Wireless PPG Heart Rate Monitoring
Development of a Wireless PPG-Based Heart Rate Monitoring System
A wireless system that reads heart-rate signals from the finger and the wrist at the same time, built to attack a long-standing problem: the signal falls apart the moment the wearer moves.
- Role
- Visiting Student Researcher
- Period
- Feb. 2025 – Present
- Institution
- Stony Brook University Supervised by Dr. Shan Lin
Why this matters
Photoplethysmography is how a smartwatch measures heart rate, but it is extremely sensitive to motion — a shake of the hand can bury the pulse under noise. Getting trustworthy data during real activity means first knowing which segments were corrupted by movement.
What I did
- Designed and implemented a wireless system for synchronous acquisition of finger- and wrist-based PPG signals, enabling time-aligned multi-channel data transmission.
- The first build ran on an ESP8266, but the link was unstable enough that measurements still depended on cables — a wireless rig that left the subject tethered, which defeats the point. Moving to the ESP32 with the ESP-NOW protocol cut latency and held the link steady; only then could subjects move freely, which is the precondition for the whole study.
- Incorporated motion event detection to identify motion-induced artifacts and support robust signal segmentation under dynamic conditions.
- Improved the device's efficiency and stability in practical applications through wireless communication technology and low-power design.
- Integrated signal processing features with machine learning models to analyze cross-channel similarity and improve the robustness of identity consistency assessment.
- Extended the system architecture to support additional sensing channels and ongoing refinement of signal processing methods for operation under motion and environmental variability.
Technologies
- Embedded Systems
- Wireless Communication
- Low-Power Design
- Signal Processing
- Machine Learning
- PPG Sensing