Regulator

• US 20050273081A1
• Filed: 06/07/2004
• Published: 12/08/2005
• Est. Priority Date: 06/07/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Olsen, James M.
• Granted Patent: US 8,251,981 B2
• Time in Patent Office: Days
• US Class Current: 604/891.100
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• 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

A flow regulator (19, 208, 308, 408) may be used in a drug delivery system 10. The regulator includes a chamber that is divided by a diaphragm (111, 211, 311, 411) into a first and second subchamber. A third subchamber is in fluid communication with the first subchamber. A valve (26, 217, 317, 417) is operatively connected to the diaphragm, wherein pressure differences between the first subchamber and second subchamber result in movement of the diaphragm and movement of the diaphragm controls operation of the valve. A flow restrictor (116, 216, 316, 416) is in fluid communication between the first and second subchambers. Flow of a drug (11, 101) is thereby regulated.

Claims

1. A pump mechanism for use in an implantable drug delivery system having a positive pressure reservoir, the pump mechanism comprising:

a) a pump having a pump inlet and a pump outlet;

b) a pressure regulator, the pressure regulator comprising;

i) a housing having a chamber;

ii) a diaphragm dividing the chamber into a first subchamber and a second subchamber;

iii) the first subchamber having a first inlet and a first outlet; and

iv) the second subchamber having a second inlet and a second outlet;

c) a valve for controlling flow through the first inlet, the valve operatively connected to the diaphragm, the diaphragm being moveable within the chamber in response to difference in pressure between the first subchamber and the second subchamber; and

d) the pump inlet in fluid communication with the first outlet and the pump outlet in fluid communication with the second inlet.

2. The pump mechanism of claim 1, further comprising:

a) an infusion pump housing defining a drug reservoir;

b) a propellant chamber within the pump housing and proximate the drug reservoir, wherein pressure is exerted on the drug reservoir; and

c) the drug reservoir having a reservoir inlet for receiving a drug and a reservoir outlet, the reservoir outlet in fluid communication with the first inlet of the first subchamber.

3. The pump mechanism of claim 2, wherein the valve is a normally closed valve.

4. The mechanism of claim 3, wherein the diaphragm is constructed from titanium.

5. The mechanism of claim 4, further comprising a biasing member positioned proximate the valve, wherein a pressure difference to open the valve is determined.

6. The mechanism of claim 4, further comprising a biasing member to bias the valve to a closed position.

7. The mechanism of claim 3, further comprising the second subchamber outlet is in fluid communication with ambient pressure, whereby the drug is delivered independent of changes in reservoir pressure and ambient pressure.

8. A drug delivery system for implantation in a body for delivery of a liquid drug, the system comprising:

a) a housing having a chamber;

b) a diaphragm dividing the chamber into a first subchamber in a first flow path and a second subchamber in a second flow path;

c) the diaphragm moveable in response to difference in pressure between the first subchamber and the second subchamber to regulate pressure difference between the first flow path and the second flow path;

d) a valve operatively linked with the diaphragm to open the first flow path when pressure in the second flow path exceeds pressure in the first flow path by a predetermined amount;

e) a pump having an inlet in fluid communication with the first flow path and an outlet in fluid communication with the second flow path;

f) an infusion pump housing defining a drug reservoir;

g) a propellant chamber within the pump housing and proximate the drug reservoir, wherein pressure is exerted on the drug reservoir; and

h) the drug reservoir having a reservoir inlet for receiving the liquid drug and a reservoir outlet, the outlet in fluid communication with the first flow path, whereby the liquid drug is delivered independent of changes in reservoir pressure and ambient pressure.

9. An implantable flow regulator for use with a drug delivery system, the flow regulator comprising:

a) a chamber;

b) a diaphragm dividing the chamber into a first subchamber and a second subchamber;

c) a third subchamber in fluid communication with the first subchamber through a first inlet;

d) a valve operatively connected to the diaphragm, the valve for controlling flow from the third subchamber to the first subchamber through the first inlet, wherein pressure differences between the first subchamber and the second subchamber result in movement of the diaphragm and the movement of the diaphragm controls operation of the valve;

e) the first subchamber having a first outlet and the second subchamber having a second inlet and a second outlet; and

f) a flow restrictor having a first end in fluid communication with the first outlet and a second end in fluid communication with the second inlet, wherein flow of a drug from a drug delivery system through the second outlet is regulated.

10. The implantable flow regulator of claim 9, wherein the valve is a normally closed valve and is open when there is no pressure differential across the diaphragm.

11. The implantable flow regulator of claim 10, wherein the diaphragm is constructed from titanium.

12. The regulator of claim 9, further comprising:

a) the chamber having an outer surface;

b) the flow restrictor comprising a spiral groove operatively connected to the outer surface and an outer cylinder positioned over the spiral groove, wherein a capillary is formed by the groove and outer cylinder.

13. The regulator of claim 12, wherein the spiral groove is formed in the outer housing.

14. The regulator of claim 13, wherein the outer cylinder has a friction fit over the spiral groove.

15. The regulator of claim 9, further comprising a biasing member positioned on the diaphragm in the second subchamber and over the valve, whereby an opening pressure to open the valve is effected.

18. The drug delivery system of claim 9, further comprising:

a) a valve biasing spring; and

b) an actuator rod extending into the third subchamber and positioned to compress the valve biasing spring; and

c) a motor operatively connected to the rod, thereby controlling flow rate of the drug.

19. A drug delivery system for implantation in a body for delivery of a liquid drug, the system comprising:

a) a chamber;

b) a diaphragm dividing the chamber into a first subchamber and a second subchamber;

c) a third subchamber in fluid communication with the first subchamber through a first inlet;

d) a valve operatively connected to the diaphragm, the valve for controlling flow from the third subchamber to the first subchamber through the first inlet, wherein pressure differences between the first subchamber and the second subchamber result in movement of the diaphragm and the movement of the diaphragm controls operation of the valve;

e) the first subchamber having a first outlet and the second subchamber having a second inlet and a second outlet; and

f) an infusion pump housing defining a drug reservoir;

g) a propellant chamber within the pump housing and proximate the drug reservoir, wherein pressure is exerted on the drug reservoir;

h) the drug reservoir having a reservoir inlet for receiving a drug and a reservoir outlet, the reservoir outlet in fluid communication with the first inlet of the first subchamber; and

i) a flow restrictor having a first end in fluid communication with the first outlet and a second end in fluid communication with the second inlet, wherein flow of a drug from a drug delivery system through the second outlet is regulated.

16. The drug delivery system of claim 19, further comprising:

a) a fourth subchamber;

b) a second diaphragm between the third and fourth subchambers;

c) a valve biasing spring carried by the second diaphragm; and

d) the fourth subchamber having a volume of fluid that is changeable, thereby moving the diaphragm and changing spring force on the valve biasing spring.

17. The drug delivery system of claim 16, further comprising a septum operably connected to the fourth subchamber, wherein the volume of fluid in the fourth subchamber is changeable through the septum by a syringe.

20. The drug delivery system of claim 19, the valve is a normally closed valve and is open when there is no pressure differential across the diaphragm.

21. The drug delivery system of claim 20, wherein the diaphragm is constructed from titanium.

22. The drug delivery system of claim 19, further comprising:

a) the chamber having an outer surface;

b) the flow restrictor comprising a spiral groove operatively connected to the outer surface and an outer cylinder positioned over the spiral groove, wherein a capillary is formed by the groove and outer cylinder.

23. The drug delivery system of claim 22, wherein the spiral groove is formed in the outer housing.

24. The drug delivery system of claim 23, wherein the outer cylinder has a friction fit over the spiral groove.

25. The drug delivery system of claim 19, further comprising a biasing member positioned on the diaphragm in the second subchamber and over the valve, whereby an opening pressure to open the valve is effected.

26. An implantable flow regulator and flow restrictor combination for use with a drug delivery system, comprising:

a) a chamber;

b) a diaphragm dividing the chamber into a first subchamber and a second subchamber;

c) a third subchamber in fluid communication with the first subchamber through a first inlet;

d) a valve operatively connected to the diaphragm, the valve for controlling flow from the third subchamber to the first subchamber through the first inlet, wherein pressure differences between the first subchamber and the second subchamber result in movement of the diaphragm and the movement of the diaphragm controls operation of the valve;

e) the first subchamber having a first outlet and the second subchamber having a second inlet and a second outlet;

f) the chamber having an outer surface; and

g) a flow restrictor comprising a spiral groove operatively connected to the outer surface and an outer cylinder positioned over the spiral groove, wherein a capillary is formed by the spiral groove and outer cylinder.