Patent Description:
Liners in prosthetic uses are widely known and are used as an interface between a residual limb and a prosthetic socket, allowing a user to comfortably and safely wear the prosthetic socket and prostheses attached thereto, such as prosthetic limbs. Liners may, for instance, provide cushioning between the end of the residual limb and the prosthetic socket, protecting the limb from developing pressure points as a user's weight is applied to the hard components of the prosthetic socket during use. Liners may additionally provide for improved pressure distribution along the residual limb and within the prosthetic socket. In vacuum suspension-type prosthetic systems, a liner may also protect the residual limb from being exposed to an elevated vacuum for extended periods of time. <CIT> discloses a moisture permeable composite material e.g. for a prosthetic liner. The pre-amble of claim <NUM> is based on this document. <CIT> discloses a knitted interface comprising a knitted structure formed from a plurality of elastomeric polymer filaments, and <CIT> discloses a liner for a prosthesis, which liner has a proximal opening for receiving an amputation stump, and a distal end lying opposite to the proximal opening.

Polymeric, particularly elastomeric, materials are commonly used for constructing liners. For example, a medical-grade silicone may be used that is naturally compatible with human tissue and resistant to fluids and bacteria, reducing the risk of infection. These liners, despite limitations on breathability, often are designed to remain fresh and odor-free after each use, and have lasting strength and thickness despite repeated use. But many liners may not achieve such desired results upon repeated use, depending on the characteristics of the user.

An elastomeric material may be preferred, although not limited, for constructing the liner because it has inherent elasticity that conforms to a residual limb. The elasticity of the liner may be tailored to inhibit elasticity in different directions, such as axially, but enhanced in one direction (radially) relative to another direction such (axially).

Normally a liner is constructed by molding the elastomeric material between male and female molds to form a solid layer of elastomeric material that may closely encapsulate the residual limb. The elastomeric material may be extruded into a predetermined shape. Either in molding or extrusion, the liner is created as having a fixed cross-section profile, without control for adapting the molded or extruded part profile.

This fixed cross-section profile is generally a solid mass of elastomeric material that is both vapor- and-liquid impermeable, and the solid layer is formed cohesively as an entirely monolithic body. To provide sufficient cushioning and protection of the residual limb, such liners typically comprise a relatively thick layer of fluid-impermeable elastomeric material. The thickness may be increased at a distal end of the liner to provide additional cushioning at the point of the liner where the weight of the user is most pronounced against the prosthetic socket.

Because the liner is constructed from a unitary wall or solid layer of elastomeric material, usually formed or cured from a liquid resin poured into the molds or extruded into shape, the material may have uniform properties throughout the body of the liner, or simplified properties among various components to the liner (e.g. a taper in thickness). An example of a method for manufacturing a liner is found in <CIT>, and an example of a liner having multiple components and/or properties is found in <CIT>.

A common practice is to attach a textile material to an exterior surface of the liner, the textile material having defined properties that may provide customized or desired features at specific locations. The solid elastomeric layer may be cured against the textile material, which requires pre-processing steps, such as sewing and shaping, to have desired properties. One example of the time-consuming and cost-increasing pre-processing steps is the stitching of a distal seam in a textile tube to shape the textile tube into a liner shape. Other components may be provided in a liner, such as a hard distal end cap.

Stitching and securing a textile to a liner body of an elastomeric material, and additional components of a liner may cause pressure points when the liner is worn by a user and pressed against a hard socket. Efforts have been made to minimize such effects, as in <CIT>. But attention is still desired for simplifying processes used to provide such textile or other components to a liner body and by yet further minimizing pressure points.

A known problem in liners is the buildup of moisture and heat between the residual limb and the liner, which can lead to discomfort, unpleasant odors, "milking," "pistoning," and breakdown of tissue. For example, medical-grade silicone is hydrophobic because it is vapor- and liquid-impermeable. Sweat may build-up between the residual limb and the liner, which may cause slippage of the liner from the residual limb and discomfort. This may lead to the risk of non-compliant use of the prosthetic system or even of catastrophic failure of the prosthetic system during use.

There is a balance between providing a liner having sufficient cushioning and thickness to protect the residual limb from harmful extended contact with hard or rigid surfaces and providing a liner that is breathable to mitigate heat and moisture buildup. A concern arises in whether the liner can maintain the same strength, thickness, compression, and general functionality in a liner having a ventilated structure as in a conventional solid-walled liner. There is likewise a desire to maintain the liner as constructed from an approved and accepted medical-grade elastomeric material, such as silicone.

Efforts to bridge this gap have included providing wicking layers or absorbent materials within the silicone layer or between the silicone layer and the textile material, which steps may increase the cost and complexity of constructing a liner. An example of such efforts is found in <CIT>. Efforts to provide apertures, or wicking layers and absorbent materials may impair the functionality of a liner or result in a liner having inferior mechanical properties relative to a conventional solid-walled liner. Such past ventilated liners may prevent or preclude other desirable features in liners, such as external surface peripheral profiles, as in <CIT>, and seal systems as in <CIT>.

There still exists a need for a liner that achieves the structural and cushioning benefits of solid-walled, conventional liners but which can mitigate the buildup of heat and moisture, while preserving its construction from a medical-grade material and accommodating various features common in conventional liners.

Another problem in existing systems and methods for producing liners is the difficulty and cost of providing a custom-fitted prosthetic system with features that correspond to the needs at different portions of the residual limb. Each residual limb has unique dimensions and shape, and the efforts of a trained prosthetist must assess a user's needs should the user's needs be outside normal shapes and sizes of liners. Individuals may have different bony mass structure and soft-tissue, depending on how the residual limb occurred, and it is difficult to meet the unique limb shape and needs of the individual residual limb, particularly as, due to swelling or weight change, the dimensions and needs of a particular user may be dynamic and change.

As it is difficult to achieve the structural and functional needs of each residual limb, it is desirable to provide a liner that can meet the demands of each user, whether the liner is for lower or upper extremities, and whether the user requires elevated vacuum, seal-in expulsion, and locking suspension systems. Custom liners may be provided for amputees of all lifestyles and activity levels, and there is difficulty meeting the demands of all such individuals with standard conventional-sized liners. Individuals may require material additives for easier donning and doffing, and skin-treatment additives, and desire conventional liner features in a custom-fitted liner.

Because many medical devices having elastomeric materials such as medical-grade silicone are formed by injection molding, where a silicone resin is injected into a space defined by a negative mold of the medical device, most medical devices do not have a desired degree of customized properties based on the functionality of different regions of a user's body but have uniform properties throughout. In the example of a liner, however, it may be desired to have more elasticity at and behind the knee compared to above, below, and to the sides of the need, or a different degree of breathability may be desired at regions proximate active muscle groups that generate more heat and fluid. There is a need for a medical device that provides custom properties at desired locations around the medical device rather than uniform properties.

There is a need for a liner that can be tailored to the demands of an individual user while offering accommodation for conventional liner features. More generally, there is a need for medical devices constructed from elastomeric materials that offer a desirable balance of breathability and mechanical properties to withstand an ordinary daily use of the device.

The balance of strength, comfort, breathability, and other desired properties of elastomeric and other polymer-based, preferably elastomer-based medical-grade materials in medical devices such as prosthetic and orthopedic devices, is addressed in embodiments of the disclosure. These embodiments exemplify a liner comprising discretely and continuously deposited layers based on filaments of a polymeric material, such as silicone or other elastomers, used in conventional liners while maintaining at least equivalent mechanical strength and other mechanical properties of such conventional liners. While such liners may be constructed from the same medical-grade elastomeric material and possess the same mechanical and chemical properties of conventional liners, the lattice structure of the embodiments provides improved cushioning, moisture removal, and/or breathability over known conventional liners.

The embodiments may be provided in combination with textile covers, reinforcement layers, material additives, and other desired features in conventional liners while having the improved features. While medical-grade elastomeric material is discussed, it will be understood that the disclosure is by no means limited to medical-grade material and may make use of any suitable material.

The exemplary embodiments possess characteristics that can be extended to a wide range of medical devices including prosthetic or orthopedic parts, medical implants, medical tubing, prostheses, and other parts or devices. The characteristics may be adapted according to desired properties or needs and customized to address the needs of users. For example, the characteristics of the embodiments can be used in devices made by known medical-grade elastomeric materials, thereby removing the necessity for material approval and streamlining regulatory acceptance.

Exemplary liner embodiments are arranged to effectively manage perspiration formed by a limb, prevent slippage of the liner on the limb, and provide suitable cushioning for a limb. The exemplary embodiments described are discussed and shown within the context of a liner in a prosthetic system for use with a hard socket. However, the disclosure is not limited to such a prosthetic embodiment or the exact uses described and embraces any use requiring perspiration management, prevention of slippage, cushioning of the limb, or any other structural and/or functional benefit that may derive in whole or in part from the principles of the disclosure. Principles described herein may be extended to any prosthetic, orthopedic, or medical device, and are in no manner merely limited to liners.

In an exemplary embodiment, a liner advantageously bridges the gap between the strength of a solid-layer wall liner and the need for breathability while using a medical-grade material. The liner may be customized to have features at particular locations corresponding to the needs of individual users, minimizing cost and complexity of manufacturing, and offering physical structure and functionality that benefit different requirements. The liner is just an example of the different structures that can be manufactured and configured according to principles described herein.

According to the exemplary embodiment, the liner has a first or proximal end, a second or distal end, and a tubular liner body defined between the first and second ends. The liner body preferably comprises a base layer formed from an elastomeric material, such as silicone, and having an inner surface extending along with an interior of the tubular liner and defining a periphery thereof. The base layer defines a plurality of openings extending preferably through a thickness thereof. As the base layer should secure against the skin of a user about the residual limb, the base layer may have more combined solid surface area than a combined area of the plurality of openings to provide an effective skin interface. The inner surface of the base layer is preferably smooth because it has a generally uniform surface elevation aside from the openings.

The base layer may comprise a plurality of filaments integrally adjacent to and/or chemically bonded to one another to form a continuous solid layer. The filaments are aligned along one another and are chemically bonded to along their length to an adjacent filament without a gap or interruption. Such structure can be formed to constitute a film that is both vapor and liquid impermeable. One filament may be continuously formed against an adjacent filament, whereas the adjacent filament may be formed with gaps along its length, with yet another filament on an opposing side of the adjacent filament to form an apertured or ventilated layer; however such apertured or ventilated layer has apertures positively formed without mechanically or chemically perforating a solid layer to form such apertures, offering control in shape and size of such apertures. A solid or continuous film or layer may be formed, and then material may be removed in any suitable manner to define the apertures.

A first layer formed from an elastomeric material is secured to an outer surface of the base layer (so the base layer is secured to the inner side of the first layer) and comprises a first set of interstices having axes corresponding to axes of the openings of the base layer. The first layer comprises a first sub-layer including a plurality of first filaments arranged in a first direction and a second sub-layer including a plurality of second filaments arranged in a second direction. The second sub-layer overlaps the first sub-layer and forms the plurality of interstices therebetween. The material properties of an elastomeric material forming the base layer may differ from material properties of an elastomeric material forming the first layer, such as having a different durometer, such as a skin-friendly durometer. The base layer may include a skincare additive such as a moisturizer, an antimicrobial composition, aloe vera, or otherwise, whereas the first layer may not, and vice versa.

Each filament may have a uniform cross-section extending along its length in a predetermined shape. Each filament is formed discretely and extends continuously relative to adjacent filaments. These discretely formed filaments may constitute basic building blocks of the liner or medical device structure. While the preferred embodiments display the filaments as arranged in a lattice-like network to form a lattice structure, they may be arranged relative to one another at varying distances and orientations relative to one another. The filaments may be arranged relative to one another in an infinite number of coordinates relative to one another in X-, Y-, Z- planes and/or coordinates. A cross-section of the filaments may be modified to resemble any desired geometric shape such as a square, rectangle, triangle, or circle, while an exemplary shape is a generally round configuration. The cross-section may be asymmetric and be different at various lengths or locations of a continuous filament.

The first and second sub-layers of the first layer are preferably chemically bonded to one another, and might be formed from the same elastomeric material but are compatible materials nonetheless to assure bonding. Likewise, the base layer and the first sub-layer are chemically bonded to one another from compatible materials. In this manner, the sub-layers integrally form an inseparable structure and continuous structure bonded together to act mechanically as a monolithic structure. By chemically bonding, a preferred embodiment is without an adhesive, in that the filaments are bonded together as the elastomeric material defining the filaments is a curing material and sufficiently fluid for the layers to at least slightly blend at an interface, however it is not outside the scope of the disclosure to use an adhesive, a primer, or any other suitable means.

Additional layers may be secured to a second or outer side of the first layer (i.e., a second layer formed similarly to the first layer and secured to the first layer). These additional layers are likewise preferably formed together as an inseparable and continuous structure to act mechanically as a monolithic structure. The second layer may be chemically bonded to the second sub-layer of the first layer and comprise a plurality of interstices that have axes corresponding to the interstices of the first layer.

A textile or fabric layer may be secured to the outer periphery of the first layer or the additional layers, and may be breathable to permit passage of air from the inner surface of the base layer through an entire thickness of the first layer and additional layers, so an axis extends through each interstice of the first layer and the corresponding interstice of an additional layer, and a respective or corresponding opening of the base layer. The breathability is not limited to merely passing through a wall thickness, but air may transfer in all directions within the lattice network of interstices which define the lattice structure. At least one layer of filaments may be arranged, such as by size or material properties, to impregnate at least part of the textile layer.

The openings of the base layer and the interstices of the first layer and additional layers are arranged in a predetermined shape and pattern in a controlled manner to form a lattice structure. While materials of the base, first, and additional layers may be elastomeric, they may be formed of the same material or of different materials. The base, first, and additional layers may have different or similar mechanical properties. Regarding the mechanical properties, the layers may be tailored to different mechanical properties according to the location of the layer relative to the liner. For example, the base layer may have a lower durometer as a whole than the first layer. A region corresponding to a joint such as a knee may be formed from materials imparting greater elasticity or breathability than an adjacent region.

The materials are preferably compatible materials to allow for chemical bonding, so they permanently are joined to each other and may share at least a blended region in which the materials of the layers intermix or interlock to form the permanent chemical bond. Other features, such as seals, volume control pads, cushioning pads, distal caps, etc. may be formed from compatible materials and chemically bonded to or within a thickness of the liner body. Intermediate layers may be provided among layers to improve adhesion among layers, textiles, or other elements chemically bonded or mechanically interlock.

By arranging discretely deposited filaments and layers of materials having different properties, the liner advantageously provides enhanced precision in attaining desired mechanical properties, structures, and functions over existing liners. Inner layers may provide greater comfort through having a lower durometer, for example, while outer layers may have a greater thickness and greater elasticity to provide mechanical strength and desired functional properties. In some embodiments, the discretely deposited layers of material may comprise multi-layer depositions, points, or filaments of different materials having different properties.

According to a variation, the filaments may be arranged with co-extruded materials, so two materials are co-axial, with an outer layer formed from a material having a different hardness (or other property) than a material forming the inner layer. Among some reasons, the outer layer can protect a soft inner layer and form strong chemical bonds with adjacent filaments. In other variations, the elastomeric material may be co-extruded with textiles such as yarn. In other embodiments, the elastomeric material may be extruded as a continuous filament with different properties at different locations provided by in-line dosing of additives, for example the addition of oil at certain locations to achieve a lower durometer. The filaments may be hollow to allow for using higher durometer, higher durability materials while maintaining cushioning associated with lower durometer materials. The stretchability of the inner layer can be controlled by the outer layer while permitting compressibility of the soft inner layer. This allows the discretely formed filaments to have the advantage of providing multiple types of materials simultaneously. For example, the liner can have properties and advantages of a hard, durable material and the properties and advantages of a soft cushioning material.

The combination or bonding of adjacent filaments can be extended to solid wall portions of the liner that are vapor- and liquid-impermeable solid-walled liners, or other medical devices having solid wall portions or which are solid entirely. Preferably, the solid wall portions may be formed from a plurality of adjacent and abutting filaments also discrete and continuous. The resultant structure is preferably smooth and continuous in the sense there is no identification of each filament of the plurality of discrete filaments due to their direct adjacent proximity, whether mechanical, tactile, or functional. The resultant structure of the adjacent filaments is other filaments having blended chemical bonding by adjacent and abutting filaments in X-, Y-, Z- planes and/or coordinates.

A plurality of filaments may define a layer of a medical device, with each filament of the plurality of filaments extending a distance in a Z-axis to define a thickness of the layer. Each filament may utilize the liquid rope-coiling effect to define a coiled structure. The plurality of filaments may define a lattice structure. The filaments may interlock with adjacent filaments to provide desired properties in X- and Y-axes, with the layer having uniform properties as production parameters are maintained despite the plurality of filaments by which it is defined. A layer so constructed may advantageously be simple to produce while having desired and predictable properties.

A textile is provided over an outer or inner surface or intermediate layer of an elastomeric liner body, and the elastomeric material is used to seal and secure the textile on the liner body. For example, the textile may be placed over the liner body and mechanically interlock with the elastomeric material of the liner body impregnates the textile, and a discrete portion of elastomeric material is used to close the textile material about the liner body, removing any stitching. This feature is advantageous because the embodiment can avoid uncomfortable pressure points by eliminating seams and stitching. This feature is also advantageous because the textile can be attached to the liner body over many points on the textile, ensuring a strong, durable bond. The manufacturing process is also simplified by the removal of the separate stitching procedure.

Because of the controllability of forming the liner according to the structure described above, versatility is provided in forming custom-fitted liners having a variety of features, which are integrally formed or secured to one another. The liners may be custom formed by a lay-up of compatible materials having different yet compatible properties to accommodate uniquely shaped residual limbs.

These and other features of the present disclosure will become better understood regarding the following description, appended claims, and accompanying drawings.

Embodiments of a liner overcome limitations of existing liners by providing a liner structure that advantageously allows for breathability, minimizing the buildup of heat and moisture, without sacrificing the robustness, cushioning, strength, and other advantageous features of solid-walled liners. The liner provides for discrete zones of different features that better address the needs of individual users and the shapes and needs of different residual limbs. Embodiments according to the disclosure are not limited to a liner, but the liner is merely provided as an exemplary medical device created according to the principles of the present disclosure. Methods and apparatuses that may make devices according to the principles of the disclosure are described in the co-pending U. application no. [ ] entitled "ADDITIVE MANUFACTURING SYSTEM, METHOD AND CORRESPONDING COMPONENTS FOR ELASTOMERIC MATERIALS," by the certain inventors of this disclosure and filed on November <NUM>, <NUM>.

According to the methods and systems of the co-pending application, partially cured or uncured medical-grade elastomeric material, such as silicone, is sequentially deposited onto a substrate by a nozzle or similar device from a material source in a controlled manner according to computer control to define a definitive shape, such as an elongate or continuous filament. The deposited elastomeric material may be a thermoset material such as a silicone or a thermoset polyurethane, resulting in curing after it has been deposited from a nozzle. The additive manufacturing system of the co-pending application can deposit elastomeric material with a preferred blend of elastomeric materials to attain a preferred property at a desired location along or within a medical device so a continuous filament may have different properties, compositions, and shapes at different locations along its length.

An exemplary liner <NUM> having a ventilated structure formed from a plurality of discretely deposited elastomeric materials in filaments is depicted in <FIG> and <FIG>. The term discrete, and variations thereof, is intended have its ordinary meaning of being individually separate and distinct. The liner <NUM> comprises a proximal P or open first end portion <NUM> into which a residual limb is inserted, and a distal D or closed second end portion <NUM> arranged proximate a distal D or extreme end of the residual limb. The first end portion <NUM> and the second end portion <NUM> define the extreme ends of a liner body <NUM> which may taper in diameter toward the second or distal end to a solid-walled structure <NUM>. The liner body <NUM> and the solid-walled structure <NUM> define an inner cavity <NUM> contoured to receive a residual limb. An exterior E surface of the liner <NUM> may be configured to interface or interact with a prosthetic socket, while an interior surface I of the liner <NUM> may be configured to abut and cushion against a residual limb.

The elastomeric material according to the embodiments herein is discretely deposited as filaments in the sense that each filament is individually, separately, and distinctly formed. While abutting layers or filaments may form a solid and unitary structure, such structure comprises such discretely deposited elastomeric material in contradistinction to a mass of elastomeric material injected into a mold without distinction of discretely composed filaments or similar structures and deliberate properties at specific locations.

According to the embodiments, the elastomeric material is continuously deposited in the sense that a layer or filament is formed without interruption until it has reached an individual length. There may be varying lengths of filaments adjacent or proximate to one another in a structure, such as in an apertured or ventilated structure. The length of a filament may be short, such as but not limited to, <NUM> or longer, such as <NUM>.

Either way, the elastomeric material is continuously formed as a filament from a discrete mass of material having a predetermined solid cross-section and a predetermined and continuous length that combines with other filaments to make the definitive structure of a liner or other medical device. This feature is advantageous because it allows for a high-level of customization of these structures. The properties of the filaments may be varied and chosen to attain any suitable final product. In embodiments, the size, diameter, and other properties may vary to arrive at a thin film-like layer; in others, the properties of the filaments may cause a thick and/or textured layer of adjoined and identifiable discrete filaments.

The liner body <NUM> may have a tubular configuration or a conical configuration in certain embodiments, and advantageously defines a ventilated structure <NUM> allowing the liner <NUM> to be breathable and permeable to fluids, including moisture, and by consequence heat. The advantageous components and structure of the ventilated structure <NUM> allow for breathability and permeability of fluids without sacrificing the robustness, mechanical strength, and cushioning offered by solid-walled liners, as described in greater detail below.

In contrast to the ventilated structure <NUM>, the solid-walled structure <NUM> may be configured with an additional thickness relative to the liner body <NUM> at the distal end portion <NUM>. The additional thickness of the distal end <NUM>, having a closed configuration, provides additional cushioning at the distal end of the residual limb to support the user's weight. The solid-walled structure <NUM> also maintains an area of the liner <NUM> that can create suction against the residual limb, counteracting any loss of suction that existing breathable liners have experienced; whereas mechanical adhesion to the skin may otherwise be relied upon, the solid-walled structure <NUM> advantageously provides a secure attachment between the liner <NUM> and the limb. While "solid," the solid-walled structure <NUM> comprises a plurality of discrete filaments directly adjacent and bonded to one another without a gap between to form the "solid" wall structure, in contrast to a lattice structure forming a plurality of cells or cellular configuration described below, adjacent in an X-axis with the filaments generally aligned in a Y-axis, as depicted in <FIG>. The solid-walled structure <NUM> may, in embodiments, have a durometer of between approximately <NUM> and approximately <NUM>, and preferably approximately <NUM> - <NUM> Shore OO. The solid-walled structure <NUM> may further comprise a thixotropic agent for structural stability during a manufacturing procedure.

In the embodiment of <FIG>, the distal end portion <NUM> defines a solid and impermeable wall thickness along an entirety of the solid-walled structure <NUM>. The "solid" structure could be considered a film, and a thickness thereof may be modified according to desirable material properties. While defined as a plurality of filaments directly adjacent and bonded to one another in a plane due to the closeness of their proximity, the solid-walled structure <NUM> may define a plurality of layers adjacently stacked over each other in a Z-axis, as shown in <FIG>. The solid-walled structure <NUM> may also provide additional strength and rigidity for a pin attachment, for example, allowing the pin structure connecting the liner <NUM> and a corresponding socket to remain in firm engagement with each other without the risk of damage to the liner <NUM>.

The ventilated structure <NUM> and the solid-walled structure <NUM> are preferably formed together as a monolithic structure from a plurality of discretely deposited layers of elastomeric material filaments chemically bonded to one another. In this manner, the liner <NUM> is monolithically formed and acts mechanically as a single object intractably indivisible. This arrangement ensures a durable bond between the liner body <NUM> and the distal end portion <NUM>. Although both may be preferably monolithic in structure, the ventilated structure <NUM> and the solid-walled structure <NUM> preferably have different mechanical properties, such as tensile strength, elasticity (in radial and axial directions), and hardness. This provides an ability to create a product to fit a patient's individual needs. The ventilated structure <NUM> and the solid-walled structure <NUM> may be individually formed and secured together mechanically and/or chemically, such as by adhesives, and allows for production flexibility and using different materials and processes.

The liner body <NUM> and the solid-walled portion <NUM> may be formed from one or more elastomeric materials. Either or both of the liner body <NUM> and the solid-walled portion <NUM> are preferably formed from a medical-grade elastomer. Such medical-grade elastomeric materials preferably include silicone, polyurethane, or other elastomeric material. For the disclosure, the embodiments will be described as formed from medical-grade silicone. Examples of medical-grade silicone and other elastomeric materials are obtainable from NuSil Technology of Carpinteria, Calif. , under product designations CF13-<NUM>, MED-<NUM>, MED-<NUM> or MED-<NUM>. Other silicone compositions can be used, and the embodiments herein are not limited to the exemplary silicone materials, but rather may be formed from other suitable polymeric or elastomeric compositions such as polyurethane, block copolymer, etc..

The liner body <NUM> may be formed of a different material or one having different properties than the solid-walled portion <NUM>, and individual layers, including a first layer <NUM> of the liner body <NUM>, may have a different material than material found at the second end portion <NUM>. Materials forming the first layer <NUM>, the liner body <NUM>, the second end portion <NUM>, or combinations thereof may comprise the same material but may be configured to have different structural and functional properties.

An interface <NUM> may provide a robust attachment between the ventilated structure <NUM> of the liner body <NUM> and the solid-walled structure <NUM> of the distal end portion <NUM>. The interface <NUM> may comprise an added layer of elastomeric bonding between components of the solid-walled structure <NUM> and the ventilated structure <NUM>. The liner body <NUM> and the distal end portion <NUM> are preferably integrally formed with and chemically bonded to one another. The liner body <NUM> is secured along the interface <NUM> to the solid-walled structure <NUM> by chemical bonding between the material forming the liner body <NUM> and the material forming the solid-walled structure <NUM>. The materials of the ventilated structure <NUM> and the solid-walled structure <NUM> may be blended at the interface <NUM>, which may be minimal in thickness or extension and merely comprise portions of each the ventilated structure <NUM> and the solid-walled structure <NUM>. The degree at which the blending at the interface occurs may be minimal so as not to alter the shape of the filament, but sufficient to assure bonding of the adjacent portions of the filaments.

Turning to <FIG>, a wall thickness <NUM> extends between a base layer <NUM> and a layer <NUM>. The layer <NUM> is arranged on an outwardly facing surface of the liner <NUM> and is configured to interface with a corresponding prosthetic socket. The layer <NUM> may be formed by a textile or an alternative to a textile. The layer <NUM> may be formed by a plurality of filaments that define a fine pattern imitating a semi-closed surface, such as in a textile. The fine layer of filaments may be formed from an elastomeric material having a friction-reducing coating. And the fine layer of filaments may have a composition mixed with the elastomer, such as Parylene C, which is a chemical vapor deposited as poly(p-xylylene) polymers used as moisture and dielectric barriers. The base layer <NUM> is arranged on an inwardly facing surface of the liner <NUM> and configured to interface with the residual limb. Multiple layers <NUM>, <NUM>, <NUM> may extend between the base layer <NUM> and the textile <NUM>. Each layer <NUM>, <NUM>, <NUM>, <NUM>, <NUM> has unique properties and features, which allows for a high degree of customization corresponding to the user's dimensions and needs.

In an embodiment, the base layer <NUM> may be configured as a substantially solid film of elastomeric material formed from joined filaments and extending over and around a residual limb. A benefit of this arrangement is an optimized frictional engagement with the skin at an inner surface <NUM> of the base layer <NUM> to prevent pistoning, milking, or catastrophic failure of the prosthetic system due to poor engagement between the residual limb and the liner <NUM>.

The base layer <NUM> may comprise apertures or openings <NUM> arranged in a predetermined pattern and preconfigured shape in a fixed manner, as described below, referring to <FIG>. The openings <NUM> are arranged fixedly to assure the openings <NUM> intersect or correspond to other layers and corresponding openings in the thickness of the liner body <NUM>. The openings <NUM> may advantageously extend through an entirety of a thickness Tb of the base layer <NUM>. In an embodiment, the openings <NUM> may align with and define a portion of an interstice axis <NUM> extending through the thickness <NUM> of the liner body <NUM>, providing a substantially direct channel or passage through which fluid and heat may pass from the residual limb through each layer <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to the exterior E of the liner <NUM>.

An inner surface <NUM> of the base layer <NUM> defines the inner cavity <NUM> of the liner <NUM>, and comprises a solid surface area greater than a cumulative surface area of openings <NUM>, to provide an effective and reliable skin interface. The solid surface should be smooth because it generally has a uniform elevation aside from the openings <NUM>. The smooth surface avoids pressure points against the skin of the user and assures even adherence to the skin of the residual limb for effective frictional engagement. The base layer <NUM> defines a generally uniformly arcuate and/or circular profile, as it conforms to and defines the tubular shape of the liner body <NUM>. The inner surface <NUM> may be flat if arranged in a planar configuration, due to the properties of the smooth surface. The arcuate and/or circular profile mitigates pressure peaks or points and absorbs shear forces during use, protecting skin and possible scar tissue of a residual limb.

The inner surface <NUM> may be additionally prepared with an active skincare additive for enhanced comfort and skincare and for easier donning and doffing. The skincare additive may be silicone oil, Vaseline®, menthol, antimicrobial compositions, aloe vera, or any other suitable skin-care additive to mitigate irritation, dermatological issues, or mechanical issues. For example, the base layer <NUM> may comprise a composite material including silicone elastomer and silicone oil dispersed through the silicone elastomer, and/or the base layer <NUM> may contain a plurality of hollow microspheres of silicone oil or other additive dispersed through the silicone elastomer.

The base layer <NUM> is preferably formed by a plurality of discretely deposited filaments or material depositions to form its structure. Aside from the openings <NUM>, the base layer <NUM> is preferably solid-walled, and the filaments abut the filaments adjacent to one another to form such a solid-wall structure. The deposition of the filaments is controlled, in that certain filaments may be interrupted in deposition, to form the predetermined shape of the openings <NUM>. This advantageously provides a controlled and clean plurality of openings <NUM> and also simplifies the manufacturing process by mitigating the need for negative removal or "punching out" of material to form the openings after formation of the base layer.

As in the embodiments herein, the filaments can have different sizes and shapes relative to another. According to certain embodiments, the filaments have a circular cross-section, but they may have other shapes and cross-sections according to the deposition equipment used to deposit the filaments. Such cross-sections may include predetermined shapes such as square, rectangle, triangle, circular oval, etc., as the shapes are only restricted by the equipment employed for filament deposition. An embodiment or certain layers need not have filaments consistently of the same shape, but may have variable shapes according to the desired properties and form of the embodiment or layers. The cross-sections need not by symmetric and may change along a length of the filament.

The dimensions of the filaments can be modified appropriately according to the desired properties of a layer. For example, the filaments can have an exemplary precise diameter of <NUM> or be arranged in a rectangular form of <NUM> x <NUM>. The ability to precisely control the size enables variable structures in the liner, and to a greater extent of a medical device. The filaments may have different predetermined lengths relative to one another to form precise surface features (i.e., openings) in a certain layer, or may be stacked along other layers to form precise surface elevations or protruding elements. For an example, a volume control pad may be formed along the inner surface of the liner by gradual deposition of filament segments stacked upon one another in different lengths and a predetermined protruding shape in <FIG>.

The base layer <NUM> may have a durometer ranging from approximately <NUM> Shore OO to approximately <NUM> Shore OO, and may vary from a top end to a lower end; at a lower end proximate a user's skin, the durometer may be in certain embodiments approximately <NUM> Shore OO, whereas at a top end opposite the lower end, the durometer may be higher, preferably approximately <NUM> Shore OO. The base layer <NUM> may have a tensile strength at the top end of between <NUM> and <NUM> N at <NUM>% elongation, and preferably approximately <NUM> N at <NUM>% elongation. The lower end may have a tensile strength of between <NUM> N and <NUM> N at <NUM>% elongation, and preferably approximately <NUM> N at <NUM>% elongation.

In embodiments, the base layer <NUM> may be a textile layer. The textile layer may be provided on a surface, such as an inside surface, thereof with an elastomeric material that facilitates skin adhesion by providing frictional features and other properties. The elastomeric material on the inside surface of the textile layer may be interlocked with the textile material (for example, by bleeding into and curing against the textile material) and may define any suitable pattern. For example, the pattern may be a mesh pattern, a grid pattern, repeating shapes, dots, or other formations that may define frictional and skin-engaging features. The pattern defined by the elastomeric material on the surface may cumulatively comprise approximately half of the surface area of the base layer <NUM>. The depicted embodiment is merely exemplary and is not limiting.

A first layer <NUM> may be formed from silicone and arranged adjacent to and concentric with the base layer <NUM> and may attach to the base layer <NUM> through chemical bonding, adhesives, or any other suitable attachment mechanism. In an exemplary embodiment, an innermost portion or surface of the first layer <NUM> is chemically bonded to the base layer <NUM> at a junction <NUM>, with the integral formation of the base and first layers <NUM>, <NUM> allowing the layers <NUM>, <NUM> to have different properties and structures but to be reliably and permanently secured to one another to prevent separation under loads and to retain the mechanical advantages of solid elastomeric liners.

The first layer <NUM> may be formed of a material having different or the same mechanical properties as the base layer <NUM>, although arranged in a different structure than the base layer <NUM>. For example, while the filaments defining the base layer <NUM> may define a substantially laminar or solid film of soft silicone perforated or interrupted by the openings <NUM>, the first layer <NUM> may be formed from filaments, strands, ribs, or other structures that allow for a plurality of substantial openings <NUM> to be defined in and through a thickness of the first layer <NUM>. The first layer <NUM> may have a higher durometer or hardness than the base layer <NUM>. In certain arrangements, the first layer <NUM> comprises a higher stiffness than the base layer <NUM>. The increased stiffness enables the first layer <NUM> to provide stability, such as through circumferential and axial elasticity, while the softer base layer <NUM> provides shock absorption, comfort, and frictional engagement with or against the residual limb.

The openings <NUM> preferably define a predetermined pattern and predetermined shape. The openings <NUM> correspond to and are aligned to be coaxial or overlap with the openings <NUM> of the base layer <NUM>, and coinciding with the interstice axes <NUM>. The openings <NUM> may extend through an entire thickness T1 of the first layer <NUM>. A thickness T1 of the first layer <NUM> may be greater than a thickness Tb of the base layer <NUM>, with the increased thickness T1 providing strength and mechanical support to the liner <NUM> while the openings <NUM> reduce overall weight and bulk. The openings <NUM> may comprise a different shape than the openings <NUM> and may have a different surface area. For instance, the openings <NUM> may be larger or smaller than the openings <NUM>, and the combined solid surface area of the first layer <NUM> may be less than a combined surface area of the openings <NUM>, in contrast to the base layer <NUM>.

In embodiments, the base layer <NUM> may, in an unstretched state, comprise between approximately <NUM>% and approximately <NUM>% of its surface area as open areas, for example, defined by the openings <NUM>. The first, second, and third layers <NUM>, <NUM>, <NUM> may be formed so between approximately <NUM>% and approximately <NUM>% of a surface area of the first, second, and third layers <NUM>, <NUM>, <NUM> is open area, and preferably between <NUM>% and <NUM>%. The percentages are merely exemplary and may change based on a load applied to the liner <NUM> or based on the dimensions of a user wearing and using the liner <NUM>.

The filaments, strands, ribs, or other structures forming the first layer <NUM> may additionally be formed from a material having different properties than the material forming the base layer <NUM>. While the base layer <NUM> may define a frictional material, for example, the first layer <NUM> may comprise a material having a lower durometer than the base layer <NUM>, greater elasticity, anisotropic elastic properties, or enhanced heat transfer characteristics. These characteristics are exemplary, and the material forming the first layer <NUM> may comprise any number or combination of other advantageous properties.

A second layer <NUM> may be formed from silicone or another elastomeric material and arranged adjacent to and concentrically with the first layer <NUM>. The second layer <NUM> may possess the same or different properties and structures compared to the base and first layers <NUM>, <NUM>. As exists between the first and base layers <NUM>, <NUM>, an innermost portion of the second layer <NUM> may be integrally formed and/or blended with an outermost portion of the first layer <NUM>, preferably by chemical bonding. The integral formation of the materials of the first and second layers <NUM>, <NUM> allows the layers to be reliably attached during the liner <NUM>, which provides the benefits of a solid-walled structure and to still maintain distinct properties and structures.

The second layer <NUM> may define structures <NUM>, such as filaments, strands, ribs, or other structures having a thickness T2, through an entirety of which a plurality of apertures or openings <NUM> may be defined. The apertures <NUM> are formed from interrupted segments of filaments in the continuous direction of the second layer <NUM> and the filaments that define it. The openings <NUM> may be advantageously arranged as coaxial or overlapping with the openings <NUM>, <NUM> of the base and first layers <NUM>, <NUM>, and may have a predetermined shape and a predetermined pattern, as in the base and first layers <NUM>, <NUM>.

The openings <NUM> further define and extend along the interstice axes <NUM>, and form a substantially direct channel for moisture and heat to escape from the interior I of the liner <NUM>. In embodiments, the openings <NUM> may be staggered relative to the openings <NUM> of first layer <NUM>. The staggered relationship of the structures <NUM> and the openings <NUM> relative to the openings <NUM> and structure of the first layer <NUM> advantageously allow for columns <NUM> of solid structures to extend continuously between the inner surface <NUM> of the base layer <NUM> to an outer surface <NUM> of the textile <NUM>. The columns <NUM> are formed because at least some of the filaments from layers <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> overlap along an axis from the inner surface I to the exterior surface E. The columns <NUM> may provide mechanical strength and cushioning when the outer surface <NUM> of the textile <NUM> contacts and receives a load from a corresponding prosthetic socket.

As with the first layer <NUM>, the second layer <NUM> may have different properties than the base layer <NUM> and the first layer <NUM>. For example, the second layer <NUM> may have increased stiffness, increased elasticity, anisotropic elasticity, or any other property that complements the cushioning effect of the base layer <NUM> and the properties of the first layer <NUM>. Another consideration is the liner <NUM> may become more ventilated as the liner <NUM> is distended, as the ventilated structure <NUM> enlarges and expands the openings of the layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

An exemplary third layer <NUM> may be formed from an elastomeric material and arranged adjacent to and concentric with the second layer <NUM>. Similar to the base, first, and second layers <NUM>, <NUM>, <NUM>, the third layer <NUM> may be adhered to the second layer <NUM> by chemical bonding, adhesives, or any other suitable attachment method. In preferable chemical bonding, there is blending of an innermost portion of the third layer <NUM> with an outermost portion of the second layer <NUM>, so the second and third layers <NUM>, <NUM> are integrally formed and fixedly joined, yet retain distinct properties.

The third layer <NUM> may define structures <NUM> comprising filaments, strands, ribs, or any other structure that may define a plurality of openings <NUM> extending through a thickness T3 of the third layer <NUM>. As with the other layers, the openings <NUM> may have a predetermined shape and may be arranged in a predetermined pattern. The openings <NUM> may be arranged to at least partially correspond to the openings <NUM>, <NUM>, <NUM> of the other layers, and extend along with the interstice axis <NUM>. As with the second layer <NUM>, the structures <NUM> of the third layer <NUM> may be arranged in size and shape to at least partially overlap with and abut the structures <NUM> of the second layer <NUM>, extending and defining the columns <NUM> for radial strength and stability.

The first, second, and/or third layers <NUM>, <NUM>, <NUM> may individually or in combination define a center section of the liner body <NUM> and may be provided to have a durometer of between about <NUM> Shore A and about <NUM> Shore A, and preferably approximately <NUM> Shore A. The center section may have a tensile strength of between about <NUM> MPa (<NUM> psi) and about <NUM> MPa (<NUM> psi), and preferably approximately <NUM> MPa (<NUM> psi), and thixotropic properties to retain a desirablre or predetermined shape.

It will be appreciated that additional layers may be provided adjacent to and concentric with the base, first, second, and third layers <NUM>, <NUM>, <NUM>, <NUM>, and other structures or layers may discretize one or more of the base, first, second, and third layers <NUM>, <NUM>, <NUM>, <NUM> from the other layers. For example, a matrix of stiffening material extending longitudinally from the distal end portion <NUM> may extend between the first and second layers <NUM>, <NUM>. The matrix may provide additional mechanical strength in axial or radial directions. The layers <NUM>, <NUM>, <NUM>, <NUM> may extend entirely to the distal end portion <NUM> of the liner <NUM> without interruption by the solid-walled portion <NUM>. The distal end portion <NUM> may comprise structures such as an umbrella connector, additional layers having additional cushioning, spacer materials, wicking materials, or other components.

In embodiments, a second base or skin-facing layer may be provided immediately adjacent to the base layer <NUM> and between the base layer <NUM> and the first layer <NUM>. The second base layer may comprise the same material as the first, second, and/or third layers <NUM>, <NUM>, <NUM>, and may preferably be defined by thinner filaments. The second base layer may provide support and strength for the base layer <NUM>.

Each layer may have different mechanical properties and may be formed from different materials, although such materials are compatible to permit chemical bonding. For example, the second or third layers <NUM>, <NUM>, <NUM> may have greater stiffness or hardness, as the more inward layers, e.g. layers <NUM>, <NUM>, have lower hardness and greater compressibility. It will be appreciated that the arrangement of the structures and openings of each layer <NUM>, <NUM>, <NUM>, and <NUM> may vary circumferentially as suitable, and also may vary axially. For instance, the depicted arrangement with the columns and the interstice axes may be well-suited to a particular portion of a liner or medical device; while another embodiment (e.g. in which a greater or smaller number of openings may be provided and may be differently aligned with the structures and openings of adjacent layers) may be suited to a different region. In embodiments, the structures of layers may be arranged adjacent an opening of an adjacent layer rather than defining the columns.

Each layer <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may have a different thickness as suitable for a particular user, for a particular application, or otherwise. In embodiments, the base layer <NUM> may have a thickness ranging from <NUM> to <NUM>, and may preferably have a thickness of approximately <NUM>. The second base layer may have a similar thickness as the base layer <NUM>, for example, <NUM>. The first, second, and third layers <NUM>, <NUM>, <NUM> may have thicknesses of <NUM> to greater than <NUM>, and may preferably have a larger thickness than the base layer <NUM>. In embodiments, the first, second, and third layers <NUM>, <NUM>, <NUM> may have a thickness of approximately <NUM>. The textile layer <NUM> may have a thickness of <NUM> to <NUM>, with a preferred thickness of approximately <NUM>, and may be attached to an adjacent layer by an adhesive having a thickness of <NUM> to <NUM>, and preferably of about <NUM>. A total thickness of the liner body <NUM> may be approximately <NUM> to approximately <NUM>, with a preferred thickness of approximately <NUM> - <NUM>. The dimensions described are not limiting and are merely exemplary.

A lattice structure formed by the interstices <NUM>, <NUM>, <NUM>, <NUM> can be varied among different layers and in different coordinates of a layer itself or in correspondence with other layers. For example, a rib may be formed by the layers at a predetermined location of the circumference of the liner <NUM> and generally extend axially between the first and second end portions <NUM>, <NUM> of the liner <NUM>. The lattice structure at the rib may comprise of the interstices as being smaller relative to other interstices, or may not exist with the filaments of each sub-layer abutting one another to form the rib, but spaced beside one another outside the rib.

A fabric or textile material may form a textile layer <NUM> at an outward-facing portion or periphery E of the liner <NUM>. The textile layer <NUM> may be secured against an immediately adjacent layer, such as the third layer <NUM>, by impregnation of the material of the textile layer <NUM> with elastomer from the third layer <NUM>. The third layer <NUM> may be attached via adhesives or any other suitable attachment mechanism to the textile layer <NUM>. The third layer <NUM> may impregnate the textile layer <NUM> at portions corresponding and adjacent to the structures <NUM>, leaving portions of textile layer <NUM> corresponding and adjacent to openings <NUM> unimpregnated by the elastomeric material.

The textile layer <NUM> may be configured for interfacing with a corresponding prosthetic socket, for resisting wear and tear, for providing desired properties regarding anisotropy or moisture wicking, for absorbing moisture, for providing desired levels of stiffness in a certain axis such as to control pistoning, or for facilitating donning and doffing of the liner <NUM>. The textile material may modify stretching of the liner body <NUM>, for example by increasing radial stretch of the liner body <NUM> and offering counteracting elasticity to the liner body <NUM> by having a different elasticity than one or more layers <NUM>, <NUM>, <NUM>, <NUM>. Further, the textile material may facilitate breathability. The textile layer <NUM> may comprise functional zones defined by distinct sections of knitted patterns that impart certain shapes, elasticities, stiffnesses, or tendencies to the liner <NUM>.

The textile layer <NUM> may be formed of a breathable material, so the fluid and heat flowing through channels defining the interstice axes <NUM> may diffuse or bleed through the textile layer <NUM> to an exterior of the liner <NUM>. Because the material of the third layer <NUM> impregnates the textile layer <NUM> only at portions of the textile layer <NUM> corresponding and adjacent to the structures <NUM>, portions of the textile layer <NUM> corresponding to the interstice axes <NUM> remain breathable and permeable to fluid and heat, while the textile layer <NUM> remains firmly attached to the liner body <NUM>. The textile layer <NUM> may have a thickness Tt that is less than a thickness T1, T2, T3 of the first, second, and third layers <NUM>, <NUM>, <NUM>.

Due to the elasticity of elastomers such as silicone or other materials forming the layers <NUM>, <NUM>, <NUM>, <NUM>, the openings <NUM>, <NUM>, <NUM>, <NUM> defined through the layers <NUM>, <NUM>, <NUM>, <NUM> may distend upon donning of the liner <NUM>, as the residual limb forces the layers <NUM>, <NUM>, <NUM>, <NUM> to assume a larger circumference and to cover a greater surface area than in a contracted resting condition of the liner <NUM>. As the openings <NUM>, <NUM>, <NUM>, <NUM> distend and enlarge upon donning due to the materials forming the layers <NUM>, <NUM>, <NUM>, <NUM> spreading apart, permeability of the liner <NUM> to fluid and heat may increase, while the solid structures defining layers <NUM>, <NUM>, <NUM>, <NUM> may continue to provide structural and mechanical strength and comfort to the residual limb from pressure points, contact with the prosthetic socket, or otherwise. The thicknesses Tb, T1, T2, T3, Tt of the layers may decrease as the liner <NUM> expands and distends, and the structures may be continued to define the columns <NUM>, providing strength and support.

The layers <NUM>, <NUM>, <NUM>, <NUM> and the textile layer <NUM> together define the thickness <NUM> of the liner body <NUM>. <FIG> depicts a perspective cross-sectional view of the liner <NUM>. The inner cavity <NUM> is surrounded by concentric layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The concentric layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM> extend through an entirety of the liner body <NUM> and comprise different materials and/or different properties to define a comfortable, robust, and breathable liner <NUM>. It will be understood that the liner body <NUM> may comprise discrete or tapered sections comprising different layers and different materials from the embodiment shown, which is exemplary and non-limiting.

<FIG> a detailed view of the base layer <NUM>. The base layer <NUM> defines the inner surface <NUM> of the liner <NUM> and the plurality of openings <NUM>. The openings <NUM> are not limited in shape and may be formed in many geometric shapes suitable for facilitating the flow of air and sweat. The openings <NUM> may be distributed in a non-uniform pattern, with a greater density of openings <NUM> in areas where greater flexibility and/or breathability is desired, and with a lower density of openings <NUM> in areas where less flexibility or less breathability is desired.

<FIG> show a variation of the liner structure of <FIG>. A liner structure <NUM> in <FIG> may comprise a base layer <NUM> having an apertured structure <NUM> in <FIG>. A center section <NUM> may comprise at least two layers <NUM>, <NUM>, <NUM>, and <NUM>, arranged in a grid-like configuration and stacked over each other in alternating X and Y directions, as shown in <FIG>. For example, at least two layers have filaments <NUM> extending over each other in an X-axis, and spaced apart by each other in a Z-axis by filaments <NUM> extending in a Y-axis. It has been found that stacking filaments parallel with one another in the Z-axis creates a significantly cushioned center section <NUM>. Stacked filaments staggered relative to one another in the Z-axis (exemplified in <FIG>) may provide less cushioning. <FIG> shows an outer layer <NUM> as having a ventilated structure <NUM>, so a transfer of air and other fluids is created from the base layer <NUM>, through the center section <NUM> and through the outer layer <NUM>. The outer layer <NUM> may be an elastomeric layer formed by filaments, a textile layer, or any other suitably formed structure.

Referring to <FIG>, the base layer <NUM> may have a substantially thinner thickness <NUM> than a thickness <NUM> of the center section <NUM>. The base layer <NUM> may be formed from a single layer of filaments or a plurality of filaments. The center section <NUM> comprises a plurality of the filaments, and each filament may be selected to have a thickness greater than or less than the total thickness <NUM> of the base layer <NUM>. At least in the depicted embodiment, the center section <NUM> has a total thickness <NUM>, defined as a combination of each layer of filaments, and is substantially greater than a thickness of base layer <NUM>. For example, by "substantial," it is meant that the center section thickness <NUM> may be at least twice the thickness <NUM> of the base layer <NUM>. The outer layer <NUM> preferably has a thickness <NUM> greater than the thickness <NUM> of the base layer <NUM>, but less than the thickness <NUM> of the center section <NUM>, as the center section <NUM> is arranged to serve as the primary cushioning feature of the liner structure <NUM>.

<FIG> is a variation of <FIG> in that a first layer of filaments <NUM> extend in a first direction, a second layer of filaments <NUM> extends in a second direction different and relative to the first direction. For example, the first and second layers of filaments <NUM>, <NUM> extend in oblique angles relative to the X and Y axes, forming vertices <NUM>. The vertices <NUM> can be any number of desirable angles, such as those represented in <FIG>. In the depicted embodiment, the first and second layers may extend obliquely relative to the x and y axes and at right angles or perpendicularly to each other. A third layer of filaments <NUM> may be vertically arranged along the Y-axis and may bisect the vertices <NUM>, or may be offset from the vertices <NUM>. By arranging a layer of filaments <NUM> relative to the first and second layers of filaments <NUM>, <NUM>, this third layer of filaments <NUM> may be disposed to facilitate or inhibit elongation in a direction relative to the X-Y axis.

In a variation, the third layer or the layers of filaments may comprise a composite of filaments adjacent and bond to one another. For example, the third layer of filaments may comprise of each filament formed by two filaments each having a different material property to inhibit or facilitate elongation along its length.

<FIG> exemplifies vertical flow paths or channels <NUM> defined through a longitudinal length of the layers <NUM>, <NUM>, <NUM>, <NUM>. The vertical flow paths or channels <NUM> define openings between solid structures forming the layers <NUM>, <NUM>, <NUM>, <NUM>, and allowing breathability or permeability toward fluids and heat that allows fluids and heat to escape from the residual limb not only in a radial direction but also in a vertical direction. Fluid and heat may be expelled via the vertical flow paths <NUM> in either a distal or a proximal direction. The vertical flow paths <NUM> are depicted as extending in an alternating fashion between multiple of the layers <NUM>, <NUM>, <NUM>, <NUM>, but it will be appreciated that vertical flow paths <NUM> may extend through all layers, select layers, or a single layer, and uniformly or non-uniformly through the layers and the liner body <NUM>.

In the illustrated embodiment of <FIG>, the first layer <NUM> comprises sub-layers of structures, which are layers of filaments, together forming the first layer <NUM>. In a first sub-layer <NUM>, a plurality of first filaments <NUM> extends in a direction D1, with separate first filaments <NUM>, <NUM> extending parallel to one another and spaced apart a distance d1 as exemplary for the arrangement of the first filaments <NUM>. A second sub-layer <NUM> adjacent to the first sub-layer <NUM> comprises a plurality of second filaments <NUM> defining the second sub-layer <NUM> and extend in a second direction D2. The second direction D2 may be perpendicular to direction D1 or may extend in any direction relative to the first direction D1. The second filaments <NUM> may likewise comprise separate second filaments <NUM>, <NUM> spaced apart a distance d2, and extend parallel to one another.

The second sub-layer <NUM> is arranged to overlap or underlap the first sub-layer <NUM> and to define between the first and second filaments <NUM>, <NUM> the openings <NUM> corresponding to the predetermined location of interstice axes <NUM>. The arrangement of the first and second sub-layers <NUM>, <NUM> defines a lattice structure. Each opening or interstice <NUM> may be arranged to define the interstice axis <NUM> extending perpendicularly or orthogonally through a thickness T1 of the first layer <NUM>. The distances D1, D2 define the dimensions of the openings <NUM>, as established by spaces between separate filaments <NUM>, <NUM>, <NUM>, <NUM>.

The first sub-layer <NUM>, comprising separate filaments <NUM>, <NUM>, may be arranged within the first layer <NUM> to be closer to an interior I of the liner <NUM> than the second sub-layer <NUM>, with the first and second sub-layers <NUM>, <NUM> comprising different material properties suited for their respective locations. For example, the first sub-layer <NUM> may comprise a lower durometer, lower tensile strength, greater elongation, or greater tear strength, or may include different skin additives, any of which properties may provide for greater comfort at the residual limb and/or enhanced frictional engagement between the liner <NUM> and the residual limb particularly owing to the closer proximity of the first sub-layer <NUM> to the user's skin. The properties of the first and second sub-layers <NUM>, <NUM> may change throughout the length and circumference of the liner <NUM>.

<FIG> depicts a perspective cross-sectional view of an intersection between the first and second filaments <NUM>, <NUM> of the first layer <NUM> taken along line V-V in <FIG>. The first filaments <NUM> are configured to overlap and extend over the second filaments <NUM>, with discrete intersections <NUM> of the first and second filaments <NUM>, <NUM> occurring in a predetermined pattern throughout the first layer <NUM> according to the first and second directions D1, D2 in which the first and second filaments <NUM>, <NUM> continuously extend relative to each other. The first and second sub-layers <NUM>, <NUM> may secure to each other at blended portions <NUM> at one or more intersections <NUM>, so the filaments of the first and second sub-layers <NUM>, <NUM> are continuous and contiguous with one another at the intersections <NUM>. If the first and second filaments <NUM>, <NUM> are formed from silicone or other elastomeric material, the blended portion <NUM> may comprise a chemical of material at the edges or outermost portions of first and second filaments <NUM>, <NUM>, creating an integrally formed intersection of first and second sub-layers <NUM>, <NUM>. In an exemplary embodiment, the first and second filaments or sub-layers <NUM>, <NUM> are formed from medical-grade silicone. The bonding or attachment of the filaments <NUM>, <NUM> at the intersections <NUM> can ensure that the layer <NUM> maintains structural integrity and desired mechanical properties.

<FIG> depicts an embodiment of the second layer <NUM> adhered and adjacent to the first layer <NUM> and the first and second sub-layers <NUM>, <NUM>, to juxtapose both the first and second layers <NUM>, <NUM> arranged in lattice structures. The second layer <NUM> comprises third and fourth sub-layers <NUM>, <NUM>, relative to the first and second sub-layers <NUM>, <NUM>, and are arranged in a pattern defining openings and intersections between the third and fourth sub-layers <NUM>, <NUM>. As with the first and second sub-layers <NUM>, <NUM>, the third sub-layer <NUM> defines distinct and separate filaments <NUM>, <NUM> extending parallel to each other and spaced apart a distance d3, while the fourth sub-layer <NUM> defines distinct and separate filaments <NUM>, <NUM> extending parallel to and spaced apart a distance d4. The distances d3, d4 define the dimensions of openings <NUM> extending through a thickness of the second layer <NUM>.

The openings <NUM> are arranged to at least partially correspond with the openings <NUM> of the first layer <NUM>, so the interstice axes <NUM> may be defined and extend through a thickness of both the first and the second layers <NUM>, <NUM>. The filaments <NUM>, <NUM>, <NUM>, <NUM> may be staggered within the first layer <NUM>, and the filaments <NUM>, <NUM>, <NUM>, <NUM> may be staggered within the second layer <NUM>, and between the filaments of the first and second layers <NUM>, <NUM>. This arrangement advantageously provides channels along interstice axes <NUM> that may allow the flow of fluid and heat from the residual limb to the exterior E of the liner <NUM>. It will be appreciated that while the first and second layers <NUM>, <NUM> are described, filaments or other structures may be arranged in additional layers, such as the third layer <NUM>, in similar ways or alternative configurations.

The staggering of the filaments <NUM>, <NUM>, <NUM>, <NUM> of the first layer <NUM> and filaments <NUM>, <NUM>, <NUM>, <NUM> of the second layer <NUM> further provides beneficial cushioning effects and mechanical strength to the liner body <NUM>. When the liner <NUM> is donned and used, the liner <NUM> receives loads owing to the weight of the user bearing down upon the prosthetic socket system, pressing the liner <NUM> into and against the corresponding prosthetic socket. As the liner <NUM> presses downwardly and outwardly into and against the socket, the layers <NUM>, <NUM>, <NUM>, <NUM>, and the textile layer <NUM> may be radially compressed between the socket and the residual limb. The columns <NUM> of solid material comprising portions of layers <NUM>, <NUM>, <NUM>, <NUM>, and the textile layer <NUM> advantageously resist compression and provide cushioning to the residual limb, minimizing pressure points against the residual limb while maintaining the interstice axes <NUM> to enable transfer of fluid and heat.

The columns <NUM> may further provide relief by means of the staggered arrangement of filaments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as the layers <NUM>, <NUM>, <NUM>, <NUM>, and textile layer <NUM> are compressed by providing that the columns <NUM> may "lay down" against an adjacent column <NUM>, forming a reinforced or cushioned arrangement of layers of the columns <NUM>. As the liner <NUM> is compressed, each filament running parallel to each other (e.g., sub-layers <NUM> and <NUM>) will lean to one side of the sub-layer of filaments below it, causing the column <NUM> to lean into an adjacent column <NUM>. The ease by which the filaments can be compressed (because the staggered arrangement does not force two or more filaments to be compressed directly on top of one another) is advantageous because it creates a cushioned effect. The proximity of each column <NUM> to another column <NUM> will give support because a compressed column which lays down will lean into an adjacent column, spreading the pressure of the compression to a larger area reducing the pressure felt by the wearer.

The filaments of the first and second layers <NUM>, <NUM> may be formed from different but compatible materials depending on their material properties. Even among the first and second layers <NUM>, <NUM>, the sub-layers <NUM>, <NUM>, <NUM>, <NUM> may have different mechanical properties which may vary along a length of any of the filaments, while all being permanently joined to one another by chemical bonding.

<FIG> exemplify different patterns of layers of filaments, which can change the stiffness or other properties of the combination of the overlapping layers of filaments, as exemplified in <FIG>. It has been found that as the angle of the vertices increases, so does the radial stiffness of a corresponding tubular liner, as in <FIG>. The stiffness can be adapted in localized areas or about an entirety of a circumference of a liner. For example, in a liner, these benefits could be applied to a trans-tibial liner where the localized elastomeric stiffness in the knee area could be reduced, allowing easier knee flexion. Another example could be a gradual reduction in stiffness towards the proximal opening of a liner to improve comfort and to ease donning and doffing of the liner <NUM>.

<FIG> shows a layer <NUM> with first and second filament layers <NUM>, <NUM>, having vertices <NUM> oriented toward the Y-axis of <NUM>°. <FIG> shows a layer <NUM> with first and second filament layers <NUM>, <NUM> as having vertices <NUM> oriented toward the Y-axis of <NUM>°. <FIG> shows a layer <NUM> with first and second filament layers <NUM>, <NUM> as having vertices <NUM> oriented toward the Y-axis of <NUM>°. <FIG> shows a layer <NUM> with first and second filament layers <NUM>, <NUM> as having vertices <NUM> oriented toward the Y-axis of <NUM>°.

<FIG> exemplifies how a lattice structure <NUM> of a liner of the embodiments creates a damping effect among a plurality of layers of filaments <NUM> between opposed sides or inner and outer layers <NUM>, <NUM> of the liner. It has been found there is a "damping" effect at a thickness <NUM> between the opposed sides <NUM>, <NUM> of the lattice structure <NUM>, when using the liner, and is described as the difference between walking on grass (such as the embodiment of <FIG> and schematically shown in <FIG>) and walking on concrete (such as a traditional solid-walled liner).

In a traditional solid elastomeric prior art liner, the lattice structure provides damping to axial and torsional forces usually transferred directly from a hard prosthetic socket to a residual limb. The inner and outer layers of a liner can be fixed to the residual limb L and socket S, respectively. The center section <NUM> may allow the inner and outer layers <NUM>, <NUM> to move in directions MI, Mo, respectively, independently relative to each other to some extent without exerting high or significant shear forces on the skin. These forces are associated with skin irritation and discomfort.

From <FIG>, during a stance phase in gait, there may be axial downwardly directed movement ML of the limb L from a neutral position into or toward the socket S, which may have a positive "shock-absorbing" effect. However, during a swing phase in gait, axial downwardly directed movement ML from the neutral position may cause the socket to pull away from the limb. <FIG> exemplifies how multiple layers <NUM>, <NUM>, <NUM>, <NUM> of the filaments arranged in a lattice structure <NUM> can be aligned in such a way to promote only movement in the desired direction by inhibiting movement in the downwardly directed movement ML.

<FIG> shows how unlike in conventional liners, a lattice structure <NUM> has air pockets <NUM> that can allow the lattice structure <NUM> to be more easily compressed without displacing solid material and transferring pressure to another location. Residual-limb volume fluctuation is one of the main issues faced by amputees and can cause socket fit becoming too loose or uncomfortably tight. The lattice structure <NUM> addresses this shortcoming in known liners.

Bony prominences B on the residual limb L can cause uncomfortable pressure points. The volume-compensation characteristics of the lattice structure <NUM> accommodate these bony prominences on a local level, easily deforming around bony prominences B with a local deformation D, relieving localized pressure points. A solid liner, generally having a solid construction, may likewise be custom formed by including a plurality of filaments customized to a specific residual limb having bony protuberances or other irregularities creating pressure points with localized areas of the lattice structure to provide for pressure relief.

This arrangement is further beneficial because it mitigates the challenges of a user's needs or dimensions changing and rendering the liner less effective. A user whose limb changes in size due to swelling or weight changes is better accommodated by a liner according to the embodiments which does not require the additional provision of padding, recesses, or other features to accommodate the user's dimensions. Rather, the lattice structure <NUM> provides improved forgiveness for bony prominences, bulging, swelling, reductions thereof, and other changes in a user's dimensions owning to the improved volume-compensation characteristics.

<FIG> depicts an elevational view of another embodiment of a liner <NUM>. The liner <NUM> may be formed from silicones or other elastomeric materials having multiple durometers. The liner <NUM> comprises a distal end portion <NUM> and a proximal portion <NUM>, with the proximal portion <NUM> being open for receiving a residual limb. A liner body <NUM> may be formed from multiple layers of material, with an outer layer <NUM> having a high durometer and an inner layer <NUM> having a lower durometer than the outer layer <NUM>. As with the embodiment introduced in <FIG>, the inner and outer layers <NUM>, <NUM> may define at least partially aligned interstices <NUM> allowing the transfer of fluid and heat from an interior portion of the liner <NUM>.

As with previous embodiments, the liner <NUM> comprises a solid-walled portion <NUM>, providing added strength and cushioning to the distal end portion <NUM> whereat an attachment pin or other components may attach. The solid-walled portion <NUM> may define a gradient <NUM> increasing toward the distal opening <NUM>, with the areas immediately surrounding the distal opening <NUM> having increased stiffness. The increased stiffness may be due to a change in the properties of the material approaching the distal opening <NUM>, a change in the material or of the choice of material approaching the distal opening <NUM>, additives, or embedded structures approaching the distal opening <NUM>, or other suitable measures.

An interface <NUM> may join the solid-walled portion <NUM> of the distal end portion <NUM> with the liner body <NUM>. The liner body <NUM> may comprise the outer and inner layers <NUM>, <NUM>. A ledge, ridge or thickness <NUM> may be formed at the interface <NUM>. The thickness <NUM> provides added mechanical strength and interfacing features with a corresponding prosthetic socket.

<FIG> depict the outer layer <NUM> as comprising sub-layers, including first and second filaments <NUM>, <NUM>. The inner layer <NUM> may likewise comprise first and second filaments <NUM>, <NUM>. The first filaments <NUM>, <NUM> may extend parallel to each other and perpendicularly to the second filaments <NUM>, <NUM>, which may extend parallel to each other. The distance by which the filaments are spaced apart from each other may define a size of interstices <NUM>, allowing for breathability without sacrificing the mechanical advantages of a solid-walled liner.

The liner <NUM> may further comprise a base layer attached and adjacent to the inner layer <NUM>. The base layer comprises a substantially solid layer of silicone perforated by a pattern of orifices corresponding at least partially to the interstices <NUM>, as described in previous embodiments.

As described concerning the embodiment introduced in <FIG>, the inner and outer layers <NUM>, <NUM> may advantageously comprise different properties, materials, or configurations. Various durometers may be attained by providing filaments containing multiple layers of materials having different properties. The inner and outer layers <NUM>, <NUM> need not have uniform properties throughout their entirety, but rather may have different properties at different locations.

In the embodiment in <FIG>, a cross-sectional view of a multi-layer filament <NUM> is depicted. The filament <NUM> has an inner layer <NUM> and an outer layer <NUM> concentric with and adjacent to the inner layer <NUM>. The outer and inner layers <NUM>, <NUM> may have different properties relative to one another. For example, the inner layer <NUM> may have a softer or lower durometer than the outer layer <NUM>. The outer and inner layers <NUM>, <NUM> may have different curing rates to facilitate chemical bonding to adjacent sub-layers or filaments. Preferably, the outer and inner layers <NUM>, <NUM> are coextruded or co-deposited and are chemically bonded to one another to form a fixed and permanent integral structure of the multi-layer filament <NUM>.

The inner layer <NUM> of the multi-layer filament <NUM> may advantageously have a different durometer relative to the filaments <NUM>, <NUM> of the inner layer <NUM>. The outer layer <NUM> may be formed from a material having a color profile different than a color profile or a clear color of material forming the inner layer <NUM>. The pigments or other materials admixed with the material of outer layer <NUM> to define the color profile thereof may additionally provide the outer layer <NUM> with different properties from the inner layer <NUM>, including a higher durometer, greater elasticity, or other properties at desired locations along with the liner. Additional layers adjacent to the outer layer <NUM> may be provided, or outer and inner layers <NUM>, <NUM> may be provided adjacently in a laminar fashion, as examples of additional embodiments of the multi-layer filament of <FIG>. Any number of layers having any suitable properties may be provided in any suitable shape and at any location along a length of a filament.

According to a variation, the multi-layer filament <NUM> may be modified so a diameter of the cross-section of the inner layer <NUM> varies along the length of the filament <NUM>. An outer diameter of the outer layer <NUM> may remain constant or vary, and the inner diameter of the outer layer <NUM> varies according to the diameter of the inner layer <NUM>. From this variation, the multi-layer filament <NUM> may have varying properties according to its length due to the different properties of the outer and inner layers <NUM>, <NUM>.

Additional layers or structures may be included in the liner <NUM> to facilitate breathability, to improve the mechanical features, or to provide other functions for a liner.

<FIG> exemplify another embodiment <NUM> of a medical device such as a liner. In this embodiment, a base layer <NUM> is defined over a first side of a lattice structure <NUM> and a textile layer <NUM> is defined over a second side of the lattice structure <NUM>. <FIG> shows how the lattice structure <NUM> has a grid-like structure of layers of filaments <NUM>, <NUM> along the X and Y axes, respectively, with voids or cells <NUM> defined between or amid the generally perpendicularly arranged filaments <NUM>, <NUM>. Each layer <NUM>, <NUM> may be stacked upon each other and aligned in the X and Y axes, or they may be staggered relative to one another, so the layers are directly above or below each cell <NUM>, and adjacent layers may include filaments overlapping the cell <NUM>.

<FIG> shows a base layer <NUM> having an apertured layer <NUM> with substantially finer apertures <NUM> than the lattice structure <NUM>. The base layer <NUM> may be formed by a plurality of filaments forming a generally solid thickness aside from the apertures <NUM> and may be formed by segments of filaments in one of the X and Y directions adjacent to continuous filaments. The base layer <NUM> may have different material properties than the lattice structure <NUM>, such as a substantially soft surface for facing skin of a residual limb. The apertures <NUM> may have a surface area lower than the cells <NUM>, so the combined surface area of the base layer <NUM> is greater than the combined surface area of the apertures <NUM>.

<FIG> shows a variation of a lattice structure <NUM>. In this variation, there are portions 392a, 392b of the lattice that have a generally uniform spacing of cells <NUM>, although there may be different spacings among filaments in one direction, such as the Y direction, versus the X direction. Such relative spacings can be modified according to a desired elasticity, as mentioned referring to the embodiments of <FIG>. The lattice structure <NUM> may have localized regions where there is a gradual spacing among filaments of layers and directions, as in regions 394a, 394b. The gradual spacing may cause enhanced or minimized localized elasticity of the lattice structure <NUM> and may transition the lattice structure <NUM> from the portions 392a, 392b to a second, or other region with different properties.

<FIG> exemplifies how filaments <NUM>, <NUM>, <NUM> may be arranged with a different thickness in the Z-axis. For example, a first layer of filaments <NUM> extending in a first direction D5 have a smaller thickness <NUM> than a thickness <NUM> of a second layer of filaments <NUM> extending in a second direction D6, which may be orthogonal to the direction D5. A third layer of filaments <NUM> extending in the first direction D5 may have a greater thickness <NUM> than the second layer of filaments <NUM>; however, the layers may have the same thickness as another layer. In embodiments, the filaments <NUM>, <NUM>, <NUM> may have dynamic thicknesses and diameters that change throughout the lattice structure <NUM>. The overlap and blending of layers (for instance, at intersections between filaments of different layers or sub-layers) may be varied as suitable. Areas with larger diameters of the filaments <NUM>, <NUM>, <NUM> and/or with greater overlap and blending at the intersections of adjacent layers may have lower breathability than an area with smaller diameters of the filaments <NUM>, <NUM>, <NUM> and/or with reduced overlap between filaments of adjacent layers.

<FIG> exemplifies a film <NUM> formed from a plurality of filaments <NUM> arranged in the same direction, such as along a Y-axis. The plurality of filaments <NUM> is arranged directly adjacent to one another, so they each have a continuous and contiguous border <NUM> blending into one another. While shown with lines between each filament <NUM>, in an actual sample the borders <NUM> among each filament <NUM> are indistinguishable and are not visually apparent due to the blending of the borders <NUM>. The plurality of filaments <NUM> may comprise a single layer or multiple layers, whereby the borders of the filaments over the other filaments in a Z-axis likewise blend to be continuous and contiguous. The different layers of filaments may be bonded to adjacent layers of filaments in any suitable way. For instance, the attachment between layers may be continuous or may be in particular parts.

<FIG> illustrate another embodiment of a liner <NUM> having a plurality of filaments <NUM> defining a vertically coiled lattice structure in a direction of the Z-axis, and in X- and Y-axes. The filaments <NUM> are arranged adjacent one another in X and Y directions in a layer. Each filament 402a, 402b, 402c, 402d extends along the height of the thickness of the layer in the Z-axis, and interlock in the X- and Y-axes with the adjacent filaments <NUM>, and form cells <NUM> in a pattern therebetween in the X, Y and Z-axes.

It has been found that vertically coiled filaments exhibit a generally consistent shape when parameters are maintained. The cells <NUM> vary in shape according to the shape of the coiled lattice structure. A medical device according to embodiments of the disclosure may utilize one or more layers having the plurality of filaments <NUM> extending in a Z-axis according to height or length of the filaments. For instance, one or more of the base, first, second, and third layers <NUM>, <NUM>, <NUM>, <NUM> of the embodiment introduced in <FIG> may be formed from a plurality of filaments <NUM>.

The filaments <NUM> may be arranged to utilize the phenomenon known as the liquid rope-coiling effect, so the filaments <NUM> may each be deposited as a linear, straight, or otherwise uncurled filament of uncured elastomeric material which can be in a liquid phase. As the linear uncured filament contacts a build surface on which the layer is being built, the liquid rope-coiling effect causes and propagates the coiling or torqued effect observed in the filaments <NUM>. As the filaments <NUM> cure, solidify, and interact with adjacent filaments and the build surface, the shape of the coil is maintained.

It has been found that using the liquid rope-coiling effect to create a layer defined by the plurality of filaments <NUM> simplifies the manufacturing process, as a relatively short and linear filament of uncured elastomeric material may be deposited at a particular location to create a filament <NUM> without depositing lengthy and uninterrupted filaments in X and Y directions and with no precise depositions for any of the plurality of filaments <NUM>, while retaining desired properties across a portion of the layer. Across the portion of the layer defined within specific lengths in the X and Y directions, the properties of the filaments and, therefore the layer such as elasticity, may average to the desired value despite varying properties of individual filaments <NUM>.

As the filaments <NUM> are deposited to form a layer, the individual filaments <NUM> may be deposited to interlock with adjacent filaments <NUM> at intersections <NUM>, <NUM>, in which the coils of adjacent filaments <NUM> are intertwined. The interlocking of the filaments <NUM> at the intersections <NUM>, <NUM> may advantageously provide properties in terms of elasticity, anisotropy, or other properties in the X and Y directions and toward the Z-axis. The interlocking of the filaments <NUM> at the intersections <NUM>, <NUM> advantageously allows for the filaments <NUM> to define the layer without a backing or solid layer to which the filaments <NUM> are deposited or attached.

Depending on the properties of the individual filaments <NUM>, for example, the interlocking at the intersections <NUM>, <NUM> may increase the stiffness of the medical device, may facilitate extension in a desired direction, or may provide for a desired cushioning at a particular region. The adjacent filaments 402a, 402b, 402c, 402d may be chemically bonded to each other at the intersections <NUM>, <NUM>, as described in previous embodiments. The intersections <NUM>, <NUM> may, like the properties of the individual filaments <NUM>, have individual variation throughout the layer while still attaining a desired average property for a particular portion of the layer.

In an alternative embodiment of a portion of a liner <NUM> depicted in <FIG>, the liner <NUM> may comprise a first layer <NUM>, a second layer <NUM> adjacent to and concentric with the first layer <NUM>, and a third layer <NUM> adjacent to and concentric with the second layer <NUM>. A volume control pad or protruding feature <NUM> extends over portions of an inner surface <NUM> of the liner body and is integrally formed from the first layer <NUM>. An uneven surface <NUM>, such as used for vacuum sealing applications, may extend over an exterior surface of third layer <NUM>.

Non-uniform openings <NUM> may be defined through a thickness of first layer <NUM>, with outlets <NUM> from the non-uniform openings <NUM> and defined through a portion of the second layer <NUM> aligned with the non-uniform openings <NUM> and defining a vertical channel facilitating enhanced axial transfer of fluid and heat and in place of radial channels, such as along interstice axes <NUM> in the embodiment introduced in <FIG>. It will be appreciated that the depicted configurations, sizes, patterns, materials, properties, and numbers of openings, channels, layers, and other features in the depicted embodiments are exemplary, and other configurations of features and structures may achieve a medical device according to the disclosure.

<FIG> exemplifies how the thickness of a lattice structure <NUM> according to embodiments of the disclosure may have a tapered or stepped profile to interlock with a distal end <NUM> of a liner, as shown in <FIG>. The distal end <NUM> may be a solid-wall construction formed from discrete filaments and may be formed from an elastomeric or polymeric material different from the lattice structure <NUM>. According to the depicted embodiment, an interface <NUM> between a stepped end portion <NUM> of the lattice structure <NUM> and a corresponding stepped end portion <NUM> of the distal end <NUM> may be continuous and contiguous with both end portions <NUM>, <NUM> blending to form a chemical bond.

In an embodiment, the ventilated structure <NUM> and solid-walled structure <NUM> of the embodiment of <FIG> could be formed with inverse tapers at the interface <NUM>. An embodiment is illustrated in <FIG>. The solid-walled structure <NUM> defining the stepped end portion of the distal end <NUM> decreases in thickness at the interface <NUM>. The solid-walled structure <NUM> at the interface <NUM> is structured near the interior surface I of the liner. The thickness of the ventilated structure <NUM> defining the stepped end portion of the lattice structure <NUM> increases at the interface <NUM> until it has reached the desired thickness. The ventilated structure <NUM> at the interface <NUM> is structured near the exterior surface E of the liner. This feature is advantageous because it reduces pressure points at the interface <NUM> between the ventilated structure <NUM> and the solid-walled structure <NUM>. This embodiment provides a larger surface area for the interface <NUM>, which ensures a stronger and more durable bond between the ventilated structure <NUM> and the solid-walled structure <NUM>.

In a variation, the solid-walled structure <NUM> and the ventilated structure <NUM> taper at the interface <NUM> as described above. However, in this embodiment, the solid-walled structure <NUM> at the interface <NUM> is structured near the exterior surface E of the liner. Inversely, the ventilated structure <NUM> at the interface <NUM> is structured near the interior surface I of the liner. This feature is advantageous because it extends the ventilating structure <NUM> further down into the distal end <NUM> providing better wicking of heat and fluid from the distal end <NUM>. The tapering of the interface <NUM> can be increased or decreased from the taper demonstrated in <FIG>, increasing or decreasing the reach of the ventilated structure <NUM> into the distal end <NUM>. This may also cushion the limb against pressure points because of the features of a lattice structure as described herein.

The stepped interface <NUM> between the solid-walled structure <NUM> and the ventilated structure <NUM> advantageously provides a gradual change in compression. A compression profile is smoother and reduced as the solid-walled structure <NUM> gradually transitions via the stepped interface <NUM> into the ventilated structure <NUM>.

In another embodiment of a liner <NUM> depicted in <FIG>, the liner <NUM> includes a liner body <NUM> at a distal end of the liner <NUM>, with a textile <NUM> covering a portion of the liner body <NUM> proximally of the distal end and attaching at a seam or seal <NUM>. The textile <NUM> may be discretized from the distal end by a distal seam <NUM> at which the textile <NUM> is reinforcedly bonded to the liner body <NUM>. First and second edges <NUM>, <NUM> of the textile cover <NUM> are advantageously joined using the material forming the liner body <NUM>.

In contrast to existing prosthetic liners in which textile covers must be joined at a seam using stitching, sewing, or other attachment means, which increase the costs and complexities of manufacturing liners, the textile <NUM> may be joined at the first and second edges <NUM>, <NUM> by attaching or impregnating the textile <NUM> with the elastomer forming the liner body <NUM>.

The liner <NUM> may comprise throughout an entirety of the liner body <NUM> a matrix arranged for limiting axial elongation while allowing circumferential or radial elongation, this arrangement advantageously mitigating "pistoning," "milking," and other undesirable effects between a liner and residual limb. The liner body <NUM> may comprise layers of filaments or other materials arranged to receive the matrix.

By providing a medical device according to embodiments described, the problems of medical devices such as liners poorly navigating the tension between mechanical strength needed to cushion and protect a body portion such as a residual limb and the need for a breathable device to mitigate the buildup of fluid and heat are addressed. The structures forming layers, multi-layer filaments, and openings and structures defined advantageously provide for permeability of the liner to fluid and heat while retaining needed structural strength to cushion the residual limb. The liner further provides for simplified manufacturing processes by incorporating the stitching or sewing of a textile cover in the material forming the layers or liner body.

Claim 1:
A prosthetic liner (<NUM>) defining a proximal end (<NUM>) and a distal end (<NUM>), the prosthetic liner having a liner body (<NUM>) defined between the proximal end and the distal end, and the liner body having a tubular shape, the liner (<NUM>) comprising:
a lattice structure defined as a plurality of layers monolithically formed as an inseparable and continuous structure;
wherein the lattice structure includes a first layer (<NUM>) of first filaments (<NUM>) discretely formed from a first elastomeric material, and overlapping a second layer (<NUM>) of second filaments (<NUM>) discretely formed from a second elastomeric material, the first and second filaments (<NUM>, <NUM>) of the first and second layers (<NUM>, <NUM>), respectively, overlapping and forming a first set of interstices (<NUM>) located therebetween in a predetermined pattern, wherein the first filaments (<NUM>) are spaced apart from each other, and extend in a first direction oriented differently from a second direction in which the second filaments (<NUM>) extend;
wherein the first and second filaments extend continuously about the tubular shape of the liner body, and the first and second layers are relatively concentric to one another, characterized in that the first and second layers of the first and second filaments are permanently and chemically bonded to one another, the first and second layers are blended at least in part with one another in a blended region.