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

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.

To accurately characterize the mapping of somatosensory presentation of the whole-body surface of subjects during functional (f)MRI scans.

Prospective.

A water phantom and six healthy participants (age 23-27 years; two males) were recruited for the fMRI experiment.

T₁ -weighted magnetization-prepared rapid acquisition gradient-echo, T₂ *-weighted gradient echo sequence at 3T.

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.

Pared-samples t-test for the conditions in SII.

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.

This stimulation device characterized the mapping of somatosensory representation of the whole-body surface in individual participants during fMRI scans.

2.

1. J. Magn. Reson. Imaging 2020;52:1093-1101.