CN111050711B

CN111050711B - Anti-deformation wound treatment devices and related methods of use

Info

Publication number: CN111050711B
Application number: CN201880049890.1A
Authority: CN
Inventors: 林正纶
Original assignee: Individual
Current assignee: Lin Weihua
Priority date: 2017-07-29
Filing date: 2018-07-26
Publication date: 2022-05-27
Anticipated expiration: 2038-07-26
Also published as: CN110996866B; CN111050711A; WO2019027809A1; WO2019027808A1; CN110944608B; WO2019027807A1; CN110958866B; WO2019027810A1; CN111343949A; CN110996866A; CN110944608A; WO2019027806A1; CN110958866A

Abstract

A wound treatment apparatus is disclosed that may include a wound interface sealably secured to a skin surface surrounding a wound bed for enclosing the wound bed within a fluid-tight enclosure. The fluid can be in communication with the enclosed space for a pressure range p_min≤p₀≤p_maxPeriodically varying the pressure p in the enclosed space₀. When the pressure p in the enclosed space₀Less than ambient pressure p_ambThe wound interface may have sufficient resistance to deformation to expand at least a portion of the wound bed into the enclosed space. The wound treatment apparatus may include a pad receivable within the enclosed space, the pad being in communication with the expanded wound bed for absorbing exudate from the expanded wound bed. Related methods of use of the wound treatment apparatus are also disclosed.

Description

Anti-deformation wound treatment 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 29.7.2017, us patent application No. 15/663,709 filed on 29.7.7.2017, us patent application No. 15/663,710 filed on 29.7.7.7, us patent application No. 15/663,713 filed on 29.7.7.7, us patent application No. 15/663,714 filed on 29.7.7.2017. All priority-claims patent applications are hereby incorporated by reference in their entirety as if fully set forth herein.

Background

Technical Field

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

Background

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

For example, a wound may require a long time to heal due to impaired blood circulation and hypoxia of the tissue. In 2012, based on a study at the us wound registry, reimbursement data for 5240 trauma patients and 7099 wounds was analyzed, and it was determined that the cost of treating 640 million wounds in the us would reach an alarming $ 500 billion, more than twice the previous estimate, which costs 10 times the world health organization's budget. 65.8% of wounds had an average healing time of 15 weeks, and 10% of wounds had a healing time of 33 weeks or more. Nearly 8 million amputations occur in the united states each year, each amputation potentially representing failure of expensive treatment for many months or even years.

Current Negative Pressure Wound Therapy (NPWT) devices may include a dressing filled into a wound bed, a polymeric elastic film that is entirely fluid impermeable and back-covered with an adhesive, and a drainage tube in fluid communication with the dressing. Clinically commonly used membranes, often referred to as "occlusive" or even "semi-permeable", it is understood that its permeability is usually limited to evaporation (allowing the skin to "breathe") and fluid cannot pass through. The dressing may be, for example, cotton gauze, or an open-cell foam made of polyethylene or polyurethane.

After the wound bed is filled with dressing, the film may be centered over the dressing and wound bed, and then the seal adhesively secured to the skin surrounding the wound bed to seal the wound bed and dressing. Finally, a hole is created in the film above the dressing, to which the adapter and the drainage tube are sealingly connected. Air in the region between the membrane and the wound bed is drawn through the tube to create a pressure p less than atmospheric in the region_ambNegative pressure p of_s. Due to the pressure in the region passing through the negative pressure p_sAnd decreases, causing the atmospheric pressure to press the film and dressing against the wound bed, which shrinks with the surrounding skin. Exudate from the wound bed may be drawn through the dressing and directed out through the drainage tube.

However, current NPWT apparatus have various disadvantages. For example, because the dressing overlaps normal skin, which may result in maceration of the normal skin, the dressing must be trimmed to conform to the precise geometry of the wound bed. Undetected dressing fragments and trimmed dressing fragments in the wound may lead to infection of the lesion. The dressing may require frequent replacement, usually every other day, with each dressing change being possibleCan be extremely painful, such distress resulting in the need for a stronger analgesic or local anesthetic as a preoperative medication prior to dressing changes. The dressing is in constant contact with the wound bed and the granulation tissue required may be due to the negative pressure p_sAnd is absorbed into the micro-crevices of the dressing, which can tear or damage granulation tissue each time the dressing is changed, resulting in repeated frustration of the healing process. Furthermore, dressing changes are expensive in terms of time, medical personnel and consumables.

Because of the negative pressure p_sThe negative pressure p on the wound bed is achieved by different thicknesses of the dressing and different distances from the drainage tube position_sMay be non-uniform. This uneven negative pressure distribution, as well as the uneven pressure resulting from a dressing of the same thickness being pressed into a wound bed of uneven thickness, may be an obvious significant cause of reduced blood flow near the wound boundary of the wound bed. (see, e.g., Borgquist, O., R. Ingemansson, M. for example

Effects of negative pressure on thermal on regional flow, wind coupling and fluid removal- -Examining low pressure levels, intermitent and variable thermal, san Anthony, Texas USA, "24 th annual clinical seminar of skin and wound care progression" - -2009, 22-25 days 22/10). Reduced blood flow within the wound boundary may prevent healing of the wound bed, as healing is usually a decrease in the wound bed from the periphery to the center. For example, in a wound bed of severe potential vascular lesions, such as may be found in advanced diabetes, due to the negative pressure p_sCompressing the capillaries in the wound bed, current NPWT devices may not be able to sufficiently increase blood flow, although the goal of the NPWT device is to increase blood flow.

Drainage of wound bed exudate can also be problematic in current NPWT devices, as protein rich exudate from the wound bed may remain in the dressing and drainage tubes, often leading to occlusion of the aspiration system, pressure display errors, and abnormal cessation of NPWT therapy.

Furthermore, current NPWT devices can only be used after initial cleaning and debridement, and may not be used at the final stages of wound healing because the presence of the dressing, acting as a foreign body in the wound bed, may prevent complete closure of the wound bed.

Accordingly, there is a need for improved devices for wound treatment and related methods of wound treatment.

Disclosure of Invention

These and other needs and disadvantages are met and overcome by the wound treatment devices and associated methods of use disclosed herein. Additional modifications and advantages may be recognized by those skilled in the art upon studying this disclosure. A wound treatment device is disclosed herein. In various aspects of the invention, a wound treatment apparatus may comprise a wound interface sealably secured to a skin surface surrounding a wound bed, forming an enclosed space with a fluid-tight wound interface enclosing a wound boundary of the wound bed within the enclosed space. When the pressure p in the enclosed space₀Less than ambient pressure p_ambThe wound interface may have sufficient resistance to deformation to expand at least a portion of the wound bed into the enclosed space. In various aspects of the invention, the wound treatment apparatus may include a port disposed about the wound interface for fluid communication with the enclosed space to vary the pressure p within the enclosed space when the wound interface is sealingly secured to the skin surface₀In the pressure range p_min≤p₀≤p_maxPeriodically circulating in the inner circle. In various aspects of the invention, the wound treatment apparatus may comprise a pad positionable within the enclosed space for absorbing exudates from the wound bed. In various aspects of the invention, the pressure p is such that when the wound interface is sealingly secured to the skin surface surrounding the wound bed₀The change in pressure causes the wound bed to expand into contact with the pad placed within the enclosed space, and the change in pressure p0 causes the wound bed to move out of contact with the pad placed within the enclosed space. Also disclosed herein are related methods of use of the wound treatment devices.

This summary provides a basic explanation of some aspects of the apparatus 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 apparatus and methods disclosed herein.

Drawings

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

FIG. 2A illustrates a cross-sectional view of an exemplary implementation of a wound treatment apparatus;

FIG. 2B illustrates, in an enlarged cross-sectional view, a circled area of an exemplary implementation of the wound treatment apparatus shown in FIG. 2A;

FIG. 3 illustrates a perspective view of a second exemplary implementation of a wound treatment apparatus;

FIG. 4A illustrates, in perspective view, a portion of the exemplary wound treatment apparatus of FIG. 3;

FIG. 4B illustrates, by an exploded view, a portion of the exemplary wound treatment apparatus of FIG. 3;

fig. 5A illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of fig. 3 at a first stage of exemplary operation.

Fig. 5B illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of fig. 3 in a second stage of exemplary operation;

FIG. 6 illustrates a perspective view of a third exemplary implementation of a wound treatment apparatus;

fig. 7A illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of fig. 6 at a first stage of exemplary operation.

FIG. 7B illustrates a cross-sectional view of a portion of the exemplary wound treatment apparatus of FIG. 6 in a second stage of exemplary operation;

FIG. 8 illustrates a cross-sectional view of a fourth exemplary implementation of a wound treatment apparatus;

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

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

FIG. 11A illustrates a cross-sectional view of a portion of a seventh exemplary implementation of a wound treatment apparatus at a first stage of operation;

FIG. 11B illustrates a cross-sectional view of a portion of the exemplary implementation of the wound treatment apparatus of FIG. 11A in a second stage of operation;

fig. 12 illustrates a cross-sectional view of an eighth exemplary implementation of a wound treatment apparatus;

fig. 13A illustrates a cross-sectional view of a ninth exemplary implementation of a wound treatment apparatus;

fig. 13B illustrates a cross-sectional view of a portion of the exemplary implementation of the wound treatment apparatus of fig. 13A.

Fig. 14 illustrates a schematic diagram of a tenth exemplary implementation of a wound treatment apparatus; and the combination of (a) and (b),

fig. 15 illustrates a flow diagram of an exemplary method of using a wound treatment apparatus.

The illustrations are exemplary only, and the embodiments illustrated herein have been chosen for ease of explanation. The numbers, locations, relationships, and dimensions of the elements shown in the drawings are explained herein to constitute different embodiments described herein, as are the various dimensions and dimensional ratios to meet specific force, weight, strength, flow, and the like requirements, or the numbers, locations, relationships, and dimensions of these elements, as well as the various dimensions and dimensional ratios, will be readily understood by one of ordinary skill in the art after studying this disclosure. The same reference numbers may be used in different drawings to identify the same or similar elements. Furthermore, when the terms "top," "bottom," "right," "left," "front," "back," "first," "second," "inner," "outer," and similar terms are used, they should be understood with reference to the orientation of the embodiments shown in the drawings and utilized to aid in the description thereof. Relative terms used herein, such as generally, approximately, substantially, may refer to engineering, manufacturing, or scientific tolerances, such as ± 0.1%, 1%, 2.5%, 5%, or other such tolerances, as would be readily understood by a worker of ordinary skill in the art after studying this disclosure.

Detailed Description

A wound treatment device and associated methods of use are disclosed herein. In various aspects of the invention, a wound treatment apparatus comprises a wound interface sealably secured to a skin surface surrounding a wound bed, a portion of the wound bed on the skin surface enclosed within an enclosed space by forming the enclosed space within a fluid-tight wound interface. At some time, when the pressure p in the enclosed space is₀Less than ambient pressure p_ambThe wound interface has sufficient resistance to deformation to expand at least a portion of the wound bed into the enclosed space. The wound interface may be functionally connected to other devices, from a manual source of negative pressure to a control module, which is capable of monitoring and interacting with various parameters within the enclosed space to deliver different treatment methods to the wound bed.

At times, a pad is provided in communication with the enclosed space to absorb exudates from the wound bed. The wound treatment apparatus may include one or more ports for fluid communication with the enclosed space, the pressure p within the enclosed space being periodically varied by flowing gaseous fluid into or out of the enclosed space from the one or more ports₀In the pressure range p_min≤p₀≤p_maxAn internal variation. At some time, the pressure p₀The period of time for the periodic change may range from about 5 minutes (12 times per hour) to about 6 minutes (10 times per hour), or may be shorter or longer. Periodically changing pressure p in the enclosed space₀The wound bed and surrounding tissue may be massaged, for example, by suction pressure p₀＜p_ambExpanding the wound bed into the enclosed space, and at p₀≈p_ambWill be released from the wound bed expanded into the enclosed space to a baseline state, alternating.

Exudate as referred to herein includes, for example, proteinaceous liquids exuded from the wound bed, as well as various plasma and blood components. Exudate may also include other liquids used to treat wound beds.

Reference herein to fluid includes liquid, gas and combinations thereof. Liquids may include, for example, saline solutions, proteolytic enzyme solutions, antimicrobial lavage solutions, amniotic fluids, and exudates. The gas may include, for example, air, oxygen, nitric oxide, nitrogen, a therapeutic gas or an inert gas, and combinations thereof.

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 times, "fluid-tight" means having sufficient resistance to leakage to maintain a pressure p within the enclosed space₀Above 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.

The pad, as referred to herein, may comprise a series of exudate absorbing absorbent materials, including open cell foams comprised of materials such as polyvinyl alcohol (PVA), polyurethane or other polymeric foams. The pad may comprise a plurality of fibers, for example sodium carboxymethylcellulose fibers

Or a nonwoven fabric comprised of multicomponent fibers of nylon and polyester that have been subjected to a hydroentangling process

Split longitudinally into their individual components. The pad may comprise woven fibres, for example in a woven fabric, predominantly hydrophobic fibres on the outer surface and predominantly hydrophilic fibres on the inner side, to act as conduits for fluid transfer. The mat may also comprise a nonwoven fabric that has been wound together, cross-laid and/or twisted together into a suitable shape, such as a cylindrical shape or a ribbon shape of various sizes and thicknesses, with a plurality of linear channels formed between the fibers for flow guidance by capillary action. The hydrophobic fibers may be comprised of polyester and the hydrophilic fibers may be comprised of aliphatic or semi-aromatic polyamides (e.g., nylon). Polyester-polyurethane copolymer fibers (e.g., polyester-polyurethane copolymer fibers)

Or

) May additionally be combined with a fabric to impart stretchability and open-ended properties to the pad. The hydrophobic fibers may be remote from the liquid to prevent moisture accumulation, thereby causing maceration of the tissue with which they come into contact. The hydrophilic fibers may help transport fluid toward the exit port of the wound interface by capillary action.

Sometimes, as described herein, the wound interface has sufficient resistance to deformation to maintain a closed space when the pressure p is applied₀＜＜p_ambSufficient to draw the wound tissue toward the enclosed space until the enclosed space is occupied. At times, the wound interface has sufficient resistance to deformation to maintain the enclosed space through a pressure within the enclosed space that is less than the ambient pressure p_ambPressure p of₀Expanding at least a portion of the wound bed toward or into the enclosed space. The wound interface is sufficiently resistant to change at all timesShape ability to maintain an enclosed space above the wound bed by a pressure p sufficiently below ambient within the enclosed space_ambPressure p of₀Expanding at least a portion of the wound bed toward or into the enclosed space. At least a portion of the wound interface forming the enclosed space is, at times, substantially rigid. At all times, the wound interface has sufficient resistance to deformation, in the pressure range p_min≤p₀≤p_maxKeeping the seal fixed to the skin and fluid-tight.

The terms "distal" and "proximal," as used herein, are defined from the perspective of a healthcare provider when treating a patient with a wound therapy device. When treating a patient, the distal portion of the wound therapy device faces the patient and the proximal portion of the wound therapy device faces the physician. While the proximal portion of the structure may be the portion closest to the physician, the distal portion of the structure is the portion closest to the patient.

Massaging the wound bed by pressure changes, including the regular deformation of the wound bed volume, may be accompanied by an increase in blood flow. The terms massage, regular deformation, tissue deformation, wound bed expansion, are used interchangeably in this disclosure to refer to the general process of subjecting the wound bed to pressure fluctuations, and the resulting changes in the wound bed, including blood flow, blood oxygenation, cell tension, macroscopic and microscopic deformations, and other changes. Increased surging blood flow near the wound bed can lead to increased nutrients and immune elements, reduce infection and inflammation, and confer other beneficial effects that can promote wound bed healing. Massage of the wound bed may promote movement of exudate from the interstitial spaces of the wound to the wound crater outlet. This may reduce secondary edema caused by capillary compression and improve microcirculation in wounds and wounds. One of the at least one or more ports may be in fluid communication with the pad to allow transfer of exudate from the pad. Optionally, one of the at least one or more ports may be fluidly used to directly or indirectly monitor parameters within the enclosed space, such as pressure, temperature, humidity, pH, tissue oxygenation levels, blood flow, and the like, to achieve improved treatment.

Fig. 2A and 2B illustrate an exemplary wound treatment apparatus 1000. As shown in fig. 2A, the wound treatment device includes a wound interface 1015 secured to a skin surface 1011 forming an enclosed space 1017 to enclose a wound bed 1013 within the enclosed space 1017. As shown in fig. 2A, the wound interface 1015 includes a cover 1002 that may have a degree of transparency from transparent to opaque, an annular base flange 1004, and one or more ports, such as port 1003 emanating from the wound interface. In this embodiment, the port is optional, for example for wound protection and humidification. As shown, port 1003 is in fluid communication with the enclosed space 1017 and can be connected to conduits in communication with various fluid sources or reservoirs for fluid communication between the fluid sources or reservoirs and the enclosed space 1017. The port 1003 may be used to directly or indirectly monitor parameters within the enclosed space 1017. The port 1003, for example, may be connected to a source of negative pressure, such as the negative pressure ball 1034 shown in fig. 2A, to provide intermittent NPWT. The negative pressure ball 1034 may have one-

way valves

1032a, 1032b to ensure one-way negative pressure suction of the enclosed space. An optional relief valve 1030 may be incorporated into the wound interface 1015 or interposed between the port 1003 and the negative pressure ball 1034 to limit the minimum negative pressure within the enclosed space. The port 1003 may be sealingly opened or closed by a variety of principle means, including a self-sealing one-way valve 1032a that may be frequently used in medical applications. The negative pressure ball 1034 may be similarly equipped with a coupling port to connect to the valve 1032a to provide intermittent negative pressure therapy, such as may be required in a remote military mission or rural health care setting.

In this embodiment, the base flange 1004 is designed to be flexible, conformable, and capable of relieving diffusion pressure. This can be achieved individually or in various combinations including: the base flange 1004 has a reduced thickness compared to the remainder of the wound interface 1015, by being molded or co-molded with a softer polymer, and/or by suitable structural modifications, to allow for increased flexibility and flexibility, either broadly or locally.

FIG. 2B illustrates one embodiment of this enhanced flexibility, wherein a living hinge 1020 is provided along the perimeter of the base flange 1004. Not shown, but will be understood by those of ordinary skill in the art upon studying this disclosure, is the incorporation of engineering of the blade diaphragm portion and the elasticity enhancement dispersed in the repeating sections or regions across the base flange 1004. The result is better conformity to changing skin topography. While the base flange 1004 may be secured directly to the skin 1011 by adhesive, one embodiment is to insert an optional annular cushion 1005 between the base flange and the skin, the cushion 1005 may take the form of a closed cell foam 1012A (as shown on the left side of FIG. 2A) or an air bladder 1012b (as shown on the right side of FIG. 2A). In another exemplary variation for securing the wound interface 1015 to the skin, an annular skirt 1007 formed of a suitable bandage material, such as polyurethane, having an adhesive primer 1008 is adhered proximally to the base flange and distally to the skin to sealingly secure the wound interface to the skin 1011.

At times, a pad, such as

pad

50, 150, 450, 550, 650, may optionally be configured for communication with the enclosed space to absorb exudate from the wound bed. The cover 1002 forms a raised wound interface having a generally circular, rectangular, or oval space with the base flange 1004 extending along the entire perimeter of the cover 1002. Wound interface 1015 is sealed to skin surface 1011 by means of base flange 1004, and an additional but optional cushion 1005 or skirt 1007. As shown, the wound interface 1015 is fluid-tight in nature, with the enclosed space 1017 completely surrounding the wound bed 1013. The pressure p inside is set by introducing a fluid into the closed space 1017 or by discharging a fluid from the closed space 1017 through the port 1003₀. Pressure p₀Can be in the pressure range p_min≤p₀≤p_ambPeriodically changed to periodically expand the wound bed 1013 into the enclosed space 1017 and release the wound bed to a baseline state by reducing or releasing the negative pressure.

When the pressure p in the enclosed space₀Sufficiently below ambient pressure p_ambTemporary injuryThe mouth interface 1015 may have sufficient resistance to deformation to accommodate expansion of at least a portion of the wound bed into the enclosed space 1017. For example, in this embodiment, at pressure p₀＜p_ambIn use, the wound interface 1015 maintains the concave surface 1025 of the enclosed space 1017 facing the wound bed 1013 to allow at least a portion of the wound bed 1013 to expand into the enclosed space 1017.

Fig. 3, 4A, 4B, 5A and 5B illustrate an exemplary wound treatment apparatus 10. As shown in fig. 3, the exemplary wound treatment apparatus 10 includes a wound interface 15, the wound interface 15 including a base 20, a cushion 30 and a cover 40, the cushion 30 being secured around a perimeter circumference of the base 20 to enclose a perimeter of the base 20, the cover 40 being hingedly connected to the base 20. As shown, the base 20, having an annular shape, defines an outer surface 21 and an inner surface 23 of the base 20.

As shown, the bumper pad 30 is in the shape of a ring that corresponds in shape to the base 20 (see FIG. 5A), the bumper pad 30 defining an outer surface 31 and an inner surface 33. As shown, the distal surface 32 of the cushion 30 (the surface of the cushion 30 facing the patient) is circumferentially and sealingly secured to the skin surface 11 via an adhesive layer 90, and the proximal surface 34 of the cushion 30 (the surface of the cushion 30 facing the physician) is sealingly secured to the distal surface 22 of the base 20 along the perimeter of the base 20. In this embodiment, the cushion 30 cushions the skin surface 11 from the wound interface 15 and sealingly conforms to the contours of the skin surface. In this embodiment, the outer surface 21 is generally aligned with the outer surface 31 along the entire circumference of the base 20 and cushion 30.

The lid 40 is hingedly connected to the base 20 by a hinge 45 that allows the lid 40 to be positioned between an open position 46, shown in fig. 3, and a closed position 48, shown in fig. 5A and 5B, to correspondingly unseal or engage the lid 40 from the proximal surface 24 of the base 20. The hinge 45 may be configured to releasably engage the cover 40 with the base 20 to allow the cover 40 to be replaced, such as a new cover, a non-transparent cover, or a cover with a different function, such as the cover 140 of the wound treatment apparatus 100 (see fig. 6, 7A, 7B). Hinge 45 may be, for example, a living hinge, a pinned hinge, a releasably engageable catch, or other hinge, as will be appreciated by one of ordinary skill in the art in view of this disclosure.

In some embodiments, the lid 40 can engage the base 20 by a variety of other mechanisms, such as threaded engagement, or frictional engagement, to allow the lid 40 to sealingly engage the base 20, and to allow the lid 40 to disengage the base 20. In some embodiments, the cover 40 may be removably or non-removably engaged with the base 20. Various seals, compression fittings, and the like, may be provided on the cover 40, the base 20, or both the cover 40 and the base 20 to sealingly engage the cover 40 with the base 20. It should be noted that the hinge 45 is optional and may sometimes be omitted, for example the exemplary wound treatment apparatus 100 as illustrated in fig. 6, 7A and 7B, for example the hinge 45 may be omitted in the case where no direct intervention on the wound bed 13 is planned.

When the cover is in the open position 46, it allows for a variety of direct interventions on the enclosed space 17, such as the use of medical maggots to remove necrotic tissue, the placement of transplanted skin or other tissue on the wound bed 13. With the cover 40 in the closed position 48, the distal surface 32 of the cushion 30 is circumferentially and sealingly secured to the skin surface 11. in this embodiment, the enclosed space 17 may be defined by the inner surface 43 of the cover 40, the inner surface 23 of the base 20, and the inner surface 33 of the cushion 30, and the enclosed space 17 is essentially fluid-tight when the wound interface 15 is secured to the skin surface 11.

Although the illustrated wound interface 15 is a cylindrical shape that encompasses a circular area of the skin surface 11, it should be understood that a wound interface, such as the wound interface 15, may, in some embodiments, assume other geometric shapes, such as rectangular, polygonal, or oval, to enclose wounds or areas of different shapes on the skin surface 11. For example, the wound interface may be oval and low profile to enclose a linear incision, such as from a caesarean section. The wound interface may be oval and have a higher profile to cover the breast after breast augmentation, or when reconstructing the breast after mastectomy. The term "annular" as used in this disclosure is meant to include other geometric shapes, such as polygonal, rectangular or oval shapes surrounding a chamber.

As shown, port 42 and second port 44 are disposed on cap 40 between outer surface 41 and inner surface 43 in fluid communication with enclosed space 17 such that enclosed space 17 can be in fluid communication with sensors external to outer surface 41, e.g., a fluid reservoir, a fluid source, a fluid sink, a pump, a controller, a control module, e.g., control module 880 (see fig. 14), via port 42 and second port 44, via tubing including hoses, tubing, valves, and other various fluid transports and fittings that can mate with port 42 and second port 44. The port 42 and the second port 44 may be in fluid communication with: such as a compressed mechanical spring ball, a re-expandable enclosure driven by a variety of spring-like mechanisms, a mechanical or electrical pump, or a pump in combination with other elements, such as one or more sensors, valves, control modules, electronic circuitry, tubing, processors and software, to cooperate to provide fluid and therapy to enclosure 17 or to withdraw fluid from enclosure 17. In this embodiment, the port 42 is located in a central location and the second port 44 is located at a periphery, but in other embodiments, the port 42 and the second port 44 may be located at different locations of the wound interface 15, may have mutually, or varying flow directions. Input fluid 78 may be input into enclosed space 17 via port 44, output fluid 76, which may contain exudate 18 (see fig. 5A and 5B), may be directed out of enclosed space 17 via port 42 (see fig. 5A and 5B), or may flow in reverse with the fluid.

As shown in FIG. 3, stop means, such as stop means 49a, 49b, are circumferentially disposed about the periphery of the cover 40 in mechanical cooperation with corresponding base stop means 29a, 29b, the base stop means 29a, 29b being circumferentially disposed along the rotatable locking ring 27 for releasably retaining the cover 40 in the closed position 48 relative to the base 20 such that the enclosed space 17 is fluid tight. As shown, in this embodiment, a locking ring 27 is provided below the outer surface 21 of the base 20 to lock or release the cover by rotating or sliding in certain directions.

Various numbers of interengaging stops, such as

stops

49a, 49b and base stops 29a, 29b, may be provided between the cover and base 20, and their functional equivalents which may be provided in certain embodiments, may have a variety of shapes, sizes, operative configurations, etc., as will be appreciated by those of ordinary skill in the art in view of this disclosure. In certain embodiments, the fluid-tight seal between the cover and base is formed by employing face seals, radial seals, compression seals, with and without O-rings or gaskets, and other sealing means, as will be readily understood by those of ordinary skill in the art in view of this disclosure.

In this embodiment, the cushion 30 forms a cushion chamber 37 (see fig. 5A and 5B). The cushion 30 may be formed of, for example, rubber or a polymer such as PVC or silicone. An optional cushion port 35 extends forward from the outer surface 31 of the cushion 30, through the cushion port 35, and is in fluid communication with the cushion chamber 37. The fluid, including air or other gas or liquid, within the cushion chamber 37 of the cushion 30 can be controllably adjusted through the cushion port 35 to provide a desired level of cushioning and sealing of the wound interface 15 relative to the skin surface 11. In other embodiments, cushion 30 may be formed from, for example, a variety of compressible, conformable, fluid-tight, closed-cell foams.

In certain embodiments, the base 20 may be formed, for example, from one or more medical polymers including, for example, ABS, polystyrene, or polypropylene. The cover 40 may be at least partially transparent to allow visual observation of the conditions within the enclosed space 17, including the wound bed 13 and the portion of the enclosed skin surface 11 within the enclosed space 17. The cover 40 may be made of, for example, polycarbonate, acrylic, or other transparent polymeric material such as a copolyester, for example, Eastman Tritan available from Eastman Chemical Co^TM。

Fig. 3 illustrates a pad 50 disposed within the enclosed space 17 of the wound treatment apparatus 10. In this embodiment, the pad 50 is cylindrical, substantially annular, to leave a portion of the enclosed space 17, in particular the space just above the wound bed, unoccupied by the pad 50, at least during some stage of treatment, such that the pad 50 does not make continuous contact with the wound bed. In this embodiment, the outer surface 51 of the cushion 50 can be biased toward at least a portion of the inner surface 33 of the cushioning pad 30, at least a portion of the inner surface 23 of the base 20, or at least a portion of the inner surface 43 of the cover 40, wherein the cover 40 is in the closed position 48. In certain embodiments, the pad 50 may be used during the initial exudation phase of wound therapy and removably placed within the enclosed space 17 to allow periodic removal and replacement of the pad 50 while the cover 40 is in the open position 46. In other embodiments, the pad 50 is securely affixed to the wound interface 15 within the enclosed space 17, in which case the replacement of the pad 50 involves replacing the pad 50 and at least a portion of the wound interface 15, such as the pad 50 affixed to a removable and replaceable cover 40.

Fig. 4A and 4B illustrate a pad 50 of the wound treatment apparatus 10. In this embodiment, the cushion 50 is comprised of

cushion members

60, 70, 80, the

cushion members

60, 70, 80 being die cut to the thickness of the material, such as with absorbent foam.

Pad components

60, 70, 80 may be stacked upon one another or partially bonded together in a manner that does not impede fluid flow through pad 50. As shown, when stacked on top of each other,

distal surfaces

62, 72 are biased toward respective

proximal surfaces

74, 84. In this embodiment, proximal surface 64 of pad component 60 forms proximal surface 54 of pad 50, distal surface 82 of pad component 80 forms distal surface 52 of pad 50,

inner surfaces

63, 73, 83 form inner surface 53 of pad 50, and

outer surfaces

61, 71, 81 form outer surface 51 of pad 50 when stackable one on top of the other.

Pad 50 may include a different number of pad components, such as

pad components

60, 70, 80, and the number of pad components (such as

pad components

60, 70, 80) forming pad 50 may be selected to make up a pad 50 of a desired thickness. An optional polymer thread may be disposed on the mat 50 for removing the mat 50 from the enclosed space 17. Alternatively, the pad 50 may be formed as a unitary structure of preselected dimensions. In some embodiments, pad 50 absorbs exudate as a conduit for the passage of exudate 18, out of enclosed space 17 through port 42, as shown in FIG. 5B. In certain embodiments, the

pad components

60, 70, 80 may be formed of the same material or different materials in different spatial structural relationships, such as layers or columns, to form different fluid flow paths or wicking features, if desired. In some embodiments, pad assembly 60 may have at least one diagonal instead of beams, such as

beams

65, 67, or pad assembly 60 may have three or more beams instead of two beams in this embodiment. In some embodiments, pad component 60 may be formed as a continuous structure from outer surface 51 to axis 69, in which case the annular region within pad component 60 would be omitted. Various embodiments of the pad 50 may include a single unitary molded or woven structure sized.

In the embodiment of fig. 4B, the

pad components

70, 80 are annular in configuration. Pad assembly 60 is annular and includes at least one cross member, such as

cross members

65, 67, emanating from an inner surface 63 of pad assembly 60 and passing through an axis 69 of the annulus, as shown. The cross-members 65, 67 intersect one another near the axis 69 to form a central portion 68, the central portion 68 being in fluid communication with the port 42, the port 42 being correspondingly positioned on the lid 40, the port 42 being in fluid communication with the central portion 68 of the cushion 50 when the lid 40 is in the closed position 48.

Different designs of the absorbent pad 50 may be possible for directing exudates away from the enclosed space 17, in this embodiment, from the peripheral portion of the pad 50 toward the central portion 68 of the pad 50, the central portion 68 being in contact with the port 42. Exudate 18 may be transported from pad 50 to central portion 68 and then directed out of pad 50 through port 42. As shown in fig. 4A, the output fluid 76 and the input fluid 78 may be in communication with the enclosed space 17 or wound bed 13 at least partially through the apertures 58 of the pad 50.

Fig. 5A and 5B further illustrate cross-sectional views of the wound treatment apparatus 10, taken along the axis 5-5 of fig. 3, where fig. 5A illustrates the wound treatment apparatus 10 in an exemplary first stage of operation 14 and fig. 5B illustrates the wound treatment apparatus 10 in an exemplary second stage of operation 16. As shown in fig. 5A and 5B, wound interface 15 is sealingly secured to skin surface 11 to close wound boundary 12 such that a portion of wound bed 13 on skin surface 11 is enclosed within fluid-tight enclosed space 17. At least a portion of the wound bed 13, such as the undercut, sinus and tunnel (see fig. 1), is located below the skin surface 11 and may be in fluid communication with the enclosed space 17. It should be noted that the wound boundary 12 may be enclosed within the enclosed space 17, and the eroded area may extend below the skin surface 11 and beyond the enclosed space 17.

As shown on the left side of fig. 5A, the adhesive layer 90 secures the distal surface 32 of the bumper pad 30 to the skin surface 11, the adhesive layer 90 being interposed between the distal surface 32 of the bumper pad 30 and the skin surface 11. As shown on the right side of fig. 5A, adhesive layer 90 may optionally extend beyond a portion of skin surface 11 to encompass all of the skin surface in the area below and near wound interface 15. Adhesive layer 90 is a member of the medically appropriate class of cyanoacrylates, such as N-butyl-2-cyanoacrylate (Histoacryl Blue) or octyl 2-cyanoacrylate (dermobond), and a water resistant coating covers the wound perimeter on the skin surface to protect normal skin from secondary maceration caused by prolonged exposure of the skin to fluids. The adhesive layer 90 may be, for example, acrylic, silicone or hydrocolloid. In some embodiments, other securing mechanisms, such as straps with hook and loop fasteners, may also be used to secure, or at least partially secure, wound interface 15 to skin surface 11.

In certain embodiments, the dressing may be omitted from the wound bed 13, which would allow direct assessment of the wound condition through the transparent portion of the cover 40 during a substantial portion of the wound treatment, since there is no contact of the dressing with the wound bed 13. In certain embodiments, the pad 50 may be in intermittent contact with the wound bed 13 during certain stages of operation. Even in such embodiments, at least a portion of the wound bed may be directly visible through the transparent portion of the cover 40 and the corresponding aperture 58 in the pad 50. Without continuous contact of the dressing with the wound bed 13, the painful problem of tearing of granulation tissue during dressing changes and the interruption of the healing process due to tearing can be avoided. The wound interface 15 may only need to be replaced once a week, saving medical personnel time. Furthermore, since there is no dressing in the wound bed, the wound treatment apparatus 10 may be used from initial treatment until the wound bed 13 is fully healed, except that a dressing may be required during the initial exudation phase of the wound bed 13 on an intermittent basis. The wound treatment device 10 may support a range of treatments such as proteolytic hydrolysis, drug maggot debridement, antibiotic lavage and incubation of tissue matrix, skin grafting and stem cell culture, etc.

In a first stage 14 of operation shown in fig. 5A, the pressure p within the enclosed space 17 of the wound treatment apparatus 10₀≈p_amb. (Note that in some embodiments, the pressure p of the first stage 14 is operated₀＞p_amb). As shown in fig. 5A, the wound bed 13 and the skin surface 11 within the enclosed space 17 are in a baseline state 93, the wound bed 13 being spaced from the distal surface 62 of the pad assembly 60 of the pad 50 such that the wound bed 13 does not directly contact the pad 50, particularly the distal surface 62 of the pad assembly 60. As shown in fig. 5A, the wound interface 15 forms the entrance 26 of the enclosed space 17, and as shown, the portion of the wound bed 13 enclosed within the wound interface 15 may be entirely outside of the entrance 26 at the baseline condition 93 (e.g., the entrance 26 not drawn upward beyond the baseline condition 93). As shown, the capillaries 96 adjacent the wound bed 13 are in a baseline unexpanded state 98, delivering substantial blood flow to the wound bed 13.

As shown in FIG. 5B, during the second phase 16 of operation of the wound treatment apparatus 10, due to the output of the output fluid 76, the pressure p within the enclosed space 17₀＝p_min，p_min＜p_ambOutput fluid 76 may include air and other gases and liquids, as well as exudate 18 conducted from enclosed space 17 through port 42. As shown in fig. 5B, the pressure p in the closed space 17₀＝p_minAt least a portion of the wound bed 13 is expanded and enters the enclosed space 17 through the inlet 26 such that the wound bed 13 is in an expanded state 94. In the dilated state 94, the wound bed 13 at the skin surface 11 and the portion of the skin surface 11 enclosed by the enclosed space 17 are inflated, dilated and stretched, and the capillaries 96, including capillaries, arterioles and venules proximate the wound bed, e.g., the capillaries 96, can be in the dilated state 99. In thatIn the dilated state 99, the capillaries may be engorged and the blood flow to the wound bed 13 may increase above baseline with corresponding beneficial benefits. In addition, swelling, which includes deformation and stretching of the tissue surrounding the Wound bed, has been found to stimulate fibrocyte differentiation and Wound healing (cf. Saxena, V.et. al., Vacuum acquired trauma: Microdeformation of Wound and Cell promotion. Amer. Soc. Plastic surg.1086-1096, 10 months 2004).

In the expanded state 94, a portion of the wound bed 13, the skin surface 11, or both the wound bed 13 and the skin surface 11 may be biased toward at least a portion of the pad 50, such as a portion of the distal surface 62 of the pad member 60, as shown in fig. 5B. In the expanded state 94, a portion of the wound bed 13, the skin surface 11, or portions of the wound bed 13 and the skin surface 11 may be biased toward the inner surface 53 of the pad 50. Pressure p_minThe expanded state 94 may be selected to produce a biased connection of the pad 50 to at least a portion of the wound bed 13. The pad 50 absorbs exudate 18 from the wound bed 13 (as indicated by the solid black arrows in fig. 5B) through the biased connection between the pad 50 and the wound bed 13. The pad member 80 of the pad 50, which surrounds the wound bed 13, contacts the skin surface 11, as shown, and may absorb exudate 18 from the periwound area within the enclosed space 17. Thus, exudate 18 may be absorbed by at least a portion of pad 50 in different directions across wound interface 15 and then drawn through port 42 and out of pad 50.

After the pad 50 absorbs the exudate 18, the exudate 18 may pass through the pad 50 to the central portion 68 through a combination of capillary action and a suction gradient, and the exudate 18 may then be conducted out of the pad 50 at the central portion 68 through the port 42 connected to the central portion 68, thereby conducting the exudate 18 out of the enclosed space 17. When negative pressure is released by the input of input fluid 78 through second port 44, input fluid 78 into the enclosed space, particularly when it is a sudden input, may provide a pushing force to push exudate 18 from mat 50 forward into a tube connected to port 42, into a container, such as container 881 (see fig. 14), to evacuate the conduit. It should be noted that the output fluid 76 from the enclosed space 17 may include gasThe fluid in the state, or other fluid accompanying the exudate 18, within the enclosure 17, serving to reduce the pressure p within the enclosure 17₀。

By periodically varying the pressure p in the enclosed space 17₀Substantially in the pressure range p_min≤p₀≤p_ambb, the wound treatment apparatus 10 may be periodically changed between a first stage of operation 14 and a second stage of operation 16, where p_minIs the minimum pressure at which the pressure varies periodically. Pressure p₀Can be altered by introducing the input fluid 78 into the enclosed space 17 and removing the output fluid 76 from the enclosed space 17, a control module, such as a control module 880 of the wound treatment apparatus 800 (see fig. 14), can be operatively connected to the wound interface 15 to introduce the input fluid 78 into the enclosed space 17 and to remove the output fluid 76 from the enclosed space 17. The minimum pressure may be, for example, p_min≈p_amb-150mm Hg.. The minimum pressure may be, for example, p_min≈p_amb-70mm Hg. The minimum pressure may be, for example, generally in the pressure range (p)_amb-130mm Hg)≤p_min＜(p_amb-80mm Hg). Minimum pressure p_minCan be generally in the pressure range (p)_amb-90mm Hg)≤p_min＜p_ambAnd (4) the following steps.

In certain embodiments, the pressure p₀Is usually located in a pressure range p_min≤p₀≤p_maxIn which p is_max＞p_amb. For example, p_max≈(p_amb+30mm Hg). In certain embodiments, p_max≈p_amb. In some embodiments, p_max＜p_ambE.g. maximum pressure p_maxMay be at ambient pressure p_ambAnd less from about-5 mm Hg to about-20 mm Hg.

The pressure p is varied as the wound treatment apparatus 10 changes from the first stage of operation 14 to the second stage of operation 16₀Reduction of p₀→p_minIn the expanded state 94 during the second stage 16 of operation, the wound bed 13 is expanded through the inlet 26 into the enclosed space 17 to provide an expanded lengthAnd 19 degrees. As the wound treatment apparatus 10 changes from the second stage of operation 16 to the first stage of operation 14, with the pressure p₀Increase p of₀→p_maxThe wound bed 13 is released from the tensioned state to the baseline state 93. In the first stage 14 of operation, the wound bed 13 is in a baseline state 93 with essentially no expanded length, such as expanded length 19. Thus, between the expanded state 94 and the baseline state 93, at least a portion of the wound bed 13 expands into the enclosed space 17 and releases from expanding into the enclosed space 17, respectively, periodically corresponding to the pressure p₀In the pressure range p_min≤p₀≤p_maxPeriodically changing. Normal pressure p₀In the pressure range p_min≤p₀≤p_maxPeriodically varying, the wound bed, including surrounding tissue, may be massaged to induce a corresponding fresh blood flow, periodically flushing the wound bed to provide, for example, nutrients, immune factors, and oxygen.

Further, in this embodiment, the pressure p₀The periodic variation of (a) results in a transient and intermittent contact between the pad 50 and the wound bed 13 such that granulation tissue of the wound bed 13 will not grow into the pad 50 at times, in other words will not tear or damage the granulation tissue when the pad 50 or the wound interface containing the pad 50 is replaced. At a particular moment during the pressure change, the pressure p₀May be substantially constant throughout the enclosed space 17 such that the entire wound bed 13 is exposed to the pressure p₀Thus, no significant pressure gradient is created around the wound bed 13, which may result, for example, in a reduction of blood flow near the wound boundary 12. It should be noted that as exudate 18 is absorbed, pad 50 may become swollen, thus allowing pad 50 to maintain a varying degree of contact with wound bed 13, despite pressure p₀In the pressure range p_min≤p₀≤p_maxPeriodically changing, the wound bed is inflated to increase contact between the wound bed 13 and the pad 50, or the wound bed 13 is retracted to decrease contact between the wound bed 13 and the pad 50, but the pad 50 remains in contact with the wound bed 13 at all times.

From a gas orAn input fluid 78 formed by a gas mixture can be introduced into the closed space 17 via the second port 44 to at least partially regulate the pressure p in the closed space 17₀Or to control the composition of the gaseous fluid within the enclosed space 17. For example, by introducing the input fluid 78 into the enclosed space 17 through the second port 44 and the output fluid 76 out of the enclosed space 17 through the port 42, the wound treatment apparatus 10 may be periodically changed between the first stage of operation 14 and the second stage of operation 16. The introduction of input fluid 78 into enclosed space 17 through second port 44 and the removal of output fluid 76 from enclosed space 17 through port 42, or vice versa, may enhance the removal of exudate 18 from enclosed space 17 and may increase the fluid velocity in the conduit by increasing the flow rate, thereby preventing clogging. In certain embodiments, where oxygen supplementation is particularly important for rescuing hypoxic tissue at the margin of death, as well as for supporting cellular functions, such as cell division and collagen synthesis, the input fluid 78 may include a gas with a greater oxygen concentration than atmospheric air. The added oxygen can inhibit the growth of anaerobic bacteria. The input fluid 78 may be a liquid, such as saline, to irrigate wounds, enclosed spaces and drains, or other therapeutic fluids, including antibiotic irrigation, or amniotic fluid for stimulating regenerative effects.

Fig. 6, 7A, and 7B illustrate another exemplary embodiment of a wound treatment apparatus 100. As shown in fig. 6, in this embodiment, wound interface 115 of wound treatment apparatus 100 includes base 120 and apron 180. The underside of skirt 180 is coated with adhesive 190, skirt 180 being annular in shape and disposed about the entire periphery of base 120, base 120 occupying a portion of the annular region defined by skirt 180. In this embodiment, the distal periphery of skirt 180 is sealingly secured to skin surface 111 by adhesive 190. Apron 180 may be sized to provide sufficient adhesive force to maintain wound interface 115 attached to skin surface 111. Apron 180 may be formed of a bandage material such as polyurethane. As shown in fig. 6, wound interface 115 includes a port 142 at the wound interface that forms a lumen 143 for fluid communication with enclosed space 117. Via the lumen 143 of the port 142, as indicated by the arrows in fig. 6, the input fluid 178 may be introduced, or the output fluid 176 may be directed out of the enclosed space 117.

As shown in fig. 7A, wound interface 115 of wound treatment apparatus 100 includes a cushion 130 secured to flange 129 of base 120 and an apron 180. In this embodiment, wound interface 115 is resistant to deformation. In this embodiment, the flange 129 is sealingly secured around the entire perimeter of the base 120, which can spread pressure and conform to the skin surface 111. The flange 129, which may be made of a medical grade polymer such as polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE), polypropylene (PP), Polyurethane (PU) and silicone, for example, may be sealingly secured to the skin surface 111 by an adhesive. Cushion 130 is optional and may assist in spreading localized pressure or in providing a fluid-tight seal between wound interface 115 and skin surface 11 l. As shown in fig. 7A, the bumper pad 130 has a ring shape, and the bumper pad 130 is fixed around the entire circumference of the base 120. As shown, the proximal side 134 of the bumper pad 130 is sealingly secured to the distal side 131 of the flange 129 along the entire perimeter of the base 120. As shown in fig. 7A, the distal side 132 of the cushion 130 is biased toward the skin surface 111 around the wound bed 113 to cushion the force of the wound treatment device against the skin surface 111 or to conform to the contour of the skin surface 111. In this embodiment, the cushion 130 forms a cushion chamber 137. In some embodiments, cushion 130 can be omitted, in which case base 120 can be held biased toward attachment to skin surface 111 by skirt 180, or by distal side 131 of flange 129, or by the cooperation of skirt 180 and distal side 131 of flange 129 with adhesive layer 190. In embodiments where cushion 130 is omitted, base 120 can be supported by skirt 180 in a spaced relationship with skin surface 111.

As shown, skirt 180 is sealingly secured to proximal side 133 of flange 129, skirt 180 being sealingly secured to skin surface 111 along the entire perimeter of base 120 by adhesive layer 190 such that wound boundary 112 is covered by fluid-tight enclosure 117.

As shown in fig. 7A, a portion of the base 120 is bifurcated to form a void 127, and the pad 150 is received in at least a portion of the void 127. In this embodiment, channels, such as

channels

128a, 128b, 128c, are formed in at least a portion of the distal end 122 of the base 120 to allow fluid communication between the enclosed space 117 and the void 127 containing the pad 150, the pad 150 being received within the void 127. Exudate 118 emanating from wound bed 113 may pass through channels, such as

channels

128a, 128b, 128c, into void 127 for absorption by pad 150. As shown, port 142 is in fluid communication with void 127 containing pad 150 through lumen 143 to direct output fluid 176 containing exudate 118 from pad 150. When enclosed space 117 is in fluid communication with port 142 through a passage, such as

passages

128a, 128b, 128c, output fluid 176 may be directed out of enclosed space 117 through lumen 143 of port 142. A variety of numbers of channels, such as

channels

128a, 128b, 128c, may be provided in different applications. The port 142, as well as any additional ports, may be configured for connection to a conduit, via the port 142, through the conduit, for fluid communication with the enclosed space 117. A control module, such as control module 880 of wound treatment apparatus 800 (see fig. 14), may be operatively connected to lumen 143 of port 142 to direct input fluid 178 into void 127 and enclosed space 117 through lumen 143 or to direct output fluid 176 containing exudate 118 from enclosed space 117 and void 127 through lumen 143.

In this embodiment, base 120 includes one or more windows made of a transparent material, such as

windows

139a, 139b, 139c, 139d, to allow visual inspection of wound bed 113 through base 120 and pad 150. As shown, the

windows

139a, 139b, 139c, 139d pass between the proximal side 124 and the distal side 122 of the chassis 120, including passing through a portion of the gap 127.

In the first stage 114 of exemplary operation, as shown in FIG. 7A, the pressure p within the enclosed space 117₀≈p_amb. The wound bed 113 is in the baseline state 193, and the wound bed 113 is in a spatial relationship with a portion of the distal side 122 of the chassis 120, including the channels, such as the

channels

128a, 128b, 128c, such that the wound bed 113 does not directly contact the channels or pads 150. As shown in FIG. 7A, wound interface 115 is formed intoThe inlet 126 into the enclosed space 117, in the baseline state 193, the portion of the wound bed 113 enclosed by the enclosed space 117 may be outside of the inlet 126.

As shown in FIG. 7B, in a second stage 116 of exemplary operation of the wound treatment apparatus 100, output fluid 176 is directed from the enclosed space 117 through the lumen 143 of the port 142, and the enclosed space 117 is evacuated to a degree such that a pressure p within the enclosed space 117 is generated₀Less than ambient pressure p_amb(i.e. p)₀＜p_amb) This causes at least a portion of the wound bed 113 to expand into the enclosed space 117 through the inlet 126 in the expanded state, with at least a portion of the wound bed 113 biased toward the distal side 122 of the chassis 120, including channels, such as

channels

128a, 128b, 128 c. During the second stage of operation 116, exudate 118 may be conducted therefrom out of wound bed 113 into void 127 through channels, such as

channels

128a, 128b, 128c, for absorption by pad 150. Pad 150 is in fluid communication with lumen 143 of port 142 such that exudate 118, as at least a portion of output fluid 176, may be directed out of pad 150 through port 142 via external suction applied to port 142.

By total pressure in the pressure range p_min≤p₀≤p_maxPeriodically varying the pressure p in the enclosed space 117₀The wound treatment apparatus 100 may be periodically changed between the first stage 114 of operation and the second stage 116 of operation to correspondingly expand the wound bed 113 into the enclosed space in the expanded state 194 and relax the wound bed 113 from expanding into the enclosed space 117 back to the baseline state 193 to massage the wound bed 113. In this embodiment, p is usually_min＜p_ambAnd p_amb≤p_max. At a specific time during the pressure change, the pressure p₀Is substantially constant throughout the enclosed space 117 such that the entire wound bed 113 is exposed to the pressure p₀This, for example, may result in an increase in blood flow near the wound boundary. Periodically disconnecting the wound bed 113 from contact with the distal side 122 of the base 120 may prevent the wound bed 113 from adhering to the distal side 122 of the base 120, channels, such as

channels

128a, 128b, 128c, or the pad 150. When in usePressure p₀＝p_minAt this point, wound interface 115 may have sufficient resistance to deformation to maintain the fluid-tightness of enclosed space 117, thereby allowing wound bed 113 to expand into enclosed space 117 and be released from expansion back to baseline state 193. When pressure p is₀＝p_minAt this time, the wound interface 115 may have sufficient resistance to deformation to maintain the inlet 126 to the enclosed space 117, thereby allowing the wound bed 113 to expand into the enclosed space 117 and be released from expansion back to the baseline state 193.

As shown in fig. 7A, when the wound bed 113 is in the baseline state 193, the capillaries 196 adjacent the wound bed 113 are in the baseline unexpanded state 198, and a baseline amount of blood is delivered to the wound bed 113 in the first stage 114 of operation. As shown in fig. 7B, when in the second stage of operation 116, the wound bed 113 is in an expanded state 194, capillaries proximate the wound bed, such as capillaries 196, may be in an expanded state 199.

Through the port 142, the input fluid 178 may be input into the enclosed space 117, as indicated by the arrow in FIG. 6, for example, to at least partially regulate the pressure p within the enclosed space 117₀To control the composition of the gaseous fluid within the enclosed space 117, or for other therapeutic purposes. For example, the wound treatment apparatus 100 may be periodically changed between the first stage of operation 114 and the second stage of operation 116 by continuously inputting the input fluid 178 into the enclosed space 117 and exporting the output fluid 176 from the enclosed space 117 through the port 142.

Fig. 8 illustrates an exemplary wound treatment apparatus 200. As shown in fig. 8, wound treatment apparatus 200 includes a deformation-resistant wound interface 215, wound interface 215 forming an enclosed space 217, enclosed space 217 being fluid-tight when wound interface 215 is coupled to skin surface 211 to enclose wound bed 213 on skin surface 211. As shown in fig. 8, wound interface 215 includes a cover 240, cover 240 being slidably, sealingly, frictionally, removably connected to base 220. The cover 240 may include at least a portion that is transparent to allow visual inspection of the wound bed 213 through the cover 240. As shown, the base 220 may include a flange 209 along an outer periphery of the base 220 that may be used to provide a structural support or sealing surface when mated with the cover 240. In other embodiments, the cover 240 and the base 220 may form a unitary structure.

As shown in fig. 8, the base 220 may include a flange 229 generally along the periphery of the outer side 223 at the distal end 222 of the base 220, the flange 229 being secured to the skin surface 211 by an adhesive 290. As shown in fig. 8, flange 229 may be designed to be flexible and conformable to skin surface 211 by its thickness and/or polymeric material to enable sealing wound interface 215 to wound 213 in a fluid-tight manner while distributing the forces of wound interface 215 from pressure p within enclosed space 217 to skin surface 211₀. Is in fluid communication with the enclosed space 217 through the lumen 243 of the port 242 located on the wound interface 215. A pad, such as

pads

50, 150, 450, 550, 650, 750 (see fig. 10, 11A, 11B, 12, and 13A), may be disposed within the enclosed space 217, and the pad may be in fluid communication with the inner lumen 243 of the port 242 to allow exudate from the wound bed 213 to be transferred out through the pad and the inner lumen 243 of the port 242. One or more additional ports, such as port 244, in fluid communication with the enclosed space 217, located on the wound interface 215, may be used to monitor internal space parameters within the enclosed space 217, may be used for communication with fluid within the enclosed space 217, or may be used for intervention of other therapies within the enclosed space 217. When not in use, port 244 may be closed by a valve 299, including, but not limited to, for example, a plug, a clip, various switches, and a solenoid valve.

Fig. 9 illustrates an exemplary wound treatment apparatus 300. As shown in fig. 9, wound therapy apparatus 300 includes a wound interface 315, wound interface 315 comprising a base 320 and a cover 340. Base 320 is formed to include flange 329 and receptacle 310. Flange 329 is an annular structure extending outwardly from outer side 323 at distal end 322 of base 320. Flange 329 may be a unitary part of base 320. As shown in fig. 9, flange 329 may be adhered to skin 311 at the periphery of wound bed 313 by adhesive 390. The cover 340 may be inserted into a hole formed in the container 310, and as shown in fig. 9, the container 310 may have a groove for easy insertion. In this embodiment, stop 309, formed by an inward flange, limits the insertion of lid 340 into container 310, providing an additional sealing surface between the lid and base to form a fluid-tight seal between lid 340 and base 320 so that enclosed space 317 is sealed. A pad, such as

pad

50, 150, 450, 550, 650, 750, may optionally be disposed within enclosed space 317 in fluid communication with lumen 343 of port 342.

Fig. 10 illustrates a portion of an exemplary wound treatment apparatus 400. As shown in FIG. 10, the wound interface 415 includes a cover 440, the cover 440 forming, or partially forming, an enclosed space 417 enclosing a wound bed 413 on a skin surface 411, a pad 450 attached to an inner surface 446 of the cover 440 in communication with an interior 443 of the port 442 when a pressure p within the enclosed space 417₀When reduced, the wound bed 413 is caused to expand into contact with the pad 450, the pad 450 being connected to at least a portion of the wound bed 413. With the wound bed 413 in contact with the pad 450, exudate may be transferred from the wound bed 413 into the pad 450, via the lumen 443 of the port 442, and out of the enclosed space 417. The lumen 443 passes between the inner surface 446 and the outer surface 448 of the cap 440 as shown.

In this embodiment, the pad 450 has a generally cylindrical configuration of unitary construction, with the pad 450 extending outwardly from the distal side 446 of the cover 440 into contact with the wound bed 413 during at least a portion of the periodic pressure change. The length X of the pad 450 may be less than the length Y from the distal side 446 of the cover 440 to the skin surface 411 or to the wound bed 413. Although the pad 450, if soft and compressible, may be configured to always contact the wound bed 450(X ═ Y), one consequence of X < Y is that only the pressure p within the enclosed space 417 is₀Sufficiently lower than p_ambTo allow the wound bed 413 to expand into contact with the pad 450, the pad 450 is in contact with the wound bed 413. During such intermittent contact, exudate may be conducted from the wound bed to the pad 450, through the port 442, and in turn from the enclosed space 417.

Fig. 11A and 11B illustrate

stages

505, 510, respectively, of an exemplary operation of an exemplary wound treatment apparatus 500. As shown, the exemplary wound treatment apparatus 500 includes a wound interface 515 having an inner surface 543 and an outer surface 546, the inner surface 543 forming an enclosed space 517. As shown, the pad 550 is disposed within the enclosed space 517, and the port 542 defines an internal cavity 549 between an inner end 545 and an outer end 547 of the port 542. An inner lumen 549 passes through the inner surface 543 and the outer surface 546 of the wound interface for fluid communication with the enclosed space 517.

As shown in FIG. 11A, in a first phase of operation 505, the pressure p within the enclosed space₀Is less than p_amb. Output fluid 563 in gaseous form passes from enclosed space 517 through pad 550, then through inner chamber 549, and out inner end 545 to outer end 547, as shown by the solid arrows in fig. 11A. As shown, the resulting pressure gradient biases the portion of surface 551 of pad 550 toward the inner end 545 of port 542. Exudate 561, as shown by the dashed arrows in fig. 11A, passes through pad 550 and then through interior chamber 549, exiting from interior end 545 to exterior end 547. It is noted that in certain embodiments, output fluid 563 may comprise a liquid, a gas, or a combination of gas and liquid.

In a second stage 510 of operation, shown in FIG. 11B, the pressure p in the enclosed space₀Is greater than or equal to p_ambSurface 551 of pad 550 disengages from inner end 545 of port 542. Thus, in this exemplary application of the wound treatment apparatus 500, in the first phase of operation 505, when fluid is being directed from enclosed space 517 through port 542, surface 551 of pad 550 is biased toward inner end 545 connecting port 542, and in the second phase of operation 510, when no fluid is being directed from enclosed space 517 through port 542, or fluid is being input, surface 551 of pad 550 is out of contact with inner end 545 of port 542. As shown in fig. 11A, aspiration of output fluid 563 through port 542 pulls pad 550 toward inner end 545 of connection port 542, and then allows exudate 561 to be directed out of pad 550 through port 542. When the attractive force exerted at port 542 ceases, as shown in fig. 11B, pad 550 is released from contact with the inner end 545 of port 542.

As shown in fig. 12, the example wound treatment device 600 includes a wound interface 615 having an inner surface 643 and an outer surface 646, the inner surface 643 forming an enclosed space 617. The pad 650 is disposed within the enclosed space 617, with the port 642 within the port 642 as shownAn interior cavity 649 is formed between the end 645 and the outer end 647. The lumen 649 passes through the inner surface 643 and the outer surface 646 of the wound interface. As shown in fig. 12, the pressure p in the enclosed space₀Is approximately equal to p_ambNo attractive force is applied to port 642 to remove fluid from enclosed space 617. In contrast to the exemplary wound treatment apparatus 500 illustrated in fig. 11A and 11B, the surface 651 of the pad 650 remains biased toward the inner end 645 of the port 642, as shown in fig. 12. Thus, in this embodiment, surface 651 is biased into contact with the inner end 645 of port 642 during the period of time that fluid is being conducted out of enclosed space 617, or during the period of time that fluid is ceasing to be exhausted from enclosed space 617 through port 642, or even during the period of time that fluid is being input into the enclosed space through port 642.

Fig. 13A and 13B illustrate an exemplary wound treatment apparatus 700. As shown in fig. 13A, wound interface 715 of wound treatment apparatus 700 defines an enclosed space 717, and pad 750 is disposed within enclosed space 717 in fluid communication with lumen 743 of port 742. As shown in fig. 13A, 13B, the pad 750 is formed of a woven composite of synthetic fibers and may include hydrophobic fibers 792, hydrophilic fibers 790 and elastic fibers 794.

Various braided structures may be configured to hold

fibers

790, 792, and 794 together. In one embodiment, a simple wool knit is used to form a two-layer structure, one layer being primarily hydrophilic fibers 790 and the other layer being primarily hydrophobic fibers 792. The structure can then be folded upon itself and sewn at the open perimeter to form a pad 750, with the surface 751 adjacent the pad 750 being primarily hydrophobic fibers 792 and the interior 753 disposed within the pad 750 being primarily hydrophilic fibers 790, as shown in fig. 13B. The hydrophobic fibers 792 force exudates, including other liquids from the surface 751 to flow onto the hydrophilic fibers 790 within the interior 753. Exudate may be retained on the hydrophilic fibers 790 and transported through the hydrophilic fibers 790 to the lumens 743 of the ports 742 by the negative pressure applied to the lumens 743, and directed out of the enclosure 717.

In fig. 13A, the pad 750 takes the form of an inverted bowl positioned above the wound bed 713. The pad 750 may not directly contact the wound bed except at the wound treatment apparatus 700During a certain phase of operation, when the pressure p in the enclosed space 717₀When the negative pressure is sufficient, the wound bed is pulled into contact with the pad 750. When wound bed 713 is in contact with pad 750, exudate from wound bed 713 may transfer from wound bed 713 into pad 750, through pad 750, from pad 750 to port 742. Pad 750 can have optional regions 796, regions 796 being in at least intermittent contact with port 742, with no or very few hydrophobic fibers 792 at regions 796 of surface 751. The pad 750 may additionally have different weave structures in different areas of the pad 750 for specific applications. For example, at a portion of the surface 751, the fibers 792 are primarily hydrophobic in order to reduce the humidity at the surface 751 and, thus, reduce the likelihood of skin maceration due to prolonged wet contact with that portion of the surface 751. In certain embodiments, the pad 750 may be alternatively and removably deployed within the wound interface 715, or the pad 750 may be fixedly joined with the wound interface 715.

Fig. 14 illustrates an exemplary wound treatment apparatus 800. As shown in fig. 14, the wound treatment apparatus 800 includes a gas source 882 and a liquid source 884 in fluid communication with a control module 880, which control module 880 is in fluid communication with the wound interface 815. As shown, a wound interface 815 is secured to the skin surface 811, forming an enclosed space 817 above a wound bed (e.g., wound

beds

13, 113, 213, 313, 413, 713, 1013). Wound interface 815, may be similar to, for example, wound

interface

15, 115, 215, 315, 415, 515, 615, 715, 1015, enclosed space 817 may be correspondingly similar to

enclosed space

17, 117, 217, 317, 417, 517, 617, 717, 1017. The control module 880 may monitor various parameters within the enclosed space 817, such as the pressure p₀Control module 880 may interact with these parameters to provide different treatment methods.

In this embodiment, the control module 880 includes a control group 893 and a receptacle 881, the control group 893 including a microcontroller 887, the microcontroller 887 being in operable communication with the power source 898, a user I/O (input/output) 886, a valve 888, a pump 889 and a pressure sensor 891 to control or monitor operation of the power source 898, the valve 888, the pump 889 and the pressure sensor 891, at least in part in response to user input entered via the user I/O886. Microcontroller 887 may include, for example, a microprocessor, memory, analog/digital converters, digital/analog converters, clocks, I/O connectors, and the like, and microcontroller 887 may be configured, for example, as a single chip or chip set mounted on a board, as will be readily appreciated by those of ordinary skill in the art after studying this disclosure.

The power supply 898 may be, for example, a mains supply or a battery, and the power supply 898 may include, for example, a transformer, an inverter, a rectifier, or a voltage filter. In this illustration, the valve 888 and the pressure sensor 891 can accordingly represent a different number and configuration of valves and a different number and configuration of pressure sensors. Various communication paths may be arranged around control module 880 to transmit power from power supply 898 to microcontroller 887, valve 888, pump 889, and pressure sensor 891.

The user I/O886 may include a variety of switches, buttons, dials, etc., whether virtual or physical, for obtaining user input, which is then communicated to the microcontroller 887 to allow the user to direct the operation of the wound treatment apparatus 800. Various communication paths such as electrical, electromagnetic (such as bluetooth), optical (such as laser, infrared radiation) and networking communications may be employed for communication between microcontroller 887 and user I/O886. The microcontroller 887 controls the operation of the wound treatment apparatus 800 including a control module 880, which communicates to the microcontroller 887, at least in part, based on user input from the user I/O886. The microcontroller 887 may communicate reference data for the operation of the wound treatment apparatus 800 to the user I/O886, which the user I/O886 may display to the user. In some embodiments, user I/O886 may be located near microcontroller 887, and user I/O886 may be, at least in part, remote from microcontroller 887, in network communication with microcontroller 887.

As shown in FIG. 14, a gas source 882 fluidly communicates gas 883 with the control group 893 of the control module 880 and a liquid source 884 fluidly communicates liquid 885 with the control group 893 of the control module 880. The control group 893 of the control module 880 is controlled by the microcontroller 887 and is operable to select whether the input fluid 846 is gas 883 from the gas source 882, or liquid 885 from the liquid source 884, or a combination of gas 883 from the gas source 882 and liquid 885 from the liquid source 884. An input fluid 846, controlled by a control group 893 of the control module 880, is directed into the enclosed space 817. The input fluid 886 may, for example, be equivalent to the

input fluids

78, 178.

In this embodiment, a control group 893 of the control module 840, controlled by the microcontroller 887, can use the valve 888, the pump 889, and the pressure sensor 891, operatively to control the flow of the input fluid 846 from the control module 880 to the enclosed space 817 of the wound interface 815, or to control the flow of the output fluid 848 from the enclosed space 817 of the wound interface 815 to the control module 880, or to control the discharge of at least a portion of the output fluid 848 into the ambient environment. Output fluid 848 may be, for example, identical to

output fluids

76, 176, 563.

By controlling the flow of input fluid 846 into enclosed space 817 and the flow of output fluid 848 from enclosed space 817, control module 880 may circulate pressure p within enclosed space 817₀E.g. in the pressure range p_min≤p₀≤p_max. The valve 888 may include one or more valves disposed on the control module 880 and operable, for example, to select the input fluid 846 from the gas 883 of the gas source 882 or the liquid 885 of the liquid source 884 to control the flow of the input fluid 846 from the control module 880 to the enclosed space 817 of the wound interface 815 and to control the output fluid 848 to be directed out of the enclosed space 817 of the wound interface 815 into the control module 880. The pressure sensor 891 may include at least one or more pressure sensors operable, for example, to monitor the gas 883, liquid 885, input fluid 846, output fluid 848, or pressure p at various locations within the enclosed space 817 of the wound interface 815₀The pressure of (a). The microcontroller 887 can alter the operation of the valve 888 or the pump 889 in response to a signal from the pressure sensor 891. The input fluid 846 may be circulated under pressure from the gas source 882 or liquid source 884, and the pump 889 may be used to deliver the output fluid 848 from the enclosed volume 817 to the reservoir 881 to prevent entry into the surrounding environment.

The wound treatment apparatus 800 may include a variety of fluid delivery devices, such as hoses, lines, valves, conduits, connectors, pressure regulators, and a variety of other fittings to communicate gas 883 and liquid 885 from gas source 882 and liquid source 884, respectively, to the control module 880 for communicating input fluid 846 and output fluid 848 between the enclosed space 817 of the wound interface 815 and the control module 880.

After the output fluid 848 is directed out of the enclosed volume 817 of the wound interface 815, exudate 819 or liquid, such as liquid 885, from the output fluid 848 flows through the reservoir 881 when returning to the control module 880, is captured from the output fluid 848 in the cavity 899 of the reservoir 881. As illustrated, the gaseous portion of output fluid 848, or the gas exhausted from cavity 899 of container 881 by capturing exudate or liquid within cavity 899, may then be exhausted from control module 880 to the ambient environment

In operation, a wound treatment device, such as

wound treatment device

10, 100, 200, 300, 400, 500, 600, 700, 800, 1000, is used to treat a wound bed, such as

wound bed

113, 113, 213, 313, 413, 7131013, within an enclosed space, such as

enclosed space

17, 117, 217, 317, 417, 517, 617, 717, 817, 1017, is fluid-tight, enclosing a wound bed on a skin surface. A wound interface, such as

wound interface

15, 115, 215, 315, 415, 515, 615, 715, 815, 1015 of a wound treatment apparatus is secured to a skin surface, such as

skin surface

11, 111, 211, 311, 411, 711, 811, 1011, surrounding a wound bed such that at least a portion of the wound bed proximate the skin surface is located within the enclosed space. A variety of adhesives may be applied to the skin surface around the wound bed to protect the skin surface or to secure portions of the wound treatment device to the skin surface. After fixation to the skin surface surrounding the wound bed, fluid may be expelled from the enclosed space through a port in fluid communication with the enclosed space, e.g.,

port

42, 142, 242, 342, 442, 542, 642, 742, 1003, and fluid may be input into the enclosed space through a port in fluid communication with the enclosed space or through a second port, e.g.,

port

44, 144, 244, to periodically vary the pressure p within the enclosed space₀In the pressure range p_min≤p₀≤p_maxVariations, in certain embodiments, p_maxMay be greater than ambient pressure p_ambMaximum pressure p_maxMay be approximately equal to ambient pressure p_ambOr maximum pressure p_maxMay be less than ambient pressure p_amb. Pressure range p during wound therapy_min≤p₀≤p_maxMay be changed.

Periodically changing pressure p in an enclosed space₀The wound bed may be alternately expanded into the enclosed space and released from the expanded state back to the baseline state to massage the wound bed and surrounding tissue, and the vascular system adjacent to the wound bed may be massaged, thereby increasing blood flow to the wound bed. The resulting surge of blood flow near the wound bed may promote healing of the wound bed. Massaging the wound bed may facilitate the distribution and drainage of exudate from the wound bed. It should be noted that when p is₀Becomes smaller than p_ambExpansion of the wound bed into the enclosed space typically does not begin immediately, but with pressure p₀Becomes sufficiently smaller than p_ambIt is started.

A control module, such as control module 880, may control the entry and exit of input fluid into and out of the enclosed space, which may include a liquid, a gas, or a mixture of liquid and gas. A variety of liquids, gases, and combinations of liquids and gases may be introduced into the enclosed space, and the liquids, gases, and mixtures of liquids and gases may be varied during wound treatment.

A pad, such as

pad

50, 150, 450, 550, 650, may be disposed within the enclosed space to absorb exudate from the wound bed. Periodically changing pressure p₀Accordingly, the wound bed may be expanded into the enclosed space from the baseline state to the expanded state and released from the expanded state back to the baseline state, whereby the wound bed may be alternately brought into contact with the pad, exudate from the wound bed transferred into the pad, and the wound bed and pad are disconnected from contact to prevent the pad and the wound bed from sticking together. When pressure p is₀In periodic variation, multiple gaseous fluids may be input through the port or the second portEnclosed space or derived from enclosed space. Exudate may be drained from the enclosed space through a port in fluid communication with the pad. The exudate may be captured in a container of the control module, such as container 881.

The wound bed in the enclosed space may be viewed through a cover, such as

cover

40, 140, 240, 340, 440, which may be at least partially formed of a transparent material. Windows, such as

windows

139a, 139b, 139c, 139d, may be provided on the wound therapy device to allow viewing of the wound bed within the enclosed space. In certain embodiments, the cover may be in an open position, such as open position 46, and a closed position, such as closed position 48, to respectively allow direct access to, or seal closed, an enclosed space including a wound bed.

The dressing may be omitted from the wound bed at least during part of the healing process. The absence of a dressing in constant contact with the wound bed may allow the wound treatment apparatus to be used throughout, and even until the final stage of healing of the wound bed, may allow the wound bed to be viewed through the wound interface. During the healing process, a portion of the wound treatment device, such as the pad, may be replaced, or the entire wound treatment device replaced, as desired. The wound therapy device is removed after the wound bed has healed.

Fig. 15 provides an exemplary method 1500 of use of the wound treatment apparatus disclosed herein. At step 1501, method 1500 begins. At step 1505, the wound interface is secured to the skin, thereby closing the wound bed through the enclosed space.

At step 1510, fluid is directed out of the enclosed space, thereby inflating the wound bed into communication with a pad disposed within the enclosed space. Exudate may be conducted from the wound bed into the pad. Pressure decrease p₀-＞p_minThe capillaries close to the wound bed are in an expanded state.

At step 1515, exudate is directed out of the pad through the port. A periodic negative pressure may be applied to draw exudate from the pad.

At step 1520, fluid is introduced into the enclosed space to increase the pressure p₀-＞p_maxThereby retracting the wound bed from the enclosed spaceOut of communication with the pad. The fluid input in step 1520 may be a liquid or a gas, and if a gas, may have an oxygen concentration greater than atmospheric air (greater than 20.95% by volume).

At step 1525,

steps

1510, 1515, 1520 are repeated, thereby massaging the wound bed.

Steps

1510, 1515, 1520 may be repeated for a period of time, such as about 5 minutes or about 6 minutes. Exemplary method 1500 terminates at step 1529.

Thus, a method of using a wound therapy device may comprise the steps of: sealingly securing a wound interface to the skin surface along the periphery of the wound bed to form a fluid-tight enclosure and enclosing the wound bed against the skin surface, wherein the wound interface has sufficient resistance to deformation to maintain the enclosure when a pressure p within the enclosure is present₀Sufficiently below ambient pressure p_ambAt least a portion of the contained wound bed expands into the enclosed space. The use method can comprise the following steps: absorbing exudate from the wound bed using a pad disposed within the enclosed space, and directing the exudate from the pad via a port disposed at the wound interface. The use method can comprise the following steps: alternately, fluid (gas or liquid) is input into the enclosed space through the port and then removed through the port. The use method can comprise the following steps: fluid (gas or liquid) is input into the enclosed space through the port and liquid is output through the second port. The use method can comprise the following steps: varying the pressure p in the enclosed space₀So that at least a portion of the wound bed is sufficiently rhythmically expanded into the closed space cavity, which can produce surging blood flow and micro-deformation of the wound bed, beneficial to healing. The use method can comprise the following steps: the wound bed is inflated into communication with the pad for removing exudate from the wound bed, and then the wound bed is disconnected from communication with the pad. The use method can comprise the following steps: the wound interface is sealingly conformably secured to the skin surface surrounding the wound bed using an annular cushion biased to follow the skin surface surrounding the wound. The use method can comprise the following steps: the wound interface is sealingly conformably secured to the skin surface surrounding the wound bed using an apron disposed over the wound interface. Use ofThe method may comprise the steps of: the cover portion of the wound interface is positioned between the sealed position and the open position, thereby allowing direct intervention into the enclosed space. The use method can comprise the following steps: the wound bed was observed through the transparent portion of the wound interface. The use method can comprise the following steps: the use or non-use of a pad or dressing associated with the wound bed is selected. The use method can comprise the following steps: will be the pressure p in the enclosed space₀Evenly distributed over the wound bed, thereby reducing uneven pressure gradients that may lead to reduced blood flow near the wound boundary. The use method can comprise the following steps: a range of other therapies (including various liquids and gases) and incubation of biological materials, such as tissue matrix or skin grafts, are delivered over a range of pressures from positive to negative pressure. The use method can comprise the following steps: the wound treatment device is used in a number of possible ways in human or veterinary applications for the following situations: acute and chronic wounds, prevention of surgical site infection and increased rates of chemotherapy response.

Although the foregoing discussion has focused on wound care, the wound treatment devices disclosed herein may have beneficial applications in other areas of human and veterinary medicine. For example, in chemotherapy for cancer treatment, many drugs are not selective enough to kill only tumor cells. However, by selectively increasing the metabolism of tumor cells, higher kill rates can be achieved during the use of chemotherapy. An effective way to increase metabolic rate is to raise body temperature, but raising body temperature throughout the body is not feasible and harmful, similar to fever. However, at least for the treatment of tumors on opposite surfaces, such as skin and breast cancers, it is entirely feasible to place a wound interface of appropriate shape and size at the tumor site, with chemotherapy, injecting very warm fluids (e.g., 42℃. or 107F.), much higher than the temperature at which clinical fever is highest. When the chemotherapeutic drug is circulating, the kill rate should be higher for tumors that have been subjected to such localized hyperthermia.

The foregoing discussion discloses and describes various exemplary applications in connection with the accompanying drawings. These applications are not intended to limit the scope of coverage, but, rather, to assist in understanding the context of the language used in the specification and claims. Having studied the disclosure and the illustrative applications herein, one of ordinary skill in the art will readily recognize various changes, modifications and variations which may be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. A wound treatment apparatus comprising:

a wound interface sealably secured to a skin surface surrounding a wound bed to form a fluid-tight enclosure over the wound bed;

a void formed by a portion of a base of the wound interface bifurcating into a distal side and a proximal side, at least a portion of the wound interface being substantially rigid, the void being located between the distal side and the proximal side, the distal side interposed between the void and the enclosed space to separate the void from the enclosed space;

a pad for absorbing exudate from the wound bed, the pad contained within the void;

a plurality of channels configured distally to communicate fluid between the enclosed space and the void;

a port disposed on the wound interface in fluid communication with the void; and

wherein the wound treatment device is responsive to pressure within the enclosed spacep ₀Displacing the wound bed proximally less than ambient pressure.

2. The device of claim 1, wherein the plurality of channels are formed as distal holes.

3. The device of claim 2, wherein the pad comprises a material selected from the group consisting of: polyvinyl alcohol, polyurethane, aliphatic polyamide fibers, semi-aromatic polyamide fibers, or polyester fibers.

4. The apparatus of claim 1, further comprising:

fluid communication with the enclosed space through the port to cause pressure within the enclosed space(p ₀ )At a minimum pressure of (p _min )And maximum pressure (p _max )Periodically changing in between.

5. The device of claim 1, wherein the fluid in communication with the enclosed space through the port comprises a gas having an oxygen concentration greater than atmospheric air.

6. A wound treatment apparatus comprising:

a wound interface sealably secured to a skin surface surrounding a wound bed to form a fluid-tight enclosure over the wound bed, a portion of the wound interface forming the enclosure having a substantially rigid structure throughout;

a port disposed on the wound interface in fluid communication with the enclosed space to provide a minimum pressure (fp _min )And maximum pressure (p _max )To change the pressure in said enclosed space(p ₀ )A pad contained within the enclosed space for absorbing exudate from the wound bed, a distal most portion of the pad always being proximal to the skin surface when the wound interface is sealingly secured to the skin surface; and

a position of the pad within the enclosed space, the position being adapted to be under pressure(p ₀ )At a minimum pressure of (p _min )While the pad is in contact with the wound bed and under pressure(p ₀ )At a maximum pressure of (p _max )While the pad is out of contact with the wound bed.

7. The apparatus of claim 6, wherein the maximum pressure (Vp _max )Approximately equal to ambient pressure (p _amb )。

8. The device of claim 6, wherein the port is in at least intermittent biased contact with the pad for conducting exudate away from the pad.

9. The device of claim 6, wherein the pad comprises more hydrophobic fibers than hydrophilic fibers on a distal surface of the pad to transfer exudate from the wound bed and more hydrophilic fibers than hydrophobic fibers on an interior of the pad to transfer exudate from the distal surface to the port through the pad.

10. The device of claim 6, wherein the pad comprises a material selected from the group consisting of: polyvinyl alcohol, polyurethane, aliphatic polyamide fiber, semi-aromatic polyamide fiber, or polyester fiber.

11. The apparatus of claim 6, further comprising:

a void formed within the wound interface by a portion of the base of the wound interface diverging into a distal side and a proximal side, at least a portion of the wound interface being substantially rigid, the void being interposed distally between the void and the enclosed space to separate the void from the enclosed space, wherein the void is located between the distal side and the proximal side;

a pad received within the void, wherein a distal surface of the pad is distally enclosed; and

a plurality of channels configured through the distal end for fluid communication between the enclosed space and the void.

12. The apparatus of claim 6, wherein the pad is replaceably received within the wound interface.

13. The apparatus of claim 6, wherein the wound interface further comprises:

a lid positionable between a sealing engagement position and an open engagement position, the open engagement position allowing direct access to the enclosed space.

14. The apparatus of claim 6, wherein the wound bed is visible through a transparent portion of the wound interface.

15. The apparatus of claim 6, the wound interface further comprising:

a cushion forming a closed annular perimeter, the cushion comprising an inflatable bladder or closed cell foam, the cushion being adhesively and sealingly securable to the skin surface to sealingly secure the wound interface to the skin surface.

16. The apparatus of claim 6, the wound interface further comprising:

a skirt extending radially forward from portions of the wound interface defining the enclosed space to form a closed perimeter for conformably and sealingly securing the wound interface to the skin surface.

17. The apparatus of claim 6, the wound interface further comprising:

a flange disposed distal to the wound interface outer surface to seal and conformably secure the wound interface to the skin surface, the flange operable to pressurize (a) the enclosed spacep ₀ )The resulting force is distributed to the skin surface.

18. The apparatus of claim 6, wherein the wound interface is sealingly securable to a skin surface of an oval or elongated shaped area along the wound boundary of the wound bed.

19. The apparatus of claim 6, wherein the first and second electrodes are disposed on opposite sides of the substrate,

wherein the minimum pressure (p) is selected_min) To increase capillary blood flow above baseline.

20. The apparatus of claim 6, wherein the first and second electrodes are disposed on opposite sides of the substrate,

wherein the selection is at a minimum pressure (p _min )And maximum pressure (p _max )The pressure in the enclosed space between (a), (b), (c), (d) and (d)p ₀ ) To promote oxygenation of the wound bed.

21. A wound treatment apparatus comprising:

a wound interface sealingly secured to a skin surface surrounding a wound bed, wherein a portion of the wound interface forms a fluid-tight enclosed space above the wound bed, the wound interface portion having a rigid structure;

a port disposed on the wound interface in fluid communication with the enclosed space for a minimum pressure (f) over a period of timep _min )And maximum pressure (a)p _max )To change the pressure in said enclosed space(p ₀ );

A pad contained within the enclosed space for absorbing exudate from the wound bed; and

the position of the pad in the enclosed space, said position being adapted to follow pressure(p ₀ )At a minimum pressure of (p _min )And maximum pressure (p _max )To vary the degree of contact or release of the pad with the wound bed, the most distal portion of the pad being adjacent the skin surface.

22. The wound treatment apparatus of claim 21, wherein the time period is less than or equal to 6 minutes.

23. The wound treatment apparatus of claim 21, the maximum pressure (max pressure: (max pressure))p _max )Greater than ambient pressure (p _amb )。