#$%^&*AU2015221535A120150924.pdf#####ABSTRACT The invention provides an implantable medical device, comprising: a frame comprising a first opening, a second opening, and a longitudinal axis there-between, and comprising a plurality of struts interconnected by a plurality of joints, wherein the joints comprise a rotation axis with an orientation substantially normal to an outer surface of the frame and an actuation mechanism coupled to the frame at two anchor points and configured to selectively actuate expansion and collapse of the frame by applying longitudinal forces to the two anchor points to move the two anchor points longitudinally relative to each other, wherein the actuation mechanism is self-locking to maintain the frame at a desired diameter, wherein the actuation mechanism comprises a rotational interface that comprises a rod and a first threaded mount, wherein the rod comprises a first helical thread, and the first threaded mount is configured to cooperate with the first helical thread, and wherein the implantable medical device is configured to be inserted into a patient.
