Application of subject-specific helmets for the study of human visuomotor behavior using transcranial focused ultrasound: a pilot study

Tae Young Park; Ji Hyeok Jeong; Yong An Chung; Sang Hoon Yeo; Hyungmin Kim

doi:10.1016/j.cmpb.2022.107127

Application of subject-specific helmets for the study of human visuomotor behavior using transcranial focused ultrasound: a pilot study

Comput Methods Programs Biomed. 2022 Nov:226:107127. doi: 10.1016/j.cmpb.2022.107127. Epub 2022 Sep 13.

Authors

Tae Young Park¹, Ji Hyeok Jeong², Yong An Chung³, Sang Hoon Yeo⁴, Hyungmin Kim⁵

Affiliations

¹ Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
² Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Department of Brain and Cognitive Engineering, Korea University, Seoul, 136-713, Republic of Korea.
³ Incheon St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
⁴ School of Sport, Exercise & Rehabilitation Sciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom. Electronic address: s.yeo@bham.ac.uk.
⁵ Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea. Electronic address: hk@kist.re.kr.

PMID: 36126434
DOI: 10.1016/j.cmpb.2022.107127

Abstract

Background and objective: As a novel non-invasive human brain stimulation method, transcranial focused ultrasound (tFUS) is receiving growing attention due to its superior spatial specificity and depth penetrability. Since the focal point of tFUS needs to be fixated precisely to the target brain region during stimulation, a critical issue is to identify and maintain the accurate position and orientation of the tFUS transducer relative to the subject's head. This study aims to propose the entire framework of tFUS stimulation integrating the methods previously proposed by the authors for tFUS transducer configuration optimization and a subject-specific 3D-printed helmet, and to validate this complete setup in a human behavioral neuromodulation study.

Methods: To find the optimal configuration of the tFUS transducer, a numerical method based on subject-specific tFUS beamlines simulation was used. Then, the subject-specific 3D-printed helmet has been applied to effectively secure the transducer at the estimated optimal configuration. To validate this tFUS framework, a common behavioral neuromodulation paradigm was chosen; the effect of the dorsolateral prefrontal cortex (DLPFC) stimulation on anti-saccade (AS) behavior. While human participants (n=2) were performing AS tasks, tFUS stimulations were randomly applied to the left DLPFC right after the fixation target disappeared.

Results: The neuromodulation result strongly suggests that the cortical stimulation using the proposed tFUS setup is effective in significantly reducing the error rates of anti-saccades (about -10 %p for S1 and -16 %p for S2), whereas no significant effect was observed on their latencies. These observed behavioral effects are consistent with the previous results based on conventional brain stimulation or lesion studies.

Conclusions: The proposed subject-specific tFUS framework has been effectively used in human neuromodulation study. The result suggests that the tFUS stimulation targeted to the DLPFC can generate a neuromodulatory effect on AS behavior.

Keywords: DLPFC; Focused ultrasound; anti-saccade; neuromodulation; transcranial; visuomotor behavior.

MeSH terms

Brain / diagnostic imaging
Brain / physiology
Brain Mapping* / methods
Head Protective Devices*
Humans
Pilot Projects
Transducers