PPG-Based Heart Rate & SpO₂ Sensor System

Research project, Western University.

Designed an analog front-end for photoplethysmography (PPG) using an LED driver and a photodiode sensing
Implemented a transimpedance amplifier (TIA) with adaptive gain to handle a wide dynamic range
Developed synchronous detection techniques to improve signal extraction under ambient light
Supported SpO₂ estimation (red/IR switching) and optimized for low-power wearable operation
Validated performance across varying skin tones and motion conditions