Non-contact motion measurement of mastication by integration of multiple sensors

点击翻译按钮获取中文摘要

Motion measurement of lower jaw is important for clinical diagnosis of jaw function. Three dimensional measurement of lower jaw movement is especially important in order to diagnose mastication function which reflects jaw joint status ; these jaw joints are usually unseen from appearance. An altenative of the jaw motion measurement is the measurement of facial motion around lips. The motion obviously reflects mastication-related motion. In the research, we developed a stereo vision facial motion measurement system, and an integration algroithm of multiple sensors in order to diagnose dental disorder from appearance.1) Integration of multiple sensor dataAn integration algorithm has proposed to integrate range-sensor data and stereo vision data. The algorithm is based on Baysian estimation and Kalman filter.2) System for multi-point movement measurement of lips and adjacent regionA multi-point measurement system has developed. In the system, the 3D coordinates of 15 markers stuck to the skin around lips are tracked by a stereo vision. With the system, we analyzed the relationships beween lower-face motion and disorders of jaws, muscles, and occlusion. The method decomposes the time-series data into principal components. Generally, lower-face motion can be precisely described with two or three components.3) The design of realtime measurement systemWe renewed the image capturing system which we developed in the first year. The new lip-motion measurement system can record 10 second image sequences, and analyze the data points in realtime. In the beginning of the research, we planned to use a DSP chip, however, we were able to construct a system without DSP because of the progress of CPU technology.