WO2013017726A2

WO2013017726A2 - Continuous passive motion device

Info

Publication number: WO2013017726A2
Application number: PCT/ES2012/070600
Authority: WO
Inventors: Rafael DONAT ROCA; Martin Andreas KOCH
Original assignee: Althaia, Xarxa Assistencial De Manresa, F.P.; Fundació Ctm Centre Tecnològic
Priority date: 2011-08-01
Filing date: 2012-08-01
Publication date: 2013-02-07
Also published as: ES2398426R1; EP2740457A2; ES2398426A2; WO2013017726A3; ES2398426B1

Abstract

The invention relates to a continuous passive motion device for rehabilitating a diarthrotic, synovial joint between a near limb with a first joint surface and a distal limb with a second joint surface. The device includes means for inducing a flexion-extension motion of the joint (50; 50') and is characterized in that it additionally includes means for inducing sliding between both joint surfaces (10; 20; 20'), said means acting on one of the joint limbs during the flexion-extension motion.

Description

Continuous Passive Movement Device

The present invention relates to continuous passive motion devices for rehabilitation therapies. Specifically, to a device for rehabilitation of a diartrodia and synovial joint comprising means for inducing a flexion-extension movement of the joint.

STATE OF THE PREVIOUS TECHNIQUE Continuous passive motion devices are used in postoperative rehabilitation, for example after an arthrotomy, an open fracture reduction, a patelectomy, ligament lesions, synovectomy, biological surface repair for large defects (with periodic grafting), surgical repair of a tendon section, a rigid internal fixation of a metaphyseal osteotomy or a total joint prosthesis.

In the diartrodial or synovial joints (for example the knee or elbow) one of the bones has a convex articular surface and the other has a concave articular surface, which roll over each other when a joint flexion or extension movement is performed . However, the presence of ligaments and tendons causes the angular rotation or bearing to overlap, in addition, a sliding between both articular surfaces.

For example, in the case of the knee joint, it is a sliding of the articular surface of the femur with respect to the articular surface of the tibia. This slip has an anteroposterior or posteroanterior trajectory in the sagittal plane, depending on whether it is extension or flexion of the leg respectively.

In the prior art, there are documents that describe the movement of a joint as a slide attached to an angular rotation. The documents US4665899, US4974830 or US5228432 describe devices comprising some type of floating or pivoting support that allows certain slides. Other systems such as those described, for example, in US4825852, US4671257 comprise some type of special hinge that allows a polycentric rotation of the joint.

However, the known devices fail to reproduce the natural joint movement in the way that a physiotherapist does, who when acting (with their hands) on the joint takes into account both the flexion / extension movement and the sliding, so that the Passive exercise performed with the patient is satisfactory.

EXPLANATION OF THE INVENTION

The objective of the present invention is to improve, at least partially, the rehabilitation performance performed with continuous passive motion devices. One aspect of the invention describes a continuous passive movement device for rehabilitation of a synovial and diartrodia joint between a proximal member with a first articular surface and a distal member with a second articular surface, the device comprising means for inducing a flexion movement. extension of the joint, characterized by the fact that it also comprises means to induce a sliding between both articular surfaces, said means acting on one of the members of the joint, during the flexion-extension movement. According to this aspect, the means for inducing a sliding between both articular surfaces print an external thrust directly on one of the members of the joint, during the flexion-extension movement. Consequently, they allow to reproduce with greater fidelity the natural joint movement, in a similar way to what a physiotherapist would do by printing said external thrust or force with his hands. Therefore, they improve at least partially the rehabilitation performance.

In some embodiments, the means for inducing a slip may comprise first means that can act on the proximal member of the joint. In some embodiments, the means for inducing a slip between both articular surfaces of the joint may comprise a second means for inducing a slip. Said second means can act on the distal joint member, during the flexion-extension movement. In some cases it may be preferable to induce sliding on the distal limb; if both the first means and the second means for inducing a slip are also included, the precision with which the natural joint movement is reproduced can be improved.

Other objects, advantages and features of embodiments of the invention will be apparent to the person skilled in the art from the description, or can be learned with the practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular embodiments of the present invention will now be described by way of non-limiting example, with reference to the accompanying drawings, in which:

Figures 1 a and 1 b schematically show the landslides that accompany the angular rotation in the flexion and natural extension of the knee;

Figure 2 shows a perspective of a continuous passive movement device for knee rehabilitation;

Figure 3 shows a perspective of an embodiment of the present invention in an extended position;

Figure 4 shows a side view of Figure 3;

Figure 5 shows a side view of the device of Figures 3 or 4, but in a flex position;

Figure 6 shows a perspective of another embodiment of the present invention in flexion position;

Figure 7 shows an exploded view of Figure 6; Figures 8a-8f schematically show the operation of different embodiments of the present invention;

Figures 9 and 10 show in perspective another embodiment of the present invention, in the position of extension and flexion;

Figures 1 1 and 12 show an enlarged detail of Figures 9 and 10; Y

Fig. 13 is a diagram showing a procedure for extending a conventional rehabilitation device by a kit according to an embodiment of the present invention.

DETAILED EXHIBITION OF MODES OF EMBODIMENT

In every joint there is a proximal member comprising a first articular surface and a distal member comprising a second articular surface. For example in the knee joint, the proximal limb is the femur and the distal limb is the tibia; while in the ankle joint the proximal limb is the tibia-fibula joint and the distal limb is the talus and in the elbow joint the proximal limb is the humerus and the distal limb is the cube.

Throughout the present specification, the term "proximal" is used for the member that is attached to the body and the term "distal" is used for the member furthest from the point of attachment to the body. Thus, the members can change their relative position with respect to the main body. For example, the tibia is the distal member in the knee joint and is the proximal member in the ankle joint.

Figure 1 shows schematically, with arrows, the sliding of the articular surface of the femur 1 over the articular surface of the tibia 2 during the natural flexion movement of the leg. Specifically, two specific moments are shown, approximately 30 ° and 60 °. The Arrows in Figure 1 b schematize the slippage that occurs during the natural movement of the leg extension.

Figure 2 shows a knee device comprising means for inducing a flexion-extension movement 50 and which is not within the scope of patent protection, but which is described in order to facilitate the understanding of the embodiments of the invention. . The means for inducing a flexion-extension movement 50 may comprise a first pivot point 30a which, in operation, may be associated with a proximal end of the femur (proximal member of the knee joint), that is, the joint of the hip These means 50 may also comprise a second pivot point 30c which, in operation, may be associated with a distal end of the tibia (distal member of the knee joint), that is, with the ankle joint.

Thus, the means for inducing flexion-extension movement 50 may comprise three well-defined articulation points: first pivot point or hip-femur joint 30a, proper joint (femur-tibia) 30b and second pivot point or tibial joint -pie 30c.

In addition, the means for inducing flexion-extension movement 50 may comprise a support for the femur (proximal member) 31 which may comprise a pair of parallel bars 31 a, 31 b that can be connected to each other by means of a profile in "U" 33.

The support for the femur 31 may be doubly articulated. One of its ends 36 may be articulated to a base 3 of the device, at the first pivot point 30a. The other end 37 may be articulated at one end 38 of a support for the tibia 34 in the joint itself 30b. Similarly, the support for the tibia 34 may comprise a pair of parallel bars 34a and 34b, which may be connected to each other by means of an "IT 35" profile.

The support for tibia 34 can also be articulated at both ends. As mentioned, its end 38 may be articulated in the joint 30b itself (femur-tibia) to the end 37 of the support for the femur 31. And its other end 32 may be articulated at the second point. from pivot 30c (tibia-foot joint) to a foot support 40.

Figures 3 and 4 show a continuous passive movement device for the knee according to an embodiment of the invention, in the leg extension position. This embodiment may be mounted for the left leg. Figure 3 shows a perspective view and Figure 4 a side view. In this example, the device can be for the knee, therefore, the proximal limb is the femur and the distal limb is the tibia. As shown in Figure 3, the device may comprise a base 3, means for inducing a flexion-extension movement of the leg such as those described in relation to Figure 2 and means for inducing a slide 10, 20 which They will be described later. In Figures 2 and 3 it is shown that the base 3 can be firmly placed on a flat surface and can comprise a control 5 (wireless or connected to the base 3 by means of a cable as it is drawn).

The base 3 may comprise an extension 6. Said extension 6 may be telescopic. The base 3 of the device may also comprise means for regulating the length of the extension 6 at different leg lengths. Said means for regulating the length of the extension 6 can be, for example, a screw 7. In Figures 2 and 3 it is also shown that each bar of the pair of parallel bars 31 a, 31 b of the femur support can have a length different. The longest bar 31 a may be articulated to the extension of the base 3. Said longer bar 31 a may be that on which it supports the outer leg area. In this way, the internal area of the leg is left free, at the height of the joint with the hip 30a, being more comfortable for the user, in addition, the final weight of the device is reduced. However, in some embodiments both bars 31 a, 31 b may have the same length, whereby the device may be more stable. In addition, the extension 6 of the base may comprise an adjustable length bar. Said bar can be inserted in holes 300 of the base 3. Thus, the base 3 can comprise at least two holes 300, right and left, where the extension can be inserted, depending on the leg to be rehabilitated, right or left.

The base 3 may comprise an upper area or surface 301. Said upper surface 301 may comprise a track, groove or guide 8 arranged longitudinally. On track 8, a first scrollable element 12 and a second scrollable element 4 can be moved.

The first movable element 12 can actuate first means for inducing a slide 10 and the second movable element 4 can actuate the means for inducing the flexion-extension movement 50.

On the other hand, the first means for inducing a slide 10 may comprise a support for the femur 1 1. Said support for the femur 1 1 can be mounted at one of its ends 1 1 1, pivotally, at the first pivot point 30a of the means for inducing the flexion-extension movement 50, that is to say in the articulation of the hip. In this way, the support for the femur 1 1 can move around the first pivot point 30a separately to the movement of the support for the femur 31 of the means to induce a flexion-extension movement 50.

The support for the femur 1 1 may comprise a pair of parallel bars 1 1 a, 1 1 b that can be joined at its end 1 12, opposite the end 1 1 1, by means of a "U" profile 14. Said "U" profile 14 may be articulated to the first movable element 12 by means of a rigid bar 13 (see also figures 8a and 8b). In some embodiments, the rigid bar 13 may be replaced by a hydraulic cylinder (reference 19 in Figures 8c and 8e) and the first movable element may coincide with the second movable element 4 that drives the means to induce the flexion-extension movement 50 (see figures 8c and 8e). Or, the hydraulic cylinder (reference 19a of Figure 8f) may be attached to a pivot point of the means for inducing the flexion-extension movement which, in operation, may be associated with the joint 30b (See Figure 8f) . In addition, each bar of the pair of parallel bars 1 1 a, 1 1 b can have a different length. The longest bar 1 1 a can be articulated to the base 3 (or to an extension 6 of the base) and can be the one on which the outer leg area.

The support for the femur 1 1 may further comprise a "L" profile 15, arranged horizontally with the short line of the "L" facing down. Said short stroke can be coupled to the shortest bar 1 1 b of the support 1 1, leaving the long line of the "L" in contact with the upper part of the leg. In this way, the side that contacts the outer leg area is left open, which facilitates rehabilitation with placed drains. In turn, the rigid bar 13 can be doubly articulated, to the "U" profile 14 of the support for the femur 1 1 and to the first movable element 12.

Also, in figure 3 it is shown that the device can also comprise second means for inducing a slide 20 which in turn comprise a support for the tibia 21. The support for the tibia 21 can be articulated, at one end 212, to a second pivot point 30c of the means for inducing the flexion-extension movement 50 where a support for the foot 40 also articulates. Thus, the support for the tibia 21 can pivot separately to the movement of the tibia support 34 of the means to induce a flexion-extension movement 50.

The support for the tibia 21 may comprise a pair of parallel bars 21 a and 21 b joined at one end 21 1, opposite the end 212, by means of a "U" profile 24. Said "U" profile 24 may be articulated to the first movable element 12 by means of a hydraulic cylinder 23 (see also figure 8e). In some embodiments, the "U" profile 24 may be articulated to a third movable element 29 by means of a rigid bar 23a (see Figure 8d). Or, the hydraulic cylinder (reference 23b of Figure 8f) may be articulated to a pivot point of the means for inducing the flexion-extension movement which, in operation, may be associated with the joint 30b (see Figure 8f) .

On the other hand, at the same end 21 1 where the pair of parallel bars 21 a and 21 b are attached, the support for the tibia 21 can also comprise a "L" profile 25, arranged horizontally with the short line of the "L" down. Said short stroke can be coupled to one of the bars of the support for the tibia 21, specifically to the bar 21 b that supports the inner part of the leg, leaving the long line of the "L" in contact with the upper leg.

Depending on whether the right or left leg is rehabilitated, the "L" profiles 15, 25 of the supports for the femur 1 1 and for the tibia 21 can be mounted on one or another bar of the pair of bars 1 1 a, 1 1 by 21 a, 21 b. In addition, in the case of the support for the femur 1 1, the two bars of the pair of bars 1 1 a, 1 1 b can also be interchangeable, in those embodiments in which they do not have the same length.

In addition, both the "U" profiles 14, 24 and the "L" profiles 15, 25 can be rigid profiles that can comprise pads or any other padded element that allows them to cover, at least partially, so as to convert them into an element comfortable for, for example, a leg.

In addition, the "L" profiles 15, 25 can be mounted in such a way that they can slide along a groove 16, 26 present in a housing 17, 27 of the bar 1 1 b, 21 b, of the pair of bars on which the "L" profiles are mounted 15, 25. This sliding can be regulated, for example, by means of a screw 18, 28 (see also figure 4). In this way, these "L" profiles are slidably mounted on the supports for the femur 1 1 and the tibia 21 and can be adjusted to the length of the proximal and distal members (the femur and the tibia) they support.

Figures 4 and 5 show two side views of the same embodiment of the device in the position of extension and flexion respectively. From the comparison of both figures, it follows that, in order to move from the extension position (figure 4) to the flexion position (figure 5), the first movable element 12 and the second movable element 4 move along the groove (reference 8 of Figure 3) according to the direction of arrow A (distal-proximal direction for flexion and proximal-distal direction for extension). Said movement, indicated by arrow A, can cause the rigid bar 13 to push the "U" profile 14 of the support for the femur 1 1. Due to this thrust, the support for the femur can rotate around the first point of pivot 30a (hip-femur joint). This rotation translates, in the area of the femur-tibia joint 30b (i.e. in the knee joint itself), as a displacement d1 of the bars 1 1 a and 1 1 b of the support for the femur 1 1 of the first means for inducing a slide 10 with respect to the bars 31 a and 31 b of the support for the femur 31 of the means for inducing a flexion-extension movement 50. The displacement d1 is posteroanterior in the sagittal plane in the flexion and in the anteroposterior direction in the extension (arrow B of figure 5). The displacement, indicated by arrow A, can also cause the hydraulic cylinder 23 to push the "U" profile 24 of the tibia support 21. Due to this thrust, the tibial support can rotate around the second pivot point 30c (tibia-foot or ankle joint). This rotation translates, in the area of the femur-tibia joint 30b (i.e. the knee joint itself), as a displacement d2 of the bars 21 a and 21 b of the support for the tibia 21 of the second means for inducing a sliding 20 with respect to the bars 34a and 34b of the support for the tibia 3 of the means for inducing a flexion-extension movement 50. The displacement d2 is anteroposteriorly in the sagittal plane in the flexion and in the posteroanterior direction in the extension (arrow C of figure 5).

Some parameters of the device, for example the length of the rigid bar 13 or the distance between the movable elements 4, 12, 29 or the travel speed of the movable elements 4, 12, 29 are adjustable so as to allow the means to induce sliding 10, 20 induce proper sliding.

Proper sliding is understood as the one that maintains the distance between the articular surfaces during the rotation of the joint. To achieve this goal, the pivot points 30a, 30b, 30c of the device can be placed at the height of the centers of the hip, knee and ankle joints respectively. Additionally, the proximal and distal limbs of the leg can be attached to the supports of the femur 1 1 and tibia 21 of the first and second means to induce a slide 10, 20 respectively. Thus, the displacements d1, d2 of said supports of the femur 1 1 and of the tibia 21 can induce, in the knee joint 30b, a sliding in the same plane of the natural flexion-extension movement of the leg.

Figure 6 shows a device comprising means for inducing a flexion-extension movement 50 and first means for inducing a slide 10. This embodiment does not comprise second means for inducing a slide acting on the tibia as the device of the previous embodiment. . The rest of its operation corresponds to that described in relation to Figures 3 to 5. Figure 7 shows an exploded view of the device of Figure 6 in which certain components, such as the first movable element, are shown in detail. 12 or the second movable element 4 among others.

An embodiment is shown in Figures 6 and 7 in which the first movable element 12 and the second movable element 4 can be joined (see also Figure 8a). This connection is achieved, for example, by mounting both movable elements 4, 12 on the same platform 9. Said platform 9 may be provided with sliding coupling means to the track or groove 8 disposed on the upper surface 301 of the base 3.

The sliding coupling means to the track 8 may comprise a protuberance 90 disposed on an upper surface of the platform 9. The protuberance 90 may comprise, in its upper part, a saddle-shaped longitudinal groove mount 91 and a pair of side flanges 92 (or projections) protruding from a lower part of the mount 91. Said side tabs 92 and an upper surface of the platform 90 define a side groove (indicated schematically by arrow 93). Said side slot 93 can be fitted to a side wall of the track or slot 8.

In addition, the first movable element 12 may comprise a pair of parallel plates 121 each with a hole 122 for articulated coupling to the rigid bar 13 that articulates with the support for the femur 1 1. The first movable element 12 may also comprise a dovetail profile 123 that can fit into the dovetail groove of the mount 91 of the platform 90. The first movable element 12 may also comprise adjustment means 124 (for example a screw) of the dovetail profile 123 to the mount 91. In this way, the distance between the first movable element 12 and the second movable element 4 can be regulated (increased or decreased), in those embodiments in which they are joined (see also figure 8a).

On the other hand, the second movable element 4 can comprise a pair of parallel plates or tongues 401 provided with a pair of holes 402 for articulated coupling with the "U" profile 35 of the tibia holder 34.

In addition, the platform 90 can comprise a hole 94 through which an axis (not drawn), threaded or not, can pass that allows the platform 90 to move along said axis. Said shaft may be provided with stops to limit the movement of the platform 90. Also, the platform 90 may be driven (in the direction of arrow A of Figures 4 and 5) by a pneumatic cylinder.

In the embodiment shown in Figures 6 and 7, the movement of the platform 90 (schematically shown by the arrow A in Figures 4 and

5), involves a movement of the means to induce a flexion-extension movement and the first means to induce a slip. However, the platform could also actuate the second means for inducing a slip, in those embodiments in which said means were attached to the first means for inducing a slip (figures 3 to 5). Alternatively, the platform may comprise two or three separate sections, one for the means for inducing flexion-extension movement, another for the first means for inducing slippage and / or another for the second means for inducing slippage. Also possible are embodiments in which, for example, the first and second means for inducing sliding are actuated from the same movable element and the means for inducing flexion-extension movement are induced from another movable element. In all these cases, the speed of the movable elements can be adjustable.

Figures 8a-8c show schematics of some possible embodiments in which means for inducing a slip comprise only first means for inducing slip and FIGS. 8d-8f show diagrams of some possible embodiments in which means for inducing slippage comprise first and second means for inducing slip.

Thus, Figure 8a shows an embodiment in which the means for inducing a flexion-extension movement 50 can be actuated from a second movable element 4, the first means for inducing a slide 10 can be actuated from a first movable element 12 attached to said means 10 through a rigid bar 13 and where the first movable element 12 may be attached to the second movable element 4. Figure 8b shows an embodiment that is distinguished from the previous one (figure 8a) in which the First movable element 12 may not be attached to the second movable element 4 and both can be moved synchronously. Synchronization contributes positively so that, in the joint, the flexion-extension movement is accompanied by a sliding between both articular surfaces.

Figure 8c shows an embodiment in which the means for inducing a flexion-extension movement 50 can be actuated from a second movable element 4 and the first means for inducing a slide 10 can be actuated from the same second movable element. 4 through a hydraulic cylinder 19. Figure 8d shows an embodiment in which the means for inducing a flexion-extension movement 50 can be actuated from a second movable element 4, the first means for inducing a slide 10 can being actuated from a first movable element 12 connected to said means 10 through a rigid bar 13 and the second means to induce a slide 20 can be actuated from a third movable element 29 connected to said means 20 through another rigid bar 23a. In this case the three elements Movable 12, 4 and 29 can act in a synchronized manner.

Figure 8e schematizes an embodiment that differs from the previous one (figure 8d) in that the means for inducing a slide 10 and the second means for inducing a slide 20 can be actuated from two hydraulic cylinders 19 and 23 attached to the second movable element 4 of the means for inducing the flexion-extension movement 50. And Figure 8f schematizes an embodiment that differs from the previous ones in that the hydraulic cylinders 19a and 23b that actuate the first 10 and second 20 means to induce a sliding they can be attached to a pivot point 30b of the means for inducing flexion-extension movement which, in operation, may be associated with the joint itself (femur-tibia).

In alternative embodiments, the movable elements may comprise a trolley with wheels at its bottom. In these cases, the track or guide may include stops to limit its displacement.

The device of the present invention can be powered by any power source or battery.

While the device has been described in detail for the knee joint, if the appropriate size adaptations are made, it could be valid for other diartrodial and synovial joints.

Another embodiment of the invention is shown in Figures 9 to 12. Figures 9 and 10 are perspective views of this other embodiment, in extension position and in flexion position, respectively. This embodiment has some elements similar to embodiments described above, in which no greater emphasis will be placed. In this case, means 50 'for inducing a flexion-extension movement can include a first pivot point 30a' associated in a specific case to the hip joint, a second pivot point 30c ' associated in a specific case to the ankle joint, and movable on the base 3 'as in the case of the previous embodiment, and a pivot point 30b' associated in a specific case to the femur-tibia joint itself.

In addition, the means for inducing the flexion-extension movement 50 'may comprise a support for the tibia 34', with a pair of first parallel bars 34a ', 34b' (joined through rigid bars to the pivot point 30c ') , and a support for the femur 31 ', which in this case comprises on each side an articulated parallelogram 31 a', 31 b ', in order to allow the patient to adopt a more suitable position, with the hip farthest from the point of pivot 30a '.

These articulated parallelograms include a pair of second bars 31 a ", 31 b", of which Figure 9 only shows the second bar 31 a ": this bar can be angled at its two ends, and can extend between the point of pivot 30a 'and a pivot point 31 a' "in which the second bar 31 a" is articulated to a point of the first bar 34a '. The bar 31 b "is mounted in the same way, on the other side of the device .

According to the embodiment shown, the device comprises means 20 'for inducing a sliding between the two articular surfaces during the flexion-extension movement, which in this case may comprise a support 21' for the tibia; this support 21 'can extend parallel to the pair of first bars 34a', 34b ', and be mounted on these first bars so that it is movable with respect to these bars in a direction substantially perpendicular to the direction thereof, as will be explained later. The support 21 'can comprise more specifically a pair of parallel bars 21 a', 21 b ', of which in figures 9 and 10 the bar 21 b' is very visible, while a good part of the bar 21 a 'remains hidden behind bar 34a '.

The support 21 'may further comprise a first clamp piece 25' for the tibia, which can extend between the two bars 21 a ', 21 b', and second clamp piece 26 ', which can have a coupler 27' for fit in one of two corresponding hooks 28 'integral with the bars 21 a', 21 b ', so that it can be mounted in each case on the most convenient side of the device. The second holding piece 26 'can have a hinge to close in order to hold the tibia between the pieces 25' and 26 '.

At the free end of the bars 21 a ', 21 b', which can be telescopic to fit the size of each patient, the foot support 40 'can be articulated.

The support 21 'for the tibia can be mounted with respect to the bars 34a', 34b 'in the manner described below.

On the one hand, at one end of the bars 34a ', 34b' guides 60 'can be mounted, on which corresponding slides 61' which are integral to the bars 21 a ', 21 b' can slide, so that they allow and guide the displacement of the support 21 'in a direction perpendicular to the pair of first bars 34a', 34b '. On the other hand, in the support 21 'it can be coupled to the first bars

34a ', 34b' by a cam unit 70 ', which causes it to move away from the first bar during a flexing movement of the device.

The cam unit 70 'may comprise two similar parts 70a', 70b ', one on each side of the device, which may be interposed between the first bars 34a', 34b 'and the bars 21 a', 21 b 'of the support 21 ', respectively.

Details related to cam unit 70 'will be better understood with reference to Figures 1 1 and 12, which show an enlarged view of cam unit 70', in the same extension and flexion positions of Figures 9 and 10 .

As can be seen, the part 70a 'of the cam unit 70' may be associated with the pivot point 31 a '"mentioned above, and may have a cam surface 71 a' practiced therein (hidden and drawn in line of lines in figures 9 and 1 1), in which a cam follower 72a 'integral to the bar 21 a' can slide. The part 70b 'of the cam unit 70' (visible in figures 9 and 10) is mounted analogously, and the assembly may have means (not shown) to ensure synchronization between the two parts.

The part 70a 'of the cam unit 70' may be associated with the pivot point 31 a '"so that, when the device is used in a rehabilitation, the cam unit 70' rotates together with the bar 31 a"; a specific way in which the coupling between the part 70a 'and the bar 31 a "can be carried out" will be explained later.

When the cam unit 70 'rotates dragged by the rotation of the pivot point 31 to' ", (that is, during the flexion-extension movement, in which the bar 31 a" rotates with respect to the bar 34a 'as is appreciated by the comparison of figures 9 and 10), the cam surface 71 a 'also rotates, and the follower 72a' moves, because it follows the cam surface 71 a '.

The shape of the cam surface 71 a 'may be appropriate for the follower 72a' to drag the bar 21 a 'and move it perpendicular to the bar 34a', so that during the flexion-extension movement the support 21 'can move the tibia perpendicularly to the pair of bars 34' and thus cause a sliding between the two articular surfaces.

More specifically, the cam surface can cause the support 21 'away from the pair of bars 34' (in the direction of the arrow D in Figure 12) during a bending movement, as can be seen by comparing Figures 1 1 and 12.

The cam surface 71 a 'can be substantially in the form of an ellipse portion. It has been found that an ellipse shape allows the induced sliding between the articular surfaces for each angle of flexion to approximate the values recommended in the literature.

It should be noted that the angle of rotation of the cam unit 70 'associated with the pivot point 31 a'"essentially coincides with the angle of rotation of the pivot point 30a ': that is, the one corresponding to the joint between the tibia and the Femur undergoing rehabilitation. Mount the cam associated with the point of pivot 31 to '"allows to keep the pivot point 30a' free, for example, for an angle sensor rotated in flexion.

In order for a device according to the invention to allow rehabilitation treatment with a greater or lesser degree of sliding between the articular surfaces, for example depending on the degree of rehabilitation achieved, the pain felt by the patient, etc., is It has been provided that in embodiments of the invention the cam unit can have an adjustable position, such that to each mounting position of the cam unit corresponds a magnitude of the displacement of the movable support 21 'with respect to the pair of bars 34' , during the flexion movement.

To perform this adjustable assembly, the cam unit 70 'is rotatably mounted around a point (not visible in the figures) of the bar 34a', and the device comprises a pair of auxiliary plates, of which the plate 80a 'is visible in figures 9 to 12.

As these figures show, the auxiliary plate 80a 'can be secured by means of flanges with the bar 31 a ", and there may be means for adjusting the position of the cam unit 70' with respect to the plate 80a ': for example, the figures show an embodiment with a hole in the plate 80a ', a series of holes 81 a' made in the part 70a 'of the cam unit 70', and a pin 82a 'intended to be introduced through the holes for fixing the relative position of the two pieces 70a ', 80a', and therefore the position of the cam unit 70 'with respect to the bar 31 a ".

It will be understood that when the position of the cam unit 70 'with respect to the auxiliary plates is modified, by rotating the cam unit around its articulation point in the bar 34a' and then fixing it by means of the pin 82a ', the surface of Ellipse-shaped cam 71 a 'tilts more or less with respect to the direction of bar 34a': therefore, the displacement that cam surface 71 a 'induces in cam follower 72a' (and therefore in the support 21 'of the tibia) will go.

The invention also relates to a kit that allows expanding a conventional rehabilitation device comprising means for inducing a flexion-extension movement of the joint, so that it can also induce a sliding between both articular surfaces.

An embodiment of the kit comprises means for inducing a sliding between both articular surfaces, intended to act on one of the

members of the joint during flexion-extension movement, and means for coupling to the device; according to figures 9 to 12, the kit can comprise the movable support 21 'and the cam unit 70' to couple said movable support to the pair of first bars 34 ', so that said support is movable in a direction substantially perpendicular to said pair of bars 34 ', as described.

The kit may also comprise other elements suitable for mounting the movable support 21 'and the cam unit 70', such as guides 60 ', slides 61', auxiliary plates, etc.

Figure 13 schematically shows a method of adapting a kit to a conventional rehabilitation device comprising means for inducing a flexion-extension movement of the joint.

As can be seen, the procedure may include releasing the foot support 40 ', mounting the guides 60', installing the cam unit 70 '(with its auxiliary plate if necessary), mounting the support 21' for the tibia between the cam unit 70 'and the guide 60', and place the foot support 40 'at the end of the support 21' for the tibia.

It should be noted that although the embodiment of Figures 9 to 13 has been described in relation to a device for the rehabilitation of the knee joint, similar devices (and corresponding extension kits) could also be used for other joints. ; in the same way, devices (and corresponding extension kits) could be designed to induce a slide acting on the proximal joint member (for example the femur), instead of acting on the distal member (for example the tibia).

An analogous kit to that described with reference to Figure 13 could also be used to adapt or expand other conventional devices, for example the one represented in figure 2, with the modifications that may be necessary at the kinematic, mechanical level, etc.

On the other hand, although reference has been made to continuous passive movement devices, active or non-continuous movement devices that induce a sliding between the articular surfaces could be designed.

Although only some particular embodiments and examples of the invention have been described herein, the person skilled in the art will understand that other alternative embodiments and / or uses of the invention are possible, as well as obvious modifications and equivalent elements. In addition, the present invention encompasses all possible combinations of the specific embodiments that have been described. The numerical signs relating to the drawings and placed in parentheses in a claim are only intended to increase the understanding of the claim, and should not be construed as limiting the scope of the claim's protection. The scope of the present invention should not be limited to specific embodiments, but should be determined only by an appropriate reading of the appended claims.

Claims

one . Continuous passive movement device for rehabilitation of a diartrodia and synovial joint between a proximal member with a first articular surface and a distal member with a second articular surface, the device comprising means for inducing a flexion-extension movement (50; 50 ') of the joint, characterized in that it further comprises means for inducing a sliding (10; 20; 20 ') between both articular surfaces, said means (10; 20; 20') acting on one of the members of the joint, during the flexion-extension movement.

2. Continuous passive movement device according to claim 1, wherein the means for inducing a slide (10; 20; 20 ') and the means for inducing flexion-extension movement (50; 50') act in a synchronized manner.

3. A device for continuous passive movement according to one of claims 1 or 2, wherein the means for inducing a slide (10; 20) comprise a number of means (10) acting on the proximal member of the joint.

4. Continuous passive movement device according to claim 3, wherein the means for inducing a flexion-extension movement (50) comprise a first pivot point (30a) which, in operation, is associated with a proximal end of the proximal member of The joint and the first means for inducing a slide (10) comprise a first support (1 1) for the proximal member, one end of said first support being pivotally mounted on said first pivot point (30a).

5. Continuous passive movement device according to claim 4, wherein the first support (1 1) is actuated from a first movable element (12) arranged in the base of the device (3), said first element being longitudinally movable in the direction of flexion-extension movement.

6. Continuous passive motion device according to claim 5, where the first support (1 1) is actuated from the first movable element (12) through a rigid rod (13) or a double articulated hydraulic cylinder (19).

7. Continuous passive movement device according to claim 4, wherein the first support (1 1) is actuated through a hydraulic cylinder (19a) mounted between one end of the first support (1 1) and a pivot point of the means to induce flexion-extension movement that, in operation, is associated with the joint.

8. Continuous passive movement device according to one of claims 5 to 6, wherein the first movable element (12) is connected to a second movable element (4) longitudinally in the direction of the flexion-extension movement that drives the means to induce the flexion-extension movement.

9. Continuous passive movement device according to one of claims 1 to 8, wherein the means for inducing a sliding between both articular surfaces of the joint comprise second means (20) acting on the distal joint member, during movement of flexion-extension.

10. Continuous passive movement device according to claim 9, wherein the second means for inducing a slide (20) comprise a second support (21) for said distal member, one end of said second support being pivotally mounted on a second pivot point (30c) of the means for inducing flexion-extension movement (50) which, in operation, is associated with a distal end of the distal joint member.

eleven . Continuous passive movement device according to claim 10, wherein the second support (21) is actuated from a third movable element (29) longitudinally in the direction of the flexion-extension movement, said third movable element (29) being arranged in a device base (3).

12. Continuous passive movement device according to claim 1, where the second support (21) is actuated from the third movable element (29) through a rigid bar (23a) or a double articulated hydraulic cylinder (23).

13. Continuous passive movement device according to one of claims 1 or 12, wherein the first movable element (12) and the third movable element (29) act synchronously.

14. Continuous passive movement device according to claim 13, wherein the first movable element and the third movable element are the same movable element.

15. Continuous passive motion device according to claim 10, wherein the second support (21) is actuated through a hydraulic cylinder (23b) mounted between one end of the second support (21) and a pivot point of the means for inducing the flexion-extension movement that, in operation, is associated with the joint.

16. Continuous passive movement device according to one of claims 4 to 15, wherein each support (1 1; 21) comprises a lower part (14, 24) in the form of a "U" and an upper part (15, 25) in "L" shape connected by one of its ends to the support (1 1, 21), the upper part (15, 25) being slidably mounted on the support (1 1, 21) so as to adjust to the length of the members they support.

17. Continuous passive movement device according to one of the

claims 1 or 2, wherein the means for inducing a flexion-extension movement (50 ') comprise at least a first bar (34') associated with the distal joint member, and the means for inducing a sliding between both articular surfaces comprise a movable support (21 ') for said distal joint member, the support (21') being mounted on said first bar (34 ') so that it is movable with respect thereto in a substantially direction

perpendicular to the direction of said first bar (34 ').

18. Continuous passive movement device according to claim 17, wherein the movable support (21 ') is arranged parallel to the first bar (34 '), the movable support being coupled to said first bar by means of a cam unit (70') that causes it to move away from the pnmera bar (34 ') during a flexion movement.

19. Continuous passive movement device according to claim 18, wherein said cam unit (70 ') is associated with a pivot point (31 to' ") of the means for inducing a flexion-extension movement (50 ') whose angle of rotation essentially corresponds to the angle of rotation of the joint object of the rehabilitation, and is adapted to rotate when said joint rotates.

20. Continuous passive movement device according to one of the

claims 18 or 19, wherein the cam unit (70 ') is fixed to the means for inducing a flexion-extension movement (50') in an adjustable manner, such that at each mounting position of the cam unit ( 70 ') corresponds a magnitude of the displacement of the movable support (21') with respect to the first bar (34 '), during the flexion movement.

twenty-one . Continuous passive movement device according to one of the

claims 18 to 20, wherein the cam unit (70 ') comprises a cam surface (71 to ¹ ) whose shape is substantially a portion of an ellipse, and in which a cam follower (72a ¹ ) slides integral with the support movable (21 ').

22. Continuous passive movement device according to one of the

claims 18 to 20, wherein the movable support (21 ') is also coupled to said first bar (34') at another point by means of a guide (60 ', 61') that allows the movement perpendicular to the first bar (34 ').

23. Extension kit for a continuous passive movement device for rehabilitation of a synovial and diartrodia joint between a proximal member with a pnmera articular surface and a distal member with a second articular surface, comprising means (50; 50 ') for inducing a flexion-extension movement of the joint, the kit comprising means for inducing a sliding between both articular surfaces (20 '), intended to act on one of the members of the joint during flexion-extension movement, and means for coupling to the device (70 ', 60', 61 ').

24. Extension kit according to claim 23, comprising a movable support (21 ') for said distal joint member, and a cam unit (70') intended to couple said movable support (21 ') to a first bar ( 34 ') of the means for inducing a flexion-extension movement (50'), so that said support (21 ') is movable with respect to said first bar (34') in a direction substantially perpendicular thereto, and of so as to cause it to move away from the first bar (34 ') during a flexion movement.