CN110958866A

CN110958866A - Wound covering devices and related methods of use

Info

Publication number: CN110958866A
Application number: CN201880049904.XA
Authority: CN
Inventors: 林正纶
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-07-29
Filing date: 2018-07-26
Publication date: 2020-04-03
Anticipated expiration: 2038-07-26
Also published as: CN111050711B; CN111050711A; CN110996866A; CN110944608B; WO2019027806A1; WO2019027808A1; WO2019027807A1; WO2019027809A1; CN110944608A; CN110958866B; WO2019027810A1; CN111343949A; CN110996866B

Abstract

Disclosed herein is a wound treatment apparatus that, in various inventive aspects, includes a wound interface that forms a fluid-tight enclosure over a wound bed to maintain a pressure p relative to an ambient pressure within the enclosure_ambDifferent pressures p₀. In aspects of the invention, a dressing interfacing with the wound may contact the wound bed, and the dressing may include a hydrophobic material, or a distal layer including silicone having channels therein. The enclosure may include an O that is circulated into the enclosure₂A gas having a concentration greater than atmospheric air, and the pressure of the enclosed space may vary over a range of pressures. Related methods of using the wound treatment devices are also disclosed herein.

Description

Wound covering devices 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 devices for wound therapy and related compositions and methods of use.

Background

Wounds afflict hundreds of millions of people worldwide. In the united states, there are 650 thousands of chronic wounds with an average healing time of 23 weeks, mainly due to insufficient blood flow and insufficient oxygen. There are 7100 thousands of acute surgical wounds, and the incidence of surgical site infection is increasing. Various types of bandages and dressings have been created to improve various aspects of healing. However, most of these different bandages and dressings offer only a narrow benefit, focusing only on certain aspects of the numerous requirements of wound bed healing, such as maintaining the wound moist and maintaining a sterile environment. For example, silver ion impregnated dressings can inhibit infection due to antimicrobial properties, but silver ions also inhibit fibroblast differentiation and healing. Hydrocolloids can absorb exudate from the wound bed, but do not help to improve blood flow and cellular oxygen. Silicone dressings may help to reduce scar formation, but silicone dressings lack absorbent properties and may be a barrier to exudate transfer.

The application of silicone sheets to wound beds has been shown to reduce scar formation. Silicone sheets are typically applied to the already-healing wound bed to induce collagen reorganization, resulting in a non-prominent scar. Silicone sheets are an obstacle to exudate transfer and therefore, according to conventional wisdom, silicone sheets are not suitable for use in the exudative phase of wound bed healing.

Absorbent bandages, e.g. Smith&Pico of Nephew and Prevena of Acelity^TMTo provide suction of NPWT (negative pressure wound therapy) on wound beds was introduced in the us in the early 2010. The negative pressure in these devices is generated by a disposable battery-driven pump to apply a constant negative pressure to the wound. After 7 days of use, the pump was "killed" (permanently disabled) by the software and both the dressing and the pump were discarded. While helpful in removing exudate, constant negative pressure may collapse certain capillaries, reducing blood flow in certain areas and tissue oxygen pressure, both of which are not conducive to healing. This is often the case when NPWT is used to treat acute and chronic wounds.

Accordingly, there is a need for improved devices for wound therapy and related methods, for example, to provide a combination of benefits and address the challenges of multiple wound healing.

Disclosure of Invention

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

Sometimes, the wound treatment devices disclosed herein comprise a wound interface secured to the skin surface surrounding a wound bed to form a fluid-tight enclosure over the wound bed to maintain a pressure p within the enclosure₀Different from ambient pressure p_amb. At times, wound therapy devices include a dressing interfacing with the wound to contact the wound bed. A layer of adhesive is disposed on the distal surface of the wound interface to secure the wound interface to the skin surface. At times, when secured to the skin surface, the wound treatment device includes a gas in an enclosed space, the gas having O₂O with a concentration greater than atmospheric air₂Concentration, no gas flows into or out of the enclosed space.

At times, the dressing may include a hydrophobic material that removes exudate from the wound bed, and a hydrophilic material that fluidically cooperates with the hydrophobic material to remove exudate from the hydrophobic material. In some cases, the dressing includes at least one distal layer comprised of at least silicone, a distal end of the distal layer contacting the wound bed when the wound interface is secured to the skin, and a channel disposed in the distal layer in fluid communication between the distal and proximal sides of the distal layer.

The related usage method can comprise the following steps: by introducing an input fluid into the enclosed space or removing an output fluid from the enclosed space via one or more internal chambers, in a pressure range p_min≤p₀≤p_maxVarying the pressure p in the enclosed space₀. At all times, the maximum pressure p_maxMay be greater than ambient pressure p_amb. At times, the input fluid may be O₂The concentration is greater than that of O in the atmosphere₂A concentration of gas. The input of fluid may be liquid at times, and the input of liquid into the enclosed space and then the output from the enclosed space may be performed sequentially, or the input of liquid into the enclosed space and the output from the enclosed space may be performed simultaneously at times.

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

Drawings

FIG. 1A illustrates a schematic diagram of an exemplary implementation of a wound treatment apparatus;

FIG. 1B illustrates a perspective view of a portion of an exemplary implementation of the wound treatment apparatus of FIG. 1A;

FIG. 2 illustrates a perspective view of a portion of the exemplary wound treatment apparatus of FIG. 1A;

FIG. 3 illustrates, in cross-sectional view through section 3-3 of FIG. 1B, a portion of the exemplary wound treatment apparatus of FIG. 1 in a first stage of operation;

FIG. 4A illustrates, in cross-sectional view through section 3-3 of FIG. 1B, a portion of the exemplary wound treatment apparatus of FIG. 1 in a second stage of operation;

FIG. 4B illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of FIG. 1A;

FIG. 4C illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of FIG. 1A;

FIG. 5 illustrates a cross-sectional view of a second exemplary implementation of a wound treatment apparatus;

fig. 6A illustrates a plan view of a portion of the exemplary wound treatment apparatus of fig. 5;

fig. 6B illustrates a plan view of a portion of the exemplary wound treatment apparatus of fig. 5;

FIG. 7 illustrates a plan view of a third exemplary implementation of a wound treatment apparatus;

fig. 8A illustrates a plan view of a fourth exemplary implementation of a wound treatment apparatus;

fig. 8B illustrates a plan view of a fifth exemplary implementation of a wound treatment apparatus;

fig. 9 illustrates a cross-sectional view of a sixth exemplary implementation of a wound treatment apparatus;

FIG. 10 illustrates a cross-sectional view of a seventh exemplary implementation of a wound treatment apparatus;

fig. 11 illustrates a cross-sectional view of an eighth exemplary implementation of a wound treatment apparatus;

fig. 12A illustrates a cross-sectional view of a ninth exemplary implementation of a wound treatment apparatus at a first stage of operation;

fig. 12B illustrates a cross-sectional view of the exemplary wound treatment apparatus of fig. 12A in a second stage of operation;

fig. 13A illustrates a cross-sectional view of a tenth exemplary implementation of a wound treatment apparatus at a first stage of operation;

FIG. 13B illustrates a cross-sectional view of the exemplary wound treatment apparatus of FIG. 13A in a second stage of operation;

fig. 13C illustrates a perspective view of the exemplary wound treatment apparatus of fig. 13A; and

fig. 14 illustrates, by way of a flow chart, an exemplary method of operation of a wound treatment apparatus, such as the exemplary wound treatment apparatus of fig. 1A, 5, 7, 8A, 8B, 9, 10, 11, 12A, 13A.

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 are readily understood by one of ordinary skill in the art in light of the present 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 represent engineering, manufacturing, or scientific tolerances, such as ± 0.1%, ± 1%, ± 2.5%, ± 5%, or other such tolerances, as would be readily understood by one of ordinary skill in the art having the benefit of this disclosure.

Detailed Description

A wound treatment device is disclosed herein. At times, the wound treatment apparatus includes a wound interface securable to the skin surface surrounding the wound bed to form a sufficiently fluid-tight enclosed space above the wound bed to maintain a pressure p0 within the enclosed space greater than or less than ambient pressure pamb. At times, a gas may be provided into the enclosed space, the gas having a concentration of O2 greater than atmospheric air, or greater than about 20.95% by volume dry air oxygen or greater than 0.2095 moles of O2 per mole of atmospheric air. The wound treatment apparatus may include a dressing disposed within the enclosed space, biased toward the wound bed, the dressing may include at least a distal layer and a proximal layer having different compositions. The wound interface may include an adhesive layer to adhesively secure the wound interface to the skin surface surrounding the wound bed.

Wound bed, as referred to herein, refers to a local breach of the outer surface of normal skin, for example, caused by trauma (e.g., abrasion, avulsion, laceration, puncture, incision, chemical or thermal injury) or microbial infection. The wound bed may include varying degrees of subcutaneous tissue and structural exposure, as well as possible infection and tissue changes. The wound bed represents an unhealed wound. In contrast, a healed wound refers to a skin surface that was previously injured but with a local gap now completely sealed and covered by a different amount of epidermal and scar tissue.

The silicone, as referred to herein, including silicones, polysiloxanes, silicone-like materials, and combinations thereof, can be generally solid. The silicone resin may have the formula [ R₂SiO]_nWherein R is an organic group. 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 polydimethylsiloxane derivatives), copolymers such as stearyl methyl-dimethylsiloxane copolymer, polysiloxane-11 (a vinyl terminated siloxane and (dimethylhydrogenated) organoCrosslinked silicone rubber resulting from the reaction of silicon in the presence of cyclomethicone), cetearyldimethicone/vinyl dimethicone crosspolymer (copolymer of cetearyldimethicone crosslinked with vinyl dimethicone), dimethicone/phenyl vinyl dimethicone crosspolymer (copolymer of dimethicone crosslinked with phenyl vinyl dimethicone)/vinyl dimethicone crosspolymer (copolymer of dimethicone crosslinked with vinyl dimethicone).

Sometimes, the enclosed space has O therein₂The gas at a concentration greater than atmospheric air may be medical grade oxygen. Medical grade oxygen may meet certain standards, such as the U.S. food and drug administration standards or other appropriate regulatory standards. At times, the medical grade oxygen may be U.S. pharmaceutical grade oxygen.

The wound treatment apparatus may comprise a port or ports having a lumen or lumens in fluid communication with the enclosed space via which the fluid is introduced into and removed from the enclosed space by way of the port or ports to provide a range of pressures p_min≤p₀≤p_maxPeriodically varying the pressure p in the enclosed space₀. The wound treatment device may include a variety of fluid delivery devices or fluid sources operatively interfaced with the wound to direct input fluid into the enclosed space or to direct output fluid out of the enclosed space. At times, the input of fluid into the enclosed space and the output of fluid from the enclosed space may be sequential, such that the input of fluid into the enclosed space and the output of fluid from the enclosed space cannot occur simultaneously.

At times when liquid is flowing through the enclosure, it may be desirable to introduce the liquid into the enclosure while removing the liquid from the enclosure. At times, the duration of liquid passage through the enclosed space may be limited, for example, for 30-90 minutes, to prevent (1) local hypothermia and vasoconstriction of the wound, and (2) tissue maceration of the skin surrounding the wound. This undesirable side effect can be further prevented by (1) preheating the liquid and (2) applying a layer of cyanoacrylate adhesive around the wound skin prior to treatment to prevent prolonged contact of the skin with the liquid.

The sequential introduction of the input fluid into the enclosed space (at the end of an NPWT cycle) and the withdrawal of the output fluid from the enclosed space (at the beginning of the next NPWT cycle) means that the introduction of the input fluid and the withdrawal of the output fluid do not occur simultaneously, except for the flow of liquid through the enclosed space. With this exception, when the input fluid is introduced and the output fluid is withdrawn in sequence, 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 are not performed simultaneously.

As used herein, fluid includes liquids, gases, and combinations thereof. The liquid may include, for example, Dakins solution, saline solution, antioxidant solution, proteolytic enzyme solution, antimicrobial solution, amniotic fluid, and exudate. The liquid may comprise a solution for perfusing the wound bed, removing infectious bacteria or wetting the wound bed. The gas may include, for example, atmospheric air, oxygen, nitric oxide, nitrogen, moisture, or a suitable therapeutic or inert gas, and combinations thereof. Reference herein to humidity includes water vapor and mist. Exudate as referred to herein includes, for example, proteinaceous fluids exuded from wounds, as well as various plasma and blood components. Exudate may also include other liquids, including other liquids exuded from the wound bed.

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 in an enclosed space that may be above or below ambient pressure, by insufflation or vacuum suction_ambPressure p of₀. The term "fluid-tight" is sometimes used to refer to a material having sufficient resistance to leakage to substantially maintain fluid within the enclosed space, including gases and liquids, except by controlling fluid communication through one or more lumens that are in fluid communication with the enclosed space through the wound interface. At some point, "fluid-tight" means having sufficient resistance to leakage to maintain an enclosed spaceInternal pressure p₀Above or below ambient pressure p_amb。

Reference herein to ambient pressure p_ambRefers to the pressure of the area surrounding the wound treatment device. Ambient pressure p_ambFor example, atmospheric pressure, hull pressure where the wound treatment device is used, such as in an aircraft or submarine, or pressure substantially maintained within a building or other structure may be referred to. Ambient pressure p_ambMay differ, for example, due to altitude or weather conditions. Pressure p_minRefers to the minimum pressure achieved within the enclosed space of the wound treatment device; periodically changing pressure p₀Pressure 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.

Minimum pressure p_minMay be, for example, at approximately ambient pressure p_ambThe lower range is from-40 mmHg to-150 mmHg. At all times, the maximum pressure p_maxMay be, for example, substantially above ambient pressure p_ambFrom +5mmHg to +40 mmHg. At all times, the maximum pressure p_maxMay be approximately equal to ambient pressure p_amb. At all times, the maximum pressure p_maxApproximately at ambient pressure p_amb·The lower range is from-5 mmHg to-20 mmHg. Minimum pressure p during use of the wound treatment device_minMaximum pressure p_maxThe period of the pressure cycle, and the shape of the pressure cycle (e.g., sine wave, square wave) may vary. At times, the pressure p in the enclosed space₀Can be above or below ambient pressure p_ambAnd is static for a period of time. The wound treatment device may provide intermittent negative pressure (p)_o＜p_amb) Including periodic characteristics to achieve refill and reperfusion of the capillary when negative pressure is reduced or closed (po → pamb). At times, the pressure cycle may vary from one to another depending on the particular treatment being delivered and the effect desired to be achieved. For example, can eachSaline flush is given 2 minutes at 2 hours, and antibiotic lavage can be delivered for 5-10 minutes every 8-12 hours, while infusion of local anesthetic may be required for only 2-4 minutes every 4-12 hours, depending on the drug used. At some time by having O₂Air, air or air O, of greater concentration than atmospheric air₂The combined fluids release a negative pressure to enhance blood flow and oxygen. At times, the negative pressure is released by the liquid.

At times, the material forming the dressing may include, for example, a foam formulation made of polyvinyl alcohol, polyurethane (particularly open cell), polyurethane foam containing polyethylene glycol (PEG) to enhance its water absorption and transport properties, or other suitable polymers, fibers such as sodium carboxymethylcellulose hydrogel fibers (Aquacel), which may be woven, non-woven, or a combination of woven and non-woven. The material forming the dressing may sometimes include, for example, a nonwoven fabric of multicomponent fibers of nylon and polyester, which is hydroentangled (

) Split longitudinally into their respective components. Sometimes, the material forming the dressing comprises, for example, knitted fibers, such as in a plain knit pattern, with the hydrophobic fibers being located primarily on the side closest to the wound and the hydrophilic fibers being located primarily on the side of the wound away to act as conduits for fluid transfer.

The materials forming the dressing may be organized into layers, where the layers, for example, have different compositions (e.g., different proportions of polypropylene and nylon from one side of the layer to the other, different concentrations or densities of a single additive material (e.g., silicone thread from one side to the other, open cell polyvinyl alcohol and cellulose) or different configurations of the same material (e.g., woven and non-woven), the dressing may include two or more layers. The distal layer or surface may be formed primarily of a hydrophobic material and the surface of the layer or dressing relatively proximal to the wound bed may be formed of a hydrophilic material. The hydrophobic material may transport liquid (e.g., exudate) away from the wound bed to prevent the accumulation of liquid and, thus, prevent maceration of the tissue (including the skin surface surrounding the wound bed) in contact with the dressing. The hydrophilic material may transport liquid from the hydrophobic material, e.g. towards the lumen, for conducting liquid out of the enclosed space. The hydrophobic material may be, for example, a polyester-like material and the hydrophilic material may be, for example, an aliphatic or semi-aromatic polyamide (e.g., nylon). The dressing may include polyester-polyurethane copolymer fibers (e.g., spandex or lycra) for stretchability and conformability, and to apply a gentle compressive force to the wound bed. Polyurethane foams incorporating polyethylene glycol (PEG) may enhance absorbency and exudate transport. Since PEG can swell several times (7-fold to 12-fold or more depending on composition) and only requires application of slight pressure, it can be used in skin grafts to provide gentle compression without damage. This slight compressive force exerted by the dressing on the wound bed may reduce potential edema and, in the case of a surgical incision wound, may help bring the two wound edges into apposition and reduce the formation of subcutaneous fluid accumulation therebetween. At times, the distal side of the dressing in contact with the wound bed may be formed of a known material that is easily separated from the wound during dressing changes, minimizing pain, discomfort and damage to granulation tissue. Examples include a silicone sheet with fenestrations, a suitable mesh woven silicone thread or other perforated non-stick polymer film, such as polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE), or other fluoropolymers.

The dressing may include a drug, which may be pre-configured onto the dressing, and which may be delivered to the wound bed when the wound interface is secured to the skin surface. Sometimes, the drug may be supplied to the dressing while the wound interface including the dressing is secured to the skin surface. In addition, it is contemplated that certain drug delivery clips may be functionally associated with the dressing and that prior to use, the drug is delivered to the dressing by, for example, a pre-filled delivery device, such as a pre-filled syringe, a breakable ampoule or a piercing squeeze delivery device. The drug may include, for example, silver ion releasing agents or antibiotics for antimicrobial activity, analgesics for analgesia, antioxidants, amnion or placenta derived cytokines and growth factors, platelet rich plasma, hemostatic and blood clotting agents for hemostasis, compounds for oxygen generation and release, or exothermic or endothermic agents.

The terms distal and proximal as used herein are relative and not necessarily absolute positions defined from the perspective of a physician treating a patient with a wound therapy device, including nurses, technicians, and other care givers. The distal portion of the wound therapy device may face the patient and the proximal portion of the wound therapy device may face the physician. For example, when deployed, the distal portion of the wound therapy device may be closer to the patient and the proximal portion of the wound therapy device may be closer to the physician. As another example, the distal surface in the multi-layer wound interface is closer to the wound bed, but not necessarily the layer in contact with or closest to the wound bed.

At times, the wound treatment apparatus may include a distal layer of absorbent material applied over the wound, a proximal layer of (typically) impermeable material covering the distal layer of material, the proximal layer fluidly sealing the distal layer from the external environment, and at least one port disposed atop the proximal layer, in functional connection with the absorbent material, wherein the port is in functional connection with a source of negative pressure and a fluid source, such as an oxygen source.

Sometimes, the wound treatment device may include a distal layer of silicone, including other non-stick polymers such as polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE) or other fluoropolymers, connected to the wound bed, with channels in the distal layer of silicone to allow fluid transport through the layer. A proximal layer of absorbent material may be juxtaposed proximal to the distal layer, the proximal layer being capable of absorbing and wicking exudates away from the distal layer.

At times, the wound treatment apparatus may include a distal layer of absorbent material applied to the wound bed, and a substantially fluid impermeable (other than water vapor) member overlying the distal layer of material and sealing the distal layer from the external environment in a substantially fluid tight manner. At least one port may be provided on the member in fluid communication with the absorbent material, and in fluid communication with a source of negative pressure and a source of oxygen.

At times, the wound treatment apparatus may include a fluid conducting material in contact with the wound bed, the fluid conducting material also being in functional contact with at least one interface, the at least one interface being connectable to a source of controlled negative pressure and oxygen for treating the wound. The adhesive proximal layer may secure the absorbent material to the wound and form a fluid-tight seal and enclosure around the wound.

Sometimes, fluid conducting materials have structural elements or differences in internal material composition to help transfer and absorb fluid from the wound during negative pressure and oxygen therapy, such structural elements including conduits, channels, grooves, tunnels, spacer layers, interstitial cavities, pads and baffles, at least some of which may additionally communicate or change the concentration or proportion of materials from one surface or layer to another.

A progressive marking or designation system (e.g., 1, 2, 3 or color coding from red to yellow to green) may be used to indicate the suitability of an embodiment of the wound therapy device, e.g., settings for indexing a corresponding controller, to indicate the capacity of the absorption volume, for a particular stage of wound healing or for a particular type of wound bed. For example, a distal layer formed of silicone with larger channels and a thicker absorbent layer may be suitable for the early stages of the healing process, and a distal layer with a thinner absorbent layer and a smaller channel may be suitable for the later stages of the healing process (little or no exudate being drained from the wound bed).

At some point, the devices described herein and related usesThe methods and compositions can be used to impart specific functions to them, including accelerating healing, preventing infection at the surgical site, regulating surface tension at the surgical incision, and reducing scar formation. For example, with current wound treatment devices, treatment of chronic wounds can be prolonged, with 24 hours a day already being fully utilized to treat up to weeks, even months, or even longer. At times, a variety of beneficial treatments may be applied to the wound bed using the wound treatment apparatus and associated methods of use disclosed herein without introducing a fixed flow of other therapeutic agents and without reducing the duration of the wound treatment. In other words, it is as if a person had available many additional times a day, except for 4 hours that he had been doing. It is disclosed herein how additional treatment can be achieved, e.g. by using a pressure p_minThe therapeutic agent is drawn into the enclosed space to initiate additional treatment. At times, additional therapies are clipped or inserted into the "drop" or remission phase of the NPWT cycle. For example, the pressure cycle may have a pressure p of 4 minutes_minAnd a pressure p of 2 minutes_maxIs released. For example, at a pressure p_maxUsing this 2 minutes to provide oxygen, then, would result in an additional oxygen supplement of 8 hours/day, which was not previously needed. Similarly, at a pressure p_maxDuring the release (at pressure p)_minIn between) the cycle of saline flush, antibiotic or local anesthetic instillation inserted, now enables the continuous maintenance of a completely new and more healing-beneficial environment, therapeutic efficacy and patient comfort that has not previously been achieved.

At times, the wound treatment devices disclosed herein and related methods of use and combinations combine periodic NPWT with topical oxygen therapy for healing and infection-inhibiting properties. At times, the wound treatment devices disclosed herein provide periodic NPWT treatment, with the NPWT being released by oxygen or other treatment fluid to increase the overall therapeutic benefit. Sometimes, the wound treatment devices disclosed herein provide a dressing having a perforated silicone layer in combination with an absorbent layer to not only absorb exudate, but in addition to the silicone regulating scar action, also regulate incision tension. Wound treatment devices and related methods of use sometimes provide other beneficial treatments, such as healing cytokines from amniotic fluid. At times, the wound treatment device may have uses other than wound care, such as treatment of wrinkles, inflammation, pain, autoimmune processes, pigmented spots or vitiligo.

Fig. 1A illustrates an exemplary wound treatment apparatus 10. As shown in fig. 1A, the wound treatment apparatus includes a gas source 82 and a liquid source 84 in fluid communication with the controller 80, the controller 80 being in fluid communication with the wound interface 15. A wound interface, secured to the skin surface 11 to form an enclosed space 17 (see fig. 4A) above the wound bed 13, as shown.

In this embodiment, the controller 80, includes an administration set 93 and a reservoir 81 having a lumen 99. The container 81, which may include a filter and an exudate solidifying material, such as a Super Absorbent Polymer (SAP) like sodium polyacrylate, within the chamber 99, may be removed from the controller 80 for replacement. In some embodiments, the container 81 may be omitted.

The control group 93 includes a microcontroller 87, the microcontroller 87 being in operative communication with the power supply 98, the user I/O86, the valve 88, the pump 89 and the pressure sensor 91 to control or monitor the operation of the power supply 98, the valve 88, the pump 89 and the pressure sensor 91, at least in part in response to user input. The microcontroller 87 may include, for example, a microprocessor, memory, A/D converter, D/A converter, clock, I/O connector, etc., as will be readily understood by one of ordinary skill in the art in view of this disclosure.

The power source 98 may be, for example, a mains power line or a battery, and the power source 98 may include, for example, a transformer, an inverter, a rectifier, or a power filter. In this illustration, valve 88 and pressure sensor 91 may represent multiple valves and multiple pressure sensors, respectively. Various transmission paths may be arranged around the controller 80 to transmit power from the power source 98 to the microcontroller 87, the valve 88, the pump 89, and the pressure sensor 91.

The user I/O86 may include a variety of switches, buttons, dials, displays, etc., whether virtual or physical, for obtaining user input, and then interface with the microcontroller 87 to allow the user to direct the operation of the wound treatment apparatus 10. Various transmission paths, such as electrical (e.g., bluetooth), optical (e.g., LASER, IR), and networking communications, may be employed for communication between microcontroller 87 and user I/O86. The user I/O86 may be at least partially remote from the other components of the control group 93, and the user I/O86 may communicate with the other components of the control group 93 over a network including the Internet. The microcontroller 87 may control operation of the wound therapy device 10, including the controller 80 based at least in part on user input communicated from the user I/O86 to the microcontroller 87. Microcontroller 87 may communicate data to the user I/O indicating operation of wound treatment apparatus 10, and user I/O86 may display this data to the user.

As shown in FIG. 1A, the gas source 82 places the gas 83 in fluid communication with the control group 93 of the controller 80, and the liquid source 84 places the liquid 85 in fluid communication with the control group 93 of the controller 80. The control group 93 of the controller 80 is controlled by the microcontroller 87 and is operable to select neither gas nor liquid input (which inputs are in conjunction with the pump vacuum) to create and maintain a preset negative pressure within the enclosed space 17 in the wound interface 15, the control group 93 being operable to select either gas 83 from the gas source 82 or liquid 85 from the liquid source 84 as the input fluid 16 to release the negative pressure in a cyclical or intermittent manner. A control group 93 of the controller 80, controlled by the microcontroller 87, is operable to selectively control the flow of the input fluid 16 from the controller 80 to the enclosed space 17 of the wound interface 15, and the flow of the output fluid 18 from the enclosed space 17 of the wound interface 15 to the controller 80, and the discharge of at least a portion of the output fluid 18 to the reservoir 81 or atmosphere, using the valve 88, the pump 89, and the pressure sensor 91.

In certain embodiments, for example, the input fluid 16 may comprise a gas having an oxygen concentration greater than atmospheric air, and the output fluid 18 may comprise an exudate and a plurality of gases, in which case the exudate may optionally be captured in one or more layers of absorbent material within the wound interface 15 and not further transported to the container 81. In certain embodiments, particularly when the input fluid 16 may include a liquid, such as a flushing fluid, the output fluid 18 may be delivered into the cavity 99 of the container 81.

The valve 88 can include one or more valves disposed about the controller 80 and operable, for example, to select gas 83 from the gas source 82 or liquid 85 from the liquid source 84 as the input fluid 16 to control the flow of the input fluid 16 from the controller 80 to the enclosed space 17 of the wound interface 15 and to control the flow of the output fluid 18 from the enclosed space 17 of the wound interface 15 to the controller 80. Pressure sensor 91 may include one or more pressure sensors operable, for example, to monitor the pressure of gas 83, liquid 85, input fluid 16, output fluid 18, or enclosed space 17 of wound interface 15 at various locations of pressure. The microcontroller 87 may vary the operation of the valve 88 in response to signals from the pressure sensor 91. The input fluid 16 may be in communication under pressure with a gas source 82 or a liquid source 84 and a pump 89 may be used to draw the output fluid 18 from the enclosed space 17 to the container 81. Despite the pressure p in the enclosed space 17₀Is maintained at p_maxOr p_maxBut there may be no input of input fluid 16 into enclosed space 17. When the pressure p in the enclosed space 17₀At p_minAt this time, an input fluid from the gas source 82 or the liquid source 84 may be introduced into the enclosed space 17 of the wound interface 15 to change the pressure p₀From p_minIncrease to p_max。

The wound treatment apparatus 10 may include a variety of fluid delivery devices, such as, for example, hoses, tubes, valves, tubing, connectors, pressure regulators, and a variety of other fittings, in operative communication with the valve 88, the pump 89, the pressure sensor 91, the gas source 82, the liquid source 84, and the ports 42, 44 (see fig. 1B) of the wound interface 15 to communicate the gas 83 and the liquid 85 from the gas source 82 and the liquid source 84, respectively, with the controller 80, and to transmit the input fluid 16 and the output fluid 18 between the enclosed space 17 of the wound interface 15 and the controller 80.

In certain embodiments, at least a portion of the output fluid, such as exudate 19 (see fig. 4A), may be captured in an absorbent material within wound interface 15, and wound interface 15 may be replaced as needed. In certain embodiments, the output fluid 18 is transferred to a container 81 where the exudate 19 or liquid (such as liquid 85) is captured within a cavity 99 of the container 81. The gaseous portion of the output fluid 18 may then be vented from the controller 80 to the atmosphere.

As shown in fig. 1B, in a first stage of operation, the wound interface 15 of the wound therapy device 10 includes the member 20, the release paper 30, the

wings

33, 34, the tape 35, the

ports

42, 44, and the dressing 50. In this embodiment of the wound interface 15, the

wings

33, 34, and release paper 30 may be releasably removably secured to adhesive (see fig. 3) interposed between the release paper 30 and the member 20 at the distal side 22 of the member 20. Removal of the release paper 30 from being secured to the adhesive and removal of the

wings

33, 34 from being secured to the adhesive may expose the adhesive to allow the member 20, along with the tape 35, dressing 50, and

ports

42, 44, to be secured to a skin surface, such as skin surface 11 (see fig. 4), by the exposed adhesive. A label, such as label 25, which can be grasped by the user, is provided around the member 20 to easily separate the release paper 30 or

wings

33, 34 from the member 20 or to apply adhesive to the skin surface 11.

As shown in fig. 1B, 3 and 4A,

ports

42, 44 extend forwardly from proximal side 24 of member 20, through lumen 45 of port 42 for introducing input fluid 16 into enclosed space 17, and through lumen 47 of port 44 for conducting output fluid 18 out of enclosed space 17. In this embodiment,

lumens

45, 47 are in fluid communication with enclosed space 17 through

ports

42, 44, respectively. As shown,

ports

42, 44 are mounted on flange 41, with a portion of flange 41 secured to distal side 22 of member 20 such that

ports

42, 44 extend through aperture 28 in member 20 between distal side 22 and proximal side 24. In this embodiment, flange 41 is sized larger than the diameter of hole 28 to allow a portion of flange 41 to be secured to distal side 22 of member 20.

As shown, the controller 80 is in fluid communication with the enclosed space 17 of the wound interface 15 through the

lumens

45, 47 of the

ports

42, 44, respectively. The controller 80 may monitor or control the pressure p within the enclosed space 17₀Introduction of the input fluid 16 into the enclosed space containing the dressing 50 through the lumen 45 of the port 42, and throughThe lumen 47 of the port 44 directs the output fluid 18 out of the enclosed space 17 containing the dressing 50. In this embodiment, tubing may be connected to the

ports

42, 44 for communicating the input fluid 16 through the lumen 45 or the output fluid 18 through the lumen 47.

As shown in fig. 1B, the wound interface 15 of the wound treatment apparatus 10 includes a dressing 50 secured to a portion of the distal side 22 of the member 20. In this embodiment, the dressing 50 is in fluid communication with the

lumens

45, 47 of the

ports

42, 44, respectively, for exchanging the input fluid 16 and the output fluid 18. In certain embodiments, the

ports

42, 44 may be proximate to one another or located near diametrically opposite ends of the wound interface 15. As shown, the member 20 may include a window 26 formed of a transparent material through which window 26 a user may view the dressing 50 from the proximal side 24 of the member, for example, to determine the status of the dressing 50, such as the degree of exudate absorption. Various other embodiments may include a window or windows that are longer in extension than the dressing, such as window 26, or window 26 may be omitted.

As shown, the tape 35 is secured to the distal side 22 of the member 20 along the perimeter of the dressing 50, the dressing 50 being located within the area 36 defined by the tape 35. The straps 35 may further ensure a fluid-tight enclosed space 17 around the wound bed 13 (see fig. 4A). In certain embodiments of the wound interface 15, the tape 35 may be omitted.

The member 20 may be formed of, for example, polyurethane or polyethylene. All of the member 20 may be transparent, or the member 20 may be a shade of skin. The release paper 30 and

wing portions

33, 34 can be formed from any of a variety of release paper materials, such as release paper or plastic film. The

ports

42, 44 and flange 41 may be formed from a variety of suitable polymers, such as polystyrene, polyethylene or polypropylene. The band 35 may be formed, for example, from a hydrocolloid or similar deformable adhesive that conforms to the contours of the skin surface 11 around the wound bed 13. The adhesive layer 90 may be formed of, for example, an acrylic, silicone adhesive or hydrocolloid resin suitable for medical use.

The wound interface 15 of the illustrated wound therapy device 10 is oval. Other embodiments of wound interface 15 may have other shapes, such as circular, square, and rectangular. As shown, the band 35 and the area 36 defined by the band 35 are oval in shape, generally conforming to the shape of the wound interface 15 of the wound therapy device. In certain embodiments, the band 35 and the region 36 may have other shapes or combinations of shapes that conform or do not conform to the wound interface 15.

Fig. 2 illustrates a dressing 50 for the wound interface 15. As shown in fig. 2, the dressing 50 includes a distal layer 60 and a proximal layer 70, with the proximal side 64 of the distal layer 60 being attached to the distal side 72 of the proximal layer 70 to form the dressing 50. As shown in fig. 2, the proximal side 74 of the proximal layer 70 forms the proximal side 54 of the dressing 50 and the distal side 62 of the distal layer 60 forms the distal side 52 of the dressing 50.

The distal layer 60 may be formed at least in part from a hydrophobic material, such as polyester fibers, to transfer exudate 19 (see fig. 4A) from the wound bed 13, from the distal side 62 to the proximal side 64, and then through the distal side 72 into the proximal layer 70. The distal layer 60 may be formed from a knit of predominantly polyester type fibers interwoven with predominantly hydrophilic nylon type fibers of the dressing 50. The distal layer 60 may be connected to various portions of the proximal layer 70 or may extend to various portions of the proximal layer 70.

The proximal layer 70 may be formed at least in part of a hydrophilic material, such as polyamide fibers, to remove exudate 19 from the enclosed space 17 containing the dressing 50, transfer from the distal side 72 to the proximal side 74, and then enter the lumen 47 of the port 44. The proximal layer 70 may also be composed of an absorbent foam, such as polyvinyl alcohol (PVA) or Polyurethane (PU). A channel, such as channel 55, passes through the proximal layer 70 generally parallel to the distal side 49 of the flange 41 (see fig. 3, 4A) to transport the input fluid 16 or the output fluid 18 within the proximal layer 70. A channel, such as channel 56, passes between the distal side 72 and the proximal side 74 of the proximal layer 70 to transmit the input fluid 16 or the output fluid 18 between the distal side 72 and the proximal side 74 of the layer 70. The proximal side 54 of the dressing includes a channel, such as channel 55, as shown, to deliver the output fluid 18 from the proximal layer 70 into the lumen 47 of the port 44, or to disperse the input fluid 16 from the lumen 45 of the port 42 around the proximal side 74 of the proximal layer 70. In certain embodiments, the channels, such as

channels

55, 56, may be of any geometry, including slits. In certain embodiments, a variety of numbers of channels may be formed in the proximal layer 70, and the channels may have a variety of distributions, orientations, spatial relationships, and interconnectivity. Some embodiments of the proximal layer 70 may include only channels, such as channel 56, between the distal side 72 and the proximal side 74. Other embodiments of the proximal layer 70 may include only channels, such as channel 55, that are generally parallel to the distal side 49 of the flange 41. Other embodiments of the proximal layer 70 may omit channels, such as

channels

55, 56, entirely. Other embodiments of the proximal layer 70 may include only a distal 49 channel, such as channel 55, generally proximal of the proximal layer 70 parallel to the flange 41 to fluidly communicate between the proximal side 74 and the

lumens

45, 47.

Fig. 3 illustrates the wound interface 15 of the wound therapy device 10 in the first stage of operation 95 with the release paper 30 secured to the member 20 by the adhesive to cover the distal side of the wound interface 15, the wound interface 15 including at least a portion of the distal side 92 of the adhesive, the distal side 37 of the tape 35, and the distal side 52 of the dressing 50 to allow a user to operate the wound interface 15 in the first stage of operation 95 without contact with the adhesive and to protect the dressing 50 from contamination.

As shown in FIG. 3, proximal side 94 of the adhesive is secured to distal side 22 of member 20 and flange 41 is biased toward distal side 92 of the adhesive to secure flange 41 to member 20. In certain embodiments, flange 41 may be otherwise secured to distal side 22 of member 20. As shown, at least a portion of dressing 50 proximate proximal side 54 is located within region 36. In certain embodiments, the entire dressing 50, from proximal side 54 to distal side 52, is located within region 36. In other embodiments, band 35, as well as region 36, are omitted. In this embodiment, side 51 (fig. 4A) of dressing 50 may be separated from tape 35 by a gap 57 to allow dressing 50 to expand without affecting the seal provided by tape 35.

As shown in fig. 3, in this embodiment, the proximal side 54 of the dressing 50 is attached to the flange 41. The proximal side 54 of the dressing 50 is in fluid communication with the

lumens

45, 47 of the

ports

42, 44, respectively. Various channels, such as channel 55, may be formed in the proximal side 54 of the dressing 50, in the distal side 49 of the flange 41 (not shown), or in both the proximal side 54 of the dressing 50 and the distal side 49 of the flange 41 to convey the input fluid 16 and/or the output fluid 18 between the proximal side 54 of the dressing 50 and the

lumens

45, 47 corresponding to the

ports

42, 44.

Fig. 4A illustrates the wound interface 15 of the wound therapy device 10 in a second stage of operation 97. In the second stage of operation 97, the release paper 30 and

wings

33, 34 have been removed, at least a portion of the distal side 92 of the adhesive layer 90 is exposed by removing the release paper 30 and

wings

33, 34, and the wound interface 15 is secured to the skin surface 11 by the exposed adhesive layer 90, as shown. A user may selectively remove a portion of the release paper 30 or a portion of the

wings

33, 34 to expose only a portion of the adhesive so that the user may place the wound interface 15 in partial adhesion to the skin surface 11. As shown, when portions of the adhesive layer 90 are secured to the skin surface 11, a portion of the member 20 can flex to conform to the skin surface 11. Adhesive layer 90 may be secured to the skin surface along the perimeter of wound interface 15 to form a fluid-tight seal between wound interface 15 and skin surface 11. In certain embodiments comprising tape 35, an optional annular thick deformable adhesive forms a fluid-tight seal between distal side 37 of tape 35 and skin surface 11 around wound interface 15. In embodiments where the tape 35 is omitted, the adhesive is secured to the skin surface along the perimeter of the wound interface 15, forming a seal between the wound interface 15 and the skin surface 11. In certain embodiments, adhesive layer 90 and tape 35 may form a fluid-tight seal between wound interface 15 and skin surface 11.

In this embodiment, a user may, for example, manually grasp member 20 in a first stage of operation 95, and then may releasably remove release paper 30 from distal side 92 of adhesive layer 90 to expose the portion of adhesive layer 90 distal side 92 attached to release paper 30, as well as distal side 37 of tape 35. After removing the release paper 30, the user may position the wound interface 15 relative to the wound bed 13 and then press the distal side 92 of the adhesive layer 90 and the distal side 37 of the tape 35 against the skin surface 11 to secure the wound interface 15 to the skin surface 11. When release paper 30 is releasably removed or positioned, the user can manipulate wound interface 15 with the

noted wings

33, 34, or label, such as label 25, and then compress at least a portion of distal side 92 of adhesive layer 90 exposed by removal of release paper 30 and distal side 37 of tape 35 against attachment skin surface 11. The user may then remove

wings

33, 34 from connection with distal side 92 of adhesive layer 90 and then compressibly attach a portion of distal side 92 of adhesive layer 90 exposed by removal of

wings

33, 34 to skin surface 11 to further secure wound interface 15 to skin surface 11 and thereby form fluid-tight enclosed space 17. The member 20 or the band 35 may be curved to conform to the skin surface 11 to bias the band 35 into attachment to the skin surface 11. When coupled to skin surface 11 in a biased manner, band 35 may form a fluid-tight seal between distal side 37 of band 35 and skin surface 11 around the perimeter of wound interface 15.

As shown in FIG. 4A, in a second stage 97 of operation, the wound interface 15 is secured to the skin surface 11 to form an enclosed space 17 above the wound bed 13, the input fluid 16 may be directed into the enclosed space 17 through the lumen 45 of the port 42 and the output fluid 18 may be directed out of the enclosed space 17 through the lumen 47 of the port 44 by the controller 80, as shown, to approximate a pressure range p_min≤p₀≤p_maxChanges the pressure p in the enclosed space 17 within a pressure cycle of₀Wherein p is_minIs the minimum pressure in the pressure cycle, p_maxIs the maximum pressure in the pressure cycle. In other embodiments, there may be a single port, e.g.,

ports

42, 44, with a corresponding single lumen, such as

lumens

45, 47, with the input fluid (e.g., input fluid 16) and the output fluid (e.g., output fluid 18) passing through the single lumen of the single port.

The input fluid 16 may include a gas (such as gas 83), a liquid (such as liquid 85), or a combination of gas and liquid. In certain embodiments, the input fluid 16 may have a higher O than atmospheric air₂A concentration of gas. In certain embodiments, the input fluid 16 may be medical grade oxygen. In certain embodiments, the input fluid 16 may be a liquid with certain therapeutic benefits, such as a saline flush, an antibiotic, or an analgesic.

As shown in fig. 4A, exudate 19 is conducted away from wound bed 13 through distal layer 60. Exudate 19 is directed from distal side 62 to proximal side 64 of distal layer 60, then into distal side 72 of layer 70, from distal side 72 to proximal side 74, and from proximal side 74 into lumen 47 of port 44 for exit from the wound bed. Based on the intended use, the wound interface 15 may be discarded or replaced when the dressing 50 is deemed to be near absorbent capacity, or continued application of negative pressure to the device 15 to transfer the output fluid 18 containing exudate 19 from the enclosed space 17 containing the dressing 50 to a container 81 (see FIG. 1A)

The output fluid 18 may comprise air directed out of the enclosed space 17. When the input fluid 16 is led out of the closed space 17, the pressure p is periodically changed in the pressure cycle₀When desired, the output fluid 18 may include the input fluid 16.

As shown in fig. 4B, a channel, such as channel 56, passing between the distal side 72 and the proximal side 74 of the proximal layer 70 may pass the input fluid 16 through the proximal layer 70, from the proximal side 74 to the distal side 72, into the distal layer 60, and the input fluid 16 may flow through the distal layer 60 to the wound bed 13. Channels, such as channel 55, can allow the input fluid 16 to traverse the proximal layer 70 of the dressing to evenly distribute the input fluid 16 over the layer 60 and wound bed 13. Channels, such as

channels

55, 56, may flow the output fluid 18 laterally through the proximal layer 70 from the distal side 72 to the proximal side 74, respectively, to allow the output fluid 18 to be directed out of the entire wound bed 13 and dressing, as shown in fig. 4B. The output fluid may flow from the wound bed 13, through the distal layer 60, and then be transmitted through the proximal layer 70 to the entire proximal layer 70 or be directed out of the proximal layer 70 through the lumen 47.

Since the dressing on the wound bed 13 overlaps the skin surface 11, possibly leading to maceration of the skin surface 11, and since trimming the dressing to the exact geometric contour of the wound bed 13 is cumbersome, a method is provided herein to maximize the absorbent capacity while avoiding maceration problems. Fig. 4C illustrates the distal end 52 of the dressing 50 biased toward the wound bed 13 and the skin surface 11, and in a second operational stage 97, the wound treatment apparatus 10 includes the wound interface 15. As shown in fig. 4C, the side 51 of the dressing extends beyond the wound boundary 12 by a length 31 to connect a portion of the distal side 52 with the skin surface 11, while the other portion of the distal side 52 is biased toward connecting with the wound bed 13. Thus, in this embodiment, the dressing 50 including the distal end 52 does not match the wound bed 13, and the perimeter of the dressing 50 extends beyond the wound boundary 12 at the distal end 52. To prevent maceration of the skin over time in contact with a dressing 50 that may be wetted by exudate, a water impermeable skin protective polymeric film may be created by applying or coating the skin around the wound with a layer of a suitable polymer 32, which may withstand prolonged contact with a moist dressing. One solution is to use a cyanoacrylate-based liquid adhesive, such as 2-octyl cyanoacrylate. Another solution is to coat the wound with a fast drying formulation of ethyl acetate.

Fig. 5 illustrates an exemplary wound treatment apparatus 100 including a wound interface 115. As shown in fig. 5, wound interface 115 includes member 120, member 120 having a layer of adhesive 190 applied to at least a portion of distal surface 122 of member 120 for securing member 120 to skin surface 111. When secured to skin surface 111 along the perimeter of member 120 by adhesive layer 190, wound interface 115 encloses wound bed 113 of skin surface 111 within fluid-tight enclosed space 117. As shown in FIG. 5, port 142 is secured to member 120 by flange 114, and flange 114 is adhesively secured to member 120 by portions of adhesive layer 190. Port 142 allows fluid communication with enclosed space 117 through lumen 145. A controller, such as controller 80 of a wound treatment apparatus, may communicate input fluid 116 into enclosed space 117 through lumen 145 of port 142 and direct output fluid 118 from enclosed space 117 through lumen 145 of port 142, e.g., to be generally at pressure range p_min≤p₀≤p_maxPeriodically changing p in the enclosed space 117₀Wherein p is_minIs the minimum pressure on the pressure cycle, p_maxIs the maximum pressure over the pressure cycle. The member 120 may be formed from a variety of polymer layers or woven materials. The input fluid 116 may be a liquid, a gas, or a combination of a liquid and a gas, such as liquid 85 and gas 83, and the input fluid 116 may have a greater than atmospheric airLarger O₂And (4) concentration. Directing the output fluid 118 out through the lumen 145 of the port 142 may direct the exudate 119 from the wound bed 113 into layers within the wound interface 115, such as

layers

160, 170, which may absorb the exudate 119.

As shown in fig. 5, dressing 150 of wound treatment apparatus 100 includes a proximal layer 160, an intermediate layer 170, and a distal layer 180 positioned within enclosed space 117, dressing 150 being secured to member 120 to form a portion of wound interface 115. In other embodiments of wound interface 115, a variety of numbers of layers may be included, such as

layers

160, 170, 180, which may be arranged in a variety of ways. In some embodiments of wound interface 115, only distal layer 180 may be included. As shown, a portion of the distal layer 180 is secured to the distal side 122 of the member 120, with or without any encircling treatment, and a portion of the distal side 182 of the distal layer 180 is biased toward the skin surface 111 and the wound bed 113. Intermediate layer 170 is between distal layer 180 and proximal layer 160, with distal side 172 of intermediate layer 170 being biased toward proximal side 184 of distal layer 180 and proximal side 174 of intermediate layer 170 being biased toward distal side 162 of proximal layer 160. As shown, the proximal layer 160 is between the layer 170 and the spacer 130, with the proximal side 164 of the proximal layer 160 biased toward the distal side 132 of the spacer 130.

In this embodiment, spacer 130 is secured to member 120 by securing proximal side 134 of spacer 130 to distal side 122 of member 120 within enclosed space 117. The spacer 130 will form a space 137 within the spacer 130, and the spacer 130 maintains the proximal layer 160, the intermediate layer 170, and the distal layer 180 in biased connection with one another, as shown. Spacer 130 may generally be a two-layer polymer structure with or without additional distribution channels that may be created by a localized weld 133 from distal side 132 to proximal side 134 to confine space 137 to a positive pressure (p)₀＞p_amb) And (3) downward expansion. In this embodiment, the purpose of the spacer 130 is to evenly distribute the input fluid 116 through the space 137 over the proximal side 164 of the layer 160, and thus evenly distribute the input fluid 116 over the wound bed 113. Spacers 130 may also have the purpose of facilitating exudate 119 or other fluid removal during the egress of output fluid 118. The spacer 130 may have a variety of shapes and sizes, ranging from circular, rectangularTo an oval, etc., which substantially approximates the trajectory of the proximal side 164 of the layer 160. The spacer 130 may be omitted in some embodiments of the wound interface 115, or functionally replaced by a surface structure in an adjacent layer (e.g., the surface structure of the dressing 50 shown in fig. 2).

The lumen 145 enters the space 137 through the port 142 and through the proximal side 134 of the septum 130, and the input fluid 116 or the output fluid 118 may pass between the space 137 and the lumen 145. For example, the input fluid 116 may enter the space 137 through the internal chamber 145 and then disperse within the space 137 such that substantially the same pressure p exists throughout the space 137₀. The input fluid 116 may then flow from the space 137 through a septum passage, such as septum passage 135, in the distal side 132 of the septum 130, through the proximal side 164 and into the proximal layer 160. The spacer channels may be evenly distributed on the distal side 132 of the spacer 130 such that the input fluid 116 from the space 137 is evenly distributed on the proximal side 164 of the proximal layer 160 (see fig. 6A). The input fluid 116 may then flow through the proximal layer 160, through the intermediate layer 170, through channels in the distal layer 180, such as

channels

185a, 185B, 185c, 185d (see fig. 6B), to contact the wound bed 113 and the skin 111. The

channels

185a, 185b, 185c, 185d, which may vary in number, shape and size, may be evenly distributed across the wound contacting surface of the distal layer 180 between the proximal side 184 and the distal side 182 of the distal layer 180 such that the input fluid 116 is evenly distributed across the skin surface 111 and the wound bed 113.

In certain embodiments, the thickness between the proximal side 184 and the distal side 182 of the distal layer 180 may be in the range of about 0.1mm to about 2 mm. In certain embodiments, the thickness between the proximal side 184 and the distal side 182 of the distal layer 180 can range from about 0.2mm to about 1 mm. In certain embodiments, the

channels

185a, 185b, 185c, 185d may generally range in size from about 250 microns to 2500 microns or equivalent in diameter, or from about 500 microns (#35 mesh) to about 1000 microns (#18 mesh) in diameter or equivalent. In certain embodiments, the

channels

185a, 185b, 185c, 185d may generally range in size from about 50 microns (#270 mesh) to about 1000 microns (#18 mesh) in diameter or an equivalent, or from about 100 microns (#140 mesh) to about 750 microns (about #22 mesh) orAnd (4) an equivalent value. In certain embodiments, the number of

channels

185a, 185b, 185c, 185d in the distal layer 180 per square centimeter may be approximately about 45/cm²To about 2500/cm²Within the range of (1). In certain embodiments, the number of

channels

185a, 185b, 185c, 185d in the distal layer 180 per square centimeter may be about 25/cm²To about 200/cm²Within the range of (1).

Thus, for example, the input fluid 116 may provide enhanced O to the wound bed 113 and skin surface 111₂. Since the input fluid 116 and the output fluid 118 may flow throughout the enclosed space 117, including through the proximal layer 160, the intermediate layer 170, the distal layer 180, and the spacer 130, the pressure p₀Typically present throughout the enclosed space 117, including the wound bed 113 and the skin surface 111. In other embodiments, for a simpler design, the layer 180 may be adhered horizontally to the adhesive layer 190, substantially in the same plane as the skin layer 111. Spacer 130, and the multiple layers of material are optional features of wound interface 115.

Exudate 119 may flow from wound bed 113 into intermediate layer 170, from intermediate layer 170 into proximal layer 160, from proximal layer 160 through spacer channels, such as spacer channels 135, into space 137 via channels of distal layer 180, such as

channels

185a, 185b, 185c, 185 d. In this embodiment, output fluid 118, which includes exudate 119 and input fluid 116, may flow through distal layer 180, intermediate layer 170, and proximal layer 160, through spacer channel 135 into space 137, and output fluid 118 may pass through lumen 145, exiting space 137 via port 142.

As shown in fig. 5, the wound bed 113 has the form of an incision with sutures 199. Distal layer 180 is formed from an open sheet of silicone including polydimethylsiloxane. The silicone may include other non-tacky polymers such as polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE), or other fluoropolymers. While silicone is known to have beneficial effects in reducing the visibility of hypertrophic scars or other scars that have formed, the use of silicone sheets with openings, such as

channels

185a, 185b, 185c, 185d, is disclosed herein to modulate scar formation while the wound 113 is healing. It should be noted that silicone does not have any effect on exudate transfer, and for moist wounds, such blockage can lead to skin maceration and other adverse effects. Channels contained in the distal layer 180, such as

channels

185a, 185b, 185c, 185d, may allow exudate to be transferred and absorbed away from the wound bed 113. Thus, the wound treatment apparatus 100 may be used to continue the full initial phase of the healing process so that there may be no or less need to repair a significant scar (after it has undesirably formed).

As shown, the wound bed 113 is newly started, i.e., the healing process of scar formation is about to begin. In general, application of a liquid impermeable silicone layer to a newly initiated wound bed (e.g., wound bed 113) that may have a significant degree of exudation may result in skin maceration. However, the wound interface 115 includes channels in the silicone, such as

channels

185a, 185b, 185c, 185d, forming the distal layer 180, on the proximal side 184 of the distal layer 180, providing for absorption of exudate and/or transfer of exudate to prevent maceration of the skin surface 111. In the embodiment shown in this figure, the distal layer 180 comprising open-celled silicone is used prophylactically to prevent significant scar formation and is not used to treat an already formed scar. Of course, in various other embodiments, the wound bed 113 may be any type of wound bed. Channels, such as

channels

185a, 185b, 185c, 185d, allow fluid exchange between the wound bed 113 and the skin surface 111 through the distal layer 180, which may, for example, prevent maceration of the skin 111. The distal layer 180, and in particular the distal side 182, may be impregnated with various drugs, such as steroids, hormones or other drugs in a controlled release form.

Healing of an incision, such as wound bed 113, with little or no visible scarring, may require, inter alia, proper blood flow, oxygen, no infection, proper moisture balance, and uniform tension dispersion across the wound area relative to (alignment with) the wound edges. Typical unsightly "rail" scars may be caused by local tension created by a limited number of sutures, which may be further exacerbated by some degree of wound inflammation, swelling and dehiscence (separation of wound edges). In view of the high coefficient of friction of silicone with the skin surface 111, the distal layer 180 of the wound treatment device 100 may be formed of silicone, which may ensure a spatial relationship of one side of the incision to the other, resisting shear and relative movement. This can minimize the risk of scarring due to uneven tension by coordinating and homogenizing the wound tension on the incision line, e.g., as if hundreds of thinner sutures are working. The use of open-cell silicone for distal layer 180 may also reduce the risk of dehiscence, graft failure and significant scarring (1) by preventing skin maceration caused by fluid accumulation on the skin, and effectively preventing intermediate layer 170 from possibly becoming wet from prolonged contact with the skin surrounding the wound, and (2) selectively transferring exudate from the wound bed and (3) by neutralization of uniform forces and shear forces to reduce lateral wound tension and stress on the suture thread.

Intermediate layer 170 may include a drug 177, such as amniotic fluid or Bone Morphogenic Protein (BMP) or other scar regulating healing factors, and drug 177 may be delivered from layer 170 to wound bed 113 over time through fluid communication of intermediate layer 170 and distal layer 180. The layer 170 may be made of an alginate-like substance impregnated with the drug 177, and the layer 170 may be configured to deliver the drug 177 to the wound bed 113 in a controlled release manner.

Layer 160 may be made from a variety of materials, including cotton gauze, polyester or polyamide fibers, or open cell foams of polyurethane or polyvinyl alcohol. Closed cell polyurethane foam may be used when polyethylene glycol (PEG) formulations are added to the polyurethane to make the matrix highly absorbent, fluid conductive and tissue biocompatible. These materials may help transfer exudate 119 from wound bed 113 to lumen 145. Layer 160 may include a superabsorbent polymer such as sodium polyacrylate.

Fig. 6A illustrates a distal side 132 of a spacer 130 including a spacer channel, such as spacer channel 135. In this embodiment, a septum passage, such as septum passage 135, transmits the input fluid 116 and the output fluid 118 between the distal side 132 and the space 137. Although illustrated as circular, in some embodiments, the spacer channels 135 can have a square, circular, rectangular, slit, or other cross-section.

Fig. 6B illustrates the distal side 182 of the distal layer 180 including channels, such as

channels

185a, 185B, 185c, 185d having circular, cross-slit, straight slit, and zigzag slit cross-sections, respectively. In other embodiments, the channels may have other geometries. In this embodiment, a channel passes between the distal side 182 and the proximal side 184 to transmit the input fluid 116 and the output fluid 118 between the distal side 182 and the proximal side 184 of the distal layer 180.

Fig. 7 illustrates a wound treatment apparatus 200 including wound interfaces 215, 225 secured to a skin surface 211. The wound interfaces 215, 225 may include

respective dressings

250, 260 disposed in the

enclosed spaces

217, 227. In this embodiment, the

enclosed spaces

217, 227 formed by the wound interfaces 215, 225, respectively, are fluid-tight, and the dressing 250, 260 may include two or more layers, such as in the dressing 50, 150, 350, 550, 650, 750.

As shown in fig. 7, the wound interfaces 215, 225 operate in parallel. A controller, such as controller 80 of the wound treatment apparatus 10, may simultaneously input an input fluid 216 into the

enclosed spaces

217, 227 and simultaneously derive an output fluid 218 from the

enclosed spaces

217, 227. As shown in fig. 7, conduit 253 is connected to fitting 251 for fluid communication with

conduits

243, 246,

conduits

243, 246 being in fluid communication with

lumens

245, 247 of

ports

242, 244, respectively. Thus, as shown in fig. 7, the input fluid 216 may enter the

enclosed spaces

217, 227 of the wound interfaces 215, 225 through the conduit 253, through the fitting 251, through the

conduits

243, 246, through the

lumens

245, 247 of the

ports

242, 244, respectively. As shown in fig. 7, output fluid 218 may flow from the

enclosed spaces

217, 227 of the wound interfaces 215, 225, through

lumens

245, 247 corresponding to the

ports

242, 244, through

tubes

243, 246, through the fitting 251, and through tube 253, respectively. In some embodiments, any number of wound interfaces, such as wound interfaces 215, 225, may be disposed around skin surface 211, transmitting in parallel. In certain embodiments, various configurations of tubing including fittings (such as fitting 251), such as

tubing

243, 246, 253, as well as various connectors and other fluid paths may be provided.

Fig. 8A illustrates a portion of an exemplary wound treatment apparatus 300 including a wound interface 315 secured to a skin surface 311. As shown, the wound interface 315 includes a member 320 and

ports

342, 344 forming

lumens

345, 347, respectively, for fluid communication with the enclosed space 317, wherein the enclosed space 317 includes a dressing 350 within the enclosed space 317. As shown, the

ports

342, 344 are disposed about the member 320. In this embodiment, wound interface 315 is secured to skin surface 311, wound interface 315 at least partially forming a substantially fluid-tight enclosed space 317. Dressing 350 may include two or more layers, such as within

dressings

50, 150, 250, 550, 650, 750, or may be formed from a single layer. It should be noted that although the wound interface 315 and dressing 350 are depicted as rectangular in the exemplary wound therapy device 300, in certain embodiments, the wound interface 315, dressing 350, or wound interface 315 and dressing 350 may exhibit a variety of other geometries, such as circular, oval, or square.

As shown, the

ports

342, 344 are disposed a distance 348 apart from each other to be in fluid communication with different portions of the proximal side 354 of the dressing 350 via

lumens

345, 347, respectively. Distance 348 may be selected such that input fluid 316 through

lumens

345, 347 is substantially uniformly input onto proximal side 354 and output fluid 318 is substantially uniformly output from proximal side 354 of dressing 350. As shown in fig. 8A, tube 353 is connected to fitting 351 to be in fluid communication with

conduits

343, 346,

conduits

343, 346 being in fluid communication with

respective lumens

345, 347 of

ports

342, 344. Thus, the input fluid 316 can be delivered through the tube 353, through the fitting 351, through the

tubes

343, 346, respectively, through the

lumens

345, 347 of the

ports

342, 344, respectively, to the proximal side 354 of the dressing 350 within the enclosed space 317, as shown in fig. 8A. Output fluid 318 may be directed out of proximal side 354 of dressing 350 within enclosed space 317 through

lumens

345, 347 of

ports

342, 344, respectively, through

conduits

343, 346, through fitting 351, and out through conduit 353, as shown in fig. 8A. A controller, such as controller 80 of wound treatment apparatus 10, may be in fluid communication with wound interface 315 via tube 353 to input fluid 316 into enclosed space 317, while exporting output fluid 318 from enclosed space 317. In certain embodiments, any number of ports, such as

ports

342, 344, may be configured on the wound interface 315 to be in fluid communication with various portions of the proximal side 354 of the dressing 350 within the enclosed space 317.

Fig. 8B illustrates a portion of an exemplary wound treatment apparatus 400 including a wound interface 415 secured to a skin surface 411. As shown, the wound interface 415 includes

ports

442, 444 that form

lumens

445, 447, respectively, for fluid communication with the enclosed space through a controller, such as controller 80 of the wound treatment apparatus 10, the enclosed space 417 including a dressing 450 within the enclosed space 417. In this embodiment, at least a portion of member 420 forms a substantially fluid-tight enclosed space 417 secured to skin surface 411 by wound interface 415.

As shown, the

ports

442, 444 are disposed a distance 448 apart from each other to fluidly communicate with different portions of the proximal side 454 of the dressing 450 via

lumens

445, 447, respectively. As shown in fig. 8B, the

lumens

445, 447 of the

ports

442, 444 are in fluid communication with the

conduits

443, 446, respectively. In certain embodiments, input fluid 416 is introduced into enclosed space 417 through lumen 445 of port 442, while output fluid 418 is withdrawn from enclosed space 417 through lumen 447 of port 444. In certain embodiments, input fluid 416 is input into enclosed space 417 through lumen 445 of port 442, and in turn, output fluid 418 is output from enclosed space 417 through lumen 447 of port 444, with input fluid 416 allowed to reside within enclosed space 417. In this embodiment, the input fluid 416 and the output fluid 418 are liquids. This may provide certain benefits in terms of clearing exudates or bacterial infections and maintaining the conduits (e.g., conduits 443, 446) open. For example, for a wound bed of the lower limb, where the input fluid 416 may enter the port 442 in an upper position and the output fluid 418 exits the port 444 in a lower position relative to the port 442, the use of gravity will facilitate the removal of waste material and fluid from the wound area, particularly in embodiments where the input fluid 416 and output fluid 418 are liquids, such as liquid 85. Various configurations of tubes, such as

tubes

443, 446, including fittings, connectors, and other fluid paths may be provided in certain embodiments, which may depend on the desired effect.

Fig. 9 illustrates an exemplary wound treatment apparatus 500. As shown in fig. 9, wound treatment apparatus 500 includes wound interface 515, wound interface 515 including member 520, proximal layer 570, distal layer 580, and adhesive layer 590. As shown, wound interface 515 is secured to skin surface 511 by adhesive layer 590 such that distal side 582 of distal layer 580 contacts wound bed 513, wound interface 515 forming enclosed space 517, including proximal layer 570, distal layer 580, above wound bed 513. In this embodiment, the proximal layer 570 and the distal layer 580 form the dressing 550. In this embodiment, enclosed space 517 may be fluid-tight with no lumen passing between distal side 522 and proximal side 524 of member 520.

As shown in fig. 9, the placement of the proximal layer 570 between the proximal side 584 of the distal layer 580 and the distal side 522 of the member 520, the proximal side 574 of the proximal layer 570 biased toward the distal side 522 of the member 520, and the distal side 572 of the proximal layer 570 biased toward the proximal side 584 of the distal layer 580. In this embodiment, exudate 519 is wicked from wound bed 513 through a channel (e.g., channel 585) in distal layer 580, past the distal side 572 of layer 570, and out into layer 570. In this embodiment, when layer 570 becomes sufficiently saturated with exudate 519, wound interface 515 may be removed and another wound interface similar to wound interface 515 may be placed over wound bed 513.

As shown, distal layer 580 may be made of silicone, which includes an open-celled silicone-like material. Proximal layer 570 may be made of, for example, polyvinyl alcohol, polyurethane foam with polyethylene glycol (PEG) to enhance its water absorption and transport properties, or other absorbent material, such as gauze, which may be impregnated with, for example, chitosan, silver, or a super-absorbent polymer such as sodium polyacrylate, to retain exudate 519 within layer 570.

Fig. 10 illustrates a portion of an exemplary wound treatment apparatus 600. As shown in fig. 10, wound therapy device 600 includes a wound interface 615. As shown, wound interface 615 includes a member 620 with an adhesive layer 690 disposed on member 620. As shown, dressing 650 is secured to flange 641 of port 642 for fluid communication with lumen 645. When wound interface 615 is secured to the skin surface by adhesive layer 690, port 642 is secured to member 620 by a portion of flange 641, member 620 at least partially forming enclosed space 617. As shown, injection port 630 and pressure relief valve 635, symbolically shown, are disposed about flange 641. In other embodiments, injection port 630 or pressure relief valve 635 may be disposed at other locations of wound interface 615. Injection port 630 may be any of a variety of ports known in medical devices, including, for example, a Luer, compression fit port, or self-sealing membrane type, to allow introduction of a medicament into dressing 650 or into enclosed space 617.

In this embodiment, injection port 630 includes a membrane 631, e.g., a needle cannula may be inserted through membrane 631 to provide medication therethrough to dressing 650, or generally into enclosed space 617. Membrane 631 may be formed of a self-sealing rubber or other such material and injection port 630 may be configured in a manner that facilitates insertion of a hypodermic needle and delivery of the medicament to dressing 650.

Relief valve 635 is configured for relieving pressure p in enclosed space 617₀Exceeding a certain limiting pressure p_lWhen this occurs, fluid is allowed to escape from enclosed space 517. Limiting pressure p_lIt may be a pressure that, if exceeded, would cause the structure 600 to loosen from the skin surface.

As shown, the proximal side 654 of the dressing 650 is attached to at least a portion of the distal side 649 of the flange 641, with the distal side 652 of the dressing 650 facing the wound bed. As shown, the dressing 650 includes a distal layer 660 and a proximal layer 670. As shown, a channel (such as channel 656) may optionally be formed in the proximal layer 670 to convey the input fluid 616 or the output fluid 618 between the distal 672 and the proximal 674 of the proximal layer 670. Although the channel 656 is illustrated as straight, it should be appreciated that the channel 656 can extend curvedly and can have a variety of extensions between the distal 672 and proximal 674 sides of the proximal layer 670.

As shown in fig. 10, when the output fluid 618 enters the lumen 645 from the proximal side 654 of the dressing 650, a filter 680 may be interposed between the proximal side 654 of the dressing 650 and the lumen 645 to remove exudate or other liquids from the output fluid 618, but without removing gases, the filter 680 may also be interposed anywhere between the dressing and the negative pressure source, such as in the form of a disc filter or endoluminal filter within the tube to prevent liquids from reaching the negative pressure source. Removal of exudate or other liquids through the filter 680 may prevent damage to components downstream of the filter 680, such as the pump 89 of the controller 80 in the wound therapy device 10. The filter 680 may be formed from a variety of materials, including Polytetrafluoroethylene (PTFE).

As shown in fig. 8A, 8B and 10,

connectors

321, 323, 421, 423 and 621 are provided on one or more flanges, such as flange 641, for electrical communication with

wound interfaces

315, 415, 615, respectively. As shown, in some embodiments,

connectors

321, 323, 421, 423, 621 are electrically conductive for electrically connecting with

wound interfaces

315, 415, 615 of

wound treatment apparatuses

300, 400, 600, respectively. A portion of the

wound interface

315, 415, 615, including at least a portion of the dressing 350, 450, 650, respectively, may be formed of an electrically conductive material. For example, a portion of the wound interface 615 including the proximal layer 670 or the distal layer 660 of the dressing 650 can include a conductive material for electrical communication with the connector 621.

The

connectors

321, 421, 323, 423 or 621 may be electrically or electromagnetically coupled to a power source by a wired or wireless pathway to flow power to the

connectors

321, 421, 621, 323, 423 to generate an electrical, magnetic or electromagnetic field to pass through at least a portion of the wound bed. In some embodiments, a voltage gradient may be generated between the conductive portions of the wound interfaces 315, 415, 615 and the wound bed, while in other embodiments, electricity may be transmitted between

connectors

321, 421 and

connectors

323, 423, respectively, through the electrical power paths of the wound interfaces 315, 415, 615 for generating a magnetic field around the wound bed. Such electric or magnetic fields may accelerate wound healing by increasing angiogenesis, or stimulate the response of immune factors by increasing phagocytosis of macrophages.

Fig. 11 illustrates a portion of an exemplary wound treatment apparatus 700 including a dressing 750. In this embodiment, the dressing 750 has a distal side 752 and a proximal side 754. As shown in fig. 11, the dressing 750 includes a proximal layer 760, a first intermediate layer 770, a second intermediate layer 780, and a distal layer 790. The distal side 792 of the distal layer 790 forms the distal side 752 of the dressing 750, which may be biased toward the wound bed, and the proximal side 764 of the proximal layer 760 forms the proximal side 754 of the dressing 750, as shown. As shown, the second intermediate layer 780, the first intermediate layer 770, and the proximal layer 760 are successively adjacent to layer 790. In this exemplary embodiment, the distal side 782 of the second intermediate layer 780 is in biased connection with the proximal side 794 of the distal layer 790, the distal side 772 of the first intermediate layer 770 is in biased connection with the proximal side 784 of the second intermediate layer 780, and the distal side 762 of the proximal layer 760 is in biased connection with the proximal side 774 of the first intermediate layer 770. Any or all of proximal layer 760, first intermediate layer 770, second intermediate layer 780, and distal layer 790 may be impregnated with, for example, a plurality of drugs for delivery to the wound bed. In this embodiment, the proximal layer 760, the first intermediate layer 770, the second intermediate layer 780, and the distal layer 790 may be configured to impart a variety of fluid-related properties or impart a variety of mechanical, biological, or electrical properties onto the dressing. Other embodiments may have an increased number of intermediate layers, such as first intermediate layer 670 and second intermediate layer 780, for example, to include a third intermediate layer, a fourth intermediate layer, or more.

Fig. 12A and 12B illustrate a portion of a wound treatment apparatus 800, including a portion of a wound interface 815. As shown, wound interface 815 includes a member 820, member 820 including a pressure relief valve 840. The pressure relief valve 840 is shown in a first stage of operation 804, shown in fig. 12A, and a second stage of operation 808, shown in fig. 12B. In this embodiment, when wound interface 815 is secured to a skin surface, members 820 of wound interface 815, at least in part, form a fluid-tight enclosed space 817. As shown in fig. 12B, when the pressure p in the enclosed space 817 is low₀Excess of ambient pressure p_ambReaches the limiting pressure p_l(i.e., p)₀-p_amb＞p_l) Pressure relief valve 840 allows fluid 818 to escape from enclosed space 817 to reduce pressurep₀. As shown, the pressure relief valve 840 forms an overflow 825, the overflow 825 passing between the distal 822 and proximal 824 sides of the member 820, as shown. As shown, the standoffs 843 are disposed around the circumference of the overflow 825. In the first stage of operation 804, the plate 841 is connected to the bracket 843 to seal the overflow port 825. Slots 895 formed in plate 841 provide a structural weakness in plate 841, and slots 895 are designed such that when pressure p within enclosed space 817 is applied₀Exceeding the limit pressure p_lIn doing so, the plate 841 is caused to structurally deform along the slot 895. As shown in fig. 12B, in the second stage 808 of operation, when the plate 841 is deformed along the slot 895, the plate 841 bifurcates into

plate segments

842, 844, allowing the fluid 818 to escape from the enclosed space 817 through the overflow 825, thereby applying the pressure p₀Towards p_ambAnd decreases. The overflow ports 825 and the plate 841 are shown as circular, but in other embodiments the overflow ports 825, the plate 841 and the

plate segments

842, 844 can have other geometries.

Fig. 13A, 13B, 13C illustrate a portion of a wound treatment apparatus 900, including a portion of a wound interface 915. Wound interface 915 includes member 920, and member 920 includes a pressure relief valve 940, as shown. In this embodiment, member 920 of wound interface 915, when wound interface 915 is secured to a skin surface, at least partially forms a fluid-tight enclosure 917. As shown, when the pressure p in the enclosed space 917₀Excess of ambient pressure p_ambReach the limit pressure p_l(i.e., p)₀-p_amb＞p_l) While, pressure relief valve 940 allows fluid 918 to escape from enclosed space 917 to reduce pressure p₀. As shown, the relief valve 940 forms an overflow port 925, the overflow port 925 passing between the distal 922 and proximal 924 sides of the member 920.

Fig. 13A and 13B illustrate the pressure relief valve 940 in the first phase of operation 904 and the second phase of operation 908, respectively. In a first stage of operation 904, protrusions, such as

protrusions

995a, 995b, are provided around the plate 941 and attached to the bracket 943, the bracket 943 being disposed around the periphery of the overflow 925 to force the plate 941 into sealing engagement with the flange 927, as shown in fig. 13A. As shown in FIG. 13B, in the second stage of operation 908, when inside the enclosed space 917Pressure p of₀By limiting the pressure p_lExcess of ambient pressure p_ambAt this time, the protrusions, such as the

protrusions

995a, 995b, elastically deform to release the sealed connection of the plate 941 with the flange 927, thereby allowing the fluid 918 to escape from the enclosed space 917 via the overflow 925 between the plate 941 and the flange 927 along the circumference of the plate 941, reducing the pressure p₀Towards p_amb. Fig. 13C illustrates protrusions, such as

protrusions

995a, 995b, disposed circumferentially along plate 941. The protrusions, such as

protrusions

995a, 995b, are conical in this embodiment, but may take other shapes in other embodiments, such as circumferential ridges. The overflow 925, flange 927, bracket 943 and plate 941 are shown as circular in shape, but may have other geometries in other embodiments.

In operation, a wound interface (e.g., wound

interface

15, 115, 215, 225, 315, 415, 515, 615, 815, 915) of a wound treatment device (e.g., wound

treatment device

10, 100, 200, 300, 400, 500, 600, 700, 800, 900) can be secured to a skin surface (e.g.,

skin surface

11, 111, 211, 311, 411, 511) along a perimeter of a wound bed (e.g., wound

bed

13, 113, 513) to form an enclosed space on the wound bed, e.g.,

enclosed space

17, 117, 217, 227, 317, 417, 517, 617, 817, 917. The enclosed space may be fluid-tight, and an input fluid (e.g.,

input fluid

16, 116, 216, 316, 416, 616) may be introduced into the enclosed space or an output fluid (e.g.,

output fluid

18, 118, 218, 318, 418, 618) may be withdrawn from the enclosed space by a controller, such as controller 80 of wound treatment apparatus 10, via a lumen (e.g.,

lumen

45, 47, 145, 245, 247, 345, 347, 445, 447, 645) formed by a port (e.g.,

port

42, 44, 142, 242, 244, 342, 344, 442, 444, 642) configured on the wound interface.

The method of operation may include: a dressing (e.g., dressing 50, 150, 250, 250, 350, 450, 550, 650, 750) is placed within the enclosed space, biased toward the wound bed. The dressing may include at least one distal layer (e.g.,

distal layer

60, 180, 580, 660, 790) and a proximal layer (e.g.,

proximal layer

70, 160, 570, 670, 760), the dressing may be in fluid communication with one or more lumens that communicate input fluids into the dressing and output fluids from the dressing. The dressing may be in fluid communication between the wound bed and the inner chamber, whereby an input fluid is delivered through the inner chamber into the enclosed space, to the wound bed, and an output fluid, which may contain exudate from the wound bed, is delivered to the inner chamber for egress from the enclosed space through the inner chamber. In some methods of operation, the distal layer and the proximal layer may be formed of materials that cooperate to transfer exudate from the wound bed to the lumen for egress from the enclosed space. In some methods of operation, the dressing may include an intermediate layer (such as intermediate layer 170), a first intermediate layer 670, and a second intermediate layer 680, providing for delivery of a drug (e.g., drug 177) to the wound bed. The intermediate layer may be impregnated with the medicament at least during part of the use of the wound therapy device. In some methods of operation, the distal or proximal layer may be impregnated with a drug, which may be delivered to the wound bed from the distal or proximal layer, respectively. In some methods of operation, the dressing may be impregnated with a drug, for example, to prevent bacterial growth within the dressing. Some procedures may include placing a distal layer formed of open-cell silicone over the wound bed to promote healing, with minimal or no scarring due to the surgical incision.

In operation, an input fluid may be introduced into the enclosed space, or an output fluid may be directed out of the enclosed space, through one or more lumens to operate at a pressure range p_min≤p₀≤p_maxInternal variation of pressure p in enclosed space₀. For example, the output fluid may be directed out of the enclosed space to derive the pressure p₀Reduced to a minimum pressure p_minWherein p is_minLess than ambient pressure p_amb. Pressure p₀Can be maintained at p_min＜p_amb(suction or negative pressure) for a period of time during which output fluid including exudate (e.g., exudate 19, 119) may be directed out of the enclosed space. By introducing the input fluid into the enclosed space, the pressure p₀Then may be increased to a maximum pressure p_max. The input fluid may be a gas, such as gas 83, which may have a greater O than atmospheric air₂Concentration of O in the enclosed space₂At a concentration greater than atmospheric air, the wound bed is exposed to an enhanced concentration of O₂In (1). At input O₂After an input fluid of greater concentration than atmospheric air, an output fluid may be directed from the enclosed space to induce a pressure p₀Reduced to a minimum pressure p_min. Whenever at pressure p₀Equal to the minimum pressure p_minWhile the negative pressure is released by the input fluid containing oxygen-enriched air, the wound bed is at pressure p₀Lower exposure to enhanced concentration of O₂In (1). The wound bed is thus exposed to an enhanced concentration O₂And the benefits of negative pressure therapy.

In certain exemplary operations, the input fluid may be a liquid, such as liquid 85, and the input of the liquid may be at a pressure p₀Increase to a maximum pressure p_max. The liquid may provide therapeutic benefits to the wound bed, the skin surface surrounding the wound bed, or both the wound bed and the skin surface surrounding the wound bed.

The method of operation may include applying a negative pressure cycle (p) to the wound bed_o＜p_amb) Wherein at least one negative pressure cycle is formed by introducing O₂An input fluid having a concentration greater than atmospheric air.

These operations are generally illustrated by the operational method 2000, shown in the flow diagram of FIG. 14. The method of operation 2000 as shown in fig. 14 and the associated description are merely exemplary. As shown in fig. 14, the operational methodology 2000 begins at step 2001. 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. 14, 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 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 duration period T₄The liquid then 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. At step 2010, the liquid may be pulsed to clear blockages in various channels in fluid communication with the enclosed space. At step 2010, the liquid may sweep the enclosed space, including the wound bed and dressing, e.g., removing primary bacteria or exudate, cleansing the wound bed, moisturizing the wound bed. At step 2010, liquid may be input and output by instillation (steady flow). The exemplary method of operation 2000 then terminates at step 2011.

In step 2010, suction through the source, such as source 84, is passed through the enclosed space below ambient pressure p_ambPressure p of₀The liquid can be sucked into the enclosed space. When the enclosed space is filled with liquid, the pressure p₀Can tend to the ambient pressure p_ambWhen the liquid fills the enclosed space, an ambient pressure p is reached_amb. In certain embodiments, there is no energy gradient between the liquid source and the enclosed space, other than the pressure difference p_amb-p₀So that once in principle p₀＝p_ambThe flow of liquid into the enclosed space is terminated, thereby preventing overfilling of the enclosed space, which could dislodge the wound interface. In some embodiments, the controller may limit the pressure p of the liquid within the enclosed space₀E.g. approximately equal to ambient pressure p_ambTo prevent movement of the wound interface.

Exemplary method 2000 may repeat any number of 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 in

steps

2003, 20042005, 2006, 2007, 2008, 2009, 2010, time period T₁，T₂，T₃，T₄And a minimum pressure p_minAnd maximum pressure p_maxMay be changed during various iterations of method 2000.

Some methods of operation may include the steps of: when the dressing is connected to the wound bed, a drug is provided to the dressing, which may, for example, be through a lumen or through an injection port provided for this purpose, such as injection port 630.

In some methods of operation, the pressure p when the enclosed space is at₀Exceeding the limit pressure p_lAt ambient pressure p_ambIn the above, relief valves, such as

relief valves

635, 840, 940, may be operable to relieve pressure p in the enclosed space₀Is reduced to not exceed the desired limit pressure p_l，。

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 thus devised the present disclosure and the exemplary implementations herein, those of ordinary skill in the art will readily recognize various changes, modifications, and alterations that may be made therein 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 secured to a skin surface surrounding a wound bed to form a fluid-tight enclosure over the wound bed;

a dressing positioned within the enclosed space interfacing with the wound;

a lumen through the wound interface in fluid communication with the enclosed space; and

a gas having O greater than atmospheric air₂A concentration of said gas being sequentially input into and output from said enclosed space via said internal cavity,to be in a pressure range of p_min≤p₀≤p_maxVarying the pressure p of said enclosed space within a pressure cycle₀Wherein p is_minIs the minimum pressure during said pressure cycle, p_maxIs the maximum pressure during the pressure cycle.

2. The apparatus of claim 1, wherein the dressing comprises a distal layer comprised of silicone, a distal side of the distal layer contacting the wound bed; and

a channel disposed in the distal layer, the channel in fluid communication between a distal side and a proximal side of the distal layer.

3. The apparatus of claim 1, further comprising:

a second lumen passing through the wound interface in fluid communication with the enclosed space, an

A liquid introduced into the enclosed space through the lumen and directed out of the enclosed space via the second lumen.

4. The apparatus of claim 1, wherein p_maxRelative to the ambient pressure p_ambIn the range of about-15 mmHg to about +10 mmHg.

5. The apparatus of claim 1, wherein p_maxRelative to the ambient pressure p_ambIn the range of about-10 mmHg to about +40 mmHg.

6. The device of claim 1, wherein the minimum pressure p_minRelative to the ambient pressure p_ambIn the range of about-40 mmHg to about-150 mm.

7. The apparatus of claim 1, wherein the dressing comprises a drug for delivery to the wound bed.

8. The apparatus of claim 1, further comprising:

a pressure relief valve disposed on the wound interface to limit a pressure p within the enclosed space₀Less than limit pressure p_l。

9. The apparatus of claim 1, further comprising:

an injection port functionally connected to the wound interface to allow drug delivery into the enclosed space.

10. The apparatus of claim 1, further comprising:

a connector disposed on the wound interface for electrical communication with the wound interface to generate an electromagnetic field around the wound bed.

11. The apparatus of claim 1, further comprising:

a filter disposed between the dressing and a negative pressure source to restrict flow of the exudate in a direction toward the negative pressure source, the negative pressure source providing negative pressure suction to the lumen.

12. A wound treatment apparatus comprising:

a wound interface securable to a skin surface surrounding a wound bed to form a fluid-tight enclosed space over the wound bed to maintain a pressure p different from the ambient pressure within the enclosed space_ambPressure p of₀；

A dressing coupled to the wound interface within the enclosed space, the dressing comprising at least a distal layer at least partially comprising silicone, a distal side of the distal layer contacting the wound bed when the wound interface is secured; and

a channel disposed on the distal layer for fluid communication between a distal side and a proximal side of the distal layer.

13. The apparatus of claim 12, further comprising:

a gas within the enclosed space, the gas having an O greater than atmospheric air₂And (4) concentration.

14. The apparatus of claim 12, further comprising:

a port disposed on the wound interface and having a lumen passing through the port in fluid communication with the enclosed space.

15. The apparatus of claim 14, further comprising:

a spacer disposed between the dressing and the lumen within the enclosed space to form a space in fluid communication with the lumen and a proximal side of the dressing.

16. The apparatus of claim 12, further comprising:

a hydrophobic material cooperating with the proximal side of the distal layer to remove exudate from the proximal side of the distal layer, and

a hydrophilic material that cooperates with the hydrophobic material to remove exudate from the hydrophobic material.

17. The apparatus of claim 12, wherein the dressing further comprises:

a second layer proximal to the distal layer, the second layer comprising a drug to be released to the wound bed.

18. The apparatus of claim 12, wherein the dressing further comprises:

a second layer proximal to the distal layer, the second layer forming a channel for conveying a fluid in the second layer.

19. A wound treatment apparatus comprising:

a wound interface secured to a skin surface surrounding a wound bed to form a fluid-tight enclosed space over the wound bed to maintain a pressure p different from the ambient pressure within the enclosed space_ambPressure p of₀(ii) a A dressing interfacing with the wound to contact the wound bed; and

a gas containing O at a concentration greater than atmospheric air in the enclosed space₂No gas flows into or out of the enclosed space.

20. The apparatus of claim 19, further comprising:

a hydrophobic material forming part of the dressing, the hydrophobic material transferring exudate from the wound bed; and

a hydrophilic material in fluid cooperation with the hydrophobic material to transfer exudate from the hydrophobic material.