Catheter with adjustable bending site and/or rotational radius as well as directional operability

PURPOSE: To provide a catheter consisting of a slender tubular part wherein multiple inner cavities are formed in the circumferential direction at a certain distance and mandrels extending to the distal end of the catheter are arranged in respective inner cavities to make the bending radius of the tip end easily changeable. CONSTITUTION: This catheter 21 has a flexible slender tubular part 22 made of plastics and so on. An incision electrode 26 is arranged at a tip end 24 of the catheter and a manually controlling mechanism 27 is arranged at a base part 23, respectively. In the tubular part 22, multiple inner cavities arranged at a certain distance in a circumferential direction and an inner cavity positioned at the center are formed along an axial direction. Flexible slender parts 46 made of material having negative expansive index are inserted into three inner cavities positioned at a 120 degree distance. These parts 46 are connected to an operation control unit 47 containing an operation lever 48. A bending control means 56 is arranged within a terminal part 24. The means is formed of a shape memory unit 57, in which a shape to become straight when heated by turning on electricity is memorized. COPYRIGHT: (C)1994,JPO