Development of a Compact, IoT-Enabled Electronic Nose for Breath Analysis

• Main Authors: Akira Tiele, Alfian Wicaksono, Sai Kiran Ayyala, James A. Covington
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Electronics
• Subjects: breath analysis; electronic nose (e-nose); internet-of-things (iot)
• Online Access: https://www.mdpi.com/2079-9292/9/1/84

In this paper, we report on an in-house developed electronic nose (E-nose) for use with breath analysis. The unit consists of an array of 10 micro-electro-mechanical systems (MEMS) metal oxide (MOX) gas sensors produced by seven manufacturers. Breath sampling of end-tidal breath is achieved using a heated sample tube, capable of monitoring sampling-related parameters, such as carbon dioxide (CO₂), humidity, and temperature. A simple mobile app was developed to receive real-time data from the device, using Wi-Fi communication. The system has been tested using chemical standards and exhaled breath samples from healthy volunteers, before and after taking a peppermint capsule. Results from chemical testing indicate that we can separate chemical standards (acetone, isopropanol and 1-propanol) and different concentrations of isobutylene. The analysis of exhaled breath samples demonstrate that we can distinguish between pre- and post-consumption of peppermint capsules; area under the curve (AUC): 0.81, sensitivity: 0.83 (0.59&#8722;0.96), specificity: 0.72 (0.47&#8722;0.90), <i>p</i>-value: &lt;0.001. The functionality of the developed device has been demonstrated with the testing of chemical standards and a simplified breath study using peppermint capsules. It is our intention to deploy this system in a UK hospital in an upcoming breath research study.