Systems and methods of controlling pressure within a prosthetic knee
View Patent ↗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.
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.