Mapping variable loop catheter handle

A deflecting and sizing apparatus for a catheter handle comprising a catheter shaft having a deflectable distal end portion including a loop member, the apparatus comprising:

• a deflection mechanism positioned inside the handle and including a pull wire for deflecting the distal end deflectable portion of the catheter shaft;
• and
• a loop member adjustment mechanism for adjusting a diameter of the loop member, the loop member adjustment mechanism comprising:
• a loop member pull wire, wherein a distal end of the loop member pull wire is attached to the loop member;
• and
• a sliding member, located within the handle, wherein the sliding member is configured to translate within the handle, and wherein a proximal end of the pull wire is attached to the sliding member.

A method of adjusting the diameter of a loop member on a catheter shaft of a catheter, the method comprising:

• providing a catheter including:
• a longitudinally-extending catheter shaft comprising a proximal end portion and a distal end deflectable portion, wherein the distal end deflectable portion includes a loop member;
• a handle attached to the proximal end portion of the catheter shaft;
• a deflection mechanism positioned inside the handle and including a pull wire for deflecting the distal end deflectable portion of the catheter shaft;
• and
• a loop member adjustment mechanism for adjusting a diameter of the loop member, the loop member adjustment mechanism comprising:
• a loop member pull wire, wherein a distal end of the loop member pull wire is attached to the loop member;
• and
• a sliding member, located within the handle, wherein the sliding member is configured to translate within the handle, and wherein a proximal end of the pull wire is attached to the sliding member;
• and
• translating the sliding member within the handle to adjust the diameter of the loop member on the catheter shaft.