In recent years, several wearable devices have been proposed for monitoring nutrition intake, tracking energy expenditure, and performing activity recognition. Long device lifetimes are critical because frequent battery replacements increase user burden and yield poor long-term compliance rates.
Though countless wearable devices have been proposed in recent years with varying sensors and applications, most system flows are generalizable in terms of their major components: sampling, buffering, processing, and transmission. In this paper, we discuss and evaluate energy-efficiency optimizations for wearable devices, using the NIMON nutrition-monitoring necklace as a case study.