Patent Publication Number: US-2019167861-A1

Title: Dressings, Systems, And Methods For Treating A Wound On A Patient&#39;s Limb Employing Liquid Control

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/229,422, filed Aug. 5, 2016, which is a continuation of U.S. patent application Ser. No. 13/674,782, filed Nov. 12, 2012, now U.S. Pat. No. 9,433,711, which claims the benefit, under 35 USC § 119(e), of the filing of U.S. Provisional Patent Application Ser. No. 61/558,544, entitled “Dressings, Systems, and Methods for Treating a Wound on a Patient&#39;s Limb Employing Liquid Control,” by Pratt et al., filed Nov. 11, 2011, which is incorporated herein by reference for all purposes. 
    
    
     FIELD 
     The present disclosure relates generally to medical treatment systems suitable for use with venous leg ulcers (VLU) and, more particularly, but not by way of limitation, to dressings, systems, and methods for treating a wound on a patient&#39;s limb, e.g., a venous leg ulcer, that employs liquid control or management. 
     BACKGROUND 
     Venous leg ulcers (VLU), which are sometimes called varicose or stasis ulcers, result from damage to the valves in the veins of the legs, leading to raised venous pressure. VLUs have a multi-faceted negative effect on the health and wellbeing of patients. Physical symptoms include pain and immobility, which in turn, may lead to sleep disturbance, lack of energy, work limitations, frustration, and a lack of self-esteem. 
     The main treatment has been the application of compression to minimize edema or swelling. Compression treatments include wearing compression stockings, multi-layer compression wraps, or wrapping an ACE bandage or dressing from the toes or foot to the area below the knee. Other wounds may also be experienced on limbs of a patient. 
     SUMMARY 
     According to an illustrative embodiment, a wound dressing for treating a wound on a patient&#39;s limb includes a tubular sleeve member for receiving the patient&#39;s limb and a pressure source fluidly coupled to the tubular member. The tubular sleeve member includes an elastic compression member formed as a sleeve having a first side and a second, patient-facing side and a fluid-directing member having a first side and a second, patient-facing side. The first side of the fluid-directing member is disposed proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The tubular sleeve member also includes a pathway member having a first side and a second, patient-facing side. The first side of the pathway member is proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The pressure source is fluidly coupled to the pathway member for moving fluid therein. The wound dressing further includes at least one exhaust port fluidly coupled to the pathway member for allowing fluids to exit the wound dressing. The tubular sleeve member may also include one or more of the following: an absorbent member, a transition member, or a patient-interface member. 
     According to another illustrative embodiment, a dressing for treating a wound on a patient&#39;s limb includes a means for compressing the limb proximate the wound and a means for receiving liquid from the wound into the dressing. The dressing further includes a means for forcing air to flow through the dressing to facilitate vaporization and removal of liquids from the dressing. 
     According to another illustrative embodiment, a method for treating a wound on a patient&#39;s limb includes providing a wound dressing. The wound dressing includes a tubular sleeve member that includes an elastic compression member formed into a sleeve having a first side and a second, patient-facing side and a fluid-directing member having a first side and a second, patient-facing side. The first side of the fluid-directing member is disposed proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The tubular sleeve member further includes a pathway member having a first side and a second, patient-facing side. The first side of the pathway member is proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The method further includes disposing the wound dressing around the patient&#39;s limb proximate to the wound, receiving liquid from the wound into the wound dressing, and creating a pressure gradient within the wound dressing to cause air flow in the wound dressing to evaporate liquid from the wound dressing. The air enters the wound dressing at one location and is exhausted at another location. 
     According to another illustrative embodiment, a method of manufacturing a wound dressing for treating a wound on a patient&#39;s limb includes forming a tubular sleeve member for receiving the limb of the patient. The step of forming a tubular sleeve member includes forming an elastic compression member as a sleeve having a first side and a second, patient-facing side; forming a fluid-directing member having a first side and a second, patient-facing side; and disposing the first side of the fluid-directing member proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The step of forming a tubular sleeve member further includes forming a pathway member having a first side and a second, patient-facing side and disposing the first side of the pathway member proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The method of manufacturing a wound dressing further includes fluidly coupling the pressure source to the pathway member for moving fluid therein. 
     According to another illustrative embodiment, a system for treating a wound on a patient&#39;s limb includes a wound dressing comprising a tubular sleeve member. The tubular sleeve member includes a plurality of pressure compartments. Each pressure compartment is operable to form a pressure gradient on a portion of the patient&#39;s limb. The system further includes a pressure source that is fluidly and separately coupled to each of the pressure compartments; and a controller coupled to the pressure source to control pressure delivery to the plurality of pressure compartments. The controller and pressure source are operable to cause a first pressure compartment of the plurality of pressure compartments to compress around the patient&#39;s limb, then subsequently a second pressure compartment of the plurality of pressure compartments to compress in order to encourage fluid movement in the patient&#39;s limb from proximate the first pressure compartment towards the second pressure compartment. 
     According to another illustrative embodiment, a method for treating a wound on a patient&#39;s limb includes forming a plurality of pressure compartments on the patient&#39;s limb proximate the wound, sequentially compressing each pressure compartment in a cephaladic direction, and flowing air over a majority of the pressure compartments to vaporize and remove liquid. 
     Other aspects, features, and advantages of the illustrative embodiments will become apparent with reference to the drawings and detailed description that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevation view of an illustrative embodiment of a dressing for treating a venous leg ulcer or other wound on a patient; 
         FIG. 2  is a cross section (medial) of the dressing of  FIG. 1  taken along line  2 - 2 ; 
         FIG. 3  is a cross section of a portion of an illustrative embodiment of a wound dressing for treating a wound, such as a venous leg ulcer, that shows another seal against a patient&#39;s epidermis; 
         FIG. 4  is a perspective view of an illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer or other wound; 
         FIG. 5  is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer; 
         FIG. 6  is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer; 
         FIG. 7  is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer; 
         FIG. 8  is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer; 
         FIG. 9  is a cross section of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer; 
         FIG. 10  is an elevation view of an illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer, on a patient; 
         FIG. 11  is a schematic diagram of a control subsystem for use with a dressing for treating a wound, such as venous leg ulcer; and 
         FIG. 12  is an elevation view of another dressing for treating a wound, such as venous leg ulcer, on a patient. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     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. 
     In treating a venous leg ulcer (VLU) or other wounds, it is desirable to apply compression, remove exudate, and control the liquid produced by the wound that is retained in a dressing. VLU&#39;s produce considerable liquids that can saturate a dressing, cause an undesirable odor, and cause maceration of healthy skin. The dressings and systems herein control the liquid from the wound in a way to avoid one or more of these conditions. 
     Referring to the figures, and initially to  FIGS. 1-2 , a dressing  102  for treating a wound  104 , such as a venous leg ulcer, on a limb  106  or extremity of a patient  108  is presented. The wound  104  may involve epidermis  103 , dermis  105 , and subcutaneous tissue  107 . The dressing  102  reduces the amount of liquid from the wound  104  that is retained within the dressing  102  by using air movement to vaporize and remove fluids. The dressing  102  may reduce odor and may facilitate an overall smaller size dressing than might otherwise be possible. The dressing  102  may have a longer use time than otherwise possible. 
     The dressing  102  includes a tubular sleeve member  110  for receiving the limb  106  or extremity of the patient  108 . The tubular sleeve member  110  has limb openings  112 : a first limb opening  114  and a second limb opening  116 . The limb openings  112  allow the tubular sleeve member  110  to receive the limb  106  therein. The tubular sleeve member  110  and the limb openings  112  may be sized to accommodate different sized limbs  106 . 
     The tubular sleeve member  110  may include an elastic compression member  118  formed as a sleeve. The elastic compression member  118  is the outermost (furthest from patient  108 ) member of the tubular sleeve member  110 . The elastic compression member  118  has a first side  120  and a second, patient-facing side  122 . The elastic compression member  118  may be formed from one or more of the following materials: Nylon Powernet material; Velband; materials with combinations of relatively non-elastic nylon fibers and highly-elastic fibers (e.g., Spandex, Elastene); Lycra materials, stretch cotton; rubber materials; urethanes; silicones; or other stretch based materials. The elastic compression member  118  is optional in that an embodiment may be used as a dressing without this layer. In such a case, the next layer, a fluid-directing member  124 , may securely hold the dressing  102  in place. 
     The tubular sleeve member  110  also includes the fluid-directing member  124 . The fluid-directing member  124  has a first side  126  and a second, patient-facing side  128 . The first side  126  of the fluid-directing member  124  is disposed proximate to the second, patient-facing side  122  of the elastic compression member  118 . The fluid-directing member  124  is operable to inhibit fluids from flowing through the fluid-directing member  124 . The fluid-directing member may comprise one or more of the following: a polyurethane (PU) drape; an elastomer (e.g., natural rubbers, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene monomer, chlorosulfonated polyethylene, polysulfide rubber, EVA film, co-polyester, and silicones; silicone drape material; a 3M Tegaderm® drape; or a polyurethane (PU) drape. The fluid-directing member  124  directs fluids so that airflow is primarily out of the exhaust ports. 
     At the limb openings  112 , the fluid-directing member  124  may extend beyond any other layers to form an extension  130 . The extension  130  forms a seal with the patient&#39;s epidermis  103  as shown best in  FIG. 2 . The extension  130  has a first side  134  and a second, patient-facing side  136 . An adhesive  138  is applied to the second, patient-facing side  136  of the extension  130  to facilitate attachment to the patient&#39;s epidermis  103 . A port  140 , which depending on mode of operation is an intake port or an exhaust port, is formed through the fluid-directing member  124  and any other members as necessary to access air beyond the wound dressing  102 . The port  140  allows fluid to enter or exit the wound dressing  102 . 
     As shown in  FIG. 3 , in another illustrative embodiment, the elastic compression member  118  and fluid-directing member  124  both extend over transverse edges  142  and, because of compression, impinge upon the epidermis  103  to form a seal. In this embodiment, the port  140  extends through both the elastic compression member  118  and fluid-directing member  124 . In still another embodiment, all the layers may be coterminous and the entire edge may serve to exhaust vapor. 
     Referring again primarily to  FIG. 2 , the tubular sleeve member  110  further includes a pathway member  144 . The pathway member  144  has a first side  146  and a second, patient-facing side  148 . The first side  146  of the pathway member  144  is proximate to the second, patient-facing side  128  of the fluid-directing member  124 . The pathway member  144  is operable to transport a fluid under a pressure gradient. The pathway member  144  functions to present pathways that allow a gas to flow and has sufficient rigidity to allow pathways to remain open even when compressed during use. The pathway member  144  may comprise one or more of the following: open-cell foam; non-woven material (e.g., Libeltex Hydrophobic non-woven); or Vilmed range from Freundenberg  1522 . As suggested by arrows  150  in  FIG. 2 , air moves within the pathway member  144 . Arrows  150  show airflow in one direction, but another direction is possible as is explained elsewhere. 
     The tubular sleeve member  110  may optionally include an absorbent member  152 . The absorbent member  152  at least temporarily retains liquids from the wound  104  away from the patient&#39;s epidermis  103 . The absorbent member  152  has a first side  154  and a second, patient-facing side  156 . The first side  154  of the absorbent member  152  is proximate to the second, patient-facing side  148  of the pathway member  144 . The absorbent member  152  acts as a buffer to hold liquid from the wound  104  while waiting for the liquid to be evaporated and carried away by airflow in the pathway member  144 . The absorbent member  152  may be any material that functions to hold liquid. The absorbent member  152  may be formed from one or more of the following: a super absorbent polymer material (e.g., LUQUAFLEECE from BASF), Vilmed range from Freundenberg  1522 , or other material. 
     The tubular sleeve member  110  may optionally include a transition member  158 . The transition member  158  may be formed from the same materials as the pathway member  144 . The transition member  158  has a first side  160  and a second, patient-facing side  162 . The first side  160  of the transition member  158  is disposed proximate to the second, patient-facing side  156  of the absorbent member  152 . The transition member  158  wicks liquids from the wound  104  to help keep fluids away from the epidermis  103  or wound  104 . 
     The tubular sleeve member  110  may optionally include a patient-interface member  164  that has a first side  166  and a second, patient-facing side  168 . The first side  166  of the patient-interface member  164  is disposed proximate to the second, patient-facing side  162  of the transition member  158  or the second, patient-facing side  156  of the absorbent member  152 . The second, patient-facing side  168  of the patient-interface member  164  is for disposing proximate to the patient  108 . The patient-interface member  164  is designed to be against the epidermis  103  for extended periods of time and may include an anti-microbial material, e.g., silver. The patient-interface member  164  may be formed from a Silver Miliken or other material. 
     A pressure source  170  is fluidly coupled to the tubular sleeve member  110 . The pressure source  170  may be, for example, a reduced-pressure source or a positive pressure source. Thus, the pressure source  170  may be a micro-pump  172  as shown in  FIG. 2 , a remote reduced-pressure source  174  as shown in  FIG. 10 , a wall-based suction source, or a wall-based positive pressure source. 
     As suggested by arrows  176  in  FIG. 1 , the pressure source  170  may be configured to pull air into the wound dressing  102  at an inboard location. The wound dressing  102  may be configured to discharge the air at the edges. The air is discharged through one port  140  at the limb opening  112  as suggested by arrows  178 . Alternatively, the pressure source  170  may be configured to pull air as suggested by arrows  180  in  FIG. 10  from the limb openings  112  to the pressure source  170  and then exhaust the air at the reduced-pressure source  174 . 
     The wound dressing  102  includes at least two ports: port  140  and port  182 . The limb openings  112  typically include at least one port  140 . As shown best in  FIG. 4 , a plurality of ports  140  may be included. The port or ports  140  may function as exhaust ports or intake ports depending on the configuration of the pressure source  170 . Thus, in  FIGS. 1-2 , the port  140  is an exhaust port. In  FIG. 10 , the ports  140  are intake ports. The port  182  is associated with the pressure source  170  and may include an extension portion  185  to provide fluid communication with a desired layer of the wound dressing  102 . For example, the extension portion  185  may fluidly couple the pressure source  170  to the pathway member  144  as shown in  FIG. 2  or to another layer if desired. 
     The pressure source  170  causes a pressure gradient in the wound dressing  102  that will move air. Depending on how the wound dressing  102  is configured, air either enters at the edges (e.g., at the limb opening  112 ) and moves to port  182  or enters at the port  182  and moves to the limb opening  112  and out ports  140 . The ports  140  and  182  may both may be inboard if a compartment wall is used as is described elsewhere herein. The pressure gradient is typically established primarily in the pathway member  144 , but may be established in other layers in some embodiments. 
     Each port  140 ,  182  may have a filter associated with the port  140 ,  182 . For example, a filter  184  is associated with port  140 , and a filter  186  is associated with port  182 . The filters  184 ,  186  may be odor filters, e.g., charcoal filters, or anti-bacterial filters. In  FIG. 2 , the filter  184  is a charcoal filter for removing odor from the airflow before the airflow is released into the atmosphere. The filter  186  is an intake filter for removing bacteria before the air enters the wound dressings  102 . In  FIG. 10 , the intake filters (not explicitly shown) associated with ports  140  are anti-bacterial intake filters. 
     Of the various layers mentioned (e.g., elastic compression member  118 , fluid-directing member  124 , pathway member  144 , absorbent member  152 , transition member  158 , and patient-interface member  164 ), some may be omitted, some combined, and some rearranged. As a few non-exhaustive examples, consider the embodiments of  FIGS. 5-8 . In  FIG. 5 , the tubular sleeve member  110  of the wound dressing  102  comprises only an elastic compression member  118 , a fluid-directing member  124 , and pathway member  144 . In  FIG. 6 , the tubular sleeve member  110  of the wound dressing  102  comprises an elastic compression member  118 , a fluid-directing member  124 , pathway member  144 , and an absorbent member  152 . In  FIG. 7 , the tubular sleeve member  110  of the wound dressing  102  comprises an elastic compression member  118 , a fluid-directing member  124 , pathway member  144 , an absorbent member  152 , and a transition member  158 . In  FIG. 8 , the tubular sleeve member  110  of the wound dressing  102  comprises an elastic compression member  118 , a fluid-directing member  124 , and a woven-open-structure member  188 . The woven-open-structure member  188  functionally combines the pathway member  144 , absorbent member  152 , and the transition member  158  into one material. The woven-open-structure member  188  is operable to retain fluids and at the same time allow gases to move in the woven-open-structure member  188 . The woven-open-structure member  188  may be formed from Vilmed range from Freundenberg  1522  or other similar material, for example. 
     Referring now to  FIG. 9 , another illustrative embodiment of a wound dressing  102  for treating a wound  104  on a limb  106  of a patient  108  is presented. The cross section is a medial cross section of the limb  106  with the wound dressing  102  applied thereto. The wound dressing  102  is analogous in most respects to the wound dressing of  FIGS. 1-2 , except the elastic compression member  118  is omitted and additional features added as will be explained. The wound dressing  102  may be formed as an annular sleeve, as an isolated dressing, or island dressing. The wound dressing  102  may be used with or without compression. If compression is desired, the compression is developed by application of the fluid-directing member  124  in tension. The wound dressing  102  is held by adhesive  138  to the patient  108 . 
     In this embodiment, a control subsystem  202  is included. The control subsystem  202  includes at least one saturation sensor  190 . The saturation sensor  190  is coupled to the absorbent member  152 . In other embodiments, the saturation sensor  190  may be coupled to other layers, e.g., the transition member  158 . The saturation sensor  190  may be a galvanic cell with two electrodes that produce voltage when saturated, a resistive pathway that is completed by exudate, or a capacitor-based sensor. 
     The saturation sensor  190  is coupled to a control circuit or controller  192 . The controller  192  is configured to monitor the saturation sensor  190 . When the controller  192  detects a change indicative that the absorbent member  152  is saturated or partially saturated, the controller  192  activates the pressure source  170  in response. The pressure source in this embodiment pulls gas from the port  182  and discharges the gas to the atmosphere as suggested by arrows  194 . The air is pulled from the transverse edges  142  through one or more ports  140 . In this embodiment, the ports  140  may have a control valve  196  associated with each port  140 . The control valve  196  may be wirelessly or electrically coupled by a lead  199  to the controller  192 . The control valve  196  regulates air flow through the one or more ports  140  to keep air moving in the wound dressing  102 , but also to control the rate such that, if desired, a reduced pressure may be maintained in a sealed space  198  at a desired level. 
     As an alternative to the control valve  196 , controlled leaks in the fluid-directing member  124  may be used. The controlled leaks allow air to flow in at or near the transverse edges  142  towards the pressure source  170 . For example, apertures (not explicitly shown) in the fluid-directing member  124  may be covered by an adhesive film that is removed later when a leak is desired. 
     With the embodiment of  FIG. 9 , a reduced pressure may be applied to the wound  104  and liquids removed and managed. The reduced pressure is initially applied by the pressure source  170 . When sufficient liquids reach the absorbent member  152  and saturate the absorbent member  152 , the control valve  196  may be at least partially opened to allow some fluid flow into the wound dressing  102  and at the same time the pressure source  170  may be sufficiently increased to hold the desired reduced pressure notwithstanding the introduction of air through ports  140 . As shown in the diagram of  FIG. 11 , a display  200  may be added to the control subsystem  202  to provide feedback to a user. The display  200  may be a series of LED indicators, a bi-stable LCD type, or other compact display. The display  200  is compact and low power. The display  200  may display information such as remaining battery capacity, duration of therapy, and the fill status of the dressing as well as confirmation that the system is operating within its normal parameters. 
     Referring now primarily to  FIG. 10 , another illustrative embodiment of a wound dressing  102  for treating a wound  104  on a limb  106  of a patient  108  is presented. The wound dressing  102  is analogous to those previously presented, except in this embodiment, the pressure source  170  is a remote reduced-pressure source  174 . The remote reduced-pressure source  174  is fluidly coupled by a pressure conduit  204  to the tubular sleeve member  110 . A pressure interface  206  may be used to fluidly couple the pressure conduit  204  to the intake port (see port  182  in  FIG. 2 ). The intake port is at an inboard location on the wound dressing  102 . In one illustrative embodiment, the pressure interface  206  is a T.R.A.C.® Pad or Sensa T.R.A.C.® Pad available from KCI of San Antonio, Tex., or another interface. In another embodiment, a “bridge” (an open-cell foam or other passageway material enclosed in a gas-impermeable material) is used to deliver reduced pressure to the wound dressing  102 . 
     Referring now primarily to  FIG. 11 , the control subsystem  202  includes a controller  192  that is coupled to a saturation sensor  190  and to a pressure source  170 . In addition, a control valve  196  may be coupled to the controller  192  and also a display  200 . The control subsystem  202  may control the leak rate by opening the control valve  196  when included or may turn on, turn off, increase, or decrease the pressure produced by the pressure source  170 . As used through out this document, “or” does not require mutual exclusivity. The control valve  196  may be a solenoid valve such a Pneutronics X valve with a fixed size orifice from Parker Hannifin, Cleveland, Ohio; a mechanical proportional valve; or a PZT proportional valve such as those supplied by Festo. 
     It should be understood that the control subsystem  202  of  FIG. 11  or aspects of the control subsystem  202  may be applied to any of the embodiments herein. Thus, for example, when the control subsystem  202  is added to the wound dressing  102  in  FIGS. 1-2 , the saturation sensor  190  and controller  192  determine when the absorbent member  152  is saturated or partially saturated. The controller  192  may then activate the pressure source  170  to initiate airflow in the wound dressing  102  to evaporate and remove liquids from the wound dressing  102 . The sensor  109  and controller  192  may detect saturation as a scale. The duration of the airflow or the speed of the airflow may be set by the controller  192  in response to the degree of saturation involved. The control system  202  may also display information such as remaining battery capacity, duration of therapy, and the fill status of the dressing as well as confirmation that the system is operating within its normal parameters. 
     Referring now primarily to  FIG. 12 , another illustrative embodiment of a wound dressing  102  is presented. The wound dressing  102  is analogous in most respects to the previously presented wound dressings, except in this embodiment, a plurality of pressure compartments  208  are added and are used to massage the limb  106 . Each pressure compartment  208  is operable to form a pressure gradient on a portion of the patient&#39;s limb  106  to move air for the purposes previously presented. In addition, the pressure compartments  208 , which are formed with a plurality of compartment walls  209 , allow squeezing or sequenced movement in a cephaladic direction. 
     A pressure source  170  is fluidly coupled separately to each of the pressure compartments  208  by a plurality of pressure conduits  205 . Each pressure compartment  208  has a pressure interface  206  for fluidly coupling the pressure conduit  205  to the pressure compartment  208 . Each pressure conduit  205  is also fluidly coupled to the pressure source  170 . 
     A controller  192  is coupled to the pressure source  170  to control pressure delivery to the plurality of pressure compartments  208 . The controller  192  and pressure source  170  are operable to cause a first pressure compartment  210  of the plurality of pressure compartments  208  to compress around the patient&#39;s limb  106 , then subsequently a second pressure compartment  212  of the plurality of pressure compartments  208  to compress around the patient&#39;s limb  106  in order to encourage fluid movement in the patient&#39;s limb  106  from proximate the first pressure compartment  210  towards the second pressure compartment  212 . The coordinated compression of pressure compartments  208  may continue with the others. 
     The pressure source  170  may have a controller  192  associated with the pressure source  170 . The controller  192  may be configured to control a plurality of pumps within the pressure source  170  or a plurality of valves (not explicitly shown) to allow varying pressure within the pressure compartments  208 . The controller  192  can sequentially supply a pressure gradient to the pressure compartments  208  to cause sequential compression of the compartments on the patient&#39;s limb  106 . The sequential compression of each pressure compartment results in moving fluids in the patient&#39;s limb in a cephaladic direction (in the direction that goes from the feet towards the head). This motion thus creates a massage like motion on the limb  106 . At the same time, as with the previous embodiments, air flow may be introduced into the wound dressing  102  to facilitate evaporation and removal of liquids. 
     The compression of each pressure compartment  208  may be achieved using positive pressure or reduced pressure from the pressure source  170 . If positive pressure is used, the pressure compartments  208  may include bladders that fill to cause compression. If reduced pressure is used, the reduced pressure may cause the fluid-directing member  124  to pull down on the other layers which act as a bolster and thereby generate a compressive force. 
     With reference generally to the figures, in operation according to one illustrative embodiment, a wound dressing  102  is provided. The wound dressing  102  may be any of those presented or suggested herein or combinations thereof. The wound dressing  102  includes a tubular sleeve member  110 . The wound dressing  102  is disposed around the patient&#39;s limb  106  proximate to the wound  104 . This may entail sliding the patient&#39;s limb  106  through the limb openings  112  or using an open and closeable seam (not explicitly shown). 
     Once the wound dressing  102  is in place on the limb  106 , the wound dressing  102  may receive liquid from the wound  104  into the wound dressing  102 . Either all the time, in response to saturation or partial saturation, or based on a timer, the pressure source  170  is activated. The pressure source  170  creates a pressure gradient within the wound dressing  102  that causes air flow in the wound dressing  102  to evaporate liquid from the wound dressing  102 . The air enters the wound dressing  102  at one location (e.g., port  182  or port  140 ) and is exhausted at another location (e.g., port  140  or  182 ). 
     The air typically will travel within the wound dressing  102  at a rate of at least 0.1 m/s and is typically in the range 0.01 (or less) to 0.2 m/s. If a saturation sensor  190  and controller  192  are included, they may detect when the saturation has dropped below a threshold level and then signal the pressure source  170  to cease. With spaced intake and exhaust ports, the air will flow over a large portion of the interior of the wound dressing  102 . For example, the air may flow over 50 percent, 75 percent, 90% percent or more of the surface area of the pathway member  144  (or other layer if coupled to another layer). 
     In operation according to another illustrative embodiment, reduced pressure may also be applied to the wound  104  as an aspect of treatment. For example, with respect to  FIG. 9 , the control valve  196  may remain closed or restricted while reduced pressure is applied to the sealed space  198  to allow the creation of reduced pressure in the sealed space  198 . The pressure may be, for example, without limitation, in the −25 mm Hg to −200 mm Hg range. If saturation is detected, the control valve  196  may be opened to allow for increased air flow. In addition, the output of the pressure source  170  may be increased to allow the reduced pressure level to be maintained in the sealed space  198  notwithstanding the leak or bleeding of air. 
     The air entering or exiting the wound dressing  102  through ports  140  and  182  may first go through a filter  184 ,  186 . The filters  184 ,  186  remove bacteria or odor. The intake filter will keep bacteria from entering the wound dressing  102  and potentially infecting the wound  104 . The exit filter helps remove particulates or remove odors. The configuration of the pressure source  170  determines whether a filter is an intake filter or exit filter. 
     According to another illustrative embodiment, a method of manufacturing a wound dressing  102  for treating a wound  104  on a patient&#39;s limb  106  is contemplated. The method includes forming a tubular sleeve member  110  for receiving the patient&#39;s lower extremity or limb  106 . The step of forming the tubular sleeve member  110  includes forming an elastic compression member  118  as a sleeve having a first side  120  and a second, patient-facing side  122 ; forming a fluid-directing member  124  having a first side  126  and a second, patient-facing side  128 ; and disposing the first side  126  of the fluid-directing member  124  proximate to the second, patient-facing side  122  of the elastic compression member  118 . The fluid-directing member  124  is operable to inhibit fluids from flowing through the fluid-directing member  124 . The step of forming the tubular sleeve member  110  further includes forming a pathway member  144  having a first side  146  and a second, patient-facing side  148  and disposing the first side  146  of the pathway member  144  proximate to the second, patient-facing side  128  of the fluid-directing member  124 . The pathway member  144  is operable to transport a fluid under a pressure gradient. The method further includes fluidly coupling the pressure source  170  to the pathway member  144  for moving fluid therein. 
     With respect to the preceding method, the step of forming a tubular sleeve member  110  may further include disposing an absorbent member  152 , which is for at least temporarily retaining liquids, into the wound dressing  102 . The absorbent member  152  has a first side  154  and a second, patient-facing side  156 . The first side  154  of the absorbent member  152  is disposed proximate to the second, patient-facing side  148  of the pathway member  144 . The step of forming a tubular sleeve member  110  may further include disposing a transition member  158  proximate to the absorbent member  152  or disposing the patient-interface member  164  into the wound dressing  102 . One or more layers may be omitted and the order of the layers may be varied. 
     While air flow through the pathway member  144  is a prominent illustrative embodiment, it should be noted that the wound dressing  102  may be configured to accommodate air flow in others layers except the fluid-directing member  124 . Thus, for example and without limitation, the extension portion  185  ( FIG. 2 ) of the port  182  may extend to the absorbent member  152  or the transition member  158  to cause airflow primarily therein. 
     It should be understood that airflow may be from an inboard location to the transverse edges  142 , from the transverse edges  142  to an inboard location, or from an inboard location to another inboard location. With respect to the lastly mentioned flow pattern and with general reference to  FIGS. 2 and 3 , an embodiment of a wound dressing  102  has the intake port and exhaust port that are both inboard of the transverse edges  142 , but separated by a medial compartment wall (not shown, but analogous to compartment wall  209  in  FIG. 12  and running medially). In this latter embodiment, the transverse edges  142  are sealed, air enters the intake port proximate to the compartment wall, the air transversely flows around the limb  106 , and then the air exits the exhaust port proximate to the compartment wall but on the opposite side from the intake port. 
     The wound dressings  102  herein may require fewer changes than other wound dressings because of the liquid management, i.e., the liquid removed by the airflow. The liquid management may also avoid maceration on the patient. The wound dressings  102  may provide less odor and bulk than other dressings. The wound dressing  102  may process more liquid over time that the dressing is otherwise capable of retaining. 
     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. For example, the control subsystem  202  of  FIG. 11  may be added to any of the other embodiments. As another example, pressure compartments  208  of  FIG. 12  may be added to any of the other wound dressings  102  herein. As another example, the tubular sleeve members  110  shown in  FIGS. 5-8  may be used with any of the wound dressing  102  embodiments herein. 
     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. It should be apparent that the power supply is implicitly present. 
     The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. 
     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. 
     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.