Orthopaedic device and hydraulic system

Abstract

The invention relates to an orthopaedic device (2) having a hydraulic system (4) with a first hydraulic chamber (6), which has a first shell (8) defining a first chamber volume (9) of the first hydraulic chamber (6), and a second hydraulic chamber (10), which has a second shell (12) defining a second chamber volume (13) of the second hydraulic chamber (10) and is connected to the first hydraulic chamber (6) by a fluid line (14), wherein the first shell (8) has a first portion (16) that is elastic.

Description

[0001] Orthopaedic equipment and hydraulic system

[0002] The invention relates to an orthopedic device comprising a hydraulic system with a first hydraulic chamber having a first shell defining a first chamber volume of the first hydraulic chamber, and a second hydraulic chamber having a second shell defining a second chamber volume of the second hydraulic chamber, and connected to the first hydraulic chamber by a fluid line. Furthermore, the invention relates to a hydraulic system for an orthopedic device.

[0003] Orthopedic devices with a hydraulic system are known from the prior art. The hydraulic system has, for example, a hydraulic cylinder in which a piston is guided, spatially separating a first hydraulic chamber from a second hydraulic chamber. The hydraulic system can be designed as linear hydraulics or rotary hydraulics. In other hydraulic systems, the two hydraulic chambers are arranged in different cylinders and are preferably each delimited by a movable piston. A hydraulic chamber has a chamber volume, the size of which is usually delimited by at least one piston and which is filled with hydraulic fluid. The chamber volume is delimited by a shell, which could also be referred to as a wall or partition. The part of the piston that comes into contact with the hydraulic fluid located in the chamber volume of the hydraulic chamber forms part of this shell.The piston is preferably movable relative to another part of the shell, whereby the chamber volume can be increased or decreased.

[0004] US 7,572,299 B2 shows a prosthetic foot with a first forefoot element and a second forefoot element, as well as a first heel element and a second heel element. A first hydraulic chamber with a first sleeve is arranged between the first forefoot element and the second forefoot element. A second hydraulic chamber with a second sleeve is arranged between the first heel element and the second heel element. The first hydraulic chamber and the second hydraulic chamber are fluidically connected to one another. The first sleeve and the second sleeve are each formed by flexible bladders. This allows the available volumes within the orthopedic device to be utilized particularly efficiently, since the geometric shape of the sleeve and thus of the corresponding hydraulic chamber can be adapted to the volumes.Should these volumes change during use of the orthopaedic device, as is known in the state of the art, the shell can follow this change due to its flexibility as long as the existing volume is sufficient.

[0005] US 6,820,866 B2 relates to a damping device comprising an outer housing with an elastic sleeve filled with a fluid and extending into a gas-filled chamber. The device has a piston that is displaceable relative to the sleeve, thus exerting pressure on the fluid in the sleeve. As the pressure increases, the fluid, and thus the sleeve, is forced into the gas-filled chamber, compressing the gas. In this way, the acting force is elastically dampened.

[0006] A disadvantage of the known systems is that hydraulic systems themselves do not achieve elastic properties, such as suspension or damping, and therefore these functions have to be provided with considerable design and equipment effort and thus cost-intensive.

[0007] The invention is based on the object of developing an orthopedic device that avoids or at least mitigates the disadvantages of the prior art. The invention achieves this object by an orthopedic device according to the preamble of claim 1, which is characterized in that the first cover has a first section that is elastic.

[0008] The chamber volumes and the fluid line are preferably filled with a hydraulic fluid. Hydraulic systems are generally used in one of two designs. In the first design, which can be referred to as the passive design, the movement of two components of the orthopedic device relative to one another increases the volume of one of the two hydraulic chambers and simultaneously reduces the volume of the other hydraulic chamber. This forces hydraulic fluid out of the shrinking hydraulic chamber and into the expanding hydraulic chamber. It is often sufficient if the movement of the two components only reduces the volume of one of the hydraulic chambers. The hydraulic fluid thus forced out of the hydraulic chamber then displaces part of the casing in the other hydraulic chamber, for example a piston, and thus increases the chamber volume of the other hydraulic chamber.In these passive designs, a valve is often arranged in the fluid line, allowing the flow resistance of the fluid line to be adjusted. This counteracts the movement of the two components of the orthopedic device with a resistance that can be adjusted, for example, by adjusting the flow-through cross-sectional area of ​​the valve.

[0009] In a second embodiment, which can be referred to as an active embodiment, the fluid is pumped from one of the hydraulic chambers into the other hydraulic chamber by a pumping device. This allows the volume of one hydraulic chamber to be reduced and the volume of the other hydraulic chamber to be increased, for example driven by a motor. This allows two articulated components to be moved. The volume of a hydraulic chamber is generally increased or decreased by displacing a piston, which forms part of the shell of the respective hydraulic chamber. This piston is connected to one of the components of the orthopedic device and thus ensures the movement. In orthopedic devices according to embodiments of the present invention, the hydraulic system is an active or a passive hydraulic system.

[0010] A hydraulic system that has a pumping device and can therefore be regarded as an active design can of course also be operated passively, in that the hydraulic system allows the chamber volumes of the two hydraulic chambers to be changed by moving two components of the orthopaedic device.

[0011] In prior art hydraulic systems, movement of the pistons or other moving components relative to one another, by whose movement the size of one chamber volume or both chamber volumes can be changed, can be prevented by closing the fluid line. If it is not possible to conduct hydraulic fluid from one hydraulic chamber to the other hydraulic chamber, the chamber volumes cannot change and movement is excluded. In a device according to the invention, this is different, at least for the first hydraulic chamber. It has a casing with a first section that is elastic. A force acting on the casing from the outside, for example a compressive force, can therefore result in an elastic deformation of this first section, whereby the geometric shape and / or the size of the chamber volume of the first hydraulic chamber can be changed.Preferably, a part of the first shell of the first hydraulic chamber is formed by a piston which is displaceable relative to another part of the first shell, preferably relative to the rest of the first shell. It is connected, for example, to a joint part of the orthopedic device. If an external force, for example in the form of an impulse, acts on the piston or on the joint part connected to it, the piston can be displaced relative to the other part of the first shell because the elasticity of the first section of the first shell allows it to absorb the fluid displaced by the displacement of the piston. Because the first section is elastic, this creates a restoring force which moves the piston back to its original position as soon as the external force is no longer present.

[0012] Such a combination of hydraulic system and elastic properties could previously only be achieved through considerable design effort, as described, for example, in DE 10 2021 132 201 A1. There, several hydraulic chambers, which require complex interconnection, are used to achieve an elastically movable joint around a hydraulically fixed home position. The inventive design of an orthopedic device and its hydraulic system makes this possible using significantly simpler means.

[0013] The elastically configured section is preferably made of an elastic material, for example, elastomers, in particular polyurethane foams, polymers, or foams. Elastic materials preferably have a modulus of elasticity of at most 5000 MPa, preferably at most 4500 MPa, particularly preferably at most 4000 MPa. The modulus of elasticity is preferably at least 10 MPa, preferably at least 50 MPa, particularly preferably at least 100 MPa. The elastically configured section is made, for example, of an elastomer-based fiber composite material. With these materials, the elasticity can be limited by the fibers used, so that a progressive spring behavior can be achieved.

[0014] Alternatively, a material having a modulus of elasticity of more than 5000 MPa, preferably more than 7500 MPa, particularly preferably more than 10000 MPa, is used as the material from which the elastically formed portion is made.

[0015] The first section preferably extends over the entire first shell, such that the first shell of the first hydraulic chamber is completely elastic. This is particularly advantageous when the first hydraulic chamber is designed, for example, as a compensating volume and thus there is no piston that forms part of the first shell and whose displacement results in a change in the size of the chamber volume. Of course, it is also possible to design the first shell to be completely elastic and yet use a piston that forms part of this shell. Preferably, the part of the shell formed by the piston is not elastic. Then only the part of the shell not formed by the piston is elastic.The entire first shell can be designed to be elastic even if there is no piston as part of the shell, but rather the reduction or increase of the respective chamber volume is achieved by components acting on the shell from the outside. For example, it is possible to position a hydraulic chamber between two components that move toward each other when a joint is moved, thus reducing the chamber volume of the hydraulic chamber located between the two components.

[0016] In a preferred embodiment, the second sleeve has a second section that is elastic. This is particularly advantageous when the orthopedic device has components whose movement relative to one another results in hydraulic fluid being directed from one hydraulic chamber into the other hydraulic chamber because the volume of one hydraulic chamber increases and the volume of the other hydraulic chamber decreases. This is the case, for example, when both a part of the first sleeve and a part of the second sleeve are formed by a displaceable piston. These pistons are preferably connected to the two components described. In a particularly simple embodiment, the two hydraulic chambers are located in a common housing in which a displaceable piston is located, which forms part of both sleeves and thus delimits both the first hydraulic chamber and the second hydraulic chamber.If, in such a configuration, the fluid line is closed, for example, by a valve, it is not sufficient for only the first sleeve to have an elastically designed first section to displace the piston. This could indeed displace the piston in such a way that the first section is elastically expanded or compressed. However, since this would simultaneously result in a change in the volume of the second hydraulic chamber, an elastic section must also be present here, in this case the second elastic section. If only elastic deformability of the first sleeve is to be achieved, it is of course sufficient to equip only this with an elastic component.

[0017] If the fluid line is closed by a valve, it is no longer possible to direct hydraulic fluid from the first hydraulic chamber into the second hydraulic chamber, or vice versa. This defines a zero position of the hydraulic system and preferably also of components connected to the hydraulic system, which are preferably pivotally connected to one another. External forces acting on the components can move these components relative to one another, and the elastic sections can be expanded or compressed accordingly. This elasticity creates restoring forces that move the components back to the zero position of the hydraulic system once the external force is removed.

[0018] Preferably, the second section extends over the entire second shell, so that the second shell of the second hydraulic chamber is completely elastic. Preferably, the part of the shell formed by the piston is not elastic. Then, only the part of the shell not formed by the piston is elastic.

[0019] Preferably, the first section and / or the second section are made of a nonlinear elastic material, particularly preferably a viscoelastic material. Depending on the elastic behavior, for example, the stress-strain curve, the most suitable elastic material can be selected for the respective application.

[0020] The hydraulic system preferably comprises a linear actuator with a piston that separates the first hydraulic chamber and the second hydraulic chamber from one another, or a rotary hydraulic system with a pivoting piston that separates the first hydraulic chamber and the second hydraulic chamber from one another. Advantageously, the first section and the second section have different stiffnesses. This ensures that the elastic deformation of the first section and the second section is different in magnitude for an identical externally acting force. This is advantageous, for example, if the orthopedic device is a prosthetic foot and the deformation of the first section and the second section occurs when an externally acting force pivots a foot part of the prosthetic foot relative to the lower leg part of the prosthetic foot.For this purpose, it is advantageous to use different elastic materials for the first and second sections. Alternatively, the first and second sections can have the same stiffness.

[0021] Preferably, at least one controllable valve is arranged in the fluid line, by means of which a flow resistance through the fluid line can be adjusted, preferably continuously. Preferably, the flow resistance can be adjusted differently for different flow directions. Preferably, the orthopedic device has an adjustment device configured to adjust the flow resistance of the at least one valve in at least one direction. Preferably, the flow resistance can be adjusted by means of an electric motor. Alternatively or additionally, the flow resistance can be adjusted manually.

[0022] Advantageously, the valve can be brought into a closed position. In this closed position, the fluid line is also closed, and it is no longer possible to conduct fluid from one of the hydraulic chambers into the other hydraulic chamber through the fluid line. Nevertheless, due to the elastic properties of the first section and / or the second section, it is possible to change the geometric shape of the chamber volume and the hydraulic chamber and thus, for example, enable movement of components of the orthopedic device relative to one another. Due to the elastic design of the first section of the first shell and / or the second section of the second shell, the previously described restoring force occurs, which moves the corresponding components of the orthopedic device back to their original position.

[0023] Alternatively or additionally, a non-controllable valve and / or a non-controllable throttle is arranged in the fluid line. It is also possible for no valve or throttle to be arranged in the fluid line.

[0024] Preferably, the at least one valve is designed as a throttle valve, shut-off valve, or solenoid valve. Preferably, the at least one valve is electronically controllable. Alternatively, the at least one valve is manually controllable. A mechanically and / or electronically adjustable throttle is preferably connected upstream of the valve.

[0025] Preferably, at least one check valve connected in parallel to the at least one valve is arranged in the fluid line. This configuration creates a direction-dependent flow resistance. Particularly preferably, two valves, each with a check valve connected in parallel, are arranged in the fluid line. The two check valves act in different directions. One of the two check valves allows flow from the first hydraulic chamber into the second hydraulic chamber, but prevents flow in the opposite direction. The other of the two check valves acts in the opposite direction. It therefore allows flow from the second hydraulic chamber into the first hydraulic chamber and prevents flow in the opposite direction.The fluid must therefore flow through the parallel valve in the flow direction not permitted by the respective check valve and thus against the flow resistance generated by this valve.

[0026] Advantageously, the first hydraulic chamber or the second hydraulic chamber or another hydraulic chamber is designed as a compensation volume. A compensation volume serves, for example, as a collecting container for hydraulic fluid. It is advantageous, for example, when the total volume of the rest of the hydraulic system, i.e. the hydraulic system without the compensation volume, changes. This is the case, for example, when a piston moves that has a piston rod that runs through a hydraulic chamber. As a result, the volume of one hydraulic chamber can increase more than the volume of another hydraulic chamber decreases, or vice versa. In the first case, the total volume of the rest of the hydraulic system increases, and hydraulic fluid is removed from the compensation volume and fed into the rest of the hydraulic system.In the second case, the total volume of the remaining hydraulic system increases and fluid is stored in the compensation volume.

[0027] The compensation volume is also advantageous if, for example, the total volume of the hydraulic fluid in the rest of the hydraulic system changes due to thermal expansion.

[0028] A further development of the invention has at least one overload protection element which is arranged and configured such that it limits the maximum expansion of the first section by limiting the expansion of the first hydraulic chamber in at least one direction. The overload protection element is designed, for example, as a housing in which the first shell is located at least partially, but preferably completely. The housing is made, for example, from a metal. Preferably, an elastic hydraulic chamber is arranged in an interior of an overload protection element, wherein the overload protection element in this case preferably has at least one vent opening for venting the interior. Alternatively or additionally, the overload protection element has at least one stop for limiting the expansion of the first hydraulic chamber in at least one direction.An overload protection element also structurally limits the maximum mechanical load on the first section of the first hydraulic chamber.

[0029] The orthopedic device preferably has at least one further overload protection element arranged and configured to limit the maximum expansion of the second section. Preferably, it limits the expansion of the second hydraulic chamber in at least one direction.

[0030] Preferably, the first section and / or the second section are pre-tensioned in an unloaded state of the orthopedic device. Preferably, the pre-tension of the first section and / or the second section is adjustable. Preferably, the pre-tension of the first section and / or the second section is automatically adjustable. Alternatively or additionally, the pre-tension of the first section and / or the second section is manually adjustable.

[0031] The orthopedic device preferably comprises a foot prosthesis with a spring arrangement that extends from a heel region to a forefoot region. The spring arrangement comprises a distal spring and a proximal spring that is arranged proximally to the distal spring. The first hydraulic chamber is preferably arranged in the heel region between the distal spring and the proximal spring. When the heel strikes, pressure is therefore exerted on the first hydraulic chamber. The proximal spring and / or the distal spring are preferably designed as leaf springs or each have at least one leaf spring. The proximal spring and the distal spring are preferably fixed to one another in an anterior region, for example in the forefoot region. The first hydraulic chamber is preferably attached to the proximal spring and / or the distal spring, for example by means of a form-fitting or force-fitting attachment or by adhesive bonding.It may be advantageous if the first hydraulic chamber is not attached to the proximal spring so that the proximal spring can lift off from the first hydraulic chamber.

[0032] In a preferred embodiment, a belt is guided around a heel region of the proximal spring and the distal spring, which belt limits the maximum distance that the heel region of the proximal spring can assume from the heel region of the distal spring. This also predetermines and limits the maximum extension of the first section in at least one direction, but preferably in all directions. Preferably, the length of the belt and the quantity of fluid contained in the hydraulic system are selected such that a predetermined pressure prevails in the first hydraulic chamber, preferably in the entire hydraulic system. This results in the first section of the first shell of the first hydraulic chamber having a predetermined preload caused by the predetermined pressure.

[0033] The second hydraulic chamber is preferably not located in the heel area between the proximal spring and the distal spring, and particularly preferably is not surrounded by the strap. It is preferably located in the heel area of ​​the prosthetic foot, but on the side of the proximal spring facing away from the first hydraulic chamber. If the prosthetic foot is on a horizontal floor, the first hydraulic chamber in this embodiment is located below the proximal spring and the second hydraulic chamber is located above it, although both hydraulic chambers are located in the heel area of ​​the proximal spring.

[0034] In this embodiment, it is advantageous if a valve arranged in the fluid line between the two hydraulic chambers is opened when rolling over the forefoot, so that fluid is directed from the first hydraulic chamber into the second hydraulic chamber. In this way, the second section of the second shell of the second hydraulic chamber is expanded and additional energy is stored. When the load is relieved, the hydraulic fluid flows back into the first hydraulic chamber and releases this additional energy for the "push-off". In the described embodiment, the valve can also be open when the heel strikes, so that fluid is directed from the first hydraulic chamber into the second hydraulic chamber. In this case, too, additional energy is stored in the form of elastic deformation of the second section of the second shell of the second hydraulic chamber.

[0035] The proximal spring preferably has a first partial spring and a second partial spring. This preferably extends from the heel area into the forefoot area. The two partial springs are preferably arranged one above the other, so that the first partial spring can be referred to as the distal (lower) partial spring and the second partial spring as the proximal (upper) partial spring. The second hydraulic chamber is preferably arranged anterior to the first hydraulic chamber and between the first partial spring of the proximal spring and the second partial spring of the proximal spring. In this embodiment, the second sleeve preferably has the second section, which is elastic. The second section is then compressed, in particular when the forefoot is loaded, thereby providing an elastic restoring force.

[0036] Preferably, a contact element is arranged between the first partial spring and the second partial spring, preferably posterior to the second hydraulic chamber, for example, in the heel region of the prosthetic foot. Particularly preferably, the first partial spring and the second partial spring are designed and arranged such that the second partial spring moves away from the first partial spring when the forefoot is subjected to a load, which occurs, for example, during the rollover. In this state, the second partial spring then lifts off the contact element in the heel region.

[0037] A further development of the invention is characterized in that the orthopaedic device has a joint with a first joint part and a second joint part which is arranged on the first joint part so as to be pivotable about a pivot axis, wherein the hydraulic system is arranged and configured such that a fluid flows from the first hydraulic chamber into the second hydraulic chamber or vice versa when the first joint part is pivoted relative to the second joint part.

[0038] Preferably, the joint is a hip joint, a knee joint or an ankle joint of an orthosis or a prosthesis

[0039] The invention further achieves the stated object by a hydraulic system for an orthopedic device according to the invention. Preferably, the first shell of the first hydraulic chamber and the second shell of the second hydraulic chamber are formed integrally. Alternatively, the first shell and the second shell are designed as separate components.

[0040] A further development of the invention provides that the first hydraulic chamber, the second hydraulic chamber, and / or at least one further hydraulic chamber is arranged as a leaf spring chamber in a leaf spring element. The orthopedic device preferably comprises a foot prosthesis with such a leaf spring element.

[0041] Such a leaf spring element represents a separate invention independent of its use in an orthopedic device. Such a leaf spring element is preferably designed for use in an orthopedic device described here.

[0042] The leaf spring element has a base body. Within this base body, at least one cavity is arranged, which forms the respective hydraulic chamber. The material of the base body surrounding the cavity forms the shell of this hydraulic chamber and, since it is the base body of a leaf spring element, is elastic. The cavity is preferably a single cavity arranged within the base body. In an alternative embodiment, the cavity is formed from several sub-chambers that are fluidically connected to one another and together form the respective hydraulic chamber. The individual sub-chambers are preferably identical. Alternatively, however, it is also possible to use differently shaped sub-chambers. The sub-chambers preferably run parallel to one another and along the longitudinal extent of the leaf spring.In a particularly preferred embodiment, the sub-chambers run equidistant from one another, thereby resulting in a particularly uniform influence on the elastic properties of the leaf spring element. The cavity, regardless of whether it is designed as a single cavity or in the form of several sub-chambers, is preferably located on one side of the neutral fiber. The neutral fiber of a leaf spring is the imaginary line whose length does not change when the leaf spring is bent, i.e., in which the material is neither stretched nor compressed. When the leaf spring is bent, the curvature and radius of curvature of the leaf spring change. This means that for all imaginary lines parallel to the neutral fiber that are located radially inward to the neutral fiber with respect to this radius of curvature, their length decreases with increasing bending, i.e., decreasing radius of curvature.However, for all imaginary lines parallel to the neutral axis that are located radially outside the neutral axis, the length increases in this situation. Therefore, if the cavity is located radially inside or outside the neutral axis, the volume of the cavity and thus the chamber volume of the respective hydraulic chamber will change when the leaf spring bends.

[0043] If the leaf spring element is elastically deformed, the volume of at least one leaf spring chamber, i.e. at least one hydraulic chamber present in the leaf spring element, changes. This either pushes hydraulic fluid out of this chamber or draws it into it. For this purpose, the leaf spring chamber is fluidly connected to another hydraulic chamber, which can also be a leaf spring chamber and therefore can also be arranged within the leaf spring element. It is also possible to arrange a hydraulic chamber outside the leaf spring. The fluid connection is a fluid line in which an adjustable valve, for example a throttle valve, also referred to as a throttle, is arranged. Actuating the throttle valve changes the flow resistance that the valve creates and opposes the fluid. This changes the spring constant of the leaf spring element.

[0044] Preferably, a base body of the leaf spring element is made of a fiber-reinforced plastic, for example, carbon fiber-reinforced plastic or glass fiber-reinforced plastic. In this context, a leaf spring element is understood to be a leaf spring that deforms under the forces encountered in orthopedic technology, particularly prosthetics and orthotics. These forces are caused by the wearer of the orthopedic device, particularly by their body weight and movement.

[0045] Preferably, a chamber volume of the at least one leaf spring chamber is arranged more than 50%, but preferably completely proximal or distal to a neutral fiber of the leaf spring element.

[0046] Preferably, the at least one leaf spring chamber is fluidly connected to a compensation volume by a fluid line.

[0047] Advantageously, a valve is then arranged in the fluid line. The advantage of this design is that the stiffness of the leaf spring element depends on whether the valve is in an open or a closed position. The leaf spring element provides greater stiffness when the valve is in the closed position, since the fluid in the chamber volume of the leaf spring chamber cannot then flow toward the compensation volume. However, when the valve is in the open position, the leaf spring element provides less stiffness.

[0048] Preferably, the first hydraulic chamber and the second hydraulic chamber are arranged as leaf spring chambers in the leaf spring element.

[0049] The leaf spring element preferably extends from a heel region to a forefoot region. Preferably, at least one leaf spring chamber in the leaf spring element extends from a heel region to a forefoot region. Alternatively or additionally, at least one leaf spring chamber is arranged in the heel region or in the forefoot region. The leaf spring element can, in particular, be the proximal spring or the distal spring, or a partial spring of the proximal spring or the distal spring.

[0050] Preferably, at least one leaf spring chamber in the leaf spring element has a rectangular or round cross-section in the frontal plane.

[0051] Preferably, at least two leaf spring chambers, preferably two, four, six, or eight, are arranged in the leaf spring element, wherein preferably two leaf spring chambers are arranged at the same distance from the neutral fiber on opposite sides of the neutral fiber. Preferably, the two leaf spring chambers, which are arranged at the same distance from the neutral fiber on opposite sides of the neutral fiber, are each fluidically connected to one another by a fluid line. Preferably, a valve is arranged in the fluid line, which valve is particularly preferably adjustable, so that the flow resistance through the fluid line is adjustable.

[0052] The orthopedic device preferably comprises a plurality of leaf spring elements with leaf spring chambers arranged therein. The first hydraulic chamber and the second hydraulic chamber are preferably arranged in different leaf spring elements. Such leaf spring elements are preferably used as dorsal springs in lower leg orthoses.

[0053] Particularly for orthopedic devices that have two components that can be moved relative to one another, for example, pivoted relative to one another, the present invention significantly increases wearing comfort. This will be described using the example of a prosthetic ankle joint.

[0054] Prior art ankle joints feature a hydraulic system with two hydraulic chambers connected by a fluid line containing a controllable valve for adjusting the flow resistance to the flowing fluid. The ankle joint connects a lower leg element, typically designed as a rigid tube, to a foot section, which typically has at least one spring element, but preferably a distal spring and a proximal spring. Equipping such an ankle joint with the present invention opens up new possibilities.

[0055] At the beginning of the start phase of a step cycle, the heel of the foot section is placed on the ground. If the first hydraulic chamber is located between the distal spring and the proximal spring in the heel area, the heel strike puts pressure on the first hydraulic chamber, forcing hydraulic fluid out of the first hydraulic chamber if the valve is open. The damping of this movement can be adjusted via the flow resistance that the valve opposes to this flowing hydraulic fluid. Preferably, the second hydraulic chamber is located between the two partial springs of the proximal spring. The fluid forced from the first hydraulic chamber into the second hydraulic chamber causes the second hydraulic chamber to expand and thus exerts pressure on the two partial springs of the proximal spring. This increases the stiffness of the proximal spring, which is formed by the two partial springs.

[0056] Preferably, the ankle joint, particularly preferably the foot part, has at least one sensor by which the movement state of the wearer of the ankle joint can be determined. This does not involve detecting the movement state of individual components, but rather the wearer's movement state extending over a longer period of time. This can be, for example, "standing," "walking uphill," or "walking downhill." These movement states can be determined from sensor data, such as torques, ankle angles, and forces, which is known in principle from the prior art. For this purpose, an electrical control system, such as an electronic data processing device, is used, which is part of the orthopedic device, preferably the ankle joint.

[0057] If it is detected that the wearer of the orthopedic device is standing, the valve is preferably closed. Unlike with prior art devices, this no longer prevents movement of the ankle joint. Since both the first hydraulic chamber and the second hydraulic chamber have an elastic section, movement of the lower leg section relative to the foot section is still possible, albeit to a significantly lesser extent. This allows the wearer of the orthopedic device to rock back and forth, just as a healthy ankle joint would.If the electrical control detects that the wearer of the device begins to walk, for example by the forefoot area exceeding a predetermined limit, the valve is opened so that the fluid can flow from the second hydraulic chamber back into the first hydraulic chamber, thus setting a stiffness of the proximal spring that is suitable for walking, in particular for walking on level ground, which forms another state of movement.

[0058] If, on the other hand, the electrical control detects the movement state "walking uphill", the valve is opened, preferably during forefoot loading, so that the pressure acting on the second hydraulic chamber pumps fluid from the second hydraulic chamber into the first hydraulic chamber. The valve is then closed. This results in the heel being perceived as stiffer, thus creating a heel lever that drives the wearer more strongly. Since the second hydraulic chamber located between the proximal spring and dorsal spring contains less fluid in this state, the forefoot is simultaneously perceived as softer because the stiffness of the proximal spring is reduced. This makes rolling over easier and therefore achieves a greater rollover angle. This stiffness ratio is maintained until a new movement state is detected. For this purpose, the valve is kept closed.

[0059] If, on the other hand, the electrical control detects the movement state “walking downhill”, both a soft heel and a soft forefoot are preferably desired. To achieve this, it is advantageous to keep the valve open throughout the entire gait cycle. In addition, the flow resistance opposite to the flowing fluid dissipates energy, thereby braking the user. The first section of the first shell of the first hydraulic chamber preferably has a fold. This is particularly advantageous when the first hydraulic chamber has the shape of a curved or kinked cylinder. This is the case, for example, when the first hydraulic chamber has the shape of a cylinder, for example with a circular base area, wherein the cylinder is curved at least in sections. The first hydraulic chamber preferably has a curvature with a radius of curvature over its entire length.The radius of curvature can be constant over the entire length of the hydraulic chamber or vary in different regions along the length of the hydraulic chamber. In particular, only one region of the hydraulic chamber can be curved, while the first hydraulic chamber outside this region is straight.

[0060] Preferably, the first section of the first sleeve, which is designed to be elastic, forms the curved region of the first hydraulic chamber. The fold is arranged in this first section of the first sleeve and is arranged on the radially inner side of the curved region of the first sleeve. The fold serves as a virtual axis of rotation about which the two regions in front of and behind the fold can be pivoted relative to one another when a corresponding torque acts on the two regions. The rigidity of this pivotability depends not only on the strength of the curvature of the first sleeve but also on the internal pressure within the first hydraulic chamber. The hydraulic system therefore has a second hydraulic chamber which is connected to the first hydraulic chamber by the fluid line.The second hydraulic chamber preferably serves as a compensation volume or as a reservoir for hydraulic fluid, which can be pressed through the fluid line into the first hydraulic chamber, for example by compressing the second hydraulic chamber. As a result, the internal pressure in the first hydraulic chamber increases and the rigidity against the described pivoting also increases. This means that a predetermined torque leads to less pivoting, i.e. a smaller pivot angle, than with a lower rigidity. The rigidity can be reduced by reducing the internal pressure in the first hydraulic chamber. For this purpose, it is sufficient to direct hydraulic fluid from the first hydraulic chamber into the second hydraulic chamber. Preferably, the fluid line connecting the first hydraulic chamber to the second hydraulic chamber can be closed by a valve.This allows the desired stiffness of the first hydraulic chamber to be adjusted to prevent the two areas in front of and behind the fold from pivoting. The desired internal pressure in the first hydraulic chamber is set, and then the valve is closed, preventing hydraulic fluid from flowing from the first hydraulic chamber into the second hydraulic chamber, even when the second hydraulic chamber is relieved of pressure. The valve can also be designed as a throttle valve.

[0061] Such a design with a curved region of the first shell can preferably be used as an elbow joint, a toe joint or an ankle joint.

[0062] With the help of the accompanying drawings, exemplary embodiments of the present invention are explained in more detail below.

[0063] Figure 1 - the schematic representation of an orthopaedic device according to the invention in a first embodiment,

[0064] Figure 2 - the schematic representation of an orthopaedic device according to the invention in a second embodiment,

[0065] Figure 3 - the schematic representation of an orthopaedic device according to the invention in a third embodiment,

[0066] Figure 4 - the schematic representation of an orthopaedic device according to the invention in a fourth embodiment,

[0067] Figure 5 - the schematic representation of an orthopaedic device according to the invention according to the fourth embodiment in a second state, Figure 6 - the schematic representation of a hydraulic system according to the invention for an orthopaedic device according to the invention according to a fifth embodiment,

[0068] Figure 7 - the schematic representation of the hydraulic system according to the invention according to the fifth embodiment in a second state,

[0069] Figure 8 - the schematic sectional view of a leaf spring element,

[0070] Figure 9 - the schematic sectional view of a leaf spring element according to a second embodiment,

[0071] Figure 10 - a further sectional view of the leaf spring element according to the second embodiment,

[0072] Figure 11 - the schematic sectional view of a leaf spring element according to a third embodiment,

[0073] Figure 12 - the schematic sectional view of a leaf spring element according to a fourth embodiment and.

[0074] Figure 13 - the schematic view of part of a hydraulic system.

[0075] Figure 1 shows an orthopedic device 2 in the form of a foot prosthesis with a hydraulic system 4. The orthopedic device 2 has a joint with a first joint part 32 and a second joint part 34. The second joint part 34 is pivotally mounted on the first joint part 32 via a pivot axis 36. At the proximal end, the second joint part 34 has a connection device 38 in the form of a pyramid adapter for connecting to another prosthetic component. The hydraulic system 4 has a first hydraulic chamber 6 with a first sleeve 8, which delimits a first chamber volume 9 of the first hydraulic chamber 6, and a second hydraulic chamber 10 with a second sleeve 12, which delimits a second chamber volume 13 of the second hydraulic chamber 10. The first hydraulic chamber 6 and the second hydraulic chamber 10 are fluidly connected to one another by a fluid line 14.The first hydraulic chamber 6, the second hydraulic chamber 10, and the fluid line are filled with a fluid. The first sleeve 8 has a first section 16, which is elastic and, in the embodiment shown, extends over the entire first sleeve 12. The second sleeve 12 has a second section 18, which is elastic and, in the embodiment shown, extends over the entire second sleeve 12. In other words, the first sleeve 8 and the second sleeve 12 are completely elastic in the embodiment shown.

[0076] A controllable valve 20 is arranged in the fluid line 14, by which a flow resistance through the fluid line can be adjusted. In particular, the valve 20 can be moved into an open position and a closed position.

[0077] The hydraulic system 4 is arranged and configured such that fluid flows from the first hydraulic chamber 6 into the second hydraulic chamber 10, or vice versa, when the first joint part 32 is pivoted relative to the second joint part 34 and the valve 20 is not in the closed position. When the valve 20 is in the closed position, fluid can no longer flow from the first hydraulic chamber 6 into the second hydraulic chamber 10, or vice versa. Pivoting the first joint part 32 relative to the second joint part 34 is still possible due to the elastic design of the first section 16 and the second section 18 when the valve 20 is in the closed position. When the first joint part 32 pivots relative to the second joint part 34, an elastic volume change of the first chamber volume 9 and the second chamber volume 13 occurs.Whether and to what extent such pivoting is possible when the valve 20 is closed depends, among other things, on the elasticity of the first section 16 and / or the second section 18. The arrangement shown allows for a very compact arrangement, since certain components that are necessary in other embodiments, such as a piston rod, can be omitted.

[0078] The orthopedic device 2 has a spring arrangement 22 extending from a heel region to a forefoot region and comprising a distal spring 24 and a proximal spring 26 arranged proximally to the distal spring 24. The proximal spring 26 has a first partial spring 28 and a second partial spring 30. The distal spring 24 and the proximal spring 26, as well as the partial springs 28, 30, are secured to one another in an anterior region (not shown). The first joint part 32 is arranged proximally on the second partial spring 30 of the proximal spring 26.

[0079] Figure 2 shows an orthopedic device 2 in a second embodiment in the form of a foot prosthesis with a hydraulic system 4 having a first hydraulic chamber 6 and a second hydraulic chamber 10, which are connected to one another via a fluid line 14. The orthopedic device has a spring arrangement 22 that extends from a heel region to a forefoot region and has a distal spring 24 and a proximal spring 26 that is arranged proximally to the distal spring 24. In the embodiment shown, the proximal spring has a first partial spring 28 and a second partial spring 30. The first hydraulic chamber 6 is arranged as a heel chamber in the heel region between the distal spring 24 and the proximal spring 26 and is fluidly connected to the second hydraulic chamber 10 via a fluid line 14. A valve present in the fluid line is not shown in Figure 2 for the sake of clarity.

[0080] The orthopedic device comprises a joint with a first joint part 32 and a second joint part 34, which is pivotably arranged on the first joint part 32 via a pivot axis 36. The second hydraulic chamber 10 is arranged between the proximal spring 26 and the first joint part 32. The hydraulic system 4 is arranged and configured such that a fluid flows from the first hydraulic chamber 6 into the second hydraulic chamber 10 or vice versa when the first joint part 32 is pivoted relative to the second joint part 34. Furthermore, a spring 40 is arranged between the first joint part 32 and the second joint part 34 such that the spring 40 is stretched or compressed when the first joint part 32 is pivoted relative to the second joint part. The first hydraulic chamber 6 has a first shell 8, which delimits a first chamber volume 9.The second hydraulic chamber 10 has a second shell 12 that defines a second chamber volume 13. The first shell 8 has an elastically formed first section 16, which in the example shown extends over the entire first shell 8. The second shell 12 has an elastically formed second section 18, which in the example shown extends over the entire second shell 12.

[0081] At the proximal end, the second joint part 34 has a connection device 38 in the form of a pyramid adapter.

[0082] Figure 3 shows an orthopedic device 2 in the form of a foot prosthesis according to a third embodiment. The orthopedic device 2 of Figure 3 differs from the orthopedic device 2 in that it has no joint and no spring. The first hydraulic chamber 6 is designed as a heel chamber. The second hydraulic chamber 10 is designed as a compensation volume. A valve 20 and a check valve 42 are arranged in the fluid line 14. The check valve 42 is connected in parallel to the valve 20, so that there is less flow resistance towards the first hydraulic chamber than towards the second hydraulic chamber.

[0083] Figure 4 shows an orthopedic device 2 in the form of a foot prosthesis according to a fourth embodiment in an unloaded state. In this embodiment, the second hydraulic chamber 10 is arranged between the first partial spring 28 and the second partial spring 30 of the proximal spring 26. A controllable valve 20 is arranged in the fluid line. The first hydraulic chamber 6 is again designed as a heel chamber. The second hydraulic chamber 10 is arranged anterior to the first hydraulic chamber 6. When the valve is open, the fluid flows from the first hydraulic chamber 6 into the second hydraulic chamber 10 when the heel is loaded, and from the second hydraulic chamber 10 into the first hydraulic chamber 6 when the forefoot is loaded. Posterior to the second hydraulic chamber 10, in the heel region, a contact element 44 is arranged between the first partial spring 28 and the second partial spring 30.

[0084] Figure 5 shows the embodiment of Figure 4, wherein the orthopedic device 2 is subjected to a forefoot load, which occurs, for example, during the rollover. The second partial spring 30 is lifted from the contact element in the heel area. Furthermore, the second hydraulic chamber 10 has a lower height in this state than in the unloaded state. As a result, the system stiffness has changed, in this case increased, which is advantageous in this section of the gait cycle.

[0085] Figure 6 shows a hydraulic system 4 according to the invention for an orthopedic device according to the invention in an unloaded state. The hydraulic system 4 has a first hydraulic chamber 6 and a second hydraulic chamber 10. The first hydraulic chamber 6 is arranged as a leaf spring chamber in a leaf spring element 46 with a base body 50. The second hydraulic chamber 10 is designed as a compensation chamber, which can also be pressurized if necessary to stiffen the entire system. The two hydraulic chambers 6, 10 are fluidly connected to one another via a fluid line 14, with a valve 20 arranged in the fluid line 14.

[0086] The first hydraulic chamber 6 has a first shell that defines a first chamber volume 9 and has an elastically configured first section. The shell can be formed, for example, by the base body 50 or by a tube inserted into the base body 50. In the embodiment shown, the first chamber volume 9 is arranged below a neutral fiber 48 of the leaf spring element 46. It is also possible to arrange the first chamber volume above the neutral fiber 48 of the leaf spring element 46.

[0087] Figure 7 shows the hydraulic system 4 of Figure 6 in a loaded state.

[0088] The leaf spring element 46 is in a bending-loaded state. Since the first chamber volume 9 of the first hydraulic chamber 6 is located below the neutral fiber 48 of the leaf spring element 46, the first chamber volume 9 has changed, resulting in a fluid flow between the first hydraulic chamber 6 and the second hydraulic chamber 10, provided the fluid line 14 is not blocked by the valve 20. By blocking the fluid line by closing the valve 20, the leaf spring element can thus be stiffened.

[0089] Figure 8 shows a leaf spring element 46 with a base body 50, a neutral fiber 48, a first hydraulic chamber 6 and a second hydraulic chamber 10 as leaf spring chambers, wherein the first hydraulic chamber 6 is arranged below the neutral fiber 48 and the second hydraulic chamber 10 is arranged above the neutral fiber 48.

[0090] The first hydraulic chamber 6 has a first shell which delimits a first chamber volume 9 and has an elastically designed first section. The second hydraulic chamber 6 has a second shell which delimits a second chamber volume 9 and has an elastically designed second section. The shells can be formed, for example, by the base body 50 or by a tube inserted into the base body 50. The two hydraulic chambers 6, 10 have a rectangular cross-section. Other cross-sectional shapes are conceivable. The first hydraulic chamber 6 is fluidly connected to the second hydraulic chamber 10 via a fluid line (not shown) and optionally via a valve (likewise not shown).

[0091] Figure 9 shows a leaf spring element 46 with a first hydraulic chamber 6 and a second hydraulic chamber 10, each designed as a leaf spring chamber. The first hydraulic chamber 6 is arranged below the neutral fiber 48. The second hydraulic chamber 10 is arranged above the neutral fiber 48. The hydraulic chambers 6, 10 each have four sub-chambers 52, which are arranged next to one another and have a round cross-section and are fluidically connected to one another. The first hydraulic chamber 6 is fluidically connected to the second hydraulic chamber 10 via a fluid line (not shown) and optionally via a valve (likewise not shown). Figure 10 shows the leaf spring element 46 in Figures 8 and 9 in a longitudinal section. The first hydraulic chamber 6 is fluidically connected to the second hydraulic chamber 10 via a fluid line 14.A valve 20 is arranged in the fluid line 14, through which the flow resistance against which the fluid flows from one hydraulic chamber to the other hydraulic chamber can be adjusted. This allows the stiffness of the leaf spring element 46 to be influenced.

[0092] Figure 11 shows a leaf spring element 46 with six hydraulic chambers 6, 10, 54 in the form of leaf spring chambers, namely the first hydraulic chamber 6, the second hydraulic chamber 10, and four additional hydraulic chambers 54. The leaf spring chambers 6, 10, 54 each have a casing that defines a chamber volume and has an elastically configured section. The casings can be formed, for example, by the base body 50 of the leaf spring element 46 or by a tube inserted into the base body 50.

[0093] Two hydraulic chambers are arranged at the same distance from the neutral fiber on opposite sides of the neutral fiber. These two hydraulic chambers are each connected to each other via a fluid line 14, each of which contains a valve 20. By opening and closing the valves 20, the stiffness of the structure can be incrementally manipulated.

[0094] Figure 12 shows a leaf spring element 46 with six hydraulic chambers 6, 10, 54 in the form of leaf spring chambers, namely the first hydraulic chamber 6, the second hydraulic chamber 10, and four further hydraulic chambers 54, as well as a further hydraulic chamber 54 in the form of a compensation volume. Here, too, two hydraulic chambers are arranged at the same distance from the neutral fiber on opposite sides of the neutral fiber. These two hydraulic chambers are each connected to one another via a fluid line 14, in each of which a valve 20 is arranged. The fluid lines 14 are fluidly connected to the compensation volume, which is optionally pressurized. By opening and closing the valves 20, the stiffness of the structure can be incrementally manipulated.

[0095] Figure 13 shows a schematic sectional view through part of a hydraulic system such as can be used in an orthopedic device, for example an artificial knee joint. It has a first hydraulic chamber 6 and a second hydraulic chamber 10, both of which have a base 56 made of a rigid material, preferably a metal, for example aluminum. In the exemplary embodiment shown, the remainder of the two hydraulic chambers 6, 10 is made of an elastic material and thus forms the first section 16 in the first hydraulic chamber 6 and the second section 18 in the second hydraulic chamber 10. The two bases 56, which are fastened to an intermediate base 58, contain the connections of the two hydraulic chambers (not shown in Figure 13). The intermediate base 58 is slidably fastened in the cylinder 60.Both hydraulic chambers 6, 10 have a cover 62 which is displaceable along a guide rail 64 and which limits the maximum extension of the first area and the second area.

[0096] List of reference symbols

[0097] 2 orthopaedic technical facilities

[0098] 4 Hydraulic system

[0099] 6 first hydraulic chamber

[0100] 8 first shell

[0101] 9 first chamber volume

[0102] 10 second hydraulic chamber

[0103] 12 second shell

[0104] 13 second chamber volume

[0105] 14 Fluid line

[0106] 16 first section

[0107] 18 second section

[0108] 20 valve

[0109] 22 Spring arrangement

[0110] 24 Distal spring

[0111] 26 Proximal spring

[0112] 28 first partial spring

[0113] 30 second partial spring

[0114] 32 first joint part

[0115] 34 second joint part

[0116] 36 swivel axis

[0117] 38 Connection device

[0118] 40 spring

[0119] 42 Check valve

[0120] 44 Contact element

[0121] 46 leaf spring element

[0122] 48 neutral fiber

[0123] 50 basic bodies

[0124] 52 sub-chamber

[0125] 54 additional hydraulic chambers

Claims

Patent claims 1. Orthopaedic device (2) with a hydraulic system (4) with a first hydraulic chamber (6) with a first sleeve (8) which delimits a first chamber volume (9) of the first hydraulic chamber (6), and a second hydraulic chamber (10) which has a second sleeve (12) which delimits a second chamber volume (13) of the second hydraulic chamber (10) and is connected to the first hydraulic chamber (6) by a fluid line (14), characterized in that the first sleeve (8) has a first section (16) which is designed to be elastic.

2. Orthopaedic device (2) according to claim 1, characterized in that the second sheath (12) has a second section (18) which is elastic.

3. Orthopaedic device (2) according to claim 2, characterized in that the first section (16) and the second section (18) have different stiffnesses.

4. Orthopaedic device (2) according to one of the preceding claims, characterized in that at least one controllable valve (20) is arranged in the fluid line (14), by means of which a flow resistance through the fluid line (14) can be adjusted, preferably continuously.

5. Orthopaedic device (2) according to one of the preceding claims, characterized in that one of the hydraulic chambers (6, 10) or a further hydraulic chamber is designed as a compensation volume.

6. Orthopaedic device (2) according to one of the preceding claims, characterized by at least one overload protection element which is arranged and configured such that it limits the maximum extension of the first section (16) by limiting the expansion of the first hydraulic chamber (6) in at least one direction.

7. Orthopaedic device (2) according to one of the preceding claims, characterized in that the first section (16) is prestressed in an unloaded state of the orthopaedic device (2).

8. Orthopaedic device (2) according to one of the preceding claims, characterized in that the orthopaedic device (2) has a foot prosthesis with a spring arrangement (22) which extends from a heel region to a forefoot region and has a distal spring (24) and a proximal spring (26) which is arranged proximal to the distal spring (24), wherein the first hydraulic chamber (6) is arranged in the heel region between the distal spring (24) and the proximal spring (26).

9. Orthopaedic device (2) according to claim 8, characterized in that the proximal spring (26) has a first partial spring (28) and a second partial spring (30) and the second hydraulic chamber (10) is arranged anterior to the first hydraulic chamber (6) between the first partial spring (28) and the second partial spring (30).

10. Orthopaedic device (2) according to one of the preceding claims, characterized in that the orthopaedic device (2) has a joint with a first joint part (32) and a second joint part (34), which is arranged on the first joint part (32) so as to be pivotable about a pivot axis (36), wherein the hydraulic system (4) is arranged and configured such that a fluid flows from the first hydraulic chamber (6) into the second hydraulic chamber (10) or vice versa when the first joint part (32) is pivoted relative to the second joint part (34).

11. Orthopaedic device (2) according to one of the preceding claims, characterized in that the device (2) is a foot prosthesis, a knee prosthesis, an orthotic ankle joint or an orthotic knee joint.

12. Hydraulic system (4) for an orthopaedic device (2) according to one of the preceding claims.

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