CONSTANT FORCE MECHANISMS FOR REGULATING RESTRICTION DEVICES

• US 20090171378A1
• Filed: 12/27/2007
• Published: 07/02/2009
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Moore, Kyle P., Ortiz, Mark S., Zwolinski, Andrew M., Adams, Thomas E., Overmyer, Mark D., Coe, Jonathan A.
• Granted Patent: US 8,377,079 B2
• Time in Patent Office: Days
• US Class Current: 606/157
• CPC Class Codes: A61F 5/0056 using injection ports

Abstract

Methods and devices are provided for regulating a restriction system. In one exemplary embodiment, a restriction system is provided having a restriction device coupled to a port with a fluid disposed therein, such that the restriction device is adapted to form a restriction in a pathway corresponding to an amount of fluid contained therein, and a pressure adjustment unit in communication with the port and effective to maintain a substantially constant equilibrium pressure between the pressure adjustment unit and the restriction device. The pressure adjustment unit is configured to regulate an amount of fluid in the restriction device in response to a fluid pressure acting thereon.

Claims

1. A self-regulating restriction system, comprising:

a restriction device for forming a restriction in a pathway; and

a pressure adjustment unit in communication with the restriction device and effective to maintain a substantially constant equilibrium pressure between the restriction device and the pressure adjustment unit by regulating an amount of fluid in the restriction device.

2. The system of claim 1, wherein the pressure adjustment unit includes a constant force mechanism coupled to a fluid communication chamber that is in fluid communication with the restriction device.

3. The system of claim 2, wherein the constant force mechanism comprises a nitinol spring.

4. The system of claim 2, wherein the constant force mechanism comprises a spring in contact with a cam surface.

5. The system of claim 4, wherein the spring comprises a cantilever beam, and the system further comprises a set-point adjustment mechanism having an adjustable block movably disposed along the cantilever beam to adjust an effective length of the cantilever beam and thereby adjust the substantially constant pressure.

6. The system of claim 2, wherein the constant force mechanism comprises a constant force spring disposed in a chamber and coupled to a piston.

7. The system of claim 6, further comprising a set-point adjustment mechanism that includes an adjustable bladder coupled to the piston and configured to adjust the substantially constant pressure by adjusting an amount of friction generated between the adjustable bladder and the chamber.

8. The system of claim 2, wherein the constant force mechanism comprises a compression coil spring and the fluid communication chamber comprises an expandable fluid bladder that is coupled to the compression coil spring.

9. The system of claim 8, further comprising a set-point adjustment mechanism having an expandable bellows coupled to the compression coil spring and configured to adjust a length of the compression coil spring to adjust the substantially constant pressure.

10. The system of claim 2, wherein the constant force mechanism comprises a saturated fluid disposed in a chamber and configured to maintain the substantially constant pressure independent of a volume of the chamber.

11. The system of claim 10, further comprising a set-point adjustment mechanism configured to change a composition of the saturated fluid to adjust the substantially constant pressure.

12. The system of claim 2, wherein the constant force mechanism comprises a chamber under vacuum force.

13. The system of claim 12, further comprising a set-point adjustment mechanism configured to change a pressure acting on the chamber under vacuum force to adjust the substantially constant pressure.

14. The system of claim 2, wherein the constant force mechanism comprises an osmotic pump effective to maintain the substantially constant pressure.

15. The system of claim 14, wherein the osmotic pump comprises:

an actuation chamber having an osmotic fluid disposed therein and in fluid communication with the restriction device; and

a semi-permeable membrane separating the actuation chamber from a fluid chamber.

16. The system of claim 15, wherein the osmotic pump further comprises a biodegradable plug covering at least a portion of the semi-permeable membrane and configured to disintegrate over a desired period of time.

17. The system of claim 14, wherein the osmotic pump comprises:

a fluid chamber having fluid disposed therein;

an actuation chamber having a piston disposed therein; and

a semi-permeable membrane separating the fluid chamber from the actuation chamber.

18. The system of claim 1, wherein the restriction device includes a fluid bladder capable of forming a restriction in a pathway, and wherein an amount of restriction corresponds to an amount of fluid contained in the fluid bladder.

19. The system of claim 1, further comprising a set-point adjustment mechanism configured to adjust the substantially constant pressure of the pressure adjustment unit.

20. The system of claim 19, wherein the set-point adjustment mechanism comprises an expandable bladder that is inflatable to adjust the substantially constant pressure, and a constant pressure spring disposed around the expandable bladder.

21. The system of claim 19, wherein the set-point adjustment mechanism comprises:

a lever configured to apply a force to the pressure adjustment unit; and

an adjustable fulcrum coupled to the lever and movable along the lever to adjust the force applied by the lever and thereby adjust the substantially constant pressure.

22. A system for automatically adjusting a restriction device, comprising:

a fluid reservoir;

a restriction device in fluid communication with the fluid reservoir and configured to form a restriction in a pathway that corresponds to an amount of fluid contained within the restriction device; and

a constant force mechanism coupled to the fluid reservoir and configured to apply a substantially constant force to the fluid reservoir to maintain a substantially constant pressure in the restriction device.

23. The system of claim 22, wherein the constant force mechanism comprises a constant pressure spring.

24. The system of claim 22, wherein the constant force mechanism comprises a constant force spring disposed in a chamber and coupled to a piston.

25. The system of claim 22, wherein the gastric restriction device includes a fluid bladder for containing fluid therein.

26. The system of claim 22, further comprising a set-point adjustment unit coupled to the constant force mechanism and adapted to change the substantially constant force applied by the constant force mechanism.

27. The system of claim 26, wherein the set-point adjustment unit comprises an expandable bladder.

28. A method for maintaining a restriction in a pathway, comprising:

implanting a restriction device in a patient such that the restriction device forms a restriction in a pathway that corresponds to an amount of fluid contained within the restriction device, the restriction device being coupled to a pressure adjustment unit that applies a substantially constant force to fluid in the restriction device to maintain a substantially constant pressure applied by the restriction device to the pathway.

29. The method of claim 28, further comprising adjusting the substantially constant pressure using a set point adjustment mechanism.

30. The method of claim 28, wherein the restriction device is implanted to form a restriction in a patient'"'"'s stomach.

31. The method of claim 28, wherein the flow of fluid into the restriction device increases an amount of restriction applied by the restriction device to the pathway.