DE102023120962A1 - Orthopaedic joint device and method for its control - Google Patents

Abstract

The invention relates to an orthopedic joint device with an upper part and a lower part which are mounted on one another so as to be pivotable relative to one another about a pivot axis and at least one resistance device which is arranged between the upper part and the lower part. The resistance device is designed to influence a pivoting or pivotability of the upper part relative to the lower part, wherein a motor drive and at least one energy accumulator are arranged between the upper part and the lower part, which are designed and arranged to effect, support or hinder a pivoting or pivotability of the upper part relative to the lower part.

Description

The invention relates to an 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 at least one resistance device which is arranged between the upper part and the lower part. The resistance device is designed to influence a pivoting or pivotability of the upper part relative to the lower part. The invention also relates to a method for controlling such an orthopedic joint device.

Orthopedic joint devices are in particular orthoses, exoskeletons or prostheses that have an upper part and a lower part that is articulated to it. In orthoses and exoskeletons, the upper part and the lower part are attached to a limb that is still present, for example by means of shells, belts, straps, cuffs or other fastening devices. Orthoses and exoskeletons can be used to guide movements, limit pivoting around a pivot axis, prevent pivoting movements or support or fix the alignment of limbs with respect to one another. In addition, orthoses can be provided with resistance devices to influence a pivoting movement around the pivot axis. The resistance devices can be provided with a control system so that a changed resistance in the flexion direction and/or extension direction can be provided depending on sensor data. It is also known to assign energy storage devices to the upper part or the lower part so that movement support can be provided by releasing the stored energy from the energy storage device.

Prostheses replace a missing or no longer existing limb and are used to provide functionality that is as close as possible to the functionality of the natural limb. In addition, prostheses are used to provide the most natural appearance possible for the prosthetic user. For example, a prosthetic upper part is designed as a prosthetic shaft or as a component attached to a prosthetic shaft, where the prosthetic shaft is used to attach it to a limb or a 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 can have further prosthetic components, for example a lower leg tube, a prosthetic foot or a prosthetic hand.

Particularly in the case of orthoses, exoskeletons and prostheses of the lower extremities, but also of the upper extremities, dampers, in particular hydraulic dampers or other resistance devices, are arranged between the upper part and the lower part, which 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 movement 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. Passively damped, in particular passively hydraulically damped prostheses or orthoses work purely dissipatively. Energy is taken from the movement of the upper part relative to the lower part, whereby very high moments or forces can be generated. At the same time, passive damping in an open state, for example when no valves are closed or throttles are activated, has only a very low resistance. The working range of such an orthosis or prosthesis is limited in that no energy can be directed into the movement in order to support it or actively counteract the movement or to make a change from a static state.

In addition, 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 braked by activating, deactivating or modulating the drive. For this purpose, stored electrical energy from a battery or accumulator is converted in the actuator. The motor drives also serve to influence the movement behavior between the components of the orthosis or prosthesis as part of a generator circuit, for example to brake a pivoting movement and thereby charge or support the energy storage device. Braking can also be achieved in short-circuit operation. In this operating mode, the energy taken from the movement is converted into heat within the drive. The maximum achievable moments or forces that can be achieved by a motor drive are limited.

The EP 2 535 024 A1 describes a prosthetic leg with a knee element connecting an upper part to an elongated lower leg part to allow relative movement. A serial elastic actuator is connected between the knee element and the lower leg portion and configured to apply torque to the knee element to cause relative movement between the knee element and the lower leg element. The series elastic actuator includes a motor coupled to an elastic device.

The DE 10 2018 126 324 A1 describes an orthopedic joint with a first component, a second component that is arranged on the first component so as to be pivotable about a pivot axis, and an actuator for pivoting the first component relative to the second component in at least one direction. The actuator is detachably arranged on a medial or lateral side on the first component or the second component. The joint can have at least one damper that is designed and arranged to dampen pivoting of the first component relative to the second component. The actuator can have an elastic element and/or a serial elastic actuator and/or a parallel elastic actuator.

In the article “ A Comparison of Parallel and Series Elastic Elements in an Actuator for Mimicking Human Ankle Joint in Walking and Running” by Martin Grimmer, Mahdy Eslamy, Stefan Gliech and André Seyfarth, published at the IEEE International Conference on Robotics and Automation, 2012 , the reduction of the peak power and energy consumption of actuators through the use of elastic elements in prostheses is discussed. With the current commercially available motor technologies, it is not possible to imitate the behavior of a human ankle for higher speeds and when walking with a single motor solution using a series elastic actuator. With a parallel elastic actuator, the required peak power of the drive can be further reduced. The combination of both elastic actuators leads to a further reduction.

In the article “ Effects of Unidirectional Parallel Springs on Required Peak Power and Energy in Powered Prosthetic Ankles: Comparison between Different Active Actuation Concepts” by Mahdy Eslamy, Martin Grimmer and Andre Seyfarth, pp. 2406 to 2412, Proceedings of the 2012 IEEE International Conference on Robotics and Biomimetics, December 11th - 14th, 2012, Guangzhou, China , the same problem is discussed and a concept of a motor with two energy storage devices, one serial and one parallel, is presented.

The object of the present invention is to provide an orthopedic joint device and a method for controlling it, with which the orthopedic joint device can be operated reliably and with a low weight over the largest possible working range.

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 subclaims, the description and the figures.

The orthopedic joint device with an upper part and a lower part, which are mounted on one another so as to be pivotable relative to one another about a pivot axis, and with at least one resistance device which is arranged between the upper part and the lower part, wherein the resistance device is designed to influence a pivoting or pivotability of the upper part relative to the lower part, additionally has that a motor drive and at least one energy accumulator are arranged between the upper part and the lower part, which are designed and configured to cause, support or hinder a pivoting of the upper part relative to the lower part. While the resistance device, in particular a hydraulic damper, a pneumatic system, a friction brake, a magnetorheological resistance device and/or a locking mechanism, can dissipate a high degree of kinetic energy between the upper part and the lower part with a comparatively low weight or simply blocks a relative movement between the upper part and the lower part, for example by blocking the fluidic connection between the chambers, it is possible to actively apply a driving or braking moment about the pivot axis using the motor drive or the energy storage device. The motor drive is designed, for example, as an electric motor and is optionally coupled to the upper part and the lower part via a gear. The gear can be designed, for example, as a spindle gear, gear transmission, lever gear, cable gear, friction gear or in another gear form. If an existing movement is to be supported, the resistance by the resistance device is reduced to the minimum value specific to the resistance device, e.g. 0, if possible, so that the drive only has to apply the torque to overcome the residual resistance or the internal friction and to accelerate the lower part relative to the upper part. In the event that the orthopaedic joint device is designed on an orthosis, the respective limb is connected to the upper part or lower part with moved. In addition, there is a power storage device in which otherwise dissipated kinetic energy can be stored as potential energy, in particular in order to be able to handle peak loads. Motor drives can only reach a limited speed or linear speed. Depending on the design, this limit is below the maximum movement speed of the power storage device. While motor drives work comparatively slowly, a power storage device can be released in such a way that the desired amount of energy is supplied to the joint device at short notice at the desired time in order to provide a driving or braking moment about the pivot axis. By combining at least one resistance device with at least one drive and at least one power storage device, the installation space for the active drive can be kept small, since the power storage device and the resistance device compensate for the structural weaknesses of an electric drive. The operating range of the orthopedic joint device is expanded overall and the drive requires less energy, so that the supply components of the drive, in particular the energy storage devices, can be made smaller and lighter. The mechanical loads on the drive components are also reduced by the absorption of forces and moments via the resistance device and, if necessary, the force storage device, thereby improving the durability of the system as a whole.

In a further development, the at least one resistance device and/or the energy storage device are adjustable, in particular depending on current load variables, conditions or expected movement sequences, which are determined in particular via sensors. The sensor values determined by the sensors are fed to a control system and evaluated therein. Based on the evaluation, the settings within the resistance device and/or the energy storage device are changed, e.g. those of the valves or throttles of the hydraulic damper, the contact pressure of the braking device, the magnetic field of the magnetorheological device and the like. The movement resistance of a hydraulic or pneumatic damper can be changed via switching valves or proportional valves. Likewise, the storage of energy or the release of energy from the energy storage device can be initiated on the basis of the sensor values and their evaluation. The energy storage device can in particular be locked, e.g. in order to charge the energy storage device successively and to be able to retrieve the stored energy at the desired time.

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 adjustable valve is arranged, which 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, wherein a fully open or closed switching position can be the second switching position. The two switching positions can also be the fully open and the fully closed switching position. 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 be able 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 with a servomotor for each valve is necessary. Active orthopedic joint devices with a motor to solely influence the relative movement require a large motor or large gears in order to be able to fully and independently absorb the forces that occur. With the orthopedic device claimed, it is possible to make the complex structure of purely passive resistance devices or purely active actuators for orthopedic joint devices much simpler, without losing the ability to react finely and appropriately to the respective movement situations or conditions. The switching valves switch between several discrete states, at least between two switching positions, for example completely open or completely locked and a partially open or partially closed switching position. This is done, for example, by moving or simply switching between the respective positions, for example by activating a coil, without having to activate motors. This makes it possible to lock the orthopedic joint device against flexion and extension in a completely closed position and to set a movement resistance that is often required in a partially open switching position. In order to be able to modify the corresponding resistance around this swivel resistance, a motor drive is assigned to the orthopaedic joint device or connected to it in order to influence the swivel movement. The motor drive can be activated at certain times or be switched on in certain 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 switched on 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 orthopaedic joint device from a static state. In any case, an additional moment is generated in the joint, either a driving or a braking or damping moment. The motor drive can be used to fine-tune the resistance behavior or damping behavior of the resistance device, particularly in a design as a hydraulic damper, which can be designed as a linear damper or a rotary damper.

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, in the open switching position the hydraulic damper can be moved along with a pivoting movement 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 completely 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 with regard to the degree of opening, the actuator counteracts the resistance from the resistance device or supports it when operated accordingly.

In one embodiment, the partially open switch position is reduced by a certain percentage compared to the fully open switch position in terms of the flow cross-section, so that a preset output damping is present between a fully open and fully closed state, i.e. greater than the minimum damping in the fully open state and smaller than the maximum damping in the closed state. is present. The movement behavior is then changed around this position via the actuator. The additional drive now makes it possible to influence the preset movement resistance in the prosthetic joint or orthotic joint. The resistance can be influenced in such a way that it can be weakened or increased within a certain range by means of appropriate control of the drive. Likewise, the course of the resistance over time, position, speed or acceleration of a component or limb of the patient can be adapted. The flow cross-section can be adapted to the respective application form or the respective user. If, for example, experience shows that a certain damping moment or a certain damping force must be applied very frequently, for example a certain high level of damping against flexion in an artificial knee joint, a corresponding reduction in the flow cross-section can be provided for the partially open switching position. If predominantly low levels of damping or resistance are to be applied by the resistance device, particularly in the form of a hydraulic damper, it is sensible to increase the flow cross-section accordingly and set it to the value that is likely to be used most frequently.

In a further embodiment, the drive or motor is arranged in parallel to a system of one or more passive resistance devices. Furthermore, this system can also have one or more energy storage devices that act in parallel or in series with the resistance device. The respective energy storage device can have an adjustment mechanism to influence the characteristics of the energy storage device. At least one of the several resistance devices has an adjustment mechanism to adjust the resistance. This mechanism can be adjusted via an actuator. The actuator can be adjusted automatically based on sensor values. Various advantageous variants for controlling the drive or motor can be implemented using the system mentioned.

An adjustable resistance device, for example, has an adjustment mechanism that requires the time period T1 to increase or decrease the resulting resistance in the joint to a desired value. The time period T1 is longer than the time period T2 in which the corresponding resistance should be set in order to achieve the desired behavior of the orthopedic joint device. The response behavior of the drive T3 to apply resistance is significantly faster than T1 and thus T3 is smaller than T1. In order to approximate the overall behavior to the duration T2, the drive can be controlled so that the resistance is applied by the drive during T1. The drive resistance is adjusted in such a way that the drive only has to adjust the difference between the desired resistance in the orthopedic joint device and the desired resistance. voltage and the resistance applied by the resistance device. The resulting adjustment time can thus be virtually reduced. The entire system behaves as if it had the adjustment time T3.

There are further advantages based on the system described. Depending on the design of the resistance device, in particular as an adjustable hydraulic damper, which can be fully lockable, it can absorb large forces or moments without consuming electrical energy. This is particularly advantageous for isometric or very slow movements. In contrast, drives in these operating states require a lot of electrical energy to achieve the same behavior. The sensors built into the system can detect such states. As soon as the resistance device has reached the set resistance, the drive is completely deactivated. The resistance device now holds the entire load and the drive does not require any energy.

Another form of drive control arises from the fact that an electric drive can be operated as a resistance device that converts mechanical energy into electrical energy within a certain range of resistance moments or forces and speeds. In contrast, passive resistance devices convert mechanical energy into heat. This energy is lost or causes problems due to an increase in temperature in the system.

The energy flow of the mechanical energy in the joint device can be controlled by a coordinated adjustment of the resistance of the passive resistance device and the resistance of the drive acting as a resistance device. This makes it possible to direct more mechanical energy into the drive during movement states in which the drive can generate electrical energy. This reduces the energy input into the passive resistance device, which also reduces heating. In addition, part of the mechanical energy directed into the drive can be converted into electrical energy by the drive and stored in the electrical energy storage device, which in turn can extend the operating time of the orthopedic joint device or reduce the size of the electrical energy storage device required.

In one embodiment, the drive is designed as an electric motor that is coupled to the upper part or the lower part via a gear. The gear 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 from the upper part to the lower part or to move the upper part relative to the upper part. The gear can be designed, for example, as a spindle gear, gear transmission, lever transmission, cable transmission, friction gear or in another form of gear.

In one embodiment, the drive and/or the resistance device and/or the energy storage device is assigned a controller that has a data processing device to process sensor data. The data processing device has the necessary components for this, 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 designed to activate, deactivate and/or modulate the drive and/or the resistance device and/or the energy storage device on the basis of 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.

A further development provides that the resistance device, the energy storage device and the drive are designed as a modular unit and are fixed together at the fastening points on the upper part or lower part. This makes it possible to have different modifications and designs of drives, resistance devices or energy storage devices ready as part of a prefabricated unit in order to then mount these units or modules as a whole on the orthopedic joint device. The system can also be designed as a logical unit, with a common control including sensors for the resistance device, energy storage device and drive. The advantage of this is a simplified interface for controlling the system. The common control only has to specify the behavior of the orthopedic joint device. The energy flows within the mechanical system are controlled within the logical unit. This shortens the development time for the behavior control of the higher-level control.

In a further development, the energy accumulator is designed as a spring, in particular a compression spring or designed as a pressure accumulator, in particular as a pneumatic or hydraulic pressure accumulator, which is integrated in the resistance device. A spring in the form of a compression spring or an elastomer element can be connected in series to the resistance device. A spring is considered to be an elastic deformation of a solid body or a compression of a hydraulic spring or a compressible hydraulic fluid.

The energy accumulator is designed to be adjustable, with the energy accumulator or the spring being assigned an adjustment device for adjusting the spring preload or spring stiffness. This makes it possible to change the amount of energy to be stored and the manner in which the energy is released. Alternatively or additionally, a pump and/or a valve are assigned to the pressure accumulator of the energy accumulator in order to charge the pressure accumulator or to reduce pressure in order to change the pressure level. This also makes it possible to manipulate both the amount of stored energy and the manner in which it is released. In a pressure accumulator, there is a pre-pressure or there is a transmission ratio of the pressure to the force generated by the energy accumulator.

If the spring preload or spring stiffness is to be adjusted by motor, in one embodiment the adjustment device is designed in the form of the drive, which can also generate a moment around the pivot axis. This makes it possible not to have to provide a separate component for changing the spring preload and/or spring stiffness, but to use the drive as the device for adjusting the energy storage device. In this case, the actual spring stiffness or preload is not adjusted, but the resulting mechanical behavior of the joint is changed so that it behaves as if the spring had a different stiffness and/or preload. The overall spring stiffness of the orthopedic joint device is changed.

In one embodiment, the energy storage device and the drive are arranged in relation to one another and mechanically coupled to one another in such a way that they are arranged in parallel and effective relation to one another. The drive introduces a driving or braking moment around the pivot axis of the orthopaedic joint device, the energy storage resistance device arrangement acting in parallel enables the moment to be modified or supported by the drive. Conversely, the drive modulates the damping moment through the resistance device or the use of the energy storage device. In a further development, the energy storage device and the resistance device are arranged in a series circuit, which is particularly easy and compact with a hydraulic damper via a pressure accumulator. This also enables the orthopaedic joint device to oscillate unaffected by the energy storage device when the resistance device is open.

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 and the energy storage device. The resistance device and the energy storage device are designed as passive elements, since they do not have a motor drive. In combination with the motor drive, it is possible to expand the application of an orthopedic joint device, in particular for orthoses or prostheses, and to give the orthopedic joint devices properties that would not be possible with the individual components. The passive elements are coupled to the electromechanical or electrohydraulic drive, so that the moments or forces applied around the pivot axis result from the forces or moments of the three components. The effect of the energy storage device parallel to the drive leads to a support or a change in the moment applied by the drive and in particular supplements the drive by providing comparatively high amounts of energy in a short time. This increases the moment of the drive by the moment that is provided by the energy storage device when it is released. The active drive can therefore be designed in such a way that it does not have to provide the full torque for all applications. This means that the motor drive can be smaller or optimized for other working ranges or speeds. The energy storage device, the resistance device and the drive can be arranged parallel to one another; alternatively, the energy storage device and the resistance device can be arranged in series and the drive parallel to both. If the resistance device is adjustable, the energy storage device can be "deactivated" by switching the resistance device to pass through.

In one embodiment, the drive and/or the resistance device and/or the energy storage device is activated, deactivated and/or modulated on the basis of sensor data in order to be able to change the movement behavior of the upper part relative to the lower part during use.

The modulation of the overall characteristics of the system is carried out in a design based on on the characteristics of the resistance device and/or the energy storage device through the drive, in particular a reduction or increase in the resistance, the resistance curve, the stiffness, the stiffness curve, the damping and/or the damping curve through the drive. At certain times or in certain conditions or when certain limit values are reached, the drive is activated, deactivated or modulated so that a moment applied by the energy storage device is increased or reduced. This means that adjustments to the required behavior of the orthopaedic joint device can be carried out quickly and in an energy-saving manner.

In a further development, the energy stored in the energy storage device is converted into electrical energy via the drive and vice versa, for example by operating an electric motor in generator mode or vice versa.

The invention provides a combination of energy storage and parallel motor drive. The resulting torque is the sum of the torques applied by the energy storage and motor. The energy storage is not just to be seen as a pure spring, but can be embedded in a hydraulic system that enables parallel and/or serial damping behavior. In one embodiment, the hydraulic spring storage can only be loaded in the flexion direction and discharged in the extension direction, the oil flow in and out of the spring storage is throttled by a proportional valve until it is blocked. In the combination, the energy storage can be used to apply the basic characteristics and the motor to modulate them. This enables much more flexible control than with the energy storage alone, or higher energy efficiency and a higher bandwidth, or a higher maximum torque, can be achieved than with just one motor. As an alternative to a parallel arrangement of motor and energy storage, they can also be arranged in series. In this case, it is not the torques that add up, but the displacements. The motor then modulates the path as a function of the force.

A basic idea is to change the force-displacement behavior of the energy storage device through the drive, in particular a parallel motor. The motor can be used to make an adjustment based on a basic characteristic of the energy storage device. A motor torque that is aligned with the energy storage torque increases the resulting torque, while an opposite motor torque reduces the resulting torque. A constant torque applied by the motor corresponds, for example, to a preload of a spring characteristic or the displacement of a spring zero point; a displacement-dependent motor torque corresponds to the superposition of two springs, whereby a non-linear spring characteristic can be generated, in particular by the motor. If non-conservative forces occur in the energy storage device, these can also be taken into account in the control of the motor. In addition, the torque or a parameter of a characteristic of the motor can be changed over time, thereby achieving transient behavior. For example, direction-dependent behavior, hysteresis or decaying behavior, e.g. a continuous, temporal reduction of a torque, can be implemented. It is also possible to dynamically change the moment characteristics in real time during a movement, to adapt from one repetition of a movement to the next repetition, for example on the basis of autonomous optimization in order to make the characteristics adjustable via software and electronic interfaces.

The motor torque can be selected so that it is identical in magnitude to the torque generated by the energy storage device, or at least sufficiently similar and opposite. The resulting total torque from the motor and energy storage device is therefore zero or correspondingly low. No significant additional resistance is offered to the movement or support is provided. This can be useful in individual phases of movement in order to switch off the active energy storage device, switch it on in a controlled manner or to specifically add or remove energy from the energy storage device without significantly influencing the movement.

For walking on the level, an almost linear spring behavior with parallel damping, if necessary, is advantageous in the stance phase flexion and extension. The optimal moment characteristic varies, however, with body weight, the individual movement sequence and needs, as well as the gait parameters such as step length or walking speed. Dynamic adjustment of spring stiffness is difficult to implement. The modulation can be adapted to the body weight and height of the person using it, but also to personal preferences. In addition, the total moment can be adjusted from step to step or in real time to the movement, the progress of the movement or the load in a control law. For example, if the inclination of the leg tendon detects that it is a terminal stance phase, but the joint is still strongly flexed or has not yet stretched sufficiently from a maximum stance phase flexion, the extension moment can be increased via the motor. Such an adjustment typically occurs continuously and not abruptly.

The moment behavior in the stance phase can be adapted to the context using the combined actuator. Different contexts such as steps, ledges, inclines, surface conditions or environments require different types of support. When walking downhill on inclines, higher extension moments are typically required in the stance phase than when walking on level ground. Accordingly, the incline can be determined using sensors and the total moment from the energy storage unit and motor can be modulated. In particular, the motor moment can be increased in a certain incline range with increasing downward incline in order to achieve a higher overall stiffness, preferably in the stance phase flexion. The extension moment in the stance phase extension can also be adjusted compared to walking on level ground. For example, the change in stiffness or moment during the stance phase flexion and extension can be adjusted over time or based on sensor signals when walking downhill, e.g. to cause a greater hysteresis and thus greater dissipation. Similar adjustments can also be made for other contexts. The possibility of increasing or reducing the resistance in the stance phase is provided via the control.

With a power storage device, energy must always be introduced before energy can be withdrawn, with the same or even higher forces and moments being required for charging than for discharging. In addition, a relative movement may be necessary for charging the power storage device if it is physically coupled with the pivoting movement. For example, it is not possible or only possible with difficulty to charge the power storage device by absorbing the kinetic energy in the swing phase with a low moment and a large range of motion and to release the energy in the stance phase, in which a high moment and a small range of motion is required. This problem can be solved using the combined actuator. For example, in the swing phase flexion, the power storage device can be charged by a motor torque that is opposite to the power storage device. If the moments generated are opposite and equal in magnitude, they cancel each other out and the movement is not influenced, or the movement is not subjected to any additional resistance by the power storage device. With increasing flexion, the motor torque is increased until the power storage device is fully charged or no further flexion occurs. By maintaining the bending moment of the motor or switching off the energy storage, the release of the energy storage can be delayed or only take place at a later point in time. When climbing stairs, the energy stored in the energy storage can be released in the stance phase extension. The extension moment generated by the energy storage can be supported here by a motor moment in the same direction, which can increase the total extension moment.

If the energy storage device is charged and the stored energy cannot be used sensibly, the energy storage device can be discharged. This typically occurs dissipatively. The discharge can generate a moment, which is undesirable. Alternatively or additionally, the motor can be used to provide a moment that is opposite to the energy storage device and essentially the same in magnitude, so that the resulting moment is almost zero or sufficiently small. This means that the energy storage device can be discharged in such a way that it has no significant influence on the movement. It is also possible to reduce the moment of the energy storage device via the motor. For example, the energy storage device can charge up undesirably during the stance phase flexion when walking down stairs. If the stored energy is not needed in the gait cycle of walking down stairs and the energy storage device is to be discharged again during the subsequent initial contact, the energy storage device must be discharged before the initial contact. This can be done, for example, in the swing phase extension, whereby the extension moment of the energy storage device is counteracted by a bending moment by the motor during discharge, which sufficiently reduces the resulting extension moment or compensates for the extension moment of the energy storage device.

A combined actuator consisting of an energy storage unit and a motor can also improve energy recuperation via the motor and thus the generation of electrical energy. Operating a motor as a generator is not possible or only possible inefficiently at low speeds. However, with a combined actuator it is possible to store energy in the energy storage unit during slow movements and thus at low speeds and later use the energy storage unit at high speeds to operate the motor in generator mode for efficient energy recuperation. Another advantage is the low heat generation compared to the dissipation of energy in the phase in which the energy storage unit is charged.

When walking downhill on slopes, the energy storage can be charged, for example, in the stance phase flexion and later in the swing phase extension, especially during fast Stretching speeds, whereby the stretching moment of the energy storage device is counteracted by a bending moment via the motor. The motor is controlled in such a way that it operates as a generator and generates electrical energy. The motor and energy storage device are preferably controlled in such a way that the motor torque and the torque generated by the energy storage device cancel each other out and do not significantly affect the movement.

The motor torque can be used to obtain movement information, e.g. inclination of the lower leg, leg tendon, upper body inclination or force information, e.g. COP (Center Of Pressure), ankle torque, forces and moments in the interface to the person using the aid and the contralateral side. The control also includes variables derived from sensor data such as the thigh angle, which can be calculated from the knee angle and lower leg angle, or the lever arm as a quotient of torque and force. Human-machine interfaces or AI algorithms can also be used as additional inputs. It is also possible for several variables to be used to control the torque. The resulting total torque from the motor torque and the torque from the force storage is therefore in particular a function of the knee angle due to the physical coupling of the knee angle and force storage and possibly other input variables.

Method for controlling an orthopaedic joint device as described above provides that the drive for influencing the resistance is operated parallel to the resistance device of the force storage device.

In one embodiment, the drive, the resistance device and/or the energy storage device are activated, deactivated and/or modulated on the basis of sensor data, wherein the sensor data are in particular assigned to and transmitted to a controller or control device. Alternatively or additionally, the resistance device and/or the energy storage device are activated, deactivated and/or modulated on the basis of sensor data, in particular the control device is also supplied with the sensor data and is coupled to the resistance device and/or the energy storage device in order to make the corresponding changes to or in the resistance device and/or the energy storage device on the basis of the sensor data.

The modulation of the overall characteristics of the orthopedic joint device is carried out in one embodiment based on the characteristics of the resistance device, which represents the basis or basis for influencing the movement behavior of the orthopedic joint device. This basic characteristic is modulated by the drive. The basic characteristic can also be carried out by the energy storage device or a combination of energy storage device and resistance device, in particular in the form of passive components. The drive then makes the appropriate adjustments to the respective basic characteristics. In particular, there is a reduction or increase in the resistance, the resistance curve, the stiffness, the stiffness curve, the damping and/or the damping curve.

In a further development, the conversion of energy stored in the energy storage device into electrical energy takes place via the drive and vice versa.

The energy storage device can be decoupled from the other components, i.e. the resistance device and the drive, and kept in a charged state in order to be switched on again at a later time so that the energy stored in the energy storage device can be fed into the system in a controlled manner.

In one embodiment, the drive is operated in such a way that the effect of the resistance device is canceled, so that the upper part can be freely pivoted relative to the lower part.

• 1 - eine schematische Darstellung eines Prothesenbeins;
• 2 - ein Ausführungsbeispiel eines Hydraulikschaltbildes;
• 3 - Varianten mit Orthesen;
• 4 bis 15 - Anwendungsbeispiele anhand eines Prothesenbeines; .
• 16 bis 26 - verschiedene Momentenverläufe;
• 27 - einen Momentenverlauf mit mehreren Eingangssignalen; sowie
• 28 - einen Zusammenhang zwischen mehreren Eingangsgrößen.

In the following, embodiments of the invention are explained in more detail with reference to the attached figures. They show:

• 1 - a schematic representation of a prosthetic leg;
• 2 - an embodiment of a hydraulic circuit diagram;
• 3 - Variants with orthoses;
• 4 to 15 - Application examples using a prosthetic leg; .
• 16 to 26 - different torque curves;
• 27 - a torque curve with several input signals; and
• 28 - a relationship between several input variables.

In the 1 is a schematic representation of an orthopaedic joint device as part of a prosthetic leg with a femoral shaft as upper part 10 and a lower leg part as lower part 20. The 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 there is a resistance device 30 in the form of a schematically illustrated hydraulic damper 30, which provides or can provide resistance to pivoting in both the extension direction and the flexion direction. In the exemplary embodiment shown, the hydraulic damper 30 is designed as a linear damper and has a housing 32 in which a cylinder 34 is formed. A piston 36 is arranged on a piston rod 33 within the cylinder 34 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 mechanically coupled 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 be able to dampen the movement in a way that is adapted to the respective situation. In addition, a drive 60 is arranged between the upper part 10 and the lower part 20, which is designed and configured to cause, support or hinder a pivoting of the upper part 10 relative to the lower part 20. This is done, for example, by the drive 60 in the form of an electric motor applying 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 supports or influences on 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 in order 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.

As an alternative to the design of the orthopaedic joint device as a component in a prosthetic leg, 3 Two alternative applications are shown in which the orthopaedic joint device is designed as part of an orthosis. The embodiments in the 3 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 are attached 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 takes place on the upper arm and the forearm, for the knee orthosis, the attachment takes place via thigh cuffs 19 and lower leg cuffs 29. The knee orthosis shows that the hydraulic damper 30 and the drive 60 act around the pivot axis 15. The hydraulic damper 30 is again attached to the upper part 10 with one end of the piston rod and to the lower part 20 with the housing part. Furthermore, sensors 95 are arranged on the upper part 10 and the lower part 20 or are associated with them and are connected to a control device 80. The connection can be made either by wire or radio or by another type of signal transmission. The control device 80 is coupled to the drive 60 and the hydraulic damper 30 and enables activation, deactivation or modulation of the drive 60 and adjustment of valves within the hydraulic damper 30. The control device 80 has all the necessary data processing devices, memory, software, hardware, interfaces and a power supply in order 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 an 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 the resistance to swiveling is increased. The sensors 95 can be force sensors, torque sensors, position sensors, pressure sensors, temperature sensors and IMUs. Several sensors can be arranged on both the upper part 10 and the lower part 20. The corresponding switching commands are then issued by the control device 80 on the basis of the transmitted sensor values.

In the design according to the 1 as well as in the design according to 3 In addition to the resistance device 30 and the motor drive 60, a force accumulator 90 is installed between the upper part 10 and the lower part 20. arranged to support, hinder or effect a pivoting or pivotability of the upper part 10 relative to the lower part 20. The energy storage device 90 in the 1 is arranged distally on the resistance device 30 and is connected in series with the resistance device 30. The same applies to the design of the 3 , in which the energy accumulator, for example in the form of an adjustable and lockable mechanical or pneumatic spring or an elastomer element, is arranged below the housing of the resistance device 30.

In the 2 a hydraulic circuit diagram of the hydraulic damper 30 is shown, 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 downwards, for example during flexion. Conversely, hydraulic fluid from the second chamber 342 is guided through the fluid connection 40 into the first chamber 341 when an extension movement takes place. 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 compensating volume 38 is arranged in the hydraulic damper 30 or coupled thereto.

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 a 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 the flow in the opposite direction, so that the hydraulic fluid emerging from the chamber 341, 342 must be guided through the switching valve 50.

In the embodiment shown, the switching valves 50 are designed as 3-way switching valves that can be switched between three discrete states. In the switching state shown, the fluid connection 40 is interrupted, i.e. 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 the position.

A throttle 56 is arranged upstream of the respective switching valve 50 in the flow direction 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. Parallel to this throttle 56, a flow channel with a maximum or fully open flow cross-section is present and leads to the switching valve 50. If the switching valve 50 is moved downwards from the interrupted and thus blocked position shown, which can be done by an electromagnet or another actuator or drive, the line not acted upon by the throttle 56 is acted upon by hydraulic fluid and can pass the hydraulic fluid through unhindered during an extension movement in which the piston 36 is moved upwards.

If the switching valve 50 is moved upwards from the shown locked position, hydraulic fluid from the second chamber 342 must first pass through the upstream throttle 56 in order to then pass through the check valve 55 into the first chamber 341. In this position, there is then an increased flow resistance, so that the pivoting movement in the extension direction is dampened. The switching for the switching valve 50 assigned to the first chamber 341 is correspondingly for the flexion movement.

The adjustment or displacement of the switching valves 50 is carried out sensor-based via the control device 80. Based on the sensor data of the sensors 95, the respective actuator for the switching valve 50 is activated or deactivated and the corresponding switching position is assumed.

If the one-time reduction in the flow cross-section provided by the throttle 56 is not sufficient or is too much 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 gear box, which either counteracts the movement or supports it in order to increase or reduce the resistance. The activation of the motor 60 also takes place via the controller 80 on the basis of sensor values and control programs and software that are stored in the controller 80.

In the 4a is a schematic representation of an orthopedic joint device illustrated using a prosthetic leg. The upper part 10 is, for example, the femoral shaft or the upper part of a prosthetic knee joint, the lower part 20 is the lower leg tube, which is mounted on the upper part 10 so that it can pivot about the pivot axis 15. The resistance device 30 is in the form of a hydraulic linear damper with the piston rod attached to the upper part 10, the housing in which the piston is moved downwards during flexion and upwards during extension is attached to the lower part 20 with the energy accumulator 90 interposed. The energy accumulator 90 is designed as a spring or pressure accumulator and can have an adjustment device with which the spring preload and/or spring stiffness can be adjusted. In the design of the energy accumulator 90 as a pressure accumulator, a pump and a valve are assigned to the pressure accumulator in order to increase or decrease the pressure and thereby adjust the spring preload or the spring stiffness. The resistance device 30 and the energy storage device 90 can be designed as a module and combined to form a structural unit. Also associated with the orthopedic joint device is a motor drive 60 which is set up and designed to cause a pivoting movement of the upper part 10 relative to the lower part 20, to counteract such a pivoting movement or to support it.

The drive 60 thus also acts as a resistance device when the drive 60 is controlled by the control device 80 (not shown) in such a way that it counteracts a pivoting movement. The drive 60 for influencing the resistance against a pivoting movement or for supporting a pivoting movement of the upper part 10 relative to the lower part acts parallel to the resistance device 30 and the energy accumulator 90 connected in series therewith.

In the 4b is one of the 4a shown, in which the energy storage device 90 is adjustable, a damping device or resistance device 30, which in the 4a arranged in series or in series with the energy accumulator 90, is in the 4b unavailable.

The fundamentally same structure of the 4a is in the 5 shown, with the difference that the resistance device 30 is adjustable in order to be able to set the resistance against a pivoting movement. In a design as a hydraulic damper, the adjustment is made by changes in the flow cross-section within the hydraulic lines in the resistance device 30, for example by changes in passage cross-sections in valves or throttles. The adjustment is made on the basis of sensor data, for example, adaptively during the movement or once by an orthopedic technician to adapt the resistance device 30 to the patient and the individual components of the orthopedic joint device. The adjustability also enables adaptation to changing properties of the orthopedic joint device, to wear, changes with regard to the different types of use or due to changing abilities or preferences of the respective user.

In the 6 instead of the resistance device 30, the energy storage device 90 is adjustable, in particular adjustable and also lockable. The adjustability of the energy storage device 90 enables an adjustment of the amount of energy that can be stored in the energy storage device 90 and thus also the amount of energy that can be used to support the pivoting movement or to act in the opposite direction, i.e. to hinder or prevent a pivoting movement. The adjustment of both the energy storage device 90 and, if applicable, the resistance device 30 is carried out, for example, sensor-controlled via the sensors described above and the control system, which is not shown for reasons of clarity.

In the 7 Both the resistance device 30 and the energy accumulator 90 are adjustable, in particular adjustable and lockable.

In the 8 A variant of the arrangement of resistance device 30, drive 60 and energy storage 90 is shown, all of which are arranged on the front side of the orthopaedic joint device. In the embodiment shown, the resistance device 30 and the energy storage 90 are not adjustable or adjustable, but can be combined with the drive 60 as desired in order to provide the desired resistance against a pivoting movement or to support a pivoting movement accordingly. In the 9 and 10 The resistance device 30 or the energy storage device 90 are adjustable and as in the arrangement according to 8 used. In the 11 Both the energy accumulator 90 and the resistance device 30 are designed to be adjustable.

A variant of the arrangement of resistance device 30, drive 60 and energy storage 90 is shown in 12 The drive 60 is arranged in parallel to the energy storage device 90 and connected in series to the resistance device 30. Both the resistance device 30 and the energy storage device 90 are adjustable or adjustable. In this configuration it is possible to to charge the energy accumulator 90 via the drive 60. The drive 60 is then the adjustment device for adjusting the spring preload or the spring stiffness or for setting the pressure within the pressure accumulator if such is designed as an energy accumulator 90. The energy accumulator 90 and the drive 60 are thus arranged in parallel to one another. If the drive 60 is to be operated in generator mode, for example, it is sensible and possible for the energy accumulator 90 to be locked in order to use the kinetic energy from the relative movement between the upper part 10 and the lower part 20 to move the drive 60 without losses. For this purpose, the resistance device 30 is also designed to be lockable and is advantageously locked in generator mode. This makes it possible to convert all of the kinetic energy from the relative movement of the upper part 10 to the lower part 20 into electrical energy via the drive 60 in generator mode and to feed it to a corresponding energy store or accumulator. The movement of upper part 10 and lower part 20 relative to each other is influenced by all three components, namely resistance device 30, drive 60 and energy storage 90, by supporting, hindering or preventing pivoting.

In the 13 is a further variant of the orthopedic joint device with an upper part 10, a lower part 20 and a joint arranged between them for pivoting relative to one another about a pivot axis 15, as an example for either a prosthetic leg or a leg orthosis. A resistance device 30, for example in the form of a hydraulic or pneumatic damper, a magnetorheological resistance device or a friction brake, is arranged parallel to a force accumulator 90, which is designed for example as a compressed air reservoir, an elastomer element or a mechanical spring. The force accumulator 90 is adjustable and also switchable. Also parallel to this is a motor drive 60 in the upper part 10 and the lower part 20 in order to influence a pivoting movement in the extension direction and/or flexion direction. The motor drive 60 supports or counteracts a pivoting movement of the lower part 20 relative to the upper part 10. The energy storage device 90 is switchably coupled to the resistance device 30, so that the resistance device 30 can be operated in combination with the drive 60, in combination with the energy storage device 90 or in combination with the drive 60 and the energy storage device 90, in addition to the option that the resistance device 30 can be used without a further component to influence the pivoting movement. In the embodiment according to the 13 The drive is designed as a rotary motor drive parallel to the energy accumulator 90.

In the 14 The resistance device 30, the energy storage device 90 and the motor drive 60 are arranged parallel to each other, the motor drive 60 is designed as a linear drive. In the 15 the motor drive 60 is designed as a linear drive which is arranged in series with the other components connected in parallel, namely the energy accumulator 90 and the resistance device 30.

In all embodiments of the 13 to 15 can store the mechanical work performed on it as internal energy in the energy storage device 90 shown and perform work on its surroundings in the course of releasing energy. The energy storage devices 90 are designed in particular as mechanical, hydraulic or pneumatic springs. The respective energy storage device 90 can be coupled out of the chain of action and coupled into it, for example via a valve of a hydraulic circuit or via a mechanical coupling. This makes it possible to couple the energy storage device 90 with the upper part 10 and/or with the lower part 20, or to disengage it, whereby this can take place at any knee angle or joint angle between the upper part 10 and the lower part 20.

When the motor drive 60 is arranged in series with the energy storage device 90, the moments around the pivot axis 15 do not add up, but rather the transmitted forces or moments are identical for both components and the lengths or displacements add up or are combined with each other, but a superposition occurs which modulates the characteristic curves, for example the force-displacement behavior or the moment-angle behavior, so that a change in preload and stiffness, non-monotonic characteristics, transparent modes and a transfer of energy from the drive 60 to the energy storage device 90 and vice versa can occur. A shift in the characteristic curve is thus modulated as a function of the moment.

In the 14 a positive superposition M _Σ of the characteristic curve M _A of the drive 60 and the characteristic curve M _S of the energy storage device 90 over the pivot angle φ is shown. The representation of the positive superposition M _Σ refers to the generated knee moment as a function of the knee angle φ, in which the energy storage device 90 is climatically coupled to the knee angle 4 in at least one movement phase. In general, the knee angle φ is the actuated degree of freedom and M is the associated moment or the associated force. In the embodiment of the 14 The energy storage 90 is a progressive Spring with a preload. The drive 60 is a motor that is controlled like a linear spring, whereby the torque generated by the motor is aligned with the torque of the energy storage device 90. The torques generated by the energy storage device 90 and the drive 60 therefore add up, resulting in a characteristic curve of the positive superposition M _Σ with increased rigidity compared to the characteristic curve M _S of the energy storage device 90 alone. The preload in the characteristic curve M _S at an initial angle φ ₀ remains unchanged by the torque of the motor or drive 60. The drive 60 modulates the overall characteristic curve in the form of the positive superposition M _Σ starting from the characteristic curve M _S of the energy storage device.

In the 17 is a representation of the lines with a weakening modulation by the drive 60. The characteristic curve MS of the energy storage device is corresponding to that of the 16 while the MA characteristic curve of the drive is linear, as shown in the 16 , but has an opposite direction of action. The drive 60 acts according to a linear characteristic curve, which at the starting angle φ ₀ corresponds in magnitude to the stiffness of the energy storage device 90 and thus has an offset opposite to the preload of the energy storage device 90. In the range from the starting angle φ ₀ to the limit angle φ ₁ , the moments about the pivot axis 15 essentially cancel each other out. As the joint angle increases, the moment of the energy storage device 90 increases more strongly due to the progression than that of the drive 60, so that a progressive increase in moment or stiffness results, which is clear from the superposition M _Σ , which increases from the limit angle. The resulting characteristic curve of the superposition M _Σ is determined by the drive 60 in comparison to the superposition M _Σ of the 16 changed significantly, both in terms of the effective preload and in terms of the total torque and characteristics. By applying a drive torque that is opposite to the torque of the energy accumulator 60, the resulting torque about the swivel axis can be reduced as desired.

In the 18 a complete compensation of the moment of the energy storage device 90 by the drive 60 takes place, the drive 60 applies a moment of the same magnitude but in the opposite direction to the moment of the energy storage device 90, so that both moments essentially cancel each other out. The superimposed moment or the superposition M _Σ is 0 or essentially 0 over the entire angular range. Such a control makes it possible to charge or discharge the energy storage device 90 without affecting the movement of the orthopedic device. Such a complete compensation of the moment of the energy storage device by the drive is also called transparent mode.

In the 19 the modulation of the resulting moment or the superposition M _Σ of a moment M _S of the energy storage device 90 by a moment M _A of the drive 60 is shown as a function of the direction of movement. The moment M _A applied by the drive 60 is changed as a function of the direction of movement in order to achieve a direction-dependent characteristic of the superposition M _Σ or the resulting moment. In the 19 the moment M _S of the energy storage device 90 is amplified by the drive torque M _A during flexion and weakened during extension, whereby the initial angle φ ₀ represents the fully extended position of the joint. Overall, this leads to a hysteresis of the superposition M _Σ .

In the 20 it is shown that the moment M _A applied by the drive 60 is changed depending on the direction of action of the energy storage device 90. An amplification takes place in the flexion direction, starting from a zero point at the intersection point of the coordinate axes; in the extension direction, a weakening takes place due to the moment M _A of the drive 60. The changes or modulations described above can be combined with one another; instead of a zero crossing of the speed or a zero point, an exceedance or undershoot of a threshold value can also be used for the change in the characteristic curve of the moment M _A by the drive 60.

In the 21 is a non-monotonic combination of an amplification or weakening of a moment M _S applied by the energy accumulator 90 by a moment M _A of the drive 60. At the initial angle, the drive 60 applies a moment opposite to the moment due to the preload of the energy accumulator 90, so that the total moment is zero. Between the initial angle and the limit angle, the drive 60 is operated according to a linear spring stiffness, wherein as the joint angle φ increases, the sign of the moment M _A from the drive 60 changes from an opposing to a supporting moment. This occurs approximately halfway between the initial angle φ ₀ and the limit angle φ ₁ . From the limit angle φ _1, the moment M _A applied by the drive 60 is reduced and shortly after the limit angle φ ₁ counteracts the moment M _A of the energy accumulator 90, whereby from the limit angle φ ₁ there is a smooth change to a negative spring stiffness for the control of the drive 60. With a further increasing joint angle φ, the moment M _A of the drive 60 counteracts the moment M _S of the energy storage device 90. The resulting torque characteristic M _Σ as a superposition of motor torque M _A and energy storage torque M _A initially starts torque-free at the starting angle φ ₀ , increases between the starting angle φ ₀ and the limit angle φ ₁ and is weakened again from the limit angle φ ₁ with increasing joint angle φ.

In the 22 a combination of moments of the drive 60 and the energy storage device 90 is implemented in such a way that from an initial angle φ ₀ up to a limit angle φ ₁ a moment M _S from the energy storage device 90 initially applies a moment M _A of the drive 60 that counteracts the energy storage moment Ms, so that the superposition M _Σ results in essentially 0, so that the orthopaedic joint device is not influenced in terms of pivotability. From the limit angle φ _1, the drive 60 is controlled in such a way that the moment M _A applied by the drive 60 is reduced in magnitude and subsequently changes from a counteracting moment to a supporting moment, so that the moment M _A of the drive and the moment M _S of the energy storage device 90 act in the same direction. The modulation of the characteristic curve of the moment M _S of the energy accumulator 90 by the drive 60 results in the characteristic curve of the superposition M _Σ of a one-sided, progressive spring. Only when the limit angle φ ₁ is exceeded does a total moment or a superposition M _Σ result, which influences the pivoting movement.

In the 23 and 24 various characteristic curves and angle profiles over time are shown which occur for charging the energy storage device 90 or an energy storage device when the joint is flexed, for example when the knee is bent. The names of the moments correspond to the names of the aforementioned figures, the angle φ _K is the knee angle. The moments which act on the drive in the form of an electric motor and the energy storage device are designated M _A and M _S. The moments at the respective fastening points of the components on the upper part and lower part act in opposite directions. If the energy storage device coupled with the knee angle φ _K is charged, a moment is normally opposed to the movement or the knee flexion, since work must be done on the energy storage device. In combination with a motor, the work to be done can be done by the motor, so that the pivoting movement of the upper part relative to the lower part is not affected. The energy stored in the energy storage device can then be released again at a later time. If the energy storage and the motor act in the same direction when releasing energy, the total torque M _Σ can be increased significantly. In the 23 the energy storage device is first charged by the motor. At the start of the flexion movement, the energy storage device is decoupled from the knee angle φ _K , so that no moment is generated by the energy storage device. In the flexion phase, a supporting moment, in this case a moment that increases with the knee angle, is initially applied by the motor to facilitate the flexion movement. From time t ₁ , the energy storage device is switched on. Further knee flexion with an increase in the knee angle φ _K results in an increase in force in the energy storage device according to its characteristic curve. The motor torque is adjusted accordingly so that the moment of the energy storage device is compensated. The resulting moment as a superposition of the motor torque and the energy storage moment then corresponds to the desired curve for supporting the flexion movement. The work performed by the motor is greater than the work performed on the energy storage device, which means that no resistance to movement is encountered when the upper part pivots relative to the lower part, but rather positive work is performed. Alternatively, the movement in flexion can not be supported, for example the motor torque would be selected so that the torques from the motor and the energy storage cancel each other out or so that the torque of the energy storage is sufficiently weakened. After charging the energy storage, the energy storage is decoupled from the orthopedic joint device and is independent of the joint angle φ _K , so that the energy stored in the energy storage is retained.

In the 24 a discharge of the energy storage device is shown. When discharging, the energy storage device generates an extension moment between the upper and lower parts and does work. To increase the extension moment, the motor can apply an additional extension moment or stretching moment so that the total moment M _Σ is higher than that of the energy storage device. With the extension, i.e. a decreasing knee angle φ _K , the motor torque is reduced in the variant shown here. The moment M _S through the energy storage device is also reduced in accordance with the characteristic curve of the energy storage device, which creates the decreasing torque curve shown. The energy storage device is completely discharged before the knee joint has been fully extended. Decoupling and coupling the energy storage device enables the energy storage device to charge and discharge in different knee angle ranges.

The 23 and 24 The phases shown can also be used independently of each other, whereby a not fully charged energy storage device is required for charging and a not completely discharged energy storage is a prerequisite.

In the 25 The charging of the energy storage device is shown during a flexion movement on an artificial knee joint. Initially, only the moment M _S of the energy storage device acts and the knee moment increases with increasing knee flexion. From time t _1, the total moment MS is limited by an opposing moment M _A of the motor, whereby the energy storage device continues to be charged. Alternatively, the energy storage device can be charged without using the motor, although in this case a further increase in moment would occur. A fully or partially charged energy storage device can be decoupled from the joint so that no change occurs in the energy storage device regardless of the knee angle. The energy storage device can be coupled back in at any time to either charge the energy storage device or discharge it to support a movement.

In the 26 The discharging of the energy storage device during a stretching movement is shown. While the energy storage device is doing work, work is being done on the motor at the same time. This is achieved by operating the motor in generator mode. In generator mode, the work done by the energy storage device can be converted into electrical energy and stored in an accumulator. This is particularly advantageous when the energy stored in the energy storage device is not needed to support the movement. In the illustrated embodiment of the 26 the motor is operated in such a way that the moment generated by the motor is essentially as large as the moment of the energy storage device, but acts in the opposite direction, whereby the two moments cancel each other out. This means that the movement of the orthopaedic joint device is not affected when the energy storage device is discharging. Instead of full compensation, the moment of the energy storage device can also be weakened or overcompensated. In principle, it is not necessary for the electrical energy generated by the motor during braking to be stored and used to charge an accumulator. The energy can also be converted into heat via resistors. It is also possible for electrical energy to be used for the braking operation of the motor. In this case, the moment of the motor serves primarily to sufficiently weaken the stretching moment when the energy storage device is discharging in order to achieve a controlled discharge of the energy storage device. Discharging the energy storage device in this way may be necessary if the stored energy is not needed and the energy storage device must be partially or completely discharged for a subsequent movement phase.

The recuperation of energy via a generator is particularly efficient when the generator is running at high speeds. It is therefore intended to recuperate electrical energy in phases when the generator or motor is running at the highest possible speed in generator mode. These can be phases with a high knee angle speed. In a design with a variable gear ratio, phases with a high gear ratio can also be used. The discharging of the energy storage device using recuperation can be delayed so that the motor is running at correspondingly high speeds during recuperation by the motor. In particular, charging the energy storage device in the standing phase and discharging and recuperating in the swing phase are advantageous. Discharging and recuperating in accordance with the 25 and 26 The controls shown can be used independently or in combination.

In particular, it is possible to bring about an energy exchange between the drive 60 and the energy storage device 90 in the energy storage device, wherein in particular the energy storage device 90 is charged via the drive 60 or the electrical energy generated during recuperation is stored in the energy storage device until it is needed.

In the 27 the change in the torque curve is shown on the basis of further input variables. The generation of a torque via a motor drive makes it possible to vary the torque not only with the coupled degrees of freedom of the joint, but alternatively or additionally to use another or further input signal or several other or further input signals for the modulation. In particular, sensor values can be used to modulate the torque. For example, the absolute angle of the upper part and/or lower part and/or load variables such as forces, moments and lever arms can be used as further input variables. Signals from a human-machine interface or artificial intelligence can also be used. In the 27 the moment characteristic M _Σ is shown as a superposition of a parallel arranged force storage device with the moment MS and the motor drive with the moment MA in a movement phase. The characteristic M _Σ depends both on the actuated degree of freedom, in the example shown the knee angle φ, and on an additional signal X, for example the absolute angle of the lower part. While in the embodiment shown the moment M _S generated by the force storage device only depends on the joint angle φ, the motor torque M _A can be varied both with the joint angle φ and with the absolute angle X. Shown in the 27 is a change in the stiffness in the M- φ plane with the additional input signal X, i.e. the absolute angle. At X ₀ the torque Ms of the energy accumulator is amplified by the motor with the motor torque M _A (M _A , X ₀ ) so that the sum results in the characteristic curve M _Σ , X ₀ , whereas at an absolute angle X ₁ the total torque (M _Σ , X ₁ ) is weakened by the motor torque M _A at the angular position X _1. The characteristic curve can be continuously adjusted between the two values of X; in the embodiment shown the adjustment is linear. The dependence of the motor torque M _A on the input variable X can take on any continuous or discontinuous form; it is also possible for the motor torque M _A to only depend on the input variable X.

In the 28 is the relationship between the input variables absolute angle X, joint angle cp, the moments MA from the drive and MS from the energy storage as well as the total moment for the 27 shown characteristic surface.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 2 535 024 A1 [0006]
• DE 10 2018 126 324 A1 [0007]

Cited non-patent literature

• A Comparison of Parallel and Series Elastic Elements in an Actuator for Mimicking Human Ankle Joint in Walking and Running” by Martin Grimmer, Mahdy Eslamy, Stefan Gliech and André Seyfarth, published at the IEEE International Conference on Robotics and Automation, 2012 [0008]
• Effects of Unidirectional Parallel Springs on Required Peak Power and Energy in Powered Prosthetic Ankles: Comparison between Different Active Actuation Concepts” by Mahdy Eslamy, Martin Grimmer and Andre Seyfarth, pp. 2406 to 2412, Proceedings of the 2012 IEEE International Conference on Robotics and Biomimetics, December 11th - 14th, 2012, Guangzhou, China [0009]

Claims (18)

Orthopaedic joint device with 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 at least one resistance device (30) which is arranged between the upper part (10) and the lower part (20), the resistance device (30) is designed to influence a pivoting or pivotability of the upper part (10) relative to the lower part (20), characterized in that a motor drive (60) and at least one energy accumulator (90) are arranged between the upper part (10) and the lower part (20), which are designed and arranged to bring about, support or hinder a pivoting or pivotability of the upper part (10) relative to the lower part (20). Orthopaedic joint device according to claim 1 , characterized in that the resistance device (30) and/or the energy accumulator (90) are adjustable and/or decoupleable. Orthopaedic joint device according to claim 1 or 2 , 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 adjustable valve (50) is arranged, in particular a multi-way valve with a closed switching position, an open switching position and at least one partially open switching position. Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) is designed as a linear damper or rotational damper. 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 to the upper part (10) and the lower part (20) via a gear (70). Orthopaedic joint device according to one of the preceding claims, characterized in that the resistance device (30) and/or the energy accumulator (90) and/or the drive (60) is assigned a controller (80) which is coupled to at least one sensor (95) and is set up to activate, deactivate and/or modulate the resistance device (30) and/or the energy accumulator (90) and/or the drive (60) on the basis of the sensor values. Orthopaedic joint device according to one of the preceding claims, characterized in that the force accumulator (90) is designed as a spring or pressure accumulator. Orthopaedic joint device according to claim 7 , characterized in that the spring is associated with an adjusting device for adjusting the spring preload and/or spring stiffness. Orthopaedic joint device according to claim 7 , characterized in that a pump and/or a valve are assigned to the pressure accumulator as an adjusting device. Orthopaedic joint device according to claim 8 or 9 , characterized in that the adjusting device is the drive (60). Orthopaedic joint device according to one of the preceding claims, characterized in that the energy accumulator (90) and the drive (60) are arranged to operate parallel to one another. Orthopaedic joint device according to one of the preceding claims, characterized in that the force accumulator (90) and the resistance device (30) are connected in series. 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 parallel to the resistance device (60) and the energy accumulator (90). procedure according to claim 13 , characterized in that the drive (60) and/or the energy accumulator (90) and/or the resistance device (30) is activated, deactivated and/or modulated on the basis of sensor data. procedure according to claim 13 or 14 , characterized in that the modulation of the overall characteristic is carried out by the drive (60) based on the characteristic of the resistance device (30) and/or energy accumulator (90). Method according to one of the Claims 13 until 15 , characterized in that a conversion of energy stored in the energy storage device (90) energy into electrical energy via the drive (60) and vice versa. Method according to one of the Claims 13 until 15 , characterized in that the energy accumulator (90) is decoupled and kept in a charged state. Method according to one of the Claims 13 until 17 , characterized in that the drive (60) is operated such that the effect of the resistance device (30) is canceled.

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