Personalized long-term health monitoring has the potential to improve medicine’s capabilities for diagnosing and correctly treating diseases at an early stage. Here, electronic textile based sensors were designed and fabricated to measure ECG and respiration. Recommendations are made for developing an unobtrusive, wireless, health monitoring garment. Wireless sensor networks (WSN’s) provide unprecedented spatial and temporal sensory resolution.
Two versions of fabric based active electrodes were designed and fabricated for use in ECG monitoring, Figure 1 and Figure 2. In the first active electrode, surface mount components were attached directly to a textile substrate; using a screen printed circuit and polymer thick film ink. The second ECG system used an interposer board, to simplify the electronic textile circuit. These two ECG systems gave results that compared favorably to results obtained from commercially available Ag/AgCl electrodes. The interposer system even survived a five cycle washing test.
This research also explored the use of capacitive sensing for long-term respiration monitoring, Figure 3. Capacitive sensors were designed and fabricated to detected chest or abdominal circumference changes. These capacitive sensors gave good linearity, sensitivity, and resolution. Respiration measurements obtained with these new sensors were integrated into a prototype belt. Tests show that they are capable of measuring respiration rate, and possibly lung function parameters too.
Lastly, a new modular wireless sensor node (MWSN) system for wearable health monitoring is presented, Figure 4. Experiments show that the MWSN is capable of interfacing to a wide range of health monitoring sensors while maintaining signal fidelity, Figure 4. This research was funded by the National Textile Center (NTC).