Steerable catheter with shaft support system for resisting axial compressive loads

A catheter comprising:

• a sheath including a proximal region and a distal-end region;
• a first steering tendon housed within the sheath, the first steering tendon having a first end attached to the distal-end region at a point proximate an inner surface of the sheath, and a second end exiting a proximal end of the sheath, wherein movement of the first steering tendon in a proximal direction causes the sheath distal-end region to deflect;
• a second steering tendon housed within the sheath, the second steering tendon having a first end attached to the distal-end region at a point proximate the inner surface of the sheath and proximal the attachment point of the first steering tendon, and a second end exiting the proximal end of the sheath, wherein movement of the second steering tendon in the proximal direction causes the sheath distal-end region to deflect;
• and
• a compression cage having a proximal end, a distal end and a lumen there between, the compression cage sized to fit within the distal-end region of the sheath and configured to deflect laterally and to support an axial load.

A catheter for use with biological tissue, the catheter comprising:

• a sheath including a proximal region and a distal-end region;
• at least one electrode located in the distal-end region for transferring energy to the biological tissue;
• a first steering tendon housed within the sheath, the first steering tendon having a first end attached to the distal-end region at a point proximate an inner surface of the sheath, and a second end exiting a proximal end of the sheath, wherein movement of the first steering tendon in a proximal direction causes the sheath distal-end region to deflect;
• a second steering tendon housed within the sheath, the second steering tendon having a first end attached to the distal-end region at a point proximate the inner surface of the sheath and proximal the attachment point of the first steering tendon, and a second end exiting the proximal end of the sheath, wherein movement of the second steering tendon in the proximal direction causes the sheath distal-end region to deflect;
• a compression cage having a proximal end, a distal end and a lumen there between, the compression cage sized to fit within the distal-end region of the sheath and configured to deflect laterally therewith and to resist axial compression;
• and
• a torque transfer system housed within the compression cage and adapted to transfer torsional forces from the proximal region of the sheath to the distal-end region of the sheath.