Multimodal Smart Eyewear for Longitudinal Eye Movement Tracking

• Published in: Matter Vol. 3; no. 4; pp. 1275 - 1293
• Main Authors: Homayounfar, S. Zohreh, Rostaminia, Soha, Kiaghadi, Ali, Chen, Xingda, Alexander, Emerson T., Ganesan, Deepak, Andrew, Trisha L.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 07.10.2020
• Subjects: electro-oculography; eye movement; hydrogel electrode; pressure sensor; smart garment; hydrogel electrode; pressure sensor; electro-oculography; MAP4: Demonstrate; smart garment; eye movement
• ISSN: 2590-2385; 2590-2385
• DOI: 10.1016/j.matt.2020.07.030

Contextual measurements of multiple physiological signals using familiar garments or accessories can provide insights into health and behavior. Recording these signals on or near the face is challenging because most subjects are sensitive to implements placed on the face or head. Here, fabric electrodes and garment design strategies are used synergistically to afford an unobtrusive platform, Chesma, for longitudinal acquisition of physiological signals from a user's face. Chesma contains two novel fabric-based electrodes: a hydrogel electrode (tAgTrode) that retains its ionic character after multiple uses/washes, does not cause skin irritation, and can be continuously operated for upward of 8 h without losing signal integrity. Second is an ion-conductive fabric pressure sensor (Press-ION) that captures pulse waveforms. When sewn onto a lightweight eye mask, these electrodes simultaneously gather complementary electro-oculography and cardiac data, which can enable sleep quality and psychological studies and improve the accuracy and usability of virtual reality headsets. [Display omitted] •Initiated chemical vapor deposition affords a reusable hydrogel electrode on fabrics•An ion-conductive fabric electrode measures pulse waveforms when placed on the face•Eye masks decorated with fabric hydrogel electrodes allow for wireless eye tracking•Chesma, a lightweight and tailorable mask, simultaneously tracks eye motion and pulse Unobtrusive, contextual measurements of multiple, complementary physiological signals using familiar garments or accessories can provide deep insights into health and behavior. Recording these signals on or near the face is challenging because most subjects are particularly sensitive and reactive to implements placed on the face or head. These practical considerations limit development of improved technology that can accurately monitor the ophthalmological and cardiac signals needed for studies on sleep quality and mental health. Here, we show how fabric-based electrodes and garment design methods work synergistically to afford an unobtrusive platform, Chesma, for longitudinal monitoring of pulse and eye parameters in everyday environments. Being able to track pulse and eye movement in a single wearable device will enable a host of biomedical, physiological, and psychosocial studies, in addition to improving the accuracy and usability of gaming and virtual reality headsets. We present a first-of-its-kind fabric hydrogel electrode that is reusable and washable, does not cause skin irritation, and can be continuously operated for upward of 8 h without losing signal integrity. Second, we report an ion-based fabric pressure sensor that measures pulse waveforms when placed on the face. We decorate a lightweight eye mask with these novel fabric electrodes to create a portable detection platform named “Chesma,” which can wirelessly track eye motion and pulse in natural environments over long periods of time.