Remote Patient Monitoring

Photoplethysmography (PPG), now ubiquitous within wearables of all form-factors, has become the workhorse of biometric wearable sensor technology. Once limited to the resting use case of fingertip pulse oximetry in hospitals and clinics, contemporary innovations have liberated PPG technology for use in a diversity of form-factors (earbuds, wrist devices, armbands, smart rings, patches, eye-wear, etc.) and a diversity of free-living use cases, spanning from exercise monitoring in sports and fitness to continuous medical monitoring in telehealth. Moreover, the artificial intelligence (AI) revolution has positioned PPG at the heart of sensor fusion applications, where numerous miniaturized, orthogonal sensors contribute towards advanced biometric monitoring solutions. While many technical challenges confronting the scalability of PPG in wearables have been addressed over the past decade, many still remain. Limitations associated with PPG motion artifacts have become so stubbornly endemic that many manufacturers have simply “thrown-in the towel” in making meaningful improvements, thereby precluding important new use cases. Additionally, PPG has faced challenges in enabling accurate medical monitoring across a broad diversity of patients having a broad diversity of physical characteristics, such as differences in skin tone and vascular health. Fortunately, through a combination of thoughtful use case planning, modern technical innovations, and comprehensive clinical experimental design, these challenges can be overcome. Ultimately, PPG of the future will provide data that is more accurate (for all form-factors and activities), more available (for all use cases), and more generalizable (for a broad diversity of patient populations), enabling medical use cases that improve patient health, make life easier for medical professionals, and reduce lifetime healthcare costs for healthcare payors.