An improved 3D geometric Tongue model

This study describes an improved geometric articulatory model based on MRI and CBCT (Cone Beam Computer Tomography) data. The basic idea is to improve the coherence of the vertices of tongue meshes so as to obtain more accurate tongue model. This is conducted in two aspects: i) The representative vertices of tongue surface are depicted in Cartesian coordinate system rather than in a semi-polar gridline coordinate system. ii) tongue surface meshes are modeled with reference to anatomical landmarks. Then, guided PCA is used to extract the control components based on MRI data. The average reconstruction error is less than 1.0 mm. Both qualitative and quantitative evaluation indicates that the proposed method surpasses the conventional semi-polar gridline system based method.