Design Of Mixed Gas Standard Data Acquisition System Based On Sensor Array

With the development of the times,the research focus of blood glucose testing has shifted from blood glucose testing to breath testing.Respiratory testing is to detect the concentration of blood glucose markers in the human body’s exhaled mixed gas to achieve non-invasive blood glucose testing.Respiration detection equipment is composed of a mixed gas data acquisition system and a gas concentration pattern recognition system.The mixed gas data acquisition system is an important support platform for breathing detection equipment.Its development is of great significance to the study of gas concentration pattern recognition algorithms.This paper designs a mixed gas standard data acquisition system based on MEMS gas sensor array.The purpose of this paper is to study how to realize the standard data acquisition system of mixed gas for data acquisition of trace mixed gas.After analyzing the design requirements of the system,the design of the acquisition system based on the MEMS gas sensor array is proposed,and then from the hardware design and software design of the acquisition system 3.Three aspects of system testing discuss the design and verification process of the entire acquisition system.In terms of hardware design,firstly,design the gas box and the corresponding gas inlet and outlet channels for the gas test to contain the mixed gas and the gas sensor array reaction;secondly,select multiple MEMS gas sensors according to the mixed gas of acetone,ethanol,formaldehyde,and toluene.Carry out the gas sensor array design;finally select the system control unit and design the gas sensor sampling circuit.In terms of software design,the lower computer software is based on TI-RTOS to complete the sensor data acquisition program design,and the wireless data transmission program design between the lower computer and the upper computer;the upper computer software uses Lab VIEW to write the sensor data and perform the data The program block diagram of display,processing,and storage is designed with a good user interface.By setting up a mixed gas test environment,a single-gas response experiment was carried out at the end of this article.The experimental data was processed to verify the responsiveness recovery curve and sensitivity of the acquisition system.135 groups of mixed gas response experiments were carried out,using 4 mixed gas component concentrations.The algorithm recognizes the experimental data,and conducts a comprehensive power consumption test on the sensor array and the control unit at the front end of the acquisition system.Experimental verification results show that the mixed gas standard data acquisition system based on the sensor array designed in this paper supports fourchannel gas sensor data acquisition.The response time of the system is less than 50 s,the recovery time is less than 150 s,the gas concentration test limit is 0.2ppm,and the sensitivity is high.The gas component concentration algorithm has a comprehensive accuracy rate of 90.8% for the collected data recognition,the collection accuracy is better than 5‰,and the power consumption is less than 50 m W,which meets the design requirements of the mixed gas standard data collection system.