Steerable catheter with torque transfer system

A catheter comprising:

• a sheath including a proximal region and a distal-end region having a distal tip;
• 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 the inner surface of the sheath, and a second end exiting the proximal end of the sheath, wherein movement of the first steering tendon in a proximal direction causes die 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 ribbon having a length which is less than the length of the sheath, the ribbon being housed within the distal-end region of the sheath and configured to deflect therewith, the ribbon having a first end attached to the distal tip of the sheath and a second end attached to a distal portion of the proximal region of the sheath.

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

• a sheath including a proximal region having a first torque transfer strength and a distal-end region having a distal tip and a second torque transfer strength less than the first torque transfer strength;
• 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 the inner surface of the sheath, and a second end exiting the 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 torque transfer system adapted to increase the torque transfer strength of the distal-end region to facilitate the transfer of torsional forces from the proximal region to the distal-end region, the torque transfer system including a ribbon having a length which is less than the length of the sheath, the ribbon being housed within the distal-end region of the sheath and configured to deflect therewith, the ribbon having a first end attached to the distal tip of the sheath and a second end attached to a distal portion of the proximal region of the sheath.

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

• a sheath including a proximal region having a first torque transfer strength and a distal-end region having a second torque transfer strength less than the first torque transfer strength, and a centerline throughout the length of the sheath;
• 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 the inner surface of the sheath, and a second end exiting the 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;
• an eyelet secured within the proximal region of the sheath having a non-circular shape proximal end having a cross-sectional diameter greater than the inner diameter of the sheath;
• and
• a ribbon positioned along the centerline of the sheath and housed within the distal-end region of the sheath and configured to deflect therewith, the ribbon having a first end secured within the distal tip of the distal-end region and a second end secured within the eyelet.