抄録
Clenching during waking hours as well as grinding during sleep are known to be contributory factors to the perpetuotion of masticatory muscle pain.
Although studies have been conducted on nocturnal bruxism and daytime clenching in controlled laboratory settings, few reports have focused on the management of daytime clenching in natural environments with the utilization of biofeedback training. One of the reasons for the non-utilization of EMG biofeedback for patients exhibiting clenching behavior is that the biofeedback devices are too cumbersome to be carried around by the test subject. To expand the applicability of biofeedback training on a daily basis, the device should be small enough to be ignored by others.
This paper introduces a newly developed customized EMG recording device with two main components, namely the data-recording and auditory feedback portions. The dual-channel EMG recording system consists of on Ag-AgCl electrode pair unit and digital recorder with a 12-bit A/D converter. Hum filter of 50 Hz and band pass filter of 23-450 Hz are also equipped for EMG data collection. EMG activity is displayed on a small LCD on the surface of the device in root mean square values ranging from 0 to 1250μV. This unit permits continuous recording for 8 h 40 min at a data-sampling rate of 4Hz. An auditory feedback signal informs the user via a headset when EMG activity exceeds the arbitrarily defined threshold in each channel.
Since this EMG biofeedback device is easy to carry around, it should help to reduce daytime clenching behavior in natural environments.
