Patent ID: 7951105

Claim:
A body fluid shunt comprising: a. an inlet port; b. an outlet port; c. a fluid passage between the inlet and outlet ports; d. a valve situated between the inlet and outlet ports, the valve defining: (1) an upstream side of the fluid passage between the inlet port and the valve, and (2) a downstream side of the fluid passage between the valve and the outlet port, and wherein the valve is at least partially defined by a drain port extending between the upstream and downstream sides of the fluid passage; e. a piston: (1) having a piston face defined on the upstream side of the fluid passage, wherein at least a portion of the piston face is defined by a deformable diaphragm, (2) being rotationally displaceable to actuate the valve, and (3) having a cutout defined therein, the cutout being alignable with the drain port when the piston is displaced, wherein: i. fluid bearing on the piston face at or above a shunting pressure will displace the piston to actuate the valve, with alignment of the cutout and the drain port opening the valve to thereby allow passage of fluid between the inlet and outlet ports, and ii. the position of the piston is independent of the pressure in the downstream side of the fluid passage.