WO2024121151A1

WO2024121151A1 - Prosthetic or orthotic knee joint and method for the control thereof

Info

Publication number: WO2024121151A1
Application number: PCT/EP2023/084352
Authority: WO
Inventors: Roland Pawlik; Ute Hantsch
Original assignee: Otto Bock Healthcare Products Gmbh
Priority date: 2022-12-06
Filing date: 2023-12-05
Publication date: 2024-06-13
Also published as: DE102022132341A1

Abstract

The invention relates to a prosthetic or orthotic knee joint comprising an upper part (10) and a lower part (20) mounted on the upper part (10) such that it can pivot about a pivot axis (15), and a resistance unit (30) between the upper part (10) and the lower part (20), with which the pivotability of the upper part (10) relative to the lower part (20) can be influenced at least in the flexion direction, comprising a control unit (40) which is coupled to the resistance unit (30) and via which the resistance against a flexion is changed according to the position of the upper part (10) relative to the lower part (20), wherein the control unit (40) is designed to block or significantly inhibit a flexion movement at a blocking angle (a) when reaching or before reaching a mechanical end stop (80).

Description

Prosthetic or orthotic knee joint and method for controlling it

The invention relates to a prosthetic knee joint or orthotic knee joint with an upper part and a lower part mounted on the upper part so as to be pivotable about a pivot axis and a resistance device between the upper part and the lower part, with which the pivotability of the upper part relative to the lower part can be influenced at least in the flexion direction, with a control device which is coupled to the resistance device and via which the resistance to flexion is changed depending on the position of the upper part in relation to the lower part. The invention also relates to a method for controlling such a prosthetic knee joint or orthotic knee joint.

Prosthetic knee joints replace knee joints of a human body that are no longer present or do not exist and have an upper part and a lower part that are mounted so that they can be moved relative to one another about a pivot axis. The pivot axis can be either stationary or non-stationary. The prosthetic knee joint has a simple structure with a single, spatially defined pivot axis and is designed in the form of a hinge joint, with a resistance device being arranged between the upper part and the lower part, for example a linearly acting hydraulic damper, in order to influence the pivoting movement about the pivot axis. The prosthetic knee joint can have a locking device with which the prosthetic knee joint is locked in the desired position, in particular in an extended position, so that a locking knee joint is formed. i Orthoses stabilize or guide the movement of the natural knee joint and can limit the angle of rotation, for example to prevent full extension or full flexion of the natural knee for medical reasons. Orthotic knee joints are arranged in orthoses that span the natural knee joint when worn. The orthotic knee joint also has an upper part and a lower part, on which rails or similar components are arranged, via which the orthotic knee joint is attached to the thigh or lower leg. Knee orthoses usually have two orthotic knee joints, one of which is arranged medially and the other laterally to the natural knee joint. To influence the pivoting movement from thigh to lower leg, resistance devices or dampers are arranged in or on the orthosis, which act between the upper and lower parts of the orthosis.

To support the movement, active drives can be arranged on an orthosis as well as on a prosthesis, which are designed, for example, as electric motors or energy storage devices to support flexion or extension in the respective situation. The energy storage devices or drives can also be designed to counteract the respective movement and can be arranged on the orthosis or prosthesis. The influence on the movement of the upper part relative to the lower part with the resistance device or the drive can be adapted to the respective situation or load. This is done, for example, via a control device that activates, deactivates or modulates an actuator on the basis of sensor values that is assigned to the resistance device or is part of the resistance device and changes parameters of the resistance device in order to provide the desired resistance in each case. The actuator can, for example, be a relay that can be used to switch a switching valve between two states. An electric motor can bring a control valve into the desired position in order to generate the required resistance, for example in a flow channel. An electromagnet can generate the desired magnetic field to change the viscosity of a magnetorheological fluid to create the desired resistance to displacement. The control device has a microprocessor or a data processing device with which the sensor data processed promptly, especially in real time, and used as the basis for control. With the resistance device it is also possible to completely prevent the pivoting or pivotability from the upper part to the lower part.

Due to their design, prosthetic knee joints and orthotic knee joints have a predetermined maximum pivot angle in both the extension direction and the flexion direction. At the end of the maximum pivoting range there are mechanical end stops that prevent further movement of the upper and lower parts in the extension direction or flexion direction. Particularly with fast movements, the problem can arise that the prosthetic components are brought to the mechanical end stop without braking or at high speed, which leads to a high impulse in the prosthetic knee joint or the orthotic knee joint. This is unpleasant for the user of the artificial knee joint and can also lead to damage to the orthosis or prosthesis, in particular to the mechanical components of the prosthetic knee joint and orthotic knee joint. In order to prevent the lower part from hitting the mechanical extension stop or flexion stop hard, mechanical dampers are provided, for example elastomer elements, which become effective shortly before the mechanical end stop is reached due to the solid-state damping and convert the kinetic energy.

Prostheses and orthoses are designed to make everyday movements easier for the user. The main applications of prosthetic knee joints and orthotic knee joints are sitting, standing and walking and the transitions between them. In addition, there are a number of activities that deviate from these states or purposes, such as everyday household chores, picking up things that have fallen down, shopping or the like. Looking after pets or small children also requires movements that can be challenging for users of prosthetic knee joints and orthotic knee joints. Instead of bending forward with the upper body, users of prostheses or orthoses often have to bend their knees. Since this is comparatively strenuous, compensatory movements are carried out or such activities are omitted, which limits the quality of life.

The object of the present invention is to provide a prosthetic knee joint or orthotic knee joint and a method for controlling such a knee joint, with which an increase in comfort and additional areas of application can be achieved for the user.

This object is achieved by a prosthetic knee joint or orthotic knee joint with an upper part and a lower part mounted on the upper part so as to be pivotable about a pivot axis, and a resistance device between the upper part and the lower part, with which the pivotability of the upper part relative to the lower part can be influenced at least in the flexion direction, then a control device which is coupled to the resistance device and via which the resistance to flexion is changed depending on the position of the upper part and the lower part, wherein the control device is set up to block or to dampen a flexion movement at a locking angle at or before a mechanical end stop is reached. The sensor-dependent activation, deactivation or modulation of the resistance device for blocking or increased damping of a flexion movement when a locking angle is reached before the mechanical end stop is reached either prevents the mechanical end stop from being reached or dampens the reaching of the mechanical end stop so much that the prosthetic knee joint or orthotic knee joint is not damaged or the mechanical loads are reduced. Increased flexion resistance is provided even before the mechanical end stop is reached, but this can also be dimensioned so that the mechanical end stop is still reached, but at a reduced, in particular greatly reduced, speed.

At the locking angle, which is preferably in front of the mechanical end stop, the resistance against flexion by the resistance device is maximum, In particular, with the locking angle, the flexion movement is blocked before the mechanical end stop is reached.

In one embodiment, the control device is designed to increase the flexion resistance over a defined angle range up to the locking before the locking angle is reached. The locking angle is determined or calculated in the control device or the defined locking angle is monitored. If the joint angle of the upper part relative to the lower part exceeds a threshold value for the angle range, for example the lower part of a flexion movement approaches the locking angle within 15°, the resistance is increased before the locking angle is reached in order to achieve a gentle reduction in the flexion speed by increasing the flexion resistance over an angle range. The closer the lower part approaches the locking angle, the greater the flexion resistance advantageously becomes due to the resistance device.

In one embodiment, the control device is coupled to at least one sensor for detecting the joint angle between the upper part and the lower part or for detecting the orientation of the upper part in space and is also designed to change the resistance by the resistance device on the basis of the sensor values of the sensor or sensors. This change takes place in particular after a threshold value of the joint angle has been reached. In addition or alternatively, the change in the resistance takes place on the basis of the duration of an unchanged joint angle, a determined orientation of the upper part in space and/or a locking command. The change in particular causes the resistance to be increased until it is locked against flexion. As a result, the resistance can be increased to the maximum for any angular position based on a locking command and further flexion movement can be prevented. Locking can also take place in a static state over a certain period of time, i.e. with an unchanged position from the upper part to the lower part. The resistance is also increased for a predetermined orientation or when a predetermined joint angle is reached, possibly until it is locked. This allows the user to, for example, squat or perform kneeling activities more easily, as the user can place a load on the knee joint that is locked in the direction of flexion. The locking mechanism creates a support or abutment, which means that it is no longer necessary to apply a knee-extending moment using the muscles. In addition, support when standing up is also possible through active propulsion and/or the muscles of the healthy extremities.

In order to unlock the locked knee joint, the control device is coupled to at least one sensor for detecting an unlocking signal with which the lock is removed. The unlocking signal can be a manual signal via a button, a switch or the like. Alternatively, a certain movement, a certain force curve, a change in state or an orientation or a change in orientation of, for example, the upper part can lead to an unlocking of the prosthetic knee joint or orthotic knee joint. If, for example, the upper part is moved over a certain pivot angle in the extension direction relative to the lower part, this can be interpreted as a signal to unlock the resistance device against the flexion movement.

In one embodiment, the control device is designed to increase the flexion resistance as the flexion increases. The increase in resistance is positively coupled with the change in the joint angle; the closer the joint angle approaches the locking angle, the greater the resistance becomes. The coupling can be linear, progressive or degressive.

In particular, in the case of a pneumatic or hydraulic design of the resistance device, at least one control valve or an adjustment device is arranged in the resistance device, which is coupled to an actuator that is activated, deactivated or modulated via the control device. Hydraulic or pneumatic damping devices often already exist in prosthetic knee joints and orthotic knee joints in order to influence the most frequent or most important movements. Using a corresponding control device, it is possible to control the control valve or an adjustment device to activate via an actuator in such a way that the desired resistance is set, in particular the flexion resistance is increased before the mechanical end stop is reached, in particular a locking of the joint in the flexion direction is brought about before the mechanical end stop is reached. The resistance device can be designed as a linear damper or a rotary damper, whereby in both embodiments the resistance device can be based on the hydraulic or pneumatic principle. Alternatively or additionally, a magnetorheological resistance device can be arranged or assigned to the hydraulic resistance device. The hydraulic resistance device can be operated with a magnetorheological fluid, the viscosity can also be changed as desired by a controllable electromagnet. In principle, it is also possible to use an active drive as a resistance device.

In one embodiment, the control device provides that parameters are stored in it that lead to the locking or increase of the flexion resistance, whereby the parameters for the locking can be set in the control device. This makes it possible to define resistance curves, signal durations for locking activations, unlocking signals and positions of the locking angles that are adapted to the patient.

One embodiment provides that the locking angle at which further flexion is blocked or maximum damping is provided by the resistance device is set between 2° and 40°, in particular between 5° and 30°, before the mechanical end stop. This also ensures that in the case of a permanent load on a hydraulic resistance device or a pneumatic resistance device, any leakage or delays in the action of the actuator do not lead to a hard stop in the mechanical end stop.

In the method for controlling such a prosthetic knee joint or orthotic knee joint, the flexion resistance before reaching the locking angle after reaching a threshold value of the joint angle with increasing flexion and/or at a constant joint angle, and/or constant orientation of the upper part in space over a specified period of time and/or when a blocking signal is given.

In one embodiment of the method, the resistance is increased linearly or progressively as the locking angle is approached. In one embodiment, the flexion resistance is increased over an angle range of more than 5° before the locking angle is reached in order to have a sufficient period of time or sufficient distance to increase the damping and reduce the flexion speed.

In one embodiment of the method, the control device is coupled to a foot part that is mounted on a lower leg tube in a prosthetic knee joint or a lower leg splint in an orthotic knee joint. The prosthetic knee joint or orthotic knee joint is unlocked or locked based on the position and/or load of the foot part. Depending on how the foot part is loaded, whether there is a forefoot load, whether there is flexion or whether there is a bend in a sole part or a sole element, the prosthetic knee joint or orthotic knee joint is locked or unlocked. For this purpose, sensors can be arranged on the lower part or the foot part, which are coupled to the control device and the locking or unlocking or increasing the resistance or reducing the flexion resistance is carried out on the basis of sensor data.

A further development of the method provides that the position of the body's center of gravity is recorded or determined relative to the treated leg and that during a movement, on the basis of the course of the body's center of gravity, a distinction is made between an increase in resistance or a blockage. The body's center of gravity is determined or calculated, for example, relative to the foot point or the force introduction point of the ground reaction force, the pivot axis of the ankle joint or, for example, the knee joint. Based on the course of the body's center of gravity relative to the The respective reference value or reference position can be used to distinguish which movement the user of the orthosis or prosthesis is currently performing. If, for example, the body's center of gravity remains behind the knee joint axis as well as the ankle joint axis during flexion of the knee joint, it can be assumed that the user is sitting down or at least is not performing a kneeling movement or wants to kneel down. Based on this information, which is transmitted in addition to other information from the control device, a distinction is then made as to whether a blocking or an increase in resistance is initiated or not initiated, or whether another change in resistance is initiated.

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

Figure 1 - a schematic representation of a prosthesis;

Figure 2 - a schematic representation of an orthosis;

Figure 3 - another schematic representation in a bent position; and

Figure 4 - an application example.

Figure 1 shows a schematic representation of a prosthetic knee joint as part of a prosthesis and Figure 2 shows an orthotic knee joint as part of an orthosis. The prosthetic knee joint has an upper part 10 and a lower part 20 which are pivotably mounted on one another about a pivot axis 15. In a design as a prosthesis, a prosthetic foot 60 is arranged on the distal end of the lower part 20. In the design of the artificial knee joint as an orthotic knee joint, as shown in Figure 2, the lower part 20 is designed as a lower leg splint on which no foot part is arranged, but on which an optional foot part 60 can be arranged, which is shown in the broken line. In the case of a KAFO, a foot part 60 is arranged on the lower part 20 on which a foot can be placed. However, this can also be omitted to create a pure knee orthosis. In the In the embodiment as a prosthetic leg according to Figure 1, a prosthetic shaft or another device for receiving a thigh stump or for securing to a person is arranged or formed on the upper part 10. In the embodiment according to Figure 2, the orthosis is secured to a leg via fastening means 101, 201, which are designed, for example, as straps, shells or the like, in order to removably secure the orthosis to the leg.

A resistance device 30 is arranged between the upper part 10 and the lower part 20 as a linearly acting hydraulic damper. In the exemplary embodiment shown, the hydraulic actuator 30 is designed with a hydraulic chamber or a cylinder which is arranged or formed in a housing or base body 31. A piston 32 is displaceably mounted in the cylinder. The piston 32 can be displaced along the longitudinal extent of the cylinder and is fastened to a piston rod 33 which protrudes from the housing or base body 31. The piston 32 divides the cylinder into chambers which are fluidically connected to one another via a hydraulic line. The base body 31 or the housing can be pivotably mounted on the lower part 20 at a fastening point 23 in order to prevent the piston 32 from tilting during a pivoting movement of the upper part 10 relative to the lower part 20. The end of the piston rod 33 facing away from the piston 32 is attached to the upper part 10, in the embodiment shown on a boom to increase the distance to the pivot axis 15, at an upper fastening point 21. During flexion, the piston 32 is pressed downwards so that the volume of a flexion chamber decreases, and correspondingly the volume of an extension chamber increases, reduced by the volume of the retracting piston rod 33. An electric motor can be arranged in the housing 31 to generate a pressure within one of the chambers, which drives a pump (not shown) in order to apply pressure to the hydraulic fluid within one of the two chambers and thereby move the piston 32 within the cylinder in one direction or the other. This causes a flexion movement or an extension movement of the orthopedic device in the form of the prosthetic leg. The electric motor for driving the pump is an option that can be used in one embodiment in combination with the linear damper 30. In principle, a drive or motor is not required for a passive Prosthetic knee joint is not necessary. An alternative design of the resistance device provides for a rotary damper, in particular a rotary hydraulic system, a magnetorheological resistance device or an electric motor, e.g. in generator mode, instead of a linear damper, in particular a linear hydraulic system. A combination of several of the resistance devices mentioned is also implemented in one design.

An actuator 34 is arranged within the housing 31 or on the housing 31 and is coupled to at least one control valve 35, via which the hydraulic resistance in the resistance device 30 can be changed. The actuator 34 is coupled to a control device 40, which activates, deactivates or modulates the actuator 34 on the basis of sensor values in order to be able to provide an adapted resistance and, if necessary, a hydraulic lock. If the resistance device 30 is designed as a magnetorheological resistance device, the resistances are changed by activating, deactivating or modulating a magnetic field, the actuator 34 is then the electromagnet or the magnetic coil.

At least one sensor 50 for detecting the spatial orientation of the lower part 20 or the upper part 10 is arranged on both the upper part 10 and the lower part 20. In particular, the sensor 50 for detecting the spatial orientation is only arranged on the upper part 10. This sensor 50, which can be designed as an IMU (inertial measurement unit), for example, is used to determine the solid angle or the absolute angle to a fixed spatial orientation, for example the direction of gravity, during use of the prosthetic knee joint or the orthotic knee joint. Instead of being designed as an IMU for detecting spatial positions, the sensor 50 can also detect other status data, in particular status data relating to the artificial knee joint. In particular, positions, angular positions, speeds, accelerations, forces and their progressions or changes are recorded as status data. The determined solid angle of the upper part 10 and/or the lower part 20 or another status variable is compared with a threshold angle. When a threshold value stored in a controller 40 for the respective sensor value or a value derived therefrom is reached or exceeded, the actuator 34 is modulated, activated or deactivated in order to otherwise change the flow resistance in the resistance device 30 in the design as a hydraulic damper, the viscosity, the braking force or the force counteracting the flexion movement.

The resistance device 30 in an artificial knee joint is usually used to modulate a flexion movement and an extension movement in order to generate or support an appropriate or desired movement sequence. An extension movement is supported if necessary and advantageously braked shortly before reaching maximum extension in order to avoid a hard impact. A flexion movement is braked or prevented in the stance phase and in the swing phase in order to ensure that the flexion is limited. In order to be able to drive the actuator 34, an energy storage device, in particular in the form of an accumulator, is also assigned to the actuator 34. The energy storage device can be arranged directly next to the actuator 34 or at another location in the orthopedic device where more space is available or where this appears advantageous due to the weight distribution.

One difference between the design according to Figure 1 and the design according to Figure 2 is that according to Figure 2, a drive 70 is provided in which an electric motor 70 is coupled to a pulley, possibly via a gear. A V-belt or toothed belt can then be used to bring about or support flexion or extension of the knee joint, depending on the direction of rotation of the motor 70. The design with the drive with an electric motor 70 via a mechanical power transmission device and parallel damping via a hydraulic damper can also be used for a prosthetic knee joint. As already explained in relation to Figure 1, the resistance device in an orthosis can also be designed as a motor, e.g. in generator mode.

The direct mechanical coupling of the electric motor as a resistance device 30 with the upper part 10 and the lower part 20 can be carried out via a power transmission device, for example via a spindle drive, so that instead of a piston rod 33, a spindle is driven out of the housing 31 by turning a spindle nut, which is driven by the electric motor. is retracted or extended. In another embodiment, the motor as a resistance device is coupled to the upper part 10 and the lower part 20 via a gear device, for example via a planetary gear, in order to cause or slow down and influence a displacement of the upper part 10 relative to the lower part 20.

Furthermore, the control device 40 and at least one angle detection device as a sensor 50 are arranged on the prosthesis or orthosis. The angle detection device 50 detects the angle between the upper part 10 and the lower part 20 and is designed, for example, as a direct angle sensor that detects the angle directly. Alternatively, the angle between the upper part 10 and the lower part 20 can be determined by evaluating the sensor data from two spatial position sensors 50. Both methods can also be used simultaneously or in addition to one another. All sensors arranged on the prosthesis or orthosis are coupled to a control device 40, and their sensor values serve as the basis for controlling the actuator 34 of the resistance devices 30 if this is designed as a damper, or as input signals for a motor control if the resistance device 30 is designed as a motor. In the case of magnetorheological damping, the sensor values are used to control the magnetic field or its change. On the basis of the sensor data, in particular the spatial positions and/or angular positions as well as position data and data on the load, orientation, acceleration and/or deformation of other components, the actuator 34 is controlled, for example to activate, deactivate or modulate the electric motor 70, for example to reduce or increase a swivel resistance, to limit an end stop and/or to generate or support a relative movement between the upper part 10 and the lower part 20.

Figure 3 shows a schematic representation of a prosthetic knee joint or orthotic knee joint with an upper part 10, a lower part 20 and a resistance device 30 between the upper part 10 and the lower part 20 in a bent position. The upper part 10 can be pivoted relative to the lower part 20 about the pivot axis 15 against the resistance of the resistance device 30. In this case, a Joint angle ß changes. In the exemplary embodiment shown, the joint angle ß is measured on the back between the upper part 10 and the lower part 20. In a fully extended position, the joint angle ß is 180°; with increasing flexion, the joint angle ß decreases accordingly by the pivot angle. The pivoting is mechanically limited by the mechanical end stop 80, which is shown schematically and can also be formed, for example, by reaching the maximum retracted position of the piston rod of the resistance device 30. When the maximum mechanical end stop 80 is reached, the joint angle ß2 is minimal. If the lower part 20 reaches predetermined positions before reaching the mechanical end stop 80 with the joint angle ß2, namely when the locking angle a is reached, the resistance in the resistance device 30 is increased in order to prevent further flexion movement or to dampen it more. The joint angle ß is detected by one or more sensors, as described above. The sensor values are transmitted to the control device 40, which in one embodiment is set up to increase the resistance in the resistance device 30 before the locking angle a is reached, namely from reaching a threshold value ß1, in order to prevent a hard impact on the mechanical end stop 80. Alternatively or in addition to an automatic increase in the flexion resistance when either the locking angle a or a threshold value ß1 before the locking angle a is reached, the flexion resistance can occur due to a fixed orientation of the upper part 10 in the room or, for example, due to an unchanged joint angle ß or another fixed movement pattern that is carried out over a certain period of time.

In addition, a locking command can be transmitted to the control device 40 shown in Figures 1 and 2 via an input device 90, for example a switch on the upper part 10 or via another input device, for example a remote control or a microphone with voice recognition, in order to either increase the resistance before the locking angle a is reached or to increase the resistance independently of reaching the locking angle a, in particular to increase it until the joint is locked.

In Figure 3, a foot part 60 is also arranged on the lower part 20, which can also be provided with or coupled to sensors 50, which in turn are coupled to the control device 40 and which detect a load on the foot part 60 or a pivoting or position of the foot part 60 in space or relative to the lower part 20. If, for example, a load on a forefoot part is detected in conjunction with a moment in the dorsal flexion direction, a kneeling position can be concluded if the position of the joint angle ß changes at the same time, so that automatic locking and blocking can take place via the resistance device 30. Alternatively, in a kneeling position, the artificial knee joint can be blocked by actuating the actuating device 90. The loads detected in the position, for example forces or moments about the pivot axis 15 and/or forces or moments on the foot part 60 or the positioning of the foot part 60 relative to the lower part, can serve to unlock the lock and allow further flexion. By recording the corresponding sensor values and assigning the recorded values to specific situations or assumed situations, a flexion movement lock that has been set can be lifted again. The flexion lock can also be lifted when extension is detected, although extension can advantageously always be possible.

Figure 4 shows an artificial orthotic knee joint in the applied state on a person, in which a resistance device 30 is arranged on the upper part, which blocks a flexion movement at the joint angle ß shown. The blocking can be initiated actively and arbitrarily by the user by actuating an actuating element, which is not shown. Alternatively or additionally, the control system is set up so that the resistance device 30 automatically increases the flexion resistance before the mechanical end stop is reached and blocks the flexion before the mechanical end stop is reached or at least dampens it to such an extent that the lower part does not hit the mechanical end stop hard when the mechanical end stop is reached. The automatic blocking can also take place if the user is in the kneeling position for a longer period of time, for example to pick up an object or to perform an activity in the kneeling position. If the body's center of gravity is then behind the pivot axis 15, the user can Resistance device 30 is supported on the orthosis. The corresponding behavior is also achieved when used with a prosthetic knee joint. Figure 4 shows that the flexion lock can be used both with a raised knee, the right knee in Figure 4, and with a raised, bent knee, the left knee in Figure 4. In particular, by recording the position of the lower leg and thus the lower part or the load on a foot part, it is possible to distinguish whether and which joint is manipulated in what way, i.e. which flexion resistance is increased and a lock is used or not.

The automatic activation and adjustment in both the orthosis and the prosthesis is carried out in such a way that a hydraulic lock and an increase in the flexion resistance is effected before the mechanical end stop is reached. In addition, the requirements for kneeling can be calculated and adapted to the respective patient, taking into account the course of the respective lever arm change during flexion.

By selecting the appropriate threshold value ß1, it is also possible to make kneeling easier. If, for example, the evaluation of the sensors 50 detects that a patient wants to kneel down, the threshold value ß1 can be set relatively early before the locking angle a is reached and a controlled knee bending movement can be initiated once the threshold value ß1 is reached. In particular, this is done by arbitrarily triggering the corresponding function, i.e. by pressing a button, switch or, for example, a voice input. The devices for this can be located on the prosthesis or orthosis, for example the prosthesis shaft or an orthosis splint itself, or can be arranged on or in a remote control. The remote control can, for example, be wirelessly linked to the control device, for example as an app on a smart device, a smartphone or the like. Personal configuration via an app on the smart device on which an orthosis or prosthesis control is stored is also possible. The speed at which the knee is then bent or can be bent can be individually adapted to the respective patient. A distinction as to whether the patient wants to kneel down or another If the patient is carrying out an activity, for example if he wants to sit down, this can be done by determining the body's center of gravity relative to the leg being treated. While when sitting down the center of gravity shifts backwards once a certain pivot angle ß is reached, when kneeling the center of gravity remains in the area of the force introduction of the ground reaction force vector in the foot part or in the direction in front of it. For example, this can be used to distinguish whether the patient wants to kneel down or sit down.

The locking angle a can also be adjusted depending on the detected situation as well as depending on a trigger command by an actuating device. Usually, when kneeling, joint angles ß of approx. 35° to 45° are reached, from which locking is sensibly possible. The locking angle a can therefore also be set to a joint angle ß of 45°, for example, if this is desired by the patient. Shortly before the locking angle a is reached, the flexion resistance is then increased and, if necessary, once the locking angle a is reached, further flexion is prevented. Unlike when sitting down, after a maximum resistance is reached to support the sitting down movement, the flexion resistance is not reduced to make sitting easier, but is increased further or a locking is initiated to divert the body weight or the loads via the orthosis or prosthesis.

Claims

Patent claims

1. Prosthetic or orthotic knee joint with an upper part (10) and a lower part (20) mounted on the upper part (10) so as to be pivotable about a pivot axis (15), and a resistance device (30) between the upper part (10) and the lower part (20), with which the pivotability of the upper part (10) relative to the lower part (20) can be influenced at least in the flexion direction, with a control device (40) which is coupled to the resistance device (30) and via which the resistance to flexion is changed depending on the position of the upper part (10) to the lower part (20), characterized in that the control device (40) is set up to block or to dampen a flexion movement to a greater extent at a locking angle (a) when or before a mechanical end stop (80) is reached.

2. Prosthetic or orthotic knee joint according to claim 1, characterized in that the control device (40) is arranged to increase the flexion resistance before reaching the locking angle (a) over a predetermined angle range up to the locking.

3. Prosthetic or orthotic knee joint according to claim 1 or 2, characterized in that the control device (40) is coupled to at least one sensor (50) for detecting the joint angle (ß) between the upper part (10) and the lower part (20) or the orientation of the upper part (10) in space and is set up to change the resistance by the resistance device (30) on the basis of the sensor values, in particular to increase the resistance until locking when a threshold value (ß1 ) of the joint angle (ß) and/or the duration (t1 ) of an unchanged joint angle (ß) or an orientation of the upper part (10) and/or a locking command is reached.

4. Prosthetic or orthotic knee joint according to claim 1 or 2, characterized in that the control device (40) is coupled to at least one sensor (50) for detecting an unlocking signal with which the locking is canceled.

5. Prosthetic or orthotic knee joint according to claim 2 or 3, characterized in that the control device (40) is arranged to increase the flexion resistance with increasing flexion.

6. Prosthetic or orthotic knee joint according to one of the preceding claims, characterized in that at least one control valve (32) or an adjustment device (36) is arranged in the resistance device (30), which is coupled to an actuator (34) which is activated, deactivated or modulated via the control device (40).

7. Prosthetic or orthotic knee joint according to one of the preceding claims, characterized in that the resistance device (30) is designed as a linear damper or rotational damper, in particular as a hydraulic, pneumatic, magnetorheological resistance device or drive.

8. Prosthetic or orthotic knee joint according to one of the preceding claims, characterized in that parameters for locking can be set in the control device (40).

9. Prosthetic or orthotic knee joint according to one of the preceding claims, characterized in that the locking angle (a) is set between 2° and 40°, in particular between 5° and 30°, in front of the mechanical end stop (80).

10. Method for controlling a prosthetic or orthotic knee joint according to one of the preceding claims, characterized in that the flexion resistance before reaching the locking angle (a) after reaching a threshold value (ß1 ) of a joint angle (ß) with increasing flexion and/or with a constant joint angle (ß) or constant orientation of the Upper part (10) in space is increased over a defined period of time and/or a blocking signal. Method according to claim 10, characterized in that the resistance is increased linearly or progressively. Method according to claim 10 or 11, characterized in that the flexion resistance is increased over an angular range of greater than 5° before the blocking angle (a) is reached. Method according to one of claims 10 to 12, characterized in that the control device (40) is coupled to a foot part (60) and blocking and/or unlocking takes place on the basis of the position and/or load of the foot part (60). Method according to one of claims 10 to 13, characterized in that the position of the body's center of gravity relative to the treated leg is detected or determined and during a movement a distinction is made between an increase in resistance and a blocking on the basis of the course of the body's center of gravity.