Abstract: A catheter is provided that has a basket-shaped electrode assembly with an improved mechanism for expanding and contracting the electrode array. The expansion mechanism is designed to permit reproducible reintroduction of the catheter into the heart. The catheter comprises an elongated catheter body having at least one lumen therethrough. A basket-shaped electrode assembly is mounted at the distal end of the catheter body. The basket assembly comprises a plurality of spines connected at their proximal and distal ends, each of which comprises at least one electrode. The basket assembly has an expanded arrangement wherein the spines bow radially outwardly and a collapsed arrangement wherein the spines are arranged generally along the axis of the catheter body. An expander is attached at or near its distal end to the distal ends of the spines and extends through the catheter body. The expander has a proximal end that extends out the proximal end of the catheter body a lumen extending therethrough.

Abstract: A deflectable device, such as a catheter, is provided that includes a hinge that enhances the ability of the device to deflect or bend within a predetermined plane. The catheter comprises an elongated tubular catheter body having proximal and distal ends and at least one lumen extending therethrough. A distal segment is provided distal to the distal end of the catheter body. A tubular hinge is provided between the distal end of the catheter body and the proximal end of the distal segment. The hinge has an axis and at least one lumen extending therethrough. The tube includes at least one slot, and preferably a plurality of slots, extending part of the way through the hinge generally transverse to the axis of the hinge.