U.S. patent application number 11/698166 was filed with the patent office on 2007-05-31 for adhesive dressing.
Invention is credited to Ryuichi Utsugi.
Application Number | 20070123810 11/698166 |
Document ID | / |
Family ID | 31976007 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070123810 |
Kind Code |
A1 |
Utsugi; Ryuichi |
May 31, 2007 |
Adhesive dressing
Abstract
To provide an adhesive dressing that allows a wearer to
determine growth of bacteria, if any, as early as possible when the
adhesive dressing is staying on the skin of the wearer for wound
healing. The adhesive dressing includes a see-through backing made
of a silicone material and four circular keepers provided on one
surface of the backing. The keepers are impregnated with chemical
compositions that change in color to the extent that the color
change is visible to the naked eye when bacteria in a wound grow.
The conditions to trigger the color change varies from composition
to composition. An adhesive is applied along the periphery of the
backing. When bacteria grow in the wound, the change in color of
the chemical compositions impregnated in the keepers can be
visually checked through the backing. This contributes to prompt
and early treatment of infected wounds.
Inventors: |
Utsugi; Ryuichi; (Tokyo,
JP) |
Correspondence
Address: |
PAUL, HASTINGS, JANOFSKY & WALKER LLP
P.O. BOX 919092
SAN DIEGO
CA
92191-9092
US
|
Family ID: |
31976007 |
Appl. No.: |
11/698166 |
Filed: |
January 26, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10228080 |
Aug 27, 2002 |
7183455 |
|
|
11698166 |
Jan 26, 2007 |
|
|
|
Current U.S.
Class: |
602/58 |
Current CPC
Class: |
A61F 2013/00846
20130101; A61F 13/0246 20130101; A61F 13/0226 20130101; A61F 13/42
20130101; A61F 13/0206 20130101 |
Class at
Publication: |
602/058 |
International
Class: |
A61F 13/00 20060101
A61F013/00 |
Claims
1. An adhesive dressing designed to be placed over a wound,
comprising: a backing having a first surface and a second surface
opposite the first surface; an adhesive layer provided on at least
a part of the first surface of said backing to secure the adhesive
dressing to the skin of a person or an animal with the first
surface facing the skin; and a chemical composition applied to the
first surface of said backing, said chemical composition changing
in color to the extent that the color change is visible to the
naked eye through said backing when bacteria grow in the wound.
2. An adhesive dressing designed to be placed over a wound,
comprising: a backing having a first surface and a second surface
opposite the first surface, said backing being made of an absorbent
or water-permeable material; an adhesive layer provided on the
first surface of said backing to secure the adhesive dressing to
the skin of a person or an animal with the first surface facing the
skin; and a chemical composition impregnated in said backing, said
chemical composition changing in color to the extent that the color
change is visible to the naked eye when bacteria grow in the
wound.
3. The adhesive dressing as claimed in claim 1, wherein said
chemical composition is incorporated into said adhesive layer.
4. The adhesive dressing as claimed in claim 1, further comprising
keeper provided on the first surface of said backing to keep said
chemical composition, said chemical composition being impregnated
in said keeper.
5. The adhesive dressing as claimed in claim 1, wherein said
chemical composition comprises two or more kinds of chemical
compositions that change in color under different conditions.
6. The adhesive dressing as claimed in claim 2, wherein said
chemical composition comprises two or more kinds of chemical
compositions that change in color under different conditions.
7. The adhesive dressing as claimed in claim 1, wherein said
chemical composition is two or more kinds of chemical compositions
that change in color under different conditions, the chemical
compositions being incorporated into said adhesive layer at
different locations.
8. The adhesive dressing as claimed in claim 4, wherein said
chemical composition is two or more kinds of chemical compositions
that change in color under different conditions, the chemical
compositions being impregnated in said keeper at different
locations.
9. The adhesive dressing as claimed in claim 2, wherein said
chemical composition is two or more kinds of chemical compositions
that change in color under different conditions, the chemical
compositions being impregnated in said backing at different
locations.
10. The adhesive dressing as claimed in claim 1, wherein said
backing is made of a transparent or translucent material.
11. The adhesive dressing as claimed in claim 2, wherein said
backing is made of a transparent or translucent material.
12. The adhesive dressing as claimed in claim 1, wherein said
backing is water-impermeable.
13. The adhesive dressing as claimed in claim 1, wherein said
backing is made of a resin.
14. The adhesive dressing as claimed in claim 2, wherein said
backing is made of fabric.
15. The adhesive dressing as claimed in claim 2, wherein said
backing is made of paper.
16. The adhesive dressing as claimed in claim 1, wherein said
chemical composition serves as a pH indicator that changes in color
to the extent that the color change is visible to the naked eye
when said chemical composition varies from neutral to acidic.
17. The adhesive dressing as claimed in claim 2, wherein said
chemical composition serves as a pH indicator that changes in color
to the extent that the color change is visible to the naked eye
when said chemical composition varies from neutral to acidic.
18. The adhesive dressing as claimed in claim 16, wherein the pH
indicator changes in color to the extent that the color change is
identifiable to the naked eye between acidic and neutral pHs.
19. The adhesive dressing as claimed in claim 17, wherein the pH
indicator changes in color to the extent that the color change is
identifiable to the naked eye between acidic and neutral pHs.
20. The adhesive dressing as claimed in claim 1, wherein the pH
indicator includes at least one of the following: Indigo Carmine,
Nile Blue, Methyl Red, Phenolphthalein, Congo Red, Bromcresol
Green, Bromphenol Red, Bromthymol Blue, Cresol Red, Thymol Blue,
Bromphenol Blue, Tetrabromphenol Red, Bromcresol Purple, Alizarin
Yellow, Aniline Blue, Litmus, Andrade, and Neutral Red.
21. The adhesive dressing as claimed in claim 2, wherein the pH
indicator includes at least one of the following: Indigo Carmine,
Nile Blue, Methyl Red, Phenolphthalein, Congo Red, Bromcresol
Green, Bromphenol Red, Bromthymol Blue, Cresol Red, Thymol Blue,
Bromphenol Blue, Tetrabromphenol Red, Bromcresol Purple, Alizarin
Yellow, Aniline Blue, Litmus, Andrade, and Neutral Red.
22. The adhesive dressing as claimed in claim 1, wherein said
chemical composition serves as a hydrogen sulfide indicator that
changes in color to the extent that the color change is visible to
the naked eye when said chemical composition reacts with hydrogen
sulfide.
23. The adhesive dressing as claimed in claim 7, wherein said
chemical composition serves as a hydrogen sulfide indicator that
changes in color to the extent that the color change is visible to
the naked eye when said chemical composition reacts with hydrogen
sulfide.
24. The adhesive dressing as claimed in claim 22, wherein the
hydrogen sulfide indicator is at least one of lead acetate and a
ferric ion.
25. The adhesive dressing as claimed in claim 23, wherein the
hydrogen sulfide indicator is at least one of lead acetate and a
ferric ion.
26. The adhesive dressing as claimed in claim 1, wherein said
chemical composition comprises an auxiliary agent that is useful to
cause said chemical composition to change in color.
27. The adhesive dressing as claimed in claim 2, wherein said
chemical composition comprises an auxiliary agent that is useful to
cause said chemical composition to change in color.
Description
[0001] This application is a continuation of application Ser. No.
10/228,080 filed Aug. 27, 2002 and is incorporated herein by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an adhesive dressing for
medical purposes, such as wound dressings, bandage strips, and
surgical tapes.
[0003] Adhesive dressings are widely used in various clinical
services in the form of bandage strips or other dressings. For
example, adhesive dressings are used to treat wounds including
blisters, cuts, scratches, and burn injuries. More recent
treatments for laser burns also employ adhesive dressings. Such
adhesive dressings typically comprise a backing, and an adhesive
layer on the surface of the backing that is to be brought into
contact with the skin of a person. Typical conventional backings
for adhesive dressings are made of a non-transparent material. This
means that the condition of a wound under a dressing cannot be
visually checked while the dressing is staying on the skin.
Accordingly, a wound may be aggravated under the dressing if
bacteria grow in the wound before it heals. In this invention, the
word "bacterium" contains virus and microorganism it is supposed
that it will not be bacterium if a definition is generally
given.
[0004] In order to avoid deterioration of the wound, an adhesive
dressing may frequently be removed for medical attention to be
received. However, some situations do not allow for frequent
removal of the dressings. This is particularly true when occlusive
or wet dressings are applied. When an occlusive or wet dressing is
used, the area under treatment is completely covered with the
dressing. The area is kept wet until the wound has healed. The
wound is placed in contact with body fluid during this healing
period. Wounds have traditionally been covered with dry dressings
such as gauze. Occlusive dressings and wet dressings, on the other
hand, have attracted a lot of attention as an approach that can
enhance the healing process and reduce healing time. The wet
dressings have a potential of reducing healing time. However, if a
wound is infected with bacteria, they are more likely to grow. The
growth of the bacteria, if any, should be identified as early as
possible. The wound should be cleaned, disinfected, and dressed
with a sterile adhesive dressing. To this end, the adhesive
dressing may be removed in certain intervals to check the condition
of the wound. However, this often takes some work. In other words,
it is more advantageous to avoid unnecessary removal of dressings
and treatment of wounds, and cover the area under treatment for a
longer period of time for helping a wound to heal.
[0005] Therefore, an object of the present invention is to provide
an adhesive dressing that allows a wearer to determine growth of
bacteria, if any, as early as possible when the adhesive dressing
is staying on the skin of the wearer for wound healing.
SUMMARY OF THE INVENTION
[0006] The present inventor undertook thorough research to obtain
such adhesive dressings. As a result, the present invention was
thus accomplished.
[0007] More specifically, the present invention provides an
adhesive dressing designed to be placed over a wound, comprising: a
backing having a first surface and a second surface opposite the
first surface; an adhesive layer provided on at least a part of the
first surface of the backing to secure the adhesive dressing to the
skin of a person or an animal with the first surface facing the
skin; and a chemical composition applied to the first surface of
the backing, the adhesive layer changing in color to the extent
that the color change is visible to the naked eye through the
backing when bacteria grow in the wound.
[0008] Alternatively, the present invention provides an adhesive
dressing designed to be placed over a wound, comprising: a backing
having a first surface and a second surface opposite the first
surface, the backing being made of an absorbent or water-permeable
material; an adhesive layer provided on the first surface of the
backing to secure the adhesive dressing to the skin of a person or
an animal with the first surface facing the skin; and a chemical
composition impregnated in the backing, the chemical composition
changing in color to the extent that the color change is visible to
the naked eye when bacteria grow in the wound.
[0009] These adhesive dressings are stuck to the skin to use. In
the former adhesive dressing, the chemical composition on the wound
changes in color when bacteria grow in the wound while the dressing
is staying on the skin. The color change is visible through the
backing. In the latter adhesive dressing, the chemical composition
impregnated in the backing and brought into contact with exudate
changes in color when bacteria grow in the wound. The color change
is visible to the naked eye as the color change of the backing.
[0010] By using the adhesive dressing of the present invention, a
person who has no special expertise in medical treatments can
properly identify the growth of bacteria, if any, in a wound. When
color change is observed, the person can easily clean, disinfect
and dress the wound with a sterile adhesive dressing. This allows
prompt treatment for infected wounds.
[0011] This indicates that there is little possibility of wound
infection unless the color of the chemical composition does not
change. Adhesive dressings may be kept over the area under for a
longer period of time, wherever possible.
[0012] The backing of the present invention may be any backing as
long as any change in color of the chemical composition is visible
through the backing while the dressing is staying on the skin. For
example, the backing may be formed of a colorless transparent,
colored transparent, translucent, semi-transparent, or even
clear-colored material. In addition, the backing may be formed as a
sheer mesh of a non-transparent or opaque material. What is
required for the backing is that the color change is visible
through the backing.
[0013] The backing according to the former aspect of the present
invention may be water-permeable or water-impermeable. When the
backing is water-impermeable, the resulting adhesive dressings are
suitable as wet dressings.
[0014] The backing according to the former aspect of the present
invention may be made of any one of suitable materials as long as
the color change in color of the chemical composition can visually
be checked through the backing. For example, the backing may be
made of a resin material. Resins may be used to provide
transparent, translucent, or water-impermeable backings.
[0015] The backing according to a latter aspect of the present
invention may be made of any absorbent or water-permeable
materials. Of course, an absorbent and water-permeable backing may
be used. Materials of the backing are not specifically limited as
long as the above-mentioned requirements are satisfied. However,
fabric (woven fabric and non-woven fabric) or paper may suitably be
used.
[0016] The chemical composition indicates the growth of bacteria,
if any, by means of change in color to the extent that the color
change is visible to the naked eye. In the former aspect of the
present invention, the chemical composition is provided on at least
a part of the surface of the skin to be brought into contact with
the skin. The chemical composition may be provided over a different
range from the adhesive layer. Alternatively, the chemical
composition may be incorporated into the adhesive layer. The
surface of the backing to be opposed to the skin (contact surface)
may be provided with keeper to keep the chemical composition. In
such a case, the chemical composition is impregnated in the keeper
on the contact surface of the backing.
[0017] On the other hand, the chemical composition according to the
latter aspect of the present invention is impregnated in the
backing. In such a case, the chemical composition may be
impregnated in the entire backing or only in a predetermined area
of the backing.
[0018] The chemical composition according to the present invention
may be a single composition or may include different compositions
that change in color under different conditions. In the latter
case, the chemical composition may be a combination of pH
indicators, hydrogen sulfide indicators or other chemical
compositions described below.
[0019] In the present invention, two or more kinds of chemical
compositions may be incorporated into the adhesive layer at
different locations. Alternatively, these chemical compositions may
be impregnated in the keeper or in the backing at different
locations. The chemical composition(s) according to the present
invention may be any one of suitable compositions that change in
color to the extent that the color change is visible to the naked
eye when bacteria grow in the wound.
[0020] For example, the chemical indicator of the present invention
may be a pH indicator that changes in color to the extent that the
color change is visible to the naked eye when the chemical
composition varies from neutral to acidic. This chemical
composition is based on the fact that human body fluids are
naturally maintained at about neutral pH but shift to acidic as
bacteria grow. The pH indicator is not specifically limited. Any
one of appropriate compositions may be used that exhibits different
colors between the acidic and neutral pHs to the extent that the
color change is visible to the naked eye.
[0021] More specifically, the pH indicator of the present invention
may be selected from the group consisting of Indigo Carmine, Nile
Blue, Methyl Red, Phenolphthalein, Congo Red, Bromcresol Green,
Bromphenol Red, Bromthymol Blue, Cresol Red, Thymol Blue,
Bromphenol Blue, Tetrabromphenol Red, Bromcresol Purple, Alizarin
Yellow, Aniline Blue, Litmus, Andrade, Neutral Red. Alternatively,
two or more of them may be combined.
[0022] Chemical compositions that exhibit different colors between
a pH value of equal to or larger than 3 and a pH value of equal to
or smaller than 3, to the extent that the color change is visible
to the naked eye, can indicate the growth of bacteria more
precisely. For example, Thymol Blue, Phenol Blue, and Phenol Red
may be used for such purposes.
[0023] Besides or in addition to the pH indicator, a hydrogen
sulfide indicator may also be used for the chemical composition of
the present invention that changes in color to the extent that the
color change is visible to the naked eye when the chemical
composition reacts with hydrogen sulfide. This chemical composition
is based on the fact that hydrogen sulfide is produced during the
decomposition of organic matter by bacteria. Examples of the
hydrogen sulfide indicator include lead acetate and ferric ions. At
least one of them may be used for this purpose. Alternatively,
various tests are available to detect or indicate bacteria. Of
these, any tests that can exhibit different colors to the extent
that the color change is visible to the naked eye in response to
the increase in number of bacteria may be used for the chemical
compositions of the present invention.
[0024] The chemical composition(s) of the present invention may be
mixed with an auxiliary agent that is useful to cause the chemical
composition(s) to change in color. For example, phenylalanine may
be used as the auxiliary agent when the phenylalanine deaminase
test is applied. The phenylalanine deaminase test is for
demonstrating whether a bacterium can break down the amino acid
phenylalanine to phenylpyruvic acid. In such a case, the amino acid
phenylalanine that serves as the pH indicator to cause the color
change in response to a shift of pH corresponds to the auxiliary
chemical composition of the present invention.
[0025] Other examples of the tests that can be applied to the
present invention include, but not limited to, phosphatase tests,
acid fermentation tests, Methylene Blue milk reduction tests,
malonate tests, and Litmus milk tests. The phosphatase test is
based on the principle that the phosphatase enzyme liberates
phenolphthalein from a phenolphthalein diphosphate substrate. With
bacteria, phenolphthalein changes from colorless to orange-pink.
The phosphatase test is mainly used to determine whether
staphylococci or Escherichia coli is present. The acid fermentation
is to indicate the change in pH to acidic due to metabolites
produced by oxidation or fermentation of sugar by bacteria. As the
chemical composition, Prussian Blue or Bromcresol Purple is used.
The Methylene Blue milk reduction test is to determine the amount
of bacteria in a medium supplemented with milk. The reaction
involves the reduction of Methylene Blue by enzymatic
hydrolysis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view showing an example of a
adhesive dressing according to an embodiment of the present
invention;
[0027] FIG. 2 is a perspective view showing an example of a
adhesive dressing according to another embodiment of the present
invention; and
[0028] FIG. 3 is a perspective view showing a adhesive dressing
according to still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Adhesive dressings according to first and second preferred
embodiments of the present invention are described below.
First Embodiment
[0030] An adhesive dressing according to the first embodiment
comprises a backing and an adhesive layer. The adhesive layer is
provided on the back surface (to be brought into contact with the
skin of a wearer) by means of applying an adhesive to the backing
at a predetermined location.
[0031] The backing of the adhesive dressing according to this
embodiment may be colored or colorless transparent,
semi-transparent, or translucent. The transparency is such that at
least the surface of the skin is visible when the adhesive dressing
is staying on the skin. In this embodiment, the backing is
colorless transparent.
[0032] The backing may be made of one, two or more of various
materials. Examples include resins and rubbers such as, but not
limited to, silicone, tetron, acrylics, cellophane, fluorocarbon
resins, ionomers, nylon, polycarbonate, polyester, polyethylene,
polypropylene, polystyrene, polyurethane, polyvinyl alcohol,
polyvinylidene chloride, polyvinyl chloride, vinyl acetate, rubber
chloride, and vinyl chloride. The backing may be subjected to
secondary processing such as coating and corona treatment.
[0033] When the adhesive dressing is designed for occlusive
dressings or wet dressings, the backing is water-impermeable
material. The above-mentioned material(s) may be used to provide
occlusive or wet dressings by means of, for example, controlling
the thickness of the backing. In this embodiment, silicone or
polyurethane is used to form a backing of 0.2 mm in thickness.
[0034] The adhesive layer in the adhesive dressing according to
this embodiment is required to be applied to the back surface of
the backing at a predetermined location or locations. The adhesive
layer may be applied over the entire back surface of the backing.
Alternatively, the adhesive layer may be applied to the portion of
the back surface that is not brought into contact with a wound. The
adhesive layer is applied to the entire back surface of the
backing.
[0035] The adhesive for the adhesive layer may be any one of
appropriate adhesives that can hold the backing on the surface of
the skin of a wearer for a relatively long period of time. The
adhesive may be selected from a range of adhesives that do not have
adverse effects on the skin. The adhesive may be, for example, "SK
dyne MD-1" available from the Soken Chemical & Engineering Co.,
Ltd., Tokyo, Japan. In addition, an aluminum chelate cross-linking
agent "M-5A" may optionally be added.
[0036] Any method may be used to form the adhesive layer on the
back surface of the backing. For example, transcription may be
used. For this purpose, a release liner made of polyethylene
laminate may be used. The release liner may be the one obtained by
means of, for example, thermally depositing a polyethylene layer of
15 .quadrature.m thick on quality paper and applying a releasing
agent based on a silicon resin to the polyethylene layer.
[0037] The adhesive contains a chemical composition incorporated
therein that changes in color when the number of bacteria in the
wound increases, to the extent that the color change is visible to
the naked eye. More specifically, the adhesive in this embodiment
contains a pH indicator that changes in color to the extent that
the color change is visible to the naked eye when the chemical
composition varies from neutral (pH=7) to acidic (pH<7). The
amount of the pH indicator may be such that the color change is
visible to the naked eye and may be determined depending on the
type of the pH indicator to be used. Examples of the pH indicator
include those that exhibit different colors between the acidic and
neutral pHs to the extent that the color change is visible to the
naked eye. For example, Bromthymol Blue may be used as a pH
indicator. Alternatively, the pH indicator may be a substance that
changes in color at a pH value of about 3.5 to the extent that the
color change is visible to the naked eye. That is, the boundary
line which the change of the color of the pH indicator produces is
in the neighborhood of pH 3.5. The pH indicator may be a substance
that differentiates by color between a pH value of about 2 and a pH
value of about 4, to the extent that the color change is visible to
the naked eye. For example, at least one of Thymol Blue and Phenol
Blue may be used for such purposes.
[0038] An adhesive containing the pH indicator may be applied to
the back surface of the backing through the above-mentioned
transcription technique. This provides the adhesive layer having
the pH indicator incorporated therein on the back surface of the
backing.
[0039] In place of the pH indicator, the adhesive may contain a
hydrogen sulfide indicator that changes in color to the extent that
the color change is visible to the naked eye when the chemical
composition reacts with hydrogen sulfide. For example, at least one
of lead acetate and ferric ions may be incorporated into the
adhesive which may then be applied to the back surface of the
backing through the transcription.
[0040] An auxiliary agent may be contained in the above-mentioned
chemical composition(s). For example, phenylalanine which serves as
an auxiliary agent may be mixed with Thymol Blue which serves as a
pH indicator. In such a case, the phenylalanine deaminase test is
performed before the use of the adhesive dressing. In addition, the
chemical composition of the present invention may be mixed with an
auxiliary agent that is useful to cause the chemical composition to
change in color. For example, when the phenylalanine deaminase test
is performed, phenylalanine may be used as the auxiliary agent. The
phenylalanine deaminase test is for demonstrating whether a
bacterium can break down the amino acid phenylalanine to
phenylpyruvic acid. In such a case, the amino acid phenylalanine
that serves as the pH indicator to cause the color change in
response to a shift of pH corresponds to the auxiliary chemical
composition of the present invention.
[0041] Different chemical compositions may be provided at different
locations in the adhesive. For example, a repeated cycle of the
transcription process can produce an adhesive having different
chemical compositions provided at different locations thereof. The
chemical compositions in this embodiment change in color under
different conditions. For example, Phenol Blue is provided at one
location and a ferric ion is provided at another location.
[0042] The adhesive dressing is designed to be put on the skin with
the back surface facing to the skin having a wound so that the
wound is completely covered with the dressing.
[0043] If bacteria grow in the wound, either the pH indicator or
the hydrogen sulfide indicator indicates the growth through the
change in color thereof. The color change is visible through the
backing. The wound can be cleaned, disinfected, and dressed with a
sterile adhesive dressing immediately after a wearer is aware of
it.
[0044] In the first embodiment, the chemical composition is
contained in the adhesive that is provided on the contact surface
of the backing. Alternatively, the following modification is also
contemplated in the present invention. A keeper may be provided on
the contact surface of the backing to keep the chemical composition
or compositions. The keeper may be impregnated with the chemical
composition to hold it therein. For example, paper or fabric may be
used for this purpose.
[0045] The keeper may be formed into any desirable shape. The
keeper or keepers may be provided on the contact surface of the
backing at any location(s). For example, the keeper may be provided
as shown in FIGS. 1 to 3 which are perspective views of a backing 1
from the perspective of the contact surface.
[0046] In the example shown in FIG. 1, the adhesive dressing
comprises a rectangular backing 1. Four circular keepers 2 are
provided on the contact surface of the backing 1 in a rectangular
pattern. The circular keepers 2 are made of a filter paper and are
impregnated with a chemical composition that changes in color under
different conditions from each other.
[0047] In the example shown in FIG. 2, the adhesive dressing
comprises a rectangular backing 1. Strips of keepers 2 are
vertically and horizontally provided on the contact surface of the
backing 1. The strip keepers 2 are made of fabric and are
impregnated with a chemical composition that changes in color under
different conditions from each other.
[0048] In the example shown in FIG. 3, the adhesive dressing
comprises a rectangular backing 1. A keeper 2 made of two filter
papers is provided on the contact surface of the film backing 1.
The keeper 2 has a circular hole formed therein so that the portion
of the backing corresponding to the hole is exposed outside. The
halves of the keeper 2 are impregnated with a chemical composition
that changes in color under different conditions from each
other.
[0049] An adhesive 5 (as shown in FIG. 1) is applied around the
periphery of the adhesive dressings shown in FIGS. 1 to 3 at
positions where the backing 1 is exposed outside. The backings 1
shown in FIGS. 1 to 3 as well as the adhesive used are similar to
those described above.
Second Embodiment
[0050] An adhesive dressing according to this embodiment comprises
a backing and an adhesive layer as in the first embodiment. The
adhesive layer is provided on the back surface (to be brought into
contact with the skin of a wearer) by means of applying an adhesive
to the backing at a predetermined location. The second embodiment
differs from the first embodiment in the material of the
backing.
[0051] The backing of the adhesive dressing according to this
embodiment is made of a water-permeable and absorbent material such
as paper or fabric. More specifically, the backing is made of gauze
that is an example of a woven fabric. A transparent resin coating
is applied to the surface of the gauze, which may be eliminated
when appropriate.
[0052] Similar adhesives to those described in conjunction with the
first embodiment may be used as the adhesive for the adhesive layer
in this embodiment. The adhesive layer in the second embodiment is
formed only around the periphery of the backing. Since the
transparent resin layer is larger than the gauze and runs off the
edge of the gauze. The adhesive layer may be applied only to the
back surface of the portion of the resin that runs off the edge of
the gauze.
[0053] The adhesive for the adhesive dressing according to the
second embodiment of the present invention is not required to
contain the chemical composition that changes in color to the
extent that the color change is visible to the naked eye when the
number of bacteria increases. Instead, the chemical composition is
impregnated in the gauze that serves as the backing of the adhesive
dressing in this embodiment. The chemical composition impregnated
in the gauze is similar to those described in conjunction with the
first embodiment. In other words, the backing of the adhesive
dressing in this embodiment is impregnated with a pH indicator or a
hydrogen sulfide indicator. Alternatively, different chemical
compositions may be impregnated in the gauze at different locations
that change in color under different conditions from each
other.
[0054] The adhesive dressing according to the second embodiment is
also used as in conventionally.
[0055] If bacteria grow in a wound, either the pH indicator or the
hydrogen sulfide indicator indicates the growth through the change
in color thereof. The color change is visible through the backing.
The wound can be cleaned, disinfected, and dressed with a sterile
adhesive dressing immediately after a wearer is aware of it.
* * * * *