An active catheter with integrated circuit for communication and control

Abstract

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 ps. 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.

Shape Memory Microactuator for Surgical Instruments

“…A similar configuration with active SMA-wires, making the servo-motors unnecessary, seems possible. A steerable miniature catheter was presented in [3]. This device was only 1.2 [mm] in diameter with a 0.3 [mm] diameter working channel and consisted of a sequence of segments.…”

A simulator for helping in design of a new active catheter dedicated to coloscopy

“…Its diameter is 8mm and only the head is controlled. Another has been proposed in (Park, K. & Esashi, M. 1999). This prototype is of diameter 1.7mm and is dedicated to interventions in ureter.…”

“…This will be achieved by using a polymer gel actuated prism. (Park & Esashi, 1999) As medical device, a flexible polymer sheath should protect the whole system. Each joint is provided with two antagonist electrically commanded SMA spring-like actuators allowing the control of the relative orientation of consecutive links.…”

A Dynamical Training and Design Simulator for Active Catheters

“…Developments of new prototypes, aiming at improving the navigation of endoscopes in the inspected ducts, are in progress. A prototype developed in Japan (Park, K. & Esashi, M. 1999) is constituted of trays interconnected by SMA threads (Fig. 1).…”