Wearable wireless heart rate monitor for continuous long-term variability studies.

Prototyping of a home care system for activity surveillance and sleep assessment targeted to elderly people involves the compromise of wearing comfort and measurement performance. We propose a wearable heart rate variability monitor connected via wireless digital link to a home-embedded infrastructure of multimodal health surveillance system. The coin-size wearable recorder acquires and processes the electrocardiogram and sends annotated tachogram data accordingly to the subject's status and programed schedule. Thanks to remote programmability, in case of predefined thresholds excess, the recorder response is immediate, whereas the regular reports are organized in packets and delivered in bulk in short transmission sessions. This approach significantly reduces the data rate and the energy required to supply the communication module. The prototype weighting 11.2 g is based on the ARM7 (Atmel Corporate Headquarters 2325 Orchard Parkway San Jose, CA, USA) processor running at 18 MHz and with a 300-mA h rechargeable battery allows for up to 10 days of seamless tachogram monitoring.