US Patent 7322960 Catheter with puncture sensor

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 of protruding from a distal end portion of the sheath portion. The injection needle is disposed in the distal end portion of the insertion member for injecting a therapeutic composition to a target tissue. The paired electrodes are disposed in a distal end portion of the catheter for measuring impedance.