An investigation and optimization of effective parameters on thrust force in drilling cortical bone process using response surface methodology

Bone drilling process is the most prominent process in orthopedically surgeries and curing bone breakages. It is also very common in dentistry and bone sampling operations. Due to complexity of the material that is machined, bone, and the sensitivity of the process, bone drilling is one of the most important, common and sensitive processes in biomedical engineering field. Developed a three-axis robotic bone-drilling system and mechatronic bone-drilling tools improved the orthopedic operations. Furthermore, imposing higher forces to bone might lead breaking or cracking and consequently serious damage in bone. In this paper a mathematical second order linear regression model is introduced to predict process force behavior during bone drilling process as a function of tool drilling speed, feed rate, tool diameter and effective interactions. This model can predict carefully force behavior during bone drilling within the acceptable range. Moreover, applying design of experiments, modeling and optimization of effective parameters using response surface method in bone drilling process optimized drilling speed, feed rate and tool diameter were obtained to minimize force. Results show that to minimize force increasing the drilling speed would decrease the thrust force, whereas decreasing the feed rate and tool diameter would decrease the Thrust force.