Towards a SMA-actuated Neurosurgical Intracerebral Hemorrhage Evacuation (NICHE) robot

This paper presents a prototype of a meso-scale medical robot for Neurosurgical Intracerebral Hemorrhage Evacuation (NICHE). We use shape memory alloy (SMA) actuators for actuating individual degrees-of-freedom (DoFs). Pairs of antagonistic SMA wires enable bidirectional motion of bending joints. A novel torsion joint formed by a pair of antagonistic SMA torsion springs is installed at the distal end together with a pair of antagonistic SMA wires. This design provides articulation within the hemorrhage at the robot tip, thereby enabling effective hemorrhage evacuation. In this paper we derive the forward kinematics of the robot and the constitutive model of the SMA-actuated torsion joint. We also present experimental procedures to characterize parameters of the constitutive model. Finally, a proof-of-concept experiment is presented to show the working of the robot.