CN114376541A - Device and method for monitoring human vital signs - Google Patents

Abstract

The invention discloses a human body vital sign monitoring device and a method, wherein a central module comprises a first NRF52832 Bluetooth minimum system board, a PPG module, a body temperature module and a storage module; human PPG signal is gathered to the PPG module, human body surface temperature signal is gathered to the body temperature module, human chest heart sound signal is gathered to first heart sound module, the heart sound signal of wrist is gathered to wrist heart sound module, each vital sign signal that storage module will gather stores, the minimum system board of first NRF52832 bluetooth reads the PPG module, the signal and the data of body temperature module and first heart sound module, control write in data and send data to the host computer through BLE4.2 agreement in to storage module. According to the invention, the relevant characteristic value is obtained by combining the heart sound signal and the PPG signal and then is introduced into the blood pressure prediction model, so that the blood pressure value of the human body can be accurately obtained in real time, and meanwhile, the system can be conveniently connected to modern mobile phones, tablets and other upper computers by adopting a BLE4.2 protocol so as to realize better universality of the system.

Description

Device and method for monitoring human vital signs

technical field

The invention belongs to the field of medical sensor wireless ad hoc network data collection, and particularly relates to a human vital sign monitoring device and method.

Background technique

The application of Bluetooth technology in the medical field can greatly facilitate the monitoring of the health status of residents. By using the MESH networking technology of Bluetooth, the health status of the human body can be more accurately reflected by collecting the vital signs of different parts of the human body, which is convenient and convenient. It has played a vital role in residents seeking medical treatment and alleviating social medical pressure.

The current related products have the following problems:

(1) The equipment can only monitor the basic vital signs such as heart rate and temperature, which cannot fully reflect the health status of the human body.

(2) Most of the devices using Bluetooth technology are often only worn on the wrist in the form of a bracelet, which makes the measurement of blood pressure, cardiac output and other data have large errors.

(3) The traditional blood pressure measurement equipment can only measure the blood pressure signal within a period of time, and cannot realize the continuous monitoring of the blood pressure signal.

(4) The current device's blood pressure prediction method using photoplethysmography is too complicated and difficult to implement on low-power and low-speed devices. In order to solve the problems of incomplete measurement signals of traditional vital signs monitoring equipment, inaccurate detection of blood pressure signals at the wrist, inability to monitor continuous blood pressure signals, and high complexity of blood pressure prediction algorithms, we developed a human life solution that solves the above pain points. A sign monitoring system is necessary.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a human vital sign monitoring device, including a center module, a first heart sound module and a wrist heart sound module, wherein the first heart sound module and the wrist heart sound module are both connected to the center module, wherein,

The central module includes the first NRF52832 Bluetooth minimum system board, a PPG module, a body temperature module and a storage module; the PPG module, the body temperature module and the storage module are all connected to the first NRF52832 Bluetooth minimum system board, the PPG module collects human PPG signals, and the body temperature module Collect the body surface temperature signal, the first heart sound module collects the human chest heart sound signal, the wrist heart sound module collects the wrist heart sound signal, and the storage module stores the collected vital signs signals. The first NRF52832 Bluetooth minimum system board Read the signals and data of the PPG module, the body temperature module and the first heart sound module, control to write data into the storage module and send data to the upper computer through the BLE4.2 protocol;

The first heart sound module includes a PVDF sensor, an analog-to-digital signal converter, and a signal filtering and amplifying circuit that are connected in sequence, wherein the PVDF sensor collects the heart sound information of the human body and converts it into a voltage signal, and the signal filtering and amplifying circuit generates the PVDF sensor. The electrical signal is filtered and processed to reduce the interference of noise on the heart sound signal and the signal is amplified. The analog-to-digital signal converter receives the electrical signal processed by the signal filtering and amplifying circuit, converts it into a digital signal and outputs it to the central module.

Preferably, the wrist heart sound module includes a connected second NRF52832 Bluetooth minimum system board and a second heart sound module, the second heart sound module collects the wrist heart sound signal, and the second NRF52832 Bluetooth minimum system board receives the second heart sound module collection data and send it to the central module.

Preferably, the PPG module includes a MAX30100 pulse oximetry and heart rate detection sensor.

Preferably, the body temperature module includes a CJMCU30205 human body temperature sensor.

Preferably, the memory module includes W25Q16 memory.

Based on the above purpose, the present invention also provides a method for monitoring human vital signs, using the above device, comprising the following steps:

S1, the center module is arranged on the chest of the human body. After power-on, the first NRF52832 Bluetooth minimum system board sets the basic Bluetooth broadcast mode so that other Bluetooth devices can discover and establish connections. The host computer configures the center module as a node in the MESH network, and Initialize various Bluetooth services;

S2, create a timer task to periodically collect the data of the PPG module, the body temperature module and the first heart sound module, and store them in the storage module;

S3, after receiving the wrist heart sound transmitted by the wrist heart sound module, obtain the real-time blood pressure signal through the blood pressure prediction model, package all vital signs and send data packets to the host through the Bluetooth service;

S4: Receive the returned data from the host computer to verify whether the data transmission is normal, and resend the data packet if packet loss or data error occurs.

Preferably, the S2 specifically includes the following steps:

S21, the first heart sound module is initialized by the central module after being powered on;

S22, the PVDF sensor collects the heart sound signal of the human body, and the collected signal is processed by the signal filtering and amplifying circuit to filter out the power frequency noise and environmental noise, and amplify the signal amplitude to the range of 2.0V to 3.3V;

S23 , the amplified signal is converted into a digital signal by an analog-to-digital signal converter and waits for collection by the central module.

Preferably, the S3 specifically includes the following steps:

S31, the wrist heart sound module is arranged at the wrist. After power-on, the second NRF52832 Bluetooth minimum system board sets the basic Bluetooth broadcast mode so that other Bluetooth devices can discover and establish connections. The upper computer configures the wrist heart sound module as a MESH network. node, and initialize various Bluetooth services;

S32 , a timer task is created to periodically collect the second heart sound module, and the wrist heart sound signal is sent to the central module through the Bluetooth service.

Compared with the prior art, the present invention can obtain heart rate, temperature, human heart sounds, PPG and other signals through direct measurement, and can obtain human blood pressure signals through indirect measurement. The present invention calculates the blood pressure value from the corresponding blood pressure prediction model by extracting characteristic values from the chest and wrist heart sound signals and PPG signals. The algorithmic complexity of predicting blood pressure signals using eigenvalue methods is low and can be run on low-power, low-rate devices. Using the heart sound signal and PPG signal at the wrist and chest at the same time to extract the eigenvalues to calculate the blood pressure can improve the accuracy of the blood pressure signal.

Description of drawings

In order to make the purpose, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following drawings for description:

1 is a structural block diagram of a human vital sign monitoring device according to an embodiment of the present invention;

2 is a block diagram of a central module structure of a human vital sign monitoring device according to an embodiment of the present invention;

3 is a structural block diagram of a first heart sound module of a human vital sign monitoring device according to an embodiment of the present invention;

4 is a structural block diagram of a wrist heart sound module of a human vital sign monitoring device according to an embodiment of the present invention;

5 is a flowchart of steps of a method for monitoring human vital signs according to an embodiment of the present invention;

6 is a flow chart of S3 wrist heart sound collection in a method for monitoring human vital signs according to an embodiment of the present invention;

FIG. 7 is a flowchart of blood pressure prediction steps of a method for monitoring human vital signs according to an embodiment of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1-4, the device embodiment includes a central module 1, a first heart sound module 5 and a wrist heart sound module 10, and the first heart sound module 5 and the wrist heart sound module 10 are both connected with the central module 1, wherein,

The central module 1 includes a first NRF52832 Bluetooth minimum system board 2, a PPG module 3, a body temperature module 4 and a storage module 6; the PPG module 3, the body temperature module 4 and the storage module 6 are all connected to the first NRF52832 Bluetooth minimum system board 2, and the PPG module 3 collects the PPG signal of the human body, the body temperature module 4 collects the temperature signal of the human body surface, the first heart sound module 5 collects the heart sound signal of the human chest, the wrist heart sound module 10 collects the heart sound signal of the wrist, and the storage module 6 stores the collected life The physical sign signal is stored, the first NRF52832 Bluetooth minimum system board 2 reads the signals and data of the PPG module 3, the body temperature module 4 and the first heart sound module 5, and controls the writing of data to the storage module 6 and upward through the BLE4.2 protocol. Bit machine sends data;

The detection of human heart rate using photoplethysmography (PPG) technology is an application of infrared non-destructive testing technology in biomedicine. It uses photoelectric sensors to detect the difference in reflected light intensity after absorption by human blood and tissue , trace the changes of vascular volume during the cardiac cycle, and calculate the heart rate from the obtained pulse waveform.

The first heart sound module 5 includes a PVDF sensor 9, an analog-to-digital signal converter 7 and a signal filtering and amplifying circuit 8 connected in sequence, wherein the PVDF sensor 9 collects the heart sound information of the human body and converts it into a voltage signal, and the signal filtering and amplifying circuit 8 The electrical signal generated by the PVDF sensor 9 is filtered to reduce the interference of noise on the heart sound signal and the signal is amplified. The analog-to-digital signal converter 7 receives the electrical signal processed by the signal filtering and amplifying circuit 8 and converts it into a digital signal for output to the center. Module 1.

Heart sounds are the shock and vibration of the chest wall during the beating of the heart, and the mechanical vibration of heart sounds can be recorded by instruments such as polyvinylidene fluoride (PVDF) piezoelectric sensors, which is called a phonocardiogram. When detecting the simulated human heart sound, the PVDF sensor 9 first converts the heart sound vibration signal into a weak electrical signal, and the heart sound measurement system passes the weak electrical signal through a two-stage preamplifier, a band-pass filter, a 50Hz notch filter, and a voltage boost. After the circuit is processed, it is sent to the oscilloscope as an output signal, and the heart sound waveform is displayed on the oscilloscope and various indicators (including heart rate, amplitude, diastolic and systolic time limit, etc.) are measured, and then compared with the standard value of the simulated human heart sound.

The wrist heart sound module 10 includes a connected second NRF52832 Bluetooth minimum system board 11 and a second heart sound module 12 , the second heart sound module 12 collects the heart sound signal of the wrist, and the second NRF52832 Bluetooth minimum system board 11 receives the second heart sound module 12 The collected data is sent to the central module 1.

PPG module 3 includes a MAX30100 pulse oximetry and heart rate detection sensor. Two LED lights are used, one photodetector to optimize optics, and a low noise analog signal processor, and the other to detect pulse oxygen and heart rate signals. The operating voltage of the Max30100 is between 1.8V and 3.3V, and it can be controlled by software. The standby current is very small and can be ignored, so that the power supply can be kept connected at any time.

The body temperature module 4 includes a CJMCU30205 human body temperature sensor.

The storage module 6 includes a W25Q16 memory, which is a 16M-bit (1bytes=8bits) flash, which can store voice, text, and data.

Referring to Figure 5, the method embodiment includes the following steps:

S1, the central module 1 is arranged on the chest of the human body. After power-on, the first NRF52832 Bluetooth minimum system board 2 sets the basic Bluetooth broadcast mode so that other Bluetooth devices can discover and establish connections. The host computer configures the central module 1 as a network in the MESH network node, and initialize various Bluetooth services;

S2, create a timer task to periodically collect the data of the PPG module 3, the body temperature module 4 and the first heart sound module 5, and store them in the storage module 6;

S3, after receiving the wrist heart sound transmitted by the wrist heart sound module 10, obtain the real-time blood pressure signal through the blood pressure prediction model, and package all the vital signs to send data packets to the host through the Bluetooth service;

S4: Receive the returned data from the host computer to verify whether the data transmission is normal, and resend the data packet if packet loss or data error occurs.

S2 specifically includes the following steps:

S21, the first heart sound module 5 is initialized by the central module 1 after being powered on;

S22, the PVDF sensor 9 collects the heart sound signal of the human body, and the collected signal is processed by the signal filtering and amplifying circuit 8 to filter out power frequency noise and environmental noise, and amplify the signal amplitude to the range of 2.0V to 3.3V;

S23 , the amplified signal is converted into a digital signal by the analog-to-digital signal converter 7 and waits for collection by the central module 1 .

Referring to Figure 6, S3 specifically includes the following steps:

S31, the wrist heart sound module 10 is arranged at the wrist, after power-on, the second NRF52832 Bluetooth minimum system board 11 sets the basic Bluetooth broadcast mode so that other Bluetooth devices can discover and establish connections, and the upper computer configures the wrist heart sound module 10 as Nodes in the MESH network and initialize various Bluetooth services;

S32 , a timer task is created to periodically collect the second heart sound module 12 , and the wrist heart sound signal is sent to the central module 1 through a Bluetooth service.

Referring to FIG. 7 , it is a flowchart of the blood pressure prediction steps of the present invention. After the central module 1 and the wrist heart sound module 10 collect the PPG signal and the heart sound signal at the chest and wrist, after smooth filtering, the PPG signal and the heart sound signal at the wrist are collected. The starting point of the heart sound signal is identified, the signal is divided into periods according to the starting point, and then the eigenvalues of the PPG signal and the heart sound signal are calculated with the period as the basic unit, and the eigenvalues are brought into the blood pressure prediction model to calculate the blood pressure value. The blood pressure prediction model The parameters are empirical values.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. Inside.

Claims (8)

1. A human body vital sign monitoring device is characterized by comprising a central module, a first heart sound module and a wrist heart sound module, wherein the first heart sound module and the wrist heart sound module are both connected with the central module,

the central module comprises a first NRF52832 Bluetooth minimum system board, a PPG module, a body temperature module and a storage module; the PPG module, the body temperature module and the storage module are all connected with a first NRF52832 Bluetooth minimum system board, the PPG module collects PPG signals of a human body, the body temperature module collects body surface temperature signals of the human body, the first heart sound module collects precordial heart sound signals of the human body, the wrist heart sound module collects heart sound signals of the wrist, the storage module stores the collected vital sign signals, the first NRF52832 Bluetooth minimum system board reads signals and data of the PPG module, the body temperature module and the first heart sound module, and controls to write data into the storage module and send the data to an upper computer through a BLE4.2 protocol;

the first heart sound module comprises a PVDF sensor, an analog-digital signal converter and a signal filtering and amplifying circuit which are sequentially connected, wherein the PVDF sensor collects heart sound information of a human body and converts the heart sound information into a voltage signal, the signal filtering and amplifying circuit carries out filtering processing on an electric signal generated by the PVDF sensor to reduce noise interference on a heart sound signal and amplifies the signal, and the analog-digital signal converter receives the electric signal processed by the signal filtering and amplifying circuit and converts the electric signal into a digital signal to be output to the center module.

2. The human vital signs monitoring device of claim 1, wherein the wrist heart sound module comprises a second NRF52832 bluetooth minimal system board and a second heart sound module connected to each other, the second heart sound module collects heart sound signals of the wrist, and the second NRF52832 bluetooth minimal system board receives data collected by the second heart sound module and transmits the data to the central module.

3. Human vital signs monitoring device according to claim 1, wherein the PPG module comprises a MAX30100 pulse oximetry and heart rate detection sensor.

4. The human vital signs monitoring device of claim 1, wherein the body temperature module comprises a CJMCU30205 human body temperature sensor.

5. Human vital signs monitoring device according to claim 1, wherein the memory module comprises a W25Q16 memory.

6. Method for monitoring human vital signs, characterized in that the device according to any one of claims 1 to 5 is used, comprising the following steps:

s1, arranging a center module in front of the chest of a human body, setting a basic Bluetooth broadcast mode by a first NRF52832 Bluetooth minimum system board after electrification to enable other Bluetooth devices to discover and establish connection, configuring the center module as a node in an MESH network by an upper computer, and initializing various Bluetooth services;

s2, a timer task is established to acquire data of the PPG module, the body temperature module and the first heart sound module at regular time and store the data in a storage module;

s3, after receiving the wrist heart sounds transmitted by the wrist heart sound module, obtaining real-time blood pressure signals through a blood pressure prediction model, packaging all vital signs and sending data packets to a host through Bluetooth service;

and S4, receiving the returned data of the upper computer to verify whether the data transmission is normal, and resending the data packet if packet loss or data error occurs.

7. The method according to claim 6, wherein the S2 specifically comprises the following steps:

s21, the first heart sound module is initialized by the central module after being electrified;

s22, acquiring heart sound signals of a human body by the PVDF sensor, filtering power frequency noise and environmental noise after the acquired signals are processed by a signal filtering and amplifying circuit, and amplifying the signal amplitude to a range from 2.0V to 3.3V;

and S23, converting the amplified signal into a digital signal by the analog-to-digital signal converter to wait for the acquisition of the central module.

8. The method according to claim 6, wherein the S3 specifically comprises the following steps:

s31, the wrist heart sound module is arranged on the wrist, after the wrist heart sound module is powered on, the second NRF52832 Bluetooth minimum system board sets a basic Bluetooth broadcast mode to enable other Bluetooth devices to discover and establish connection, the wrist heart sound module is configured into nodes in an MESH network by the upper computer, and various Bluetooth services are initialized;

and S32, creating a timer task to acquire a second heart sound module at regular time, and sending the wrist heart sound signal to the center module through the Bluetooth service.

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