Background of the Invention Hospital patient care can generate considerable quantities of infectious medical waste in primary and acute care facilities. One of the substantial components of such medical waste is disposable fabrics or garments. Typically, hospitals employ disposable garments and other fabrics to prevent the spread of infection to hospital workers and/or patients through the reuse of a fabric.

While such fabrics effectively inhibit infection, they must be disposed of in some manner. One way that these fabrics can be disposed is by using conventional solid waste management techniques. For instance, it is estimated that disposable medical fabrics comprise approximately one-half of infectious waste (0.5 million tons) generated by operating rooms each year. While this type of infectious waste may only contribute a small percentage of the total solid waste generated by hospitals yearly, the cost to dispose of such waste (as well as other infectious waste types) can be significantly greater than the costs of disposing of general waste.

As a result, disposable fabrics and garments have been developed that can be disposed of in alternative ways. In particular, fabrics were developed that would completely dissolve in hot water.

For example, one such fabric, which is described in U. S. Patent No.

5,207,837 to Honeycutt, discloses a fabric made from polyvinyl alcohol fibers that is completely soluble in water at certain temperatures. This fabric can also be hydroentangled and/or

thermally bonded. However, one of the problems of such completely soluble fabrics is that they lack sufficient strength and dimensional stability.

In addition to fabrics that are completely soluble in hot water, other fabrics have been developed that are only partially soluble in hot water. For example, one garment (OREXO), made by Isolyser Company, Inc., can be partially dissolved in hot water. In particular, this garment, which is described in more detail in U. S. Patent 5,268,222 to Honeycutt, contains a reusable component that is substantially insoluble in aqueous solutions such that it can be repeatedly relaundered and disinfected while a second component within the garment dissolves when contacted with hot water and washes down the drain. These fabrics can have increased strength over completely soluble fabrics.

However, despite the benefits of such fabrics, a fabric having a reusable component is not always desired. In many instances, for example, a fabric is required that can be completely disposed of using waste water disposal techniques, but that also has strength characteristics of a fabric containing a reusable component. As such, a need currently exists for a strong fabric that can be partially dissolved in hot water and that does not have a reusable component such that the entire fabric can be disposed of with waste water treatment methods.

Summary of the Invention The present invention recognizes and addresses the foregoing disadvantages and drawbacks of prior art constructions. Objects and addition advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

These and other objects of the present invention are achieved by providing a fabric containing a hot water soluble component and a dispersible component. In one embodiment, a fabric of the present

invention includes non-soluble, but generally dispersible pulp fibers and polyvinyl alcohol fibers that are soluble in hot water such that the resulting fabric can be disposed of using waste water treatment techniques, i. e. disposal of fabrics with hot water.

It should be noted that any given range presented herein is intended to include any and all lesser included ranges. For example, a range of from 45-90 would also include 50-90; 45-80; 46-89 and the like. Thus, the range of 95% to 99.999% also includes, for example, the ranges of 96% to 99.1 %, 96.3% to 99.7%, and 99.91 to 99.999%.

In accordance with the present invention, any material known in the art to dissolve in aqueous solutions at high temperatures can generally be used as a hot water soluble component of the present invention. In particular, fibers that dissolve in aqueous solutions at temperatures above about 37°C can generally be used as the hot water soluble component of the present invention. In one embodiment, fibers that dissolve in water at temperatures between about 80°C and about 95°C are employed. For example, in one embodiment of the present invention, polyvinyl alcohol fibers that dissolve at the above temperature ranges are utilized as a hot water soluble component of the present invention.

In addition to a hot water soluble component, a fabric of the present invention also includes a dispersible non-soluble component.

In general, a dispersible component of the present invention can be made from any material that is capable of dispersing in an aqueous solution. For example, in one embodiment, the dispersible component is made from pulp fibers either alone or in combination with other fibers. It has been discovered that the addition of a dispersible component, such as pulp fibers can provide strength and dimensional stability to the fabric and can also allow the fabric to be completely disposed of by waste water treatment techniques In some applications, it is desired that the residue of the dispersible component remaining after the fabric is contacted with hot

water be minimized to ease in later waste water treatment. As such, a dispersible component of the present invention, such as pulp fibers, typically comprises less than about 55% by weight of the total content of the fabric. In one embodiment, the dispersible component comprises less than about 40%, and in particular, less than about 20% of the total content of the fabric.

Besides the above-mentioned components, other materials and/or chemicals can be generally added to a fabric of the present invention. In particular, any material that does not affect the solubility and/or dispersability of the fabric components can be added. For example, dyes can be applied to the fabric to impart color. Moreover, surface chemicals can be applied to impart water or alcohol repellancy to the fabric surface.

In accordance with the present invention, the dispersible component can also be entangled with the hot water soluble component to further increase the strength of a fabric formed therefrom. Any known method of entangling fibers, such as air entangling or hydraulic (hydro) entangling, can be used. Hydraulic entangling may be accomplished utilizing conventional hydraulic entangling equipment such as may be found in, for example, in U. S.

Pat. Nos. 3,485,706 to Evans or 5,389,202 to Everhart et al., the disclosures of which are hereby incorporated by reference. The hydraulic entangling of the present invention may be carried out with any appropriate working fluid such as, for example, water. The working fluid flows through a manifold which evenly distributes the fluid to a series of individual holes or orifices. These holes or orifices may be from about 0.003 to about 0.015 inch in diameter. For example, the invention may be practiced utilizing a manifold produced by Honeycomb Systems Incorporated of Biddeford, Maine, containing a strip having 0.007 inch diameter orifices, 30 holes per inch, and 1 row of holes. Many other manifold configurations and combinations may be used. For example, a single manifold may be used or several

manifolds may be arranged in succession.

As such, in one embodiment of the present invention, the dispersible component, e. g. pulp fibers, is hydraulically entangled into a web of the hot water soluble component, e. g. polyvinyl alcohol fibers, to form a fabric of the present invention. In another embodiment, each component can be mixed with cold water to form a liquid suspension of fibrous material which is thereafter formed into a web and hydraulically entangled. Even if not specifically mentioned herein, any other method of forming and/or entangling a fabric that is known in the art can be used to produce a fabric of the present invention.

Generally, the hot water soluble and dispersible components can also be formed into a multi-ply structure. In particular, a multi- component structure of the present invention can have two or more layers. For example, in one embodiment, the hot water soluble component can be adhered to the dispersible component with a dispersible adhesive. In one embodiment, the adhesive is a hot melt adhesive that disperses in a pH greater than about 8. In another embodiment, the adhesive disperses in a pH greater than about 9.

Such a pH sensitive adhesive can enhance the ability of a fabric to be disposed of in alkaline-aqueous solutions sometimes used in medical applications.

Fabrics having a multi-component structure can also be entangled as described above. Specifically, one or more components, or the entire fabric, can be hydroentangled to enhance strength characteristics of the fabric. For example, in one embodiment, one of the layers of the multi-component structure is made from pulp fibers that have been hydroentangled. In another embodiment, the multi- component structure includes a web of polyvinyl alcohol fibers adhered to a web of pulp fibers. The entire multi-component structure, in this embodiment, can be entangled such that the pulp fibers sufficiently entangle with the polyvinyl alcohol fibers to increase the strength of the fabric.

Other objects, features and aspects of the present invention are discussed in greater detail below.

Detailed Description Reference now will be made in detail to various embodiments of the invention, one or more examples of which are set forth below.

Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

In general, the present invention is directed to a fabric for various uses, such as a garment, that is dispersible when contacted with an aqueous solution. It should be understood that an aqueous solution can include any liquid or solution, such as water or solutions thereof. In particular, a fabric of the present invention contains at least one component that is soluble in hot water and at least one component that is dispersible, but not completely soluble. It has been discovered that a fabric of the present invention can partially dissolve in hot water to aid in waste management. Moreover, it has also been discovered that a fabric of the present invention can retain enhanced strength characteristics and dimensional integrity during everyday use.

For example in one embodiment, polyvinyl alcohol fibers and pulp fibers are incorporated into a fabric such that the polyvinyl alcohol

fibers can dissolve when the fabric is contacted with hot water, whereas the pulp fibers only disperse into individual fibers.

As stated, a fabric of the present invention includes at least one hot water soluble component. As used herein,"hot water"generally refers to liquids having a temperature sufficient to dissolve a component, whereas"cold water"generally refers to liquids having any other temperature. In particular, the hot water soluble fibers of the present invention are normally dissolvable at temperatures above about 37°C. In one embodiment, the fibers dissolve in water at temperatures above about 80°C, and in particular, between about 80°C to about 95°C.

Any fibers that can be dissolved in water or an aqueous solution having a certain temperature, such as above about 37°C, can generally be used in the present invention as the hot water soluble component. In one embodiment, the hot water soluble component is made from polyvinyl alcohol fibers. As stated above, one embodiment of polyvinyl alcohol fibers are those that dissolve in water at a temperature between about 80°C to about 95°C. In one embodiment, for example, polyvinyl alcohol fibers are provided that dissolve in water at 92°C. In another embodiment, polyvinyl alcohol fibers are provided that dissolve in water at 80°C. Commercially available polyvinyl alcohol fibers that are suitable for use in the present invention are VPB 201 or 304 staple fibers made by Kuraray Company, Ltd. (Japan).

Other examples of suitable polyvinyl alcohol fibers are disclosed in U. S. Patent No. 5,268,222 to Honeycutt, which is herein incorporated by reference.

In accordance with the present invention, a fabric of the present invention also includes at least one component that is dispersible. It has been discovered that a fabric of the present invention can have increased dimensional stability and strength by utilizing dispersible fibers in conjunction with hot water soluble fibers, as described above.

Moreover, although a fabric of the present invention is not completely

hydrolytically degradable, it can nevertheless be substantially disposed of when the hot water soluble fibers dissolve in a hot liquid.

Any material that is dispersible in water can generally be used as a dispersible component of the present invention. In particular, components that are dispersible and do not significantly affect the solubility of other components within the fabric can be utilized in accordance with the present invention. In one embodiment, the hot water dispersible component is made from pulp fibers either alone or in combination with other fibers. For instance, the pulp fibers can be softwood fibers having an average fiber length of greater than 1 mm and particularly from about 2 to 5 mm based on a length-weighted average. Such fibers can include Northern softwood kraft fibers, redwood fibers, pine fibers, spruce fibers, or a combination thereof.

Secondary fibers obtained from recycled materials may also be used.

In a preferred embodiment, a dispersible component of the present invention is made from about 50%-70% black spruce fibers and about 25%-50% jack pine fibers.

In addition to the above components, other chemicals and/or additives can also be employed in forming a fabric of the present invention. In general, any chemical that does not significantly affect the solubility and/or dispersability of fibers within a fabric of the present invention can be added. For instance, in one embodiment, anionic or cationic dyes can be used to impart a particular color to the resulting fabric. An example of an anionic dye suitable for use in the present invention is Pergasol Blue 2R made by Ciba Speciaity Chemicals. Moreover, an example of a suitable cationic dye is Cartsol Blue GDF. A dye can generally be applied to a fabric of the present invention by any manner known in the art, such as by saturating the fabric in the dye or utilizing a weir device installed onto a hydroentangling line. In addition to dyes, surface chemicals can also be added to the fabric to provide water or alcohol repellancy.

Various embodiments of a fabric made according to the present

invention will now be described. In one embodiment, the fabric is made from polyvinyl alcohol and pulp fibers. It should be understood, however, that various other components and/or materials may be used in accordance with the present invention and that the following description is for exemplary purposes only. In particular, it should be understood that the following concentration ranges and parameters can widely vary depending upon the particular application.

In this regard, a fabric of the present invention typically contains a hot water soluble component. In one embodiment, the hot water soluble component is made from polyvinyl alcohol fibers. Moreover, in some embodiments, the hot water soluble component can be formed into a web using any technique known in the art for making nonwoven webs. Such nonwoven techniques useful for making polymer sheets include spun bonding, melt blowing, wet laying, hydroentangling with cold water, and/or thermally bonding.

In addition, in one embodiment, the hot water soluble component is carded into a carded web as is well-known in the art.

For example, in a preferred embodiment, a web of polyvinyl alcohol fibers is formed by carding the fibers into a carded web. Although not required, the fibers can also be cross-layed (cross-lapped) in the machine direction and/or cross machine direction and thereafter thermally bonded to achieve further strength. In one embodiment, the web of polyvinyl alcohol fibers has a basis weight above about 40 grams per square meter.

As discussed above, one embodiment of a fabric of the present invention also includes a generally non-soluble, dispersible component that includes pulp fibers either alone or in combination with other fibers. In general, by increasing the amount of pulp fibers added, the strength of the fabric can often increase proportionately. For example, the pulp fibers typically comprise up to about 55% of the fabric by weight. In one embodiment, the pulp fibers comprise up to about 40% by weight of the fabric, and even more preferably, up to about 20%.

For instance, in one embodiment, the pulp fibers comprise 37% by weight of the fabric. In another embodiment, the pulp fibers comprise 17% by weight of the fabric. Although it is normally desired to utilize such low levels of pulp fibers, it should also be understood that the acceptable range of pulp fiber concentrations can vary drastically depending on the particular application as well as on the amount and type of other materials present. Thus, pulp fiber concentrations greater those recited above may be equally suitable in some embodiments.

When adding dispersible fibers, it is typically desired to entangle the fibers with the hot water soluble fibers to form a stronger web. In particular, any method known in the art, such as air entangling or hydraulic entangling, can be used in the present invention to entangle different fibers together. For example, in one embodiment, dispersible fibers are entangled into a web of hot water soluble fibers.

In another embodiment, dispersible fibers are combined with hot water soluble fibers in a liquid suspension to form a web that is thereafter entangled. In still another embodiment, a sheet of dispersible fibers is adhered to a sheet of hot water soluble fibers by an adhesive to form a multi-component structure that is thereafter entangled. In addition to the above mentioned embodiments, other methods of entangling dispersible fibers with hot water soluble fibers are equally suitable and can be used in the present invention.

In one embodiment, pulp fibers are hydraulically entangled into a carded web of polyvinyl alcohol fibers to form a fabric having increased strength. Hydroentangled webs, which are also known as spunlace webs, refer to webs that have been subjected to columnar jets of a fluid that cause the fibers in the web to entangle. Particularly when fibers of different lengths are present, hydroentangling can increase the strength of the web by entangling the shorter fibers around the longer fibers. Thus, according to the present invention, the strength of the fabric can be increased by hydraulically entangling the

dispersible fibers into a web of hot water soluble fibers.

Another embodiment of a fabric made according to the present invention can include the use of hot water soluble fibers, dispersible fibers, and an adhesive that is dispersible in an aqueous environment.

Suitable hot melt adhesives, for example, are described in U. S. Patent No. 5,527,845 to Strelow et al., which is incorporated herein by reference. One such adhesive disclosed in Strelow includes about 10% to about 80%, by weight, of an alkali soluble polymer ; about 0 to about 30%, by weight, of a poly (vinyl methyl ether); about 30% to about 70%, by weight, of a tackifying resin ; and about 5% to about 30%, by weight, of a suitable plasticizer. Examples of suitable adhesives include HX 9236-01 or HX 9237-01 hot melt adhesives, which are obtainable from ATO Findley, Inc..

In one embodiment, the hot melt adhesive is also capable of dispersing in an alkaline aqueous solution. The use of such a pH sensitive adhesive can result in a fabric that is compatible with dispersion techniques and conditions used by hospitals. For instance, hospitals typically prefer to dispose of fabrics using an aqueous-alkali bath containing detergent and bleach (or other suitable caustics).

Many of these baths have a pH of about 8 or greater. Thus, in some embodiments, a fabric of the present invention can include an adhesive that disperses in an aqueous environment having a pH greater than about 8, and in other embodiments, greater than about 9.

It should be understood, however, that adhesives which disperse at pH levels less than about 8 can also be utilized in the present invention, particularly when used in applications that employ an aqueous solution having a pH less than about 8 to dispose of a fabric.

One example of a multi-component fabric of the present invention can be formed as follows. It should be understood, however, that a multi-component fabric of the present invention is not limited to the particular embodiment described below. In this regard, hot water soluble polyvinyl alcohol fibers can be formed into a web of carded

staple fibers and thermally point bonded into a fabric. Thereafter, a hot melt adhesive, such as meltblown fibers of HX 9236-01 or HX 9237-01 hot melt adhesives, can be attached to the web of polyvinyl alcohol fibers. Various plies can then be applied to the carded web of polyvinyl alcohol fibers by the adhesive. For example, in one embodiment, a dispersible low strength tissue can be attached to the hot water soluble carded web of polyvinyl alcohol fibers by the hot melt adhesive. Typically, a low strength tissue can be made from pulp fibers. One commercially available example of such a water dispersible low strength tissue is Owensboro bath tissue base, type 72000 made by Kimberly-Clark Corporation of Neenah, Wisconsin.

Moreover, in another embodiment, a second carded web or film of hot water soluble polyvinyl alcohol fibers can be attached onto the first carded web of polyvinyl alcohol fibers by the hot melt adhesive.

In general, when forming a multi-component structure according to the present invention, either one or more layers of the structure can be entangled. For example, when dispersible fibers are adhered to hot water soluble fibers as described above, the resulting multi- component structure can be hydraulically entangled as described above to provide further strength to the fabric. In one embodiment, when pulp fibers are adhered to polyvinyl alcohol fibers as described above, the resulting multi-component structure can also be hydraulically entangled to form a stronger fabric.

The present invention may be better understood with reference to the following examples.

EXAMPLE The ability of a fabric of the present invention to provide increased strength was demonstrated. Two types of polyvinyl alcohol fibers were used as the hot water soluble component for the samples, i. e. one being soluble in water at 80°C (VPB 201), the other being soluble in water at 92°C (VPB 304).

As shown below in Table 1, the five samples are represented

by the letters"A","B","C","D", and"E". Samples A & B contained VPB 201 fibers bonded at temperatures of 386°F and 390°F, respectively. Samples C, D, and E contained VPB 304 fibers bonded at temperatures of 390°F, 440°F, and 440°F, respectively. The bonding of the polyvinyl alcohol fibers above was achieved using thermal point bonding without the addition of any additives. Various characteristics of Samples A-E are shown below.

Table 1: Characteristics of Samples A-E Sample PVA Thermal Basis Tensile Normalized Type Point Wt. Strength Strength Bonding (GSM) (GMs) (GMs/GSM) Temp °F A VPB 386 37 60 + 38 1.62 201 B VPB 390 54 225 + 94 4.17 201 C VPB 390 43 686 15.95 304 D VPB 440 30 888 29.60 304 E VPB 440 47 1384 + 29.45 304 554 From the above samples, varying degrees of hydroentanglement and/or pulp content were tested. In particular, pulp fibers were wet formed onto a forming wire and then transferred onto the various samples. A pulp stock (12 Ibs of 50%-70% black spruce fibers and 25%-50% jack pine fibers, per 3000 gallons of water) was used as the dispersible component for each sample. The conditions and equipment utilized were similar to that of U. S. Patent

No. 5,587,225 to Griesbach et al., which is incorporated herein by reference. Specifically, pilot line equipment, which includes 103 A-M PET hydroentangling wire, 6/40/1 strips in each manifold, and three manifolds, was used for the appropriate hydroentangling.

The strengths of the above sample fabrics at varying degrees of hydroentanglement and/or pulp content were then determined. Pulp content was varied for the samples by adjusting the degree of hydroentangling and the speed of the wire supporting the fibers under the hydroentangling manifolds. Moreover, various hydroentangling energies were utilized to determine the effect hydroentangling on fabric strength. Specifically, the energies (i. e. Energy/Mass) used are described in U. S. Patent No. 5,023,130 to Simpson et al., which is incorporated herein by reference.

For each set of conditions, the tensile strength was determined using modified ASTM methods E4-83a and E74-93. In particular, this test used a 3"x 6"specimen with the long direction corresponding to the orthogonal direction, having the least amount of fibers orientation (cross direction or CD) after fabrication. The entire width of the specimen is held between 1"x 3"jaws spaced 3 inches apart. As the specimen was extended at 300 mm/min, the resisting force was measured with respect to the amount of extension. The tensile strength was the maximum load before the specimen ruptures. For each sample and set of conditions, multiple specimens were tested to determine tensile strength. The average of these tensile strength values was calculated for each set of conditions and reported in Tables 2-6, along with the standard deviation for each average value.

The data for each of Tables 2-6 are arranged in ascending order based on the ratio of normalized strength values as compared to the normalized strength of the sample with 100% polyvinyl alcohol fibers as indicated in Table 1. The normalized strength values generally measure strength increases or decreases based on hydroentangling and pulp content conditions, taking into account that

the fabric will inevitably have some increase in strength due to increases in other parameters such as basis weight. The results are shown below in Tables 2-6.

TABLE 2: Impact of Pulp and Hydroentangling on Strength of Sample A % Energy/Mass Basis Tensile Normalized Ratio Pulp (KW-hr/kg) Wt. Strength Strength (GSM) (GMs) (GSM/GMs) 0 0 37 60 ~ 38 1. 62 100% 0 1.325 29 126 ~ 28 4. 345 268% 37.0 0.835 46 2185 ~ 133 47. 5 2929 % 35.6 1.751 45 3245 + 346 72 4447 % TABLE 3: Impact of Pulp and Hydroentangling on Strength of Sample B % Energy/Mass Basis Tensile Normalized Ratio Pulp (KW-hr/kg) Wt. Strength Strength (GSM) (GMs) (GSM/GMs) 0 0.985 39 48 + 12 1. 23 29% 0 0 54 225 ~ 94 4.167 99% 0 2. 02 39 414 + 76 10. 62 253% 0 1.713 46 606 + 167 13. 17 314% 36.9 0.591 65 3045 ~ 46. 85 1115 767 % 35.9 1.231 64 5890 ~ 92. 03 2191 473 % 45.3 2.101 75 8700 116 2762 520 % TABLE 4 : Impact of Pulp and Hydroentangling on Strength of Sample C

% Energy/Mas Basis Tensile Normalized Ratio Pulp s (KW-hr/kg) Wt. Strength Strength (GSM) (GMs) (GM/GMs) 0 1. 921 41 164 + 46 4 25% 0 0. 873 44 227 ~ 65 5. 16 32% 0 0 43 686 15.95 100% 21.8 0.699 55 1664 ~ 324 30. 25 189% 18. 9 1.486 53 4156 ~ 650 78. 42 490% TABLE 5: Impact of Pulp and Hydroentangling on Strength of Sample D % Energy/Mas Basis Tensile Normalized Ratio Pulp s (KW-hr/kg) Wt. Strength Strength (GSM) (GMs) (GM/GMs) 0 3. 030 26 317+48 12. 19 41% 0 6.305 25 323 ~ 46 12. 92 44% 35.0 1.970 40 1069 ~ 192 26.73 90% 0 30 888 29. 6 100% 51.9 2. 918 54 1733 + 150 32.09 108% TABLE 6 : Impact of Pulp and Hydroentangling on Strength of Sample E % Energy/Mass Basis Tensile Normalized Ratio Pulp (KW-hr/kg) Wt. Strength Strength (GSM) (GMs) (GM/GMs) 0 3.425 46 358+93 7.78 26% 0 1.751 45 469+318 10.42 35% 0 0.817 47 1132 + 24.09 82% 629 0 0 47 1384 + 29.44 100% 554 25.8 0.620 62 2188 + 34.29 120% 510 24.6 1.291 61 3770 + 61.80 210% 386 42.5 1.970 80 7054 + 88.18 299% 957 The results shown in Tables 2-6 clearly demonstrate that hydroentangling and pulp content can increase the strength of a fabric.

Referring to Tables 2 or 3, for example, a fabric containing only underbonded polyvinyl alcohol fibers generally increased in strength after hydroentangling. However, as pulp was added to the fabric and hydroentangling was utilized, the normalized strength values increased dramatically.

Similarly, Tables 4-6 also demonstrated the ability of pulp content and hydroentangling to increase strength. Fabrics containing only optimally bonded polyvinyl fibers, as shown in Table 4,5, or 6, demonstrated a general decrease in strength after hydroentangling. In contrast, with the addition of pulp to the optimally bonded fibers, the normalized strengths for the hydroentangled fabrics increased in

almost every instance.

Although various embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.