Background
A range of smart watches and fitness bands now monitor the pulse oximetry signal (also known as the photoplethysmogram, or PPG signal), from which they derive the user's heart rate. The aim of this project is to assess the feasibility of acquiring PPG data during daily living. If it is feasible, then furthe research could be conducted to develop tools to extract further parameters from the PPG, which may be indicative of the user's health. However, most wearable devices only output the heart rate derived from the PPG signal, and not the PPG signal itself. Therefore, this study will use a specialist device which does provide the PPG signal, but has the disadvantages of being slightly larger than a typical watch, and using a pulse oximetry probe which wraps around the finger or thumb to acquire the signal. Therefore, it is not clear whether this device will be suitable for use in daily living.
The principal research question addressed by this study is whether PPG signals can be acquired using a wearable device during daily living. This is the first pilot study, and it is not powered to provide a statistically significant result. If successful, then this study will provide evidence to support further studies into the use of PPG signals acquired during daily living. Furthermore, the data acquired in this study is expected to be hypothesis generating.