ORTHOPAEDIC DEVICE AND ENERGY STORAGE DEVICE

Abstract

The invention relates to an orthopedic device with an energy storage device 2 that comprises at least one cylinder 4, in which a first cylinder chamber 6, a second cylinder chamber 8, which is fluidically connected to the first cylinder chamber 6 by at least one fluid line 14, and a piston 10 are located, wherein the piston 10 is arranged relative to the cylinder 4 such that it can be displaced in such a way that by displacing the piston 4, an operating medium, which is a fluid, is conveyed through the at least one fluid line 14 from one cylinder chamber 6, 8 into the other cylinder chamber 8, 6, wherein the energy storage device 2 has at least one compensation volume 24, which is fluidically connected to the fluid line 14 via a fluid connection 22, and a first controllable valve 26, by means of which the fluid connection 22 can be opened and closed.

Claims

1-12. (canceled)

13. An orthopedic device with an energy storage device that comprises at least one cylinder in which a first cylinder chamber, a second cylinder chamber, which is fluidically connected to the first cylinder chamber by at least one fluid line, and a piston, are located, wherein the piston is arranged relative to the cylinder such that displacing the piston causes an operating medium, which is a fluid, to be conveyed through the at least one fluid line from one of the first or second cylinder chamber into the other of the first or second cylinder chamber, and the energy storage device has at least one compensation volume, which is fluidically connected to the fluid line via a fluid connection, and a first controllable valve configured to open and close the fluid connection.

14. The orthopedic device according to claim 13, wherein the operating medium is a compressible fluid, preferably an oil, especially preferably a silicone oil.

15. The orthopedic device according to claim 13, wherein the operating medium is an oil.

16. The orthopedic device according to claim 13, wherein the operating medium is a silicone oil.

17. The orthopedic device according to claim 13, further comprising at least one second controllable valve in the fluid line configured to adjust a flow resistance of the fluid connection.

18. The orthopedic device according to claim 17, wherein the fluid connection is located between the first and second controllable valves in the fluid line.

19. The orthopedic device according to claim 13, wherein the energy storage device comprises at least one additional volume that is fluidically connected to at least one of the first cylinder chamber or the second cylinder chamber,

20. The orthopedic device according to claim 19, the energy storage device (2) having a third controllable valve (34) configured to open and close the connection.

21. The orthopedic device according to claim 19, wherein the energy storage device has multiple additional volumes and multiple third controllable valves configured to open and close the connections of the additional volumes to at least one of the first cylinder chamber or the second cylinder chamber

22. The orthopedic device according to claim 21, wherein the multiple third controllable valves are capable of opening and closing independently of each other.

23. The orthopedic device according to claim 21, wherein the multiple additional volumes are fluidically connected to each other in series.

24. The orthopedic device according to claim 21, wherein the multiple additional volumes are fluidcally connected to each other in parallel.

25. The orthopedic device according to claim 13, further comprising an electric control unit that is configured to control the controllable valves independently of each other.

26. The orthopedic device according to claim 13, wherein the piston is displaceable along a circular path.

27. The orthopedic device according to claim 13, wherein the device is a knee prosthesis or a knee orthosis.

28. The orthopedic device according to claim 13, wherein at least one of a diameter of a piston rod, a volume of the first cylinder chamber, a volume of the second cylinder chamber or a compression modulus of the operating medium are selected in such a way that a spring constant of at most 750 N/mm occurs when the fluid connection is closed.

29. The orthopedic device according to claim 28, wherein the spring constant is less than 600 N/mm.

30. The orthopedic device according to claim 28, wherein the spring constant is less than 400 N/mm.

31. The orthopedic device according to claim 28 wherein the spring constant is greater than 100 N/mm.

32. An energy storage device \ for an orthopedic device, the energy storing device comprising: at least one cylinder, a first cylinder chamber located in the at least one cylinder, a second cylinder chamber located in the at least one cylinder, wherein the second cylinder chamber is fluidically connected to the first cylinder chamber by at least one fluid line, a piston located in the at least one cylinder, at least one compensation volume, which is fluidically connected to the fluid line via a fluid connection, and a first controllable valve configured to open and close the fluid connection, wherein the piston is arranged relative to the cylinder such that displacing the piston causes an operating medium, which is a fluid, to be conveyed through the at least one fluid line from one of the first or second cylinder chamber into the other of the first or second cylinder chamber.

Description

[0053] In the following, examples of embodiments of the present invention will be explained in more detail by way of the attached drawings:

[0054] They show:

[0055] FIGS. 1 to 5-different states of an energy storage device according to a first example of an embodiment of the present invention, and

[0056] FIGS. 6 to 10-different states of a second embodiment of an energy storage device.

[0057] FIG. 1 schematically depicts an energy storage device 2 for an orthopedic device. The energy storage device features a cylinder 4, containing a first cylinder chamber 6 and a second cylinder chamber 8 that are separated from a piston 10, which is mounted in a piston rod 12.

[0058] The first cylinder chamber 6 is connected to the second cylinder chamber 8 via a fluid connection 14. In the fluid line 14 there is a first throttle valve 16 and a second throttle valve 18, each of which is bypassed by a non-return valve 20. The non-return valves 20 are arranged in such a way that no operating medium can escape the first cylinder chamber 6 when the first throttle valve 16 is closed and no operating medium can escape the second cylinder chamber 8 when the second throttle valve 18 is closed. In the example of an embodiment shown, the first throttle valve 16 with its assigned non-return valve 20 form a second controllable valve. The second throttle valve 18 and its assigned non-return valve 20 also form a second controllable valve.

[0059] Between the two throttle valves 16, 18, a compensation volume 24 is fluidically connected via a fluid connection 22 to the fluid line 14 and thus to the first cylinder chamber 6 and the second cylinder chamber 8. In the fluid connection 22 there is a first controllable valve 26 that can be brought into an open state, depicted in FIG. 1, and a closed state by disconnecting the compensation volume 24 from the rest of the fluid system. Such an energy storage device 2, as schematically depicted in FIGS. 1 to 5, may be arranged in a prosthetic knee, for example, so that a step cycle as described in FIGS. 1 to 5 can take place.

[0060] FIG. 1 shows the situation upon heel strike. The compensation volume 24 is connected to the fluid line 14 via the open switch valve 26. The first throttle valve 16 and the second throttle valve 18 are open, wherein openings of different sizes can be achieved by the respective throttle valves 16, 18, so that the flow resistance countering a fluid movement can be adjusted.

[0061] Upon heel strike, a flexion of the prosthetic knee occurs, the energy storage device 2 being installed in said prosthetic knee. As a result, the piston 10 is displaced downwards in the cylinder 4. This situation is depicted in FIG. 2. The piston 10 has been displaced downwards, thereby making the first cylinder chamber 6 smaller. At the same time, the second cylinder chamber 8 has been enlarged. However, the overall volume of the two cylinder chambers 6, 8 has decreased, as a larger part of the piston rod 12 is now arranged inside the cylinder 4. When the piston 10 was lowered, the situation shown in FIG. 1 prevailed so that the compensation volume 24 is connected to the rest of the fluid system. Since the overall volume of both cylinder chambers 6, 8 decreased while lowering the piston 10, part of the fluid was pressed into the compensation volume 24.

[0062] In FIG. 2, the arrow 28 indicates that the first controllable valve 26 is closed, for example, during the so-called “foot flat”, when the entire foot rests on the ground. As a result, the connection to the compensation volume 24 and the fluid line 14 is disconnected. The part of the operating medium that was pushed into the compensation volume 24 when the foot was lowered and thus the piston 10 was lowered inside the cylinder 4 can no longer leave this compensation volume 24. A further flexion of the prosthetic knee, in which the energy storage device 2 is installed, would cause the piston 10 to be lowered further and therefore to a further reduction in overall volume of the two cylinder chambers 6, 8. This would result in a compression of the fluid contained within, for example a silicone oil. As a result, the pressure inside the silicone oil is increased and thus potential energy stored. As there in no way for the operating medium to leave the system from the first cylinder chamber 6, the second chamber 8 and the fluid line 14, the energy is stored in this system and released again when the inflecting force decreases. In this way, for example, the natural stance phase flexion angles of up to 25° can now be achieved with a prosthetic knee without the user having to worry that the stored energy is lost so that they can no longer extend the knee independently from this flexion.

[0063] The energy storage device 2 stores the further supplied potential energy from the moment the switching valve 26 closes and then releases it again. This pushes the piston 10 in FIG. 2 upwards, as the pressure in the two cylinder chambers 6, 8 is identical, but the lower side of the piston 10 exposed to the pressure is greater than the upper side exposed to the pressure, so that an overall upward force is achieved.

[0064] This situation is depicted in FIG. 3. The piston 10 with the piston rod 12 has been pushed upwards. This occurs until the position in which the first controllable valve 26 was closed. If, unlike in FIG. 2, this already occurs at an earlier point in time, i.e. when a piston 10 with piston rod 12 has not been inserted so far into the cylinder 4, the position shown in FIG. 3 can be achieved. The switch valve 26 remains closed.

[0065] If, contrary to the figures shown, the switch valve 26 is closed immediately upon heel strike, i.e. in the position depicted in FIG. 1, there is no fluid inside the compensation volume 24, as the switch valve 26 was closed already before the volume of the two cylinder chambers 6, 8 was compressed for the first time.

[0066] The arrangement depicted renders it possible to release absorbed potential energy from the moment that the switch valve 26 is closed by bending the prosthetic knee or another joint of an orthopedic device, thereby supporting the wearer of the orthopedic device during the opposite movement of the joint of the orthopedic device. During this process, the filling level of the compensation volume 24 remains unchanged.

[0067] FIG. 4 depicts the situation in which the first controllable valve 26 is open in accordance with the arrow 28. In a prosthetic knee, for example, this can occur during the swing phase, in which a flexion of the knee joint with as little resistance as possible is desired. The two throttle valves 16, 18 are opened, thereby enabling a fluid flow between the first cylinder chamber 6 and the second cylinder chamber 8 with as little resistance as possible. Due to the reduction in overall volume of the first cylinder chamber 6 and the second cylinder chamber 8, this causes the compensation volume 24 to be filled, which is indicated by the filling level 30.

[0068] FIG. 5 depicts how the first controllable valve 26 is closed in this state in accordance with the arrow 28. The filling level 30 of the compensation volume 24 remains unchanged. In this state, a further displacement of the piston 10 inside the cylinder 4 leads to a change in the overall volume of the first cylinder chamber 6 and the second cylinder chamber 8, so that potential energy can be stored in the fluid, for example the silicone oil, said energy being released again once the force that produces it disappears.

[0069] FIGS. 6 to 10 depict a further embodiment of an energy storage device 2. It also features the cylinder 4 with the first cylinder chamber 6, second cylinder chamber 8, piston 10 and piston rod 12. The compensation volume 24 is connected via the fluid connection 22 to the fluid line 14 such that it can be switched via the first controllable valve 26, the previously known valves being located in said fluid line. In addition to the embodiment from FIGS. 1 to 5, the energy storage device 2 according to FIGS. 6 to 10 has an additional volume 32 that can be connected to or disconnected from the fluid line 14 via a third controllable valve 34.

[0070] In FIG. 6 both the first controllable valve 26 and the third controllable valve 34 are open, so that both the compensation volume 24 and the additional volume 32 are connected to the fluid line 14 and therefore also to the first cylinder chamber 6 and the second cylinder chamber 8.

[0071] If such an energy storage device 2 is installed in a prosthetic knee, for example, the embodiment can render sitting down and in particular standing up later much easier for the wearer of the orthopedic device, i.e. the prosthetic knee in this case.

[0072] For sitting down itself, the switch arrangement shown in FIG. 7 is used. In accordance with the arrow 28, the switch valve 26 is closed, so that the compensation volume 24 is decoupled from the fluid line 14. The third controllable valve 34 remains open. When the piston 10 is lowered into the first cylinder chamber 6, as already shown in FIGS. 1 to 5, the overall volume of the first cylinder chamber 6 and the second cylinder chamber 8 is reduced, which of course is not changed by the additional volume 32 still connected to the fluid line 14. The overall volume available to the operating medium decreases, so that the fluid, for example the silicone oil, is compressed. In this state, potential energy is therefore stored in the energy storage device 2.

[0073] After sitting down, the switch arrangement shown in FIG. 8 is used. In accordance with the arrow 28, the first controllable valve 26 is opened, so that the compensation volume 24 is coupled with the fluid line 14. The third controllable valve 34 is also actuated and brought into the closed state, so that the additional volume 32 is decoupled from the rest of the system. It should be noted that preferably the third controllable valve 34 is actuated before the first controllable valve 26 in order to prevent a complete pressure equalization in the additional volume 32 as well. In both cylinder chambers 6, 8 the operating medium is under increased pressure following compression while sitting down, during which the piston 10 was lowered inside the cylinder 4. If the first controllable valve 26 is opened, this pressure can expand, wherein part of the fluid is pushed into the compensation volume 24, depicted by the filling level 30. If both throttle valves 16, 18 are now opened as far as possible, the opposing flow resistance is minimal, thereby enabling almost free movement of the knee. This is particularly desirable in the seated state.

[0074] When standing up again, the switch arrangement shown in FIG. 9 is used. The two controllable valves 26, 34 are actuated in accordance with the arrows 28. However, the piston 10 is first brought back into the position that corresponds to a fully flexed knee, which was also achieved when sitting down. The first controllable valve 26 is consequently actuated and the compensation volume 24 disconnected from the rest of the fluid system. The third controllable valve 34 can then be actuated and brought into the open state, so that the additional volume 32 is re-connected to the rest of the fluid system. The highly pressurized fluid is still in said system, the fluid now ensuring a pressure equalization with the two cylinder chambers 6, 8 as well.

[0075] This now increased pressure provides an upward force on the piston 10, so that the piston 10 is pushed upwards out of the cylinder. This is shown in FIG. 10. The operating medium contained in the first cylinder chamber 6, the second cylinder chamber 8 and the additional volume 32 expands and releases its stored potential energy. As a result, the piston 10 is pushed upwards and the wearer of the orthopedic device, for example the prosthetic knee, is supported while standing up.

[0076] Of course, the arrangements can also be installed in other orthopedic devices, so that a displacement of the piston 10 inside the cylinder 4 does not correspond to a bending of the knee, but the movement of another joint.

REFERENCE LIST

[0077] 2 energy storage device [0078] 4 cylinder [0079] 6 first cylinder chamber [0080] 8 second cylinder chamber [0081] 10 piston [0082] 12 piston rod [0083] 14 fluid line [0084] 16 first throttle valve [0085] 18 second throttle valve [0086] 20 non-return valve [0087] 22 fluid connection [0088] 24 compensation volume [0089] 26 first controllable valve [0090] 28 arrow [0091] 30 filling level [0092] 32 additional volume [0093] 34 third controllable valve