Systems and methods of controlling pressure within a prosthetic knee

• US 7,691,154 B2
• Filed: 05/06/2005
• Issued: 04/06/2010
• Est. Priority Date: 05/07/2004
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Hsu, Henry H., Asgeirsson, Sigurdur Asgeir, Bisbee, Charles R. III
• Primary Examiner(s): Willse; David H.
• Application Number:
  US11/124,637
• Publication Number:
  US 20060085082A1
• Time in Patent Office: 1,796 Days
• Field of Search: 623/26, 623/43, 623/44, 188/267.1, 188/267.2, 267/140.14, 267/140.15
• US Class Current: 623/26
• CPC Class Codes: A61F 2/5044 Designing or manufacturing processes
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/741 using powered actuators, e.g. stepper motors or solenoids
• CPC Class Codes: A61F 2002/5004 operated by electro- or magnetorheological fluids
• CPC Class Codes: A61F 2002/5033 for adjusting damping damping means A61F2002/5003
• CPC Class Codes: A61F 2002/5073 Helical springs, e.g. having at least one helical spring
• CPC Class Codes: A61F 2002/5078 2-D spiral springs
• CPC Class Codes: A61F 2002/6818 for braking
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer for implantable prostheses A61F2250/0002
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/7645 for measuring torque, e.g. hinge or turning moment, moment of force
• CPC Class Codes: A61F 2002/769 Displaying measured values

Abstract

The invention in some embodiments relates to systems and methods of controlling pressure within a prosthetic knee. The knee in one embodiment comprises a flexible diaphragm that substantially prevents or mitigates undesirable pressure build-up in a sealed chamber of the knee. The knee in another embodiment comprises a compressible gas in the chamber that substantially prevents or mitigates undesirable pressure build-up in the chamber.

Claims

1. A prosthetic knee, comprising:

a chamber being at least partially filled with a magnetorheological fluid to control rotation of said prosthetic knee;

a resilient solid diaphragm having a first side exposed to pressure within said chamber and an opposed second side exposed to ambient pressure with said first and second sides being substantially sealingly isolated from one another;

wherein said diaphragm is configured to mitigate pressure build-up in said chamber and maintains said pressure within said chamber substantially the same as said ambient pressure;

wherein said chamber contains a compressible gas in fluid communication with said fluid and said first side of said diaphragm; and

wherein said gas is substantially intermediate said fluid and said first side of said diaphragm.

2. The prosthetic knee of claim 1, wherein said prosthetic knee comprises a plurality of blades that shear said fluid.

3. The prosthetic knee of claim 1, wherein said gas is at said pressure within said chamber which is substantially the same as said ambient pressure.

4. The prosthetic knee of claim 1, wherein said chamber has a free space volume, and wherein said fluid occupies about 60% to about 80% of the free space volume of said chamber.

5. The prosthetic knee of claim 1, wherein said fluid has a volume in the range from about 1 mL to about 10 mL.

6. The prosthetic knee of claim 1, wherein said prosthetic knee comprises a cap portion connected to said diaphragm.

7. The prosthetic knee of claim 6, wherein said cap portion has a passage in fluid communication with said second side of said diaphragm and exposed to said ambient pressure.

8. The prosthetic knee of claim 7, wherein said cap portion has a substantially convex dome that abuts against a connector of said prosthetic knee.

9. The prosthetic knee of claim 8, wherein said connector has a passage exposed to said ambient pressure and in fluid communication with said passage of said cap portion.

10. A prosthetic knee, comprising:

a chamber being at least partially filled with a magnetorheological fluid to control rotation of said prosthetic knee;

a resilient solid diaphragm having a first side exposed to pressure within said chamber and an opposed second side exposed to ambient pressure with said first and second sides being substantially sealingly isolated from one another; and

a plurality of blades that shear said fluid;

wherein said diaphragm is configured to mitigate pressure build-up in said chamber and maintains said pressure within said chamber substantially the same as said ambient pressure.

11. The prosthetic knee of claim 10, wherein said chamber contains a compressible gas in fluid communication with said fluid and said first side of said diaphragm.

12. The prosthetic knee of claim 11, wherein said gas is at said pressure within said chamber which is substantially the same as said ambient pressure.

13. The prosthetic knee of claim 10, wherein said chamber has a free space volume, and wherein said fluid occupies about 60% to about 80% of the free space volume of said chamber.

14. The prosthetic knee of claim 10, wherein said fluid has a volume in the range from about 1 mL to about 10 mL.

15. The prosthetic knee of claim 10, wherein said prosthetic knee comprises a cap portion connected to said diaphragm.

16. A prosthetic knee, comprising:

a chamber being at least partially filled with a magnetorheological fluid to control rotation of said prosthetic knee;

a resilient solid diaphragm having a first side exposed to pressure within said chamber and an opposed second side exposed to ambient pressure with said first and second sides being substantially sealingly isolated from one another; and

a cap portion connected to said diaphragm, said cap portion having a passage in fluid communication with said second side of said diaphragm and exposed to said ambient pressure;

wherein said diaphragm is configured to mitigate pressure build-up in said chamber and maintains said pressure within said chamber substantially the same as said ambient pressure.

17. The prosthetic knee of claim 16, wherein said cap portion has a substantially convex dome that abuts against a connector of said prosthetic knee.

18. The prosthetic knee of claim 17, wherein said connector has a passage exposed to said ambient pressure and in fluid communication with said passage of said cap portion.

19. The prosthetic knee of claim 16, wherein said chamber contains a compressible gas in fluid communication with said fluid and said first side of said diaphragm.

20. The prosthetic knee of claim 16, wherein said prosthetic knee comprises a plurality of blades that shear said fluid.