Research Of VOCs Gas Detection System For Lung Cancer

As a common malignant tumour, lung cancer leads to a lower survival rate because of its late exact diagnosis, so its early detection is very important.In this article, the methods on VOCs gas detection in disease diagnosis, especially on lung cancer detection were introduced. A VOCs gas detection system for lung cancer was designed based on the response mechanism of the porphyrin sensor to VOCs gas.The main work of this thesis is listed as follows:â‘ According to the requirements of the lung cancer breath detection system's function, the master and slave structure of the hardware was selected. The entire system was controlled by the master computer Micro-PC, while the reaction conditions of flow, humidity and temperature were monitored and controlled by the slave MCU PIC16F877A.â‘¡Based on the MPLAB development environment, the control programs of the peripheral modules, which included the monitoring module of reaction conditions, the controlling module of reaction conditions, the LED lighting module and the USB 100 communication module, were compiled for the PIC MCU. According to the work flow of the detection system, the main controlling program of PIC MCU was designed.â‘¢Based on the fact that the detection result can be impacted by the flow change of sampling gas, a flow control system based on increment PID algorithm was designed.â‘£The functions of the detection system have been tested. Nine VOCs markers of lung cancer were detected. The conclusions that preliminary qualitative identification can be achieved, and quantitative identification also is feasible, have been confirmed.