Development of Swallowing-Movement-Sensing Device and Swallowing-State-Estimation System

In elderly nursing care, various food-related problems, such as low nutrition, dehydration, binge eating, aspiration, and suffocation, arise. To prevent such problems, caregivers must continuously monitor elderly patients' swallowing of food/water, which is burdensome. Hence, a monitoring system that can automatically estimate whether an elderly patient has swallowed food, water, or a highly viscous bolus is required. In this paper, we propose a sensing device based on the bi-directional electret condenser microphone that measures vibrations due to swallowing, along with an estimation system that estimates elderly swallowing behavior utilizing the developed sensing device. To verify the validity of the proposed method, we perform verification experiments with four swallowing states f(1)-f(4) corresponding to swallowing of nothing, tea, tea with thickener, and rice cake, respectively. The proposed method is validated based on the estimation of f(1)-f(4), and the accuracies of 0.99, 0.81, 0.84, and 0.91, respectively, are achieved. Therefore, this technique can be feasibly applied in elderly nursing care.