Three stage intracranial pressure control valve

• US 4,714,459 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:
  US06/812,779
• Time in Patent Office: 729 Days
• Field of Search: 604/8-10, 604/247, 137/504, 137/508, 137/859
• US Class Current: 604/9
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• 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 which positions a valve seat in response to the pressure differential between the inlet and outlet of the valve. The valve seat defines a fluid orifice. An improved valve stem, preferably of one-piece construction, and provided with a series of cooperating diverging and converging frusto-conical portions, extends through the orifice to provide four stages or conditions of fluid flow and pressure control in response to relative movement between the valve seat and stem. In a first stage or condition of operation of the valve, wherein the fluid pressure differential falls below a threshold level, fluid flow is prevented. In a second stage, sufficient fluid flow is permitted to maintain a first substantially constant predetermined differential pressure. In a third stage, fluid flow through the valve is maintained at a substantially constant rate, and in a fourth stage sufficient fluid flow is permitted to maintain a second substantially constant predetermined differential pressure.

Claims

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

a housing having first and second interior chambers;

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

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

a flexible diaphragm in said housing and dividing the same into said first and second chambers, said diaphragm being moveable in response to pressure differentials established between said first and second chambers;

a relatively rigid valve seat mounted on said diagphragm for movement therewith, said valve seat being disc-shaped and centrally thereof defining an annular fluid flow passageway having an interior wall which is flat in an axial direction and which extends in the direction of fluid flow between said first and second chambers, said interior wall defining a first valving surface; and

a one-piece valve stem of over-all generally cylindrical configuration mounted on said housing and projecting into said first interior chamber toward said second chamber and in coaxial alignment with said fluid flow passageway, said valve stem in the direction of fluid flow consisting of a cylindrical upper mounting portion of relatively substantial axial extent and having a relatively large diameter, said mounting portion having a substantial part thereof fixed in said housing to mount said valve stem thereon, said mounting portion in the direction of fluid flow merging with a first frusto-conical portion of decreasing diameter defining a second valving surface for engagement with said valve seat to establish a first condition of fluid flow whereby in the absence of fluid pressure differential fluid flow between said first and second chambers is prevented, said first portion in the direction of fluid flow merging with a second generally frusto-conical portion of increasing diameter defining a third valving surface cooperating with said second valving surface to coact with said first valving surface to establish a second condition of fluid flow wherein a first substantially constant predetermined pressure is maintained in said first chamber, and said second portion in the direction of fluid flow merging with a third generally spherical portion defining a fourth valving surface of progressively decreasing diameter cooperating with said third valving surface to coact with said first valving surface to establish a third condition of fluid flow wherein a substantially constant rate of fluid flow from said first chamber into said second chamber is maintained, said fourth valving surface further coacting with said first valving surface to establish a fourth condition of fluid flow wherein a second substantially constant predetermined pressure is maintained in said first chamber.

2. A regulating valve as defined in claim 1 wherein said housing includes a threadedly advancable and retractable member exposed externally of said housing for adjustable engagement, said upper mounting portion of said valve stem being engaged with said advancable and retractable member for adjustable movement of said valve stem in said housing relative to said valve seat.