# Patent

## Title
Suspension liner with seal component

## Abstract

A suspension liner is provided for use as an interface between a residual limb and a prosthetic socket. The liner has an elongate, generally conical liner body formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition and including proximal and distal end areas, and a seal component connected to the liner body and having an exterior surface defining at least one exterior seal protruding from the exterior surface and extending radially outwardly from the seal component relative to a longitudinal axis of the liner body. The at least one interior seal is located along an interior surface of the seal component and defines at least one blade extending obliquely toward the liner body. A portion of the seal component carrying the interior seal extends freely and is movable relative to the liner body.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of priority from U.S. Provisional Application No. 61/526,035, filed on Aug. 22, 2011, the entirety of which is incorporated by reference.


FIELD OF THE DISCLOSURE
This disclosure relates to a suspension liner for prosthetic devices, and more particularly to a suspension liner for enveloping a residual limb and having a seal component for engaging a prosthetic socket.
BACKGROUND
Suspension liner systems are widely used in prosthetic systems for residual limbs in order to stabilize soft tissue, minimize pistoning or stretching, assist circulation of the residual limb and add comfort.
Various solutions are found in the prior art, including those described in U.S. Pat. No. 7,025,793, granted on Apr. 11, 2006, and U.S. Pat. No. 8,034,120, granted on Oct. 11, 2011, both of which are incorporated herein by reference. According to these publications, a liner includes a liner body and a seal component located at the distal end area of the liner body. The seal component is flexible so it can conform to the shape of the residual limb and the internal wall of the prosthetic socket, thereby providing an airtight seal. The seal component minimizes movement of the limb within the socket, so as to prevent pistoning and rotation. In operation, the residual limb is stepped into the socket and expels air through a distal valve on the socket so as to create hypobaric suction below the seal component.
Some users find that known liners having sealing means fail to sufficiently tolerate volume fluctuations, and may leave pressure marks on the residual limb after periods of sustained use. Additional improvements may be required for some users in that known liners do not adequately conform to the user's anatomy, and therefore fail to provide necessary comfort and skin protection. Moreover, as with all suspension liners having sealing means, it is necessary that the liner provides reliable suspension after an initial phase of volume and shape conditioning after the liner is donned on the user's residual limb.
SUMMARY
A suspension liner with a seal component is described herein and provides a connection and interface between a prosthetic socket and residual limb. The connection is made by using a suspension liner with a seal so as to create a vacuum to suspend the residual limb to the socket. The suspension liner removes the need for distal pin that is commonly employed in suspension liners and is used to couple to a hard, prosthetic socket and other prosthetic leg components. Moreover, because the seal is formed by the suspension liner itself, a sleeve of an exemplary type discussed in U.S. Pat. No. 6,592,539, granted Jul. 15, 2003 and incorporated herein by reference, is not required to seal the liner to the socket.
The suspension liner with a seal component has at least the benefits of mitigating distal pistoning from a distal pin. There is no restriction over the knee of the wearer to any sleeve. Therefore, the suspension liner with a seal component provides a reliable suspension without distal attachments or suspension sleeves.
Due to the particular liner and seal component embodiments discussed, herein the suspension liner provides a secure connection over varying residual limb volumes between the socket and the residual limb. Also, the liner and seal component embodiments provide a comfortable connection between the socket and the limb by reducing noticeable pressure marks.
According to an embodiment, the suspension liner includes an elongate, generally conical liner body formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition and including proximal and distal end areas, and a seal component connected to the liner body. The seal component has at least one exterior configuration for engaging a prosthetic socket and at least one interior configuration for movably engaging the liner body.
The exterior configuration may be arranged to have at least one seal that protrudes radially outwardly from an exterior surface of the seal component relative to a longitudinal axis of the liner body.
The interior configuration may be arranged to protrude inwardly toward the liner body, and may be yet further arranged to extend at an oblique angle relative to the longitudinal axis of the liner body. In a variation, the interior configuration defines at least one blade extending obliquely toward the liner body. The blade may taper toward its distal and proximal ends along a segment of the length of the liner body, such as tapering in thickness from an interior wall of the seal component toward the liner body exterior surface.
A portion of the seal component carrying the interior configuration extends freely and movable relative to the liner body
In a variation of the interior configuration of the seal component, the seal component defines an inwardly pitched portion at the proximal end thereof and directed toward the liner body exterior surface.
In another variation, the interior configuration defines at least one blade extending toward the liner body with the blade being bounded by an outwardly pitched portion of the interior configuration located near a distal end of the seal component and an inwardly pitched portion at the proximal end of the seal component and directed toward the liner body exterior surface.
The seal component may define a base portion circumferentially secured to an exterior surface of the liner body. The base portion may have an attachment portion entirely secured to the exterior surface of the liner body, with the remainder of the seal component outside and proximally located relative to the attachment portion extending generally freely from the liner body.
The seal component may define a lip arranged against the liner body; the interior configuration may be located proximal relative to the lip. A clearance may be formed between the lip and an outwardly pitched portion of the interior configuration extending from a base portion located at a distal end of the seal component.
In another embodiment, the suspension liner includes an elongate, generally conical liner body formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition and including proximal and distal end areas, and a seal component connected to the liner body and having an exterior surface for engaging a prosthetic socket and at least one interior seal located along an interior surface of the seal component and arranged for engaging the liner body. A portion of the seal component carrying the interior seal extends freely and movable relative to the liner body.
The exterior seal may protrude from the exterior surface and extend radially outwardly from the seal component relative to a longitudinal axis of the liner body and opposite to the interior seal. The at least one interior seal can define at least one blade extending obliquely toward the liner body. The seal component may define a lip arranged against the liner body and the interior seal is located proximal relative to the lip.
In yet another embodiment, the suspension liner has an elongate, generally conical liner body formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition and including proximal and distal end areas, and a seal component connected to the liner body and having an exterior surface defining at least one exterior seal protruding from the exterior surface and extending radially outwardly from the seal component relative to a longitudinal axis of the liner body. The at least one interior seal is located along an interior surface of the seal component and defines at least one blade extending obliquely toward the liner body. A portion of the seal component carrying the interior seal extends freely and movable relative to the liner body.
According to any of the suspension liner embodiments having a seal embodiment, the seal component may be located at various locations along the exterior surface of the liner body relative to the proximal and distal ends. For example, a “high profile” suspension liner may have a seal component which is located 3-6 cm more proximally than a convention suspension liner with a seal component. This particular configuration may be employed for those users that require a more proximal seal, particularly trans-tibial amputees. By locating the seal component more proximally relative to the liner body, a larger vacuum chamber is created distally of the seal component than in conventional suspension liners having a seal component. Moreover, the seal component may be located proximal from a sensitive distal end of the residual limb.
Any of the liner body embodiments described herein may define a circumferential recess arranged to receive a length of the seal component. The seal component may be fixedly secure to the liner without permitting adjustment of the location of the seal component relative to the liner body, or alternatively the seal component may be securable over any desirable location of the liner body by a clinician.
The liner body may have a variable thickness. In an exemplary embodiment, the liner body may have a significantly greater thickness at the distal end, and gradually taper toward the proximal end. In doing so, a circumferential recess of the liner body may define a reduced thickness region compared to regions adjacently outside the circumferential recess.



BRIEF DESCRIPTION OF THE DRAWINGS
The numerous other advantages, features and functions of embodiments of a suspension liner will become readily apparent and better understood in view of the following description and accompanying drawings. The following description is not intended to limit the scope of the suspension liner, but instead merely provides exemplary embodiments for ease of understanding.
FIG. 1 is an elevational view of an embodiment of a suspension liner having a seal component.
FIG. 2 is an elevational view of the suspension liner without the seal component.
FIG. 3 is a cross-section view of the suspension liner according to FIG. 2.
FIG. 4 is a schematic view showing the seal component according to FIG. 1.
FIG. 5 is a cross-section view of the seal component of FIG. 4 taken along line V-V.
FIG. 6 is a sectional view corresponding to detail VI in FIG. 5.
FIGS. 7A-7E are schematic views showing the donning and doffing of the suspension liner with a prosthetic socket.
FIG. 8 is a schematic view showing minimization of the movement of the residual limb in a socket.



It should be noted that the drawing figures are not necessarily drawn to scale, but instead are drawn to provide a better understanding of the components thereof, and are not intended to be limiting in scope, but rather to provide exemplary illustrations. It should further be noted that the figures illustrate exemplary configurations of a liner, and in no way limit the structures or configurations of a liner thereof according to the present disclosure.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS
A better understanding of different embodiments of the invention may be had from the following description read in conjunction with the accompanying drawings in which like reference characters refer to like elements.
A. Overview of Suspension Liner Embodiments
In each of the embodiments discussed herein, the suspension liner is intended for use between a residual limb and a prosthesis, such as a hard socket, and to be air-tight when donned over a residual stump. The internal surface of the liner may be formed of a layer of silicone elastomer, therefore serving as a skin interface. Silicone is advantageous in that it allows for different levels and softness and strength to be incorporated into the liners of the present application. Moreover, silicone permits the addition of selected supplements, such as petroleum jelly and aloe vera, which improve skin care and comfort.
An elasticity controlling matrix material may be provided on the exterior of the liner, the matrix material preferably being relatively compliant in a radial direction and substantially rigid or inelastic in an axial direction. The matrix material may extend over the distal or external side of the prosthesis, and is advantageous in that it prevents movement of the liner when a prosthesis is worn thereover.
A liner in accordance with this disclosure may be fabricated in a sufficient number of sizes to accommodate various sizes of residual limbs. In use, a liner of the type described herein is rolled up from the proximal to the distal end, placed over the distal end of the residual stump and rolled back up or “donned” over the stump like a stocking. This procedure and the benefits achieved thereby are described in detail in U.S. Pat. No. 4,923,474, granted on May 8, 1990 and incorporated herein by reference. In addition, any of the liners and sleeves mentioned herein may be constructed in the manner prescribed by U.S. Pat. No. 4,923,474.
The embodiments of the suspension liner of the present application may be constructed according to the molding methods described in U.S. Pat. No. 6,485,776, granted on Nov. 26, 2002 and the entirety of which is incorporated herein by reference.
B. Specific Embodiments of the Suspension Liner with a Seal Component
FIG. 1 illustrates an embodiment of a suspension liner 10 in accordance with the invention. The liner 10 includes a liner body 12, and a seal component 14 connected to the liner body 12.
The liner body 12 preferably has an elongate, generally conical shape. The liner body 12 defines a longitudinal axis A-A, and includes proximal and distal end portions. The liner body 12 may be formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition.
As depicted in FIG. 2, the liner body 12 is preferably formed with a circumferential recess 16 for receiving the seal component. Particularly, the recess 16 compensates for the thickness of the seal component in such a manner that the seal component does not extend or substantially extend in excess or at all beyond an exterior surface ES of the liner body 12 located outside of regions of the recess 16. The seal component 14 may be secured against the exterior surface EE of the liner body located within the recess 16. Moreover, another exterior surface EEE located within the recess 16 is arranged for received a portion of the seal component, the base portion 20 described in FIGS. 3 and 4, defines an attachment portion that is adhered or otherwise fastened to the liner body 12.
The liner body 12 forms a proximal beveled circumferential edge 17 at a proximal end portion of the recess, a distal beveled edge 21 at a distal end portion of the recess, and a middle beveled circumferential edge 19 located between the proximal and distal end portions of the recess. The beveled edges receive portions of the seal component and minimize sharp or harsh edges that may cause discomfort when the residual limb is in a socket with the liner donned.
FIG. 1 generally shows the seal component 14 in a “conventional” location, however as also shown in FIG. 1, the seal component 14′ can be located more proximal relative to the liner body. For example, the seal component 14′ may be located 3 to 6 cm more proximal than in the conventional location. This particular configuration may be employed for those users, particularly trans-tibial amputees that require a more proximal seal. By locating the seal component more proximal relative to the liner body, a larger vacuum chamber is created distally of the seal component than in conventional suspension liners having a seal component. Moreover, the seal component may be located proximal from a sensitive distal end of the residual limb.
The entire liner body 12 may be configured, including the recess 16 for the proximal seal component 14′
FIG. 3 shows how the liner body may include a tapered thickness from the distal end to the proximal end. For example, the distal end may have a thickness 25 of 12-15 mm and taper in thickness 27 of 6-8 mm distally adjacent the recess 16. The thickness 29 proximally adjacent the recess 16 may be 4-6 mm with the thickness tapering to the proximal end to a thickness around 2.0-3.0 mm. The thickness of the liner provides additional cushioning at the distal end, and easy roll-on/off at the proximal end when the liner is donned of doffed. Additional thickness is about the recess to accommodate the seal component.
In an exemplary embodiment, FIGS. 4 and 5 show a seal component 14 having both exterior and interior configurations 18, 32. The exterior configuration 18 is arranged for engaging against a prosthetic socket wall, whereas the interior configuration is arranged for engaging the exterior surface ES of the liner body 12.
The seal component 14 includes a base portion 20 located at the distal portion of the seal component, and secures to the exterior surface EE of the recess 16. An interior surface 36 of the base portion 20 is preferably anchored circumferentially to the exterior surface EE to a pivot line 38. A seal wall 22 is located above the pivot line 38, and flexibly and movably extends relative to the liner body 12 and the base portion 20.
The seal component 14 defines a lip 40 which extends above the base portion 20 and parallel to the exterior surface EE of the liner body 12. The lip 40 is adhered to the liner exterior surface EE, and provides additional retention of the seal component to the liner body. The lip may be tapered so as to provide a gradual transition along the liner body.
A gap 42 is formed between the lip 40 and a surface 44 of a distal outwardly pitched portion 22 of the seal wall 24. The gap 42 enables the seal wall 24 to flexibly and movably extend relative to the liner body. The distal outwardly pitched portion 22 effectively forms a taper for the seal component in order to facilitate donning of the suspension liner in a prosthetic socket.
The seal wall 24 has exterior and interior surfaces 54, 56, corresponding respectively to the exterior and interior configurations 18, 32. The exterior surface 54 carries a plurality of individual exterior radially extending seal rings 26, 28. These seal rings 26, 28 are arranged to engage the interior socket wall, and expel air through a valve on the socket as the residual limb carrying the liner is stepped into the socket. The seal rings form an airtight connection between the liner and the socket, and ensure secure suspension.
While two seal rings are shown in FIG. 4, the seal component may have either one or any number of seal rings as considered necessary to form an airtight connection with a socket.
According to FIG. 6, each of the seal rings 26, 28 includes a distal pitched section 50, a proximal pitched section 52, and a peak 48 located therebetween. It will be understood that the seal rings may take any number of configurations, and are not limited to the variation depicted in FIG. 5. Indeed, the seal rings may be construed in the manner of any one of the seal rings depicted and discussed in U.S. Pat. No. 8,304,120. For example, the pitched sections may have either a linear, cross-sectional profile, or a curved, cross-sectional profile. Further yet, the seal rings may take a variety of other cross-section profiles such as in the form of a square or with rounded edges.
According to FIG. 5, the interior configuration 32 is formed along the interior surface 56 of the seal wall 24, and is bounded by the distal outwardly pitched portion 22 and a proximal inwardly pitched portion 30 located at the uppermost end of the seal component 14. As with the outwardly pitched portion 22, the inwardly pitched portion 30 acts as a transition to facilitate donning and doffing of the liner in a socket.
A plurality of blades 34 are located along the interior surface 56 of the seal wall 24, and the plurality of blades 34 extend circumferentially about the seal wall 24. The blades compensate for volume changes in the residual limb, by expanding and exerting pressure against an interior surface of the socket so as to improve suspension of the liner over known suspension liners with seals.
In the depicted embodiment of FIG. 5, the blade has a smallest width (direction of interior surface of seal wall toward the liner body) at a distal portion 60, and gradually increases across a central portion 58 to a proximal portion 62. The taper allows for a smooth transition of the interior seal to the distal and proximal end portions, thereby avoiding any sharp edges and avoiding any pressure points that may cause discomfort to the residual limb.
The arrangement of the blade width may include other variations such as the width of each of the blades tapering from a central portion 58 to a distal portion 60, and likewise from the central portion 58 to a proximal portion 62. In another variation, the blade width may be substantially uniform from distal to proximal portions.
Each blade has a greatest thickness closest to the interior surface 56 of the seal wall with a tapered thickness 46 as the blade extends toward the liner body. This configuration strengthens the blade at its interface with the seal wall as well as reduces any possible pressure points.
In the variation shown in FIG. 5, each of the blades is arranged at an oblique angle relative to the longitudinal axis A-A of the liner. This arrangement permits the blades to expand outwardly as the liner is donned onto the residual limb and fold down toward the seal wall with some overlap over each of the blades as the liner is doffed. The blades are also arranged at an angle so as to ensure that each blade folds in a proper predetermined direction so as to avoid the creation of any pressure points.
According to one variation, the blades extend at an angle approximately at 27 degrees relative to the longitudinal axis of the liner body. This angle, among other angles as well, allows for the blades to be pressed inwards relative to the liner body when the liner is donned, and obtains a proper balance of force required to draw the blades outwardly when the liner is withdrawn from the socket. Because the angle of the blades is arranged relative to the vertical axis of the liner and is combined with the orientation of the ends of the blades which press against the liner body, when a force is exerted to pull the liner out of a socket, the blades expand outwardly, which in turn creates extra pressure of the seal wall against the socket wall, thereby making it more difficult to lose suspension of the liner.
It will be noted that the blades are not limited to an obliquely extending configuration, as explained in connection with FIG. 4, but the blades may be arranged in any number of configurations such as being either generally parallel or perpendicular relative to the longitudinal axis A-A of the liner.
The seal component is preferably formed as a separate element from the liner body, and is securely attached thereto by appropriate bonding techniques that may include adhesive, heat seal, etc. The seal component may be constructed from a variety of materials, such as polymers, rubbers, coated textiles or any other suitable material. According to the embodiments, the seal component is constructed from a silicone composition.
While the seal component is described and depicted at the distal end portion of the liner, the seal component may be placed at any particular location along the exterior surface ES of the liner body.
Turning to FIGS. 7A-7E, the liner 10 carrying the seal component 14 is shown worn on a residual limb RL and stepped into a prosthetic socket 100. As the residual limb RL is placed into the socket 100, the seal component 14 forms an airtight seal with an interior surface of the socket 100 and urges air out of the distal end of the socket through a distally positioned expulsion valve 102. When it is desired to release the connection between the liner and the socket, the valve is released, and the residual limb can be removed from the socket.
When sealing against a socket, it should be kept in mind that the vacuum is formed between the seal and the distal end of the socket; no vacuum is created proximal of the socket between the liner and the socket. Moreover, the seal does not completely press against the socket wall, in that only portions of the seal press against the socket wall. For example, the seal rings press against the socket wall, but portions between the seal rings may not, and further may not touch the socket wall. Moreover, gaps between the blades may cause areas of the seal so that at such areas the seal does no exert any or much pressure against the socket wall.
As shown in FIG. 8, the pressure is inversely proportional to the suspension force needed, so as to ensure stability and rotational control. The seal component 14 forms a hypobaric sealing membrane that conforms to the shape of the internal socket wall, providing an airtight seal between the suspension liner and the socket. The recess in the liner body allows for there to be even pressure around the seal in the connection between the socket and liner. There is firm suspension, through the usage of the fins, to accommodate volume fluctuations of the residual limb.
Of course, it should be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
The skilled artisan will recognize the interchangeability of various disclosed features. In addition to the variations described herein, other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct suspension liner in accordance with principles of the present invention.
Although this invention has been disclosed in the context of certain exemplary embodiments and variations thereof, it therefore will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above.

## Claims

1. A liner for providing an interface between a residual limb and a prosthetic socket, comprising:
an elongate, generally conical liner body formed from at least one material segment that is at least radially elastically extensible from a relaxed non-extended condition and including proximal and distal end areas; and
a seal component connected to the liner body and having at least one exterior configuration defined along an exterior surface of the seal component for engaging a prosthetic socket and at least one interior configuration for movably engaging the liner body;
wherein the seal component defines an inwardly pitched portion at the proximal end thereof and directed toward the liner body exterior surface.
wherein the interior configuration defines at least one blade extending toward the liner body, the blade bounded by an outwardly pitched portion of the interior configuration located near a distal end of the seal component and an inwardly pitched portion at the proximal end of the seal component and directed toward the liner body exterior surface.

2. The liner according to claim 1, wherein the exterior configuration protrudes radially outwardly from the seal component relative to a longitudinal axis of the liner body and forms a ring.

3. The liner according to claim 2, wherein the interior configuration protrudes inwardly toward the liner body.

4. The liner according to claim 3 wherein the interior configuration extends at an oblique angle relative to the longitudinal axis of the liner body.

5. The liner according to claim 1, wherein the seal component defines a base portion circumferentially secured to an exterior surface of the liner body.

6. The liner according to claim 5, wherein the base portion defines an attachment portion entirely secured to the exterior surface of the liner body, the remainder of the seal component outside and proximally located relative to the attachment portion extends generally freely from the liner body.

7. The liner according to claim 1, wherein the seal component defines a lip arranged against the liner body, the interior configuration being located proximal relative to the lip.

8. The liner according to claim 7, wherein a gap is formed between the lip and an outwardly pitched portion of the interior configuration extending from a base portion located at a distal end of the seal component.

9. The liner according to claim 1, wherein the interior configuration defines at least one blade extending obliquely toward the liner body.

10. The liner according to claim 9, wherein the blade tapers in thickness from an interior wall of the seal component toward the liner body exterior surface.

11. The liner according to claim 1, wherein the liner body defines a circumferential recess arranged to receive a length of the seal component.

12. The liner according to claim 11, wherein the interior configuration defines a plurality of blades arranged for engaging an exterior surface of the liner body defined within the recess.

13. The liner according to claim 1, wherein the at least one blade comprises a plurality of blades extending circumferentially from the interior surface of the at least one interior seal.