EP2616033B1 - Patella gripper and device for moving a patella comprising such a patella gripper - Google Patents

Description

Technical field

The invention relates to a patella gripper and a device for moving a patella according to the preambles of the independent claims. A patella is also known as a patella.

State of the art

The knee is the largest and most complex joint in the human body and can be affected by both degenerative and traumatic diseases. With an aging population, a steady increase in degenerative knee disease has been observed ( Schabus, R. and Bosina, E., The knee - Diagnosis, Therapy and Rehabilitation, 2007, Springer Verlag ), which usually lead to defects in the knee cartilage. Such defects in the knee cartilage have led to 11026 knee replacements in Switzerland in 2006 and more than 500000 complete knee replacements worldwide according to an estimate from 2004 ( Agneskircher, JD and Lobenhofer, P., Endoprosthetics of the knee joint, trauma surgeon, 2004, 107: 219-231 ; Larsen, Ch., Training instead of surgery ?, Swiss Medical Newspaper, 2009, 90 (38): 1476-1479 ). In addition, traumatic lesions of the anterior and / or posterior cruciate ligaments often require surgical intervention ( Schabus, R. and Bosina, E., The knee - Diagnosis, Therapy and Rehabilitation, 2007, Springer Verlag ). The kneecap or patella is the flexible bone that lies in front of the knee joint and that is integrated into a tendon that connects the quadriceps muscles with the lower leg bones. Articular cartilage covers the back of the patella. The mobilization or movement of this knee region is extremely important in the rehabilitation process to prevent the knee and knee from sticking together.

After a knee injury or surgery, patients usually go through intensive rehabilitation therapy. The goal of rehabilitation therapy is to reduce any swelling, prevent further inflammation, maintain or restore mobility of the knee through a number of passive movement exercises, maintain or restore mobility of the kneecap and the strength of the quadriceps and the so-called To get hamstrings (back thigh muscles) ( Kokmeyer, D., Tutorials on rehabilitation of knee patients with arthrofibrosis, 2007, Kneeguru Information Hub ; Stalzer, S., Atkins, J., Hagerman, G., Rehabilitation Principles, in: The Crucial Principles in Care of the Knee, Publisher: Feagin, JA Jr. and Steadman, JR, 2008, Lippincott Williams and Wilkins, Philadephia ).

After knee surgery, patients typically receive rehabilitation therapy in specialized orthopedic clinics and rehabilitation centers such as sports clinics. Maintaining the mobility of the patella and its associated tendon is essential to regain a normal range of motion (so-called range of motion - ROM) and to prevent the formation of adhesions in the connection between the patella and the thigh ( Heckmann, TP, Noyes, FR, Barber-Westin, SD, Rehabilitation of Primary and Revision Anterior Cruciate Ligament Reconstructions, in: Noyes Knee Disorders Surgery, Rehabilitation, Clinical Outcomes, publisher: Noyes, FR, 2010, Saunders Elsevier, Philadephia ; Stalzer, S., Atkins, J., Hagerman, G., Rehabilitation Principles, in: The Crucial Principles in Care of the Knee, Publisher: Feagin, JA Jr. and Steadman, JR, 2008, Lippincott Williams and Wilkins, Philadephia ). Indeed, high mobility of the kneecap is extremely important for the full functioning of the knee ( Cavanaugh, JT, Rehabilitation for Nonoperative and Operative Management of Knee Injuriers, in: The adult knee, publisher: Callaghan, JJ, Rosenberg, AG, Rubash, HE, Simonian, PT and Wickiewicz, TL, 2003, Lippincott Williams Wilkins, Philadelpia ).

During rehabilitation therapy, the kneecap is usually repeatedly deflected out of its normal position. The deflection from the normal position is intended to prevent the kneecap from sticking to the inside of the knee in the slide channel provided for the kneecap in the thigh bone due to possible bleeding. Such sticking of the kneecap leads to a deterioration in the mobility of the knee, to increased stiffness and instability of the knee joint and to increased pain. The deflection from the normal position thus serves to maintain the mobility and mobility of the knee joint and the knee.

In order to prevent the kneecap from sticking, the physiotherapists usually move the kneecap by hand based on long experience. The kneecap must be moved manually several times a day by the physiotherapist for several days. The patella is moved manually in the medial-lateral direction and in the cranial-caudal direction ( Heckmann, TP, Noyes, FR, Barber-Westin, SD, Rehabilitation of Primary and Revision Anterior Cruciate Ligament Reconstructions, in: Noyes Knee Disorders Surgery, Rehabilitation, Clinical Outcomes, Publisher: Noyes, FR, 2010, Saunders Elsevier, Philadephia ; Stalzer, S., Atkins, J., Hagerman, G., Rehabilitation Principles, in: The Crucial Principles in Care of the Knee, editors: Feagin, JA Jr. and Steadman, JR, 2008, Lippincott Williams and Wilkins , Philadephia). When moving in the medial-lateral direction, the kneecap is moved from its center in the transverse direction to each side. When moving in the cranial-caudal direction, the kneecap is moved up and down in the longitudinal direction, ie towards the head and towards the opposite, lower end of the body. The terms "longitudinal direction" and "transverse direction" refer to the patient's leg.

Since the use of physiotherapists is required, this manual procedure is relatively expensive. Furthermore, because of its monotony, it is not much appreciated by physiotherapists. Manual movement of the kneecap is therefore little practiced and is even not offered in some clinics and rehabilitation centers.

The patients are instructed by the physiotherapists to manually move the kneecap even after discharge from the clinic or the rehabilitation center in the medial-lateral direction and in the cranial-caudal direction for several weeks, several times a day. Typically, the patella should be moved at home by the patient two to three times a day for about 10 to 15 minutes until the sixth week after the operation. However, a lack of self-discipline and motivation, the patient's fear of doing something wrong when moving the kneecap, and physical difficulties in performing the manual movement of the kneecap often lead to very different results and often prevent optimal recovery , In this form of manual therapy, for example, the patient has to move the kneecap himself when the leg is extended, for which several leg muscle groups have to be relaxed. However, this affects many patients difficult, especially if you have to move the kneecap at the same time with your hand on your own leg.

For the mobilization of the knee joint in the longitudinal direction, passive movement devices can be used, which perform a continuous movement of the kneecap (so-called continuous passive motion - CPM). These passive movement devices are powered by an external motor and move the leg in a controlled manner as part of a pre-defined knee flexion, leaving the muscles passive ( US 5,333,604 A ; Stalzer, S., Atkins, J., Hagerman, G., Rehabilitation Principles, in: The Crucial Principles in Care of the Knee, Publisher: Feagin, JA Jr. and Steadman, JR, 2008, Lippincott Williams and Wilkins, Philadephia ; Lenssen, TAF, van Steyn, MJA, Crijns, YHF, Waltj, EMH, Roox, GM, Geesin, RJT, van den Brandt, PA, De Bie, RA, Effectiveness of Prolonged Use of Continuous Passive Motion (CPM), as an Adjunct to Physiotherapy, After Total Knee Arthroplasty, BMC Musculoskeletal Disorders, 2008, 9:60 ; Salter, RB, Hamilton, HW, Wedge, JH, Tile, M., Torode, IP, O'Driscoll, SW, Murnaghan, JJ, Saringer, JH, Clinical Application of Basic Research on Continuous Pasive Motion for Disorders and Injuries of Synovial Joints: A Preliminary Report of a Feasibility Study, J. Orthop. Res., 1984, 1: 325-342 ). With the help of these passive movement devices, the knee joint is automatically bent, thereby improving mobility. However, this device only indirectly helps to reduce the sticking of the kneecap. The kneecap is only moved in the longitudinal direction, which, however, does not correspond to the optimal movement sequences that are to be carried out by the kneecap in rehabilitation therapy. The known passive movement devices also contain no sensors and no regulation with which the movement sequences of the knee and the kneecap could be monitored. Manufacturer of such passive movement devices are for example the companies Sutter in the USA, Chattanooga Group, Astromot, Danniger and Kinetec. US5156163 discloses a diagnostic device for measuring the displaceability of the patella.

Presentation of the invention

It is an object of the invention to provide a patella gripper by means of which a patella can be moved. It is also an object of the invention to provide a device for moving a kneecap that can move the kneecap automatically.

These tasks are solved by a patella gripper and a device for moving a patella with the features of the independent claims. A patella gripper is also known as a patella gripper.

The patella gripper according to the invention for a patella comprises a holding element and a contact finger device, the contact finger device being arranged on the underside of the holding element. The underside of the holding element is the side that faces the knee when the patella gripper is used. The top of the holding element is the side opposite the bottom. The contact finger device comprises at least two contact finger units which are arranged on opposite sides on the underside of the holding element, the contact finger device being designed in such a way that the patella can be moved linearly in the cranial-caudal and medial-lateral direction by means of the contact finger units. The movement in the cranial-caudal direction and in the medial-lateral direction takes place successively, the sequence being variable. The movement in the cranial-caudal direction also includes a movement in the caudal-cranial direction.

According to a preferred embodiment of the patella gripper according to the invention, the contact finger device comprises in the longitudinal direction two contact finger units arranged on the holding element on opposite sides of the transverse axis of the holding element. These contact finger units are adjustable in the longitudinal direction. They serve to move a kneecap in the cranial-caudal direction. The longitudinal direction corresponds to the longitudinal direction of a patient's leg. The cranial-caudal direction is the direction from the head to the opposite body end, i.e. at the feet of a patient defined. Furthermore, according to the preferred embodiment, the contact finger device comprises two contact finger units provided in the transverse direction of the holding element, these contact finger units being arranged on opposite sides of the longitudinal axis of the holding element. These contact finger units are adjustable in the transverse direction. They serve to move the kneecap in the medial-lateral direction. The transverse direction corresponds to the transverse direction of a patient's leg. The medial-lateral direction includes the directions from the center of the patella to its sides, i.e. sideways to the cranial-caudal direction.

According to a further preferred embodiment of the patella gripper according to the invention, the contact finger device is rotatably arranged on the holding element, so that it can be rotated about an axis that is perpendicular to the longitudinal axis of the holding element and perpendicular to the transverse axis of the holding element, that is to say about a height axis or Z axis especially 90 degrees. The contact finger device comprises two contact finger units which are arranged on opposite sides on the underside of the holding element. In the starting position, the contact finger units are preferably arranged in the longitudinal direction on opposite sides of the transverse axis or in the transverse direction on opposite sides of the longitudinal axis of the holding element.

A handle for guiding the patella gripper and / or for rotating the contact finger device can be provided on the upper side of the holding element. All contact finger units are preferably adjustable in height. The contact finger units preferably comprise one or more contact fingers.

The device according to the invention for moving a patella comprises a patella gripper according to the invention and a leg holding device. Furthermore, one or more drive units for moving the contact finger units of the patella gripper in the cranial-caudal direction (i.e. in the longitudinal direction) or in the medial-lateral direction (i.e. in the transverse direction) and a control unit for controlling the one or more drive units are provided. The movement of a kneecap is also understood to mean the mobilization of a kneecap. The one or more drive units can move the contact finger units directly or indirectly through the movement of the entire patella gripper.

The patella gripper according to the invention and the device according to the invention for moving a patella can be used both in clinically monitored rehabilitation therapies and in unsupervised rehabilitation therapies carried out by the patient himself. As a result of the fact that the contact finger device is designed accordingly, both a movement of the kneecap in the cranial-caudal direction and a movement in the medial-lateral direction can be achieved, the healing process after a knee operation can be improved compared to conventional methods and, if necessary, also accelerated. Mobilization of the knee joint often makes sense before an operation, and the patella gripper according to the invention and the device according to the invention can also be used for this. Through the use of the device according to the invention, the kneecap can be adjusted automatically and can be moved repeatedly in the cranial-caudal direction and in the medial-lateral direction. The movement of the kneecap therefore no longer needs to be carried out by a physiotherapist. The physiotherapist is thus relieved of this monotonous and time-consuming activity and it can thus save costs in rehabilitation therapy.

In the method for setting the device according to the invention for moving a kneecap, the device is put into a learning phase (also called learning mode) by actuating an activation button provided on the device. The patella gripper has been placed on the patient's patella by a physiotherapist or the patient himself. Alternatively, the patella gripper according to the invention can also have been applied to a patella of a patient by means of the control unit. The position in which the patella gripper is located after the application represents the initial position or zero position of the patella gripper, which is preferably stored in the control unit, for example by actuating an operating element provided on the patella gripper. Preferably, only when the zero position is defined for the transverse axis and the longitudinal axis of the patella gripper in this way, can the patella gripper move in the direction to be learned, i.e. only then is the movement in the direction to be learned next released or unlocked.

The control finger units are then moved in a cranial-caudal direction towards the patient's head via a drive unit until the patient presses the activation button again, the value of the force exerted on the patella at the time the activation button is pressed and / or the Value of the maximum deflection of the patella gripper or the contact finger units are saved directly or indirectly in the device (first cranial-caudal process step). Furthermore, by means of the control unit, the contact finger units are moved via the drive unit in the cranial-caudal direction towards the end of the patient's body opposite the head until the patient presses the activation button, the value of the force exerted on the patella at the time the activation button is pressed and / or the value of the maximum deflection of the patella gripper or the contact finger units is stored directly or indirectly in the device (second cranial-caudal process step). “Operating an activation key” means, inter alia, both pressing the activation key and releasing the activation key that is held down.

After the first and the second cranial-caudal process step have been carried out, the knee cap gripper is preferably returned to the zero position by means of the control unit. Thereafter, the contact finger units are moved by means of the control unit via the same or a different drive unit in a medial-lateral direction from an initial position to the patient's left side of the body as seen by the patient, until the patient presses the activation key, the value of which at the time the activation key is actuated force exerted on the kneecap and / or the value of the maximum deflection of the kneecap gripper or the contact finger units are stored directly or indirectly in the device (first medial-lateral method step). Finally, by means of the control unit, the contact finger units are moved via the same drive unit as in the last method step in the medial-lateral direction from the initial position to the patient's right side of the body as seen by the patient, until the patient presses the activation button, again the value of the time at which the Activation button on the patella force and / or the value of the maximum deflection of the patella gripper or the contact finger units are stored directly or indirectly in the device (first medial-lateral method step).

A direct storage of the exerted force is understood to mean the storage of the exerted force actually measured by means of one or more force sensors. Indirect storage of the force exerted is understood to mean the storage of a measured variable from which the force exerted can be derived. This can be, for example, the pressure measured by means of one or more pressure sensor units (in the case of an embodiment of the one or more drive units as a fluidic pump (s)). The contact finger units can be moved directly (even without moving the holding element) or by moving the patella gripper. A direct storage of the deflection of the patella gripper or the contact finger units is understood to mean the storage of the deflection actually measured by means of one or more linear sensor units (hereinafter also referred to as linear sensor units). Indirect storage of this deflection is understood to mean the storage of a measured variable from which the deflection can be derived. This can be, for example, a combination of the measured or the predetermined speed value for the fluidic pump and the measured time (ie the time since the start of the deflection in a specific direction) (in one embodiment of the one or more drive units as a fluidic pump ( n)).

The sequence of the first cranial-caudal method step, the second cranial-caudal method step, the first medial-lateral method step and the second medial-lateral method step is arbitrary in the method, ie these method steps can be carried out in any order. Between a cranial-caudal Method step and a medial-lateral method step (and vice versa), the contact finger device is rotated by 90 degrees if the contact finger device contains only two opposite contact finger units and is designed to be rotatable.

The method for setting the device according to the invention advantageously runs automatically or automatically, so that it can also be carried out by the patient himself without the help of a physiotherapist. By performing the procedure again, the device and thus the rehabilitation therapy can be adapted to the healing process of a patient.

Brief description of the drawings

• Fig. 1 eine perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Kniescheibengreifers mit Blickrichtung von oben,
• Fig. 2 eine perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Kniescheibengreifers mit Blickrichtung von unten,
• Fig. 3 eine perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe,
• Fig. 4 eine weitere perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe mit einem schematisch dargestellten Beinabschnitt eines Patienten,
• Fig. 5 die Darstellung gemäss Figur 4, wobei ein erstes Ausführungsbeispiel des erfindungsgemässen Kniescheibengreifers auf den Beinabschnitt des Patienten aufgebracht ist,
• Fig. 6 eine weitere perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe mit Beinabschnitt eines Patienten,
• Fig. 7 ein Blockschaltbild eines ersten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe,
• Fig. 8 eine schematische Darstellung der Beinhaltevorrichtung eines ersten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe mit eingebrachtem Bein,
• Fig. 9 ein Flussdiagramm, welches die Einstellung und den Betrieb des ersten Ausführungsbeispiels des erfindungsgemässen Geräts zur Bewegung einer Kniescheibe darstellt,
• Fig. 10 eine graphische Darstellung der gemessenen, von dem ersten Ausführungsbeispiel des erfindungsgemässen Geräts ausgeübten Kraft in kranial-kaudaler Richtung in Abhängigkeit von der Zeit,
• Fig. 11 eine graphische Darstellung der gemessenen, von dem ersten Ausführungsbeispiel des erfindungsgemässen Geräts ausgeübten Kraft in kranial-kaudaler Richtung und der gemessenen Auslenkung der Kniescheibe in Abhängigkeit von der Zeit,
• Fig. 12 eine perspektivische Darstellung eines zweiten Ausführungsbeispiels eines erfindungsgemässen Kniescheibengreifers, welches an einen Beinabschnitt eines Patienten angebracht ist, und eine Beinhaltevorrichtung,
• Fig. 13 eine perspektivische Darstellung eines zweiten Ausführungsbeispiels eines erfindungsgemässen Kniescheibengreifers mit Blickrichtung von unten und
• Fig. 14 ein Blockschaltbild eines zweiten Ausführungsbeispiels eines erfindungsgemässen Geräts zur Bewegung einer Kniescheibe.

Further advantageous refinements of the invention result from the dependent claims and the exemplary embodiments illustrated below with reference to the drawings. Show it:

• Fig. 1 2 shows a perspective illustration of a first exemplary embodiment of a patella gripper according to the invention, viewed from above,
• Fig. 2 1 shows a perspective illustration of a first exemplary embodiment of a patella gripper according to the invention, viewed from below,
• Fig. 3 2 shows a perspective illustration of a first exemplary embodiment of a device according to the invention for moving a patella,
• Fig. 4 1 shows a further perspective illustration of a first exemplary embodiment of a device according to the invention for moving a kneecap with a leg section of a patient shown schematically,
• Fig. 5 the representation according to Figure 4 , wherein a first embodiment of the patella gripper according to the invention is applied to the leg section of the patient,
• Fig. 6 1 shows a further perspective illustration of a first exemplary embodiment of a device according to the invention for moving a patella with a leg section of a patient,
• Fig. 7 2 shows a block diagram of a first exemplary embodiment of a device according to the invention for moving a patella,
• Fig. 8 1 shows a schematic illustration of the leg holding device of a first exemplary embodiment of a device according to the invention for moving a kneecap with an inserted leg,
• Fig. 9 1 shows a flowchart which shows the setting and the operation of the first exemplary embodiment of the device according to the invention for moving a patella,
• Fig. 10 2 shows a graphical representation of the measured force exerted by the first exemplary embodiment of the device according to the invention in the cranial-caudal direction as a function of time,
• Fig. 11 2 shows a graphic representation of the measured force exerted by the first exemplary embodiment of the device according to the invention in the cranial-caudal direction and the measured deflection of the kneecap as a function of time,
• Fig. 12 2 shows a perspective illustration of a second exemplary embodiment of a patella gripper according to the invention, which is attached to a leg section of a patient, and a leg holding device,
• Fig. 13 a perspective view of a second embodiment of a patella gripper according to the invention with a view from below and
• Fig. 14 a block diagram of a second embodiment of an inventive device for moving a patella.

In the figures, the same reference symbols designate the same or the same components.

Way (s) of carrying out the invention

In the Figures 1 and 2 A first embodiment 1 of a patella gripper according to the invention is shown. The patella gripper 1 comprises a handle 2, a holding element 3 and a contact finger device 4 with four contact finger units 4.1, 4.2. The handle 2 is on the top of the holding element 3 and the contact finger device 4 is arranged on the underside of the holding element 3. The handle 2 is preferably arranged centrally on the top of the holding element 3 and is preferably screwed to the holding element 3. Each contact finger unit 4.1, 4.2 is assigned an adjustment unit 5, which comprises guide rails 6 and a height adjustment unit 7. Handle 2 is optional. It is also possible to guide the patella gripper 1 directly over the holding element 3.

Two contact finger units 4.1 are arranged on the longitudinal axis 8 of the patella gripper 1 (and thus of the holding element 3) in such a way that one contact finger unit 4.1 is arranged on each side of the transverse axis 9 of the patella gripper 1 or the holding element 3. If the patella gripper 1 is applied to a patella of a patient, the patella can be moved back and forth in the cranial-caudal direction via the contact finger units 4.1 by appropriate guidance / movement of the patella gripper 1.

Each contact finger unit 4.1 preferably comprises two contact fingers 10, which are attached to a patella attack the attached state. The contact fingers 10 are arranged such that they are located on opposite sides of the longitudinal axis 8 of the patella gripper 1 or holding element 3. With two contact fingers 10 arranged in this way per contact finger unit 4.1, a particularly good fit of the patella gripper 1 on a patella and a well-guided movement of the patella in the cranial-caudal direction can be brought about. Furthermore, when applying the contact finger unit 1 to a patient's leg, any scars that often run in the longitudinal direction and any swellings can be taken into account by positioning one contact finger 10 of each contact finger unit 4.1 on one side of the scar or swelling, so that painful contact with the scar / swelling is avoided. Depending on the application, each contact finger unit 4.1 can of course also have more or less than two contact fingers 10.

Furthermore, two contact finger units 4.2 are arranged on the transverse axis 9 of the patella gripper 1 (and thus of the holding element 3) in such a way that one contact finger unit 4.2 is arranged on each side of the longitudinal axis 8 of the patella gripper 1 or of the holding element 3. If the patella gripper 1 is applied to a patella of a patient, the patella can be moved back and forth in the medial-lateral direction via the contact finger units 4.2 by appropriate guidance / movement of the patella gripper 1.

Each contact finger unit 4.2 preferably comprises a contact finger 10 which, when attached to a patella, engages it. The contact fingers 10 are arranged such that they are located on the transverse axis 8 of the patella gripper 1 or holding element 3. This can result in a well-guided movement of the patella in the medial-lateral direction become. Of course, each contact finger unit 4.2 can also have more than one contact finger 10.

The ends of the contact fingers 10, which are further away from the holding element 3, are preferably spherical in shape in order to allow the patient's contact with the patient's leg and knee to be comfortable. At these ends, the contact fingers 10 are preferably provided with protective hoods (not shown). The protective hoods preferably consist of or comprise a silicone or a silicone-like material. The protective hoods are preferably glued to the ends of the contact fingers 10. The provision of such protective hoods can better avoid or at least reduce pain and irritation that can arise as a result of the patient's leg coming into contact with the patella gripper.

The contact finger units 4.1, 4.2 are preferably attached to the holding element 3 so that their height can be adjusted via the height adjustment units 7 of the adjustment units 5 assigned to them. Furthermore, the contact finger units 4.1 are preferably adjustably attached to the holding element 3 in the longitudinal direction and the contact finger units 4.2 preferably in the transverse direction via the guide rails 6 of the setting units 5 assigned to them, the guide rails 6 of the contact finger units 4.1 in the longitudinal direction and the guide rails 6 of the contact finger units 4.2 in Cross direction. The guide rails 6 and the height adjustment units 7 can have latching points for different positions of the contact finger units 4.1, 4.2 in the longitudinal direction or in the transverse direction and in height. Furthermore, the guide rails 6 are preferably each assigned a scale or a graduation 11. Correspondingly, the height adjustment units 7 can also be assigned a scale or a scale.

The position of the contact finger units 4.1, 4.2 and thus the contact finger 10 relative to the knee of the respective patient can be manually adjusted by means of the setting units 5. Both the vertical and the horizontal position of the patella gripper 1 can also be manually adjusted relative to the knee. The manual positioning of the contact finger units 4.1, 4.2 is preferably carried out by a physiotherapist. The initial distances between the contact finger units 4.1, 4.2 in the longitudinal and transverse directions are preferably adapted to the typical dimensions of the knees of men, women or, depending on the application, of children, so that the distances are slightly above the extensions of typical knees in the longitudinal and in Lie in the transverse direction.

The holding element 3 is preferably diamond-shaped, with each tip of the diamond-shaped holding element 3 receiving a contact finger unit 4.1, 4.2 and its associated setting unit 5. The edges of the diamond-shaped holding element 3 are preferably curved inwards for more comfortable handling of the patella gripper 1 and can act as grip surfaces as a handle for moving the patella gripper 1.

The patella gripper 1 according to the invention can be used manually by a physiotherapist or a patient in the context of rehabilitation therapy. However, it can also be used as part of a device 20 for the automatic movement of a patella, as is shown in FIGS Figures 3 to 7 is shown, whereby Figure 7 the block diagram of the device 20 reproduces. For this purpose, the device 20 preferably has an adapter 21 for connecting the patella gripper 1. The patella gripper 21 is designed to receive the adapter 21. The adapter 21 preferably comprises two height-adjustable gripping arms 22 arranged laterally and parallel to one another in the longitudinal direction. The handle 2 is preferably removable from the holding element 3, so that the adapter 21 is inserted between the handle 2 and the holding element 3 can be, wherein the handle 2 can be detachably attached to the adapter 21 or again on the holding element 3 after attaching the adapter 21 to the holding element 3, which preferably has corresponding latching elements.

In the Figures 3 to 7 A first exemplary embodiment 20 of a device according to the invention for moving a patella is shown. The device 20 comprises a patella gripper 1 according to the first exemplary embodiment and a leg holding device 23, which preferably has supports 35 for the lower leg and the thigh of a patient. The device 20 has an adjusting device 24 which serves, among other things, to adjust the height of the kneecap gripper 1 and in which the gripping arms 22 of the adapter 21 engage in such a way that they can be adjusted in height, preferably by latching. By adjusting the height of the gripping arms 22, the knee cap gripper 1 can be adjusted in height via the adapter 21 and in this way lowered to a patient's knee. Furthermore, the adjusting device 24 can preferably be pivoted about a transverse axis and preferably also about a longitudinal axis, so that the position of the patella gripper 1 on the patella can be optimized, depending on the position of the leg in the leg holding device 23. The device 20 according to the invention to move a kneecap can be used for both right and left legs. For transport, the device 20 preferably has a locking mechanism, so that the setting device 24 and the patella gripper 1 are fixed.

The device 20 also has a first drive unit 25 for the movement of the patella gripper 1 in the cranial-caudal direction, ie in the longitudinal direction, a second drive unit 26 for the movement of the patella gripper 1 in the medial-lateral direction, ie in the transverse direction, and a control unit 27 control and preferably for regulating the first drive unit 25 and the second drive unit 26 (compare Figure 7 ). The first drive unit 25, the second drive unit 26 and the control unit 27 are preferably accommodated in a common housing 48 for protection. A battery (not shown) is preferably used to supply energy to the device 20, so that the device 20 can be easily transported. The battery is preferably also located in the housing 48. However, a connection for a building power network can also be provided in addition or as an alternative to the power supply. The first and second drive units 25, 26 control the movement and position of the patella gripper 1 via the movement / position of the adjusting device 24.

Figure 4 shows the device 20 according to the invention for moving a kneecap with a schematic representation of a leg section 49 of a patient, the leg section 49 encompassing the patient's knee 30 and the kneecap gripper 1 being shown at a distance from the leg section 49. This in Figure 5 Device 20 shown corresponds to device 20 in Figure 4 , wherein the patella gripper 1 is now lowered onto the knee 30 by means of the adjusting device 24 and engages it. Figure 6 corresponds to the representation in Figure 5 , in which a real leg 38 with a knee 39 is shown in the drawing, to which the patella gripper 1 engages.

Figure 7 shows a block diagram of the device 20 according to the invention for moving a patella, which comprises a patella gripper 1 according to the first exemplary embodiment. The control unit 27 controls the cranial-caudal movement or the movement in the longitudinal direction of the patella gripper 1 and thus the patella of a patient via the first drive unit 25 when the patella gripper 1 engages the patella. The control unit 27 also controls via the second drive unit 26 the medial-lateral movement or the movement in the transverse direction of the patella gripper 1 and thus in the applied state of the patella of a patient. The first and the second drive unit 25, 26 each have a motor 28, in particular an electric motor (preferably a DC motor) and a linear guide unit 29, the linear guide unit 29 of the first drive unit 25 the patella gripper 1 in the longitudinal direction and the linear guide unit 29 of the second drive unit 26 moves the patella gripper 1 in the transverse direction. A transmission unit 30, in particular a transmission, is preferably provided between the respective motor 28 and the linear guide unit 29 assigned to it, wherein the transmission unit 30 can comprise a clutch. A power electronics unit 31 is connected upstream of the motors 28, via which the control unit 27 controls the motors 28. The power electronics units 31 can comprise power amplifiers. Furthermore, various sensors are preferably provided, which will be discussed further below.

As already stated, the first and the second drive units 25, 26 are operated in such a way that they engage the patella gripper 1 according to a Cartesian coordinate system in the X and Y directions, i.e. move in the longitudinal and transverse directions or in the cranial-caudal and medial-lateral directions.

To measure the linear movement or to deflect the patella gripper 1 in the cranial-caudal and medial-lateral direction, a corresponding linear sensor unit 32, in particular a linear potentiometer, is provided for each direction, which measures the extent of the change in position on the respective linear guide unit 29 and thus measures the position / deflection of the patella gripper in the longitudinal or transverse direction and transmits the measured values to the control unit 27. The linear sensor units 32 are also referred to as position sensor units. Furthermore, each motor 28 is assigned an encoder or encoder 33, which measures the position of the motor shaft and transmits it to the respective power electronics unit 31 and / or the control unit 27. Depending on the measured values of the linear sensor units 32 and possibly the encoder 33, the control unit 27 regulates the patella gripper 1 via the first and the second drive units 25, 26, in particular in the event that the encoders 33 and / or the linear sensor units 32 fail , position limit switches, not shown, are preferably provided. If a position limit switch is moved by a linear guide unit 29 when the patella gripper 1 is moved, this is detected by the control unit 27 when the maximum permissible deflection has been reached, and the patella gripper 1 is moved back to the zero position by the control unit 27 for safety reasons.

Furthermore, force sensors 34 are provided, which measure the force exerted on the patella gripper 1 and transmit the measured force to the control unit 27. The control unit 27 also regulates the patella gripper 1 as a function of the measured force by appropriately actuating the first and second drive units 25, 26. The force sensors 34 are preferably attached to the adapter 21 or integrated therein and comprise or are strain gauges as such educated. The force sensors 34 can alternatively or additionally be arranged in the contact finger units 4.1, 4.2. Furthermore, the motor currents are preferably monitored by means of the control unit 27 by means of corresponding current sensors (not shown) assigned to the motors 28 in order to prevent uncomfortable impacts of the patella gripper 1 on the patella of a patient. The measurement of the motor currents represents a measurement that is redundant to the force measurement and serves to protect the patient. Furthermore, device 20 is preferred A temperature sensor (not shown) is integrated to measure the temperature in the device for safety reasons so that overheating can be detected. The provision of sensors for different measurement variables results in a redundant measurement system which guarantees the safety of the patient and offers several monitoring options for the entire healing process of the patient.

By means of the force sensors 34, the linear sensor units 32, the position limit switches (not shown), the current sensors (not shown), the temperature sensor (not shown) and the monitoring and evaluation of the measured values fed back by them by the control unit 27, the safety of the use of the device 20 for the Patients are ensured. The tolerable limit values for the measured values or quantities, in particular for the measured force and the measured change in position / deflection, depend on the respective patient and are therefore preferably determined before the actual rehabilitation therapy as part of a learning phase and stored in the device 20. In the event that the measured force exceeds the limit value stored for it, the control unit 27 initiates a reversal of the movement of the patella gripper 1, so that the patella gripper 1 is moved back into the initial position. If the value measured for a motor current by means of the current sensors (not shown) exceeds the limit value stored for it, the control unit 27 goes into a safety mode in which the device 20 is automatically shut down by the control unit 27 and the linear guide units 29 by one by the control unit 27 caused decoupling of the motors 28 from the mechanical parts of the transmission units 30 to be freely movable, so that the patella gripper 1 is also freely movable, the respective coupling of the transmission units 30 preferably being designed magnetically. Even with the others Measured values such as the change in position / deflection and the temperature, for safety reasons, if the corresponding previously stored limit values are exceeded, the control unit 27 preferably sets the device 20 into safety mode. If the limit value for the change in position / deflection is exceeded by its measured value, analogously to the exceeding of the limit value for the force, it can alternatively be provided that the control unit 27 moves the patella gripper 1 into the initial position. In the safety mode, the setpoint speed values for the motors 28 are set to zero by the control unit 27, the power electronics units 31 are deactivated and the — preferably magnetic — couplings between the motors 28 and the mechanical parts of the transmission units 30 are released. The limit value can be monitored both by the control unit 27 and by a — preferably external — user interface, such as a laptop connected to the device 20.

Figure 8 shows the leg holding device 23 of the device 20, which has two supports 35, wherein one support 35 can accommodate a thigh and the other support 35 a lower leg of a patient. The leg holding device 23 is suitable for holding both a left and a right leg. To hold a leg 38, holding straps 36 are used, which are fastened to the supports 35. For the therapeutic movement of a patient's kneecap, the leg 38 should be in either an extended or slightly bent state. Even a bend of the leg 38 of more than 20 degrees can hinder the mobility of the kneecap, since the knee cap is usually already in the thigh groove at such an angle. The leg holding device 23 is designed or connected to the housing 48 of the device 20 in such a way that it can be inclined so that the patient is comfortable Can take position. The leg holding device 23 is also attached to the housing 48 such that it can be adjusted in height in order to increase the comfort for the patient. Furthermore, the leg holding device 23 is designed such that the angular position of the supports 35 relative to one another can be changed, which leads to a change in the knee flexion. For this purpose, the supports 35 are connected to one another via a corresponding joint 37. The knee can be bent by the in Figure 8 specified angle α can be defined. Together with the above-described adjustability of the patella gripper 1 by means of the preferably swiveling adjusting device 24, the adjustability of the leg holding device 23 enables the device 20 to be adjusted in relation to different leg morphologies and knee pathologies.

The device 20 is preferably operated via an external user interface (not shown), such as a laptop. The device 20 can be controlled via the external user interface and the rehabilitation therapy carried out by the device on a patient's knee can be displayed and monitored. The Labview application program installed on the external user interface can be used for this purpose. Various therapy phases for activation can be stored in the external user interface. To connect the external user interface, the device 20 preferably has a corresponding interface (not shown) such as a serial interface, for example a USB interface (USB: Universal Serial Bus), so that only one cable for connecting the external user interface to the device 20 is needed. Alternatively, the device can also communicate with an external user interface using radio transmission, for example according to the Bluetooth protocol. Of course, the user interface can also be integrated in the device 20 and provided on the outside of the housing 48.

The device 20 according to the invention for moving a patella is preferably used in two successive phases. In the first phase, the deflections / displacements or movements of the patella are taught to the device 20. This first phase represents a learning phase in which the device is set or calibrated for a specific patient. In the second phase, the device 20 then executes the learned or set movement of the patella.

The first phase or the learning phase serves at the beginning of a rehabilitation therapy to adapt the device 20 to the specific pathology and morphology of a patient. For the respective patient, this learning phase only has to be repeated after its initial implementation if parameters of the rehabilitation therapy have changed between two therapy sessions. The learning phase can be carried out manually or automatically or automatically by the device 20.

If the learning phase is carried out manually by, for example, a physiotherapist, the physiotherapist moves the kneecap gripper 1 in order to move the kneecap up and down in the cranial-caudal direction and from the inside out and back in the medial-lateral direction. Based on feedback from the respective patient, the physiotherapist decides which maximum movements / deflections or displacements of the kneecap will not cause pain to the patient. The physiotherapist stores or stores the force / deflection values corresponding to these maximum movements / deflections or displacements in the device 20, in particular by pressing corresponding buttons on the patella gripper 1. The force / deflection values can also be via an internal or external user interface in the Device 20 can be stored. The stored force / deflection values are then used by the device in the subsequent second phase, the actual therapy phase with successive therapy sessions 20 used for the movement of the patella of the respective patient by means of the patella gripper 1.

If the learning phase is carried out automatically or automatically, the device 20 moves the patella gripper 1 - e.g. after pressing an activation button provided on the device 20 for activating the learning phase - automatically gently and slowly, preferably in 2 millimeter steps, first in the cranial-caudal direction and then down and then in the medial-lateral direction first to one and then on the other hand, until the patient begins to feel pain, and this signals the device 20, for example, by releasing or pressing the activation button again or by actuating a corresponding further activation button, so that the learning movement is interrupted in the learning phase and the kneecap gripper 1 from the control unit 27 is moved back to its initial position. Of course, the patella can first be moved in the medial-lateral direction and then in the cranial-caudal direction. When changing from the cranial-caudal direction to the medial-lateral direction or vice versa, the kneecap gripper 1 is preferably first moved back to its initial position. As an alternative or in addition to the activation button, the device 20 can also be designed such that it processes acoustic signals from the patient and e.g. the learning phase is interrupted at the word "stop".

The current force / displacement values or deflection values when the learning phase is interrupted are stored in the device 20 via the force sensors 34 and / or the linear sensor units 32. They can be uploaded again and again at any time and are used in the later second phase during the therapy sessions as values for the movement of the kneecap by the device 20, so that the learning phase does not have to be carried out for every therapy session, which saves time. The automatic execution of the learning phase offers is particularly interested in the patient's own therapies that he carries out in his home. During the first phase, he can easily assume a relaxed and comfortable position.

During the second phase, the actual therapy phase, the control unit 27 controls the device 20 in such a way that the kneecap gripper 1 executes a uniform, rhythmic movement in order to displace the kneecap. The amplitude of the deflection / displacement of the kneecap is gradually increased up to the values stored for the deflections and / or the forces in the respective direction (cranial-caudal or medial-lateral), so that pain-free treatment can be ensured.

Via the preferably external user interface, the physiotherapist can set parameters of the rehabilitation therapy, e.g. using the Labview application program, e.g. the duration of each therapy session / treatment in minutes and the cycle rate, i.e. the number of up and down movements in the cranial-caudal direction per minute and the number of back and forth movements in the medial-lateral direction per minute.

For a change from the cranial-caudal to the medial-lateral direction, the kneecap gripper 1 is preferably returned by the control unit 27 to the middle position (initial position), which also represents the initial position or zero position of the kneecap gripper 1. Since the second phase runs fully automatically, it is completely repeatable and comprehensible, even by the patient himself. The applied forces / displacements or deflections are preferably carried out by the device 20 and / or the external user interface by the force sensors 34 and / or the linear sensor units 32 recorded so that not only the result of each therapy session, in particular graphically on the user interface and / or the device 20, can be displayed and evaluated, but also therapy results from multiple therapy sessions can be compared over a longer period of time. In this way, healing progress can be recorded and monitored. Such a comparison of therapy results is particularly important for the knee surgeon or the physiotherapist if the patient carries out self-therapy and comes to the clinic for regular check-ups. Furthermore, the graphical representation of the therapy results and the healing progress represents an additional motivation for the patient to carry out the rehabilitation therapy independently at home, which in turn leads to an acceleration of the healing process. The patient's conscious recording of the therapy results also serves to increase the patient's self-discipline for carrying out the rehabilitation therapy on his own.

In Figure 9 the learning phase and the second phase (the actual therapy phase) are shown separately for the cranial-caudal direction and for the medial-lateral direction. In a first step 40, the device 20 or a user, for example a physiotherapist, of the device 20 checks whether the values for the movement of the patella in the medial-lateral direction are set. If this is not the case, the first phase, ie the learning phase, for the medial-lateral direction is carried out either manually or automatically in step 41. After completion of the learning phase, the second phase for the medial-lateral direction begins in step 42, in which the force / deflection values stored in the learning phase are used by the control unit 27 to control the patella gripper 1 and thus to move the patella in the medial-lateral direction become. The displacement / deflection of the kneecap in the medial-lateral direction takes place according to a predetermined cycle rate. In step 43 it is checked whether the cycle rate has been reached. If this is the case, then in step 44 either automatically or by the user checks whether the values for the movement of the kneecap in the cranial-caudal direction are set. If this is not the case, the learning phase for the cranial-caudal direction takes place in step 45 either manually or automatically. After completion of the learning phase, the second phase is carried out in step 46 corresponding to step 42 for the cranial-caudal direction. In step 47, the number of displacements / deflections of the kneecap in the cranial-caudal direction is monitored (corresponding to step 43) and the therapy session is ended when the predetermined cycle rate is reached.

Of course, steps 44, 45, 46, 47 for the cranial-caudal direction and then steps 40, 41, 42, 43 for the medial-lateral direction can also be carried out first. Furthermore, it can also first be checked whether the values for the movements in the medial-lateral direction and in the cranial-caudal direction are set (steps 40 and 44), and depending on the result of the test, the learning phases can be carried out for both directions (steps 41 and 45) and only after both learning phases have been completed can the second, actual therapy phases be carried out for both directions (steps 42, 43 and 46, 47). When changing from the cranial-caudal to the medial-lateral direction or vice versa, the kneecap gripper 1 is preferably returned by the control unit 27 to the middle position (initial position) first.

Figure 10 shows an exemplary course of the force exerted by the device 20 for moving / deflecting the patella in the cranial-caudal direction during a therapy session over time. The force values gradually increase during a settling phase of 12 seconds. If a limit value for the force stored in the device 20 is exceeded at about 1.8 minutes, the control unit 27 automatically reduces the amplitude of the force and thus the deflection. The force varies corresponding to the deflection and the direction of the deflection (ie in the cranial-caudal direction upwards towards the patient's head and downwards towards the patient's feet). The greater the deflection of the kneecap, the greater the force exerted.

Figure 10 shows exemplary courses of the measured force values (dashed curve) and deflection values (solid curve) during a learning phase in the cranial-caudal direction, within which the maximum permissible force (the limit value for the force) was previously determined as 20 Newtons and stored in the device 20 was. First, the deflection of the kneecap by means of the kneecap gripper 1 of the device 20 increases steadily and steadily in the direction of the patient's head to 8 millimeters (-8 millimeters starting from the initial position or zero position of the kneecap gripper 1) and then in the direction of the body end opposite the head 8 millimeters increased. The force values measured here oscillate between approximately -15 Newtons (towards the body end opposite the head) and approximately 10 Newtons (towards the head). After about 1.8 minutes of the learning phase, an external force is applied to the kneecap via the user interface and the control unit 27 by means of the kneecap gripper 1, which exceeds the predetermined limit value of 20 Newtons in order to check whether the monitoring of the force values for exceeding the limit value works. How from Figure 10 it can be seen that the deflection and the force are automatically and directly reduced by the device 20 with the aid of the control unit 27 when the applied force exceeds the stored limit value. When the measured force values exceed the force limit value, the patella gripper 1 is automatically and immediately moved back into its initial position by the control unit 27. After the automatic reduction of the deflection and the force that occurs as a result, the device 20 starts a new learning phase in which the force applied again is gradually increased. The measurement of the applied force by means of the force sensors 34 and the feedback of the measured force values to the control unit 27 ensure painless treatment of the patient. If the current limit value for one of the motor currents is exceeded, the drive units 25, 26 are automatically and immediately deactivated by the control unit 27, the speed setpoints for the motors 28 are set to zero and the linear guide units 29 are set into freewheeling.

In the Figures 12 and 13 A second exemplary embodiment 51 of a patella gripper according to the invention is shown, with which a patella can be moved. The patella gripper 51 comprises a holding element 53, on the underside of which a contact finger device 54 is arranged. The contact finger device 54 comprises two contact finger units 54.1 arranged on opposite sides on the underside of the holding element 53, each of which comprises at least one, preferably two, contact fingers 55. Regarding the contact fingers 55 or any protective hoods provided for them, what has been said above about the first exemplary embodiment 1 of the patella gripper according to the invention applies.

The contact finger device 54 and thus the contact finger units 54.1 are rotatably arranged on the holding element 53, so that the contact finger units 54.1 move from one position in the longitudinal direction on opposite sides of the transverse axis of the holding element 53 (for moving the patella in the cranial-caudal direction or in the longitudinal direction) Position in the transverse direction on opposite sides of the longitudinal axis of the holding element 53 (for moving the patella in the medial-lateral direction or in the transverse direction) and vice versa. For this purpose, the contact finger device 54 can preferably be rotated by at least 90 degrees. The holding element 53 preferably has for rotating the contact finger device 54 at least one, preferably two arcuate openings 56. A corresponding number of handles 52 for rotating the contact finger device 54 is provided on the upper side of the holding element 53, the one or more handles 52 being connected to the contact finger device 54 and preferably a handle 52 being connected to the contact finger device 54 via an opening 56.

A fluidic actuator 59 is assigned to each contact finger unit 54.1, the term fluid being intended to encompass both “pneumatic” and “hydraulic”. They are preferably pneumatic actuators. Each fluidic actuator 59 can be, for example, a cushion that can be filled with a fluid, with each cushion being several (preferably three) in succession, i.e. sequentially, arranged fillable chambers 59.1 may include. The fluidic actuators 59 are preferably arranged between the respective contact finger unit 54.1 and the edge of the holding element 53 and act on the respective contact finger unit 54.1. Each contact finger unit 54.1 is therefore applied to a fluidic actuator 59.

The fluidic actuators 59 are preferably driven or filled with fluid via a fluidic pump 58, the fluidic pump 58 being part of a second exemplary embodiment 60 of a device according to the invention for moving a patella. The device 60 according to the invention is shown as a block diagram in FIG Figure 14 shown.

Figure 12 shows, in addition to the patella gripper 51, the leg holding device 63 of the device 60 according to the invention, the patella gripper 51 being mounted on a leg splint 64 of the leg holding device 63, which leg splint 64 can be attached to the top of a leg. The leg splint 64 preferably has an opening for the knee, above which the patella gripper 51 is arranged, and receptacles 65 and 66 for the thigh and for the lower leg, against which the thigh and lower leg can rest. The angle between the receptacles 65 and 66 can preferably be changed / set, which leads to a change in the knee flexion. By adjusting the angle between the receptacles 65 and 66, the patient's leg can be angled or stretched again for the therapeutic movement of the kneecap. Retaining straps 67, which form part of the leg holding device 63, are provided for fastening the receptacles 65 and 66 and the patella gripper 51 to the leg 49 of a patient. Figure 12 shows the kneecap gripper 51 spaced apart from the patient's leg 49 for better illustration.

The patella gripper 51 preferably has an adjusting device 57, by means of which the height of the patella gripper 51 can be adjusted in relation to the knee. The adjusting device 57 - and thus the patella gripper 51 firmly connected to it - can preferably be pivoted about the transverse axis, so that the position of the patella gripper 51 on the patient's patella can be optimized. The patella gripper 51 and the device 60 can be used for both right and left patella or legs. For the transport of the device 60, the receptacles 65, 66 of the leg holding device 63 are preferably folded or folded down below the patella gripper 51.

By rotating the contact finger device 54, the patella can be mobilized by means of the contact finger units 54.1 both in the cranial-caudal direction and in the medial-lateral direction. For the mobilization of the patella in one of the directions mentioned, the contact finger units 54.1 are moved accordingly by means of the fluidic actuators 59, for which the fluidic actuators 59 are controlled by a fluidic pump 58, one of the fluidic actuators 59 depending on the direction of movement (back and forth) Fluid is filled. By introducing fluid into one of the fluidic actuators 59, the latter is filled and thereby expanded and thereby moves the contact finger unit 54.1 assigned to it in the direction of its expansion, which in turn causes the patella to be moved in the corresponding direction by the force of the contact finger unit 54.1.

As already described, the contact finger device 54 of the patella gripper 51 can be rotated such that the contact finger units 54.1 via the fluidic actuators 59 firstly in the cranial-caudal or caudal-cranial direction (that is to say back and forth in the longitudinal direction) and secondly in the medial-lateral direction ( ie in the transverse direction) can be moved back and forth so that the patella can be mobilized in the corresponding direction. The one or more contact fingers 55 of the contact finger units 54.1 specifically transmit the force introduced via the fluidic actuators 59 to the patella.

Figure 14 shows a block diagram of the device 60 according to the invention for moving a patella. The device 60 comprises a control unit 67 for controlling or regulating the drive unit 68 formed by the fluidic pump 58 and the fluidic actuators 59 for the contact finger units 54.1, the control unit 67 and the fluidic pump 58 for protection preferably in a separate housing (not shown) are accommodated. The fluidic pump 58 is connected via valves 69 to the fluidic actuators 59, which likewise form part of the drive unit 68. The valves 69 and the fluidic pump 58 are controlled or regulated by the control unit 67 via power electronics unit (s) 70.

The control unit 67 controls the movement of the patella via the control of the fluidic pump 58, which then fluid depending on the desired direction of movement in one of the fluidic actuators 59 promotes, whereby the knee cap can be moved in the longitudinal direction or in the transverse direction by rotating the contact finger device 54 by 90 degrees. By supplying a fluidic actuator 59 with fluid, this exerts pressure on the contact finger unit 54.1 assigned to it and moves it (and thus the patella) in the desired direction.

Pressure sensor units 71 are preferably provided, which in particular measure the pressure exerted by the fluidic actuators 59 and transmit the measured pressure value to a pressure regulator 72, which compares the measured pressure value with a stored target pressure value and in particular via a corresponding signal to the control unit 67 adjusts the target pressure value. Furthermore, the sensors or sensor units described in connection with the patella gripper 1 and the device 20 or at least some of them can be provided. The device 60 can be supplied with energy as described above for the device 20. The same applies to the operation or an external user interface of the device 20. Furthermore, linear sensor units / linear sensor units 73 are preferably provided, which measure the deflection of the contact finger units 54.1 and transmit the measured values to the control unit 67. The safety of the use of the device 60 for the patient can be ensured by means of the pressure sensor units 71 and the preferably additionally provided linear sensor units 73 and the monitoring and evaluation of the measured values fed back from them by the control unit 67.

Of course, in the first embodiment 1 of a patella gripper according to the invention and in the first embodiment 20 of a device according to the invention for moving a patella, as shown in FIGS Figures 1 to 8 a movement of the patella gripper 1 by means of a fluidic pump and fluidic actuators can be provided, as in relation to the second exemplary embodiment 51 of a patella gripper according to the invention and the second exemplary embodiment 60 of a device for moving a patella Figures 12 to 14 intended. Accordingly, one or more drive units for the contact finger units 54.1 can also be provided in the patella gripper 51 and the device 60, each of which comprises a motor, in particular an electric motor, and a linear guide unit. The device 20 can also include a leg holding device as shown in FIG Figure 12 is shown. Accordingly, device 60 may include a leg restraint as shown in FIG Figure 8 is shown.

With regard to the in Figure 7 The flowchart described method is carried out in the patella gripper 51 and the device 60 between a change in the direction of movement for the patella from the longitudinal direction to the transverse direction or vice versa, a rotation of the contact finger device 54 by 90 degrees. Furthermore, there is only one drive unit 68 and only one contact finger unit 54.1, which can advantageously be used both for the mobilization of the kneecap in the longitudinal direction and (due to the rotation) for the mobilization of the kneecap in the transverse direction.

While preferred embodiments of the invention are described in the present application, it should be clearly pointed out that the invention is not limited to these and can also be embodied in other ways within the scope of the following claims.

Claims (15)

1. A patella gripper for a patella, characterised by a retaining element (3; 53) and a contact finger apparatus (4; 54), wherein the contact finger apparatus (4; 54) is arranged on the lower face of the retaining element (3; 53), wherein the contact finger apparatus (4; 54) comprises at least two contact finger units (4.1, 4.2; 54.1), which are arranged on opposite sides of the retaining element (3; 53), and wherein the contact finger apparatus (4; 54) is designed in such a manner that the patella can be moved linearly in the cranial-caudal direction and in the medial-lateral direction by means of the contact finger units (4.1, 4.2; 54.1).
2. The patella gripper according to claim 1, characterised in that the contact finger units (4.1, 4.2; 54.1) comprise one or several contact fingers (10; 55), wherein

   the ends of the contact fingers (10; 55), which ends are further away from the retaining element (3; 53), are preferably spherical in shape, or

   wherein the contact fingers (10; 55) of the contact finger units (4.1, 4.2; 54.1) at the ends located away from the retaining element (3; 53) comprise protective hoods,

   which protective hoods preferably comprise silicon as a material.
3. The patella gripper according to any one of the preceding claims, characterised in that

   - the contact finger apparatus (4) comprises two contact finger units (4.1) arranged in the longitudinal direction on opposite sides of the transverse axis (9) of the retaining element (3), which contact finger units (4.1) are adjustable in the longitudinal direction relative to the retaining element (3) and are used for moving the patella in the cranial-caudal direction, and in that

   - the contact finger apparatus (4) comprises two contact finger units (4.2), arranged in the transverse direction on opposite sides of the longitudinal axis (8) of the retaining element (3), which contact finger units (4.2) are adjustable in the transverse direction relative to the retaining element (3) and are used for moving the patella in the medial-lateral direction.
4. The patella gripper according to claim 3, characterised in that the contact finger units (4.1) arranged in the longitudinal direction in each case comprise two contact fingers (10) that are arranged on opposite sides of the longitudinal axis (8) of the retaining element (3).
5. The patella gripper according to claim 3 or 4, characterised in that the contact finger units (4.2) arranged in the transverse direction in each case comprise a contact finger (10) that in particular is arranged on the transverse axis (9) of the retaining element.
6. The patella gripper according to any one of claims 1 to 2, characterised in that the contact finger apparatus (54) is rotatably arranged on the retaining element (53) so that the contact finger apparatus (54) can be rotated on an axis that is aligned perpendicularly to the longitudinal axis of the retaining element (53) and perpendicularly to the transverse axis of the retaining element (53), wherein the contact finger apparatus (54) comprises two contact finger units (54.1) that are arranged on opposite sides of the retaining element (53),
   wherein each contact finger unit (54.1) preferably comprises two contact fingers (55).
7. The patella gripper according to any one of the preceding claims, characterised in that each contact finger unit (54.1) is associated with a fluidic actuator (59).
8. The patella gripper according to any one of the preceding claims, characterised in that the contact finger units (4.1, 4.2) are arranged on the retaining element (3) so as to be height-adjustable, and/or

   in that a handle (2; 52) for guiding the patella gripper (1) and/or for rotating the contact finger apparatus (54) is provided, which handle (2; 52) is arranged on the upper face of the retaining element (3; 53),

   wherein the handle (2) is preferably arranged in the centre on the upper face of the retaining element (3).
9. The patella gripper according to any one of the preceding claims, characterised in that it is designed in such a manner that it can be connected to an adapter (21).
10. A device for moving a patella with a patella gripper (1; 51) according to any one of the preceding claims and with a leg holding device (23; 63), characterised in that one or several drive units (25, 26; 68) for moving the contact finger units (4.1, 4.2; 54.1), and a control unit (27; 67) for controlling the one or several drive units (25, 26; 68) are provided.
11. The device according to claim 10, characterised in that the one or several drive units (25, 26) in each case comprise a motor (28) and a linear guide unit (29), wherein preferably a first drive unit (25) for the movement in the cranial-caudal direction and a second drive unit (26) for the movement in the medial-lateral direction are provided.
12. The device according to claim 10, characterised in that the one or several drive units (68) comprise a fluidic pump (58) and a fluidic actuator (59) and in particular one or several valves (69).
13. The device according to any one of claims 10 to 12, characterised in that linear sensor units (32; 73) for measuring the deflection of the patella gripper (1) or of the contact finger units (54.1) are provided, and/or that force sensors (34) and/or pressure sensor units (71) for measuring the force applied by the patella gripper (1) or by the contact finger units (4.1, 4.2; 54.1) are provided.
14. The device according to any one of claims 10 to 13, characterised in that the leg holding device (23; 63) is height-adjustable and/or adjustable in terms of its inclination and/or adjustable for various instances of knee flexion,

    wherein an adjustment device (24; 57) for the patella gripper (1; 51) is preferably provided, by means of which the height of the patella gripper (1; 51) can be adjusted,

    wherein the adjustment device (24; 57) is preferably pivotable.
15. The device according to any one of claims 10 to 14, characterised in that an activation button is provided by means of which the device (20; 60) can be made to assume a teach-in phase, in which the device is adjusted in relation to a particular patient or is calibrated in relation to said patient.

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