Hydraulic prosthetic ankle
A prosthetic ankle device is disclosed herein. The prosthetic ankle device includes a hydraulic cylinder with a first chamber, a second chamber, and a piston separating the first chamber and the second chamber. The chambers are filled with hydraulic fluid. During plantarflexion, the hydraulic fluid flows between the first chamber and the second chamber via a first passage and a first check valve. During dorsiflexion, the hydraulic fluid flows between the first chamber and the second chamber via a second passage and a second check valve. The ankle device includes a third passage and a third check valve, where the third passage diverts flow of the hydraulic fluid from the second passage based at least in part on a system status.
1 . A prosthetic ankle, the prosthetic ankle comprising:
a hydraulic cylinder, the hydraulic cylinder comprising a first chamber, a second chamber, and a piston separating the first chamber and the second chamber, the first chamber and the second chamber filled with a hydraulic fluid;
a first valve disposed along a first passage, the first passage and the first valve allowing dampened fluid flow between the first chamber and the second chamber during plantarflexion;
a second valve disposed along a second passage, the second passage and the second valve allowing dampened fluid flow between the first chamber and the second chamber during dorsiflexion; and
a diverter valve being in selective communication with the second passage and a third passage, a third valve disposed along the third passage, the third passage and the third valve allowing flow between the first chamber and the second chamber during dorsiflexion in a swing phase of gait, wherein a dampening resistance on the flow through the third passage is lower than a dampening resistance on the flow through the second passage,
wherein the diverter valve diverts the flow from the second passage to the third passage based on a system status.
2 . The prosthetic ankle of claim 1 , further comprising a spring disposed in the hydraulic cylinder and operatively coupled to the piston, the spring configured to impart a force on the piston during swing phase to dorsiflex a prosthetic foot coupled to the prosthetic ankle to lift a toe of the foot.
3 . The prosthetic ankle of claim 1 , wherein the third passage and the third valve allow non-restrictive flow between the first chamber and the second chamber.
4 . The prosthetic ankle of claim 1 , wherein the system status comprises a pressure threshold amount.
5 . The prosthetic ankle of claim 1 , wherein the system status comprises a degree of dorsiflexion.
6 . The prosthetic ankle of claim 1 , wherein the system status comprises an indication of toe off.
7 . The prosthetic ankle of claim 1 , further comprising an accumulator in fluid communication with the hydraulic cylinder, wherein hydraulic fluid is pressurized in the accumulator during plantarflexion and the pressurized hydraulic fluid in the accumulator applies a biasing force on the piston toward dorsiflexion.
8 . The prosthetic ankle of claim 1 , further comprising a drain passage between the diverter valve and the first passage.
9 . A prosthetic device comprising:
a foot portion; and
an ankle portion coupled to the foot portion, the ankle portion comprising:
a hydraulic cylinder, the hydraulic cylinder comprising a first chamber, a second chamber, and a piston separating the first chamber and the second chamber, the first chamber and the second chamber filled with a hydraulic fluid,
a first valve disposed along a first passage, the first passage and the first valve allowing dampened fluid flow between the first chamber and the second chamber during plantarflexion,
a second valve disposed along a second passage, the second passage and the second valve allowing dampened fluid flow between the first chamber and the second chamber during dorsiflexion, and
a diverter valve being in selective communication with the second passage and a third passage, a third valve disposed along the third passage, the third passage and the third valve allowing flow between the first chamber and the second chamber during dorsiflexion in a swing phase of gait, wherein a dampening resistance on the flow through the third passage is lower than a dampening resistance on the flow through the second passage,
wherein the diverter valve diverts the flow from the second passage to the third passage based on a system status, and
wherein an orientation of a top portion of the ankle portion is configured to change based at least in part on a position of the piston within the hydraulic cylinder.
10 . The prosthetic device of claim 9 , further comprising a spring disposed in the hydraulic cylinder and operatively coupled to the piston, the spring configured to impart a force on the piston during swing phase to dorsiflex the foot portion to lift a toe of the foot portion.
11 . The prosthetic device of claim 9 , wherein the third passage and third valve allow non-restrictive flow between the first chamber and the second chamber.
12 . The prosthetic device of claim 9 , wherein the system status comprises a pressure threshold amount.
13 . The prosthetic device of claim 9 , wherein the system status comprises a degree of dorsiflexion.
14 . The prosthetic device of claim 9 , wherein the system status comprises an indication of toe off.
15 . The prosthetic device of claim 9 , further comprising an accumulator in fluid communication with the hydraulic cylinder, wherein hydraulic fluid is pressurized in the accumulator during plantarflexion and the pressurized hydraulic fluid in the accumulator applies a biasing force on the piston toward dorsiflexion.
16 . The prosthetic device of claim 9 , further comprising a drain passage between the diverter valve and the first passage.