A guidewire for use in guiding a catheter has a tip construction that includes a core wire within a helical coil. The core wire has a distal tip segment that is tapered and is further impressed with a pair of opposed flattened surfaces extending along the taper, the surfaces lying at an angle to each...http://www.google.es/patents/USRE37148?utm_source=gb-gplus-sharePatente USRE37148 - Guidewire tip construction
