Development of VOCs Mixture Biomarker Classification System Based on Preconcentrator with Embedded Sensing Control

A volatile organic compound (VOCs) classification system is developed for non-invasive biomarker screening tests. The developed system utilizes a preconcentrator, which contains an absorbent material for trapping VOCs at low temperatures and thermally desorbing at specific elevated temperatures. This system is especially useful for detection of odor mixture at low concentration and target VOCs biomarkers in the odor sample can also be measured with enhanced selectivity. All sensing processes, including a PID temperature controller for heating preconcentrator, odor sensor interface, and solenoid valve control, are performed using only a single embedded microcontroller. An odor mixture with low concentration is measured and classified in order to investigate the developed system. The result of the experiment and the principal component analysis (PCA) shows that the system with the preconcentrator can measure the VOCs mixture of odor sample in terms of sensitivity and selectivity. This system prototype is useful for screening tests of exhaled breath biomarker.