Time frequency analysis of swallowing sound for non-invasive swallowing function evaluation

Abstract

This study defined parameters expressing the temporal positional relationship of the three components of swallowing sounds, by approximating swallowing sound signals with a three-dimensional spline curve, and proposes a method for quantifying swallowing function. We also explored a method for automatically detecting signals representing swallowing function from among multiple swallowing sound signals obtained during the measurement time. An approximation curve with three peaks corresponding to the three sounds composing the swallowing sound was obtained. The T expressing the relative position of the second sound to the continuous time of the overall swallowing sound was determined from the T1 and T2 obtained from the approximation curve, enabling quantitative evaluation of swallowing function. Moreover, swallowing sound signals that represented the swallowing function of the subject could be automatically detected from among multiple swallowing sound signals obtained from the subject.