Health monitoring and characterization system based on visible light communication and its application

Abstract

The present invention discloses a health monitoring and characterization system based on visible light communication, which includes a transmitting end and a receiving end; wherein the transmitting end includes a first single-chip microcomputer core circuit, which is used to modulate and encode a first electrical signal corresponding to the collected human vital signs information to obtain a modulated signal; a power amplifier and LED driving circuit, which is used to amplify the modulated signal to obtain an amplified signal; an LED light-emitting module, which is used to generate and send a visible light signal under the drive of the amplified signal; the receiving end includes: a visible light detection circuit, which is used to receive the visible light signal and convert it into a second electrical signal; a second single-chip microcomputer core circuit, which is used to demodulate the second electrical signal to extract human vital signs information, thereby realizing health monitoring. The system has the characteristics of portability, safety and functional diversity, can well meet actual needs, and can also be used to realize body surface channel characterization.

Description

Technical Field

[0001] The present invention belongs to the technical field of body-centered communication, and in particular relates to a health monitoring and characterization system based on visible light communication and its application. Background Art

[0002] With the continuous development of wearable devices and the continuous increase in residents' income, people are paying more and more attention to health monitoring and disease prevention. From medical environments such as hospitals to daily life, health monitoring and disease prevention equipment can basically be classified as a combination of vital sign sensors and transmission technology. These devices can help medical staff monitor the health status of patients in real time, thereby early detection, diagnosis and monitoring of diseases, and provide timely medical assistance to patients.

[0003] The existing health sensing / monitoring devices mainly have the following transmission modes:

[0004] The first type is a large-scale medical health monitoring device based on wired transmission. This device is rich in functions, has good real-time performance, and is free of electromagnetic interference. It can conduct all-round real-time health monitoring of patients. However, its disadvantages are also very obvious: the bulky machine prevents patients from moving freely, and is only suitable for professional medical institutions such as hospitals, with poor mobility.

[0005] The second type is medical health monitoring equipment based on radio frequency communication. This type of equipment is mobile, and as the technology continues to mature, real-time performance can also be guaranteed. However, the emergence of a large number of radio frequency devices in recent years has made the radio frequency electromagnetic spectrum bandwidth increasingly crowded, and radio frequency communication has electromagnetic interference, which has certain hazards to medical equipment and human health.

[0006] The third type is a wearable health monitoring device based on Bluetooth. This type of device is generally small in size, portable, and has a storage function. It can record and save the body's vital signs in real time in the device, and transmit it to electronic devices such as mobile phones or laptops via Bluetooth when the data needs to be viewed. However, due to the size limitation, this device cannot carry a variety of sensors, so it can only monitor the most basic human vital signs information, and can only play an auxiliary role in disease detection, and its functions are relatively simple.

[0007] In summary, an ideal health monitoring device needs to be portable, safe, and versatile. However, it is clear that the most common health monitoring devices currently cannot meet actual needs well. Summary of the invention

[0008] In order to solve the above problems existing in the prior art, the present invention provides a health monitoring and characterization system based on visible light communication and its application. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0009] In a first aspect, the present invention provides a health monitoring and characterization system based on visible light communication, comprising a transmitting end for converting an electrical signal into a visible light signal and a receiving end for converting a visible light signal into an electrical signal; wherein,

[0010] The transmitting end is arranged on the surface of the human body to be monitored, and comprises:

[0011] The first single-chip microcomputer core circuit is used to modulate and encode the first electrical signal to obtain a modulated signal; wherein the first electrical signal is an electrical signal corresponding to the collected human body vital sign information;

[0012] A power amplifier and LED driving circuit, connected to the first single-chip core circuit, is used to amplify the modulated signal to obtain an amplified signal;

[0013] An LED light-emitting module, connected to the power amplifier and LED driving circuit, used to generate and send out a visible light signal under the drive of the amplified signal;

[0014] The receiving end comprises:

[0015] A visible light detection circuit, used for receiving the visible light signal and converting it into a second electrical signal;

[0016] The second single-chip microcomputer core circuit is connected to the visible light detection circuit and is used to demodulate the second electrical signal to extract human vital sign information, thereby realizing health monitoring.

[0017] In one embodiment of the present invention, the first single-chip microcomputer core circuit and the second single-chip microcomputer core circuit both use the UART register of the single-chip microcomputer to complete data reception and transmission; at the same time, the first single-chip microcomputer core circuit and the second single-chip microcomputer core circuit both use the PCA register of the single-chip microcomputer to complete signal modulation and demodulation.

[0018] In one embodiment of the present invention, the first single-chip microcomputer core circuit uses the PWM mode in the PCA register to generate a PWM wave with a specified duty cycle, thereby completing PWM-based signal modulation.

[0019] In one embodiment of the present invention, the power amplifier and LED driving circuit includes a photocoupler, a first resistor, a second resistor, a third resistor, a fourth resistor, a first indicator light, a field effect transistor, a voltage regulator diode, and a diode; wherein,

[0020] Port 1 of the photoelectric coupler is connected to port P20 of the control chip in the core circuit of the first single-chip microcomputer through the first resistor;

[0021] Port 2 of the photoelectric coupler is grounded to GND through the first indicator light;

[0022] The port 3 of the photoelectric coupler is connected to the gate of the field effect tube through the third resistor, and the drain ground terminal DGND of the field effect tube;

[0023] Port 4 of the photoelectric coupler is connected to the DC+ terminal of the power supply;

[0024] The fourth resistor and the voltage stabilizing diode are connected in parallel between the third resistor and the ground terminal DGND;

[0025] One end of the diode is connected to the source of the field effect tube, and the other end is connected to the DC+ terminal of the power supply;

[0026] One end of the second resistor is connected to the DC+ end of the power supply; the second indicator light is an LED light-emitting module serving as a transmitting end and is connected between the other end of the second resistor and the source of the field effect tube.

[0027] In one embodiment of the present invention, the model of the photoelectric coupler is LTV217; the model of the voltage regulator diode is ZM4728A.

[0028] In one embodiment of the present invention, the visible light detection circuit includes a photosensitive diode, a fifth resistor, a dual voltage comparator, a first capacitor, a second capacitor, a third indicator light, a sixth resistor, a fourth indicator light, a seventh resistor, an eighth resistor, and a variable resistor, wherein:

[0029] One end of the photodiode is connected to the dual voltage comparator, and the other end is connected to the ground terminal GND;

[0030] The fifth resistor is connected between the photosensitive diode and the power supply VCC terminal;

[0031] One end of the first capacitor is connected to the common end of the fifth resistor and the photosensitive diode, and the other end is connected to the ground terminal GND;

[0032] Port 1 of the dual voltage comparator is connected to the control chip P35 port in the second single-chip core circuit, port 2 is connected to the control chip data input terminal in the second single-chip core circuit, port 3 is connected to the control chip P10 port in the second single-chip core circuit, port 4 is connected to the ground terminal GND, and port 8 is connected to the ground terminal GND through the second capacitor;

[0033] The third indicator light and the sixth resistor are connected in series to the power supply VCC terminal and the ground terminal GND;

[0034] The fourth indicator light and the seventh resistor are connected in series between the power supply VCC terminal and the control chip P35 in the second single-chip core circuit;

[0035] One end of the eighth resistor and the variable resistor are commonly connected to the power supply VCC terminal, the other end of the eighth resistor is connected to the control chip P35 in the second single-chip core circuit, and the other end of the variable resistor is connected to the ground terminal GND.

[0036] In one embodiment of the present invention, the dual voltage comparator is of model LM393.

[0037] In a second aspect, the present invention provides an application of a health monitoring and characterization system based on visible light communication, which uses the health monitoring and characterization system based on visible light communication described in the above embodiment to perform a body surface channel characterization experiment, wherein the body surface channel characterization experiment method includes:

[0038] The transmitting end is configured as a wearable device fixed at a certain position on the human body surface, and a plurality of receiving ends are evenly placed at other different positions on the human body surface other than the fixed position of the transmitting end, so as to form different body surface channels with the transmitting end; wherein the azimuth angle between the photodetector and the LED in each receiving end is different;

[0039] The LED light-emitting module at the transmitting end is set to send a signal with a constant carrier;

[0040] The receiving end removes the signal from the carrier and analyzes and processes the signal's amplitude, frequency, phase and other information to calculate the path loss of visible light on the corresponding channel, the cumulative probability density of the path loss and the energy attenuation data;

[0041] By comparing the path loss results corresponding to different channels, the factors affecting the path loss of visible light in the human body surface channel are obtained.

[0042] Beneficial effects of the present invention:

[0043] 1. The health monitoring and characterization system based on visible light communication provided by the present invention combines visible light communication with the body center, converts the collected human vital signs information into visible light signals, obtains the vital signs information after visible light transmission at the receiving end, and analyzes and calculates the data, thereby realizing the monitoring of human vital signs information. The system has the characteristics of mobility, safety and functional diversity, and can well meet practical needs;

[0044] 2. The present invention uses the designed health monitoring and characterization system based on visible light communication to carry out a channel characterization experiment. By controlling the different placement positions of the receiving end on the human body surface in the experiment, the factors affecting the path loss and energy attenuation of visible light communication transmission on the human body surface are obtained, thereby realizing the body surface channel characterization based on visible light communication.

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a structural block diagram of a health monitoring and characterization system based on visible light communication provided by an embodiment of the present invention;

[0047] Figure 2 is a detailed circuit diagram of a power amplifier and LED driving circuit provided by an embodiment of the present invention;

[0048] Figure 3 is a detailed circuit diagram of a visible light detection circuit provided by an embodiment of the present invention;

[0049] Figure 4 is a schematic diagram of a connector circuit provided by an embodiment of the present invention;

[0050] Figure 5 It is a schematic diagram of a body surface channel characterization experiment scenario provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0052] Embodiment 1

[0053] See also Figure 1 , Figure 1 is a structural block diagram of a health monitoring and characterization system based on visible light communication provided by an embodiment of the present invention, which includes a transmitting end 1 for converting an electrical signal into a visible light signal and a receiving end 2 for converting a visible light signal into an electrical signal; wherein,

[0054] The transmitting end 1 is arranged on the surface of the human body to be monitored, and includes:

[0055] The first single-chip core circuit 11 is used to modulate and encode the first electrical signal to obtain a modulated signal; wherein the first electrical signal is an electrical signal corresponding to the collected human body vital sign information;

[0056] The power amplifier and LED driving circuit 12 is connected to the first single-chip microcomputer core circuit 11 and is used to amplify the modulated signal to obtain an amplified signal;

[0057] The LED light emitting module 13 is connected to the power amplifier and the LED driving circuit 12, and is used to generate and send out a visible light signal under the drive of the amplified signal;

[0058] The receiving end 2 includes:

[0059] The visible light detection circuit 21 is used to receive the visible light signal and convert it into a second electrical signal;

[0060] The second single-chip core circuit 22 is connected to the visible light detection circuit 21 and is used for demodulating the second electrical signal to extract human vital sign information, thereby realizing health monitoring.

[0061] Specifically, in this embodiment, the transmitter 1 is configured as a wearable device and is arranged on the surface of the human body to be monitored, and is connected to a sensor for collecting human vital signs information, such as a monitoring device for heart rate, blood pressure, etc., to obtain an electrical signal corresponding to the human vital signs information, that is, the first electrical signal in this embodiment, and then realizes the conversion of the electrical signal to a visible light signal. The design is completed according to the parameters of the transmitter such as the luminous flux, spectral distribution, color temperature, and color rendering angle.

[0062] It should be noted that, at the transmitting end, one or more human vital signs information collection devices can be connected to realize the monitoring and transmission of different information.

[0063] The receiving end 2 completes the conversion of visible light information into electrical signals, and its design is mainly based on parameters such as the photosensitive area, dark current, sensitivity and response time of the receiver.

[0064] In this embodiment, the first single-chip microcomputer core circuit 11 and the second single-chip microcomputer core circuit 22 are both implemented using existing single-chip microcomputer chips. For example, a control chip of model STC12C5A60S2 can be used and relevant programs can be written to realize specific functions.

[0065] Specifically, the first single-chip microcomputer core circuit 11 and the second single-chip microcomputer core circuit 22 both use the single-chip microcomputer's UART (universal asynchronous receiver / transmitter) register to complete data reception and transmission; at the same time, the first single-chip microcomputer core circuit 11 and the second single-chip microcomputer core circuit 22 both use the single-chip microcomputer's PCA (programmed counter array) register to complete signal modulation and demodulation.

[0066] Optionally, as an implementation method, the first single-chip microcomputer core circuit 11 uses the PWM mode in the PCA register to generate a PWM wave with a specified duty cycle, thereby completing PWM-based signal modulation. The second single-chip microcomputer core circuit 21 determines the starting point of each bit of data through the capture mode in the PCA register, and determines whether the information represented by the bit is "1" or "0" by calculating the duration of its high level, thereby completing data demodulation.

[0067] For further information, see Figure 2 , Figure 2 Detailed circuit diagram of the power amplifier and LED driving circuit provided by the embodiment of the present invention, which includes: a photocoupler U2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first indicator LED1, a field effect transistor Q1, a voltage regulator diode D1, and a diode T1; wherein,

[0068] Port 1 of the photocoupler U2 is connected to the control chip P20 port in the first single-chip microcomputer core circuit 11 through the first resistor R1;

[0069] Port 2 of the photocoupler U2 is connected to ground GND through the first indicator LED1;

[0070] Port 3 of the photocoupler U2 is connected to the gate of the field effect transistor Q1 through a third resistor R3, and the drain of the field effect transistor Q1 is connected to the ground terminal DGND;

[0071] Port 4 of the optocoupler U2 is connected to the DC+ terminal of the power supply;

[0072] The fourth resistor R4 and the voltage stabilizing diode D1 are connected in parallel between the third resistor R3 and the ground terminal DGND;

[0073] One end of the diode T1 is connected to the source of the field effect transistor Q1, and the other end is connected to the DC+ terminal of the power supply;

[0074] One end of the second resistor R2 is connected to the DC+ end of the power supply; the second indicator LED2 as the LED light emitting module 13 of the transmitting end 1 is connected between the other end of the second resistor R2 and the source of the field effect tube Q1.

[0075] In this embodiment, the LED light emitting module 13 of the transmitting end 1 and the power amplifier and LED driving circuit 12 are integrated together, which can reduce the circuit complexity and circuit area.

[0076] Preferably, in this embodiment, the model of the photoelectric coupler U2 is LTV217; the model of the voltage regulator diode D1 is ZM4728A.

[0077] Specifically, the main functions of the power amplifier and LED drive circuit are power amplification, LED drive, and photoelectric coupling of input and output signals. The LTV217 photocoupler uses a phototransistor as its output element with a forward voltage drop of 1.2V. When the device is working, it can convert external electrical signals into optical signals by turning on its internal LED. Then the optical signal emitted by the LED will be received by the phototransistor inside the photocoupler. The voltage generated by the phototransistor base electrode with different strengths will be different, and the conduction of the phototransistor will be different accordingly, so that electrical signals with different strengths can be obtained at the output end of the photocoupler. During the signal transmission process, the input and output of the photocoupler are electrically insulated, thus isolating the input signal from the output signal. LED1 in the circuit plays a role of level indication. When the P20 port (the general input and output port of the control chip, i.e. GPIO) inputs a low level, the LED element in the photocoupler is in the cut-off state, and LED1 is also in the cut-off state. When the P20 port inputs a high level, the LED element in the photocoupler and LED1 are turned on, thereby playing an indication role that LED1 lights up when a high level is input and LED1 goes out when a low level is input.

[0078] For further information, see Figure 3 , Figure 3 Detailed circuit diagram of the visible light detection circuit provided by the embodiment of the present invention, comprising: a photosensitive diode PD1, a fifth resistor R5, a dual voltage comparator U3, a first capacitor C1, a second capacitor C2, a third indicator LED3, a sixth resistor R6, a fourth indicator LED4, a seventh resistor R7, an eighth resistor R8, and a variable resistor RW1, wherein:

[0079] One end of the photodiode PD1 is connected to the dual voltage comparator U3, and the other end is connected to the ground terminal GND;

[0080] The fifth resistor R5 is connected between the photosensitive diode PD1 and the power supply VCC terminal;

[0081] One end of the first capacitor C1 is connected to the common end of the fifth resistor R5 and the photosensitive diode PD1, and the other end is connected to the ground terminal GND;

[0082] Port 1 of the dual voltage comparator U3 is connected to the control chip P35 port in the second single-chip core circuit 22, port 2 is connected to the control chip data input terminal in the second single-chip core circuit 22, port 3 is connected to the control chip P10 port in the second single-chip core circuit 22, port 4 is connected to the ground terminal GND, and port 8 is connected to the ground terminal GND through the second capacitor C2;

[0083] The third indicator LED3 and the sixth resistor R6 are connected in series to the power supply VCC terminal and the ground terminal GND;

[0084] The fourth indicator LED4 and the seventh resistor R7 are connected in series between the power supply VCC terminal and the control chip P35 in the second single-chip core circuit 22;

[0085] One end of the eighth resistor R8 and the variable resistor RW1 are connected to the power supply VCC terminal, the other end of the eighth resistor R8 is connected to the control chip P35 in the second single-chip core circuit 22, and the other end of the variable resistor RW1 is connected to the ground terminal GND.

[0086] Specifically, after receiving the visible light information, the photodiode PD1 converts the visible light signal into a reverse current and transmits the analog quantity to the AO port in the circuit. The pin led out from the AO port in the circuit can be connected to an external A / D (analog-to-digital conversion) module for A / D conversion, or the high-speed A / D of the control chip can be used to complete the A / D conversion.

[0087] This embodiment uses the LM393 dual voltage comparator to complete the A / D conversion. The principle of the conversion is to compare the analog value AO with a given reference voltage. The reference voltage can be set by adjusting the resistance of the adjustable resistor, that is, to adjust the sensitivity of the receiver. When the photodiode PD1 is in a dark environment or the incident light intensity does not reach the set threshold, the DO port outputs a high level. When the incident light intensity exceeds the set threshold, the DO port outputs a low level. The DO port is directly connected to the GPIO port of the microcontroller, and the high and low levels of the GPIO port of the microcontroller can be used to determine whether the detected light intensity reaches the threshold.

[0088] It can be understood that, according to the selected single chip signal and the designed power amplifier and LED drive circuit and visible light detection circuit, the corresponding plug-in circuit is designed to realize the connection between the various parts of the system. Figure 4 Plug-in circuit.

[0089] In addition, after the receiving end completes the extraction of vital signs information, the output data of the receiving end can be compared with the input data of the sending end to calculate the bit error. This embodiment compares and calculates the output data with the input data, and it can be concluded that the designed system can complete the low bit error transmission of human vital signs information, thereby proving the feasibility and good performance of combining visible light communication with the body center.

[0090] The present invention innovatively combines visible light communication with the body center, builds a hardware platform for a health monitoring and characterization system based on visible light communication, converts the collected human vital signs information into visible light signals, obtains the vital signs information after visible light transmission at the receiving end, and analyzes and calculates the data, thereby realizing the monitoring of human vital signs information and completing the transmission and analysis of human vital signs information. Compared with the current mainstream health monitoring equipment, information transmission based on visible light communication can be compatible with mobility, security and functional diversity at the same time, and can well meet actual needs. In addition, since there are few related studies on the combination of visible light communication and the body field, the present invention can provide a certain reference for the exploration and in-depth research in this field, which has important practical significance.

[0091] Embodiment 2

[0092] This embodiment provides an application of a health monitoring and characterization system based on visible light communication, which uses the health monitoring and characterization system based on visible light communication provided in the above-mentioned embodiment 1 to conduct a body surface channel characterization experiment. By controlling the different placement positions of the receiving end on the human body surface in the experiment, the factors affecting the path loss and energy attenuation of visible light communication transmission on the human body surface are obtained.

[0093] Among them, the experimental methods for characterizing body surface channels include:

[0094] The transmitter is configured as a wearable device fixed at a certain position on the human body surface, and a plurality of receiving ends are evenly placed at other different positions on the human body surface other than the fixed position of the transmitter to form different body surface channels with the transmitter; wherein the azimuth angle between the photodetector and the LED in each receiving end is different;

[0095] The LED light-emitting module at the transmitting end is set to send a signal with a constant carrier;

[0096] The receiving end removes the signal from the carrier and analyzes and processes the signal's amplitude, frequency, phase and other information to calculate the path loss of visible light on the corresponding channel, the cumulative probability density of the path loss and the energy attenuation data;

[0097] By comparing the path loss results corresponding to different channels, the factors affecting the path loss of visible light in the human body surface channel are obtained.

[0098] For details, see Figure 5 , Figure 5Schematic diagram of the body surface channel characterization experimental scenario provided by an embodiment of the present invention. For the stability of signal transmission, this experiment fixed the wearable device to the human body with a strap to prevent the experimental device from slipping during the measurement process. During the experiment, the transmitter was placed in the middle of the human navel, and the receiver was evenly placed at 11 other different positions on the surface of the human body. The corresponding relationship between the number and the placement position is shown in Table 1 below.

[0099] Table 1 Correspondence between numbers and placement positions

[0100] serial number Placement serial number Placement serial number Placement A palm E Shoulder I thigh B Upper arm F Chest J ankle C ear G rib cage K Knee D head H thigh

[0101] In this embodiment, the difference brought by different placement positions of the receiving end is not only the difference in the center distance between it and the transmitting end, but also the azimuth angle between the photodetector and the LED in each receiving end is different. In the experiment, one transmitting end position is used to correspond to multiple different receiving end positions, so as to obtain multiple different channels on the human body surface (such as the channel between the navel and the chest). During the experiment, the young people under test wore a tight black top (black can reduce the reflection of light by clothes, thereby reducing the impact on the experiment) and tight pants.

[0102] In addition, since this experiment characterizes the characteristics of the static channel of visible light on the human body surface, the young man was asked to stand still at a fixed position in the room, and the data was obtained through multiple measurements to obtain the results. During the entire experiment, the LED at the transmitting end sent an analog signal with a constant 400Hz carrier, and the receiving end removed the signal from the carrier, analyzed and processed the signal's amplitude, frequency, and phase information, and thus calculated the path loss of visible light on the corresponding channel.

[0103] Based on the designed system, this embodiment conducts a channel characterization experiment, analyzes and processes the amplitude, frequency, phase and other information of the received signal obtained in the experiment, and calculates the path loss of visible light in the static channel on the human body surface, the cumulative probability density of the path loss and the energy attenuation data. In addition, by comparing the path loss results corresponding to different channels, it can be obtained that the path loss of visible light in the human body surface channel is not only related to the center distance between the transmitter and the receiver, but also to the relative angle and the position of the transmitter and the receiver on the body. At the same time, the attenuation trend of the energy of visible light in the human body surface channel over time is also obtained.

[0104] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A health monitoring and characterization system based on visible light communication, characterized in that: It comprises a transmitting end (1) for converting an electrical signal into a visible light signal and a receiving end (2) for converting a visible light signal into an electrical signal; wherein: The transmitting end (1) is arranged on the surface of a human body to be monitored and connected to one or more sensors for collecting human body vital signs information, and comprises: A first single-chip core circuit (11) is used to modulate and encode a first electrical signal to obtain a modulated signal; wherein the first electrical signal is an electrical signal corresponding to the collected human body vital sign information; A power amplification and LED driving circuit (12), connected to the first single-chip core circuit (11), is used to amplify the modulated signal to obtain an amplified signal; An LED light-emitting module (13), connected to the power amplifier and LED driving circuit (12), and used for generating and sending out a visible light signal under the drive of the amplified signal; The receiving end (2) is arranged at a different position on the surface of the human body to be monitored other than the fixed position of the transmitting end, so as to form a different body surface channel with the transmitting end; and the receiving end (2) comprises: A visible light detection circuit (21), used for receiving the visible light signal and converting it into a second electrical signal; The second single-chip core circuit (22) is connected to the visible light detection circuit (21) and is used to demodulate the second electrical signal to extract human body vital sign information, thereby realizing health monitoring and body surface channel characterization.

2. The health monitoring and characterization system based on visible light communication according to claim 1, characterized in that: The first single-chip microcomputer core circuit (11) and the second single-chip microcomputer core circuit (22) both use the UART register of the single-chip microcomputer to complete data transmission and reception; at the same time, the first single-chip microcomputer core circuit (11) and the second single-chip microcomputer core circuit (22) both use the PCA register of the single-chip microcomputer to complete signal modulation and demodulation.

3. The health monitoring and characterization system based on visible light communication according to claim 2, characterized in that: The first single-chip core circuit (11) uses the PWM mode in the PCA register to generate a PWM wave with a specified duty cycle, thereby completing PWM-based signal modulation.

4. The health monitoring and characterization system based on visible light communication according to claim 1, characterized in that: The power amplification and LED driving circuit (12) comprises a photoelectric coupler (U2), a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a first indicator light (LED1), a field effect tube (Q1), a voltage regulator diode (D1), and a diode (T1); wherein: Port 1 of the photoelectric coupler (U2) is connected to port P20 of the control chip in the first single-chip microcomputer core circuit (11) via the first resistor (R1); Port 2 of the photoelectric coupler (U2) is connected to ground GND through the first indicator light (LED1); The port 3 of the photoelectric coupler (U2) is connected to the gate of the field effect tube (Q1) through the third resistor (R3), and the drain ground terminal DGND of the field effect tube (Q1); Port 4 of the photoelectric coupler (U2) is connected to the DC+ terminal of the power supply; The fourth resistor (R4) and the voltage stabilizing diode (D1) are connected in parallel between the third resistor (R3) and the ground terminal DGND; One end of the diode (T1) is connected to the source of the field effect transistor (Q1), and the other end is connected to the DC+ terminal of the power supply; One end of the second resistor (R2) is connected to the DC+ end of the power supply; the second indicator light (LED2) is connected between the other end of the second resistor (R2) and the source of the field effect tube (Q1) as an LED light emitting module (13) of the transmitting end (1).

5. The health monitoring and characterization system based on visible light communication according to claim 4, characterized in that: The model of the photoelectric coupler (U2) is LTV217; the model of the voltage regulator diode (D1) is ZM4728A.

6. The health monitoring and characterization system based on visible light communication according to claim 1, characterized in that: The visible light detection circuit (21) comprises a photosensitive diode (PD1), a fifth resistor (R5), a dual voltage comparator (U3), a first capacitor (C1), a second capacitor (C2), a third indicator light (LED3), a sixth resistor (R6), a fourth indicator light (LED4), a seventh resistor (R7), an eighth resistor (R8), and a variable resistor (RW1), wherein: One end of the photodiode (PD1) is connected to the dual voltage comparator (U3), and the other end is connected to the ground terminal GND; The fifth resistor (R5) is connected between the photosensitive diode (PD1) and a power supply VCC terminal; One end of the first capacitor (C1) is connected to a common end of the fifth resistor (R5) and the photosensitive diode (PD1), and the other end is connected to a ground terminal GND; Port 1 of the dual voltage comparator (U3) is connected to the control chip P35 port in the second single-chip core circuit (22), port 2 is connected to the control chip data input port in the second single-chip core circuit (22), port 3 is connected to the control chip P10 port in the second single-chip core circuit (22), port 4 is connected to the ground terminal GND, and port 8 is connected to the ground terminal GND through the second capacitor (C2); The third indicator light (LED3) and the sixth resistor (R6) are connected in series to the power supply VCC terminal and the ground terminal GND; The fourth indicator light (LED4) and the seventh resistor (R7) are connected in series between the power supply VCC terminal and the control chip P35 in the second single-chip core circuit (22); One end of the eighth resistor (R8) and the variable resistor (RW1) are commonly connected to a power supply VCC terminal, the other end of the eighth resistor (R8) is connected to a control chip P35 in the second single-chip core circuit (22), and the other end of the variable resistor (RW1) is connected to a ground terminal GND.

7. The health monitoring and characterization system based on visible light communication according to claim 6, characterized in that: The model of the dual voltage comparator (U3) is LM393.

8. An application of a health monitoring and characterization system based on visible light communication, characterized in that: A body surface channel characterization experiment is performed using the health monitoring and characterization system based on visible light communication according to any one of claims 1 to 7, wherein the body surface channel characterization experiment method comprises: The transmitting end is configured as a wearable device fixed at a certain position on the human body surface, and a plurality of receiving ends are evenly placed at other different positions on the human body surface other than the fixed position of the transmitting end, so as to form different body surface channels with the transmitting end; wherein the azimuth angle between the photodetector and the LED in each receiving end is different; The LED light-emitting module at the transmitting end is set to send a signal with a constant carrier; The receiving end removes the signal from the carrier and analyzes and processes the amplitude, frequency and phase information of the signal to calculate the path loss of visible light on the corresponding channel, the cumulative probability density of the path loss and the energy attenuation data; By comparing the path loss results corresponding to different channels, the factors affecting the path loss of visible light in the human body surface channel are obtained.

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