U.S. patent application number 16/212366 was filed with the patent office on 2019-06-06 for dressings, systems, and methods for treating a wound on a patient's limb employing liquid control.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Christopher Brian LOCKE, Benjamin Andrew PRATT.
Application Number | 20190167861 16/212366 |
Document ID | / |
Family ID | 47215802 |
Filed Date | 2019-06-06 |
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United States Patent
Application |
20190167861 |
Kind Code |
A1 |
PRATT; Benjamin Andrew ; et
al. |
June 6, 2019 |
Dressings, Systems, And Methods For Treating A Wound On A Patient's
Limb Employing Liquid Control
Abstract
Wound dressings, systems, and methods are presented for treating
a wound on a patient's limb, such as a venous leg ulcer. The
dressings, systems, and methods involve creating airflow within the
dressing to vaporize and remove liquid. The airflow may begin when
the dressing becomes saturated. The dressings may be used to
provide compression and reduced pressure to the wound. Other
systems, methods, and dressings are presented herein.
Inventors: |
PRATT; Benjamin Andrew;
(Poole, GB) ; LOCKE; Christopher Brian;
(Bournemouth, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
47215802 |
Appl. No.: |
16/212366 |
Filed: |
December 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15229422 |
Aug 5, 2016 |
10179196 |
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16212366 |
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13674782 |
Nov 12, 2012 |
9433711 |
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15229422 |
|
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61558544 |
Nov 11, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y10T 29/49826 20150115;
A61F 13/00063 20130101; A61M 1/0031 20130101; A61M 1/0092 20140204;
A61F 13/8405 20130101; A61F 13/0216 20130101; A61F 13/08 20130101;
A61F 2013/8408 20130101; A61M 1/009 20140204; A61F 13/085 20130101;
A61F 13/00068 20130101; A61M 1/0023 20130101; A61F 13/00987
20130101; A61F 13/45 20130101; A61F 13/022 20130101; A61M 2205/7536
20130101 |
International
Class: |
A61M 1/00 20060101
A61M001/00; A61F 13/00 20060101 A61F013/00; A61F 13/45 20060101
A61F013/45; A61F 13/08 20060101 A61F013/08; A61F 13/84 20060101
A61F013/84; A61F 13/02 20060101 A61F013/02 |
Claims
1.-33. (canceled)
34. A system for treating a wound on a patient's limb, the system
comprising: a wound dressing comprising a tubular sleeve member,
the tubular sleeve member comprising a plurality of pressure
compartments, wherein each pressure compartment of the plurality of
pressure compartments is operable to form a pressure gradient on a
portion of the patient's limb; a pressure source fluidly coupled
separately to each pressure compartment of the plurality of
pressure compartments; a controller coupled to the pressure source
to control pressure delivery to the plurality of pressure
compartments; and wherein the controller and pressure source are
operable to cause a first pressure compartment of the plurality of
pressure compartments to compress around the patient's limb, then
subsequently a second pressure compartment of the plurality of
pressure compartments to compress in order to encourage fluid
movement in the patient's limb from proximate the first pressure
compartment towards the second pressure compartment.
35. A method for treating a wound on a patient's limb, the method
comprising: forming a plurality of pressure compartments on the
patient's limb proximate the wound; sequentially compressing each
pressure compartment in a cephaladic direction; and flowing air
over a majority of the pressure compartments to vaporize and remove
liquid.
36. (canceled)
37. The system of claim 34, wherein each pressure compartment of
the plurality of pressure compartments is operable to form a
pressure gradient to move air into the wound dressing.
38. The system of claim 34, further comprising a plurality of
pressure conduits configured to fluidly couple the pressure source
to the plurality of pressure compartments.
39. The system of claim 38, wherein each pressure compartment of
the plurality of pressure compartments further comprises a pressure
interface configured to fluidly couple the pressure compartment of
the plurality of pressure compartments to a respective pressure
conduit of the plurality of pressure conduits.
40. The system of claim 34, wherein the controller is configured to
control a plurality of pumps within the pressure source to allow
varying pressure within the plurality of pressure compartments.
41. The system of claim 34, wherein the controller is configured to
control a plurality of valves to allow varying pressure within the
plurality of pressure compartments.
42. The system of claim 34, wherein each pressure compartment of
the plurality of pressure compartments further comprises a bladder
configured to be fluidly coupled to the pressure source.
43. A system for treating a wound on a patient's limb comprising: a
tubular sleeve having a plurality of pressure compartments, each
pressure compartment of the plurality of pressure compartments
being operable to form a pressure gradient on a portion of the
patient's limb when the tubular sleeve is disposed on the patient's
limb; a pressure source fluidly coupled to each pressure
compartment of the plurality of pressure compartments; and a
controller coupled to the pressure source and operable to control
pressure delivery to successively compress each pressure
compartment of the plurality of pressure compartments to encourage
fluid movement in the patient's limb.
44. The system of claim 43, wherein the tubular sleeve further
comprises an elastic compression member having a first side and a
second side forming a sleeve.
45. The system of claim 44, wherein the each pressure compartment
of the plurality of pressure compartments comprises a
fluid-directing member having a first side and a second side,
wherein the first side is positioned adjacent the second side of
the elastic compression member, and wherein the fluid-directing
member is configured to inhibit fluids from flowing through the
fluid-directing member.
46. The system of claim 45, wherein each pressure compartment of
the plurality of pressure compartments comprises a pathway member
having a first side and a second side, wherein the first side is
positioned adjacent the second side of the fluid-directing member,
and wherein the pathway member is configured to permit flow of a
fluid when the tubular sleeve is under a pressure gradient.
47. The system of claim 46, wherein each pressure compartment of
the plurality of pressure compartments comprises at least one
exhaust port fluidly coupled to the pathway member and operable to
allow fluids to exit the pressure compartment.
48. The system of claim 46, wherein each pressure compartment of
the plurality of pressure compartments further comprises an
absorbent member having a first side and a second side, wherein the
first side is positioned adjacent the second side of the pathway
member, and wherein the absorbent member is configured to at least
temporarily retain liquids.
49. The system of claim 48, wherein each pressure compartment of
the plurality of pressure compartments further comprises a
transition member having a first side and a second side, wherein
the first side of the transition member is disposed proximate to
the second side of the absorbent member, the transition member
configured to wick liquids.
50. The system of claim 49, wherein each pressure compartment of
the plurality of pressure compartments further comprises a
patient-interface member having a first side and a second side,
wherein the first side of the patient-interface member is disposed
proximate to the second side of the transition member and the
second side of the patient-interface member is adapted to be
disposed proximate to the patient.
51. The system of claim 48, wherein each pressure compartment of
the plurality of pressure compartments is separated from adjacent
pressure compartments by a compartment wall.
52. A wound dressing for treating a wound on a patient's limb, the
wound dressing comprising: an elastic compression member having a
first side and a second side forming a sleeve; a fluid-directing
member having a first side, a second side, and being operable to
inhibit fluids from flowing through the fluid-directing member,
wherein the first side is positioned adjacent the second side of
the elastic compression member; a pathway member having a first
side, a second side, and being operable to permit flow of a fluid
when the wound dressing is under a pressure gradient, wherein the
first side is positioned adjacent the second side of the
fluid-directing member; an absorbent member having a first side, a
second side, and being operable to at least temporarily retain
liquids, wherein the first side is positioned adjacent the second
side of the pathway member; and at least one exhaust port fluidly
coupled to the pathway member and operable to allow fluids to exit
the wound dressing.
53. The wound dressing of claim 52, wherein the fluid directing
member comprises a drape layer.
54. The wound dressing of claim 52, wherein the wound dressing
further comprises a sensor fluidly coupled to the pathway member,
wherein the sensor is coupled to a controller, and the sensor and
the controller are configured to determine if the pathway member is
saturated and, in response, to activate a pressure source.
55. The wound dressing of claim 52, wherein the wound dressing
further comprises a sensor fluidly coupled to the absorbent member,
wherein the sensor is coupled to a controller, and the sensor and
the controller are configured to determine if the absorbent member
is saturated and, in response, to activate a pressure source.
56. The wound dressing of claim 52, wherein the pathway member
comprises an open-cell reticulated foam.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/229,422, filed Aug. 5, 2016, which is a
continuation of U.S. patent application Ser. No. 13/674,782, filed
Nov. 12, 2012, now U.S. Pat. No. 9,433,711, which claims the
benefit, under 35 USC .sctn. 119(e), of the filing of U.S.
Provisional Patent Application Ser. No. 61/558,544, entitled
"Dressings, Systems, and Methods for Treating a Wound on a
Patient's Limb Employing Liquid Control," by Pratt et al., filed
Nov. 11, 2011, which is incorporated herein by reference for all
purposes.
FIELD
[0002] The present disclosure relates generally to medical
treatment systems suitable for use with venous leg ulcers (VLU)
and, more particularly, but not by way of limitation, to dressings,
systems, and methods for treating a wound on a patient's limb,
e.g., a venous leg ulcer, that employs liquid control or
management.
BACKGROUND
[0003] Venous leg ulcers (VLU), which are sometimes called varicose
or stasis ulcers, result from damage to the valves in the veins of
the legs, leading to raised venous pressure. VLUs have a
multi-faceted negative effect on the health and wellbeing of
patients. Physical symptoms include pain and immobility, which in
turn, may lead to sleep disturbance, lack of energy, work
limitations, frustration, and a lack of self-esteem.
[0004] The main treatment has been the application of compression
to minimize edema or swelling. Compression treatments include
wearing compression stockings, multi-layer compression wraps, or
wrapping an ACE bandage or dressing from the toes or foot to the
area below the knee. Other wounds may also be experienced on limbs
of a patient.
SUMMARY
[0005] According to an illustrative embodiment, a wound dressing
for treating a wound on a patient's limb includes a tubular sleeve
member for receiving the patient's limb and a pressure source
fluidly coupled to the tubular member. The tubular sleeve member
includes an elastic compression member formed as a sleeve having a
first side and a second, patient-facing side and a fluid-directing
member having a first side and a second, patient-facing side. The
first side of the fluid-directing member is disposed proximate to
the second, patient-facing side of the elastic compression member.
The fluid-directing member is operable to inhibit fluids from
flowing through the fluid-directing member. The tubular sleeve
member also includes a pathway member having a first side and a
second, patient-facing side. The first side of the pathway member
is proximate to the second, patient-facing side of the
fluid-directing member. The pathway member is operable to transport
a fluid under a pressure gradient. The pressure source is fluidly
coupled to the pathway member for moving fluid therein. The wound
dressing further includes at least one exhaust port fluidly coupled
to the pathway member for allowing fluids to exit the wound
dressing. The tubular sleeve member may also include one or more of
the following: an absorbent member, a transition member, or a
patient-interface member.
[0006] According to another illustrative embodiment, a dressing for
treating a wound on a patient's limb includes a means for
compressing the limb proximate the wound and a means for receiving
liquid from the wound into the dressing. The dressing further
includes a means for forcing air to flow through the dressing to
facilitate vaporization and removal of liquids from the
dressing.
[0007] According to another illustrative embodiment, a method for
treating a wound on a patient's limb includes providing a wound
dressing. The wound dressing includes a tubular sleeve member that
includes an elastic compression member formed into a sleeve having
a first side and a second, patient-facing side and a
fluid-directing member having a first side and a second,
patient-facing side. The first side of the fluid-directing member
is disposed proximate to the second, patient-facing side of the
elastic compression member. The fluid-directing member is operable
to inhibit fluids from flowing through the fluid-directing member.
The tubular sleeve member further includes a pathway member having
a first side and a second, patient-facing side. The first side of
the pathway member is proximate to the second, patient-facing side
of the fluid-directing member. The pathway member is operable to
transport a fluid under a pressure gradient. The method further
includes disposing the wound dressing around the patient's limb
proximate to the wound, receiving liquid from the wound into the
wound dressing, and creating a pressure gradient within the wound
dressing to cause air flow in the wound dressing to evaporate
liquid from the wound dressing. The air enters the wound dressing
at one location and is exhausted at another location.
[0008] According to another illustrative embodiment, a method of
manufacturing a wound dressing for treating a wound on a patient's
limb includes forming a tubular sleeve member for receiving the
limb of the patient. The step of forming a tubular sleeve member
includes forming an elastic compression member as a sleeve having a
first side and a second, patient-facing side; forming a
fluid-directing member having a first side and a second,
patient-facing side; and disposing the first side of the
fluid-directing member proximate to the second, patient-facing side
of the elastic compression member. The fluid-directing member is
operable to inhibit fluids from flowing through the fluid-directing
member. The step of forming a tubular sleeve member further
includes forming a pathway member having a first side and a second,
patient-facing side and disposing the first side of the pathway
member proximate to the second, patient-facing side of the
fluid-directing member. The pathway member is operable to transport
a fluid under a pressure gradient. The method of manufacturing a
wound dressing further includes fluidly coupling the pressure
source to the pathway member for moving fluid therein.
[0009] According to another illustrative embodiment, a system for
treating a wound on a patient's limb includes a wound dressing
comprising a tubular sleeve member. The tubular sleeve member
includes a plurality of pressure compartments. Each pressure
compartment is operable to form a pressure gradient on a portion of
the patient's limb. The system further includes a pressure source
that is fluidly and separately coupled to each of the pressure
compartments; and a controller coupled to the pressure source to
control pressure delivery to the plurality of pressure
compartments. The controller and pressure source are operable to
cause a first pressure compartment of the plurality of pressure
compartments to compress around the patient's limb, then
subsequently a second pressure compartment of the plurality of
pressure compartments to compress in order to encourage fluid
movement in the patient's limb from proximate the first pressure
compartment towards the second pressure compartment.
[0010] According to another illustrative embodiment, a method for
treating a wound on a patient's limb includes forming a plurality
of pressure compartments on the patient's limb proximate the wound,
sequentially compressing each pressure compartment in a cephaladic
direction, and flowing air over a majority of the pressure
compartments to vaporize and remove liquid.
[0011] Other aspects, 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
[0012] FIG. 1 is an elevation view of an illustrative embodiment of
a dressing for treating a venous leg ulcer or other wound on a
patient;
[0013] FIG. 2 is a cross section (medial) of the dressing of FIG. 1
taken along line 2-2;
[0014] FIG. 3 is a cross section of a portion of an illustrative
embodiment of a wound dressing for treating a wound, such as a
venous leg ulcer, that shows another seal against a patient's
epidermis;
[0015] FIG. 4 is a perspective view of an illustrative embodiment
of a dressing for treating a wound, such as venous leg ulcer or
other wound;
[0016] FIG. 5 is a cross section of a portion of another
illustrative embodiment of a dressing for treating a wound, such as
venous leg ulcer;
[0017] FIG. 6 is a cross section of a portion of another
illustrative embodiment of a dressing for treating a wound, such as
venous leg ulcer;
[0018] FIG. 7 is a cross section of a portion of another
illustrative embodiment of a dressing for treating a wound, such as
venous leg ulcer;
[0019] FIG. 8 is a cross section of a portion of another
illustrative embodiment of a dressing for treating a wound, such as
venous leg ulcer;
[0020] FIG. 9 is a cross section of another illustrative embodiment
of a dressing for treating a wound, such as venous leg ulcer;
[0021] FIG. 10 is an elevation view of an illustrative embodiment
of a dressing for treating a wound, such as venous leg ulcer, on a
patient;
[0022] FIG. 11 is a schematic diagram of a control subsystem for
use with a dressing for treating a wound, such as venous leg ulcer;
and
[0023] FIG. 12 is an elevation view of another dressing for
treating a wound, such as venous leg ulcer, on a patient.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0024] In the following detailed description of the illustrative,
non-limiting embodiments, reference is made to the accompanying
drawings that form a part hereof. 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 embodiments described
herein, 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 illustrative
embodiments are defined only by the appended claims.
[0025] In treating a venous leg ulcer (VLU) or other wounds, it is
desirable to apply compression, remove exudate, and control the
liquid produced by the wound that is retained in a dressing. VLU's
produce considerable liquids that can saturate a dressing, cause an
undesirable odor, and cause maceration of healthy skin. The
dressings and systems herein control the liquid from the wound in a
way to avoid one or more of these conditions.
[0026] Referring to the figures, and initially to FIGS. 1-2, a
dressing 102 for treating a wound 104, such as a venous leg ulcer,
on a limb 106 or extremity of a patient 108 is presented. The wound
104 may involve epidermis 103, dermis 105, and subcutaneous tissue
107. The dressing 102 reduces the amount of liquid from the wound
104 that is retained within the dressing 102 by using air movement
to vaporize and remove fluids. The dressing 102 may reduce odor and
may facilitate an overall smaller size dressing than might
otherwise be possible. The dressing 102 may have a longer use time
than otherwise possible.
[0027] The dressing 102 includes a tubular sleeve member 110 for
receiving the limb 106 or extremity of the patient 108. The tubular
sleeve member 110 has limb openings 112: a first limb opening 114
and a second limb opening 116. The limb openings 112 allow the
tubular sleeve member 110 to receive the limb 106 therein. The
tubular sleeve member 110 and the limb openings 112 may be sized to
accommodate different sized limbs 106.
[0028] The tubular sleeve member 110 may include an elastic
compression member 118 formed as a sleeve. The elastic compression
member 118 is the outermost (furthest from patient 108) member of
the tubular sleeve member 110. The elastic compression member 118
has a first side 120 and a second, patient-facing side 122. The
elastic compression member 118 may be formed from one or more of
the following materials: Nylon Powernet material; Velband;
materials with combinations of relatively non-elastic nylon fibers
and highly-elastic fibers (e.g., Spandex, Elastene); Lycra
materials, stretch cotton; rubber materials; urethanes; silicones;
or other stretch based materials. The elastic compression member
118 is optional in that an embodiment may be used as a dressing
without this layer. In such a case, the next layer, a
fluid-directing member 124, may securely hold the dressing 102 in
place.
[0029] The tubular sleeve member 110 also includes the
fluid-directing member 124. The fluid-directing member 124 has a
first side 126 and a second, patient-facing side 128. The first
side 126 of the fluid-directing member 124 is disposed proximate to
the second, patient-facing side 122 of the elastic compression
member 118. The fluid-directing member 124 is operable to inhibit
fluids from flowing through the fluid-directing member 124. The
fluid-directing member may comprise one or more of the following: a
polyurethane (PU) drape; an elastomer (e.g., natural rubbers,
polyisoprene, styrene butadiene rubber, chloroprene rubber,
polybutadiene, nitrile rubber, butyl rubber, ethylene propylene
rubber, ethylene propylene diene monomer, chlorosulfonated
polyethylene, polysulfide rubber, EVA film, co-polyester, and
silicones; silicone drape material; a 3M Tegaderm.RTM. drape; or a
polyurethane (PU) drape. The fluid-directing member 124 directs
fluids so that airflow is primarily out of the exhaust ports.
[0030] At the limb openings 112, the fluid-directing member 124 may
extend beyond any other layers to form an extension 130. The
extension 130 forms a seal with the patient's epidermis 103 as
shown best in FIG. 2. The extension 130 has a first side 134 and a
second, patient-facing side 136. An adhesive 138 is applied to the
second, patient-facing side 136 of the extension 130 to facilitate
attachment to the patient's epidermis 103. A port 140, which
depending on mode of operation is an intake port or an exhaust
port, is formed through the fluid-directing member 124 and any
other members as necessary to access air beyond the wound dressing
102. The port 140 allows fluid to enter or exit the wound dressing
102.
[0031] As shown in FIG. 3, in another illustrative embodiment, the
elastic compression member 118 and fluid-directing member 124 both
extend over transverse edges 142 and, because of compression,
impinge upon the epidermis 103 to form a seal. In this embodiment,
the port 140 extends through both the elastic compression member
118 and fluid-directing member 124. In still another embodiment,
all the layers may be coterminous and the entire edge may serve to
exhaust vapor.
[0032] Referring again primarily to FIG. 2, the tubular sleeve
member 110 further includes a pathway member 144. The pathway
member 144 has a first side 146 and a second, patient-facing side
148. The first side 146 of the pathway member 144 is proximate to
the second, patient-facing side 128 of the fluid-directing member
124. The pathway member 144 is operable to transport a fluid under
a pressure gradient. The pathway member 144 functions to present
pathways that allow a gas to flow and has sufficient rigidity to
allow pathways to remain open even when compressed during use. The
pathway member 144 may comprise one or more of the following:
open-cell foam; non-woven material (e.g., Libeltex Hydrophobic
non-woven); or Vilmed range from Freundenberg 1522. As suggested by
arrows 150 in FIG. 2, air moves within the pathway member 144.
Arrows 150 show airflow in one direction, but another direction is
possible as is explained elsewhere.
[0033] The tubular sleeve member 110 may optionally include an
absorbent member 152. The absorbent member 152 at least temporarily
retains liquids from the wound 104 away from the patient's
epidermis 103. The absorbent member 152 has a first side 154 and a
second, patient-facing side 156. The first side 154 of the
absorbent member 152 is proximate to the second, patient-facing
side 148 of the pathway member 144. The absorbent member 152 acts
as a buffer to hold liquid from the wound 104 while waiting for the
liquid to be evaporated and carried away by airflow in the pathway
member 144. The absorbent member 152 may be any material that
functions to hold liquid. The absorbent member 152 may be formed
from one or more of the following: a super absorbent polymer
material (e.g., LUQUAFLEECE from BASF), Vilmed range from
Freundenberg 1522, or other material.
[0034] The tubular sleeve member 110 may optionally include a
transition member 158. The transition member 158 may be formed from
the same materials as the pathway member 144. The transition member
158 has a first side 160 and a second, patient-facing side 162. The
first side 160 of the transition member 158 is disposed proximate
to the second, patient-facing side 156 of the absorbent member 152.
The transition member 158 wicks liquids from the wound 104 to help
keep fluids away from the epidermis 103 or wound 104.
[0035] The tubular sleeve member 110 may optionally include a
patient-interface member 164 that has a first side 166 and a
second, patient-facing side 168. The first side 166 of the
patient-interface member 164 is disposed proximate to the second,
patient-facing side 162 of the transition member 158 or the second,
patient-facing side 156 of the absorbent member 152. The second,
patient-facing side 168 of the patient-interface member 164 is for
disposing proximate to the patient 108. The patient-interface
member 164 is designed to be against the epidermis 103 for extended
periods of time and may include an anti-microbial material, e.g.,
silver. The patient-interface member 164 may be formed from a
Silver Miliken or other material.
[0036] A pressure source 170 is fluidly coupled to the tubular
sleeve member 110. The pressure source 170 may be, for example, a
reduced-pressure source or a positive pressure source. Thus, the
pressure source 170 may be a micro-pump 172 as shown in FIG. 2, a
remote reduced-pressure source 174 as shown in FIG. 10, a
wall-based suction source, or a wall-based positive pressure
source.
[0037] As suggested by arrows 176 in FIG. 1, the pressure source
170 may be configured to pull air into the wound dressing 102 at an
inboard location. The wound dressing 102 may be configured to
discharge the air at the edges. The air is discharged through one
port 140 at the limb opening 112 as suggested by arrows 178.
Alternatively, the pressure source 170 may be configured to pull
air as suggested by arrows 180 in FIG. 10 from the limb openings
112 to the pressure source 170 and then exhaust the air at the
reduced-pressure source 174.
[0038] The wound dressing 102 includes at least two ports: port 140
and port 182. The limb openings 112 typically include at least one
port 140. As shown best in FIG. 4, a plurality of ports 140 may be
included. The port or ports 140 may function as exhaust ports or
intake ports depending on the configuration of the pressure source
170. Thus, in FIGS. 1-2, the port 140 is an exhaust port. In FIG.
10, the ports 140 are intake ports. The port 182 is associated with
the pressure source 170 and may include an extension portion 185 to
provide fluid communication with a desired layer of the wound
dressing 102. For example, the extension portion 185 may fluidly
couple the pressure source 170 to the pathway member 144 as shown
in FIG. 2 or to another layer if desired.
[0039] The pressure source 170 causes a pressure gradient in the
wound dressing 102 that will move air. Depending on how the wound
dressing 102 is configured, air either enters at the edges (e.g.,
at the limb opening 112) and moves to port 182 or enters at the
port 182 and moves to the limb opening 112 and out ports 140. The
ports 140 and 182 may both may be inboard if a compartment wall is
used as is described elsewhere herein. The pressure gradient is
typically established primarily in the pathway member 144, but may
be established in other layers in some embodiments.
[0040] Each port 140, 182 may have a filter associated with the
port 140, 182. For example, a filter 184 is associated with port
140, and a filter 186 is associated with port 182. The filters 184,
186 may be odor filters, e.g., charcoal filters, or anti-bacterial
filters. In FIG. 2, the filter 184 is a charcoal filter for
removing odor from the airflow before the airflow is released into
the atmosphere. The filter 186 is an intake filter for removing
bacteria before the air enters the wound dressings 102. In FIG. 10,
the intake filters (not explicitly shown) associated with ports 140
are anti-bacterial intake filters.
[0041] Of the various layers mentioned (e.g., elastic compression
member 118, fluid-directing member 124, pathway member 144,
absorbent member 152, transition member 158, and patient-interface
member 164), some may be omitted, some combined, and some
rearranged. As a few non-exhaustive examples, consider the
embodiments of FIGS. 5-8. In FIG. 5, the tubular sleeve member 110
of the wound dressing 102 comprises only an elastic compression
member 118, a fluid-directing member 124, and pathway member 144.
In FIG. 6, the tubular sleeve member 110 of the wound dressing 102
comprises an elastic compression member 118, a fluid-directing
member 124, pathway member 144, and an absorbent member 152. In
FIG. 7, the tubular sleeve member 110 of the wound dressing 102
comprises an elastic compression member 118, a fluid-directing
member 124, pathway member 144, an absorbent member 152, and a
transition member 158. In FIG. 8, the tubular sleeve member 110 of
the wound dressing 102 comprises an elastic compression member 118,
a fluid-directing member 124, and a woven-open-structure member
188. The woven-open-structure member 188 functionally combines the
pathway member 144, absorbent member 152, and the transition member
158 into one material. The woven-open-structure member 188 is
operable to retain fluids and at the same time allow gases to move
in the woven-open-structure member 188. The woven-open-structure
member 188 may be formed from Vilmed range from Freundenberg 1522
or other similar material, for example.
[0042] Referring now to FIG. 9, another illustrative embodiment of
a wound dressing 102 for treating a wound 104 on a limb 106 of a
patient 108 is presented. The cross section is a medial cross
section of the limb 106 with the wound dressing 102 applied
thereto. The wound dressing 102 is analogous in most respects to
the wound dressing of FIGS. 1-2, except the elastic compression
member 118 is omitted and additional features added as will be
explained. The wound dressing 102 may be formed as an annular
sleeve, as an isolated dressing, or island dressing. The wound
dressing 102 may be used with or without compression. If
compression is desired, the compression is developed by application
of the fluid-directing member 124 in tension. The wound dressing
102 is held by adhesive 138 to the patient 108.
[0043] In this embodiment, a control subsystem 202 is included. The
control subsystem 202 includes at least one saturation sensor 190.
The saturation sensor 190 is coupled to the absorbent member 152.
In other embodiments, the saturation sensor 190 may be coupled to
other layers, e.g., the transition member 158. The saturation
sensor 190 may be a galvanic cell with two electrodes that produce
voltage when saturated, a resistive pathway that is completed by
exudate, or a capacitor-based sensor.
[0044] The saturation sensor 190 is coupled to a control circuit or
controller 192. The controller 192 is configured to monitor the
saturation sensor 190. When the controller 192 detects a change
indicative that the absorbent member 152 is saturated or partially
saturated, the controller 192 activates the pressure source 170 in
response. The pressure source in this embodiment pulls gas from the
port 182 and discharges the gas to the atmosphere as suggested by
arrows 194. The air is pulled from the transverse edges 142 through
one or more ports 140. In this embodiment, the ports 140 may have a
control valve 196 associated with each port 140. The control valve
196 may be wirelessly or electrically coupled by a lead 199 to the
controller 192. The control valve 196 regulates air flow through
the one or more ports 140 to keep air moving in the wound dressing
102, but also to control the rate such that, if desired, a reduced
pressure may be maintained in a sealed space 198 at a desired
level.
[0045] As an alternative to the control valve 196, controlled leaks
in the fluid-directing member 124 may be used. The controlled leaks
allow air to flow in at or near the transverse edges 142 towards
the pressure source 170. For example, apertures (not explicitly
shown) in the fluid-directing member 124 may be covered by an
adhesive film that is removed later when a leak is desired.
[0046] With the embodiment of FIG. 9, a reduced pressure may be
applied to the wound 104 and liquids removed and managed. The
reduced pressure is initially applied by the pressure source 170.
When sufficient liquids reach the absorbent member 152 and saturate
the absorbent member 152, the control valve 196 may be at least
partially opened to allow some fluid flow into the wound dressing
102 and at the same time the pressure source 170 may be
sufficiently increased to hold the desired reduced pressure
notwithstanding the introduction of air through ports 140. As shown
in the diagram of FIG. 11, a display 200 may be added to the
control subsystem 202 to provide feedback to a user. The display
200 may be a series of LED indicators, a bi-stable LCD type, or
other compact display. The display 200 is compact and low power.
The display 200 may display information such as remaining battery
capacity, duration of therapy, and the fill status of the dressing
as well as confirmation that the system is operating within its
normal parameters.
[0047] Referring now primarily to FIG. 10, another illustrative
embodiment of a wound dressing 102 for treating a wound 104 on a
limb 106 of a patient 108 is presented. The wound dressing 102 is
analogous to those previously presented, except in this embodiment,
the pressure source 170 is a remote reduced-pressure source 174.
The remote reduced-pressure source 174 is fluidly coupled by a
pressure conduit 204 to the tubular sleeve member 110. A pressure
interface 206 may be used to fluidly couple the pressure conduit
204 to the intake port (see port 182 in FIG. 2). The intake port is
at an inboard location on the wound dressing 102. In one
illustrative embodiment, the pressure interface 206 is a
T.R.A.C..RTM. Pad or Sensa T.R.A.C..RTM. Pad available from KCI of
San Antonio, Tex., or another interface. In another embodiment, a
"bridge" (an open-cell foam or other passageway material enclosed
in a gas-impermeable material) is used to deliver reduced pressure
to the wound dressing 102.
[0048] Referring now primarily to FIG. 11, the control subsystem
202 includes a controller 192 that is coupled to a saturation
sensor 190 and to a pressure source 170. In addition, a control
valve 196 may be coupled to the controller 192 and also a display
200. The control subsystem 202 may control the leak rate by opening
the control valve 196 when included or may turn on, turn off,
increase, or decrease the pressure produced by the pressure source
170. As used through out this document, "or" does not require
mutual exclusivity. The control valve 196 may be a solenoid valve
such a Pneutronics X valve with a fixed size orifice from Parker
Hannifin, Cleveland, Ohio; a mechanical proportional valve; or a
PZT proportional valve such as those supplied by Festo.
[0049] It should be understood that the control subsystem 202 of
FIG. 11 or aspects of the control subsystem 202 may be applied to
any of the embodiments herein. Thus, for example, when the control
subsystem 202 is added to the wound dressing 102 in FIGS. 1-2, the
saturation sensor 190 and controller 192 determine when the
absorbent member 152 is saturated or partially saturated. The
controller 192 may then activate the pressure source 170 to
initiate airflow in the wound dressing 102 to evaporate and remove
liquids from the wound dressing 102. The sensor 109 and controller
192 may detect saturation as a scale. The duration of the airflow
or the speed of the airflow may be set by the controller 192 in
response to the degree of saturation involved. The control system
202 may also display information such as remaining battery
capacity, duration of therapy, and the fill status of the dressing
as well as confirmation that the system is operating within its
normal parameters.
[0050] Referring now primarily to FIG. 12, another illustrative
embodiment of a wound dressing 102 is presented. The wound dressing
102 is analogous in most respects to the previously presented wound
dressings, except in this embodiment, a plurality of pressure
compartments 208 are added and are used to massage the limb 106.
Each pressure compartment 208 is operable to form a pressure
gradient on a portion of the patient's limb 106 to move air for the
purposes previously presented. In addition, the pressure
compartments 208, which are formed with a plurality of compartment
walls 209, allow squeezing or sequenced movement in a cephaladic
direction.
[0051] A pressure source 170 is fluidly coupled separately to each
of the pressure compartments 208 by a plurality of pressure
conduits 205. Each pressure compartment 208 has a pressure
interface 206 for fluidly coupling the pressure conduit 205 to the
pressure compartment 208. Each pressure conduit 205 is also fluidly
coupled to the pressure source 170.
[0052] A controller 192 is coupled to the pressure source 170 to
control pressure delivery to the plurality of pressure compartments
208. The controller 192 and pressure source 170 are operable to
cause a first pressure compartment 210 of the plurality of pressure
compartments 208 to compress around the patient's limb 106, then
subsequently a second pressure compartment 212 of the plurality of
pressure compartments 208 to compress around the patient's limb 106
in order to encourage fluid movement in the patient's limb 106 from
proximate the first pressure compartment 210 towards the second
pressure compartment 212. The coordinated compression of pressure
compartments 208 may continue with the others.
[0053] The pressure source 170 may have a controller 192 associated
with the pressure source 170. The controller 192 may be configured
to control a plurality of pumps within the pressure source 170 or a
plurality of valves (not explicitly shown) to allow varying
pressure within the pressure compartments 208. The controller 192
can sequentially supply a pressure gradient to the pressure
compartments 208 to cause sequential compression of the
compartments on the patient's limb 106. The sequential compression
of each pressure compartment results in moving fluids in the
patient's limb in a cephaladic direction (in the direction that
goes from the feet towards the head). This motion thus creates a
massage like motion on the limb 106. At the same time, as with the
previous embodiments, air flow may be introduced into the wound
dressing 102 to facilitate evaporation and removal of liquids.
[0054] The compression of each pressure compartment 208 may be
achieved using positive pressure or reduced pressure from the
pressure source 170. If positive pressure is used, the pressure
compartments 208 may include bladders that fill to cause
compression. If reduced pressure is used, the reduced pressure may
cause the fluid-directing member 124 to pull down on the other
layers which act as a bolster and thereby generate a compressive
force.
[0055] With reference generally to the figures, in operation
according to one illustrative embodiment, a wound dressing 102 is
provided. The wound dressing 102 may be any of those presented or
suggested herein or combinations thereof. The wound dressing 102
includes a tubular sleeve member 110. The wound dressing 102 is
disposed around the patient's limb 106 proximate to the wound 104.
This may entail sliding the patient's limb 106 through the limb
openings 112 or using an open and closeable seam (not explicitly
shown).
[0056] Once the wound dressing 102 is in place on the limb 106, the
wound dressing 102 may receive liquid from the wound 104 into the
wound dressing 102. Either all the time, in response to saturation
or partial saturation, or based on a timer, the pressure source 170
is activated. The pressure source 170 creates a pressure gradient
within the wound dressing 102 that causes air flow in the wound
dressing 102 to evaporate liquid from the wound dressing 102. The
air enters the wound dressing 102 at one location (e.g., port 182
or port 140) and is exhausted at another location (e.g., port 140
or 182).
[0057] The air typically will travel within the wound dressing 102
at a rate of at least 0.1 m/s and is typically in the range 0.01
(or less) to 0.2 m/s. If a saturation sensor 190 and controller 192
are included, they may detect when the saturation has dropped below
a threshold level and then signal the pressure source 170 to cease.
With spaced intake and exhaust ports, the air will flow over a
large portion of the interior of the wound dressing 102. For
example, the air may flow over 50 percent, 75 percent, 90% percent
or more of the surface area of the pathway member 144 (or other
layer if coupled to another layer).
[0058] In operation according to another illustrative embodiment,
reduced pressure may also be applied to the wound 104 as an aspect
of treatment. For example, with respect to FIG. 9, the control
valve 196 may remain closed or restricted while reduced pressure is
applied to the sealed space 198 to allow the creation of reduced
pressure in the sealed space 198. The pressure may be, for example,
without limitation, in the -25 mm Hg to -200 mm Hg range. If
saturation is detected, the control valve 196 may be opened to
allow for increased air flow. In addition, the output of the
pressure source 170 may be increased to allow the reduced pressure
level to be maintained in the sealed space 198 notwithstanding the
leak or bleeding of air.
[0059] The air entering or exiting the wound dressing 102 through
ports 140 and 182 may first go through a filter 184, 186. The
filters 184, 186 remove bacteria or odor. The intake filter will
keep bacteria from entering the wound dressing 102 and potentially
infecting the wound 104. The exit filter helps remove particulates
or remove odors. The configuration of the pressure source 170
determines whether a filter is an intake filter or exit filter.
[0060] According to another illustrative embodiment, a method of
manufacturing a wound dressing 102 for treating a wound 104 on a
patient's limb 106 is contemplated. The method includes forming a
tubular sleeve member 110 for receiving the patient's lower
extremity or limb 106. The step of forming the tubular sleeve
member 110 includes forming an elastic compression member 118 as a
sleeve having a first side 120 and a second, patient-facing side
122; forming a fluid-directing member 124 having a first side 126
and a second, patient-facing side 128; and disposing the first side
126 of the fluid-directing member 124 proximate to the second,
patient-facing side 122 of the elastic compression member 118. The
fluid-directing member 124 is operable to inhibit fluids from
flowing through the fluid-directing member 124. The step of forming
the tubular sleeve member 110 further includes forming a pathway
member 144 having a first side 146 and a second, patient-facing
side 148 and disposing the first side 146 of the pathway member 144
proximate to the second, patient-facing side 128 of the
fluid-directing member 124. The pathway member 144 is operable to
transport a fluid under a pressure gradient. The method further
includes fluidly coupling the pressure source 170 to the pathway
member 144 for moving fluid therein.
[0061] With respect to the preceding method, the step of forming a
tubular sleeve member 110 may further include disposing an
absorbent member 152, which is for at least temporarily retaining
liquids, into the wound dressing 102. The absorbent member 152 has
a first side 154 and a second, patient-facing side 156. The first
side 154 of the absorbent member 152 is disposed proximate to the
second, patient-facing side 148 of the pathway member 144. The step
of forming a tubular sleeve member 110 may further include
disposing a transition member 158 proximate to the absorbent member
152 or disposing the patient-interface member 164 into the wound
dressing 102. One or more layers may be omitted and the order of
the layers may be varied.
[0062] While air flow through the pathway member 144 is a prominent
illustrative embodiment, it should be noted that the wound dressing
102 may be configured to accommodate air flow in others layers
except the fluid-directing member 124. Thus, for example and
without limitation, the extension portion 185 (FIG. 2) of the port
182 may extend to the absorbent member 152 or the transition member
158 to cause airflow primarily therein.
[0063] It should be understood that airflow may be from an inboard
location to the transverse edges 142, from the transverse edges 142
to an inboard location, or from an inboard location to another
inboard location. With respect to the lastly mentioned flow pattern
and with general reference to FIGS. 2 and 3, an embodiment of a
wound dressing 102 has the intake port and exhaust port that are
both inboard of the transverse edges 142, but separated by a medial
compartment wall (not shown, but analogous to compartment wall 209
in FIG. 12 and running medially). In this latter embodiment, the
transverse edges 142 are sealed, air enters the intake port
proximate to the compartment wall, the air transversely flows
around the limb 106, and then the air exits the exhaust port
proximate to the compartment wall but on the opposite side from the
intake port.
[0064] The wound dressings 102 herein may require fewer changes
than other wound dressings because of the liquid management, i.e.,
the liquid removed by the airflow. The liquid management may also
avoid maceration on the patient. The wound dressings 102 may
provide less odor and bulk than other dressings. The wound dressing
102 may process more liquid over time that the dressing is
otherwise capable of retaining.
[0065] 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 connection to any one embodiment may also be
applicable to any other embodiment. For example, the control
subsystem 202 of FIG. 11 may be added to any of the other
embodiments. As another example, pressure compartments 208 of FIG.
12 may be added to any of the other wound dressings 102 herein. As
another example, the tubular sleeve members 110 shown in FIGS. 5-8
may be used with any of the wound dressing 102 embodiments
herein.
[0066] It will be understood that the benefits and advantages
described above may relate to one embodiment or may relate to
several embodiments. It will further be understood that reference
to "an" item refers to one or more of those items. It should be
apparent that the power supply is implicitly present.
[0067] The steps of the methods described herein may be carried out
in any suitable order, or simultaneously where appropriate.
[0068] Where appropriate, aspects of any of the embodiments
described above may be combined with aspects of any of the other
embodiments described to form further examples having comparable or
different properties and addressing the same or different
problems.
[0069] It will be understood that the above description of
preferred embodiments is given by way of example only and that
various modifications may be made by those skilled in the art. The
above specification, examples and data provide a complete
description of the structure and use of exemplary embodiments of
the invention. Although various embodiments of the invention have
been described above with a certain degree of particularity, or
with reference to one or more individual embodiments, those skilled
in the art could make numerous alterations to the disclosed
embodiments without departing from the scope of the claims.
* * * * *