Abstract
This project advances the development of a wearable ECG “smart shirt” by combining electrode material innovation, impedance characterization, and full hardware–software integration. Novel PEDOT: PSS-CMC hydrogels, carbon fabrics, and silver cloth electrodes were synthesized and tested under stationary and overnight conditions, with crosslinking, ultrasonic treatments, and vapor-barrier or sponge-wick strategies extending hydration and enabling stable ECG signals for over 12 hours. A dedicated Arduino Nano 33 IoT–based impedance measurement device was developed to quantify electrode–skin interactions with ~5% accuracy over 100 Ω–1 MΩ, addressing the limitations of DC-only resistance measurements. In parallel, a complete ECG system was built using an AD8232 front-end and Arduino Nano ESP32, implementing Pan–Tompkins QRS detection and arrhythmia classification with wireless BLE/Wi-Fi data transmission to companion PC and iOS applications for real-time visualization and alerts. Together, these efforts demonstrate a pathway toward a washable, comfortable, and reliable ECG shirt that integrates optimized electrode materials with robust signal processing and communication, enabling long-term monitoring, arrhythmia detection, and timely alerts for at-risk individuals.