A balloon dilatation catheter device and method adapted for use in percutaneous transluminal angioplasty, where the catheter has several lumens so arranged to more efficiently channel and cleanse harmful materials from within the catheter, thereby preventing dangerous materials, such as air, from entering...http://www.google.com.au/patents/US5224933?utm_source=gb-gplus-sharePatent US5224933 - Catheter purge device
