Catheter steering mechanism

A steering mechanism including

• a steering shaft having a proximal end and a distal end and a lumen therethrough;
• a coiled spring mounted in the steering shaft;
• a lead spring positioned within the distal end and fixed in place distally of the coiled spring;
• a first steering wire extending through the steering shaft lumen having a distal end attached to the lead spring at a first location and having a proximal end exiting the proximal end of the steering shaft;
• a second steering wire extending through the steering shaft lumen having a distal end attached to the lead spring at a second location and having a proximal end exiting the proximal end of the steering shaft;
• a controller positioned at the proximal end of the steering shaft and attached to the proximal ends of the first and second steering wires for placing tension on at least one of the steering wires for causing the distal end of the steering shaft to bend toward the tensed steering wire, and
• the steering shaft including a section of enlarged diameter for bending the steering shaft to a greater degree near the section than in a region removed from the section.

A steerable catheter having a proximal end and a distal end and a lumen, comprising:

• a lead spring disposed in the distal end within said lumen and having a distal end and a proximal end, and further having a first side and a second side;
• means for fixing said lead spring relative to said distal end to prevent relative longitudinal movement but to allow lateral flexing of said lead spring and the distal end;
• a first steering wire having a distal tip affixed to said lead spring near said lead spring distal tip on said first side;
• first means, attached to the proximal end of the catheter, for exerting tension on said first steering wire;
• a second steering wire having a distal tip affixed to said lead spring near said lead spring distal tip on said second side;
• and
• second means, attached to the proximal end of the catheter, for exerting tension on said second steering wire;
• a steering shaft having a central lumen and positioned within said lumen of said catheter;
• and
• a coiled spring positioned within said steering shaft lumen;
• wherein
• said fixing means includes a ferrule mounted at a distal end of said coiled spring, said ferrule including a longitudinal bore and a transverse slot;
• said lead spring is mounted within said slot;
• said first and second steering wires pass through said longitudinal bore;
• and
• each of said steering shaft lumen and said bore has an inner diameter which is less than a combined outer diameter of said lead spring and said first and second steering wires.

A steering mechanism, including:

• a steering shaft having a proximal end and a distal end and a lumen therethrough;
• a coiled spring mounted in the steering shaft;
• a lead spring positioned within the distal end and fixed in place distally relative to said coiled spring;
• a steering wire extending through said lumen, having a first end attached to said lead spring at a first location and having a second end exiting said proximal end;
• and
• a controller positioned at said proximal end and attached to said second end, for placing tension on said steering wire for causing said distal end to bend toward the tensed steering wire, wherein said controller includes:
• a housing connected to said steering shaft;
• a shaft rotatably carried by said housing and having an axis mounted nonparallel to a longitudinal axis of said housing;
• means for attaching said second end to said shaft, such that roataion of said shaft places tension on said steering wire;
• means attached to said shaft for rotating said shaft;
• and
• means for adjusting rotational friction on said steering shaft.

A steering mechanism, including:

• a steering shaft having a proximal end and a distal end and a lumen therethrough, wherein said steering shaft includes a section of enlarged diameter for bending said steering shaft to a greater degree near said section than in a region removed from said section;
• a coiled spring mounted in said steering shaft;
• a lead spring positioned within said distal end and fixed in place located distally relative to said coiled spring;
• a steering wire extending through said lumen, having a first end attached to said lead spring at a first location and having a second end exiting said proximal end;
• and
• a controller positioned at said proximal end and attached to said second end, for placing tension on said steering wire for causing said distal end to bend toward the tensed steering wire.

A steering mechanism comprising

• a shaft having a proximal end and a distal end and a lumen therethrough;
• steering means carried within the shaft for bending a region of the shaft to steer it;
• a steering wire extending through the shaft lumen and having a distal end attached to the steering means and having a proximal end exiting the proximal end of the steering shaft;
• and
• a controller positioned at the proximal end of the steering shaft including
• a control member,
• means for moving the control member subject to friction and including adjustment means for adjusting the friction, and
• means attaching the proximal end of the first steering wire to the control member for placing tension on the steering wire in response to movement of the control member to cause the distal end of the steering shaft to bend toward the tensed steering wire.

A steering mechanism comprising

• a shaft having a proximal end and a distal end and a lumen therethrough;
• steering means carried within the shaft for bending a region of the shaft to steer it;
• a steering wire extending through the shaft lumen and having a distal end attached to the steering means and having a proximal end exiting the proximal end of the steering shaft;
• and
• a controller positioned at the proximal end of the steering shaft and attached to the proximal end of the steering wire for placing tension on the steering wire for causing the distal end of the steering shaft to bend toward the tensed steering wire, and
• the steering shaft including a section of enlarged diameter for bending the steering shaft to a greater degree near the section than in a region removed from the section.