VACUUM DRESSING WITH CONTROL FEEDBACK

Abstract

A wound management system (WMS) is provided that includes dressings, bandages, or implantable medical devices that are equipped with filters, environmental controls, and sensors that promote the formation of a natural biologic seal between the skin and the dressing to form a barrier to microbial invasion into the body that accelerates healing and mitigates wound or exit site infection. Percutaneous access devices (PAD) used with the WMS or other devices including peritoneal dialysis (PD) catheters, Steinman pin, Kirschner wires, and chronic indwelling venous access catheters that require skin penetration. The WMS minimizes risk of exit site infection by reducing the bioburden in the exit tunnel environment in the acute and subacute phases of the PD catheter post-implant. Visualization of the wound without taking off the dressing is provided via a window in the wound area or exit-site to visually monitor for signs of infection and the presence of exudate.

Claims

1. A wound management system for monitoring and controlling environmental conditions of a wound area of a patient comprising: a wound dressing configured to be positioned over the wound area, said wound dressing defining a wound environment; at least one of a humidity sensor, a pressure sensor, a temperature sensor, and a chemical sensor integrated into the wound dressing to provide physiologic parameters that correlate to a degree of wound healing; a pump in fluid communication with said wound environment; and a controller configured to control operation of said pump.

2. The system of claim 1 further comprising a strain relieving fixture.

3. The system of claim 1 further comprising an extrudate reservoir.

4. The system of claim 1 further comprising an air quality sensor integrated into the wound dressing to provide physiologic parameters indicative of infection.

5. The system of claim 1 wherein said wound dressing includes at least one port for introducing moisture or an anti-infection treatment into the wound environment.

6. The system of claim 1 wherein said wound dressing accommodates a variation in catheter diameters.

7. The system of claim 1 wherein said at least one humidity sensor, pressure sensor, or temperature sensor determine a degree of wound hermaticity via measurements of humidity in a vacuum line.

8. The system of claim 1 wherein said at least one humidity sensor, pressure sensor, or temperature sensor determine a degree of wound hermaticity via measurements of local tissue oxygenation in the immediate vicinity of said wound in a patient's skin.

9. The system of claim 1 wherein said environmental conditions are communicated by wired or wireless connection to a computing or a communication device for immediate or remote monitoring.

10. The system of claim 1 wherein said at least one sensors require an external power source and said external power source is a battery used to supply a vacuum source.

11. The system of claim 1 wherein said at least one sensors are passive elements which do not require an external power source.

12. The system of claim 1 wherein said physiologic parameters are employed for local closed-loop control of a vacuum supply to said wound dressing.

13. The system of claim 1 further comprising an observation window in said dressing providing a view of the wound.

14. The system of claim 1 wherein the controller has a microprocessor that receives input from said at least one sensors and compares the signals to a set of controller sensors to adjust the vacuum levels.

15. The system of claim 1 wherein the controller controls a diaphragm pump/motor assembly, a display screen, a pressure sensor, and a slow-leak flow restrictor.

16. A method for measuring and monitoring wound conditions of a patient comprising: placing one or more sensors for measuring parameters that correlate to a degree of wound healing at a wound area of a patient; and wherein said one or more sensors are incorporated into a wound dressing positioned to cover the wound area.

17. The method of claim 16 wherein said one or more sensors determine said degree of wound healing via measurements of humidity, temperature, air quality, and pressure in a vacuum line to said wound dressing.

18. The method of claim 16 wherein said one or more sensors determine a degree of wound hermaticity via measurements of local tissue oxygenation in the immediate vicinity of the wound area on the patient's skin.

19. The method of claim 16 wherein said wound conditions are communicated by wired or wireless connection to a controller, computing, or a communication device for immediate or remote monitoring.

20. The method of claim 16 wherein said sensor parameters are employed for local closed-loop control of a vacuum supply to said wound dressing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like reference numerals refer to like parts throughout the several views, and wherein:

[0048] FIGS. 1A and 1B are photos of driveline infection at a skin exit site in a heart failure patient supported by a prior art left ventricular assist device (LVAD);

[0049] FIG. 2 is a photo of an exit site infection illustrating the catheter, contaminated exit site, and subcutaneous location of subcutaneous cellulitis;

[0050] FIG. 3 illustrates the four phases for marsupialization of walls of a tunnel: Phase (P)1: beginning of downward epidermal migration; P2 along the subcutaneous tissue, P3 down to the cuff, and P4 the deeper portion of the catheter;

[0051] FIG. 4 illustrates prior art wearable and implanted components of a cardiac assist system with a percutaneous access device (PAD) and internal driveline;

[0052] FIG. 5 is a prior art, partial cutaway view of a flanged percutaneous access device (PAD) with relative dimensions of aspect exaggerated for visual clarity;

[0053] FIGS. 6A-6C are perspective views of a prior art modular external interface seal for a PAD appliance secured with adhesive dressings to a subject;

[0054] FIG. 7A illustrates a negative pressure wound dressing in a low vacuum state of approximately 30 mm Hg in accordance with an embodiment of the invention;

[0055] FIG. 7B illustrates a negative pressure wound dressing in a high vacuum state of approximately 125 mm Hg in accordance with an embodiment of the invention;

[0056] FIG. 8 illustrates an embodiment of the inventive wound management system (WMS);

[0057] FIG. 9 is an exploded view of the WMS of FIG. 8;

[0058] FIG. 10 illustrates an alternative dressing for the WMS of FIG. 8;

[0059] FIG. 11 illustrates a dressing humidity and temperature sensor along with a slow leak valve positioned within the mechanical structure of the WMS of FIG. 8; and

[0060] FIG. 12 is a schematic diagram illustrating an overall view of communication devices, computing devices, and mediums for implementing embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0061] Embodiments of the invention provide a wound management system that includes dressings, bandages, or implantable medical devices that are equipped with filters, environmental controls, and sensors that promote the formation of a natural biologic seal between the skin and the dressing to form a barrier to microbial invasion into the body that accelerates healing and mitigates wound or exit site infection. Percutaneous access devices (PAD) may also illustratively be used with the inventive wound management system or other devices including peritoneal dialysis (PD) catheters, Steinman pin, Kirschner wires, and chronic indwelling venous access catheters that require skin penetration.

[0062] It is noted that previous efforts have concentrated on removing moisture or humidity from wound areas, however a level of moisture is required to allow fibroblasts to actively attach to an implanted PAD and to promote the establishment of intact biological barrier function of the stratum corneum layer of skin and for wound healing in general. It is also noted that moisture and pressure levels may be needed to change as the wound healing process progresses through different stages. It is further noted that pressure levels may require adjustment to preclude skin prolapse around an implanted device or improper wound healing.

[0063] Embodiments of the inventive wound management system (WMS) are designed to improve wound healing while minimizing the risk of wound area infection by enhanced wound monitoring using sensors, providing for visual inspection without a need to remove the dressing, and providing moisture and temperature controls. According to embodiments, the WMS minimizes risk of exit site infection by reducing the bioburden in the exit tunnel environment in the acute and subacute phases of the PD catheter post-implant. Currently available wound dressings do not permit visualization of the exit site, which risks delayed detection of infection until the dressing is removed, and such removal of existing wound dressings can be counterproductive to the proper and speedy healing of the wound in that removal of dressings applies undue forces to the wound and exposes the wound to potential infection from the environment. To address this clinical need, the inventive WMS enables visualization of the wound without taking off the dressing by providing the following features. A window to visualize the wound area or exit-site for signs of infection and the presence of exudate. These observations assist the caretakers in determining whether to change the dressing. According to embodiments, strain relief for a catheter is present to limit repetitive trauma due to movement, tension, and twisting of the catheter during the healing process. The ability to measure and monitor pressure, humidity, and temperature at the wound area or exit site, and closed-loop vacuum control feedback to maintain a constant humidity level (92% relative humidity). A controlled localized vacuum (−125 mm Hg) at the wound area or exit-site while avoiding exposing the neighboring normal epidermis to vacuum and the risk of maceration. Intermittent cycling of the vacuum to evacuate bioburden from the wound area or exit tunnel. An intentional controlled slow leak within the dressing to allow air exchange within embodiments of the inventive WMS. The ability to maintain a vacuum level set-point to keep the tissue surrounding the wound area or exit site in close approximation to the tissue/biomaterial interface to promote healing. A collection container (35 ml) to hold biohazard fluid to be discarded after use.

[0064] Embodiments of the inventive wound management system combine the use of vacuum assist technology with a novel wound dressing to control the environment within and around the wound area or medical device penetration/exit site. Embodiments of the inventive WMS employ algorithms to control humidity and temperature to apply appropriate vacuum levels. The humidity and temperature control algorithms, combined with a slow leak approach allow air exchange in the dressing, and represent a new innovative approach to wound care. Unlike other negative pressure wound dressings, embodiments of the inventive wound management system (WMS) are specifically designed to treat the local wound conditions unique to the skin exit site of a catheter crossing the skin. Such embodiments of the inventive device are designed to stabilize passage of a catheter through a dressing with a strain relieving component to protect the exit site from trauma while applying negative pressure to treat the wound in a highly controlled manner. Embodiments of the inventive WMS provide a fully vacuum sealed system via injection molded and/or insert molded components to create the desired hermetic seal.

[0065] Embodiments of the inventive WMS include five core components: (1) a vacuum assist technology (VAT) wound dressing; (2) humidity, pressure, temperature sensors, and/or chemosensors identifying volatile compounds (such as sulfur-containing compounds and/or other chemotransducer-detectable compounds emitted from the wound into the gaseous environment of the NPWT dressing, integrated into the wound dressing system to provide physiologic parameters for time-varying control of the milieu surrounding the catheter exit site; (3) an exudate reservoir; (4) a pump; and (5) a controller. Embodiments of the inventive WMS also include a strain relieving fixture.

[0066] Embodiments of the inventive WMS employ a more compliant dressing with a unique design to accommodate the variation in catheter diameters produced by multiple manufacturers.

[0067] In specific inventive embodiments, a single-use controller has a microprocessor that receives input from the wound dressing sensors and compares the signals to the controller sensors to adjust the vacuum levels and/or to turn the vacuum on and off. The system controls a diaphragm pump/motor assembly powered by four (4) AA batteries, a display screen, an interlock for canister engagement, battery pack, pressure sensor, and a slow-leak flow restrictor. Alarms/Alerts provide visual and audible alerts to the user. The foam within the wound dressing provides a tactile/visual indication of vacuum ON/OFF and cycling conditions. The controller may be a direct current (DC) powered pressure regulator that delivers negative pressure to the wound dressing ranging from −30 mmHg to −125 mmHg. The set point (threshold) for the optimal percent humidity is a critical consideration when developing the humidity/temperature algorithm for automated control of the inventive WMS. In a specific inventive embodiment, the rationale for selecting 92% humidity is based on the need to maintain a moist environment surrounding the wound area or exit site wound while keeping the environment less than 100% humid. The percent humidity detected by the humidity sensor can be adjusted to any threshold over the entire range from 0% to 100%. According to embodiments, the WMS includes a tube configured to introduce moisture into the dressing in the event, for example the humidity sensors indicate that the humidity within the dressing, i.e. the environment surrounding the wound area or exit site wound, falls below the set point (threshold) for the optimal percent humidity. Other triggers could include information from the chemosensors indicating that infection may be of increasing importance in the wound melieu. Such information could be used to signal medical care personnel or trigger the release of cleansing agents, antiseptic agents, or antibiotic agents. The present invention thereby functions to monitor a wound healing environment and adjust that environment in response to a condition that is outside of a preselected threshold or detection of a pathogen or metabolite thereof. By way of example, a chemical sensor detecting specific compounds, such as amines or thiols, concentrations, or certain ratios thereof are indicative of the growth an anaerobic pathogens. In still other embodiments, an alarm is triggered in such a condition, a therapeutic administered, or a combination thereof in response to a potentially dangerous condition, as detailed below.

[0068] In embodiments of the inventive WMS, controlled negative pressure wound therapy (NPWT) is applied to aspirate wound exudate and bioburden carrying microorganisms out of the wound area or peri-catheter region while protecting the surrounding skin from harsh vacuum exposure. During a NPWT low vacuum state as shown in FIG. 7A, wound exudate accumulates within tunnel gap (TG). During a NPWT high vacuum state as shown in FIG. 7B, bioburden/exudate is expressed (as shown by multiple arrows) from within the diminished tunnel gap TG and the adjacent subcutaneous tissue is approximated to the contour of the DACRON® cuff and outer wall of PD catheter. In specific inventive embodiments the duration of use for each dressing will be up to seven days. Embodiments of the WMS are designed to promote rapid approximation of the tissue to the catheter by providing controlled vacuum up to approximately 125 mm Hg and both mechanical and vacuum-based stabilization of the composite construct of the PD catheter/adjacent tissues/WMS dressing during the healing process. The availability of an electronically modulable vent valve can allow both low frequency and high frequency modulation of the strength of the vacuum.

[0069] A central element of the inventive WMS is the vacuum assist technology (VAT) wound dressing that provides the benefits of NPWT to bear on wound management of the wound and in the vicinity of skin exit site of a PD catheter. The extensive investigations of the mechanism of action of NPWT by Orgill has led to the proposed four basic mechanisms of action: 1) macro-deformation or wound shrinkage; 2) microdeformation or micromechanical cellular changes at the wound-interface surface; 3) removal of fluids; and 4) maintenance of a moist wound environment. Orgill found that granulation tissue formation is affected by the time and frequency of application of vacuum to the wound environment.

[0070] Embodiments of the inventive WMS are designed to: (1) refresh the environment adjacent to the wound with air; (2) permit direct visualization of the wound to monitor healing and early signs of infection; (3) monitor relative humidity, pressure, temperature and/or the presence of chemotransducer-detectable biologically produced compounds emanating from within the external environment adjacent to the wound, (4) remove wound exudate/bioburden; (5) control and modulate vacuum relative to the pressure, humidity, and temperature with feedback control at the wound site; and (6) treat the wound area with anti-infection treatments when signs of infection have been detected.

[0071] Embodiments of the inventive WMS have integrated pressure, relative humidity, and temperature sensors to measure water vapor production adjacent to the wound area or skin entry site. Specific embodiments of the inventive WMS include integrated air sensors that monitor the gases within the wound environment for chemicals associated with infections. In such embodiments, the inventive WMS may additionally include an introducer configured to introduce anti-infection treatments, such as antibiotics, into the wound environment when the integrated air sensors detect chemicals associated with an infection in the air sampled from the wound environment. This allows the detected infection to be treated without removing the wound dressing. According to embodiments, a slow leak valve as shown in FIG. 11 enables air exchange within the dressing. A series of algorithms enable vacuum control of the wound environment based upon water vapor production metrics, as well as avoidance of unintended vacuum leaks throughout the dressing. Controllable flow restrictors are optimized for air exchange rates, and the algorithms compare humidity and temperature surrounding the wound to the conditions outside the wound to control the ON/OFF vacuum cycle to remove moisture and draw trapped fluid from around the wound site or any catheter that is present and the exit site and provide a fully vacuum sealed system. Visualization of the wound site is provided to a user through a window positioned above the wound area or access site.

[0072] Embodiments of the invention monitor and dynamically control levels of humidity and pressure to optimize wound closure about an implanted device or when a PAD is not present a wound itself at a wound dressing. Embodiments of the method and system for actively assessing wound closure are incorporated into the design of percutaneous skin access devices (PAD), bone anchors, or a wound dressing or bandage alone without at PAD. The pressure and humidity sensor provide active feedback for making changes to the ecology of the wound site or PAD insertion site. In specific inventive embodiments a filter, which illustratively includes a submicron filter, is used to aerate the wound while also preventing pathogens in the ambient air from reaching the wound.

[0073] In certain embodiments of the present invention, an assessment of hermaticity may be determined with measurements of humidity in the vacuum line to a wound dressing or PAD. The humidity readings may be taken with impedance humidity sensors. In still other embodiments, local tissue oxygenation in the immediate vicinity of the dressing or PAD or other measurements may be used to determine wound healing.

[0074] In certain embodiments of the present invention, an assessment of air quality may be determined with measurements of chemical sniffing sensors in the vacuum line to a wound dressing or PAD. These sensors are capable to sniffing the air in the vacuum line for chemicals associated with infection. The air quality readings may be taken with air sniffing sensors. Such an air sniffing/air quality sensor illustratively tests for oxygen, or sulfur; exudate biochemical such as electrolytes such as sodium, potassium, or chloride; small molecules such as urea, creatinine, fibrinogen, matrix metalloproteinases (MMPs); proteins such as tumor necrosis factor (TNFα) and C-reactive protein (CRP); and combinations thereof.

[0075] The hermaticity, temperature, and/or air quality measurement parameters are readily communicated by wired or wireless connection to a computing or communication device for immediate or remote monitoring. Known and future wireless standards and protocols such as, but not limited to, Bluetooth, Zigbee, WiFi, and others may be used to transmit hermaticity, temperature, and/or air quality measurements. Remote monitoring may be facilitated via an Internet or cellular network enabled device in communication with the output of a hermaticity measurement device or sensor. The hermaticity, temperature, and/or air quality measurement devices or sensors may require an external power source such as a battery, or may be passive elements such as radio frequency identification elements (RFID), which obviate the need for an electrical power source to be directly incorporated into the PAD or wound dressing. A passive RFID element retransmits a signal using the energy of an incoming interrogation signal, where in embodiments of the inventive hermaticity sensor, temperature sensor, and/or air quality sensor the transmitted signal will vary in frequency or phase with the respective measurement. In certain embodiments, battery power used to supply the vacuum source of the wound dressing or PAD may also be utilized to supply power to the one or more hermaticity, temperature, and/or air quality sensors.

[0076] The hermaticity, temperature, and/or air quality sensors measurement information is readily employed for local closed-loop control of the vacuum supply to the wound dressing or PAD, and to alert the patient with regards to progress or problems with the wound dressing or PAD-skin interface. Additionally, the hermaticity, temperature, and/or air quality information may be transmitted wirelessly to medical personnel to allow for remote monitoring of the healing wound. For example, as impedance or humidity in a vacuum line stabilizes, medical personnel may be notified that the wound has healed. Alternatively, if the impedance or humidity deviated from expected values or if an air quality sensors detects a chemical commonly associated with an infection, medical personnel could be notified that there may be an infection or a mechanical disruption to the wound; alarms could also be set to notify the patient. In an embodiment, the vacuum supplied to the wound dressing or PAD could automatically be increased or decreased based on the wound healing, moisture could automatically be introduced to the wound environment, and/or an anti-infection treatment could automatically be supplied to the wound environment.

[0077] According to embodiments, the dressing includes a fiber provided within the wound environment or interwoven with the dressing. The fiber illustratively includes monofilament, polyfilament, hollow fibers, or combinations thereof. A fiber modifies properties by affording capillary draw to promote drying, fibroblast infiltration, and in some circumstances monitoring of serous fluid for early indications of infection. Hollow fibers are particularly well suited for such sampling. It is appreciated that fibers, such as quartz fibers can be used to transmit biocidal ultraviolet light emissions, while hollow fibers can convey therapeutic fluids, or biocidal gases such as oxygen alone, or in combination with ozone.

[0078] In specific inventive embodiments, integrated multi-lumen tubing as disclosed in US Patent Publication US20200289810A1 to Kantrowitz is used for delivering a vacuum. Integrated multi-lumen tubing provides a combination of intravenous (IV) infusion lines, vacuum lines, and in some instances monitoring lines for attachment to a percutaneous access device or long term implant. The integration of the intravenous infusion lines, vacuum lines, and monitoring lines that connect to the wound dressing or PAD and other inserted instruments organizes the myriad of intravenous infusion lines, vacuum lines, and monitoring lines that connect to the wound dressing or PAD and other inserted instruments that tend to get tangled, interfere with patient comfort and movement, and are potentially difficult for health care workers to change and maintain. Furthermore, by using the lines associated with the IV already present in a hospital or medical facility allows for use of the existing vacuum source used in the facility.

[0079] FIGS. 8 and 9 illustrate an embodiment of the inventive WMS. FIG. 10 illustrates an alternative dressing for the WMS of FIG. 8. The WMS has two primary modules. Module 1 (M1) is made up of the wound dressing that includes: (a) dressing that permits visualization of the wound and/areor exit-site through a window (G); (b) skin protection layers (H & O) that prevent necrosis of the surrounding skin; (c) restricting the application of vacuum only to the wound area or exit-site (O & P); (d) slow-leak port (D) that permits filtered air to be exchanged in the wound dressing to reduce bioburden; (e) humidity, air quality, and/or temperature sensors (J) to monitor relative humidity, air quality, and temperature and permit algorithm control of the wound environment via control of the temperature, introduction of moisture or anti-infection treatment via introduction port (I); (f) according to embodiments, integrated strain relief to secure a catheter, if used, during healing (K & L); and (g) dual supply line with a single connector to draw vacuum from the site and deliver replacement air (M & N). The inventive WMS skin dressing provides a means to enhance wound healing for patients with a chronic or non-healing wound or peritoneal dialysis catheter (Q).

[0080] Module 2 (M2) includes a battery powered controller with innovations that include: (a) reusable, quiet controller for 7-days of continuous use (A) that delivers controlled vacuum to the wound dressing; (b) integrated orifice flow restrictor and filter for wound air exchange (D & inside controller housing); (c) disposable exudate collection canister with filters to protect the controller from contamination (B); (d) optional system controls with a display to permit multiple modes of operation including intermittent, continuous and smart. The smart mode maintains optimum vacuum level based upon relative humidity and temperature sensors that permit cycling the vacuum and introduces moisture and/or anti-infection treatments to the wound environment.

[0081] FIG. 12 is a schematic diagram illustrating an overall view of communication devices, computing devices, and mediums for implementing the wound monitoring system platform according to embodiments of the invention. The elements of the embodiments of FIGS. 7-11 are included in the networks and devices of FIG. 12.

[0082] The system 1100 includes multimedia devices 1102 and desktop computer devices 1104 configured with display capabilities 1114 and processors for executing instructions and commands. The multimedia devices 1102 are optionally mobile communication and entertainment devices, such as cellular phones and mobile computing devices that in certain embodiments are wirelessly connected to a network 1108. The multimedia devices 1102 typically have video displays 1118 and audio outputs 1116. The multimedia devices 1102 and desktop computer devices 1104 are optionally configured with internal storage, software, and a graphical user interface (GUI) for carrying out elements of the wound monitoring system platform according to embodiments of the invention. The network 1108 is optionally any type of known network including a fixed wire line network, cable and fiber optics, over the air broadcasts, satellite 1120, local area network (LAN), wide area network (WAN), global network (e.g., Internet), intranet, etc. with data/Internet and remote storage capabilities as represented by server 1106. Communication aspects of the network are represented by cellular base station 1110 and antenna 1112. In a preferred embodiment, the network 1108 is a LAN and each remote device 1102 and desktop device 1104 executes a user interface application (e.g., Web browser) to contact the server system 1106 through the network 1108. Alternatively, the remote devices 1102 and 1104 may be implemented using a device programmed primarily for accessing network 108 such as a remote client. Hermaticity/temperature/pressure/air quality sensors in the wound monitoring system may communicate directly or via the controller module M2 with remote devices 1102 and 1104 via near field communication standards such as Bluetooth or Zigbee, or alternatively via network 1108.

[0083] The software for the wound monitoring system platform, of certain inventive embodiments, is resident in the controller module M2, on multimedia devices 1102, desktop or laptop computers 1104, or stored within the server 1106 or cellular base station 1110 for download to an end user. Server 1106 may implement a cloud-based service for implementing embodiments of the platform with a multi-tenant database for storage of separate client data.

[0084] The present invention is further detailed with respect to the following non limiting examples. These examples are not intended to limit the scope of the invention but rather highlight properties of specific inventive embodiments and the superior performance thereof relative to comparative examples.

EXAMPLES

Example 1

[0085] Ten WMS systems were fabricated and tested for the ability to aspirate at three simulated exudate viscosities (100 cSt, 500 cSt, 1000 cSt). Algorithms based on relative humidity and temperature were tested to verify the ability to automatically control vacuum level. Algorithms based on air quality of the wound environment were tested to verify the ability to sniff the sampled air for chemicals associated with infection and then automatically introduce anti-infection treatments to the wound environment in response to detected infection indicating chemicals. The following dressing modules were tested: (1) controller simulator—electronics; (2) simulator—fluid reservoir to contain drainage solutions, vacuum port, humidity and temperature sensors, air quality sensor, pressure sensor port (for determining vacuum level), and flow restrictor port; (3) collection canister—hydrophobic filters for contamination control; and (4) heater module—to raise the exudate temperature to provide exudate evaporation and collection.

[0086] The ten systems were demonstrated to be capable of removing viscosities ranging from 100 cSt to 1000 cSt.

Example 2

[0087] The ten WMS systems of example 1 demonstrated the ability to control humidity to 92%±2%, vacuum level to −125 mmHg±10 mmHg, temperatures of 99° F.±2° F., and air quality.

Example 3

[0088] The ten WMS were evaluated to be capable of conforming to multiple anatomic locations and body types.

[0089] The dressing was shown to be fully compliant to conform to the contour of the PD catheter placement sites.

Example 4

[0090] Stress tests were performed on the ten WMS and were run for 14-days (2-times the intended duration) to assure performance/reliability. Battery life was challenged under worst-case conditions of viscosity and vacuum leak. Software algorithms were developed for adaptive control and response to the delta pressure (P) and range over time relative to wound temperature and humidity.

Example 5

[0091] A Design of Experiments (DOE) study was conducted to evaluate the ability to control pressure and the optimal conditions to remove the wound exudate, as well as, evaluate humidity sensor accuracy, evaluate wound temperature accuracy, evaluate air quality sensor accuracy, refine algorithms for balancing humidity, temperature, air quality, and vacuum level, evaluate fluid removal rate consistent with the wound types, and evaluate moisture levels and ability to dry with slow leak.

[0092] Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.

[0093] The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention.