Abstract: A blood vessel access closure device includes an inner blood vessel wall support member and an outer blood vessel wall support member. The closure device also includes a deployment member and an electrode. The deployment member is configured to draw the inner and outer blood vessel wall support members towards each other when the inner and outer blood vessel wall members are deployed on opposite sides of a blood vessel wall during closure of a hole in the blood vessel wall. The electrode is configured to be attached to the deployment member and configured to be used to measure impedance.

Abstract: A introducer is disclosed that includes an introducer sheath for introducing a catheter into a blood vessel at an insertion point, a plurality of electrodes on the introducer sheath, a flush line coupled to the introducer sheath including a proximal end and a distal end. In addition, the introducer includes an impedance assessment unit coupled to the flush line between the proximal end and the distal end and electrically coupled to the electrodes. The impedance assessment unit is configured to inject a predetermined current or voltage into a first of the plurality of electrodes and measure a resulting voltage or current, respectively, from a second of the plurality of electrodes.