Skull base surgery is technically the most demanding of all of the neurosurgical procedures because of the intertwining of the hard, thick skull and delicate neural and vascular structures. A safer, quicker and more precise way to remove the bony skull base will not only decrease demand on the surgeon, but will also serve to equalize the experience differential among surgeons and improve overall outcome for these procedures. If a new technique can improve time and safety in this approach, it should be readily beneficial in other aspects of neurosurgery. Widespread acceptance of this technique would be a natural and inevitable outcome if successful. The Overall Aim of this project is to validate the effectiveness of Precision Freehand Sculpting (PFS) techniques for skull base neurosurgery procedures. PFS, originally implemented for orthopaedic applications, involves robotically controlling the cutting tip of a handheld surgical drill according to a preoperative plan. Phase I Hypothesis: Precision Freehand Sculpting can surpass standard techniques in accuracy and efficiency for bone removal operations in the lateral skull base. Specific Aim 1 - Develop and test new algorithms and data structures optimized for skull base procedures. These new models and algorithms will be developed and tested in a block cutting experiment. Specific Aim 2 - Develop and test a new PFS prototype handpiece for skull base procedures. This Aim will create a prototype device with appropriate form factor with multiple control modes to be tested in later experiments. Specific Aim 3 - Design and implement semi-automated planning algorithms and interfaces for temporal bone surgery. Preoperative planning must be fast and easy to be acceptable for widespread clinical use. This Aim will ensure that the preoperative planning is acceptable to the PFS user base. Specific Aim 4 - Testing of the skull base PFS prototype system using realistic data. Surgeons will perform "surgery" on phantom models created from real patient data in a series of timed trials to compare PFS methods with traditional surgical technique. PUBLIC HEALTH RELEVANCE: The proposed work will apply computer-assisted and robotic techniques to neurosurgery. The presented technology will allow surgeons to accurately plan and execute skull base drilling procedures using a handheld robotic cutting instrument designed to increase efficiency and safety.