Modeling and multi objective optimization of effective parameters in drilling cortical bone

3one drilling is one of the common processes in orthopedic operations for therapy and maintaining different parts of a broken bone with together. The most important possible problem during operation is the unwanted increase in drilling process temperature (higher than 67o C) which causes thermal necrosis or cell death and local burnt in bone tissue.Applyinghigher forces to the bone may lead to break or crack and consequently serious damage in the bone. In this paper, a second order linear regression model is introduced to predict process temperature during bone drilling as a function of drilling speed, feed rate and effective interactions. This model can specify the maximum speed of the surgery to stay within the acceptable range. Applying design of experiments, modeling and optimization of effective parameters using response surface method in bone drilling, optimized drilling speed and feed rate were obtained to minimize force and surface roughness. Using multi objective optimization, this was done within the acceptable temperature range without tissue damage which can remarkably reduce the regeneration of the bone cells and less therapy period. Drilling speed and feed rate variations were considered in wide ranges of 500 to 2500 rpm and 60 to; 0 mm