Clinical application of biofeedback treatment with a microvibration transducer.

This article demonstrates one clinical application of biofeedback treatment with a microvibration (MV) transducer to relieve functional tremors. A MV transducer, a kind of accelerometer, was originally developed to detect invisible tremors from the body surface but this equipment is also utilized to detect visible tremors to convert them to auditory signals. Our method uses almost the same procedure as electromyographic biofeedback treatment. The threshold level for production of auditory signals should be determined as high as possible between the superimposed amplitudes of essential MV and tremor components. As the sessions progress, the predeterminate threshold level should be gradually lowered to almost the same amplitude as MV itself. In determining the threshold, it is more appropriate to utilize records of the frequency band in which the tremor components are described more clearly, in order to remove noises or MV waves of different frequency ranges. Because of the high sensitivity of this accelerometer, such "tremor feedback" treatment can be recommended only if the tremor is present while the patient is resting or remains still.