Electronic Noses for Cyber-Physical Systems

Abstract

Cyber-physical systems (CPS) use algorithms to interpret sensor’s responses and model the physical environment they are connected to. Among the many application domains where CPS are used, the health-related field is one of the most promising areas that can benefit from CPS. This paper considers the development of sensors to be integrated into an electronic nose, e-nose, that will be responsible for collecting the information to be fed to the cyber component of a CPS. The work presented addresses the challenge of detecting Volatile Organic Compounds (VOCs) in the air at low concentrations with the main goal of diagnosing diseases through breath samples, using an electronic nose (e-nose) concept. Since the identification process of several VOCs can be highly sensitive to the level of humidity in the breath samples, the incorporation of a humidity sensor in the e-nose is proposed as a way of providing information that can be used to guarantee the accuracy of the results to be obtained. To this effect, a TiO2-based sensor was tested as a solution, and preliminary results are presented. Results demonstrated clearly that it is necessary to maintain the e-nose at a controlled humidity to ensure that the responses from the different e-nose sensors are correct and reliable.