A catheter for percutaneous insertion includes a sheath portion, an insertion member, an injection needle, and paired electrodes. The sheath portion has a lumen extending therein. The insertion member is disposed slidably in the lumen of the sheath portion and provided with a distal end portion capable...http://www.google.com/patents/US7322960?utm_source=gb-gplus-sharePatent US7322960 - Catheter with puncture sensor
