押し込み試験による皮膚組織のヤング率測定におけるHertz接触理論の展開

抄録

An advantage of the indentation test is that it can be used to easily measure the elastic modulus of biological soft tissue in noninvasive. To measure Young's modulus, E^*, of skin tissue by an indentation test, we expanded the Hertz contact theory to a contact problem of pressurizing an elastic plate of a finite thickness with an spherical indenter and devised a method to properly evaluate the modulus of skin tissue. To verify the validity of the indentation test method, we performed a tensile test and indentation test using artificial skin, and then, the optimum indent depth, δ_T0, was calculated at which the stiffness of both became equivalent. The modulus for the depth, δ_T0, was estimated for finite thickness plate from the modified Hertz contact equation, F_Tn = Cδ^m_T. Furthermore, we measured the strain distribution of subcutaneous tissue from ultrasonic echo tomography of human skin and found the effective depth, <z>, relating to stress transfer. Thus, we considered the practical applicability of a method for measuring the Young's modulus of skin tissue using an indentation tester.