Better Battery Life: Towards Energy-Efficient Smartwatch-Based Atrial Fibrillation Detection in Ambulatory Free-living Environments

Atrial Fibrillation (AF) is an important medical condition that can be passively detected and tracked using a smartwatch. Diagnosis and monitoring of AF can be more effective and reliable if the smartwatch senses continuously, but this can lead to significant battery consumption by the LED in the photoplethysmography (PPG) sensor. In this paper, we explore the feasibility of leveraging downsampling to achieve energy-efficient AF detection. We collect data from participants with paroxysmal AF in real ambulatory free-living environments using a commercial smartwatch and separately study the impact of uniform downsampling and compressed sensing on AF detection. Our results reveal that downsampling enables the AF detection system to consume about 77.4% less LED power than the original sampling strategy without a significant performance drop.