Development of an MR-compatible configurable brush stimulation device.

Abstract

In order to evaluate sensory disturbance, a subjective method is performed, so that the evaluation result is influenced by subjective factors. fMRI is used for observing brain activity objectively. Therefore the brain response to a stimulation measured by fMRI could become a useful identification tool for the objective evaluation of the sensory disturbance. The purpose of this study is to develop an MR-compatible sensory stimulation device capable of providing brush stimulation to several positions with separate modules, and to confirm the feasibility of the device by a basic operation experiment and an fMRI experiment. The developed device consists of both an MR-compatible stimulator placed inside the MRI room, a tube-rod mechanism and a driver placed outside the MRI room. The tube-rod mechanism is adopted for power transmission from the driver to the stimulator. Also, in order to provide the stimulation to several positions in the limited space, the device consists of the stimulation module and the positioning module that moves the stimulation module. For the basic operation experiment, we measure a variation of the automated and manual brush stimulation period. For the fMRI experiment, the brush stimulation is provided to the middle fingertip and the palm of a subject in a trial using the developed device. As a result, the standard deviations of the automated brush stimulation period is less than 7.0 ms. This result was smaller than that of the manual stimulation period. Also, the brush stimulation to the fingertip and the palm activated the somatosensory areas respectively. In conclusion, we confirmed the feasibility of the developed device through the experiments.