Analysis of the tongue surface movement using a spatiotemporally coherent deformable model

We present a system that extracts and tracks 2D mid-sagital tongue surfaces from ultrasound image sequences produced by a head and transducer support system (HATS). Such a system can be a valuable and practical tool for speech and swallowing research. We extend our previous work by introducing a deformable contour model to impose restrictions of spatiotemporal coherency by assuming that the 2D mid-sagital tongue surface contours sweep a coherent 3D structure in spatiotemporal 3D space. Another novel contribution of this paper is a dynamic programming minimization method to optimize the new energy functional, which can be employed in general snake minimization tasks. We tested this system on a number of speech and swallowing sequences each containing 24 to 30 frames. We verified with speech experts and found that our system produces promising results, especially for the swallowing sequences, which are more problematic