An implantable medical device and method of implanting a medical device in a hollow organ or cavity lined with the mucosa includes providing a medical device having a wall configured to the size and shape of a portion of a cavity or hollow organ lined with the mucosa. Next, a change amount of the pointing position is calculated. The assembly may include recesses in the bottom surface of the plate, spacers, and spacing portions extending from the bottom surface of the plate that allow the plate to be secured to the interbody implant when the trailing end of the interbody implant is positioned in a recessed, flush or overhanging position relative to the laterally facing surfaces of the vertebrae. In one embodiment, agent is introduced to the tissue prior to attachment of the barrier to the tissue. The engagement member 12a is provided on the opposite side to the moving body 14. Delete states indicate whether a specific node has not been deleted, or whether it may have been deleted.