2019 Volume 23 Issue 6 Pages 277-283
Currently, many elderly people in Japan suffer from dysphagia (difficulty related to swallowing). The likelihood of aspiration of food owing to the state of the swallowing function has not yet been estimated. The change in the frequency domain for the classification of swallowing sounds ( I, II, and III sound) is confirmed in this study. The optimum number of microphones and their placement are examined by performing principal component analysis on the data gathered from a multi-channel microphone. Differences in frequency are found to confirm the classification of swallowing sounds. A higher frequency is generated in the latter part of III sound. Analysis in the frequency domain proved to be able to classify 80% of the signals. In addition, multi-channel measurement and analysis using principal component analysis is shown to be effective for feature extraction of swallowing sounds, which suggests that classification accuracy would be further improved by combining it with frequency analysis. In addition, it is suggested that by releasing the measurement position, it is possible to extract signals with different characteristics from each microphone.
