| 摘要 |
<p>A surgically implantable flow control device (10) positionable over a burr-hole through a patient's skull is provided for use in shunt systems for controlling the release of entrapped body fluids. The device (10) includes a rigid base (22) including an inlet port (42), a valve seat (26) which surrounds the inlet port (42), and a flow control member (50) secured to the base (22). The flow control member (50) has an asymmetric membrane (56) which is resiliently biased to contract the valve seat (26) in a manner forming a releasable seal therebetween, to provide controlled resistance to proximal-to-distal fluid flow through the device (10). The membrane (56) includes a septum portion (58) overlying the inlet port (42), and a relatively thin portion (60) responsive to fluid pressure differentials on inlet and outlet sides thereof. A membrane shield (62) overlies an outlet side of the membrane, and includes a needle guide aperture (66) in alignment with the septum portion (58) of the membrane (56) and the inlet port (42).</p> |
