Methods of Fabricating Skeletal Stabilization Liner System

Abstract

Methods of fabricating a liner for reducing motion between a socket and a skeletal structure in a body part are described. Methods include selecting a plurality of compression areas, lying the compression areas along the longitudinal axis of the liner, and spacing the compression areas circumferentially around the liner. The durometer, radial thickness, width, and longitudinal dimension of the compression areas are selected to compress soft tissue of the body part against the skeletal structure to reduce motion of the skeletal structure towards a wall of the socket. Methods also include selecting a plurality of attachment areas on the liner and affixing a plurality of attachment area materials to the plurality of attachment areas. The durometer, radial thickness, width, and longitudinal dimension of the attachment area materials are selected to compress soft tissue of the body part and reduce motion of the skeletal structure towards a wall of the socket.

Claims

1. A method of fabricating a liner for reducing motion between an interface and a skeletal structure in a body part, the method comprising: selecting a plurality of compression areas each having a durometer, a radial thickness, a width, and a longitudinal dimension; lying the longitudinal dimension of each compression area along a longitudinal dimension of the liner, wherein the longitudinal dimension of the liner extends from a distal end to a proximal end of the liner; spacing each compression area circumferentially around the liner; and selecting the durometer, radial thickness, width, and longitudinal dimension of the plurality of compression areas to compress soft tissue of the body part against the skeletal structure when the interface and liner are worn on the body part such that motion of the skeletal structure towards a wall of the interface is reduced.

2. The method of claim 1, wherein each compression area comprises a gel.

3. The method of claim 2, wherein the gel is selected from the group consisting of a shear-thinning gel, a shear-thickening gel, a magneto rheological gel, an electrorheological gel, and a thermoresponsive gel.

4. The method of claim 1, wherein each compression area extends at least approximately 10% the longitudinal dimension of the liner.

5. The method of claim 1, wherein the plurality of compression areas have an increased thickness relative to the spaces between the compression areas.

6. The method of claim 1, wherein a maximum radial thickness of each compression area is at least 0.4 mm greater than a minimum radial thickness of the areas between the compression areas.

7. The method of claim 1, wherein the proximal end and distal end of the liner are both open ends.

8. The method of claim 1, wherein at least one area between the plurality of compression areas is an open or low-compression area.

9. The method of claim 1, further comprising the step of integrating or attaching one or more sensors with one or more compression areas.

10. The method of claim 9, further comprising the step of sending data from the one or more sensors to a device.

11. The method of claim 10, wherein the data includes a localized pressure.

12. The method of claim 1, further comprising the step of adjusting a volume or durometer of at least one compression area.

13. A method of fabricating a liner for reducing motion between an interface and a skeletal structure in a body part, the method comprising: selecting a plurality of attachment areas each having a durometer, a radial thickness, a width, and a longitudinal dimension; lying the longitudinal dimension of each attachment area along a longitudinal dimension of the liner, wherein the longitudinal dimension of the liner extends from a distal end to a proximal end of the liner; spacing each attachment area circumferentially around the liner; selecting an attachment area material for each of the plurality of attachment areas, wherein each attachment area material has a durometer, a radial thickness, a width, and a longitudinal dimension; affixing the attachment area materials to the plurality of attachment areas, respectively, such that the longitudinal dimension of each attachment area material aligns with the longitudinal dimension of the liner; selecting the durometer, radial thickness, width, and longitudinal dimension of each attachment area material to compress soft tissue of the body part against the skeletal structure when the interface and liner are worn on the body part such that motion of the skeletal structure towards a wall of the interface is reduced.

14. The method of claim 13, wherein at least one of the attachment areas is in a discontinuous configuration.

15. The method of claim 13, wherein at least one of the attachment areas comprises a pocket.

16. The method of claim 15, wherein the step of affixing the attachment area materials to the plurality of attachment areas comprises enclosing the attachment area material inside the pocket.

17. The method of claim 15, wherein the step of affixing the attachment area materials to the plurality of attachment areas comprises inserting a shim into the pocket.

18. The method of claim 13, wherein the step of affixing the attachment area materials to the plurality of attachment areas comprises embedding a material in the attachment areas to increase the thickness of the attachment areas.

19. The method of claim 13, wherein the plurality of attachment areas have an increased thickness relative to the spaces between the attachment areas.

20. The method of claim 13, wherein the step of selecting the radial thickness, width, and longitudinal dimension of the attachment area materials comprises selecting the attachment area materials from a plurality of component parts.

21. The method of claim 13, wherein each of the attachment area materials has a durometer adapted to permit a user to don and doff the liner while the attachment area materials are attached to the attachment areas.

22. The method of claim 13, further comprising the step of applying an alignment indicator to the liner in such a way that a user can align the alignment indicator to an anterior midline of the body part.

23. The method of claim 22, wherein the alignment indicator represents zero degrees, and the plurality of attachment areas comprise four attachment areas circumferentially located approximately at 45, 135, 225, and 315 degrees relative to the alignment indicator.

24. The method of claim 13, wherein the liner is integrally formed with the attachment area materials.

25. The method of claim 13, wherein the attachment area or attachment area materials have a raised texture such that friction is increased against the socket wall to resist or prevent slippage of the liner with respect to the socket wall.

26. The method of claim 13, further comprising the step of donning the liner and affixing the attachment area materials to the attachment areas after the liner is donned.

27. The method of claim 13, wherein at least one of the plurality of attachment areas comprises a hook or loop fastener material.

28. The method of claim 13, wherein the attachment area materials are selected from a plurality of attachment area materials having different durometers.

29. The method of claim 13, wherein the proximal end and distal end of the liner are both open ends.

30. The method of claim 13, wherein at least one area between the plurality of attachment areas is an open or low-compression area.

31. A method of fabricating a socket for a limb using a liner having a plurality of compression areas, the method comprising: donning the liner on the limb such that the plurality of compression areas compress soft tissue of the limb at target areas, wherein the target areas (i) are longitudinally-shaped, (ii) have a longitudinal axis that is substantially parallel to a longitudinal axis of a skeletal structure within the limb, and (iii) are disposed circumferentially around the longitudinal axis of the skeletal structure; and casting or scanning the limb while the liner is donned on the limb and the limb is in a compressed state.

32. The method of claim 31, wherein the plurality of compression areas are spaced circumferentially around the limb and at least one area between the plurality of compression areas is an open or low-compression area.

33. The method of claim 31, further comprising the step of creating a virtual model of the limb in the compressed state.

34. The method of claim 31, wherein the compressed state of the limb determines an internal volume of the socket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 depicts an SSLS embodiment looking up from its bottom end, at the distal end of the SSLS.

[0036] FIG. 2 depicts a cross-sectional view of another embodiment of the SSLS, where the liner has affixed to its external surface four longitudinally oriented, external pockets.

[0037] FIG. 3 depicts an inventory or kit of shims for an embodiment of the SSLS from which the clinician or wearer may select a shim or shims.

[0038] FIG. 4 depicts an embodiment of the SSLS in a traditional closed-ended design.

[0039] FIG. 5 depicts an SSLS embodiment with a shim attached to one of the attachment areas.

[0040] FIG. 6 depicts the SSLS embodiment inserted into a compression stabilized socket, which is cut-away to show the SSLS, including a shim mounted to the attachment area.

[0041] FIG. 7 depicts a top view of an SSLS embodiment showing the open top.

[0042] FIG. 8 depicts an embodiment of the SSLS showing generally longitudinally oriented attachment areas whose vertical placement varies to align with respective target areas of a wearer once the SSLS is donned.

[0043] FIG. 9 depicts an embodiment of a shim where a face of the shim is covered with hook or loop fastener material to correspond with the hook or loop fastener material used for an attachment area.

[0044] FIG. 10 depicts an SSLS embodiment inserted inside an open-cage compression stabilized socket so that the attachment area affixed to the liner is aligned with one of the compression struts and a shim is attached to the attachment area.

[0045] FIG. 11 depicts a cross-sectional view of an embodiment where gel is embedded directly into the liner at the attachment areas to provide the increased radial thickness desired for bone control.

DETAILED DESCRIPTION OF THE INVENTION

[0046] FIG. 1 depicts an SSLS embodiment looking up from its bottom end 13, at the distal end of the SSLS. The liner 11 in this embodiment includes four longitudinally oriented attachment areas 10 made of hook and loop strips that are affixed to the external surface of the liner in areas associated with target areas of the residual limb.

[0047] FIG. 2 is a cross-sectional view of another embodiment of the SSLS, where the liner 11 has affixed to its external surface four longitudinally oriented, external pockets 21, also in areas associated with target areas of the residual limb. The SSLS in FIG. 2 is also shown inserted in a socket 22.

[0048] In the embodiments shown in FIG. 1 and FIG. 2, the centerlines of the attachment areas 10 are placed circumferentially and approximately equally spaced apart at 90 degree increments from one another. In one application of this embodiment shown in FIG. 4, the clinician or user aligns the longitudinal midline of the anterior surface of the residual limb with a reference line 43 that represents 0 degrees, and the SSLS is donned by the wearer so that the centerlines of the attachment areas are at approximately 45, 135, 225, and 315 degrees relative to the reference line once the SSLS is on the residual limb and the reference line is aligned with the midline of the anterior surface of the residual limb. It is to be appreciated that the liner can have alignment indicators other than a reference line that are also suitable for assisting the clinician or user in aligning the liner attachment areas so that the attachment areas are at approximately 45, 135, 225, and 315 degrees relative to the longitudinal midline of the anterior surface of the residual limb.

[0049] In FIG. 1, the attachment areas have a narrowest width of approximately 5.9% of the limb circumference, but a narrowest width of at least approximately 4.7% of the limb circumference may be selected, or narrower widths may be selected in particular applications. In FIG. 1, the attachment areas have a broadest width of approximately 8.5% of the liner circumference, but the attachment areas may have a broadest width adapted to permit a plurality of relief areas 15 between each attachment area for displacement of tissue of the residual limb. The plurality of relief areas 15 are also shown in FIG. 2.

[0050] Each attachment area is configured so that it can receive or couple with a shim 12, as shown in FIG. 1 and FIG. 2. FIG. 3 depicts an inventory or kit of shims 31 from which the clinician or wearer may select a shim. The shims in this inventory or kit vary in length, width, and thickness, but the inventory may also include shims of different curvatures, or shape. The shim embodiments depicted in FIG. 3 are 1.6 and 2.4 mm thick (thickness not shown), but shims of approximately 0.8 mm or larger would be suitable, depending on the fit of the socket.

[0051] Once attached to an attachment area, each shim adds an additional thickness to the attachment area of the liner in order to increase the compression normally provided by the socket and SSLS (without shims) to a level that minimizes motion of the underlying bone. In the embodiment shown in FIG. 3, the shims are manufactured so that portions easily snap-off at the curved lines 32 to allow the clinician to modify a shim length to match a wearer's target area. In other embodiments (not shown), different snap-off features allow the clinician to easily modify the shim width, again to match the wearer's target area. In still other embodiment (not shown), the shims can be thermo-formed to add desired curvature

[0052] The shim embodiments shown in FIG. 3 are made of plastic, but other suitable material may be used. A thermo-formed shim embodiment (not shown) is made of carbon composite, but other suitable material may be used. Yet another embodiment of the shim is made of a sealed gel packet (not shown), where the gel is made of a silicone material, but urethane or other suitable material may be used. It is to be appreciated that such gel material could also be enclosed directly into a pocket of a SSLS embodiment and the pocket sealed, so that that the attachment area is comprised of such gel material. In SSLS embodiments where the shim or gel is of sufficiently low durometer, the SSLS can be donned or doffed while the shim, gel, or gel packet remains in the pocket or otherwise attached to the liner.

[0053] FIG. 11 depicts another liner embodiment where gel 16 is embedded directly into the liner 11 at the attachment areas to provide the increased radial thickness desired for bone control.

[0054] Where an SSLS will be used with a socket that has not yet been fabricated, an embodiment of the SSLS can be used during the casting process with or without the shims in order to set the appropriate internal volume of the prosthetic socket when the socket is fabricated. Similarly, the appropriate internal volume of the prosthetic socket can be set using an embodiment of the SSLS during a scanning process, again with or without the shims.

[0055] FIG. 4 depicts an embodiment of the SSLS in a traditional closed-ended design, but other embodiments can be in an open-end sleeve configuration. FIG. 5 depicts an SSLS embodiment similar to that in FIG. 4, but showing a shim 12 attached to one of the attachment areas 10. FIG. 6 depicts the SSLS inserted into a compression stabilized socket 61, which is cut-away to show the SSLS, including a shim 12 mounted to the attachment area.

[0056] The embodiment of the SSLS depicted in FIG. 4 has a rigid bottom 13, but non-rigid materials may also be used, or the bottom may be a continuation, for example, of the liner 42 material and attached at the distal end to form a sock-like configuration. The embodiment in FIG. 4 is constructed of elastomeric material, but other suitable materials could be used.

[0057] In the SSLS embodiment depicted in FIG. 4, the liner is open at the top 14 or proximal end to receive the residual limb. FIG. 7 depicts a top view of this embodiment showing the open top 14.

[0058] FIG. 8 depicts an embodiment of the SSLS with a first attachment area 81, a second attachment area 82, and third attachment area 83, each approximately 90 degrees apart. These attachment areas are generally longitudinally oriented, but their vertical placement varies so that they are aligned with respective target areas of a wearer once the SSLS is donned. For instance, the first attachment area 81 is shorter and extends more distally than the second attachment area 82.

[0059] In the embodiment depicted in FIG. 8, the shortest length of the attachment area is approximately 35% of the liner length, however, a shorter attachment area, such as 10% of the liner length, or even shorter, can be selected in particular applications, where the liner length means the finished length of the liner as worn by a wearer and as generally depicted in the drawings of this application. It is to be appreciated that liner embodiments using very short attachment areas coupled with shims with longer lengths, such as shim lengths that are 10% or more of the liner length, would be within the spirit and scope of the invention since in such embodiments it is the overall length of the shim that primarily defines the length of the compression area.

[0060] In the pocket embodiment depicted in FIG. 2, the pocket 21 material that is affixed to the liner 11 may be made of elastomeric material, fabric, silicone, or other suitable material. In this embodiment, the pocket opening for inserting the shim 12 is located on the proximal end of the pocket, but the pocket opening can be in any location such that the shim can be inserted and removed from the pocket.

[0061] In a variation of the embodiment depicted in FIG. 2, the pocket 21 material surrounds and adheres to the liner 11 to form a second liner layer (not shown) and additional pocket material attaches to the second liner layer to form one or more pockets for one or more shims 12.

[0062] FIG. 9 depicts an embodiment of the shim 12 where a face of the shim is covered with hook or loop fastener material 91 to correspond with the hook or loop fastener material used for an attachment area 10 (shown, for example, on FIG. 1 and FIG. 4), so that the shim may be attached to an attachment area.

[0063] In the embodiments depicted in FIG. 1 and FIG. 2, the thickness of the hook and loop attachment area 10 material and the pocket 21 material increases the attachment area thickness so that the pocket or the attachment material provides some of the desired compression to the wearer even when no shim is inserted or attached. For example, in the embodiment shown in FIG. 1, the loop strip is approximately 0.4 mm thick. In another embodiment (not shown), the underlying liner 11 material may be fabricated or modified to be thicker in the attachment area to provide the desired compression to the wearer even when no shim is inserted or attached.

[0064] In the embodiment shown in FIG. 4, the thickness of the SSLS liner is increased in the attachment area by bonding an additional liner material layer 41 on top of the primary liner 42 material that surrounds the residual limb after donning. The additional liner material layer can be of variable thickness to provide for tapering at the edges of this additional liner material.

[0065] In other embodiments (not shown), one or more sensors can be integrated into or attached to one or more shims 12 and be in wireless communication with a smartphone or other computer device to provide socket 22 and SSLS fit information, such as localized pressure, during all phases of the wearer's use of the socket. Similarly, in other embodiments (not shown), one or more sensors can be attached to or integrated into one or more attachment areas 10 of the SSLS.

[0066] FIG. 10 depicts the SSLS inserted inside an open-cage compression stabilized socket. In this embodiment, the attachment area 10 is aligned with one of the compression struts 101, so that a shim 12 can be attached to the attachment area affixed to the liner 11, resulting in increased compression on the residual limb as compared to if no shim were attached.

[0067] Liner Fabrication and Shim Use

[0068] An exemplary method for fabricating the liner for the SSLS comprises selecting at least three attachment areas on a liner lying along a longitudinal dimension of the liner, wherein the longitudinal dimension runs from the distal end to the proximal end of the liner, wherein each attachment area has a centerline, wherein the selecting at least three attachment areas further comprises: substantially aligning each centerline parallel to the longitudinal dimension; spacing each attachment area centerline circumferentially and approximately equally around the liner; selecting a circumferential width of each attachment area in such a way as to permit a plurality of relief areas between each attachment area, wherein the liner has a minimum radial thickness; selecting a length of each attachment area, wherein each attachment area is adapted to extend at least approximately 10% the longitudinal dimension; a) selecting a first attachment area material; b) dimensioning the first attachment area material to overlay a first attachment area; and c) affixing the first attachment material to the liner in such a way as to overlay the first attachment area to form a first enhanced compression area; repeating steps a)-c) with additional attachment area materials and the remainder of the attachment areas to form a plurality of enhanced compression areas, wherein the plurality of enhanced compression areas includes the first enhanced compression area, wherein a maximum radial thickness of each of the plurality of enhanced compression areas is at least 0.4 mm greater than the minimum radial thickness.

[0069] It is to be appreciated that the step of spacing each attachment area centerline circumferentially and approximately equally around the liner may be adjusted by a fabricator to accommodate the particular anatomy of a wearer or asymmetrical limb loads expected during use, such as higher anterior and lateral loads that a particular fabricator may anticipate for humeral applications.

[0070] In a variation of this method, the first attachment area material and the additional attachment area materials comprise sealed pocket material, further comprises selecting a thickness of the first attachment area material and the additional attachment area materials in such a way as to prevent substantial movement of a skeletal structure within the limb when the liner is worn with a socket.

[0071] Besides using the exemplary method for fabricating the liner, the liner can also be integrally formed by a variety of molding processes, including casting, injection molding, extrusion molding, thermoforming, and rotational molding,

[0072] It is to be appreciated that one skilled in the art can embed additional liquid or solid materials or gels into the liner at attachment areas in accordance with the invention using methods known in the art to cause the thickness of the attachment areas to be sufficiently greater relative to the thickness of the liner outside the attachment areas, so that the liner provides the desired bone control.

[0073] Additional steps for adding shims to the liner of the SSLS comprise: a) selecting an enhanced compression area from the plurality of enhanced compression areas; b) selecting a shim to attach to the enhanced compression area, wherein the shim is selected from an inventory of shims of at least one varying dimension selected from the group consisting of length, width, radial thickness, and curvature; c) attaching the shim to the enhanced compression area, d) repeating steps a)-c) with additional shims and the remainder of the plurality of enhanced compression areas as necessary to prevent substantial movement of the skeletal structure within the limb when the liner is worn with a socket.

[0074] In a variation of this method for adding shims, the step of attaching a shim to the enhanced compression area comprises attaching two or more shims to the enhanced compression area.

[0075] A variation of the exemplary method for fabricating the liner comprises selecting the liner from a kit of component parts comprising a variety of liner shapes and configurations.

[0076] In a variation of the method for adding shims to the liner, the shim and the additional shims have a maximum durometer adapted to permit a user to don and doff the liner while the shims are attached to the liner.

[0077] A variation of the exemplary method for fabricating the liner comprises: applying an alignment indicator to the liner in such a way that the user can align the alignment indicator when worn to an anterior longitudinal midline of the limb, wherein the alignment indicator represents zero degrees, wherein the plurality of enhanced compression areas number four and are circumferentially located at 45, 135, 225, and 315 degrees relative to the alignment indicator.

[0078] A second method for attaching shims to a liner such as the liner fabricated according to the exemplary method described above comprises: selecting a first shim; selecting a second shim, wherein the first shim has a first thickness, wherein the second shim has a second thickness; attaching the first shim to a first attachment area chosen from the at least three attachment areas; attaching the second shim to a second attachment area chosen from the at least three attachment areas; and repeating the above steps with additional shims and the remainder of the attachment areas as necessary to prevent substantial movement of a skeletal structure within the limb when the liner is worn with the socket, wherein the first thickness, the second thickness, and the thickness of additional shims are selected in such a way as to prevent substantial movement of the skeletal structure within the limb when the liner is worn with the socket.

[0079] If the shim durometers allow it, the user may attach the shims before donning a socket or after donning a socket.

[0080] It will be apparent to those skilled in the art that changes and modifications may be made in the embodiments illustrated and described, without departing from the spirit and the scope of the invention. Thus, the invention is not to be limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claim.