EVAPORATIVE FLUID POUCH AND SYSTEMS FOR USE WITH BODY FLUIDS

Abstract

An inline storage-and-liquid-processing pouch for use with body fluids from a patient is presented that involves introducing body fluids into a first chamber in the storage-and-liquid-processing pouch and flowing air through a second chamber. The chambers are separated by a high-moisture-vapor-transfer-rate member. The air flow in the second chamber enhances liquid removal from the first chamber across the high-moisture-vapor-transfer-rate member. Other systems, devices, and methods are disclosed herein.

Claims

1. An inline pouch for delivering reduced-pressure to a reduced-pressure dressing, comprising: a pouch body; a dividing member disposed within the pouch body, the dividing member partitioning the pouch body into a first chamber and a second chamber; a wicking member disposed within the first chamber; a manifold member disposed within the second chamber; a first port disposed on the pouch body, the first port being in fluid communication with the first chamber, the first port adapted to fluidly couple the first chamber to a reduced-pressure source; and a second port disposed on the pouch body, the second port being in fluid communication with the second chamber.

2. The inline pouch of claim 1, wherein the dividing member is adapted to permit vapor transfer between the first chamber and the second chamber.

3. The inline pouch of claim 1, wherein the second port is configured to allow air to enter the second chamber from an external environment.

4. The inline pouch of claim 1, wherein: the second port is located at an end of the pouch body; and the second port is configured to allow air to enter the second chamber from an external environment and flow along a length of the second chamber.

5. The inline pouch of claim 1, further comprising a third port in fluid communication with the second chamber.

6. The inline pouch of claim 5, wherein: the second port is located at an end of the pouch body; and the second port is configured to allow air to enter the second chamber from an external environment and flow along a length of the second chamber to exit the second chamber through the third port.

7. The inline pouch of claim 5, further comprising a fourth port in fluid communication with the first chamber.

8. The inline pouch of claim 7, wherein: the first port is disposed at an end of the pouch body; the first port is configured to allow reduced-pressure to enter the first chamber from the reduced-pressure source; and the fourth port is configured to allow reduced-pressure to be communicated from the first chamber to the dressing.

9. The inline pouch of claim 1, wherein the pouch body comprises is formed with exterior walls having an interior portion.

10. The inline pouch of claim 9, wherein the dividing member divides the interior portion into the first chamber and the second chamber.

11. The inline pouch of claim 9, wherein the exterior walls are formed by a first sealing member and a second sealing member.

12. The inline pouch of claim 11, wherein the first sealing member is bonded to the second sealing member at a periphery of the first sealing member and the second sealing member.

13. The inline pouch of claim 12, wherein the dividing member is disposed between the first sealing member and the second sealing member.

14. The inline pouch of claim 1, wherein the wicking member comprises a non-woven fabric.

15. The inline pouch of claim 1, wherein the wicking member comprises a 3D spacer fabric.

16. The inline pouch of claim 1, wherein the wicking member comprises a textile.

17. The inline pouch of claim 1, wherein the wicking member comprises an open-cell foam.

18. The inline pouch of claim 1, wherein the wicking member comprises a fabric layer.

19. The inline pouch of claim 1, wherein the wicking member is configured to allow fluid to flow in the first chamber.

20. The inline pouch of claim 1, wherein the manifold member is configured to allow air to flow in the second chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a schematic, cross sectional view of an illustrative embodiment of a system for treating a tissue site on a patient with reduced pressure that includes an inline storage-and-liquid-processing pouch;

[0012] FIG. 2 is a schematic, lateral cross sectional view of the inline storage-and-liquid-processing pouch of FIG. 1 taken along line 2-2 and made into a whole cross section;

[0013] FIG. 3 is a schematic, lateral cross sectional view of an illustrative embodiment of an inline storage-and-liquid-processing pouch;

[0014] FIG. 4 is a schematic, longitudinal cross sectional view of an illustrative embodiment of an inline storage-and-liquid-processing pouch;

[0015] FIG. 5 is a schematic, plan view of an illustrative embodiment of an inline storage-and-liquid-processing pouch;

[0016] FIG. 6 is a schematic, perspective view, with a portion in cross section (lateral), of an illustrative embodiment of an inline storage-and-liquid-processing pouch; and

[0017] FIG. 7 is a schematic, longitudinal cross sectional view of the inline storage-and-liquid-processing pouch of FIG. 6 with some alterations.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0018] In the following detailed description of the illustrative, non-limiting embodiments, reference is made to the accompanying drawings that form a part hereof. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is not to be taken in a limiting sense, and the scope of the illustrative embodiments are defined only by the appended claims.

[0019] Referring now to the figures and primarily to FIG. 1-2, a system 100 for treating a tissue site 102, such as a wound 103, on a patient 104 with reduced-pressure is presented. The system 100 includes an illustrative embodiment of an inline storage-and-liquid-processing pouch 106 that allows the system 100 to process more liquids from the tissue site 102 than would otherwise be possible as well as offering other potential benefits.

[0020] The depicted wound 103 at tissue site 102 is through epidermis 108 and into dermis 110. A reduced-pressure dressing 112 is disposed on the tissue site 102 and is operable to receive fluids from the tissue site 102. The reduced-pressure dressing 112 may be any type of dressing for receiving fluids from the patient, but is shown as a dressing with a wound-interface manifold 113 and a drape 115. Indeed, the reduced-pressure dressing 112 may involve only removing fluids from a body-fluid container, such as an ostomy bag. Fluids, including liquids, from the tissue site 102 are delivered through a reduced-pressure interface 114 to a first reduced-pressure conduit 116 that is fluidly coupled to the inline storage-and-liquid-processing pouch 106.

[0021] As an overview of the illustrative embodiment of the inline storage-and-liquid-processing pouch 106, the inline storage-and-liquid-processing pouch 106 includes a pouch body 118 formed with exterior walls 119 and having an interior portion 120 that divided into two parts by a first high-moisture-vapor-transfer-rate member 122. The exterior walls 119 and first high-moisture-vapor-transfer-rate member 122 form a first chamber 124 and a second chamber 126. A storage material 128 is disposed within the first chamber 124. An air-movement manifold 130 is disposed in the second chamber 126. These aspects of the inline storage-and-liquid-processing pouch 106 and others will be further described.

[0022] A first port 132 is formed on the pouch body 118 and fluidly coupled to the first chamber 124. A second port 134 is formed on the pouch body 118 and fluidly coupled to the first chamber 124. A first evaporation port 136 is formed on the pouch body 118 and is fluidly coupled to the second chamber 126. A second evaporation port 138 is formed on the pouch body 118 and fluidly coupled to the second chamber 126. Reduced pressure is applied to the second port directly by a reduced-pressure source, e.g., a micro-pump (see FIG. 4), or by a second reduced-pressure conduit 140 (FIG. 1). The first evaporation port 136, which is the outlet to the second chamber 126, may have a bacteria filter over the first evaporation port 136 to filter the air before the air exits the second chamber 126.

[0023] Thus, liquids are pulled into the first chamber 124 as suggested by arrows 142 from the reduced-pressure dressing 112. A hydrophobic filter 135 or other device may be placed at the downstream port, i.e., the second port 134 in FIG. 1, to prevent liquids from exiting through the downstream port. As suggested by arrows 144, air is caused to flow in the second chamber 126 that helps create or maintain a relative humidity gradient across the first high-moisture-vapor-transfer-rate member 122 and that helps remove liquids from the inline storage-and-liquid-processing pouch 106 and more generally the system 100. While air is mentioned throughout this document, it should be understood that another working gas could be used and that air is being used in a broad sense to reference a gas that creates the humidity gradient across the first high-moisture-vapor-transfer-rate member 122.

[0024] The first high-moisture-vapor-transfer-rate member 122 may be formed from any material that allows vapor to egress but not liquids. “Moisture Vapor Transmission Rate” or “MVTR” represents the amount of moisture that can pass through a material in a given period of time. The first high-moisture-vapor-transfer-rate member 122 typically has a moisture vapor transmission rate greater than 300 g/m.sup.2/24 hours and more typically 1000 g/m.sup.2/24 hours or more. The first high-moisture-vapor-transfer-rate member 122 allows vapor to egress or diffuse from the first chamber 124 to the second chamber 126, but not liquids.

[0025] The first high-moisture-vapor-transfer-rate member 122 may comprise one or more of the following: hydrophilic polyurethane, cellulosics, hydrophilic polyamides, an INSPIRE 2301 material from Exopack Advanced Coatings of Wrexham, United Kingdom; a thin, uncoated polymer drape; or polyvinyl alcohol, polyvinyl pyrrolidone, hydrophilic acrylics, hydrophilic silicone elastomers and copolymers of these. The INSPIRE 2301 illustrative film has an MVTR (inverted cup technique) of 14500-14600 g/m.sup.2/24 hours. See www.exopackadvancedcoatings.com. The first high-moisture-vapor-transfer-rate member 122 may have various thicknesses, such as 10 to 40 microns (μm), e.g., 15, 20, 25, 30, 35, 40 microns (inclusive of all numbers in the stated range).

[0026] A patient-facing side 123 of the first high-moisture-vapor-transfer-rate member 122 may be coupled by an attachment device (not shown), e.g., adhesive or cement, to the top side (for the orientation shown in FIG. 1) of the storage material 128, e.g., top of the second wicking member 162. In such an embodiment, the performance of the first high-moisture-vapor-transfer-rate member 122 with respect to MVTR may be enhanced by only covering a limited surface area of the patient-facing side 123 with the attachment device. For example, according to one illustrative embodiment, only 30 to 60 percent of the surface area of the patient-facing side 123 is covered with the attachment device. The limited coverage by the attachment device on the patient-facing side 123 may be accomplished by applying the attachment device in a pattern, e.g., grid, spaced dots, swirls, or other patterns. In another embodiment, the first high-moisture-vapor-transfer-rate member 122 may be coupled by welding (e.g., ultrasonic or RF welding), bonding, stitching, staples, or another coupling device to the storage material 128. In other embodiments, there is no attachment device.

[0027] The air flow in the second chamber 126 may be achieved in either direction and is shown in FIG. 1 flowing in a direction opposite the reduced pressure flow of the first chamber 124. In the embodiment shown, a positive pressure is applied to the second evaporation port 138. The positive pressure may be applied directly by a micro-pump or other device (see FIG. 4) or by positive pressure delivered by a pressure conduit 146. When configured to apply positive pressure to the second evaporation port 138, the first evaporation port 136 functions as an outlet for flowing air to exit the second chamber 126. Alternatively, reduced pressure may be applied either directly or through pressure conduit 146 to the second evaporation port 138. In that instance, the first evaporation port 136 functions as an intake for allowing air to enter the second chamber 126.

[0028] The pouch body 118 may be formed in numerous ways. According to one illustrative embodiment, the exterior walls 119 are formed by a first sealing member 148 and a second sealing member 150. The first sealing member 148 is bonded by bond 149 to the second sealing member 150 at peripheral ends 152. The first high-moisture-vapor-transfer-rate member 122 is disposed between the first sealing member 148 and second sealing member 150 and may be bonded with bonds 149 as well. The first high-moisture-vapor-transfer-rate member 122 thereby forms two parts or bisects (not necessarily equal parts) the interior portion 120 to form the first chamber 124 and the second chamber 126.

[0029] The first sealing member 148 is formed from any material that inhibits air flow through the first sealing member 148 and typically that is liquid impermeable as well. In some embodiments, the first sealing member 148 may be a high-moisture-vapor-transfer-rate material to allow additional liquid to egress the second chamber 126. The second sealing member 150 is formed from any liquid-impermeable material. Typically, the first sealing member 148 and second sealing member 150 are formed from one or more of the following: natural rubbers, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene monomer, chlorosulfonated polyethylene, polysulfide rubber, polyurethane (PU), EVA film, co-polyester, silicones, silicone drape, a 3M Tegaderm® drape, or a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Pasadena, Calif., or any material mentioned for the first high-moisture-vapor-transfer-rate member 122, or other appropriate material. The first sealing member 148 need not be liquid impermeable and could also be formed from a woven or non-woven material as long as the material is coated or constructed to contain the air flow.

[0030] The ports 132, 134, 136, and 138 are formed through the pouch body 118. Typically, the respective pairs of ports (132 and 132; 136 and 138) are displaced as far as possible from each other to maximize distribution of liquids or evaporation. Thus for example, typically the first port 132 is positioned on a first end 154 of the pouch body 118 and the second port 134 is positioned on the second end 156. Likewise, the first evaporation port 136 is on the first end 154 and the second evaporation port 138 is on the second end 156.

[0031] The storage material 128 is disposed in the first chamber 124. The storage material 128 is any material that receives fluids, including liquids, and retains the fluids. For example, without limitation, the storage material 128 may be formed from one or more of the following: an absorbent member 158, a first wicking member 160, a second wicking member 162. In the illustrative embodiment of FIG. 2, the storage material 128 comprises the absorbent layer 158 and two wicking members 160, 162. In the illustrative embodiment of FIG. 3, the storage material 128 is only an absorbent member 158.

[0032] The absorbent member 158 may be any material that retains liquids and may comprise one or more of the following: BASF 402c, Technical Absorbents 2317, sodium polyacrylate super absorbers, cellulosics (carboxy methyl cellulose and salts such as sodium CMC), or alginates. The first wicking member 160 and second wicking member 162 may be formed from one or more of the following: non-woven fabrics such as Libeltex TDL2, woven fabrics including 3D spacer fabrics and Textiles (Baltex, Ilkeston, Derby, UK), open-cell foam, or sintered polymers.

[0033] In the illustrative embodiment of FIGS. 1-2, the storage material 128 includes a first wicking member 160, an absorbent member 158, and a second wicking member 162, which is proximate to the first high-moisture-vapor-transfer-rate member 122. The first wicking member 160 and the second wicking member 162 may be coupled at their peripheral edges 165 as shown by a coupling 163. The coupling 163 may be formed using any known technique, including without limitation welding (e.g., ultrasonic or RF welding), bonding, adhesives, cements, stitching, staples, or another coupling device. Alternatively, the first wicking member 160 and the second wicking member 162 may be disposed adjacent to one another at least at their peripheral ends (overlapping portions) and held in contact with one another to allow fluid communication therebetween. The wicking layers 160, 162 may thus be in fluid communication with each other to allow fluid flow between the wicking layers 160, 162 and along the wicking layers 160, 162 at times when the flow of fluid in the absorbent layer 158 is inhibited or blocked.

[0034] Referring now to FIG. 4, another illustrative embodiment of an inline storage-and-liquid-processing pouch 106 for use with body fluids from a patient is presented. The inline storage-and-liquid-processing pouch 106 is analogous in many respects to the inline storage-and-liquid-processing pouch 106 of FIGS. 1-3, and accordingly, some parts are labeled but not further discussed. The inline storage-and-liquid-processing pouch 106 includes a first micro-pump 164 coupled to the pouch body 118 and fluidly coupled to the second port 134. The first micro-pump 164 is operable to produce reduced pressure that is delivered to the second port 134. The first micro-pump may be any pump capable of producing reduced pressure and small and light weight enough to be attached directly to the pouch body 118. For example, and not by way of limitation, the micro-pump shown in United States Patent Publication 2009/0240185 (application Ser. No. 12/398,904; filed 5 Mar. 2009), entitled, “Dressing and Method for Applying Reduced Pressure To and Collecting And Storing Fluid from a Tissue Site,” which is incorporated herein for all purposes, may be used.

[0035] Similarly, a second micro-pump 166 is coupled to the pouch body 118 and fluidly coupled to the second evaporation port 138. The second micro-pump 166 is operable to produce air flow in the second chamber 126 between the first evaporation port 136 and the second evaporation port 138. The second micro-pump 166 is analogous to the first micro-pump but may configured to either pull air as shown and suggested by arrows 168 or to push air. In the latter situation, air goes from the second evaporation port 138 through the second chamber 126 to the first evaporation port 136. The inline storage-and-liquid-processing pouch 106 may be formed with one or both of the micro-pumps 164, 166 or with one or more conduits 140, 146 as shown in FIG. 1. A first reduced-pressure conduit 116 is fluidly coupled to a wound dressing (not shown), such as the reduced-pressure dressing 112 in FIG. 1, and to the first port 132. As shown in FIG. 5, the reduced-pressure dressing may also be directly coupled to the first port 132.

[0036] Referring now primarily to FIG. 5, a plan view of an illustrative system 100 for treating a tissue site on a patient with reduced-pressure that includes an inline storage-and-liquid-processing pouch 106 is presented. The inline storage-and-liquid-processing pouch 106 is analogous in most respects to the inline storage-and-liquid-processing pouch 106 of FIGS. 1-3, and accordingly, some parts are labeled but not further discussed. In addition, components referenced but not explicitly shown are analogous to those previously presented. The embodiment of FIG. 5 differs primarily in that the pouch body 118 has a main portion 170 and a neck portion 172 and the first port 132 is coupled directly to the reduced-pressure dressing 112.

[0037] It should be noted that that the inline storage-and-liquid-processing pouch 106 may take many different shapes. Some embodiments of the inline storage-and-liquid-processing pouch 106 are for wearing on the patient and others may be for a stationary position near the patient. In some embodiments, the second chamber 126 may encircle the first chamber 124 or other configurations may be used. The pouch body 118 may take different sizes too. In one illustrative embodiment, the pouch body 118 has surface area in plan view greater than 200 centimeters.sup.2 and less than 730 centimeters.sup.2.

[0038] In the embodiment of FIG. 5, reduced pressure is developed into the first chamber and that reduced pressure pulls liquids from the reduced-pressure dressing 112 directly into the first port 132 and is distributed in the first chamber. A micro-pump 166 pushes or pulls air into the air-movement manifold. Thus, air will enter or exit through the first evaporation port 136, which in this embodiment comprises a plurality of apertures. The movement of air in the second chamber establishes a strong humidity gradient across a first high-moisture-vapor-transfer-rate member and liquid is thus processed out of the system 100.

[0039] Referring now primarily to FIGS. 6 and 7, another illustrative embodiment of an inline storage-and-liquid-processing pouch 106 is presented. The inline storage-and-liquid-processing pouch 106 is analogous in most respects to the inline storage-and-liquid-processing pouch 106 of FIGS. 1-3, and accordingly, some parts are labeled but not further discussed. In addition, components referenced but not explicitly shown are analogous to those previously presented. This embodiment differs primarily in that three chambers are formed in the interior portion 120 in order to provide for evaporation on two sides of the first chamber 124.

[0040] A pouch body 118 is formed having exterior walls 119. The pouch body 118 is partitioned by a first high-moisture-vapor-transfer-rate member 122 and a second high-moisture-vapor-transfer-rate member 174 to form the first chamber 124, a second chamber 126, and a third chamber 176. The second high-moisture-vapor-transfer-rate member 174 may formed from the same materials as the first high-moisture-vapor-transfer-rate member 122 as previously presented. The first chamber 124 is between the second chamber 126 and third chamber 176. As with previous embodiments, a storage material 128 is disposed within the first chamber 124 and an air-movement manifold 130, which is a first air-movement manifold 178, is disposed within the second chamber 126. In addition, a second air-movement manifold 180 is disposed in the third chamber 176. The first air-movement manifold 178 and second air-movement manifold 180 are formed from one or more of the same materials previously mentioned for the first air-movement manifold 130 in FIGS. 1-3.

[0041] The storage material 128 may be any of the materials previously mentioned. FIGS. 6 and 7 differ from one another slightly with respect to the storage material 128. The storage material 128 in FIG. 6 has an absorbent member 158 disposed between a first wicking member 160 and a second wicking member 162. In contrast, the storage material of 128 of FIG. 7 is only an absorbent member 158.

[0042] Referring primarily to FIG. 7, a schematic, longitudinal cross section of the inline storage-and-liquid-processing pouch 106 of FIG. 6 is presented. The various ports are shown best in this view. The pouch body 118 is formed with a first port 132 formed on the pouch body 118 and is fluidly coupled to the first chamber 124. A second port 134 is also formed on the pouch body 118 and is fluidly coupled to the first chamber 124. A first evaporation port 136 and a second evaporation port 138 are formed on the pouch body 118 and are fluidly coupled to the second chamber 126. In addition, a third evaporation port 182 is formed on the pouch body 118 and is fluidly coupled to the third chamber 176. Likewise, a fourth evaporation port 184 is formed on the pouch body 118 and is fluidly coupled to the third chamber 176. To maximize distribution or evaporation, the pairs of ports are typically remote from each other and usually one is on the first end 154 and the other on the second end 156.

[0043] Referring generally to FIGS. 6 and 7, according to one illustrative embodiment, in operation, the first port 132 is fluidly coupled to the wound dressing (e.g., reduced-pressure dressing 112 in FIG. 1) and receives fluids, including liquid, therefrom. The liquid is pulled through the second port 134 into the first chamber 124 by reduced pressure applied to the first chamber 124 through the first port 132. The liquid is distributed within the storage material 128 from the second port 134 to the first port 132 as suggested by arrows 142. The liquid in the storage material 128 interacts with both the first high-moisture-vapor-transfer-rate member 122 and the second high-moisture-vapor-transfer-rate member 174.

[0044] An air flow is produced in the second chamber 126 as suggested by arrows 144. Air may flow to or from the first evaporation port 136 and from or to the second evaporation port 138. The air flow in second chamber 126 is caused by applying positive or reduced pressure to one of the evaporation ports 136, 138. In addition, an air flow is produced in the third chamber 176 as suggested by arrows 186. Air may flow to or from the third evaporation port 182 and from or to the fourth evaporation port 184. The flow in third chamber 176 is caused by applying positive or reduced pressure to one of the evaporation ports 182, 184. In this way, air flowing on both sides of the first chamber 124 enhances the inline storage-and-liquid-processing pouch 106's ability to process liquids out of the inline storage-and-liquid-processing pouch 106.

[0045] In all the embodiments herein, the air movement through the second chamber 126 (and third chamber 176 when applicable) may be continuous, intermittent, or actively controlled. In the latter situation, a saturation sensor may be applied in the first chamber 124 or an outward facing side of the high-moisture-vapor-transfer-rate members 122, 174. The saturation sensor may be any device that allows monitoring of the saturation status of the storage material 128. For example, without limitation, the saturation sensor may be a resistive element that changes resistance when liquid covers the sensor, a galvanic cell that creates a voltage when covered with liquid from a wound, a capacitive sensor that changes properties when saturated liquid is nearby, or any other electrical saturation sensor. The saturation sensor is coupled to a controller, and the controller and saturation sensor determine when the storage material 128 or high-moisture-vapor-transfer-rate members 122, 174 are saturated. Upon detecting the same, the controller may activate a pressure source that supplies either reduced pressure or positive pressure to one of the evacuation ports 136, 138. When the saturation sensor and controller determine that the storage material 128 is not saturated, the controller may deactivate the pressure source.

[0046] In another illustrative embodiment, an inline storage-and-liquid-processing pouch 106 is coupled directly to a body-fluid bag, e.g., an ostomy bag. The inline storage-and-liquid-processing pouch 106 may form an outer wall of the fluid-bag itself.

[0047] The illustrative systems and inline storage-and-liquid-processing pouches presented herein offer a number of perceived advantages. These include the ability to manage a higher volume of fluid than otherwise possible. In this regard, one may consider that exudate from a wound often has about 88 percent water and 12 percent other materials. With such a device in use, the system may not need changing for a relatively extended period of time. In addition, the inline storage-and-liquid-processing pouch is multi-directional and involves fewer parts than canisters in use. In addition, the inline storage-and-liquid-processing pouch has a low profile and is light. These are only some of the potential advantages.

[0048] Although the present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments, it should be understood that various changes, substitutions, permutations, and alterations can be made without departing from the scope of the invention as defined by the appended claims. It will be appreciated that any feature that is described in connection to any one embodiment may also be applicable to any other embodiment.

[0049] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to “an” item refers to one or more of those items.

[0050] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate.

[0051] Where appropriate, aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further examples having comparable or different properties and addressing the same or different problems.

[0052] It will be understood that the above description of preferred embodiments is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of the claims.