An ultra low power personalizable wrist worn ECG monitor integrated with IoT infrastructure

Cardiovascular diseases are the leading cause of death in the UK, 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 the photoplethysmography (PPG) 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 ultra low power consumption electronics with personalizable 3D 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.