Designing Fabric Based Physiological Sensors for Virtual Reality

Abstract

This thesis explores the development of fabric electrodes for integration into Virtual Reality (VR) Head Mounted Displays (HMDs). It covers the development and validation of these novel electrodes, and their integration into a VR HMD for the collection of various physiological signals. The work detailed in this thesis has been motivated by the convergence of the fields of Extended Reality (XR) - encompassing both VR and Augmented Reality (AR) - and physiological sensing. The last decade has seen an exponential growth of commercially available, affordable physiological sensors and HMDs. This has spurred the development of new research approaches to measure quantities such as cognitive load and emotion in AR and VR. However, this work has also demonstrated a need for sensors that are not made up of hard material, or require gels or saline solutions to perform optimally. These are uncomfortable to wear, and limit the time that can be spent wearing an HMD. This thesis addresses the issue by detailing the development and validation of a comfortable fabric sensor that could be integrated into a VR HMD. As part of the development process, a gel based head phantom was also developed to test and validate these electrodes. Results demonstrate that the fabric electrode performance is on par with existing electrode types. Both gold cup electrodes and gel electrodes were comparable to the textile electrodes when tested on the phantom. The developed Galvanic Skin Respone (GSR) sensor also showed similar performance to the shimmer3 GSR+ sensor. Pilot testing with a VR HMD integrated with fabric electrodes demonstrated that they were capable of recording good quality physiological data. The electrodes also proved to be comfortable in comparison to gel based, hard plastic or metal electrodes.