Single gear drive bidirectional control handle for steerable catheter

A bidirectional steerable catheter comprising:

• an elongated, tubular catheter body having proximal and distal ends and at least one lumen extending therethrough;
• a tip section comprising flexible tubing having proximal and distal ends and at least two lumens extending therethrough, the proximal end of the tip section being fixedly attached to the distal end of the catheter body;
• a control handle mounted to the proximal end of the catheter body, the control handle comprising:
• a generally-hollow handle housing having proximal and distal ends and inside and outside surfaces,
• a generally tubular core extending longitudinally within the housing,
• a generally-circular spur gear rotatably mounted within the handle housing, the spur gear having teeth about its outer circumference, and
• first and second pistons slidably mounted on diametrically opposed sides of the spur gear and at least partially in surrounding relation to the tubular core within the handle housing, each having an interior edge generally facing the interior edge of the other piston and comprising a series of teeth along its interior edge that engage the teeth of the spur gear, whereby proximal movement of one piston results in rotational movement of the spur gear and distal movement of the other piston;
• a longitudinally movable thumb control fixedly attached to the first piston and accessible from outside the handle housing;
• and
• first and second puller wires having proximal and distal ends, each puller wire extending from the control handle, through a lumen in the catheter body and into a lumen in the tip section, the distal end of each puller wire being fixedly attached to the tip section, the proximal end of the first puller wire being anchored to the first piston and the proximal end of the second puller wire being anchored to the second piston;
• whereby proximal movement of the thumb control relative to the handle housing results in proximal movement of the first piston and first puller wire relative to the handle housing and catheter body, which results in deflection of the tip section in the direction of the lumen into which the first puller wire extends;
• and further whereby distal movement of the thumb control relative to the handle housing results in distal movement of the first piston, causing proximal movement of the second piston and puller wire relative to the handle housing and catheter body, which results in deflection of the tip section in the direction of the lumen into which the second puller wire extends.