DE9419208U1 - Artificial link - Google Patents

Description

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RÜGER, BARTH ELT Sc ABEL or-mg^

Dipl.-Ing. H. R Barthelt

Patent Attorneys · European Patent Attorneys Patent Attorneys

European Patent Attorneys Dr.-Ing. T. Abel Patent Attorney

PO Box 348 29 November 1994 D-73703 Klingen a. N.

, , Webergasse 3

Gm 3 Joaen 0-73728 Essiingen a. N,

Telephone (0711)35 65 359019

Fax (0711)3599 Telex 7 25ool0smru

Telegram Patent Protection Esslingenneckar

VAT DG 145 265

Felix Carstens, Villenstraße 16, 67433 Neustadt/Weinstraße Artificial limb

US Patent 5,108,456 describes a lower leg prosthesis consisting of a hard, cup-shaped shaft whose outer contour is adapted to the contour of the missing lower leg. In the cup-shaped interior, which is designed to accommodate the lower leg stump, there is a soft-walled inner funnel that fills the space between the lower leg stump and the wall of the hard shaft and at the same time serves to cushion the shaft.

Since the dimensions of the stump vary greatly from individual to individual, several pads in the form of air chambers are provided between the soft-walled inner funnel and the inner wall of the shaft, which can be filled as required to ensure that the prosthesis fits tightly to the remaining stump. The pads sit in corresponding recesses on the outside of the soft-walled funnel and a tube leads from each chamber to the outside of a valve block on the outside of the shaft. The chambers can be inflated or deflated using this valve block, which sits on the outside of the shaft, and a rubber balloon that can be connected to the valve block, as is also used on the cuffs of blood pressure monitors.

Accounts: Deutsche Bank AG, Rliaie Essigen{3*04$4 (S£2 ö\\ 7$Q 7S)!- F&siscneck Stuttgart 62451 -700 (BLZ 600 100 70)

The rubber pump is attached to the corresponding connection on the valve block and removed again after the chamber has been filled.

With the help of this construction, the patient can adjust the volume of the pad to the dimensions of the leg stump, which vary depending on the day. It is well known that even in healthy people, the circumference of the limbs varies depending on the temperature, because the blood flow to the muscles is, among other things, temperature-dependent.

This basic advantage of the known solution is offset by a significant disadvantage, which is that the chamber volume can only be changed if the patient has direct access to the prosthesis. Before changing the chamber volume, he is forced to remove the legwear in the relevant area, at least in the sense of inflating the pad. In the case of lower leg prostheses, this may still be possible, because it is sufficient to pull up the trouser leg accordingly. With upper leg prostheses, access is no longer so easy.

Beyond this, the publication does not deal further with securing the prosthesis to the leg stump.

For knee ex prostheses and similar prostheses, it is also known from practice that the shaft is attached to the corresponding condyles, e.g. the femoral condyles above the knee joint. For this purpose, corresponding inwardly convex bulges are used in the shaft, which are intended to form locking connections with the condyles. However, in order for this connection to work properly, these bulges must be very pronounced, which of course also makes it considerably more difficult for the condyles to pass through when getting into the prosthesis.

Based on this, the object of the invention is to create a femoral prosthesis which can be put on more easily while providing equally good anchoring to the condyles.

This object is achieved with an artificial limb having the features of claim 1.

The use of the chamber or chambers allows the patient to empty the chambers before getting into the prosthesis, thus creating a large passage. As soon as the stump is properly inserted into the prosthesis, the chambers are filled again. The pads, which bulge inwards, now narrow the passage and provide a secure anchoring of the prosthesis to the condyles.

Before removing the prosthesis, the chambers are emptied again to create a wide passage that does not hinder the passage of the condyles.

The stationary pump in the area of the shaft ensures that the pump is always present on the prosthesis shaft and does not have to be connected to a corresponding tube that leads to a pad. The patient can adjust the pad volume unobtrusively within a short time, for example, he can deflate the pads at any time while sitting to relieve the pressure on the stump, because then, when he wants to move from the sitting position to the standing position, he can quickly ventilate the pads again and thus bring them to a volume that ensures that the prosthesis fits tightly.

As a rule, the wall thickness of the prosthesis shaft is sufficient to accommodate a significant part of the pump, especially since its pumping volume does not need to be too large in view of the relatively small pad volume. In addition, because the actuating means

the pump is accessible through an opening in the outer shaft, it can be operated at any time through clothing. The material of the clothing lying over the pump's operating means does not prevent it from being operated.

The situation is particularly simple if the medium with which the pad or pads are filled is air and the pump is an air pump. Leaks do not contaminate the clothing and can be corrected at any time by pumping in more air.

The new artificial limb is suitable for all types of prostheses, i.e. both for those prostheses that have a so-called removable soft-wall inner funnel and for prostheses that do not have an inner funnel, as well as for prostheses that have neither a fixed nor a removable soft-wall inner funnel.

A compressible inner wall, for example, consists of a foamed material.

When it comes to accommodating the pump, it is ultimately irrelevant whether it is located at the level of the interior and thus of the stump in the interior or whether it is arranged below the stump in the prosthesis. Mounting the pump at the level of the interior has the advantage of being easier to manufacture because no hoses are required. However, this means that parts of the pump protrude beyond the outer wall of the shaft, which does not cause any problems if the pump is arranged cleverly.

Another way of accommodating the pump is, for example, to place it in the space between the end of the stump, i.e. the end of the inner space, and the end of the shaft above the

artificial knee. There is enough space to accommodate the pump in a corresponding recess, so that no protrusions can occur beyond the cosmetic outer contour of the prosthesis. The pump is therefore better protected and less conspicuous.

Depending on the application, the chambers forming the pads can be embedded in the elastic inner wall, arranged on the outside of the elastic inner wall or attached to the inner wall of the hard outer wall or outer shell. The type of accommodation depends on the type of prosthetic device. In the case of a soft-wall inner funnel, for example in a lower leg or knee prosthesis, it is advantageous to accommodate the chambers on the inside of the hard outer wall, as this causes the least problems with regard to accommodating the pump. The pump always remains stationary relative to the outer wall, regardless of the soft-wall funnel.

With some prostheses it can be advantageous if all the pads have approximately the same internal pressure. In such a case it is sufficient to use a pump that is connected to all the pads via tubes. However, it is also possible to connect the pad directly to a pump and to connect the other pads to this chamber via tubes. The manufacture of the artificial limb is particularly simple if the tubes are also made from the same foil cuts that form the walls of the pads.

If the pads of the new artificial limb have very different volumes and therefore very different surfaces, or if they have to be filled with different pressures, it is advantageous if each pad has its own pump. This is also easily possible with the new solution, whereby the use of tubes means that the position of the pumps can be largely adjusted.

can be freely selected or the pumps can be glued directly onto the pads.

A particularly simple and space-saving design for a pump is to use a flexible molded part that represents only five sides of the pump chamber in the case of a cuboid-shaped pump chamber. One wall of the pump chamber can then simultaneously be either the wall of a chamber or a distributor piece.

Operation is particularly easy if the pump also includes a draining device. This also saves assembly effort.

Furthermore, further developments of the invention are the subject of subclaims.

The drawing shows an embodiment of the subject matter of the invention. It shows:

Fig. 1 a femoral prosthesis in a schematic side view,

Fig.2 the shaft for the prosthesis according to Fig. 1 in a perspective view, partially extended,

Fig. 3 the chambers of the shaft according to Fig. 2 in a plan view and partially opened,

Fig. 4 a section of the shaft according to Fig. 2 in a section along the line III-III according to Fig. 2 and

Fig. 5 shows the shaft according to Fig. 2 in a longitudinal section.

In Fig. 1, a knee disarticulation prosthesis 1 or a comparable prosthesis (ζ, β, Syme stump) is shown, which has a substantially hard shaft 2 which receives the femoral stump and to which a support tube 3 replacing the missing lower leg is hinged. The connection between the shaft 2 and the support tube 3 forms a hinge joint replacing the knee, which is surrounded by a cuff 4. An artificial foot 5 is attached to the lower end of the support tube 3.

The shaft 2 consists of a hard, cup-shaped outer wall or outer shell 6 with an outer side 7 and an inner side 8. The inner side 8 defines a sack-shaped interior 9. At least part of the interior 9 is lined by a flexible inner wall 11, also cup-shaped, with an inner side 12 and an outer side 13. The inner side 12 defines a sack-shaped interior 14. This interior 14 accommodates the thigh stump of the patient in question and is adapted to the stump accordingly.

Fig. 2 shows only the shaft 2 on an enlarged scale, but for a right leg stump. Accordingly, the side of the shaft 2 facing the viewer of the figure is the frontal side, so that the medial side is on the right and the dorsal side is facing away from the viewer and therefore not visible. The lateral side is shown on the left in Fig. 2, which ends at the upper end of the shaft 2 in a trochanter pocket 15.

Only on the cup-shaped inner wall 11 shown removed can a tuber bank 16 be seen on the back, which has a corresponding counterpart on the outer wall.

On the inner side 8 of the hard outer wall 7 there are two approximately square pads laterally and medially

17a and 17b in the form of chambers to be filled with air. The outlines of the pads 17a and 17b are shown in dashed lines in Fig. 2, while Fig. 3 shows the pads individually. An air pump 18 is provided for filling or emptying the air chambers 17a and 17b, which is combined with an emptying device 19. The pump 18 and emptying device 19 can be seen through an opening 21 in the outer wall 6.

According to the top view of the partially opened chamber 17a from Fig. 3, the chambers consist of two plastic films 22 and 23 cut to the same size. From each cut 22, 23 forming a chamber, a one-piece neck part 24 extends, which widens at the upper end. A weld seam running along the circumference of the cuts 22, 23 and the neck part 24 connects the two cuts 22 and 23 neck parts 24 to one another in an airtight manner. The combined air pump and emptying device 18/19 is glued to the upper end of the neck parts 24 in an airtight manner. The neck parts 24 welded at the edges form hoses that connect the chambers 17a, 17b to the pump 18 or emptying device 19.

The position of the two air chambers 17a and 17b can also be seen in Fig. 12, which shows the shaft 58 from Fig. 5 in longitudinal section without a soft-wall inner funnel, as is usually used in knee ex prostheses. The two chambers 17a and 17b are located a short distance above a floor 20 of the interior 14.

The internal structure of the air pump 18 and the emptying device 19 is shown in the section in Fig. 4. The air pump 18 consists of an elastomer molded part 25, for example made of rubber, in the upper half of which a cup- or bowl-shaped cavity 26 is molded, which is bordered by a total of four sides 27 and a cover surface. The bowl-shaped interior 26 is to be opened in the direction of the neck part 24 of the film blank 23.

open. Below the shell-shaped interior 26, the molded part 25 forms a more or less solid body 29, into which a sack-shaped bushing 31 is vulcanized. Both the shell-shaped interior 26 and the section 29 are surrounded by a widening flange in order to enlarge the adhesive surface on the film blank 23.

The sack-shaped bushing 31 ends with a flat base 33, which contains a through hole 34, which is aligned with a corresponding small opening 35 in the foil blank 23. On the inside of the base 33 there is a small elevation 36, which is concentrically surrounded by an O-ring 37.

The interior of the sack-shaped bushing 31 is surrounded by a smooth cylindrical wall 38, which is connected to the base 33. The cylindrical wall 38 merges into a thread 39 at the upper end. An insert 41 is screwed into the thread 39, which has an actuating button 42 at its outer end. The insert 41 is hollow and contains a shut-off valve (not shown) whose inlet is formed by a hole 43 in the lower end and which can be opened optionally by an actuating tappet 44 leading through the actuating button 42. In the rest position, the shut-off valve is closed.

Above the inlet bore 43, an O-ring seal 45 is located in a recessed annular groove 44, which seals against the cylindrical inner wall 38.

The front side of the insert piece 41 is a flat surface which is arranged opposite the O-ring seal 37.

Between the base 33 and the O-ring seal 45, an inlet hole leads through the wall of the sack-shaped bushing 31.

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tion 46, which communicates with a check valve 47, which is located in a molded bore that connects the bowl-shaped interior 26 with the sack-shaped bushing 31. Another check valve 48 leads through the upper side wall 27.

The shaft described above is manufactured as follows:

The mass of the flexible inner wall 11 with the desired layer thickness is applied to a mold core, the outer contour of which is adapted to the leg stump of the patient in question according to the type of prosthetic treatment. Another manufacturing option is to deep-draw a corresponding blank over the mold core using the deep-drawing process.

As soon as the mass of the flexible inner wall 11 has hardened or cooled, a dummy cut is placed on the outside 13 of the inner wall 11, the thickness and outer contour of which corresponds to the later air chambers 17a, 17b. The dummy cut carries a correspondingly large molded piece, which has the same transverse dimensions as the later opening 21, at the corresponding point where the air pump 18 and the emptying device 19 are located in the finished air chambers 17a, 17b. The dummy cut for the air chambers 17a, 17b is temporarily fixed on the outside 13. Both the outer side 13 and the dummy cut for the air chambers 17a, 17b and the air pump 18 are provided with a release agent so that the laminate now applied, which is to form the hard outer wall 6, does not adhere to the outer side 13 or the dummy cut.

When the mass forming the hard outer wall 6 has reacted, i.e. has hardened, the mold core is pulled out of the shaft 2. The flexible inner wall 11, which does not adhere to the inner side 8 of the outer wall 6, with

the dummy cut for the air chambers 17a, 17b located thereon can now be removed from the sack-shaped interior 9. Since the dummy cut for the air chambers 17a, 17b is only temporarily fixed, it can be easily removed from the outside 13.

The dummy for the opening 21 produced a corresponding stool during the production of the outer wall 6, which is now removed, whereby the opening 21 leading through the outer wall 6 with the corresponding contours is automatically created.

The air chambers 17a, 17b with the glued-on pump 18, which have been prepared in the meantime, are glued to the place on the inner wall 8 that was previously kept free by the dummy cut when laminating the outer wall 6. The recess on the inner wall 8 created by the dummy cut defines exactly the correct position of the air chambers 17a, 17b without the need for complicated measurements. At the same time, the air pump 18 is also positioned correctly in the opening 21. Then, after the release agent has been removed, the flexible inner wall 11 is inserted back into the outer wall 6 and glued there over the entire surface.

The shaft 2 is thus finished as far as the invention is concerned. This is a shaft as is usually used as a suction shaft.

Depending on the current volume ratio on the stump or depending on whether he wants to put the prosthesis on or take it off, the patient can fill the air chambers 17a, 17b more or less. To do this, he first turns the actuation button 42 half a turn so that the front side of the insert 41 is free from the O-ring 37. This releases the flow connection between the interior of the air chambers 17a, 17b and the check valve 47. By pressing the shell-shaped

When the cover surface 28 of the pump is released, the air located there is pressed through the check valve 47 into the interior of the sack-shaped bushing 31 and from there through the bore 34 and the opening 35 into the interior of the air chambers 17a, 17b. When the cover surface 28 of the pump is released, the elastomer molded part 25 returns to its original shape shown and sucks air from the outside into the bowl-shaped interior 26 via the check valve 48. The air is sucked through the gap created between the molded part 25 and the opening 21. By compressing the bowl-shaped interior 26 again by pressing the cover surface 28 down with the fingers, a further portion of air is conveyed into the air chambers 17a, 17b. The patient will repeat this process until the desired pressure is exerted on the stump and the prosthesis 1 is anchored firmly enough to the condyles.

In order to prevent accidental venting of the air chambers 17a, 17b, the actuating button 42 of the emptying device is turned back approximately half a turn until the flat front side of the insert piece rests against the O-ring 37 and thus seals the bore 34.

When the patient wants to remove the prosthesis, he empties the air chambers 17a, 17b so that the constriction between the inflated pads disappears. To do this, the patient turns the actuating button 42 half a turn in the OPEN direction and, if he now presses down the actuating plunger 44, the shut-off valve contained in the insert piece is opened, whereby the air can flow from the air chambers 17a, 17b via the bore 34 to the inlet bore 43 to the shut-off valve. The air flows out of the shut-off valve via a corresponding channel surrounding the valve plunger 44. The patient can now get out of the prosthesis unhindered.

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If the shaft 2 is a shaft with a soft-walled inner funnel, the soft-walled inner funnel is first modeled on the stump model and then the process continues as described above. After the inner wall 11 and the outer wall 6 have been produced, the inner wall 11 is bonded to the outer wall 6 in a material-locking manner, for example by gluing, so that the inner wall 11 can no longer be removed, while the soft-walled inner funnel remains removable. In this case, the air chamber 17 can be glued either to the inner side 8 or the outer side 13. In all cases, the air chamber 17 is fixed in place between the inner side 12 of the inner wall 11 and the inner side 8 of the hard outer wall 6 .

In a design such as that used for a lower leg or knee prosthesis, the flexible inner wall can also be formed by the non-removable inner funnel. The inner wall is then not only flexible but also soft, i.e. compressible. The description of production given above applies accordingly.

A lower edge 50 of the chambers 17a, 17b may be slightly curved upwards to better adapt to the condyles.

Although the invention is explained using a knee prosthesis, it is clear that the invention is also suitable for foot prostheses or arm prostheses. In other words, for all types of prostheses where anchoring to condyles is possible.

Claims (36)

Protection claims: 1. Artificial limb (1), with a cup-shaped prosthetic shaft (2) which accommodates the stump and has an interior (8), the shape of which is adapted to the type of stump and the type of prosthetic treatment, the prosthetic shaft having an essentially dimensionally stable outer wall, with at least one chamber (17) which can be optionally filled with a medium or ventilated, which is located adjacent to the inner side (8) of the outer wall (6), fixed in the prosthesis shaft (2) and which is arranged above a condyle of the last bone present on the stump, and with a counter pad (17) above the opposite condyle. 2. Artificial limb according to claim 1, characterized in that the counter cushion is also a chamber (17) that can be optionally filled with a medium or ventilated. 3. Artificial limb according to claim 1 or 2, characterized in that the cup-shaped prosthesis shaft (2) receiving the stump has a flexible inner wall (11) within its essentially dimensionally stable outer wall (6) and that the chamber or chambers are arranged between an inner side (8) of the outer wall (6) and an inner side (12) of the inner wall (11). 4. Artificial limb according to claim 1 or 2, characterized s * · - 15 - characterized in that the chamber or chambers [17] are formed by two film cut-outs (22, 23, 24) that are bonded together at the edges. 5. Artificial limb according to claim 1 or 2, characterized in that the chamber or chambers (17) are fixed in position in the prosthesis shaft (2). 6. Artificial limb according to claim 1 or 2, characterized in that at least one of the chambers or the chamber (17) is assigned a pump (18) which is fixed in position relative to the prosthesis shaft (2), which is fluidically connected to the at least one chamber (17) and is assigned actuating means (28) which are accessible through an opening (21) in the hard outer wall (6). 7. Artificial limb according to claim 6, characterized in that the medium is air and the pump (18) is an air pump. 8. Artificial limb according to claim 1 or 2, characterized in that the chamber or chambers (17) are arranged above the femoral condyle. 9. Artificial limb according to claim 1 or 2, characterized in that the chamber or chambers (17) are arranged above the condyles of the ankle joint. 10. Artificial limb according to claim 1 or 2, characterized in that the chamber or chambers (17) are arranged above the elbow joint condyles. 11. Artificial limb according to claim 1 or 2, characterized in that the outer wall (6) and the inner wall (11) are integrally connected to one another. 12. Artificial limb according to claim 1, characterized in · ■ - 16 - characterized in that the inner wall (11) is separable from the outer wall (6). 13. Artificial limb according to claim 1 or 2, characterized in that the inner wall (11) is compressible. 14. Artificial limb according to claim 1 or 2, characterized in that the inner wall (11) consists of a foam. 15. Artificial limb according to claim 1, characterized in that the inner wall (11) is a soft-walled inner funnel. 16. Artificial limb according to claim 1 or 2, characterized in that a removable soft-wall inner funnel is located within the space delimited by the inner wall (11). 17. Artificial limb according to claim 1 or 2, characterized in that the pump (18) is arranged at the level of the interior space (14). 18. Artificial limb according to claim 1 or 2, characterized in that the pump (18) is arranged below the interior space (14) relative to the normal position of use. 19. Artificial limb according to claim 1 or 2, characterized in that the at least one chamber or the chambers (17) are attached to the inner side (8) of the outer wall (6). 20. Artificial limb according to claim 1 or 2, characterized in that the at least one chamber or chambers (17) are attached to the outside (13) of the inner wall (11). 21. Artificial limb according to claim 1 or 2, characterized in that the at least one chamber or chambers (17) are embedded in the inner wall (11). 22. Artificial limb according to claim 6, characterized in that the at least one chamber or chambers (17) are connected to the pump (18) via one or more hoses (24). 23. Artificial limb according to claim 22, characterized in that the tubes (24) are formed from foil blanks which are integral with the blanks (22, 23) for the chamber or chambers (17). 24. Artificial limb according to claim 6, characterized in that the pump (18) is integrally connected to one of the chambers (17). 25. Artificial limb according to claim 6, characterized in that the pump (18) has a flexible pump chamber (26), one wall (28) of which represents the actuating member of the pump (18). 26. Artificial limb according to claim 6, characterized in that the pump (18) has a flexible molded part (25) which forms at least five sides of the pump chamber (26). 27. Artificial limb according to claim 26, characterized in that a wall of the pump chamber (26) is formed by a chamber (17) which is associated with the interior (14). 28. Artificial limb according to claim 25, characterized in that the pump chamber (26) is connected to a check valve (48) leading to the outside and to a valve (47) in fluid communication with the chamber (17). • * 4 - 18 - 29. Artificial limb according to claim 1, characterized in that the chamber (17) is associated with an emptying device (19) which has an actuating member (44) operable by the user. 30. Artificial limb according to claim 29, characterized in that the emptying device (19) has a valve leading to the chamber (17), which is a valve controllable by a user, which has an actuating member (44). 31. Artificial limb according to claim 30, characterized in that the actuating member (44) of the emptying device (19) is accessible through an opening (21) in the outer wall (6). 32. Artificial limb according to claim 1 or 2, characterized in that in a knee disarticulation prosthesis (58), a comparable prosthesis or foot prosthesis above the condyles in the knee area or in the ankle area, one chamber (63) is provided medially and one chamber laterally. 33. Artificial limb according to claim 6, characterized in that if there are several chambers (17) only one pump (18) is provided. 34. Artificial limb according to claim 1 or 2, characterized in that if there are several chambers (17), at least one of them is separated from the others in terms of flow. 35. Artificial limb according to claim 1 or 2, characterized in that, in the case of several chambers (17), at least some of them are fluidically connected to one another via channels. 36. Artificial limb according to one or more of the • · ♦ · · t - 19 - Proverbs 1 to 35, characterized in that it is an arm prosthesis.