An active catheter with integrated circuit for communication and control

This paper describes an active catheter with flexible polyimide-based integrated CMOS interface circuits for communication and control (C&C IC) to be used for applications in biomedicine. The active catheter has a multilink structure and distributed micro Shape Memory Alloy (SMA) coils are utilized as actuators for multi-degree of freedom movement. The C&C ICs are incorporated within the links and require three common lead wires to address all the links and control the selected SMA actuators in the active catheter. A MOS transistor with large channel width is used for switching the SMA actuator. To reduce system size and simplify assembly work, the C&C circuit and three lead wires are fabricated on the same substrate using a CMOS-compatible polyimide-based process. The outer diameter of the fabricated active catheter is approximately 2.0 mm. The fabricated C&C IC measures 1.0 mm x 3.35 mm x 0.2 mm. The link addressing and the actuator switching functions of the fabricated chip were confirmed. The minimum access time for addressing and actuating a single unit was 6.4 mu s. The active catheter was actuated by the fabricated C&C IC chip with flexible interconnect leads in response to the C&C signals from the outside controller.