Document Type
Article
Original Publication Date
2015
Journal/Book/Conference Title
PNAS
Volume
112
Issue
13
DOI of Original Publication
10.1073/pnas.1424875112
Date of Submission
April 2015
Abstract
Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain–computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain–computer interface and elicitation of an event-related potential (P300 wave).
Rights
Copyright © The Authors.
Is Part Of
VCU Mechanical and Nuclear Engineering Publications
Comments
PDF presented here as originally published by PNAS at www.pnas.org/cgi/doi/10.1073/pnas.1424875112. PDF includes supplemental material.