A Novel Multi-sensor Detection System Design for Low Concentrations of Volatile Organic Compounds

In this paper, we investigate a novel multi-sensor odor detection system (electronic nose) for low concentration volatile organic compounds (VOCs). In order to break through the limitation for detecting low concentration volatile organic compounds, we design a conformal symmetric pre-concentration unit structure based on the finite element method. A typical application for exhaled breath is developed to investigate the proposed scheme. The designed pre-concentration system can increase the concentration of the concentrated substance, so that the sensor can detect it. Besides, we choose the alveolar gas at the bottom of the human lung, which can better represent the health status of the human body, to carry out the effectiveness test of the system. In order to combine the gas acquisition system with the pre-concentration system, this paper further designs a cost-effective alveolar gas collection device by a doubled adaptive Pulse Width Modulation (PWM) operation. Finally, the effectiveness of the pre-concentration system is judged by the detection results of gas chromatography-mass spectrometry (GC-MS). We also use the classical algorithm to classify lung cancer and non-lung cancer patients, which proves the effectiveness of our proposed integrated design system and shows the potential of practical application of the system.