WO2009086580A1

WO2009086580A1 - Negative pressure treatment device

Info

Publication number: WO2009086580A1
Application number: PCT/AU2008/001682
Authority: WO
Inventors: Michael Gordon Winlo; Benjamin Phillip Readhead
Original assignee: Cerulean Medical Pty Ltd
Priority date: 2008-01-07
Filing date: 2008-11-13
Publication date: 2009-07-16

Abstract

The invention is related to the field of negative pressure treatment, particularly, a device capable of providing such treatment for wounds and other conditions susceptible to amelioration with negative pressure. Methods of using the device, and performing such treatment, are also included. The device of the invention comprises at least two lumens; one lumen is dedicated to extracting fluids and other non-gaseous materials, while the other lumen is dedicated to extracting gaseous materials. Use of these lumens permits non-rigid waste collection vessels, with advantages associated therewith.

Description

NEGATIVE PRESSURE TREATMENT DEVICE

Cross-Reference to Related Applications

This application is related to and claims the benefit of U.S. Provisional Application No. 61/010,042, filed on January 7, 2008, which is incorporated herein by reference.

Field of the Invention

The invention is related to the field of negative pressure treatment, particularly, a device capable of providing such treatment for wounds and other conditions susceptible to amelioration with negative pressure. Methods of using the device, and performing such treatment, are also included.

Background of the Invention

There are many ways of interacting with a bodily site for various purposes, such as for medical or treatment purposes. For example, in negative pressure wound therapy ("NPWT"), negative pressure is applied to a wound in order to treat the wound. Alternatively, in the context of breast pumping, negative pressure is applied to a nipple of a breast, hi the context of aspiration, negative pressure may be applied to a variety of locations, such as a respiratory tract, a gastrointestinal tract, a peritoneal space, a mediastinal space, a pleural space, a subdural space, or subarachnoid space.

In the case of wounds, the suction is usually applied to a wound under a cover placed over the wound and sealed in relation to the edges or periphery of the wound. A source of suction is typically in communication with the wound via tubing connected to the wound cover. When suction is applied, exudate and/or other fluid is removed from the wound and/or the wound environment.

The arrangement of device components differs for different NPWT devices. A NPWT device typically has a device body, a disposable canister for collecting exudate, a disposable tubing assembly, and means for coupling a distal portion of the tubing assembly to the wound. The device body often consists of a housing suitable for being carried or worn by the treatment subject, such as a human patient, for example. The housing typically houses a vacuum source, a venting mechanism, a pressure transducer, a pressure feedback loop, a controller unit, and a power source. An interface, external to the housing, is provided for control of the device and the setting of treatment parameters via external devices. The housing is often designed for attachment of an exudate canister on the outside of the housing. The tubing assembly attached to the canister usually extends toward a wound to be treated.

Treatment variables, such as the cycling of applied pressure and the magnitude of applied pressure, for example, may influence a subject's response to NPWT. A treatment regime may comprise continuous application of negative pressure ("continuous NPWT"), wherein substantially constant pressure conditions are provided at a wound site, or intermittent application of negative pressure ("intermittent NPWT"), wherein varying pressure conditions, anywhere from a condition of absolute vacuum to a condition of atmospheric pressure, for example, are provided at a wound site according to a specified time regime.

Some NPWT systems or devices comprise a pressure transducer for measuring pressure associated with wound treatment. The transducer is typically housed within the body of the treatment device. The transducer is in fluid communication with the wound undergoing treatment and communicates a pressure measurement in a feedback loop for managing further treatment. When the wound site and the transducer are situated at different vertical heights, a column of fluid, such as liquid and/or gas, may accumulate in the treatment device. This column can affect a pressure transducer measurement and, via a feedback loop, can cause a pressure to be applied to the wound that is other than the desired or predicted pressure. Such a situation may arise when an upright or standing subject is wearing a NPWT device on his or her waist for the treatment of a foot ulcer, for example. In such a situation, the pressure transducer and the wound site may be apart by up to about 1 meter in vertical height. Such a separation may lead to an undesirable increase in the pressure applied to the wound via a feedback loop by up to about 80 rnmHg. Some attempts have been made to overcome this problem by using NPWT devices that have separate lumens for removal of fluid and for measurement of pressure.

A typical NPWT system employs a rigid canister, in communication with a source of suction, for the collection of exudate and/or other fluid. In such a system, the source of suction creates a negative pressure in the canister and subsequently any tubing leading to the wound, thereby causing the accumulation of exudate and/or other fluid in the tubing until it is deposited in the rigid canister. The rigid canister is typically in communication with the source of suction via an outlet that should not become occluded if the device is to function normally. As such, it may be desirable or necessary to orient the NPWT device in such a way as to guard against occlusion of the outlet of the rigid canister. Attempts have been made to manage this potential problem via the use of "tilt alarms" in many NPWT devices.

There are further drawbacks associated with NPWT devices that employ a rigid canister. In the use of such a device, there will often be a volume of empty space in the canister. At the beginning of each treatment cycle, vacuum must be sufficient to act on the wound area, the tubing assembly, and on any volume of empty space in the canister to reach the desired target pressure at the beginning of each treatment cycle. A device in which such "dead space" must be evacuated in this manner has an associated noise profile and energy consumption profile that is less than ideal.

Further, when a rigid canister of a NPWT device is partially emptied of its gas, in the formation of negative pressure conditions, gases existing in the dead space are also exhausted to the environment. These gases can be malodorous. As such, it may be difficult for a subject to use or wear such a device discreetly, or free from distress, embarrassment, or personal discomfort.

Still further, in a NPWT device employing a rigid canister, the canister may be a bulky component that contributes significantly to the overall size of the device. This may be an undesirable characteristic, particularly when the NPWT device is to be used as an ambulatory device. A rigid canister that is disposable may also contribute significantly to the bulk of discarded materials associated with NPWT.

Many other means of treating wounds exist, such as the delivery of topical preparations to wounds to aid different parts of the healing process. For example, saline may be delivered to a wound to irrigate the wound and thereby remove wound debris and devitalized tissue, which may be beneficial to the healing of the wound. Other examples of topical preparations that may be delivered to a wound include antiseptics, antibiotics, biological agents, and gaseous oxygen. Currently, there is no widely available clinical device that provides both NPWT treatment and delivery of topical wound-treating facilitators or agents. United States Patent Appln. No. 7,316,672 describes a portable wound treatment apparatus comprising a vacuum source, a tubing member that connects fluidly to a wound and a rigid canister housing for collection of wound exudate.

Development of systems, devices, methods, and/or associated technologies suitable for use in the treatment of wounds is generally desirable. Particularly, the art is in need of improved devices and methods for providing NPWT.

Summary of the Invention

The device of the invention provides advantages in treating a bodily site by removing fluid from a site such as a wound. The negative pressure applied to the site may be that suitable for positively affecting tissue proliferation and/or antisepsis at the site, for example.

The invention is achieved by removing gaseous and nongaseous fluids from a bodily site using separate lumens dedicated to each, which confers substantial advantages over prior negative pressure devices, hi one aspect, the device of the invention provides a negative pressure treatment device for removing material from a bodily site, comprising: a first lumen for removal of a non-gaseous fluid from the site; a chamber, defining an interior space, for drawing the non-gaseous fluid from the first lumen into the interior space; a valve disposed between the first lumen and the chamber to provide unidirectional flow of the nongaseous fluid from the first lumen toward the chamber; a second lumen for removal of a gaseous fluid from the site, said second lumen being operably connected with a vacuum source; and at least one vent for maintaining or releasing a vacuum supplied by the vacuum source. By "vent" it is meant any means by which pressure may be maintained or released. Thus, a vent may be a simple opening to the atmosphere, a spring loaded device for maintaining pressure up to a predetermined level controlled by spring tension, a bulb of compressed gas controllable for normalizing pressure, or the like. hi another aspect, the chamber and vent are removable from the device, and may optionally be constructed as a removable and disposable cassette. hi another aspect, the vent is controlled by a second valve. The chamber is capable of expelling non-gaseous fluid from the interior space, and the chamber may be compressible and decompressible. In another aspect of the invention, material from a bodily site is removed from the site in the absence of a trap. Non-gaseous fluid may be removed regardless of the orientation of the chamber with respect to gravity. The first lumen and the second lumen may be in fluid communication with the site via an intermediary chamber comprising a chamber opening, the chamber opening being in fluid communication with the site.

In another aspect, the device has a cover for placement over the site, wherein the first lumen and the second lumen are in fluid communication with the site via the cover. The cover may have a screen capable of inhibiting collapse of the site when the site is exposed to negative pressure. The cover may form a substantially fluid-impermeable seal with respect to the first lumen and the second lumen.

In another aspect, the device is provided with a vessel in fluid communication with the chamber for collection of non-gaseous fluid therefrom. The vessel may be collapsible. The device of the invention may be used for removal of material from a variety of bodily sites, including wounds, lactating breasts, and other bodily fluids.

In another aspect of the invention, therapeutic agents may be introduced to the site through one of the lumens.

The device of the invention may employ a sensor-based feedback loop system for controlling the application and adjustment of negative pressure.

In another aspect, the invention provides a method of removing material from a bodily site, comprising the step of applying and activating any of the devices of the invention to remove material from the site. Additionally, a therapeutic agent may be administered via a device of the invention contemporaneously or serially with removal of the material.

These and various other aspects, features, and embodiments are further described herein. Any other portion of this application is incorporated by reference in this summary to the extent same may facilitate a summary of subject matter described herein, such as subject matter appearing in any claim or claims that may be associated with this application. Brief Description of the Drawings

Figs. IA- ID, collectively "Fig. 1", are schematic illustrations of embodiments of the device of the invention.

Fig. 2 is a schematic illustration of an embodiment of the device of the invention. Fig. 3 is a schematic illustration of an embodiment of the device of the invention. Fig. 4 is a schematic illustration of an embodiment of the device of the invention. Fig. 5 is a schematic illustration of an embodiment of the device of the invention.

Figs. 6A-6C, collectively "Fig. 6", are schematic illustrations of embodiments of the device of the invention.

Fig. 7 is a schematic illustration of an embodiment of the device of the invention. Fig. 8 is a schematic illustration of an embodiment of the device of the invention. Fig. 9 is a schematic illustration of an embodiment of the device of the invention.

Figs. 1 OA-I OB, collectively "Fig. 10", are schematic illustrations of embodiments of the device of the invention in use by a subject.

Fig. 11 is a plot of a pressure/time curve during a period of active vacuum applied by an embodiment of the device of the invention, during which the vacuum is operating to reduce the pressure at the wound to the target pressure.

Fig. 12 is a schematic illustration of the use of sensors to monitor pressure at a wound, and control changes in pressure, in an embodiment of the device of the invention.

Fig. 13 is a schematic illustration of a portion of the control loop in an embodiment of the device of the invention, illustrating several components of the invention and their interactive connections.

Detailed Description of the Invention

A system or device, method, and associated technology suitable for use in interacting with a bodily site, such as treating a bodily site, is described herein. Additionally, a description of various aspects, features, and embodiments, is provided herein. It will be understood that a word appearing herein in the singular encompasses its plural counterpart, and a word appearing herein in the plural encompasses its singular counterpart, unless implicitly or explicitly understood or stated otherwise. Further, it will be understood that for any given component described herein, any of the possible candidates or alternatives listed for that component, may generally be used individually or in any combination with one another, unless implicitly or explicitly understood or stated otherwise. Additionally, it will be understood that any list of such candidates or alternatives, is merely illustrative, not limiting, unless implicitly or explicitly understood or stated otherwise. Still further, it will be understood that any Fig. or number or amount presented herein is approximate, and that any numerical range includes the minimum number and the maximum number defining the range, whether the word "inclusive" or the like is employed or not, unless implicitly or explicitly understood or stated otherwise. Generally, the term "approximately" or "about" or the symbol "~" in reference to a figure or number or amount includes numbers that fall within a range of ± 5% of same, unless implicitly or explicitly understood or stated otherwise. Yet further, it will be understood that any heading employed is by way of convenience, not by way of limitation.

AU patents, patent applications, publications of patent applications, and other material, such as articles, books, specifications, publications, documents, things, and/or the like, referenced herein are hereby incorporated herein by this reference in their entirety for all purposes, excepting any of same or any prosecution file history associated with same that is inconsistent with or in conflict with the present document, or that may have a limiting affect as to the broadest scope of the claims now or later associated with the present document. By way of example, should there be any inconsistency or conflict between the description, definition, and/or the use of a term associated with any of the incorporated material and that associated with the present document, the description, definition, and/or the use of the term in the present document shall prevail.

Various terms may be generally described, defined, and/or used herein to facilitate understanding. It will be understood that a corresponding general description, definition, and/or use of these various terms applies to corresponding linguistic or grammatical variations or forms of these various terms. It will also be understood that a general description, definition, and/or use, or a corresponding general description, definition, and/or use, of any term herein may not apply or may not fully apply when the term is used in a non- general or more specific manner. It will also be understood that the terminology used herein, and/or the descriptions and/or definitions thereof, for the description of particular embodiments, is not limiting. It will further be understood that embodiments described herein or applications described herein, are not limiting, as such may vary.

Generally, the term "subject" refers to any suitable target for the application of pressure. Although this term may denote a human, or a human patient, the term may also refer to any animal or any mammal, such as any animal or any mammal that might benefit from the application of pressure.

Generally, the term "treatment" refers to an application of pressure to a subject. The pressure may comprise a negative pressure, a positive pressure, atmospheric pressure, and/or any suitable pressure. The treatment may be provided for any beneficial effect. Merely by way of example, any such treatment may comprise continuous or intermittent therapy, or a combination therapy which may comprise delivery of fluid, such as any suitable medicament or therapeutic agent, for example. Further, merely by way of example, the treatment may comprise an application of negative pressure to a subject, as may be accomplished via negative pressure wound therapy ("NPWT"), for example. Generally, continuous treatment refers to a treatment regime wherein pressure is supplied at a fairly constant level. Generally, intermittent treatment refers to a treatment regime wherein various pressures are supplied in at least one cycle. Merely by way of example, intermittent treatment may comprise an application of any number of different pressures according to a suitable time regime in any number of suitable cycles. Further merely by way of example, an intermittent treatment may comprise applying a negative pressure of 125 mmHg for 5 minutes and atmospheric pressure for 2 minutes.

Generally, the term "site" refers to a location associated with a subject that is targeted for a pressure application. Merely by way of example, in the context of NPWT, the site may refer to a location of a wound; in the context of breast pumping, the site may refer to a location of a lactation, such as a nipple of a breast; and in the context of aspiration, the site may refer to a location in a respiratory tract, a gastrointestinal tract, a peritoneal space, a mediastinal space, a pleural space, a subdural space, or subarachnoid space.

Generally, the term "wound" refers to any breach of skin or a mucosal layer. Examples include acute wounds (short-term wounds subject to normal healing), such as post-surgical wounds and traumatic wounds, and chronic wounds (longer term wounds, often associated with impaired or altered healing), such as vascular ulcers and diabetic ulcers, merely by way of example.

Generally, the term "exudate" refers to any matter that is produced by a wound. Exudate may comprise fluid, but may also comprise at least one solid component.

Generally, the term "fluid" refers to any matter having fluidic characteristics, such as a liquid or a gas. Generally, the term "non-gaseous fluid" refers to any such matter that is not a gas, such as a liquid, and may include solid or semi-solid components associated therewith, such as debris that is carried by or within the fluid.

Generally, in the context of or a combination therapy which may comprise application of pressure and delivery of fluid to a site, the term "fluid" may refer to any matter removed from the site, such as exudate, a therapeutic agent, and/or the like.

Generally, the term "negative pressure" refers to a pressure below atmospheric pressure. A negative pressure may be measured in mmHg and may be related to or compared with atmospheric pressure (gauge pressure). Generally, the term "vacuum" or the term "suction" may be used interchangeably with negative pressure. Generally, the term "positive pressure" refers to a pressure above atmospheric pressure.

The invention is made possible by the appreciation that removal of gaseous and nongaseous fluids from a bodily site using separate lumens dedicated to each confers substantial advantages over prior negative pressure devices. Not only does the invention allow for more odor-free operation, it also provides the ability to operate without the need of a waste "trap" and its concomitant concern for gravitational orientation of the trap. In the art's device, where a single lumen removes fluids with gaseous and non-gaseous components together, the receptacle or vessel to which the lumen transports the fluid will necessarily contain a quantity of liquids and solids settled at the bottom, with gaseous fluids above. As the vessel continues to fill, the gaseous layer continues to accummulate malodorous components, which are ultimately vented to the atmosphere, much to the discomfort of not only the subject but any persons nearby. Additionally, in order to even allow for such venting and the maintenance of fluid flow into the vessel, the vessel must be somewhat rigid, and must be kept oriented in relation to gravity, which may be difficult for many subjects.

By contrast, the invention allows for a vessel which maybe constructed of rigid, semirigid, or more preferably flexible material, needs no particular orientation with respect to gravity, and avoids the build-up of malodorous gases because the gases removed from the bodily site may be released immediately into the atmosphere, or may be filtered prior to such release.

Additionally, the device of the invention allows for the administration of medicaments through one of the lumens, all controlled by the same pressure control system as described below. Li a preferred embodiment, for example, the medicament is delivered via the second lumen during a time period in which the second lumen is not being used to remove gaseous fluid. After delivery of the medicament, removal of gaseous fluid is resumed.

Thus, in one embodiment of the invention, a device is provided capable of applying negative pressure, the device comprising a first lumen for removal of a non-gaseous fluid from the site; a chamber, defining an interior space, for drawing the non-gaseous fluid from the first lumen into the interior space; a valve disposed between the first lumen and the chamber to provide unidirectional flow of the nongaseous fluid from the first lumen toward the chamber; a second lumen for removal of a gaseous fluid from the site, said second lumen being operably connected with a vacuum source; and at least one vent for maintaining or releasing a vacuum supplied by the vacuum source.

The invention also includes methods of using the devices of the invention. In one embodiment, then, the invention is directed to a method of removing material from a bodily site comprising removal of gaseous and nongaseous fluids via a device comprising separate lumens dedicated to either gaseous and nongaseous fluid removal. The methods of the invention may also be used in administering therapeutic agents to a bodily site, concurrently or serially with removal of material therefrom.

The following Examples serve to illustrate the present invention and are not intended to limit its scope in any way.

Examples

Example 1: AnNPWT device of the invention A device 10 suitable for removing fluid from a bodily site 200 is now described in relation to Fig 1. The device 10 may be sufficient for removing fluid from the bodily site 200 via negative pressure, suction, or vacuum from an appropriate source. The bodily site 200 may be one associated with bodily fluid or with a fluid applied to the site. The fluid may be nongaseous fluid, and/or other fluid, whether gaseous or non-gaseous, from the bodily site or the environment of the bodily site. When the site comprises a natural bodily site, such as a lactating breast, for example, such a non-gaseous fluid may comprise a natural product of that bodily site, such as milk. When the site comprises a bodily site undergoing surgery, such as tissue being cut, for example, such a non-gaseous fluid may comprise a fluid resulting from that surgery, such as blood. When the site comprises a wound, for example, such a nongaseous fluid may comprise exudate from the wound or wound environment, and/or an agent applied to the wound or wound environment. In any of these examples, such a gaseous fluid may comprise air and/or oxygen, for example. It is contemplated that a system or device 10 suitable for removing fluid from a bodily site 200 may also be suitable for removing solid or semi-solid components that may be associated with the fluid, such as debris that is carried by or within the fluid, for example.

Merely by way of example, the device 10 is shown in relation to a site 200 that comprises a wound 210 in Figure 1. The device 10 may be used to apply negative pressure to the bodily site 200 that is suitable to remove non-gaseous fluid 220 and/or gaseous fluid 230 from the wound 210 and/or wound environment. As shown in Fig. 1, the device 10 may comprise at least one cover 212 sufficient for placement over the site 200. Such a cover 212 may comprise a screen 214 suitable for placement within or over the site 200 or wound 210. Such a screen 214 may be sufficient to at least reduce collapse of the site or the wound when the site or wound is exposed to negative pressure or a vacuum condition. Such a cover 212 may comprise a drape 216, which may be sufficient for placement over a screen 214, if any.

The cover 212 may be sufficient to form a seal around the site 200 or wound 210. For example, the cover 212 may be suitable for sealing in relation to suitable tissue or skin at or near the site 200 or wound 210, such as suitably healthy or viable tissue located at the edges of or suitably peripheral to the wound itself, for example. In some cases, the cover 212 may be impermeable to liquids. In some cases, the cover 212 may be substantially impermeable to liquids. In some cases, the cover 212 may be semi-impermeable to gases. A suitable cover 212 may be characterized by a high moisture vapor transmission rate ("MVTR"), such as at least about 3000 g/m2/day, for example, may be sufficient to allow transmission of water vapor and/or other gaseous fluid through the cover, and/or may be sufficient to facilitate a suitable local wound environment. The cover 212 may be sufficient to allow fluid communication between site 200 or wound 210 and various portions of the device 10, as further described herein. In such a case, the device 10 may be used to apply negative pressure to a site 200 or a wound 210 located under and sealed from its surroundings by the cover 212.

The device 10 may comprise at least one lumen 12 sufficient for removal of non-gaseous fluid 220 from the site 200 when the lumen is in fluid communication with the site. The lumen 12 may comprise an upstream opening 14 and a downstream opening 16 for removal of non-gaseous fluid 220 through the upstream opening and subsequently the downstream opening during operation of the device. The device may comprise at least one chamber 30 in fluid communication with the lumen 12, as shown. This chamber 30 may define an interior space 32 and be sufficient for drawing non-gaseous fluid 220 from the lumen 12 into the interior space. The device 10 may comprise at least one valve 40 sufficient to allow a flow of non-gaseous fluid 220 from the lumen 12 to a location beyond the valve in a direction toward the at least one chamber 30 and to substantially prevent non-gaseous fluid flow from a location beyond the valve in a direction toward the site 200. Merely by way of example, a suitable valve may be a one-way, or unidirectional, duck-bill valve, an umbrella-type valve, an actively driven process valve, which may be opened and closed to accommodate suitable fluid movement, or any suitable combination thereof.

The device 10 may comprise at least one lumen 20 sufficient for removal of gaseous fluid 230, to the relative exclusion of non-gaseous fluid 220, from the site 200. The lumen 20 may comprise an upstream opening 22 and a downstream opening 24 for removal of gaseous fluid 230 through the upstream opening and subsequently the downstream opening via vacuum from a vacuum source (not shown). The removal of gaseous fluid 230 in such a manner may be independent of removal of fluid from the site via the lumen 12, when the upstream opening 22 of lumen 20 is in fluid communication with the site 200, as shown, and the lumen 20 is in fluid communication with the vacuum source. The downstream opening 24 of lumen 20 may serve as a port or connection point sufficient to facilitate fluid communication with the vacuum source. Any suitable connection device may be used. Any suitable vacuum source may be used, such as a diaphragm vacuum pump, a peristaltic pump, a wall-suction pump, a syringe-type vacuum pump, or any suitable combination thereof. When the device 10 comprises a cover 212, as previously described, the lumen 12 may be that sufficient for fluid communication with the site 200 via the cover 212. In such a case, the cover 212 allows for fluid communication between the site 200 and the lumen 12, such that non-gaseous fluid 220, such as wound exudate and/or a wound-irrigation or wound-treatment agent, for example, may be removed from the site. When the device 10 comprises a cover 212, as previously described, the lumen 20 may be that sufficient for fluid communication with the site 200 via the cover 212. In such a case, the cover 212 allows for fluid communication with the site 200 and the lumen 20, such that a vacuum condition may be provided at the site, and gaseous fluid 230, such as air and/or oxygen, for example, may be removed from the site. The cover 212 may be sufficient to form a seal, such as a substantially fluid-impermeable seal, for example, with respect to the lumen 12 and the lumen 20.

The device 10 may comprise at least one vent 50 sufficient to facilitate a vacuum condition at the site 200 via vacuum from the vacuum source and sufficient to relieve a vacuum condition at the site. The vent^' 50 may be closed to facilitate such a vacuum condition and open to relieve such a vacuum condition. The vent 50 may be in fluid communication with the lumen 20, as shown. The vent 50 may be in communication with the atmosphere or other source of ambient or suitable pressure. The vent 50 may be controlled by any suitable means, such as a valve or valves, such as the two valves 52 and 56 shown in Fig. 1. Valve 40 allows one-way movement of fluid from the exudate lumen 12 into the exudate bulb 32. This fluid flow occurs through expansion of the internal volume of 32, causing an internal pressure reduction and subsequent pressure difference across the valve. Valve 52 allows intermittent one-way movement of fluid between the atmosphere or therapy reservoir and the Vent/Therapy Bulb 50. This selective communication is caused by the use of a compressible item (ie spring) 54 which places a closing force on the inlet valve 52, preventing a venting action. The dimensions of 54 and the bulb 50 are such that this closing pressure is exerted, in all but the "Renormalisation/Administer Therapy" Stage.

The device 10 may be designed such that the chamber 30 and the vent 50 are in a form sufficient for removal from the device. For example, the chamber 30 and the vent 50 may be housed in a cassette, such as a disposable cassette, for example, sufficient for removal from the device 10, as further described herein. In such a case, these portions of the device maybe easily discarded and replaced with corresponding replacement portions of the device via a new cassette, for example. As previously described, the chamber 30 may be sufficient for drawing non-gaseous fluid 230 from the lumen 12 into its interior space 32. The chamber 30 may be so sufficient in absence of a trap. Traps require specific orientations to gravity, causing the non-gaseous fluids to collect at a point that is consistently lower than the vacuum source. Due to the manipulation of the internal volume of compartment 92, non-gaseous fluid is drawn into compartment 92 and subsequently expelled into 62 past valve 64, the exudate is isolated from the vacuum circuit. This allows departure from conventional systems that require a trap, and allows unimpaired functionality though all orientations to gravity. The chamber 30 may be so sufficient regardless of orientation to gravity. The chamber 30 may be sufficient for expelling non-gaseous fluid from the interior space 32, as further described herein.

The device 10 may comprise at least one chamber 30 that may be moveable, such as compressible and decompressible, for example. Li a compressed state, as shown in Fig. IA, the chamber 30 may be in a suitable condition for the activation of vacuum in the system at the beginning of a vacuum cycle. In a partially to fully decompressed state, as shown in Fig. IB, the chamber 30 may be in a suitable condition for facilitating accumulation of nongaseous fluid in the lumen 12 and eventually in the interior space 32. In a fully decompressed state, as shown in Fig. 1C, the chamber 30 may be in a suitable condition for facilitating accumulation of non-gaseous fluid more fully in the interior space 32. In a compressed state, as shown in Fig. ID, the chamber 30 may be in a suitable condition for the expulsion of nongaseous fluid from the interior space 32. The at least one chamber 30 may be moveable, compressible, and/or decompressible in any suitable manner, such as via a moveable structure of the chamber, such as a bellows, a moveable wall, and/or the like, for example, or via any suitable activating device, such as a plunger, for example. Any suitable alternative or additional movement mechanism, such as a mechanism for exerting peristaltic action on a compression tube, for example, may be employed. The at least one chamber 30 may be controlled via any suitable mechanism or system, such as a cam system driven by a motor, a linear actuator, a solenoid sufficient to exert longitudinal force, compressed gas, or any suitable combination thereof.

The device 10 may comprise at least one vessel 60 sufficient for collection of non-gaseous fluid from the at least one chamber 30. As shown in Fig. ID, the vessel 60 is in fluid communication with the chamber 30, such as via at least one lumen 62, for example, so that it may receive non-gaseous fluid 220 from the interior space 32. The device 10 may comprise at least one valve 64 sufficient to allow a flow of non-gaseous fluid 220 from the lumen 62 to a location beyond the valve in a direction toward the vessel 60 and to substantially prevent non-gaseous fluid flow from a location beyond the valve in a direction toward the chamber 30. The vessel 60 may be rigid or non-rigid, such as collapsible, for example. A non-rigid or collapsible vessel 60 may be suitable for being worn by a subject, may correspond to the body contours of a subject, may be of reduced bulk, or may otherwise facilitate the comfort of a subject. The vessel 60 may be substantially free of gaseous fluid during the course of operation. Such a vessel 60 may facilitate the comfort of a subject, particularly in that substantially no malodorous gaseous fluid is present, for example, and may reduce a volume of waste to be discarded, for example. The vessel 60 may be designed for convenient removal from the device 10. hi such a case, this portion of the device may be easily discarded and replaced with corresponding replacement portion of the device, for example.

The device 10 may comprise at least one intermediary chamber 70 that comprises a chamber opening 72. The lumen 12 and the lumen 20 may be in fluid communication with the site 200 via the at least one intermediary chamber 70, when the chamber opening 72 is in fluid communication with the site 200, as shown in Fig. 1. The upstream opening 14 of the lumen 12 and the upstream opening 22 of the lumen 20 may be arranged within the intermediary chamber 70 in any suitable manner such that each is in fluid communication with fluid entering the intermediary chamber 70 from the site 200. When at least one cover 212, such as a cover comprising a drape 216, for example, is placed within or over the site 200, the at least one intermediary chamber 70 and the at least one cover 212 may be coupled and the chamber opening 72 may be in communication with the site 200, as shown in Fig. 1. The cover 212 may be that sufficient to form a substantially fluid-impermeable seal with respect to the intermediary chamber 70. A suitable cover 212 may be substantially impermeable to liquids, semi-impermeable to gases, and/or characterized by a high moisture vapor transmission rate ("MVTR"), as previously described. A suitable cover 212 may be sufficient to allow transmission of water vapor and/or other gaseous fluid through the cover, and/or may be sufficient to facilitate a suitable local wound environment, such as one free of excessive moisture, for example. When at least one cover 212, such as a cover comprising a screen 214, for example, is placed within or over the site 200, the screen may be that sufficient to allow fluid communication between the site and the chamber opening 72.

As shown in Fig. 1, the upstream opening 14 of the lumen 12 and the upstream opening 22 of the lumen 20 may be arranged such that the former is upstream (that is, closer to the site 200 or the chamber opening 72, for example) relative to the latter. Such an arrangement may facilitate the entry of non-gaseous fluid 220 into lumen 12 in preference to, or as opposed to, the entry of non-gaseous fluid 220 into lumen 22. The device 10 may comprise a filter (not shown in Fig. 1) sufficient to at least reduce or substantially prevent removal of non-gaseous fluid 220 from the site 200 through the downstream opening 24 of lumen 20. Any suitable filters may be used. A suitable filter may be one composed of polytetrafiuoroethylene (PTFE), polyvinylidene fluoride (PVDF), ultrahigh molecular weight polyethylene (UPE) filter (UPE), acrylic, glass fiber, and/or any suitable combination thereof. A suitable filter may comprise pores having a pore size of about 0.45 microns or less. The device may comprise a sensor-based feedback loop (not shown in Fig. 1) sufficient to at least reduce or substantially prevent removal of non-gaseous fluid 220 from the site 200 through the downstream opening 24 of lumen 20. Fig. 11 demonstrates a pressure/time curve during a period of active vacuum, during which the vacuum is operating to reduce the pressure at the wound to the target pressure. From time period 1 to 5, a constant gradient of pressure change can be seen. Between periods 5 and 6, this gradient suddenly increases, indicating an occlusion in the filter within the chamber 70. The instantaneous pressure is measured by the pressure transducer 162, and the change in pressure gradient above a threshold value is detected by the microprocessor/controller unit 163. This causes the vacuum pump to stop, and movement of mechanism 98, causing exudate exchange, and removal of the occlusion at the filter site. Subsequent to this, via process valve 82, venting is commenced, returning system pressure to atmospheric pressure. Once this has occurred, the active vacuum stage is recommenced. This process of events is summarized schematically in Fig. 12.

A portion 110 of a device suitable for removing fluid from a bodily site (not shown) is now described in relation to each of Figs. 2, 3, and 4. As described previously, the upstream opening 14 of the lumen 12 and the upstream opening 22 of the lumen 20 may be arranged within the intermediary chamber 70 in any suitable manner such that each is in fluid communication with fluid entering the intermediary chamber 70 from the site 200 via the chamber opening 72. A suitable arrangement for such a portion 110 of the device is shown in each of Fig.s 2-4, wherein the upstream opening 14 of the lumen 12 may be upstream (that is, closer to the site 200 or the chamber opening 72, for example) relative to the upstream opening 22 of the lumen 20. Such an arrangement may facilitate the entry of non-gaseous fluid 220 into lumen 12 in preference to, or as opposed to, the entry of non-gaseous fluid 220 into lumen 22. The portion 110 may comprise at least one lumen 112 arranged within the intermediary chamber 70, as shown in Fig. 2. The lumen 112 may comprise an upstream opening 114 and a downstream opening 116. For example, as shown, the lumen 112 may comprise an upstream opening 114 located about evenly with the chamber opening 72 and a downstream opening 116 located about evenly with a mid-length portion 74 of the intermediary chamber 70. The downstream opening 116 may be upstream relative to the upstream opening 22 of the lumen 20 and downstream relative to the upstream opening 14 of the lumen 12, as shown. Further by way of example, the lumen 112 may be arranged such that its downstream opening 116 is about concentric with the upstream opening 22 of the lumen 20. When the downstream opening 116 is located substantially centrally within the portion 110, nongaseous fluid 220 that may accumulate within the portion 110 is less likely or unlikely to return to the downstream opening 116 and flow back toward the upstream opening 114 or the site 200. The lumen 112 may comprise a rigid or semi-rigid tube. The lumen 112 may be of sufficient construction, such as of sufficient rigidity, for example, such that in all orientations of the portion 110, the lumen 112 substantially maintains the relatively central position of the downstream opening 116 relative to portion 110.

A support or plate 111 may be employed to hold the lumen 112 in place, such that downstream opening 116 remains in a position relatively central to portion 110. The plate 111 may be sealed around its edges to the bottom of the intermediary chamber 70. The plate 111 is of a construction sufficient such that the lumen 112 is the only pathway for fluid to enter the intermediary chamber 70 from the site 200 and for fluid to return to the site 200 from the intermediary chamber 70.

The portion 110 may comprise at least one lumen 120 arranged within the intermediary chamber 70, as shown in Fig. 3. The lumen 120 may comprise an upstream opening 122 and a downstream opening 124. For example, as shown, the lumen 120 may comprise an upstream opening 122 located about evenly with a mid-length portion 74 of the intermediary chamber 70 the chamber opening 72 and a downstream opening 124 located about concentrically in relation to the upstream opening 22 of the lumen 20. The upstream opening 122 may be upstream relative to the upstream opening 22 of the lumen 20 and downstream relative to the upstream opening 14 of the lumen 12, as shown. The downstream opening 124 may be downstream relative to the upstream opening 22 of the lumen 20 and downstream relative to the upstream opening 14 of the lumen 12, as shown. When the downstream opening 122 is located substantially centrally within the portion 110, non-gaseous fluid 220 that may accumulate within the portion 110 is less likely or unlikely to flow back toward the site 200.

Preferably, the opening 122 is a passage only for gaseous fluid, but accidental entry of nongaseous fluids (especially at different orientations) must be minimized, hi this embodiment, such risk of accidental contamination is minimized by having opening 122 relatively central to the internal space of 110, such that the level of exudate is highly unlikely to occlude opening 122 in any of the three axes. The lumen 120 may comprise a rigid or semi-rigid tube. The lumen 120 may be of sufficient construction, such as of sufficient rigidity, for example, such that in all orientations of the portion 110, the lumen 120 substantially maintains the position of the downstream opening 122 relatively central within portion 110.

The portion 110 may comprise at least one filter 126 arranged within the intermediary chamber 70, as shown in Fig. 4. The filter 126 may be that suitable for at least reducing or preventing passage of non-gaseous fluid 220 into the lumen 20. Any suitable filter may be used, such as any suitable filter previously described. Merely by way of example, a suitable filter may be a hydrophobic filter, such as a hydrophobic filter comprising polytetrafluoroethylene (PTFE), for example, or such as a hydrophobic filter comprising relatively wide-pore PTFE, for example. Merely by way of example, the filter 126 may comprise pores having a pore size of about 0.45 microns or less. The filter 126 may comprise an upstream opem^'ng 128 and a downstream opening 130, which may be arranged in a similar manner to the upstream opening 122 and the downstream opening 124 of lumen 122 described in relation to Fig. 2, although the upstream opening 128 may be slightly more upstream than the mid-length portion 74 of the intermediary chamber 70, as shown. This filter assists to further minimize the risk that nongaseous fluids are not drawn into lumen 20, while allowing passage of gas.

At least one filter, such as filter 126, may used in connection with the portion 110 shown in Fig. 2, where the filter is located in a similar manner to filter 126 of Fig. 4. At least one filter, such as a modified filter 126, may be used in connection with the portion 110 shown in Fig. 3, where the filter may be located in a similar manner to filter 126 of Fig. 4 and modified (such as by creating a bore therein) to accommodate lumen 120. At least one filter, such as a modified filter 126, may be used in connection with the portion 110 shown in Fig. 3, where the filter may be located in a similar manner to filter 126 of Fig. 4, but in relation to lumen 122 rather than lumen 20, and modified in size to accommodate lumen 122. Any suitable filters may be used, such as any of those previously described and/or the like. Other suitable arrangements of lumens and filters in relation to the portion 110 are possible and contemplated herein. Merely by way of example, at least one lumen may be arranged in any suitable manner, such as concentrically arranged, for example, within at least one other lumen. For example, the lumen 12 may be arranged in any suitable manner within the lumen 20, and same is contemplated herein.

As previously described, the device 10 may comprise a sensor-based feedback loop (not shown in Fig. 1; see Figs. 12, 13) sufficient to at least reduce or substantially prevent removal of non-gaseous fluid 220 from the site 200 through the downstream opening 24 of lumen 20.

A portion 110 of a device suitable for removing fluid from a bodily site (not shown) is now described in relation to Fig. 5 As described previously, the upstream opening 14 of the lumen 12 and the upstream opening 22 of the lumen 20 may be arranged within the intermediary chamber 70 in any suitable manner such that each is in fluid communication with fluid entering the intermediary chamber 70 from the site 200 via the chamber opening 72. A suitable arrangement for such a portion 110 of the device is shown in Fig. 5, wherein the upstream opening 14 of the lumen 12 maybe downstream (that is, farther from the site 200 or the chamber opening 72, for example) relative to the upstream opening 22 of the lumen 20. In the arrangement shown, the lumen 20 is configured somewhat differently than the lumen 20 shown in Figs. 1-4, by virtue of the presence of at least one filter 132, as further described herein. Such an arrangement may facilitate the entry of non-gaseous fluid 220 into lumen 12 in preference to, or as opposed to, the entry of non-gaseous fluid 220 (not shown) into lumen 22, as further described below.

The filter 132 may be located within the interior 76 of the intermediary chamber 70, as shown in Fig. 5. The filter 132 may be shaped (such as bored, for example) to accommodate the lumen 12 in a close-fit manner, as shown. The filter 132 may be shaped to substantially mimic or parallel the shape of the interior 76, as defined by the chamber 70. The filter 132 may be located within the interior 76 of the chamber 70, such that a gap 78 exists therebetween, as shown. This gap 78 may serve to effectively extend the lumen 20, such that its upstream end 22 is about even with the chamber opening 72. The filter 132 may be any suitable filter, such as any described herein, for example. The filter 132 may have a relatively large surface area, as compared to the filters discussed in relation to Figs. 2-4, for example. In such a case, as compared to such other filters, the filter 132 is less likely to become partially occluded or completely occluded.

A device 10 suitable for removing fluid from a bodily site (not shown) is now described in relation to Fig. 6. Merely by way of illustration, the device 10 is shown in a disconnected manner in Fig. 6A (see disconnection points A and B), and in a connected manner in Fig. 6B and Fig. 6C, as further described herein. The device 10 may comprise at least one lumen 12 for the removal of non-gaseous fluid (not shown) from the site via an upstream opening (not shown). The device 10 may comprise at least one lumen 20 for the removal of gaseous fluid (not shown) from the site via an upstream opening (not shown). These upstream openings may communicate with the site in any suitable manner, such as any of those described in relation to any of Figs. 1-4, for example.

The device 10 may comprise at least one chamber 30. The chamber 30 may comprise an interior space 32 that may comprise a sub-interior space 34 and another sub-interior space 36. As shown in Fig. 6, a downstream opening 16 of the lumen 12 may communicate with at least one chamber 30, and thereby, with the sub-interior space 34. At least one valve 40 may be present in the lumen 12 to allow non-gaseous fluid to flow through the valve in a direction toward the chamber 30 and sub-interior space 34, while substantially preventing non-gaseous fluid to flow through the valve in the opposite direction.

As also shown in Fig. 6, at least one lumen 62 may be present to allow non-gaseous fluid to flow from the sub-interior space 34 of the chamber 30. Such a lumen 62 may further communicate with at least one vessel (not shown), such as the vessel 60 described in relation to Fig. 1, for example, for collection and disposal of the non-gaseous fluid. At least one valve 64 may be present in the lumen 62 to allow non-gaseous fluid to flow through the valve in a direction away from chamber 30 and the sub-interior space 34, while substantially preventing non-gaseous fluid to flow through the valve in the opposite direction.

As also shown in Fig. 6, a downstream opening 24 of the lumen 20 may communicate with at least one chamber 30, and thereby, with the sub-interior space 36. At least one valve 58 may be associated with the lumen 20 to selectably or selectively isolate the lumen 20 from changes in pressure that may occur in the chamber 30, such as when an internal volume of the sub-interior space 36 is increased, for example, as further described herein. As additionally shown in Fig. 6, at least one lumen 80 may be present to allow fluid communication between a source of vacuum (not shown) and the chamber 30, the sub- interior space 36, and the lumen 20. At least one vent 50 in fluid communication with the lumen 80 may be present to facilitate a vacuum condition or other pressure condition at the site and to relieve any such condition at the site. At least one valve 82 may be associated with the lumen 80 to selectably or selectively open the lument 80 to atmosphere, which may result in a venting of or pressure normalization in the chamber 30, and if the valve 58 is open, a venting of or pressure normalization in the lumen 20.

The chamber 30 of the device 10 has been shown in a disconnected manner in Fig. 6 A and a connected manner in Fig. 6B and Fig. 6C to illustrate the interior space 32 and its component sub-interior spaces 34 and 36. The chamber 30 may comprise a housing 90 that when disconnected at point A and point B, for example, may appear as shown in Fig. 6A, with a portion 9OA and another portion 9OB separated from one another. The chamber 30 may comprise a housing 90 that when connected at point A and point B, for example, may appear as shown in Fig. 6B and Fig. 6C, with the portion 9OA and the portion 9OB connected to one another, hi the latter case, the housing 90 may be sealed at any points of connection, such as points A and B, for example, to substantially isolate the interior space 32 from the environment external thereto other than via the various lumens in communication therewith.

The chamber 30 may comprise a compartment 92 that is attached to the portion 9OA. The compartment 92 may be flexible or otherwise moveable. Merely by way of example, the compartment 92 may comprise a flexible portion 94. The flexible portion 94 may comprise a bellows- or accordion-type portion, which may be associated with sides of the compartment 92, for example. The compartment 92 may comprise a relatively inflexible portion 96, such as a relatively flat or planar or solid surface, for example, which may be associated with a bottom of the compartment, for example. Other arrangements for a flexible or moveable compartment 92 are possible and are contemplated herein. The compartment 92 may be that sufficient to fit within the sub-interior space 34 when the housing 90 is fully assembled, as shown in Fig. 6B and Fig. 6C. The compartment 92 may be that sufficient for conforming to variations in volume, such as variations caused by the filling of the compartment with nongaseous fluid, the emptying of non-gaseous fluid from the compartment, and/or variations caused by movement of the compartment 92. The compartment 92 may be that sufficient for containing its contents, such as non-gaseous fluid, for example. The compartment 92 may be that sufficient for at least reducing or preventing contamination of the interior of housing 90 with contents of the compartment. The compartment 92 may be composed of any suitable material, such as any suitable polymeric material, polyurethane material, rubber material, nitrile material, latex material, or any suitable combination thereof, for example. The compartment 92 may be lubricated on its outer surface adjacent the housing 90. Any suitable lubricant, such as a lubricant sufficient to at least reduce friction and/or increase durability, for example. A suitable lubricant may be a water-based lubricant, merely by way of example. The compartment 92 may be sufficient to maintain operational integrity for at least about 10,000 movements back and forth, for example, and/or for at least about one month of constant use, for example.

The chamber 30 may comprise a mechanism 98 suitable for moving the compartment 92 within the housing 90 when the housing is fully assembled. The mechanism 98 may be that sufficient to fit within the sub-interior space 36 when the housing 90 is fully assembled, as shown in Fig. 6B and Fig. 6C. The mechanism 98 may comprise a plunger-type device or other type of device suitable for moving within the housing 90 in one direction to apply pressure to the compartment 92 and thereby move it, and in another direction to relieve any such pressure or to respond to a pressure applied to it by the compartment 92. An example of the former is illustrated in Fig. 6B, where the direction of movement is indicated by the arrow shown therein. An example of the latter is illustrated in Fig. 6C, where the direction of movement is indicated by the arrow shown therein. The movement illustrated in both of Fig. 6B and Fig. 6C is axial movement along a longitudinal axis of the housing 90, merely by way of example. The mechanism 98 may comprise a portion 100, such as a relatively flat or planar or solid surface, for example, suitable for interacting with the portion 96 of the compartment 92, for example. The mechanism 98 may comprise rollers or bearings or a like device 102 to facilitate movement, such as the movement of portion 100, for example, along the interior of the housing 90. The device 102 may be sufficient to provide a seal against leakage designed to prevent all leakage (both gas and liquid) between the sub-interior space 34 and the sub-interior space 36. Merely by way of example, a suitable device 102 may comprise an o-ring, such as a rubber o-ring, disposed around the circumference of the portion 100 and sufficient for sliding along the internal surface of the housing 90 while maintaining a suitable seal. The mechanism 98 may be activated or moved by any suitable means (not shown), such as a threaded rod turned by a motor, for example. Other movements or directions of movement are possible and are contemplated herein, particularly if other arrangements for a flexible or moveable compartment 92 are employed and/or other movement mechanisms are employed.

As previously discussed, the housing 90 may be disassembled or disconnected, such as at points A and B, merely by way of example. The housing 90 may be disassembled such that the compartment 92 remains associated with the portion 9OA, as illustrated in Fig. 6A. The portion 9OA, along with anything attached to it, such as the compartment 92, the lumen 12, and/or the lumen 62, for example, may be suitable for disposal. Disposal of this portion or these portions of the device 10 may be suitable after use by a subject and prior to use by another subject, for example.

Fig. 6 illustrates an embodiment of the invention designed for provision of NPWT and NPWT with therapeutic delivery of a medicament. Fig. 6A shows separation between a disposable element of the device and device 30. Device 30 is designed to allow attachment, detachment and replacement of disposable element as shown. The apparatus as shown in Fig. 6 is designed to provide a reciprocating fluid volume transfer between lumens 20 and 12, while causing the expulsion of collected fluid through lumen 62.

At commencement of a vacuum phase for NPWT, the device configuration is as shown in Fig 6B. The disposable element is shown attached to the device 30, with end plate 100 occupying the position that minimizes volume 34 and maximizes volume 36. Valve 82 remains closed, and valve 58 remains open. The vacuum pump 160 commences suction via lumen 80, causing evacuation of chamber 36, vacuum lumen 20 and the treatment site 200. Once target pressure is detected by the pressure transducer 162, the vacuum pump ceases operation, and will only recommence operation, if the pressure transducer detects a pressure increase larger than a specified threshold (e.g. 5%). Once the user specified time for active vacuum has elapsed, the phase of exudate transfer occurs. This involves movement of end-plate 100 to a position that minimizes volume 36, as shown in Fig. 6C. This action is completed with valve 82 closed, valve 58 open and the vacuum pump 160 off. The act of increasing the internal volume of 92, decreases the internal pressure, causing fluid from lumen 12 to flow past a one-way valve 40 into 92. This is accompanied by a movement of fluid (eg atmospheric gas) from chamber 36 into lumen 20 and treatment site 200 to ensure pressure conditions at the site are not altered by the fluid exchange.

Following the exudate transfer, end plate 100 is driven towards the position shown in Fig 6B. This reduces the internal volume of 92, causing an increase in internal pressure and subsequent fluid movement from 92, into lumen 62 past one-way valve 64 into receptacle 60. Throughout this stage, valve 58 remains closed, and 82 remains open for the first part of the movement of 100. Valve 82 closes at the stage where the internal volume of 36 is at some fraction of its maximised volume. This fraction is determined such that when the valve is closed at this internal volume and the chamber 36 volume is maximized, the pressure within 36 is at the target pressure. This ensures that subsequent opening of valve 58 does not lead to fluctuation in pressure conditions in lumen 20 and treatment site 200.

These stages of exudate transfer and expulsion can be performed at any stage of the treatment cycle (ie during suction or at normal atmospheric pressure conditions).

In the case of intermittent NPWT, after each stage of active vacuum, pressure conditions at the wound site are required to renormalise to a higher pressure (eg atmospheric pressure). This is accomplished through the opening of valve 82 and valve 58. Once pressure is measured to be the target rest pressure (eg atmospheric pressure), valve 82 is closed. During this time the vacuum pump 160 remains off, and the system remains unchanged until the user specified resting period has elapsed.

At commencement of a vacuum phase for NPWT with therapy delivery, the device configuration is as shown in Fig 7. Said device is designed similarly to the device shown in Fig 6, however the entire device shown is a disposable element. The end plate 100 is shown occupying the position that minimizes volume 34 and maximizes volume 36. Valve 82 is a three-way valve in Fig. 7, and allows selective communication between 36 and vent 50 and lumen 140 connecting to a reservoir of therapeutic agent (not shown) for delivery to the treatment site. During this stage, valve 82 remains completely closed, and valve 58 remains open. The vacuum pump 160 commences suction via lumen 80, causing evacuation of chamber 36, vacuum lumen 20 and the treatment site 200. Once target pressure is detected by the pressure transducer 162, the vacuum pump ceases operation, and will only recommence operation, if the pressure transducer detects a pressure increase larger than a specified threshold (eg 5%). Once the user specified time for active vacuum has elapsed, the phase of exudate transfer occurs. This involves movement of end-plate 100 to a position that minimizes volume 36, as shown in Fig. 6C. This action is completed with valve 82 closed, valve 58 open and the vacuum pump 160 off. The act of increasing the internal volume of 92, decreases the internal pressure, causing fluid from lumen 12 to flow past a one-way valve 40 into 92. This is accompanied by a movement of fluid (eg atmospheric gas) from chamber 36 into lumen 20 and treatment site 200 to ensure pressure conditions at the site are not altered by the fluid exchange.

Following the fluid transfer, end plate 100 is driven towards the position shown in Fig 6B. This reduces the internal volume of 92, causing an increase in internal pressure and subsequent fluid movement from 92, into lumen 62 past one-way valve 64 into receptacle 60. Throughout this stage, valve 58 remains closed, and 82 remains open for the first part of the movement of 100. Valve 82 can be altered to selectively allow movement of therapeutic agent via 140 or atmospheric gas via 50 into chamber 36 in response to the increase of internal volume 36. Valve 82 closes at the stage where the internal volume of 36 is at some fraction of its maximised volume. This fraction is determined such that when the valve is closed at this internal volume and the chamber 36 volume is maximized, the pressure within 36 is at the target pressure. This ensures that subsequent opening of valve 58 does not lead to fluctuation in pressure conditions in lumen 20 and treatment site 200. hi the case of combined NPWT and delivery of therapeutic agent, following the ingress of therapeutic agent to chamber 36, end plate 100 is moved to a position similar to Fig 6C, causing the expulsion of therapeutic agent from 36, past open valve 58 into lumen 20, towards the treatment site. Following this stage of therapeutic agent delivery, chamber 36 can be refilled and emptied of therapeutic agent a number of times as specified by the user. Following the final cycle of these therapeutic agent delivery stages, the device will perform at least one movement from positions shown in 6B and 6C, with ingress of atmospheric gas into chamber 36 via valve 82. This allows total transfer of therapeutic agent from lumen 20 towards the treatment site, preventing subsequent aspiration of therapeutic agent into the vacuum pump during the later stages when the vacuum pump 160 is turned on.

A device providing NPWT and therapy delivery may include use of an appropriate filter (not shown) in lumen 80, before vacuum pump 160. Such a filter may comprise a hydrophobic filter. Such a hydrophobic filter may comprise a PTFE filter. Such a filter may comprise a PTFE filter with a pore size of 0.45 microns or less. Said filter would provide additional protection against aspiration of therapeutic agent into the vacuum pump 160.

A device providing NPWT and therapy delivery may comprise a chamber 110 without use of a filter, to allow unimpeded movement of therapeutic agent down the vacuum lumen 20 to the treatment site 200. Said device could minimize wound fluid movement into the vacuum lumen 20 through pressure gradient monitoring as illustrated in Fig 11 and Fig 12. These stages of fluid transfer/therapy delivery and fluid expulsion can be performed at any stage of the treatment cycle (ie during suction or at normal atmospheric pressure conditions). Further, these stages can be performed to cause the delivery of specific flow rates or dosage of therapeutic agent to the treatment site 200, which can be achieved through multiple repeated cycles of the above stages.

In the case of intermittent NPWT with therapy delivery, after each stage of active vacuum, pressure conditions at the wound site are required to renormalise to a higher pressure (eg atmospheric pressure). This is accomplished through the opening of valve 82 and valve 58. Once pressure is measured to be the target rest pressure (eg atmospheric pressure), valve 82 is closed. During this time the vacuum pump 160 remains off, and the system remains unchanged until the user specified resting period has elapsed.

A device 10 suitable for removing fluid from a bodily site (not shown) is now described in relation to Fig. 7 (FIG. 7). The device 10 comprises many of the same features, elements and components as those described in relation to the device 10 of Fig. 6. As such, these features, elements and components will not be fully described in relation to the device 10 shown in Fig. 7.

As shown, the device 10 of Fig. 7 may lack a compartment such as the compartment 92 of the device 10 of Fig. 6. As described above, this embodiment relates to delivery of therapeutics, in which case contamination of chamber 36 may occur. Hence the entire apparatus depicted in Fig. 7 is preferably designed to be disposable. The device 10 may comprise at least one lumen 140 for delivery of at least one agent to the site 200. Any suitable agent may be used. Examples of suitable agents include irrigation agents, such as saline solution, for example; treatment or medical agents, such as topical antiseptics, topical antibiotics, topical anti- fibrotics, topical chemotherapeutics, gaseous oxygen, supersaturated oxygen solutions, biological agents, and growth factors, for example; palliative agents, such as topical analgesics, topical anaesthetics, pain-relief agents, and itching-relief agents, for example; protective agents; debriding agents, such as topical fibrolytics, for example; and any suitable combination thereof. A valve 82 may be associated with the lumen 80 and the lumen 140 to modify or control flow therethrough. Any suitable valve, such as a three-way valve, for example, may be used. In the device 10 of Fig. 7, at least one of valve 58 and valve 82 may comprise a length of compressible tubing and a device for compressing that tubing, such as a cam for compressing that tubing via an externally applied force. Any suitable compressible tubing may be used, such as tubing composed of any suitably compressible material, such as rubber, nitrile, latex, silicone, or any suitable combination thereof, for example. Such a valve or valves may be relatively simple and inexpensive, although other suitable devices may be used and are contemplated herein.

While various parts of the device 10 shown in Fig. 7, such as any of the parts described in relation to the device 10 of Fig. 6, for example, the entire device 10 shown in Fig. 7 may be suitable for disposal. Disposal of the device 10 may be suitable after use by a subject and prior to use by another subject, for example.

A device 10 suitable for removing fluid from a bodily site, such as any described herein, may be configured in any suitable manner. A schematic illustration of a suitable configuration for such a device 10 is shown in Fig. 8 (FIG. 8) (repeat?), merely by way of example. The device 10 may comprise many of the same features, elements and components as those described in relation to the device 10 of Fig. 6 or Fig. 7. As such, these features, elements and components will not be fully described in relation to the device 10 shown in Fig. 8. The device 10 may comprise some features, elements and components that may be slightly reconfigured relative to the device 10 of Fig. 6 or Fig. 7. For example, the process valve 58, the lumen 80, the process valve 82 and the vent 50, for example, may be reconfigured as shown in Fig. 8.

As described previously, the device 10 may comprise a mechanism 98, which may be activated or moved by any suitable means 150, as shown in Fig. 8. Suitable means 150 may comprise a coupling 152, such as a threaded coupling suitable for mating with threading on the mechanism 98, for example, and a driver 154, such as motor suitable for driving the coupling 152 and thus the mechanism 98, for example. Other activation means 150 are possible and are contemplated herein. The device 10 may comprise at least one source 160 of suction, negative pressure or vacuum, such as a vacuum pump, for example. The device 10 may comprise at least one pressure sensor 162, such as a pressure transducer, for example. The source 160 and the sensor 162 may be in fluid communication with the lumen 20 in any suitable manner. The device 10 may comprise at least one source 166 of power, such as at least one battery, for example. The source 166 may provide power to the driver 154 and/or the source 160 of vacuum.

Fig. 13 illustrates the functional connections between the components of the device that sense the device state, assimilate the feedback and actuate necessary changes congruent with the specified treatment regime. The controller/microprocessor unit 163 coordinates the timely control of the Vacuum Pump 160, the Actuator 154 for End Plate 100, User Interface 172, Valves 82 and 58. The position of the End-Plate 100 is measured by Position Sensors (not shown in diagrams), which feed into 163. Pressure conditions at the treatment site are inferred by measurement of the pressure in the circuit continuous with Vacuum Lumen 20, by the Pressure Transducer 162.

The Power Source 166 provides power to the User Interface 172, Position Sensors for 98/100 and the Pressure Transducer 162. The Power Source 166 also provides power to 163, and indirectly, via 163, provides power to Valve 82, Valve 58, Actuator 154 and Vacuum Pump 160.

The device 10 may comprise a housing 170 for various portions of the device, as shown in Fig. 8. While a certain configuration of various portions of the device is shown in Fig. 8, other configurations are possible and are contemplated herein. As previously described, portion 9OA of the housing 90 may be disconnected from portion 9OB, along with various components attached to it, such as the compartment 92 and any attached lumens, such as the lumen 12 and the lumen 62, for example. As such, these portions of the device 10 may be configured and designed as disposable components, to be removed and replaced with replacement counterparts. This feature advantageously assists in the prevention of contamination of the device, the reuse of the device, and associated operational economy.

A device 10 suitable for removing fluid from a bodily site, such as any described herein, is now described in relation to Fig. 9. The device 10 may comprise many of the same features, elements and components as those described in relation to any device 10 described or shown in the drawings herein. As such, these features, elements and components will not be fully described in relation to the device 10 shown in Fig. 9.

The device 10 may comprise a multi-lumen assembly 178 comprising the lumen 12 and the lumen 20. This assembly 178 may be in communication with the intermediary chamber 70, as shown. The assembly 178 and/or the holding chamber may be in communication with the site 200 via at least one cover 212, such as a cover comprising a drape 216 and/or a screen 214. The multi-lumen assembly 178 and the lumen 62 may be in communication with a device body or housing 170, such as that described in relation to Fig. 8, merely by way of example. The lumen 62 may be in communication with the vessel 60 in any suitable manner, as previously described. The device body or housing 170 may comprise a display 172. The display 172 may display or provide information or prompts to the user, such as information regarding the use of the device, the control of the device, and/or the subject or site undergoing treatment, and/or prompts for instructions, merely by way of example. Any suitable display may be used. The device body 170 may comprise an interface 174, such as an interface suitable for a user to control the device or to input instructions or information, merely by way of example. Any suitable interface may be used. Any suitable electronics or circuitry (not shown) may be used in connection with any of the display 172, the interface 174, the mechanism 98, the activation means 150, the driver 154, the source 160, the sensor 162, the source 166, any components of the device 10, and the control of the device, such as via a feedback loop, for example.

A front view and a rear view of a carrier 180 for a device suitable for use in interacting with a bodily site are schematically illustrated in Fig. 1OA and Fig. 1OB, respectively. The carrier 180 may comprise a garment 182, such as a garment worn by a subject 300 on a portion of the body, for example, a portion 184 of a garment, such as a pocket 184, for example, or another suitable portable vehicle, such as any vehicle (such as a belt-based vehicle, velcro- based vehicle, and/or the like) that can be attached to a subject 300 and carry the device body 170, for example. The front view may correspond to a front of a carrier or a garment 182 and the rear view may correspond to a rear of a carrier or a garment 182, although any suitable configuration may be used and is contemplated herein. The carrier 182 may be that sufficient to apply a compressive force to the subject 300, a treatment site, and/or a wound, as may be useful in various treatment regimes. Any suitable means of applying such a compressive force may be used.

The carrier 182 may comprise at least one area 186, such as a perforated area, for example, sufficient to provide access to a site (not shown). The area may be that sufficient to allow the multi-lumen assembly 178 access to a site, such as a site or a cover 212 placed over the site beneath the carrier 182. The carrier 182 may be that sufficient to allow the multi-lumen assembly 178 and the lumen 62 access to the device body 170. As shown, the lumen 62 may be in communication with a vessel 60.

Any suitable carrier 182 may be used and is contemplated herein. Merely by way of example, the carrier 182 may comprise portions, such as pockets, for example, for replacement or extra components, such as a power source, a disposable cassette, a vessel 60, a reservoir for an agent, and/or the like. Further, merely by way of example, the carrier 182 may be tailored to provide lumen access to a particular site and/or for multiple sites.

A device housing in one embodiment of the invention is in the range of about 6 inches long, 3 inches wide, and 1 inch deep. Compartments 30 and 92 may be constructed in a range of sizes, but an internal volume of approximately 5mL would be suitable. The exudate reservoir 60 could be a range of sizes depending on the circumstances of the treatment, but volume capacities of 250ml, 50OmL, 75OmL, 100OmL and 200OmL are envisaged. Lumens 20, 12 and 62 could typically have an internal diameter between ¹A and 1/8 inch. The internal volume of chamber 70 would typically be equal to or less than the internal volume of 30 92 (ie less than 5mL). While such size ranges are provided as examples, those of skill in the art will appreciate the suitability of the invention to a wide range of other sizes.

Various modifications, processes, as well as numerous structures that may be applicable herein will be apparent. Various aspects, features or embodiments may have been explained or described in relation to understandings, beliefs, theories, underlying assumptions, and/or working or prophetic examples, although it will be understood that any particular understanding, belief, theory, underlying assumption, and/or working or prophetic example is not limiting. Although the various aspects and features may have been described with respect to various embodiments and specific examples herein, it will be understood that any of same is not limiting with respect to the full scope of the appended claims or other claims that may be associated with this application. The present invention is not to be limited in scope by the specific embodiments described above, which are intended as illustrations of aspects of the invention. Functionally equivalent methods and components are within the scope of the invention. Various modifications of the invention, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.

Claims

We claim:

1. A negative pressure treatment device for removing material from a bodily site, comprising: a first lumen for removal of a non-gaseous fluid from the site; a chamber, defining an interior space, for drawing the non-gaseous fluid from the first lumen into the interior space; a valve disposed between the first lumen and the chamber to provide unidirectional flow of the nongaseous fluid from the first lumen toward the chamber; a second lumen for removal of a gaseous fluid from the site, said second lumen being operably connected with a vacuum source; and at least one vent for maintaining or releasing a vacuum supplied by the vacuum source.

2. The device of claim 1 , wherein the chamber and vent are removable from the device.

3. The device of claim 2, wherein the chamber and vent are a removable cassette.

4. The device of claim 1, wherein the vent is controlled by a second valve.

5. The device of claim 1, wherein the chamber is capable of expelling non-gaseous fluid from the interior space.

6. The device of claim 1, wherein the chamber is compressible and decompressible.

7. The device of claim 1, wherein the chamber comprises at least one moveable structure.

8. The device of claim 1, wherein material is removed from the site in the absence of a trap.

9. The device of claim 1, wherein non-gaseous fluid is removed regardless of the orientation of the chamber with respect to gravity.

10. The device of claim 1, wherein the first lumen and the second lumen are in fluid communication with the site via an intermediary chamber comprising a chamber opening, the chamber opening being in fluid communication with the site.

11. The device of claim 1, further comprising a cover for placement over the site, wherein the first lumen and the second lumen are in fluid communication with the site via the cover.

12. The device of claim 11, wherein the cover comprises a screen capable of inhibiting collapse of the site when the site is exposed to negative pressure.

13. The device of claim 11, wherein the cover forms a substantially fluid-impermeable seal with respect to the first lumen and the second lumen.

14. The device of claim 1, further comprising a vessel in fluid communication with the chamber for collection of non-gaseous fluid therefrom.

15. The device of claim 14, wherein the vessel is collapsible.

16. The device of claim 1 , wherein the site is a wound.

17. The device of claim 1, wherein the site is a site associated with bodily fluid.

18. The device of claim 1, wherein the non-gaseous fluid comprises exudate.

19. The device of claim 1, wherein the non-gaseous fluid comprises milk.

20. The device of claim 1, wherein therapeutic agents may be introduced to the site through one of the lumens.

21. The device of claim 1, further comprising a sensor-based feedback loop system for controlling the application and adjustment of negative pressure.

22. A method of removing material from a bodily site, comprising the step of applying and activating the device of claim 1 to remove material from the site.

23. The method of claim 22, wherein a therapeutic agent is administered via the device contemporaneously or serially with removal of the material.