Abstract
A material test system combined with X-ray computed tomography (CT) is newly developed for material characterization of biological tissue in non-invasive manner. An identification method of in vivo displacement field is investigated through the CT images obtained by the system. Two voxel models are constituted by laying up thicken pixels of the cross-sectional tomograms taken under initial and loaded conditions. Representing the displacement field in terms of mapping function from initial voxel model to deformed voxel model, we pose an inverse problem to identify unknown parameters in the mapping function set by power series of N-th order. A virtual voxel model is embodied through virtual trans-formation of the initial voxel model via tentative mapping function. An error function defined by the voxel values, which is related to brightness of voxels, is minimized with respect to unknown coefficients by means of the SCE-UA method (Shuffled Complex Evolution Method Developed at the University of Arizona). The proposed method is demonstrated through an experimental example using specimen harvested from chicken.
