Patent ID: 12193952

The drawing figures are not necessarily drawn to scale, but instead are drawn to provide a better understanding of the components, and are not intended to be limiting in scope, but to provide exemplary illustrations. The figures illustrate exemplary configurations of a prosthetic liner, and in no way limit the structures or configurations of a prosthetic liner according to the present disclosure.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

According to embodiments of the disclosure, the provision of an elastomer, such as a silicone material, having fast-cure properties in cooperation with a textile layer arranged to prevent unwanted bleed-through of uncured elastomeric material advantageously simplify manufacturing processes for prosthetic liners by omitting a pre-coating stage and by facilitating the use of pre-formed textile sleeves or socks. The fast-cure properties of a silicone material are compared to curing properties of a conventional silicone material having slower cross-linking properties, measured in time as a function to reach at least 90% cross-linking of originally uncured silicone material.

Preferably, the textile material has a high-density knit structure, as measured by a kitting machine gauge in an exemplary range of 16 to 26, to prevent unwanted bleed-through in combination with the fast-cure silicone material. The fast-cure silicone material and textile layer in cooperation therewith also allows for the use of pre-formed textile sleeves or socks having numerous advantageous features, regions, and patterns of textile material, as these textile sleeves do not require the numerous pre-coating, cutting, shaping, and stitching steps required by existing textile layers in prosthetic liners.

“Silicone,” as used herein, is used generally to denote a cured silicone or elastomeric material, preferably a silicone that was configured to cure more rapidly than conventional silicone materials, whereas “silicone material,” or “fast-cure silicone material,” as used herein, are used generally to denote an as-yet uncured silicone material.

Discussions on the relationship between knitting machine gauge and yarn count can be found in Chapter 18.16, “Yarn and its selection for knitting,” in Fundamentals and Advances in Knitting Technology, by Sandhan Chandra Roy, 2012; Chapter 9, “Quality control in the knitting process and common knitting faults,” in Advances in Knitting Technology, edited by K. F. Au, 2011; each of which is incorporated by reference.

As shown inFIGS.1A-1C, a prosthetic liner100comprises an inner layer101which may be formed from a polymeric or elastomeric material (in the exemplary form of silicone) and an outer textile layer102adjacent to the inner layer101. The inner layer101is arranged to define an inner cavity and to be adjacent to a user's limb residuum while the textile layer102is arranged to contact a prosthetic socket or other attachment. The prosthetic liner100may define a proximal portion106and a distal portion108distinct from and/or defining a body portion110extending between the proximal portion106and the distal portion108. The distal portion108may define a shape configured for attachment to a corresponding prosthetic socket. The body portion110is arranged to contact a length of a user's limb residuum at least corresponding to a length of the prosthetic socket or attachment.

The inner layer101may be formed directly on the textile layer102from a fast-cure silicone material comprising at least a silicone functional polymer, a catalyst, and a crosslinking agent. The silicone functional polymer may comprise one or more functional polymers arranged to be polymerized or crosslinked by the catalyst and the crosslinking agent to form a solid silicone structure with desired properties, including durometer and tensile force. The silicone functional polymer may comprise vinyl functional silicones comprising functional groups lending desired properties to the silicone liner100, or any arrangement or combination of functional polymers suitable for forming a prosthetic liner.

The fast-cure silicone material may further have a viscosity configured to enable fast-cure of the silicone material without bleed-through, as it has been found that a higher viscosity of the uncured silicone material slows the rate at which the silicone material impregnates the interstices between individual yarns of the textile layer. This facilitates curing of the silicone material before the silicone material penetrates an entirety of a thickness of the textile layer.

To form the inner layer101, the uncured silicone material is added to a mold and disposed against a surface, preferably an inner surface, of the textile layer102, allowing the silicone functional polymer to form a solid inner layer101attached to the textile layer102, by action of the catalyst and crosslinking agent forming polymeric bonds and attachments among the silicone functional polymer. Heat or UV radiation may be added or used to expedite the curing process. In embodiments, a male mold and a corresponding female mold may be provided. The textile layer, sleeve, or sock may be placed on the male mold, and the male mold is then inserted into the female mold. The male and female molds may be configured to correspond to a particular user's limb residuum, thereby producing a prosthetic liner closely corresponding to the user's dimensions and needs. In other embodiments, the male and female molds may correspond to a general or off-the-shelf shape or size.

A distance may be defined between the textile layer on the male mold and the female mold when the male mold and the female mold are engaged, the distance corresponding to a desired thickness of the inner layer101. The uncured silicone material may be introduced to the distance between the male and female molds and then cured therebetween such that the inner layer101assumes a configured corresponding to the distance defined by the molds and cures against a surface of the textile layer. To expedite or control the rate of curing, one or both of the male and female molds may be heated by any suitable heating element or heat source, or may be cooled by any suitable heat-transfer element. The temperature of the molds may be controlled or regulated in any suitable manner so as to control the rate of curing. The described embodiment is merely exemplary, and any suitable means may be used to cure the silicone material against a surface of the textile.

In embodiments of the present disclosure, the fast-cure silicone material may comprise silicone functional polymer, catalyst, and crosslinking agent in sufficient quantities to cure or polymerize the silicone functional polymer into a solid inner layer at an expedited rate and without compromising the qualities of the inner layer, such that bleed-through is prevented. The rate of polymerization is proportional to the quantities of catalyst and crosslinking agent, but excessive quantities of catalyst and crosslinking agent may cause reduced inner layer quality. For instance, excessive quantities of catalyst may adversely affect the stability of the inner layer and may discolor the silicone. Excessive quantities of crosslinking agent may reduce or adversely affect mechanical properties and make the final inner layer too tacky to the touch.

The fast-cure silicone material forming the inner layer101may have predetermined quantities of silicone functional polymer, catalyst, and crosslinking agent to create an expedited curing process without reducing the quality of the inner layer101relative to existing or conventional elastomeric prosthetic liners. The inner layer101may be cured according to other optimized factors, including the heat provided at the mold. In embodiments, the inner layer101may have a durometer gauge OO in a range from about 20 to about 60, and preferably about 30 to about 36, and a tensile force at 100% elongation of about 0.5 N to about 5 N, and preferably about 0.95 N to about 1.81 N.

Existing processes for curing silicone typically have a cure time, as a condition at which the functional polymer of the uncured silicone is 90% crosslinked, ranging from 8-10 minutes for the silicone to cure, and forming an inner layer with a thickness ranging from about 1 mm proximate a proximal end of the liner to about 15 mm proximate a distal end of the liner. The fast-cure silicone material of the disclosure advantageously provides a faster cure time, and hence “fast-cure,” ranging from generally about 1 minute or 60 seconds to about 10 minutes or 600 seconds, preferably about 2 minutes or 120 seconds to about 6 minutes or 360 seconds, and more preferably about 2.5 minutes or 150 seconds to about 3 minutes or 180 seconds; or any combination of low and high of the aforementioned range. Accordingly, a preferred range is 150 to 210 seconds. This shortened or “fast-cure” time allows for the fast-cure silicone material to form an inner layer directly on the textile without bleeding through the textile layer as occurs in existing processes. This allows for the omission of a pre-coating process which aims to prevent bleed-through. This example is at least one manner in which “fast curing” may be characterized and does not limit other manners.

In contradistinction to the fast-cure silicone material of this disclosure, thereby forming the definitive silicone inner layer of the liner according to this disclosure, in U.S. Pat. No. 6,485,776 a cure time of about 6 minutes is required, and such cure time is in combination with the already-formed coating on the innermost layer of the fabric or textile layer. U.S. Patent Application Publication no. 2010/0016993, published Jan. 21, 2010, incorporated herein by reference, describes a cure time for certain silicone components of as much as one hour. Similarly, U.S. Patent Application Publication no. 2004/0137178, published Jul. 15, 2004, incorporated herein by reference, describes a cure time of 50 minutes.

The fast-cure silicone material forming the inner layer101may be further arranged with quantities and selections of silicone functional polymer, catalyst, and/or crosslinking agent to form an inner layer101in combination and cooperation with a textile layer102. The silicone and textile layers101,102form a liner100having an axial percent elongation at25N of about 20 to about 150, preferably about 60 to about 150, and a radial percent elongation at25N of about 10 to about 150, preferably about 70 to about 135. The inner layer101and the textile layer102of the liner100may further be arranged such that the liner100has an axial force at 30% elongation of about 0 N to about 10 N, preferably about 3.5 N to about 6.5 N, and a radial force at 30% elongation of about 2 N to about 8 N, preferably 2.8 N to about 6.5 N. Other properties and other configurations of the prosthetic liner are envisioned.

In embodiments, the fast-cure silicone material is arranged to cooperate with the textile layer102so as to form the inner layer101with none of the silicone functional polymer, catalyst, or crosslinking agent bleeding through an entirety of a thickness of the textile layer102. Advantageously, the inner layer101may attach to a surface, preferably an interior or user-facing surface, of the textile layer102by impregnating interstices defined between certain fibers and individual threads of the textile layer102during the curing and polymerization process, without compromising the qualities of the textile layer102on its outer or socket-facing surface.

In certain embodiments, the fast-cure silicone material may be an addition-cured silicone preparation from Nusil Technology LLC of Carpinteria, California, and may be provided in two parts, “part A” and “part B.” Part A may comprise vinyl functional silicones and the catalyst, while Part B comprises vinyl functional polymer, crosslinking agent, and a cure inhibitor arranged to adjust the cure rate of the system. Curing occurs as a silicon-hydrogen bond (provided in a vinyl functional silicone) is added across the unsaturated carbon-carbon double bound of an olefin (provided in a vinyl functional polymer).

The crosslinking agent may comprise a hydrogen-functional crosslinker, such as a Si—H functional crosslinker or any other suitable crosslinking agent, which may facilitate the solidifying attachment between polymers in the inner layer101. Part A and Part B may be provided in any suitable ratio, including a 1:1 ratio, a 10:1 ratio, or otherwise. The cure inhibitor may operate to adjust the cure rate of the uncured silicone material by influencing a maximal rate of curing, and may be provided in any suitable quantity or proportion.

While silicone is provided as an exemplary species of polymer or elastomer, other species of polymer may be provided to serve as the inner layer101. For example, other elastomeric polymers such as polyisoprene, polybutadiene, polychloroprene, butyl rubber, styrene rubber, nitrile rubber, ethylene propylene rubber, polyacrylic rubber, polyamides, fluoroelastomers and perfluoroelastomers, polyether block amides, ethylene-vinyl acetate, polyolefin elastomers, polyurethanes, copolyesters, copolymers or block copolymers of different polymers, or any other suitable polymeric material may be used.

The fast-cure silicone material that forms the inner layer101is advantageously arranged to cooperate with and attach to a surface of, but not bleed through an entirety of, the textile layer102. In the embodiment ofFIGS.1A-1C, the textile layer102is a textile sleeve, pre-formed in the depicted configuration, with the distal portion108, the proximal portion106, and the body portion110. The use of a textile sleeve for the textile layer102is precluded in existing or conventional prosthetic liner manufacturing processes because of the necessity of pre-coating the textile layer of existing liners with a coating or film formed from silicone or other polymeric material that prevents bleed-through of the uncured silicone material, which is not feasible or economical if the textile is already formed into a sleeve or sock with a distal end portion.

The textile layer102is advantageously selected specifically to cooperate with the fast-cure silicone forming the inner layer101. In contrast to the pre-coating, cutting, shaping, and stitching steps of existing processes for manufacturing a prosthetic liner, the textile layer102may be a functional textile sleeve or sock advantageously arranged with sufficient knit structures and materials to prevent bleed-through of the fast-cure silicone material and having discrete regions with structures and functionality appropriate for regions of the limb residuum or prosthetic socket requiring, for example, greater flexibility or alternatively increased stiffness, or any other desired property.

In a preferred embodiment, the textile layer102comprises pique-knitted yarns of a high knitting machine gauge, for example, the yarns are gauge 24. The higher gauge helps to seal in and slow the impregnation of interstices between the yarns by the uncured silicone material, preventing bleed-through. The body portion110of the textile layer102may comprise tencel yarn, while a distal end portion108may comprise thermal yarns that assist in capturing the shape of the distal end portion108, preventing wrinkles and unwanted folding.

In another preferred embodiment, the textile layer102may comprise a jersey knit of a high knitting-machine gauge, for example gauge 19. The jersey-knit yarns may further comprise a terry knit, with a looped side on one surface, such as the inner surface, of the textile layer102to facilitate impregnation of the interstices between yarns of the textile layer102by the uncured silicone material. It has been found that providing a textile layer102comprising jersey knitting with terry provides improved sealing-in of the silicone material. Terry has also been found to help align the textile layer102to a shape or configuration of the male mold, over which the textile layer102is placed to facilitate the molding process. A second, opposite surface, such as the outer surface, of the textile layer102may be a substantially flat surface compared to the looped surface.

The jersey-knit textile layer102may alternatively be provided without terry knitting. It has been found that a textile layer102defining jersey knitting without terry provides improved elongation. The textile layer102may comprise any suitable material, including synthetic fibers such as bare or covered elastane, taslanized or air-textured yarn, PET, polyamides, nylons, or other synthetic fibers, natural fibers such as cotton, silk, or wool, modified or combined natural fibers such as tencel thread, combinations thereof, or any other suitable material.

The jersey-knit textile layer102may comprise a taslanized yarn in the body portion110, for example a taslanized yarn with a density of about 190 Decitex (dTex). It has been surprisingly found that a taslanized yarn provides improved sealing-in of the uncured silicone material. The textile layer102may be steamed prior to disposing the uncured silicone material and curing thereagainst, as it has been found that steaming the textile layer102using suitable steaming means increases the density of the textile layer102, which results in less bleed-through.

In embodiments, the material of the textile layer102may be air-textured to configure the interstices between the individual threads or yarns, particularly on an inner side of the textile layer102, to receive and engage with the silicone material. The jersey-knit textile layer102may alternatively comprise a bare elastane material, which has been found to provide improved elongation in both axial and radial directions. In embodiments the elastane of the jersey-knit textile layer102may be covered to reduce bleed-through of the silicone material.

By providing the fast-cure silicone material forming the inner layer101of the present disclosure, with silicone functional polymer, catalyst, and crosslinking agent provided in amounts that allow an expedited curing process without adversely affecting the material properties, and a cooperating textile material that prevents bleed-through of the uncured silicone material, no pre-coating step is needed to prevent bleed-through of the inner layer101through the textile layer102as in U.S. Pat. No. 6,485,776. While no pre-coating step is required according to the methods described herein, the general process of molding the inner layer to the textile layer may be adopted from U.S. Pat. No. 6,485,776, with the modification of skipping the pre-coating step by using the fast-cure silicone material and high-density knit textile layer.

Rather, the inner layer101may be formed directly on the textile layer102in a greatly simplified process compared to existing manufacturing methods for prosthetic liners. The combination of a fast-cure silicone material forming inner layer101and a textile layer102arranged to cooperate with the fast-cure silicone material to prevent bleed-through allows for a simplified manufacturing process and for using advantageous textile layers.

In embodiments of the present disclosure, the textile layer102may comprise a knit structure arranged to provide optimal sealing of and cooperation with the fast-cure silicone material without compromising textile qualities relative to existing or conventional textile layers. The knit structure may be selected to have optimal or maximal sealing of the fast-cure silicone material while retaining a desired elongation.

The textile layer102comprises a textile material104that may additionally define parameters and properties that further cooperate with the fast-cure silicone material to prevent bleed-through without compromising the performance or comfort of the textile layer102. The textile layer102or the textile material104may comprise a jersey knit structure, which has been found to minimize or prevent entirely bleed-through of the fast-cure silicone material and may comprise stretchy single-knit fabric. The jersey knit structure of the textile layer102may be modified with terry toweling or fabric with long and/or cross loop structures with interstices between the yarns while increasing the absorptivity of the fabric to further minimize bleed-through. In other embodiments, the jersey knit structure may omit terry toweling. In yet other embodiments, the textile layer102may comprise a pique knit structure.

In embodiments, the textile layer102may have increased density compared to existing textile layers, the higher density further preventing bleed-through. To increase the density, the material or yarn forming the textile layer102may have increased thickness or knitting machine gauge relative to existing textiles. The material of the textile layer102may be roughened, for example with a brush, to prevent bleed-through; this may provide additional surface area for a locking effect between the fast-cure silicone material and the textile layer102, and to distribute the fast-cure silicone material during the curing process. The textile layer102may comprise a material with taslanized or air-textured yarn, bare elastane yarn, covered elastane yarn, tencel yarn, cotton, nylon, polyester, polyamide, or any other suitable material.

In embodiments, a variable-durometer liner may be provided by adding an uncured silicone material comprising a variable number of durometer-dependent components such as oil at specific locations to a mold through a dynamic mixer and extrusion die prior to molding. The base materials that form an uncured silicone material, such as functional silicone polymer, crosslinking agents, catalyst, additives, and durometer-affecting components like oils may be blended together using the dynamic mixer, with a servo motor controlling the dosing of the blended materials. The extrusion die may be positioned using the servo motor to extrude the blended material at designated positions relative to a textile sleeve or sock, with the proportions of the base materials varying based on the location of the textile sock. Because a percentage of oil in the uncured silicone material is proportional to the final durometer, the content of oil in the uncured silicone material may be controlled to increase or decrease the durometer at chosen locations of the inner layer101.

In other embodiments, the type of polymer, crosslinking agents, or other base materials may be varied to effect desired changes in the durometer or other properties, such as stretch. The locations and proportions of oil or other durometer-affecting components may be chosen based on a desired property relative to the user. For example, a lower durometer may be desired proximate a distal end portion to cushion the limb residuum against the prosthetic socket. A higher durometer may be desired at portions of the prosthetic liner that contact various components of the prosthetic socket for rotation control or other benefits.

The durometer, stretch, or any other suitable property, such as elongation, tear strength, and others, of the inner layer101may correspond to and cooperate with properties of the textile sleeve102at corresponding locations. The textile sleeve102may be provided with similarly adjusted thickness, stretch, elongation, or other properties as appropriate.

FIG.1Dshows a flowchart150describing an existing process for manufacturing a prosthetic liner, with a coating or pre-molding process151comprising the steps of: mixing silicone, coating a tubular textile material with the mixed silicone to prevent bleed-through during the molding process, and cutting textile to form the coated tubular textile material into a configuration suitable for a textile layer of a prosthetic liner. Depending on whether the prosthetic liner is destined for use as a cushion liner or a locking liner (two potential dispositions for a prosthetic liner), the coating or pre-molding process151further comprises the steps of distal end gluing or sewing, respectively, to further form the coated tubular textile material into a configuration usable as a textile layer of a prosthetic liner.

FIG.1Dfurther shows a locking liner flow chart152and a cushion liner flow chart164according to the present disclosure. By using a fast-cure silicone material and a textile material arranged to cooperate with the fast-cure silicone material according to the disclosure, the pre-molding or coating process151may be entirely omitted, as there is no need to coat, cut, and shape a uniform tubular textile material to prevent bleed-through prior to the molding process. The prosthetic liner of the present disclosure greatly simplifies the costs and complexities of producing a prosthetic liner by reducing the process to a single molding process shown in flowcharts152,164, without the pre-molding steps required of existing or conventional sockets and liners.

To produce a locking liner according to locking-liner flowchart152, a textile layer may be pre-molded at step153, especially at the distal end, with a layer of silicone or other suitable material to facilitate support and use of a locking pin. The liner is then main-molded at step154with a fast-cure silicone material to form the inner layer without the need for any of the pre-coating processes of the pre-molding process151shown above dividing line170.

The steps of the pre-molding process151, including the steps of silicone mixing, coating, textile cutting, and sewing/gluing are necessary in existing processes to prevent bleed-through of uncured silicone material through the textile material and to form a tubular textile into a suitable shape for a prosthetic liner, but are advantageously omitted through the use of a fast-cure silicone material and cooperating textile material according to the embodiments. Likewise, to produce a cushion liner according to cushion-liner flowchart164, a textile layer may be main-molded at step166with a fast-cure silicone material to form an inner layer without the pre-coating processes of the pre-molding process151shown above the dividing line170.

As seen inFIG.1C, using a fast-cure silicone material to form an inner layer on a textile layer arranged to cooperate with the fast-cure silicone material reduces the cost and complexities of manufacturing as the majority of steps may be omitted entirely, and further allows for a wider variety of textile layers, including pre-formed tubular sleeves or socks, to be used, as it is no longer required to use a uniform tubular textile material to facilitate the coating step at step151. The inner layer101may have a first thickness T1and the textile layer102may have a second thickness T2, both thicknesses T1and T2suitable for use in a prosthetic liner and together defining a total thickness of the prosthetic liner100. The thicknesses T1, T2may be variable along a length or about a circumference of the prosthetic liner100.

The textile layer102may be pre-formed and may have different distal closing configurations, as depicted inFIGS.1D-1E. The closed distal end180shown inFIG.1Emay be formed as a Y-shaped seam182, with branches spacing over the distal end108of the prosthetic liner100. Alternatively inFIG.1F, the distal closing190may be formed as an I-shaped seam192, with a branch extending down a center portion of the distal end108. The distal closings180,190may be chosen in different prosthetic liners based on the desired configurations of the prosthetic liner100, a corresponding prosthetic socket, and/or according to the needs of a particular user. The closed distal end180,190is not limited to the depicted configurations and may be formed in any suitable or convenient shape or configuration.

Among the benefits of using a wider variety of textile materials to form the textile layer102according to the present disclosure is the possibility of including regions of distinct structures and functionality, such as a matrix, within a pre-formed textile material as shown in the embodiment ofFIGS.2A-2C. As shown, a prosthetic liner200may comprise an inner layer201and a textile layer202adjacent and attached thereto and comprising a textile material204. The shape of the prosthetic liner200is defined by a distal seam209which discretizes a distal portion208and a body portion210, which is also discrete from a proximal portion206. The distal seam209may be provided as part of the textile sleeve202or may be added to the sleeve202during manufacturing. The material of the textile layer202may be different in the distal portion208, the body portion210, and/or the proximal portion206as suitable for a particular user or for a particular function. For instance, the textile layer202in the distal portion208may comprise nylon yarns, while the textile layer202in the body portion210may omit the nylon yarns in favor of a different material. Different sections having different materials may have different knit structures, or may have the same knit structure, such as jersey-knit gauge-19 yarns with terry.

Because of the provision of a fast-cure silicone material and cooperating textile material204which allow the inner layer201to be formed directly on the textile layer202without a pre-coating process and without bleed-through, the textile layer202may be provided in a pre-formed configuration and may include a matrix207defined by a material212comprising thermofusible yarns which may be configured to contribute added structure and stiffness in desired directions, such as axially, upon molding.

A matrix207may extend from the distal portion208up to a region of the body portion210. A remainder of the body portion210may comprise a textile material214without the thermofusible yarns. As seen inFIG.2B, the materials212and214may be defined within a single, continuous, and pre-formed textile sleeve202, mitigating the need in existing or conventional prosthetic liners to cut, size, and stitch together materials, such as tubular textile materials, with different properties into a textile layer.

In embodiments, thermofusible yarns may be used to close the I- or Y-shaped seam182,192shown inFIGS.1E-1F, the thermofusible yarns serving to improve the adhesion and connection at the seam182,192by fusing with adjacent yarns or threads when a threshold temperature has been met. The thermofusible yarns may be a low-temperature fusing yarn, such as a threshold of about 85° C., or may be a high-temperature fusing yarn, such as a threshold of about 110° C. to about 150° C., or any other suitable threshold. The thermofusible yarns of the seam182,192may be provided in the textile sleeve or sock, or may be added during the manufacturing process.

As seen in cross-sectional view inFIG.2C, the inner layer201may be formed directly adjacent to the textile layer202without a pre-coating inner layer interposed therebetween, as the fast-cure silicone material and cooperating textile layer of the disclosure allow for the omission of a pre-coating stage to prevent bleed-through. The inner layer201may have a first thickness T3, and the textile layer202may have a second thickness T4, with both thicknesses T3and T4suitable for use in a prosthetic liner200and defining a total thickness of the prosthetic liner200. The thicknesses T3and T4may vary along a length or a circumference of the prosthetic liner200for added comfort at a distal end, for example, and/or for ease in donning/doffing the prosthetic liner200.

FIGS.3A-3Cdepict another embodiment of a prosthetic liner300according to the present disclosure. A prosthetic liner300comprises an inner layer301and a textile layer302adjacent and attached to the inner layer301. Similar to the previously depicted embodiment ofFIG.2A-2C, the prosthetic liner300may define a continuous body portion310defined between a proximal portion or end306and a distal portion or end308.

The textile layer302may advantageously comprise multiple layers of altogether different materials and knit structures. An inner or base yarn312adjacent to the inner layer301may comprise a first yarn type, and an outer or covering yarn314adjacent and attached to the inner yarn312may comprise a different second yarn type. The base and covering yarns312,314may have properties suitable for their respective positions. The inner layer301may have a first thickness T5, while the base yarn312has a second thickness T6and the covering yarn314has a third thickness T7, the thicknesses T5, T6, T7defining a thickness of the prosthetic liner300, which, as before, may be continuous or may vary at different locations of the liner300. The covering yarn314may have different elongation, axially or radially, compared to the base yarn312.

The base yarn312may have a knit structure and material arranged to interlock on an inner surface thereof with the fast-cure silicone material of the inner layer301to ensure a firm attachment between the inner layer301and the textile layer302. The covering yarn314may be arranged with a knit structure and material314configured for aesthetic appeal, enhanced comfort, and/or optimal attachment to a prosthetic socket. As in previous embodiments, the layers312,314of the textile layer302may be arranged to cooperate with the fast-cure silicone material to prevent bleed-through, allowing for a simplified manufacturing process and the use of advanced and/or customized textile materials. The properties of the base yarn312and the covering yarn314, for instance, may be varied about or along the liner300as appropriate for providing desired shapes, elasticities, cushioning, or friction properties, for example.

In an embodiment, the base yarn312may comprise a different material than the material of the covering yarn314. The base yarn312may comprise a jersey-knit gauge-19 uncovered nylon material without terry, while the covering yarn314may comprise a jersey-knit gauge-19 elastane. In other non-limiting embodiments, the base yarn312may comprise a jersey-knit gauge-19 elastane, while the covering yarn314comprises a jersey-knit gauge-19 elastane having a different density. In yet other embodiments, the base yarn312may comprise a pique-knit gauge-24 elastane, while the covering yarn314may comprise a pique-knit gauge-24 elastane comprising tencel threads.

The base yarn312may comprise low-melt thermal yarns or threads, particularly in the distal end portion308of the liner300. The low-melt threads, which may be configured to melt and fuse with adjacent threads at approximately 85° C., may define a matrix extending approximately 12 inches from the distal end portion308into the body portion310of the liner300. The body portion310extending proximally from the distal end portion308may have a different composition of base yarn312and covering yarn314.

While the depicted embodiment shows the base yarn312and the covering yarn314extending throughout the textile layer302, it will be appreciated that the base yarn312and the covering yarn314may extend only through discrete portions of the textile layer302and may vary at different locations. For example, a distal end portion308of the liner300may have a different base yarn and covering yarn arrangement than a body portion310of the liner300.

Another advantage of the present disclosure is depicted in the prosthetic liner400ofFIGS.4A-4D. Using a fast-cure silicone material to form the inner layer401, and a textile layer402arranged to cooperate with the fast-cure silicone material to prevent bleed-through, facilitates the use of a textile material404that may be pre-formed with features, such as discrete bands or regions of different material properties, that would be cumbersome if not impossible to provide using conventional techniques. In the depicted embodiment, the discrete regions may provide alternating or periodic bands422in the textile layer402. The bands422may comprise coarse inelastic textile that allows for uncured silicone material to bleed through an entirety of a thickness thereof to define silicone seal-in bands420, and bands414of dense, fine, elastic textile material that does not permit bleed-through of uncured silicone material. These bands414define regions412of non-bleed textile material404. A body portion410may be distinct from a proximal end406and a distal portion408, with the distal portion408devoid of the different bands422,414. The distal portion408may comprise any of the bands414or420so as to allow bleed-through (where desired) or to prevent bleed-through (where desired). The bands422may have different elongation, axially or radially, compared to the bands414.

By providing the bands or zones422, the seal-in bands420may be provided on discrete and desired regions of an outer or socket-facing surface of the prosthetic liner400to interface with the socket, such as for vacuum-sealing, for donning/doffing purposes, and/or for rotational control between the liner400and the socket. The provision of the zones422in a pre-formed textile layer or sleeve402further simplifies the manufacturing process without compromising needed structural properties. While the seal-in bands420are shown as extending laterally around band-like portions of the prosthetic liner400, it will be understood that any configuration, size, quantity, and/or pattern of controlled bleed-through sections422may be defined by the textile layer402for desired properties, such as tackiness and texture, breathability, shape, stiffness, cushioning, or otherwise.

As seen in greater detail in the cross-sectional view ofFIG.4D, the inner layer401may be arranged to directly abut and attach to the textile layer402, with portions of uncured silicone material bleeding through the bands422to define seal-in bands420that extend to an outer surface of the prosthetic liner400at desired and discrete locations. The inner layer401may have a first thickness T8and uncured silicone material may bleed through an entire thickness T9of the textile layer402, with the thicknesses T8, T9defining substantially an entire thickness of the prosthetic liner400. Portions of silicone forming the seal-in bands420may extend a distance beyond the outer surface of the textile layer402or may be flush with the outer surface of the textile layer402.

The bands422may be arranged to allow bleed-through of uncured silicone material by defining portions of the textile material404whereat a predetermined number of threads, filaments, or other patterns that define the textile material404are skipped or omitted. Alternatively, the density, gauge, material type, or any other property of the textile material can be varied as desired to facilitate controlled bleed-through. This arrangement provides regions422of reduced density that facilitate bleed-through by and of the uncured silicone material before the silicone cures.

The textile material404may be arranged to be denser throughout the main body of the textile layer402than an existing tubular textile layer, such that bleed-through of uncured silicone is prevented. The predetermined number of omitted threads at bands422facilitate a lower density conducive to bleed-through and the formation of seal-in bands420or other features. The bands422may also be provided for desired elasticity properties.

Like the matrix of thermofusible yarns embedded in the pre-formed textile sleeve202of the embodiment depicted inFIGS.2A-2B, the textile layer402may be pre-formed, in contrast to the tubular textile structures of existing or conventional liners which must be painstakingly cut, sized, and adhered together. To provide a smoother profile and an improved sealing of the uncured silicone material, the textile layer402may be arranged with a closing seam at the distal end408with a low-melt yarn. This arrangement provides for improved sealing while also providing an expedited and simplified manufacturing process. As with previous embodiments, the textile layer402may define base and covering layers or a single layer of fabric, and may have uniform properties throughout or varied properties at different locations.

The prosthetic liner500according to the embodiment ofFIGS.5A-5Cfurther demonstrates the advantages of the present disclosure. As with the foregoing embodiments, by forming the inner layer501from a fast-cure silicone material that cooperates with a textile layer502arranged to prevent bleed-through of the uncured silicone material, a pre-coating process may be omitted entirely, and the textile layer502may be a pre-formed material with added structural and functional properties compared to existing textiles used in prosthetic liners.

A pre-formed textile layer502may comprise different materials in a body portion510compared to a distal portion508, which is located on an opposite end of the prosthetic liner500from a proximal portion or end506. The body portion510may comprise a first textile material504, and the distal portion508may comprise a second textile material505. The first textile material504may define a two-system textile, with a first system512comprising, for example, two yarns of polyester or polyamide material in a 1 by 1 alternating knit structure, and a second system514comprising, for example, one yarn of a premium-stretch fiber, with the first and second systems512and514in a knitted and/or alternating arrangement with each other. The first textile material504is depicted in greater detail inFIG.5B.

In an alternative embodiment, the first material504may comprise a single system, which may comprise two yarns in a 1 by 1 alternating knit structure. It will be understood that the first and second textile materials504,505, and the first and second systems512,514may comprise other types of knit structures and materials and may vary from the depicted embodiment in number of yarns, number of layers, stitching patterns, and other details. The provision of the first and second textile materials504,505may advantageously allow for desired properties at desired locations, such as different elasticities at different portions of a user's anatomy, different stiffness, better rotation control relative to the socket, increased cushioning at particular portions, or otherwise.

By providing a fast-cure silicone material with a cooperating textile layer502according to the present disclosure, the textile layer502may comprise the above-mentioned discrete zones of different material, such as in the distal end portion508and in the body portion510, to serve different structural needs. Greater thickness, padding and comfort can be provided in the distal portion508with greater breathability or frictional engagement with a socket provided in the body portion510.

In other embodiments, the first textile material504may define regions of high stretch and elasticity, which may be advantageous for providing flexibility over a joint. Regions of reduced stretch or increased stiffness may be provided for, e.g., a popliteal region, so as to prevent discomfort and bunching. Advantageously, the textile layer502, with the first and second textile materials504,505, may be pre-formed, eliminating the need to cut, size, and stitch or otherwise glue together portions of different materials after a pre-coating process as in existing or conventional liners.

Similar to previously depicted embodiments, the inner layer501and the textile layer502of the prosthetic liner500may have respective first and second thicknesses T10, T11, which may be constant or dynamic over a length of the prosthetic liner500, and which together define a thickness of the prosthetic liner500. By utilizing a fast-cure silicone material according to the disclosure, the inner layer501may be formed directly on the textile layer502without the need for a separate layer of silicone pre-coating on the textile layer502to prevent bleed-through of uncured silicone material and without compromising a required thickness at portions of the prosthetic liner500. For example, the inner layer501may be thicker at the distal end508for added cushioning.

Another embodiment of a textile layer arranged to cooperate with the fast-cure silicone material of the disclosure is shown in an elevational view inFIGS.6A-6B.FIG.6Ashows a front or anterior side A of a textile layer that may be formed as a textile sleeve or sock600having distinct, particular regions having different advantageous properties, the provision of which in existing tubular and/or open-ended textile materials is cumbersome and costly owing to the cutting, shaping, and stitching stages required to provide different regions from different materials. By contrast, the textile sleeve600may be pre-formed with the particular regions, requiring no such cutting, shaping, and stitching stages prior to curing with a fast-cure silicone material. A distal portion of the textile sleeve600may be formed from a low-stretch portion602, the low-stretch portion602configured to limit axial stretching and thereby minimize pistoning in a prosthetic system.

Proximal and attached to the distal portion of the textile sleeve600is a high-stretch portion604, configured to facilitate axial stretching of a prosthetic liner. This may be particularly advantageous for allowing a user to bend their knee, for example, with minimized resistance from the prosthetic liner and may facilitate donning and doffing of the prosthetic liner. The high-stretch portion604may extend toward a proximal portion of the textile sleeve or sock600. The high-stretch portion604may define a region or regions having stiffened material relative to a remainder of the high-stretch portion604, the stiffened material forming a patella support610. The patella support610may be arranged to substantially surround and support a patella during flexion and extension of the limb residuum, with the enhanced stiffness of the patella support610helping to maintain the patella in its proper position and apply desired amounts of pressure thereto.

On a rear or posterior side P of the textile sleeve600shown inFIG.6B, a pattern of fold lines605may be provided proximate a popliteal region of a user in the form of softer yarns, the softer yarns facilitating folding at desired locations during flexion of the knee. The yarns at the fold lines605may also be thinner than a remainder of the textile sleeve600. This advantageously can reduce bunching and associated discomfort (including moisture buildup and reduced breathability) in the popliteal region during use. More or fewer fold lines605, and different configurations and constructions thereof, may be provided as suitable for a particular application or use, and are not limited to the depicted arrangement.

Discrete regions, in the depicted embodiment taking the form of a plurality of dots607of material, may be provided in the textile sleeve600and may have lighter (e.g. less dense) knitting to facilitate breathability particularly in the popliteal region over which the dots607are arranged. The dots607may define patterns corresponding to regions requiring greater heat-transfer characteristics. In other embodiments, the dots607having lower density may be provided to control or facilitate bleed-through of the fast-cure silicone material, the silicone features defined over the dots607on an exterior or socket-facing surface of the prosthetic liner providing rotation-control effects or other desired properties. The dots607may have any configuration or be provided in any number or pattern necessary, and are not limited to the depicted configuration and pattern.

The use of the fast-cure silicone material allows for the use of the textile sleeve600, which may be pre-formed, with its distinct regions602,604,610,605,607having distinct characteristics that provide advantageous structures and functions to a prosthetic liner, without the cumbersome and costly steps of pre-coating, cutting, shaping, and stitching distinct portions of different materials having the desired properties, these steps precluding the use of textile sleeves in existing prosthetic liner manufacturing processes. The fast-cure silicone material and cooperating textile material of the disclosure thereby further reduce the costs and complexities of manufacturing while providing a superior prosthetic liner that better corresponds to a particular user's needs.

The prosthetic liner according to the disclosed embodiments advantageously streamlines and simplifies the manufacturing process for a prosthetic liner by providing a fast-cure silicone material that forms an inner layer with a textile layer arranged to cooperate with the fast-cure silicone material to prevent bleed-through of the uncured silicone material. The prevention of bleed-through by the fast-cure silicone material and the cooperating textile layer allows for the omission of the steps of silicone pre-mixing, coating, cutting, and sewing prior to molding or curing the prosthetic liner, and therefore allow for pre-formed textile layers, which may define numerous structural and functional properties.

It is to be understood that not necessarily all objects or advantages may be achieved under any embodiment of the disclosure. Those skilled in the art will recognize that the prosthetic liner and methods for making the same may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without achieving other objects or advantages as taught or suggested herein.

The skilled artisan will recognize the interchangeability of various disclosed features. Besides the variations described herein, other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct a prosthetic liner and to utilize a method for making the same under principles of the present disclosure. It will be understood by the skilled artisan that the features described herein may be adapted to other types of prosthetic, orthopedic, medical, or other devices.

Although this disclosure describes certain exemplary embodiments and examples of an elastomeric prosthetic liner, it will be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed elastomeric prosthetic liner embodiments to other alternative embodiments and/or uses of the disclosure and obvious modifications and equivalents thereof, including liners formed from other polymeric materials and in other configurations. It is intended that the present disclosure should not be limited by the disclosed embodiments described above and may be extended to other applications that may employ the features described herein.