the second coherent light source generated by each of the second laser devices is different from the wavelength of Y first coherent light sources; Y is an integer less than or equal to P, and Y is greater than zero.

5. The signal acquisition device according to claim 1, characterized in that: When K is greater than or equal to 2, the shortest distance between each of the K second windows and the first window is equal; and the P laser devices are arranged in the K second windows.

6. The signal acquisition device according to claim 1, characterized in that: The signal acquisition device comprises a plurality of acquisition units, and the plurality of acquisition units are arranged in a symmetrical array.

7. The signal acquisition device according to any one of claims 1 to 6, characterized in that: The signal acquisition device is a photodiode array device.

8. The signal acquisition device according to any one of claims 1 to 6, characterized in that: It also includes a printed circuit board, the light shielding plate is arranged on the printed circuit board, the signal acquisition device is arranged on the printed circuit board through the first window, and the N laser devices are arranged on the first surface of the printed circuit board through the K second windows.

9. The signal acquisition device according to claim 8, characterized in that: It also includes a protection plate, which is arranged at the positions of the first window and the K second windows on the first surface of the light blocking plate, and the second surface of the light blocking plate is in contact with the first surface of the printed circuit board.

10. A signal acquisition method, characterized in that: The method is applied to the signal acquisition device according to any one of claims 1 to 9, comprising: Controlling each laser device to close in sequence according to a preset time interval; According to the closing order of each of the laser devices, the photoplethysmography (PPG) signal and / or the speckle plethysmography (SPG) signal are collected in sequence.

11. The method according to claim 10, characterized in that The method further comprises: Acquire multiple PPG signals; each of the PPG signals is obtained based on a corresponding coherent light source; Performing noise reduction processing on each of the PPG signals to obtain a plurality of processed PPG signals; Based on the multiple processed PPG signals, parameters corresponding to each of the processed PPG signals are obtained.

12. The method according to claim 11, characterized in that The method further comprises: Acquire multiple SPG signals; each of the SPG signals is obtained based on a corresponding coherent light source; Performing noise reduction processing on each of the SPG signals to obtain a plurality of processed SPG signals; Feature extraction is performed on the multiple processed SPG signals to obtain blood flow features corresponding to each of the processed SPG signals.

13. A signal acquisition method, characterized in that: The method is applied to the signal acquisition device according to any one of claims 1 to 9, comprising: According to the order of each acquisition frame in the acquisition time, each laser device is controlled to close in turn; The photoplethysmography (PPG) signal and / or the speckle plethysmography (SPG) signal corresponding to each acquisition frame are acquired.

14. The method according to claim 13, characterized in that The method further comprises: Acquire multiple PPG signals; each of the PPG signals is obtained based on a corresponding coherent light source; Performing noise reduction processing on each of the PPG signals to obtain a plurality of processed PPG signals; Based on the multiple processed PPG signals, parameters corresponding to each of the processed PPG signals are obtained.

15. The method according to claim 13, characterized in that The method further comprises: Acquire multiple SPG signals; each of the SPG signals is obtained based on a corresponding coherent light source; Performing noise reduction processing on each of the SPG signals to obtain a plurality of processed SPG signals; Feature extraction is performed on the multiple processed SPG signals to obtain blood flow features corresponding to each of the processed SPG signals.

16. An electronic device, characterized in that: The electronic device comprises the signal acquisition device according to any one of claims 1-9.

17. An electronic device, characterized in that: include: Processor and memory; The processor is connected to the memory; Wherein, one or more computer programs are stored in the memory, and the one or more computer programs include instructions; when the instructions are executed by the processor, the electronic device executes the signal acquisition method as described in any one of claims 10-12, or executes the signal acquisition method as described in any one of claims 13-15.

18. A computer storage medium, characterized in that: It includes computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the signal acquisition method as described in any one of claims 10 to 12, or executes the signal acquisition method as described in any one of claims 13 to 15.

19. A computer program product, characterized in that When the computer program product runs on a computer, the computer executes the signal acquisition method according to any one of claims 10 to 12, or executes the signal acquisition method according to any one of claims 13 to 15.

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