Signal or Noise? How User Movement and Sensor Placement Impact Physiological Data Collection in 6DoF Virtual Reality

To evaluate user experience in Virtual Reality (VR), researchers are increasingly using physiological data, such as electrocardiograms (ECG) and electrodermal activity (EDA), in conjunction with questionnaires. However, in 6-Degrees-of-Freedom VR, user movements and interactions can introduce noise on captured signals, making them potentially unusable. This noise depends on the movements performed and on sensor positions. Unfortunately, no study has addressed this issue, significantly hindering the effective use of physiological data in VR. To address this gap, we conducted a user study to evaluate the effects of sensor positions and user movements on signal quality, as well as sensor comfort and intrusiveness. We compared three positions for EDA and two for ECG on 36 users, who performed a series of five gestures. Results indicate that positioning EDA sensors on the palm offers the best balance between signal quality and user comfort. For ECG, a position closer to the heart is better. Most tested movements affect quality, with the worst being when users close their hand (for ECG and EDA) and move their arm (for ECG), where sensors are located. Based on these findings, we provide recommendations for the effective use of EDA and ECG sensors in 6DoF VR.