A catheter for carotid artery dilatation that includes a multi-chamber balloon assembly mounted at the distal end of the elongated tube that has at least two tandem chambers. Each chamber communicates with a separate lumen and each separate lumen terminates at the proximal end at a lumen valve head....http://www.google.ca/patents/US8142395?utm_source=gb-gplus-sharePatent US8142395 - Tapered multi-chamber balloon
