Patent ID: 8364234

Claim:
A system for sensing multiple local electric voltages from endocardial surface of a heart, comprising: a first elongate tubular member having a lumen, a proximal end and a distal end; a basket assembly comprising: a plurality of flexible splines for guiding a plurality of exposed electrodes, the splines having proximal portions, distal portions and medial portions therein between; a proximal anchor for securably affixing the proximal portions of the splines; said proximal anchor being secured at the distal end of the first elongate tubular member; a distal tip consisting essentially of means for only securably affixing the distal portions of the splines, said proximal anchor and said distal tip defining a longitudinal axis therein between about which the splines are disposed; wherein the splines approach the distal tip at an angle of about 90° or less than about 90° as measured from a line segment between the proximal anchor and the distal tip along the longitudinal axis; wherein the splines comprise a superelastic material such that the basket assembly exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; wherein at least some of the splines in the radially expanded non-spherical shape contain a distal excurvate outward bend disposed at the distal portion of the spline at a location near to the distal tip of the basket assembly to bend the splines back towards the proximal anchor; and wherein, when the basket assembly is in said radially expanded non-spherical shape, the splines extend beyond the distal tip; and, when the basket assembly is in said radially expanded non-spherical shape, apices of the distal excurvate bends are disposed beyond the distal tip.