Pneumatical‐Mechanical Tactile Stimulation Device for Somatotopic Mapping of Body Surface During fMRI

• Published in: Journal of magnetic resonance imaging Vol. 52; no. 4; pp. 1093 - 1101
• Main Authors: Jia, Shikui, Wang, Luyao, Wang, Heng, Lv, Xiaoyu, Wu, Jinglong, Yan, Tianyi, Li, Chunlin, Hu, Baomin
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.10.2020; Wiley Subscription Services, Inc
• Subjects: Adult; Arm; Brain Mapping; device; Field strength; fMRI; Functional magnetic resonance imaging; Humans; Magnetic fields; Magnetic Resonance Imaging; Male; Mapping; Physical Stimulation; pneumatical‐mechanical; Population studies; Prospective Studies; Scanners; Somatosensory Cortex; somatosensory mapping; Statistical analysis; Statistical methods; Statistical tests; Stimulation; tactile stimulation; Tactile stimuli; Young Adult; fMRI; tactile stimulation; device; somatosensory mapping; pneumatical-mechanical
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.27144

Background There is a need for devices that allow reproducible stimulation of skin areas of humans for investigating somatosensory mapping of the whole‐body surface. However, their design is not simple, due to the magnetic field of MRI scanners. Purpose To accurately characterize the mapping of somatosensory presentation of the whole‐body surface of subjects during functional (f)MRI scans. Study Type Prospective. Population A water phantom and six healthy participants (age 23–27 years; two males) were recruited for the fMRI experiment. Field Strength/Sequence T1‐weighted magnetization‐prepared rapid acquisition gradient‐echo, T2*‐weighted gradient echo sequence at 3T. Assessment The stimulation device for somatotopic mapping was composed of three units: an air‐generating unit, a control unit, and an execution unit. The fMRI in response to tactile stimulation was measured to characterize somatotopic mapping of the right‐side body consisting of hand, arm, and leg in six healthy subjects. Statistical Tests Pared‐samples t‐test for the conditions in SII. Results The pneumatical‐mechanical tactile stimulation offered a wide range of stimulation intensities (0–400 g) in each channel. The predetermined physical pressure was successfully reached within ~5 msec and returned to baseline within 5 msec after the end of stimulation. With this tactile device, the digressive rate of the signal‐to‐noise ratio (SNR) (271.44 without the device, 269.68 with the device) was 0.65% in the magnetic field environment. For the fMRI experiment, the primary somatosensory activation contralateral to the stimulation site was detected in response to spatial task and attentive task. Data Conclusion This stimulation device characterized the mapping of somatosensory representation of the whole‐body surface in individual participants during fMRI scans. Level of Evidence 2. Technical Efficacy Stage 1. J. Magn. Reson. Imaging 2020;52:1093–1101.