The present invention relates to an anchor device comprising an elongated tubular body having an expandable member disposed on its distal end portion. The invention also relates to a system adapted to position and anchor the distal end of an ablation device at a location where a pulmonary vein extends...http://www.google.co.uk/patents/US7881807?utm_source=gb-gplus-sharePatent US7881807 - Balloon anchor wire
