WO2020014061A1

WO2020014061A1 - Regulated mechanical wall-suction regulator with remote telemetry monitoring

Info

Publication number: WO2020014061A1
Application number: PCT/US2019/040463
Authority: WO
Inventors: Christopher Brian Locke; Justin Alexander Long
Original assignee: Kci Licensing, Inc.
Priority date: 2018-07-13
Filing date: 2019-07-03
Publication date: 2020-01-16

Abstract

Systems, methods, and apparatuses for providing feedback for reduced-pressure therapy are described. A regulator may include a supply chamber fluidly coupled to a dressing, a control chamber fluidly coupled to the dressing, a charging chamber fluidly coupled to the supply chamber through a port, and a valve operable to control fluid communication through the port based on a pressure differential between the control chamber and a target pressure. A feedback system may include a control sensor and a processor communicatively coupled to the control processor. The control sensor may be fluidly coupled to the control chamber to determine the pressure in the control chamber. The feedback system may further comprise a supply sensor communicatively coupled to the processor and fluidly coupled to the supply chamber to determine the pressure therein. The processor may be coupled to output devices including remote wireless devices that can indicate a state of the reduced-pressure therapy.

Description

REGULATED MECHANICAL WALL-SUCTION REGULATOR WITH REMOTE

TELEMETRY MONITORING

RELATED APPLICATION

[0001] This application claims the benefit, under 35 U.S.C. § 119(e), of the filing of U.S. Provisional Patent Application Serial No. 62/697,781, entitled “REGULATED MECHANICAL WALL-SUCTION REGULATOR WITH REMOTE TELEMETRY MONITORING” filed July 13, 2018, which is incorporated herein by reference for all purposes.

TECHNICAL FIELD

[0002] The subject matter described herein relates generally to monitoring reduced- pressure therapy and, more particularly, but not by way of limitation, to electronic feedback of reduced-pressure therapy supplied by a wall-suction source.

BACKGROUND

[0003] Clinical studies and practice have shown that reducing pressure in proximity to a tissue site can augment and accelerate growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but it has proven particularly advantageous for treating wounds. Regardless of the etiology of a wound, whether trauma, surgery, or another cause, proper care of the wound is important to the outcome. Treatment of wounds with reduced pressure is commonly referred to as“reduced-pressure therapy,” but may also be known by other names, including“negative pressure wound therapy” and“vacuum therapy,” for example. Reduced-pressure therapy may provide a number of benefits, including migration of epithelial and subcutaneous tissues, improved blood flow, and micro deformation of tissue at a wound site. Together, these benefits can increase development of granulation tissue and reduce healing times.

[0004] While the clinical benefits of reduced-pressure therapy are widely known, the cost and complexity of reduced-pressure therapy can be a limiting factor in its application, and the development and operation of reduced-pressure systems, components, and processes continues to present significant challenges to manufacturers, healthcare providers, and patients.

SUMMARY

[0005] New and useful systems, apparatuses, and methods for monitoring reduced- pressure therapy and, more particularly, but not by way of limitation, to electronic feedback of reduced-pressure therapy supplied by a wall- suction source to a dressing in a negative- pressure therapy environment are set forth in the appended claims. Illustrative embodiments are also provided to enable a person skilled in the art to make and use the claimed subject matter.

[0006] For example, in some embodiments, a mechanical regulation system may be utilized with a wall-suction source of negative pressure in lieu of a separate negative pressure pump to provide negative pressure therapy. However, some embodiments of such mechanical regulation systems may be difficult to control and monitor the application of therapy or various operating states of the mechanical regulation system associated with the therapy such as, for example, whether a fluid blockage condition or and over-pressure condition has developed during therapy. Additionally, the mechanical regulation system may be oversimplified and make it more do for a clinician to apply the desired therapy in an acute care environment. In some embodiments, for example, a mechanical regulation system may be modified or configured to comprise sensors and actuators that provide closed-loop feedback to facilitate the control and monitoring of therapy treatments in a more timely and accurate manner. Some embodiments of such mechanical regulation systems may further comprise wireless technology for providing therapy data to a clinician and allow the clinician to set therapy inputs and respond to alarms associated with the application of the therapy. Such feedback and wireless improvements can be structured as a separate module that can be a low-cost upgrade to a mechanical regulation system depending on the need in an acute care setting and/or in different regions or facilities.

[0007] More generally, one such illustrative embodiment may be described as a reduced-pressure system comprising a dressing, a regulator, and a feedback system. The regulator generally includes a supply chamber that can be fluidly coupled to the dressing through a supply lumen, a control chamber adapted to be fluidly coupled to the dressing through a feedback lumen, and a charging chamber fluidly coupled to the supply chamber through a port. A regulator valve can be coupled to the control chamber and operable to reciprocate at least partially within the control chamber to control fluid communication through the port based, at least in part, on a differential between a control pressure in the control chamber and a therapy pressure in the supply chamber. The feedback system may include a control sensor adapted to be fluidly coupled to the control chamber and having an output for providing a control signal indicative of a control pressure. The feedback system may further comprise a processor having an input electrically coupled to the output of the control sensor for receiving the control signal and an output. The processor may be adapted to indicate an operating state of the reduced-pressure system based on the control signal, wherein the output of the processor is adapted to provide an operational signal for providing an indication of the operating state. In some embodiments of the reduced-pressure system, the feedback system may further comprise a supply sensor adapted to be fluidly coupled to the supply chamber and having an output for providing a supply signal indicative of a supply pressure. Additionally, the processor may further comprise an input electrically coupled to the output of the supply sensor for receiving the supply signal and be adapted to indicate an operating state of the reduced-pressure system based on the supply signal.

[0008] In some embodiments, the reduced pressure system as described above may provide operational signals identifying various operational states such as, for example, the therapy pressure, the therapy range, the control pressure during a draw-down process, leak conditions, blockage conditions, canister full conditions, and overpressure conditions. Such reduced pressure systems may also provide outputs indicating these operating states such as, for example, LED outputs, liquid crystal displays, and wireless communication devices, or facilitating the application and control of negative pressure therapy.

[0009] Another illustrative embodiment may be described as an apparatus for providing negative pressure to a dressing comprising a regulator and a feedback system. The regulator generally includes a first chamber having a supply port for receiving negative pressure, and a second chamber adapted to sense a control pressure at the dressing. The regulator further comprises a valve operably coupled to the second chamber to control fluid flow through the supply port based on a differential pressure between the control pressure in the second chamber and a therapy pressure. The feedback system may include a control sensor having an input coupled to the second chamber and an output for providing a control signal indicative of the control pressure. The feedback system may further comprise a processor having an input coupled to the output of the control sensor and adapted to indicate an operating state based on the control signal. The processor also may have an output adapted to provide an operational signal to provide an indication of the operating state. In some embodiments of the apparatus, the feedback system may further comprise a supply sensor having an input coupled to the first chamber and an output for providing a supply signal indicative of a supply pressure within the first chamber. Additionally, the processor may further comprise an input coupled to the output of the supply sensor and adapted to indicate an operating state of the apparatus based on the supply signal. In some embodiments, the apparatus may further comprise a diaphragm disposed between the first chamber and the input of the supply sensor that is adapted to prevent fluid from flowing out of the first chamber. In some embodiments, the apparatus may also comprise another diaphragm disposed between the second chamber and the input of the control sensor that is adapted to prevent fluid from flowing out of the second chamber. In some embodiments, the apparatus may further comprise a wireless communication device communicatively coupled to the processor for providing an indication of the operating state to a remote wireless device and for setting a therapy inputs such as, for example, target therapy pressure and therapy pressure range.

[0010] Another illustrative embodiment may be described as an apparatus for providing negative pressure to a dressing comprising a regulator and a feedback system. The regulator generally includes a supply port adapted to be coupled to a source of negative pressure and sense a supply pressure, and a control port adapted to be coupled to the dressing to sense a control pressure. The regulator may further comprise a valve configured to control fluid flow through the supply port based on a differential pressure between the control pressure and a therapy pressure. The feedback system generally includes a control sensor having an input adapted to sense the control pressure and an output for providing a control signal indicative of the control pressure. The feedback system may further comprise a processor having an input coupled to the output of the control sensor and adapted to indicate an operating state based on the control signal. The processor may further comprise an output adapted to provide an operational signal to provide an indication of the operating state. In some embodiments, the feedback system may further comprise a supply sensor having an input adapted to sense the supply pressure and an output for providing a supply signal indicative of the supply pressure. Additionally, the processor may further comprise an output adapted to provide an operational signal to provide an indication of the operating state.

[0011] Another illustrative embodiment relates to a method for regulating therapeutic pressure in a reduced-pressure therapy system. The method generally includes fluidly coupling a manifold to a supply chamber through a supply lumen and fluidly coupling the manifold to a control chamber through a feedback lumen. The supply chamber can be fluidly coupled to a charging chamber, and the control chamber can be fluidly coupled to a pressure sensor. A charging pressure in the charging chamber can be reduced below a predetermined target pressure, and fluid communication can be regulated between the supply chamber and the charging chamber based, at least in part, on a differential between a control pressure in the control chamber and a therapy pressure. The therapy pressure can be delivered from the supply chamber to the manifold, and a manifold pressure in the manifold can be fluidly communicated to the control chamber. The control pressure in the control chamber can be measured and a control signal may be generated that corresponds to the control pressure as measured by the pressure sensor. An operational state of the reduced -pres sure therapy system may be determined in response to receiving the control signal.

[0012] Objectives, advantages, and a preferred mode of making and using the claimed subject matter may be understood best by reference to the accompanying drawings in conjunction with the following detailed description of illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a functional block diagram of an example embodiment of a reduced-pressure therapy system that can regulate therapeutic pressure in accordance with this specification;

[0014] Figure 2A is a graph illustrating an example embodiment of pressure control modes for the reduced-pressure therapy system of Figure 1 wherein the x-axis represents time in minutes (min) and/or seconds(sec) and the y-axis represents pressure generated by a pump in Torr (mmHg) that varies with time in a continuous pressure mode and an intermittent pressure mode that may be used for applying reduced pressure in the therapy system;

[0015] Figure 2B is a graph illustrating an example embodiment of another pressure control mode for the reduced-pressure therapy system of Figure 1 wherein the x-axis represents time in minutes (min) and/or seconds(sec) and the y-axis represents pressure generated by a pump in Torr (mmHg) that varies with time in a dynamic pressure mode that may be used for applying reduced pressure in the therapy system;

[0016] Figure 3A is a schematic cross-section of an embodiment of a regulator for use with a reduced-pressure therapy system;

[0017] Figure 3B is a schematic exploded view of the regulator of Figure 3A;

[0018] Figure 3C is a schematic cross-section of the regulator of Figure 3A having a regulator valve in an open position;

[0019] Figure 4 is a schematic cross-section of an example embodiment of a reduced- pressure therapy system using the regulator of Figure 3A;

[0020] Figure 5 is a schematic cross-section of an example embodiment of a feedback system using the regulator of Figure 3A;

[0021] Figure 6A is a schematic cross-section of the regulator of Figure 3A modified for use with the feedback system of Figure 5;

[0022] Figure 6B is a schematic side view of a first flexible diaphragm for use with the regulator of Figure 6A;

[0023] Figure 6C is a schematic side view of a second flexible diaphragm for use with the regulator of Figure 6A; and [0024] Figure 7 is a schematic cross-section of the regulator of Figure 3A modified for use with the feedback system of Figure 5.

DETAILED DESCRIPTION

[0025] New and useful systems, methods, and apparatuses associated with monitoring pressure are set forth in the appended claims. Objectives, advantages, and a preferred mode of making and using the systems, methods, and apparatuses may be understood best by reference to the following detailed description in conjunction with the accompanying drawings. The description provides information that enables a person skilled in the art to make and use the claimed subject matter, but may omit certain details already well-known in the art. Moreover, descriptions of various alternatives using terms such as“or” do not necessarily require mutual exclusivity unless clearly required by the context. The claimed subject matter may also encompass alternative embodiments, variations, and equivalents not specifically described in detail. The following detailed description should therefore be taken as illustrative and not limiting.

[0026] The example embodiments may also be described herein in the context of reduced-pressure therapy applications, but many of the features and advantages are readily applicable to other environments and industries. Spatial relationships between various elements or to the spatial orientation of various elements may be described as depicted in the attached drawings. In general, such relationships or orientations assume a frame of reference consistent with or relative to a patient in a position to receive reduced-pressure therapy. However, as should be recognized by those skilled in the art, this frame of reference is merely a descriptive expedient rather than a strict prescription.

[0027] Figure 1 is a simplified functional block diagram of an example embodiment of a reduced-pressure therapy system 100 that can regulate therapeutic pressure in accordance with this specification. As shown in the illustrative embodiment of Figure 1, the reduced- pressure therapy system 100 may include a dressing 102 fluidly coupled to a reduced- pressure source 104. A regulator or controller, such as a regulator 106, may also be fluidly coupled to the dressing 102 and the reduced-pressure source 104. The dressing 102 generally includes a drape, such as a drape 108, and a tissue interface, such as a manifold 110. The reduced-pressure therapy system 100 may also include a fluid container, such as a container 112, coupled to the dressing 102 and the reduced-pressure source 104.

[0028] In general, components of the reduced-pressure therapy system 100 may be coupled directly or indirectly. For example, the reduced-pressure source 104 may be directly coupled to the regulator 106 and indirectly coupled to the dressing 102 through the regulator 106. Components may be fluidly coupled to each other to provide a path for transferring fluids (i.e., liquid and/or gas) between the components. In some embodiments, components may be fluidly coupled with a tube, for example. A“tube,” as used herein, broadly refers to a tube, pipe, hose, conduit, or other structure with one or more lumina adapted to convey fluids between two ends. Typically, a tube is an elongated, cylindrical structure with some flexibility, but the geometry and rigidity may vary. In some embodiments, components may additionally or alternatively be coupled by virtue of physical proximity, being integral to a single structure, or being formed from the same piece of material. Coupling may also include mechanical, thermal, electrical, or chemical coupling (such as a chemical bond) in some contexts.

[0029] In operation, a tissue interface, such as the manifold 110, may be placed within, over, on, against, or otherwise adjacent to a tissue site. For example, the manifold 110 may be placed against a tissue site, and the drape 108 may be placed over the manifold 110 and sealed to tissue proximate to the tissue site. Tissue proximate to a tissue site is often undamaged epidermis peripheral to the tissue site. Thus, the dressing 102 can provide a sealed therapeutic environment proximate to the tissue site. The sealed therapeutic environment may be substantially isolated from the external environment, and the reduced- pressure source 104 can reduce the pressure in the sealed therapeutic environment. Reduced pressure applied uniformly through the tissue interface in the sealed therapeutic environment can induce macrostrain and microstrain in the tissue site, as well as remove exudates and other fluids from the tissue site. The removed exudates and other fluids can be collected in the container 112 and disposed of properly.

[0030] The fluid mechanics of using a reduced-pressure source to reduce pressure in another component or location, such as within a sealed therapeutic environment, can be mathematically complex. However, the basic principles of fluid mechanics applicable to reduced-pressure therapy are generally well-known to those skilled in the art, and the process of reducing pressure may be described illustratively herein as“delivering,”“distributing,” or “generating” reduced pressure, for example.

[0031] In general, exudates and other fluids flow toward lower pressure along a fluid path. This orientation is generally presumed for purposes of describing various features and components of reduced-pressure therapy systems herein. Thus, in the context of reduced- pressure therapy, the term “downstream” typically implies something in a fluid path relatively closer to a reduced-pressure source, and conversely, the term“upstream” implies something relatively further away from a reduced-pressure source. Similarly, it may be convenient to describe certain features in terms of fluid“inlet” or“outlet” in such a frame of reference. However, a fluid path may also be reversed in some applications, such as by substituting a positive-pressure source, and this descriptive convention should not be construed as a limiting convention.

[0032] The term“tissue site” in this context broadly refers to a wound or defect located on or within tissue, including but not limited to, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. A wound may include chronic, acute, traumatic, subacute, and dehisced wounds, partial-thickness burns, ulcers (such as diabetic, pressure, or venous insufficiency ulcers), flaps, and grafts, for example. The term“tissue site” may also refer to areas of tissue that are not necessarily wounded or defective, but are instead areas in which it may be desired to add or promote the growth of additional tissue. For example, reduced pressure may be used in certain tissue areas to grow additional tissue that may be harvested and transplanted to another tissue location.

[0033]“Reduced pressure” generally refers to a pressure less than a local ambient pressure, such as the ambient pressure in a local environment external to a sealed therapeutic environment provided by the dressing 102. In many cases, the local ambient pressure may also be the atmospheric pressure in a patient’s vicinity. Alternatively, the pressure may be less than a hydrostatic pressure associated with tissue at the tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. Similarly, references to increases in reduced pressure typically refer to a decrease in absolute pressure, while decreases in reduced pressure typically refer to an increase in absolute pressure.

[0034] A reduced-pressure source, such as the reduced-pressure source 104, may be a reservoir of air at a reduced pressure, or may be a manual or electrically-powered device that can reduce the pressure in a sealed volume, such as a vacuum pump, a suction pump, a wall- suction port available at many healthcare facilities, or a micro-pump, for example. A reduced-pressure source may be housed within or used in conjunction with other components, such as sensors, processing units, alarm indicators, memory, databases, software, display devices, or operator interfaces that further facilitate reduced-pressure therapy. While the amount and nature of reduced pressure applied to a tissue site may vary according to therapeutic requirements, the pressure typically ranges between -5 mm Hg (-667 Pa) and -500 mm Hg (-66.7 kPa). Common therapeutic ranges are between -75 mm Hg (-9.9 kPa) and - 300 mm Hg (-39.9 kPa).

[0035] A tissue interface, such as the manifold 110, can generally be adapted to contact a tissue site or other layers of a dressing, such as the dressing 102. A tissue interface may be partially or fully in contact with a tissue site. If a tissue site is a wound, for example, a tissue interface may partially or completely fill the wound, or may be placed over the wound. A tissue interface may take many forms, and may be many sizes, shapes, or thicknesses depending on a variety of factors, such as the type of treatment being implemented or the nature and size of a tissue site. For example, the size and shape of a tissue interface may be adapted to the contours of deep and irregular shaped tissue sites.

[0036] Generally, a manifold, such as the manifold 110, for example, is a substance or structure adapted to distribute or remove fluids from a tissue site. A manifold may include flow channels or pathways that can distribute fluids provided to and removed from a tissue site. In one illustrative embodiment, the flow channels or pathways may be interconnected to improve distribution of fluids provided to or removed from a tissue site. For example, a manifold may be an open-cell foam, porous tissue collection, and other porous material such as gauze or felted mat that generally includes structural elements arranged to form flow channels. Liquids, gels, and other foams may also include or be cured to include flow channels.

[0037] In one illustrative embodiment, the manifold 110 may be a porous foam pad having interconnected cells adapted to distribute reduced pressure across a tissue site. The foam material may be either hydrophobic or hydrophilic. In one non-limiting example, the manifold 110 may be reticulated polyurethane foam such as GranuFoam^® dressing available from Kinetic Concepts, Inc. of San Antonio, Texas.

[0038] In some embodiments, such as embodiments in which the manifold 110 may be made from a hydrophilic material, the manifold 110 may also wick fluid away from a tissue site while continuing to distribute reduced pressure to the tissue site. The wicking properties of the manifold 110 may draw fluid away from a tissue site by capillary flow or other wicking mechanisms. An example of a hydrophilic foam is a polyvinyl alcohol, open cell foam such as V.A.C. WhiteFoam^® dressing available from Kinetic Concepts, Inc. of San Antonio, Texas. Other hydrophilic foams may include those made from polyether. Other foams that may exhibit hydrophilic characteristics include hydrophobic foams that have been treated or coated to provide hydrophilicity.

[0039] A tissue interface may further promote granulation at a tissue site if pressure within a sealed therapeutic environment is reduced. For example, any or all of the surfaces of the manifold 110 may have an uneven, coarse, or jagged profile that can induce microstrains and stresses at a tissue site if reduced pressure is applied through the manifold 110.

[0040] In some example embodiments, a tissue interface may be constructed from bioresorbable materials. Suitable bioresorbable materials may include, without limitation, a polymeric blend of polylactic acid (PLA) and poly glycolic acid (PGA). The polymeric blend may also include without limitation polycarbonates, polyfumarates, and capralactones. The tissue interface may further serve as a scaffold for new cell-growth, or a scaffold material may be used in conjunction with the tissue interface to promote cell-growth. In general, a scaffold material may be a biocompatible or biodegradable substance or structure used to enhance or promote the growth of cells or formation of tissue, such as a three-dimensional porous structure that provides a template for cell growth. Illustrative examples of scaffold materials include calcium phosphate, collagen, PLA/PGA, coral hydroxy apatites, carbonates, or processed allograft materials.

[0041] The drape 108 is an example of a sealing member. A sealing member may be constructed from a material that can provide a fluid seal between two environments or components, such as between a therapeutic environment and a local external environment. The sealing member may be, for example, an impermeable or semi-permeable, elastomeric film or barrier that can provide a seal adequate to maintain a reduced pressure at a tissue site for a given reduced-pressure source. For semi-permeable materials, the permeability generally should be low enough that a desired reduced pressure may be maintained. An attachment device may be used to attach a sealing member to an attachment surface, such as undamaged epidermis, a gasket, or another sealing member. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure- sensitive adhesive that extends about a periphery, a portion, or an entire sealing member. Other example embodiments of an attachment device may include a double-sided tape, paste, hydrocolloid, hydrogel, silicone gel, organogel, or an acrylic adhesive.

[0042] A " container," such as the container 112 in Figure 1, broadly includes a canister, pouch, bottle, vial, or other fluid collection apparatus. The container 112, for example, can be used to manage exudates and other fluids withdrawn from a tissue site. In many environments, a rigid container may be preferred or required for collecting, storing, and disposing of fluids. In other environments, fluids may be properly disposed of without rigid container storage, and a re-usable container could reduce waste and costs associated with reduced-pressure therapy.

[0043] In general, reduced -pres sure therapy can be beneficial for wounds of all severity, but the cost and complexity of reduced-pressure therapy systems often limit the application of reduced-pressure therapy to large, highly-exudating wounds present on patients undergoing acute or chronic care, as well as other severe wounds that are not readily susceptible to healing without application of reduced pressure. Many developing regions may not have access to dedicated, electrically-operated reduced-pressure sources for reduced- pressure therapy. Instead, these regions may rely on wall-suction sources for the supply of reduced pressure. These wall-suction sources may be seen as a practical, suitable, and lower cost alternative to a dedicated therapy unit with electronic controls.

[0044] Wall-suction sources are capable of providing continuous, or nearly continuous, supplies of reduced pressure. However, wall-suction sources may provide a broad range of reduced pressures and may require an operator to select an appropriate reduced pressure to be supplied. If the reduced pressure is set too low at the wall-suction source, removal of exudates and other wound fluids from the tissue site will not occur. If the reduced pressure is too high, the reduced-pressure therapy may cause internal bleeding and further damage to a tissue site. For at least these reasons, treatment of a tissue site with reduced pressure provided by a wall-suction source requires regulation of the amount of reduced pressure delivered to the tissue site.

[0045] The reduced-pressure therapy system 100 may overcome these shortcomings and others by providing feedback and mechanical regulation of therapeutic pressure. In some embodiments, for example, a regulator can regulate fluid communication between a supply chamber and a charging chamber, and a feedback systems can provide feedback to alert operators of an operating state of reduced-pressure therapy during the provision of reduced- pressure therapy. For example, the feedback systems may provide an operator with an operating state of one or more of the following: a control pressure, a supply pressure, a differential between the control pressure and the supply pressure, a leak condition, a blockage condition, a canister full condition, and an overpressure condition. In some embodiments, the reduced-pressure therapy system 100 may provide a highly configurable system that is low cost, disposable, single-patient use, or reusable.

[0046] Referring more specifically to Figure 2A, a graph illustrating an example embodiment of pressure control modes 200 that may be used for the reduced-pressure therapy system of Figure 1 is shown wherein the x-axis represents time in minutes (min) and/or seconds (sec) and the y-axis represents pressure generated by a pump in Torr (mmHg) that varies with time in a continuous pressure mode and an intermittent pressure mode that may be used for applying negative pressure in the therapy system. The target pressure (TP) may be set by the user in a continuous pressure mode as indicated by solid line 201 and dashed line 202 wherein the wound pressure (WP) is applied to the tissue site until the user deactivates the reduced source 104. The target pressure (TP) may also be set by the user in an intermittent pressure mode as indicated by solid lines 201, 203 and 205 wherein the wound pressure (WP) is cycled between the target pressure (TP) and atmospheric pressure. For example, the target pressure (TP) may be set by the user at a value of 125 mmHg for a specified period of time (e.g., 5 min) followed by the therapy being turned off for a specified period of time (e.g., 2 min) as indicated by the gap between the solid lines 203 and 205 by venting the tissue site to the atmosphere, and then repeating the cycle by turning the therapy back on as indicated by solid line 205 which consequently forms a square wave pattern between the target pressure (TP) level and atmospheric pressure. In some embodiments, the ratio of the“on-time” to the“off-time” or the total“cycle time” may be referred to as a pump duty cycle (PD).

[0047] In some example embodiments, the decrease in the wound pressure (WP) at the tissue site from ambient pressure to the target pressure (TP) is not instantaneous, but rather gradual depending on the type of therapy equipment and dressing being used for the particular therapy treatment. For example, the reduced source 104 and the dressing 102 may have an initial rise time as indicated by the dashed line 207 that may vary depending on the type of dressing and therapy equipment being used. For example, the initial rise time for one therapy system may be in the range between about 20-30 mmHg/second or, more specifically, equal to about 25 mmHg/second, and in the range between about 5-10 mmHg/second for another therapy system. When the therapy system 100 is operating in the intermittent mode, the repeating rise time as indicated by the solid line 205 may be a value substantially equal to the initial rise time as indicated by the dashed line 207. [0048] The therapy pressure may also be a variable target pressure (VTP) controlled or determined by a controller that varies in a dynamic pressure mode. For example, the variable target pressure (VTP) may vary between a maximum and minimum pressure value that may be set as an input determined by a user as the range of negative pressures desired for therapy at the tissue site. The variable target pressure (VTP) may also be processed and controlled by the controller that varies the target pressure (TP) according to a predetermined waveform such as, for example, a sine waveform or a saw-tooth waveform or a triangular waveform, that may be set as an input by a user as the predetermined or time-varying reduced pressures desired for therapy at the tissue site.

[0049] Referring more specifically to Figure 2B, a graph illustrating an illustrative embodiment of another pressure control mode for the negative-pressure and instillation therapy system of Figure 1 is shown wherein the x-axis represents time in minutes (min) and/or seconds (sec) and the y-axis represents pressure generated by a pump in Torr (mmHg) that varies with time in a dynamic pressure mode that may be used for applying negative pressure in the therapy system. For example, the variable target pressure (VTP) may be a reduced pressure that provides an effective treatment by applying reduced pressure to tissue site in the form of a triangular waveform varying between a minimum and maximum pressure of 50-125 mmHg with a rise time 212 set at a rate of +25 mmHg/min. and a descent time 211 set at -25 mmHg/min, respectively. In another embodiment of the therapy system 100, the variable target pressure (VTP) may be a reduced pressure that applies reduced pressure to tissue site in the form of a triangular waveform varying between 25-125 mmHg with a rise time 212 set at a rate of +30 mmHg/min and a descent time 211 set at -30 mmHg/min. Again, the type of system and tissue site determines the type of reduced pressure therapy to be used.

Regulator

[0050] Figure 3A is a cross-sectional view illustrating a regulator 300 that may be associated with some embodiments of the reduced-pressure therapy system 100. The regulator 300 is another example embodiment of the regulator 106. The regulator 300 may include a housing 302 and a regulator valve 326. The housing 302 may have an end wall 303, one or more side walls 301, and an open end 305 opposite the end wall 303. The side walls 301 may be coupled to peripheral portions of and generally perpendicular to the end wall 303. [0051] The housing 302 may be partitioned by a first wall 304 and a second wall 306 to form a charging chamber 308, a supply chamber 310, and a control chamber 312. In the illustrative embodiment, the charging chamber 308 may adjoin the supply chamber 310, disposed between the end wall 303, the first wall 304, and the side walls 301. The supply chamber 310 may be disposed between the charging chamber 308 and the control chamber 312. For example, in Figure 3A, the first wall 304 separates the charging chamber 308 and the supply chamber 310. The supply chamber 310 may be bounded by the first wall 304, the side walls 301, and the second wall 306. The control chamber 312 may adjoin the supply chamber 308, as shown in the illustrative embodiment of Figure 3 A. For example, the second wall 306 may separate the supply chamber 310 and the control chamber 312. The supply chamber 310 may be bounded by the second wall 306, the side walls 301, and the open end 305 of the housing 302. The first wall 304 and the second wall 306 may be coupled to the side walls 301 of the housing 302 at peripheral portions of the first wall 304 and the second wall 306. In some embodiments, no fluid communication may occur between the charging chamber 308, the supply chamber 310, and the control chamber 312 at the locations where the first wall 304 and the second wall 306 couple to the housing 302.

[0052] The housing 302, the first wall 304, and the second wall 306 may be formed of a material having a sufficient strength to resist collapse when a reduced pressure is supplied to the charging chamber 308, the supply chamber 310, and the control chamber 312, such as metals, hard plastics, or other suitable materials. For example, the housing 302, the first wall 304, and the second wall 306 may resist collapse when a reduced pressure of about 150 mm Hg (-150 mm Hg gauge pressure) is supplied to the charging chamber 308, the supply chamber 310, or the control chamber 312. In other exemplary embodiments, the housing 302, the first wall 304, and the second wall 306 may resist collapse when a reduced pressure of about 600 mm Hg (-600 mm Hg gauge pressure) is supplied to the charging chamber 308, the supply chamber 310, or the control chamber 312.

[0053] The charging chamber 308 may include a source port 314 and a charging port 316. The source port 314 may be disposed in one of the side walls 301 of the charging chamber 308 and may be fluidly coupled to the charging chamber 308. In the illustrative embodiment, the source port 314 may be configured to be fluidly coupled to a supply of reduced pressure, such as an electric pump, a manual pump, or wall-suction source, for example. In some embodiments, the source port 314 may be fluidly coupled to a wall-suction source by a conduit or tube. A one-way valve may be disposed in the source port 314 and oriented to prevent fluid flow into the charging chamber 308 through the source port 314 and permit fluid flow out of the charging chamber 308 through the source port 314.

[0054] In some embodiments, the charging port 316 may be disposed in the first wall 304, as shown in the illustrative embodiment of Figure 3 A. The charging port 316 may fluidly couple the charging chamber 308 and the supply chamber 310. In some embodiments, the charging port 316 may have a cylindrical wall 315 and a central passage 317 that extends between the charging chamber 308 and the supply chamber 310. The cylindrical wall 315 may include a portion extending into the supply chamber 310 from the first wall 304 so that the charging port 316 terminates near a center portion of the second wall 306. In some embodiments, the charging port 316 may be disposed in other locations of the first wall 304.

[0055] The supply chamber 310 may include a supply port 318 and a monitor port 319. In the illustrative embodiments, the supply port 318 may be fluidly coupled to the supply chamber 310 and provide an interface to the supply chamber 310. For example, the supply port 318 may be configured to be coupled to a tube, which can be coupled to a dressing or other upstream component. A one-way valve may be disposed in the supply port 318 and oriented to permit fluid flow into the supply chamber 310 through the supply port 318 and prevent fluid flow out of the supply chamber 310 through the supply port 318.

[0056] The monitor port 319 may also be fluidly coupled to the supply chamber 310, providing a second interface to the supply chamber 310. In some embodiments, for example, the monitor port 319 may be disposed in one of the side walls 301, opposite the supply port

318. In other embodiments, the monitor port 319 may be proximate to or adjacent to the supply port 318. The monitor port 319 may be fluidly coupled to a monitoring device, such as a sensor, indicator, or overpressure valve, for example. In some embodiments, the monitor port 319 may be capped so that no fluid communication may occur through the monitor port

319.

[0057] The control chamber 312 may include a control port 321 and a monitor port 323. In the illustrative embodiment, the control port 321 may be fluidly coupled to the control chamber 312 and provide an interface to the control chamber 312. In some embodiments, the control port 321 may be disposed on a same side of the regulator 300 as the supply port 318. In still other embodiments, the control port 321 may be vertically aligned with the supply port 318. In the illustrative embodiment of Figure 3 A, the control port 321 may be configured to be coupled to a tube, which can be coupled to a dressing or other upstream component. A one-way valve may be disposed in the control port 321 and oriented to prevent fluid flow into the control chamber 312 through the control port 321 and permit fluid flow out of the control chamber 312 through the control port 321.

[0058] The monitor port 323 may also be fluidly coupled to the control chamber 312. In some embodiments, the monitor port 323 may be opposite the control port 321. In other embodiments, the monitor port 323 may be disposed on a same side of the regulator 300 as the control port 321. In other embodiments, the monitor port 323 may be vertically aligned with the monitor port 319. The monitor port 323 may be fluidly coupled to a monitoring device, such as a sensor, indicator, or overpressure valve, for example. In some embodiments, the monitor port 323 may be capped so that no fluid communication may occur through the monitor port 323.

[0059] The second wall 306 may include an opening 320 in a center portion proximate to the distal end of the charging port 316. As illustrated in Figure 3A, the opening 320 may be axially aligned with the central passage 317. The opening 320 may be larger than the distal end of charging port 316, providing a gap between a peripheral portion of the opening 320 and the distal end of the charging port 316. The gap provides a fluid path between the charging port 316 and the supply chamber 310. In some embodiments, the gap between the peripheral portion of the opening 320 and the distal end of the charging port 316 may be about 0.5 mm. In other embodiments, the gap between the peripheral portion of the opening 320 and the distal end of the charging port 316 may be less than 0.5 mm. In yet other alternative or additional embodiments, the distal end of the charging port 316 may be vertically separated from the second wall 306. For example, the distal end of the charging port 316 may be vertically separated from a lower surface of the second wall 306 a distance of about 0.5 mm. In other embodiments, the distance separating the distal end of the charging port 316 and the lower surface of the second wall 306 may be greater than 0.5 mm.

[0060] The regulator valve 326 can be operably associated with the charging port 316 to regulate fluid communication between the charging chamber 308 and the supply chamber 310. The regulator valve 326 can be biased to either open or close the charging port 316. In some embodiments, the regulator valve 326 may be coupled to the open end 305 of the housing 302, as illustrated in Figure 3A. The regulator valve 326 may be coupled to ends of the side walls 301 of the housing 302, opposite the end wall 303 of the housing 302. In some embodiments, the regulator valve 326 may substantially limit or prevent fluid communication through the open end 305 of the housing 302. The regulator valve 326 may include a valve member 322, a valve body, such as a stem 328, and an actuator 330. The regulator valve 326 may also include a cap portion 332, a regulator spring 334, an adjustment shaft 336, and a tension adjuster, such as a push button, a lever, or a dial 338.

[0061] Figure 3B is a schematic sectional assembly view of the regulator 300 illustrating additional details that may be associated with some embodiments. In some embodiments, the valve member 322 may be a flexible membrane, such as a diaphragm. In some embodiments, the valve member 322 may have a generally disc-like shape with a diameter larger than the diameter of the opening 320 in the second wall 306. In other embodiments, the valve member 322 may have a shape matched to a shape of the opening 320, for example, square, rectangular, ovoid, triangular, or amorphous shapes. The valve member 322 may have peripheral portions coupled to the second wall 306, and the valve member 322 may extend across the opening 320. When the valve member 322 is coupled to the second wall 306, the valve member 322 may fluidly isolate the control chamber 312 from the supply chamber 310. For example, a difference in the pressures in the supply chamber 310 and the control chamber 312 may cause deflection of the valve member 322. In some embodiments, the valve member 322 may be formed from a silicone material. In some embodiments, the valve member 322 may have a hardness rating between about 30 Shore A and about 50 Shore A.

[0062] As illustrated in Figure 3B, some embodiments of the charging port 316 may have a valve seat 324 on the distal end. The valve seat 324 may provide a tapered or beveled edge proximate to the central passage 317 of the charging port 316. In some embodiments, the valve member 322 may include an enlarged portion or contact node 325 configured to engage the valve seat 324. For example, the valve member 322 may be positioned so that the contact node 325 of the valve member 322 may engage a beveled edge of the valve seat 324 of the charging port 316 in a closed position. If engaged in such a manner, the valve member 322 can substantially prevent fluid communication through the passage 317 of the charging port 316.

[0063] The stem 328 may be cylindrical and have an end coupled to the valve member 322. In some embodiments, a first end of the stem 328 may be coupled to the contact node 325 of the valve member 322. The stem 328 is elongated so that the stem 328 may extend through the open end 305 when the end of the stem 328 is coupled to the valve member 322. A second end of the stem 328 may include a cavity 340. The cavity 340 may be a recess into the stem 328 from the second end of the stem 328. The cavity 340 may have a diameter less than a diameter of the stem 328 so that a shoulder 349 may be formed at the end of the stem 328 adjacent to an opening of the cavity 340. The shoulder 349 may face away from the housing 302. The stem 328 may also have a recess 333 disposed between ends of the stem 328. In some embodiments, the recess 333 is annular and may be disposed proximate to a center of a length of the stem 328.

[0064] The actuator 330 may be coupled to the housing 302 so that the actuator 330 covers the open end 305. In some embodiments, the actuator 330 extends across the open end 305 to fluidly isolate the control chamber 312 from the ambient environment. In some embodiments, the actuator 330 may be a diaphragm having peripheral portions coupled to the ends of the side walls 301 of the housing 302. The actuator 330 may have an elasticity permitting a center portion of the actuator 330 to deflect from an equilibrium position while the peripheral portions of the actuator 330 remain affixed to the housing 302. In some embodiments, the actuator 330 may be formed of an elastomeric material. For example, the actuator 330 may be formed of a silicone. In some embodiments, the actuator 330 may be formed from a material having a hardness rating between about 30 Shore A and about 50 Shore A.

[0065] The actuator 330 may have an opening 331 proximate to a center portion of the actuator 330. The opening 331 may receive the stem 328 so that the stem 328 extends through the actuator 330. In some embodiments, the actuator 330 may be coupled or otherwise sealed to the stem 328. For example, the actuator 330 may be welded to the stem 328 at the opening 331. For example, at least a portion of the actuator 330 adjacent the opening 331 may be inserted into the recess 333 to couple the actuator 330 to the stem 328. In some embodiments, movement of the stem 328 along an axis of the stem 328 causes movement of the center portion of the actuator 330, and movement of the actuator 330 along an axis of the stem 328 may cause movement of the stem 328.

[0066] When assembled, as shown in Figure 3A, the cap portion 332 may be coupled to the housing 302 so that the cap portion 332 is adjacent to the control chamber 312 and the open end 305. In the illustrative embodiments, the cap portion 332 covers the open end 305 of the housing 302 and includes a raised portion extending away from the control chamber 312 near a center of the cap portion 332. In some embodiments, the raised portion may be coextensive with the open end 305 so that the cap portion 332 may be separated from the actuator 330 near the open end 305. The stem 328 may extend through the raised portion of the cap portion 332. The cap portion 332 may be sealed to the stem 328. In some embodiments, the stem 328 may move relative to the cap portion 332 while remaining sealed to the cap portion 332. In other embodiments, the stem 328 may not be fluidly sealed to the cap portion 332 so that an ambient pressure adjacent an exterior of the cap portion 332 may be substantially equivalent to a pressure in the area between the raised portion of the cap portion 332 and the actuator 330.

[0067] The regulator spring 334 may be disposed on the stem 328 so that the regulator spring 334 circumscribes the stem 328. The regulator spring 334 may have a first end adjacent to the cap portion 332. In some embodiments, the first end of the regulator spring 334 may contact the cap portion 332 so that the regulator spring 334 may be compressed against the cap portion 332. A second end of the regulator spring 334 may be adjacent to the end of the stem 328 that has the cavity 340 disposed therein. The regulator spring 334 may have a length Y when in an equilibrium position. In the equilibrium position, the regulator spring 334 may be neither extended nor compressed so that the regulator spring 334 does not exert a spring force.

[0068] The adjustment shaft 336 may have an end disposed within the cavity 340 and may be coupled to the stem 328 so that the adjustment shaft 336 and the stem 328 can move as integral members. The adjustment shaft 336 may be cylindrical and have an enlarged distal end forming a cap 337 of the adjustment shaft 336. A portion of the adjustment shaft 336 may be threaded between the cap 337 and the end disposed within the cavity 340. In some embodiments, the adjustment shaft 336 may be threaded between the cap 337 and an opening of the cavity 340 of the stem 328.

[0069] The dial 338 may be a tubular body having a first portion 339 and a second portion 341. The first portion 339 may have a cavity 345, and the cavity 345 has a width or diameter substantially equal to the outer diameter of the threaded portion of the adjustment shaft 336. The second portion 341 may also have a cavity 347, the width or diameter of the cavity 347 may be substantially equal to the outer diameter of the stem 328. The first portion 339 and the second portion 341 are preferably joined, in the illustrative embodiments of Figure 3A, forming a shoulder 343 between the cavity 345 and the cavity 347. The dial 338 can be disposed on the stem 328 so that the shoulder 343 faces the cavity 340. As shown in the illustrative embodiment of Figure 3A, the shoulder 343 may have an annular width substantially equal to the width of a shoulder 349 of the stem 328 formed by the cavity 340. The dial 338 may be moveably coupled to the adjustment shaft 336 proximate to the cap 337 of the adjustment shaft 336. In some embodiments, the first portion 339 of the dial 338 is adjacent to the cap 337 of the adjustment shaft 336. In some embodiments, the surface of the cavity 345 of the first portion 339 may be threaded. The dial 338 may be threaded to the adjustment shaft 336, allowing the dial 338 to be rotated about the adjustment shaft 336. Rotation of the dial 338 about the adjustment shaft 336 may cause the dial 338 to move parallel to an axis of the adjustment shaft 336. In this manner, the dial 338 may be moved along the adjustment shaft 336.

[0070] Figure 3C is a schematic sectional view of the regulator 300 illustrating additional details that may be associated with some embodiments of the regulator 300 in an open position. As shown in Figure 3C, the dial 338 may initially be positioned on the adjustment shaft 336 so that an end of the second portion 341 of the dial 338 contacts the distal end of the regulator spring 334. For example, the dial 338 may be threaded onto the adjustment shaft 336, and additional rotation of the dial 338 relative to the adjustment shaft 336 may move the dial 338 axially closer to the cap portion 332 to compress the regulator spring 334. Compression of the regulator spring 334 by the dial 338 shortens the length of the regulator spring 334 a distance from the equilibrium position Y. This compression distance may cause the regulator spring 334 to exert a force on the dial 338 urging the dial 338 away from the cap portion 332. The force exerted by the regulator spring 334 is directly proportional to a spring constant of the regulator spring 334 and the distance the regulator spring 334 is compressed from the equilibrium position Y. The force exerted by the regulator spring 334 on the dial 338 similarly urges the adjustment shaft 336, the coupled stem 328, and the coupled valve member 322 upward. In the illustrative embodiment, the force also urges the valve member 322 away from the charging port 316 into an open position. In the open position, fluid communication may occur through the charging port 316.

[0071] A differential force may also operate on the actuator 330. The differential force may be a force generated by a difference in pressures between the control chamber 312 and the ambient environment of the regulator 300. The pressure in the control chamber 312 may also be referred to as a control pressure. If the control pressure in the control chamber 312 and the pressure in the ambient environment are substantially equal, the differential force may be approximately zero. If the control pressure in the control chamber 312 is less than the ambient pressure, for example, if the regulator 300 is being used to provide reduced-pressure therapy, the differential force may act to urge the actuator 330, the coupled stem 328, and the valve member 322 toward the distal end of the charging port 316. [0072] If the differential force is greater than the force of the regulator spring 334 acting on the stem 328, the valve member 322 may be urged into contact with the distal end of the charging port 316 to prevent fluid communication through the charging port 316 in a closed position, as shown in Figure 3A. If the differential force is less than the force on the regulator spring 334, the valve member 322 may be urged away from the distal end of the charging port 316 to permit fluid communication through the charging port 316 in the open position, shown in Figure 3C. The dial 338 can be threaded down the adjustment shaft 336 to control the displacement of the regulator spring 334 from the equilibrium position Y. Thus, the displacement of the regulator spring 334 from the equilibrium position Y can be controlled to select a particular differential pressure, so that the force of the regulator spring 334 may be overcome when a particular pressure is reached in the control chamber 312.

[0073] In other embodiments, a differential force may act on the valve member 322. For example, the supply pressure in the supply chamber 310 may exert a force on the valve member 322, and the control pressure in the control chamber 312 may exert a force on the valve member 322. The sum of the forces acting on the valve member 322 may be referred to as a valve force. The valve force may urge the valve member 322 into or out of contact with the charging port 316. In some embodiments, the valve force may act in opposition to the differential force acting on the actuator 330. The relative dimensions of the valve member 322 and the actuator 330 may be selected so that the actuator 330 is several times larger than the valve member 322. For example, the actuator 330 may have a major dimension that is greater than a corresponding dimension of the valve member 322. In some embodiments, the actuator 330 may have a diameter that is greater than a diameter of the valve member 322. A large difference in size between the actuator 330 and the valve member 322 correlates to a similarly large difference in the surface areas of the actuator 330 and the valve member 322. The larger surface area of the actuator 330 allows the differential force acting on the actuator 330 to act over a larger area than the valve force acting on the valve member 322. As a result, the differential force acting on the actuator 330 may overcome other forces acting on other components of the regulator 300, such as the valve member 322, allowing the actuator 330 to control the movement of the stem 328. In some embodiments, the opening 320 may be made smaller than depicted, and the charging port 316 may be further separated from the lower surface of the second wall 306. In such an embodiment, the valve member 322 may be made relatively smaller so that the valve force acts on a smaller surface area than the differential force. Reduced-Pressure Therapy System

[0074] Figure 4 is a schematic illustration of a reduced-pressure system 400 illustrating additional details that may be associated with the operation of the regulator 300. The reduced-pressure system 400 is an example embodiment of the reduced-pressure system 100 and, more specifically, a mechanical, fluid dynamics embodiment of the reduced- pressure system 100. The reduced-pressure system 400 includes a reduced-pressure source

402, a container 403, and a dressing 404. The reduced-pressure source 402 may be a wall- suction source, a manual pump, or an electric pump, for example. In the illustrative embodiment, the reduced-pressure source 402 may be a wall-suction source, and may be fluidly coupled to the source port 314. For example, a tube 406 may fluidly couple the reduced-pressure source 402 to the source port 314, as shown in the illustrative embodiment of Figure 4. The container 403 is an example embodiment of the container 112, and may be fluidly coupled to the supply port 318. In some embodiments, for example, a tube 410 may fluidly couple the container 403 to the supply port 318. The container 403 may include a filter, such as a hydrophobic filter 414 adjacent to an end of the tube 410. The dressing 404 is an example embodiment of the dressing 102, and may be fluidly coupled to the container

403 For example, a tube 412 may fluidly couple the dressing 404 to the container 403. The dressing 404 may have a pressure that may also be referred to as a manifold pressure. In some embodiments, the tube 410 and the tube 412 may each have at least one lumen. The at least one lumen in the tube 410 and the tube 412 may collectively be referred to as a supply lumen. In other embodiments, the container 403 may be omitted, and the tube 410 may be coupled directly to the dressing 404. In these embodiments, the at least one lumen in the tube 410 may be considered a supply lumen. The dressing 404 may also be fluidly coupled to the control port 321. For example, a tube 408 may fluidly couple the dressing 404 to the control port 321. In some embodiments, the tube 408 may have at least one lumen. The at least one lumen of the tube 408 may also be referred to as a feedback lumen.

[0075] The dressing 404 may be fluidly coupled to the supply port 318 and the control port 321 so that fluid communication may occur between the supply chamber 310 and the dressing 404 through the container 403, and between the dressing 404 and the control chamber 312. Fluid communication between the dressing 404, the supply chamber 310 and the control chamber 312 may equalize the pressures in the supply chamber 310, the dressing

404, and the control chamber 312. For example, fluid communication between the dressing 404, the supply chamber 310, and the control chamber 312 may equalize the supply pressure in the supply chamber 310, the manifold pressure in the dressing 404, and the control pressure in the control chamber 312. If the source port 314 is not coupled to the reduced- pressure source 402, the charging port 316 may remain open and the ambient pressure may equalize between the charging chamber 308, the supply chamber 310, the dressing 404, and the control chamber 312.

[0076] The reduced-pressure source 402 may be coupled to the source port 314, providing a reduced pressure to the charging chamber 308. If the regulator valve 326 is in the open position, the charging port 316 provides a fluid path between the charging chamber 308 and the supply chamber 310. As the supply of reduced pressure reduces the pressure within the charging chamber 308, the pressure in the supply chamber 310 may similarly drop. The pressure in the supply chamber 310 may also be referred to as a supply pressure. Fluid communication through the supply port 318 will similarly lower the pressure in the dressing 404, and fluid communication through the control port 321 may similarly begin to lower the pressure in the control chamber 312. As the control pressure in the control chamber 312 drops, the differential force, acting in opposition to the force of the regulator spring 334 will increase, eventually overcoming the force of the regulator spring 334, causing the stem 328 to move downward and forcing the regulator valve 326 into the closed position in which the valve member 322 is seated in the charging port 316. In the closed position, the valve member 322 may block fluid communication through the charging port 316. Decreases in reduced pressure at the dressing 404 may decrease the differential force, so that the biasing force of the regulator spring 334 overcomes the differential force to open the regulator valve 326. In the open position, fluid communication through the charging port 316 may resume until the pressure at the dressing 404, and in turn the control chamber 312, drops sufficiently to overcome the regulator spring 334, again closing the regulator valve 326.

[0077] Repeated opening and closing of the regulator valve 326 may occur while reduced-pressure therapy is provided. In some embodiments, the repeated opening and closing of the regulator valve 326 may correspond to the“off-time” and“on-time” of a therapy cycle when the therapy system 100 is operating in an intermittent mode. When not in use, the monitor ports 319 and 323 may be covered with caps 342 and 344, respectively, to maintain the pressure in the supply chamber 310 and the control chamber 312, respectively, during operation of the therapy system 100 and the regulator valve 326. When a user desires to monitor such pressures, the caps 342 and 344 may be removed and fluidly coupled directly or indirectly by a fluid conductor or conduit to a feedback system for monitoring and/or controlling the regulator 300.

[0078] The regulator 300, when used in a reduced pressure therapy system such as the reduced pressure therapy system 400, may be fluidly coupled to a wall suction source of reduced pressure such as the reduced-pressure source 402 to provide a manual regulation system that is relatively low cost. However, in some cases a manual regulation system may be too simple for more complicated therapies to be implemented by a clinician in an acute care setting. In some embodiments, it may be desirable to utilize a mechanically regulated system driven by a wall suction source of reduced pressure that may be modified to include additional pressure sensor(s) and a feedback system that may be coupled with other sensors in order to compile more data in a processor to provide such data the user or clinician more quickly and accurately so that they may respond accordingly to various conditions. In addition to compiling and communicating data, some embodiments of a feedback system may further comprise outputs responsive to such data inputs for providing closed-loop control to adjust the regulator valve. In some embodiments, the feedback system may further comprise a wireless communication module that may be paired to other remote devices so that such data can provide closed-loop feedback and updates on the status of the therapy being provided. When using a mechanical regulating system, a user must be close to the mechanical system to detect an alarm condition indicated by some visual or audio signal. Communicating such information to a remote device enables the user or clinician to receive data or be alerted to an alarm condition even though that person is not near the fixed location of the wall suction source of reduced pressure.

Feedback Systems

[0079] Figure 5 is a schematic view illustrating an example embodiment of a feedback system 500 that may be used with some embodiments of the reduced-pressure therapy system 400. In Figure 5, for example, the feedback system 500 may be used with the regulator 300 and/or with other example embodiments of regulators such as, for example, regulator 600 and regulator 700 shown in Figures 6A and Figure 7 which are modifications of, but substantially similar to, the regulator 300 in many respects described below. In some embodiments, the feedback system 500 may include a printed circuit board 502 having pressure sensors including a control sensor 504 and a supply sensor 514, and a controller 501 disposed thereon. The printed circuit board 502 may be an electronic device having one or more electronic components electrically coupled by conductive pathways. In some embodiments, the controller 501 may comprise a processor 503 and may further comprise a wireless communication module 505 electrically coupled to the processor 503 to enable wireless communication with other components of the therapy system 100 or other peripheral devices located remote from the therapy system 100. Printed circuit boards may include electrical conductors and electronic components such as capacitors, resistors, or other active devices mounted on or within the printed circuit board. In some embodiments, the printed circuit board 502 may be coupled directly or indirectly to the regulator 300 as an upgrade for monitoring and/or controlling the regulator 300 or any other mechanical regulator used in conjunction with a therapy system similar to the therapy system 100 and/or the reduced pressure system 400.

[0080] In some embodiments, the printed circuit board 502 may include a power supply or electric potential source, such as a battery 506, for providing voltage to the components mounted on the printed circuit board 502. In some embodiments, the printed circuit board 502 also may include a signal interface or indicator electrically coupled to outputs of the processor 503 that provides some indication of the signal to a user of the therapy system 100. In some embodiments, the indicator may be a visual device, such as a liquid crystal device (LCD) 508 or a light emitting diode (LED) 511, an auditory device, such as a speaker or auditory pulse emitter, a tactile device, such as a moving protrusion, or an olfactory device. In some embodiments, the indicator may be multiple devices such as, for example, a display comprising multiple LEDs emitting different wavelengths of light including, for example, LEDs 511, 512, and 513.

[0081] The LCD 508 may be a display that presents images using the light- modulating properties of liquid crystals. In general, an LCD includes a layer of molecules aligned between two electrodes and two polarizing filters. Each filter has an axis of transmission that is perpendicular to the other so that when one filter is transparent, the other is not. A voltage may be applied to the electrodes, and in response the molecules of the layer are aligned to either block or allow the passage of light. An image is visible if light is blocked. The LCD 508 may be coupled to outputs of the processor 503 to receive a signal from the control sensor 504 and the supply sensor 514. In the some embodiments, the LCD 508 may signal operating states and other information, such as a current pressure, a pressure differential, a leak condition, a blockage condition, an overpressure condition, or a canister full condition, for example. [0082] The printed circuit board 502 may further include an electronic storage device, such as a memory, and other devices configured to operate the feedback system 500 such as, for example, other passive and active devices including input and output devices. In some embodiments, the printed circuit board 502 may include switches or a touchscreen for a user for providing signals indicative of the therapy pressure (TP) and/or a therapeutic range (TR) as related to the therapy pressure (TP) to the processor 503. For example, the printed circuit board 502 may include a switch 518 and/or a switch 519 electrically coupled to input leads of the processor 503 for setting the processor with the desired therapy pressure (TP) and/or the desired therapeutic range (TR). In some embodiments, the printed circuit board 502 may include other input buffers or controllers needed by peripheral devices associated with the other components of therapy system 100 and/or the reduced pressure system 400.

[0083] In some embodiments, the controller 501 may be a single chip comprising the processor 503 and the wireless communication module 505 electrically coupled to the processor 503. Using a wireless communications module 505 has the advantage of eliminating an electrical conductor between the regulator 300 and other components of the reduced pressure system 400 or remote peripheral devices when in use during therapy treatments. In some embodiments, for example, the electrical circuits and/or components associated with the control sensor 504, the supply sensor 514, the switch 518, the switch 519, and other inputs and output devices may be electrically coupled to other components of the therapy system 400 and other peripheral devices having wireless capability by wireless means such as, for example, an integrated device implementing Bluetooth^® Low Energy wireless technology. More specifically, the wireless communication module 505 may be a Bluetooth^® Low Energy system-on-chip that includes a microprocessor (an example of the microprocessors referred to hereinafter) such as the nRF5l822 chip available from Nordic Semiconductor. The wireless communications module 505 may be implemented with other wireless technologies suitable for use in the medical environment such as radio frequency identification (RFID). In some embodiments, for example, the wireless communications module 505 may include wireless communication technologies that not only provide operators with a method of retrieving therapy data such as therapy duration, pressures, and alarm conditions, but also provide closed-loop feedback to the processor 503 for automatically adjusting and correcting pressure parameters that control the regulator valve 326. [0084] Each of the pressure sensors, the control sensor 504 and the supply sensor 514, may be an electronic device mounted on the printed circuit board 502 and communicatively coupled to the processor 503 to provide signals representative of control pressure and the supply pressure and powered by the battery 506. In some embodiments, each of the pressure sensors may be a piezo-resistive strain gauge, a capacitive sensor, an electromagnetic sensor, a piezoelectric sensor, an optical sensor, or a potentiometric sensor, for example. The pressure sensors can measure a strain caused by an applied pressure. The pressure sensors also may be calibrated by relating a known amount of strain to a known pressure applied. The known relationship may be used to determine an unknown applied pressure based on a measured amount of strain. In some embodiments, each of the pressure sensors may be a piezo-resistive pressure sensor having a pressure sensing element covered by a dielectric gel such as, for example, a Model 1620 pressure sensor available from TE Connectivity. The dielectric gel provides electrical and fluid isolation from the fluids in order to protect the sensing element from corrosion or other degradation. This allows the pressure sensors to measure the pressure being applied within the respective chambers, i.e., the control chamber 312 and the supply chamber 310, from a remote location.

[0085] The pressure sensors may each be disposed in a receptacle mounted on the printed circuit board 502 such as, for example, receptacles 520 and 521 that may be configured to couple the pressure sensors, i.e., control sensor 504 and supply sensor 514, to the monitor ports 323 and 319, respectively, for receiving and sensing an applied pressure within the respective chambers, i.e., the control chamber 312 and the supply chamber 310. The receptacles 520 and 521 may be fluidly coupled to the regulator 300 either directly as shown or indirectly by a tube (not shown). The pressure sensors may be positioned in close proximity to the monitor ports 319 and 323 to optimize fluid coupling and accurately measure the control pressure and the supply pressure within the chambers. In some embodiments, the regulator 300 may be modified or supplied as original equipment to mechanically couple the pressure sensors 504 and 514 to the monitor ports 323 and 319, respectively, for sensing an applied pressure within the respective chambers. In some embodiments, the pressure sensors 504 and 514 may be coupled directly to the monitor ports 323 and 319, respectively, for sensing pressure within the respective chambers.

[0086] Referring to 6A, a schematic cross-section of a regulator 600 is shown that is a modification of the regulator 300 for use with the feedback system of Figure 5 as described above. The regulator 600 may comprise diaphragm assemblies 602 and 603 having flexible diaphragms 604 and 605, respectively, covering the monitor ports 319 and 323 to seal the respective chambers from fluid communication with the sensors while being sufficiently flexible for mechanically modulating the pressure sensors 504 and 514 in response to an applied pressure therein. In some embodiments, the diaphragm assemblies 602 and 603 may further comprise diaphragm retainers 606 and 607 for supporting the flexible diaphragms 604 and 605 within the monitor ports, and diaphragms seals 608 and 609 for sealing the perimeter of the flexible diaphragms 604 and 605 within the monitor ports. In some embodiments, the regulator 600 may be modified or supplied as original equipment to include the diaphragm assemblies 602 and 603 which mechanically couple the pressure sensors 504 and 514 to the monitor ports 323 and 319, respectively, for sensing pressure within the respective chambers. Moreover, the diaphragm assemblies 602 and 603 may be configured to fluidly isolate the control chamber 312 and the supply chamber 310 from the pressure sensors 504 and 514, while at the same time sensing the pressure within the chambers. In some embodiments, the flexible diaphragms 604 and 605 may comprise a soft polymeric membrane that is non- permeable such as, for example, Santoprene, that forms a seal over the monitor ports to prevent the flow of air between the pressure sensors and the corresponding chambers when in operation. In some embodiments, the seal also may protect the chambers from being contaminated from exposure to the outside environment when the pressures in the chambers are not being monitored.

[0087] Referring to both Figures 5 and 6A, the feedback system 500 may be fluidly coupled to the regulator 600 to determine pressures in the chambers of the regulator 600 and indicate an operating state of the regulator 600 in response. In some embodiments, the operating state of the regulator 600 may include a current pressure, a pressure differential, a leak condition, a blockage condition, a canister full condition, or an overpressure condition, for example. In some embodiments, the control sensor 504 may be fluidly coupled to the control chamber 312. For example, the control sensor 504 may be fluidly coupled by the receptacle 520 to the monitor port 323, and the supply sensor 514 may be fluidly coupled by the receptacle 521 to the monitor port 319. A reduced pressure may be supplied to the charging chamber 308, and the regulator 600 may operate as described above to control delivery of reduced-pressure therapy. The control pressure in the control chamber 312 may be fluidly communicated to the control sensor 504. The control sensor 504 may determine an amount of strain caused by the control pressure applied to the control sensor 504. The control sensor 504 may determine a value of the control pressure based on the measured strain. Similarly, the supply sensor 514 may determine an amount of strain caused by the supply pressure applied to the supply sensor 514 through the receptacle 521. The supply sensor 514 also may determine a value of the supply pressure in response to the measured amount of strain.

[0088] The feedback system 500 may provide a signal for one or more operating states. For example, the feedback system 500 may provide a generic alarm for a leakage condition, a blockage condition, or a canister full condition. In another example, the feedback system 500 may illuminate the LED 511 if the pressure sensor 504 measures a control pressure within a therapeutic range (TR) of the therapy pressure. In some embodiments, the target pressure (TP) may be a pressure of about -125 mm Hg, for example, and the therapeutic range may have a tolerance of about 10 mm Hg above or below the target pressure (TP), i.e., a therapeutic range (TR). As used herein, a pressure exceeding an upper limit of the therapeutic range refers to a reduced pressure that is greater than the therapeutic range. Referring to Figure 2A, for example, if the therapy pressure is -125 mm Hg, the upper limit of the therapeutic range is -135 mm Hg indicated by the dashed line 221. The reduced pressure during the first five minute“on-cycle” remains within the therapeutic range (TR) because the reduced pressure does not exceed the upper limit of the therapeutic range, whereas a reduced pressure of -131 mm Hg indicated at 223 during the second five minute on-cycle would exceed the upper limit of the therapeutic range. Similarly, as used herein, a pressure exceeding a lower limit of the therapeutic range refers to a reduced pressure that is less than the therapeutic range. For example, if the therapy pressure is -125 mm Hg, the lower limit of the therapeutic range is -115 mm Hg indicated by the dashed line 222. The reduced pressure during the first five minute“on-cycle” remains within the therapeutic range (TR) because the reduced pressure is not exceed the lower limit of the therapeutic range, whereas a reduced pressure of -114 mm Hg indicated at 224 during the second five minute on-cycle would exceed the lower limit of the therapeutic range.

[0089] In some embodiments, if the control pressure determined by the pressure sensor 504 is within the therapeutic range of the therapy pressure, a signal may be communicated to the LED 511, causing the LED 511 to illuminate. The illumination of the LED 511 may continue so long as the control pressure in the control chamber 312 is within the therapeutic range. If the control pressure in the control chamber 312 exceeds the upper limit or the lower limit of the therapeutic range, the feedback system 500 may no longer illuminate the LED 511. In this manner, the feedback system 500 may signal an operating state of the reduced-pressure therapy system 400 is an application of reduced pressure.

[0090] In some embodiments, if the pressure communicated to the pressure sensor 504 through the tube 510 is within the therapeutic range of the therapy pressure, the pressure sensor 504 may generate a signal that completes an electrical circuit on the printed circuit board 502. Completion of the electrical circuit may provide current to the LED 511, causing the LED 511 to illuminate. In other embodiments, if the pressure communicated to the pressure sensor 504 through the tube 510 is within the therapeutic range of the therapy pressure, the pressure sensor 504 may generate a signal that interrupts an electrical circuit on the printed circuit board 502. In this embodiment, interruption of the circuit may prevent current from reaching the LED 511 so that the LED 511, which may have been illuminated, will cease illumination.

[0091] In some embodiments, the therapy pressure may be selected during the manufacturing of the feedback system 500. For example, the therapy pressure may be hardwired to the printed circuit board 502. In other embodiments, the printed circuit board 502 may include a controller or central processing unit having the therapy pressure programmed into the controller or central processing unit. In other embodiments, the feedback system 500 may include an input device, such as a switch, a dial, or a keyboard, for example, that may permit an operator to input the therapy pressure.

[0092] In still other embodiments, the LED 511 may be capable of illumination in multiple wavelengths so that different colors may be illuminated in response to different control pressures determined by the pressure sensor 504. In these embodiments, the colors may be coordinated to a particular control pressure determined by the pressure sensor 504 so that the LED 511 may provide a greater range of information outside of whether or not the control pressure is within the therapeutic range of the therapy pressure. In some embodiments, all three LEDs 511, 512, and 513 may be utilized to display different colors indicative of different control pressures provided by the pressure sensor 504 such as, for example, a green LED, a blue LED, and a red LED. For example, the feedback system 500 may illuminate a red LED if the control pressure determined by the pressure sensor 504 exceeds the upper limit of the therapeutic range of the therapy pressure, indicating an overpressure condition. The feedback system 500 may illuminate a blue LED if the pressure determined by the pressure sensor 504 exceeds a lower limit of the therapeutic range of the therapy pressure, indicating a leak condition. The feedback system 500 may illuminate a green LED if the pressure determined by the pressure sensor 504 is within the therapeutic range of the therapy pressure, indicating an application of reduced-pressure therapy. In other embodiments, a single LED may be utilized to selectively emit light having a blue tone, a red tone, a green tone, or other colors.

[0093] In still other embodiments, the regulator 600 may include a potentiometer 612 communicatively coupled to the adjustment shaft 336 and the dial 338. The potentiometer 612 may be a three-terminal resistor, for example, with a sliding contact that forms an adjustable voltage divider. In some embodiments, the feedback system 500 may further comprise a controller 615 electrically coupled to the output of the potentiometer 612 and configured to provide signals from the potentiometer 612 to the processor 503. The potentiometer 612 may provide a variable voltage output to the controller 615 in response to operation of the sliding contact. In some embodiments, the potentiometer 612 may be calibrated to provide a voltage signal that corresponds to the axial position of the dial 338 relative to the adjustment shaft 336. When the dial 338 is moved relative to the adjustment shaft 336, the voltage signal provided by the potentiometer 612 may change. In some embodiments, the voltage signal provided by the potentiometer 612 may be related to the therapy pressure.

[0094] The voltage output signal received by the processor 503 and stored as the therapy pressure (TP) may provide corresponding output signals to the LCD 508 and/or the wireless communication module 505 to adjust the operation of the regulator 600 in response to a change in therapy pressure. For example, if the dial 338 is positioned so that a therapy pressure of about -125 mm Hg may be desired, the voltage signal communicated to the processor 503 may cause the processor 503 to adjust the output of the LCD 508 so that the LCD 508 provides no indication until the control sensor 504 determines that a control pressure of about -125 mm Hg has been communicated through the monitor port 323. If the dial 338 is then positioned so that a therapy pressure of -115 mm Hg may be desired, the voltage signal communicated to the processor 503 by the potentiometer 612 may cause the processor 503 to adjust the output of the LCD 508 so that the LCD 508 does not provide an indication until the pressure sensor 504 provides a signal indicating that a control pressure of about -115 mm Hg has been communicated through the monitor port 323.

[0095] In some embodiments, the valve member 322 may have a metallic component capable of closing an electrical circuit when opening to allow supply pressure to be communicated to the tissue site. For example, the contact node 325 of the valve member 322 may comprise a metallic element that is electrically conductive and closes a valve circuit (not shown) when the contact node 325 of the valve member 322 engages the beveled edge of the valve seat 324 of the charging port 316 in a closed position. If engaged in such a manner, the valve member 322 can substantially prevent fluid communication through the passage 317 of the charging port 316. When the valve member 322 disengages the contact node 325 from the valve seat 324 in an open position, the valve circuit opens and fluid communication through the passage 317 of the charging port 316 continues. In some embodiments, an contact output of the valve circuit (not shown) may be electrically coupled to the processor 503 to provide pulse rate signals indicating the cycling of on-off pulses over time as the valve member 322 of the regulator 600 opens and closes. In some embodiments, the pulse rate data provided to the processor 503 may provide an indication of the work accomplished by the regulator 600 based upon the frequency of the pulses or the rate at which the regulator valve 326 opens and closes.

[0096] In some embodiments, the pulse rate data may provide an indication that a leak condition has occurred and/or that a canister full/blockage condition has occurred. More specifically, if the regulator 600 is open for a continuous period of time such as, for example, greater than 10 minutes between measured pulses, and the processor 503 determines that the control pressure determined by the control sensor 504 exceeds the lower limit of the therapeutic pressure range (TR), then the processor 503 can display on the LCD 508 that a leak condition has occurred. However, if the regulator 600 remains closed for a set period of time such as, for example, greater than 10 minutes duration of measured pulses, then the processor 503 can display on the LCD 508 that either a blockage condition or a full canister condition exists because there is no fluid flow and/or because the supply pressure exceeds the upper limit of the therapeutic range (TR). In some embodiments, the pulse rate signals may fluctuate at a higher frequency such that several pulses may occur within the on-time of a therapy cycle creating a pressure ripple such as, for example, the pressure variations indicated by solid line 201 during the first five minute on-time as shown in Figure 2A. In some embodiments, the processor 503 may be configured to monitor the magnitude of the pulse rate signals that may provide an indication of the volume of fluid in the container 403 and the associated tubes 408, 410, and 412. If the container 403 is full, the magnitude of the pulse rate signals may be magnified and detectable by the control sensor 504 so that the processor 503 can display on the LCD 508 that a canister full condition has occurred. However, if the container 403 is not full, the magnitude of the pulse rate signals will be reduced indicating that the container 403 is still partially empty.

[0097] Referring to Figure 7, a schematic cross-section of a regulator 700 is shown that is a modification of the regulator 300 and/or 600 for use with the feedback system of Figure 5 as described above. In some embodiments, the regulator 700 may comprise a linear actuator assembly that includes both a linear actuator and a feedback device such as, for example, linear actuator assembly 710. In some embodiments, the linear actuator assembly 710 may comprise a linear actuator that may include a drive motor 711 operatively coupled by a gear assembly 712 to a driveshaft 713. The driveshaft 713 may be operably coupled to the stem 328 for providing linear motion. The linear actuator assembly 710 may further comprise a potentiometer 714 operatively coupled to the driveshaft 713 to provide feedback regarding the position of the driveshaft 713 and correspondingly the position of the stem 328 and the position of the valve member 322 as described above. The drive motor 711 may be electrically coupled to an output of the processor 503 for receiving signals from the processor 503 responsive to pressures measured by the pressure sensors 504 and 514. In some embodiments, the potentiometer 714 may be substantially similar in operation to the potentiometer 612 in operation as described above. In some embodiments, the linear actuator and the potentiometer 714 may be combined in a single component referred to in the art as a linear actuator with feedback such as, for example, those models available from Glideforce (e.g., Model No. LACT), Acttonix, and many others depending on the load that can be applied to the linear actuator, the no-load speed, and the stroke length required to operate the valve member 322.

[0098] In some embodiments, the regulator 700 may be a modified version of the regulator 300 that includes the linear actuator assembly 710 that may provide significant advantages over the more simple mechanically regulated system including the adjustable shaft 336, the adjustable cap 337, and the dial 338. For example, the linear actuator provides a closed-loop control system for automatically adjusting the stem 328 and the valve member 322 rather than relying on a user or operator to adjust the stem 328 accurately and on time. In those embodiments of the regulator 700 that include the potentiometer 714 in addition to the linear actuator assembly 710, operation of the regulator 700 would be greatly simplified because the operator would not need to constantly monitor signals provided by the various indicators such as, for example, the LCD 508, and then manually adjust the dial 338 when necessary in response to those indicators. The linear actuator provides additional protection by virtue of the quickness and speed in which the linear actuator can respond to adjust the stem 328 and the valve member 322 without significant therapeutic delays. The linear actuator provides further advantages of providing an immediate response that may be confirmed subsequently by the indicators being modified by an operator. For example, the linear actuator may adjust the regulator 700 to ensure that the therapy pressure is within the therapeutic range as described above and/or that operating states have been properly identified which can then be confirmed by observing the indicators.

[0099] In some embodiments, the printed circuit board 502 may include a power button that may selectively provide voltage or potential to the printed circuit board 502. In some embodiments, the power button may be an electric switch that, if opened, interrupts a circuit on the printed circuit board 502. In other embodiments, the power button may take the form of a pull tab positioned between the battery 506 and a contact terminal on the printed circuit board 502. If the pull tab is removed, a circuit on the printed circuit board 502 may be closed.

[00100] The printed circuit board 502 may further include a speaker (not shown) coupled to the printed circuit board 502 or the processor 503. In these embodiments, the signal may be an audible alarm. If the pressure changes by a predetermined amount, the printed circuit board 502 may supply the speaker with a current to cause the speaker to provide an audible alarm. In some embodiments, the printed circuit board 502 may include an audio pause button. The audio pause button may permit the audio capability of the printed circuit board 502 to be muted.

[00101] In some embodiments, the dressing may be supplied with reduced pressure, i.e., a manifold pressure, such that the pressure at the dressing transitions from an ambient pressure to the supply pressure. The changing pressure may be fluidly communicated to the control sensor 504 through the control chamber 312. The control sensor 504 may generate a signal to the processor 503 corresponding to the changing control pressure determined by the control sensor 504. In response, the processor 503 of the feedback system 500 may display a numerical value on the LCD 508 corresponding to the control pressure determined by the control sensor 504. In some embodiments, the numerical value may change as the control pressure changes. It should be understood, that any signals provided by outputs of the processor 503 also may be transmitted by the wireless communication module 505 to other remote devices such as, for example, the remote device 530. Thus, any reference herein to signals being provided to the LCD 508 also applies to signals being provided to other devices not mounted on the printed circuit board 502. Moreover, any pressure measurements provided by either the control sensor 504 or the supply sensor 514 to the processor 503 may be stored therein for further processing relating to the target pressure (TP), the therapeutic range (TR), and the operating states of the regulators 300, 600, and 700 including a current pressure, a pressure differential, a leak condition, a blockage condition, a canister full condition, or an overpressure condition, for example.

[00102] The feedback system 500 may provide additional information regarding the provision of reduced-pressure therapy using the processor 503, the supply sensor 514, and the control sensor 504. In some embodiments, the processor 503 may be configured to monitor a difference between the control pressure determined by the control sensor 504 and the supply pressure determined by the supply sensor 514. For example, when a dressing is first applied to a tissue site, the regulator 700 may be used in a draw-down process. In the draw-down process, the pressure at the dressing, the manifold pressure, is reduced from an ambient pressure to the supply pressure that in some embodiments may be set to a target pressure (TP) as described above. The processor 503 may be configured to monitor the control sensor 504 and the supply sensor 514 to determine if the draw-down process is occurring within desired parameters such as, for example, the target pressure (TP) and the therapeutic range (TR). In some embodiments, the processor 503 may be configured to determine whether the control pressure determined by the control sensor 504 has reached the desired therapy pressure that may be determined by setting the target pressure (TP) in the processor 503 at the desired therapy pressure. In such embodiments, the desired therapy pressure and the target pressure (TP) may be the same pressure values. In some embodiments, the processor 503 may be configured to determine the difference between the control pressure determined by the control sensor 504 and a supply pressure determined by the supply sensor 514 and store the pressure difference or pressure differential for display on the LCD 508. In this manner, the feedback system 500 may signal an operating state of the dressing draw-down. Additionally, the linear actuator assembly 710 may adjust the regulator valve 326 to ensure that the therapy pressure is within the therapeutic range as described above and/or that operating states have been properly identified which can then be confirmed by observing the LCD 508.

[00103] In some embodiments, if the control pressure is within the therapeutic range (TR) of the target pressure (TP), the processor 503 may be configured to continue monitoring the control pressure provided by the control sensor 504 and the supply pressure determined by the supply sensor 514. If the processor 503 determines that the control pressure determined by the control sensor 504 exceeds the lower limit of the therapeutic pressure range (TR) of the target pressure (TP), and the supply pressure determined by the supply sensor 514 is within the therapeutic range of the target pressure (TP), then the processor 503 can display on the LCD 508 that a leak condition has occurred. For example, in some embodiments, the reduced-pressure therapy system 400 may be leaking between the supply port 318 and the control port 321. Similarly, if both the control sensor 504 and the supply sensor 514 determine that the control pressure and the supply pressure, respectively, exceed the lower limit of the therapeutic range of the therapy pressure, then the processor 503 can display on the LCD 508 that a leak condition has occurred. For example, in some embodiments, the reduced pressure therapy system may be leaking between the reduced- pressure source 402 and the source port 314. In some embodiments, the processor 503 also may provide an output signal to the linear actuator assembly 710 indicating that a leak condition has occurred and adjusting the target pressure (TP) to compensate for the leak condition in order to achieve the desired therapy pressure. In other embodiments, the processor 503 may provide an output signal to the reduced-pressure source 402 indicating that a leak condition has occurred and increasing the supply pressure being provided by the reduced-pressure source 402 to compensate for the leak condition in the system 400.

[00104] In some embodiments, if the processor 503 determines that the control pressure provided by the control sensor 504 remains static while the supply pressure provided by the supply sensor 514 changes, such as an increase or decrease in pressure, the processor 503 can display on the LCD 508 that a blockage condition has occurred. For example, the supply sensor 514 may provide a signal indicating that the supply pressure exceeds the upper limit of the therapeutic range of the therapy pressure. If the control sensor 504 provides a signal indicating that the control pressure remains within the therapeutic range of the therapy pressure, the processor 503 can display on the LCD 508 and/or any remote device that the operating state of the reduced-pressure therapy system 400 is a blockage condition. In some embodiments, the processor 503 also may provide an output signal to the linear actuator assembly 710 indicating that a blockage condition has occurred and activating the regulator valve 326 to close the valve member 322 to maintain the desired therapy pressure. In other embodiments, the processor 503 may provide an output signal to the reduced-pressure source 402 indicating that a blockage condition has occurred and decreasing the supply pressure being provided by the reduced-pressure source 402 to identify the location of the blockage in the system 400. [00105] In some embodiments, the processor 503 may be configured to determine if a canister full condition has occurred. For example, if the supply sensor 514 provides several signals to the processor 503 that is configured to determine that the supply pressure is rising during a preset time at a rate that exceeds a preset rate tolerance, and the control sensor 504 provides a signal indicating that the control pressure in the control chamber 312 remains static, the processor 503 can provide an output signal for display on the LCD 508 or remote device indicating that a canister full condition has occurred. In some embodiments, the processor 503 may provide an output signal to the reduced-pressure source 402 indicating that a canister full condition has occurred and turning off the supply pressure being provided by the reduced-pressure source 402 so that the system pressure is disabled. In some embodiments, the system pressure remains disabled and the alarms continue, e.g., visual and/or audible, until the user or clinician empties or replaces the container 403. In other embodiments, the processor 503 also may provide an output signal to the linear actuator assembly 710 indicating that a canister full condition has occurred and activating the regulator valve 326 to open the valve member 322 to vent the negative pressure from the system to equalize the pressure within the container 403 and returning the pressure to ambient pressure.

[00106] The feedback system 500 may further include circuitry or devices configured to track the level of pressure delivered over a period of time. In some embodiments, the processor 503 and peripheral memory devices may be configured to store the level of pressure delivered over a period of time such as, for example, the five-minute on- times during the therapy cycle shown in Figure 2A. By tracking a level of pressure over a period of time, the processor 503 may be configured to determine how a pressure in a particular chamber, such as the control pressure in the control chamber 312, is changing during the application of reduced-pressure therapy. In some embodiments, the processor 503 may be further configured to provide an output showing a histogram of the level of pressures over time. In some embodiments, the feedback system 500 may further include circuitry, devices, or software to display the histogram of pressures on the LCD 508 or other remote device such as, for example, a mobile phone, display monitor or a printer.

[00107] The processor 503 may also be configured to determine a pressure differential between a manifold pressure at a dressing and a pressure supplied to the regulator 700 to provide an indication of the efficiency of the system such as, for example, the system 400. For example, the processor 503 may be configured to determine the supply pressure in the supply chamber 310 with the supply sensor 514, and also the control pressure in the control chamber 312 with the control sensor 504. The processor 503 may be configured to determine the difference between the supply pressure in the control pressure and display the difference as a pressure differential on the LCD 508 and other remote devices. The processor 503 may be further configured to provide an output signal to the linear actuator assembly 710 for adjusting the regulator valve 326 to achieve the desired therapy pressure to compensate for the efficiency of the system.

[00108] The processor 503 may be further configured to determine when an overpressure condition has occurred. For example, the processor 503 may be configured to determine the supply pressure in the supply chamber 310 with the supply sensor 514, and also the control pressure in the control chamber 312 with the control sensor 504. If the supply pressure determined by the supply sensor 514 and the control pressure determined by the control sensor 504 both exceed the upper limit of the therapeutic range (TR) of the therapy pressure, the processor 503 may indicate that an overpressure condition has occurred. An overpressure condition may be caused in part by a malfunction of the regulator 700 permitting excess reduced pressure to be supplied to the dressing. In some embodiments, the processor 503 may provide an output signal to the reduced-pressure source 402 indicating that a overpressure condition has occurred and immediately turning off the supply pressure being provided by the reduced-pressure source 402 until the source of the problem can be identified by a user.

[00109] In some embodiments, a secondary regulator may be positioned in-line between a reduced-pressure source and the regulator 700 to purge blockages. A secondary regulator may include a release mechanism allowing the secondary regulator to flood the charging chamber 308 with a higher pressure in an attempt to eliminate blockages. Feedback can be provided to an operator that a blockage is cleared as described above. Additionally, the system may have a relief valve to ensure that once a blockage is cleared pressure at a tissue site may not rise above a predetermined safe limit.

[00110] In some embodiments, the desired therapy pressure, the target pressure (TP), and/or the therapy range (TR) may be selected during the manufacturing of the feedback system 500. For example, the therapy pressure may be pre-programmed into the processor 503. In other embodiments, the processor 503 may include a controller or other peripheral device having the therapy pressure programmed into the controller or peripheral device. In other embodiments, the feedback system 500 may include an input device, such as a switch, a dial, or a keyboard, for example, that may permit an operator to input the therapy pressure. For example, the feedback system 500 may include the switch 518 and/or the switch 519 electrically coupled to the processor 503 for setting the processor with the desired therapy pressure, the target pressure (TP), and/or the desired therapeutic range (TR) as described above. Alternatively, the processor 503 may be programmed to receive inputs setting the desired therapy pressure and/or the desired therapeutic range provided by the wireless communication module 501 that are received from an operator using the remote device 532 input these values. In still other embodiments, the processor 503 may receive a signal from the potentiometer 612 that the processor 503 may use to determine the desired therapy pressure. In yet other embodiments, the processor 503 may be further configured to process the signal from the potentiometer 612 and provide an output signal to the linear actuator assembly 710 to adjust the potentiometer 612 to achieve the desired therapy pressure.

[00111] The feedback system 500 and the linear actuator assembly 710 may be a low cost solution that is tailored for specific regions and markets. For example, by using a single pressure sensor such as, for example, the control sensor 504, and an LED indicator, the cost may be substantially reduced. If additional functionality is desired, additional components, such as additional LEDs or pressure sensors such as, for example, the supply sensor 514, may be added to provide additional information. In other embodiments, starting with a simple mechanical regulator structure for use with a wall-suction source of reduced pressure and then upgrading the system to include a feedback system comprising a linear actuator for closed-loop operation as described above can be a more cost-effective method for providing such care. For example, the mechanical regulator may be modified to include the flexible diaphragms assemblies 602 and 603 for coupling the control chamber 312 and the supply chamber 310, respectively, to the control sensor 504 and the supply sensor 514. The mechanical regulator may be modified further to replace the mechanical adjustment shaft 336 with the linear actuator assembly 710 and the potentiometer 612. In some embodiments, the printed circuit board 502 may be fastened to the mechanical register so that the pressure sensors are coupled as a single component to both of the diaphragm assemblies as described above and assembled with the linear actuator assembly to enclose the original mechanical regulator as an upgrade.

[00112] In some forms, the feedback systems may provide generic visual feedback to indicate whether reduced-pressure therapy is being effectively administered using a wall- suction source. Such generic visual feedback may be provided directly to remote devices such as mobile phones as indicated above to ensure that a user or an operator can conveniently monitor the negative pressure being provided by a wall-suction source while tending to other patients or users. By creating different functional configurations, the feedback systems can be modified to fit a variety of different needs depending on the nature of the therapy, costs, and other factors.

[00113] The devices and systems described herein may provide variable negative pressure settings to an operator, feedback to an operator on leak conditions, feedback to an operator on blockage conditions, feedback to an operator on canister full conditions, may be low cost, may be disposable, may be for single patient use or reusable, and may be highly configurable.

[00114] It should be apparent from the foregoing that systems, methods, and apparatuses having significant advantages has been described. While shown in only a few forms, the systems, methods, and apparatuses illustrated are susceptible to various changes, modifications, and uses encompassed within the claims that follow.

Claims

CLAIMS We claim:

1. A reduced-pressure system for providing negative pressure to a dressing, comprising:

a regulator comprising:

a supply chamber adapted to be fluidly coupled to the dressing, a control chamber adapted to be fluidly coupled to the dressing, a charging chamber fluidly coupled to the supply chamber through a port, and a regulator valve coupled to the control chamber and operable to reciprocate at least partially within the control chamber to control fluid

communication through the port based on a differential between a control pressure in the control chamber and a therapy pressure; and a feedback system comprising:

a control sensor adapted to be fluidly coupled to the control chamber and

having an output for providing a control signal indicative of a control pressure,

a processor having an input electrically coupled to the output of the control sensor for receiving the control signal and adapted to indicate an operating state of the reduced-pressure system based on the control signal, the processor further having an output adapted to provide an operational signal for providing an indication of the operating state.

2. The reduced-pressure system of claim 1, wherein the processor provides an operational signal indicating that the operating state is an application of reduced pressure to deliver a therapy pressure.

3. The reduced-pressure system of claim 2, wherein the processor has an input adapted to receive a signal setting the therapy pressure.

4. The reduced-pressure system of claim 3, wherein the regulator further comprises a potentiometer communicatively coupled to the regulator valve and adapted to provide the therapy pressure.

5. The reduced-pressure system of claim 2, wherein the processor provides an operational signal indicating that the control pressure is within a therapy range of the therapy pressure.

6. The reduced-pressure system of claim 5, wherein the processor has an input adapted to receive a signal setting the therapy range.

7. The reduced-pressure system of claim 5, wherein the processor is adapted to provide a signal indicating that the control pressure is outside therapy range.

8. The reduced-pressure system of claim 1, wherein the feedback system further comprises a supply sensor adapted to be fluidly coupled to the supply chamber and having an output for providing a supply signal indicative of a supply pressure, and wherein the processor further comprises an input electrically coupled to the output of the supply sensor for receiving the supply signal and adapted to indicate an operating state of the reduced- pressure system based on the supply signal.

9. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state occurring during a draw-down process, and wherein the processor is further adapted to provide an indication of a differential pressure by comparing the control pressure to the supply pressure.

10. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state for identifying a leak condition, and wherein the processor is further adapted to compare the control pressure and the supply pressure to a therapy range having a lower limit and an upper limit.

11. The reduced-pressure system of claim 10, wherein the processor is further adapted to provide an indication of the leak condition when the control pressure is less than the lower limit and the supply pressure is within the therapy range.

12. The reduced-pressure system of claim 10, wherein the processor is further adapted to provide an indication of the leak condition when the control pressure in the supply pressure are less than the lower limit.

13. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state for identifying a blockage condition, and wherein the processor is further adapted to provide an indication of a blockage when the control pressure remains static while the supply pressure changes.

14. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state for identifying a blockage condition, and wherein the processor is further adapted to compare the control pressure and the supply pressure to a therapy range having a lower limit and an upper limit.

15. The reduced-pressure system of claim 14, wherein the processor is further adapted to provide an indication of the blockage condition when the supply pressure exceeds the upper limit and the control pressure remains within the therapy range.

16. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state for identifying a canister full condition, and wherein the processor is further adapted to provide an indication of a canister full when the supply pressure rises during a preset time that exceeds a preset tolerance and the control pressures remains static during the preset time while the supply pressure changes.

17. The reduced-pressure system of claim 8, wherein the feedback system indicates the operating state for identifying an overpressure condition, and wherein the processor is further adapted to compare the control pressure and the supply pressure to a therapy range having a lower limit and an upper limit.

18. The reduced-pressure system of claim 17, wherein the processor is further adapted to provide an indication of the overpressure condition when both the supply pressure and the control pressure exceed the upper limit.

19. The reduced-pressure system of any of claims 1 or 8, further comprising a light emitting diode electrically coupled to the output of the processor for providing an indication of the operating state.

20. The reduced-pressure system of any of claims 1 or 8, further comprising a liquid crystal display screen electrically coupled to the output of the processor for providing an indication of the operating state.

21. The reduced-pressure system of any of claims 1 or 8, further comprising a wireless communication device electrically coupled to the output of the processor for providing an indication of the operating state.

22. The reduced-pressure system of any preceding claim, further comprising a wall-suction source fluidly coupled to the charging chamber to provide reduced pressure.

23. An apparatus for providing negative pressure, comprising:

a regulator comprising:

a supply chamber,

a control chamber,

a charging chamber fluidly coupled to the supply chamber through a port, and a regulator valve coupled to the control chamber and operable to reciprocate at least partially within the control chamber to control fluid

a control sensor adapted to be fluidly coupled to the control chamber and

a processor having an input electrically coupled to the output of the control sensor and adapted to indicate an operating state of the apparatus based on the control signal, the processor further having an output adapted to provide an operational signal for providing an indication of the operating state.

24. The apparatus of claim 23, wherein the feedback system further comprises a supply sensor adapted to be fluidly coupled to the supply chamber and having an output for providing a supply signal indicative of a supply pressure, and wherein the processor further comprises an input electrically coupled to the output of the supply sensor and adapted to indicate an operating state of the apparatus based on the supply signal.

25. The apparatus of claim 24, further comprising a wireless communication device electrically coupled to the output of the processor for providing an indication of the operating state to a remote wireless device.

26. The apparatus of claim 24, further comprising a wireless communication device electrically coupled to the output of the processor, wherein the processor has an input adapted to receive a signal from a remote wireless device for setting a therapy pressure.

27. The apparatus of claim 24, further comprising a wireless communication device electrically coupled to the output of the processor, wherein the processor has an input adapted to receive a signal from a remote wireless device for setting a therapy range.

28. A method for regulating therapeutic pressure in a reduced-pressure therapy system, the method comprising:

reducing a charging pressure in a charging chamber below a therapy pressure; regulating fluid communication between a supply chamber and the charging chamber based on a differential between a control pressure in a control chamber and the therapy pressure;

generating a control signal corresponding to the control pressure as measured by a pressure sensor; and

signaling an operating state of the reduced-pressure therapy system in response to receiving the control signal.

29. The method of claim 28, wherein signaling the operating state comprises illuminating a light emitting diode.

30. The method of claim 28, wherein signaling the operating state comprises operating a liquid crystal display to present the operating state.

31. The method of claim 30, wherein the operating state is at least one of the control pressure, the supply pressure, a differential between the control pressure and the supply pressure, a leak condition, a blockage condition, a canister full condition, and an overpressure condition.

32. The method of any of claims 28-31, wherein signaling the operating state comprises signaling that the operating state is a leak condition if the control pressure is an absolute pressure that is greater than the therapy pressure.

33. The method of any of claims 28-31, wherein signaling the operating state comprises signaling that the operating state is an overpressure condition if the control pressure is an absolute pressure that is less than the therapy pressure.

34. The method of any of claims 28-31, further comprising generating a supply signal corresponding to the supply pressure as measured by a pressure sensor.

35. The method of claim 34, further comprising:

comparing the control pressure to the supply pressure for a time period; and if the control pressure is an absolute pressure greater than the supply pressure

during the time period, signaling that the operating state is a leak condition.

36. The method of claim 34, wherein if the control pressure and the supply pressure during a time period are absolute pressures that are greater than the therapy pressure, signaling that the operating state is a leak condition.

37. The method of claim 34, further comprising:

comparing the control pressure to the supply pressure for a time period; and if the control pressure remains within a therapeutic range of the therapy pressure and the supply pressure rises during the time period, signaling that the operating state is a canister full condition.

38. The method of claim 34, further comprising:

comparing the control pressure to the supply pressure for a time period; and if the control pressure does not change in response to a change in the supply

pressure, signaling that the operating state is a blockage condition.

39. The method of claim 34, wherein if the control pressure and the supply pressure are absolute pressures that are less than the therapy pressure, signaling that the operating state is an overpressure condition.

40. The method of any of claims 28-39, further comprising fluidly coupling a wall-suction source to the charging chamber to supply reduced pressure to the charging chamber.

41. An apparatus for providing negative pressure to a dressing, comprising:

a regulator comprising:

a first chamber having a supply port for receiving negative pressure, a second chamber adapted to sense a control pressure at the dressing, and a valve operably coupled to the second chamber to control fluid flow through the supply port based on a differential pressure between the control pressure in the second chamber and a therapy pressure; and

a feedback system comprising:

a control sensor having an input coupled to the second chamber and an output for providing a control signal indicative of the control pressure, and a processor having an input coupled to the output of the control sensor and adapted to indicate an operating state based on the control signal, the processor further having an output adapted to provide an operational signal to provide an indication of the operating state.

42. The apparatus of claim 41, further comprising a diaphragm disposed between the second chamber and the input of the control sensor and adapted to prevent fluid from flowing out of the second chamber.

43. The apparatus of claim 41, wherein the feedback system further comprises a supply sensor having an input coupled to the first chamber and an output for providing a supply signal indicative of a supply pressure within the first chamber, and wherein the processor further comprises an input coupled to the output of the supply sensor and adapted to indicate an operating state of the apparatus based on the supply signal.

44. The apparatus of claim 43, further comprising a diaphragm disposed between the first chamber and the input of the supply sensor and adapted to prevent fluid from flowing out of the first chamber.

45. The apparatus of claim 43, further comprising a wireless communication device coupled to the output of the processor for providing an indication of the operating state to a remote wireless device.

46. The apparatus of claim 43, further comprising a wireless communication device coupled to the output of the processor, wherein the processor has an input adapted to receive a signal from a remote wireless device for setting a therapy pressure.

47. The apparatus of claim 43, further comprising a wireless communication device coupled to the output of the processor, wherein the processor has an input adapted to receive a signal from a remote wireless device for setting a therapy range.

48. The apparatus of claim 43, wherein the processor provides an operational signal indicating that the operating state is an application of reduced pressure to deliver a therapy pressure.

49. The apparatus of claim 48, wherein the processor has an input adapted to receive a signal setting the therapy pressure.

50. The apparatus of claim 49, wherein the regulator further comprises a potentiometer communicatively coupled to the valve and adapted to be adjusted to provide the therapy pressure.

51. An apparatus for providing negative pressure to a dressing, comprising:

a regulator having a supply port adapted to be coupled to a source of negative

pressure and sense a supply pressure, a control port adapted to be coupled to the dressing and sense a control pressure, and a valve configured to control fluid flow through the supply port based on a differential pressure between the control pressure and a therapy pressure; and a feedback system comprising:

a control sensor having an input adapted to sense the control pressure and an output for providing a control signal indicative of the control pressure, and

a processor having an input coupled to the output of the control sensor and adapted to indicate an operating state based on the control signal, the processor further having an output adapted to provide an operational signal to provide an indication of the operating state.

52. The apparatus of claim 51, further comprising a wireless communication device electrically coupled to the output of the processor for providing an indication of the operating state to a remote wireless device.

53. The apparatus of claim 51, wherein the feedback system further comprises a supply sensor having an input adapted to sense the supply pressure and an output for providing a supply signal indicative of the supply pressure, and wherein the processor further comprises an input coupled to the output of the supply sensor and adapted to indicate an operating state of the apparatus based on the supply signal.

54. The apparatus of claim 53, further comprising a wireless communication device electrically coupled to the output of the processor for providing an indication of the operating state to a remote wireless device.

55. The apparatus of claim 53, further comprising a wireless communication device coupled to the output of the processor, wherein the processor has an input adapted to receive a signal from a remote wireless device for setting a pressure value to a target value.

56. The apparatus of claim 55, wherein the pressure value is the therapy pressure.

57. The apparatus of claim 55, wherein the pressure value is a pressure of a therapy range associated with the therapy pressure.

58. The apparatus of claim 55, wherein the pressure value is the therapy pressure and wherein the regulator further comprises a linear actuator operatively coupled to the valve and communicatively coupled to the processor, the linear actuator adapted to adjust the therapy pressure to the target value in response to the signal from the remote wireless device.

59. The apparatus of claim 58, wherein the regulator further comprises a potentiometer operatively coupled to the valve and communicatively coupled to the processor, and adapted to provide a modified signal to the processor indicating that the therapy pressure is about equal to the target value.

60. The apparatus of claim 59, wherein the wireless communication device is adapted to send the modified signal to the remote wireless device.