Prosthetic Liner With External Elastomeric Seal

Abstract

A prosthetic liner for use with a prosthetic socket that has a thermoplastic elastomeric (TPE) layer that is in contact with the amputee's residual limb. The TPE layer is not uniform in thickness but has ridges to extend circumferentially around the TPE layer. A fabric exterior layer covers the outer surface of the TPE layer conforming to the ridges and is used as a substrate to form a mechanical bond to an elastomeric material. Impregnating the elastomeric material within the fabric exterior occurs by applying an uncured material to the fabric exterior layer and onto at least the apex surfaces located within the sealing regions thereby creating an air tight boundary layer when inserted into a socket. When a vacuum is applied the air is evacuated from the volume below the seal layer. An alternative embodiment comprises a silicone or elastomeric liner with at least one non-unitary sealing element made of silicone or other thermoplastic elastomer further comprising a single radially extending, straight or arcuate silicone or a elastomeric engaging member.

Claims

1. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising a cushioning material having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one sealing element bonded to the said fabric exterior layer which is non-unitary with the thermoplastic elastomer material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single engaging member which extends radially outward.

2. The suspension liner sleeve of claim 1 wherein the engaging member is substantially straight.

3. The suspension liner sleeve of claim 1 wherein the engaging member is arcuate.

4. The suspension liner sleeve of claim 1 wherein the tubular body portion further comprises a distal lock at the closed distal end.

5. The suspension liner sleeve of claim 1 wherein the suspension liner sleeve incorporates at least three sealing elements.

6. The suspension liner sleeve of claim 1 wherein the sealing element is bonded at a mid-point along the suspension liner sleeve.

7. The suspension liner sleeve of claim 1 wherein the sealing element is bonded about one third of a distance from the closed distal end towards the open proximal end.

8. The suspension liner sleeve of claim 1 wherein the sealing element is bonded at the closed distal end.

9. The suspension liner of claim 5 wherein a first sealing element is bonded at a mid-point along the suspension liner sleeve, a second sealing element is bonded about one third of a distance from the closed distal end and towards the open proximal end, and a third sealing element is bonded at the closed distal end.

10. The suspension liner of claim 1 wherein the cushioning material comprises silicone.

11. The suspension liner of claim 1 wherein the cushioning material comprises an elastomeric compound.

12. The suspension liner of claim 13 wherein the elastomeric compound is urethane.

13. The suspension liner of claim 13 wherein the elastomeric compound is a thermoplastic elastomeric gel.

14. The suspension liner of claim 10 wherein the sealing element comprises an elastomeric compound.

15. The suspension liner of claim 11 wherein the sealing element comprises silicone.

16. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising a cushioning material having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end, and a distal lock integrally within the closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one sealing element bonded to the said fabric exterior layer which is non-unitary with the cushioning material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single straight engaging member which extends radially outward.

17. The suspension liner sleeve of claim 16 wherein the tubular body portion further comprises a distal lock at the closed distal end.

18. The suspension liner sleeve of claim 16 wherein the suspension liner sleeve incorporates at least three sealing elements.

19. The suspension liner sleeve of claim 16 wherein the sealing element is bonded at a mid-point along the suspension liner sleeve.

20. The suspension liner sleeve of claim 16 wherein the sealing element is bonded about one third of a distance from the closed distal end towards the open proximal end.

21. The suspension liner sleeve of claim 16 wherein the sealing element is bonded at the closed distal end.

22. The suspension liner of claim 20 wherein a first sealing element is bonded at a mid-point along the suspension liner sleeve, a second sealing element is bonded about one third of a distance from the closed distal end and towards the open proximal end, and a third sealing element is bonded at the closed distal end.

23. The suspension liner of claim 16 wherein the cushioning material is silicone.

24. The suspension liner of claim 16 wherein the cushioning material is an elastomeric compound.

25. The suspension liner of claim 26 wherein the elastomeric compound is urethane.

26. The suspension liner of claim 26 wherein the elastomeric compound is a thermoplastic elastomeric gel.

27. The suspension liner sleeve of claim 23 wherein the sealing element comprises an elastomeric compound.

28. The suspension liner sleeve of claim 24 wherein the sealing element comprises silicone.

29. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising a cushioning material having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end, and a distal lock at the closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one silicone sealing element bonded to the said fabric exterior layer which is non-unitary with the cushioning material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single arcuate engaging member which extends radially outward.

30. The suspension liner sleeve of claim 29 wherein the suspension liner sleeve incorporates at least three sealing elements.

31. The suspension liner sleeve of claim 29 wherein the sealing element is bonded at a mid-point along the suspension liner sleeve.

32. The suspension liner sleeve of claim 29 wherein the sealing element is bonded about one third of a distance from the closed distal end towards the open proximal end.

33. The suspension liner sleeve of claim 29 wherein the sealing element is bonded at the closed distal end.

35. The suspension liner of claim 30 wherein a first sealing element is bonded at a mid-point along the suspension liner sleeve, a second sealing element is bonded about one third of a distance from the closed distal end and towards the open proximal end, and a third sealing element is bonded at the closed distal end.

36. The suspension liner of claim 29 wherein the cushioning material is silicone.

37. The suspension liner of claim 29 wherein the cushioning material is an elastomeric compound.

38. The suspension liner of claim 38 wherein the elastomeric compound is urethane.

39. The suspension liner of claim 38 wherein the elastomeric compound is a thermoplastic elastomeric gel.

41. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising an elastomeric compound having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one silicone sealing element bonded to the said fabric exterior layer which is non-unitary with the cushioning material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single arcuate engaging member which extends radially outward.

42. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising silicone having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one silicone sealing element bonded to the said fabric exterior layer which is non-unitary with the cushioning material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single arcuate engaging member which extends radially outward.

43. A suspension liner sleeve configured to create a vacuum between a residual limb and a prosthetic socket comprising: an elongate, tubular body portion comprising an elastomeric compound having a tubular thickness, a vertical axis, defining an open proximal end and a closed distal end; a fabric exterior layer bonded to the tubular body portion; and at least one sealing element comprising an elastomeric compound bonded to the said fabric exterior layer which is non-unitary with the cushioning material of the tubular body portion wherein the sealing element further comprises a sealing element base and a single arcuate engaging member which extends radially outward.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following descriptions, taken in conjunction with the accompanying drawings, in which:

[0013] FIG. 1 is a cross-sectional view of the thermoplastic elastomeric layer;

[0014] FIG. 2 is a cross-sectional view of the preferred embodiment of the suspension sleeve liner;

[0015] FIGS. 3-11 are cross-sectional views of suspension sleeve liners corresponding to FIG. 2 wherein alternate embodiments of the raised and recessed portions are shown;

[0016] FIGS. 12-13 are cross-sectional views of suspension sleeve liners wherein alternate embodiments of the raised portions are shown;

[0017] FIGS. 14-15 are cross-sectional views of suspension sleeve liners wherein alternate embodiments of the raised portions are shown, specifically liners having an elastomeric material impregnated within a fabric exterior layer;

[0018] FIG. 16 is a perspective view of an alternative embodiment of the thermoplastic elastomeric liner wherein the sealing element is glued to the fabric exterior;

[0019] FIG. 17 is a cross-sectional view of FIG. 16 along line A-A;

[0020] FIG. 17-1 is a magnified view of the cross-sectioned portion showing Detail B of the sealing element area of FIG. 16;

[0021] FIG. 18 is a perspective view of the thermoplastic elastomeric liner wherein multiple sealing elements are glued onto the fabric exterior;

[0022] FIGS. 19-21 are perspective views of the thermoplastic elastomeric liner showing the sealing element in various locations on the liner;

[0023] FIGS. 22 and 23 are perspective views of the thermoplastic elastomeric liner prior to the sealing element being glued to the fabric exterior;

[0024] FIG. 24 is a perspective view of another alternative embodiment wherein the thermoplastic elastomeric liner include a lock at the distal end as well as the sealing element; and

[0025] FIG. 25 is a cross-sectional view of FIG. 24 along line C-C.

[0026] Similar reference numerals refer to similar parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.

[0028] FIG. 1 illustrates a thermoplastic elastomeric layer 400 of the seal liner 100 in which the thermoplastic elastomer layer 400 (also known as TPE) having an inner elastomer surface 410 and outer elastomer surface 420 is formed within a mold having wall thicknesses between 2 and 9 mm. The liner 100 preferable has an open proximal end 120 with a larger circumference and volume than of the closed distal end 140.

[0029] FIG. 2 illustrates a preferred embodiment of the seal liner 100 in which the thermoplastic elastomer layer 400 further comprises at least one sealing region 430 that extends preferably between 3 and 20 mm outward from the interior surface 410 of the thermoplastic elastomeric layer 400 and includes at least one raised portion 440. If more than one raised portion 440 is included within the sealing region 430, the plurality of raised portions 440 will be accompanied by at least one recessed portion 450. Thus, if there are two raised portions 440 then three recessed portions 450 will be distributed as shown in FIG. 1. Alternatively, the sealing region 430 may begin with a raised portion 440 instead of a recessed portion 450. In this instance, the distribution would be as follows: raised portion 440, recessed portion 450, raised portion 440. Thus, the recessed portions 450 do not always have to surround distal and proximal ends of the sealing region 430.

[0030] A fabric exterior 300 is synonymous with “reinforcement layer” and is bonded to the outer elastomer surface 420 of the thermoplastic elastomer layer 400 and conforms to the at least one sealing region 430. The fabric exterior 300 advantageously forms a suitable substrate for bonding a seal layer 200. The seal layer 200 conforms to the shape of the fabric exterior 300 and thermoplastic elastomer layer 400. The seal layer 200 is applied in an uncured state to the fabric and with a viscosity such that it is able to “wet out” the fabric in that area so that once cured it forms an air tight seal thus isolating the fabric above the seal layer (not shown) from the fabric exterior 300 below the seal layer 200. Thus, this application of the outer sealing layer 200 to the fabric exterior 300 provides an air-impermeable interface between the thermoplastic elastomeric layer 400 and the surrounding exterior area of the liner 100. The outer sealing layer 200 is preferably applied such that it impregnates the reinforcement layer 300 so as to form a composite.

[0031] This outer sealing layer 200 may be comprised of natural rubber, silicone, polyurethane, latex, polysulfide, vinyl, polyisoprene, or a styrene block copolymer gel, although the preferred material is rubber due to their high abrasion resistance and high force to stretch. The force to stretch this layer is determined by the modulus of elasticity of the sealing material multiplied by the cross-sectional area of the sealing material.

[0032] The thermoplastic elastomer layer 400 is preferably of a type compatible with long periods of dynamic wearer contact. Such materials are known in the art and may include the following polymers, as well as gels which comprise them: silicones polyurethanes; block copolymers such as styrene block copolymer gels, general non-limiting examples of which may include SEBS-, SEPS-, SEEPS-, SEEBS-, and other type styrene block copolymer gels. Further non-limiting examples of styrene block copolymer gels which may be useful in the liner of the present invention include so called “controlled distribution polymers,” such as, for example, those disclosed in U.S. Pat. No. 7,226,484; United States Patent Application Publication No. 20070238835; and United States Patent Application Publication No. 20050008669, the disclosure of which is hereby incorporated by reference herein. Other potentially useful polymers may include certain so-called “crystalline” polymers, such as, for example, polymers disclosed in U.S. Pat. Nos. 5,952,396; 6,420,475 and 6,148,830, the disclosures of which are hereby incorporated by reference herein. The above list is non-limiting, and in general, the list of acceptable polymers and gels includes those known in the art to be useful for the fabrication of prosthetic liners. The term “gel” is defined to be a polymer mixed with a plasticizer. An example of current liner using such gel is the “EZ Gel”™ liner, available from Alps South, LLC.

[0033] The term “sealing region” 430 may include only one raised portion 440 or may include a plurality. If it includes a plurality of raised portions 440, the sealing region 430 will have each raised portion 440 contiguously adjacent to any other raised portion 440. However, if there are a plurality of raised portions 440 collectively near the distal end of the tubular body portion as well as a plurality of raised portions 440 collectively near the proximal end of the tubular body portion, there will be two sealing regions 430 with only continuous lengths among their group. That is, the sealing region 430 in the distal end will have one continuous length of material while the sealing region 430 in the proximal end will have its own continuous length of material. The continuous length of material refers to the elastomeric material used to create the durable and flexible sealing region 430.

[0034] FIGS. 2-11 show that the raised portions 440 within the elastomeric material can have a multitude of different geometries relative to the vertical axis of the invention. For example, the raised portions 440 can have a square/rectangular (FIGS. 2-4, 6), parabolic (FIG. 11), triangular, oval, spear-like, parallelogram-like (FIG. 5), dome-like (FIG. 11), ripples (FIGS. 7 and 9), or protrusions that resemble “gripping” mechanisms or shapes that one skilled in the art would use to “grip” an object to another object. For example, a finger-like projection (FIGS. 8 and 10) that resembles a hook similar to the “hook” portion of a “hook and loop” configured as used in Velcro®. Each raised portion 440 preferably is not co-linear with the fabric exterior layer 300, as can be seen in the relevant figures.

[0035] FIGS. 12 and 13 show the seal liner 100 without recessed portions 450 in the elastomeric layer 400. The raised portions 440 protrude from the elastomeric layer 400 without recessed portions 450 located between, among, or near the raised portions 440. This embodiment of the seal liner 100 is useful because of its ease of manufacturing and slimmer profile. Only the reinforcement layer 200 and fabric exterior layer 300 have recessed portions 450 which correspond to the recesses 450 between each raised portion 440.

[0036] FIG. 14 shows an additional embodiment of the seal liner 100 which includes having elastomeric material impregnated within the fabric exterior 300 along the entire length of the sealing region 430. The elastomeric material penetrates at least partially within the fabric exterior 300 and, preferably, is completely impregnated within the fabric exterior 300.

[0037] Furthermore, having the elastomeric material impregnated within the fabric exterior 300 allows the resulting composite to have more durable properties as compared to having the elastomeric material attached as its own layer apart from the fabric exterior 300 (FIGS. 2-13). That is, the fabric exterior 300 in conjunction with the impregnated elastomeric material has similar characteristics as having reinforcing bars (“rebar”) positioned within concrete structures.

[0038] FIG. 15 shows the uses of having an apex surface 470 of the raised portions 440. The elastomeric material is fully impregnated within the fabric exterior 300 only on the apex surface 470 of the raised portions 440, as opposed to FIG. 14, which shows the elastomeric material impregnated into the fabric exterior 300 along the entire length of the sealing region 430.

[0039] Furthermore, the apex surface 470 is just that, the highest or furthest point from the recessed portion 450. In the case of the embodiment shown in FIG. 7, for example, the apex surface 470 would be relatively at the “tip” of the triangular-like raised portion 440 and extend down towards the recessed portion 450. In FIG. 8, the apex surface 470 would be the end of the finger-like projection. The apex surface 470 may also be viewed as the surface area of the raised portion 440 that comes into contact with the socket wall.

[0040] Preparing the embodiment shown in FIGS. 14 and 15 involves four steps. First, a tube having an inflatable bladder is inserted into the seal liner 100. The inflatable bladder is positioned to be near the sealing region 430. Vinyl tape is then used to wrap the areas of the raised portions 440 to prevent any unwanted silicone from bonding to any other area apart from the apex surface 470 of the raised portions 440. The borders created from the applied vinyl tape will define the edges of the seal area. Compressed air is then used to inflate the bladder, which will stretch the fabric exterior 300 to allow the silicone to penetrate the fabric exterior 300. The tube is then placed on a rotating arm which will rotate the seal liner 100 to allow uniform coating of the apex surface 470 of the raised portions 440, while preventing the silicone from dripping by using the principle of centrifugal force.

[0041] Second, a calibrated scale and clean mixing container are used to prepare and mix the required silicone to be applied to the apex surface 470 of the raised portions 440. Although in this method, silicone is used as the sealing material, any equivalent material may be used.

[0042] Third, the seal liner 100 is rotated while a brush or other applier is used to apply the prepared silicone to the apex surface 470 of the raised portions 440. The applied silicone is uniform and only introduced to the areas within the sealing region 430 that do not have the vinyl tape applied. No bubbles are be present within the applied silicone. The bladder is then deflated and vinyl tape removed.

[0043] Fourth, the seal liner 100 is slowly rotated on the rotating arm while an infrared heat lamp is applied approximately 1 inch from the surface of the silicone. The seal liner 100 is left to cure for approximately 10 to 20 minutes or until the silicone is no longer tacky to the touch. If the silicone coating is still liquid or soft, the seal liner 100 is left rotating to cure longer. Once the silicone is cured enough to remain in place without rotating, the seal liner 100 is moved to a clean location to finish curing overnight at room temperature.

[0044] Moreover, the impregnating process of the silicone onto the fabric exterior 300 can be accomplished in a variety of ways, including applying pre-made, semi-cured silicone strips onto the apex surface 470 of the raised portions 440. The process of applying may include painting, spraying, coating, spreading, injecting, forming, or dipping the seal liner 100 into the silicone material without inflating the seal liner 100.

[0045] Many stress and abrasion tests were successfully performed to show that the seal liner 100 would retain a vacuum while in use because of its durable sealing region 430. The seal liner 100 was first subjected to a vacuum test to establish a baseline for the level of vacuum achieved within the seal liner 100 and socket (vacuum achieved 23 inches Hg, vacuum maintained 20 inches Hg, and the duration of test was 24 hours). After the baseline was established, the elastomeric material impregnated within the fabric exterior layer 300 was gradually removed by abrasive forces to monitor the resulting vacuum level. The first sanding step removed a small layer of the elastomeric material impregnated within the fabric exterior 300 at the apex surface 470 of the raised portions 440 (vacuum achieved 22.5 inches Hg, vacuum maintained 20 inches Hg, and the duration of test was 24 hours). There was no noticeable loss of vacuum. The second sanding step removed a much thicker layer of elastomeric material impregnated with the fabric exterior 300 and again, no noticeable loss of vacuum was achieved (vacuum achieved 18.5 inches Hg, vacuum maintained 17.5 inches Hg, and the duration of test was 24 hours). The sanding steps continued until progressively, each raised portion 440 had a significant loss of impregnated elastomeric material within the fabric exterior 300 (vacuum achieved 23 inches Hg, vacuum maintained 20 inches Hg, and the duration of test was 24 hours). No noticeable loss of vacuum was achieved. Over the course of the many trials of the sanding steps, the seal liner 100 never lost more than 4.5 inches Hg and on average never lost more than 2 inches Hg.

[0046] When worn by an amputee and inserted into a socket for use with a vacuum system, the volume of air within the socket and below the seal layer is evacuated thereby securing the residual limb within the socket. The present invention thereby preferably reduces any potential for a tourniquet effect created by the vacuum process and provides high abrasion resistance.

[0047] An alternative embodiment is provided for in FIGS. 16-25. Here, as shown in FIGS. 16-17, instead of having the elastomeric seal be integral with the thermoplastic elastomer layer 400 and impregnating the fabric exterior 300, the seal liner 100 will have a sealing element 500, which can be made of either silicone or an elastomeric compound such as urethane, which is non-unitary with either the fabric exterior 300 or a cushioning layer 900, which can be made of either silicone or a thermoplastic elastomer such as SEEPS. This sealing element 500 is preferably made from either silicone or some other thermoplastic elastomer and is bonded to the fabric exterior 300 of the seal liner 100 thereby forming a bond layer 510. Preferably the bond of the bond layer 510 is a glue. The sealing element 500 further comprises an engaging member 520 which extends radially outwardly from the sealing element base 530. The engaging member 520 can be substantially straight, as shown in FIG. 17-1, or may be arcuate, as seen in FIG. 23. A benefit of this embodiment is that it allows for the thermoplastic elastomer layer 400 to be made from a material that is different from the sealing element 500. For example, the sealing element 500 can be made of silicone while the cushioning layer 900 could be made from a SEEPS gel or vice versa.

[0048] As shown in FIG. 18, the seal liner 100 may have one sealing element 500 but may have up to two additional sealing elements 600, 700 which may be bonded in any position on the seal liner 100 but is preferably located near the closed distal end 140 in order to provide the greatest level of support to the user. Alternatively, as shown in FIGS. 19-21, the sealing element 500 may be placed in different locations on the seal liner 100; at the closed distal end 140 as seen in FIG. 19, about a third of the distance from the closed distal end 140 as seen in FIG. 20, and at a mid-point 650 of the seal liner 100 as seen in FIG. 21. As shown in FIGS. 22 and 23, the sealing element 500 is initially separate from the seal liner 100 and glue is applied only to the interior surface 540 of the sealing element 500.

[0049] In yet another embodiment, as shown in FIGS. 24 and 25, the sealing element 500 can be used on liners incorporating a distal lock 800 at the closed distal end 140. Such a distal locking system has been previously disclosed in commonly-owned U.S. Pat. No. 11,224,527 to Laghi. The benefit to this arrangement is further support for the user while a prosthesis is in use. As in the previous embodiments, the sealing element 500 is glued to the fabric exterior 300.

[0050] The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.

[0051] Now that the invention has been described,