Testbed Produces a Wearable Board and Algorithm to Advance Circadian Rhythm Estimation

Achievement date: 

Richard Sawyer, a student in the Research Experiences for Undergraduates (REU) program at the Lighting Enabled Systems & Applications ERC (LESA) – a National Science Foundation (NSF)-funded Engineering Research Center (ERC) headquartered at Rensselaer Polytechnic Institute – designed a wearable data acquisition board for human circadian rhythm estimation. The circadian rhythm sensor is significantly more advanced than actigraph sensors commonly used today.


Circadian rhythm regulation, known as entrainment, is critical to the well-being of most living organisms. In humans, circadian disruption has been linked to cancer, heart disease, diabetes, digestive problems, and a myriad of other health problems. The wearable board is capable of interfacing with light (intensity and spectra), activity, pulse rate, and higher accuracy temperature measurements that can be set to an algorithm for circadian rhythm measurement and light-based control developed at the Smart Lighting ERC.


Research being conducted in the LESA ERC’s Drosophila Testbed is leading to new models for estimating circadian rhythm and developing light-based, automated control algorithms for achieving optimal circadian rhythm maintenance in humans. This research is a key part of the ERC’s vision for using smart lighting systems to foster human health.

Circadian rhythms are light-driven physical, mental, and behavioral changes that follow a roughly 24-hour cycle, derived primarily from light and darkness cycles in an organism’s environment. Circadian rhythms impact sleep-wake cycles, hormone release, body temperature and other important bodily functions. The new wearable circadian rhythm sensor robustly extracts the underlying periodic signal from noisy data, seamlessly integrates sensor data from multiple sources, and fits to a model for prediction and control.