Apparatus and methods for detecting and processing EMG signals

Methods are provided for smoothing input signals having rapidly changing amplitudes, such as EMG signals from the tongue, which are detected by an intraoral device. One method calls for amplifying the EMG signals, converting the EMG signals to digital format, providing a moving average of the amplitudes of the EMG signals utilizing a moving the average processor, and windowing the averaged signals to discrete and stable amplitude levels. An adaptive moving average technique may be utilized, which includes a plurality of parallel moving average processes and a differentiator which determines which process is used, depending on the rate of change of the signal amplitude. Another method calls for the use of a plurality of moving average processes in series which calculate the moving average of the same number of signals as a single moving average process, but has a faster response time. An intraoral device is used to detect the EMG signals. The intraoral device includes acrylic maxillary and mandibular splints. The maxillary splint has reference electrodes attached to its palate side, while the mandibular splint has active electrodes attached to the gum side. The intraoral device is strengthened by the use of woven fiberglass imbedded in its acrylic body.