Apparatus for reversibly closing a body passage

Claim 1

In an apparatus for implantation in a patient's body to control the flow of a body fluid through a body passage, wherein the apparatus has an inflatable means which can be inflated to close the body passage and deflated to open the body passage, and tubing connected at one end to the inflatable means to carry hydraulic fluid to and from the inflatable means, the improvement which comprises a push button actuated and expandable hydraulic fluid reservoir assembly also adapted to be implanted within the body which assembly includes: (a) a support coupled to the other end of said tubing, said support having a passage therethrough for conveying hydraulic fluid; (b) a rigid cap spaced from the support; (c) an elongated pumping chamber extending from the support to the cap and attached to the cap, said chamber communicating with said passage in the support to receive and transmit hydraulic fluids and containing a substantial amount of hydraulic fluid even in its unexpanded state; (d) a tension spring positioned within said pumping chamber and extending longitudinally between the support and the cap, said tension spring preventing the pumping chamber from being completely collapsed and emptied of hydraulic fluid in its unexpanded state; (e) a push rod connected at one end to said cap and having the other end extending through and past the support, said push rod being located outside of the pumping chamber; and (f) a push button mounted at the other end of the push rod; and wherein said inflatable means, said tubing, said support passage and said pumping chamber form a closed system adapted to contain a pressurized fluid, so that when said push button is actuated said push rod will move said cap and thereby expand said pumping chamber from an initial volume containing a substantial amount of hydraulic fluid to a larger volume which will accommodate an added volume of hydraulic fluid from the inflatable means and cause said inflatable means to deflate due to the flow of hydraulic fluid through said tubing from said inflatable means to said pumping chamber.