Multispectral blood pressure imaging device and method

Abstract

The embodiment of the present application provides a multi-spectral blood pressure imaging device and method, which relates to the field of medical detection. The device includes: a functional layer for emitting white light to a preset skin part and collecting a multi-wavelength photoplethysmography pulse signal, also known as a MWPPG signal, from each first sampling point of the preset skin part; a control layer for respectively obtaining corresponding pixel values ​​according to the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and determining a target image according to the relative position of each first sampling point and the corresponding pixel value, the position of each pixel point in the target image corresponding to the relative position of the corresponding first sampling point. The device provided in the embodiment of the present application realizes the dimensional leap from one-dimensional signal to two-dimensional imaging in non-invasive dynamic blood pressure measurement based on optical imaging technology, providing multi-level reference value for the analysis of vascular status.

Description

Technical Field

[0001] The present application relates to the field of medical detection technology, and in particular to a multispectral blood pressure imaging device and method. Background Art

[0002] Authoritative reports indicate that cardiovascular disease has been the leading cause of death for the majority of people over the past 20 years. Consequently, the rapid increase in the number of patients suffering from cardiovascular diseases (CVDs) has become a public health crisis of considerable international concern. In 2020, approximately 19.1 million people died from cardiovascular disease worldwide, a 20.5% increase from 2010. This number is projected to rise to over 23 million by 2030. Among the various risk factors for CVDs, hypertension is a high-risk factor. Hypertension is often a "silent killer." For example, CVD patients often develop hypertension at night when unattended and, due to lack of further treatment, lack of access to appropriate care. Therefore, implementing non-invasive, cuff-free, and non-intrusive continuous blood pressure monitoring over a 24-hour period has become crucial for clinical treatment.

[0003] In addition, commonly used optical blood pressure measurement technologies include traditional photoplythysmography (PPG) technology, multiwavelength PPG (MWPPG) technology with the potential for single-point blood pressure measurement estimation, and camera-based blood pressure signal measurement technology. All of these technologies only provide simple one-dimensional blood pressure information, such as single-point blood pressure values, beat-by-beat blood pressure, and arterial blood pressure maps, and cannot provide more information reflecting the status of blood vessels. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a multispectral blood pressure imaging device and method to solve one of the above technical problems. To achieve this purpose, the embodiments of the present application provide the following solutions.

[0005] In one aspect, an embodiment of the present application provides a multispectral blood pressure imaging device, comprising:

[0006] The functional layer is used to emit white light to a preset skin part and collect MWPPG signals from each first sampling point of the preset skin part.

[0007] A control layer is configured to obtain corresponding pixel values ​​based on the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and to determine a target image based on the relative position of each first sampling point and the corresponding pixel value, wherein the position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point.

[0008] Optionally, the functional layer includes:

[0009] A plurality of preset light sources; each preset light source is used to emit white light.

[0010] Multiple optical sensors; each optical sensor is used to receive light signals of at least two wavelengths reflected from a preset skin site, and convert the light signals of each wavelength into their respective corresponding PPG signals to obtain a MWPPG signal corresponding to each optical sensor.

[0011] The optical sensors are distributed around the preset light source.

[0012] Optionally, each first sampling point has a corresponding optical sensor; and the control layer is specifically configured to:

[0013] An initial image is created; pixels corresponding to the corresponding optical sensors in the initial image are determined based on the relative position of each optical sensor among all optical sensors; pixel values ​​corresponding to each optical sensor are set at the corresponding pixel points, and the set initial image is determined as the target image.

[0014] Optionally, the substance in the functional layer that contacts the predetermined skin site includes a hydrogel; the hydrogel is used to adhere the functional layer to the predetermined skin site.

[0015] Optionally, the device further includes an isolation layer, which is located between the functional layer and the control layer. The isolation layer is used to isolate the sampling process of the functional layer from interference by various environmental data, where the environmental data includes ambient light and current signals generated by the functional layer.

[0016] Optionally, the functional layer is also used to:

[0017] Receive ECG signals collected from each second sampling point at a preset skin site; calculate pulse transit time based on each ECG signal and each MWPPG signal, and obtain blood pressure values ​​corresponding to multiple depths below the preset skin site based on each pulse transit time; determine pixel values ​​corresponding to the multiple depths based on the blood pressure values ​​corresponding to the multiple depths, and determine a target 3D image based on the pixel values ​​corresponding to the multiple depths; the position of each pixel point in the target 3D image corresponds to the relative position of the corresponding first sampling point.

[0018] On the other hand, an embodiment of the present application provides a multispectral blood pressure imaging method, the method comprising:

[0019] emitting white light toward a predetermined skin portion, and collecting MWPPG signals from each first sampling point at the predetermined skin portion;

[0020] A corresponding pixel value is obtained based on the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and a target image is determined based on the relative position of each first sampling point and the corresponding pixel value, wherein the position of each pixel point in the target image corresponds to the relative position of the corresponding first sampling point.

[0021] The beneficial effects of the technical solution provided by the embodiments of the present application are:

[0022] An embodiment of the present application provides a multispectral blood pressure imaging device, comprising a functional layer and a control layer. After the functional layer emits white light to a predetermined skin region, it collects MWPPG signals based on the reflected light. The control layer then collects MWPPG signals from each first sampling point at the predetermined skin region and obtains corresponding pixel values. Each pixel value can represent both the blood pressure value determined by the corresponding MWPPG signal and the corresponding MWPPG signal. After obtaining the pixel values, the control layer determines a target image based on the relative position of each first sampling point and the corresponding pixel value. The position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point. Finally, a display operation can be performed based on the target image. The key to the device provided by the embodiment of the present application is to obtain optical information reflected by white light after it penetrates the skin and to create an image based on this optical information. This image can represent information about tissues and blood vessels distributed under the skin, such as a spatial distribution map of local vascular wall pressure, a map of vascular diameter changes, and a dynamic visual map of vascular boundary distribution. Compared with traditional optical technology used for blood pressure measurement, the non-invasive dynamic blood pressure measurement based on optical imaging technology provided by this solution achieves a dimensional leap from one-dimensional signals to two-dimensional imaging, providing multi-level reference value for the analysis of vascular status. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments of the present application.

[0024] Figure 1 A schematic diagram of the structure of a device for measuring a photoplethysmography signal provided in an embodiment of the present application;

[0025] Figure 2 A schematic structural diagram of the functional layers in the device for measuring photoplethysmography signals provided in an embodiment of the present application;

[0026] Figure 3 Schematic diagram of the application scenario of the TCS34725 color sensor provided in the embodiment of the present application;

[0027] Figure 4A schematic diagram of a process for estimating blood pressure based on MWPPG-PTT provided in an embodiment of the present application;

[0028] Figure 5 A schematic structural diagram of a multispectral blood pressure imaging device provided in an embodiment of the present application;

[0029] Figure 6 A schematic diagram of the structure of the functional layers in the multispectral blood pressure imaging device provided in an embodiment of the present application;

[0030] Figure 7 A schematic diagram of an application scenario of the multispectral blood pressure imaging device provided in an embodiment of the present application;

[0031] Figure 8 A schematic diagram of the imaging process of the multispectral blood pressure imaging device provided in an embodiment of the present application;

[0032] Figure 9 These are the three images created by the multispectral blood pressure imaging device provided in the embodiments of the present application;

[0033] Figure 10 A flowchart of an image reconstruction algorithm provided in an embodiment of the present application;

[0034] Figure 11 A schematic diagram of the principle of adjusting pixel brightness in a screen provided in an embodiment of the present application;

[0035] Figure 12 A schematic flow chart of 3D imaging of dorsal blood vessels is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present application in conjunction with the accompanying drawings. It should be understood that the embodiments described below in conjunction with the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0037] Those skilled in the art will understand that, unless otherwise stated, the singular forms "a", "an", "said", and "the" used herein may also include plural forms. It should be further understood that the terms "including" and "comprising" used in the embodiments of the present application mean that the corresponding features can be implemented as the presented features, information, data, steps, operations, elements, and / or components, but do not exclude implementation as other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by the present technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or it can refer to the element and the other element establishing a connection relationship through an intermediate element. In addition, the "connection" or "coupling" used here can include wireless connection or wireless coupling. The term "and / or" used here indicates at least one of the items defined by the term, for example, "A and / or B" can be implemented as "A", or as "B", or as "A and B".

[0038] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0039] First, several terms involved in this application are introduced and explained:

[0040] A tonoarteriogram (TAG) is a graphical record of a continuous arterial blood pressure signal, which can be obtained using a non-intrusive, wearable, or cuffless continuous arterial blood pressure measurement device.

[0041] Optical sensor: collects light signals and converts them into current signals for output.

[0042] Photoplethysmography (PPG): When light passes through skin tissue and reflects back to the optical sensor, it experiences a certain degree of attenuation due to absorption by the skin. Light absorption by muscle, bone, veins, and other connective tissues remains essentially constant (assuming the measurement site does not move significantly). However, blood, however, experiences variations in light absorption due to the flow of blood through arteries. When light is converted into an electrical signal, the resulting signal can be divided into a direct current (DC) and an alternating current (AC) signal, precisely because arterial absorption varies while absorption by other tissues remains largely unchanged. Extracting the AC signal reveals the characteristics of blood flow. This technology is called photoplethysmography, or PPG. These DC and AC signals can be understood as PPG signals.

[0043] After collecting the PPG signals corresponding to light of different wavelengths, all PPG signals can be combined to obtain the MWPPG signal.

[0044] The following describes several exemplary embodiments to illustrate the technical solutions of the embodiments of the present application and the technical effects produced by the technical solutions of the present application. It should be noted that the following embodiments can refer to, draw on, or combine with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be repeated.

[0045] Figure 1 FIG. 1 shows a device 10 for measuring a photoplethysmography signal provided by an embodiment of the present application. Figure 1 As shown, the device 10 includes a protective shell (including a protective shell 1 and a protective shell 2 ), a functional layer 110 and a control layer 120 .

[0046] The functional layer 110 includes white light LEDs and RGB photodetectors. Specifically, the white light LED is used to emit white light; the RGB photodetector is an optical sensor that can collect red light signals, green light signals, and blue light signals. There are various layout structures for the number and arrangement of white light LEDs and RGB photodetectors in the functional layer, including but not limited to Figure 2 The four layout structures are shown.

[0047] The control layer 120 includes various components and wiring information between the components.

[0048] After a white LED emits white light into the skin, the light detection units of the RGB photodetector collect the light signals reflected by the skin and convert each wavelength of light signal into a corresponding PPG signal. The individual PPG signals are then combined to create the MWPPG signal. The MWPPG signal is then sent to the control layer, where it is used to estimate multi-parameter physiological information, such as blood pressure, blood oxygen, and respiratory rate.

[0049] Since white light can reach a depth of about 2 mm from the surface of the skin, which includes tissues such as blood vessels, the MWPPG signal can reflect the information of blood vessels at a depth of about 2 mm from the surface.

[0050] In order to more clearly understand the process of the RGB photodetector generating the MWPPG signal, the embodiment of the present application also provides a device 20 with a TCS34725 color sensor (ie, an RGB photodetector) as an example to observe blood pressure and other information through the TCS34725 color sensor. Figure 3 .

[0051] In this example, the device 20 includes an Arduino Uno development board, a TCS34725 color sensor, and DuPont cables. The TCS34725 color sensor includes a white LED and an RGB photodetector. The Arduino Uno development board is connected to the TCS34725 color sensor via multiple DuPont cables. Furthermore, the Arduino Uno development board is connected to a PC via USB or a wireless module, allowing code written on the PC to be input into the Arduino Uno development board.

[0052] In this example, the Arduino Uno development board is configured with the following code.

[0053]

[0054] The logic for tcs.getRawData(&r,&g,&b,&c) in "Adafruit_TCS34725.h" is as follows: The RGB photodetector collects raw data corresponding to red, green, and blue light, such as the values ​​R, G, and B. These values ​​are then processed using the RGB-to-HIS conversion formula to obtain color information. Table 1 below provides the RGB-to-HIS conversion formula, which uses the values ​​R, G, and B to determine hue, saturation, and brightness.

[0055] Table 1

[0056]

[0057] Among them, the waveforms corresponding to red light, green light and blue light can also be smoothed to obtain good MWPPGs signals (including the PPG signal corresponding to red light, the PPG signal corresponding to green light and the PPG signal corresponding to blue light).

[0058] This example also provides a method to estimate blood pressure based on MWPPG, such as Figure 4 As shown. Wherein, MWPPG_PTT can be the vertex of a red PPG signal and a green PPG signal multiplied by the rate divided by the distance (D) between the red light detection unit and the green light detection unit in the RGB photodetector. Wherein, Figure 4 The process shown involves the following four formulas.

[0059] MBP=HR*(k1*MWPPG_PTT+b1); / / Formula 1

[0060]

[0061]

[0062]

[0063] Where HR (heart rate) is the heart rate; k1, k2, b1, and b2 are dependent variables, which can be calculated by substituting various PPG signals into the above formula. SBP0, DBP0, PP0, MBP0, and the corresponding PTT0 can be measured and calibrated using a blood pressure cuff. MWPPG_PTT is calculated based on PTT = D / PWV (where D is the distance between the red and green light detection units in the RGB photodetector) and PWV (Pulse Wave Velocity).

[0064] Among them, SBP is systolic blood pressure and DBP is diastolic blood pressure.

[0065] Based on the principles of the apparatus for collecting MWPPG signals in the above embodiments, the present application further proposes an embodiment of an apparatus for multispectral blood pressure imaging using multiple RGB photodetectors. Specifically, one or more white light LEDs can be used as light emitters, and one or more RGB photodetectors can be used as light receivers. The light signal reflected by the white light penetrating the skin is converted into an electrical signal. Then, through image reconstruction processing, various blood pressure maps can be obtained in the form of two-dimensional images.

[0066] like Figure 5 As shown, the multispectral blood pressure imaging device 50 includes:

[0067] The functional layer 510 is used to emit white light to a preset skin part and collect MWPPG signals from each first sampling point of the preset skin part.

[0068] The control layer 530 is configured to obtain corresponding pixel values ​​based on the MWPPG signal collected at each first sampling point, where each pixel value represents a blood pressure value determined by the corresponding MWPPG signal, or represents the corresponding MWPPG signal; and to determine a target image based on the relative position of each first sampling point and the corresponding pixel value, where the position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point.

[0069] In a possible implementation of this embodiment, the device 50 may further include an isolation layer 520 and a display layer 540. The isolation layer 520 is located on one side of the control layer 530 and is adjacent to the functional layer 510, while the display layer 540 is located on the other side of the control layer 530.

[0070] Specifically, the isolation layer is located between the functional layer 510 and the control layer 530 . The isolation layer 520 is used to isolate the sampling process of the functional layer 510 from interference by various environmental data, including ambient light and current signals generated by the functional layer 510 .

[0071] In a possible implementation of this embodiment, the functional layer 510 may include the following multiple units.

[0072] A plurality of preset light sources, each of which is configured to emit white light, such as a white light LED.

[0073] Multiple optical sensors; each optical sensor is used to receive light signals of at least two wavelengths reflected from a preset skin site, and convert the light signals of each wavelength into respective PPG signals to obtain MWPPG signals corresponding to each optical sensor. For example, the optical sensor can be an RGB photodetector that receives red light, green light, and blue light, that is, the at least two wavelengths include wavelengths corresponding to red light, green light, and blue light. Among them, the wavelength of red light is 625nm to 740nm, the wavelength of green light is 577nm to 492nm, and the wavelength of blue light is 400nm to 450nm. In addition, the at least two wavelengths can also include wavelengths corresponding to NIR (Near Infrared). The light signals of at least two wavelengths can be the ones listed above, or other wavelengths, and the present application does not limit this.

[0074] The optical sensors are distributed around the preset light source.

[0075] See for example Figure 6 There are many ways to arrange the functional layer 510, the preset light source and the optical sensor, including but not limited to Figure 6 Several layouts are shown.

[0076] In a possible implementation of this embodiment, the substance in the functional layer 510 that contacts the predetermined skin site includes a hydrogel; and the hydrogel is used to adhere the functional layer 510 to the predetermined skin site.

[0077] Specifically, the functional layer 510 needs to be well adhered to the skin, so a flexible material with good adhesion effect, such as hydrogel, can be used. Hydrogel is an elastic hybrid and can include a bioadhesive. Hydrogel can be adhered to various parts of the body, including but not limited to the ears, neck, wrists, fingers and nails, such as Figure 7 In each application scenario, long-term continuous detection and blood pressure imaging can be achieved.

[0078] In a possible implementation of this embodiment, each first sampling point has a corresponding optical sensor; the control layer 530 is specifically configured to perform the following steps Sa1 to Sa3 in determining the target image according to the relative position of each first sampling point and the corresponding pixel value.

[0079] Sa1, creating an initial image. Specifically, the size of the initial image is determined according to the layout of all optical sensors in the functional layer 510, that is, the number and arrangement of pixels included in the initial image are determined, so that the pixels matching each optical sensor are determined in the initial image.

[0080] Sa2, determining a pixel point in the initial image corresponding to the corresponding optical sensor according to the relative position of each optical sensor among all optical sensors.

[0081] Sa3, setting the pixel value corresponding to each optical sensor at the corresponding pixel point, and determining the set initial image as the target image.

[0082] The pixel point can be understood as the smallest unit pixel of the image.

[0083] In order to more clearly understand the specific process of determining the target image, the embodiment of the present application further provides an example. In this example, the target image is a blood vessel diameter change graph.

[0084] like Figure 8 In the illustrated process, the microcontroller first drives the LED array to emit white light. The RGB photodetector array (RGB photodetectors are optical sensors) then receives the reflected light and processes it through a transmembrane amplifier, converting the light into a photocurrent. The resulting photocurrent is then passed to the filter, analog-to-digital converter, and microcontroller in the control layer 530 for processing, resulting in an RGB array unit. Each RGB in the array represents a pixel value. An initial image is created based on the RGB array units, and each RGB value is assigned to the corresponding pixel in the initial image, ultimately yielding the target image.

[0085] This description demonstrates that the pixels in the target image correspond to the RGB photodetectors, enabling, to a certain extent, information about the vascular status at a predetermined skin location. For example, if the pixel values ​​represent blood pressure, the target image can be a spatial distribution map of local vascular wall pressure. For example, if the pixel values ​​represent MWPPG signals, the chromaticity information of the pixel values ​​reflects certain morphological features of the blood vessels, such as vascular boundaries, and the target image can be a vascular boundary distribution map. For example, if the pixel values ​​represent a specific PPG signal within the MWPPG signal, the target image can be a map of vascular diameter changes.

[0086] Since RGB photodetectors correspond to pixels on the target image, but the number of RGB photodetectors is limited after all, the resulting image still has problems such as image blur, low quality, and lack of interest.

[0087] In order to solve this problem, this example also includes image processing of the low-resolution target image through an image reconstruction algorithm to obtain a high-resolution image. The specific process of the image reconstruction algorithm can be as follows: first, the input low-resolution image is pre-processed by denoising, upsampling, etc. through feature extraction, including spatial component features such as brightness and chrominance, and then interpolation operations are performed to scale the image. The processed image is then sent to the neural network to fit the nonlinear features in the image, enter the convolution layer, pooling layer, and fully connected layer to extract high-frequency information representing image details, reconstruct the image, and obtain a high-resolution image. Figure 8 As shown, finally the high-resolution image is displayed on the screen of the mobile terminal.

[0088] The display effect on the mobile terminal display interface can be referred to Figure 9 .in, Figure 9 (1) shows the spatial distribution of local blood vessel wall pressure. Figure 9 (2) shows the blood vessel boundary distribution map, and Figure 9 (3) shows the change in blood vessel diameter.

[0089] In addition, this example also uses the image reconstruction algorithm to process the blood vessel diameter change map as an example to illustrate the specific implementation process of the algorithm. Figure 10 shown.

[0090] Generally speaking, the color of each pixel on an image is a mixture of color blocks corresponding to the three primary color channels. When displaying a pixel in an image, the color blocks corresponding to the three primary color channels are mixed to obtain the pixel. For example, a general color image includes an R channel (red color block), a G channel (green color block), and a B channel (blue color block). In an embodiment of the present application, red light, green light, and blue light are collected by RGB photodetectors and converted into their respective corresponding PPG signals. The PPG signal corresponding to red light is then converted into the value of the R channel, the PPG signal corresponding to green light is converted into the value of the G channel, and the PPG signal corresponding to blue light is converted into the value of the B channel, and then combined to obtain a pixel value. Finally, when displaying according to the pixel value, the display brightness on the screen can be adjusted by the specific values ​​of each channel. For example Figure 11 As shown in Figure 1, the conversion process from red light, green light, and blue light collected from an RGB photodetector to a pixel displayed on the screen. Bout is the voltage value corresponding to blue light; V Gout is the voltage value corresponding to green light; V Rout is the voltage value corresponding to red light.

[0091] In a possible implementation of this embodiment, the functional layer 510 may also be used to perform the following steps Sb1 to Sb3.

[0092] Sb1, receiving ECG signals collected from each second sampling point at a preset skin part.

[0093] Each second sampling point corresponds to an ECG electrode, which is used to measure the ECG signal at a preset skin site.

[0094] Sb2, calculating the pulse transit time based on each ECG signal and each MWPPG signal, and obtaining blood pressure values ​​corresponding to multiple depths under a preset skin location according to each pulse transit time.

[0095] Sb3, determining pixel values ​​corresponding to the multiple depths according to the blood pressure values ​​corresponding to the multiple depths, and determining a target 3D image according to the pixel values ​​corresponding to the multiple depths; the position of each pixel point in the target 3D image corresponds to the relative position of the corresponding first sampling point.

[0096] The steps Sb1 to Sb3 are actually a sampling group consisting of a first sampling point and a second sampling point, which samples a preset skin part to obtain detailed information representing the blood pressure in the blood vessels at various depths below the preset skin part.

[0097] like Figure 12 In the example scenario shown, multiple sampling groups can be set up on the back of a person. Based on these sampling groups, the corresponding blood pressure distribution at each depth level below the back can be obtained. Specifically, an ECG sampling array corresponding to the second sampling point and an RGB photodetector array corresponding to the first sampling point are set up to collect MWPPG signals from the first sampling point and ECG signals from the second sampling point, respectively. PTT is calculated based on the MWPPG and ECG signals, and 3D imaging is performed based on all PTTs. The corresponding blood pressure value is obtained based on each PTT, and 3D imaging is performed based on all blood pressure values.

[0098] Based on the above-mentioned multispectral blood pressure imaging device, the embodiment of the present application further provides a multispectral blood pressure imaging method, which includes the following steps Sc1 to Sc2.

[0099] Sc1, emitting white light to a preset skin part, and collecting MWPPG signals from each first sampling point of the preset skin part.

[0100] Sc2, obtaining corresponding pixel values ​​based on the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and determining a target image based on the relative position of each first sampling point and the corresponding pixel value, wherein the position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point.

[0101] The terms "first," "second," "third," "fourth," "1," "2," and the like (if any) in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the application described herein can be implemented in an order other than that shown or described in the drawings.

[0102] It should be understood that, although each operation step is indicated by arrows in the flowchart of the embodiment of the present application, the order of implementation of these steps is not limited to the order indicated by the arrows. Unless otherwise clearly stated herein, in some implementation scenarios of the embodiment of the present application, the implementation steps in each flowchart can be performed in other orders according to demand. In addition, some or all of the steps in each flowchart can include multiple sub-steps or multiple stages based on actual implementation scenarios. Some or all of these sub-steps or stages can be executed at the same time, and each sub-step or stage in these sub-steps or stages can also be executed at different times respectively. Under different scenarios at the execution time, the execution order of these sub-steps or stages can be flexibly configured according to demand, and the embodiment of the present application does not limit this.

[0103] The above description is only an optional implementation method for some implementation scenarios of this application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the solution of this application, the use of other similar implementation methods based on the technical ideas of this application also falls within the protection scope of the embodiments of this application.

Claims

1. A multispectral blood pressure imaging device, characterized in that: The device comprises: The functional layer includes a plurality of preset light sources, each of which is a white light LED, and each of the preset light sources is configured to emit white light toward a preset skin portion and collect MWPPG signals from each first sampling point of the preset skin portion; a control layer, configured to respectively obtain corresponding pixel values ​​based on the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and determine a target image based on the relative position of each first sampling point and the corresponding pixel value, wherein the position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point; Wherein, when the pixel value is a blood pressure value, the target image is specifically a spatial distribution map of local blood vessel wall pressure.

2. The device according to claim 1, characterized in that The functional layer further comprises: A plurality of optical sensors; each of the optical sensors is configured to receive light signals of at least two wavelengths reflected from the predetermined skin portion, and convert the light signals of each wavelength into respective corresponding PPG signals to obtain MWPPG signals corresponding to each optical sensor; Wherein, the optical sensors are distributed around the preset light source.

3. The device according to claim 2, characterized in that Each of the first sampling points has a corresponding optical sensor; and the control layer, in determining the target image according to the relative position and corresponding pixel value of each of the first sampling points, is configured to: Create the initial image; Determining a pixel point in the initial image corresponding to the corresponding optical sensor according to the relative position of each optical sensor among all optical sensors; The pixel value corresponding to each of the optical sensors is set at the corresponding pixel point, and the set initial image is determined as the target image.

4. The device according to claim 2, characterized in that The substance in the functional layer that contacts the predetermined skin part includes a hydrogel; the hydrogel is used to adhere the functional layer to the predetermined skin part.

5. The device according to any one of claims 1 to 4, characterized in that: The device also includes an isolation layer, which is located between the functional layer and the control layer. The isolation layer is used to isolate the sampling process of the functional layer from interference caused by various environmental data, including ambient light and current signals generated by the functional layer.

6. The device according to claim 2, characterized in that The functional layer is also used to: receiving ECG signals collected from each second sampling point at the preset skin part; Calculating pulse transit time based on each of the ECG signals and each of the MWPPG signals, and obtaining blood pressure values ​​corresponding to a plurality of depths below the preset skin location according to each of the pulse transit times; Pixel values ​​corresponding to the multiple depths are determined based on the blood pressure values ​​corresponding to the multiple depths, and a target 3D image is determined based on the pixel values ​​corresponding to the multiple depths; the position of each pixel point in the target 3D image corresponds to the relative position of the corresponding first sampling point.

7. A multispectral blood pressure imaging method, characterized in that: The method comprises: Multiple preset light sources emit white light to preset skin parts, and collect MWPPG signals from each first sampling point of the preset skin parts; wherein the preset light sources are white light LEDs; Obtaining corresponding pixel values ​​according to the MWPPG signal collected at each first sampling point, each pixel value representing a blood pressure value determined by the corresponding MWPPG signal, or representing the corresponding MWPPG signal; and determining a target image according to the relative position of each first sampling point and the corresponding pixel value, wherein the position of each pixel in the target image corresponds to the relative position of the corresponding first sampling point; Wherein, when the pixel value is a blood pressure value, the target image is specifically a spatial distribution map of local blood vessel wall pressure.

Images