Electronic Textile-Based Sensors and Systems for Long-Term Health Monitoring by Carey

MERRITT, CAREY REID. Electronic Textile-Based Sensors and Systems for Long-Term Health Monitoring. (Under the direction of Edward Grant). Personalized long-term health monitoring has the potential to improve medicine’s capabilities for diagnosing and correctly treating diseases at an early stage. Recently, progress has been made towards producing clothing that is suitable for such long-term monitoring. This work first reviews the current electronic textile based sensors that are used to measure two vital healthcare parameters, ECG and respiration. The techniques used for designing and fabricating these sensors are discussed and summarized. Furthermore, recommendations are proposed in regards to the development of an unobtrusive, wireless health monitoring garment. The second part of this research involved designing and fabricating two versions of fabric based active electrodes to provide a solution for long-term ECG monitoring clothing. The first version of active electrode involved attaching surface mountable components directly to a textile screen printed circuit using polymer thick film techniques. The second version involved attaching a significantly smaller active electrode interposer board to a simplified electronic textile circuit. Results from ECG tests on the active electrodes indicate that the performance of these new devices is comparable to commercial Ag/AgCl electrodes. The interposer based active electrodes were even found capable of surviving a five cycle washing test. This research also explores the potential for using capacitive sensing to serve as an inexpensive method for long-term respiration sensing. Two capacitive sensors were designed and fabricated for detecting chest or abdominal circumference changes. These sensors gave good linearity, sensitivity, and resolution. Respiration measurements obtained with these new sensors that were implemented into a prototype belt show that they are capable of measuring respiration rate and possibly lung function parameters. Finally this research presented a new modular wireless sensor node (MWSN) system for health monitoring clothing applications. The applications for this research involved integrating the MWSN into a custom designed ECG belt, a capacitive sensor respiration belt and an activity patch. Results obtained from these applications demonstrate that the MWSN is capable of interfacing with a diverse selection of health monitoring sensors while maintaining signal fidelity. Electronic Textile-Based Sensors and Systems for Long-Term Health Monitoring by Carey Reid Merritt A dissertation submitted to the Graduate Faculty of North Carolina State University In partial fulfillment of the Requirements for the degree of Doctor of Philosophy Electrical Engineering Biomedical Engineering Raleigh, North Carolina