[Problems to be solved] In a medical diagnosis system, a diagnosis system for estimating stress distribution on vascular wall with a high degree of accuracy under a rational assumption which is only based on mechanical equilibrium equation, even in a case where vascular wall surrounding blood domain obtained from a medical image by a diagnosis apparatuses such as MRI, CT and ultrasound echo includes a complicated curvilinear surface shape, is to be realized. [Solving Means] There is disclosed a stress estimating system comprising a polygon data input unit of vascular wall, an interactive analysis condition setting unit for setting the tensile force acting on the vascular wall boundary, blood pressure and constraint estimated as proper on the boundary, a stress analysis unit for obtaining two-dimensional stress by solving mechanical equilibrium equation with respect to the membrane stress on a curvilinear surface of vascular wall under the condition given by the polygon data input unit and interactive analysis condition setting unit, and an interactive visualization unit for displaying distribution of stress component designated by a system user, wherein without assuming any symmetry for curvilinear configuration and stress distribution , a complicated stress distribution is estimated only out of mechanical equilibrium equation with respect to membrane stress.
