This paper presents an objective method for analysis of temporal pattern of swallowing mechanism based on analysis of swallowing sounds and submental surface electromyogram (EMG). In this study, swallowing sound signal and submental EMG of 12 healthy subjects were recorded. Swallowing sound signals were divided into 25 millisecond segments each of which was represented by waveform fractal dimension (WED). Temporal pattern of swallowing sound signal was identified based on hidden Markov modeling (HMM) of the WED sequences. Submental muscle contraction was marked by thresholding the RMS values of the EMG signals. Duration of the swallowing sound phases, duration of the submental muscle contraction, and time difference between the onset of submental muscle contraction and the opening of cricopharynx were calculated. Experimental results suggest that the proposed method is efficient in the study of temporal pattern of swallowing mechanism and can provide an objective and accurate approach for swallowing mechanism analysis.
