Abstract
The body structure influences the tactile sensation and stiffness evaluation. This suggests conversely an estimation of internal body structure and viscoelasticity from skin surface. This paper deals with an estimation of not only body structure but also viscoelasticity under skin surface, by using an acoustic random vibration (30-1000Hz). This method is characterized by morphological and functional measurement of inside of the body. The shape and viscoelasticity of internal object (tumor: silicone-gel) are estimated with a mechanical impedance, which is measured from the surface. The viscoelasticity and effective vibrating radius are calculated from the impedance spectrum and they give a relationship between a depth and viscoelasticity of internal object. The experimental silicone-gel model includes internally two hemisphere gels, whose viscoelasticities are different from that of peripheral silicone-gel. The 3-D image of internal hemisphere gel is reconstructed, based on the relation between a depth and the effective vibrating radius. The viscoelasticity of internal hemisphere gel is also estimated, based on the relation between the depth and the measured viscoelasticity of silicone-gel slope model.
