Disclosed is a focal balloon having at least one reference zone and a focal zone. In one embodiment, the reference zone and focal zone are inflatable to a first generally cylindrical profile at a first pressure. At a second, greater pressure, the focal section expands to a second, greater diameter, while...http://www.google.co.uk/patents/US6409741?utm_source=gb-gplus-sharePatent US6409741 - Focalized intraluminal balloons
