SUMMARY

Manual manipulation of passive surgical tools is time consuming with uncertain results in cases of navigating tortuous anatomy, avoiding critical anatomical landmarks, and reaching targets not located in the linear range of these tools. We introduce the design of a micro-scale COaxially Aligned STeerable (COAST) guidewire robot that demonstrates variable and independently controlled bending length and curvature of the distal end. The design of the robot involves three coaxially aligned superelastic micromachined tubes with a single tendon running centrally through the length of the robot. By varying the lengths of the tubes as well as the tendon, and by insertion and retraction of the entire assembly, various joint lengths and curvatures may be achieved. Kinematic and static models, and a controller for this robot are presented. The capability of the robot to accurately navigate through phantom anatomical bifurcations and tortuous angles is also demonstrated in 2D phantom vasculature. In the proposed work, this work will be extended to a 3D vascular demonstration by adding a translation/rotation stage to the robot. This work also introduces the design, analysis and control of a meso-scale two degree-of-freedom robotic bipolar electrocautery tool that increases the workspace of a pediatric neurosurgical procedure. Pure kinematic modeling and control for this tool may not provide precise control performance due to kinematic uncertainties arising from tendon elongation, tendon slacking, gear backlash, etc. A static model is proposed for each of the joints of the handheld robotic tool that avoids several of these problems. A control system is developed that comprises of a disturbance observer to provide precise force control and compensate for joint hysteresis. In the proposed work, the handheld robotic neuroendoscope tool, equipped with high deflection shape sensing, will be tested in a phantom brain model with neurosurgeons to measure the efficacy of the tool.