Simultaneous Measurement of Swallowing Sound and Mechanomyogram of Submental Muscle with PVDF Film.

The difficulty of swallowing, called dysphagia, causes aspiration pneumonia which is particularly a big health concern in aging society. Therefore, prevention and treatment of dysphagia would contribute to extending healthy-life and QOL of elderly people and decreasing healthcare cost. Conventional reliable methods for evaluating swallowing function require special equipment and are not suitable for long-term monitoring at home or welfare facilities. Therefore, various kinds of quantitative assessment method using biological signals such as swallowing sound, electromyography, and so forth have been proposed as a non-invasive and accessible method. The goal of this study is to realize comprehensive quantitative assessment of swallowing function using multiple biological signals simultaneously measured by a single sensor device. In this study, we propose the use of PolyVinylidene DiFluoride (PVDF) film to measure both mechanomyogram (MMG) signal for evaluating muscle activity and swallowing sound for detecting swallowing sequence. In our previous study, we confirmed PVDF film can detect MMG signal of swallowing-related muscles. We conducted experiments to confirm that PVDF film can detect swallowing sound in this study. The experimental results indicated that swallowing sound can be measured in parallel with MMG signal at the same position by changing frequency band of the signal of PVDF film.