Dry electrode geometry optimization for wearable ECG devices

Wearable electronic devices, particularly for health monitoring, have seen rapid advancements in recent times. Among the various biophysical parameters that are of interest in a wearable device, an electrocardiogram (ECG) is critical as it enables detection of cardiovascular-related ailments and assessment of overall cardiac health. In a wearable ECG device, the choice of electrode design and material plays a key role in the performance of the sensor. In this work, we have explored various dry electrode-based sensor design geometries to realize a compact, lightweight, portable, gel-free wearable ECG patch that would aid in point-of-care (PoC) diagnostics. Furthermore, we have studied the influence of the region of the body at which the measurements were made under different body positions across varying external stimuli. We have studied the influence of surface area, perimeter and resistance offered by the electrodes on the ECG signal acquisition, its effects on device performance and found the hexagonal labyrinth configuration to be the most suitable candidate. A prototype of a wearable ECG patch was made by combining this electrode configuration and interfacing with wireless communication capabilities, and the results were compared with a commercially available portable ECG monitor. Such a device could find potential application in remote healthcare and ambulatory care settings, and as a PoC and a preventive medical device.