Voxel-Based Variable Posture Models of Human Anatomy

With the advancement of computer and medical imaging technology, several high-resolution anatomically realistic whole-body voxel-based models have been developed. These models have been frequently used in electromagnetic dosimetry. However, since they are generally available only in upright configurations, simulations of the actual situation are greatly limited. In this paper, we propose a new posture transformation technique. First, body surface boundaries of the voxel-based model are extracted as polygon mesh data. Next, the posture of the surface mesh model is transformed with a mesh deforming technique applied in computer graphics modeling tool. Lastly, because the body surface meshes have only surface contour information, the coordinates of the voxels corresponding to the points of the internal region of the mesh model are calculated by a volume-refilling algorithm. We applied this proposed technique to Japanese male and female models with standing posture and developed models with sitting posture. The postured models were smoothly transformed while maintaining the continuity of their internal tissues and organs. Moreover, the tissue and organ masses of the postured model were reasonable deviations from those of the original standing models for the practical numerical dosimetry of human body exposure to an electromagnetic field.