Implantable drug infusion regulator

• US 4,299,220 A
• Filed: 05/03/1979
• Issued: 11/10/1981
• Est. Priority Date: 05/03/1979
• Status: Expired due to Term

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Dorman, Frank D.
• Primary Examiner(s): ROSENBAUM, C FRED
• Application Number:
  US06/035,535
• Time in Patent Office: 922 Days
• Field of Search: 128/204, 128/29, 128/205.15-205.16, 128/207.16, 128/213 R, 128/214 F, 128/260, 128/274, 128/DIG. 12-DIG. 13, 137/487, 137/489, 137/500, 417/299, 417/302-303
• US Class Current: 604/118
• CPC Class Codes: A61M 2005/14264 with means for compensating influence from the environment
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• 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

Abstract

An implantable flow regulator for the infusion of drugs into an animal body from a pressure actuated drug delivery device, such as an implantable infusion pump. The flow regulator comprises a body having a shallow cavity divided into two chambers by a flexible diaphragm. The first of these chambers is a pressure sensing chamber. The other is a valving chamber through which the drug flows, the outlet from that chamber being centrally disposed underlying the diaphragm whereby flexing of the diaphragm in one direction as a result of increased pressure in the other chamber contacts an elastomeric sealing ring around the outlet and closes off the flow path. At least one capillary restrictor is disposed in the flow line between the drug delivery device and flow regulator. The pressure drop across this restrictor governs operation of the flow regulator valve.

Claims

1. In a drug delivery system for implantation in an animal body for the infusion of liquid drugs into said body including a pressure actuated drug delivery device which is sensitive to ambient pressure and temperature conditions and a liquid catheter flow line for transfer of drug from the delivery device to an infusion site within the body, the improvement which consists in a pressure sensitive flow regulator in said flow line, said regulator comprising:

(A) a body,

(B) a shallow cavity within said body,

(C) a flexible diaphragm in said body dividing said cavity into two chambers,

(D) an inlet to the first of said chambers connected to the flow line,

(E) an inlet to the second of said chambers connected to the flow line to receive the drug from the drug delivery device,

(F) an outlet from the second of said chambers to the flow line downstream from the regulator, said outlet being centrally disposed in the wall of the cavity underlying said diaphragm, whereby flexing of the diaphragm in one direction in response to increased pressure in the flow line closes said outlet, and

(G) at least one capillary flow restrictor in the flow line upstream from the inlet to the second chamber and in series with the inlet and outlet of said second chamber.

2. A flow regulator according to claim 1 wherein said outlet from said second chamber includes:

(A) a shallow recess in the cavity wall, and

(B) a resilient ring in said recess surrounding the outlet passage, the thickness of said ring being greater than the depth of said recess.

3. A flow regulator according to claim 1 wherein said body, diaphragm and fittings are composed of inert non-toxic biocompatible material.

4. A flow regulator according to claim 3 wherein said material is titanium.

5. A flow regulator according to claim 1 wherein:

(A) an outlet is provided from said first chamber,

(B) said outlet is provided with a fitting for connection to a capillary flow line extending to the inlet of said second chamber, whereby the flow from the drug delivery device to the infusion site is through the first chamber, and

(C) said capillary restrictor is between said first chamber outlet and second chamber inlet.

6. A flow regulator according to claim 1 wherein:

(A) said body is comprised of mating members, each having a cavity-forming recess in its inner face, and

(B) said diaphragm is a thin disc supported at its periphery between said members.

7. A flow regulator according to claim 1 wherein:

(A) said body is comprised of mating members, each having a cavity-forming recess in its inner face, and

(B) said diaphragm is supported by a bellows.

8. A flow regulator according to claim 1 wherein:

(A) at least two capillary restrictors of different flow resistance are upstream from the inlet to the second chamber and in series with the inlet and outlet of said second chamber, and

(B) a valved by-pass flow line extends around the restrictor of greater resistance.

9. In a drug delivery system for implantation in an animal body for the infusion of liquid drugs into said body including a pressure actuated drug delivery device which is sensitive to ambient pressure and temperature conditions and a liquid catheter flow line for transfer of drug from the delivery device to an infusion site within the body, the improvement which consists in a pressure sensitive flow regulator in said flow line, said regulator comprising:

(A) a body,

(B) a shallow cavity within said body,

(C) a flexible diaphragm in said body dividing said cavity into two chambers,

(D) an inlet to the first of said chambers, said inlet being provided with a fitting for connection to the flow line from the drug delivery device,

(E) an outlet from the first of said chambers,

(F) an inlet to the second of said chambers,

(G) a capillary flow line between said first chamber outlet and second chamber inlet, and

(H) an outlet from the second of said chambers, said outlet including a centrally disposed shallow recess in the cavity wall and a resilient ring in said recess surrounding the outlet passage, the thickness of said ring being greater than the depth of said recess, whereby flexing of the diaphragm in one direction in response to increased pressure in the flow line closes the outlet, and a fitting for connection to the catheter flow line extending to an infusion site within the animal body, said regulator body, diaphragm and fittings being composed of inert, non-toxic biocompatible material.

10. A flow regulator according to claim 9 wherein said material is titanium.

11. A flow regulator according to claim 9 wherein:

(A) at least two capillary flow restrictors of different flow resistance are upstream from the inlet to the second chamber and in series with the inlet and outlet of said second chamber, and

(B) a valved by-pass flow line extends around the restrictor of greater resistance.

12. A system for implantation in an animal body for the infusion of liquid drugs into said body, said system comprising:

(A) a pressure actuated drug delivery device comprising;

(1) a housing,

(2) a collapsible drug chamber within the housing,

(3) an inlet passage to said drug chamber,

(4) a penetrable resilient stopper in that passage,

(5) a propellant chamber within the housing surrounding the drug chamber, and

(6) a liquid within the propellant chamber whose vapor pressure is such that, under conditions of normal body temperature, pressure is exerted upon the collapsible chamber; and

(B) a pressure sensitive flow regulator connected to the drug chamber of the drug delivery device and comprising;

(1) a body,

(2) a shallow cavity within said body,

(3) a flexible diaphragm in said body dividing said cavity into two chambers,

(4) an inlet to the first of said chambers, said inlet being connected to the drug chamber of the drug delivery device,

(5) an inlet to the second of said chambers connected to receive the drug from the drug chamber,

(6) an outlet from the second of said chambers, said outlet being centrally disposed in the wall of the cavity underlying said diaphragm, whereby flexing of the diaphragm in one direction closes said outlet, and

(7) at least one flow restrictor in series with the inlet and outlet of said second chamber.

13. A system according to claim 12 wherein said outlet from said second chamber of the flow regulator includes:

(A) a shallow recess in the cavity wall, and

(B) a resilient ring in said recess surrounding the outlet passage, the thickness of said ring being greater than the depth of said recess.

14. A system according to claim 12 wherein:

(A) said inlets to the flow regulator are provided with fittings for connection to a flow line from the drug delivery device, said flow line including at least one capillary restrictor, and

(B) said outlet from the flow regulator is provided with a fitting for connection to a catheter flow line extending to an infusion site within the animal body.

15. A system according to claim 14 wherein:

(A) an outlet is provided from said first chamber of the flow regulator,

(B) said outlet is provided with a fitting for connection to a capillary flow line extending to the inlet of said second chamber, whereby the flow from the drug delivery device to the infusion site is through the first chamber, and

(C) said capillary restrictor is between said first chamber outlet and second chamber inlet.

16. A system according to claim 12 wherein:

(A) said body of the flow regulator is comprised of mating members, each having a cavity-forming recess in its inner face, and

(B) said diaphragm is a thin disc supported at its periphery between said members.

17. A system according to claim 12 wherein:

(A) at least two capillary restrictors of different flow resistance are in series with the inlet and outlet of said second chamber of the flow regulator, and

(B) a valve by-pass flow line extends around the restrictor of greater resistance.