Dynamic 3-D tongue model−Progress report.

Abstract

An approximate computational model of the tongue including both intrinsic and extrinsic muscles has been constructed based on histological sections of tongue specimens. The tongue is represented by several geometrical solid primitives (blocks) forming local curvilinear coordinate systems, in reference to which muscle fiber directions are specified. Control vertices serve as reference points for each block, and their positional variation allows anatomical scaling. Each block is divided into several finite elements, within each of which fiber directions and muscle activation parameters are computed using linear and quadratic interpolation. The deformation and movement of the tongue is simulated by solving the equations of motion, assuming large deformation and incompressibility of the continuum. A new algorithm has been devised for maintaining deformations isochoric, using a projection method for reduced stress computation. The muscular stresses are computed with a simple model of muscle tissue, in which the active stress depends on an activation parameter for each fiber group, and on the elongation in the direction of the muscle fibers and its rate of change.