CN110944608A

CN110944608A - Control devices for wound therapy delivery and related methods of use

Info

Publication number: CN110944608A
Application number: CN201880049910.5A
Authority: CN
Inventors: 林正纶
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-07-29
Filing date: 2018-07-26
Publication date: 2020-03-31
Anticipated expiration: 2038-07-26
Also published as: CN111050711B; CN110958866A; CN111050711A; CN110996866A; CN110944608B; WO2019027806A1; WO2019027808A1; WO2019027807A1; WO2019027809A1; CN110958866B; WO2019027810A1; CN111343949A; CN110996866B

Abstract

In various aspects of the invention, the wound treatment apparatus disclosed herein includes a wound interface that forms a fluid-tight enclosed space over a wound bed when the wound interface is secured to a skin surface surrounding the wound bed. In various aspects of the invention, a wound treatment apparatus includes a control group cooperating with a wound interface for regulating fluid input into an enclosed space and fluid output from the enclosed space to be at substantially a minimum pressure p_minTo a maximum pressure p_maxChange the actual pressure p in the enclosed space_aMinimum pressure p_minLess than ambient pressure p_ambWherein the input fluid contains O₂A gas having a concentration greater than atmospheric air. The introduction of the fluid and the discharge of the fluid may be performed sequentially. Related methods of using wound therapy devices are disclosed herein.

Description

Control devices for wound therapy delivery and related methods of use

Cross Reference to Related Applications

This application claims priority from the following patent applications: us patent application No. 15/663,708 filed on 29.7.7.2017, us patent application No. 15/663,709 filed on 29.7.7.7.7. 15/663,710 filed on 29.7.7.2017, us patent application No. 15/663,713 filed on 29.7.7.2017, and us patent application No. 15/663,714 filed on 29.7.7.2017. All priority-claims patent applications are hereby incorporated by reference in their entirety as if fully set forth herein.

Background

Technical Field

The present disclosure relates to medical devices, and more particularly, to apparatus for wound therapy and related methods.

Background

The wound bed, as referred to herein, comprises a localized area of tissue that has lost its cortex affected by adverse factors, resulting in, for example, cellular abnormalities such as swelling, inflammation, degeneration, infection or cell death. The wound bed may contain underlying tissue and structures that are exposed to varying degrees, with possible infection and tissue changes. The wound bed represents an unhealed wound. By contrast, a healing wound is meant the surface of the skin, previously wounded, but now the major gap has been completely closed and covered by a varying amount of epidermis and scar tissue. The wound bed may be located within a wound boundary that extends along the affected area at the skin surface of the skin. The wound bed may continue deep into the dermis and the wound bed may extend deeper, for example, deep into the subcutaneous fat, muscle, or deeper. Thus, the wound bed may include damaged flaps, sinuses, tracts and fistulas, as well as surrounding affected tissue. Fig. 1 illustrates a wound bed including some of the anatomical structures involved therein. Wound boundary, as referred to herein, refers to the perimeter of the wound bed at the skin surface of the skin.

A variety of Negative Pressure Wound Therapy (NPWT) devices are currently used to treat wound beds, including dressings, films, and drainage tubes. To use the current NPWT apparatus, the wound is filled with a dressing and a drainage tube is placed over the dressing. The film is then placed over the wound bed and adhered to the skin surface around the wound bed to seal the wound bed, dressing, and drainage tube in place. Finally, air in the region between the membrane and the wound bed is removed through a drain tube in fluid communication with the dressing to create a sub-ambient pressure p in the enclosed space between the membrane and the wound bed_ambNegative pressure p of_s. When negative pressure p_sReduced to below ambient pressure p_ambIn time, the wound bed and surrounding skin are compressed. Exudate from the wound bed may be transported through the dressing and then discharged through the drainage tube. Suction pressure p applied to the wound bed that may be static_sBetween about-80 mm Hg to about-175 mm Hg, below ambient pressure p_amb。

The negative pressure p being other than during dressing change_sCan be statically maintained continuously for weeks or even months until the treatment is finished. Since capillaries are extremely thin-walled, tiny blood vessels, capillariesIs easy to be sucked flat due to the suction pressure. Studies have shown that at distances of 2.5cm from the wound edge, the increase in blood flow is associated with a negative pressure p_sProportionally, blood flow is deleteriously reduced at 0.5cm from the wound edge, and closer to the wound bed, where increased blood flow is most needed.

It has therefore been recognized that the negative pressure p is relieved from time to time_sTo allow for re-filling of the capillaries adjacent the wound bed may be advantageous. However, the negative pressure p_sThe mitigation of (b) is achieved in current NPWT apparatus by introducing atmospheric air into the enclosed space between the membrane and the wound bed, if provided at all. Negative pressure p_sCan be mitigated, for example, to p_amb-25mm Hg instead of p_ambTo keep the membrane sealingly secured to the wound bed. In some arrangements, the negative pressure p_sThe release in this manner of (a) may occur only intermittently, or not at all.

NWPT lasts on average about 6 months, demonstrating that it is challenging to get sufficient blood flow and oxygen to the wound bed to enable healing. NWPT requires intensive care and supervision by physicians, and NWPT may need to be performed in a hospital or other similar facility. NWPT often fails due to wound-related complications, resulting in thousands of deaths, with 8 million amputations per year in the united states, each amputation potentially representing months, or even years, of failure of expensive treatment. Worldwide, nearly 100 million amputation surgeries will be performed every month. NPWT can be difficult to apply and dressing changes are often very painful, as granulation tissue destruction will occur with each dressing change, which typically occurs every other day. This damage to the granulation tissue may impede the healing process. Approximately 66% of the wound beds require 15 weeks of NWPT, while another 10% require 33 weeks or more for the healing.

Furthermore, due to protein exudates, the drainage tube may become clogged, which may lead to an interruption of the NWPT. When there is actually little or no negative pressure in the enclosed space above the wound bed, the negative pressure p_sMay not accurately sense andindicating negative pressure p_sAt the desired value. Because of the cumbersome application of the dressing, and the pain associated with removal, repeated removal of the dressing to attach devices for delivery of other therapies is considered impractical.

NPWT has been combined with antibiotic perfusion to treat particularly difficult wound beds. The system inserts one or more liquid treatments several times a day, with the solution introduced into the wound bed and allowed to "dwell" for a period of time, then removed. Such "infused NPWT" requires a prior measurement of the wound bed volume, and input of the wound bed volume to an infusion pump, so that no excessive infusion occurs, which could compromise the seal integrity of the cover around the wound bed. Additional time, equipment and great attention need to be provided to manage the NPWT in conjunction with perfusion.

Another common wound treatment is systemic hyperbaric oxygen (HBO). The patient is placed in a hyperbaric chamber and is exposed to medically pure oxygen, typically at 2.5ATA (absolute atmospheric pressure), for 90 minutes. Probably due to peroxides, H₂O₂Or other oxidative free radical formation, exposure for 120 minutes increases the risk of oxygen poisoning, possibly leading to seizures and other serious consequences. Such a 90 minute treatment period corresponds to only 6% of the day providing oxygen enrichment to the wound bed. The U.S. branch of medical insurance typically approves 30-40 HBO treatments per treatment session, which costs hundreds to $ 1000 per treatment session. This underscores not only the high cost of chronic wound care and the low ability to affect healing through only a few courses of HBO, but also the general lack of a more effective treatment modality. Other alternatives, such as wrapping a plastic bag around a wound bed and inflating it with pure oxygen under high pressure for 90 minutes, are less costly but suffer from similar drawbacks, since static compression of the wound bed during treatment generates a counter-force pressure that largely counteracts the low arterial perfusion.

Thus, for at least these reasons, it is apparent that there is a strong and unmet need to improve wound treatment devices and related wound treatment methods and related combinations of modalities.

Disclosure of Invention

These and other needs and disadvantages are met and overcome by the wound treatment devices and associated methods of use disclosed herein. Additional modifications and advantages may be recognized by those skilled in the art upon studying the disclosure.

Sometimes, the wound treatment apparatus disclosed herein includes a wound interface that forms an enclosed space above a wound bed, the wound interface being fluid-tight when secured to a skin surface surrounding the wound bed. At times, the wound treatment apparatus includes a control group that cooperates with the wound interface to regulate the introduction of an input fluid, including O, into the enclosed space₂A gas having a concentration greater than atmospheric air, and a regulated output fluid is directed from the enclosed space to be at substantially the minimum pressure p_minTo a maximum pressure p_maxIn the closed space, the actual pressure p in the closed space is changed_aMinimum pressure p_minLess than ambient pressure p_amb. At some time, O₂The input of a gas having a concentration greater than atmospheric air, and O₂The removal of gases with a concentration greater than atmospheric air is carried out sequentially.

Sometimes, the wound treatment devices disclosed herein include a source of liquid, O₂A source of gas at a concentration greater than atmospheric air, and a wound interface coupled to the skin surface surrounding the wound bed to form an enclosed space surrounding the wound bed, the enclosed space being fluid-tight. At times, the wound treatment apparatus includes a control group operatively connected to the liquid source, the gas source and the enclosed space to selectively input the liquid and gas into the enclosed space and to regulate the output fluid to be directed out of the enclosed space.

A related method of use of the wound treatment devices disclosed herein may include the steps of: connecting the wound interface to the skin surface surrounding the wound bed, thereby forming an enclosed space, and the steps of: at times, using the control group, the introduction of the regulated input fluid into the enclosed space and the discharge of the regulated output fluid from the enclosed space are sequenced, so as to be in accordance with the target pressure p₀Is periodically cycledVarying the actual pressure p in the enclosed space_a. At some point in time, the pressure cycle has a minimum pressure p_minAnd maximum pressure p_maxThe input fluid comprising O₂A gas having a concentration greater than atmospheric air.

This summary presented provides a basic understanding of some aspects of the devices and methods disclosed herein, as a prelude to the detailed description that follows. Accordingly, this summary is not intended to identify key elements or to delineate the scope of the apparatus and methods disclosed herein.

Drawings

FIG. 1 depicts a cross-sectional view of an exemplary wound bed with erosion, wound tunnels, and fistulas;

FIG. 2 illustrates, by way of a schematic diagram, one exemplary implementation of a wound treatment apparatus;

FIG. 3A illustrates, by way of a schematic diagram, a first operative configuration of a second exemplary implementation of a wound treatment apparatus;

FIG. 3B illustrates schematically a second operational configuration of an exemplary implementation of the wound treatment apparatus of FIG. 3A;

FIG. 4A illustrates a cross-sectional schematic view of a portion of the exemplary wound treatment apparatus of FIG. 3A in a first operative configuration;

FIG. 4B illustrates a schematic cross-sectional view of a portion of the exemplary wound treatment apparatus of FIG. 3A in a second operational configuration;

FIG. 5 illustrates schematically the operational state of the exemplary wound treatment apparatus of FIG. 3A;

fig. 6A illustrates a cross-sectional elevation view of a third exemplary implementation of a wound treatment apparatus at a first stage of operation.

Fig. 6B illustrates a cross-sectional elevation view of a portion of the wound treatment apparatus of fig. 6A at a second stage of operation.

FIG. 7 illustrates, in a cut-away perspective view, a fourth exemplary embodiment of a wound treatment apparatus

FIG. 8 illustrates a fifth exemplary embodiment of a wound treatment apparatus in a cross-sectional elevation view

Fig. 9A illustrates, by cartesian diagram, an exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatus of fig. 2, 3A, 6A, 7, and 8);

fig. 9B illustrates, by cartesian plot, a second exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9C illustrates, by cartesian diagram, a third exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9D illustrates, by cartesian plot, a fourth exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9E illustrates, by cartesian plot, a fifth exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9F illustrates, by cartesian plot, a sixth exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9G illustrates, by cartesian plot, a seventh exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9H illustrates, by cartesian plot, an eighth exemplary pressure cycle delivered to a wound bed by a wound treatment device (e.g., the exemplary wound treatment devices of fig. 2, 3A, 6A, 7, and 8);

fig. 9I illustrates, by cartesian plot, a ninth exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8);

fig. 9J illustrates, by cartesian plot, a tenth exemplary pressure cycle delivered to a wound bed by a wound treatment apparatus (e.g., the exemplary wound treatment apparatuses of fig. 2, 3A, 6A, 7, and 8); and

fig. 10 illustrates, by way of a flow chart, an exemplary method of using a wound treatment apparatus (e.g., the exemplary wound treatment apparatus of fig. 2, 3A, 6A, 7, and 8);

the illustrations are exemplary only, with the illustrated embodiments selected herein for convenience of explanation. The elements shown in the figures, such as numbers, positions, relationships, and dimensions, constitute various implementations described herein, and similarly, the dimensions and proportions are consistent with the particular force, weight, strength, flow, and similar requirements explained herein, or readily understood by one of ordinary skill in the art in view of this disclosure. Wherever possible, the same reference numbers are used in different drawings to refer to the same or like elements. Furthermore, when the terms "top," "bottom," "right," "left," "front," "rear," "first," "second," "inner," "outer," and similar terms are used, they should be understood with reference to the orientation of the embodiments as shown in the drawings and utilized to facilitate the description thereof. Relative terms used herein, such as substantially, approximately, substantially, may refer to engineering, manufacturing, or scientific tolerances, such as, for example, ± 0.1%, ± 1%, ± 2.5%, ± 5%, or other such tolerances, as would be readily understood by one of ordinary skill in the art after studying this disclosure.

Detailed Description

Wound treatment devices and related methods of wound treatment are disclosed herein. In some instances, the wound treatment apparatus includes a wound interface secured to a skin surface surrounding a wound bed to form an enclosed space over the wound bed, the enclosed space being fluid-tight. At times, the control group, in cooperation with the wound interface, regulates the introduction of input fluid into the enclosed space and regulates the discharge of output fluid from the enclosed space to be at approximately the minimum pressure p_minAnd maximum pressure p_maxIn the closed space, the actual pressure p in the closed space is changed_a. At all times, the minimum pressure p_minLess than ambient pressure p_amb，O₂The input and output of the gas with the concentration higher than the atmospheric air are performed in sequence. Control ofThe group may be at a minimum pressure p_minAnd maximum pressure p_maxPeriodically changing the actual pressure p in the enclosed space during the pressure cycle in between_a. The gas may have a greater than atmospheric O₂Concentration (about 20.95 vol% or about 0.2095 moles of O per mole of dry air)₂)。

Fluids, including, liquids, gases, and combinations thereof, are described herein. Liquids, such as saline solutions, dactinous solutions, proteolytic enzyme solutions, biofilm degrading solutions, cytokines, antibiotic lavage solutions, amniotic fluid, platelet rich plasma, antibiotics, analgesics, anesthetics, and combinations thereof. The liquid may comprise saline or a water-based solution, for example, to rinse the wound bed, remove initial contaminants, or wet the wound bed.

The gas may include, for example, air, oxygen, nitric oxide, nitrogen, or a suitable therapeutic or inert gas, as well as combinations thereof. The gas, for example, may be nitric oxide diluted with nitrogen at about 200ppm to about 800 ppm. At some point, the actual pressure p in the enclosed space is input into the enclosed space_aFrom the minimum pressure p_minIncrease to a maximum pressure p_maxOf gas (a) O₂The concentration is greater than atmospheric air (about 21.95% by volume). At times, the gas may be medical grade oxygen. Medical grade oxygen may meet certain standards, for example, the U.S. food and drug administration standards, or other appropriate regulatory standards. Sometimes, the medical grade oxygen may be U.S. medical grade oxygen. At times, the input fluid 16 provided to the wound interface 115 may be a liquid with certain therapeutic benefits.

The sequential exit of the output fluid from the enclosed space and the introduction of the input fluid into the enclosed space means that the exit of the output fluid and the introduction of the input fluid do not occur simultaneously. The input fluid may be introduced into the enclosed space or the output fluid may be withdrawn from the enclosed space, but the introduction of the input fluid and the withdrawal of the output fluid do not occur simultaneously. One exception is when the input fluid is a liquid and the liquid is both input and output, for example, during a wound bed irrigation procedure. The wound bed can be irrigated or rinsed by an amount of input liquid that is several times the volume of the enclosed space to clean the wound bed, for example, to clean bacteria, cell debris and biofilm.

Using the "down time" of the relaxation phase of NPWT, programmed delivery of oxygen or other therapeutic fluids (including gases and liquids) into an enclosed space, a large number of new beneficial treatments can be effectively generated in the 24 hour range, which has not even previously existed for negative pressure therapy. The net result is that many new uniform, periodic, additional hours of beneficial therapy are interspersed between negative pressure therapies, which may accelerate healing by synergistic effects. Since chronic wounds heal very long, lasting on average 23 weeks, the ability to increase daily the important required treatments without reducing the duration of the basic negative pressure therapy can produce other synergistic effects as accelerated healing. For example, assume a pressure cycle of 6 minutes duration, where the pressure p₀At p_minFor 4 minutes, and pressure p₀Is released to p_maxLasting 2 minutes (i.e., 1/3 for the negative pressure cycle was pressure released). In this example, p_maxMay be ambient pressure p_ambOr larger. In this example, O is used₂A fluid at a concentration higher than atmospheric air, resulting in a local oxygen therapy at about ambient pressure or higher for 2 minutes. This topical oxygen therapy was performed 10 times an hour for 2 minutes, increasing up to 240 cycles per day, corresponding to 8 hours per day topical oxygen therapy, without reducing the total amount of negative pressure therapy delivered. This may provide additional therapy without replacing or shortening the underlying preferential negative pressure therapy. It is to be noted that p_min，p_maxAnd p_ambAre approximate and relative and may vary from pressure cycle to pressure cycle depending on the equipment and environmental factors, including altitude. But the therapeutic result can be substantially achieved regardless of whether the target pressure is accurately or approximately achieved.

As a second example, the pressure cycle has a duration of 6 minutes, where the pressure p₀At p_minFor 3 minutes, the pressure is released to p_maxFor 3 minutes (1/2 for the duration of the pressure cycle), this resulted in the delivery of topical oxygen therapy to the wound bed approximately at or above ambient pressure for a total of 12 hours per day. Thus, in the healing phase towards the later stage, when edema and exudation are greatly reduced, less negative pressure p is required_minThe duration of local oxygen can be increased accordingly to accelerate the healing of the next stage.

At times, each release of the nth pressure cycle (where n is any suitable number such as 2 to 60 or even 120 or more) is performed with a liquid.

A method of wound treatment includes, at times, providing a treatment regimen to a wound bed within an enclosed space, the treatment regimen comprising continuously delivering an actual pressure p within the enclosed space_aEach pressure cycle typically including a pressure range p_min≤p_a≤p_maxWherein p is_min≤p_amb，p_amb≤p_max，p_min＜p_max，p_ambIs ambient pressure, when each pressure cycle is from p_minTo p_maxIn operation, an input fluid comprising a gas and a liquid is introduced into the enclosed space. Pressure p_min，p_maxAnd the duration of the pressure cycle, as well as the fluid introduced into the enclosed space, may vary in each pressure cycle, depending on the desired therapeutic goal.

At times, the method of wound treatment may include the steps of: the wound interface is connected to the skin surface surrounding the wound bed, thereby forming an enclosed space. At times, the method of wound treatment may include the steps of: using the control group, the introduction of the regulated input fluid into the enclosed space and the discharge of the regulated output fluid from the enclosed space are sequenced, thereby periodically varying the actual pressure p within the enclosed space_aSubstantially according to the target pressure p₀Pressure cycle having a minimum pressure p_minAnd maximum pressure p_maxThe input fluid containing O₂A gas having a concentration greater than atmospheric air. At times, the method of wound treatment may include the steps of: tong (Chinese character of 'tong')The exudate is removed from the enclosed space by flowing the output fluid to the container. The input fluid may be a liquid at times, in which case the introduction of the input liquid and the withdrawal of the output liquid may occur sequentially or simultaneously, depending on the goal of the treatment. At times, the method of wound treatment may include the steps of: receiving data from a user side through an I/O interface; and communicating data from the user I/O to the controller to thereby change the target of the pressure cycle. At times, the method of wound treatment may include the steps of: delivering a treatment regime to the wound bed, the treatment regime comprising an actual pressure p within the enclosed space_aA series of pressure cycles.

At some point, during the partial pressure cycle, by adding O₂At a concentration greater than O found in the atmosphere₂The gas with concentration is input into the closed space, and rich O is generated₂Can resuscitate hypoxic wound cells, resuscitate cells that can support cell division and collagen synthesis, can inhibit the growth of anaerobic bacteria, can enhance the efficacy of antibiotics, and can improve the survival of stem cells and tissue grafts, and enhance the therapeutic benefits of other bioengineered materials. In addition, so rich O is provided to the wound bed₂May be beneficial because of the abundance of O₂[1]Under favorable concentration gradient; [2]At an advantageous pressure gradient that does not interfere with baseline arterial perfusion (e.g., 20-60mm Hg, but may be higher for a brief duration), and [3]During relatively reflective hyperemia of a tissue region, where capillaries may have previously collapsed under negative pressure. The result is that maximum absorption and uptake of oxygen is achieved with increased flow. In addition, O provides high pressure conditions in a fluid tight enclosure₂The amplitude and period of delivery may additionally be used and programmed to provide external pulsed pressurization O₂In a form in which beneficial circulatory effects are in some ways similar to providing external CPR to a wound bed.

At times, the method of wound treatment may include the steps of: introducing a liquid into the enclosed space, and comprising the steps of: the liquid is conducted out of the enclosed space. Methods of wound therapy may include irrigating a wound bed using sequential fluid input and output to and from an enclosed space. A method of wound treatment may include providing treatment to a wound bed by inputting a liquid of therapeutic nature into an enclosed space. Therapeutic attributes may include, for example, proteolytic, analgesic, antimicrobial, or healing attributes. Similarly, at times, if the goal is to achieve a fast flow flush, the liquid input and output relative to the enclosed space may occur simultaneously rather than sequentially.

Reference herein to ambient pressure p_ambRefers to the pressure in the area surrounding the wound treatment device. Ambient pressure p_ambFor example, atmospheric pressure, hull pressure within an aircraft in which the wound therapy device is used, or pressure generally maintained within a building or other structure in which the wound therapy device is used may be referred to. Ambient pressure p_ambMay change due to, for example, altitude or weather conditions. At some time, the pressure p_minRefers to the minimum pressure reached within the enclosed space of the wound treatment device, the pressure p varying periodically₀Pressure change, varying pressure and similar terms refer to a time-varying pressure p within an enclosed space₀Is changed. Pressure p_maxRefers to the maximum pressure reached within the enclosed space of the wound treatment device. Exudate as referred to herein includes, for example, proteinaceous fluids exuded from the wound bed, as well as various plasma and blood components. The exudate may also include waste liquids, such as irrigation fluids.

The term "fluid-tight" or related terms, as used herein, at times, refers to having sufficient leak-resistance to permit the creation of a pressure p within the enclosed space at the wound interface that may be above or below ambient pressure p by insufflation or vacuum suction_ambActual pressure p of₀. Or to substantially maintain fluid within the enclosed space, including gases and liquids, except through one or more lumens in fluid communication with the enclosed space. The term "fluid-tight" or related terms, as used herein, sometimes refers to a leak-resistant material having sufficient resistance to allow insufflation or vacuum suction to maintainActual pressure p in the enclosed space holding the wound interface₀Above or below ambient pressure p_amb。

The terms "distal" and "proximal", as used herein, are defined from the perspective of a user using the wound treatment apparatus to treat a patient, such as a doctor, nurse, or medical care provider. The distal portion of the wound therapy device faces the patient and the proximal portion of the wound therapy device faces the healthcare provider. When the distal portion of the device is near the patient, the proximal portion of the device is near the user treating the patient.

At times, the wound interface described herein resists deformation to resist collapse and substantially maintain its shape, including forming an enclosed space within which to apply an actual pressure p_a≤p_ambWhen it is sufficient to direct a portion of the wound bed toward or into the enclosed space, including the enclosed space occupied by the wound bed. At least a portion of the wound interface forming the enclosed space may be substantially rigid at times. At all times, the wound interface, with sufficient deformability to remain sealingly fixed to the skin surface, is maintained over the entire pressure range p_min≤p_a≤p_maxThe inner part is not sealed by fluid.

The apparatus, associated methods of use, and associated compositions disclosed herein may be implemented, at least in part, by software in the form of readable instructions operably received by one or more computers to cause, at least in part, one or more computers to operate as an apparatus, or to perform steps of a method of use. At times, the methods of use disclosed herein may be implemented as a combination of hardware and software operably received. The compositions disclosed herein include a non-transitory computer-readable medium, which is operatively received by one or more computers to cause, at least in part, one or more computers to function as a device, or to perform steps of a method of use.

The computer referred to herein comprises computer readable instructions operable to be received by a processor for execution. The computer may be, for example, a single processor computer, a multi-core computer, a minicomputer, a mainframe computer, a supercomputer, a distributed computer, a personal computer, a handheld computing device, a tablet, a smartphone, and a virtual machine, and the computer may include multiple processors in networked communication with one another. At times, the computer may include memory, screens, keyboards, mice, storage devices, I/O devices, etc., which are operatively coupled to the network. The computer may execute a variety of Operating Systems (OSs), such as Microsoft Windows, Linux, UNIX, MAC OS X, real-time operating system (RTOS), VxWorks, INTEGRITY, Android, iOS, or a single software or firmware implementation without a traditional operating system.

The networks referred to herein may include the internet cloud, and other local to global networks. The network may include, for example, data storage devices, input/output devices, routers, databases, computers including servers, mobile devices, wireless communication devices, cellular networks, optical devices, cables, and other hardware and software operable, as would be readily recognized by one of ordinary skill in the art upon review of the present disclosure. The network may be wired (e.g., optical, electromagnetic), wireless (e.g., Infrared (IR), electromagnetic), or a combination of wired and wireless, and the network may conform, at least in part, to a variety of standards (e.g., Bluetooth FDDI, ARCNET IEEE 802.11, IEEE 802.20, IEEE 802.3, IEEE 1394-1995, USB).

Fig. 2 illustrates an exemplary wound treatment apparatus 10, as shown in fig. 2, a wound interface 15 is secured to a skin surface 11 to form a fluid-tight enclosed space 17 over a wound bed (e.g., wound

beds

213, 313, 413). In this embodiment, the wound treatment apparatus 10 includes a gas source 82 and a liquid source 84 in fluid communication with the enclosed space 17 of the wound interface 15. As shown in FIG. 2, the wound treatment apparatus 10 comprises an administration set 30, the administration set 30 including a controller 87, a user I/O86, a valve 88, a pump 89 and a pressure sensor 91. As shown, the control group 30 regulates gas 22 from a gas source 82, liquid 24 from a liquid source 84, or a combination of gas 22 and liquid 24, as the input fluid 16, into the enclosed space 17. As shown, the control group 30 regulates the egress of the output fluid 18 from the enclosed space 17. the output fluid 18 may include, for example, input fluid 16, exudate 19, and air, which are then vented from the enclosed space 17 after the wound interface 15 is secured to the skin surface 11. It should be appreciated that in this embodiment, the controller 87, user I/O86, valve 88, pump 89 and pressure sensor 91 are combined into the control group 30, merely for purposes of explanation, the controller 87, which has no space or other physical structure or proximity, the user I/O86, valve 88, pump 89 and pressure sensor 91 are hidden from each other or from the gas source 82, the liquid source 84 or wound interface 15 by being combined into the control group 30.

Controller 87 is operatively connected to user I/O86 and user I/O86 for communicating data 74 via communications path 64. The controller 87 is operable to communicate with the valve 88, the pump 89 and the pressure sensor 91 via the

communication paths

61, 62, 66 to control operation of the valve 88, the pump 89 and the pressure sensor 91, respectively, to vary the pressure p within the enclosed space 17 by regulating the introduction of the input fluid 16 into the enclosed space 17 and the removal of the output fluid 18 from the enclosed space 17 in response, at least in part, to data 74 received by the controller 87 from the user I/O86₀For example, according to exemplary pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 (see fig. 9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9I, 9J, respectively). The controller 87 can control operation of the valves 88, pumps 89, and pressure sensors 91 to respond, at least in part, to the data 74 from the user I/O86, for example, to deliver therapy protocols 1, 2, 3, or 4 to a wound bed surrounded by the wound interface 15 (see example 1). Using user I/O86, a user may select a pressure cycle, such as pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, and a user may select a treatment protocol, such as treatment protocol 1, 2, 3, or 4.

The controller 87 controls operation of the wound treatment apparatus 10 based, at least in part, on the data 74 transmitted to the controller 87 from the user I/O86. The controller 87 can control operation of the wound treatment apparatus 10, at least in part, based on the

data

71, 72, 73, communicated between the controller 87 and the valve 88, the pump 89 and the pressure sensor 91, respectively. In this embodiment, for illustrative purposes, the valve 88 and the pressure sensor 91 are illustrated as a single valve and a single pressure sensor. It should be appreciated that the valve 88 may include one or more valves disposed at various locations of the wound treatment apparatus 10 and the pressure sensor 91 may include one or more pressure sensors disposed at various locations of the wound treatment apparatus 10, as will be readily appreciated by those of ordinary skill in the art having reviewed the present disclosure. The controller 87 may include, for example, a processor, memory, software, operative to communicate with a microprocessor, A/D converter, D/A converter, clock, I/O connector, etc., and the controller 87 may be configured, for example, as a single chip or as a combination of chips disposed on a circuit board, as will be readily recognized by those of ordinary skill in the art having the benefit of this disclosure. In certain embodiments, the controller 87 may be configured as software, operatively received by a computer, the location of which may be at least partially remote from, for example, the valve 88, the pump 89, and the pressure sensor 91.

The user I/O86 may include a variety of switches, buttons, dials, sliders, graphics, etc., whether virtual or physical, for obtaining data 74 from the user and then communicating to the controller 87 to allow the user to direct the operation of the wound treatment apparatus 10, including the pressure p within the enclosed space 17₀Pressure cycling and the provision of multiple treatment protocols. In some embodiments, the user I/O is formed as software that is operably received by the computer. The controller 87 may communicate the data 74 with a user I/O to direct the operation of the wound treatment apparatus 10, which the user I/O86 may display to the user.

As shown in fig. 2, a gas source 82 is in fluid communication with gas 22 in the enclosed space 17 of the wound interface 15, a liquid source 84 is in fluid communication with liquid 24 in the enclosed space 17 of the wound interface 15, and input fluid 16 is controlled by a controller 87 using a valve 88. For example, when controlled by the controller 87, the valve 88 may select gas 22 from the gas source 82, liquid 24 from the liquid source 84, or a combination of gas 22 from the gas source 82 and liquid 24 from the liquid source 84 as the input fluid 16 to the enclosed space 17. The valve 88 can regulate, at least in part, the ingress of the input fluid 16 into the enclosed space 17 of the wound interface 15. The gas source 82 may be, for example, a cylinder containing oxygen, an oxygen bag, an oxygen generator, or a mains gas containing mains oxygen. The liquid source 84 may be, for example, a container of liquid 24, or a mains supply of liquid 24.

As shown in fig. 2, the output fluid 18 directed from the enclosed space 17 passes through the container 81, and the container 81 captures exudate 19 or liquid, such as liquid 24, from the output fluid 18 in the chamber 99 of the container 81. The gaseous portion of output fluid 18, or gas that is expelled from chamber 99 of container 81 by capturing liquid 24 or exudate 19, may then be discharged from pump 89 to the atmosphere. The valve 88, pump 89, or a combination of the valve 88 and pump 89, can regulate the output fluid 18 to be directed out of the enclosed space 17 of the wound interface under the control of the controller 87. The container 81 may be omitted when the amount of exudate 19 is minimal or no liquid, such as liquid 24, is present in the output fluid 18.

By the pressure p in the chamber 99 of the container 81_rWhen the pressure in the chamber p_rLess than ambient pressure p_ambAt least a portion of the liquid 24 can be conducted out of the closed space 17. Chamber 99, which may be disposable and replaceable, provides a reservoir for liquid 24 flowing through enclosed space 17 such that a volume of liquid 24 approximately equal to the volume of chamber 99 may flow through enclosed space 17 and collect in chamber 99. When the pump 89 is in the closed position and the pressure p in the chamber_rLess than ambient pressure p_ambWhen the liquid 24 guided out of the closed space 17 collects in the chamber 99, the pressure p in the chamber_rTowards ambient pressure p_ambAnd (4) reducing. For example, when the pressure p in the chamber_rTo a sub-ambient pressure p_ambAt some set point, e.g., -10mm Hg, or when liquid 24 fills a particular portion of cavity 99, to prevent excessive pressure p within enclosed space 17₀The input of liquid into the enclosed space 17 may be stopped when the seal of the wound interface 15 to the skin surface 11 may be broken.

As illustrated in the schematic of fig. 2, valve 88 is in operative communication with gas 22, liquid 24, input fluid 16, and output fluid 18. Thus, in the illustrated embodiment, the valve 8 may comprise one or more valves configured on the wound treatment apparatus to select whether the input fluid 16 is a gas 22, a liquid 24, or a combination of gas 22 and liquid 24 to at least partially regulate the introduction of the input fluid 16 into the enclosed space 17 of the wound interface 15 and to at least partially regulate the exit of the output fluid 18 from the enclosed space 17 of the wound interface 15. Data 71 may control the operation of valve 88, and data 71 may indicate the operation of valve 88. For example, the data 71 may position the valve 88 from an open position to a closed position, or the data 71 may indicate that the valve 88 is in an open position or in a closed position.

As shown in the schematic of fig. 2, pressure sensor 91 is in operative communication with gas 22, liquid 24, input fluid 16, and output fluid 18, and enclosed space 17. Pressure sensor 91 may include one or more pressure sensors operable, for example, to detect the pressure of gas 22, liquid 24, input fluid 16, output fluid 18, gas source 82, liquid source 24, or enclosed space 17 of wound interface 15 at various locations. The pressure sensor 91 may communicate data 73 to the controller 87 indicating the pressure in the plurality of locations of the gas 22, liquid 24, input fluid 16, output fluid 18, gas source 82, liquid source 84, or enclosed space 17, and the controller 87 may vary the operation of the valve 88 or pump 89 in response to the data 73 from the pressure sensor 91. Specifically, the controller may control the valve 88 or the pump 89 to maintain the actual pressure p in the enclosed space 17_aIs maintained approximately at a minimum pressure p_minAnd maximum pressure p_maxAnd the actual pressure p in the enclosed space 17 may be varied in accordance with a pressure cycle, such as the pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 described in relation to fig. 9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9I, 9J, for example_a. When p is in the enclosed space 17_aExceeding the maximum pressure p_maxIn operation, the output fluid 18 can be directed out of the enclosed space 17 through the control stack 30, and the gaseous portion of the output fluid can be vented to atmosphere. As another example, if liquid 24 is introduced as input fluid 16, the actual pressure p in the enclosed space is increased_aExceeding the minimum pressure p_minOnce the actual pressure p_aControl to a preset value (e.g., -20mmHg)The array may stop the input of liquid 24 to prevent fluid from escaping the enclosed space, which could disrupt the connection of the wound interface 15 to the skin surface 11. As another example, when liquid 24 is input as input fluid 16 while output fluid 18 is being directed from the enclosed space, the control group may adjust the input of liquid 24 to maintain the actual pressure p of liquid 24 in enclosed space 17_aEqual to the target pressure p₀(e.g., -20mmHg or ambient pressure p_amb) To prevent fluid spillage from the enclosed space which could break the link of the wound interface 15 with the skin surface 11.

Data 73 may be communicated between controller 87 and pressure sensor 91 to control the sensing of pressure, e.g., the frequency of pressure sensing, by pressure sensor 91. Data 73 may be indicative of the pressure sensed by pressure sensor 91.

The input fluid 16 may be delivered under pressure from a gas source 82 (e.g., a compressed gas tank), a liquid source 84 (e.g., a pressure tap at a liquid source), suction from a pump 89, and combinations thereof. Pump 89 may direct output fluid 18 from enclosed space 17. In certain embodiments, the pump 89 may be, for example, a centrifugal pump, a positive displacement pump, or a peristaltic pump. Data 72, for example, may be communicated from the controller 87 to the pump 89 to control the speed of the pump 89, or data 72 may be communicated from the pump 89 to the controller 87 to indicate the actual speed of the pump 89.

The wound treatment apparatus 10 may include a variety of fluid delivery devices, such as hoses, tubes, valves, conduits, connectors, pressure regulators, plenums, and a variety of other fittings to convey gas 22 and liquid 24 from the gas source 82 and liquid source 84, respectively, as input fluid 16 and to conduct output fluid 18 from the enclosed space 17 of the wound interface 15. In certain embodiments, the

communication paths

61, 62, 63, 64 may be, for example, wired, wireless, optical (e.g., fiber optic, infrared), networked (e.g., the internet), or various combinations thereof. The valve 88, pump 89 and pressure sensor 91 may include, for example, an a/D converter, D/a converter, actuator, solenoid valve, stepper motor, microprocessor to direct the operation of the valve 88, pump 89 and pressure sensor 91 by using the

data

71, 72, 73 to control the operation of the valve 88, pump 89 and pressure sensor 91, respectively, or to communicate the

data

71, 72, 73 to the controller 87, as will be readily recognized by one of ordinary skill in the art in studying this disclosure. In certain embodiments, the

data

71, 72, 73, 74 may be digital, analog, or a combination thereof.

One or more power supplies may be provided on the wound treatment apparatus 10 in electrical communication with the controller 87, valve 88, pump 89 and pressure sensor 91. The power source may be, for example, mains electricity, a battery, or a combination of mains electricity and a battery, and the power source may include, for example, a transformer, an inverter, a rectifier, a filter, and a surge protector, as would be readily recognized by one of ordinary skill in the art in view of this disclosure.

Fig. 3A, 4A and fig. 3B, 4B illustrate the operating

configurations

111, 113, respectively, of an exemplary wound treatment apparatus 100. In operative configuration 111, as shown in FIG. 3A, an administration set 130, including a reservoir housing 120, and a control pack 160, are releasably secured to one another. As shown in FIG. 3B, the receptacle housing 120 has been removed from releasable securement to the control pack 160 such that, in the operating configuration 113, the control group 130 includes only the control pack 160. Thus, in the exemplary wound treatment apparatus 100, the control group 130 may be operably configured to be releasably secured to the receptacle housing 120 of the control package 160 in the operational configuration 111, or to a separate control package 160 in the operational configuration 113.

As shown in fig. 3A and 3B, wound treatment apparatus 100 includes a gas source 112, a moisture source 114, a wound interface 115 defining an enclosed space 117, and an administration set 130. As shown in fig. 3A, 3B, the control package 160 of the control group 130 selects whether the input fluid 116 is gas 125 from the gas source 112 plus moisture 129 from the moisture source 114, or air 128 from the atmosphere 127. Control package 160 controls the introduction of input fluid 116 into enclosed space 117 of wound interface 115, controls the exit of output fluid 118 from enclosed space 117 of wound interface 115, and vents at least a portion of output fluid 118 to the atmosphere. Wound treatment apparatus 100 includes multiple fluid transport modesSuch as hoses, tubes, valves, conduits, connectors, plenums, containers and various other fittings, to deliver gas 125 from the gas source 112 and air 128 from the atmosphere 127 as input fluid 116 into the enclosed space 117 and to communicate output fluid 118 between the wound interface 115 and the control group 130. In the event of a power outage in the wound treatment apparatus 100, air 128 from, for example, the atmosphere 127 may be introduced into the enclosed space 117 as the input fluid 116 to establish the actual pressure p within the enclosed space 117_aSet to ambient pressure p_amb。

As shown in fig. 3A, the reservoir housing 120 includes a reservoir 150, and the output fluid 118 directed from the enclosed space 117 flows through the reservoir 150. The container 150 captures exudate 152 (including other liquids) from the output fluid 118 in a chamber 155 of the container 150, as shown in the implementation of fig. 3A. As shown, the gaseous portion of output fluid 118, or gas vented by the capture of exudate 152 by chamber 155 of container 150, may then be vented to atmosphere 127 by pump 189. The container 150 may be, for example, a tank, a shipping container, or a space within the container housing 120 that generally includes the interior of the container housing 120. In certain embodiments, the reservoir 150 and the reservoir housing 120 may be formed as a unitary structure. In certain embodiments, the container 150 may be removable and replaceable. In certain embodiments, the container 150 may be openable to allow the container 150 to be emptied and reused. In certain embodiments, the container 150 is sealed and non-reusable. In such embodiments, the reservoir housing 120 may be functionally a reservoir and may be entirely replaceable. Thus, the container 150, with or without the container housing 120 of the container 150, may be configured to be disposable. The chamber 155 of the container 150 may contain a pad or super absorbent polymer bag to gel the exudate 152. An odor neutralizer can also optionally be included in the reservoir housing 120, within the chamber 155.

As shown in FIG. 3B, in the operating configuration 113, the container housing 120 has been removed from releasable securement to the control pack 160, and the control group 130 includes only the control pack 160. In the operational configuration 113, the input fluid 116 is directed to the wound interface 115 and the output fluid 118 flows from the wound interface 118 toward the control package 160 without flowing through the containment housing 120, as shown in fig. 2B, under the control of the control package 160. In the operational configuration 113, the containment housing 120 may be disengaged from the control package 160 in which the control group 130 is placed, due to, for example, when exudate 152 is low to nonexistent from the wound bed, or when the wound interface 115 holds exudate 152 within the wound interface 115, or when the patient desires to be unimpeded by the containment housing 120. The control group 130 may identify the change in configuration and deliver the therapy appropriate for the corresponding configuration applicable.

As shown in fig. 4A, the control package 160, including the power source 162, the power source 162 may be different, such as a battery, a mains power supply, or a combination of a mains power supply and a battery, to provide backup power. In certain embodiments, the power source 162, which may include, for example, a transformer, an inverter, and a conditioning circuit, will be readily understood by those of ordinary skill in the art having the benefit of this disclosure. If power source 162 includes a battery, the battery may be, for example, a nickel-cadmium, nickel-metal hydride, or lithium ion based battery.

In this embodiment, the power source 162 is electrically connected to the various components of the control package 160, including the controller 165, the pump 168, the

valves

172, 173, 174, the pressure sensor 176, the pressure sensor 178, and the user I/O145, to flow power to the above components. Various power paths may be provided around the control group 130 to transmit power from the power source 162 to the controller 165, pump 168,

valves

172, 173, 174,

pressure sensors

176, 178 and user I/O145. In certain embodiments, the pump 168 may be, for example, a rotary pump or a positive displacement pump. The

valves

172, 173, 174 may be electromechanically actuated by, for example, electromagnetic or stepper motors. In certain embodiments, one or more of the

valves

172, 173, 174 may be configured as a three-way valve, or as a combination of valves. Although this embodiment includes

pressure sensors

176, 178, other embodiments may include a combination of

pressure sensors

176, 178 or a single pressure sensor that senses pressure at different locations. Other embodiments of control group 130 may include a different number of valves, such as

valves

172, 173, 174, operatively associated with a different number of pressure sensors, such as

pressure sensors

176, 178, to measure and regulate pressure from, in, or downstream of the housing. Such multipoint sensing can enable more intelligent differential monitoring and diagnosis of system or fault conditions, and can indicate the location and nature of the condition to assist in troubleshooting, adjusting or correcting the action.

In this embodiment, controller 165 controls, at least in part, the operation of wound therapy device 10, including control group 130. The controller 165 may include, for example, a microprocessor, memory, a/D converter, D/a converter, clock, I/O connector, etc., as will be readily appreciated by those of ordinary skill in the art having the benefit of this disclosure. The controller 165 may be connected to the power source 162 to monitor the power source 162, to receive power from the power source 162, or to regulate the flow of current from the power source to the pump 168,

valves

172, 173, 174,

pressure sensors

176, 178, and user I/O145. The controller 165 may be in operative communication with the pump 168,

valves

172, 173, 174, and

pressure sensors

176, 178 to regulate operation thereof. The controller 165 may be in operable communication with the pump 168, the valve 172, the valve 174, and the

pressure sensors

176, 178 to receive information from the pump 168, the

valves

172, 173, 174, and the

pressure sensors

176, 178 indicative of operation thereof or indicative of operation of the wound treatment apparatus 100.

User I/O145, which may be located outside of control group 130 or remote from control group 130, may include a display for displaying the operational status of wound treatment apparatus 100 to the user. User I/O145 may include a variety of switches, buttons, dials, and the like, whether virtual or physical, for obtaining user input to allow a user to adjust the operation of wound treatment apparatus 100, including control group 130. User I/O145 and controller 165 may communicate with each other to transmit user input from user I/O145 to controller 165 to adjust operation of wound treatment apparatus 100, including control group 130, and to communicate information from controller 165 to user I/O145 indicating operation of wound treatment apparatus 100.

Various communication paths, such as wired, optical (e.g., LASER, IR) and network, may be included in wound treatment apparatus 100 including control group 130 for communication between controller 165 and pump 168, valve 172, valve 173, valve 174,

pressure sensors

176, 178 and user I/O145. For example, in some embodiments, at least some of the user I/Os 145 may be located remotely from the rest of the control group 130, such as on a smart phone application, through various networks that may be wireless, and the user I/Os 145 may communicate, at least in part, with the controller 165. Through a wired or wireless connection, the user I/O145 may interface with a network, communicate over a network, communicate data, indicate operation of the wound treatment apparatus 100, or receive input to adjust operation of the wound treatment apparatus 100.

As shown in FIG. 3B, the control group 130 includes a control package 160, the control package 160 including a power source 162, a controller 165, a pump 168,

valves

172, 173, 174,

pressure sensors

176, 178, and a user I/O145. In the operating configuration 113, the receptacle housing 120 has been removed from connection with the control package 160 such that the control group 130 includes the control package 160 and does not include the receptacle housing 120, as shown in FIG. 3B.

As shown in fig. 3A, the wound treatment apparatus 100 may be placed in an operating configuration 111. As shown in fig. 3A, wound interface 115 is secured to skin surface 111 to enclose a wound bed, such as

wound beds

113, 213, 313, within fluid-tight enclosed space 117. As shown in FIG. 3A, wound interface 115, the control train 130 including the reservoir housing 120 and control package 160, the moisture source 114, and the gas source 112 are then placed in fluid communication with each other. When the wound bed is exuding exudate 152, for example, in an early stage of wound treatment, the wound treatment apparatus may be in the operating configuration 111, as in the operating configuration 111 (as shown in fig. 3A, 4A) comprises a receptacle 150 for collecting exudate 152.

As shown in fig. 4A and 4B, gas 125 from gas source 112 is combined with moisture 129 from moisture source 114 and communicated to valve 174 through connector 182 of control group 130 and air 128 from atmosphere 127 is communicated to valve 173 through connector 183 of control package 160. It should be noted that in fig. 4A and 4B, the path of the input fluid 116 is indicated by the arrows with white inside, and the path of the output fluid 118 is indicated by the solid arrows with black inside. The input fluid 116 may be selected from air 128 or gas 125 including moisture 129 by operation of

valves

173, 174. The controller 165 may operate the valve 174 to select the gas 125 with the added moisture 129 as the input fluid 116, or the controller 165 may operate the valve 173 to select the air 128 as the input fluid. The input fluid 116 then flows from the valve 173 or valve 174, through the connector 184 of the control group 130, and into the enclosed space 117 of the wound interface 115.

It should be noted that in some embodiments, the moisture source 114 may be omitted, for example, when the flow rate of the input fluid 116 is low and the oxygen flow is very low, no humidification is required because there is sufficient moisture in the wound bed. Moreover, it should be appreciated that the gas source 112 may include a variety of gas sources, providing a variety of gas and gas combinations as the gas 125, and that the composition of the gas 125 may vary during the course of wound treatment. The composition of gas 125 may be variously selected for use by the user at various stages of wound treatment.

As shown in FIG. 4A, in this embodiment, the pressure sensor 176 is in operable communication with the enclosed space 117 containing the input fluid 116 (when the input fluid 116 is input into the enclosed space 117) to detect the actual pressure p within the enclosed space 117_a. The actual pressure p in the enclosed space 117, detected by the pressure sensor 176_aFrom the pressure sensor 176 to the controller 165, the controller 165 may position the valve 173 or the valve 174 to regulate the flow of the input fluid 116 into the enclosed space 117 to produce the actual pressure p_aClose to the target pressure p in the enclosed space 117₀(i.e., so that p is_a≈p₀)。

In this embodiment, the pressure sensor 178 is in operable communication with the enclosed space 117 including the output fluid 118 (when the output fluid 118 is directed out of the enclosed space 117) to detect the actual pressure p within the enclosed space 117_a. The actual pressure p in the enclosed space detected by the pressure sensor 178_aMay be communicated from the pressure sensor 178 to the controller 165, and the controller 165 may position the valve 172, regulate the pump 168, or both the valve 172 and the pump 168 to regulate the output fluid 118 directed from the enclosed space and thereby generate the actual pressure p_aIs close toTarget pressure p in enclosed space 117₀(i.e., so that p is_a≈p₀)。

As shown in FIG. 4A, output fluid 118 is directed at least partially out of the enclosed volume of wound interface 115 by pump 168 under the control of valve 172, through connector 186 of control set 130, through reservoir 150, to filter 124, to connector 188 between reservoir housing 120 and control package 160, and to pump 168. Exudate 152, including other liquids, remaining in chamber 155 flows through chamber 155 of container 150 as output fluid 118, and exudate 152, including other liquids, as output fluid is captured by filter 124 as output fluid 118 passes through filter 124, as shown. The remaining gas portion of the output fluid 118 is then vented to atmosphere on the exhaust side of the pump 168.

Filter 124 prevents exudate 152, which may include other liquids in output fluid 118, from reaching control package 160, which includes pump 168, thereby serving a protective function. For example, in certain embodiments, the filter 124 can comprise hydrophobic ultra high molecular weight polyethylene (UHMW-PE), which can optionally be impregnated with carboxymethyl cellulose. The filter 124 may comprise a hydrophobic filter material, which may comprise sintered PTFE, optionally with the addition of a super absorbent polymer, such as sodium polyacrylate or sodium carboxymethyl cellulose. When exudate 152 reaches filter 124, filter 124 suddenly clogs and expands, for example, increasing the pressure detected by pressure sensor 178, which, in turn, may trigger a protective shut-off for pump 168 by controller 165. In certain embodiments, the filter 124 may alternatively be placed in the reservoir housing 120, or the filter 124 may be omitted.

It should be noted that a variety of numbers and combinations of valves, such as

valves

172, 173, 174, and pressure sensors, such as

pressure sensors

176, 178, may be used in conjunction with controller 165 to regulate the flow of input fluid 116 into enclosed space 117 or to regulate the flow of output fluid 118 out of enclosed space 117 to produce actual pressure p_aApproaching a target pressure p in an enclosed space₀. For example,

valves

173, 174 may be replaced with a three-way valve that may be operated at no flow, at air 128, or including moistureGas 129 gas 125.

Alternatively, in operation, the wound treatment apparatus 100 may be in an operating configuration 113, as shown in fig. 3B, 4B. As shown, wound interface 115 is secured to skin surface 111 to enclose a wound bed (e.g., wound

beds

213, 313, 413) within fluid-tight enclosure 117. When the wound bed is no longer draining exudate 152, for example, during a later stage of wound bed healing, the wound treatment apparatus 100 may be in an operating configuration 113, as shown in fig. 3B, 4B. In this embodiment, the operative configuration 113 excludes the receptacle 150 including the receptacle housing 120 from the control group 130, as the receptacle 150 containing the receptacle housing 120 may not be needed. In certain embodiments, in the operating configuration 113, a filter 124 may be included in the controller bank 130 to capture stray liquids.

As shown in fig. 4B, output fluid 118, at least partially drawn by pump 168, flows out of enclosed space 117 of wound interface 115, through connector 188 of control pack 160 of control group 130, through valve 172, and through pump 168. In this embodiment, the output fluid 118 is then exhausted to the atmosphere on the exhaust side of the pump 168. As shown in fig. 3A, 4A, described with respect to the operating configuration 111, in the operating configuration 113, the input fluid 116 may flow from the gas source 112 or the atmosphere 127 into the enclosed space of the wound interface 115. In the operating configuration 113, the controller 165 interacts with the

valves

172, 173, 174,

pressure sensors

176, 178 and the pump 168 to control the flow of the input fluid 116 and the output fluid 118, e.g., to generate the actual pressure p_aApproaching a target pressure p in an enclosed space₀Or to deliver air 128 to the wound bed.

Connector 188 forms a connection point between reservoir housing 120 and control pack 160 such that in operating configuration 111 reservoir housing 120 and control pack 160 are removably secured to one another at least at connector 188. In the operational configuration 111, when the reservoir housing 120 and the control pod 160 are removably secured to one another, the connector 188 forms a fluid pathway for the flow of the output fluid 118 from the reservoir housing 120 to the control pod 160. In the operative configuration 113, the reservoir housing 120 is not present in the control group 130, and in the operative configuration 113, the connector 188 provides a fluid transfer connection point between the wound interface 115 and the control pack 160 for transferring the output fluid 118. In this embodiment,

connectors

182, 184, 186 provide connection points for the delivery of multiple fluids to the administration set 130, allowing the delivery of both the input fluid 116 and the output fluid 118 via the connection points.

In this embodiment, receptacle housing 120 may be removed from securement with control package 160 by at least disconnecting at connector 188, and a new receptacle housing 120 may be removably secured to control package 160 by at least securing to connector 188. Alternatively, in this embodiment, the receptacle housing 120 may be removed from securement with the control package 160 by at least disconnecting the connector 188, and the fluid transfer between the wound interface 115 and the control package 160 may be secured to the connector 188, whereby the wound treatment apparatus 100 may be moved from the operating configuration 111 to the operating configuration 113.

As shown in FIG. 5, the controller 165 is in operative communication with the

valves

172, 174, the

pressure sensors

176, 178 and the pump 168 to substantially within the pressure range p_min≤p_a≤p_maxBy varying the actual pressure p in the enclosed space 117_aTo correspond to the pressure range p possible_min≤p₀≤p_maxTarget pressure p varying periodically₀Wherein p is_minIs the target pressure p₀Minimum value of p_maxIs the target pressure p₀Is measured.

In certain embodiments, p_min≤p_ambWherein p is_ambIs the ambient pressure of the atmosphere 127 adjacent the wound treatment apparatus 100. In certain embodiments, p_max≥p_amb. In certain embodiments, p_max≤p_amb. The minimum pressure may be, for example, p_min≈p_amb130mm Hg. The minimum pressure may be, for example, p_min≈p_amb-90mm Hg. Minimum pressure p_minMay be, for example, in the pressure range (p)_amb-130mm Hg)≤p_min＜(p_amb-90mm Hg). Minimum pressure p_minCan be approximately in the pressure range (p)_amb-90mm Hg)≤p_min＜p_amb. In certain embodiments, the target pressure p₀May vary substantially over a pressure range p_min≤p₀≤p_maxIn which p is_max＞p_amb. For example, p_max≈(p_amb+40 mmHg). In certain embodiments, the maximum pressure p_maxMay be slightly less than ambient pressure p_ambE.g. approximately at p_amb-5mm Hg to p_ambIn the range of-20 mm Hg.

Fig. 5 illustrates exemplary operating states 132, 134, 136, target pressure p of wound treatment apparatus 100₀In the pressure range p_min≤p₀≤p_maxPeriodically, the wound treatment apparatus 100 may be varied between operating

states

132, 134, 136 to generate the actual pressure p_aTo correspond to the target pressure p₀. The

operational states

132, 134, 136 are exemplary, and not limiting, such that the wound treatment apparatus 100 may be in an operational state other than the

operational states

132, 134, 136. It is noted that the wound treatment apparatus is sequentially changed between the

operational states

132, 134, 136 such that, for example, the

operational states

132, 136 cannot exist simultaneously. For clarity of illustration, fig. 5 does not include the moisture source 114 and the container 150, and thus fig. 5 illustrates operation of the wound treatment apparatus 100 in two operating

configurations

111, 113. The valve 173, which is also omitted from fig. 5 for clarity of explanation, is in the closed position in the

exemplary operating state

132, 134, 136 shown in fig. 5 for the valve 173.

In an exemplary operating state 132, as shown in FIG. 5 (shown in phantom in FIG. 5), the output fluid 118 is directed from the enclosed space 117 of the wound interface 115 to vary the actual pressure p_aPressure p corresponding to the target₀Towards a minimum pressure p_minTo reach p_a≈p₀＝p_minOr remove exudate 152 from enclosed space 117. In the operating state 132, the pump 168 may be in an ON state. As shown, output fluid 118 is drawn from the enclosed space of wound interface 115 through valve 172, which is in an open position, and pump 168 by suction of pump 168, venting the gaseous portion of output fluid 118 to atmosphere 127. As shown in the figureValve 174 is shown in a closed position such that in operating state 132, no input fluid 116 is introduced into the enclosed space of wound interface 115. In this embodiment, pressure sensor 178 is in operative communication with the enclosed space of wound interface 115 to detect an actual pressure p within enclosed space 117 comprising output fluid 118_a. When the pressure p is in the eye₀Towards p_minAt decreasing time, the actual pressure p detected by the pressure sensor 178_aMay be communicated from the pressure sensor 178 to the controller 165, and the controller 165 may position the valve 172 between an OPEN position and a CLOSED position, including a position intermediate the OPEN position and the CLOSED position, to achieve p_a≈p₀. The controller 165 may regulate operation of the pump 168, including, for example, the speed of the pump 168 to achieve p_a≈p₀And to realize p_a≈p₀≈p_min.。

In the exemplary operating state 134, as shown in fig. 5 (by solid lines in fig. 5), the

valves

172, 174 are in the CLOSED position, such that substantially no input fluid 116 is directed into the enclosed space 117, or output fluid 118 is directed out of the enclosed space 117. For example, in operational stage 134, in enclosed space 117 of wound interface 115, p_a≈p₀≈p_minOr p_a≈p₀≈p_max。

At operational stage 134, although substantially no input fluid 116 is directed into enclosed space 117 of wound interface 115 and no output fluid 118 is directed out of enclosed space 117, it should be appreciated that there may be some leakage into or out of enclosed space 117 of wound interface 115. Thus, in operating state 134, pressure sensor 176, pressure sensor 178, or

pressure sensors

176 and 178, may detect the actual pressure p within the enclosed space of wound interface 115_aActual pressure p detected by

pressure sensors

176, 178_aMay be communicated from the

pressure sensors

176, 178 to the controller 165. During the exemplary operational phase 134, the controller 165 may position the

valves

172, 174, change the pump 168 between an OFF closed state and an ON open state, or intermittently adjust the pump 168 or

valves

172, 174, e.g. to hold p_a≈p₀≈p_minTo hold p_a≈p₀≈p_maxOr exudate 152 may be directed from enclosed space 117 of wound interface 115 as desired.

In an exemplary operating state 136, as shown in fig. 7 (indicated by dashed lines), the input fluid 116 is introduced into the enclosed space 117 of the wound interface 115 to change the actual pressure p_aSo as to correspond to the target pressure p₀Towards the maximum pressure p_maxTo reach p_a≈p₀≈p_max. In this embodiment, the input fluid 116 is introduced into the enclosed space 117 of the wound interface 115 through the valve 174 in the OPEN position, and the input fluid 116 is introduced into the enclosed space 117 by the pressure p of the gas source 112_sIs driven. Valve 172 is in the CLOSED position such that in operating state 136, when input fluid 116 is introduced into enclosed space 117, no output fluid 118 is directed out of enclosed space 117 of wound interface 115. In this embodiment, in the operating state 136, the pressure sensor 176 is in operative communication with the enclosed space 117 of the wound interface 115 containing the input fluid 116, sensing the actual pressure p within the enclosed space 117 of the wound interface 115_a. The actual pressure p detected by the pressure sensor 176_aMay be communicated from pressure sensor 176 to controller 165, and controller 165 may position valve 174 between an OPEN position and a CLOSED position, including positions intermediate the OPEN position and the CLOSED position, to achieve p_a≈p₀Target pressure p₀Towards p_maxAnd (4) increasing. In the operating state 136, the pump 168 may be in an OFF state.

Thus, as shown in FIG. 5, the

valves

172, 174 are positioned between the open and closed positions to sequentially introduce the input fluid 116 into the enclosed space 117 and to direct the output fluid 118 from the enclosed space 117, meaning that the directing of the output fluid 118 and the directing of the input fluid 116 do not occur simultaneously. In the illustrated embodiment, the input fluid 116 may be introduced into the enclosed space or the output fluid 118 may be withdrawn from the enclosed space, but the introduction of the input fluid 116 and the withdrawal of the output fluid 118 cannot occur simultaneously. Thus, in the illustrated embodiment, valve 172 may be in the OPEN position while valve 174 is in the CLOSED position, valve 172 may be in the CLOSED position while valve 174 is in the OPEN position, or valve 172 may be in the CLOSED position while valve 174 is in the CLOSED position, and

valves

172, 174 may not be in the OPEN position at the same time.

A pressure sensor 176 or other pressure sensor, disposed about control group 130, may, for example, sense pressure p of gas source 112_sBelow a certain minimum value, this indicates that the gas source 112 is being depleted. As another example, the control group 130 may be disconnected from the gas source 112. Valve 174 may then be in the CLOSED position and valve 173 may be changed between the CLOSED position and the OPEN position in place of valve 174 to change the wound treatment apparatus between operating

states

132, 134, 136. Air 128 from the atmosphere 127 is regulated by a valve 173 and then fed into the enclosed space 117, for example to change the actual pressure p_aSo as to correspond to the target pressure p₀Towards a maximum pressure p_max。

Fig. 6A and 6B illustrate the wound treatment apparatus 200 in an exemplary first operational stage 236 and a second stage of exemplary operation 238, respectively. As shown in fig. 6A, 6B, wound treatment apparatus 200 includes a deformation-resistant wound interface 215 that, when wound interface 215 is coupled to skin surface 211, forms a fluid-tight enclosure 217 for enclosing wound bed 213 on skin surface 211. As shown, wound interface 215 includes a cover 240, and cover 240 is slidably, sealingly, frictionally, removably coupled to base 220. The cover 240 may include at least partial transparency to allow visual inspection of the wound bed 213 through the cover 240. The base 220 may include a flange 209 along the outer perimeter of the base 220 that may be used to provide a structural support or sealing surface when mated with the cover 240. .

In some embodiments, the cover 240 and the base 220 may be formed as a unitary structure, or the cover 240 may be hinged or otherwise connected to the base 220. Although the illustrated wound interface 215 is cylindrical, enclosing a circular area of the skin surface 211, it should be understood that in some embodiments, structures such as the wound interface 215 may take on other geometries to enclose other geometrically shaped areas of the skin 211, such as rectangular, polygonal, or oval, to enclose wounds of various shapes, and may include other modifications, such as by modification of the base 220 to accommodate the skin surface 211 in various areas of the body. In certain embodiments, one or more additional ports in communication with the enclosed space 217 may be located on the wound interface 215 for monitoring parameters within the enclosed space 217, communication of fluid within the enclosed space 217, or other therapeutic intervention of the enclosed space 217.

In this embodiment, the base 220 includes a flange 229 along the entire perimeter of the outer side 223 of the base 220, generally at the distal end of the base 220. The flange 229 is secured to the skin surface 211 by an adhesive 290, as shown in fig. 6A and 6B, around the entire perimeter of the base 220 to form a fluid-tight enclosure 217 with the wound boundary 212 enclosed within the enclosure 217. The thickness of flange 229 and/or the polymeric material may be designed to be flexible and conformable to maintain wound interface 215 sealed against wound 213 in a fluid-tight manner while simultaneously maintaining the actual pressure p from within enclosed space 217_aIs dispersed from the wound interface 215 to the skin surface 211.

Adhesive 290 may optionally extend over portions of skin surface 211 to include all skin surfaces below and near distal end 222 of flange 229. The adhesive is a member of the class of medically suitable cyanoacrylates, such as N-butyl-2-cyanoacrylate (Histoacryl Blue), or octyl 2-cyanoacrylate (dermobond), and the water-resistant adhesive coating around the wound skin surface provides the additional function of protecting normal skin from prolonged exposure to other fluids such as exudates, proteolytic enzyme soak or saline lavage, etc., causing secondary maceration. Other medical adhesives, such as acrylic, silicone, and hydrocolloid may secure the flange 229 of the wound interface 215 to the skin surface 211. In some embodiments, other securing means, such as hook and loop tape or adhesive bandages, may also be employed to secure, at least in part, wound interface 215 to skin surface 211. The base 220 of the wound interface may be formed from any of a variety of medical-grade polymers, including, for example, polycarbonate, polystyrene, polypropylene, or ABS; additional sealing structures may further be associated, such as an inflatable adjustable circumferential cushion between the base and the adhesive layer along the perimeter of the wound bed.

In this embodiment, port 242, located on wound interface 215, is in fluid communication with enclosed space 217 via inner lumen 245. In this embodiment, the lumen 245 of the port 242 may be in fluid communication with an administration set, such as administration sets 30, 130 of the

wound treatment apparatus

10, 100, respectively, which may direct the input fluid 216 into the enclosed space 217 or the output fluid 218 out of the enclosed space 217 through the lumen 245.

The input fluid 216 may be input into the enclosed space 217 via the inner cavity 245 of the port 242, as indicated by the arrows in fig. 6A, 6B, for example, to at least partially regulate the actual pressure p within the enclosed space 217_aTo control the composition of the gaseous fluid within the enclosed space 217, or for a variety of therapeutic purposes. The input fluid 216, for example, may be directed into the enclosed space 217 to increase the actual pressure p within the enclosed space 217_aTo the target pressure p₀And (5) the consistency is achieved. The input fluid 216 may include gases, such as

gases

22, 125, plus

gases

22, 125 of moisture 129 from a moisture source, such as moisture source 114. The input fluid may include a liquid, such as liquid 24.

The output fluid 218 may include the input fluid 216 and the output fluid 218 may include the exudate 252, such that the output fluid 218 may include liquid, gas, and combinations of liquid and gas from within the enclosed space 217. The input fluid 216 or the output fluid 218 may include a liquid, such as liquid 24, which may have a variety of therapeutic purposes. As shown, the output fluid 218 is directed from the enclosed space 217 through an inner cavity 245 of the port 242, for example, to reduce the actual pressure p within the enclosed space 217_aTo conform to a target pressure p to remove exudate 252 from the enclosed space 217 or to remove liquid, e.g., liquid, from the enclosed space 21724。

A pad 250 may be disposed within the enclosed space 217 to absorb and transfer exudate 252 from the wound bed 213, the pad 250 may be in fluid communication with the port 242 to allow exudate 252 to pass from the wound bed 213 through the pad 250 and then out through the port 242. The pad 250 may be formed of a material having absorbent and fluid transfer properties to absorb exudates. These materials include, for example, open-cell foams composed of polyvinyl alcohol (PVA), polyurethane or other polymers. The pad 250 can be formed from a variety of woven or non-woven fibers, such as sodium carboxymethylcellulose water soluble fiber (Aquacel), or knitted fibers having primarily hydrophobic polyester fibers on the outer surface and primarily hydrophilic nylon fibers on the inner side to act as a conduit for fluid transfer. The hydrophobic polyester fibers may be kept away from the liquid, preventing moisture from accumulating, thereby causing a secondary maceration of tissue in constant contact with the pad 250. Depending on the specific fluid management objective, whether it is primarily to transport exudates to another location or primarily to absorb and immobilize topical exudates, an amount of superabsorbent polymer (SAP), such as sodium polyacrylate, may optionally be included in the pad 250. The addition of an amount of SAP to a closed cell polyurethane may allow liquid to pass through the matrix, thereby enhancing the absorption and fluid transfer properties of the matrix.

The wound treatment apparatus 200 may be periodically changed between the first stage of operation 236 and the second stage of operation 238 by continuously directing output fluid 218 out of the enclosed space 217 and input fluid into the enclosed space 217 via the lumen 245 of the port 242. In a first stage 236 of exemplary operation, as shown in FIG. 6A, the target pressure p₀Equal to the maximum pressure p_max(i.e., p)₀＝p_max) The maximum pressure may be substantially equal to the ambient pressure p_amb(i.e. p)_max≈p_amb) Actual pressure p_aIs substantially equal to the target pressure p in the enclosed space 217₀(i.e., p)_a≈p₀)). The wound bed 213 is in a baseline state 293 in spatial relationship to the pad 250 such that there is reduced or no contact between the pad 250 and the wound bed 213. Gaps, if any, between the pad 250 and the wound bed may be made as appropriate for the pad being manufactured250, shape, structure and material. As shown in fig. 6A, the wound interface 215 forms an inlet 226 into the enclosed space 217, and in the baseline state 293, the portion of the wound bed 213 enclosed by the enclosed space 217 is generally outside of the inlet 226. As shown in fig. 6A, in the first state of operation 236, the capillary 296 adjacent to the wound bed 213, in an unexpanded baseline state 297, delivers a baseline amount of blood to the wound bed 213.

In the second stage 238 of the exemplary operation of the apparatus 200, as shown in FIG. 6B, the enclosed space 217 is evacuated, or partially evacuated, by conducting the output fluid 218 from the enclosed space 217 through the lumen 245 of the port 242, thereby causing the target pressure p₀＝p_minActual pressure p_aIs substantially equal to the target pressure p in the enclosed space 217₀. In the expanded state 294, the pressure p_minLess than ambient pressure p_amb(i.e. p)_min＜p_amb) By a sufficient amount to expand at least a portion of the wound bed 213 through the inlet 226 into the enclosed space 217. As shown in fig. 6B, at least a portion of the wound bed, or a greater portion of the wound bed 213 than the first stage 236 of operation, is biased toward the pad 250 during the second stage 238 of operation. During the second stage of operation 238, the pad 250 may thus effectively absorb and transfer exudate from the wound bed 213 as at least a portion of the output fluid 218 through the inner chamber 245. The pad 250 is in fluid communication with the inner lumen 245 of the port 242 such that exudate may be conducted from the pad 250 through the inner lumen 245 as at least a portion of the output fluid 218 via the external negative pressure applied to the port 242. As shown in fig. 6B, in the second stage of operation 238, when the wound bed 213 is in the expanded state 294, capillaries adjacent the wound bed, such as capillary 296, may be in the expanded state 298.

One problem, for example, when the output conduit is blocked by exudate, results in the control package maintaining a false reassuring target negative pressure indication, while a much lower actual negative pressure exists at the wound site. By adding additional ports that are also in independent communication with enclosed space 217, different pressure readings from the same enclosed space can be obtained from the front and back ends of the pressure piping system, more accurate diagnostics can be achieved, problem situations can be localized, allowing more targeted solutions or precautions. The additional port may be located at a distance from the first port, both ports being in fluid communication with the wound. In addition, when a bolus of fluid is introduced through the second port to suddenly relieve negative pressure in the enclosed space, this sudden unidirectional pressure relief can be used to clear exudate from the negative pressure port, drain the tubing from one end of the wound bed toward the other, keep the catheter unobstructed, and help maintain effective therapy. The use of lavage fluid as a bolus of liquid provides further benefits of flushing any clotted exudate, cell debris and maintaining the passageway unobstructed. When used with dressing systems where the port for delivery of the negative pressure is near one end of the absorbent pad and the negative pressure port is near the other end, intermittent application of irrigation solution to relieve the negative pressure can extend the clinical life of such dressing systems, unlike self-cleaning diapers where exudate and cellular debris are washed away and the dressing is "refreshed". In addition to the savings in replacement costs, other benefits may include a lower incidence of tape allergy, which is typically due to the accumulation of repeated loss of the epidermal layer with each dressing change; the epidermis layer may isolate the subcutaneous tissue of the dermis layer from exposure to the adhesive.

Fig. 7 illustrates a wound treatment apparatus 300 including a wound interface 315. The device 300 comprises a member 315, the member 315 comprising a cover 320, the member 315 being attached to the skin surface 311 by an adhesive 390 to close the wound bed 313 of the skin surface 311, the entire wound boundary 312 being covered by the cover 320. The distal side 322 of the cover 320 faces the wound bed 313, and the cover 320 is secured to the skin surface 311 by an adhesive 390 on at least a portion of the distal side 322 of the cover 320, thereby forming a portion of the enclosed space 317. As shown, the enclosed space 317 includes at least a portion of the wound bed 313. As shown, the dressing 350 is placed against the wound bed 313 and sealingly covered by the cover 320 such that the dressing 350 is located within the enclosed space 317.

As shown in fig. 7, the

ports

342, 344 are in fluid communication with the enclosed space 317 between the distal side 322 of the cover 320 and the proximal side 324 of the cover 320 through

lumens

347, 345, respectively.

In this embodiment, the

lumens

345, 347 are in fluid communication with a control group, e.g.,

control groups

30, 130 of the

wound treatment devices

10, 100, respectively, which may regulate the introduction of the input fluid 316 into the enclosed space 317 through the lumen 347 and regulate the exit of the output fluid 318 from the enclosed space 317 through the lumen 345. In this embodiment, exudate 352 moves from the wound bed 313 into the dressing 350, and the exudate 352 may be directed out of the dressing 350 as part of the output fluid 318.

For example, when the actual pressure p in the enclosed space 317 is_aVariation from target pressure p₀In concert, input fluid 316 may be introduced into enclosed space 317 via lumen 347 of port 342, and output fluid 318 may be directed out of the enclosed space via lumen 345 of port 344. For example, the target pressure p₀Can be in the pressure range p_min≤p₀≤p_maxPeriodically varies in which p_minIs the minimum target pressure, p, over the pressure cycle_maxIs the maximum target pressure, the actual pressure p, over the pressure cycle_aWith a target pressure p₀And (5) the consistency is achieved.

Fig. 8 illustrates an exemplary wound treatment apparatus 400. As shown in fig. 8, wound treatment apparatus 400 includes a wound interface 415, wound interface 415 including a member 420, and an adhesive 490 coated on at least a portion of a distal surface 422 of member 420 for securing member 420 to skin surface 411. When secured to the skin surface 411, the distal surface 422 of the member 420 encloses the wound bed 413 on the skin surface 411 within the enclosed space 417. Member 420 may be formed from a variety of polymers, for example, polyurethane. Member 420 may be fluid tight and member 420 may be deformation resistant.

As shown in fig. 8, flange 414 of port 442 secures port 442 to member 420 for fluid communication with enclosed space 417 through lumen 445. The flange may be adhesively secured to the underside of the member 420 through the apertures of the member 420 as shown, or it may be adhesively secured to the upper and outer surfaces of the member 420, via apertures or connecting channels, in fluid communication with the enclosed space 437 within the wound interface.

Input fluid 416 may be input into enclosed space 417 via lumen 445 of port 442 and output fluid 418 may be output from enclosed space 417 via lumen 445 of port 442. Lumen 445 may be in fluid communication with a control group, such as

control groups

30, 130 corresponding to wound

therapy devices

10, 100, respectively. In this embodiment, for example, in order to make the actual pressure p_aWith a target pressure p₀When the target pressure p in the enclosed space 417 is consistent₀E.g. according to a pressure substantially in the pressure range p_min≤p₀≤p_maxIs cyclically changed, where p is_minIs the minimum target pressure, p, of the entire pressure cycle_maxWhich is the maximum target pressure for the entire pressure cycle, the control group can regulate the introduction of input fluid 416 into enclosed space 417 through lumen 445 and regulate the removal of output fluid 418 from enclosed space 417 through lumen 445.

As shown in fig. 5, the device 400 includes

layers

460, 470, and 480 within the enclosed space 417. As shown, a portion of layer 480 is secured to distal side 422 of member 420, and a portion of distal side 482 of layer 480 is proximate skin surface 411 and wound bed 413. The layer 470 is positioned between the layer 480 and the layer 460, with the distal side 472 of the layer 470 being biased toward the proximal side 484 of the layer 480 and the proximal side 474 of the layer 470 being biased toward the distal side 462 of the layer 460. Layer 460 is disposed between layer 470 and spacer 430 with proximal side 474 of layer 470 biased toward distal side 432 of spacer 430. In some embodiments, various numbers of layers, such as

layers

460, 470, 480 may be included in apparatus 400, arranged in various ways depending on the application, or certain layers may be omitted. The different layers may have particular characteristics and functions, such as liquid absorption, fluid transport, and release of therapeutic substances.

In this embodiment, the proximal side 434 of the spacer 430 is secured to the distal side 422 of the member 420 within the enclosed space 417. The spacer 430 forms a space 437 within the spacer 430, the spacer 430 maintaining the

layers

460, 470, 480 biased toward one another as shown. The space 430 may be generally a double layer polymeric bag, with or without additional shunts, which may be formed by partial bonding or welding 464. It may optionally be welded at a plurality of points 464 in the double layer volume to limit expansion of volume 437 under pressure. The purpose of the spacer 430 is to distribute the input fluid 416 across the wound surface. The spacer 430 may have a variety of sizes and shapes, such as circular, rectangular, oval, or starburst, with a perimeter substantially similar to the perimeter of the proximal side 464 of the layer 460.

Lumen 445 passes through port 442 and proximal side 434 of spacer 430 into volume 437, input fluid 416 may be delivered into volume 437 via lumen 445, or output fluid 418 may be directed out of volume 437 through lumen 445.

For example, input fluid 416 may be delivered into volume 437 via lumen 445, and input fluid 416 may then be dispersed within volume 437 such that substantially the same actual pressure p exists throughout volume 437_a. The input fluid 416 may then flow from the volume 437 through spacer channels, such as spacer channels 435, of the distal side 432 of the spacer 430 into the layer 460. The spacer channels are evenly dispersed on the distal side 432 of the spacer 430 such that the input fluid 416 from the volume 437 is evenly dispersed on the proximal side of the layer 460. Input fluid 416 may then flow through layer 460, through layer 470, and through channels in layer 480, such as layer channel 485, to contact wound bed 413 and skin surface 411. The channels on the proximal side 484 through layer 480 and evenly distributed on the distal side 482 of layer 480 allow the input fluid 416 to be evenly distributed across the skin surface 411 and wound bed 413. Thus, for example, the input fluid 416 may, for example, provide enhanced O₂The wound bed 413 and skin surface 411 are administered with an antibiotic rinse, or cytokine in amniotic fluid. Actual pressure p_aPresent throughout the enclosed space 417, the enclosed space 417 including the wound bed 413 and the skin surface 411, the input fluid 416 and the output fluid 418 may flow through the entire enclosed space 417, including the

layers

460, 470, 480, and through the spacer 430. The spacer 430 may optionally be configured farther to be near or even adjacent to the wound surface, in which case spacer channels 435 may be present in both the distal and proximal sides of the spacer 430.

Exudate 452 may flow from wound bed 413, through layer channels, such as layer channel 485 in layer 480, into layer 470, from layer 470 into layer 460, and from layer 460 through spacer channels, such as spacer channel 435, into space 437. In this embodiment, output fluid 418, including exudate 452, may flow out of

layers

480, 470, 460, through spacer channels 435 into volume 437, through lumen 445 of port 442, from which volume 437 output fluid 418 may be directed.

In this embodiment, layer 480 is formed of silicone, including similar materials with scar-regulating properties, and wound bed 413 is in the form of an incision with sutures 499. The silicone resins referred to herein, including silicones, polysiloxanes, silicone-like materials, and combinations thereof, can be generally solid. The silicone resin may have the formula [ R2SiO ] n, where R is an organic radical. The silicone may include, for example, silicone polymers having an average molecular weight in excess of 100,000 (e.g., between about 100,000 and about 10,000,000). Examples include, but are not limited to, cross-linked silicones (e.g., cross-linked polydimethylsiloxane or derivatives of polydimethylsiloxane), copolymers such as stearyl methyl-dimethicone copolymer, polysiloxane-11 (a cross-linked silicone rubber resulting from the reaction of a vinyl-terminated silicone and a (dimethylhydro) silicone in the presence of a cyclomethicone), cetearyl dimethicone/vinyl dimethicone crosspolymer (copolymer of cetearyl dimethicone cross-linked with vinyl dimethicone), dimethicone/phenyl vinyl dimethicone crosspolymer (copolymer of dimethicone cross-linked with phenyl vinyl dimethicone)/vinyl dimethicone crosspolymer (copolymer of dimethicone cross-linked with vinyl dimethicone).

In certain embodiments, wound bed 413 may be any type of wound bed and layer 480 may be formed from other silicone or similar materials. Layer channel 485 may take a variety of forms ranging from small holes, crosses, to fine slits, allowing fluid exchange between wound bed 413 and skin surface 411 through layer 480 to prevent maceration of skin 411.

Layer 470 may comprise a layer of material that delivers the therapeutic agent in a slow release manner. These therapeutic agents may include antibacterial agents such as antibiotics or silver preparations, local anesthetics for pain relief, amnion or placenta derived cytokines and growth factors such as BMP, hemostatic and clotting agents for hemostasis, oxygen generating and releasing compounds, exothermic or endothermic agents, and the like.

The layer 460 may be made of a variety of materials, including cotton gauze, polyester or polyamide fibers, or polyurethane open cell foam, or polyvinyl alcohol open cell foam. The material of these layers 460 may help transfer exudate 452 from wound bed 413 to space 437 for egress through lumen 445. The layer 460 may optionally include a super absorbent polymer such as sodium polyacrylate, particularly when the purpose is to lock the exudate 452 within the layer 460.

In operation of a wound treatment apparatus (e.g., wound

treatment apparatus

10, 100, 200, 300, 400), a control input fluid (e.g.,

input fluid

16, 116, 216, 316, 416) is introduced into the enclosed space of the wound interface and an output fluid (e.g.,

output fluid

18, 118, 218, 318, 418) is withdrawn from the enclosed space of the wound interface using a control group, e.g.,

control group

30, 130. Target pressure p within an enclosed space (e.g.,

enclosed space

17, 117, 217, 317, 417) of a wound interface (e.g., wound

interface

15, 115, 215, 315, 415)₀The actual pressure p within the enclosed space of the wound interface may vary with respect to time t according to a pressure cycle (e.g., exemplary pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 (see fig. 9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9I, 9J, respectively), with respect to time t_aCan be matched with the target pressure p₀Agree so as to reach p_a≈p₀. In certain embodiments, the input fluid may be a gas, such as

gas

22, 125, or a liquid, such as liquid 24. The output fluid may include an exudate, such as

exudate

19, 152, 252, 352, 452, and any residual gases or liquids from previous pressure cycles, or any combination thereof.

Fig. 9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9I, 9J illustrate exemplary pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, respectively, wherein a target pressure p within the enclosed space of the wound interface₀Plotted as a function of time t. Although according to the target pressure p₀Pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 are described, but with the actual pressure p_aSubstantially corresponding to a target pressure p in the enclosed space₀So that the

pressure cycle

500, 550, 600, 650, 700, 750, 800, 850, 900, 950 can be described as the actual pressure p in the enclosed space_aThe reaction of (1). In some embodiments, the input fluid has a higher O than atmospheric air₂Concentration, therefore in certain embodiments, the wound bed is exposed to O throughout the pressure cycle₂A fluid at a concentration greater than atmospheric air, which may increase the supply of oxygen to the wound bed during treatment, resulting in therapeutic benefits. Applying multiple O's to a wound bed₂The pressure circulation of the air with concentration higher than the atmospheric air can increase the O content of the wound bed₂Exposure time, and thus, increased oxygen therapy time provided to the wound bed. It should be noted that the pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 are merely exemplary and not limiting, and in certain embodiments, one or more of these exemplary pressure cycles, various combinations of these exemplary pressure cycles, or other pressure cycles may be provided to the wound bed in the enclosed space under the control of the control group 130.

In certain embodiments, the control group includes a controller, such as

controller

87, 165, and the pressure cycle includes a period, an amplitude, and other characteristics of the pressure cycle based on data (e.g., data 74) that data from a user via a user I/O (e.g., I/O86, 145) may communicate with the controller. Thus, the user may select a pressure cycle, a series of pressure cycles, and characteristics, such as amplitude and period of the pressure cycles, to deliver to the wound bed within the enclosed space using the user I/O. The controller may store preprogrammed pressure cycles in memory, which may include other programs or data in memory to determine the data for the pressure cycles to achieve, by using pumps, such as

pumps

89, 168, valves, such as

valves

88, 172, 173, 174, and pressure sensors, such as

pressure sensors

91, 176, 178, which may be included in the control group.

As shown in FIG. 9A, the pressure cycle 500 is at time t₀At the beginning, pressure p₀＝p_max. It should be noted that throughout the pressure cycle 500, the actual pressure p in the enclosed space is controlled by the control group_aMay be substantially equal to the target pressure p₀(i.e. p)_a≈p₀). According to an exemplary pressure cycle 500, pressure p₀From time t₀To time t₁At a rate S₁Linearly decreasing, then the pressure p₀At time t₁And time t₂At a rate S₂Linear decrease at time t₂Cun reaches p_min. Then pressure p₀At time t₂And time t₃Is maintained at p_min. As shown, then the pressure p₀At time t₃And time t₄At a rate S₃From p_minLinear increase to p_max. At time t₃And time t₄In the closed space, a fluid is introduced to bring the pressure p₀From p_minIncrease to p_maxThe fluid may have a greater O than atmospheric air₂And (4) concentration. Thus, during the continuous pressure cycle 500, when O is passed₂A fluid at a concentration greater than atmospheric air so that the wound bed may be exposed to O as the pressure increases in each such pressure cycle₂In an environment with a concentration greater than atmospheric air. Thus, in this embodiment, at time t₃And time t₄Pressure p between_maxThe wound bed may be exposed to O₂In an environment with a concentration greater than atmospheric air.

By directing the output fluid out of the enclosed space without any input fluid entering the enclosed space, the control group can be controlled at time t₀And t₂Between the actual pressure p_a. Similarly, by introducing the input fluid into the enclosed space while no fluid is being directed out of the enclosed space, the control group can control the flow rate at time t₃And t₄Increase the actual pressure p therebetween_a. Finally, in certain embodiments of the pressure cycle 500, at time t₂And t₃In between, no input fluid is introduced into the enclosed space, while no output fluid is directed out of the enclosed space. In certain embodiments of the pressure cycle 500, at time t₂And t₃Substantially no fluid is introduced into the enclosed space and substantially no fluid (other than exudate) is removed from the enclosed space. A controller, such as controller 480 of wound treatment apparatus 400, may control the output fluid at time t₀And t₂And the input fluid is led out at time t₃And t₄In the process of introducing.

In pressure cycle 500, for example, p_max≈p_amb，p_min＝p_amb-85mm Hg. Time period t₂-t₀May be about 40s, pressure p₀Then kept at p_mint₃-t₂240s followed by a time period t₄-t₃Such that the time period of the pressure cycle 500 is t 80s₄-t₀360s (6 minutes or 10 pressure cycles per hour). In accordance with the exemplary pressure cycle 500 approach, various other implementations may be provided, such as 12 pressure cycles per hour, 4 pressure cycles per hour, or 3 pressure cycles per hour. The slope S can be selected₁And S₂To avoid the production of pain, S₂Can be compared with S₁Small because of the pressure p₀Rapidly decrease below p_maxIt can be painful. For example, over a time period t₁-t₀10s, pressure p₀From p_ambDown to p_ambCan be generally painless at-40 mm Hg, and then again at a pressure time period t₂-t₁For 30s, apply pressure p₀From p_ambReduction of-40 mm Hg to p_ambAt-85 mm Hg, pain can be minimized. It should be noted that the pressure cycle 500 may be asymmetric, at time period t₃-t₀Greater than a time period t₄-t₃。

In various other embodiments, the pressure p₀May be at time t₀And time t₂At a single constant rate (i.e., S)₁＝S₂) Or the pressure p₀May be at time t₀And time t₂At three or more rates. The pressure cycle 500 may be at time t₄Start repetition (i.e., time t)₄Is set to time t₀) Or then some other pressure cycle, such as pressure cycles 550, 600, 650, 700, 750, 800, 850, 900, 950, may be taken from time t₄The start-up is started. The pressure cycle 500 may remain substantially constant over successive cycles, or various parameters of the pressure cycle 500 may be varied over successive cycles, such as p_max，p_min，S₁，S₂，t₃-t₂，t₄-t₀. The control group can determine various parameters of the pressure cycle 500, such as p, by communicating data with the user I/O into which the data is entered by the user_max，p_min，S₁，S₂，t₃-t₂，t₄-t₀。

Fig. 9B illustrates an exemplary pressure cycle 550. It is to be noted that the actual pressure p in the enclosed space, controlled by the control group, is throughout the pressure cycle_aMay be substantially equal to the target pressure p₀(i.e. p)_a≈p₀). As shown in FIG. 9B, the pressure cycle 550 is at time t₁₀At the beginning, pressure p₀＝p_min. Target pressure p₀From time t₁₀To time t₁₁At a rate S₁₁Linearly increasing, at time t₁₁To reach p_max. As shown, the target pressure p₀Then at time t₁₁And time t₁₂Is maintained at p_maxThen target pressure p₀At time t₁₂And time t₁₃At a rate S₁₂From p_maxTo p_minThe linearity decreases. At time t₁₀And time t₁₁To increase the actual pressure p by introducing a fluid into the enclosed space_aFrom p_minIncrease to p_maxThe input fluid may have a higher O than atmospheric air₂And (4) concentration. Thus, in exemplary pressure cycle 550, at time period t₁₃-t₁₀The wound bed may be greater than p_minActual pressure p of_aNext, exposure to enhanced oxygen. In exemplary pressure cycle 550, at time period t₁₂-t₁₁Due to the fact that in general p_amb≤p_maxThus, the wound bed may be at a pressure substantially greater than or equal to ambient pressure p_ambActual pressure p of_aNext, exposure to enhanced oxygen.

By introducing the input fluid into the enclosed space without any output fluid being conducted out of the enclosed space, the actual pressure p in the enclosed space_aMay be at time t₁₀And t₁₁Increasing in between. Similarly, by conducting the output fluid out of the enclosed space without any input fluid being conducted into the enclosed space, the actual pressure p within the enclosed space_aMay be at time t₁₂And t₁₃Is reduced. The control group can control the input fluid at time t₁₀And t₁₁Between, and controlling the output fluid at time t₁₂And t₁₃Is derived from the other. Finally, in certain embodiments of the pressure cycle 550, at time t₁₁And t₁₂In between, no input fluid is introduced into the enclosed space, while no output fluid is directed out of the enclosed space.

In pressure cycle 550, for example, approximately, p_max＝p_amb+40mm Hg，p_min＝p_amb,. Time period t₁₁-t₁₀May be about 40s and then about t₁₂-t₁₁240s target pressure p₀Is maintained at p_maxFollowing about time period t₁₃-t₁₂80s, so that the time period of the pressure cycle 550 is t₁₃-t₁₀360s (6 minutes or 10 pressure cycles per hour). In certain embodiments, the pressure p of the pressure cycle 550_maxMay be limited by the ability of the adhesive (e.g., adhesive 190, 290, 390, 490) to secure the wound interface to a skin surface (e.g.,

skin surface

211, 311, 411) from pressure p_maxThe wound interface 15 is forced away from the skin surface.

Pressure cycle 550 may be at time t₁₃Start repetition (i.e., time t)₁₃Is set to a time t₁₀) Or then some other pressure cycle, such as pressure cycles 500, 600, 650, 700, 750, 800, 850, 900, 950, may be at time t₁₃The start-up is started. The pressure cycle 550 may remain substantially constant over successive cycles, or various parameters of the pressure cycle 550, such as p, may be varied over successive cycles_max，p_min，S₁₁，S₁₂，t₁₁-t₁₀，t₁₂-t₁₁，t₁₃-t₁₂。

For example, in some embodiments, the control group may deliver several pressure cycles based on pressure cycle 550, and then deliver one pressure cycle based on pressure cycle 500, such that the actual pressure p_aAt a pressure above ambient p_ambNext, enhanced oxygen (high pressure), and sub-ambient pressure p, is delivered to the wound bed_ambTo remove exudate from the wound bed or to change between resealing the wound interface to the skin surface. Typically, several minutes of pressurized topical oxygen may be beneficial, for example about 40mmHg, which is well below MAP (mean arterial perfusion pressure). For example, the pressure cycles 500, 550 may be combined such that the time period t₁₃-t₁₀Is about 4 minutes, time period t₄-t₀About 2 minutes, hyperbaric oxygen therapy was delivered to the wound bed at a pressure cycle of about 2/3 (about 6 minutes), and negative pressure therapy was performed for a pressure cycle time of about 1/3. In this example, when the pressure cycles 500, 550 are so combined, the resulting pressure cycle is asymmetric, taking longer periods of time in delivering hyperbaric treatments and fewer periods of time in delivering negative pressure treatments.

Another exemplary pressure cycle 600 is illustrated in FIG. 9C, where the actual pressure p is over the entire pressure cycle 600_aMay be substantially equal to the target pressure p₀. In the exemplary pressure cycle 600, the target pressure p₀Decreases and increases in a sinusoidal manner (non-linear) as shown in fig. 9C, so that the actual pressure p_aDecreasing and increasing continuously in a sinusoidal manner. As shown in FIG. 9CShowing, the pressure cycle 600 at time t₂₀At the beginning, the target pressure p₀＝p_max. In this embodiment, the target pressure p₀From time t₂₀To time t₂₁Internal decrease, at time t₂₁To reach p_minTarget pressure p₀Then at time t₂₁And time t₂₂From p to p_minRise to p_maxThen pressure p₀At time t₂₂And time t₂₃From p to p_maxIs reduced to p_min. As shown, in the exemplary pressure cycle 600, the target pressure p₀Continuously decreasing and increasing. Pressure cycle 600 may be repeated any number of times. The pressure cycle 600 may remain substantially constant over successive cycles, or various parameters of the pressure cycle 600, such as p_max，p_minOr a time period t₂₂-t₂₀And may be changed in successive cycles. In certain embodiments, the target pressure p₀May increase sinusoidally and then remain at a constant p for a period of time_maxAnd finally decreases in a sinusoidal manner.

Fig. 9D illustrates another exemplary pressure cycle 650. As shown in FIG. 7D, in the exemplary pressure cycle 650, the target pressure p₀The actual pressure p is continuously decreased and then increased in the form of a triangular waveform throughout the pressure cycle 650_aMay be substantially equal to the target pressure p₀. As shown in FIG. 9D, the pressure cycle 650 at time t₃₀At the beginning, the target pressure p₀≈p_max. In this embodiment, the target pressure p₀From time t₃₀To time t₃₁Linear decrease at time t₃₁To reach p_minThen target pressure p₀At time t₃₁And time t₃₂From p to p_minLinear increase to p_maxThereby completing one pressure cycle. The next pressure cycle starts at the target pressure p₀From time t₃₂To time t₃₃Linearly decreases, at time t₃₃To reach p_min. In the exemplary pressure cycle 650, the target pressure p₀Reduced in the form of a triangular waveformAnd then increases continuously as shown. The pressure cycle 650 may be repeated any number of times. Increasing the actual pressure p by controlling the introduction of an input fluid_aTo p_maxThe introduced fluid may contain O₂Greater than atmospheric air, this increased O₂Several consecutive deliveries may be made by successive waveforms, thereby continuously exposing the wound bed to an oxygen-rich environment.

Fig. 9E illustrates another exemplary pressure cycle 700. As shown in fig. 9E, the target pressure p₀At p_minAnd p_maxWith stepwise (pulsed) changes between the actual pressure p in the enclosed space by control groups during the entire pressure cycle 700_aCorresponding to the target pressure p₀But is changed. In the pressure cycle 700, the target pressure p₀From p_minStepwise increase to p_maxAny residual exudate may be blown out of the lumens connected to the enclosed space, such as

lumens

245, 345, 347, 445, including fluid pathways in communication with the lumens to eliminate blockages caused by the solidification of the exudate including drugs and other potentially solidified substances.

A commonly encountered problem is that the concentrated protein exudate from the wound bed becomes increasingly concentrated, forming a plug that blocks the lumen, including the fluid pathways communicating with the lumen. When this occurs, not only does exudate cease to be discharged, but exudate clogging can also interfere with pressure sensing. This hinders treatment, and the entire wound interface may have to be replaced in advance (assuming that medical personnel can do so), resulting in increased costs and increased pain to the patient. To address this problem, in some embodiments, the pressure p may be suddenly or rapidly released at the end of the pressure cycle by infusing a bolus of gas or liquid_minTowards the ambient pressure p_ambTo start. This can prevent clogging of the lines by exudate clogging or, if they do form, by pressure alone, or in combination with liquid dissolution, result in forced drainage of exudate clogs. The result may be elimination or prevention of lumen blockage and more accurate sensing and delivery of negative pressure therapy.

In some embodiments, the control group may deliver a pulsed input fluid to remove blockages from the lumen, including fluid pathways communicating with the lumen or enclosed space, in accordance with the pressure cycle 700. This can maintain the patency of the drain tube, and can accurately detect the target pressure p in the closed space₀. The magnitude of this step can be produced, for example, by a high fluid flow rate or by a highly elastic storage balloon interposed between the fluid source and the valve for regulating the flow delivered to the enclosed space. Maximum pressure p_maxShould be less than the pressure that would break the fluid-tight nature of the wound interface. This depends on many factors, including the nature of the adhesive used to anchor the wound interface to the skin. Typically, such a pulsed maximum pressure p_maxCan be compared with the ambient pressure p_ambAbout 30-40mm Hg high.

Another exemplary pressure cycle 750 is illustrated in fig. 9F. As shown in fig. 9F, the target pressure p₀From p_maxLinear reduction to p_minThen target pressure p₀From p_minIncrease to p exponentially (non-linearly)_max. The actual pressure p during the entire pressure cycle 750_aSubstantially equal to the target pressure p₀. In the exemplary pressure cycle 750, a fluid having an oxygen concentration greater than atmospheric air may be present at time t₅₂And t₅₁Is introduced to adjust the actual pressure p_aFrom p_minIncrease to p_maxThen the actual pressure p_aAt a time period t₅₃-t₅₂Is kept constant at p_maxTo be in a time period t₅₃-t₅₂At a pressure p_maxOxygen is delivered down the wound bed. Loop 750 at time t₅₃Repeat the beginning at time t₅₃And t₅₄Target pressure p between₀From p_maxTo p_minLinearly decreases, and then the target pressure p₀From p_minIncrease to p exponentially_maxAs shown in fig. 9F.

Fig. 9G illustrates another exemplary pressure cycle 800. The actual pressure p throughout the pressure cycle 800_aMay be substantially equal to the target pressure p₀Due to control of the control group, the target pressure p₀From p_minTo p_maxAnd from p_maxTo p_minLinearly changing. By controlling the group, at time t₆₀And t₆₁In between, a fluid having an oxygen concentration greater than atmospheric air may be introduced to bring the actual pressure p_aIncrease to a maximum pressure p_max. In this exemplary pressure cycle, the target pressure p₀And the actual pressure p_aThus during the time period t₆₂-t₆₁Is kept constant at p_maxE.g. at pressure p_maxOxygen is delivered to the wound bed. In the exemplary pressure cycle 800, the target pressure p₀At a time period t₆₄-t₆₃Is internally kept constant at p_minFor example to remove exudate from a wound bed.

Another exemplary pressure cycle 850 is illustrated in fig. 9H. The actual pressure p is over the entire pressure cycle 850 as controlled by the control group_aMay be substantially equal to the target pressure p₀In the exemplary pressure cycle 850, the target pressure p₀From p_maxSinusoidally varying to p_minAnd from p_minSinusoidal variation of p_max,. In the exemplary pressure cycle 850, the target pressure p₀At a time period t₇₂-t₇₁Is maintained constant at p_minE.g. to drain exudate from a wound bed, and a target pressure p₀At a time period t₇₄-t₇₃Is kept constant at p_maxE.g. at pressure p_maxOxygen is delivered to the wound bed.

In the exemplary pressure cycle 900, as shown in FIG. 9I, the target pressure p₀Continuously linearly decreasing and increasing in a zigzag fashion, the actual pressure p during the entire pressure cycle 900_aMay be substantially equal to the target pressure p₀. It is noted that in the exemplary pressure cycle 900, the maximum pressure p_maxGreater than ambient pressure p_amb。

In an exemplary pressure cycle 950, as shown in FIG. 9J, at time t₉₀Pressure p₀Initially p_min. By introducing liquid into the fluidIntroduced into the closed space, the control group being at t₉₀And t₉₁In between, the actual pressure p_aFrom p_minIncrease to p_maxActual pressure p_aWith a target pressure p₀And correspondingly. In this embodiment, the control group controls the input of liquid as the input fluid and the output of liquid as at least a portion of the output fluid. In this embodiment, the liquid, which constitutes at least a portion of the input fluid, may provide a variety of therapeutic benefits. The liquid may include, for example, saline solution, proteolytic enzyme solution, biofilm degrading solution, antibiotic lavage solution, amniotic fluid, platelet rich plasma, antibiotics, anesthetics, or other liquids having therapeutic benefits. In certain embodiments, at time t₉₀And t₉₁In between, 50cc or more of liquid may be introduced into the enclosed space. At time t₉₁And t₉₂In that an input fluid in liquid form is retained within the enclosed space to provide therapeutic benefits to the wound bed due to the actual pressure p_aWith a target pressure p₀Correspondingly, at time t₉₂And t₉₃From p to p_maxReduced to p_minThe liquid is then substantially directed out of the enclosed space, including from any pads, such as pads 250, 450 or dressings, such as dressing 350, within the enclosed space. In certain embodiments, the therapeutic benefit may include debridement.

At time t₉₂And t₉₃Target pressure p between₀The decrease in pressure may be marked as the beginning of a pressure cycle, such as pressure cycles 500, 550, 600, 650, 700, 750, 850, 900. In certain embodiments, at time t₉₂And t₉₃Of target pressure p₀From p_maxTo p_minCan remove 90% or more of the liquid from the enclosed space, including from any dressing, pad or layer in the enclosed space, such as

layers

460, 470, 480 disposed therein. Liquid under pressure p_maxTime period t of lower part in closed space₉₂-t₉₁May be, for example, in the range of about 2 minutes to about 1 hour. Time period t of less than 1 hour₉₂-t₉₁Or only a few minutesTime period t₉₂-t₉₁Maceration can be prevented, particularly when the skin surface is coated with an adhesive such as cyanoacrylate. In certain embodiments, at time t₉₁And t₉₂In between, no input fluid is introduced into the enclosed space, or output fluid is withdrawn from the enclosed space, i.e. at time t₉₁And t₉₂In between, no fluid passes through the enclosed space.

In other embodiments, the liquid may pass through the enclosed space as both the input fluid and the output fluid, i.e., at time t₉₁And t₉₂Meanwhile, the liquid is led in and out simultaneously. The pressure cycle 950, for example, may be intermittently interposed between other pressure cycles, such as pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, or the pressure cycle 950 may be repeated several times in succession. .

The wound therapy device may deliver a therapy regimen to the wound bed. The treatment regime may include an actual pressure p in the enclosed space_aWith a target pressure p₀And correspondingly. The pressure cycle may be, for example, any one of exemplary pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, and the series of pressure cycles may include several consecutive pressure cycles.

Example I

Example I presents a series of pressure cycles used in an exemplary wound treatment protocol delivered to a wound bed by a wound treatment apparatus. Example I demonstrates exemplary applications of these exemplary wound treatment protocols to wound treatment of a wound bed.

In this example, a dressing, such as dressing 50, 250, may be omitted from the wound bed during at least a portion of the healing process. The absence of a dressing eliminates the need to change dressings, as well as the associated pain and disruption of the healing process due to tearing of granulation tissue, as well as the attendant costs of medical personnel and various consumables, and may allow visual inspection of the wound bed and surrounding skin through a transparent portion of the wound interface. Since no dressing is used in this embodiment, the wound therapy device may be used until complete healing of the wound bed is achieved. The absence of a dressing, except possibly during the initial exudation phase of the wound bed, may allow, for example, lavage of the wound bed and incubation of tissue stromal stem cells, proteolytic enzyme soaking, medical maggot debridement or skin grafting. The wound treatment apparatus may be used until complete healing of the wound bed is achieved.

In example I, N represents pressure therapy, according to an exemplary pressure cycle 500, at time t₃And t₄O is₂Is fed into the enclosed space to increase the pressure in the enclosed space to p_max. Note that moisture may be added to O during certain pressure cycles₂Or other gases to prevent drying of the wound bed. O denotes pressure treatment, according to exemplary pressure cycle 550, at time t₁₀And t₁₁O is₂Is fed into the enclosed space to increase the pressure in the enclosed space to p_maxWherein p is_maxGreater than ambient pressure p in example I pressure cycle 550_amb。

The treatment regimen was a combination of four pressure cycles (four therapies) as follows:

treatment regimen 1-N/N/N/N (4 consecutive N treatments)

Treatment regimen 2-N/N/N/O (three N treatments in succession followed by one O treatment)

Treatment regimen 3-N/O/N/O (N therapy alternating with O therapy)

Treatment regimen 4-N/O/O/O (one N therapy followed by three O therapies)

If each pressure cycle (O-therapy or N-therapy) is delivered for 6 minutes, for example, each treatment regimen is then delivered for 24 minutes, allowing the treatment regimen to be delivered 60 times per day. Generally, more N therapy may be used during the early stages of wound treatment, as exemplified in treatment protocol 1 and treatment protocol 2, in order to remove exudates, such as exudates 51, 151, 251, 351, 419, and improve circulation, relatively speaking. Once the exudation phase is over, the need for N therapy is reduced. At this point the treatment regimen can be switched to N/O/N/O as in exemplary treatment regimen 3, and finally O treatment will become the primary treatment. Occasional N-therapies may be inserted in a series of O-therapies, such as exemplary therapy regime 4, for re-securing the wound interface to the skin. Exemplary weeks of a guided treatment regimen may be:

day 1-2: treatment protocol 1

Days 3-4: treatment protocol 2

Day 5-6: treatment protocol 3

Day 7: treatment protocol 4

According to example I, all N-therapy treatment regimen 1 was used at the beginning of wound treatment, since there may be interstitial edema with large amounts of exudate. Negative pressure p of treatment protocol 1₀Exudate may be directed away from the wound bed, and edema may be reduced by removing the exudate causing edema from the wound bed. Two days after treatment regimen 1, the wound treatment was changed from treatment regimen 1 to treatment regimen 2 with the insertion of O treatment in N treatment. In O therapy, at a pressure p₀Using a pressure generally greater than or equal to ambient pressure p_ambO of (A) to (B)₂Introducing O₂Delivery to the wound bed may aid in healing, and N therapy may continue to treat edema by drawing exudate from the wound bed.

After two days of treatment regimen 2, the wound treatment changed from treatment regimen 2 to treatment regimen 3, with O and N treatments alternating and the wound continued to heal. In O therapy, the composition containing O is used₂The use of gases at concentrations greater than atmospheric air may aid healing, and continued N therapy may continue to treat edema by drawing exudate from the wound bed.

Finally, on day 7 of example I, the wound therapy changed from treatment regime 3 to treatment regime 4, which was primarily O-therapy, with one N therapy cycle in every four cycles. The negative pressure of N therapy can re-adhere the wound interface to the skin, thereby prolonging the fluid-tight time.

Based on the duration and magnitude of the O-therapy, there may be a possibility that the seal between the wound interface and the skin surface may be compromised or even broken. The loss of adhesive integrity, during the subsequent suction cycle, allows the inflow of external air, which may dry the wound tissue, leaving the wound freeThe healing is not good. To prevent this from happening, except that a suitable maximum pressure p is selected_maxAnd beyond the duration, the use of at least a brief N therapy as the end of the O treatment sequence may allow the adhesive of the wound interface to be repositioned again and thus fixed to the skin surface again. The frequency ratio of such negative pressure cycles to positive pressure cycles may be 1: 1, 1: 2 or some other suitable ratio, depending on a number of parameters, including the duration and magnitude of the positive pressure cycles.

Once the wound interface fails to maintain a seal (typically due to skin peeling or adhesive failure), the wound interface may need to be replaced. Replacement was estimated to occur every 5 to 7 days, depending on the location of the wound bed and individual variability. It is noted that in any of treatment regimen 1, treatment regimen 2, treatment regimen 3, and treatment regimen 4, pressure cycles, such as pressure cycle 950, may be included from time to provide treatment fluid to the wound bed. The liquid may be, for example, saline solution, proteolytic enzyme solution, biofilm degrading solution, antibiotic lavage solution, amniotic fluid, platelet rich plasma, antibiotics, anesthetics, or other liquids having therapeutic benefit.

Thus, in example I, the procedure is from the initial use of N therapy to treat edema, a mix of N therapy and O therapy, which can both treat edema and promote healing, and finally, as the wound bed heals and edema subsides, primarily O therapy to promote healing. For example, treatment regimen 4 may be used when the wound is at least half healed and there is no longer any significant exudate.

For the purpose of explanation, it is assumed in example 1 that the wound bed gradually heals between day 1 and day 7. Of course, healing may take a period of time other than one week, and, accordingly, a plurality of treatment regimens, such as treatment regimens 1, 2, 3 and 4, may last for different lengths of time, and may be combined as appropriate depending on the condition of the wound bed. In certain embodiments, treatment regimens 1, 2, 3, and 4 can be connected to each other, or to other treatment regimens, in a variety of ways. In certain embodiments, a treatment regimen, such as treatment regimen 1, 2, 3, 4, can have other modes of pressure cycling, such as O/O/O/O/. In certain embodiments, the treatment protocol may have different numbers and types of cycles, such as pressure cycles 500, 550, 600, 650, 700, 750, 800, 850, 900, 950.

****

The wound treatment device can deliver a liquid, which can have a variety of therapeutic purposes, into the enclosed space of the wound interface, guided by a control group that includes a controller. The operation of the wound therapy device may include: a liquid from a liquid source, such as liquid source 84, is selected as the input fluid. The operation of the wound therapy device may include: the introduction of input fluid into, or the removal of output fluid from, the enclosed space of the wound interface is controlled in a manner suitable for therapeutic purposes by use of a control group. For example, a liquid may be introduced into the enclosed space as an input fluid and then removed from the enclosed space as an output fluid to irrigate the wound bed to remove bacterial infection or to wet the wound bed. As another example, when the liquid has healing or preservative properties, the liquid as an input fluid may be introduced into the enclosed space and allowed to remain within the enclosed space. As another example, a liquid as an input fluid may be introduced into the enclosed space and directed out of the enclosed space as an output fluid to flush various fluid pathways in communication with the input fluid or the output fluid. Using user I/O, a user can select to direct fluid into or out of the enclosed space through data communicated to the controller. Using user I/O, the user may select liquid or gas input through data communicated with the control group 65.

Fig. 10 illustrates, by way of a flow chart, another exemplary method of using a wound treatment apparatus. The method of operation 2000 as shown in fig. 10 and the associated description are merely exemplary. As shown in fig. 10, at step 2001, the operational methodology 2000 begins to proceed. In step 2002, the wound interface of the wound treatment device is secured to the skin surface, forming an enclosed space above the wound bed. In step 2003, the output fluid is directed out of the enclosed space, thereby reducing the pressure p within the enclosed space₀Up to p₀Equal to the minimum pressure p_min.. According to step 2004, the pressure p in the enclosed space₀Can then be maintained at a minimum pressure p_minDuration T₁. For example, the time period T₁And may be about 3 to 5 minutes. In step 2005, an input fluid is introduced into the enclosed space, thereby bringing about a pressure p₀From the minimum pressure p_minIncrease to a maximum pressure p_max. Input into the enclosed space in exemplary step 2005, pressure p is applied₀From the minimum pressure p_minIncrease to a maximum pressure p_maxComprising an input fluid having a ratio O₂A gas having a concentration greater than atmospheric air.

In step 2006, in certain embodiments, the maximum pressure p_maxMay be about equal to ambient pressure p_ambMaximum pressure p_maxMay be greater than ambient pressure p_ambOr maximum pressure p_maxMay be less than ambient pressure p_amb. According to exemplary step 2006, pressure p in the enclosed space₀May then be in the time period T₂Maintaining a maximum pressure p_max. For example, the time period T₂And may be about 1-3 minutes.

As shown in FIG. 10, in step 2007, output fluid is directed from the enclosed space to reduce the pressure p within the enclosed space₀Up to p₀Equal to the minimum pressure p_min. According to step 2008, the pressure p in the enclosed space₀Can then be maintained at a minimum pressure p_minLower duration period T₃. In exemplary method of operation 2000, since in step 2005 the fluid input into the enclosed space contains O₂Gas at a concentration greater than atmospheric air, the wound bed is exposed to O throughout

steps

2006, 2007 and 2008₂A gas with a concentration greater than atmospheric air.

In step 2009, an input fluid is introduced into the enclosed space to establish a pressure p₀From the minimum pressure p_minIncrease to a maximum pressure p_max. In the exemplary method of operation 2000, the input fluid in step 2009 comprises a liquid.

In exemplary method of operation 2000, in performing

steps

2003, 2004, 2005, 2006, 2007, 2008, and 2009, output fluid is directed out of the enclosed space and input fluid is directed into the enclosed space in sequence, such that either the input fluid is being input or the output fluid is being directed out. In performing

steps

2003, 2004, 2005, 2006, 2007, 2008, and 2009 of exemplary method of operation 2000, the input fluid introduction and the output fluid introduction are not performed simultaneously.

In step 2010, for a time period T₄The liquid passes through the enclosed space. In step 2010, the liquids may be sequentially introduced into the enclosed space and then removed from the enclosed space, or the liquids may be simultaneously introduced into and removed from the enclosed space. In step 2010, liquid may be pulsed to clear a variety of blockages in the channels in fluid communication with the enclosed space. In step 2010, for example, the liquid may rinse the enclosed space containing the wound bed and dressing, remove bacterial infection or exudate, clean the wound bed, wet the wound bed. At step 2010, liquid may be introduced and removed by perfusion (steady flow). The control group can limit the actual pressure p of the liquid in the closed space_aE.g. approximately equal to ambient pressure p_ambTo prevent movement of the wound interface. For example, the actual pressure p of the liquid in the enclosed space, detected by a pressure sensor_aSubstantially equal to the ambient pressure p_ambIn this case, the control group can reduce or stop the introduction of liquid into the enclosed space.

The exemplary method of operation 2000 then terminates at step 2011. Exemplary method 2000 may be repeated any number of times using various combinations of

steps

2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010. It is to be noted that the minimum pressure p_minAnd maximum pressure p_maxMay be performed at

step

2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 and time T, T₂，T₃，T₄Change in between, and minimum pressure p_minAnd maximum pressure p_maxMay be changed during various iterations of method 2000.

The method of wound treatment may comprise the steps of: connecting the wound interface to the skin surface surrounding the wound bedForming an enclosed space above the wound bed. The method of wound treatment may comprise the steps of: fluid communication is established between the wound interface, the control group, the liquid source and the gas source. The method of wound treatment may comprise the steps of: the control group is operable by the controller to sequentially regulate the introduction of the input fluid into the enclosed space and the discharge of the output fluid from the enclosed space, thereby varying the actual pressure p within the enclosed space_aWith a target pressure p₀Correspondingly, the pressure cycle has a minimum pressure p_minAnd maximum pressure p_maxThe input fluid comprising a fluid having a higher O than atmospheric air₂A concentration of gas.

The method of wound treatment may comprise the steps of: exudate is removed from the output fluid by flowing the output fluid through a container, such as

containers

81, 150.

The method of wound treatment may comprise the steps of: the data is received using an I/O interface in operable communication with the controller and transmitted to the controller to change the pressure cycle or change the input fluid between liquid and gas.

The method of wound treatment may comprise the steps of: delivering a treatment protocol to the wound bed, the treatment protocol comprising an actual pressure p within the enclosed space_aA series of pressure cycles.

A method of wound treatment may comprise the steps of: delivering a treatment protocol to the wound bed, the treatment protocol comprising inputting a liquid into the enclosed space, and may include withdrawing the liquid from the enclosed space.

The method of wound treatment may comprise the steps of: programmed delivery of multiple gases and liquids to the wound bed under the control of the controller

The method of wound treatment may comprise the steps of: when other gases and liquids are not available, air is delivered to the enclosed space. The wound treatment method may comprise the steps of: in the event of a power failure of the wound treatment apparatus, gas is delivered to the enclosed space to generate a pressure p equal to the ambient pressure within the enclosed space_ambActual pressure p of_a。

The foregoing discussion, in conjunction with the accompanying drawings, discloses and describes various exemplary embodiments. These embodiments are not meant to limit the scope of coverage, but rather, to facilitate an understanding of the language used in the specification and claims. Having studied the disclosure and the illustrative implementations herein, one of ordinary skill in the art will readily recognize various changes, modifications, and alterations that may be made without departing from the spirit and scope of the invention as defined by the following claims.

Claims

1. A wound treatment apparatus comprising:

a wound interface that forms a fluid-tight enclosure over the wound bed when secured to the skin surface surrounding the wound bed; and a control group cooperating with the wound interface for regulating the introduction of an input fluid into the enclosed space and for regulating the discharge of an output fluid from the enclosed space to be at substantially a minimum pressure p_minAnd maximum pressure p_maxIn the closed space, varying the actual pressure p in the closed space_aSaid minimum pressure p_minLess than ambient pressure p_ambSaid input fluid comprising O therein₂A gas of greater concentration than atmospheric air, having O₂The input of said gas having a concentration greater than atmospheric air and having O₂The output of said gases at a concentration greater than atmospheric air is sequential.

2. The device of claim 1, wherein there is O₂The gas at a concentration greater than atmospheric air further comprises humidity.

3. The apparatus of claim 1, wherein at least a portion of the output fluid is vented to atmosphere through the control group.

4. The device of claim 3, wherein when the actual pressure p in the enclosed space is_aExceeding the maximum pressure p_maxThe control group vents the gaseous portion of the output fluid to atmosphere.

5. The device according to claim 1, wherein the control group comprises a pressure sensor to detect the actual pressure p within the enclosed space_a。

6. The device according to claim 1, wherein the control group comprises a pressure sensor and a second pressure sensor, the pressure sensor detecting the actual pressure p in the enclosed space during the introduction of the input fluid_a(ii) a The second pressure sensor detects the actual pressure p in the enclosed space during the output fluid is being conducted out_a。

7. The device of claim 1, wherein the input fluid further comprises a liquid that is introduced into the enclosed space while being simultaneously directed out of the enclosed space.

8. The device of claim 1, wherein the input fluid further comprises a liquid, the liquid being sequentially introduced into and withdrawn from the enclosed space.

9. The device of claim 9, wherein the liquid is introduced into the enclosed space in a pulse to remove exudate from a lumen in fluid communication with the enclosed space.

10. The device of claim 1, wherein the input fluid further comprises a liquid that is introduced into the enclosed space while being simultaneously directed out of the enclosed space.

11. The apparatus of claim 1, further comprising:

an I/O interface for receiving data from a user to at least partially control the introduction of an input fluid into the enclosed space or to at least partially control the removal of an output fluid from the enclosed space.

12. The apparatus of claim 1, further comprising:

a pressure cycle which specifies a target pressure p₀Said control group varying said actual pressure p in said enclosed space substantially in accordance with said pressure cycle_a。

13. The device of claim 12, wherein the pressure cycle is selected from having a minimum pressure p_minLess than ambient pressure p_ambAnd having a maximum pressure greater than ambient pressure p_ambO pressure cycle of (1).

14. The apparatus of claim 12, further comprising:

minimum pressure p_minAnd maximum pressure p_maxSaid minimum pressure p_minLess than ambient pressure p_ambSaid maximum pressure p_maxGreater than ambient pressure p_ambSaid actual pressure p_aGreater than ambient pressure p for at least half of the time period of the pressure cycle_ambSaid actual pressure p_aSub-ambient pressure p in less than half of said time period_amb。

15. The apparatus of claim 12, further comprising:

minimum pressure p_minAnd maximum pressure p_maxSaid minimum pressure p_minLess than ambient pressure p_ambSaid maximum pressure p_maxGreater than or equal to ambient pressure p_ambSaid actual pressure p_aLess than ambient pressure p for at least half of the time period of the pressure cycle_ambSaid actual pressure p_aGreater than ambient pressure p for less than half of said time period_amb。

16. The apparatus of claim 1, wherein the control group comprises:

a controller operatively connected to the pump and the one or more valves to regulate the introduction of the input fluid into the enclosed space and to regulate the removal of the output fluid from the enclosed space.

17. The apparatus of claim 1, further comprising:

a container removably connected with the control group to capture liquid including exudate from the output fluid.

18. A method of wound treatment comprising the steps of:

connecting the wound interface to the skin surface surrounding the wound bed, thereby forming an enclosed space;

using a control group, the introduction of the input fluid into the enclosed space and the discharge of the output fluid out of the enclosed space are regulated in sequence, so as to be dependent on the target pressure p₀Periodically varying said actual pressure p in said enclosed space_aSaid pressure cycle having a minimum pressure p_minAnd maximum pressure p_maxSaid input fluid comprising O therein₂A gas having a concentration greater than atmospheric air.

19. The method of claim 18, further comprising the steps of:

removing exudate from the output fluid by flowing the output fluid through a container.

20. The method of claim 18, further comprising the steps of:

receiving user input using an I/O interface in operative communication with the microprocessor; communicating the user input to the microprocessor to thereby change the pressure cycle.

21. The method of claim 18, further comprising the steps of:

delivering a treatment protocol to the wound bed, the treatment protocol including the actual pressure p within the enclosed space_aA series of pressure cycles.

22. The method of claim 21, wherein the treatment regimen further comprises the steps of:

introducing a liquid into the enclosed space after the step of delivering a treatment regimen to the wound bed.

23. An apparatus for wound treatment, comprising:

a liquid source containing a liquid;

a gas source containing O therein₂A gas having a concentration greater than atmospheric air;

a wound interface coupled to a skin surface surrounding a wound bed to form an enclosed space over the wound bed, the enclosed space being fluid-tight; and

a control group in operative communication with the liquid source, the gas source, and the enclosed space for selectively introducing liquid and gas into the enclosed space and regulating the egress of the output fluid from the enclosed space.

24. The apparatus of claim 23, wherein the introduction of the gas and the withdrawal of the gas are performed sequentially to substantially at a minimum pressure p_minAnd maximum pressure p_maxChange the actual pressure p in the enclosed space_aSaid minimum pressure p_minLess than specific ambient pressure p_ambSaid maximum pressure being greater than said minimum pressure p_min。

25. The apparatus of claim 23, wherein the introduction of the liquid and the removal of the liquid are performed simultaneously to irrigate the wound bed.

26. The apparatus of claim 23, wherein the introduction of the gas brings the actual pressure p within the enclosed space_aIncrease, approximately from the minimum pressure p_minIncrease to maximum pressure p_maxSaid minimum pressure p_minLess than ambient pressure p_ambSaid maximum pressure being greater than the minimum pressure p_min。

27. The apparatus of claim 23, further comprising:

a container in fluid communication with the output fluid to capture liquid including exudate from the output fluid.

28. The apparatus of claim 23, further comprising:

an atmosphere in operative connection with the operational group, the control group selectively selecting an input liquid, gas, and gas from the atmosphere to enter the wound interface.