Patent ID: 8609016

Claim:
A method of forming an expandable balloon for a medical device, the method comprising the steps of: providing a balloon preform; placing said balloon preform in a first mold form, the first mold form having an interior cavity wherein a radial cross-section of the interior cavity of the first mold form is defined by a first perimeter; radially expanding said balloon preform in said first mold form at a temperature, T 1 , and a pressure, P 1 , to form a pre-formed balloon, the pre-formed balloon having a circular cross-sectional shape; placing said pre-formed balloon in a second mold form, the second mold form having an interior cavity wherein a radial cross-section of the interior cavity of the second mold form is defined by a second perimeter which is larger than the first perimeter of the first mold form; radially expanding said pre-formed balloon in the second mold form at a temperature, T 2 , wherein T 2 <T 1 and a pressure, P 2 to form a balloon having a polygonal geometric cross-sectional shape with a perimeter that is larger than that of the preformed balloon.