Half-wave Lissajous curve analysis of tongue pressure while eating gel-like food

This paper describes a spatiotemporal analysis of tongue behavior while eating a nursing-care gel-like food. First, tongue pressure while eating the gel-like food is measured using a multipoint pressure sensor attached to the palate. By considering a pressure waveform as a half sinusoidal wave, a Lissajous curve drawn with two pressure waveforms measured at two points can be used to analyze tongue behavior. Based on the curve, three feature values can be designed to characterize tongue behavior: pressure level, pressure distribution, and pressure phase difference. Finally, correlations between the feature values and the sensory evaluation of the texture are visualized. The proposed method is a potentially useful tool for investigating the relationship between tongue behavior and the texture of food.