Three stage valve with flexible valve seat

• US 4,714,458 A
• Filed: 12/23/1985
• Issued: 12/22/1987
• Est. Priority Date: 12/23/1985
• Status: Expired due to Term

• Current Assignee: NMT NeuroSciences (International), Inc.
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Hooven, Michael D.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/812,771
• Time in Patent Office: 729 Days
• Field of Search: 137/504, 137/508, 137/539, 137/859, 138/45, 604/8-10, 604/247
• US Class Current: 604/9
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• CPC Class Codes: G05D 7/012 the sensing element being deformable and acting as a valve
• CPC Class Codes: Y10T 137/7792 Movable deflector or choke
• CPC Class Codes: Y10T 137/7834 Valve seat or external sleeve moves to open valve

Abstract

An implantable valve for controlling the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm, one side of which is in pressure communication with the drainage location of the body and the other side of which is in pressure communication with the ventricular spaces of the brain. The diaphragm includes a flexible valve seat which moves relative to a valve closure means and a fluid flow control means in response to applied pressure differentials, thus regulating passage of CSF from the ventricular spaces to the drainage location. When the pressure differential is relatively small, the valve operates in a constant pressure mode to maintain a predetermined pressure differential across the valve. In response to a sudden increase in differential pressure, the valve operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the valve. Above a predetermined pressure differential, the valve operates n a constant pressure mode to maintain a predetermined maximum pressure differential across the valve.

Claims

1. A valve for regulating the flow of fluid from one location in the body to another location, comprising:

a bio-compatible housing;

a flexible one-piece bio-compatible diaphragm dividing the interior of said housing into first and second interior chambers, said diaphragm including an integral valve seat portion defining a fluid passageway opening from said first interior chamber to said second interior chamber, and defining a first valving surface concentrically oriented with respect to the axis of said fluid passageway, said valve seat portion having a static position within said housing in the absence of a pressure differential between said chambers;

inlet port means for establishing fluid communication between said first interior chamber and the one location;

outlet port means for establishing fluid communication between said second interior chamber and the other location;

means comprising an elongated bio-compatible valve stem member attached at one end to said housing primarily within said second chamber and extending therefrom along the axis of said fluid passageway toward said first chamber, said valve stem member defining a plurality of additional valving surfaces for coacting with said first valving surface to form a flow restriction within said passageway between said first and second chambers;

said additional valving surfaces including, progressing from said first chamber toward said second chamber, a first surface of generally relatively lesser radial extent from said axis for providing a relatively lesser flow restriction in said passageway, a second surface of generally relatively greater radial extent for providing a relatively greater flow restriction in said passageway and a third surface of generally lesser radial extent similar to said first surface to provide a relatively lesser flow restriction in said passageway;

valve closure means coacting with said valve seat portion in said static position to close said passageway to provide a first valving mode wherein flow between said first and second interior chambers is prevented; and

said valve seat portion being displaceable from said static position in a direction along said axis of said fluid passageway away from said valve closure member in response to an increase in pressure differential between said first interior chamber and said second interior chamber to cause said first valving surface to successively coact with said first, second and third surfaces of said valve stem member thereby providing second, third and fourth valving modes, in said second valving mode fluid flow occurring between said interior chambers so as to maintain a first substantially constant predetermined pressure in said first chamber, in said third valving mode fluid flow remaining substantially constant between said chambers notwithstanding changes in differential pressure, and in said fourth valving mode fluid flow occurring between said chambers to maintain a second substantially constant predetermined pressure in said first interior chamber.

2. A flow regulating valve as defined in claim 1 wherein said first valving surface is formed from flexible and stretchable material and is inherently biased into engagement with said valve closure member when said valve seat is in said static position to provide a predetermined threshold pressure differential at which flow occurs between said first and second interior chambers.

3. A flow regulating valve as defined in claim 1 wherein said first surface of said valve stem member is generally frusto-conical and of progressively increasing diameter, said second surface of said valve stem member is generally cylindrical and vertically extending, and said third surface of said valve stem member is generally frusto-conical and of progressively decreasing diameter.

4. A flow regulating valve as defined in claim 2 wherein said valve closure member includes an annular rib of V configuration arranged to engage said valve seat portion to prevent fluid flow between said first and second interior chambers in said static position of said valve seat portion.

5. A flow regulating valve as defined in claim 4 wherein said first surface of said valve stem member is generally frusto-conical and of progressively increasing diameter.

6. A flow regulating valve as defined in claim 1 wherein said diaphragm and valve seat portion thereof are formed from flexible and stretchable material to permit movement thereof in response to pressure differential, said first valving surface being expandable and retractable in response to such movement, said first valving surface and said valve stem member being dimensioned relative to one another so that the greatest radial dimension of said valve stem member will barely be received and through said fluid passageway.

7. A flow regulating valve as defined in claim 3 wherein said diaphragm and valve seat portion thereof are formed from flexible and stretchable material to permit movement thereof in response to pressure differential, said first valving surface being expandable and retractable in response to such movement, said first valving surface and said valve stem member being dimensioned relative to one another so that the greatest radial dimension of said valve stem member will barely be received in and through said fluid passageway.