CN217447782U - Non-contact vital sign monitoring facilities based on millimeter wave radar - Google Patents

Abstract

The utility model provides a non-contact vital sign monitoring facilities based on millimeter wave radar, including millimeter wave radar chip, ADC data collection card, RAM random access memory, SD card, DSP chip, MCU, LCD display screen and Zigbee module. The utility model has the advantages that: the data line does not need to be laid, the upper computer does not need to be used, the processing speed is high, and the cost for detecting the vital signs is greatly reduced. The scheme is a circuit structure integrating acquisition, processing and display, realizes high integration of equipment, and is convenient and quick to use; meanwhile, the problem that the data volume is too large and cannot be processed timely can be solved, the privacy leakage problem of the posture monitored by the camera is solved, and the problem that the breathing and the heartbeat are inconvenient to monitor by the wearable device is solved. The result of vital sign monitoring is directly displayed in the integrated circuit instead of the upper computer, so that the monitoring result can be viewed in real time and space.

Description

Non-contact vital sign monitoring facilities based on millimeter wave radar

Technical Field

The utility model relates to a vital sign monitoring field especially relates to a non-contact vital sign monitoring facilities based on millimeter wave radar.

Background

The monitoring of vital signs comprises monitoring of human body posture, breathing frequency and heartbeat frequency. The existing monitoring device for human body shape is a camera. In the traditional method, whether a human body falls down is identified by processing picture information acquired by a camera through a computer, but the method causes the problem of privacy disclosure of personnel and is not beneficial to being used in privacy places such as bedrooms, toilets and the like. The existing monitoring method for the breathing and heartbeat signals uses wearable vital sign detection equipment, the breathing and heartbeat signals are collected through a contact sensor, but the wearable equipment brings inconvenience to the actions of people and the wearing condition is probably forgotten, so that the monitoring is inconvenient and cannot be carried out in real time. The millimeter wave radar is used for collecting vital sign data, the data can be transmitted to an upper computer through a data line, the upper computer (a computer end) processes the data, and signals of human vital signs are extracted according to various algorithms and displayed on the upper computer. However, the method has the disadvantages that the method needs to transmit the return data of the radar into the upper computer through the network cable, so that the data cable needs to be laid, the volume occupied by the upper computer is large, and the method is not flexible and convenient to implement; the vital sign results processed by the upper computer can only be displayed on the upper computer, so that a monitored person cannot observe own vital sign signals in real time in time and space; the power consumption of the upper computer is high. The data after the ADC can be processed and then displayed through the MCU, and the method has the following defects that the MCU is used for signal processing, the processing speed is too slow, and information cannot be displayed in real time. The returned data volume of the radar is very large, and is often hundreds of megabytes, and the data memory capacity in the MCU is very small, so that enough data cannot be stored, and the result is wrong due to the loss of the returned information of the radar.

Disclosure of Invention

In order to solve the problem, the utility model provides a non-contact vital sign monitoring facilities based on millimeter wave radar, include: the device comprises a millimeter wave radar chip, an ADC data acquisition card, an RAM random access memory, an SD card, a DSP chip, an MCU, a display module and a Zigbee module, wherein two ends of the ADC data acquisition card are respectively and electrically connected with the millimeter wave radar chip and the RAM random access memory, the RAM random access memory is electrically connected with the SD card, the RAM random access memory is also electrically connected with the input end of the DSP chip, the output end of the DSP chip is electrically connected with the MCU, and the output end of the MCU is respectively and electrically connected with the display module, the Zigbee module and the SD card.

Further, the millimeter wave radar chip adopts a chip model of IWR 1443.

Furthermore, the millimeter wave radar chip is electrically connected with the transmitting antenna and the receiving antenna and is used for transmitting radio frequency signals and receiving vital sign signals returned by the human body.

Further, the model of the ADC data acquisition card is ADC 1000.

Furthermore, the model of the DSP chip is DSP56200, which processes data stored in the RAM.

Further, the model of the chip adopted by the MCU is STM32RCT 6.

Further, the Zigbee module adopts a chip CC2530, and is configured to send the monitoring result of the vital sign to the upper computer through the Zigbee network.

Further, the display module adopts an LCD display screen for displaying the monitoring result of the vital signs.

The utility model provides a beneficial effect that technical scheme brought is: the data line does not need to be laid, the upper computer does not need to be used, the processing speed is high, and the cost for detecting vital signs is greatly reduced. The scheme is a circuit structure integrating acquisition, processing and display, realizes high integration of equipment, and is convenient and quick to use; meanwhile, the problem that the data volume is too large and cannot be processed timely can be solved, the privacy leakage problem of the posture monitored by the camera is solved, and the problem that the breathing and the heartbeat are inconvenient to monitor by the wearable device is solved. The result of vital sign monitoring is directly displayed in the integrated circuit instead of the upper computer, so that the monitoring result can be viewed in real time and space.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a structural diagram of a non-contact vital signs monitoring device based on millimeter wave radar in an embodiment of the present invention.

Fig. 2 is a schematic diagram of a radio frequency signal generated by a radar according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a radar layout according to an embodiment of the present invention.

Fig. 4 is a signal diagram in the embodiment of the present invention.

Fig. 5 is a flowchart of an algorithm for extracting respiration and heartbeat signals according to an embodiment of the present invention.

Fig. 6 is a flow chart of KNN algorithm for recognizing human body posture in the embodiment of the present invention.

Fig. 7 is a circuit board structure diagram of the structure of the apparatus in the embodiment of the present invention.

Fig. 8 is a diagram of the LCD display effect in the embodiment of the present invention.

Fig. 9 is a circuit diagram of a radar chip, a power module and a crystal oscillator according to an embodiment of the present invention.

Fig. 10 is a circuit diagram of an ADC data acquisition card according to an embodiment of the present invention.

Fig. 11 is a circuit diagram of a RAM random access memory according to an embodiment of the present invention.

Fig. 12 is a circuit diagram of a DSP chip in an embodiment of the present invention.

Fig. 13 is a schematic diagram of an operation mode selection module according to an embodiment of the present invention.

Fig. 14 is a circuit diagram of the MCU module according to an embodiment of the present invention.

Fig. 15 is an interface circuit of the LCD display in the embodiment of the present invention.

Fig. 16 is a circuit diagram of a Zigbee module in an embodiment of the present invention.

Fig. 17 is a circuit diagram of the USB, serial and SD card modules in the embodiment of the present invention.

Fig. 18 is a circuit diagram of the main power module, the switch module and the reset module according to an embodiment of the present invention.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

An embodiment of the utility model provides a non-contact vital sign monitoring facilities based on millimeter wave radar.

Referring to fig. 1, fig. 1 is a schematic diagram of a non-contact vital signs monitoring device based on a millimeter wave radar in an embodiment of the present invention, which specifically includes: the millimeter wave radar chip adopts a chip model of IWR1443, is electrically connected with a transmitting antenna and a receiving antenna and can transmit radio frequency signals and receive signals returned by a human body, the two ends of the ADC data acquisition card are respectively electrically connected with the millimeter wave radar chip and the RAM random access memory, the ADC data acquisition card adopts a model of ADC1000, the RAM random access memory is electrically connected with the SD card, the RAM random access memory is also electrically connected with the input end of the DSP chip, the output end of the DSP chip is electrically connected with an MCU, the output end of the MCU is electrically connected with the LCD display screen, the Zigbee module and the SD card, and the MCU is used for playing a role of a relay system and respectively transmitting processed obtained results to the LCD display screen, the SD card and the Zigbee module.

The ADC data acquisition card is used for acquiring vital sign signals reflected by a human body and received by the millimeter wave radar chip, so that analog signals are converted into digital signals, the RAM random access memory is used for storing the digital signals acquired by the ADC data acquisition card, the RAM adopted by the ADC data acquisition card is 4GB, the problem that the digital signals cannot be processed in time due to too large data volume can be solved, information is stored in the SD card, so that the data can be checked later, and the size of the SD card is 8 GB. The model of the DSP chip is DSP56200, the DSP chip is a chip specially used for digital signal processing, is used for processing data stored in an RAM, has high data processing speed and high processing precision, and can replace an upper computer to complete extraction and processing of vital sign signals. The MCU adopts a chip model STM32RCT6, simply processes the processed result of the DSP chip, sends the processed vital sign result to the LCD display screen for display, and sends the processed vital sign result to the SD card for storage. The LCD display screen is used for displaying the vital sign information transmitted by the MCU on the LCD display screen. The Zigbee module adopts a chip CC2530 and is used for sending the monitoring result of the vital signs to an upper computer through a Zigbee network, so that the monitoring result can be observed by the upper computer and the device at the same time. The SD card is used for transmitting the collected digital signals in through the RAM, and simultaneously storing the results of monitoring vital signs after being processed by the MCU for later viewing. The equipment adopts a 5V direct current power supply for power supply.

The circuit board constructed by the scheme can integrate all devices on a circuit board with the length of 20cm and the width of 15cm, and does not need to lay data lines or use an upper computer. The scheme is a circuit structure integrating acquisition, processing and display, realizes high integration of equipment, and is convenient and quick to use;

use the millimeter wave radar to monitor, solved the privacy of using the camera monitoring gesture and revealed the problem, solved and used wearing equipment monitoring to breathe the inconvenient problem of heartbeat.

The RAM random access memory is used for storing the digital signals processed by the ADC data acquisition card, so that the problem that excessive data returned by the radar cannot be processed in time is solved.

The DSP chip is a special digital signal processing chip, and can directly process signals instead of uploading data to an upper computer for processing. Therefore, a data line does not need to be laid, an upper computer does not need to be used, the processing speed is high, and the cost for detecting the vital signs is greatly reduced.

And an LCD display screen is used for directly displaying the result of the vital sign monitoring in the integrated circuit instead of displaying the result in an upper computer. Therefore, the monitoring result can be viewed in real time and space.

The SD card is used for storing the data processed by the ADC data acquisition card and the monitoring result of the vital signs, so that the subsequent checking of the past information is facilitated.

The monitoring result of the equipment can be displayed on the spot on an LCD display screen, and also can be transmitted to an upper computer through a Zigbee network, so that the monitoring result is displayed on the upper computer, and the real-time monitoring is more favorably carried out. Compared with the transmission by using a WIFI module, the Zigbee module has lower power consumption and is more energy-saving.

The radar parameters are set as follows:

detecting whether the radar IWR1443 is correctly connected with the data acquisition board ADC 1000;

setting the radar antenna as three transmitting antennas and four receiving antennas;

setting the initial frequency of the radar signal: 77 GHZ;

setting a radar signal frequency modulation slope: 31.961 MHz/. mu.s;

setting the number of sampling points of an ADC data acquisition card under a frequency modulation pulse to be 256;

setting the sampling rate of an ADC data acquisition card to 1560 ksps;

setting the cut-off time of the radar frequency modulation pulse to 125 mu s; each frame period is set to be 50 ms.

The radio frequency signal generated by the radar is shown in fig. 2, and in this embodiment, the configured radar device is placed at the upper corner of the room to ensure that the signal of the radar covers the whole room. As shown in fig. 3, the radar can be placed at the upper right corner of the space to ensure that the signal is well covered in the area.

The using method comprises the following steps:

(1) switching on the power supply of the equipment;

(2) opening mmwave studio software, and setting a radar working mode;

(3) burning the MCU program into the MCU chip through a serial port by using a downloader ST-Link;

(4) burning the DSP program into the DSP chip by using a downloader ST-Link;

(5) burning a Zigbee program into a Zigbee chip by using a downloader ST-Link;

(6) inserting an SD card;

(7) and inserting the display screen.

(8) The radar switch is turned over, and the equipment starts to work;

the realization principle is as follows:

1. and performing fast Fourier transform in three directions on the acquired human body reflection information to obtain instantaneous speed, analyzing the relation between the instantaneous speed and a threshold value, and judging that the human body falls down if the instantaneous speed is greater than the threshold value. Compared with the traditional camera for recognizing the falling of the human body, the method omits the process of image recognition and has high privacy protection.

As shown in fig. 4, TX chirp represents the transmitted radio frequency signal, RX chirp represents the received vital sign signal reflected by the human body, and IF signal represents the mixing signal, i.e. the signal to be processed.

Assuming that there is an object in front of the radar, the received IF signal can be expressed as:

wherein:

representing the frequency of the pre-processed IF signal.

Representing the phase of the preprocessed IF signal. A represents the amplitude of the IF signal, S represents the slope of the FM wave, d represents the distance between the object and the radar, c represents the speed of light, and λ represents the wavelength of the IF signal.

And f can be obtained by carrying out distance Fourier transform on the IF signal, and the distance between the object and the radar is calculated according to f. Performing a velocity Fourier transform on the IF signal to obtain

Angular frequency ω of (c):

wherein, T _c The period of a frequency modulation wave is shown, v represents the speed of the measured object, and since the vital sign information reflected by the human body is obtained in the invention, the speed of the human body is obtained.

Whether the person falls can be identified through the fast Fourier transform of the data.

2. The property that the millimeter wave radar is sensitive to micro disturbance is utilized, and the breathing and heartbeat signals of the human body can be directly measured. Compared with the traditional method, the method has the advantages that the measured person does not need to wear any measuring equipment, and great convenience is brought to the activity of the measured person.

The respiration and heartbeat signals are steady periodic signals which can cause changes in the thoracic cavity, and are characterized by the following table 1:

TABLE 1 respiration and Heartbeat Signal characteristics

Type of signal	Frequency (HZ)	Thorax displacement (mm)
			Breathing	0.2～0.9	3～10
Heartbeat	0.9～2	0.1～2

As shown in FIG. 5, the algorithm flow chart for extracting respiration and heartbeat signals is that after phase unwrapping, the signals are respectively passed through two different filters H1 and H2, with cut-off frequencies of 0.2-0.9 HZ and 0.9-2 HZ, respectively. Wherein H1 is used to acquire respiration signals and H2 is used to acquire heartbeat signals.

Suppose the phase unwrapped signal is X (n) and the filter is H _i (n) i is 1,2, and the obtained time domain signal is S _i (n) the frequency domain signal obtained is SF _i (n) of (a). Wherein SF _i (n) is S _i (n) Fourier transform.

i-1 represents a respiration signal, and i-2 represents a heartbeat signal. For SF _i And (n) solving the frequency corresponding to the maximum value to obtain the target frequency.

3. Recognizing human body gestures

The radar is used for collecting data of four postures of standing, sitting, walking and lying of a human body.

The collected four kinds of information are used as samples, the sample information is led into an MCU chip through a downloader, and after the MCU receives the data processed by the DSP, the current data is classified by utilizing a KNN algorithm for identifying the posture of the human body as shown in figure 6, and the classification of the current data belongs to which one of standing, sitting, walking and lying categories is calculated;

the circuit board structure of the device structure is shown in fig. 7, the display effect of the LCD display screen is shown in fig. 8, fig. 9 is a millimeter wave radar chip, a power supply module and a crystal oscillator, the radar chip is composed of a chip 1 and a chip 2, wherein three transmitting antennas TX1, TX2 and TX3 are respectively connected with pins TX1, TX2 and TX3 of the chip, and four receiving antennas RX1, RX2, RX3 and RX4 are respectively connected with pins RX1, RX2, RX3 and RX4 of the chip; two ends AR _ XTALP and AR _ XTALM of the crystal oscillator are respectively connected with AR _ XTALP and AR _ XTALM of the radar chip, and basic clock signals are provided for the work of the radar. Pins AR _ NERRIN, AR _ WARMRST, CS1, AR _ SCL, AR _ SDA, AR _ NERR _ OUT and AR _ HOSTINTR1 of the power supply module are respectively connected with pins AR _ NERRIN, AR _ WARMRST, AR _ CS1, AR _ SCL, AR _ SDA, AR _ NERR _ OUT and AR _ HOSTINTR1 of the radar chip to supply power for normal operation of the radar.

The millimeter wave radar chip is connected with the ADC data acquisition card and converts the analog signals returned by the radar into digital signals. The model of the adopted ADC data acquisition card is ADC1000, as shown in fig. 10, a millimeter wave radar chip is connected to the ADC1000 by using a data line with 60 pin holes, wherein XDSET _ TCK, XDSET _ TDI, XDSET _ TMS, and XDSET _ TOO pins in the gigabit network port module are connected to the output end of the ADC1000, so as to quickly transmit the acquired digital signals.

The RAM random access memory shown in fig. 11 is used for storing digital signals after DAC acquisition, wherein pins AR _ TCK, AR _ TDI, AR _ TMS, and AR _ TDO _ SOP0 of the RAM chip are connected with pins AR _ TCK, AR _ TDI, AR _ TMS, and AR _ TDO _ SOP0 of the ADC data acquisition module to receive signals after ADC data acquisition, and wherein pins AR _ MISO1, AR _ MOSI1, AR _ SPICLK1, and AR _ CS1 are connected with corresponding pins AR _ MISO1, AR _ MOSI1, AR _ SPICLK1, and AR _ CS1 of the radar chip to adjust the operating state of the ARM chip in real time. The DSP chip shown in fig. 12 is used for signal processing to complete vital sign monitoring, and the chip inputs and processes data through the connection of the pins PMIC _ EN1, PMIC _ EN2, PMIC _ EN3 and the corresponding pins PMIC _ EN1, PMIC _ EN2, PMIC _ EN3 of the RAM.

The selection module of the operation mode is shown in fig. 13, in which the jumper cap P3 is connected with the AR _ PMIC _ CLKOUT _ SOP2 and PMIC _ CLK pins of the radar, and the jumper cap is connected to control the radar to be in the programming mode; the jumper cap P2 is connected with an AR _ SYNC _ OUT _ SOP1 pin of the radar, and the jumper cap is connected to control the radar to enter a functional mode; the jumper cap P4 is connected with the AR _ SYNC _ OUT _ SOP0 pin of the radar, and the connection of the jumper cap can control the radar to enter a development mode.

The MCU shown in FIG. 14 adopts stm32 series MCU; the pins PA2 and PA3 are respectively connected with the pins DSP _ SDA and DSP _ SCL of the DSP module, and the life monitoring result processed by the DSP module is received; pins PA0 and PA1 are respectively connected with pins AR _ RS232TX and AR _ RS232RX of the millimeter wave radar chip and are used for monitoring the working state of the radar in real time; the pins PL6 and PL7 are respectively connected with the pins P0_4 and P0_5 of the Zigbee module and the pins CAN _ TX and CAN _ RX of the SD card, and are used for transmitting the processed life monitoring data to the Zigbee module and the SD card; pins of PD0, PD1, PD2, PD3, PD4, PD5, PD6 and PD7 are connected with pin jacks of an LCD display screen and used for displaying data in real time by the LCD;

the interface circuit of the LCD display screen is shown in fig. 15, and the LCD display screen is inserted into the pin header interface to complete the function of displaying the vital sign state.

As shown in fig. 16, the Zigbee module employs a CC2530 chip; pins P0_4 and P0_5 of the module are respectively connected with pins PL6 and PL7 of the MCU module and are used for receiving the vital sign information transmitted by the MCU; the RF _ P and RF _ N pins are connected with a radio frequency antenna of the CC2530 chip and can transmit data to an upper computer through a zigbee network; wherein, P2_3 and P2_4 are connected to two ends of the crystal module X2 in fig. 16, and XOSC32M _ Q1 and XOSC32M _ Q2 are connected to two ends of the crystal module X1 in fig. 16, so as to provide basic clock signals for the operation of the Zigbee module.

The USB, serial port, and SD card modules are shown in fig. 17, where pins CAN _ TX and CAN _ RX of the modules are connected to pins PL6 and PL7 of the MCU module, respectively, to complete data transmission and storage. Fig. 18 shows a main power supply module, a switch module and a reset module, wherein a power line or a battery with 4.5-5.5V is connected to a P6 position in the main power supply and switch module to supply power to the whole module. The switch is formed by a triode, and the triode plays a role in switching. The AR _ NRST pin, the AR _ NRST _ MCU pin and the AR _ NRST _ XDS pin of the reset module are respectively connected with the AR _ NRST pin of the radar, the AR _ NRST _ MCU pin of the MCU and the AR _ NRST _ XDS pin of the DSP module, and therefore the reset function of the circuit is completed.

The utility model has the advantages that: the data line does not need to be laid, the upper computer does not need to be used, the processing speed is high, and the cost for detecting vital signs is greatly reduced. The scheme is a circuit structure integrating acquisition, processing and display, realizes high integration of equipment, and is convenient and quick to use; can solve simultaneously because of the too big problem that can't in time handle of data bulk, use the privacy of camera monitoring gesture to reveal the problem and use the inconvenient problem of wearing the equipment monitoring breathing heartbeat. The result of vital sign monitoring is directly displayed in the integrated circuit instead of the upper computer, so that the monitoring result can be viewed in real time and space.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims (8)

1. The utility model provides a non-contact vital sign monitoring facilities based on millimeter wave radar which characterized in that: the method comprises the following steps: the device comprises a millimeter wave radar chip, an ADC data acquisition card, an RAM random access memory, an SD card, a DSP chip, an MCU, a display module and a Zigbee module, wherein two ends of the ADC data acquisition card are respectively and electrically connected with the millimeter wave radar chip and the RAM random access memory, the RAM random access memory is electrically connected with the SD card, the RAM random access memory is also electrically connected with the input end of the DSP chip, the output end of the DSP chip is electrically connected with the MCU, and the output end of the MCU is respectively and electrically connected with the display module, the Zigbee module and the SD card.

2. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the millimeter wave radar chip adopts the chip model of IWR 1443.

3. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the millimeter wave radar chip is electrically connected with the transmitting antenna and the receiving antenna and used for transmitting radio frequency signals and receiving vital sign signals returned by a human body.

4. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the ADC data acquisition card is used in the type of ADC 1000.

5. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the model of the DSP chip is DSP56200, and data stored in the RAM is processed.

6. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the model of the chip adopted by the MCU is STM32RCT 6.

7. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the Zigbee module adopts a chip CC2530 and is used for sending the monitoring result of the vital signs to an upper computer through a Zigbee network.

8. The millimeter-wave radar-based contactless vital signs monitoring device of claim 1, wherein: the display module adopts an LCD display screen and is used for displaying the monitoring result of the vital signs.

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