CN111407259A

CN111407259A - Vehicle-mounted health parameter measuring device based on CAN bus

Info

Publication number: CN111407259A
Application number: CN202010238777.7A
Authority: CN
Inventors: 杨佳威; 应国宏; 葛华勇; 杨肖南; 王海杰; 刘书翰
Original assignee: Hangzhou Nanochap Electronics Co Ltd
Current assignee: Hangzhou Nanochap Electronics Co Ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-07-14

Abstract

The invention provides a vehicle-mounted health parameter measuring device based on a CAN bus, which comprises an electrocardiosignal detection module, a human body composition detection module and a control module; the control module comprises a CAN communication circuit and an analog switch; the control module is connected with the vehicle machine system through the CAN communication circuit, and the control module is respectively connected with the electrocardiosignal detection module and the human body composition detection module through the analog switch. The device has lower requirements on the measurement posture of the measured person, can effectively utilize the space and power supply in the vehicle, and is convenient for the personnel in the vehicle to measure the health condition in real time for a long time. Meanwhile, the device also has the function of measuring a plurality of health parameters, so that the health condition of the tested person is reflected in the maximum range.

Description

Vehicle-mounted health parameter measuring device based on CAN bus

Technical Field

The invention belongs to the field of vehicle-mounted health monitoring, and particularly relates to a vehicle-mounted health parameter measuring device based on a CAN bus.

Background

Automobiles as vehicles have frequently appeared in various fields of people's lives, such as traveling, logistics, and the like. In recent years, there have been increasing traffic accidents due to physical symptoms of car drivers, wherein cardiovascular diseases account for a large proportion. Because the vehicle belongs to a relatively sealed environment in the driving process, it is necessary for drivers and passengers in the vehicle to continuously monitor the physical health parameters such as heartbeat, respiration rate, body fat and the like in the vehicle in real time on the premise of not influencing driving and riding.

The patent with the application number of 201811612304.8 discloses a vehicle-mounted health detection system which comprises a vehicle-mounted intelligent health device, a vehicle-mounted large-screen APK module, a plurality of third-party application interfaces and a cloud server, wherein the vehicle-mounted health detection system adopts a PPG electrocardio measurement scheme, the accurate measurement result can be obtained only by shielding L ED light by limbs of a tested person during measurement, and the accurate measurement result is difficult to maintain for a driver of a vehicle in the driving process.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to overcome the problems, the vehicle-mounted health parameter measuring device based on the CAN bus is provided. The device has lower requirements on the measurement posture of the measured person, can effectively utilize the space and power supply in the vehicle, and is convenient for the personnel in the vehicle to measure the health condition in real time for a long time. Meanwhile, the device also has the function of measuring a plurality of health parameters, so that the health condition of the tested person is reflected in the maximum range.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a vehicle-mounted health parameter measuring device based on a CAN bus comprises an electrocardiosignal detection module, a human body component detection module and a control module; the control module comprises a CAN communication circuit and an analog switch; the control module is connected with the vehicle machine system through the CAN communication circuit, and the control module is respectively connected with the electrocardiosignal detection module and the human body composition detection module through the analog switch.

Most vehicles of prior art all adopt the car machine system based on the CAN bus, and the control module of this application passes through CAN communication circuit and car machine system connection, CAN utilize car machine system to accomplish the output of measuring result under the condition that only increases a small amount of measuring circuit modules to the maximize utilizes space resource in the car.

The automatic switching of different detection modules is realized through the analog switch and the control module, so that the extra operation of a tested person is reduced on the premise of ensuring the measurement of a plurality of health parameters.

Preferably, the control module further comprises a control chip and a power circuit, and the CAN communication circuit comprises a CAN chip; the power supply circuit is respectively connected with the control chip and the CAN chip and is provided with a protection circuit.

The vehicle-mounted power supply generally supplies 12V, and the common CAN chip and the common control chip supply voltages are 5V and 3.3V. Therefore, a special power circuit is needed to be arranged to supply power to the chips of the modules by utilizing the vehicle-mounted power supply, and the space occupied by the additionally introduced power supply in the vehicle is reduced. In addition, because a plurality of electronic systems are generally arranged in the vehicle, the power supply environment is complex, and therefore a protection circuit is purposefully added to prevent the control module from being burnt when the power supply voltage is too high or the power supply is reversely connected.

Preferably, the CAN communication circuit is also provided with a CAN protection circuit; the CAN protection circuit comprises a common mode inductor and a TVS protection diode.

Because a plurality of electronic systems are generally arranged in a vehicle, electronic signal lines are dense, coupling is easy to generate, and influence is generated on a measurement result, and therefore, the common-mode inductor and the TVS protection diode are arranged to reduce influence.

Preferably, the present application further comprises an electrode module; the electrode module is respectively connected with the electrocardiosignal detection module and the human body component detection module; the electrode module is provided with two electrodes.

The ECG signal is measured by ECG. The ECG adopts two metal electrodes to realize measurement, and the metal electrode slice can be flexibly arranged at each part in the vehicle, thereby being convenient for the measurement posture of the tested person to the maximum extent, and particularly ensuring the safety of the driver during driving.

In addition, the metal electrodes can also form an exciting electrode and a detecting electrode to complete the detection of human body components such as body fat.

Preferably, the electrocardiosignal detection module comprises a primary amplification circuit, a secondary amplification circuit, a lead falling detection module and a lead shielding driving module; the first-stage amplifying circuit is connected with two electrodes of the electrode module; the second-stage amplifying circuit is connected with the analog switch of the processing module.

The lead falling detection module is used for detecting whether the detected human body is in good contact with the electrode module or not, and avoiding outputting wrong results under the condition of poor contact or no contact.

The lead shielding driving module is used for avoiding a large amount of interference mixed with the acquired signals due to the fact that distributed capacitance in the lead reduces input impedance of the system.

To sum up, the beneficial effect of this application is: the vehicle-mounted environment is fully utilized, and a small number of circuit modules are utilized to complete long-term real-time measurement of a plurality of human health parameters. Meanwhile, the measuring device is flexible in arrangement, and detection of a driver can be guaranteed on the premise of safe driving.

Drawings

FIG. 1 is a schematic structural diagram of the present application;

FIG. 2 is a schematic diagram of a power circuit according to the present application;

FIG. 3 is a schematic diagram of a stage of an amplifying circuit according to the present application;

FIG. 4 is a schematic diagram of a conductor shield driving circuit according to the present application;

FIG. 5 is a schematic diagram of a two-stage amplifying circuit according to the present application;

FIG. 6 is a schematic diagram of a CAN communication circuit according to the present application;

fig. 7 is a schematic circuit diagram of the human body composition detection module according to the present application.

Detailed Description

The application is further illustrated by the following examples in conjunction with the accompanying drawings:

example 1: referring to fig. 1-7, a vehicle-mounted health parameter measuring device based on a CAN bus comprises an electrocardiosignal detection module, a human body composition detection module and a control module; the control module comprises a CAN communication circuit and an analog switch; the control module is connected with the vehicle machine system through the CAN communication circuit, and the control module is respectively connected with the electrocardiosignal detection module and the human body composition detection module through the analog switch.

The electrode module is arranged on the steering wheel, and two electrodes arranged on the left side and the right side of the steering wheel respectively contact the left hand and the right hand of a user to detect human body electric signals. The electrocardiosignal detection module sends the collected human body electric signals to the control module, and the control module obtains relevant characteristic parameters of the electrocardiosignals by calculating and analyzing the human body electric signals, such as: the heart rate, the respiration rate, the heart rate variability, the arrhythmia, the QT interval, the electrocardiographic waveform and the like are sent to a vehicle-mounted central control display.

The electrodes on the left and right sides also form exciting electrodes HF _ L A1 and HF _ RA1, one electrode is responsible for emitting sinusoidal current exciting signals, the other electrode is responsible for receiving the current exciting signals, meanwhile, the two electrodes form a pair of detection electrodes HF _ L A2 and HF _ RA2, the impedance measuring module applies safe current to the human body through the electrode module, the voltage of the corresponding part of the human body is detected through the electrodes, the voltage signals are sent to the control module after A/D conversion for calculation and analysis to obtain the impedance of the human body, and then characteristic parameters of human body components, such as body fat rate, human body water proportion, basal metabolism, visceral fat grade and the like, are calculated by combining with a human body model and sent to a vehicle-mounted central control for display.

The electrocardiosignal detection module and the human body component detection module simulate switch switching and time-sharing multiplexing.

The control module also comprises a control chip and a power circuit, and the CAN communication circuit comprises a CAN chip; the power circuit is respectively connected with the control chip and the CAN chip and is provided with a protection circuit;

the CAN communication circuit is also provided with a CAN protection circuit; the CAN protection circuit comprises a common mode inductor and a TVS protection diode;

the electrode module is respectively connected with the electrocardiosignal detection module and the human body component detection module; the electrode module is provided with two electrodes;

the electrocardiosignal detection module comprises a primary amplification circuit, a secondary amplification circuit, a lead falling detection module and a lead shielding driving module; the first-stage amplifying circuit is connected with two electrodes of the electrode module; the second-stage amplifying circuit is connected with the analog switch of the processing module.

The electrocardiosignal passes through a 0.05 Hz-100 Hz band-pass filter and a 50Hz power frequency wave trap, then secondary amplification and a voltage adjusting circuit are carried out to limit the waveform amplitude within an A/D measuring range, and the signal after A/D conversion is sent to a control module for processing. Wherein, the first-stage amplifying circuit and the second-stage amplifying circuit mainly realize the 1000-time amplification of the electrocardiosignal. The lead shielding driving circuit mainly has the function of improving the work mode suppression ratio of the system, so that the quality of signals acquired by the system is improved. The lead falling detection circuit is mainly used for monitoring whether a lead wire is connected to a system in real time.

Because the electrocardiosignal is weak, when the front-end amplification chip of the primary amplification circuit module is selected, a chip with strong current interference resistance and voltage interference resistance, high input impedance, small input bias current and offset voltage and high common mode rejection ratio is selected. In this embodiment, an AD8232 chip is selected as a first-stage amplification chip of the system. The AD8332 has a lead falling detection function, can be used for detecting whether the contact between a human body and the electrode module is good or not, carries out corresponding detection when the contact is good, and otherwise gives a lead falling prompt to remind a tester of timely adjustment.

The power frequency of 50Hz is the main interference of electrocardiosignals, in the embodiment, the MCP6002 chip is adopted to form a Butterworth band elimination filter to realize power frequency filtering, the attenuation at the position of the central frequency of 50Hz is not lower than 35dB, and the central frequency precision is +/-0.1%, and adjustment is not needed. As shown in figure 5, the first stage operational amplifier of the MCP6002 forms a Butterworth band elimination filter, electrocardiosignals are mainly concentrated in the range of 0.05-100Hz, and in order to reduce the influence of signals above 100Hz on the electrocardiosignals, the second stage operational amplifier forms a high-pass filter and a second stage amplification circuit, which are used for filtering direct current components in the circuit and inhibiting the baseline drift of the signals, and the cut-off frequency is 0.1 Hz.

The embodiment can enable the driver to complete long-term and real-time measurement of a plurality of health numbers of the driver under the condition of keeping a safe driving posture.

Example 2: the measurement principle is the same as that of embodiment 1, except that two electrode plates of the electrode module are respectively arranged on one side of the vehicle door and the central armrest, so that the passenger can complete the measurement when riding the vehicle.

The above embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention, and it should be noted that any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are within the protection scope of the present invention.

Claims

1. A vehicle-mounted health parameter measuring device based on a CAN bus is characterized by comprising an electrocardiosignal detection module, a human body composition detection module and a control module; the control module comprises a CAN communication circuit and an analog switch; the control module is connected with the vehicle machine system through the CAN communication circuit, and the control module is respectively connected with the electrocardiosignal detection module and the human body composition detection module through the analog switch.

2. The CAN bus-based vehicle-mounted health parameter measuring device according to claim 1, wherein the control module further comprises a control chip and a power circuit, and the CAN communication circuit comprises a CAN chip; the power supply circuit is respectively connected with the control chip and the CAN chip and is provided with a protection circuit.

3. The vehicle-mounted health parameter measuring device based on the CAN bus as claimed in claim 2, wherein the CAN communication circuit is further provided with a CAN protection circuit; the CAN protection circuit comprises a common mode inductor and a TVS protection diode.

4. The vehicle-mounted health parameter measuring device based on the CAN bus as claimed in claim 3, further comprising an electrode module; the electrode module is respectively connected with the electrocardiosignal detection module and the human body component detection module; the electrode module is provided with two electrodes.

5. The CAN bus-based vehicle-mounted health parameter measuring device as claimed in claim 4, wherein the electrocardiosignal detection module comprises a primary amplification circuit, a secondary amplification circuit, a lead fall-off detection module and a lead shielding driving module; the first-stage amplifying circuit is connected with two electrodes of the electrode module; the second-stage amplifying circuit is connected with the analog switch of the processing module.