An in-vitro study of cutting force and torque during rotary ultrasonic bone drilling

Abstract

Bone drilling is one of the steps in a typical surgical operation that is performed around the world for reconstruction and repair of the fractured bone. During the last decade, various techniques, such as two-step drilling, ultrasonic-assisted bone drilling and laser drilling, have been introduced to control the level of forces and torque during bone drilling. In this research, rotary ultrasonic bone drilling has been successfully attempted to minimize the forces and torque during bone drilling. The drilling experiments were planned and carried out on pig bones using the design of experiments (response surface methodology). Analysis of variance was carried out to find the effect of process factors such as rotational speed, feed rate, drill diameter and ultrasonic vibrational amplitude on the force and torque. Statistical models were developed for the force and torque with 95% confidential interval, and confirmation experiments have been carried out to validate the models. Microcracks developed during drilling process were characterized by scanning electron microscopy. The results revealed that rotary ultrasonic bone drilling process offered a lower force and torque making it a potential process for bone drilling in orthopedic surgery.

In-situ tool wear monitoring and its effects on the performance of porcine cortical bone drilling: a comparative in-vitro investigation

“…RUD is a non-traditional machining process in which ultrasonic vibrations are given to the hollow drill tool. Cutting mechanism in this process is different as CD (Gupta et al 2016;Gupta and Pandey 2016a;Gupta and Pandey 2016b). In RUD the tool work contact ratio is minimal due to the ultrasonic vibrations, whereas in CD, there is direct contact between the tool and the workpiece.…”

“…Vibrational frequency of 20 kHz and amplitude of 16 μm was used for the RUD. These parameters were selected on the basis of the in vitro bone drilling study performed by (Gupta and Pandey 2016a;Gupta and Pandey 2016b). Drilled holes were made to a depth of 4 mm with both the processes.…”

Effect of surface topography on pull-out strength of cortical screw after ultrasonic bone drilling: an in vitro study

“…No animal was sacrificed for this investigation. Fresh pig bone was chosen because they have similar thermal and mechanical properties as of human bones [25,26]. The porcine was approx.…”

“…A hollow tool possesses more material removal rate (MRR) as compared to a solid tool in the case of ultrasonic machining [24]. Moreover, it has been seen that an abrasive coated tool reduces the cutting force [25], temperature [26] and microcracks [19]. The geometry of drill tool affect the surface roughness with the flow of chips [14].…”

“…A preliminary study was made to decide the process parameters. Based on the pilot runs, literature review [19,20,[24][25][26][27][28][29], machine constraints and commercial availability the three factors at their three level were chosen. The selected major process parameters are rotational speed (rpm), feedrate (mm/min) and grit size (μm).…”