Design and Experiment on a Novel SMA Driven Micro-catheter for Active Navigation in Vascular Interventions

This paper presents a shape memory alloy (SMA) driven micro-catheter for active navigation in vascular interventions. SMA wires with microscale diameters and silicone rubber are employed for developing prototypes of such catheters. Selectively processed U shape SMA wires are biasedly embedded into silicone rubber to form the distal actuators with submillimeter diameters, which are characterized by infrared and CCD cameras. The transformation temperatures of SMA wires used for creation of distal actuator is proven to be approximately 35°C by the infrared imaging. The deflection angles of distal actuators are determined by the residual stress resulting from biased SMA wires and their shape memory effect. As a result, distal deflection within acute angles range is accomplished with actuators in submillimeter diameters. A micro-catheter (0.8 mm in diameter) with a distal actuator (0.5 mm in diameter) is mounted inside a vascular introducing sheath fixed on a 3D vascular model to experimentally validate the ability of proposed catheter for navigation.