A retraction device including at least one pair of opposed retraction members, with each retraction member being capable of operably engaging the tissue to be retracted. Two types of internal electrodes are alternately arranged inside the dielectric body via dielectric sheets. At least one antenna broadcasts the noise signal into the region. An arcuate portion of the first copper foil is placed in apposition with a first side of an aluminum member, an adhesive substance being situated between the first copper foil and the first side of the aluminum member. The gantry can be moved into a use position independently of the support table and the support table is fashioned such that the support plate extends through the measuring opening when the gantry assumes a use position. According to some embodiments, the shallow junction of common sourcedrain regions enables all devices to bias by only one body contact on an SOI substrate like a conventional bulk MOSFET, and the floating body effect on an SOI substrate can be prevented.