Orthopedic technology facility

Abstract

The invention relates to an orthopaedic device with at least one elastic spring element which expands elastically in at least one deformation direction under the influence of a force, and a limiting device which limits the expansion space available for expansion in the at least one deformation direction, characterized in that the limiting device has an adjustment device by which the limiting device can be influenced in such a way that the expansion space can be changed.

Description

[0001] The invention relates to an orthopaedic device with at least one elastic spring element which expands elastically in at least one deformation direction under the influence of a force, and a limiting device which limits the expansion space available for expansion in the at least one deformation direction, wherein the limiting device has an adjustment device by which the limiting device can be influenced in such a way that the expansion space can be changed.

[0002] Such an orthopedic device is known, for example, from DE 10 2010 050 318 A1. GB 1 147 909 A discloses a worktable for a machine tool whose feet have a block of elastomer surrounded by a housing. US 5 934 599 A describes a lacing device for shoes, and DE 10 2008 047 023 A1 discloses a spring arrangement such as is frequently used in vehicle chassis to mitigate the transmission of shocks from the wheels to the chassis.

[0003] Orthopedic devices have long been known in the art. Orthopedic devices within the meaning of the present invention are orthoses that protect, support, or restrict the movement of an existing body part of the wearer; prostheses that replace a missing body part of the wearer; and devices that support the wearer during physical activities and tasks, for example, when lifting heavy objects or working in awkward positions, such as overhead. The latter devices are often referred to as exoskeletons.

[0004] Orthopedic devices of the type described here have at least one elastic spring element that serves as a damper and / or energy storage device. If the orthopedic device is, for example, a prosthetic foot, such an elastic spring element is arranged, for instance, in the heel area of ​​the prosthetic foot. In this case, the spring element is compressed when the heel of the prosthetic foot strikes the ground and absorbs some of the energy, which is stored as potential energy within the elastic spring element. When the load on the heel of the prosthetic foot decreases during the stance phase of the step, the energy can be released again when the elastic spring element relaxes and returns, at least partially, preferably completely, to its relaxed initial state. In this embodiment, the elastic spring element is compressed in one direction.However, since the elastic spring element is not completely surrounded by other components that act as limiting devices, the elastic spring element can also react to the force and deflect accordingly by deformation, in particular by expansion in another direction, which is, for example, perpendicular to the direction of the acting force.

[0005] This is always possible when the elastic spring element has sufficient space for expansion, which is usually the case. A limiting device can also be formed by components of the orthotic device adjacent to the spring element, whose actual function has nothing to do with the expansion of the elastic spring element or its limitation. These components can come into contact with the elastic spring element when the force is applied and the elastic spring element reacts to this force, including by expanding in the direction of expansion. As soon as the spring element is in contact with the limiting device and the limiting device itself is immobile and inelastic, further expansion of the elastic spring element is no longer possible, at least in this direction. Deformation in another direction may still be possible.Preferably, several limiting elements are present that restrict the extension of the elastic spring element in several directions, preferably in all directions. Preferably, at least one limiting element is present that restricts the extension of the elastic spring element in several directions, preferably in all directions.

[0006] Elastic spring elements are used, for example, in prostheses and orthoses as dampers to cushion movement, such as the pivoting of a joint in the orthotic device, or impacts or shocks, such as the impact of a heel strike, which, for instance, limits the range of motion of a joint in the orthotic device. It has proven advantageous if the spring constant, which defines a measure of the force that must act on the elastic spring element to achieve a specific deformation, particularly a specific compression, can be adjusted. In hydraulic systems, this can be easily achieved by changing the flow resistance, for example, of a valve. Often, it is sufficient to alter the cross-sectional area of ​​a fluid line through which the hydraulic fluid flows.

[0007] With mechanical spring elements, such as elastomer blocks, dampers made of rubber-elastic materials, or other springs, adjusting the damping stiffness is generally not possible. Therefore, various elastic spring elements are used, which can be exchanged as needed. In the example of the elastic spring element in the heel area of ​​a prosthetic foot, the material from which the spring element is made, and thus its spring stiffness, is adjusted to the body weight of the wearer of the orthotic device. This is cumbersome and only possible to a limited extent. Furthermore, it is not possible in this way to adapt the spring stiffness to different usage situations of the orthotic device.

[0008] The invention is based on the objective of eliminating or at least mitigating these disadvantages of the prior art.

[0009] The invention solves the stated problem by means of an orthopaedic device according to the preamble of claim 1, which is characterized in that the limiting device has at least one tension element which is guided at least once around the spring element, wherein the adjusting device is arranged to change the effective length of the tension element, wherein the tension element is guided multiple times around the spring element.

[0010] The limiting device allows the expansion space available to the elastic spring element for expansion under the influence of the applied force to be modified. This modification allows the expansion space to be increased and / or decreased in at least one direction, particularly in the at least one direction of deformation. If the expansion space is increased in the direction of the at least one deformation direction, the elastic spring element can expand further in this direction and thus more easily yield to the externally applied force. This reduces the spring constant of the elastic spring element. Conversely, if the expansion space is decreased in the direction of the at least one deformation direction, the elastic spring element can expand less far and / or less easily in this direction, thus increasing the spring constant.

[0011] The spring stiffness is not to be understood as a material property of the elastic spring element, which may, for example, be designed as an elastomer block. The spring stiffness, as defined in the present invention, could also be described as the overall effective stiffness of a system comprising the elastic spring element and the limiting element. The definition given above therefore remains valid. The spring stiffness, as defined in the present invention, is a measure of the force that must act on the elastic spring element to achieve a specific deformation, in particular a specific compression. This force must be greater when the elastic spring element is in contact with the limiting element and further extension in this direction is not possible or only possible with difficulty, than when the extension of the elastic spring element is not restricted or prevented by the limiting element.

[0012] Preferably, the limiting device opposes the expansion of the elastic spring element in at least one direction that differs from the direction of the acting force. Preferably, this direction is at least one deformation direction. Advantageously, this direction extends orthogonally to the direction of the acting force.

[0013] Preferably, the elastic spring element is pre-tensioned by the limiting device. This is also understood here as a change in the expansion space. This includes, for example, embodiments in which the elastic spring element has no expansion space into which it could elastically expand. The elastic spring element itself is furthermore designed to expand elastically in at least one deformation direction under the influence of an external force; however, this is prevented by the particular design of the limiting device. If the limiting device is in direct contact with the elastic spring element along at least one deformation direction, but does not exert any force on the elastic spring element unless an external force is applied, then there is no pre-tension of the elastic spring element by the limiting device.However, such a preload is present if the limiting device not only rests against the elastic spring element along at least one direction of deformation, but also exerts a force, preferably a compressive force, on the elastic spring element.

[0014] When an external force acts on the elastic spring element, the adjacent limiting device prevents it from elastically expanding in the direction of deformation of this force. Instead, if expansion in any direction of deformation is impossible, it is compressed. The degree of this compression under the influence of the external force depends on the spring constant of the elastic spring element. This, in turn, depends on the preload of the elastic spring element imposed by the limiting device. The greater the force exerted on the elastic spring element by the limiting device, the greater the preload of the elastic spring element and the higher its spring constant.

[0015] In a preferred embodiment, the limiting device is elastic and is preferably elastically deformed by the elastic spring element when a force is applied. This is also understood here as a change in the expansion space. In a preferred embodiment, an elastically designed limiting device rests directly against the elastic spring element. In this case, the elastic spring element can only expand elastically along the deformation direction if it also elastically deforms the elastically designed limiting device. This increases the force required for a predetermined elastic expansion compared to the elastic spring element without a limiting device, and thus also increases the spring stiffness. In an alternative embodiment, an elastically designed limiting device does not rest directly against an elastic spring element.In this case, the elastic spring element is able to deform and expand elastically in at least one direction of deformation until it comes into contact with the elastically designed limiting device. Further expansion in this at least one direction of deformation is only possible if the elastic spring element also deforms the elastically designed limiting device. The spring constant therefore changes the moment the elastic spring element comes into contact with the limiting device.

[0016] According to the invention, the limiting device comprises at least one tension element, preferably a wire, cord, or rope, which is guided at least once around the spring element, and the adjusting device is configured to change the effective length of the tension element. The tension element is guided at least once around the spring element such that it surrounds the spring element in a plane in which the direction of the acting force is not located. Particularly preferably, the direction of the acting force is perpendicular to the plane in which the tension element surrounds the elastic spring element. The adjusting device preferably includes a winding mechanism with which it is possible to wind up a portion of the tension element and thus change the effective length of the tension element, in particular the length of the unwound portion of the tension element.Preferably, the winding mechanism is self-locking, so that once the effective length of the pulling element has been set, it does not change, or only changes to a very small extent, accidentally or on its own. The self-locking winding mechanism holds the pulling element at the set effective length after adjustment, without the application of any external force.

[0017] The tension element can be designed such that, without the application of an external force, the tension element does not come into contact with the elastic spring element, or at least not along its entire effective length. The elastic spring element can then expand under the influence of the external force along the direction of deformation until it comes into contact with the tension element. Once the elastic spring element has expanded to the point where the tension element is under tension, further expansion in this direction is only possible for the elastic spring element if the tension element is also elastic. Consequently, the spring constant of the elastic spring element changes at this moment.

[0018] The tension element can be designed such that it bears against the elastic spring element even without the application of an external force. This situation corresponds to the situation in which the tension element is not in contact with the elastic spring element, and the applied force deforms the elastic spring element to such an extent that contact occurs between the elastic spring element and the tension element. If the tension element is elastically designed, further deformation of the elastic spring element in the direction of deformation is possible, thereby changing the spring constant of the elastic spring element.

[0019] Preferably, the tension element has a very small cross-section and diameter compared to its length, as is the case with wires, cords, and ropes. When such a tension element rests against an outer surface of an elastic spring element whose dimensions are significantly larger than the cross-section and diameter of the tension element, a substantially linear contact occurs between the tension element and the elastic spring element. The expansion space available to the elastic spring element for elastic deformation is limited in the area of ​​linear contact, particularly if the tension element is inelastic. In other areas of the outer surface of the elastic spring element that are not in contact with the tension element, further expansion space is available for the elastic spring element.If the external force is so great that this expansion space is also utilized, a constriction and uneven deformation of the elastic spring element occur. This, too, is a consequence of the altered expansion space.

[0020] According to the invention, the tension element is guided around the spring element multiple times, in particular at least twice, preferably at least three times, and most preferably at least four times. The tension element is preferably guided around the elastic spring element in a spiral shape, such that each winding increases the contact area between the tension element and the elastic spring element.

[0021] Advantageously, the tension element is guided, at least partially, in a guide, for example, a tunnel or a tube, with the guide preferably being arranged on the spring element. When the effective length of the tension element changes and / or when the elastic spring element deforms elastically, the tension element may have to slide along the elastic spring element to maintain a homogeneous tension along its length. The materials used for the elastic spring element and the tension element may have coefficients of friction that offer high frictional resistance to this movement of the two elements relative to each other. To reduce this resistance, it is advantageous to provide a guide through which the tension element is guided. The guide can be designed as a tunnel or tube. Cup-shaped guides are also possible.It is important that the guide prevents direct contact between the elastic spring element and the tension element, thus reducing friction by selecting the appropriate guide material. Furthermore, it is crucial that the position and orientation of the tension element relative to the elastic spring element remain unchanged, even when its effective length is altered. It is not necessary for the entire effective length of the tension element to be contained within the guide. Often, it is sufficient to provide guides at points of high friction, such as the corners of the elastic spring element.

[0022] Preferably, the adjusting device comprises a coil, and the effective length of the tension element can be changed by winding the tension element onto or unwinding it from the coil. The coil preferably includes an actuating element, the actuation of which causes the tension element to be wound onto or unwound. The actuating element can be manually operated to allow the wearer of the orthotic device to manually operate the adjusting device and thus adjust the spring stiffness of the elastic spring element. Alternatively or additionally, the orthotic device has an electrical control unit, for example, an electronic data processing unit, which is configured, for example, based on sensor data, to actuate the coil's actuating element and thus automatically adjust the spring stiffness of the elastic spring element.

[0023] In a preferred embodiment, the adjusting device has a joint and / or a deformable component of the orthotic device, wherein the effective length of the tension element is variable by moving the joint and / or deforming the deformable component. In this way, for example, the spring constant of the elastic element can be automatically adjusted for certain movements and / or positions of individual elements of the orthotic device or of the orthotic device as a whole.

[0024] Preferably, the limiting device comprises at least one wall element whose distance from the spring element in the deformation direction can be changed by the adjusting device. Particularly preferably, several wall elements are present, arranged in multiple directions extending from the spring element. In this way, the expansion space can be limited in different directions. The expansion space can be changed by altering the distance between the respective wall element and the elastic spring element. This also applies when a wall element is and remains in contact with the elastic spring element, and only the force exerted by the wall element on the elastic spring element changes. As already described, this also leads to a change in the spring stiffness of the elastic spring element.

[0025] A wall element positioned between the spring element and the tension element is particularly preferred. In this way, the force applied by the tension element, or the resistance it offers against movement that increases the spring stiffness of the elastic spring element, is not only transmitted along the linear contact area between the tension element and the elastic spring element. Rather, this force or resistance is transferred from the tension element to the wall element and applied by the wall element to the elastic spring element in a significantly more uniform manner.

[0026] Preferably, the wall element surrounds the spring element in a ring-like fashion, the diameter of which can be changed by means of the adjusting device. Particularly preferably, the limiting device has several wall elements, in particular at least two wall elements, arranged on different sides of the spring element, wherein one side edge of each wall element is a connecting edge, and the wall elements are connected to each other via a connecting element. The adjusting device is configured to tilt the two wall elements about their connecting edge, thereby changing the expansion space.

[0027] With the aid of the accompanying figures, some exemplary embodiments of the present invention are explained in more detail below. They show: Fig. 1 and Fig. 2 - schematically an elastomer block with limiting device unloaded and loaded, Fig. 3, Fig. 4 to Fig. 5 - Schematic perspective view and sectional views of an elastomer block with limiting device, and Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 - Different applications of a limiting device in schematic representations.

[0028] Fig. Figure 1 schematically shows a cross-sectional view through an elastic spring element 2, which is designed as an elastomer block. It rests on a fixed base 4. A limiting device 6 abuts the side of the elastic spring element 2. In the Fig. In the unloaded state shown in Figure 1, the limiting device 6 rests loosely against the elastic spring element 2 in the illustrated embodiment and exerts no force on the elastic spring element 2. This is advantageous, but not necessary. For some applications, it is advantageous if the limiting device 6 is pre-tensioned and exerts a force on the elastic spring element 2.

[0029] Fig. Figure 2 shows the elastic spring element 2 made of Fig. 1, upon which a downward force, represented by the vertical arrow, now acts. The elastic spring element 2 would deform under this force if no limiting device 6 were present. However, since this limiting device 6 surrounds the elastic spring element 2, the deformation can only occur as shown in Fig. 2 is shown. This changes the spring constant of the elastic spring element 2.

[0030] Fig. Figure 3 schematically shows an embodiment. The elastic spring element 2 is again designed as an elastomer block. The limiting device has a tension element 8 that is wrapped once around the elastic spring element 2 in a guide 10. The tension element 8 is also connected to a spool 12, onto which it can be wound or from which it can be unwound to lengthen or shorten the effective length, in particular the part of the tension element 8 that is located in the guide 10.

[0031] The Fig. 4 and Fig. Figure 5 shows schematic cross-sectional views from which the principle becomes clear. The tension element 8 is wrapped once around the elastic spring element 2 and also runs through the coil 12. The coil 12 is rotatable, as indicated by the two curved arrows in Fig. Figure 5 shows that when the coil 12 is moved in this direction, a larger proportion of the tension element 8 is drawn into the coil 12, thus reducing the effective length of the tension element 8. This reduces the length of the loop that surrounds the elastic spring element 2, resulting in a force being exerted on the elastic spring element 2.

[0032] Fig. Figure 6 shows this embodiment, which is incorporated into an orthotic device, in this case a prosthetic foot. The prosthetic foot has two elastic elements located in the heel area of ​​the foot. The upper of the two elastic elements is formed by the elastic spring element 2, around which the tension element 8 is wrapped. The coil 12 is positioned so that the wearer of the prosthetic foot can use the coil 12 to change the spring constant of the elastic spring element 2 and thus adjust the damping of the prosthetic foot.

[0033] Fig. Figure 7 shows an elastic spring element 2 which can be inserted into a clamp 14. The clamp 14 has an adjustment element 16 by which the circumference of the clamp 14 can be changed. In this way, it is possible to limit the space available to the elastic spring element 2 for deformation and reshaping under the influence of an external force to a greater or lesser extent, and thus to influence the spring constant.

[0034] The Fig. 8 and Fig. Figure 9 shows elastic spring elements 2, each surrounded by a limiting device 6 which has several wall elements 18.

[0035] In Fig. There are 8 three wall elements, one of which is in Fig. The wall elements 18 are arranged below the elastic spring element 2. The two other wall elements are connected to this lower wall element by a hinged connection 20 and can be twisted around this connection 20. A tension element 8 is in contact with and surrounds these two wall elements 18, so that the wall elements 18 are located between the elastic spring element 2 and the tension element 8. If, for example, a tensile force is exerted on the tension element 8 by a coil 12, the effective length is reduced and the length of the loop of the tension element 8 that is placed around the elastic spring element 2 is shortened. This causes the two wall elements 18 to twist around the connections 20 and move towards the spring element 2.

[0036] Fig. Figure 9 shows an embodiment in which two wall elements 18 are present, which are also positioned between the elastic spring element 2 and the tension element 8. The tension element 8 is in Fig. The wall elements 18 are wrapped around the elastic spring element 2 in three loops. In this configuration as well, a tensile force exerted on the tension element 8 causes the wall elements 18 to move towards the elastic spring element 2 and be pressed against it, so that the spring constant can be changed.

[0037] Fig. Figure 10 shows an application of this principle in a prosthetic socket. The prosthetic socket has a fixed portion of the wall to which a pivoting element 24 is arranged via a joint 22. The pivoting element 24 is, for example, moved along the curved arrow in Fig. The pivoting element 24 pivots when an amputation stump, such as a femur stump, located in the prosthetic socket, thickens and thus exerts a force on it. At the opposite end of the pivoting element 24, shown only schematically, is the elastic spring element 2 with a tension element 8 wrapped around it multiple times. If more or less tensile force is exerted on the tension element 8, a greater or lesser external compressive force is also exerted on the elastic spring element 2, thereby making the spring stiffer or softer.

[0038] Fig. Figure 11 shows a prosthetic foot with an elastic spring element 2 in the heel area. Several loops of the tension element 8 lie around the elastic spring element 2, but unlike in Fig.6 is not connected to a coil 12, but is guided upwards along a lower leg tube 26, which is arranged on the prosthetic foot. At the upper (proximal) end of the lower leg tube 26, a prosthetic knee is shown with a distal portion of a thigh tube 28, to which the end of the traction element 8 is attached. The traction element 8 is positioned on the prosthetic knee such that a tensile force is exerted on the end of the traction element 8 when the knee is flexed. This exerts the previously described effect on the elastic spring element 2, which thus exhibits a higher spring stiffness, as defined in the present invention, when the knee is flexed than when the knee is extended. Reference symbol list 2 elastic spring element 4. Support 6 Limiting device 8 pull element 10 Leadership 12 coils 14 bells 16 Adjustment element 18 wall elements 20 connection 22 joint 24 Swivel part 26 Lower leg tube 28 thigh tube

Claims

Orthopedic device comprising: - at least one elastic spring element (2),◯ which expands elastically in at least one direction of deformation under the influence of a force, and - a limiting device (6),◯ which limits the expansion space available for expansion in the at least one direction of deformation, wherein the limiting device (6) has an adjustment device by which the limiting device (6) can be influenced in such a way that the expansion space can be changed, characterized in that the limiting device has at least one tension element (8), which is guided at least once around the spring element (2), wherein the adjustment device is configured to change the effective length of the tension element (8), wherein the tension element (8) is guided multiple times around the spring element (2). Orthopedic device according to claim 1, characterized in that the limiting device (6) counteracts an expansion of the elastic spring element (2) in at least one direction which differs from the direction of the acting force. Orthopedic device according to claim 1 or 2, characterized in that the elastic spring element (2) is pre-tensioned by the limiting device (6). Orthopaedic device according to one of the preceding claims, characterized in that the limiting device (6) is elastic and is preferably elastically deformed by the elastic spring element (2) when a force is applied. Orthopedic device according to one of the preceding claims, characterized in that the traction element (8) is a wire, a cord or a rope. Orthopaedic device according to one of the preceding claims, characterized in that the tension element (8) is guided around the spring element (2) at least twice, preferably at least three times, particularly preferably at least four times. Orthopaedic device according to one of the preceding claims, characterized in that the traction element (8) is guided at least sectionally in a guide (10), for example a tunnel or a tube, wherein the guide (10) is preferably arranged on the spring element (2). Orthopedic device according to one of the preceding claims, characterized in that the adjusting device has at least one coil (12) and the effective length can be changed by winding the traction element (8) onto the coil (12) or unwinding it from the coil (12). Orthopedic device according to one of the preceding claims, characterized in that the adjustment device has a joint (22) and / or a deformable component of the orthopedic device and the effective length can be changed by moving the joint (22) and / or deforming the deformable component. Orthopaedic device according to one of the preceding claims, characterized in that the limiting device (6) has at least one wall element (18) whose distance from the spring element (2) in the direction of deformation can be changed by the adjusting device. Orthopedic device according to claim 10, characterized in that the wall element (18) is arranged between the spring element (2) and the tension element (8). Orthopedic device according to claim 10 or 11, characterized in that the wall element (18) surrounds the spring element (2) in a ring shape and the diameter of the ring can be changed by the adjusting device. Orthopedic device according to one of claims 10 to 12, characterized in that the limiting device (6) has at least two wall elements (18) arranged on different sides of the spring element (2), wherein one side edge of each of the wall elements (18) is a connecting edge which are connected to each other via a connecting element, and wherein the adjusting device is configured to tilt the two wall elements (18) about their connecting edge and thus change the expansion space.

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