Suitability Analysis of Industrial Drills for Minimally Invasive Skull Base Surgery

Medical drilling processes, especially in the area of the otobase, pose a high risk to the patient due to the heat generated and introduced into the tissue. Two measures of reducing the heat are the parameters of the drilling process and the optimisation of the drill geometry. A spiral drill and a singlelip drill are evaluated for their suitability as medical drills in skull base surgery with the objective of integrating a temperature sensor in the tip of the drill. The two drills were chosen because of their promising heat generation properties in pretesting. In this paper the chip formation behaviour and drilling channel quality are analysed. The single-lip drill shows lack in precision of the drilling channel and unsuitable bone chip transport, as material powder is left in the drilling channel. In contrast, the spiral drill shows a good transport of the chips and the drilling channel follows the planned path. As a result, the spiral drill is chosen for the further development of a drill with integrated temperature sensor for minimally invasive drilling.