Back support for a seat

[0002] 1. Field of the Invention

[0003] This invention is related to the field of back supports, more specifically to back supports for use with a seat.

[0004] 2. Description of the Prior Art

[0005] Lower backaches and back pain are a frequent occurrence in modern-day society. While lower back problems may be attributed to a number of factors, people who spend a fair amount of time in a seated position are especially prone to the affects of stress on the lower back. This is especially true for the common businessperson, who may spend a fair amount of time traveling or seated behind a desk for a generous portion of the day.

[0006] Various back supports are known for relieving painful aches of the lower spinal column or tiring muscles of the lower back. Such back supports are particularly helpful when a person is in a situation that necessitates sitting for a long period, such as when confined in a car or other vehicle or in a plane over a long period. Recent results reveal a cumulative benefit when the back is positioned correctly and supported even for short periods of time.

[0007] U.S. Pat. No. 6,125,851 discloses a spinal support system for applying a directed and concentrated force on the sacrum to position the sacrum and pelvis in order to establish a desired spinal posture when a person is in a seated position. To accomplish this force direction, the force is applied from the sacral base level of the seated individual downwardly to a bottom seat surface and across the individual's back.

[0008] U.S. Pat. No. 5,529,383 discloses a back support device for retaining a user in a substantially upright position when seated in a chair. The back support comprises a bracket that is attached to the back of a chair and a padded strap that supports the abdomen of the sitting individual.

[0009] U.S. Pat. No. 5,624,158 discloses an adjustable backrest for use in a seat, the backrest incorporating a vertical spine member having a lumbar support and upper back support projecting therefrom. Structure is provided for adjusting the curvature of the lumbar support member to fit the curvature of an individual's lower back.

[0010] These devices are representative of various approaches that have been taken in an attempt to alleviate back pain. While they all provide some relief in one form or another, such devices suffer from the disadvantage that they fail to alleviate the potentially dangerous weight the upper torso places on the lower back.

[0011] A device designed to partially support the upper torso of an occupant in an automobile is described in U.S. Pat. No. 4,487,201. The back support described therein comprises a wideband suspension strap that wraps around a user's upper torso region and is supported by the vertical backrest of an automobile seat. Such a device imposes severe limitations on movements of the user, as well as making entry and exit from the automobile cumbersome. Such cumbersome devices do not tend to lend themselves for use by those with active lifestyles or those who find it necessary to make frequent automobile trips and are continually moving in and out of an automobile. Intermittent use of the device, whether on long or short automobile trips, requires stopping the car to disengage the strap. While it might be alternatively possible to disengage the strap while operating the automobile, this creates a potentially dangerous situation. The wideband restraining strap also must be carefully positioned to avoid wrinkling the user's clothes when the band is tightened around the user's upper torso.

[0012] U.S. Pat. No. 4,834,457 discloses another arrangement for supporting the upper torso of a user above a seat by utilizing armpit rests attached to a propping mechanism. A disadvantage of such a device is that it is difficult to adjust in order to fit each unique user and there are no means for providing variable support to the user. Another disadvantage of this device is the poor design of the armpit rests, which can place potentially damaging pressure on nerves extending into the arms of a user.

[0013] While the above-identified patents disclose various forms of back supports, none taken singularly nor in any combination disclose a back support that supports the upper torso of user for alleviating a portion of a user's weight on the lower back and which may be easily adjusted to fit a user of any size and facilitate unobtrusive intermittent use and easy ingress and egress from a chair.

[0014] The aforenoted disadvantages of known back supports are overcome by the present invention which provides an orthopedic back support readily adapted for use with a chair or vehicle seat, such as an automobile or plane, and which can relieve or prevent back discomfort or pain. In contrast to the majority of prior developed back supports that have little effect on the gravity pressure of the torso on the lower back when an individual is in a seated position, the present invention is designed to lift the torso pressure off the lower back with the biomechanical principles of relative distraction/traction. Adjustable axillary rests positioned in the axilla or armpit of a user lifts the upper body with variable force to unload the lower back from torso pressure, thereby alleviating a degree of sitting pressure on the lower back that is appropriate for each individual user.

[0015] The more pressure put in the axilla, the greater the possibility that the individual can receive potentially harmful pressure on the nerves going into the arms. The design of the axillary rest is optimized to lessen this potentially harmful and unwanted pressure. An optional elbow/forearm rest provides additional support to lessen the pressure on the axilla.

[0016] It is an object of the present invention to provide an orthopedic back support that alleviates the weight of an individual's torso on the lower back and corrects tendencies to slump or slouch.

[0017] It is another object of the present invention to provide an orthopedic back support that is adaptable to persons of different sizes.

[0018] It is yet another object of the present invention to provide an orthopedic back support that is easily portable to and between an automobile, office, home, or any other location and which allows intermittent use without having to stop the vehicle or get out of the seat to discontinue or re-engage the back support.

[0019] It is still another object of the present invention to provide an orthopedic back support that allows easy and quick entry and exit from a vehicle.

[0020] It is still yet another object of the present invention to provide an orthopedic back support that provides a variable or adjustable support to accommodate persons of various sizes as well as the percentage of weight supported and the degree of stress relief provided.

[0021] It is still yet another object of the present invention to provide an orthopedic back support that does not place harmful and potentially damaging support pressure on the user.

[0022] These objects and the attendant advantages will become readily apparent from the following Detailed Description of the Invention when considered in conjunction with the following drawings wherein like parts are represented by like reference characters throughout the several views:

[0023] FIG. 1 shows an exploded view of an exemplary embodiment of the present invention;

[0024] FIG. 2 shows a perspective view of the exemplary embodiment of FIG. 1 in combination with a seat having a seat back;

[0025] FIG. 3 shows a perspective view of the exemplary embodiment of FIG. 1 and the manner in which the invention is used;

[0026] FIG. 4 shows a perspective view of the exemplary embodiment of FIG. 1 in combination with a seat of an automobile with axillary rests turned outward and flush against the seat back;

[0027] FIG. 5 shows a perspective view of an alternative exemplary embodiment of the present invention having an optional flexible sheet material for lateral support;

[0028] FIG. 6 shows a perspective view of an alternative embodiment of the present invention having a flexible strap for placement in the axilla;

[0029] FIG. 7 shows an exploded view of an alternative embodiment of the present invention using variable compression support;

[0030] FIG. 8 shows a detail view of the variable compression support of FIG. 7.

[0031] FIG. 9 shows a perspective view of an exemplary embodiment of the present invention having an internally mounted back support;

[0032] FIG. 10 shows a perspective view of an alternative exemplary embodiment of the present invention having an internally mounted back support;

[0033] FIG. 11 shows a perspective view of a supporting plate of the alternative embodiment of FIG. 10;

[0034] FIG. 12 shows a side view of an axillary rest engaged with a supporting plate in the alternative embodiment of FIG. 10;

[0035] FIG. 13 shows a top view of an axillary rest engaged with a supporting plate in the alternative embodiment of FIG. 10;

[0036] FIG. 14 shows a side view of an alternative exemplary embodiment of the present invention having an internally mounted back support;

[0037] FIG. 15 shows a top view of the alternative embodiment of FIG. 14; and

[0038] FIG. 16 shows a perspective view of an alternative exemplary embodiment of the present invention having an internally mounted back support.

[0039] Referring to FIGS. 1 through 4, an exemplary embodiment of an orthopedic back support 2 of the present invention for use with a chair (FIG. 2) or vehicle seat (FIG. 4) is illustrated. As shown in FIG. 1, support 10 includes a back a back support frame 3 comprising a pair of side members 4, 5, a lower support 10, and an upper support 11.

[0040] Side members 4, 5 are substantially rigid, preferably tubular structures that are vertically disposable against a substantially planar surface, such as seat back 51 of a seat 50. Members 4, 5 have a substantially hollow centrical section adapted to receive the extending arms 8, 9 of lower support 10. Members 4, 5 and support 10 have sufficient structural support for sustaining a portion of weight from an individual's upper body. In the exemplary embodiment, each member 4, 5 measures between approximately 8¼ inches and 14 inches in length and has a 1 inch diameter. However, it should be appreciated that in alternative embodiments, any dimensions providing the required structural support may be utilized. It should also be appreciated that the members are not restricted to a cylindrical or tubular shape and may vary in alternative embodiments.

[0041] Referring more particularly to FIG. 1, it will be seen that each member 4, 5 has a corresponding first upper end 12, 13 and a corresponding second lower end 14, 15 wherein each first end 12, 13 terminates in an axillary rest 20, 21 that extends outwardly from ends 12, 13, respectively, and at a substantially right angle therefrom.

[0042] Each axillary rest 20, 21 is L-shape having a short leg 23, 24 and a long leg 25, 26, respectively. It is preferable that each axillary rest 20, 21 is a single element.

[0043] Short legs 23, 24 are disposed on respective members 4, 5 at first upper ends 12, 13, respectively. Rests 20, 21 are fit tightly to members 4, 5. However, members 4, 5 are allowed to rotate by design, as well be explained soon hereafter, thereby permitting easy entry and exit from back support 2, as well as intermittent use. The swiveling motion also allows variable alteration of forces from side to side to enhance adjustability of back support 2. If a user experiences temporary excess axillary pressure or arm nerve irritation, axillary rests 20, 21 can be easily rotated from the forward engaged position to an unobtrusive position flush to seatback 51, 55 in FIGS. 2 and 4, respectively.

[0044] Long axillary rest legs 25, 26 extend relatively perpendicular to members 4, 5. The dimensions of long legs 25, 26 are approximately 7½ inches in length, but may vary in alternative embodiments. A soft padding 22 of rubber, gel, or other material may be wrapped around or applied to the top surface of each long leg 25, 26 to alleviate discomfort in the axilla or to alter the girth for a customized fit and support. However, it should be appreciated that such padding is a desirable feature for comfort and is not a requirement of the invention.

[0045] As shown in the exemplary embodiment, each axillary rest 20, 21 may have an upward curvature having a radius, for example of 8 inches. Much like the curvature at the top of a typical crutch, the curvature of long legs 25, 26 provide additional support and comfort when placed in the axilla. This optimal design allows more contact and support on the posterior latissimus dorsi muscle as well as some anterior support on the pectoralis muscle. Such contact and support decreases forces in the central axilla that would tend to irritate the nerves that enervate the arms. This design of the axillary rests allows the user increased distraction forces to unload pressure on the lower back while minimizing the adverse potential of brachial plexis nerve irritation.

[0046] Lower support 10 comprises lower support members 8, 9, which are joined by a lateral cross member 7 adapted to rest on horizontal seat portion 52 of seat 50.

[0047] In operation as seen in FIG. 3, the user positions themselves in a seated position. Lower and upper supports 10, 11, respectively are joined together and placed behind the back of a user, with axillary rests 20, 21 placed in each axilla. Lower supporting cross member 7 is adjustably positioned on a seat surface 52 so as to support a portion of weight of a user's torso by virtue of cross member 7 pushing directly against seat surface 52, thereby bypassing the normal transfer of weight through the lower back.

[0048] U-shape support 7, 8, 9 may be fabricated in separate pieces telescopingly joined together in a conventional manner. Upper ends 16, 17 are received by second ends 14, 15 of joining members 4, 5, respectively. To this end, the diameter of end 16, 17 is slightly less than the diameter of each second end 14, 15 of joining members 4, 5 so that members 4, 5 may telescopingly accept ends 16, 17. This establishes a telescoping engagement between members 4, 5 and elements 8, 9, respectively of the lower U-shape support to enable vertical adjustment of the position of axillary rests 20, 21 relative to seat surface 52. While the drawings show members 4, 5 receiving ends 16, 17 of elements 8, 9, it should also be appreciated that the members may be received in a reverse relationship. As shown in FIG. 1, cross member 7 may likewise be fabricated such that one side 31 telescopingly fits in another side 32 to adjust for the width of a user. For example, by aligning a peg hole 18 of side 31 with a peg hole 19 of side 32, a pin 36 may be inserted therethrough to lock each side 31, 32 together, thereby adjusting the lateral width of cross member 7 accordingly. Alternatively, the U-shape support element may advantageously be a one-piece rigid structure with the lower support element adapted to be disposed against a seat surface.

[0049] To adjust or set the vertical position of rests 20, 21 relative to seat surface 52, U-shape element 7, 8, 9 is preferably an adjustable support to fit the frame to users of different sizes. As shown in FIG. 1, a plurality of vertically spaced peg holes 27, 28 span a portion of each end 14, 15, for receiving a pin 29, 30. Holes 27, 28, in cooperation with pin 29, 30 provide adjustments for an optional forearm rest 33, 34. The vertical positions of axillary rests 20, 21 can be adjusted by sliding each member 4, 5 along ends 16, 17 until the desired height is achieved. The pin or peg 29, 30 is then placed into one of the plurality of peg holes 27, 28 so that receiving ends 16, 17 rest against pin 29, 30 within members 4, 5, respectively. Such an engagement permits members 4, 5 to be vertically adjustable and axillary rests 20, 21 may be maintained at a comfortable position in the axilla of the user. Furthermore, members 4, 5 may rotate on receiving ends 16, 17 so that rests 20, 21 may be swiveled to a comfortable position or for easy ingress and egress from support 2. Side members 4, 5 may free rotate up to 189 degrees on ends 16, 17 of U-shape support member 7, 8, 9. Axillary rests 20, 21 and each side member 4, 5 may be fabricated as a single piece, such as by extrusion from a mold. A friction washer or snugging gasket are between the inner walls of members 4, 5 and receiving ends 16, 17 to oppose the vertical separation of members 4, 5 from ends 16, 17 but permit swiveling thereon. It should be appreciated that a telescoping peg hole arrangement may be provided in cross member 7, connecting left side 31 and right side 32 by passing pin 36 therethrough to adjust for the width of the user.

[0050] The optional forearm rest 33, 34 for the elbow or forearm may bear additional weight helping to relieve the load on the lower back. While the present embodiment shows each forearm rest 33, 34 having a sleeve around members 4, 5 which rests on pin 29, 30 for support, it should be appreciated that in alternative embodiments, forearm rests may be engaged with members 4, 5 through the use of pegs, pins, grooves, sleeves or any other means for interlocking so long as height adjustments are easily obtainable for forearm rests 33, 34 and they are free to swivel.

[0051] In accordance with the present embodiment of the invention, upper support 11 comprises a rod 35 through which passes a strap 37 which is adjustable in length by the use of a clasping mechanism 39. Clasping mechanism 39 may include, but should not be limited to, buckles, snaps, or other clasping means. Strap 37 is joined at each end to axillary rests 20, 21, providing tensioned support by pulling substantially upward on axillary rests 20, 21. Rod 35, if acting as a guide and support for strap 37, is disposable behind seat back 51 or a headrest to further enable the rests 20, 21 to support and displace a portion of weight from the torso against the top or back of seat back 51 and advantageously reduce the size and strength of the materials otherwise necessary to support heavy weight, thereby increasing its capacity for use as a mobile back support. Alternatively, the rod may be solid having the strap attached to each end of the rod. In still further alternative embodiments, the upper support may include the strap without the use of the rod. The strap may still provide reliable support by extending around the seat back. It should further be appreciated that upper support 11 is optional, and that while it may be useful to provide symmetrical support to members 4 and 5 and axillary rests 20, 21 for certain seat backs, some seats will not require the additional support from a location above the axillary rests.

[0052] FIG. 4 shows a present exemplary embodiment of back support 2 used with a seat 54 of a vehicle such as an automobile. It should be readily apparent that support 2 may be used with seats of other vehicles such as boats, planes, or the like. Upper support 11 includes rod 35 disposed behind posts/supports 56 of headrest 57 of seat 54, with strap 37 extending over the top of seat back 55 and attached to axillary rests 20, 21. Rod 30 displaces a portion of weight from the user's torso directly against headrest supports 56. Axillary rests 20, 21 are shown swiveled outward and substantially flush to the surface of seat back 55, which facilitates easy movement into or out of seat 54 normally constrained by steering wheel 58 of the automobile. It should be appreciated that although FIG. 4 depicts the back support frame 2 having a lower support 10, it is not required.

[0053] While the preferred embodiment has been described herein having a combination of a lower support and an upper support, it should be appreciated that other exemplary embodiments may independently use either a lower support or an upper support. For example, an alternative embodiment of a back support 41 having only an upper support 42 is illustrated in FIG. 5. Support for the lower back is displaced to axillary rests 43, 44 and then to upper support 42, which extends behind headrest 97. Because, no lower support is provided, an optional flexible sheet material 40 extended between side members 46, 47 help to increase the lateral stability of back support 41 to hold side members 46, 47 in proper alignment with the torso of a user. In an alternative embodiment, this flexible material may also be used to support the axillary rests with the use of pockets or sleeves into which the side members would fit. The upper support would attach to the flexible material and as a result, the lower support is unnecessary. Referring again to the present embodiment, material 40 may be a rattan, wall base rubber, canvas, nylon, or other durable, flexible material. Also shown in this embodiment is an optional stability strap 93 that is attached to lower end 98 of member 46, extends behind seat back 45, and attached at its opposite end to lower end 99 of member 47. With the absence of a lower support, strap 93 provides added stability and alignment to back support 41 when pulled taut by buckle 94, or other means for adjusting strap 93. An optional chest strap 95 is attached at one end to axillary rest 43 and attached at the opposite end to axillary rest 44. A sitting individual may be harnessed by chest strap 95 by extending it over the upper torso of a sitting individual. Chest strap 95 may include an adjustable, quick release buckle, or other fastening means, to make adjustments for individuals and to maintain the quick ingress and egress characteristics of the invention. When taut, chest strap 95 corrects tendencies to slump or slouch.

[0054] FIG. 6 shows an alternative embodiment having axillary rests 60, 61 comprising flexible straps extending between the ends of rod 62 and rigid members 63, 64, respectively. The position of members 63, 64 is shown pivoted forward from seatback 59. When in operation, straps 60, 61 are placed in each axilla of an individual to provide support. Harness 65 of rod 35 is secured to headrest 66 to provide both lateral and upright support to straps 60, 61, and thus to the torso of a user. Adjustment of to the length of straps 60, 61 may be provided using a buckle, snap, or other mechanism for adjustment. Adjustments to the height of rigid members 63, 64 or adjustments to harness 65 on headrest 66 can provide proper distribution of support to the axilla.

[0055] In an alternative embodiment as shown in FIG. 7, a back support frame 74 has only a lower support 76 comprising elements 89, 90, 91. In this embodiment, back support 74 provides variable support that raises and lowers the relative height of side members 78, 80 in response to the weight displaced from axillary rests 82, 83 when an upper support is not implemented. A compression support 85 may be varied using springs 86, 87 having an adjustable compression force or length as known by one familiar in the art. Springs 86, 87 are fit internally at each end of the U-shaped support element 89, 90 and extend up into side members 78, 80. By this arrangement, the weight of a user's torso on each axillary rest 82, 83 is counteracted by each spring 86, 87, thereby lessening the weight of the torso on the lower back.

[0056] FIG. 8 shows a detail view of left compression support 85 comprised of spring 86. A plug 88 extending up into member 78 to axillary rest 82 would compress spring 86 under the weight of an individual using back support frame 74. Plug 88 transfers the compression force from axillary rest 82 to spring 86. The end of U-shape support element 89 holds the compression force at the lower end of spring 86. A snugging gasket 92 prevents element 89 from disengaging from member 78 at a time when there are no compression forces. Also, gasket 92 maintains a snug fit between member 78 and element 89. A relatively heavy force would produce a small compression of spring 86, thereby creating an opposite, upward force to carry a percentage of the weight of a user's torso that would normally be transferred to the lower back. It should be appreciated that in alternative embodiments, plug 88 may not extend upward through side member 78 to axilla rest 82 and instead may be held firmly at an intermediate position within side member 78. It should also be appreciated that a pin or other stopper mechanism may be placed at an intermediate position in side member 78 for transferring compression forces from axilla rest 82 to spring 86.

[0057] FIG. 9 illustrates an exemplary embodiment of an internally mounted back support 102, wherein a lower support 108 is mounted within a seat back 101 of a seat 100. Seat back 101 has axillary rest openings 104, 105 through which rests 106, 107 extend. Openings 104, 105 are preferably sized and shaped to envelope rests 106, 107 when swiveled for periods of non-use, so as to provide a flush surface to seat back 101. Lower support 108 is conveniently supported on a cross beam 103 of seat 100.

[0058] FIGS. 10-13 illustrate an alternative embodiment of an internally mounted back support 202.

[0059] In the embodiment shown in FIGS. 10-13, seat back support 202 has mounted therein, at the location of openings 204, 205, a pair of supporting plates 212. Each plate includes several pairs of apertures 214, 215; 216, 217; 218, and 219 left, center, right for engaging axillary rests 206, 207 and providing height and width adjustments thereto.

[0060] Supporting plates 212 have a substantially planar surface that is internally mounted in seat back 72 of seat 70. Attachment of plates 212 to seat back 72 may be by bolting, welding or other means and will vary according to the internal structure of seat 70. While a universal location may be chosen because of the ability for height adjustments, plates 212 may also be custom fitted. To this end, factors in determining the location of adjustment plate 212 on seat back 72 include the stature of the individual that is being fitted for back support 202, and the type of seat 70. It should be appreciated that in alternative embodiments, support for axillary rests 206, 207 is not limited to adjustment plates 212 as described herein, but any support for supporting the axillary rests to the backrest may be provided, so long as the supporting means permits the axillary rests to swivel against the seat so as to permit its normal use by an occupant not requiring back support.

[0061] Each axillary rest 206, 207 is bifurcated at one end to form a fastening component 209 by cooperation with the openings in associated with support plate 212. As shown in FIG. 11, the bifurcated ends of rest 206, 207 terminate in a hook 208 and a guide pin 210 adapted to pass through a selected pair of openings such as 214, 215.

[0062] The plurality of vertical sets of apertures 214, 215; 216, 217; and 218, 219 at positions of left, center, and right on adjustment plate 212 provide multiple adjustments for height and width positioning of axillary rests 206, 207, enabling back support 202 to adjust to users of a variety of statures. Apertures 214, 216 and 218, are large compared to the cooperative apertures or openings of 215, 217, 219. Each set of apertures has a first, larger orifice, corresponding to apertures 214, 216, 218, for receiving hook 208 and a second aperture, corresponding to apertures 215, 217, 219 for receiving the guide pin 210. The diameter of the large size apertures 214, 216, 218 must be large enough to allow hook 208 to pass through when inserted. Upon insertion, rest 206, 207 is held at an angle, as shown by the dashed line to allow hook 208 to pass through to the backside of plate 212. As rest 206, 207 is moved downward (as shown by the arrow in FIG. 12) to an operational, substantially horizontal position, guide pin 210 engages the smaller aperture of the set. Concurrently, hook 208 becomes engaged with the larger orifice, holding axillary rest 206, 207 to adjustment plate 112. Hook 208 and guide pin 210 when engaged in their respective, associated apertures, prevent axillary rest 206, 207 from collapsing downward under the weight of a user's torso. The double engagement of hook 208 and guide pin 210 also prevent axillary rest 206, 207 from turning along the lengthwise central axis 211 of axillary rest 206, 207 so that hook 208 may stay in proper alignment. Such an engagement, as well as the bifurcated shape of the end of axillary rest 206, 207, permits axillary rest 206, 207 to swivel horizontally as seen in FIG. 13 for easy entry and exit, or intermittent use. Rests 206, 207 can be easily disengaged and removed by reversing the above engagement procedure, whereby rests 206, 207 would be moved upward and out of the associated apertures. It should be appreciated that in alternative embodiments, an alternative fastening component may be used to engage the bifurcated end of axillary rest 206, 207 with supporting means 212. However, such a fastening component should permit the axillary rest to swivel horizontally in the manner previously described. It should also be appreciated that apertures 214, 215; 216, 217; 218, 219; are not limited to the positions of left, center, and right and may have more positions to provide for more horizontal adjustments. Similarly, there may be more than the three sets of apertures 214, 215; 216, 217; 218, 219; to also provide for more vertical adjustments.

[0063] FIGS. 14 and 15 show an alternative exemplary embodiment of an internally mounted back support 300. Referring to FIG. 14, rest 301 is mounted to a moveable plate 302 attached to seat frame 304. In operation, support 306 provides upward support for holding the force exerted downward in rest 301 from a user's torso. A side motion, as indicated in FIG. 15, would be required to put the rest in an unsupported position, allowing a downward vertical rotation to place rest 300 into a recessed opening in seat back 308 when not in use.

[0064] FIG. 16 shows an alternative exemplary embodiment of an internally mounted back support 400. With upward rotation as indicated by the arrow in the figure, the side motion in the aforementioned embodiment would not be required. Rests 401, 402 could be pivoted into recesses 405, 406 to be flush with seat back surface 403 when not supporting the user. Bottom surfaces 407, 408 of rests 401, 402 may be fabricated to match seat back 403 when pivoted into recesses 405, 406, respectively.

[0065] While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth herein, are intended to be illustrative, not limiting. Various changes may be made without departing from the true spirit and full scope of the invention as set forth herein and defined in the claims.