Small diameter active catheter using shape memory alloy

Three kinds of active catheters whose outside diameters are less than 2 mm were fabricated. One uses polymer links, the other two are linkless active catheters using adhesive. Distributed shape memory alloy (SMA) coil were used as actuators for the active motion. There are endoskeletal type and exoskeletal type in the linkless active catheters. We have applied the endoskeletal type active catheter to intraureteral ultrasonography used in a kidney. Concept of an advanced multifunction active catheter is mentioned.