Patent ID: 7815600

Claim:
A balloon catheter having a proximal end and a distal end, for medically treating a patient, comprising: a balloon defining an interior; a hub defining a proximal inflation port; a flexible shaft having a proximal and distal end; the shaft extending between the balloon and hub; the hub being affixed to the proximal end of the shaft, and the balloon being affixed to the shaft at or near its distal end; the shaft defining an inflation lumen extending from the proximal inflation port to the interior of the balloon, the shaft defining a distal guidewire port at or near the distal end of the catheter and a proximal guidewire port positioned between the hub and balloon, the shaft defining a guidewire lumen extending between the proximal and distal guidewire ports; at least a portion of the shaft including an inner tubular body and an outer tubular body, each having a proximal and distal end; the outer body surrounding at least a portion of the inner body; wherein the outer body has a hypotube with a proximal and distal end, extending from the proximal end of the shaft to a point at or near the balloon proximal leg; a portion of the hypotube having a cut pattern having a helical shape and following an overlapping undulating serpentine path having inflection points, which provides greater resistance than a solely helical cut pattern to longitudinal changes in length under tensile forces, and a flexibility transition from a proximal portion to a distal portion of the outer body; the proximal guidewire port being positioned in the cut pattern portion of the hypotube, between a proximal and distal end of the cut pattern portion; and a fluid-tight outer layer surrounding at least the cut pattern portion of the hypotube, except for an aperture for the proximal guidewire port.