Patent ID: 7593760

Claim:
A mapping catheter comprising: an elongated tubular proximal shaft having an outer wall and proximal and distal ends; a distal shaft having proximal and distal ends, the proximal end of the distal shaft being attached to the distal end of the proximal shaft; a mapping assembly at the distal end of the distal shaft, the mapping assembly comprising: a tubular structure comprising a pre-formed generally circular main region generally transverse and distal to the proximal shaft and having an outer circumference, wherein the tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly, the non-conductive cover having a single lumen, and a plurality of electrodes carried by the generally circular main region of the mapping assembly; a control handle mounted at the proximal end of the proximal shaft; and a contraction wire extending through the proximal shaft and non-conductive cover of the mapping assembly for contracting the generally circular main region of the mapping assembly, the contraction wire having a distal end anchored in the non-conductive cover and a proximal end anchored to a mechanism in the control handle that facilitates longitudinal movement of the contraction wire relative to the distal shaft, wherein the portion of the contraction wire extending through the non-conductive cover is positioned on the side of the generally circular main region closer to the center of the generally circular region.