U.S. patent application number 16/242825 was filed with the patent office on 2019-05-16 for anisotropic drapes and systems.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Royce W. JOHNSON, Richard Marvin KAZALA, JR., Justin Alexander LONG, Robert Peyton WILKES.
Application Number | 20190142643 16/242825 |
Document ID | / |
Family ID | 40809887 |
Filed Date | 2019-05-16 |
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United States Patent
Application |
20190142643 |
Kind Code |
A1 |
KAZALA, JR.; Richard Marvin ;
et al. |
May 16, 2019 |
Anisotropic Drapes And Systems
Abstract
An anisotropic wound drape for treating a wound on a patient
includes a flexible sheet for placing over a tissue site. The
flexible sheet includes a first isotropic zone, and a second
isotropic zone. The first isotropic zone and the second isotropic
zone are configured to provide the flexible sheet with anisotropic
stretching properties. The anisotropic drape may used as part of a
reduced-pressure wound treatment system. Other systems and methods
are also presented.
Inventors: |
KAZALA, JR.; Richard Marvin;
(San Antonio, TX) ; LONG; Justin Alexander;
(Bournemouth, GB) ; WILKES; Robert Peyton; (San
Antonio, TX) ; JOHNSON; Royce W.; (Green Cove
Springs, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
40809887 |
Appl. No.: |
16/242825 |
Filed: |
January 8, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14867933 |
Sep 28, 2015 |
10226384 |
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16242825 |
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13437898 |
Apr 2, 2012 |
9173788 |
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14867933 |
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12475231 |
May 29, 2009 |
8172816 |
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13437898 |
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61144067 |
Jan 12, 2009 |
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61121362 |
Dec 10, 2008 |
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61057797 |
May 30, 2008 |
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61057798 |
May 30, 2008 |
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61057800 |
May 30, 2008 |
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61057802 |
May 30, 2008 |
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61057803 |
May 30, 2008 |
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61057805 |
May 30, 2008 |
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61057807 |
May 30, 2008 |
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61057808 |
May 30, 2008 |
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61057810 |
May 30, 2008 |
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Current U.S.
Class: |
602/43 ;
604/543 |
Current CPC
Class: |
A61F 13/00029 20130101;
A61F 13/00038 20130101; A61M 2210/1021 20130101; A61F 13/00059
20130101; A61F 2013/0028 20130101; A61F 13/00017 20130101; A61F
13/00068 20130101; A61F 2013/00174 20130101; H05K 999/99 20130101;
A61F 13/00034 20130101; A61F 13/0243 20130101; A61F 2013/0054
20130101; A61F 2013/00748 20130101; A61F 2013/00131 20130101; A61F
13/00 20130101; A61F 13/0209 20130101; A61F 2013/00136 20130101;
A61F 13/0289 20130101; A61L 15/60 20130101; Y10T 29/49 20150115;
A61F 2013/00182 20130101; A61M 1/0023 20130101; A61M 2210/1007
20130101; Y10T 29/49826 20150115; A61H 1/008 20130101; A61F 13/0223
20130101; A61M 2205/70 20130101; A61F 2013/00536 20130101; A61M
1/0088 20130101; A61M 2207/00 20130101; A61F 13/022 20130101; A61F
2013/00246 20130101; A61F 13/0216 20130101; A61F 15/008
20130101 |
International
Class: |
A61F 13/00 20060101
A61F013/00; A61F 13/02 20060101 A61F013/02; A61H 1/00 20060101
A61H001/00; A61L 15/60 20060101 A61L015/60; A61M 1/00 20060101
A61M001/00; A61F 15/00 20060101 A61F015/00 |
Claims
1.-29. (canceled)
30. A wound drape comprising: a flexible sheet; and an anisotropic
member coupled to the flexible sheet and configured to provide the
flexible sheet with anisotropic stretching properties such that the
flexible sheet stretches more in a first direction than in a second
direction.
31. The wound drape of claim 30 wherein the anisotropic member
comprises a plurality of filaments.
32. The wound drape of claim 30 wherein the anisotropic member
comprises a plurality of filaments and wherein said plurality of
filaments are substantially parallel to one another.
33. The wound drape of claim 30 wherein the anisotropic member is
an adhesive layer.
34. A wound drape comprising: a flexible sheet; and a fluidly
inflatable bladder coupled to the flexible sheet and configured to
provide the flexible sheet with anisotropic stretching properties
such that the flexible sheet stretches more in a first direction
than in a second direction.
35. The wound drape of claim 34 wherein the fluidly inflatable
bladder is substantially co-planar with the flexible sheet when
uninflated.
36. The wound drape of claim 34 further comprising: a fluid supply
tube fluidly coupled at a first end to the bladder; and a fluid
control means fluidly coupled to a second end of the fluid supply
tube, the fluid control means for selectively applying fluid to the
bladder.
37. The wound drape of claim 34 wherein the bladder is capable of
providing a compressive force to a patient's tissue.
38.-47. (canceled)
48. A wound drape comprising: a flexible sheet having an inner
portion and an edge, the thickness of the flexible sheet gradually
changes from the inner portion to the edge to provide the flexible
sheet with anisotropic stretching properties such that the flexible
sheet stretches more in a first direction than in a second
direction; and an adhesive coupled to the flexible sheet, wherein
the adhesive is operable to couple the wound drape to a patient's
epidermis.
49. The wound drape of claim 48, wherein the flexible sheet is
comprised of a liquid-impermeable elastomeric material.
50. The wound drape of claim 48, further comprising a manifold
coupled to the flexible sheet, the manifold configured to
distribute a reduced pressure to a tissue site on the patient.
51. The wound drape of claim 50, wherein the manifold is coupled to
the flexible sheet using adhesives.
52. The wound drape of claim 50, wherein the manifold is coupled to
the flexible sheet by bonding the manifold to the flexible
sheet.
53. The wound drape of claim 48, further comprising a
reduced-pressure interface.
54. The wound drape of claim 48, wherein the flexible sheet forms a
frustoconical-shaped cavity.
55. The wound drape of claim 48, wherein the inner portion is the
substantial center of the wound drape.
56. The wound drape of claim 48, wherein the modulus of elasticity
of the flexible sheet gradually changes from the inner portion to
the edge.
57. The wound drape of claim 48, wherein the thickness of the
flexible sheet gradually increases from the inner portion to the
edge such that the edge is thicker than the inner portion.
58. The wound drape of claim 48, wherein the thickness of the
flexible sheet gradually decreases from the inner portion to the
edge such that the edge is thinner than the inner portion.
59. The wound drape of claim 48, wherein the adhesive is configured
to transmit a closing force generated by the wound drape to the
patient's epidermis.
60. The wound drape of claim 48, wherein the wound drape and the
adhesive are configured to form a fluid seal over a tissue site on
the patient.
61. The wound drape of claim 60, wherein the fluid seal is adapted
to hold reduced pressure at the tissue site.
62. The wound drape of claim 48, wherein the flexible sheet is
adapted to be coupled to a reduced-pressure source for treating a
tissue site on the patient with reduced pressure.
63. The wound drape of claim 48, wherein the flexible sheet is
comprised of transparent material.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/867,933, entitled "Anisotropic Drapes and Systems,"
filed Sep. 28, 2015, which is a divisional of U.S. patent
application Ser. No. 13/437,898, entitled "Anisotropic Drapes and
Systems," filed Apr. 2, 2012, now U.S. Pat. No. 9,173,788, which is
a divisional of U.S. patent application Ser. No. 12/475,231,
entitled "Anisotropic Drapes and Systems," filed May 29, 2009, now
U.S. Pat. No. 8,172,816, which claims the benefit, under 35 USC
.sctn. 119(e), of the filing of U.S. Provisional Patent Application
Ser. No. 61/057,807, entitled "Reduced-pressure Surgical Wound
Treatment System," filed May 30, 2008; U.S. Provisional Patent
Application Ser. No. 61/057,798, entitled "Dressing Assembly For
Subcutaneous Wound treatment Using Reduce Pressure," filed May 30,
2008; U.S. Provisional Patent Application Ser. No. 61/057,808,
entitled "See-Through, Reduced-Pressure Dressing," filed May 30,
2008; U.S. Provisional Patent Application Ser. No. 61/057,802,
entitled "Reduced-Pressure Dressing Assembly For Use in Applying a
Closing Force," filed May 30, 2008; U.S. Provisional Patent
Application Ser. No. 61/057, 803, entitled "Reduced-Pressure,
Linear-Wound Treatment System," filed May 30, 2008; U.S.
Provisional Patent Application Ser. No. 61/057,800, entitled
"Reduced-Pressure, Compression System and Apparatus for use on a
Curved Body Part," filed, May 30, 2008; U.S. Provisional Patent
Application Ser. No. 61/057,797, entitled "Reduced-Pressure,
Compression System and Apparatus for use on Breast Tissue," filed
May 30, 2008; U.S. Provisional Patent Application Ser. No.
61/057,805, entitled "Super-Absorbent, Reduced-Pressure Wound
Dressing and System," filed May 30, 2008; U.S. Provisional Patent
Application Ser. No. 61/057,810, entitled "Reduced-Pressure,
Compression System and Apparatus for use on a Joint," filed May 30,
2008; U.S. Provisional Patent Application Ser. No. 61/121,362,
entitled "Reduced-Pressure Wound treatment System Employing an
Anisotropic Drape," filed Dec. 10, 2008; and U.S. Provisional
Patent Application Ser. No. 61/144,067, entitled "Reduced-Pressure,
Compression System and Apparatus for use on a Joint," filed Jan.
12, 2009. Each of the applications set forth above are incorporated
herein by reference for all purposes.
BACKGROUND
[0002] The present invention relates generally to medical treatment
systems, and more particularly, to anisotropic drapes and
reduced-pressure wound treatment systems and methods employing
anisotropic drapes.
[0003] Vapor and oxygen permeable isotropic film dressings,
frequently called drapes, may be used to cover wounds, or damaged
areas of tissue, to facilitate healing and prevent infection. The
elasticity of these isotropic drapes is substantially uniform. This
can be a problem, however, if one would like to regulate
translation or approximation of tissue, such as dermal tissue or
subdermal tissue, at a specific rate in one direction and at
another rate in another direction. Improper regulation of tissue
translation may involve negative side-effects, including, but not
limited to, blisters, hyper-pigmentation, as well as many other
skin complications and irritations. Other shortcomings may exist as
well.
BRIEF SUMMARY
[0004] Shortcomings with wound care systems and methods are
addressed by the illustrative embodiments as shown and described.
According to one illustrative embodiment, a reduced-pressure wound
treatment system for treating a tissue site on a patient includes a
wound drape that has a flexible sheet with a first isotropic zone
and a second isotropic zone. The first isotropic zone and the
second isotropic zone are configured to provide the flexible sheet
with anisotropic stretching properties. The system also includes a
manifold for disposing between the wound drape and the tissue site
and a reduced-pressure subsystem for delivering a reduced pressure
to the manifold.
[0005] According to another illustrative embodiment, a wound drape
includes a flexible sheet for placing over a tissue site. The
flexible sheet has a first isotropic zone and a second isotropic
zone. The first isotropic zone and the second isotropic zone are
configured to provide the flexible sheet with anisotropic
stretching properties.
[0006] According to another illustrative embodiment, a wound drape
includes a flexible sheet and an anisotropic member coupled to the
flexible sheet. The flexible sheet and anisotropic member are
configured to provide the flexible sheet with anisotropic
stretching properties such that the flexible sheet stretches more
in a first direction than in a second direction.
[0007] According to another illustrative embodiment, a wound drape
includes a flexible sheet and a fluidly inflatable bladder coupled
to the flexible sheet. The flexible sheet and fluidly inflatable
bladder are configured to provide the flexible sheet with
anisotropic stretching properties such that the flexible sheet
stretches more in a first direction than in a second direction. The
inflatable bladder may take numerous forms. The wound drape may
provide a closing force.
[0008] According to another illustrative embodiment, a method for
treating a tissue site on a patient with reduced pressure includes
disposing a manifold proximate the tissue site, disposing an
anisotropic wound drape over the manifold, sealing the anisotropic
drape to the patient's epidermis, and fluidly coupling a
reduced-pressure source to the manifold. The anisotropic drape
includes at least a first isotropic zone and a second isotropic
zone such that the anisotropic drape stretches more in a first
direction than a second direction.
[0009] According to another illustrative embodiment, a method of
manufacturing a wound drape includes the step of forming a flexible
sheet for placing over a tissue site with a first isotropic zone
and a second isotropic zone. The first isotropic zone and the
second isotropic zone are configured to provide the flexible sheet
with anisotropic stretching properties.
[0010] Other features and advantages of the illustrative
embodiments will become apparent with reference to the drawings and
detailed description that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A more complete understanding of the present invention may
be obtained by reference to the following Detailed Description when
taken in conjunction with the accompanying Drawings wherein:
[0012] FIG. 1 is a schematic, perspective view with a portion shown
in cross-section of an illustrative embodiment of a
reduced-pressure wound treatment system;
[0013] FIG. 2 is a schematic, cross-sectional view of a portion of
the reduced-pressure wound treatment system of FIG. 1;
[0014] FIG. 3A is a schematic, cross-sectional view of a first
isotropic zone and a second isotropic zone of an illustrative
embodiment of a wound drape;
[0015] FIG. 3B is a schematic, cross-sectional view of a first
isotropic zone of another illustrative embodiment of a wound
drape;
[0016] FIG. 4A is a schematic, top view of an illustrative
embodiment of a portion of a reduced-pressure wound treatment
system;
[0017] FIG. 4B is a schematic, cross-sectional view of the
reduced-pressure wound treatment system of FIG. 4A taken along line
4B-4B in FIG. 4A;
[0018] FIG. 5A is a schematic, top view of an illustrative
embodiment of a portion of a reduced-pressure wound treatment
system;
[0019] FIG. 5B is a schematic, cross-sectional view of the
reduced-pressure wound treatment system of FIG. 5A taken along line
5B-5B in FIG. 5A;
[0020] FIG. 6A is a schematic, top view of an illustrative
embodiment of a portion of a reduced-pressure wound treatment
system;
[0021] FIG. 6B is a schematic, cross-sectional view of the
reduced-pressure wound treatment system of FIG. 6A taken along line
6B-6B in FIG. 6A;
[0022] FIG. 7A is a schematic, top view of an illustrative
embodiment of a reduced-pressure wound treatment system; and
[0023] FIG. 7B is a schematic, cross-sectional view of the
reduced-pressure wound treatment system of FIG. 7A taken along line
7B-7B in FIG. 7A.
DETAILED DESCRIPTION
[0024] In the following detailed description of the illustrative
embodiments, reference is made to the accompanying drawings that
form a part hereof, and in which is shown, by way of illustration,
specific embodiments in which the invention may be practiced. These
embodiments are described in sufficient detail to enable those
skilled in the art to practice the invention, and it is understood
that other embodiments may be utilized and that logical structural,
mechanical, electrical, and chemical changes may be made without
departing from the spirit or scope of the invention. To avoid
detail not necessary to enable those skilled in the art to practice
the invention, the description may omit certain information known
to those skilled in the art. The following detailed description is
not to be taken in a limiting sense, and the scope of the present
invention is defined only by the appended claims.
[0025] Referring now to FIGS. 1-3B, a reduced-pressure treatment
system 100 for treating a tissue site, e.g. incision 102, is
presented. The reduced-pressure treatment system 100 is presented
in the context of a general tissue site that includes an incision
102 and an undermined subcutaneous tissue site 110, but it will be
appreciated that the reduced-pressure treatment system 100 may be
used to treat many different types of wounds including open wounds
or other tissue sites. The tissue site may be the bodily tissue of
any human, animal, or other organism, including bone tissue,
adipose tissue, muscle tissue, dermal tissue, vascular tissue,
connective tissue, cartilage, tendons, ligaments, or any other
tissue.
[0026] The reduced-pressure treatment system 100 is shown in a
peri-incisional region around incision 102, which is through
epidermis 104, or skin, and dermis 106 and reaching into
hypodermis, or subcutaneous tissue 108. The subcutaneous tissue 108
may include numerous tissue types such as fatty tissue or muscle.
An undermined subcutaneous tissue site 110 is shown extending out
from incision 102 and includes, in this instance, subcutaneous
defect or void 112. The undermined subcutaneous tissue 110 is often
caused by surgical procedures, such as liposuction. The undermined
subcutaneous tissue 110 may include voids, such as void 112, open
spaces, and various defects that can be troublesome for a number of
reasons, such as allowing fluids to build that may result in edema.
The term "fluid" as used herein generally refers to gas or liquid,
but may also include any other flowable material, including but not
limited to gels, colloids, and foams.
[0027] The incision 102 may be closed using any mechanical closing
means such as staples, sutures, or adhesive, but is shown in this
illustrative embodiment with a suture 114. The illustrative
embodiment shows the reduced-pressure treatment system 100 in use
in a peri-incisional region. It will be appreciated that the
reduced-pressure treatment system 100 may be used to treat
undermined subcutaneous tissue 110 where there is no corresponding
incision or any other kind of tissue site.
[0028] The reduced-pressure treatment system 100 generally includes
a drape, or wound drape 116, a manifold 120, and a reduced-pressure
subsystem 122. The reduced-pressure treatment system 100 may also
include gripping member 118. The wound drape 116 is generally
formed from a sheet, or flexible sheet 123, and includes one or
more first isotropic zones 124 and one or more second isotropic
zones 126. Each zone is typically a region, or area, that makes up
at least one half percent of the wound drape 116. The first and
second isotropic zones 124, 126 are configured to provide the
flexible sheet 123 with anisotropic properties. As such, the
flexible sheet 123 may help the wound drape 116 primarily stretch
in a given direction. Stated another way, the flexible sheet 123
can stretch more along one direction than along another, different
direction. As used herein, stretching may include elastic and
inelastic deformation. These anisotropic properties may be
accomplished in a variety of ways, and several illustrative
embodiments will be discussed further below beginning with the use
of different thicknesses.
[0029] In the illustrative embodiment of FIGS. 1-3B, the first
isotropic zones 124 have a first thickness (t.sub.1) of drape
material and the second isotropic zones 126 have a second thickness
(t.sub.2) of drape material, and the thickness of each first
isotropic zone 124 is greater than the thickness of each second
isotropic zone 126 (t.sub.1>t.sub.2). Because the thickness
(t.sub.1) of each first isotropic zone 124 is greater than the
thickness (t.sub.2) of each second isotropic zone 126, the flexible
sheet 123 is provided with anisotropic properties whereby the
flexible sheet 123 stretches more in the direction of a first (x)
axis 128 than in the direction of a second (y) axis 130 under equal
force in the direction of each axis. In one illustrative
embodiment, the first thickness (t.sub.1) is greater than or equal
to one hundred five percent (105%) of the second thickness
(t.sub.2), i.e., t.sub.1.gtoreq.105% t.sub.2. In another
illustrative embodiment, the first thickness (t.sub.1) is greater
than or equal to one hundred ten percent (110%) of the second
thickness (t.sub.2), i.e., t.sub.1.gtoreq.110% t.sub.2. Other
relationships between the first thickness (t.sub.1) and the second
thickness (t.sub.2) are possible.
[0030] Indeed, by selecting appropriate thicknesses, a user may
selectively control the rate or force with which the flexible sheet
123 attempts to return to its original size after it is stretched
and adhered to a patient. Thus, the rate of the translation and/or
approximation of tissue may be regulated. Regulating the
translation and/or approximation of tissue may serve to minimize
skin complications, such as blisters, hyper-pigmentation, etc., as
well as to assist in closing the incision 102. Additionally, the
thicker first isotropic zones 124 may be capable of providing a
compressive force that may be realized in the subcutaneous tissue
108 and may be beneficial in treating the undermined subcutaneous
tissue 110 and eliminating voids 112 or the like. As shown in FIG.
2, the first isotropic zones 124 may project inwardly from a
skin-facing surface 132. As shown in FIG. 3A, the first isotropic
zones 124 may project outwardly from a first surface 134 of the
flexible sheet 123. As shown in FIG. 3B, the first isotropic zones
124 may project from both of the skin-facing surface 132 and first
surface 134. It will be appreciated that any number of isotropic
zones may be employed as part of flexible sheet 123. Moreover,
while the isotropic zones 124, 126 are shown as substantially
parallel with one another, it will be appreciated that the zones
124, 126 may be arranged with different orientations with respect
to one another. While two thicknesses (t.sub.1 and t.sub.2) are
shown for two zones 124, 126, it should be understood that many
zones having varying thicknesses may be used to achieve the
anisotropic properties.
[0031] The wound drape 116 may be sized so that it overlaps the
incision 102 and/or undermined subcutaneous tissue 110 in such a
manner that a drape extension 136 extends beyond the periphery of
the incision 102 and/or undermined subcutaneous tissue 110. The
wound drape 116 may be formed from any suitable material, such as
an impermeable or semi-permeable elastomeric material.
"Elastomeric" means having the properties of an elastomer and
generally refers to a polymeric material that has rubber-like
properties. More specifically, most elastomers have elongation
rates greater than 100% and a significant amount of resilience. The
resilience of a material refers to the material's ability to
recover from an elastic deformation. Examples of elastomers may
include, but are not limited to, natural rubbers, polyisoprene,
styrene butadiene rubber, chloroprene rubber, polybutadiene,
nitrile rubber, butyl rubber, ethylene propylene rubber, ethylene
propylene diene monomer, chlorosulfonated polyethylene, polysulfide
rubber, polyurethane, EVA film, co-polyester, and silicones.
Sealing drape materials may include a silicone material, 3M
Tegaderm.RTM. drape material, acrylic drape material such as one
available from Avery Dennison Corporation of Pasadena, Calif., or
an incise drape material. However, it will be appreciated that the
wound drape 116 may be formed from any suitable material. In
addition, the first and second isotropic zones 124, 126 may be
formed from the same drape material or from different drape
materials. The isotropic zones 124, 126 may be formed via a
co-extrusion process, a molding process, or any other suitable
forming process. The varying thicknesses may be achieved by
coupling two or more portions of drape material that are not
co-extensive. Optionally, the drape material may also include one
or more suitable bioactive elements, including, but not limited to,
antimicrobial compounds or any other suitable bioactive
element(s).
[0032] The gripping member 118 may be coupled to the wound drape
116. The gripping member 118 is operable to couple the wound drape
116 to a patient's epidermis 104. Also, the gripping member 118 may
also be operable to transmit a closing force generated by drape 116
as the drape 116 attempts to return to the drape's 116 original
size after being stretched and adhered to a patient (the
transmitted force is illustrated as force vectors 138 in FIG. 2).
Additionally, the wound drape 116 and gripping member 118 work
together to form a fluid seal over the patient's epidermis 104.
"Fluid seal," or "seal," means a seal adequate to hold reduced
pressure at the desired site given the particular reduced-pressure
subsystem involved. The gripping member 118 may be any material
suitable for coupling the drape 116 to a patient's epidermis 104,
transmitting a closing force to the patient's epidermis 104, and/or
assist in forming a fluid seal over the patient's epidermis 104.
For example, the gripping member 118 may be a pressure-sensitive
adhesive, heat-activated adhesive, sealing tape, double-sided
sealing tape, paste, hydrocolloid, hydrogel, hooks, sutures,
etc.
[0033] In the illustrative embodiment, the gripping member 118 is
an adhesive layer coupled to the skin-facing surface of the drape
extension 136; however, it will be appreciated that gripping member
118 may span the entire width of the drape 116. Alternatively, the
gripping member 118 may be applied to only a selected portion of
the wound drape 116, such as the first or second isotropic zones
124, 126. The gripping member 118 may be formed as a layer or a
pattern distributed on the wound drape 116. Alternatively, in the
case of sealing tape, the gripping member 118 may be applied over
the entire first surface 134 of the wound drape 116 or over the
first surface of the drape extension 136.
[0034] The manifold 120 is positionable between the skin-facing
surface 132 of the wound drape 116 and the tissue site, e.g.,
incision 102, within a wound bed, or over an intact portion of the
epidermis 104. The term "manifold" as used herein generally refers
to a substance or structure that is provided to assist in applying
reduced pressure to, delivering fluids to, or removing fluids from
a tissue site, e.g., incision 102. The manifold 120 may be made of
many different materials.
[0035] In one illustrative embodiment, the manifold 120 is made
from a porous and permeable foam-like material and, more
particularly, a reticulated, open-cell polyurethane or polyether
foam that allows good permeability of wound fluids while under a
reduced pressure. One such foam material that may be used is the
V.A.C..RTM. GranuFoam.RTM. material available from Kinetic
Concepts, Inc. (KCI) of San Antonio, Tex. Any material or
combination of materials may be used for the manifold material
provided that the manifold material is operable to distribute the
reduced pressure. The manifold 120 typically includes a plurality
of flow channels or pathways that distribute fluids provided to and
removed from the area of tissue around the manifold 120. The flow
channels may be interconnected. Examples of manifolds may include,
without limitation, devices that have structural elements arranged
to form flow channels, cellular foam, such as open-cell foams,
textiles, porous tissue collections, and liquids, gels, and foams
that include, or cure to include, flow channels. The manifold
material may also be a combination or layering of materials. For
example, a first manifold layer of hydrophilic foam may be disposed
adjacent to a second manifold layer of hydrophobic foam to form the
manifold material.
[0036] The reticulated pores of the GranuFoam.RTM. material, that
are in the range from about 400 to 600 microns, are helpful in
carrying out the manifold function, but other materials may be
used. The manifold material may be a reticulated foam that is later
felted to a thickness of about 1/3 of the manifold material's
original thickness. Among the many possible materials, the
following may be used: GranuFoam.RTM. material or a Foamex.RTM.
technical foam (www.foamex.com). In some instances it may be
desirable to add ionic silver to the foam in a microbonding process
or to add other substances to the manifold material such as
antimicrobial agents. The manifold material may be isotropic or
anisotropic. In addition, the manifold material may be a
bio-absorbable or bio-includable material.
[0037] The manifold 120 may be coupled to the wound drape 116. As
used herein, the term "coupled" includes coupling via a separate
object and includes direct coupling. The term "coupled" also
encompasses two or more components that are continuous with one
another by virtue of each of the components being formed from the
same piece of material. Also, the term "coupled" may include
chemical, such as via a chemical bond, mechanical, thermal, or
electrical coupling. Fluid coupling means that fluid is in
communication between the designated parts or locations.
[0038] The wound drape 116 and manifold 120 may be coupled using
adhesives such as an acrylic adhesive, silicone adhesive, hydrogel,
hydrocolloid, etc. Alternatively, the wound drape 116 and manifold
120 may be bonded by heat bonding, ultrasonic bonding, and radio
frequency bonding, etc. The coupling may occur in patterns. In
addition, structure may be added to the bond to make the wound
drape 116 behave even more anisotropically in a desired
direction.
[0039] The reduced-pressure subsystem 122 includes a
reduced-pressure source 140, which can take many different forms.
The reduced-pressure source 140 provides reduced pressure as a part
of the reduced-pressure treatment system 100. As used herein,
"reduced pressure" generally refers to a pressure less than the
ambient pressure at a tissue site that is being subjected to
treatment. In most cases, this reduced pressure will be less than
the atmospheric pressure at which the patient is located.
Alternatively, the reduced pressure may be less than a hydrostatic
pressure at the tissue site. Reduced pressure may initially
generate fluid flow in the manifold 120, a reduced-pressure
conduit, or conduit 148, and proximate the tissue site, e.g.,
incision 102. As the hydrostatic pressure around the tissue site
approaches the desired reduced pressure, the flow may subside, and
the reduced pressure may be maintained. Unless otherwise indicated,
values of pressure stated herein are gauge pressures. The reduced
pressure delivered may be static, dynamic (patterned or random) and
may be delivered continuously or intermittently. The operable range
of reduced pressure may vary widely as needed, but would typically
be between -5 mm Hg and -500 mm Hg. Various sources of reduced
pressure may be utilized such as V.A.C..RTM. therapy unit, which is
available from Kinetic Concepts, Inc. of San Antonio, Tex., or a
wall suction unit. The reduced-pressure source 140 could also be
supplied by a portable mechanical means, such as a piston in a
tube, depending on how much leakage there is with the fluid seal
between the wound drape 123 and the epidermis 104.
[0040] In the illustrative embodiment, the reduced-pressure source
140 is shown having a battery compartment 142 and a canister region
144 with windows 146 providing a visual indication of the level of
fluid within canister 144. An interposed membrane filter, such as
hydrophobic or oleophobic filter, may be interspersed between
reduced-pressure conduit 148 and the reduced-pressure source
140.
[0041] The reduced pressure developed by the reduced-pressure
source 140 is delivered through the reduced-pressure conduit 148 to
a reduced-pressure interface 150, or interface 150, which may be an
elbow port 152. In one illustrative embodiment, the elbow port 152
is a TRAC.RTM. technology port available from Kinetic Concepts,
Inc. of San Antonio, Tex. The reduced-pressure interface 150 allows
the reduced pressure to be delivered to the wound drape 116 and
realized within an interior portion of wound drape 116 and the
manifold 120. In this illustrative embodiment, the elbow port 152
extends through the flexible sheet 123 to the manifold 120, but
numerous arrangements are possible.
[0042] In operation, the manifold 120 may be placed proximate the
tissue site, e.g., incision 102 and/or undermined subcutaneous
tissue 110. The wound drape 116 may be placed over the manifold 120
such that the drape extension 136 of the wound drape 116 extends
beyond the incision 102 and/or undermined subcutaneous tissue 110.
The drape 116 may be stretched to a desired length. As previously
mentioned, while stretching the drape 116, the second isotropic
zones 126 may stretch more than the first isotropic zones 124. The
drape extension 136 may then be secured to the patient's epidermis
104 by a gripping member 118 in order to form a fluid seal between
the drape 116 and the patient's epidermis 104. In some instances,
the gripping member 118 may also serve to transmit a closing force
to the patient's epidermis 104 generated by the drape 116 as the
drape 116 attempts to contract while coupled to the patient's
epidermis 104. The reduced-pressure interface 150 is then applied,
if not already installed, and the reduced-pressure conduit 148 is
fluidly coupled to the reduced-pressure interface 150. The
reduced-pressure conduit 148 is also fluidly coupled to the
reduced-pressure source 140. The reduced-pressure source 140 may
then be activated such that a reduced pressure is delivered to the
interior of the wound drape 116 and manifold 120.
[0043] As the reduced pressure is delivered, the manifold 120 may
compress and contract laterally to form a semi-rigid substrate. A
number of beneficial forces and actions may take place. The reduced
pressure is transmitted further still through the manifold 120 so
that the reduced pressure is experienced at the patient's epidermis
104 and at the incision 102. At least at the early stages of the
healing process, the reduced pressure may also be realized through
the incision 102 and into the subcutaneous tissue 108. The reduced
pressure helps close defects, such as a subcutaneous void 112, and
generally provides stability to the area. The reduced pressure
delivered to the drape 116 also develops a compressive force, as
suggested by arrows 154, which again may provide stability and
therapy. The compressive force, as suggested by arrows 154, is more
than just at the level of the epidermis 104; the compressive force
may extend down deeper and may be experienced at the level of
subcutaneous tissue 108.
[0044] Further, as the wound drape 116 and manifold 120 laterally
contract under the influence of the reduced pressure, an inward
force, as suggested by arrows 156, may develop that helps hold an
additional closing force on the incision 102 and may generally
provide additional stability to the wound. Thus, the inward force,
represented by arrows 156, from the reduced pressure and the
closing force, represented by arrows 138, generated by the
contraction of the drape 116 may act together to assist in helping
to close the incision 102 and/or maintaining the incision 102 in a
substantially closed position. At the same time, the reduced
pressure delivered to and through the manifold 120 helps to remove
any exudates and other fluids from the incision 102. All of these
actions may improve healing of the tissue site, e.g., incision
102.
[0045] It may be desirable to apply the reduced-pressure treatment
system 100 in the operating room and allow the system 100 to remain
on the patient until adequate healing has taken place. In this
regard, it may be desirable to form the wound drape 116, manifold
120, and any other layers from transparent materials to allow the
healthcare provider to gain visual cues about the healing of the
tissue site, e.g., incision 102, without having to remove the drape
116. Moreover, it should be appreciated that the reduced-pressure
treatment system 100 may be used as a primary wound-closing
treatment or as an intermediate step of a wound-closing treatment
protocol. Furthermore, it will be appreciated that the wound drape
116 may be used without the manifold 120 and/or reduced pressure
sub-system 122. Moreover, it should be appreciated that the
wound-drape 116 may be beneficial as a stand-alone dressing that is
capable of delivering a closing force and/or a compressive force to
an incision 102 and/or undermined subcutaneous tissue 110.
[0046] Referring to FIGS. 4A and 4B, a second illustrative
embodiment of a portion of a reduced-pressure treatment system 200
is shown for treating a tissue site, such as an incision,
undermined subcutaneous tissue, or other wound. The
reduced-pressure treatment system 200 is analogous in most respects
to the reduced-pressure treatment system 100 of FIGS. 1-3B and a
correlation of parts is generally indicated in this embodiment by
indexing the numerals in FIGS. 1-3B by 100. While presented with a
reduced-pressure interface 250 and conduit 248 for connection to a
reduced pressure subsystem (not shown), it will be appreciated that
the drape 216 may be used as a stand-alone dressing as well.
[0047] The wound drape 216 includes a first isotropic zone 224, a
second isotropic zone 226, and a third isotropic zone 227. The
first isotropic zone 224 is thicker than the second isotropic zone
226, and the second isotropic zone 226 is thicker than the third
isotropic zone 227. In this embodiment, isotropic regions are
created so that with equal force applied across the drape 216, the
region defined by first isotropic zone 224 will stretch less than
the region defined by second isotropic zone 226. It will be
appreciated that the isotropic zones 224, 226 227 may be of any
suitable thickness relative to one another (e.g., the third zone
227 may be the thickest, etc.). Moreover, while the present
embodiment shows three isotropic zones, it will be appreciated that
any number of isotropic zones may be employed. The isotropic zones
224, 226, 227 are concentric with one another and are
annular-square shaped areas when viewed in plan view. However, it
will be appreciated that the isotropic zones 224, 226, 227 do not
necessarily need to be concentric with one another. Additionally,
it will be appreciated that each isotropic zone 224, 226, 227 may
have any suitable shape when viewed in plan, including but not
limited to circular, elliptical, triangular, rectangular,
octagonal, etc.
[0048] In another illustrative embodiment, the wound drape 216 has
defined isotropic zones 224, 226, 227, but the transitions between
zones may be gradual. In another illustrative embodiment, the wound
drape 216 is tapered such that the thickness of the wound drape 216
either gradually increases or gradually decreases from an inner
portion 270 to the edge 272 of the wound drape 216. Thus, the
modulus of elasticity of the wound drape 216 evenly and gradually
changes across the length of the wound drape 216. In FIGS. 4A and
4B, the inner portion 270 is the substantial center of the wound
drape 216, although the inner portion 270 may be located anywhere
inside the edges 272 of the wound drape 216.
[0049] In one example, the wound drape 216 can be thickest at the
edge 272 and gradually become thinner towards the inner portion 270
such that the center 270 is the thinnest portion of the wound drape
216. The shape of the resulting cavity may approximate a cone,
including a frustoconical shape. Conversely, the wound drape 216
can be thinnest at the periphery 272 and gradually become thicker
towards the center 270 such that the center 270 is the thickest
portion of the wound drape 216. Any of the illustrative embodiments
of the wound drape described herein, including those having
substantially parallel isotropic zones, are able to have even and
gradual, or tapered, changes in thickness or elastic modulus
instead of having clearly defined isotropic zones. In an embodiment
in which the isotropic zones are substantially parallel to one
another, the inner portion 270 may extend from one edge of the
wound drape 216 to an opposing edge. Tapering of the wound drape
216 can help to relieve strain at a tissue site to which the wound
drape 216 is applied, and can alleviate skin irritation (e.g.,
blisters). Such tapering can also offer desirable stretching
characteristics to facilitate wound healing.
[0050] Referring now to FIGS. 5A and 5B, another illustrative
embodiment of a portion of a reduced-pressure treatment system 300
for treating a tissue site on a patient is shown. The
reduced-pressure treatment system 300 is generally analogous in
most respects to that of the reduced-pressure treatment system 100
of FIGS. 1-3B and a correlation of parts is generally indicated in
this embodiment by indexing the reference numerals of FIGS. 1-3B by
200. While presented with a reduced-pressure interface 350 and
conduit 348 for connection to a reduced pressure subsystem (not
shown), it will be appreciated that the wound drape 316 may be used
as a stand-alone dressing.
[0051] The wound drape 316 includes first isotropic zones 324 and
second isotropic zones 326. The first isotropic zones 324 are
formed from a material having a first modulus of elasticity
(.lamda..sub.1) and the second isotropic zones 326 are formed from
a material having a second modulus of elasticity (.lamda..sub.2).
In the illustrative embodiment, the first modulus of elasticity is
greater than the second modulus of elasticity
(.lamda..sub.1>.lamda..sub.2) such that the second isotropic
zones 326 stretch more than the first isotropic zones 324 when the
wound drape 316 is stretched. The wound drape 316 stretches
primarily in one direction versus other directions. For example, in
one embodiment, the wound drape 316 may primarily stretch in a
direction substantially perpendicular to one or more elongated
isotropic zones 324, 326.
[0052] By selecting the appropriate modulus of elasticity for each
isotropic zone 324, 326, a user may selectively control the rate or
force with which the wound drape 316 attempts to return to the
drape's 316 original size after being stretched and adhered to a
patient. Thus, the rate of or force related to the translation
and/or approximation of tissue may be regulated. While the
illustrative embodiment shows two of each isotropic zones 324, 326,
it will be appreciated that any suitable number of isotropic zones
may be employed. Additionally, it will be appreciated that the
wound drape 316 may include any number of isotropic zones of
varying moduli of elasticities or even be constructed of
continuously variable elasticity across at least one of the wound
drape surfaces. In one embodiment, the isotropic zones nearest the
edge of the wound drape 316 have the lowest modulus of elasticity
relative to other isotropic zones of the wound drape 316.
[0053] In another embodiment, one or more isotropic zones may have
a modulus of elasticity equal to or substantially similar to that
of the tissue at or near the tissue site to which the zones are
attached. As a few non-limiting examples, the modulus of elasticity
of the isotropic zone may be within twenty percent of the modulus
of elasticity of the patient's epidermis or within ten percent of
the modulus of elasticity of the patient's skin or within five
percent of the modulus of elasticity of the patient's skin.
Coordinating the modulus of elasticity of the isotropic zones with
the modulus of elasticity of tissue at the tissue site may minimize
stress applied to the tissue or stress-shielding and promote
healing and minimize scarring. Furthermore, it will be appreciated
that the isotropic zones 324, 326 may be configured such that they
are annular shaped when viewed in plan view and the isotropic zones
324, 326 may or may not be arranged such that the isotropic zones
324, 326 are concentric with one another. In addition, while the
isotropic zones 324, 326 are shown having substantially similar
thicknesses, it will be appreciated that the isotropic zones 324,
326 may be of different thicknesses. Thus, the anisotropicity of
the wound drape 316 may be achieved by combining different zones
having different moduli of elasticities as well as different
thicknesses. Also, the thickness and moduli of the wound drape 316
may evenly and gradually taper along one or more directions of the
wound drape 316 or a portion thereof. Moreover, while the isotropic
zones 324, 326 are shown as substantially parallel with one
another, it will be appreciated that the isotropic zones 324, 326
may have any suitable arrangement relative to one another.
[0054] Referring now to FIGS. 6A-6B, another illustrative
embodiment of a portion of a reduced-pressure treatment system 400
for treating a tissue site on a patient is shown. The
reduced-pressure treatment system 400 generally includes a wound
drape 416 and one or more gripping members 418. A reduced-pressure
interface 450 and conduit 448 may be coupled to the wound drape 416
for connection to a reduced-pressure source (not shown) such that a
reduced pressure may be delivered to the tissue site. It should,
however, be appreciated that the wound drape 416 may be used as a
stand alone dressing.
[0055] The wound drape 416 is generally formed from a flexible
sheet 423 having one or more anisotropic members 457 coupled
thereto. The anisotropic members 457 are configured to provide the
wound drape 416 with anisotropic properties. In this illustrative,
non-limiting example, the wound drape 416 is operable to stretch in
the areas between the anisotropic members 457, but stretches
minimally or not at all in the direction of the longitudinal axis
of the anisotropic members 457. In the illustrative embodiment, the
anisotropic members 457 comprise a plurality of filaments 458. The
filaments 458 may be formed from any suitable material, including
but not limited to, polymer, fabric, metal, composite, elastomer,
etc. In addition, the filaments 458 may be arranged such that they
are substantially parallel with one another. It will, however, be
appreciated that the filaments 458 may have any suitable
arrangement capable of providing the drape 416 with anisotropic
properties; for example, the filaments may be in a "thatched"
arrangement, a substantially random arrangement, etc. The filaments
458 may also be formed from additional drape material in some
illustrative embodiments.
[0056] The filaments 458 are coupled to the flexible sheet 423 by
any suitable means, including but not limited to, adhesive,
mechanical fasteners, bonding, sonic welding, etc. The filaments
458 may be coupled to either the skin-facing surface 432 or the
first surface 434 of the flexible sheet 423. Additionally, the
filaments 458 may be formed with the flexible sheet 423, through a
process such as co-extrusion, whereby the filaments 458 are
substantially co-planar with the flexible sheet 423. Also, while
illustrative embodiment shows two anisotropic members 457, it will
be appreciated that any number of anisotropic members 457 may be
employed. Further, while the anisotropic members 457 are shown as
substantially parallel with one another, it will be appreciated
that the anisotropic members 457 may have any suitable arrangement
relative to one another. Moreover, it will be appreciated that the
anisotropic members 457 may be arranged such that they are annular
in shape when viewed in plan and they may or may not be arranged
such that they are concentric with one another.
[0057] While the anisotropic members 457 are shown as comprising a
plurality of filaments 458 in this illustrative embodiment, it will
be appreciated that the anisotropic members 457 may have any
suitable configuration and arrangement. For example, the
anisotropic members may include adhesive layers coupled to the
flexible sheet 423. The adhesive layers may or may not be
patterned. Other possible configurations and arrangements for the
anisotropic members are possible. In addition, the gripping member
418 is the same or similar to gripping member 118 of the
reduced-pressure treatment system 100 of FIGS. 1-3B. In the
illustrative embodiment, the gripping member 418 may be coupled to
the skin-facing surface 432 of the flexible sheet 423. The gripping
member 418 may span the entire width of the flexible sheet 423 and
overlay the filaments 458 or may be located near the ends of the
flexible sheet 423 as shown in FIG. 6B.
[0058] Referring now to FIGS. 7A and 7B, another illustrative
embodiment of a portion of a reduced-pressure treatment system 500
for treating a tissue site on a patient is shown. The
reduced-pressure treatment system 500 generally includes a wound
drape 516 and one or more gripping members 518. A reduced-pressure
interface 550 and conduit 548 may be coupled to the wound drape 516
for fluidly coupling to a reduced-pressure source (not shown) such
that a reduced pressure may be delivered to the tissue site. It
will, however, be appreciated that the wound drape 516 may be used
as a stand alone dressing.
[0059] The wound drape 516 is generally formed from a flexible
sheet 523 having one or more fluidly inflatable bladders 560. Each
fluidly inflatable bladder 560 includes an interior chamber 562 for
receiving a fluid to inflate the fluidly inflatable bladder 560.
Fluid is supplied to each interior chamber 562 by a corresponding
fluid supply tube or conduit 564; however, it will be appreciated
that a single fluid supply tube may be configured to deliver fluid
to each bladder via passageways (not shown) that interconnect the
fluidly inflatable bladders 560. The fluid may be delivered to the
interior chambers 562 from a fluid control means (not shown). The
fluid control means may be any suitable device capable of storing
and selectively delivering fluid through the tube(s) 564 to the
interior chambers 562. An illustrative fluid control means
includes, but is not limited to, a pump, cylinder, reservoir, etc.
with corresponding control mechanisms, including, but not limited
to, valves, clamps, regulators, etc. The fluidly inflatable
bladders 560 may be inflated with any suitable material, including
but not limited to, air, water, saline, a gel, a foam, etc.
[0060] The fluidly inflatable bladders 560 are configured to
provide the wound drape 516 with anisotropic properties. In the
illustrative embodiment, the fluidly inflatable bladders 560
provide the wound drape 516 with anisotropic properties by virtue
of the rigidity they supply such that the wound drape 516
functionally behaves similarly to that of FIG. 1-3B whereby the
flexible sheet 523 stretches more in the area between the bladders
560 when a stretching force is applied thereto. Furthermore, it
will be appreciated that by controlling the volume of fluid
delivered through the fluid supply tubes 564, it may be possible to
control the anisotropic properties of the wound drape 516. For
example, as the fluid is delivered to the fluidly inflatable
bladders 560, the anisotropicity of the drape 516 may increase. The
fluid delivered through the tube 564 may also be varied to provide
a dynamic anisotropic sheet. A controller may be provided to
control the fluid control means in response to conditions at the
wound site. Moreover, it will be appreciated that inflating the
fluidly inflatable bladders 560 prior to stretching and applying
the wound drape 516 may further enhance the anisotropic behavior.
In addition, once the fluidly inflatable bladders 560 are inflated,
they may be operable to provide a compressive force that may be
realized in subcutaneous tissue and that may be beneficial in
treating the undermined subcutaneous tissue and eliminating voids
or the like.
[0061] The fluidly inflatable bladders 560 may be coupled to the
flexible sheet 523 by any suitable means, including but not limited
to adhesive, mechanical fasteners, bonding, sonic welding, etc. The
fluidly inflatable bladders 560 may be coupled to either the
skin-facing surface 532 or first surface 534 of the flexible sheet
523. Additionally, the fluidly inflatable bladders 560 may be
formed to be substantially co-planar with the flexible sheet 523
prior to their inflation. While the illustrative embodiment shows
four fluidly inflatable bladders 560, it will be appreciated that
any number of bladders 560 may be employed. Further, while the
fluidly inflatable bladders 560 are shown as substantially parallel
with one another, it will be appreciated that the fluidly
inflatable bladders 560 may have any suitable arrangement relative
to one another. Moreover, it will be appreciated that the fluidly
inflatable bladders 560 may be arranged such that the fluidly
inflatable bladders 560 are annular shaped when viewed in plan and
the fluidly inflatable bladders 560 may or may not be arranged such
that the fluidly inflatable bladders 560 are concentric with one
another.
[0062] In addition, the gripping member 518 is the same or similar
to the gripping member 118 of the reduced-pressure treatment system
100 of FIGS. 1-3B. In the illustrative embodiment, the gripping
member 518 may be coupled to the skin-facing surface 532 of the
flexible sheet 523. The gripping member 518 may span the entire
width of the flexible sheet 523 and overlay the filaments 558 or
may be located near the ends of the flexible sheet 523.
[0063] In one illustrative embodiment, the fluidly inflatable
bladders 560 are inflated with positive pressure through fluid
supply tubes 564 and as reduced pressure is supplied to the
reduced-pressure interface 550, the inflatable bladders 560 press
against the patient's epidermis with a compressive force. As
reduced pressure increases, the inflatable bladders 560 are drawn
toward the reduced-pressure interface 550 and thereby create a
closing force. The closing force is realized at the epidermis and
may be realized at deeper levels, e.g., the dermis.
[0064] Although the present invention and its advantages have been
disclosed in the context of certain illustrative, non-limiting
embodiments, it should be understood that various changes,
substitutions, permutations, and alterations can be made without
departing from the scope of the invention as defined by the
appended claims. It will be appreciated that any feature that is
described in a connection to any one embodiment may also be
applicable to any other embodiment.
* * * * *