Localization of drilling tool position through bone tissue identification during surgical drilling

摘要

This paper proposes a detection method to identify the drill bit position during assisted bone drilling. A platform has been developed to support the surgeon in the planning of the drilling path. Albeit constrained along a fixed trajectory, the advancement of the drilling tool is manual, in order to preserve the natural haptic perception of the surgeon, who remains in charge of modulating the drilling force and the feeding rate according to the position of the drill bit in the bone. This paper describes a custom drill, embedded with force and position sensors, which allows the evaluation of a new parameter, referred to as Average Impedance (AI), that is related to the mechanical properties of the tissues in contact with the drill bit. An algorithm for layer identification has been implemented based on the variability of the AI signal. In perspective, the AI can provide the surgeon with additional information about the position of the drill bit in the bone, in order to increase the safety level of the procedure. The algorithm has been tested ex-vivo on swine bones. The tests demonstrated a reliability better than 80% in the discrimination of bone tissues.