Materials, Devices and Systems Division, School of Electrical and Electronic Engineering, The University of Manchester, Manchester, U.K.
Sammy Krachunov
Department of Chemical Engineering and Biotechnology, Centre for Doctoral Training in Sensor Technologies and Application, University of Cambridge, Cambridge, U.K.
James Pope
SPHERE Interdisciplinary Research Centre, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, University of Bristol, Bristol, U.K.
Section for Embedded Systems Engineering, DTU Compute, Technical University of Denmark, Kongens Lyngby, Denmark
Robert J. Piechocki
SPHERE Interdisciplinary Research Centre, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, University of Bristol, Bristol, U.K.
Ian Craddock
SPHERE Interdisciplinary Research Centre, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, University of Bristol, Bristol, U.K.
Cardiovascular diseases are the leading cause of death in the U.K., motivating the use of long term wearable devices to monitor the heart in out-of-the-clinic settings. While a wide number of heart rate measuring wearable devices are now available, they are principally based upon photoplethysmography rather than the electrocardiogram (ECG) and are stand-alone devices rather than integrated with Internet-of-Things infrastructures which collect and combine information from a wide range of sensors. This paper presents a wrist worn ECG sensor which integrates with the SPHERE IoT platform-the UK's demonstrator platform for health monitoring in the home environment, combining a range of on-person and ambient sensors. The ECG device integrates ultralow power consumption electronics with personalizable 3-D printed casings which maintain gold standard Ag/AgCl electrodes to provide measurements of the raw ECG waveform, heart rate, and meanNN and SDNN heart rate variability parameters. The end device allows for more than a month of battery life for a weight of <;50 g including the watch straps. The design and heart sensing performance of the device are presented in detail, together with the integration with the SPHERE IoT platform.
