Orthopaedic joint device and method for controlling same

Abstract

The invention relates to an orthopaedic joint device having an upper part (10) and a lower part (20) which are mounted on one another so as to be pivotable about a pivot axis (15) with respect to one another, and having a passive resistance device (30) which is arranged between the upper part (10) and the lower part (20) and is designed to provide resistance to pivoting of the upper part (10) relative to the lower part (20), wherein a motor drive (60) is arranged between the upper part (10) and the lower part (20) and is configured to bring about, support or prevent pivoting of the upper part (10) relative to the lower part (20).

Description

[0001] Orthopaedic joint device and method for its control

[0002] The invention relates to an orthopedic joint device comprising an upper part and a lower part, which are mounted relative to one another so as to be pivotable about a pivot axis, and a hydraulic damper arranged between the upper part and the lower part. The hydraulic damper is designed to provide resistance to pivoting of the upper part relative to the lower part and has a housing with a cylinder in which a piston is displaceably mounted and divides the cylinder into two chambers, between which at least one fluidic connection is formed, in which at least one adjustable valve is arranged. The invention also relates to a method for controlling such an orthopedic joint device.

[0003] Orthopedic joint devices include, in particular, orthoses, exoskeletons, or prostheses, which have an upper part and a lower part articulated to it. In orthoses and exoskeletons, the upper and lower parts are attached to an existing limb, for example, by shells, belts, straps, cuffs, or other fastening devices. Orthoses and exoskeletons can guide movements, limit pivoting around a joint axis, prevent pivoting movements, or support or fix the alignment of limbs. In addition, orthoses can be provided with damping devices to dampen pivoting movements around the joint axis. The damping devices can be equipped with a control system so that, depending on sensor data, changed damping can be provided in the flexion and / or extension directions. It is also known to attach energy storage devices to the upper or lower parts.to be assigned to the lower part so that movement support can be achieved by releasing the stored energy from the energy storage device.

[0004] Prostheses replace a missing or no longer existing limb and serve to provide functionality that is as close as possible to that of the natural limb. In addition, prostheses serve to provide the most natural appearance possible for the prosthetic user. A prosthetic upper part is designed, for example, as a prosthetic socket or as a component attached to a prosthetic socket, where the prosthetic socket serves to secure it to a limb or limb stump. The prosthetic joint, for example a prosthetic knee joint, a prosthetic ankle joint or a prosthetic elbow joint, connects the upper part to a lower part, which in turn may have further prosthetic components, such as a lower leg tube, a prosthetic foot or a prosthetic hand.

[0005] Particularly in orthoses, exoskeletons, and prostheses of the lower extremities, but also of the upper extremities, dampers, especially hydraulic dampers or other resistance devices, are arranged between the upper and lower parts. These dampers provide different resistances in individual states or movement situations based on sensor data. Such resistance devices are often designed as linear actuators that provide a defined resistance to a flexion and / or extension movement. The resistance is changed by changing the position of valves. When the flow cross-section is reduced, the corresponding resistance to a movement increases. Such control valves, which are used, for example, for stance phase damping, can be adjusted mechatronically via servo valves or mechanically via a throttle valve.

[0006] Furthermore, orthoses, exoskeletons, and prostheses with motor drives are known from the state of the art, so-called active orthoses or prostheses, in which a movement is initiated, supported, or decelerated by activating, modulating, or modulating the drive. For this purpose, stored electrical energy from a battery and an accumulator is converted into the actuator. The motor drives also serve to influence the movement behavior between the components of the orthosis or prosthesis within the framework of a generator circuit, for example, to decelerate a pivoting movement. Proportional valves are used to change the resistance in a hydraulic damper, which influence movements in the flexion and / or extension directions.Proportional valves are expensive to manufacture, require their own actuator, gearbox, brake and valve body, and require increased maintenance.

[0007] The object of the present invention is to provide an orthopaedic joint device and a method for controlling the same, with which the orthopaedic joint device can be operated simply, permanently and cost-effectively.

[0008] This object is achieved by an orthopedic joint device having the features of the main claim and a method for controlling such an orthopedic joint device having the features of the independent claim. Advantageous embodiments and further developments of the invention are disclosed in the dependent claims, the description, and the figures.

[0009] The orthopedic joint device with an upper part and a lower part, which are mounted on one another so as to be pivotable about a pivot axis, and with a passive resistance device arranged between the upper part and the lower part, wherein the resistance device is designed to provide resistance against pivoting of the upper part relative to the lower part, provides that the valve is designed as a switching valve with at least two switching positions, wherein at least one switching position is a partially open switching position and a motor drive is arranged between the upper part and the lower part, which motor drive is designed to effect, assist, or hinder pivoting of the upper part relative to the lower part. In purely passive orthopedic joint devices, the relative movement of the upper part and lower part is influenced by converting kinetic energy into thermal energy.In order to adapt the influence to the respective movement behavior or movement pattern, the valve must be designed as a proportional valve and a comparatively complex control system with a servomotor for each valve is required. Active orthopedic joint devices with a motor solely for influencing relative movement require a large motor or large gears to fully and independently absorb the resulting forces. The claimed orthopedic device makes it possible to significantly simplify the complex structure of purely passive dampers or purely active actuators for orthopedic joint devices, without sacrificing the ability to respond precisely and appropriately to the respective movement situations or conditions.To allow modification of the pivoting resistance provided by the resistance device, a motor drive is assigned to the orthopedic joint device or connected to it to influence the pivoting movement. The motor drive can be activated at specific times or in specific states or positions, either as a drive to introduce additional energy into the movement, or as a brake to convert kinetic energy into heat energy or electrical energy in generator operation. If the motor drive is activated as a drive, the existing movement can be supported or used to counteract the movement. It is also possible to move one of the components of the orthopedic joint device from a static state.In either case, an additional torque is generated in the joint, either a driving or a braking or damping torque. The motor drive allows for fine adjustment of the damping behavior of the hydraulic damper, which can be designed as a linear damper or a rotary damper.

[0010] In one embodiment, the resistance device has a housing with a cylinder in which a piston is displaceably mounted and divides the cylinder into two chambers, between which at least one fluidic connection is formed, in which at least one valve, in particular an adjustable valve, is arranged. In one embodiment, the valve is designed as a switching valve with at least two switching positions, wherein at least one switching position is a partially open switching position. A partially open switching position is in particular a switching position that deviates from a fully open or fully closed switching position. The switching valve or switching valves switch between a plurality of discrete states, at least between two switching positions, for example fully open or fully closed and into a partially open or partially closed switching position.This is achieved, for example, by shifting or simply switching between the respective positions, for example, by activating a coil, without the need for motors. This makes it possible to lock the orthopedic joint device against flexion and extension in a fully closed position and to set a frequently required movement resistance in a partially open switching position. To allow modification of the corresponding resistance around this pivoting resistance, the motor drive of the orthopedic joint device is assigned to or connected to it to influence the pivoting movement.

[0011] In one embodiment, the valve is designed as a multi-way valve with a closed switching position, an open switching position, and at least one partially open switching position. In one embodiment of the multi-way valve as a 3-way valve, the hydraulic damper can be moved along with a pivoting movement in the open switching position essentially without damping, so that a negligible resistance moment is generated in the joint. In this switching position, the orthopedic joint device is operated as an active joint when the actuator is activated to exert a moment in the joint, either as a drive or as a brake. In the fully locked switching position, a relative displacement from the upper part to the lower part is not possible.In the partially open switching position, which can be adjustable in terms of the degree of opening, the actuator counteracts or supports the damping by the hydraulic damper when operated accordingly.

[0012] In one embodiment, the partially open switching position is reduced by 50% compared to the fully open switching position in terms of flow cross-section, so that an average damping between a fully open and fully closed state is present. The movement behavior is then changed around this middle position via the actuator. The flow cross-section can be adapted to the respective application or the respective user. If, for example, experience shows that a certain damping torque or a certain damping force must be applied very frequently, for example a certain high damping against flexion in an artificial knee joint, a corresponding reduction of the flow cross-section can be provided for the partially open switching position. If predominantly low damping or resistance is required by the resistance device, e.g.If a hydraulic damper is to be installed, it is advisable to increase the flow cross-section or the control variable accordingly and to set it to the value that is expected to be used most frequently.

[0013] In one embodiment, each chamber of the resistance device is assigned a valve, allowing the movement behavior to be influenced accordingly for both an extension movement and a flexion movement when the lower part is pivoted relative to the upper part. With three switching positions for each switching valve, no resistance, fixed damping, and a blocked resistance device can be provided for each direction of movement in conjunction with the respective actuator activities. This makes it possible to easily provide a wide range of adjustments for damping or supporting movements, regardless of the direction of movement.

[0014] In one embodiment of the orthopedic joint device, a parallel check valve is assigned to the valve or each valve, ensuring that even in a closed or only partially open position, hydraulic fluid can flow back when the movement is reversed. This avoids complex switching processes to ensure uninterrupted return flow of the hydraulic fluid when the movement is reversed.

[0015] In one embodiment, a switching valve with a different open switching position is provided for each chamber in order to be able to provide adaptation to the different standard values ​​of a hydraulic resistance for the corresponding direction of movement.

[0016] In one embodiment, the resistance device is designed as a hydraulic damper, pneumatic damper, magnetorheological damper, dissipative brake, or barrier. With hydraulic dampers as a resistance device, the change in the resistance provided is achieved by changing the flow cross-section at at least one point in the fluid flow, in particular by switching valves. With a direction-dependent flow resistance, a check valve can be arranged parallel to a static or adjustable throttle, so that there is a higher resistance in one flow direction than in the opposite direction. With pneumatic dampers, the compressibility of the medium results in a storage effect that can be exploited to control the movement, for example, to supply energy to a moving component during a swing phase.In magnetorheological resistance devices, the change in resistance is caused by changing the viscosity of the hydraulic fluid by applying or changing a magnetic field. Changing or switching a magnetic field occurs relatively quickly, so the change in resistance can be modified by the resistance device by supplementing or superimposing forces or torques from the drive. Other dissipative brakes, such as brakes or locks based on solid-state friction, which can be easily switched between two states, can also be supplemented by a drive. The problem of heat generation can be reduced by using a drive in generator mode, where the work performed is recuperated and stored in an energy storage device.

[0017] The resistance device, regardless of whether it is designed as a damper, brake, or lock, can be either linearly acting or rotary. Linearly acting resistance devices, in particular, comprise rods such as push rods, gear racks, or piston rods that transmit forces or are locked or braked in their respective positions. Rotary resistance devices include, for example, rotating brakes such as disc brakes or drum brakes, rotary hydraulics or rotary pneumatics with a rotary piston, or the like.

[0018] In one embodiment, the drive is designed as an electric motor that is coupled to the upper or lower part directly or via a gear mechanism. The gear mechanism makes it possible to generate comparatively large moments in the joint around the pivot axis, even with small motors, in order to influence the relative movement between the upper and lower parts or to displace the upper part relative to the upper part. Gear drives, belt drives, spindle drives, friction gears, or combinations thereof can be used as gear mechanisms. Direct coupling of the drive to the upper or lower part saves weight and space and is always advantageous when the drive can achieve the desired operating parameters without transmissions or reductions.

[0019] In one embodiment, a controller is associated with the drive and / or the resistance device, which controller has a data processing device for processing sensor data. The data management device has the necessary components, for example a microprocessor, a memory device, an integrated circuit, or the like, and is coupled to a power supply that enables the controller as a component to process and / or store data. The controller is coupled to at least one sensor and is configured to activate, deactivate, and / or modulate the drive and / or the resistance device based on the sensor values. The controller as a component has interfaces via which the controller is supplied with data from the sensors. The interfaces can be wireless or wired, for example as a transmitter-receiver device or as a plug or permanent contact.The sensors can be connected to the controller wirelessly or wired.

[0020] A further development provides for the resistance device and the drive to be designed as a modular unit and secured together at the mounting points on the upper and lower sections, respectively. The resistance device and the drive can have separate housings to increase the surface area available for heat exchange with the environment. This allows for increased thermal capacities and improved thermal performance of the overall system.

[0021] In one embodiment, an energy storage device is arranged parallel or serially to the resistance device and / or the drive, wherein the energy storage device can in particular support the drive or counteract the drive in order to influence the movement behavior of the orthopedic joint device as desired. If the drive is supported or its direction of action is counteracted, for example by unlocking the energy storage device and releasing the energy stored therein, this generally leads to a rapid release of the energy stored in the energy storage device, so that the resistance device can be influenced very quickly by a combination of drive and energy storage device. Thus, fast switching times when changing the resistance are achieved by releasing an energy storage device in a supporting or counteracting direction.

[0022] The method for controlling an orthopedic joint device, as described above, provides that the drive for influencing the resistance is operated in parallel with the resistance device, in particular a hydraulic damper, a magnetorheological resistance device, a brake or a lock. To avoid unnecessary energy consumption, in a hydraulic design of the resistance device with a switching valve, the drive is only activated and / or modulated in the partially open switching position or in the fully open switching position. Operating a drive when the resistance device is fully activated, i.e. when the resistance device is locked, makes little technical sense; however, to increase the maximum resistance provided, the drive can be activated or modulated accordingly against the displacement.This can, for example, increase leakage losses or design-related maximum resistances that can be provided by the passive resistance device. In one embodiment, the drive is activated, deactivated, and / or modulated based on sensor data in order to be able to change the movement behavior of the upper part relative to the lower part during use.

[0023] In one embodiment, the drive is operated in a generator mode to increase the resistance, with the resulting electrical energy being stored in an accumulator. This reduces heat generation by the passive resistance device and extends the operating life of the orthopedic device.

[0024] In one embodiment, the resistance is varied depending on the drive speed in generator mode, since electromechanical drives have the property that the energy recovery capability depends on the speed and the required braking torque. The resistance and the drive are then controlled in such a way that the resistance torque provided by the resistance device is adjusted according to the optimal operating point for recuperation, depending on the drive speed.

[0025] In one embodiment, the resistance device is switched between two discrete states, wherein the drive for influencing the resistance device is activated, deactivated, or modulated before and / or after switching. When switching between two states, in particular discrete states, a sudden or very rapid change in properties occurs, in particular the resistance. Such a sudden increase or decrease is not desired in many cases; rather, a controlled transition between the states is frequently desired. To compensate for or reduce possible sudden changes, the drive is activated, deactivated, or modulated before and after switching so that a smooth transition of the resistance curve can be achieved.

[0026] Particularly when the resistance device is designed as a linearly acting resistance device, for example, as a linear damper, the transmission ratio between the resistance of the resistance device and the generated torque about the pivot axis is not constant, but depends on the current configuration, in particular the pivot angle. To compensate for or amplify this change in the transmission ratio, the drive for influencing the resistance is activated, deactivated, or modulated depending on the pivot angle.

[0027] In one embodiment, the drive continuously influences the resistance or pivoting movement of the orthopedic joint device, in particular over the entire duration of use of the resistance device. The drive can counteract the resistance device, i.e., support a movement, or support the resistance device, i.e., in addition to the resistance device, decelerate or prevent a pivoting movement. In one embodiment, the resistance device is set to a maximum resistance; in particular, the pivoting movement from the upper part to the lower part is blocked, in particular mechanically or hydraulically, and the drive is then deactivated to prevent energy consumption.

[0028] Exemplary embodiments of the invention are explained in more detail below with reference to the attached figures. They show:

[0029] Figure 1 - a schematic representation of a prosthetic leg;

[0030] Figure 2 - an embodiment of a hydraulic circuit diagram;

[0031] Figure 3 - a histogram for flexion damping and extension damping;

[0032] Figure 4 - the histogram with modulation ranges of the drive; and

[0033] Figure 5 - Variants with orthoses;

[0034] Figure 6 - a moment curve over time;

[0035] Figure 7 - a representation of the modulation of discrete states;

[0036] Figure 8 - a representation of faster switching times;

[0037] Figure 9 - a representation of increased dynamics;

[0038] Figure 10 - a representation of increased spread;

[0039] Figure 11 - a barrier with resistance device and drive;

[0040] Figure 12 - a compensation of the gear ratio change;

[0041] Figure 13 - an energy dissipation;

[0042] Figure 14 - an energy recuperation;

[0043] Figure 15 - various control and regulation structures

[0044] Figure 16 - Representations of a variant of the joint device;

[0045] Figure 17 - a detailed view of an energy storage device;

[0046] Figure 18 - a design of a progressive energy storage device; and Figure 19 - a detailed view of an energy storage device.

[0047] Figure 1 shows a schematic representation of an orthopedic joint device as part of a prosthetic leg with a femoral shaft as the upper part 10 and a lower leg part as the lower part 20. The upper part 10 and the lower part 20 are pivotally attached to one another about a pivot axis 15. A prosthetic foot is arranged on the lower leg part. Between the upper part 10 and the lower part 20, a resistance device 30 in the form of a schematically illustrated hydraulic damper 30 is arranged, which provides or can provide resistance to pivoting in both the extension direction and the flexion direction. In the illustrated embodiment, the resistance device 30 or the hydraulic damper 30 is designed as a linear damper and has a housing 32 in which a cylinder 34 is formed.Within the cylinder 34, a piston 36 is arranged on a piston rod 33 and divides the cylinder 34 into two chambers. A fluid connection is formed between the chambers, which will be explained in more detail later. The hydraulic damper 30 is mechanically coupled to the upper part 10 at its proximal end on the piston rod 33 via a first fastening point 31. The housing 32 is fastened to the lower part 20 at the distal end of the hydraulic damper 34 via a second fastening point 37. The flow resistance within the hydraulic connection between the two chambers is adjustable when the piston 36 moves within the cylinder 34 in order to dampen the movement in a way that is adapted to the respective situation.Additionally, a drive 60 is arranged between the upper part 10 and the lower part 20, which drive is designed and configured to effect, assist, or hinder a pivoting of the upper part 10 relative to the lower part 20. This occurs, for example, in that the drive 60, in the form of an electric motor, applies a torque to the orthopedic joint device via a gear 70 in order to move the lower part 20 in the extension direction, for example, during the swing phase. All other support or influencing of states or movement situations between the upper part 10 and the lower part 20 can also be influenced via the drive 60 with the motor and the gear 70.Both components of the orthopedic joint device that influence the movement, i.e., the hydraulic damper 30 and the drive 60, act simultaneously or can act simultaneously and in parallel between the upper part 10 and the lower part 20 to apply a moment about the pivot axis 15. Instead of a linear damper, the hydraulic damper can also be designed as a rotary hydraulic system.

[0048] As an alternative to the design of the orthopedic joint device as a component in a prosthetic leg, Figure 5 shows two applications in which the orthopedic joint device is designed as part of an orthosis. The exemplary embodiments in Figure 5 show a first orthosis for the upper extremity in the form of an elbow orthosis and a second orthosis for the lower extremity in the form of a knee orthosis. Not all components are shown on the elbow orthosis, but all components are also present there. Each orthosis has an upper part 10 and a lower part 20, which is secured to the respective body part via fastening devices 19, 29, for example in the form of cuffs, shells, straps or similar fastening devices or combinations thereof.For the elbow orthosis, the attachment is made to the upper arm and forearm; for the knee orthosis, the attachment is made via thigh cuffs 19 and lower leg cuffs 29. The knee orthosis illustrates that the hydraulic damper 30, like the drive 60, operates around the pivot axis 15. The hydraulic damper 30 is again attached to the upper part 10 by one end of the piston rod and to the lower part 20 by the housing part. Furthermore, sensors 80 are arranged on or associated with the upper part 10 and the lower part 20, which are connected to a control device 90. The connection can be made either by wire, radio, or another type of signal transmission. The control device 90 is coupled to the drive 60 and the hydraulic damper 30 and enables activation, deactivation, or modulation of the drive 60, as well as adjustment of valves within the hydraulic damper 30.The control device 90 includes all necessary data processing devices, memory, software, hardware, interfaces, and a power supply to control or regulate both the drive 60 and the hydraulic damper 30. The drive 60 can be supplied with the necessary electrical energy via an additional energy storage device in the form of a battery or accumulator. The drive 60 can be operated both as a motor and as a generator, for example, to convert the kinetic energy back into electrical energy when additional braking power is required or when the resistance to pivoting increases.In the illustrated embodiment, a force accumulator 65 is arranged in series with the resistance device 30 to release energy stored therein, for example, in a spring or a pneumatic pressure accumulator, based on sensor values ​​transmitted to the control device 90. The release of energy from the force accumulator 65 can support or counteract the influence of the drive 60 on the movement behavior, thereby increasing the speed at which the resistance behavior can be influenced. The spontaneous release of stored energy from a force accumulator 65 can achieve very fast reaction times or switching times. The sensors 80 can be force sensors, torque sensors, position sensors, pressure sensors, high-temperature sensors, and IMUs. Multiple sensors can be arranged on both the upper part 10 and the lower part 20.Based on the transmitted sensor values, the corresponding switching commands are then issued by the controller 90.

[0049] Figure 2 shows a hydraulic circuit diagram of the hydraulic damper 30, with a housing 32 that forms or accommodates a cylinder 34. The cylinder 34 is divided by the piston 36 into a first chamber 341 and a second chamber 342. A hydraulic connection 40 in the form of flow channels is arranged between the two chambers 341, 342, so that hydraulic fluid flows from the first chamber 341 into the second chamber 342 when the piston 36 is pressed downward, for example during flexion. Conversely, hydraulic fluid from the second chamber 342 is conducted through the fluid connection 40 into the first chamber 341 when an extension movement occurs.Due to the volume difference between the displacement in the first chamber 341 in relation to the second chamber 342 due to the piston rod 33 located in the second chamber 342, a compensation volume 38 is arranged in the hydraulic damper 30 or coupled thereto.

[0050] Two adjustable valves 50 in the form of switching valves are arranged within the fluid connection 40. Each chamber 341, 342 is assigned a switching valve 50. A check valve 55 is arranged parallel to each switching valve 50 as a bypass in the fluid connection 40. With two check valves 55, one of which is assigned to each chamber 341, 342, the two check valves 55 are arranged to act in opposite directions. Both check valves 55 allow hydraulic fluid to flow into the respective chamber 341, 342, but block flow in the opposite direction, so that the hydraulic fluid exiting from the chamber 341, 342 must be directed through the switching valve 50. In the illustrated embodiment, the switching valves 50 are designed as 3-way switching valves that can be switched between three discrete states.In the illustrated switching state, the fluidic connection 40 is interrupted, meaning that no hydraulic fluid can flow from one chamber 341 into the other chamber 342. The prosthetic knee joint or the orthopedic joint device is locked in this position.

[0051] A throttle 56 is arranged upstream of the respective switching valve 50 in the direction of flow from the chamber, which, for example, halves the flow cross-section or reduces it to the desired value. The throttle cross-section is preferably adjustable. A flow channel with a maximum or fully open flow cross-section is provided parallel to this throttle 56 and leads to the switching valve 50. If the switching valve 50 is moved downward from the illustrated interrupted and thus blocked position, which can be done by an electromagnet or another actuator or drive, the line not subjected to the throttle 56 is supplied with hydraulic fluid and can pass the hydraulic fluid through unhindered during an extension movement in which the piston 36 is moved upward.

[0052] If the switching valve 50 is moved upward from the illustrated locked position, hydraulic fluid from the second chamber 342 must first pass through the upstream throttle 56 and then through the check valve 55 into the first chamber 341. In this position, there is increased flow resistance, so that the pivoting movement in the extension direction is dampened. The switching valve 50 assigned to the first chamber 341 is connected accordingly for the flexion movement.

[0053] The adjustment or displacement of the switching valves 50 is carried out sensor-based via the controller 90. Based on the sensor data of the sensors 80, the respective actuator for the switching valve 50 is activated or deactivated and the corresponding switching position is assumed.

[0054] If the one-time reduction in flow cross-section provided by the throttle 56 is insufficient or too great to provide the desired or required resistance, the drive 60 is activated, so that an additional torque is applied via the motor and, if applicable, the gearbox, which either counteracts or supports the movement to increase or decrease the resistance. The activation of the motor 60 is also carried out via the controller 90 based on sensor values ​​and control programs and software stored in the controller 90.

[0055] Figure 3 shows an example frequency distribution for flexion damping (upper image) and extension damping (lower image) for a prosthetic knee joint. For flexion damping, the most required damping values ​​were found in a fully open position with a damping value of 0, for a medium damping value of 80, and very high values ​​were found for high damping values ​​between 140 and 200. For extension damping, a cluster of damping values ​​occurs at a damping value of 0 and for very high damping values ​​above 160.

[0056] Figure 4 shows the damping value setting for such a frequency distribution using the three fixed hydraulic damping values. The open and closed switching positions of the switching valve 50 are responsible for the maximum and minimum damping values. For flexion damping, the partially closed flow cross-section was set to a fixed damping value of 165 via the partially open switching position, and for extension damping, to a value of 155. The required damping values ​​for flexion damping from 75 to just before the maximum damping value of 200 are adjusted by activating the motor drive 60. If the damping value for flexion damping is reduced, the drive 60 is activated to provide support when the joint is flexed, thereby reducing the flexion resistance to the desired value.If the flexion damping is insufficient via the partially open switching position with the throttle 56, an additional braking torque is applied via the drive 60 to increase the flexion resistance to the desired value. The damping range covered for the combined use of the hydraulic damper 30 with the partially open switching position and the actuator 60 is shown as a dark box. The same applies to the extension damping as stated for flexion damping. Due to the other required damping values, the extension damping is primarily increased to cover the range between the two fixed hydraulic dampers by the throttle 56 and the fully closed position of the switching valve 50.

[0057] Figure 6 shows the torque curve M of a resistance torque or drive torque over time t, with the torque MR being generated by the resistance device 30 (not shown) in two or more discrete states. Between the discrete states, there is a sudden or very rapid change in the properties, for example, a torque increase or decrease. This is the case, for example, with a switching valve that switches back and forth between two positions. Such a sudden increase is not advantageous in many cases. Rather, it is advantageous to achieve a slower, particularly controlled change between the two or more states.

[0058] Accordingly, the torque MR generated by the resistance device is superimposed on the torque MA of the drive 60, so that the resulting total torque Mz is achieved. In order to generate a desired continuous torque curve Mz between the two torque levels in the interval t0 to t2, the drive 60 generates a positive torque MA in the interval t0 to t1 in order to compensate for the missing torque between MR and Mz, or to increase the resulting total torque. At time t1, the resistance device 30 changes its state, whereupon the torque MR increases relatively quickly. The switching time can occur, for example, when a certain torque MA has been reached by the drive, for example a torque level between the first and the second level. In accordance with the continuous total torque curve Mz to be achieved, the torque MA of the drive is reduced from t1 onwards, and a torque opposite to the resistance device is applied.Subsequently, the drive torque MA is reduced again until no more drive torque is generated at time t2. Before t0 and after t2, the drive is deactivated and therefore requires no energy.

[0059] The resistance device 30 can, for example, be a hydraulic damper with at least one valve that can switch between a free-running and a highly damped state. This very simply constructed hydraulic damper can generate high passive torques with low energy consumption. The drive, for example, serves only to achieve the required continuous transition during a gear change. In this case, the drive only needs to be able to generate half the torque generated by the damper, which allows the drive to be particularly small and lightweight, or with a particularly low gear ratio in the case of a transmission.

[0060] Figure 7 shows the torque curve during the modulation of discrete states. By combining a drive 60 and a resistance device 30, which can switch between at least two discrete states M1 and M2, a resistance device can be constructed particularly inexpensively, simply, and robustly. A parallel arrangement of the resistance device 30 and drive 60 is shown here, so that the respective generated torques are added relative to a pivot axis of the orthopedic device.

[0061] To improve the achievable torque range and thus the functionality of the overall system, a torque MA of the drive is superimposed on the torque MR of the resistance device, resulting in an overall torque curve Mz. The drive can apply a torque MA that is parallel to or opposite to the resistance torque MR, thereby increasing or reducing the overall torque Mz. In particular, the torque MA of the drive can be continuously varied, resulting in a continuously variable overall torque curve Mz. The drive does not have to be designed to cover the entire torque range and can therefore be dimensioned smaller.

[0062] On the left in Figure 7, a state of the resistance device is shown in which a first torque level Mi is generated. The drive generates a continuous, transient torque curve MA, with the drive partly generating a torque in the same direction as the resistance device and partly in the opposite direction, so that the total torque Mz is modulated around the torque level MR of the resistance device. On the right in Figure 7, the modulation around a second state of the resistance device is shown, in which a second torque level M2 is generated by the resistance device. The discrete states of the resistance device and the torques that can be generated by the drive can, for example, be selected such that in total all the torques between the two levels M1, M2 of the resistance device can be achieved.However, it is also possible that modulation by the drive only occurs in certain states of the resistance device, for example only at a low first torque level Mi, which is used for a swing phase.

[0063] The torque MR generated by the resistance device serves as the base level for the total torque Mz, while the drive modulates the torque. For example, the drive can be designed to be particularly small and lightweight, so that it cannot generate the second, higher torque level M2 on its own. The resistance device is therefore used to initially raise the torque to level M2, and the drive modulates the torque MR to achieve the desired total torque Mz.

[0064] Figure 8 illustrates the use of a combination of a drive and a resistance device to achieve faster switching times. When using a resistance device with limited dynamics, response time, or bandwidth, such as a hydraulic system with at least one motor-driven proportional valve, greater dynamics, response time, or bandwidth can be achieved by combining it with a drive.

[0065] In the exemplary embodiment shown, in the event of a setpoint step change to change a torque at time t0, the resistance device requires a period of time until time t2 to reach the setpoint. The rise time can, for example, be composed of a dead time and a maximum rate of change, e.g., due to a manipulated variable limitation. After the setpoint step is applied, a curve of the torque MR generated by the resistance device results until time t2 of the setpoint is reached. Better overall dynamics can be achieved by an additional drive with very high dynamics, bandwidth, or fast response time, which acts, for example, in parallel to the resistance device so that the torques MR and MA generated by the resistance device and by the drive add up to the total torque Mz.For example, the torque of the drive is controlled in such a way that the torque initially increases as quickly as possible, and then the difference between the torque provided by the resistance device and the target torque is generated. Together with the drive, the target torque is already reached at time t1, for example. The rise time is reduced by the combination of the resistance device and the drive compared to the rise time of the resistance device alone. Alternatively or additionally, the maximum rate of change of the torque is increased by the combination of the resistance device and the drive compared to the resistance device alone.Alternatively, the resistance device and the drive can be configured to move to a position, a speed, or even a trajectory. Here, too, the combination of resistance device and drive can easily achieve a faster target value, improved dynamics, or a higher rate of change. In the exemplary embodiment shown, the drive no longer generates any torque after the target torque has been reached by the resistance device and thus requires no energy, which is particularly advantageous. The drive only generates a torque between tO and t2. Alternatively, the drive can also generate a torque before tO and after t2.

[0066] Figure 9 illustrates an increase in the dynamic response of the overall torque curve. The graph shows the resistance moment MR curve of the resistance device over time. The resistance device has limited dynamic response due to its design, for example, a particularly cost-effective, efficient, simple, or robust design. For example, the maximum rate of change of a torque provided by the resistance device is limited. The curve MR already shows, for example, the maximum rate of change of a torque provided by the resistance device.

[0067] In combination with a drive that has particularly high dynamics, improved behavior can be achieved. The torque curve Mz achieved jointly by the resistance device and the drive has, as shown, a significantly higher maximum rate of change. In particular, the drive and the resistance device can act or be arranged in parallel to one another so that the provided torques are added together. In such a configuration, the drive does not have to apply the entire torque Mz, but only the difference between the total torque Mz and the torque MR applied to the resistance device. Generating the torque curve MZ with the resistance device alone would not be possible, since the required curve of the total torque has a rate of change that is too high to be realized by the resistance device in the exemplary embodiment.In order to still be able to cover the desired or required system behavior with the total resistance moment Mz, a drive is used in addition to the resistance device. Compared to the resistance device, this drive can handle rapid torque changes, but is not designed for high continuous loads. Such a drive is generally more cost-effective, lighter, and smaller than a drive that can handle both high continuous loads and rapid torque changes.

[0068] Figure 10 shows the torque curve over the speed v and the increase in the spread achievable by combining a drive with a resistance device. The torque MR that can be generated by the resistance device is provided, for example, by a resistance device with variable resistance, such as a magnetorheological brake or a damper with a magnetorheological valve. By controlling the resistance device, the provided torque can be varied in the range MR.min to MR,max. In the embodiment shown, a speed-dependent component of the resistance is also present, for example viscous friction, whereby the limits MR.min and MR,max change with the pivoting speed v. The maximum torque determines the maximum degree of support or damping, for example when walking down stairs and ramps or when standing.The minimum moment determines the ease of movement against pivoting, which is of great importance for energy-efficient walking and movement.

[0069] In combination with a drive, the torque range that can be generated by the overall system can be increased. For example, an electric motor can be operated in parallel with the resistance device. The drive can act in the same direction as the resistance device, indicated by the magnitude MA+, thereby achieving a higher total torque Mz.max. Alternatively or additionally, the drive can act opposite to the resistance device, indicated by MA-, thereby reducing the total torque Mz.min. In the embodiment shown, the drive applies a torque up to a certain speed that is equal in magnitude to and opposite to the torque of the resistance device at minimum torque, whereby the torques of the resistance device and the drive cancel each other out. The smooth running of the overall system is thus improved. Alternatively, only partial compensation can take place.Alternatively or additionally, the torque opposed by the drive can be greater than the torque of the resistance device, whereby the overall system has a driving effect, in particular performs work. The torque that can be generated by the drive can also depend on the speed. For example, the torque that can be generated by an electric motor decreases with the speed. To reach ranges Mz < MR.min, or even Mz = 0, the drive compensates for the residual resistance MR.min, for example by applying a negative torque MA-. This reduces the mechanical resistance of the overall system and improves smooth running. To reach ranges Mz > MR,max, the drive supplies an additional torque MA+ in order to generate the maximum torque Mz.max, in particular the maximum resistance, of the overall system.

[0070] The adjustment range or torque range of the resistance device is limited, for example, by technological constraints, to MR.min and MR.max. In particular, the resistance device can be designed to be particularly cost-effective, simple, or robust, resulting in a limited range of the available torques MR.min and MR.max. The drive is used to expand this range. The drive can be dimensioned or operated in such a way that the range MA+ to MA- can be covered. This allows for the use of a particularly small, cost-effective drive or enables particularly efficient operation.

[0071] The implementation of a lock consisting of a combination of a drive and a resistance device is shown in Figure 11. The figure shows a curve Mz, which is again composed of the moment of the drive MA and the moment of the passive resistance device MR. The curve of <p zeigt in dem dargestellten Beispiel den Verschwenkwinkel zwischen Oberteil und Unterteil einer orthopädietechnischen Einrichtung mit einem Gelenk, deren Verschwenkbewegung von der Widerstandseinrichtung sowie dem Antrieb beeinflusst werden können. Zu Beginn des dargestellten Verlaufs findet eine Verschwenkung von Oberteil relativ zu dem Unterteil statt, dargestellt durch den zunehmenden Verschwenkwinkel cp. Die Verschwenkbewegung wird dabei durch ein von dem Antrieb aufgebrachten Moment MA beeinflusst und in der dargestellten Bewegung bis zum Zeitpunkt tO abgestoppt.For example, an electric motor in an artificial knee joint can apply a knee-extending moment and counteract a flexion movement, or it can support an extension movement and thereby stop a flexion movement during a braking step. After the movement is stopped at time t0, the moment MR applied by the resistance device is increased and the moment MA of the drive is reduced. The moment of the resistance device can also be increased in such a way that the resistance device blocks the pivoting movement, for example by activating a brake or a lock or by closing a valve in a hydraulic damper. When the moment MA of the drive is reduced, the load is completely taken over by the resistance device. The drive can also be completely deactivated after the moment of the resistance device has been increased or after the pivoting movement has been blocked.In the illustrated embodiment, the resistance device and the drive act in parallel. At time t0, the resistance device activates a lock on the pivoting movement, for example, by closing a valve in a hydraulic damper configuration. Subsequently, the torque MA of the drive, which is configured, for example, as an electric motor, is reduced, thereby absorbing the load by the resistance device. To maintain the angle <p muss das Gesamtmoment Mz aufgewendet werden. Zum Aufbringen dieses Haltemoment im statischen Fall benötigt ein elektrischer Antrieb Energie. Eine passive Widerstandseinrichtung, wie z.B. ein Hydraulikdämpfer oder eine mechanische Sperre oder Bremse, benötigt für diesen Lastfall weitaus weniger oder keine Energie.When the load changes, the total moment Mz is absorbed by the resistance device without any pivoting movement occurring between the upper and lower parts. As an alternative to a rigid lock, it is possible to arrange an elastic element between the upper and lower parts, for example a spring as part of the resistance device. The elastic element can, for example, be switched on and off. In particular, the elastic element can be switched on at time tO, if necessary with appropriate preload, and takes over the total moment Mz after the torque of the drive has been reduced. In such a case, the upper and lower parts are not locked to one another, but movement is permitted according to the properties of the elastic element, for example flexion against an increasing spring force.When the resistance device completely absorbs the load, the drive can be deactivated, meaning no energy is required for the drive. However, the entire system can still be loaded, for example, for standing. A combination of a lock and an elastic element can also be implemented, allowing pivoting only to a certain extent, and beyond this, a lock or stop is activated.

[0072] Figure 12 illustrates the possibility of compensating for a change in gear ratio when combining a drive with a resistance device. In one embodiment of the resistance device as a linear actuator, for example as linear hydraulics or as a spindle drive, the linear movement of the resistance device, for example in a 3- or 4-joint kinematics, is converted into a rotational movement about a pivot axis between the upper and lower parts. In such a case, the transmission ratio between the force of the resistance device and the generated moment about the pivot axis is typically not constant, but depends on the current configuration of the kinematics, in particular the pivot angle. In a particularly simple and cost-effective form, a 3-joint kinematics is used. The effective lever arm r, or the transmission ratio, has, for example, the curve shown in Figure 12.Starting from an initial gear ratio at the angle <p0 nimmt das Übersetzungsverhältnis zunächst mit zunehmendem Winkel <p zu und nach Erreichen des maximalen Verhältnisses wieder ab, bis es bei Erreichen des Winkels <p3 zu einer Singularität kommt, bei der im Beispiel einer 3-Gelenks Kinematik alle drei Achsen in einer Linie fluchten. Insbesondere bei großen Winkeln <p kann durch die Widerstandseinrichtung nur ein geringes Moment erzeugt werden. Dargestellt ist mit MR ein beispielhaftes maximales Moment, das durch die Widerstandseinrichtung in Abhängigkeit des Winkels <p bereitgestellt werden kann. Durch den Antrieb kann das Gesamtmoment erhöht werden, beispielsweise wenn der Antrieb parallel zu der Widerstandseinrichtung angeordnet wird. Dies ist vor allen in jenen Verschwenkwinkel-Bereichen sinnvoll, in denen das Übersetzungsverhältnis der Widerstandseinrichtung gering ist.In particular, in a design with a rotary drive whose transmission ratio does not depend on the pivot angle <p abhängt, kann das Gesamtmoment erhöht werden. Wie in der Figur 12 darstellt, ist es zum Beispiel möglich, das Gesamtmoment in einem Bereich konstant zu halten, in dem sich das Übersetzungsverhältnis ändert. In dem dargestellten Ausführungsbeispiel wird das Gesamtmoment MZ im Winkelbereich <p0 bis <p2 durch das zusätzliche Moment des Antriebs konstant gehalten. Bei besonders geringen Übersetzungsverhältnissen der Widerstandseinrichtung, wie im Bereich <p2 bis <p3, ist es bei einem kleinen Antrieb mit geringem Maximalmoment beispielsweise nicht mehr möglich das fehlende Moment der Widerstandseinrichtung vollständig zu kompensieren. Dennoch kann in diesem Bereich ein höheres Moment aufgebracht werden, insbesondere im Bereich des Totpunktes bei <p3, bei dem ohne den Antrieb kein Moment durch die Widerstandseinrichtung aufgebracht werden kann.Such a combination of drive and resistance device allows for movements over a larger pivoting range or at higher pivoting angles, for example, when yielding on ramps and walking down stairs, sitting down, standing up, or even climbing stairs. This makes it possible to both actively support movements and provide resistance.

[0073] Figure 13 shows the power P over time t for a combination of drive and resistance device. The curve shows the total power Pz that is generated or absorbed in a movement sequence in a system, the orthopedic aid with, for example, an orthosis or prosthesis, a resistance device and a drive. The power P is divided between the two components by the combination of resistance device and drive, represented by the components PR and PA. The areas WR and WA represent the amount of energy as integrative variables of the power P. Particularly in movement sequences in which movement is counteracted, energy must be absorbed by the system. In passive resistance devices such as hydraulics, brakes and the like, the work performed on the resistance device is essentially converted into heat energy.The amount of heat that can be released into the environment by the resistance device is limited and usually insufficient, which causes the temperature of the resistance device to rise. Particularly high temperatures can be harmful to resistance devices and lead to damage. This limits the maximum usage time for certain activities, for example. In addition, the released heat cannot be used again. With an additional drive, part of the energy can be absorbed by the drive, in particular recuperated by the drive and converted into electrical energy, e.g. by operating the drive as a generator. It is also possible that the energy absorbed by the drive is partially or completely converted into heat energy. By arranging the resistance device and drive accordingly, better heat dissipation or slower heating can be achieved.Limiting the heating of individual components, especially the resistance device, can be achieved. For example, the drive can absorb a base load of energy, for example, recuperating it in generator mode, and the resistance device only absorbs the additional portion that is required.

[0074] It is also possible for the resistance device and the drive to actively support a movement. Due to the limited efficiency of the direction and drive, this also generates heat energy that must be dissipated. By distributing the generated heat energy between the drive and the resistance device, the heating of the individual components can be slowed or even reduced.

[0075] If only one resistance device with the power dissipation Pz were used, the entire amount of energy Wz would have to be dissipated into the environment. This would require, for example, a large surface area or complex and expensive cooling devices. If the energy cannot be dissipated, this would result in excessive heating of the resistance device. Distributing the energy across multiple components, namely the resistance device and the drive, for example, offers the advantage of increasing the available surface area for dissipating the energy Wz and reducing the heating of the individual components.

[0076] Figure 14 illustrates parameters in a movement sequence where represents an angular velocity, for example, the pivoting speed between the upper and lower sections. During this movement, a resulting moment Mz is applied against the direction of movement in order to decelerate the movement. This means that energy is extracted from the movement. In a design with only one dissipative resistance device, such as a hydraulic system or a brake, this energy is completely dissipated and converted, for example, into thermal energy.

[0077] If an additional drive is used, for example an electromechanical drive, it is possible to recover some of the energy in the form of electrical energy. This can be achieved by using the electromechanical drive in generator mode. Electromechanical drives have the property that their ability to recover energy depends on their speed and the required braking torque. In one embodiment, the resistance device and the drive are therefore controlled in such a way that the torque MA of the drive is set according to the optimal point for recuperation depending on the speed and the resistance device only has to cover the difference between Mz and MA, represented as MR. Through this type of control, a certain amount of energy can be recovered that would otherwise be lost. The total torque Mz can still be achieved.Alternatively, control can also be carried out in a manner that deviates from the optimal recuperation of the drive.

[0078] Figure 15 shows different exemplary control and regulation structures for controlling the resistance device 30 and the drive 60.

[0079] Shown above is a controller in which one or more control variables u are used as inputs for the drive 60 and the resistance device 30. The drive 60 and the resistance device 30 do not necessarily have to be controlled with the same control variables. In particular, although not essential, there is an exchange of information between the drive 60 and the resistance device 30, or their controls, represented by the dashed line, for example in order to exchange internal states. The exchange of information has the advantage that the drive 60 and the resistance device 30 can react in a coordinated manner. The torque MA generated by the drive 60 and the torque MR generated by the resistance device 30 act on the orthopaedic aid and influence the movement of the aid, represented as a controlled system orSystem dynamics S, as well as the degrees of freedom of the device, for example, the pivot angle between the upper and lower sections. A feedback control of the states of the orthopedic device or the torques generated by the resistance device 30 and / or drive 60 is possible, but not shown.

[0080] Shown in the center is a torque control of the combined system consisting of drive 60 and resistance device 30, which act in parallel, whereby the torques add up and the total torque Mz influences the pivoting movement of the orthopedic device. The system dynamics of the orthopedic device are symbolically represented as a controlled system S. In this application example, the target torque Mz,s is fed to both the resistance device 30 and the drive 60 as a setpoint variable. Both systems exchange information with each other, represented by the dashed line. This makes it possible for the individual control of drive 60 and resistance device 30 to depend on the state of the other components, e.g. the drive torque is determined as a function of the valve angle of a resistance device designed as a hydraulic system.In the example shown, the generated total torque Mz is determined, e.g., via one or more torque and / or force sensors, and fed back for the purpose of control. Feedback can be provided for the resistance device 30 and drive 60, or just for one of the components. Feedback is not necessarily required. In the example shown, the determined total torque Mz is only fed back to the control of drive 60. The torque of the resistance device 30 is only controlled (open loop), while the total torque Mz is regulated by the drive 60 via the closed control loop according to the target torque Mz,s. This is particularly advantageous if the resistance device 30 is more difficult to control due to a particularly simple or inexpensive design, while the drive 60 has good controllability.

[0081] An exemplary embodiment of a position control of the combined system comprising resistance device 30 and drive 60 is shown at the bottom of Figure 15. The resistance device 30 has as input variable, for example, one or more degrees of freedom of the orthopaedic device, for example the pivot angle <p und die Verschwenkwinkelgeschwindigkeit zwischen Ober- und Unterteil. Gemäß eines hinterlegten Steuerungsgesetzes verändert die Widerstandseinrichtung 30 auf Basis dieser Eingangsgrößen das generierte Moment. Der Antrieb 60 hat als Eingangsgröße den Sollwert eines Freiheitsgrades, bspw. den gewünschten Verschwenkwinkel <p zwischen Ober- und Unterteil. Es kann sich um einen gewünschten Sollwert-Verlauf handeln, aber auch um einen am Ende einer Bewegung zu erreichenden Sollwert, zum Beispiel einen Verschwenkwinkel <p am Ende der Schwungphase.The actual value of the degree of freedom to be controlled is also fed back to the control system of drive 60, allowing adjustment of the target value. Both the torque MR generated by the resistance device 30 and the torque MA generated by the drive 60 act on the orthopedic device and thereby influence its movement, symbolically represented by the control system S. While the resistance device 30 is controlled, for example, according to a control surface, the degree of freedom is adjusted in the sense of a close-loop control via the drive 60.

[0082] In addition to the inputs shown for controlling the resistance device 30 and drive 60, other variables can also be used for the control, in particular other sensor variables or internal state variables that are not shown. Other controls or controllers can also be connected upstream or downstream of the controls shown, in particular to generate the setpoints and setpoint curves (u, Mz,s and (|)s in the versions shown), e.g. from sensor data. The control or control strategy can also be adapted based on the determined movement, the movement phase or even the movement mode. For example, the control shown in the middle is used in a first movement phase, while the control shown below is used in a second movement phase.The different aspects of the regulations presented can also be combined with each other or with other tax and regulatory approaches.

[0083] In one embodiment, the resistance device is hydraulic; alternatively, a magnetorheological damper, a friction brake, or a lock such as a switchable freewheel is used. A force accumulator, e.g., a spring-loaded mechanism, can also be integrated. The resistance device can absorb or generate very high forces and torques and can simultaneously cover a relatively wide range as the ratio between maximum resistance and maximum smoothness. If the same forces and torques, as well as the range, are to be achieved solely with an electric motor with a gearbox, this leads to undesirable properties such as high weight, high manufacturing costs, high complexity, high control effort, and sometimes inefficient operating points.At the same time, however, active drives enable the input of energy and very flexible control, which is essentially achieved via software and electronics that can operate at very high clock rates and with very powerful processors. To combine passive or semi-passive systems, such as spring-loaded actuators, with the advantages of active systems, the plan is to combine one of the resistance devices described above with a small, parallel electromechanical drive. The electromechanical drive can be used to counteract movements, in particular to modulate the resistance of the resistance device, but also to assist movements.This means that resistance can be modulated against a movement during specific movement phases, but the drive can also support the movement during movement phases. In combination with a dissipative resistance device, for example, the basic resistance of the resistance device must also be overcome. This combination can achieve particularly advantageous overall system behavior or significantly simplify the resistance device. Examples include the use of switching valves instead of proportional valves, the use of cheaper servo drives with slower switching times in the resistance device, the use of simpler magnetorheological dampers and brakes instead of complex hydraulic systems, or the omission of heat storage devices.The resistance device and the drive can each be designed to be rotary or linearly displaceable, although a combination of linear and rotary motion is also possible and advantageous.

[0084] The combined operation of the drive and the resistance device enables highly dynamic modulation by the drive starting from a discrete or only slowly changing output level of the resistance device, compensation of the basic resistance and / or increase of the maximum torque, selective modulation by the drive while in other areas only the resistance device is used and / or energy recuperation and reduction of heat generation in dissipative actuators.

[0085] In particular, brakes using "squeeze mode" or "valve mode" lack sufficient friction spread. This means that their design cannot simultaneously achieve a low minimum resistance and a sufficiently high maximum resistance. However, magnetorheological brakes, for example, based on the rotary piston principle, are particularly simple and cost-effective. The additional drive allows the brake to be designed to achieve the necessary maximum torque, and the drive compensates for the high base friction in situations where smooth operation is desired, such as during the swing phase.

[0086] Resistance devices that can generate high resistance in highly dynamic situations and operate according to a dissipative principle, such as hydraulics, convert the work performed on them into heat. Activities such as long downhill walking generate a lot of heat, which can lead to overheating of the resistance device. This problem is currently mitigated by thermal capacities such as heat storage, which, however, involve additional costs and weight. With an additional drive, the work performed on the system can be recuperated and fed back into a battery or converted into heat elsewhere. This can reduce the thermal capacities.

[0087] Proportional valves are typically controlled by servomotors. Depending on the choice of servomotor, the valves' adjustment times are limited. Lower-cost motors, in particular, result in longer adjustment and response times. Long adjustment times are a limiting factor, especially in highly dynamic processes, such as the swing phase or in the area of ​​end stops. By combining them with a drive, significantly shorter adjustment times can be achieved, even when using particularly cost-effective servo drives for the proportional valves. This reduces the manufacturing costs of the hydraulic system.

[0088] Switching valves are particularly simple in design and cost-effective. They also typically have very short switching times. However, they can only switch between two or more discrete states, for example, between a low and a high resistance. This represents a major functional disadvantage, as movements cannot be controlled with sufficient precision. An additional drive can achieve intermediate states, such as a provided torque, but also make the abrupt changes during a switching operation more continuous. It is therefore possible to replace expensive proportional valves with switching valves and still achieve a sufficient level of functionality. Other resistance devices with discrete states can also be used in this way.

[0089] Mechanical or mechatronic locks are particularly advantageous resistance devices. Typically, they can be switched between a locked and a free-running state. Locking mechanisms can be achieved via force-locking and / or positive-locking connections, whereby the locking can also depend on the direction of movement. For example, freewheels can be designed to be switchable. Brakes can create a locking effect. A locking effect can also be achieved using valves, for example in hydraulic or pneumatic systems. Locking mechanisms can also very efficiently absorb high forces over long periods of time without consuming energy, which can, for example, reduce the overall capacity of a battery. A major disadvantage is that locking mechanisms usually do not assume intermediate states, and therefore the movements cannot be controlled with sufficient precision.In combination with a drive, this can be improved by having the drive continuously influence movements, for example in a swing phase, while the resistance device locks or unlocks the system, for example before initial contact and in the terminal stance phase.

[0090] Braking systems such as friction brakes, disc brakes, drum brakes, wrap spring brakes, magnetic powder brakes, and the like are particularly simple in design and cost-effective, but generally cannot be controlled with sufficient precision; for example, the braking force cannot be regulated with sufficient fineness and / or repeatability. In combination with a drive that can be controlled particularly precisely and dynamically, this disadvantage of brakes can be compensated for and a resistance device designed as a brake can be used. For example, during dissipative movement phases, the drive generates the difference between the desired torque and that provided by the brake.

[0091] One-way hydraulics and pneumatics have a throttle valve through which flow occurs in both directions of movement. The position of the throttle valve influences the flow resistance in both directions. The resistance can also be direction-dependent, for example, through a parallel check valve. The use of only one valve is particularly cost-effective. If different flow resistances are to be achieved during a change of direction, for example, a different resistance in an extension movement than in a flexion movement, and this requires adjusting the valve, this can lead to undesirable force peaks during the reversal of movement, especially if adjusting the valve requires a certain amount of time or the adjustment process is subject to variation.In combination with a drive, the behavior during the change of direction or during the adjustment process of the valve can be designed to be continuous and reproducible, for example by using the drive to achieve the desired movement and compensate for excessive or insufficient torque of the resistance device.

[0092] Two-way hydraulic systems with controllable movement resistance in only one direction are more cost-effective than systems with two controllable valves. In one design, only the resistance in one direction can be controlled, while the resistance in the other direction can be adjusted manually via a mechanical throttle valve, for example, or can be fixed. For example, the hydraulic resistance of a knee prosthesis in the extension direction can be realized by a flow resistance dependent on the knee angle, whereby the flow resistance is not controllable. Such a particularly cost-effective design has the disadvantage, for example, that the influence on knee extension during swing phase extension is not optimal for all walking speeds or contexts.For example, the extension resistance may be too low at a fast walking speed, or the knee joint may be too extended at the end of the swing phase extension when walking up stairs or ramps. In combination with a drive, the overall behavior can be improved in conjunction with two-way hydraulics without controllable resistance in one direction of movement. For example, the drive can dynamically reduce or increase the extension resistance or actively support a movement during certain movement phases. This allows for better adaptation to the walking speed, but also allows for stopping an extension movement before reaching a mechanical extension stop, with the drive stopping the movement or moving to a desired knee angle.As an alternative to a two-way hydraulic system with only one controllable valve, other resistance devices can also be used, in particular resistance devices where no or only a limited control of the movement is possible in one direction of movement.

[0093] The configurations described here can also be combined with others. For example, with energy storage devices, series and / or parallel elastic elements, and the like, which can be designed to be switchable, for example.

[0094] The drive 60 can counteract the resistance device 30. In particular, when the resistance device 30 provides minimal resistance, the total resistance can be further reduced by the drive 60, so that the basic resistance provided by the resistance device 30, possibly due to the system, can be reduced to 0 relative to a relative movement in the joint device. Thus, free movement of the upper part relative to the lower part about the pivot axis is possible. In a reversed direction of action, the drive 60 supports the resistance device 30, so that the total resistance can be increased beyond the maximum resistance of the resistance device.

[0095] In order to save energy, the drive is deactivated when a maximum resistance is set, especially when the joint is mechanically or hydraulically locked, since modulating a lock via a drive does not change the relative mobility of the upper part to the lower part.

[0096] Figure 16 shows two representations of a further embodiment of the orthopedic joint device. The orthopedic joint device has an upper part 10 and a lower part 20, with the lower part 20 only partially shown. Lateral structural elements designed to accommodate pins or axle elements are missing, so that the upper part 10 can be pivoted about the pivot axis 15 relative to the lower part 20. A rotary hydraulic system acts as a resistance device 30 and is assigned to the upper part 10. A hydraulic chamber is arranged within the rotary hydraulic system 30, in which a pivoting piston is mounted. The hydraulic chamber is coupled, for example, to the lower part 20, while the pivoting piston is coupled to the upper part 10, so that when the upper part 10 is pivoted relative to the lower part 20, the piston is moved within the hydraulic chamber.The dummy piston can, for example, be formed on a pivot axis that coincides with the journals or axle elements. The pivot piston divides the chamber into an extension chamber and a flexion chamber, and hydraulic fluid is moved from one chamber to the other during pivoting.

[0097] Of course, the pivoting piston can also be rotationally fixedly coupled to the lower part 20, while the housing is rotationally fixedly coupled to the upper part 10. In the illustrated embodiment, a valve unit is assigned to the rotary hydraulics 30, in which valves 50 are arranged that influence the flow behavior of the fluid from one chamber to the other. In addition to a control valve, a check valve or several control valves or check valves can be present. The rotary hydraulics as a resistance device 30 can be controlled via servo valves in order to enable precise control of the resistance device 30. An energy accumulator can be arranged within the hydraulics, for example a spring, which can be controlled via another valve.As an alternative to a hydraulic damper device, a magnetorheological hydraulic brake can also be used as a rotationally acting resistance device 30 or a friction-based brake.

[0098] Arranged within the lower part 20 is a drive 60 in the form of an electric motor, which is coupled to the upper part 10 via a gearing device 70. The gearing device 70 has a power transmission device, for example in the form of a toothed belt, a V-belt, a chain, a rope, or gears, in order to transmit forces from the drive 60 to the upper part 10. A gear ratio can be achieved via the gearing device 70, whereby the drive torque of the drive 60 can be adapted to the respective requirements. For example, the drive torque can be increased so that small drives 30 with a high speed can be used to generate a high drive torque. The gearing device 70 is shown schematically; the drive wheels or drive pulleys for transmitting forces and torques, as well as the belts, chains, gears, or the like, are not shown for reasons of clarity.

[0099] The active drive 60, which is present in addition to the resistance device 30, not only supplies energy to provide additional, active functionality for the user, but can also compensate for existing design disadvantages of the resistance device 30. For example, the basic friction within the resistance device 30 can be eliminated or overcompensated. This allows for very good internal sealing of the pivoting piston in the rotary hydraulics through an additional sealing lip to increase the maximum braking torque of the resistance device 30 in the form of a rotary hydraulics. The additional sealing lip within the rotary hydraulics without the active drive 60 would make the orthopedic joint device difficult to pivot due to the high basic resistance, which would limit its suitability for everyday use.By compensating for the second sealing lip by the drive 60, lower tolerance requirements can be placed on the remaining components without compromising functionality, thus saving manufacturing costs. With the illustrated concept of the resistance device 30 in the area of ​​the upper part 10 or the joint head and the arrangement of the drive 60 at a distal distance therefrom, the installation space in the joint device can be better utilized. Additional installation space is available between the drive 60 and the resistance device 30 to accommodate energy storage devices or the like. The electronic control device can also be accommodated there. The gear device 70 enables a largely independent positioning of the drive 60 from the joint head, thus reducing the manufacturing complexity.The knee joint axis can be continuous, for example, coinciding with the axis on which the pivoting piston is arranged or formed, which results in greater stability of the construction.

[0100] Figure 17 shows an embodiment of a force accumulator 65 with which progressive spring deflection behavior can be provided. The force accumulator 65 is formed from several modules 65A, 65B, the two lateral modules 65A surround a central module 65B. In one embodiment, the modules 65A, 65B are made from a polyester-based polyurethane elastomer. The modules 65A, 65B have different lengths, the outer modules 65A are longer than the central module 65B. In a cylindrical embodiment of the modules 65A, 65B, the outer module 65A is formed with an annular cross-section, and the central module 65B has a preferably cylindrical cross-section that corresponds to the cavity or cylindrical free space within the module 65A and at least partially fills it.Here, too, different lengths are available, so that initially the outer module 65 A is compressed when a force is applied in the axial direction, and when the top of the inner module 65 B is reached, increased resistance is provided due to the compression of the inner module 65 B. This leads to a jump in the resistance behavior of the orthopedic joint device. Depending on the design of the modules, the increase in compression resistance will be greater or smaller when the inner module 65 B is compressed. By adjusting the material or the dimensions of the modules 65 A, 65 B, the spring characteristics as well as the force storage capabilities are adjusted. In addition to progressive spring behavior, force accumulators 65 made of an elastomer material are suitable for achieving linear or, with appropriate shaping and high deformation, degressive spring behavior.Force actuators 65 as elastomer modules are characterized by high overload resistance, so that in many applications, a travel limiter or end stop to protect the force actuator can be omitted. An elastomer material can also be used as an end stop for the joint device. Particularly when used in the area of ​​an end stop for a joint device, a progressive spring behavior can be advantageous to prevent discontinuities in the force curve. This prevents sudden force or torque changes and reduces mechanical loads. Furthermore, it reduces the controllability of the system and reduces noise.

[0101] In one embodiment, progressive spring behavior can be achieved by deliberately limiting the deformation of the force accumulator in the form of an elastomer module, for example, by means of a surrounding limiting structure. If a cylindrical elastomer module is arranged in a cylindrical bore with a larger inner diameter than the outer diameter of the undeformed elastomer module, the natural bulging of the elastomer module is limited after the gap or free space has been overcome. The material of the elastomer module is thereby forced into a different shape, namely the shape of the outer limit, which influences the internal, local deformation state in the elastomer material. This results in a stiffening of the elastomer module.In addition to an external sleeve with an interior shape corresponding to the outer contour of the elastomer element, this principle of deformation limitation can also apply to any non-cylindrical outer contour and / or inner contour. Targeted deviations between the outer contour of the elastomer module and the limiting structure can influence, and in particular, mitigate, the progression behavior.

[0102] Figure 18 shows a schematic representation of a force storage element 65 in the form of an elastomer module within a hydraulic system. The hydraulic system can be part of a passive resistance device 30. A cylinder 34, in which the elastomer module 65 is arranged, is formed within a housing 32. A valve can be arranged upstream of the cylinder 34 and the elastomer module 65. The elastomer module 65 is supported on a carrier, so that when pressure is applied with the hydraulic fluid, the elastomer element 65 is compressed and pressed against the inside of the cylinder 34. This increases the sealing effect of the elastomer element, possibly until the hydraulic fluid cannot escape from the additional oil chamber 34. This further enhances the progression effect.To avoid excessive progression and, if necessary, maintain a minimum hydraulic flow, overflow channels for the hydraulic fluid can be formed on the lateral circumference and / or within the elastomer module in the form of one or more bores. Figure 19 shows an embodiment of such an elastomer module as a force storage element 65. The force storage element 65 is designed as a substantially cylindrical elastomer module and has three overflow channels 650 for the hydraulic fluid on its outer circumference. Such a force storage element 65, particularly in combination with a hydraulic system controlled by valves, can be used in both linear hydraulics and rotary hydraulics.

Claims

Patent claims 1. An orthopaedic joint device comprising an upper part (10) and a lower part (20) which are mounted on one another so as to be pivotable relative to one another about a pivot axis (15), and comprising a passive resistance device (30) which is arranged between the upper part (10) and the lower part (20) and is designed to provide resistance against pivoting of the upper part (10) relative to the lower part (20), characterized in that a motor drive (60) is arranged between the upper part (10) and the lower part (20), which motor drive is designed to effect, assist or hinder pivoting of the upper part (10) relative to the lower part (20).

2. Orthopaedic joint device according to claim 1, characterized in that the resistance device (30) has a housing (32) with a cylinder (34) in which a piston (36) is displaceably mounted and divides the cylinder (34) into two chambers (341, 342), between which at least one fluid connection (40) is formed, in which at least one valve (50) is arranged.

3. Orthopaedic joint device according to claim 2, characterized in that the valve (50) is adjustable and is designed in particular as a switching valve with at least two switching positions, wherein at least one switching position is a partially open switching position.

4. Orthopaedic joint device according to claim 2 or 3, characterized in that the valve (50) is designed as a multi-way valve with a closed switching position, an open switching position and at least one partially open switching position.

5. Orthopaedic joint device according to claim 3 or 4, characterized in that the partially open switching position of the flow cross-section is reduced by at least 50% compared to the fully open switching position.

6. Orthopaedic joint device according to one of claims 2 to 5, characterized in that each chamber (341, 342) is assigned a valve (50).

7. Orthopaedic joint device according to one of claims 2 to 6, characterized in that a check valve (55) connected in parallel is assigned to the valve (50).

8. Orthopaedic joint device according to one of claims 2 to 6, characterized in that a different partially open switching position is present for each chamber (341, 342).

9. Orthopaedic joint device according to claim 1, characterized in that the resistance device (30) is designed as a hydraulic damper, pneumatic damper, magnetorheological damper, as a dissipative brake or lock.

10. Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) is designed to act linearly or rotatory.

11. Orthopaedic joint device according to one of the preceding claims, characterized in that the drive (60) is designed as an electric motor and is coupled directly or via a gear (70) to the upper part (10) or the lower part (20).

12. Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) and / or the drive (60) is assigned a controller (80) which is coupled to at least one sensor (90) and is configured to activate, deactivate and / or modulate the resistance device (30) and / or the drive (60) on the basis of the sensor values.

13. Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) and the drive (60) are designed as a modular unit.

14. Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) and the drive (60) have separate housings (32, 62).

15. Orthopaedic joint device according to one of the preceding claims, characterized in that a force accumulator (65) is arranged parallel or serially to the resistance device (30) and / or the drive (60).

16. Method for controlling an orthopaedic joint device according to one of the preceding claims, characterized in that the drive (60) for influencing the resistance is operated in parallel with the resistance device (30).

17. The method according to claim 16, characterized in that the drive (60) is activated and / or modulated upon partial activation of the resistance device (30).

18. Method according to claim 16 or 17, characterized in that the drive (60) is activated, deactivated and / or modulated on the basis of sensor data.

19. Method according to one of claims 16 to 18, characterized in that the drive (60) is operated in a generator state to increase the resistance and the electrical energy generated thereby is stored in an accumulator.

20. Method according to claim 19, characterized in that the resistance is changed as a function of the speed of the drive (60) in generator operation.

21. Method according to one of claims 16 to 20, characterized in that the resistance device (30) is switched between at least two discrete states and the drive (60) is activated, deactivated or modulated to influence the change in resistance before and / or after a switchover.

22. Method according to one of claims 16 to 21, characterized in that the drive (60) is activated, deactivated or modulated to influence the resistance depending on the pivoting angle.

23. Method according to claim 18, characterized in that the drive (60) continuously influences the resistance or the pivoting movement.

24. Method according to one of claims 16 to 23, characterized in that the drive (60) counteracts or supports the resistance device (30).

5. Method according to one of claims 16 to 24, characterized in that the resistance device (30) is set to a maximum resistance and the drive (60) is deactivated at maximum resistance or lock.

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