Abstract: Structure and a method of implanting the structure to assist a patient's cardiovascular system in pumping blood from a vein to an artery. A chamber is associated with a vein and an artery to allow blood from the vein to flow thereinto. A length of living muscle is associated with the chamber in a manner that contraction of the muscle will cause at least a portion of the chamber to contract and pump blood therefrom into the artery.

Abstract: A lockable joint for releasably locking two relatively articulated members in longitudinally aligned, load-bearing relation to one another is disclosed. The articulated members are connected together by a shaft carried by one member which shaft pivotally engages a cam slot carried by the other member. The confronting ends of the members are provided with a plurality of interdigitating or nesting surfaces which interlock with each other upon application of a longitudinal force applied to one or both of the members. The cam slot and shaft are designed and constructed to cause relative angular articulation of the members in response to the longitudinally applied force.