Fuzzy reasoning system design and assessment of load-bearing endoprostheses and their fabrication processes

Abstract

Five attempts of an application of a fuzzy reasoning approach to problems encountered in biomechanics and engineering of biomaterials are presented. They include: (A) assessment of maximum contact stress acting on endoprosthesis, (B) design of sintering plan to obtain a porous/scaffold implant, (C) design of oxidation plan to obtain nanotubular oxide structure on the Ti alloy, (D) and (E) design of deposition of hydroxyapatite coating on the Ti alloy. The fuzzy reasoning system is shown to well predict: the maximum contact stress estimation on acetabular surface of the load-bearing hip joint endoprosthesis for chosen and given Wiberg's angle values and patient's body weight; the optimal geometry of scaffold's architecture; the geometry of TiO 2 nanotubular layer on titanium surface and directions of the adjustment of fabrication conditions; the ratio of Ca/P and the coating crystallinity; effects of control factors (sintering temperature and content of ZnO) on mechanical properties of BHA-ZnO composite. A small deviation of the predicted values from those obtained in the course of experiments can be decreased by improvement of the proposed fuzzy model i.e. adjusting fuzzy membership functions of input and output variables.