Future of active catheters

A prototype of a catheter that can move like a snake, incorporating distributed shape memory alloy (SMA) actuators, a related device (built-in circuit) and techniques (laser CVD) are described. The outer diameter of the active catheter is 2.8 mm and it has many links fabricated using three-dimensional silicon micromachining. A silicon batch process is used for the fabrication of a link to minimize the assembly work. Problems that may occur in the fabrication of active catheters in the future are discussed and possible solutions are suggested. To minimize the number of lead wires in an active catheter that has many distributed SMA actuators, a packaged signal-processing IC for communication and control purposes has been developed. A new heating method (indirect heating), which is necessary for mounting IC chips on a link, has been developed. A micro assembly process that uses polymer as adhesive, deposited by laser CVD, has been studied to develop the future generation of smaller active catheters.