A multipolar electrode catheter includes a central and a plurality of side electrodes at its distal end. The catheter is actuable from a retracted or collapsed mode wherein the side electrodes are arranged around the tubular catheter outer surface to an expanded mode substantially coplanar with the central...http://www.google.com/patents/US5365926?utm_source=gb-gplus-sharePatent US5365926 - Catheter for mapping and ablation and method therefor
