PPG Earring: Wireless Smart Earring for Heart Health Monitoring

Heart rate is a key vital sign for cardiovascular health and fitness. However, the photoplethysmography (PPG) sensors that monitor heart rate in wearables struggle with accuracy during motion. Our day-long in-the-wild study shows Fitbit measures valid heart rates only 54.88% of the time. To address this, we developed PPG Earring, which measures 14 mm in diameter, weighs 2.0 g, and offers 21 hours of continuous sensing. Our eight-user exercise study shows that PPG Earring captures valid heart rate data for 91.74 ± 4.84 % of the time during exercise and 86.29 ± 2.96% of our day-long in-the-wild study. All participants found the PPG Earring as comfortable as their regular earrings, and most participants expressed a strong willingness to wear the PPG Earring all the time every day. Our results validate the signal quality and comfort level of the PPG Earring, highlighting its potential as a daily health monitoring device.