Patent ID: 8709038

Claim:
An apparatus for closing a puncture site adjacent to a blood vessel wall comprising: an expandable hemostatic member formed of a biocompatible member, said hemostatic member having a first contracted state and a second expanded state and being configured to expand from the first contracted state to the second expanded state when exposed to body fluid; and a control layer substantially covering the entire surface of the hemostatic member, the control layer having an initial state, in which the control layer prevents body fluid from reaching the hemostatic member, and an activated state in which the control layer no longer prevents body fluid from reaching the hemostatic member, said control layer being configured to change from the initial state to the activated state in response to an expansion triggering technique including exposure to radio signals, radiation, or ultrasonic signals; wherein the change from the initial state to the activated state delays penetration of body fluid through the control layer to the expandable hemostatic member, further wherein the hemostatic member in the first contracted state and the control layer in the initial state are sized and configured to be disposed in an opening in body tissue in a desired position adjacent a wall of a blood vessel.