Development of an MR-compatible sensory stimulation device which provides pin and brush stimulations

Abstract

In order to evaluate sensory disturbance, a subjective method is performed, in which the patient answers orally to the given stimulation. On the other hand, fMRI is a technique for observing brain activity. Therefore fMRI can be used for objective evaluation of sensory disturbance. The purpose of this study is to develop an MR-compatible device which provides both pin and brush stimulations to the surface of the human skin, and to confirm the feasibility of the device by the evaluation of the basic operations and the fMRI trial. The developed device consists of both an MR-compatible stimulator placed inside the MRI room and a driver placed outside the MRI room. The tube-rod mechanism is adopted for power transmission from the driver to the stimulator. For the evaluation of the basic operations, we measure both the pressing force and the period of the pin stimulation, and the stimulation position of the brush stimulation. For the fMRI trial, the MR-compatibility test is performed, and pin and brush stimulations are provided to the hand of a healthy subject. As a result, the standard deviations of the pressing force, period, and position were less than 0.1 N, less than 1.0 ms and less than 0.1 mm. These results were smaller than the standard deviations of manual stimulation by human. Also, MR-compatibility of the device was verified experimentally. Finally, both pin and brush stimulations activated the somatosensory areas. In conclusion, we developed an MR-compatible device which provides both pin and brush stimulations, confirming the feasibility of the device.

Keywords

• stimulation device
• mechanism
• mr-compatiblity
• fmri
• brain
• medical and welfare assistance