Smart Socks -- Heart Failure Detector

Week 3 Progress: Component Selection and Testing Over the past two weeks, I focused on circuit design and physical assembly. To improve wearability and user comfort, I decided not to use pin headers  and instead directly soldered the components together. Although the soldering process was time-consuming—mainly due to the small size of the connector holes—the connections were eventually completed successfully.

Week 2 Progress: System Testing and Redesign Planning II Over the past two weeks, my main tasks were ordering and testing the required electronic components. The new design uses the Seeed Studio NRF52840 microcontroller, which is significantly smaller—about half the size of the previous Arduino Nano—and comes without pre-soldered headers, improving overall wearability and user comfort. For motion detection, two flex sensors are used to measure ankle bending angles. A resistor is placed between them to form a voltage divider. To reduce signal noise, an op-amp is included in the circuit as an impedance buffer . The system is powered by a 3.7V lithium battery , which connects to the microcontroller through a charging module . After initial testing, all components are functioning properly, and full system assembly will begin next week.

Week 1 Progress: System Testing and Redesign Planning During the first two weeks of the project, my main task was to test the previous prototype and develop improvement plans based on its performance. The system consists of two main parts: a wristband and an anklet module. As shown in the figure, the wristband worked relatively well. Once worn, it was able to accurately display heart rate and blood oxygen levels, although the SpO₂ readings occasionally showed inconsistencies. In contrast, the anklet system had several issues. It frequently produced errors during testing and often triggered false alarms when tested with a 3D-printed cone-shaped object. Additionally, the circuit design was overly complex and bulky, making it uncomfortable to wear.