A catheter assembly comprises a stylus including a first generally conically shaped end tapering to a point at a predetermined angle and a second end. A cannula includes a first lumen for slidably receiving the stylus. The cannula includes a first end having an end wall and a second end. A catheter includes...http://www.google.es/patents/US4986814?utm_source=gb-gplus-sharePatente US4986814 - One-punch catheter
