In-line pressure check valve for drug-delivery systems

• US 5,725,017 A
• Filed: 01/27/1997
• Issued: 03/10/1998
• Est. Priority Date: 01/27/1997
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Comben, Richard H., Elsberry, Dennis D.
• Primary Examiner(s): Ferensic, Denise L.
• Assistant Examiner(s): Kim, Joanne Y.
• Application Number:
  US08/789,693
• Time in Patent Office: 407 Days
• Field of Search: 137/517, 137/529, 137/859, 604/247, 251/368
• US Class Current: 137/517
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: Y10T 137/7869 Biased open
• CPC Class Codes: Y10T 137/7905 Plural biasing means

Abstract

A pressure control valve, fabricated using micromachining techniques, comprises, in one embodiment a substrate having a central orifice therein and having a sealed chamber formed therein, one wall of which being defined by a flexible membrane. An inlet control element is supported by the membrane such that it is disposed over the central orifice, such that normally a gap is defined between the inlet control element and the central orifice and hence the valve is open. When the pressure differential, between external pressure and pressure in the chamber, exceeds a predetermined threshold, the membrane deforms, drawing the inlet control element toward the substrate such that the inlet control element seats over the central orifice, closing the valve. In another embodiment a flexible membrane cooperates with a valve substrate to form a closed chamber, and a valve lid, coupled to the membrane, extends over one or more holes in the substrate, forming a gap between the valve lid and the substrate. When a predetermined level of pressure is applied to the valve lid, the gap closes, preventing fluid from flowing through the hole(s). Valves in accordance with the present invention may be micromachined from such materials as glass or metal, and may be incorporated in-line in the filling conduit for the reservoir of an implantable drug delivery system.

Claims

1. A pressure control valve, comprising:

a substrate having a central orifice therein;

a flexible membrane defining one wall of a sealed chamber formed in said substrate;

an inlet control element, disposed over said orifice and supported by said membrane such that a gap is normally defined between said inlet control element and said substrate;

wherein a pressure differential, between external pressure and pressure in said chamber, results in deformation of said membrane such that said inlet control element is drawn toward said substrate, thereby eliminating said gap and closing said valve.

2. A pressure control valve in accordance with claim 1, wherein said substrate and said inlet control element are micromachined from glass.

3. A pressure control valve in accordance with claim 2, wherein said membrane is silicon.

4. A pressure control valve, comprising:

a substrate having a central orifice therethrough, and having a sealed chamber therein with said chamber'"'"'s top being defined by a flexible membrane;

an inlet control element, coupled around its perimeter to said membrane such that said inlet control element is disposed above said central orifice, and normally defines a gap between said inlet control element and said substrate, said inlet control element having a plurality of holes therethrough;

said valve normally having a fluid path therethrough whereby fluid enters through said plurality of holes, passes through said gap, and exits through said central orifice;

wherein a pressure differential, between external pressure and pressure in said chamber, above a predetermined threshold, causes deformation of said membrane, drawing said inlet control element toward said substrate and eliminating said gap, such that said fluid path is interrupted.

5. A pressure control valve having a normally open configuration and a closed configuration, said valve comprising:

a substrate, having at least one hole therein providing a fluid path through said valve;

a flexible membrane, coupled to said substrate; and

a valve lid, coupled to said membrane such that pressure exerted on said valve lid is applied to said membrane, said membrane flexing in response to such pressure, said valve lid extending over said at least one hole in said substrate;

wherein when no pressure is applied to said valve lid, a valve gap is defined between said valve lid and said substrate, such that fluid is permitted to flow through said at least one hole;

and wherein when pressure applied to said valve lid causing said membrane to flex draws said valve lid toward said membrane, said valve gap narrows, such that pressure above a predetermined level applied to said valve lid closes said gap and prevents fluid from flowing through said at least one hole.

6. A pressure control valve in accordance with claim 5, wherein said substrate and said valve lid are made of metal.

7. A pressure control valve in accordance with claim 6, wherein said metal is titanium.

8. A pressure control valve in accordance with claim 5, wherein said membrane and said substrate cooperate to form a closed chamber, and wherein said predetermined pressure level changes with changes in pressure in said closed chamber.