Claims
- 1. In a surgically implantable shunt system in which cerebrospinal fluid is vented from a cerebroventricular catheter to a drainage catheter, a valve for presenting a precisely controllable back pressure to the ventricles, said valve comprising:
- an elongate, hollow valve body;
- a flat plate partitioning said valve body so as to form an inlet chamber and an outlet chamber, said ventricular catheter being coupled so said inlet chamber and said drainage catheter being coupled to said outlet chamber, said plate being provided with a circular aperture connecting said inlet and outlet chambers;
- a spherical ball of diameter larger than said aperture for controllably restricting flow through said aperture; and
- a spring including a cantilevered flat portion overlying said ball and biasing it against the circular periphery of said aperture whereby a circular seal is selectively effected between said ball and said plate, providing a precisely defined back pressure with low hysteresis and low susceptibility to bridging by debris.
- 2. In a surgically implantable shunt system in which cerebrospinal fluid is vented from a cerebroventricular catheter to a drainage catheter, a valve for presenting a precisely controllable back pressure to the ventricles, said valve comprising:
- an elongate, hollow valve body;
- a stainless steel flat plate partitioning said valve body so as to form an inlet chamber and an outlet chamber, said ventricular catheter being coupled to said inlet chamber and said drainage catheter being coupled to said outlet chamber, said plate being provided with a highly polished circular aperture connecting said inlet and outlet chambers;
- a highly polished, spherical sapphire ball of diameter larger than said aperture for controllably restricting flow through said aperture; and
- a metallic spring including a cantilevered flat portion parallel to the plane of said aperture overlying said ball and biasing it against the circular periphery of said aperture whereby a circular seal is selectively effected between said ball and said plate, providing a precisely defined back pressure with low hysteresis and low susceptibility to bridging by debris.
- 3. The valve of claim 2 wherein said flat plate is approximately 0.01 inch thick.
- 4. The valve of claim 2 wherein said circular aperture is approximately 0.057 inch in diameter and said ball is approximately 0.620 inch in diameter.
- 5. The valve of claim 1 wherein said flat plate includes a struck up rear portion said struck up portion adapted to apply an adjustable level of force against said spring to establish a desired value of said back pressure.
- 6. The valve of claim 1 wherein said flat plate includes a struck up rear portion, and said spring includes a semicircular bend and is adapted for attachment to said flat plate; wherein said spring is attached to said flat plate at a location so that said semicircular bend presses against said struck up rear portion so as to establish a desired value of said back pressure.
- 7. The valve of claim 1 further including screw means threadably supported by said valve body and adapted for adjustably pressing against said cantilevered flat portion of said spring to establish a desired value of said back pressure.
BACKGROUND OF THE INVENTION
This is a continuation-in-part of U.S. Ser. No. 2,354, filed Jan. 10, 1979, and now abandoned entitled "Shunt Valve".
US Referenced Citations (5)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
2354 |
Jan 1979 |
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