Development of Orthopedic Haptic Drill for Spinal Surgery with Penetration Detection Scheme based on Viscosity Estimation

In orthopedic surgery, making an incision into the spine involves a risk of injury to the spinal cord. In addition, surgeons must determine penetration into the bone using only their haptic senses. This imposes a heavy burden on the surgeon. In this study, an orthopedic haptic drill with a penetration detection scheme based on viscosity estimation is proposed. This drill detects penetration by monitoring changes in the position and force of the linear motor in the drill. The threshold values are automatically optimized according to the estimated viscosity of the object being cut. Therefore, the proposed drill does not require prior setup of the parameters in accordance with the object being cut. The utility of the proposed drill is verified experimentally.