Signal generation method for video photoelectric volume pulse wave detection and evaluation and related device

Abstract

The invention belongs to an evaluation signal generation method, and aims to solve the technical problems that non-contact detection or non-invasive detection including an existing video photoelectric volume pulse wave detection technology lacks an effective signal evaluation method and evaluation device, and direct and accurate measurement is difficult to perform by depending on known signals. The invention provides a signal generation method for video photoelectric volume pulse wave detection and evaluation and a related device, which are used for respectively generating known ambient light signals, skin color signals and blood flow signals which are very important for video photoelectric volume pulse wave detection. Photoelectric volume pulse wave characteristic wavelength information is generated from the generated blood flow signals according to photoelectric volume pulse wave signal characteristics; then generating a visible light signal which can be displayed by a color LED display device according to a colored light superposition principle by visible light parts in the obtained ambient light signal, the skin color signal and the blood flow signal; and the characteristic wavelength signal and the visible light display signal are displayed in a time-sharing manner.

Description

Technical Field

[0001] This application pertains to a method for generating evaluation signals, specifically relating to a method and apparatus for generating signals for video photoplethysmography (PPG) wave detection and evaluation. Background Technology

[0002] Physiologically, pigments such as melanin and carotene, which affect skin color, absorb visible light, while melanin also reflects near-infrared light. Therefore, the personalized and dynamically changing skin color, especially skin pigmentation, primarily affects photoplethysmography (PPG) detection by enhancing the absorption of visible and near-infrared light, altering scattering characteristics, and decreasing the signal-to-noise ratio, waveform distortion, and detection depth. Melanin, in particular, has a strong absorption capacity for both visible and near-infrared light. The size and spatial distribution of melanin particles not only affect skin color but also alter the light propagation path in the skin, increasing the optical path length. Both of these factors combined lead to a significant decrease in the signal-to-noise ratio. Furthermore, due to the non-uniformity of light absorption and scattering, the detected signal waveform amplitude may change, and the peak and trough positions may shift, ultimately affecting the accurate measurement of physiological parameters such as heart rate and blood oxygen saturation by video PPG detection technology.

[0003] Chinese invention patent CN108606801A discloses a PPG technology multispectral skin color calibration and power consumption optimization device and method, which can use a dual-color cursor to calibrate skin color. Chinese invention patent CN112168171A discloses a skin color detection method and device based on wearable pulse signals, which uses the DC signal of a reflected photoplethysmography (PPG) wave signal to obtain skin color information. Both of these methods assume that the spatial distribution of skin pigment is static and does not need to consider individual differences. Clearly, these simulation methods do not match the current understanding of large-scale dynamic changes in skin color and cannot meet the rapidly developing needs of PPG waves, especially video-based PPG waves, for non-contact and accurate detection. Therefore, it is necessary to find and develop new methods and devices for designing and generating known evaluation signals to accurately evaluate the detection quality of PPG wave signals, including video PPG waves. Summary of the Invention

[0004] This application addresses the technical problem that existing non-contact or non-invasive detection technologies, including video photoplethysmography (PPG) detection, lack effective evaluation signal methods and devices, making it difficult to perform direct and accurate measurements based on known signals. It provides a signal generation method and related devices for video PPG detection and evaluation.

[0005] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application proposes a signal generation method for video photoplethysmography (PPG) detection and evaluation, comprising: Generate ambient light signals that can be displayed on a color LED display device; Generate skin color signals that can be displayed on a color LED display device; Generate blood flow signals with given geometric and hemodynamic features; The characteristic wavelength information of the photoplethysmography (PPG) wave signal is obtained from the blood flow signal; Based on the ambient light signal, skin color signal, and characteristic wavelength information, a visible light display signal that can be displayed by an LED display device is generated according to the principle of color light superposition. The characteristic wavelength information and the visible light display signal are displayed in a time-division manner.

[0006] Furthermore, the ambient light signal includes photometric features and colorimetric features.

[0007] Furthermore, the skin color signal includes photometric features and colorimetric features.

[0008] Furthermore, the photometric characteristics include luminous flux, luminous intensity, luminous brightness, and illuminance; The colorimetric characteristics include hue, lightness, and saturation.

[0009] Furthermore, the characteristic wavelength information includes at least one visible light characteristic wavelength and at least one near-infrared light characteristic wavelength.

[0010] Furthermore, the visible light characteristic wavelength is 660nm, and the near-infrared light characteristic wavelength is 940nm.

[0011] Secondly, this application proposes a signal generation system for video photoplethysmography (PPG) detection and evaluation, comprising: An ambient light generation module is used to generate ambient light signals that can be displayed by a color LED display device; Skin color generation module, used to generate skin color signals that can be displayed by a color LED display device; The photoplethysmography (PPG) pulse wave signal feature generation module is used to generate blood flow signals with given geometric and hemodynamic features. The visible light signal generation module is used to obtain characteristic wavelength information of the photoplethysmography (PPG) wave signal from the blood flow signal; The display generation module is used to generate a visible light display signal that can be displayed by an LED display device based on the ambient light signal, skin color signal and characteristic wavelength information, according to the principle of color light superposition. The display module is used to display the characteristic wavelength information and the visible light display signal in a time-division manner.

[0012] Furthermore, in the display module, each pixel includes a three-color LED, at least one visible light photoplethysmography (PPG) characteristic wavelength LED, and at least one near-infrared PPG characteristic wavelength LED.

[0013] Thirdly, this application proposes an electronic device, including: a memory and one or more processors; the memory is coupled to the processors; wherein the memory stores computer program code, the computer program code including computer instructions, and when the computer instructions are executed by the processor, the electronic device performs the steps of the above-described signal generation method for video photoplethysmography detection and evaluation.

[0014] Fourthly, this application proposes a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-described signal generation method for video photoplethysmography (PPG) detection and evaluation.

[0015] Compared with the prior art, this application has the following beneficial effects: This application proposes a signal generation method for video photoplethysmography (PPG) detection and evaluation. This method utilizes software or hardware algorithms to generate ambient light, skin color, and blood flow signals, respectively generating known signals crucial for PPG detection. PPG signal feature generation then extracts PPG characteristic wavelength information from the generated blood flow signals. Next, the visible light components of the obtained ambient light, skin color, and blood flow signals are used to generate visible light signals suitable for display on a color LED display device, based on the principle of color superposition. The characteristic wavelength signals and visible light display signals are then displayed in a time-division manner. This application expands each visible light composite pixel in a conventional LED display device from a three-primary-color composite pixel to a visible-near-infrared pixel comprising three primary colors and multiple characteristic wavelength LEDs, including at least one near-infrared wavelength. This enables the simultaneous and time-division display of the visible light components of programmably generated ambient light, skin color, and blood flow signals, as well as the characteristic wavelength information of PPG signals. This allows for the accurate generation and display of the visible light components of ambient light, skin color, and blood flow signals, and the characteristic wavelength information of PPG signals. This solution addresses the problem of accurately describing the visible light portion of ambient light, skin color, and blood flow signals using a single wavelength, as the individual wavelengths of the three primary colors generated during color superposition are no longer definite single wavelengths. It also solves the problem of simultaneously and time-divisionally displaying visible and near-infrared light, extending the signal generation range for ambient and skin color signals from the original visible light band to the near-infrared band. It can be used for accurate evaluation of the detection quality of photoplethysmography (PPG) signals, including video PPG signals.

[0016] This application also proposes a signal generation system for video photoplethysmography (PPG) detection and evaluation, an electronic device, and a computer storage medium, which possess all the advantages of the aforementioned signal generation method for video PPG detection and evaluation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The Luschan skin tone chart is used in standard applications. Figure 2 The classification criteria for the Luschan skin color table; Figure 3 This is the standard Hintze skin tone chart; Figure 4 A schematic diagram of the color space; Figure 5 A schematic diagram of the RGB and CMYK color spaces; Figure 6 This is a diagram illustrating the color mixing process in RGB and CMYK modes. Figure 7 This is a schematic diagram showing the relationship between the molar extinction coefficients of deoxyhemoglobin and oxyhemoglobin and wavelength. Figure 8 This is a flowchart of the signal generation method for video photoplethysmography (PPG) detection and evaluation in this application. Figure 9 This is a system structure diagram of the signal generation device used for video photoplethysmography (PPG) detection and evaluation in this application. Figure 10 This is a timing diagram illustrating the generation of evaluation signals in an embodiment of this application; Figure 11 This is a schematic diagram of the pixel arrangement in the visible light display and characteristic wavelength generation module for evaluating the signal in an embodiment of this application. Figure 12 This is a schematic diagram of a signal generation system used for video photoplethysmography (PPG) detection and evaluation according to this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of this application, it should be noted that if terms such as "upper," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Photoplethysmography (PPG) contains a wealth of physiological information, including heart rate, respiration, heart rate variability, and blood oxygen saturation. The technology has rapidly evolved from single-wavelength and dual-wavelength detection to multi-wavelength detection, and from single-point detection to multi-point detection and even two-dimensional planar and curved surface array detection. Video-based PPG detection technology has further propelled non-contact PPG detection towards practical application. However, it is worth noting that non-contact or non-invasive detection methods, including video PPG detection, still lack effective signal evaluation methods and devices. It is difficult to rely on known signals for direct and accurate measurement. Furthermore, the unknown PPG obtained from biological samples is inevitably affected by factors such as blood flow, skin color, and ambient light, significantly reducing detection accuracy. Under current conditions, designing a device to generate known evaluation signals for assessing the detection quality of PPG signals, including video PPG, and thus avoiding the influence of skin color and ambient light on PPG detection, especially video PPG detection, has become a key focus in this field.

[0025] Skin color is the color of human skin as reflected by the deposition of pigments such as melanin and carotene in the epidermis. Skin color is also related to the blood flow in capillaries, skin roughness, and moisture levels. Different living environments can cause variations in skin color; generally, people from Northern Europe have lighter skin, while those from Africa have darker skin. Even within an individual, the skin color of different parts of the body usually varies. More importantly, under physiological conditions, when skin capillaries dilate and become congested, blood flow accelerates, and the number of red blood cells increases, the local skin color can dynamically tend towards red. Excessive consumption of vegetables or juices such as carrots, pumpkins, and orange juice can cause the skin to turn yellow. Under pathological conditions, such as jaundice, the skin color may appear lemon-colored, orange-yellow, yellow-green, or dark yellow. The Luschan skin color model is commonly used to represent skin color. Figure 1 As shown, this is a commonly used Luschan skin color chart, such as... Figure 2 As shown, the Luschan skin tone chart classifies skin tones into 6 levels and 36 colors: very light, light, medium, brownish-yellow, brown, and dark. It can be approximated by superimposing the three primary colors of light in different proportions. However, the superposition of the individual wavelengths of the three primary colors no longer results in a definite single wavelength value, making it difficult for current technology to accurately describe ambient light, skin tone, and the visible light portion of blood flow signals using a single wavelength. Currently, it has been superseded by the Hintze skin tone chart in professional fields, such as... Figure 3As shown, this is the commonly used Hintze skin tone chart. Based on Friedrich Wilhelm Ostwald's color theory system, the Hintze skin tone chart can reproduce 24 basic colors, and using only the basic colors 3.0-8.0 is sufficient to represent skin tone. However, from a wavelength perspective, the wavelengths of the three primary colors formed when colored light is superimposed are no longer definite single wavelength values. This makes it difficult for current technologies to accurately describe ambient light, skin tone, and the visible light portion of blood flow signals using a single wavelength. Furthermore, the two skin tone simulation methods mentioned above only involve the visible light band and do not cover the near-infrared band. Figure 4 The diagram shows a color space. Conventionally, it uses three primary colors (R, G, and B) as a base, layering them to varying degrees to produce a rich and wide range of colors, hence the common name "three-primary-color model." Nature contains an infinite number of different colors, while the human eye can only distinguish a limited number. The RGB model can represent over 16 million different colors, and to the human eye, it closely resembles the colors of nature, thus it is also called the natural color model. Red, green, and blue represent the three primary colors of the visible spectrum, each divided into 256 levels according to its brightness. When the three primary colors of light overlap, different mixing ratios can produce various intermediate colors; for example, adding the three primary colors produces white. Therefore, the RGB model is an additive color process. While screen displays are based on the RGB model, color printing cannot use it to produce all the colors required for color printing. Therefore, the RGB model is commonly used in video, multimedia, and web design. Figure 5 The diagram shows the RGB and CMYK color spaces. Colors are typically represented by a cube of unit length for RGB colors, with the eight common colors (black, blue, green, cyan, magenta, yellow, and white) occupying the eight vertices of the cube. Black is usually placed at the origin of a three-dimensional Cartesian coordinate system, with red, green, and blue positioned on the three axes respectively. The entire cube is placed within the first octet. The CMYK color model includes cyan, magenta, yellow, and black. To avoid confusion with blue, black is represented by K. In color printing and other applications, colors are displayed by reflecting light from printing inks and colored coatings; this is a subtractive color mixing method, commonly used in reflective printed materials such as colored inks. Figure 6 The diagram illustrates the color mixing process in RGB and CMYK modes. It shows how various colors are created by adjusting the hue, brightness, and saturation of basic RGB or CMYK colors. Figure 7The diagram illustrates the relationship between the molar extinction coefficients of deoxyhemoglobin and oxyhemoglobin and wavelength. It describes the molar extinction coefficients of deoxyhemoglobin and oxyhemoglobin for different wavelengths of light, showing specific absorption at 660nm and 940nm, indicating characteristic wavelengths. Therefore, current technologies lack the ability to simulate and represent the important near-infrared band of human photoplethysmography (PPG). This makes it difficult to dynamically and accurately simulate, model, and evaluate the impact of ambient light, skin color, and other influencing factors on PPG, especially the precise detection requirements of video PPG.

[0026] Based on the above, this application proposes a signal generation method and related apparatus for video photoplethysmography (PPG) detection and evaluation. The following is a detailed description of this application in conjunction with embodiments and accompanying drawings.

[0027] like Figure 8 The diagram shown is a flowchart illustrating a signal generation method for video photoplethysmography (PPG) detection and evaluation according to this application, which may include: S101 generates an ambient light signal that can be displayed by a color LED display device.

[0028] In practical applications, the light characteristics of the current environment can be collected and converted into a signal format that the color LED display device can recognize and process. This allows the subsequently generated display signal to adapt to the ambient light, avoiding excessive contrast between the display effect and the environment. As an example, a light sensor can be installed near the LED display device to collect parameters such as ambient light intensity and color temperature. The sensor converts the light signal into an analog electrical signal, which is then processed by a signal conditioning circuit, converted into a digital signal by an A / D converter, and finally encoded according to the signal protocol of the color LED display device to generate an ambient light signal that meets the display requirements. By generating an ambient light signal, the content displayed on the LED can maintain a clear and comfortable visual effect under different lighting conditions, reducing eye strain.

[0029] Ambient light signals can include photometric characteristics such as luminous flux, luminous intensity, luminous brightness, and illuminance, as well as colorimetric characteristics such as hue, lightness, and saturation.

[0030] S102 generates a skin tone signal that can be displayed by a color LED display device.

[0031] It's important to note that by collecting the color characteristics of human skin tone and converting them into a signal recognizable by the LED display device, the subsequently generated visible light display signal can closely match human skin tone, avoiding excessive deviations between the displayed skin tone and the actual skin tone. As an example, an image acquisition device can capture images of the target object's face or skin area. Image processing algorithms can then extract the RGB or HSV values ​​of the skin tone (including hue, saturation, and brightness) from the image. These values ​​are then encoded according to the signal standard of the LED display device to generate a skin tone signal. In practical applications, a skin tone database for a specific population can be pre-established, and typical skin tone parameters can be directly used to generate the skin tone signal. By generating a skin tone signal, the content related to human skin tone displayed on the LED display device can more closely resemble real skin tone, improving the realism and applicability of the display, especially in scenarios such as medical diagnosis and virtual interaction.

[0032] Skin color signals can include photometric characteristics such as luminous flux, luminous intensity, luminous brightness, and illuminance, as well as colorimetric characteristics such as hue, lightness, and saturation.

[0033] S103 generates blood flow signals with given geometric and hemodynamic characteristics.

[0034] Based on preset vascular geometric and hemodynamic parameters, a signal generation algorithm can be used to construct a signal that accurately reflects the blood flow state. The purpose is to provide a raw signal source for subsequent extraction of blood flow-related characteristic wavelength information, ensuring that the displayed content is related to human blood flow physiological information. In practical applications, this can be achieved through a combination of two methods: first, acquiring geometric images of blood vessels using medical imaging equipment and extracting geometric feature parameters such as vessel diameter and orientation using image segmentation and reconstruction algorithms; second, acquiring hemodynamic feature parameters such as blood flow velocity and blood flow rate using blood flow monitoring sensors. These two types of parameters are input into the blood flow signal generation model, outputting a blood flow signal containing both types of features. Step S103 provides a raw signal containing the core features of blood flow for subsequent steps, ensuring that the extracted characteristic wavelength information accurately reflects the blood flow state. This lays the data foundation for the LED display device to present blood flow-related visualization content, and is particularly suitable for scenarios such as medical monitoring and biomedical teaching.

[0035] S104, Obtain the characteristic wavelength information of the photoplethysmography (PPG) wave signal from the blood flow signal.

[0036] PPG signals are obtained by irradiating human tissue with light of different wavelengths and detecting changes in the intensity of reflected / transmitted light. The different effects of different wavelengths of light on blood components determine that certain wavelengths can more accurately reflect the blood flow state. This application uses signal processing to filter characteristic wavelength parameters corresponding to PPG signals from blood flow signals containing geometric and hemodynamic features. As an implementation example, the generated blood flow signal can be input into a signal processing module. First, noise in the signal is removed using a filtering algorithm, retaining the effective components of the PPG signal. Then, a spectral analysis algorithm is used to analyze the spectral characteristics of the PPG signal, identifying the wavelength range or specific wavelength values ​​most sensitive to changes in blood flow. Based on the absorption spectra of oxyhemoglobin and deoxyhemoglobin in blood, 660nm and 940nm are determined as characteristic wavelengths. Finally, these characteristic wavelength parameters are organized into characteristic wavelength information that can be used in subsequent steps. This application extracts the core physiological information carrier from complex blood flow signals, avoiding the introduction of redundant information during subsequent display signal fusion, ensuring that the content of the final LED display can accurately correlate with blood flow physiological parameters, and improving the physiological relevance and accuracy of the display.

[0037] S105, based on the ambient light signal, skin color signal and characteristic wavelength information, a visible light display signal that can be displayed by an LED display device is generated according to the principle of color light superposition.

[0038] This approach uses ambient light signal, skin color signal, and characteristic wavelength information as three inputs. Utilizing the principle of color superposition, the parameters of these three signals are fused into the driving parameters of the three primary colors (R, G, B). This generates a visible light display signal that adapts to the environment, matches skin color, and reflects blood flow information, ensuring that the LED display content possesses environmental adaptability, skin color accuracy, and physiological information relevance. One implementation method involves using a fusion algorithm to analyze the parameters of the three input signals. This extracts the brightness adjustment coefficient from the ambient light signal, the basic R, G, B ratio from the skin color signal, and the physiologically relevant light parameters from the characteristic wavelength information. Then, following the principle of color superposition, the three parameters are fused to calculate the final driving values ​​for the three primary colors (R, G, B). Finally, the driving circuit converts the fused R, G, B driving values ​​into an electrical signal recognizable by the LED display device, generating a visible light display signal. This application achieves an organic integration of environmental adaptation, skin tone matching, and physiological correlation, ensuring that the generated visible light display signal will not cause visual discomfort due to changes in ambient light, maintains realistic skin tone texture when displaying human bodies, and can also indirectly reflect the physiological state of blood flow through light signals, providing a multifunctional and integrated signal foundation for subsequent displays.

[0039] S106, Time-division display of the characteristic wavelength information and the visible light display signal.

[0040] The visible light display signal at this point essentially includes changes in visible light caused by ambient light, skin color, and blood flow. Utilizing the persistence of vision, the display timing of the color LED display device can be controlled to load display signals with characteristic wavelength information and visible light display signals at different time segments. This allows the two types of content to be presented simultaneously or switched on demand, avoiding content overlap and confusion caused by displaying two signals at the same time. It also achieves the dual requirements of intuitive physiological parameter display and multi-functional integrated display on the same device. In practical applications, this can be achieved through a display timing control module. By adjusting the time interval, the switching gap can be made imperceptible to the human eye, creating a continuous display effect. This application achieves the orderly display of two core contents without increasing the hardware cost of the LED display device. Users can see a visible light image integrating environmental, skin color, and physiological information, and can also obtain key characteristic wavelength parameters at any time, balancing intuitive visual experience with professional parameter acquisition, thus improving the functionality and scene adaptability of the display device.

[0041] like Figure 9 The diagram shown illustrates a modular implementation of the method described above in this application, which may include: Ambient light generation module P01: Used to generate ambient light signals that require photometric characteristics, including but not limited to luminous flux, luminous intensity, luminous brightness, illuminance, etc., as well as colorimetric characteristics such as hue, brightness, saturation, etc.

[0042] Skin color generation module P02: Used to generate skin color signals that can be displayed by a color display device and have the required photometric characteristics, including but not limited to luminous flux, luminous intensity, luminance, illuminance, etc., as well as colorimetric characteristics such as hue, brightness, saturation, etc.

[0043] Blood flow change generation module P03: Used to generate blood flow signals with given geometric and hemodynamic features.

[0044] Photoplethysmography (PPG) signal feature generation module P04: Used to obtain characteristic wavelength information of PPG signals from blood flow signals, typically including but not limited to visible light 660nm and near-infrared 940nm characteristic wavelengths.

[0045] Visible light signal generation module P05: Used to generate visible light signals that can be displayed by a color display device by taking the characteristics of the acquired ambient light signal, skin color signal, and photoplethysmography pulse wave signal according to the principle of color light superposition.

[0046] Visible light display and characteristic wavelength generation module P06: used for time-division display of the characteristic wavelength signal of the photoplethysmography (PPG) signal obtained, and the obtained visible light display signal that can be displayed by a color display device. Each pixel of this module includes three primary color LEDs and at least one visible light LED (660nm) and one near-infrared LED (940nm) with characteristic PPG wavelengths.

[0047] like Figure 10 The diagram shows the timing sequence for generating video photoplethysmography (PPG) pulse wave detection and evaluation signals in an embodiment of this application. A represents the timing sequence of the visible light display and characteristic wavelength generation module performing visible light display and characteristic wavelength generation in a time-division manner. B represents the display timing sequence in one embodiment, displaying red light, green light, blue light, and characteristic wavelengths 1, 2, 3, up to characteristic wavelength n, where n is a natural number. C represents the display timing sequence in one embodiment, displaying red light, characteristic wavelength 1, green light, 2, blue light, 3, etc., up to characteristic wavelength n, where n is a natural number.

[0048] like Figure 11 The diagram shows the pixel arrangement in the visible light display and characteristic wavelength generation module for evaluating signals in this embodiment. In one embodiment, A shows visible light red, green, and blue primary color LEDs, along with characteristic wavelength 1, characteristic wavelength 2, and characteristic wavelength 3 LEDs, arranged at intervals within a single composite pixel. In this embodiment, the number of characteristic wavelengths is 3. In another embodiment, B shows visible light red, green, and blue primary color LEDs arranged at intervals in the upper ITO layer of a single composite pixel, along with characteristic wavelength 1, characteristic wavelength 2, and characteristic wavelength 3 LEDs in the lower ITO layer. In this embodiment, the number of characteristic wavelengths is 3.

[0049] This application extends the known principle of visible light tri-color superposition in the display technology to the near-infrared band. By expanding the tri-color LED composite pixel for visible light display to a composite pixel composed of tri-color LEDs, one or more visible light characteristic wavelength LEDs, and one or more near-infrared characteristic wavelength LEDs, it displays visible light and characteristic wavelengths in a time-division manner. This enables the simultaneous and time-division display of the visible light portion of programmably generated ambient light, skin color, and blood flow signals, as well as the characteristic wavelength information of photoplethysmography (PPG) pulse wave signals. It can accurately generate and display the visible light portion of ambient light, skin color, and blood flow signals, as well as the characteristic wavelength information of PPG pulse wave signals. This solves the problem that the superposition of the individual wavelengths of the three primary colors during color superposition is no longer a definite single wavelength value, making it difficult to accurately describe the visible light portion of ambient light, skin color, and blood flow signals using a single wavelength. It also solves the problem of simultaneously and time-divisionally displaying visible light and near-infrared light, extending the signal generation range for ambient light and skin color from the original visible light band to the near-infrared band. By simply expanding the number of display pixels, unexpected results have been achieved in the field of video photoplethysmography (PPG) evaluation signal generation methods and devices, solving a long-standing technical problem. It provides a simple and practical technical tool for production, research, and testing and evaluation processes. It is suitable for manufacturers of PPG-related medical devices and medical device testing units to test and evaluate medical devices based on video PPG detection technology.

[0050] like Figure 12 The diagram shown is a schematic of a signal generation system for video photoplethysmography (PPG) detection and evaluation according to this application, which may include: An ambient light generation module is used to generate ambient light signals that can be displayed by a color LED display device; Skin color generation module, used to generate skin color signals that can be displayed by a color LED display device; The photoplethysmography (PPG) pulse wave signal feature generation module is used to generate blood flow signals with given geometric and hemodynamic features. The visible light signal generation module is used to obtain characteristic wavelength information of the photoplethysmography (PPG) wave signal from the blood flow signal; The display generation module is used to generate a visible light display signal that can be displayed by an LED display device based on the ambient light signal, skin color signal and characteristic wavelength information, according to the principle of color light superposition. The display module is used to display the characteristic wavelength information and the visible light display signal in a time-division manner.

[0051] It should be noted that, in the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For instance, the division of each module is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another device, or some features may be ignored or not executed. The modules described as separate components may or may not be physically separated. The components shown as modules may be one or more physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs.

[0052] Furthermore, in the various embodiments of the present invention, the modules can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0053] This application also provides an electronic device, which may include one or more processors, memory and communication interfaces.

[0054] The memory, communication interface, and processor are coupled together. For example, the memory, communication interface, and processor can be coupled together via a bus.

[0055] The communication interface is used for data transmission with other devices. The memory stores computer program code. This computer program code includes computer instructions, which, when executed by the processor, cause the electronic device to perform the steps of the method described above for simulating the effect of skin melanin distribution on PPG detection.

[0056] The processor can be a processor or controller, such as a Central Processing Unit (CPU), a general-purpose processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with this disclosure. The processor can also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. The processor can be used to support an electronic device in performing the method steps provided in the above embodiments.

[0057] The bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. These buses can be categorized as address buses, data buses, control buses, etc.

[0058] This application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the above-described method steps for simulating the effect of skin melanin distribution on PPG detection.

[0059] The computer-readable storage media involved in this application include random access memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage media known in the art.

[0060] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0061] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A signal generation method for video photoplethysmography (PPG) detection and evaluation, characterized in that, include: Generate ambient light signals that can be displayed on a color LED display device; Generate skin color signals that can be displayed on a color LED display device; Generate blood flow signals with given geometric and hemodynamic features; The characteristic wavelength information of the photoplethysmography (PPG) wave signal is obtained from the blood flow signal; Based on the ambient light signal, skin color signal, and characteristic wavelength information, a visible light display signal that can be displayed by an LED display device is generated according to the principle of color light superposition. The characteristic wavelength information and the visible light display signal are displayed in a time-division manner.

2. The signal generation method for video photoplethysmography (PPG) detection and evaluation according to claim 1, characterized in that, The ambient light signal includes photometric features and colorimetric features.

3. The signal generation method for video photoplethysmography (PPG) detection and evaluation according to claim 1, characterized in that, The skin color signal includes photometric features and colorimetric features.

4. The signal generation method for video photoplethysmography (PPG) detection and evaluation according to claim 2 or 3, characterized in that, The photometric characteristics include luminous flux, luminous intensity, luminous brightness, and illuminance; The colorimetric characteristics include hue, lightness, and saturation.

5. The signal generation method for video photoplethysmography (PPG) detection and evaluation according to claim 1, characterized in that, The characteristic wavelength information includes at least one visible light characteristic wavelength and at least one near-infrared light characteristic wavelength.

6. The signal generation method for video photoplethysmography (PPG) detection and evaluation according to claim 1, characterized in that, The visible light characteristic wavelength is 660nm, and the near-infrared light characteristic wavelength is 940nm.

7. A signal generation system for video photoplethysmography (PPG) detection and evaluation, characterized in that, include: An ambient light generation module is used to generate ambient light signals that can be displayed by a color LED display device; Skin color generation module, used to generate skin color signals that can be displayed by a color LED display device; The photoplethysmography (PPG) pulse wave signal feature generation module is used to generate blood flow signals with given geometric and hemodynamic features. The visible light signal generation module is used to obtain characteristic wavelength information of the photoplethysmography (PPG) wave signal from the blood flow signal; The display generation module is used to generate a visible light display signal that can be displayed by an LED display device based on the ambient light signal, skin color signal and characteristic wavelength information, according to the principle of color light superposition. The display module is used to display the characteristic wavelength information and the visible light display signal in a time-division manner.

8. The signal generation system for video photoplethysmography (PPG) detection and evaluation according to claim 7, characterized in that, In the display module, each pixel includes a three-color LED, at least one visible light photoplethysmography (PPG) characteristic wavelength LED, and at least one near-infrared PPG characteristic wavelength LED.

9. An electronic device, characterized in that, include: A memory, one or more processors; the memory is coupled to the processors; wherein the memory stores computer program code, the computer program code including computer instructions, and when the computer instructions are executed by the processor, the electronic device performs the steps of the signal generation method for video photoplethysmography detection and evaluation as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the signal generation method for video photoplethysmography detection and evaluation as described in any one of claims 1-6.

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