ENVELOPING BODY WITH STIFFENING ELEMENTS

Abstract

The invention relates to an enveloping body for at least partially enveloping a limb, having an enclosed volume and a connection for supplying and removing fluid to the volume or from the volume, wherein the enveloping body forms an inner circumference and an outer circumference; on the enveloping body reinforcement elements are arranged that are designed to be brought into contact as a result of the removal of fluid from the volume or to increase their contact with one another as a result of the removal of liquid.

Claims

1. An enveloping body for at least partially enveloping a limb, the enveloping body having an enclosed volume and a connector for supplying and removing fluid to the volume and from the volume, the enveloping body forming an inner circumference and an outer circumference, wherein on the enveloping body, stiffening elements are arranged which are designed to be brought into contact as a result of removal of fluid from the volume or to strengthen their contact with one another as a result of removal of fluid.

2. The enveloping body as claimed in claim 1, wherein the stiffening elements are arranged inside the volume and/or on the outer circumference thereof.

3. The enveloping body as claimed in claim 1 wherein the enveloping body has at least two walls between which the volume is enclosed, and the stiffening elements are arranged on a side directed toward the volume and/or are integrated in said side.

4. The enveloping body as claimed in claim 1 wherein stiffening elements lie opposite one another in the volume or stiffening elements arranged next to one another can be brought into form-fit engagement with one another.

5. The enveloping body as claimed in claim 1 wherein the connector is designed with a closure device which, after the volume is evacuated and the stiffening elements are pressed onto one another, preventing a return flow of fluid into the volume.

6. The enveloping body as claimed in claim 1 wherein on their contact faces, the stiffening elements have mutually corresponding surface structures and/or a coefficient of friction μ≥0.3.

7. The enveloping body as claimed in claim 1 wherein stiffening elements that are not located in contact with one another are arranged to be movable relative to one another on or in the enveloping body.

8. The enveloping body as claimed in claim 1 wherein the enveloping body has an inner wall and an outer wall which enclose the volume.

9. The enveloping body as claimed in claim 1 wherein the volume has interconnected regions and/or extends helically in the proximal-distal direction.

10. The enveloping body as claimed in claim 1 wherein the enveloping body has a plurality of volumes which are distributed about the circumference and/or arranged radially one after another and are separated by at least one intermediate wall.

11. The enveloping body as claimed in claim 10, wherein the inner wall and/or intermediate wall and/or outer wall are/is foldable and/or elastic.

12. The enveloping body as claimed in claim 10, wherein each volume has a connector for the supply and removal of fluid.

13. The enveloping body as claimed in claim 1 wherein the stiffening elements are designed as struts, plates, granules, filaments, wovens, knits and/or structured surface material.

14. The enveloping body as claimed in claim 1 wherein the inner circumference of the enveloping body increases as a pressure of the volume increases.

15. The enveloping body as claimed in claim 1 wherein the enveloping body has an at least partially adhesive inner surface.

16. The enveloping body as claimed in claim 1 wherein the enveloping body is designed as a prosthesis liner, bandage, cuff, item of clothing or shoe.

17. The enveloping body as claimed in claim 16, wherein the enveloping body, as prosthesis liner, has at least one fastening device for a prosthesis component that is to be secured.

18. The enveloping body as claimed in claim 3, wherein elements transmitting tensile force are arranged between at least two walls.

19. The enveloping body as claimed in claim 18, wherein the elements transmitting tensile force are rigid under tension or elastic.

Description

[0034] Illustrative embodiments of the invention are explained in more detail below with reference to the attached figures, in which:

[0035] FIG. 1 shows a schematic view of an enveloping body in the form of a prosthesis liner, in two states;

[0036] FIG. 2 shows a perspective view of an enveloping body as a prosthesis liner;

[0037] FIG. 3 shows a schematic view of a bandage;

[0038] FIG. 4 shows a schematic view of an enveloping body in the form of a shoe;

[0039] FIG. 5 shows a sectional view through a liner with stiffening elements;

[0040] FIG. 6 shows a variant of the liner with an intermediate wall; and

[0041] FIG. 7 shows a variant of the invention with a reinforcement.

[0042] FIG. 1 shows a schematic view of an orthopedic enveloping body 1 in the form of a prosthesis liner as a basic implementation of the invention. The enveloping body 1 has an inner wall 14 and an outer wall 15, which between them enclose a volume 21. The enveloping body 1 is thus double-walled and has a connector 3 with a closure device 31 in the form of a valve in order to fill the volume 21 between the inner wall 14 and the outer wall 15 with a fluid or to drain fluid from the volume 21. The fluid is preferably ambient air. A large number of elements 7 for transmitting tensile force are formed between the inner wall 14 and the outer wall 15 and, in the illustrative embodiment shown, are configured as webs. Instead of the webs, there is also the possibility of providing straps, pins or also just connection points between the inner wall 14 and the outer wall 15. In the state when not filled with fluid, the inner wall 14 can bear on the outer wall 15.

[0043] The enveloping body 1 is U-shaped in longitudinal section, while it has a substantially circular, closed contour in the cross section perpendicular to the longitudinal extent of the enveloping body 1. In the unfilled state shown, an inner circumference 4 and an outer circumference 5 are thus present; the dimensions of the circumferences 4, 5 derive from the shape, size and material properties.

[0044] When fluid is introduced into the closed-off volume 21 via the connector 3, the pressure inside the volume 21 increases since both the inner wall 14 and the outer wall are made of an elastic material, preferably an elastomer, or a combination of elastic portions and non-elastic portions. As a result of the increased internal pressure, corresponding forces act on the inner wall 14 and the outer wall 15; greater forces act on the outer wall 15 on account of the latter having a larger surface area. With identical material properties in terms of elongation, for example when the inner wall 14 and the outer wall 15 are made of the same material, greater deformation and elongation take place on account of the greater forces acting on the outer wall 15, which has the effect that the enveloping body 1 as a whole is stretched out. This is shown on the right in the figure. In the state when subjected to pressure, the outer circumference 5′ is increased compared to the view on the left. The inner circumference 4′ is also increased by comparison with the initial state, which is indicated by the broken line, as also is the distance between the inner wall 14 and the outer wall 15.

[0045] Through the pressure applied via the valve 31 and the connector 3, it is possible to increase the internal diameter and thus also the circumference 4 of the receiving space of the enveloping body 1 for the limb or the stump, such that the stump (not shown) can be easily inserted. When the valve 31 at the access 3 is opened, air escapes from the volume 21 on account of the elastic restoring forces that are made available by the inner wall 14 and the outer wall 15. The volume of the receiving space for the stump decreases, the inner wall 14 bears on the stump (not shown), and a secure fit of the enveloping body 1 on the stump is permitted. Depending on the degree of pressure reduction, a suitable pressing force of the inner wall 14 on the stump is obtained, wherein the maximum pressing force is obtained when the volume 21 is minimized.

[0046] FIG. 2 shows an embodiment of the enveloping body 1 in the form of a prosthesis liner with a proximal insertion opening 9 and a closed distal end region 10. A dimensionally stable cap and a fastening device 16 such as a pyramid adapter for mechanical locking to other prosthesis components such as knee joints or the like can be arranged at the distal end region 10. In the view at the top, the prosthesis liner 1 has a first circumference 4. From the distal end region 10, a side wall extends substantially conically in the direction of the proximal access opening 9. The side wall or the side wall region has a double-walled configuration; the distal end region 10 is either formed as one layer, or the two layers of a double-walled prosthesis liner are bonded adhesively to each other or joined cohesively to each other. No pressure fluid can be introduced in the distal end region 10.

[0047] The middle view in FIG. 2 shows the acting forces when a pressure fluid is introduced into the hollow space formed in the side wall or into the volume enclosed between an inner liner and an outer liner. The view on the right shows the shape of the prosthesis liner 1 at an increased internal pressure in the volume. The inner circumference 4′ is greater than the initial inner circumference 4; the access opening 9 of the prosthesis liner closed in the distal end region 10 is considerably larger than the original access opening 9. This makes placing the stump into the prosthesis liner 1 easier. After the stump end has made contact with the inner face of the distal end region 10, the valve 31 at the connector 3 is opened, the air escapes, and the side wall of the prosthesis liner 1 conforms to the stump.

[0048] An alternative embodiment of the invention is shown in FIG. 3, in which the enveloping body 1 is configured in the form of a pneumatically modifiable bandage. The bandage can be configured as a knee bandage and bridge a joint. It can alternatively be configured as an elbow bandage, a wrist bandage or an ankle bandage. An additional possibility is that the bandage is not configured to bridge a joint and instead can engage completely around the upper leg, upper arm, lower leg or forearm, for example. The cross section of the bandage is closed in the illustrative embodiment shown. The bandage 1 is double-walled along its entire length, between the proximal access opening 9 and the distal exit opening 11, and can have pressurized air applied to it via a connector (not shown). The application of pressurized air is shown in the middle view in FIG. 3, which illustrates how the bandage 1, from the initial state shown in the left-hand view, is converted to the end state shown in the right-hand view. The inner circumference 4′ in the pressurized state according to the view on the right is greater than the initial circumference 4, such that the bandage can be easily applied. Compression takes place by release of pressurized air. Regions 8 of increased adhesiveness can be formed on the inner face of the bandage 1, such that the enveloping body 1 has an adherent coating at least partially on its inner surface 8.

[0049] FIG. 4 shows a further variant of the invention, in which the enveloping body 1 is configured as a pneumatically operated shoe or boot. The shank region of the enveloping body 1, extending above the natural ankle joint, has a double-walled configuration and forms a sleeve-like volume that can be filled with pressurized air. The filling process is shown in the middle view, while the view on the right shows how the proximal access opening 9 is considerably increased in size compared to the initial extent. The inner circumference 4′ is likewise increased in relation to the original inner circumference 4, such that insertion into the shoe or boot 1 is made much easier. After insertion, the pressure in the volume 21 can be reduced, as a result of which the shank conforms to the lower leg.

[0050] FIG. 5 shows, on the left, a partial sectional view of an enveloping body 1 in the form of a prosthesis liner with a filled volume 21, as is indicated by the sign p+, while the middle view in FIG. 5 shows the section in an evacuated state in which the volume 21 has been freed of the fluid located therein. This is illustrated by the sign p−. Inside the volume 21 formed between the inner wall 14 and the outer wall 15, stiffening elements 12 are arranged which lie opposite one another inside the volume 21. In the partial sectional view on the left, the stiffening elements 12, 13 are spaced apart from one another since a fluid, for example air, is located inside the volume 21 and for example forms an overpressure in relation to the environment. In the illustrative embodiment shown, the stiffening elements 12, 13 are designed as separate components, for example as individual plates on the inner side of the outer wall 15 and on the side of the inner wall 14 directed toward the volume. If the fluid inside the volume 21 is now drained off, for example through the connector 3 (not shown) to which a pump can be attached, the inner wall 14 adopts the individual shape of the enclosed stump. Thereafter, or at the same time, the two walls 14, 15 bear on each other and bring the stiffening elements 12, 13 into contact with one another or strengthen the contact. If a vacuum is then applied, the inner wall 14 and the outer wall 15, with the stiffening elements 11, 12 located thereon or therein, are pressed onto one another. When the stiffening elements 12, 13 which are arranged on mutually opposite sides of the respective wall 14, 15 are pressed together or brought into increased contact, the enveloping body 1 stiffens and forms a dimensionally stable envelop for the stump. Alternatively to a pump, the fluid from the volume 21 can also be forced out of the volume 21 as a result of elastic restoring forces, for example by clamping devices which are arranged between the inner wall 14 and the outer wall 15 and act against a movement of the inner wall 14 away from the outer wall 15. After the evacuation of the volume 21 or of the volumes, the valve or the closure device 31 prevents a return flow of fluid, in particular ambient air, such that the rigid form of the enveloping body is maintained until the valve 31 is opened and the stiffening elements 12, 13 are able to move relative to one another.

[0051] The stiffening elements 12, 13 on the respective wall can be designed either as mutually movable individual plates, knobs, imbricated plates or other components which, in the emptied state of the volume 21, come into contact with one another or engage with one another and impede or prevent shifting of the individual components relative to one another. The stiffening elements 12, 13 can also be designed in one piece, and it is likewise possible that the stiffening elements 12 are arranged only on one wall if the stability of the stiffening elements 12, 13 brought into contact with one another is sufficient. The stiffening elements 12, 13 can also bear on one another in the filled state of the volume 21, but they are then preferably movable relative to one another and, by evacuation and by the respective other wall bearing on the stiffening elements 12, 13, are pressed onto one another and brought into contact, such that shifting of the individual components of the stiffening elements 12, 13 relative to one another is prevented or impeded.

[0052] In the view on the right in FIG. 5, a complete prosthesis liner is shown in partial cross section with the stiffening elements 12, 13, in the filled state of the volume 21. The stiffening elements 12, 13 can also be designed as auxetic surfaces.

[0053] FIG. 6 shows a variant of the invention in which an intermediate wall 45 is arranged between the outer wall 15 and the inner wall 14, such that two volumes 21, 22 form in the enveloping body 1. The closed volumes 21, 22 can be filled or emptied separately through a separate connector 3. Stiffening elements 12, 13 in the form of felt layers or fiber layers of directed orientation are arranged inside the volumes 21, 22 and, in the filled state of the volumes 21, 22 as shown in the view on the far left, allow the walls 14, 15, 45 to move relative to one another and, on account of the mobility of the walls 14, 15, 45, permit simple engagement and application of the enveloping body 1 in the form of a prosthesis liner.

[0054] If the fluid is then sucked out of the volumes 21, 22 as is shown in the middle view, the surfaces of the walls 14, 15, 45 provided with textile elements bear on one another and lock onto one another, such that the stiffness of the whole enveloping body is increased. Alternatively to an arrangement of textile elements such as felt, structure textiles or the like, it is possible to introduce knob-like films, ribbed surfaces or other surface structures that produce a locking action into the volumes 21, 22 and, by evacuation or by releasing the internal pressure, to move them toward one another and increase the stiffness by placing them onto one another. A fastening device 16 such as a pyramid adapter can be arranged at the distal end 10. However, the fastening device 16 can in principle also be arranged at other locations, in particularly laterally, of the enveloping body. The view on the right in FIG. 6 shows an illustrative embodiment of an enveloping body as a frame socket with a frame 23 and a dorsal socket with a distal end region 10 for receiving a stump end. The fixed frame does not completely enclose the limb here; the remaining part is formed only by the enveloping body equipped with stiffening elements 12 and is thus flexible in the state when filled with fluid.

[0055] FIG. 7 shows a further variant of the invention, in which the views on the left and in the middle each show different internal pressures present in the volume 21. Arranged inside the volume 21 are granules which, upon evacuation of the volume 21 as shown in the middle figure, are compressed, as a result of which a movement of the granule particles relative to one another is prevented. The stiffness thus increases, since the stiffening elements in the form of the granule particles are brought into contact with one another or are pressed onto one another. Filament-like reinforcements 16 can be arranged or embedded in the outer wall 15 or on the outside of the outer wall 15, in order to provide length stability of the enveloping body 1. Lengthening of the enveloping body 1 is then no longer possible, or is possible only to a limited extent. By contrast, radial widening when the pressure inside the volume 21 increases is possible.

[0056] The filament reinforcement 16 can also be designed to be radially continuous and produce connecting walls or partition walls between the inner wall 14 and the outer wall 15, such that a number of individual chambers separated from one another are distributed about the circumference, with the result that a large number of volumes are formed inside the enveloping body 1. Each volume can be provided with an outlet or a valve in order to fill or empty it separately or to provide it with an underpressure when a vacuum pump is applied.

[0057] All the illustrative embodiments of FIGS. 5-7 can also be used in the examples of enveloping bodies in FIGS. 1-4, particularly in respect of the stiffening elements.