The invention provides a deflectable catheter capable of forming many variable radius spiral forms from a single, flexible, distal end section. In one aspect, the catheter employs a variable radius control wire to extend or deform a pre-formed loop structure into a three dimensional spiral-like form...http://www.google.fr/patents/US20070270679?utm_source=gb-gplus-shareBrevet US20070270679 - Deflectable variable radius catheters
