The invention relates to a system consisting of a spring adapter for arrangement on an orthopedic joint device and the orthopedic joint device having an upper part and a lower part fastened thereto so as to be pivotable about a pivot axis, the joint device having a resistance device that applies a resistance to pivoting about the pivot axis. The invention also relates to a spring adapter as such, for detachable fastening to a resistance device.
Orthopedic joint devices are used in prostheses, orthoses and what are known as exoskeletons, a special case of the orthoses. Orthopedic joint devices replace missing or lost limbs in prostheses. In orthoses, the joint functions, in particular the pivotability of two limbs with respect to one another, is reproduced by the pivotability of an upper part and the lower part about a pivot axis. In the simplest case, the respective pivot axis can be designed as a one-axis, stationary joint axis; polycentric joint devices are possible and provided as an alternative thereto, and have a non-stationary position of a pivot axis. The orthopedic joint devices often are assigned resistance devices for the purposes of influencing the pivot movement, the latter being able to influence the flexion movement and/or extension movement of the upper part relative to the lower part. The resistance devices may be combined with spring elements, for example to assist an extension movement after a present flexion movement. Actuators may be assigned to these spring elements in order to facilitate a timely output of the stored energy.
Hydraulic, pneumatic and elastic spring elements are used to influence the pivot behavior of the orthopedic joint device, with the spring elements being securely installed and serving to apply restoring forces and/or store energy. The hydraulic and pneumatic, and also elastic elements are matched to one another and are designed to absorb common loads and cover the conventional load and movement spectrum.
Furthermore, there are orthopedic components that are constructed for specialist applications. Such so-called sport prostheses or sport orthoses are designed for loads under physical exertion and have spring-damper elements that assist a large scope of movement and are able to withstand high loads. By way of example, air springs or else rope-like elastomer elements are used as spring components in this case. Such systems are not suitable for daily use and as a rule are custom-made items, which are very expensive.
It is therefore an object of the present invention to provide a patient who has to resort to the use of orthopedic joint devices with an extended range of use of the orthopedic joint device, in particular in order to be able to take part in sports using the generally individually fitted orthopedic joint devices.
According to the invention, this object is achieved by a system with an orthopedic joint device with a spring adapter having the features of the main claim. Advantageous embodiments and developments of the invention are disclosed in the dependent claims, the description and the drawings.
The system consisting of a spring adapter for arrangement on an orthopedic joint device and the orthopedic joint device having an upper part and a lower part fastened thereto so as to be pivotable about a pivot axis, with the joint device having a resistance device that applies a resistance to pivoting about the pivot axis, provides for the spring adapter to comprise at least one compression spring element, bending spring element, tension spring element or torsion spring element, which is tensioned, that is to say compressed, bent, pulled or twisted depending on the design of the spring element, when the upper part is pivoted relative to the lower part. By means of the spring adapter, which is designed as a parallel-elastic element in relation to the remaining components of the joint device, it is possible to extend the functionality of the conventional prostheses or orthoses, in particular for sporting activities such as skiing or the like, such that the additional arrangement of the spring adapter on the orthopedic joint device can increase the range of use of the orthopedic device for the respective user in cost-effective fashion. At the same time, the orthopedic joint device remains unchanged for daily care, and so it is possible to realize a cost-effective use situation that is advantageous for the patient.
The spring adapter may comprise a distal abutment portion and a proximal abutment portion which in the assembled state abut or at least in the case of compression abut against distal and proximal abutment regions of the joint device and/or the resistance device. Preferably, the abutment portions abut against the abutment regions during the whole use of the joint device and the spring adapter and the whole scope of use of the joint device, in order to avoid play, jerky engagement or bothersome rattling noises.
The spring adapter may comprise at least one tube spring, helical spring, air spring, Belleville washer, Belleville washer assembly and/or an elastomer element in order to provide the additional spring force required in each case. As a result, it is possible to provide sufficient resistance to an extraordinary and elevated load which is in the range of non-daily use.
The abutment portion, by means of which the spring adapter can be secured between two movable components, can be formed as part of the spring element. Alternatively, the respective abutment portion can be fastened to the spring element. The spring element, for example the compression spring element or the spring adapter, is arranged between two movable components of the orthopedic joint device, for example between the upper part and the lower part or in the region of the resistance device between a housing of the resistance device and the upper part or a receptacle, for example on a piston rod, if the resistance device is designed as a hydraulic linear damper. The spring element or the entire spring adapter can be assembled and removed by the respective user of the system. Elastomer elements in particular may consist of different materials and may be put together to form stacks of elastomer elements in order to produce different characteristics. By way of example, it is possible to form elastomer elements as annular disks which are slotted in the radial direction, are stacked one above the other and, for example, can be arranged around the piston rod or another guide. Different elasticity properties and stiffnesses of different elastomer disks facilitate a simple adjustment and variation of the characteristic of the compression spring element or of the spring adapter by way of a suitable composition of the respective disk assemblies.
The abutment portion may comprise a holding device for securing it to the abutment region or the joint device in interlocking fashion, for example to prevent twisting, displacing or tilting of the compression spring element or of the entire spring adapter relative to the remaining components of the joint device. By way of example, the holding device may be in the form of an undercut, a cone, a peg or a projection, which is formed in a corresponding projection or in a corresponding recess on or in the holding region.
Advantageously, the spring adapter is secured to the joint device and/or the resistance device and in interchangeable, and hence removable and re-applicable, fashion. As a result, it is possible to match the spring characteristic or the spring stiffness to the respective requirements or needs by using the suitable spring adapter.
The resistance device may comprise a housing, for example a damper housing, in which a piston divides a fluid chamber or a cylinder into a flexion chamber and an extension chamber. If the resistance device is in the form of a hydraulic linear damper, it has a piston rod that protrudes out of the damper housing. The spring adapter comprises a fastening device for securing it to the joint device and/or the resistance device, for example to the piston rod. If the spring adapter is arranged at the piston rod, the spring adapter and the compression spring or a plurality of compression spring elements are firstly assigned to the components movable relative to one another and are secondly guided and affixed such that stabilization of the entire spring adapter is achieved.
A plurality of compression springs may be arranged around the piston rod, for example be arranged around the latter in symmetric fashion or else with different spacings therebetween or be applied next to the piston rod with an axial offset. It is likewise possible for the compression spring element or for a plurality of compression spring elements to be arranged coaxially around the piston rod such that the piston rod is surrounded over at least some of its perimeter by the spring element, the spring elements or the spring adapter. The piston rod is then at least partly received by the compression spring elements surrounding it.
The fastening device for securing the spring adapter to the piston rod is preferably designed for reversibly securing the spring adapter to the piston rod in interlocking fashion and may for example have resilient components that allow the spring adapter or the compression spring elements to be secured while applying an elastic peripheral force at the piston rod or between the upper part and the damper housing. Hinges or clip-on devices may be arranged or formed to interchange the spring adapter or individual spring elements and fasten these to the piston rod.
A development of the invention provides for a plurality of individual springs to be arranged in the compression spring element and connected in parallel. The individual springs themselves may consist of series-connected individual spring components, for example elastomer disks or the like. The individual springs connected in parallel may have different spring characteristics and/or different engagement points for forming a gradated spring behavior. Thus, it is possible that initially a comparatively soft spring engages from the outset and a stiffer spring or a plurality of stiffer springs is or are compressed after a predetermined displacement travel has been reached in order thus to be able to provide a progressive overall spring characteristic.
As an alternative to or complementing the individual springs connected in parallel, the spring adapter may comprise at least one spring element with different spring stiffnesses connected in series in order to provide a resistance that varies over the deformation travel.
The resistance device may comprise a hydraulic and/or pneumatic damper, the orthopedic joint device being designed in particular as an orthosis joint or prosthesis joint, more particularly as an artificial knee joint.
The spring adapter may have an adjustable form, for example by virtue of displacing the spring characteristic by changing the pretension or by displacing the zero point. Likewise, the stiffness may be designed to be variable, for example by replacing spring elements or by virtue of varying the spring length and/or stiffness by way of an adjustment element or spacer.
The invention likewise relates to a spring adapter for detachable fastening to a resistance device, as explained above. Encapsulating a plurality of compression spring components or compression spring elements in a housing may be advantageous. Different forms may be realized when embodying the spring adapter or the compression spring elements or torsion spring elements as elastomer elements, as a result of which the frequently limited installation volume can be optimally utilized. By way of example, the compression spring elements or the spring adapter may have a U-shaped design, the open sections of the U-shaped compression spring elements optionally being arranged so as to be twisted in relation to one another in the case of elastomer components stacked one above the other, in order to obtain a uniform load and prevent a tilting moment. The characteristics of the spring elements are selectable according to the application; they may be linear, and degressive or progressive.
An identification device which is coupled to the resistance device can be arranged on the spring adapter and/or the joint device. By way of example, the identification device may be an RFID chip or a sensor or a contact, which is closed after the spring adapter is attached. There can be a modified damping behavior of the resistance device as soon as the spring adapter being arranged on the orthopedic joint device is recognized automatically. By way of example, in the case of an electronically controlled, adjustable resistance device, an appropriate program may be saved in the control unit, the program bringing about a stronger or angle-dependently adapted damping or another type of adjustment of the resistances. The identification device facilitates an automatic adjustment of the damper behavior to the additional spring elements, or else a return to the basic setting after the spring adapter has been removed.
In addition to an elastic behavior of the spring adapter or the spring elements, it is also possible to set a speed-proportional behavior by way of the viscous properties of viscous elements or of a hydraulic fluid.
Attachment to structures already present in the joint device can be achieved by removable spindles, by an interlocking fit or by clamping on components that are already present.
Exemplary embodiments of the invention are explained in more detail below on the basis of the attached drawings, in which:
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Abutment regions 31, 32 are arranged or formed on the resistance device 30 as abutment faces, with a spring adapter 10 being arranged therebetween. A distal abutment face 32 is arranged or formed in the region of the housing 35, on a damper housing of a hydraulic damper in the present case, and a proximal abutment face 31 is fastened to or formed on the proximal end of the piston rod 34. The two abutment faces 31, 32 serve to absorb forces that occur during a compression or relaxation of the spring adapter 10. In the exemplary embodiment illustrated, the spring adapter 10 comprises a compression spring 15 in the form of a helical spring or spiral coil spring, but other compression spring types may likewise be provided, for example elastomer elements or the like. In this case, it is not necessary for the spring adapter to also abut against the two abutment surfaces 31, 32 in the maximally extended state and exert a pressure force in the extension direction. There also is the option, for example for skiing, of the spring adapter 10 only being compressed after a certain angle position has been reached in the case of a flexed joint. By way of example, the spring element 15 arranged in the spring adapter 10 may only be in a neutral position at a flexion angle of 15° and only be compressed in the case of further flexion. A tensile load would be exerted between the upper part 21 and the lower part 22, up to the adjustable angle of the neutral position, by way of the resistance device 30 and the spring adapter 10. Then, the spring adapter 10 would be arranged between the abutment regions 31, 32 in tensile force-transmitting and compression force-transmitting fashion.
Instead of having a single compression spring 15, it is possible that a plurality spring elements form the spring adapter 10 or are part of the spring adapter 10. Different spring types may be combined in mixed fashion in a spring adapter 10, for example a plurality of helical springs or a helical spring in combination with one or more Belleville washers or an elastomer element. The spring adapter 10 is designed to be detachably securable to the resistance device 30 in easily replaceable fashion, preferably in a way that avoids having to separate the resistance device 30 from the joint device 20.
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Number | Date | Country | Kind |
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10 2019 121 797.0 | Aug 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/072444 | 8/11/2020 | WO |