An Ultra Low Power Personalizable Wrist Worn ECG Monitor Integrated With IoT Infrastructure

Christopher Beach,Ian Craddock,Robert J Piechocki,Sammy Krachunov,Alexander J Casson,James Pope,Xenofon Fafoutis

doi:10.1109/access.2018.2864675

Christopher Beach, Ian Craddock + Show 5 more

Open Access

https://doi.org/10.1109/access.2018.2864675

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Abstract

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.

Highlights

Ageing populations are placing an increasing burden on health care services around the world
Wearable devices have recently emerged as the body worn aspect of the Internet-of-Things (IoT), monitoring health parameters over long periods of time to allow a drive towards personalized and preventative P4 medicine [5] in which data is routinely collected outside of clinical environments
We present a high input impedance, high Common-Mode Rejection Ration (CMRR) front-end circuit which is compatible with gel-free electrodes while consuming less than 10 μW of power and using only off-the-shelf electronic devices

Summary

INTRODUCTION

Ageing populations are placing an increasing burden on health care services around the world. Wearable devices have recently emerged as the body worn aspect of the Internet-of-Things (IoT), monitoring health parameters over long periods of time to allow a drive towards personalized and preventative P4 medicine [5] in which data is routinely collected outside of clinical environments. We use a 3D printed case with painted Silver/Silver-Chloride (Ag/AgCl) electrodes which allows for custom shapes and sizes of electrodes which can be made individually for each user if desired (in addition to a fixed size/shape across all people if this is preferred) This is used to provide ECG monitoring of the heart by asking users to touch the face of the wearable with a finger. In this paper we have extended this work to include 3D printed electrodes, integration with the SPHERE IoT platform, and more detailed testing of heart rate measurement accuracy, together with testing of heart rate variability performance

WRIST BASED ECG SENSING

THE SPHERE WEARABLE AND USE CASE EXAMPLE

Findings

CONCLUSION