Ultrasonic Assisted drilling (USD) is new technique to drill difficult to machine materials. In this method, tool or workpiece vibrates with amplitude of few microns in addition to conventional drill bite rotation. In this experimental research, the bone was drilled both conventionally and using UAD, then the thrust was measured in two methods at feed rates of 50, 75 and 125 mm/s and 500, 710 and 1000 RPMs. The results show that USD method causes the thrust force decreases considerably in compare whit conventional drilling. The maximum temperature is less in USD at low RPMs.

bone drilling process is one of the most common processes in the orthopedic surgeries and bone break treatments. It is also very frequent in dentistry and bone sampling operations. bone is a complex material and the machining process itself is sensitive, so bone drilling is one of the most important, common and sensitive processes in Biomedical Engineering field. Orthopedic surgeries can be improved using robotic bone drilling systems and mechatronic bone drilling tools. In the present study, multiobjective optimization is performed on the temperature and trust force at two steps. At the first step, two regression models are developed for modeling the temperature and force in bone drilling process considering three design variables, namely tool’ s rotational speed (V), feed rate (f) and tool diameter (D). At the second step, using the regression models, multi-objective genetic algorithm is used for the Pareto based optimization of bone drilling process considering two conflicting objectives: temperature and force. It has been found out that there are considerable connections and feasible principles for an optimal design of the process in case of applying Pareto-based multi-objective optimization; otherwise, these interesting results would not be discernible.

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. The most critical problem which can occur during bone drilling is increasing the process temperature above the allowable limit (47oC) which causes thermal necrosis or cell death in the bone tissue. In this study, an empirical model is developed to enable the surgeon to predict the temperature of the process based on tool’ s rotational speed, feed rate, tool diameter and effective interactions between these parameters. Experiments were designed and modeled using response surface methodology and to ascertain operation conditions, optimization was performed. Results show that within the range of the investigated variables, with an increase in the tool diameter and cutting speed, the rate of temperature change increases. It is noted that the behavior of the feed rate is complex; in this paper it is investigated precisely. The response surface model is able to predict temperature behavior based on the input parameters. The allowable range of parameters in bone drilling operation is introduced to obtain a quick and swift desirable operation.

bone 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 47oC) which causes thermal necrosis or cell death and local burnt in bone tissue. Applying higher 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 40 to 60 mm/s, respectively. results showed that the minimum temperature increase and the best surface roughness are obtained when drilling speed and feed rate is minimum. Increasing these two parameters induced to the higher temperatures. At high drilling speeds, “temperature increase rate” decreases in the way that the response surface model represents horse saddle shape. Also, the minimum force imposed to bone tissue is ascertained in lower feed rates and the most tool drilling speed. It is noted that the lowest damage to the bone during orthopedic surgery occurs with drilling speed of 500 rpm and feed rate of 40 mm/min considering all aforementioned parameters.