Sensory Guided Surgical Micro-drill

In this paper a surgical robotic device is described that is able to discriminate tissue interfaces and other controlling parameters ahead of the drill tip. The advantage in surgery is that tissues at interfaces can be preserved. The smart tool detects ahead of the tool point and is able to control interaction with respect to the flexing tissue to avoid penetration or to control the extent of protrusion with respect to the position of the tissue. For surgical procedures where precision is required the tool offers significant benefit. To interpret drilling conditions, and conditions leading up to breakthrough at a tissue interface, a sensing scheme is used that discriminates between the variety of conditions posed in the drilling environment. The result is a fully autonomous system able to respond to tissue type, behaviour and deflection in real-time. The system is also robust in terms of disturbances encountered in the operating theatre. The device is pragmatic. It is intuitive to use, efficient to set up and uses standard drill bits. The micro-drill has been used to prepare cochleostomies in theatre and was used to remove bone tissue leaving the endosteal membrane intact. This has enabled preservation of sterility and the drilling debris to be removed prior to insertion of the electrode. It is expected that this technique will promote preservation of hearing and reduce the possibility of complications. The paper describes the device (including simulated drill progress and hardware setup) and the stages leading up to use in theatre.