Design, Development and Evaluation of a Two Way Actuated Steerable Needle

Over the last two decades, researchers have been interested to provide actuation and control for surgical needles. It has been recently suggested to utilize shape memory alloy (SMA) wires to provide bending forces to activate the conventional straight needles. In this paper a design of an active needling system has been proposed where actuation forces of SMAs as well as shape memory polymers (SMPs) were incorporated. SMP elements provide two major additional advantages to the design: (i) recovery of the SMP’s plastic deformation by heating the element above its glass transition temperature, and (ii) achieving a higher needle deflection by having a softer stage of SMP at higher temperatures with less amount of actuation force. The feasibility of providing actuation forces using both SMAs and SMPs for the surgical needle was demonstrated in this study.