Self-powered microclimate controlled mattress

Abstract

Disclosed are apparatus and methodology for reducing humidity (i.e., moisture) and/or heat within and/or adjacent a patient support mattress, without requiring any electrical power. A spacer fabric is used to create a non-crushable area of support below a patient's core area, where moisture and heat more commonly buildup. Integrated air cells in the mattress have resilient elements such as open-celled foam interiors. The air cells are connected by air tubing to the spacer fabric, and the mattress is otherwise vented externally from the spacer fabric. As a result, the patient's movement causes air to be expelled from or drawn into the air cells, which in turn results in air movement in the spacer fabric below a patient or user, resulting in cooling effects by removing moisture and/or heat, all without requiring external or internal electrical power.

Claims

1. Methodology for providing a self-powered microclimate for the prevention and treatment of decubitus ulcers of a patient received on a support surface, comprising: providing a resilient patient support, having at least one integrated air cell, and forming a patient support surface; providing a three-dimensional spacer fabric area of support relative to at least a portion of the patient support surface; pneumatically interconnecting such three-dimensional spacer fabric area directly with the at least one integrated air cell so that an air passage is formed between the interior of the at least one integrated air cell and the three-dimensional spacer fabric area; supporting a patient on such patient support surface with at least a portion of the patient received adjacent the three-dimensional spacer fabric area of support, wherein at least one physical movement of said patient received on the patient support surface causes air to be expelled from the at least one integrated air cell via said pneumatic interconnection and at least one second physical movement of said patient received on the patient support surface causes air to be drawn into the at least one integrated air cell via said pneumatic interconnection, which in turn results in air movement relative to such three-dimensional spacer fabric area, resulting in cooling effects by removing moisture and/or heat from adjacent the patient; and providing a cover around said resilient patient support and said three-dimensional spacer fabric area of support with at least one vent through said cover for passage of air therethrough both expelled from said three-dimensional spacer fabric area of support and drawn therein dependent on the physical movement of the patient received on the patient support surface; wherein said at least one integrated air cell comprises a plurality of air cylinders oriented one of length-wise and laterally within said resilient patient support, with said air cylinders positioned to be manipulated by patient movement on said resilient patient support; and supporting said patient includes receiving part of a patient's back and buttocks adjacent said three-dimensional spacer fabric area of support.

2. Methodology as in claim 1, further including modularly integrating said patient support surface with one of a mattress, a wheelchair/seating cushion, a patient positioner, a mattress coverlet, and a consumer-oriented support.

3. Methodology as in claim 1, wherein: providing said resilient patient support comprises providing a multi-piece foam shell including at least a foam shell topper, a foam header, and a foam footer; and said pneumatically interconnecting comprises interconnecting air tubing between said spacer fabric and said at least one integrated air cell.

4. Methodology as in claim 1, wherein said resilient patient support comprises a mattress which is at least partially made of foam.

5. Methodology as in claim 1, wherein: said patient support surface is integrated into a mattress system; said cover comprises moisture permeable material; and said three-dimensional spacer fabric area of support comprises a material less than about 1.0 inches thick.

6. Methodology as in claim 5, wherein said mattress system further includes an integrated sensor system for sensing at least one of temperature, moisture, and pressure of said mattress system.

7. Methodology as in claim 5, wherein said cover comprises a protective zippered sheath over said mattress system.

8. Methodology as in claim 1, wherein said patient support includes a foam topper having a plurality of surface cuts and channels forming a plurality of separate upright support elements, the size and construction of which are predetermined over the surface of said foam topper so as to provide selected support characteristics to a patient supported thereon.

9. Methodology as in claim 1, wherein said plurality of respective air cylinders each include respective resilient internal structures, so that with relatively less patient pressure on a given location of said air cylinders, expansion of such cylinders by their respective resilient internal structures causes air to be drawn back into such cylinders through said at least one vent, through the three-dimensional spacer fabric area of support through the pneumatic interconnection.

10. Methodology as in claim 1, wherein said plurality of respective air cylinders each have respective generally rectangular cross-sections.

11. Methodology as in claim 1, wherein said plurality of respective air cylinders respectively comprise cylinders integrally formed from woven nylon fabric fused to polymeric film.

12. Methodology as in claim 1, wherein said resilient patient support includes at least in part resilient support foam received between said air cylinders and a patient supported on said patient support.

13. Methodology for providing a self-actuated microclimate for the prevention and treatment of tissue damage of a patient received on a support surface, comprising: providing a resilient patient support, having at least one integrated air cell, and forming a patient support surface, with said at least one integrated air cell comprising a plurality of air cylinders oriented one of length-wise and laterally within said resilient patient support, with said air cylinders positioned to be manipulated by patient movement on said resilient patient support; providing a three-dimensional spacer fabric area of support relative to at least a portion of the patient support surface, with such three-dimensional spacer fabric area of support maintaining air flow capabilities in said area even while supporting a patient; supporting a patient on such patient support surface with a portion of the patient's back and buttocks received above the three-dimensional spacer fabric area of support, so that air movement capability is maintained relative to such three-dimensional spacer fabric area, to allow for the removal of moisture and/or heat from below a supported patient; and pneumatically interconnecting such three-dimensional spacer fabric area directly with the plurality of air cylinders, wherein at least one physical movement of said patient received on the patient support surface causes air to be expelled from the plurality of air cylinders via said pneumatic interconnection and at least one second physical movement of said patient received on the patient support surface causes air to be drawn into the plurality of air cylinders via said pneumatic interconnection so that an air passage is formed between the interiors of the plurality of air cylinders and said three-dimensional spacer fabric area which in turn results in air movement relative to such three-dimensional spacer fabric area, resulting in removing moisture and/or heat from beneath the patient; and further including at least partially venting said three-dimensional spacer fabric area of support to the surrounding environment, so that natural convection between the surrounding environment and air beneath a patient in said three-dimensional spacer fabric area of support results in removing moisture and/or heat from beneath the patient.

14. Methodology as in claim 13, wherein said resilient patient support comprises a mattress which is at least partially made of foam.

15. Methodology as in claim 13, further including modularly integrating said patient support surface with one of a mattress, a wheelchair/seating cushion, a patient positioner, a mattress coverlet, and a consumer-oriented support.

16. Methodology as in claim 13, wherein: providing said resilient patient support comprises providing a multi-piece foam shell including at least a foam shell topper, a foam header, and a foam footer; and said pneumatically interconnecting comprises interconnecting air tubing between said three-dimensional spacer fabric area and said plurality of air cylinders.

17. Methodology as in claim 13, wherein said patient support includes a foam topper having a plurality of surface cuts and channels forming a plurality of separate upright support elements, the size and construction of which are predetermined over the surface of said foam topper so as to provide selected support characteristics to a patient supported thereon.

18. Methodology as in claim 13, wherein said resilient patient support includes at least in part resilient support foam received between said air cylinders and a patient supported on said patient support.

19. Methodology as in claim 13, further comprising providing a cover around said resilient patient support and said three-dimensional spacer fabric area of support with at least one vent through said cover for passage of air therethrough both expelled from said three-dimensional spacer fabric area of support and as drawn therein, or from natural convection.

20. Methodology as in claim 19, wherein: said patient support surface is integrated into a mattress system; said cover comprises a moisture permeable material; and said three-dimensional spacer fabric area of support comprises an air flow friendly material less than about 1.0 inches thick.

21. Methodology as in claim 20, wherein said mattress system further includes an integrated sensor system for sensing at least one of temperature, moisture, and pressure of said mattress system.

22. Methodology as in claim 20, wherein said cover comprises a protective zippered sheath over said mattress system.

23. Methodology as in claim 19, wherein said plurality of respective air cylinders each include respective resilient internal structures, so that with relatively less patient pressure on a given location of said air cylinders, expansion of such cylinders by their respective resilient internal structures causes air to be drawn back into such cylinders through said at least one vent, through the three-dimensional spacer fabric area of support through the pneumatic interconnection.

24. Methodology as in claim 19, wherein said plurality of respective air cylinders each have respective generally rectangular cross-sections.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A full and enabling disclosure of the presently disclosed subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

(2) FIGS. 1 and 2 are, respectively, a generally top and partial side perspective view, in partial cutaway, and a cross sectional representation (taken generally along a middle position of the illustration of FIG. 1) of an exemplary prior art patient support surface, as discussed above in detail;

(3) FIGS. 3A and 3B are generally top and side elevational views, respectively, of certain aspects of patient support surface features in accordance with presently disclosed subject matter;

(4) FIGS. 4A and 4B are generally perspective exploded view, and end view, respectively, of the exemplary presently disclosed subject matter of present FIGS. 3A and 3B;

(5) FIGS. 5A and 5B are generally top elevational and cross sectional views, respectively, of certain aspects of patient support surface features in accordance with presently disclosed subject matter;

(6) FIG. 6 is a generally side and front perspective view (exploded) of many features of an exemplary patient support surface embodiment in accordance with presently disclosed subject matter, but with any cover features thereof removed for clarity;

(7) FIG. 7 is a generally top and side perspective view, separated, of top and bottom pieces collectively forming an exemplary cover in accordance with presently disclosed subject matter;

(8) FIG. 8 is a plan elevational view of a top cover piece portion of an exemplary embodiment of the present FIG. 7 exemplary cover in accordance with presently disclosed subject matter;

(9) FIG. 9A is a plan elevational view of a bottom cover piece portion of an exemplary embodiment of the present FIG. 7 exemplary cover in accordance with presently disclosed subject matter, and FIG. 9B is a side elevational view thereof; and

(10) FIG. 10A is a plan elevational view of a bottom cover piece portion, similar to FIG. 9A hereof, of an exemplary embodiment of the present FIG. 7 exemplary cover in accordance with presently disclosed subject matter, and illustrating various preferred stitching features thereof, and with FIGS. 10B and 10C illustrating various enlarged views of certain features of such FIG. 10A illustration.

(11) Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features, elements, or steps of the presently disclosed subject matter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) As discussed in the Summary of the Disclosure section, the presently disclosed subject matter is particularly concerned with apparatus and methodology for controlling the level of moisture and/or heat within a therapeutic mattresses or similar apparatus (or other context, such as wheel chair or other patient or consumer support) provided in accordance with presently disclosed subject matter.

(13) Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the presently disclosed subject matter. It should be noted that each of the exemplary embodiments presented and discussed herein should not insinuate limitations of the presently disclosed subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of one or more other present embodiment to yield yet further embodiments. Additionally, certain features or steps may be interchanged with similar devices, features or steps not expressly mentioned but which perform the same or similar function.

(14) Referring collectively to FIGS. 3A, 3B, 4A, 4B, 5A, 5B, and 6, a presently disclosed exemplary air and foam flotation mattress generally 102 has a foam shell portion including foam bolsters 122 and foam sides 124 running the length of the mattress 102 and on either side thereof. At the respective ends of the air flotation mattress 102 and capping the foam bolsters and sides 122 and 124 are, respectively, a foam header 126 adjacent head end 156 and foam footer 128 adjacent foot end 158, which along with the bolsters 122 form a cavity in the mattress 102. Such cavity (not numbered) is configured for positioning of air cells 135 therein. As seen from the various present figures, such exemplary selected plurality of air cells 135 in this exemplary embodiment may run from head to foot, received within such cavity. Other configurations, including different pluralities of air cells, and/or orientations and/or locations thereof may be practiced in various embodiments, as understood by those of ordinary skill in the art.

(15) Location 144 (shown by present FIG. 5A) illustrates an exemplary possibility of additional subject matter (for example, such as a sensor system, such as for temperature or moisture or pressure) included with mattress 102, but located so as to not interfere with any of the exemplary air cells 135. Details of any such adjacent devices form no particular part of the presently disclosed subject matter, beyond the exemplary location thereof relative to the remaining presently disclosed structure.

(16) The cross section of present FIG. 5B represents that a foam section generally 120 may be received above air cells 135, to further help form the cavity within which such air cells are received. While the illustration of foam section 120 is general, to represent a variety of foam configurations that may be practiced, other present figures, such as present FIGS. 3A and 4A illustrate relatively more advanced, specialized foam surfaces and/or foam/gel configurations which may also be practiced in accordance with presently disclosed subject matter. FIG. 6 additionally shows an exploded view, which represents different respective sections or subportions 170, 172, 174, 176, and 178 which may be practiced for specialized support protocols, and may be glued or otherwise joined together to form upper foam support surface, generally 154 or 120.

(17) Such figures variously illustrate an additionally presently disclosed feature, relating to a spacer or three-dimensional fabric portion generally 148 which may be positioned above at least a portion of upper support surface 154 or 120. Preferably, as illustrated (particularly by present FIGS. 3A, 4A, and 6), such spacer fabric portion may be aligned with areas under a patient's or user's back and buttocks. With air tubing or conduits (air passageways) interconnecting the spacer fabric to the air cylinders, as the patient moves, such movement causes air vis--vis the cylinders to be circulated under the patient's relatively high sweating areas of the seating and torso areas. Such air movement (whether being blown out of the mattress or drawn into the mattress) causes heat and moisture of the body to be removed.

(18) As illustrated by such features, tubing generally 168 may interconnect the ends of air cells 135 (for example, on the foot support end of mattress 102), and then communicate air (in either direction) to spacer fabric 148 such as by respective tubing lines 160 and 162, all as illustrated. Different arrangements of tubing or similar devices may be utilized, so long as air passages are formed between the interior of the air cells 135 and the interior of spacer material 148, and spacer material 148 is in turn vented to (in air communication with) the exterior of mattress 102.

(19) Other features may also be varied in particular embodiments. For example, the exploded view of present FIG. 6 further illustrates various internal foam bolster elements 180 and 182, and other internal foam components 184 and 186, but all such components may be varied to accommodate particular embodiments, so long as an internal cavity receives air cells for reacting to a patient's movement, to stimulate air movement relative to the patient's core area.

(20) Various alternative spacer fabrics may likewise be practiced, so long as sufficient non-crushable air flow space is created below a patient for the air movement described herein. In one exemplary preferred embodiment, such spacer fabric may comprise Pressless article SFE 15 W220 made out of 100% PES (Polyethersulfone, a thermoplastic polymer) at a thickness of 15 mm (0.6). Such spacer fabric has favorable characteristics also for preventing shear effects. As understood by those of ordinary skill in the art, the durometer (hardness) of such fabric may be controlled by thickness and density of the internal fibers, and the density of the outer layers being connected by such internal fibers. More generally, it may be appreciated that such spacer layer may comprise a generally non-crush, three-dimensional fabric, air flow-friendly material such as a knit, cloth, polymeric film, foam or extruded woven fibers. The structure of the spacer layer results not only in its non-crush characteristic, which is taken advantage of per the presently disclosed subject matter, but also the favorable shear effects referenced herein. Specifically, lateral flexibility of fibers or internal structure of the spacer fabric reduce shear forces on a supported patient's skin by providing a degree of upper surface lateral flexing during movement of a patient or user.

(21) Still further, those of ordinary skill in the art will appreciate that variations of nearly all dimensions shown or suggested herewith may be practiced to provide or accommodate for specifically desired embodiments, to satisfy different ranges of patient needs, such as pediatric patients or even bariatric patients. All such variations are intended as coming within the spirit and scope of the presently disclosed subject matter, and dimensional examples herewith are presented without limitation on such alternatives.

(22) Present FIG. 4B designates two particular dimensional relationships in terms of thickness and width of an exemplary mattress 102. For such example, thickness 164 may be about 7.0 inches0.5 inches, and length 166 may be about 35.5 inches0.5 inches. In present FIG. 3B, the exemplary embodiment may be about 80 inches in length, 0.75 inches.

(23) Present FIG. 5B represents other features and optional features of presently disclosed subject matter. For example, mattress 102 may include or not include a perimeter feature generally 152. Further, the spacer fabric is illustrated in some present figures as a single body of material, while present FIG. 5B represents that such spacer material may in fact be separated into two separate parts 148 and 153, if desired, for achieving a particular cumulative thickness, and/or for accommodating any desired sheer characteristics of the upper support surface in particular embodiments. A separation is illustrated by reference 151 between separated parts 148 and 153 but such reference 151 may reflect either a physical layer or merely a joint where two spacer fabric pieces are adjacent each other. Double-headed air flow arrows 150 (appearing in both spacer fabric portions 148 and 153) represent that air is capable of moving in all directions below the patient or user. In other words, this represents air movement from the air cells to out of vents in mattress 102 (via tubing and the spacer fabric) and back into the air cells drawn into such vents (and passing through the spacer fabric and the tubing), as well as movement around or within the spacer fabric(s). Therefore, the tubing pneumatically interconnects the spacer fabric with the air cells so that, as the patient moves, such movement causes air vis--vis the air cells or cylinders to be circulated under the patient's relatively high sweating areas of the seating and torso areas. All such achieved air movement, and corresponding potential movement/dissipation of moisture and heat, are intended as being encompassed by the presently disclosed subject matter. Those of ordinary skill in the art will understand from the complete disclosure herewith that such dissipation of moisture and heat, in view of the non-crushable air flow area of support underneath at least a portion of a patient established herewith, also encompasses natural convection. In other words, as understood, natural convection of heat and moisture is that which moves from high heat and moisture environments to relatively lower heat and moisture environments. Thus, the self-powered movement of air discussed herewith assists, augments, or supplements the natural convection otherwise achievable with the structure established with the present subject matter.

(24) Double-headed arrows 150 also represent lateral internal flexing of spacer fabric material, resulting in improved shear effects performance of the presently disclosed subject matter, as otherwise referenced herein.

(25) Such spacer fabric(s) has a cover material generally 146 with a relatively high MVTR (Moisture Vapor Transmission Rate) to facilitate passage of moisture/sweat while still being water resistant. Other additional layers may comprise a waterproof, vapor impermeable sheet for protection of the underlying mattress 102. Such additional layer or layers may also additionally comprise a zippered sheath for encasing the mattress 102. Notably, the spacer fabric arrangement with the remaining structure herewith would offer some degree of benefit of cooling (such as in a consumer context) even if air cells were not utilized as represented herewith for moving air in response to the user's movements on the support surface.

(26) Thus, in some present exemplary embodiments of the presently disclosed subject matter, an integrated mattress system may be provided for circulating air relative to a patient by involving inclusion of a three-dimensional or spacer material in a main patient support structure, such structure having at least one air port or vent thereof coupled through such three-dimensional material with one or more air cylinders positioned to be manipulated by patient movement on an upper support surface. Such air cylinder or cylinders may have resilient internal structures, such as open-celled foam, so that air is exhausted out of such cylinder structures through tubing, into patient-supporting three-dimensional material, and out from such mattress via one or more an air ports. Similarly, with less patient pressure on a given location of the air cylinder structures, expansion of the cylinders may result, so that air is drawn back into such cylinder structures through one or more air ports, through the patient-supporting three-dimensional material, and through tubing into such cylinder structures. As otherwise referenced herein, the presently disclosed structure also allows for natural convection, which can result in movement of moisture and/or heat away from an area underneath at least a portion of a patient. All such air movement (due to forced or drawn air, or due to natural convection) beneath a supported patient in and through such three-dimensional non-crushable material, tends to beneficially reduce moisture and/or heat generated by such supported patient. The cross sectional view of present FIG. 5B represents such open-celled foam included in a sectioned exemplary air cell 135.

(27) As also represented by the various figures, while air cells 135 may assume particular shapes or locations, a generally rectangular shape (with or without rounded edges) forms a useful and effective arrangement of such air cells for the various air cell purposes related herein.

(28) In general, present FIGS. 3A through 6 illustrate features of the presently disclosed subject matter with any outside cover removed, for greater clarity of such illustrated inside details. On the other hand, present FIGS. 7 though 10C illustrate various features of such outside cover aspects of presently disclosed subject matter, with other features generally omitted for clarity of the indicated illustrations. Otherwise, present FIG. 1 (though itself literally an illustration of a prior art device) is intended to represent the position of an external cover around a foam support chassis having internal air cylinders.

(29) FIG. 7 is a generally top and side perspective view, separated, of top and bottom pieces collectively forming an exemplary cover in accordance with presently disclosed subject matter. FIG. 8 is a plan elevational view of a top cover piece portion of an exemplary embodiment of the present FIG. 7 exemplary cover. FIG. 9A is a plan elevational view of a bottom cover piece portion of an exemplary embodiment of the present FIG. 7 exemplary cover, and FIG. 9B is a side elevational view of the same. FIG. 10A is a plan elevational view of a bottom cover piece portion, similar to FIG. 9A hereof, of an exemplary embodiment of the present FIG. 7 exemplary cover, and illustrating various preferred stitching features thereof. Present FIGS. 10B and 10C illustrate various enlarged views of certain features of such FIG. 10A illustration.

(30) FIG. 7 represents jersey knit or mesh features for venting from mattress 102, relative to top cover piece generally 190 and bottom cover piece generally 192. Zipper chain 194 and zipper pull 196 features are also represented by present FIG. 7. Additionally, feature 198 represent nylon webbing serving a handle function for mattress 102. Additional nylon webbing generally 200 serves as reinforcement. A customizable mattress label may be provided in various places, as represented in a particular location by feature 202.

(31) The top cover material piece generally 190 as represented in present FIG. 8 may have various shaped portions and various dimensions for well functioning in its top cover role. While variations may be practiced, one exemplary set of dimensions are set forth as follows in Table 1, relative to the indicated dimensional features 204 through 236 of present FIG. 8:

(32) TABLE-US-00001 TABLE 1 re FIG. 8 Reference Exemplary Dimensions No. (in inches) 204 45.0 206 4.75 208 35.5 210 4.75 212 4.75 214 4.75 216 90.5 218 67.25 220 67.25 222 0.75 224 0.75 226 14.5 228 4.0 230 4.0 232 4.0 234 35.5 236 4.0

(33) The bottom cover material piece generally 192 as represented in present FIG. 9A may have various shaped portions and various dimensions for well functioning in its bottom cover role. While variations may be practiced, one exemplary set of dimensions are set forth as follows in Table 2, relative to the indicated dimensional features 238 through 278 of present FIGS. 9A & 9B:

(34) TABLE-US-00002 TABLE 2 re FIGS. 9A & B Reference Exemplary Dimensions No. in inches 238 4.75 240 35.5 242 4.75 244 4.75 246 14.0 248 14.0 250 37.0 252 1.0 254 1.0 256 37.0 258 38.0 260 16.25 262 16.25 264 14.5 266 14.5 268 4.0 270 4.0 272 1.5 274 4.0 276 35.5 278 4.0

(35) The bottom cover material piece generally 192 as represented in present FIG. 10A may have various shaped stitching as well as various dimensions for well functioning in its bottom cover role. Stitching 298 represents the addition of stitched jersey mesh material to the bottom fabric generally 192, to create vent features in accordance with the presently disclosed subject matter. As understood by those of ordinary skill in the art from the complete disclosure herewith, air may pass in either direction relative to such vents (that is, either in to or out of mattress 102), over the course of operation of the presently disclosed subject matter. While variations may be practiced, one exemplary set of dimensions are set forth as follows in Table 3, relative to the indicated dimensional features 280 through 296 of present FIGS. 10A through 10C:

(36) TABLE-US-00003 TABLE 3 re FIGS. 10A-C Reference Exemplary Dimension No. (in inches) 280 21.0 282 6.75 284 21.0 286 6.75 288 1.0 290 8.0 292 1.0 294 1.0 296 8.0

(37) The enlarged illustration of present FIG. 10B particularly illustrates fabric outside detail for a formed handle (with the handle stitched in two places). Present FIG. 10C illustrates fabric inside handle detail, to illustrate preferred stitching reinforcement.

(38) In various other embodiments, as referenced above, the presently disclosed subject matter may be integrated with other supports including various mattresses, wheelchair/seating cushions, and/or patient positioners (whether pre-existing, disclosed herewith, or later developed). Several exemplary such support surfaces can be found in commonly owned U.S. Pat. No. 5,568,660 to Raburn et al; U.S. Pat. No. 5,797,155 to Maier et al.; and U.S. Design Pat. No. D355,488 to Hargest et al., the disclosures of which are fully incorporated herein by reference, for all purposes.

(39) While the presently disclosed subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the presently disclosed subject matter as would be readily apparent to one of ordinary skill in the art.