DE102004020368A1 - Artificial jointless foot - Google Patents

Abstract

An articular jointless foot having an elastically deformable heel assembly (9) extending in a height direction from a sole region to an ankle region and an elastically deformable forefoot structure (10) extending longitudinally from the ankle region to a toe region, the heel assembly (9) and / or the forefoot structure (10) has at least two members (2, 5; 2, 11) arranged one behind the other in the vertical direction of the heel assembly (9) or in the longitudinal direction of the forefoot assembly (10), movable relative to one another and a variable intermediate space (3; 22, 23) ), allows an automatic adaptation to the types of use "walking" and "standing" by an activatable actuating mechanism, by an activated by the actuation mechanism controllable element in the space (3, 22) in a distance between the members (2, 4 ; 2, 11), and by a return mechanism for the st renewable element.

Description

The Invention relates to an artificial jointless foot with one in a height direction of extending a sole area to an ankle area elastically deformable heel structure and in a longitudinal direction from the ankle area extending to a toe area elastically deformable forefoot structure, wherein the heel structure and / or the forefoot structure at least two in height direction the heel structure or in the longitudinal direction of forefoot construction arranged one behind the other, mutually movable and a variable gap have between forming links.

It has long been known to form artificial feet in jointless form, so that the performance characteristics of the artificial foot are determined by the elastic deformability of the material used for the foot construction. There are numerous constructions known with which in particular the gait characteristics of the artificial foot to be improved. This is the case, for example US 4,652,266 known to form the forefoot area in several parts and connect with each other by elastic joints.

It is also known to form the heel part and forefoot by leaf springs in combination with air-filled cushion, which can be varied by the air pressure in the cushion, the suspension of the aisle. By EP 0 884 033 B1 It is also known to form the forefoot by two mutually parallel leaf springs, between which an air-filled pressure pad is arranged. By loading the heel part of the air pressure in the pressure pad is influenced, so that in a dynamic gait with a strong heel strike an increase in the spring hardness of the forefoot is made. Similarly, this is achieved with a spacer between the two leaf springs whose position is shifted in response to the heel strike. The principle of these solutions is thus the adjustment of the spring stiffness as a function of the gait dynamics.

One fundamental Problem for the interpretation of an artificial foot is to make a suitable compromise for the suitability of the foot for his Main uses, namely walking and standing, to find. For a secure standing on one artificial Foot would be a tough one long forefoot suitable, the high sense of security would convey. But with such a hard and long forefoot can not be useful Realize gear dynamics. For walking, so rolling over the forefoot, It is advantageous to have a shortened and to train soft forefoot, with which, however, a secure feeling while standing can not be realized. The previously realized compromises, which both a possible natural Walking as well as allowing a safe standing are satisfactory, but not because of the need to compromise optimal.

Of the present invention is based on the object, an artificial Foot of the mentioned in the beginning To improve the way in which it is used.

to solution This object is inventively an artificial jointless foot of the mentioned in the beginning Characterized by an activatable Actuate transmission mechanism and controllable by the activated actuating mechanism Element that is in the space in a the distance between the Intervene influencing members way.

at the artificial foot according to the invention thus becomes by the movable member in the structure of the heel part and / or of the forefoot part immediately intervened. The invention is thus not exhausted the spring hardness of the forefoot to adjust, but sees a reversible change to be made the structure of the heel part and / or forefoot part by means of the. By the actuating mechanism movable member before. In particular, according to the invention, an artificial foot can be created, wherein the movable member is formed and arranged such that by its movement the effective length of the forefoot for walking and / or the height the heel part changed. It is according to the invention therefore possible for the To use a different construction of the foot than for walking, so the need to compromise between the properties of the foot when walking and standing, eliminated or at least is mitigated, because of the modification of the structure for walking another structure of the foot is usable as for standing.

The actuating mechanism which moves the member may in suitable embodiments be triggered by a deformation of the heel part or by a dorsal deformation of the forefoot part. The deformation of the heel part makes it possible to detect a firm appearance, which indicates that a walking cycle is being carried out. The provision can be activated in this case, for example, by a dorsal deformation of the forefoot part, so that the provision takes place during the swing phase. When standing, the heel part is regularly not so heavily loaded, so that in this case the actuating mechanism is not activated. The triggered by the heel strike displacement of the limb must therefore be such that the effective length of the forefoot partly shortened to the Going to facilitate. If the heel part is not loaded, it remains at a greater effective length of the forefoot part.

It is possible, too, the actuating mechanism caused by a dorsal deformation of the forefoot part, the indicates that the prosthesis wearer is walking, so for the next Step the shortening of the forefoot part is performed. The default can be effected by an example mechanical timer Be that by the the actuating mechanism triggering Action of the foot, So, for example, the dorsal deformation of the forefoot part, resettable is, so the reset mechanism will only take effect if the corresponding action until the end of the Timer is omitted.

A Activation of the actuating mechanism can also be from outside of the foot done, for example, by a moment sensor on a lower leg prosthesis.

The moved by the actuating mechanism Link can be a rigid lever between two positions is switchable and in one of these positions an elastic link between relatively less elastic parts of the forefoot part bridged. If the actuating mechanism is triggered by a deformation of the heel part, the rigid lever moved to the position in which he has the elastic link not bridged, so the elastic link during the walking process the effective length of the forefoot part shortened. The default can through the reset mechanism be activated in this case by a Dorsalverformung the forefoot lever is, so the provision at the end of each rolling process while walking and by putting on of the heel part newly triggered becomes.

The moved by the actuating mechanism Link can also be a rigid element, for example in the form of a Wedge, its in a wedge-shaped Intermediate space is moved into it. The wedge-shaped gap is through the strain in the direction of reduction of the wedge deformable. This deformation is due to the movement of the rigid element in the wedge-shaped space prevented in. The actuating mechanism for the element can be due to the heel strike as well as the dorsal deformation of the forefoot part to be activated. As a return mechanism is preferably a mechanical timer, by a Movement of the foot reset becomes. By moving the rigid element into the wedge-shaped gap The forefoot part can enter be formed in the region of the space rigid, so thereby the for standing meaningful configuration is realized and for one Detected walking the wedge out of the wedge-shaped gap out has to be moved. Alternatively, the rigid element may be in the wedge-shaped space for the Walking movement to be pulled when the wedge-shaped gap, for example located in the heel part and through the into the space inside moved rigid element, the effective height of the heel part is increased, causing while the walking process the effective length of the forefoot part is reduced.

In a further embodiment The invention may include the actuating mechanism a pumping arrangement for include a fluid and the controllable by the actuating mechanism Element disposed in the space with the fluid fillable Be pillow. For such an embodiment is a return mechanism particularly useful in the form of a timer. As fluid can preferably Air or a liquid be used.

Of the Reset mechanism can also be from outside of the foot actuated be, for example by means of a guided out of the foot assembly Bowden cable, which can also be operated manually.

The Invention will be described below with reference to in the drawing embodiments be explained in more detail. Show it:

1 A schematic side view of the internal structure of an artificial foot in a first embodiment of the invention in three different phases

2 A schematic side view of the internal structure of an artificial foot in a second embodiment of the invention in three different phases

3 A schematic side view of the internal structure of an artificial foot in a third embodiment of the invention in three different phases

4 A schematic side view of the internal structure of an artificial foot in a fourth embodiment of the invention in two different phases

5 A schematic side view of the internal structure of an artificial foot in a fifth embodiment of the invention in two different phases.

In all drawing figures, a foot insert of an artificial foot is shown, which in a known manner by a cosmetic case 1 is surrounded.

The foot insert has a fixed adapter member 2 with an adapter facing an ankle area 3 on, to which a further (not shown) prosthesis part can be connected. The adapter member 2 is over a wedge-shaped gap 3 with an approximately horizontally extending plate-shaped approach 4 over a hinge piece 5 connected. In the wedge-shaped gap 3 is an elastic wedge 6 used. Under the plate-shaped approach 4 there is a paragraph piece 7 , which may be formed of a likewise elastic material, but whose hardness is substantially greater than that of the elastic wedge 6 , Between the paragraph piece 7 and the plate-shaped approach 4 there is a rear portion of a plate-shaped spring element 8th , The adapter member 2 , the elastic wedge 6 , the plate-shaped approach 4 , the rearward portion of the plate-shaped spring element 8th and the paragraph piece 7 form a heel construction 9 thus extending in a height direction from the heel area to the ankle area of the artificial foot.

The plate-shaped spring element 8th extends into a tough area of the artificial foot and has a forefoot structure 10 extending longitudinally of the foot from the adapter member 2 extends in the ankle area to the toe area of the artificial foot.

The forefoot construction 10 consists of longitudinally successively arranged rigid members 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 as well as two elastic pontics 20 . 21 , The rigid limbs 12 to 19 adjacent to each other and allow due to their shape only a slight tilt to each other. Between the adapter member 2 and the first rigid member 11 is a first elastic intermediate member 20 and between the first rigid link 11 and the second rigid member 12 a second elastic intermediate member 21 arranged. The elastic intermediate links 20 . 21 extend over the entire height of the forefoot body 10 and thus fill corresponding spaces 22 . 23 between the rigid limbs 2 . 11 on the one hand and 11 . 12 on the other hand.

The foot structure thus described thus consists of a heel structure 9 in the vertical direction and from a forefoot structure 10 in the longitudinal direction, both consisting of several members.

At the in 1 illustrated embodiment is at one of the first elastic member 20 directed edge of the adapter member 2 a rigid lever 24 rotatably mounted, the free end 25 in the in 1 phase shown a) on an L-shaped paragraph 26 of the first rigid member 11 supported. The lever 24 thus bridges the gap 22 between the adapter member 2 and the first rigid member 11 , so that the first elastic intermediate member 20 can not be compressed.

At the plate-shaped approach 4 of the adapter member 2 There is a downward-facing approach 28 that has a flexible band 27 with the free end 25 of the lever 24 connected is.

In a strong heel load, as occurs in the phase b), as occurs when walking, the elastic wedge 6 in heel construction 9 compressed, thereby increasing the approach 28 relative to the adapter member 2 turns back and so on with the flexible band 27 the free end 25 of the lever 24 from the L-shaped approach 26 of the first rigid member 11 pulls out. This is the first elastic intermediate member 20 no longer by the lever 24 bridged and thus can be pressed resiliently in an advantageous manner for walking, thereby shortening the effective forefoot length for walking by the amount .DELTA.I, as in 1 is shown.

When rolling the artificial foot over the forefoot structure 10 becomes the plate-shaped spring element 8th bent dorsally (upwards). This bend is used in the first embodiment to form a return mechanism. This is due to the plate-shaped spring element 8th in the area of the forefoot near the toe area, ie for example in the ball area, another flexible band 29 attached, also with the free end 25 of the lever 24 connected is. Due to the dorsal bending of the plate-shaped spring element 8th becomes the other flexible band 29 cocked and pulls the lever 24 with his free end 25 in the L-shaped approach 26 back, whereby the phase according to a) is reached again. The phase a) with the extended effective Vorfußaufbau 10 is advantageous for a secure feeling of the prosthesis wearer. The advantageous for walking c) phase is automatically reset when walking continues, so again a strong heel load according to phase b) is made.

On this way, an automatic adjustment of the effective forefoot length of the succeeds artificial foot for the Standing on the one hand and walking on the other.

This in 2 illustrated embodiment has a principle consistent with the first embodiment heel structure 9 and forefoot construction 10 on. In the wedge-shaped gap 3 Here, however, is a rigid wedge 6 ' in addition, in the interspace 3 Slidably mounted in the longitudinal direction. The sliding movement of the wedge 6 ' is with a handlebar 30 controlled, rotatably on an arm of a two-armed lever 31 is articulated. The two-armed lever 31 is on the adapter member 2 rotatably arranged. To the other arm of the two-armed lever 31 is another handlebar 32 hinged, firmly with a rigid member 14 of the forefoot construction 10 connected is.

In the in 2 represented phase a) is the wedge 6 ' to the rear partly from the wedge-shaped gap 3 shifted out so that by the burden of the patient's weight of the gap 3 according to the still effective part of the wedge shape 6 ' is small. The artificial foot in this phase a) thus has a low heel height. The low heel height corresponds to a large effective forefoot length and thus creates a secure feeling when standing.

According to the phase b) in 2 the forefoot construction 10 by rolling extensively deformed and the heel structure 9 relieved, as is the case when walking, the handlebar acts 32 as a drawbar and twisted the two-armed lever 31 counterclockwise. As a result, it works with the wedge 6 ' connected handlebars 30 as a pull rod and pulls the wedge 6 ' in the wedge-shaped gap 3 into what, because of the relief of the heel structure 9 is possible. As a result, on the one hand, the heel height is increased and the effective forefoot length is reduced, so that a comfortable walking is possible.

The provision in the for standing cheap Phase a) can with a (not shown) return mechanism, for example also manually over a Bowden o. The like.

At the in 3 illustrated embodiment is again an elastic wedge in the heel structure 6 used. The first gap 22 between the adapter member 2 and the first rigid member 11 is wedge-shaped and in the phase a) of 3 through a rigid wedge 20 ' filled. Because of the gap 22 now has a maximum size, a maximum effective forefoot length is set in this phase, which is favorable for standing.

The wedge 20 ' is with a side boom 33 provided in the phase a) of the 3 on the plate-shaped approach 4 rests. The boom 33 is in turn with a in the adapter member 2 in a cylinder arrangement 34 guided piston 35 rigidly connected. In the cylinder 34 there is a return spring 36 that the piston 35 biased in the heel direction. At the bottom of the cylinder 34 there is a throttle valve 37 with which by the return spring 36 caused return movement of the piston 35 through the throttle valve 37 slowly escaping air is delayed.

If the patient leaves the standing phase shown in phase a) and begins to walk, he applies his weight to the heel in phase b) and presses the elastic wedge 6 together. This will cause the side boom 33 pushed up, leaving the wedge 20 ' is moved upwards. This will create the gap 22 between the adapter member 2 and the first rigid member 11 reduced, the effective forefoot length thus shortened. This makes walking easier. The setting of the throttle valve 37 is chosen so that at a normal walking pace while walking still no provision of the wedge 20 ' he follows. Only if for a certain time no heel action with the compression of the elastic wedge 6 takes place, worried the return spring 36 the provision of the wedge 20 ' over the boom 33 in the position according to phase a).

At the in 4 illustrated embodiment, the first space 22 between the adapter member 2 and the first rigid member 11 designed so that in him a pillow 38 is storable. In the wedge-shaped gap 3 of the heel construction 9 is a pumping arrangement 39 housed with a fluid from the pillow 38 in a pantry 40 via a check valve 41 is pumpable. This will drain the pillow 38 , which eliminates the gap 22 reduced and the effective forefoot length according to phase b) is shortened for walking. If the heel action disappears because the prosthesis wearer is standing, the pillow fills up 38 from the pantry 40 via a throttle valve 42 and a check valve 43 slowly, which increases the effective forefoot length according to phase a) and supports standing.

At the in 5 illustrated fifth embodiment is also a cushion 44 used this in the wedge-shaped interspace 3 is used, but of course in a gap 22 . 23 of forefoot construction could be.

The pillow 44 is by means of an air pumping arrangement 45 inflatable, which is like the pumping arrangement 39 in 4 in the wedge-shaped gap 3 is used, but here directly the pillow 44 inflates.

For the return of the inflated cushion this can be connected to a blow-off via a (not shown) throttle valve. If no heel action takes place (when walking), the pillow is emptied 44 to the state shown in phase a). The reduction in the height of the heel body 9 causes a larger effective forefoot length and thus supports standing.

By pumping up the pillow 44 becomes the height of the heel body 9 increases and thus shortens the effective forefoot length, resulting in Phase b) walking is supported.

The illustrated embodiments show that a change in the effective forefoot length triggered by a foot action itself is achieved by either the actual length of the forefoot structure 10 is increased or the height of the heel structure 9 is reduced. The actuation of the corresponding controllable members may be triggered by a heel action or by a bend of the foot to dorsal. Similarly, a return mechanism can be controlled by a foot action. Also possible are manual or temporally controlled provisions.

Claims (14)

Artificial jointless foot having an elastically deformable heel structure extending from a sole region to an ankle region in a height direction ( 9 ) and an elastically deformable forefoot structure extending in the longitudinal direction from the ankle area to a toe area (US Pat. 10 ), wherein the heel structure ( 9 ) and / or the forefoot structure ( 10 ) at least two in the height direction of the heel structure ( 9 ) or in the longitudinal direction of the forefoot structure ( 10 ) arranged one behind the other, movable relative to each other and a variable gap ( 3 ; 22 . 23 ) between forming members ( 2 . 5 ; 2 . 11 ), characterized by an activatable actuating mechanism, by an activatable by the activated actuating mechanism element, which in the intermediate space ( 3 . 22 ) in one the distance between the links ( 2 . 4 ; 2 . 11 ), and by a return mechanism for the controllable element. Artificial foot according to claim 1, characterized in that the actuating mechanism by a deformation of the heel structure ( 9 ) is triggered. Artificial foot according to claim 1, characterized in that the actuating mechanism by a deformation of the forefoot structure ( 10 ) can be triggered dorsally. Artificial foot according to one of claims 1 to 3, characterized in that the element controllable by the actuating mechanism is a rigid lever ( 24 ), which in one position the space ( 22 ) bridged. Artificial foot according to one of claims 1 to 3, characterized in that the controllable by the actuating element element is a rigid element ( 6 ' . 20 ' ), which is in a wedge-shaped space ( 3 . 22 ) is movable into it. Artificial foot according to claim 5, characterized in that the wedge-shaped intermediate space ( 22 ) in the forefoot structure ( 10 ) is located. Artificial foot according to claim 5, characterized in that the wedge-shaped intermediate space ( 3 ) in the heel construction ( 9 ), so that the inserted element ( 6 ' ) an increase in the height of the loaded heel structure ( 9 ) causes. Artificial foot according to one of claims 1 to 3, characterized in that the actuating mechanism is a pump arrangement ( 39 . 45 ) and that the element controllable by the actuating mechanism is in the space ( 3 . 22 ), fillable with the fluid cushion ( 38 . 44 ). Artificial foot according to one of claims 1 to 8, characterized in that the return mechanism by a deformation of the forefoot structure ( 10 ) is dorsally activated. artificial Walk to one of the claims 1 to 8, characterized in that the return mechanism is a timer that has the provision triggers and by the the actuating mechanism triggering Action of the foot resettable is. Artificial foot according to one of claims 1 to 10, characterized in that the forefoot structure ( 10 ) of a plurality of links ( 11 to 19 ) which are relatively movable relative to each other. artificial Walk to one of the claims 1 to 11, characterized in that the actuating mechanism by a outside of the foot arranged sensor arrangement can be activated. artificial Walk to one of the claims 1 to 12, characterized in that the return mechanism from outside of the foot is activatable. artificial Walk to Claim 13, characterized in that for activating the return mechanism a Bowden cable is led out of the foot structure.