ORTHOPEDIC JOINT DEVICE AND METHOD FOR CONTROLLING SAME
Systems and methods for controlling an orthopedic joint device of a lower extremity, the orthopedic device comprising an upper part, a lower part mounted in articulated fashion to the upper part, and a conversion device arranged between the upper and lower parts. The conversion device provides for, during pivoting of the upper part relative to the lower part, mechanical work from a relative movement between the upper and lower parts to be converted and stored in at least one energy store and supplied back to the joint device with a time offset in order to assist the relative movement. The stored energy is converted back and the supply of mechanical work takes place in a controlled manner during the assistance of the relative movement.
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This is a continuation application of U.S. patent application Ser. No. 14/902,537, filed 31 Dec. 2015, entitled ORTHOPEDIC JOINT DEVICE AND METHOD FOR CONTROLLING SAME, which is a U.S. National Entry Application from PCT International Patent Application No. PCT/EP2014/001807, filed 2 Jul. 2014, which claims the benefit of German Patent Application No. 10 2013 011 080.7, filed 3 Jul. 2013, the disclosures of which are incorporated, in their entireties, by this reference.
TECHNICAL FIELDThe invention relates to a method for controlling an orthopedic joint device of a lower extremity with an upper part and a lower part mounted thereon in an articulated manner, between which a conversion device is arranged, by means of which mechanical work from the relative movement during a pivoting of the upper part relative to the lower part is converted and stored in at least one energy store and re-supplied to the joint device in a time-offset manner in order to assist the relative movement. The invention likewise relates to an orthopedic joint device of a lower extremity with an upper part and a lower part mounted thereon in an articulated manner, between which a conversion device is arranged, by means of which mechanical work from the relative movement during a pivoting of the upper part relative to the lower part is converted and stored in at least one energy store and re-supplied to the joint device in a time-offset manner in order to assist the relative movement. Such an orthopedic joint device is advantageous, in particular, for prostheses, but it can also be used in orthoses.
BACKGROUNDMost prostheses of the lower extremity are constructed in such a way that movement energy is only converted into heat in order to influence the behavior of the prosthesis; there predominantly is no active supply of energy. By way of example, the prosthesis user controls a prosthetic knee joint when walking by way of his stump with the hip muscles. In this case, experiments from the gait laboratory have shown that this type of walking requires more energy than the walking of healthy subjects. Prosthesis users must apply substantially greater amounts of energy than healthy subjects, particularly in the case of slow walking and alternating climbing of steps.
If energy is supplied to the prosthesis or orthosis during specific phases of walking, the prosthesis or orthosis user needs to apply less of his own energy, the good ground clearance during the swinging phase can be increased and, overall, the movement becomes more comfortable and pleasant.
There are so-called active prosthetic knee joints, in which a drive emulates the whole movement pattern; in this case, the motor is designed in such a way that the conventional gaits can be mapped. As a consequence, the motor must be designed to be relatively powerful and the supply of energy is correspondingly difficult. In the case of sufficiently powerful motors, a malfunction in the controller may constitute a risk to the user. If the motor is designed to be less powerful, it is no longer possible to cover the whole gait spectrum. A further disadvantage consists in the user being forced to follow the movement after a specific movement has been introduced, even if the situation or the intent of the user has changed. Then, the user can no longer influence the movement and he is moved.
In addition to prosthetic knee joints driven purely by a motor, US 2010/0312363 A1 has disclosed a prosthetic knee joint with motors and spring stores, in which energy from the movement is stored in the springs for reducing the drive outlay and released again after reaching a specific angular position. Here, the assistance can be dimensioned in such a way that walking in the plane, or the climbing of steps, is made possible.
SUMMARYIt is an object of the present invention to provide a method for controlling an orthopedic joint device and such a joint device, by means of which it is possible to use an orthopedic joint device intuitively, provide high levels of safety and enable a long usage duration.
According to the invention, this object is achieved by a method having the features of the main claim or by a device with the features of the coordinate claim. Advantageous embodiments and developments of the invention are disclosed in the dependent claims, the description and the figures.
The method according to the invention for controlling an orthopedic joint device of a lower extremity with an upper part and a lower part mounted thereon in an articulated manner, between which a conversion device is arranged, by means of which mechanical work from the relative movement during a pivoting of the upper part relative to the lower part is converted and stored in at least one energy store and re-supplied to the joint device in a time-offset manner in order to assist the relative movement, provides for the stored energy to be reconverted and for the supply of mechanical work for and during assisting the relative movement to be carried out in a controlled manner. When energy is released from an energy store, for example a spring, the stored energy is abruptly supplied to the joint device, i.e. the system of upper part and lower part and an articulated mount, in the prior art in such a way that a large amount of energy is introduced over a very short period of time. According to the invention, provision is made for the stored energy to be resupplied to the system in a controlled manner and to be converted into mechanical work and assistance for the displacement of upper part in relation to lower part in order to assist the movement over a relatively long period of time such that a movement of the prosthetic or orthotic device which approximates the natural motion sequence can be carried out. An adaptation to modified gaits, the speeds or different patients can only be carried out with extraordinary amounts of outlay in accordance with the prior art by virtue of use being made of specially adapted springs, which is impractical for daily use. By contrast, the energy release into the system is controlled in such a way according to the invention that the required amount of energy can be fed in over a comparatively long period of time in order to influence the gait as desired.
The supply of mechanical work can be modified by virtue of energy being externally supplied to, or removed from, the energy store. If the energy store is a spring, the energy can be supplied by virtue of the spring being re-tensioned; the removal or reduction in the amount of energy can be brought about by the spring being relaxed, for example by displacing a spring abutment. If the energy store is embodied as an electrical energy store, for example as a capacitor, battery or accumulator, the change in the amount of energy can be brought about by activating a generator or by way of an introduction from a second energy store; the reduction in the amount of energy can be brought about by connecting a load or by means of a diversion into a second store for electrical energy.
A development of the invention provides for an actuator to be assigned to the energy store, by means of which actuator the energy store is filled to a minimum level if the relative movement is insufficient therefor. If the energy available as a result of the movement should not be sufficient to supply the energy store with a sufficient amount of energy for the next step or the movement pattern, wherein the minimum amount is dependent on the walking speed, the walking situation and the individual situation of the patient, provision is made according to the invention for the energy store to be filled to a set level during the walking and before the return of energy to assist the relative movement, for example by tensioning a spring or driving a generator which charges the electrical energy store.
In order to be able to precisely determine the time of the movement assistance, provision is made according to the invention for a release device to be assigned to the energy store, by means of which release device the energy is partly or wholly released from the energy store. The release device determines the time of energy release, the duration and the profile of the energy release is not controlled by the release device in the case of complete release; this is controlled by changes in the energy store, i.e. by the removal or supply of energy. In the case of a partial release, there was a reduction in the amount of energy released such that the initial level of the movement assistance can be set. By way of a partial release, an adaptation can be carried out to, for example, walking speeds, patients or walking situations; the fine influencing of the assistance is carried out by way of the change in the energy store.
The mechanical work can be supplied in a manner dependent on a criterion or a combination of a plurality of criteria, namely on the angular position of the upper part relative to the lower part, the position of the upper part and/or the lower part in space, an angular velocity of the upper part and/or the lower part and/or the relative velocity between upper part and lower part and/or the load situation and/or the acceleration of the upper part and/or the lower part, such that there is an assistance of the movement which is as exact as possible in terms of time and amount. The positions of the upper parts and lower parts relative to one another and in space can be determined by angle sensors or inertial sensors, the velocities in relation to one another or within space, or the accelerations, can be established by acceleration sensors or a combination of angle sensor and acceleration sensor, and the load situations can be established by way of force sensors. By way of the sensors, it is possible to determine not only the time of the release of the energy but also the respective gait situation, the walking speed and the current position of the respective components in relation to one another or in space, by way of which it becomes possible to determine and control the amount and the profile of the energy supply for the purposes of assisting the movement.
A development of the invention provides for the energy to be removed from, or re-supplied to, the energy store in a manner dependent on a criterion or a combination of a plurality of criteria, namely the angular position of the upper part relative to the lower part, the position of the upper part and/or the lower part in space, an angular velocity of the upper part and/or the lower part and/or the relative velocity between the upper part and the lower part and/or the load situation and/or the acceleration of the upper part and/or the lower part, in order to enable the controlled regulation of the movement.
The time of engagement of the conversion device can be adjusted in order to modify the amount of energy to be converted and/or the amount of energy supplied so that, for example, it is possible to set, in a manner dependent on the walking speed, the walking situation or the individual parameters of the patient, the magnitude that the amount of energy to be stored needs to be or the magnitude that the amount of energy to be emitted needs to be. In the case where a large amount of energy is desired, provision is made for an engagement in the conversion to take place as early as possible such that, for example, a generator is driven very early on and for a long time or a spring is pre-tensioned very far in order to convert the mechanical work when walking, for example upon heel strike during the standing phase flexion, to the maximum extent into the potential energy of a spring or electrical energy of an accumulator or of a capacitor. If the time of the engagement during the reconversion is adjusted, for example by displacing a stop or by virtue of an angle-dependent release, the energy is introduced at a later time within the step, as a result of which a change of the gait can be achieved. The energy store can be charged by an actuator if the conversion device is not active due to the relative movement between the upper part and the lower part such that the actuator need not work against the relative movement. Moreover, the temporal categorization of the charging of the energy store by the actuator in a phase in which no mechanical work from the joint device is converted is advantageous in that energy can be stored over a relatively long period of time, leading to it being possible to dimension the actuator in a correspondingly small manner in order to be able to provide the desired amount over a long period of time. By way of example, if a spring is tensioned by way of a motor as an actuator, the latter can have a small configuration and it can be coupled to the spring with a transmission mechanism such that the spring can be tensioned over a comparatively long period of time. The same applies to the conversion and storage of electrical energy.
A development of the invention provides for the relative movement to be additionally influenced by way of a damper device in addition to the influence of the energy store such that the control need not take place only by way of the energy store, leading to a large variation possibility being available when influencing the gait. Moreover, load peaks can easily be caught by way of an additional damper device.
The orthopedic joint device of a lower extremity with an upper part and a lower part mounted thereon in an articulated manner, between which a conversion device is arranged, by means of which mechanical work from the relative movement during a pivoting of the upper part relative to the lower part is converted and stored in at least one energy store and re-supplied to the joint device in a time-offset manner in order to assist the relative movement, provides for an actuator to be assigned to the energy store, which actuator supplies energy to, or removes energy from, the energy store in a controlled manner when assisting the relative movement. As a result of the controlled supply of energy to, or the controlled removal of energy from, the energy store by way of an actuator, particularly simple and reliable influencing of the gait is made possible in the case of semi-active joint devices, in particular in the case of semi-active prosthetic knee joints.
The conversion device can be embodied as a spring or transducer, e.g. a generator, in order to store the mechanical work, which accrues in the case of a relative movement between the upper part and the lower part, either as potential energy in a spring or as electrical energy in an electric storage device, for example in the form of an accumulator, in a rechargeable battery or in a capacitor or in another form of energy.
The energy store can be embodied as a spring, spring mechanism, e.g. a pressure store in conjunction with fluid actuators, or as an accumulator, wherein an accumulator is also understood to mean a capacitor or a rechargeable battery.
A separate damper device can be arranged between the upper part and the lower part in order to be able to control the relative movement better in the case of assistance by the energy store. There can be more precise and more reliable influencing of the gait as a result of the superposition of the influence of the energy store and the separate damper device.
The separate damper device has an adjustable embodiment in order to provide adapted damping in a manner dependent on sensor data, for example in respect of the joint angle, the walking velocity, an angular velocity or an absolute angle of a lower part and/or of an upper part. The damper device can be adjusted by way of an actuator in order to achieve a reduction or an increase in the damping.
The conversion device can be coupled in an adjustable manner to the upper part and/or the lower part in order to displace an engagement position or an adjustment travel. As a result, it is possible to influence both the amount of energy and the time of the energy supply as desired.
The conversion device, the energy store or both components can have a combination of at least two springs, which are effective over different angular ranges of the joint device. The springs can have different spring constants such that a force supply that is adapted to the requirements of the respective movement is made possible. By way of example, if provision is made for a swinging-phase initiation of the knee joint to be assisted or introduced by way of the conversion device, what needs to be taken into account is that an assistance moment, i.e. torque, required herefor is nonlinear. A nonlinear assistance moment can be produced by way of a linear spring if the latter is influenced in terms of the behavior thereof by way of a damper and/or an actuator. In order to avoid the outlay necessary for this, it is possible to couple or interconnect two or more springs, wherein the springs may have different spring characteristics or spring constants and they are effective over different angular ranges. By way of example, if a high assistance moment is required at the start of the bending, this can easily be achieved by a spring combination connected in parallel or in series. The angular dependence can be achieved by a longitudinal guidance of one of the springs which, for example, is guided in a slot or in a telescopic manner from complete relaxation onward, and so there is no effect of this spring on the movement. A second spring or further springs, for example with a different spring constant or spring length, acts or act over a longer period of time or over a larger pivoting angle of the joint device. In the case of a parallel connection, a nonlinear profile emerges, to which the desired moment profile can easily be adapted. Advantageously, the use of a damper is not necessary for adapting the moment profile, and so less energy is converted into heat that cannot be used. If only one spring were present, it would have to be designed thicker and the excess energy in certain phases of the bending movement would have to be damped away. Moreover, there is no need for any outlay such as a damper regulation.
Exemplary embodiments of the invention will be explained in more detail on the basis of the following exemplary embodiments. The same reference signs denote identical components. In detail:
In the terminal standing phase, the stored energy can be released again to assist the initiation of the swinging phase; the elastic cord 54 is drawn in and it converts the potential energy into mechanical work, in order to assist the flexion of the lower part 3. If more energy is to be stored in the energy store 54, the actuator 10 pretensions the elastic cord 54, in that the bracket 12 is displaced distally or in the rolling-up direction; if less energy is to be stored, the bracket 12 is displaced proximally or the cord is unrolled. In the exemplary embodiment represented, the energy storage device 54 is at the same time the conversion device 5, in which the mechanical work from the relative movement is converted into potential energy.
In addition to the conversion device 5 or the energy store 54, a separate damper 50 is provided in the form of a hydraulic or pneumatic damper, which is of an adjustable design, so that the damper device 50 can be used to influence the damping during walking, both in the direction of flexion and in the direction of extension.
For controlled assistance in the initiation of the swinging phase, it is provided that changing of the pretensioning of the elastic cord 54 takes place by way of the actuator 10, the transmission mechanism 11 and the displacement or turning of the bracket 12, in order to keep a better check on the release of energy. It has been found that a spring alone as the energy store has the effect of introducing too great a force too quickly, which can be perceived by the patients as unpleasant. In order to keep a check not only on the time period over which energy is introduced but also the amount of energy and the power output, a manipulation can be performed on the energy store 54 in dependence on the angular position of the upper part 2 in relation to the lower part 3, the angular position of the upper part 2 and/or the lower part 3 in relation to one another or in space, the angular velocities or the walking speed, in order to limit the power output and additionally control the time sequence of the release of energy. By relaxing the spring 54 it is possible to introduce less energy into the joint device 1; by retensioning the spring 54, it is possible to maintain assistance of the flexion over a longer time period and over a greater flexion angle, in order to achieve the desired harmonious gait pattern.
A variant of the invention is shown in
In
In
In
Apart from the embodiment shown of the energy store as a spring, by using a transmission gear mechanism and a generator it may possibly also be designed as an electrical energy store in the form of a battery, an accumulator or a capacitor. For converting the stored electrical energy back, the generator is switched as a motor, so that driving and assistance of the relative displacement of the lower part 3 in relation to the upper part 2 can take place. To increase the amount of energy, a generator may be assigned to the electrical energy store; it is similarly possible to provide a further energy store, which serves as a buffer into which excess electrical energy is fed or from which energy that is additionally required is provided.
The springs as energy stores 54 may be designed as tension springs, compression springs, torsion springs or elastomer elements, which from a certain stretching angle, which is set by the actuator 10, come into contact and from this point in time both convert mechanical work into energy and feed it back for movement assistance. The spring in this case takes up the energy from the movement in the direction of extension, and serves at the same time as a decelerating device and extension limit stop. With the initiation of the swinging phase, the energy is released again and it helps the user to initiate the swinging phase. The actuator 10 can be used to adjust the point in time of the contact of the spring in the case of the release of energy, so that different, controlled forms of assistance are possible for different walking speeds. It is similarly possible that the respective spring is retensioned by way of the motor 10, if the energy stored by the preceding movement is not sufficient to provide sufficient assistance; for example, in the case of particularly slow walking or going down steps, the mechanical work may not be sufficient to tension the spring sufficiently. As shown in
In order to ensure the triggering of the release, the joint device 1 may include a safety device, which is formed by the hydraulics in the damper 50 or by a control of the motor 10, which ensure that the spring energy applied is reduced again in good time.
On account of the fact that the kinetic energy in the extension is at least partially stored, the assistance provided by the motor can operate very economically. The battery for the actuator 10 can be made small and lightweight, as can the actuator 10 itself, since the actuator 10 has sufficient time when retensioning in the standing phase to tension the spring, and the feeding in of the energy does not have to take place as quickly as the release for the initiation of the swinging phase. The motor 10 controls the release of energy from the spring, possibly in conjunction with the separate damper 20. The flexion assistance provided by the energy store helps in achieving the necessary bending angle in the case of alternating climbing up stairs and when stepping over obstacles, and saves hip work.
In
In
Apart from the embodiment shown as flexion assistance, the device may in principle also be used for extension assistance; the statements made in relation to flexion assistance also apply correspondingly to extension assistance, it also being possible and intended that flexion assistance and extension assistance be arranged together in a joint device.
An advantage of the arrangement is that all the energy stored in the springs a, b can be used for bending the joint and no external energy needs to be applied to an actuator or no energy stored in the springs a, b needs to be dissipated by way of a damper. In the case of only one spring, the latter would need a thicker design and excessive energy in a specific angular range would have to be converted by way of a damper.
Claims
1-17. (canceled)
18. A method for controlling an orthopedic joint device of a lower extremity, comprising:
- providing the orthopedic joint device, the device comprising an upper part, a lower part mounted to the upper part in an articulated manner, a conversion device arranged between the upper and lower parts and including an energy store, and a dampening device arranged between the upper part and the lower part;
- pivoting the upper part relative to the lower part, converting mechanical work from the relative movement between the upper and lower parts to energy with the conversion device, and storing the energy in the energy store;
- re-supplying the energy from the energy store to the joint device in a time-offset manner to assist relative movement of the upper and lower parts;
- reconverting the stored mechanical work in a controlled manner to assist relative movement of the upper and lower parts; and
- dampening relative movement between the upper part and the lower part with the dampening device, wherein dampening is adjusted based on walking speeds of a wearer of the orthopedic joint device.
19. The method of claim 18, wherein the energy store comprises a spring.
20. The method of claim 19, wherein energy is externally supplied to, or removed from, the energy store.
21. The method of claim 19, wherein the energy store comprises an actuator, and the method further comprises filling the energy store to a minimum level if the relative movement is insufficient to assist relative movement of the upper part and the lower part.
22. The method of claim 19, further comprising:
- determining that the stored energy is insufficient to assist relative movement of the upper part and the lower part; and
- filling the energy store using the actuator to a level sufficient to assist relative movement of the upper part and the lower part.
23. The method of claim 19, wherein the energy store further comprises a release device capable of releasing energy from the energy store.
24. The method of claim 18, wherein the mechanical work is supplied in a manner dependent on at least one of:
- an angular position of the upper part relative to the lower part;
- a position of at least one of the upper part and the lower part in space;
- an angular velocity of at least one of the upper part and the lower part;
- a relative velocity between the upper part and the lower part;
- a load situation; and
- an acceleration of at least one of the upper part and the lower part.
25. The method of claim 19, wherein the spring is configured to store energy, and the energy is supplied or removed in a manner dependent on at least one of:
- an angular position of the upper part relative to the lower part;
- a position of at least one of the upper part and the lower part in space;
- an angular velocity of at least one of the upper part and the lower part;
- a relative velocity between the upper part and the lower part;
- a load situation; and
- an acceleration of at least one of the upper part and the lower part.
26. The method of claim 19, comprising:
- determining that the conversion device is not active due to the relative movement between the upper part and the lower part and;
- charging the energy store with the actuator when the conversion device is inactive.
27. The method of claim 18, further comprising adjusting a time of engagement of the conversion device to modify the amount of energy to be converted and/or the amount of energy re-supplied.
28. The method of claim 18, further comprising charging the energy store with an actuator if the conversion device is not active.
29. The method of claim 18, wherein the relative movement is influenced by the dampening device.
30. The method of claim 18, wherein the dampening is reduced with an increasing joint angle between the upper part and the lower part.
31. The method of claim 18, wherein a flexion damping is reduced at higher walking speeds.
32. The method of claim 31, wherein at higher walking speeds the flexion damping is increased at the end of a swing phase.
33. A orthopedic joint device of a lower extremity, comprising:
- an upper part;
- a lower part mounted to the upper part in an articulated manner;
- a conversion device arranged between the upper and lower parts, the conversion device including an actuator, and being configured to mechanically convert mechanical work from relative movement between the upper and lower parts to energy stored in the energy store, the conversion device being further configured to re-supply the stored energy to the joint device in a time-offset manner in order to assist the relative movement, wherein the actuator is operable to supply energy to, or remove energy from, the energy store in a controlled manner when assisting the relative movement.
34. The orthopedic joint device of claim 33, further comprising a separate damper device arranged between the upper part and the lower part.
35. The orthopedic joint device of claim 34, wherein the separate damper device is adjustable.
36. The orthopedic joint device of claim 33, wherein the conversion device comprises at least one of a spring, a spring mechanism, and a transducer.
37. The orthopedic joint device of claim 33, wherein the energy store comprises at least one of a spring and a accumulator.
38. The orthopedic joint device of claim 31, wherein the conversion device comprises at least two springs having different spring constants.
Type: Application
Filed: Dec 22, 2022
Publication Date: Jul 6, 2023
Applicant: OTTOBOCK SE & CO KGAA (Duderstadt)
Inventors: Lüder MOSLER (Duderstadt), Martin PUSCH (Duderstadt), Alexander PAPPE (Gottingen), Christian WILL (Gottingen)
Application Number: 18/087,708