A 3D FE dynamic model of human fingertip based on MRI data

Humans mainly use their fingertips to explore and manipulate objects in daily life. When the fingertip comes in contact with an object, the mechanoreceptors beneath the skin respond to the deformation of skin and generate electrical impulses sent to the brain. However, the mechanical state at receptor locations is not empirically observable with the current technology. It is necessary to develop reliable models of fingertips to investigate the mechanistic bases of finger sensation. In this study, therefore, a 3D Finite Element (FE) dynamic model of primate fingertip is developed based on Magnetic Resonance Imaging (MRI) data. A human fingertip was measured using a MR machine and a series of 2D image slices were obtained. Using boundary tracking algorithm, 2D boundaries of individual tissue layers were traced for each slice and a certain number of boundary nodes were generated. These boundary nodes were then used to construct a 3D geometry with tetrahedron mesh for each tissue layer of the fingertip. The 3D meshes of individual tissue layers were then combined to formulate a non-homogeneous FE dynamic model for simulating the fingertip behaviors. Simulation results with pushing and sliding operations were given to validate the proposed FE model.