Patent ID: 8795348

Claim:
A medical system comprising: an electrical energy source; an elongate shaft having a lumen defined therein; wherein the lumen extends continuously from a proximal end of the elongate shaft to a distal end region of the elongate shaft and through a turn as the lumen loops back to the proximal end of the elongate shaft, wherein the lumen has walls extending uninterrupted from the proximal end of the elongate shaft to the distal end region of the elongate shaft, through the turn and back to the proximal end; an expandable member disposed at a distal portion of the shaft; and a wire associated with the expandable member, the wire extending from the electrical energy source, through the lumen from the proximal end of the elongate shaft to the distal end region of the elongate shaft, through the expandable member, and loops back through the lumen to the proximal end of the elongate shaft, the wire having a first state in which the expandable member is unexpanded, and the wire having a second state in which the expandable member is expanded; wherein the wire contracts in length from the first state to the second state as a result of heating the wire by applying an electrical current through the wire with the electrical energy source.