Development of a spiral structure for an active catheter-overview of the spiral structure and its kinematic configuration

We propose a special structure for an active catheter: a spiral structure. It consists of a flexible belt on which actuators, sensors, and/or control units are built. The belt is spiraled or put spirally around flexible tube to work as a catheter. The actuators on one roll of the spiral move the next roll to realize the bending, twisting, and/or expanding motion of the catheter. With this method, minute and complicated actuators, sensors, and circuits can be precisely machined with very high density, fabricated and wired together in one continuous plane with silicon processes. The advantage of this method will be simple and high-density fabrication. In the paper, the overview and kinematic analysis of the spiral-structure active catheter are discussed and some types of active catheters are proposed.