Conformal in-ear bioelectronics for visual and auditory brain-computer interfaces

Zhouheng Wang; Nanlin Shi; Yingchao Zhang; Ning Zheng; Haicheng Li; Yang Jiao; Jiahui Cheng; Yutong Wang; Xiaoqing Zhang; Ying Chen; Yihao Chen; Heling Wang; Tao Xie; Yijun Wang; Yinji Ma; Xiaorong Gao; Xue Feng

doi:10.1038/s41467-023-39814-6

Conformal in-ear bioelectronics for visual and auditory brain-computer interfaces

Nat Commun. 2023 Jul 14;14(1):4213. doi: 10.1038/s41467-023-39814-6.

Authors

Zhouheng Wang^#^{1

2}, Nanlin Shi^#³, Yingchao Zhang², Ning Zheng⁴, Haicheng Li^{1

2}, Yang Jiao^{1

2}, Jiahui Cheng^{1

2}, Yutong Wang^{1

2}, Xiaoqing Zhang⁵, Ying Chen⁶, Yihao Chen^{1

2}, Heling Wang^{1

2}, Tao Xie⁴, Yijun Wang⁷, Yinji Ma^{8

9}, Xiaorong Gao¹⁰, Xue Feng^{11

12}

Affiliations

¹ Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China.
² AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China.
³ Department of Biomedical Engineering, Tsinghua University, Beijing, 100084, China.
⁴ State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
⁵ Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
⁶ Institute of Flexible Electronics Technology of THU, Zhejiang, Jiaxing, 314000, China.
⁷ Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
⁸ Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China. mayinji@tsinghua.edu.cn.
⁹ AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China. mayinji@tsinghua.edu.cn.
¹⁰ Department of Biomedical Engineering, Tsinghua University, Beijing, 100084, China. gxr-dea@mail.tsinghua.edu.cn.
¹¹ Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China. fengxue@tsinghua.edu.cn.
¹² AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China. fengxue@tsinghua.edu.cn.

^# Contributed equally.

Abstract

Brain-computer interfaces (BCIs) have attracted considerable attention in motor and language rehabilitation. Most devices use cap-based non-invasive, headband-based commercial products or microneedle-based invasive approaches, which are constrained for inconvenience, limited applications, inflammation risks and even irreversible damage to soft tissues. Here, we propose in-ear visual and auditory BCIs based on in-ear bioelectronics, named as SpiralE, which can adaptively expand and spiral along the auditory meatus under electrothermal actuation to ensure conformal contact. Participants achieve offline accuracies of 95% in 9-target steady state visual evoked potential (SSVEP) BCI classification and type target phrases successfully in a calibration-free 40-target online SSVEP speller experiment. Interestingly, in-ear SSVEPs exhibit significant 2^nd harmonic tendencies, indicating that in-ear sensing may be complementary for studying harmonic spatial distributions in SSVEP studies. Moreover, natural speech auditory classification accuracy can reach 84% in cocktail party experiments. The SpiralE provides innovative concepts for designing 3D flexible bioelectronics and assists the development of biomedical engineering and neural monitoring.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Brain-Computer Interfaces*
Calibration
Electroencephalography
Evoked Potentials, Visual
Humans
Language
Photic Stimulation