| abstract |
A bidirectional steerable catheter comprises a catheter body, a tip section, and a control handle. The catheter body has a tubular wall, proximal and distal ends, and at least one lumen extending therethrough. The tip section comprises flexible tubing having proximal and distal ends and at least one lumen extending therethrough. The proximal end of the tip section is fixedly attached to the distal end of the catheter body. The control handle is mounted at its distal end to the proximal end of the catheter body. The control handle comprises a housing having proximal and distal ends. Rotatably mounted within the housing is a generally-circular spur gear having gear teeth about its outer circumference. A pair of spaced apart rack gears are slidably mounted longitudinally on diametrically opposed sides of the spur gear within the housing. Each rack gear has an interior edge generally facing the interior edge of the other rack gear and comprises gear teeth along its interior edge for engaging the gear teeth of the spur gear. Each rack gear is longitudinally movable between first and second positions. Proximal movement of one rack gear results in rotational movement of the spur gear, and correspondingly distal movement of the other rack gear. Two puller wires extend from the control handle, through a lumen in the catheter body and into an off axis lumen in the tip section. The distal end of each puller wire is fixedly attached to the tip section, and the proximal end of each puller wire is anchored to a separate associated rack gear in the control handle. Proximal movement of a rack gear and its associated puller wire relative to the catheter body results in deflection of the tip section in the direction of the off axis lumen into which that puller wire extends. |