Design Optimization of Surgical Drills Using the Taguchi Method

Abstract

The preparation of an implant site using a surgical drill is a common procedure in orthopedic surgery, such as for the internal fixation of fractures. An increase in temperature during such a procedure results in the potential for thermal invasion of the bone, which may delay healing or reduce the stability of the fixation. Therefore, minimizing invasion during bone drilling is important to ensure the stability of the implant, and this requires surgical drills with an optimal design. This study investigated the optimal design of surgical drills by comparing the drilling characteristics (i.e., the cutting force and temperature increase) using the Taguchi fractional factorial method. The control factors (helix angle, web thickness, point angle, and the levels of these three parameters) were placed in an L9 orthogonal array and drilling tests were conducted with nine experimental drills based on the array. The results show that the optimal levels of the three design factors of the surgical drill and their percentage contribution depend on the drilling characteristics. However, confirmation tests indicated that the design optimization did not greatly affect the performance improvement and its results showed poor reproducibility. This is possibly because the various cutting conditions encountered in actual clinical situations were not adequately considered.

Keywords

• surgical drill
• drill design
• drilling bone
• internal fixation
• taguchi method