Optimization of Bone Implant Selection with Price Analysis

Abstract

This paper introduces a mathematical method based on fuzzy logic which is used in designing of bone implant. Five sets of criteria are defined as follow: total corrosion resistance, biocompatibility, adherence, technical specs and price. Each of these criterions is divided into its subsets. Then membership functions of sets are defined. In continuation the satisfactory degree is calculated. Finally, biomaterial favorability is determined and the effect of price on sensitivity analysis is analyzed. Twelve common metallic biomaterials are used in the database. These methods show the satisfactory value for bone implant as a continuous value ranging from zero to one. Therefore, biomaterial designer can compare a new material to the database systematically and he/she can determine restricted parameters to increase the performance of bone implant. The results show; the model is sensitive. In addition; price is an effective parameter in the selection of implants and it leads to customer satisfaction. Dieter defined the material selection as swiftness of the process of designing any component which its purpose is to reduce cost while gaining product performance goals [1]. Therefore, logical selection of the best material for a given application begins with properties and price of candidate materials. An Ashby plot is a scatter scheme which displays two or more properties of different materials [2]. Therefore, a material of excellent technical specs may have not sufficient biocompatibility, while a material with good compatibility may have low technical specs. Nowadays materials are developing faster than at any other time historically; the challenges and opportunities are therefore greater than ever before. Karande and Chakraborty found out that a systematic and numerical method for material selection will help the material designers to choose and compare the new material with the common materials database [3]. Ramalhete et al., Jahan et al., Chatterjee and Chakraborty concluded that on the basis of mathematical methods, it is possible to maximize the utilization of design [4, 5, 6]. Therefore, this paper deals with mathematical strategies of developing bone implant selection. A few researches, using various approaches, have been done about the selection and optimization of bone implant. Albiñanaand Vila analyzed a workflow that breaks the work down into stages and gates, and specifies how the preliminary selection is to be performed [7]. Rao and Patel used subjective and objective integrated multiple attribute decision making method for material selection [8]. Rao and Davim used a combined multiple attribute decision-making method for material selection [9]. Also, Bahraminasab and Jahan used comprehensive special method (VIKOR) for material selection of femoral component of total knee replacement [10]. José et al selected a biomaterial approach to the construction of valve leaflets for cardiac bio-prostheses[11]. Zander and Sandström expected the optimum material is strongly dependent on the chosen target functions and constraints. It is demonstrated that the two approaches for materials optimization give identical results for pressure vessel [12]. As it is clear, none of them focused on material selection of bone implants based on fuzzy logic. Fuzzy logic investigates the relative properties of the material. In order to accomplish this, fuzzy approach defines a set for each property. For example, various materials have different biologic properties and price, so these materials have different membership degree in the set of biomaterials. Using these sets and fuzzy rules, biomaterial designer can compare and evaluate different materials for specific applications. Therefore, in this