Knit Prosthetic Liner Textile With Differentiated Knit Fabric Exterior Incorporating Low-Extensibility Strips

Abstract

A prosthetic liner having a lower longitudinal stretch in the distal region than in either the proximal or optional intermediate region. The distal region may stretch anywhere from 0-30% vertically and 10-200% horizontally as compared to the proximal region's vertical stretch of 55-125% and 100-175% horizontally. The stretch of the liner at various pressure sensitive regions of a residual limb can also be lowered or heightened depending on the area. A variety of stitches may be used at the distal end to implement this lowered longitudinal stretch. Preferably, the liner is made of a stretchable material. The liner also has an interior layer of elastomer gel. The design of this prosthetic liner is primarily to prevent the “pistoning” of the amputee's residual limb within the liner and for comfort over pressure-sensitive areas of the residual limb. The liner also includes the use of a low extensibility material which is adhered to the fabric portion of a prosthetic liner or orthotic liner either internally or externally and limits the longitudinal movement while allowing for transversal movement. The customizable nature of the invention allows for shaping and personalization depending on the needs of the user.

Claims

1. A prosthetic liner comprising: a fabric covering having an open proximal end and a closed distal end knit into a tubular shape, the fabric covering further comprising a proximal region and a distal region wherein the distal region is stitched such that it has a distal longitudinal elongation of 0 to 30% from a resting position and wherein the proximal region has a proximal longitudinal elongation of 55-125% from a resting position; wherein the distal region is stitched using a distal stitching selected from the group consisting of weft, warp, stockinette, garter, seam, fagoting, tricot, elongated, plated, slip, dip, or basket stitches; a locking mechanism region below the distal region, wherein the locking mechanism region houses a locking mechanism; an styrene-based elastomeric gel layer residing on an interior surface of the fabric covering; and, a single-piece low-extensibility material comprising polyester forming a composite with the styrene-based elastomeric gel layer and the fabric covering extending up from the closed distal end between 4 and 12 inches and having a width between 0.5 and 4 inches.

2. The prosthetic liner of claim 1 wherein the single-piece low extensibility material further comprises urethane facing the fabric covering.

3. The prosthetic liner of claim 1 wherein the distal region has a distal horizontal stretch of 10-200% from a resting position.

4. The prosthetic liner of claim 1 wherein the proximal region has a proximal horizontal stretch of 100-175% from a resting position.

5. The prosthetic liner of claim 1 further comprising an intermediate region having an intermediate longitudinal elongation of 15-40% and a horizontal elongation of 80-120%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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:

[0030] FIG. 1 is a cross-sectional view of the present invention for use with a locking prosthetic assembly comprising two different types of stitches showing the different relevant regions;

[0031] FIG. 2 is a cross-sectional view of the present invention showing below-the-knee amputation pressure sensitive areas;

[0032] FIG. 3 is a cross-sectional view of the present invention showing below-the-knee-amputation pressure tolerant areas;

[0033] FIG. 4 is a cross-sectional view of the present invention showing above-the-knee amputation pressure sensitive areas;

[0034] FIG. 5 is a cross sectional view of the present invention showing above-the-knee amputation pressure tolerant areas;

[0035] FIGS. 6A-6N are various stitching types that can be used in the distal region of the present invention to prevent pistoning;

[0036] FIG. 7 is a cross-sectional view of a liner incorporating the low extensibility material internally;

[0037] FIG. 8 is a top view of the low extensibility material in one preferred shape;

[0038] FIG. 9 is a top view of the low extensibility material in a second preferred shape;

[0039] FIG. 10 is a top view of the low extensibility material in a third preferred shape and configuration;

[0040] FIG. 11 is a top view of the low extensibility material in a second preferred configuration;

[0041] FIG. 12 is a cross-sectional view of a liner with an alternative arrangement of low extensibility material placed either internally or externally;

[0042] FIG. 13 is a cross-sectional view with an alternative arrangement of low extensibility material placed either internally or externally;

[0043] FIG. 14 is a perspective view of a wrist orthotic with the low extensibility material adhered externally;

[0044] FIG. 15 is a perspective view of a back orthotic with the low extensibility material adhered externally;

[0045] FIG. 16A is a perspective view of an ankle orthotic with the low extensibility material adhered externally;

[0046] FIG. 16B is a cross-sectional view of the ankle orthotic shown in FIG. 16A;

[0047] FIG. 17 is a perspective view of a knee orthotic with the low extensibility material adhered externally; and

[0048] FIG. 18 is a perspective view of an elbow orthotic with the low extensibility material adhered externally.

[0049] Similar reference numerals refer to similar parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0050] 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.

[0051] The present invention relates to a liner 100 for use with prosthetic devices. As shown in FIG. 1, the liner 100 for use with a prosthetic assembly comprises a plurality of types of stitching. The liner 100 comprises a distal region 50, proximal region 60, and an optional intermediate region 70. In one embodiment, the distal region 50 that comprises the distal end 80 of the liner is constructed with a reduced vertical stretch when compared to the upper region 60 of the liner. Preferably, the distal region 80 has a vertical stretch of 0-30% from a resting position and a horizontal stretch of 10-200% from a resting position as compared to the proximal region 60, which preferably has a vertical stretch of 55-125% from a resting position and a horizontal stretch of 100-175% from a resting position. As used herein, “stretch” and “elongation” are considered synonymous. Furthermore, “resting position” as used herein means that the liner has not been donned by a patient yet.

[0052] Optionally, the intermediate region 70 may have a vertical stretch of 15-40% and a horizontal stretch of 80-120% or it may have the same stretch characteristics of the proximal region 60. The reduced stretch of the distal region 50 is achieved on a flatbed knitting machine by use of a variety of different stitches as described below. In a preferred embodiment, the liner 100 is knit in a single piece construction with the proximal end 90 being open and the distal end 80 being closed. Alternatively, the two halves may be independently constructed and then sewn or attached together by another means to form the completed liner textile.

[0053] Preferably, the liner 100 is knit using computerized flatbed knitting machines that allow the use of several different yarns at the same time or sequentially in the same garment, including elastomeric fibers such as Lycra, latex, and silicone among others. These machines also allow the use of different stitch types in different areas of the same garment and controls the tension of each yarn being knitted. Further, an interior gel layer 10 resides on a limb face 22 of exterior fabric layer 30. The gel layer 10 may be any form of stretchable elastomer as known in the industry or later developed but is preferably a styrene-based polymer.

[0054] In another embodiment, the liner 100 comprises regions of differing horizontal and vertical stretch stitching depending on anatomical features related to the residual limb or mechanical features related to the prosthetic socket. This means that the boundary 110 between the distal region 50 and the proximal region 60 (or intermediate region 70 if present) may shift location. The boundary 110 is preferably generally perpendicular to the central axis 120 of the liner 100. Additionally, the distal end 70 may house a locking mechanism 130. The use of a locking mechanism 130 requires a construction that is strong enough for the distal attachment plate 140 to be retained by the fabric or else a catastrophic failure of the prosthesis may result. Typically, such locking mechanisms 130 are secured to the fabric through the use of a grommet that bites into the fabric or other similar means of attachment. In order for the fabric to withstand the localized stress imparted by the grommet, the construction of the knit at the distal end must be heavier and stronger than the rest of the fabric cover. Such construction cannot be used in the intermediate region 70 or proximal region 60 because it would impart poor functionality to the liner and limit the user's movement.

[0055] More specifically, the fabric in the locking mechanism region 150 must have little to no longitudinal elongation but high circumferential elongation in order to comfortably accommodate the residual limb. The locking mechanism region 150 is limited to the area juxtaposed to the locking mechanism 130. The thickness of the fabric in the locking mechanism region 150 should greater than the thickness of the fabric in the distal region 50. The distal region 50, as compared to the locking mechanism region 150, must have a greater degree of longitudinal elongation in order to facilitate knee flexion. The intermediate region 70 may have an even greater degree of longitudinal elongation and circumferential elongation than the distal region 50 to provide greater comfort to the amputee when sitting or moving.

[0056] In another embodiment, the liner textile comprises regions of differing horizontal and vertical stretch depending on anatomical features related to the residual limb or mechanical features related to the prosthetic socket. There are various areas of the lower limbs that are more pressure sensitive, requiring more elongation, and various areas that are more pressure tolerant, which require less elongation. As shown in FIG. 2, the pressure sensitive areas for below-the-knee amputations comprise the portions of the tibia 160 such as the anterior tibia 170 and the anterior tibial crest 180 as well as parts of the fibula 190 such as the fibular head and neck 200, and the fibular nerve 210. These regions of the body exhibit sensitivity to pressure and therefore require a liner having greater longitudinal or circumferential elongation at those points. On the other hand, as shown in FIG. 3, the pressure-tolerant areas for below-the-knee amputations comprise the patellar tendon 220, the medial tibia plateau 230, the tibial shaft 240, the fibular shaft 250, and the distal end 260 of tibia 160 and fibula 190. These regions may have more restricted longitudinal or circumferential elongation due to the tolerance these regions exhibit.

[0057] Similarly, as shown in FIGS. 4 and 5, above-the-knee amputations have similarly pressure sensitive and pressure tolerant areas. The pressure sensitive areas comprise the distolateral end 280 of the femur 270, the pubic symphysis 300 of the pelvic bone 290, and the perineal area 310. The pressure tolerant areas comprise the ischial tuberosity 320 of the pelvic bone 290, the gluteals 330, the lateral sides 340 of the residual limb, and the distal end 350 of the femur 270. As with below-the-knee, pressure sensitive areas of above-the-knee amputations require greater longitudinal or circumferential elongation at those points while the pressure tolerant areas may have more restricted longitudinal or circumferential elongation due to the tolerance those regions exhibit.

[0058] The fabric of the liner can be constructed in a number of ways so as to provide the required functionality. The functionality can be altered by using different yarns or deniers, different elastomers, different weights of elastomers, and different stitches, among other ways, to provide the right longitudinal and circumferential elongation along the length of the liner. Typical yarn types include, but are not limited to, polyester, nylon, acrylic, cellulosic, aramid, natural fibers, and metal wires. Typical elastomers include Lycra/polyurethane, natural rubber, nitrile, and silicone. Typical stitch types for reduced elongation, as shown in FIGS. 6A-6N, include weft (FIG. 6A), warp (FIG. 6B), stockinette (FIGS. 6C and 6D), garter (FIG. 6E), seam (FIG. 6F), fagoting (FIG. 6G), tricot (FIGS. 6H and 6I), elongated (FIG. 6J), plated (FIG. 6K), slip (FIG. 6L), dip (FIG. 6M), and basket (FIG. 6N) and are used solely in the distal region 50 of the liner 100 so as to differentiate the elongation found in the proximal region 60.

[0059] The present invention further incorporates a low extensibility material 400 for use with prosthetic or orthotic devices using the knit design described above. As shown in FIG. 7, this low extensibility material 400 can be used with a prosthetic liner 100 having a distal attachment plate 140 at a distal end 80. The low extensibility material 400 for use with a prosthetic or orthotic assembly preferably comprises a strip of material 410 preferably made of non-elastic materials like carbon fiber, thermoplastics, and polyester on an interior face 520 and a urethane backing 530 on an exterior face 540. Alternatively, the interior face 520 can be made of strips of silk, fiberglass cloth, and other non-elastic materials. The prosthetic liner 100 comprises an elastomer layer 10 having a limb face 22 and a fabric face 20 wherein the fabric face 20 of the elastomer layer 10 is adhered to the external fabric 30 of the prosthetic liner 100. The elastomer layer 10 may be silicone, a styrene-based elastomer such as SEEPS, or any other thermoplastic elastomer now known or to be discovered in the art. In relation to the prosthetic liner 100, the low extensibility material 400 can be adhered to the fabric 30 either internally or externally. If internal placement is desired, the low extensibility material 400 is placed between the elastomer layer 10 and the fabric 30 in the desired region and adhered only to the fabric 30 as shown in the exploded view Part B, forming a composite. Preferably, the low extensibility material 400 is placed at the distal end 80 of the prosthetic liner 100 and extends towards the proximal end 90 of the prosthetic liner 100. The low extensibility material 400 preferably extends upward towards the proximal end 90 of the prosthetic liner 100, stopping at least an inch from the proximal end 90, when placed at the distal end 80. The low extensibility material 400 preferably extends from the distal end 80 about 4-12 inches, preferably 5-7 inches, and is 8-24 inches in total length, preferably 10-14 inches, and 0.5-4 inches in width in order to control distal distraction Similarly, the width of the low extensibility material 400 is between 0.5-4 inches such that it can be placed in a variety of locations and positions. For reference, a prosthetic liner 100 is generally about 18 inches in length prior to any modification made by a prosthetist or patient.

[0060] FIGS. 8-13 show the low extensibility material 400 is a variety of configurations. FIG. 8 shows the low extensibility material 400 as a strip of material having a central aperture 420 with a bulged mid-region 430. The locking mechanism 130, as shown in FIG. 7, can be fed through the central aperture 420 if the low extensibility material 400 is adhered externally to the fabric 30. As shown in FIG. 9, the low extensibility material 400 can also be configured to have multiple arms 440 extending radially outward from the central aperture 420. As shown in FIGS. 10 and 11, the central aperture 420 is optional. The low extensibility material 400 can be shaped such that a distal strip end 450 is convex while a proximal strip end 460 is concave. This allows for the low extensibility material 400 to be placed around the distal attachment plate 140 if desired or around the user's joint without impinging on joint movement.

[0061] As seen in FIGS. 12 and 13, the low extensibility material 400 can be placed in a variety of configurations according to the needs of the user. The T-shape and single strip configuration shown are not the only configurations that would be helpful to a user and any configuration determined by a medical professional to be medically helpful can be used.

[0062] Use of low extensibility material 400 as described herein has been tested and conclusively shows that use of the low extensibility material 400 limits the longitudinal stretch of the liner 100 while maintaining transversal stretch. In the first table, transversal stretch was tested:

TABLE-US-00001 Reinforced Not Reinforced before after change % before after change % 1 13 21 8 61.53846 1 13 20.375 7.375 56.73077 2 13 22 9 69.23077 2 13 21.5 8.5 65.38462 3 13 20.125 7.125 54.80769 3 13 22 9 69.23077 Average 61.85897 Average 63.78205

[0063] As seen in the table above, “before” refers to the liner in a static state, meaning no weight was applied, and “after” refers to the liner at failure (i.e. until the strip tore). The number measured is circumference in inches. As can be seen from the test data, the transversal stretch was essentially the same whether the liner was reinforced with the low extensibility material 400 or not.

[0064] A similar test was performed testing the longitudinal stretch:

TABLE-US-00002 Reinforced Not Reinforced before after change % before after change % 1 4.25 4.5 0.25 5.882353 1 4 4.75 0.75 18.75 2 4.25 4.5 0.25 5.882353 2 4.25 4.75 0.5 11.76471 3 4.5 4.75 0.25 5.555556 3 4.25 4.625 0.375 8.823529 Average 5.77342 Average 13.11275

[0065] As can be seen from this test, the longitudinal stretch was reduced by more than half when the low extensibility material 400 was used.

[0066] The low extensibility material 400 can also be used with orthotics which is useful to limit joint flexion both as a therapeutic aid in the case of injuries or as a means of injury prevention. As seen in FIG. 14, the low extensibility material 400 works with a wrist brace 470 and can be adhered externally or internally as described above. Similarly, as shown in FIG. 15, the low extensibility material 400 can be integrated with a back brace orthotic 480. Likewise, the low extensibility material 400 can be used with an ankle orthotic 490, as shown in FIGS. 16A and 16B, where the low extensibility material 400 preferably has a thickness to prevent ankle movement. FIG. 17 depicts the use of the low extensibility material 400 with a knee orthotic 500 and FIG. 18 depicts the use of the low extensibility material 400 on an elbow orthotic 510. In all configurations when in use with an orthotic, the low extensibility material 400 can be in a strip or in a specific shape, as determined by an orthotic physician, and be adhered to the fabric 30 either internally or externally.

[0067] When the low extensibility material 400 is desired to be used internally, the low extensibility material 400 is first adhered to the fabric 30 on the fabric face 20 using conventional means and then the combination is placed in a mold wherein the gel, silicon, or urethane is molded over, creating a composite. Alternatively, exterior use is performed by adhering the low extensibility material 400 onto the outside of the fabric 30 in the desired location.

[0068] 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.

[0069] Now that the invention has been described,