Note: Descriptions are shown in the official language in which they were submitted.
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PAU1TY LINER WITH SENSOR FOR PREDICTING THE START OF MENSTRUATION
FIELD OF THE INVENTION
The present invention relates to use of a pH sensor, blood sensor,
progesterone andior estrogen hormone sensor or combinations thereof in the
manufacture of a sanitary napkin or panty liner for conventional use by a
woman.
The use of the sensor is for the purpose of providing a visual advance
indication
of at least 3 hours until the start of menstruation.
BACKGROUND OF THE INVENTION
Today, disposable sanitary articles such as sanitary napkins, panty liners,
interlabial devises and tampons, are widely used in feminine protection and in
the
care of incontinent adults as a means of containing, isolating and disposing
of
bodily wastes. These articles have generally replaced reusable, washable cloth
garments as the preferred means for these applications because of their
convenience and reliability. The disposable articles respond to a discharge
event
by absorbing or containing bodily wastes deposited on the article. Some
disposable articles comprise a chemically reactive means to detect and signal
various substances in the wearer's waste. However, none of these specifically
detect or predict when menstruation is about to occur and signal to the wearer
or
caregiver that occurrence.
The so far un-met consumer need of women which is targeted by the
present invention is the desire to gain more information about the expected
timing of their menstruation. More generally it is well established that women
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would like to know more about and monitor their bodily condition as relates to
the
status of their menstruation cycle as well as a pre-warning to any kind of
related
disorder advancing.
Therefore, the present invention contains two aspects which may have to
be considered in a different claim set according to local patent law. One
aspect is
the diagnostic aspect in a medical sense of the development of the present
invention while the other is the purely non-medical benefit of providing early
information about the approach of menstruation in order to allow respective
action by the consumer such as starting to use sanitary napkins or tampons.
A lot of disclosure exists on general diagnostic aspects relating to female
menstruation cycle and genital/urinary tract related information. However,
none
of the references cited in the following does provide specific teaching to the
present invention.
US 5,217,444 to Schonfeld et. al., published June 8, 1993 discloses
absorbent pads such as tampons comprising a pH indicator material to indicate
the acidity or alkalinity of a liquid by a color change. The pH indictor is
intended
to be wetted by vaginal secretions which are absorbed by the pad. Depending on
the pH this will provide an indication of the health condition of the women's
vaginal tract.
US 5,468,236 to Everhart et. al., published November 21, 1995 discloses a
disposable absorbent product incorporating a chemically reactive substance
which can provide visual indication of a chemical component in absorbed liquid
such as vaginal discharges. The patent is un-specific as to its particular
purpose
but exemplifies a disposable diaper in which a glucose indicating gel can be
applied to the topsheet or the absorbent core. In a second example the
chemical
compound to be detected is a nitrate as indicator of urinary tract infections
by
GRAM negative bacteria. In particular Everhart provides for a reaction which
is
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endpoint stable due to a catalytic sequence such that further liquid
absorption will
not alter the indication.
US 4,231,370 to Morz et. al., published November 4, 1980 discloses
disposable diapers with a pH sensitive wetness indicator in a solid adhesive
matrix.
US 5,823,953 to Richards et. al., published October 20, 1998 relates to a
self diagnostic system for yeast or non-yeast related vaginal infections in
the
form of a catamenial pad or panty liner with detachable, color indicating pH
strip
mounted on the topsheet. The pH indicator identifies if the pH of the absorbed
liquid is above or below a thresh hold value of 4.5 and is indented to allow
health
care decisions without a physician in respect to treating a yeast or a non-
yeast
vaginal infection.
WO 97/43955 to Buck et. al., published November 27, 1997 discloses a kit
for home use for collecting vaginal fluid and exfoliated vaginal cells in
menstrual
fluid for diagnostic purposes. The fluid or cells are collected in an
absorbent
interlabial pad or in a pad which is placed inside an apertured housing which
is
placed inter vaginally for collecting fluid. The fluid can afterwards be used
for
diagnostic purposes as desirable.
EP 704 195, to Echeveria, published April 3, 1996 discloses a menstrual
detector which comprises a sanitary napkin or panty liner including a chemical
compound which provides a cooling reaction upon liquid absorption as indicator
of the start of menstruation in order to allow the wearer sufficient time to
replace
the indicating absorbent article by a full size and full capacity sanitary
napkin or
tampon.
Of course, many indicators as such are known and are usually independent
of the source of the liquid of which analysis is desired. For example, EP 386
562
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to Ismael et. al., published September 12, 1990 discloses a dry enzyme test
composition with a color indicator result. Similarly, WO 90/06511 to Buck et.
al.,
published June 14, 1990 discloses a stabilized indicator to determine the
presence of an analyte in a liquid sample. Similarly, WO 89/11643 to Bouse et
al,
published November 30, 1989 discloses an indictor composition designed to
increase the range of analyte concentration which can be analyzed.
EP 124 215 and EP 124 214 both to Oksman et al, published November 7,
1984 relate to wipe indicators for occult blood particular useful to analyze
the
presence of blood in feces. Similarly, EP 93595, to Wells, published November
9,
1983 relates to a dry diagnostic aid for use in an one-step determination of
hemoglobin, especially in occult blood in feces.
EP 113 896 to Rothe, published July 25, 1984 relates to a chemical testing
strip in which a test reagent is provided on a plastic film strip for
quantitative
evaluation. This patent exemplifies blood and glucose testing.
EP 101 980 and EP 101 979, both to Roy, published March 7, 1984 relate
to the determination of dehydrogenase for the purpose of rapid clinical
analysis
and diagnosis. In the later case it is said that the carrier can be a tampon
containing cellulose fibers.
In addition many publications in the medical field relating to pathological
conditions of the female genital and urinary organs including methods of
detecting and healing them have been published.
SUMMARY OF THE INVENTION
The present invention is about the accuracy with which the start of
menstruation can be predicted with at least 3 hours advance notice. This
serves
the purpose to allow to take a desired action, e.g. prepare to use a 'full
size'
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sanitary article such a Tampon or napkin, prepare to use a collection devise
to
allow collection of menstrual liquid for further in vitro analysis, allow
women who
have complications with their menstruation to take appropriate medication
(i.e.
utilize the prediction as part of a medication scheme). Of course the use of
menstruation prediction is not strictly limited to the female human
menstruation
prediction but could equally be used on animals. Technically the present
invention relates to the use of a pH sensor, blood sensor, progesterone and/or
estrogen hormone sensor or combinations thereof in the manufacture of a
sanitary napkin, panty liner or interlabial article/insert for conventional
use by a
woman, said use of said sensor being for the purpose of providing a visual
advance indication of at least 3 hours until the start of menstruation. Of
course it
is preferred to provide at least a full day advance warning of the start of
menstruation.
In one embodiment according to the present invention it is most desirable to
have as exact as possible a prediction on the start of menstruation for an
individual for each menstruation cycle. Therefore it is preferred if the
sensor is
selected such that it provides a visual indication of the approximate time
until
start of menstruation which time is consistent within the range of +/- 4hours
for a
specific individual over at least 3 consecutive menstruation cycles.
According to another embodiment of the present invention this accuracy
can be achieved by selecting the sensor composition appropriately. If the
sensor
includes a blood sensor then in a preferred embodiment the blood sensor is
selected from Gum Guaiac with a peroxide and optionally cyclo-dextrin; or Gum
Guaiac with epta-phtalimido-peroxy-hexanoic acid; or tetra-methyl benzidine
with
a peroxide and optionally cyclo-dextrin; tetra-methyl benzidine with epta-
phtalimido-peroxy-hexanoic acid. It is of course clear that a blood sensor
needs
to be sensitive enough to ensure that blood of a quantity which is not
discernible
by normal visual inspection by the human eye is detected.
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Alternatively if the sensor includes a pH sensor then in a preferred
embodiment the pH sensor is selected to show a pH change in the range from
pH 4 to pH 7, preferably the pH sensor is provided by a composition comprising
carminic acid
In even further improved embodiments according to the present invention the
use
of a sensor is achieved by using a combination of at least 2 separate sensors
selected from pH sensors, blood sensors, or progesterone and/or estrogen
hormone sensors. This can even be further improved by selecting the sensors
such that they provide a single output signal.
According to the present invention the articles in which sensors for
menstruation prediction is used are absorbent sanitary articles, such as
sanitary
napkins, panty liners or interlabial articles/inserts for women. Such articles
are
conventionally of a layered construction, each layer having a wearer and a
garment facing surface. In general the article comprises a liquid permeable
topsheet on the wearer facing surface, a liquid barrier backsheet on the
garment
facing surface, an absorbent core sandwiched between the topsheet and the
backsheet. According to the present invention the panty liner should be thin
with
less than 3 mm thickness and most preferred is a panty liner which is suitable
to
be worn in a string undergarment and has a generally triangular shape (also
referred to as thong shape or thong liner respectively).
It is within the scope of the present invention to supplement the sensor by
additional menstruation cycle related detectors such as additional bio-
chemical or
electro-chemical or chemical detection means suitable to detect physiological
changes in the absorbed vaginal discharges which are indicative of the time
until
the start of menstruation and preferably create a separate, strengthened or
modified visual signal to the user of such articles. However also other
sensors,
capable of indicating the potential of current or approaching health related
risks
are preferred.
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DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
As used herein, the term "absorbent article" refers to devices which absorb
and contain body exudates, and more specifically, refers to devices which are
placed against or in proximity to the body of the wearer to absorb and contain
the
various exudates discharged from the body. The term "disposable" is used
herein
to describe absorbent articles which generally are not intended to be
laundered
or otherwise restored or reused as an absorbent article (i.e., they are
intended to
be discarded after a single use). As used herein, the term "joined"
encompasses
configurations whereby an element is directly secured to another element by
affixing the element directly to the other element, and configurations whereby
an
element is indirectly secured to another element by affixing the element to
intermediate members) which in turn are affixed to the other element. A
"unitary"
absorbent article refers to absorbent articles which are formed of separate
parts
united together to form a coordinated entity so that they do not require
separate
manipulative parts like a separate holder and liner. A preferred embodiment
for
the present invention is a unitary disposable sanitary napkin, panty liner or
interlabial article/insert. Of course other unitary disposable absorbent
articles if
used during the period prior to menstruation, such as diapers, briefs, or
other
incontinence devises, tampons, and wipes can also benefit from the present
invention but are not the subject of the appended claims.
An absorbent article, such as a sanitary napkin, panty liner or interlabial
article/insert, is conventionally constructed of three main elements: The
topsheet,
facing the user of the article during use and being liquid pervious in order
to allow
liquids to pass into the article; the backsheet, providing a liquid
containment such
that absorbed liquid does not leak through the article, this backsheet
conventionally provides the garment facing surface of the article; and the
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absorbent core sandwiched between the topsheet and the backsheet and
providing the absorbent capacity of the article to acquire and retain liquid
which
has entered the article through the topsheet.
Many absorbent articles and constructions are known in the art and have
been described in ample detail over time. All of such materials are useful in
the
context of the present invention, provided they do not interfere with the
selected
menstruation prediction sensors. In the following only those examples, which
are
particularly beneficial for the use in preferred absorbent articles according
to the
present invention are mentioned. Those skilled in the art will readily be able
to
identify alternative materials which can also be used and which maybe
particularly desirable in the context of menstruation predicting absorbent
articles
according to the present invention.
Topsheet
In general the topsheet is compliant, flexible, soft feeling and non-
irritating
to the wearer's skin. The topsheet preferably also can have elastic
characteristics
allowing it to stretch in one or two directions. As used herein, the term
"flexible"
refers to materials that are compliant and will readily conform to the general
shape and contours of the human body.
The topsheet can be made from a nonwoven or woven material or a film
which has been rendered liquid pervious by aperturing. The topsheet can also
be
provided as a composite material or be comprised of more than a single layer,
e.g. it can have a secondary topsheet or flow control layer. Such films and
nonwovens or wovens can be made for example from polymers such as
polyethylene or polypropylene compositions. Conventionally such polymers have
been filled with coloring material such as titanium dioxide to provide a white
opacity. Such a topsheet can also be provided without the coloring material to
provide a transparent film or nonwoven which has a high degree of light
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transmission while the absence of a color filler, such as titanium dioxide,
does
not cause any substantial material changes. Such a topsheet would be
particularly beneficial in the context of sensors providing visual indications
which
sensors are inside the article to allow visual inspection. Hence the absence
(or
reduction below 15%, i.e. about half of the conventional quantity) of an
opaque
color filler in the polymeric material from which the topsheet can be made
provides the additional benefit of better inspection characteristics (besides
less
costs and a reduced environment burden). It would also be possible to provide
a
non opaque, tinting color filler which allows transparency or partial
transparency
while providing a color. This tinting may beneficially be used to hide the
initial or
final color of the color indicators according to the present invention, and is
preferably pale yellow or blue.
The topsheet can be transparent or can be only partially transparent. It is
however sufficient for most embodiments according to the present invention if
the
topsheet is translucent to allow visual inspection of a color change.
Backsheet
In general the backsheet is compliant, flexible and soft feeling. The
backsheet prevents the exudes absorbed and contained in the absorbent core
from wetting clothes that contact the absorbent article such as undergarments.
Preferably the backsheet is impervious to liquids (e.g., menses, sweat and/or
urine). It can be manufactured from a thin plastic film, although other
flexible
liquid impervious materials can also be used. As used herein, the term
"flexible"
refers to materials that are compliant and will readily conform to the general
shape and contours of the human body. The backsheet preferably also can have
elastic characteristics allowing it to stretch in one or two directions.
The backsheet can comprise a woven or nonwoven material, polymeric
films such as thermoplastic films of polyethylene or polypropylene, or
composite
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materials such as a film-coated nonwoven material or fiber coated film.
Conventionally absorbent articles comprise a backsheet layer of a polyethylene
film having a thickness of from about 0.012 mm to about 0.051 mm, which can
be impervious or rendered micro-porous by use of an inert filler and
subsequent
mechanical stretching.
The backsheet is preferably breathable, i.e. allows the transmission of water
vapor, or even more preferable the transmission of air, however without
sacrificing its main purpose to provide leakage protection for absorbed
liquids.
The backsheet can also comprise more than one breathable layer so as to
replace a single breathable backsheet layer by at least 2 or 3 layers of a
different
or the same material. In particular two breathable layers, in which e.g. the
one
providing the wearer facing surface is a formed, apertured film with a three
dimensional structure and e.g. the other, garment facing layer is a non-woven
composite of melt-blown and spun-bonded fibers, are preferred breathable
backsheet constructions. As with the topsheet the backsheet can be provided
from a transparent or translucent material which would allow easier inspection
of
visual signals inside the article. Similarly it can also be provided with a
tinted
color filler, preferably pale yellow or blue.
Absorbent core
Conventionally the absorbent core can be a single entity or comprise
several layers. It can include the following components: (a) optionally a
primary
fluid distribution layer; (b) optionally a secondary fluid distribution layer;
(c) a fluid
storage layer; (d) optionally a fibrous layer underlying the storage layer;
and (e)
other optional components.
a. Primary Fluid Distribution Layer
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One optional component of the absorbent core according to the present
invention is the primary fluid distribution layer. This primary distribution
layer
typically underlies the topsheet (if present) and is in fluid communication
therewith. The primary distribution layer acquires body fluid for ultimate
distribution to the storage layer. This transfer of fluid through the primary
distribution layer occurs mainly in the thickness, but may also provide
distribution
along the longitudinal and transverse directions of the thong liner.
b. Optional Secondary Fluid Distribution Layer
Also optional according to the present invention is a secondary fluid
distribution layer. This secondary distribution layer typically underlies the
primary
distribution layer and is in fluid communication therewith. The purpose of
this
secondary distribution layer is to readily acquire bodily fluid from the
primary
distribution layer and distribute it along the longitudinal and transverse
directions
of the thong liner before transfer to the underlying storage layer. This helps
the
fluid capacity of the underlying storage layer to be fully utilized.
c. Fluid Storage Layer
Positioned in fluid communication with, and typically underlying the primary
or secondary distribution layers, is a fluid storage layer. It comprises
preferably
but not necessarily super-absorbent gelling materials usually referred to as
"hydrogels," "superabsorbent" "hydrocolloid" materials. Absorbent gelling
materials are those materials that, upon contact with aqueous fluids,
especially
body fluids, imbibes such fluids and thus form hydrogels. These absorbent
gelling materials are typically capable of absorbing large quantities of
aqueous
body fluids, and are further capable of retaining such absorbed fluids under
moderate pressures. In the prior art these absorbent gelling materials are
typically in a granular form of discrete, non-fibrous particles. However,
according
to the present invention these super-absorbent gelling materials can also be
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provided in non-granular form, preferably in a fibrous form. If no absorbent
gelling
materials are provided then the storage layer can be provided by the material
conventionally used as carrier material disclosed below.
In the fluid storage layer these absorbent gelling materials can be dispersed
homogeneously or non-homogeneously in a suitable fibrous matrix also referred
to as carrier. Suitable carriers include cellulose fibers, in the form of
fluff or
tissues, such as is conventionally utilized in absorbent cores. Modified
cellulose
fibers such as the stiffened cellulose fibers or viscose fibers can also be
used.
Synthetic fibers can also be used and include those made of cellulose acetate,
polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orlon),
polyvinyl
acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene,
polyamides
(such as nylon), polyesters, bi-component fibers, tri-component fibers,
mixtures
thereof and the like. Preferred synthetic and man-made fibers have a denier of
from about 3 denier per filament to about 25 denier per filament, more
preferably
from about 5 denier per filament to about 16 denier per filament. The carrier
fibers can be provided as carded, spun-bonded, melt-blown, wet-laid, air-laid
substrates or combination of such lay down methods or combinations of such
substrates.
Also preferably, the fiber surfaces are hydrophilic or are treated to be
hydrophilic. A storage layer can also include filler materials, such as
Perlite,
diatomaceous earth, Vermiculite, etc., that lower rewet problems. Further the
storage layer may comprise a binder including but not limited to Latex binders
which can be sprayed as an aqueous solution onto the surface of the storage
layer prior to curing.
If the absorbent gelling materials are dispersed non-homogeneously in a
fibrous matrix, the storage layer can be locally homogeneous, i.e. have a
distribution gradient in one or several directions within the dimensions of
the
storage layer. Non-homogeneous distribution thus includes e.g. laminates of
the
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fibrous carriers enclosing the absorbent gelling materials or regions in which
the
absorbent gelling material has a different concentration relative to other
regions.
If absorbent gelling material is present the storage layer preferably
comprises from 5% to 95% absorbent gelling materials, preferably from 5% to
50%, most preferably from 8% to 35%, absorbent gelling materials. Further the
storage layer can comprise from 5% to 95% carrier fibers, preferably from 95%
to
50%, most preferably from 92% to 65% carrier fibers.
Suitable absorbent gelling materials for use herein will most often comprise
a substantially water-insoluble, slightly crosslinked, partially neutralized,
polymeric gelling material. This material forms a hydrogel upon contact with
water. Such polymer materials can be prepared from polymerizable, unsaturated,
acid-containing monomers. Suitable unsaturated acidic monomers for use in
preparing the polymeric absorbent gelling material used in this invention
include
those listed in U.S. Patent 4,654,039 (Brandt et al), issued March 31, 1987,
and
reissued as RE 32,649 on April 19, 1988. Preferred monomers include acrylic
acid, methacrylic acid, and 2-acrylamido-2-methyl propane sulfonic acid.
Acrylic
acid itself is especially preferred for preparation of the super-absorbent
material,
it also has a 'natural' transparency which is not optimal but acceptable if
the
desired transparency is not too high.
Whatever the nature of the basic polymer components of the hydrogel-
forming polymeric absorbent gelling materials, such materials will in general
be
slightly crosslinked. Crosslinking serves to render the hydrogel-forming
polymer
gelling materials substantially water-insoluble, and cross-linking thus in
part
determines the gel volume and extractable polymer characteristics of the
hydrogels formed from these polymeric gelling materials. Suitable crosslinking
agents are well known in the art and include, for example, those described in
greater detail in U.S. Patent 4,076,663 (Masuda et al), issued February 28,
1978.
Preferred crosslinking agents are the di- or polyesters of unsaturated mono-
or
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polycarboxylic acids with polyols, the bisacrylamides and the di- or triallyl
amines.
Other preferred crosslinking agents are N,N'-methylenebisacrylamide,
trimethylol
propane triacrylate and triallyl amine. The crosslinking agent can generally
constitute from about 0.001 mole percent to 5 mole percent of the resulting
hydrogel-forming polymer material. More preferably, the crosslinking agent
will
constitute from about 0.01 mole percent to 3 mole percent of the hydrogel-
forming polymeric gelling material.
The slightly crosslinked, hydrogel-forming polymeric gelling materials are
generally employed in their partially neutralized form. For purposes of the
present
invention, such materials are considered partially neutralized when at least
25
mole per-cent, and preferably at least 50 mole percent of monomers used to
form the polymer are acid group-containing monomers that have been
neutralized with a salt-forming cation. Suitable salt-forming cations include
alkali
metal, ammonium, substituted ammonium and amines. This percentage of the
total monomers utilized which are neutralized acid group-containing monomers
is
referred to herein as the "degree of neutralization."
While these absorbent gelling materials have typically been disclosed in the
prior art in granular form, it is possible in the context of the present
invention that
the absorbent gelling material is in a non-granular form for example as
microstructures such as fibers, sheets or strips or in a form suitable for
coating,
e.g. before curing or as part of an adhesive substance. A macrostructure can
be
prepared by forming the particulate absorbent gelling material into an
aggregate,
treating the aggregated material with a suitable crosslinking agent,
compacting
the treated aggregate to densify it and form a coherent mass, and then curing
the
compacted aggregate to cause the crosslinking agent to react with the
particulate
absorbent gelling material to form a composite, porous absorbent
macrostructure. Such porous, absorbent microstructures are disclosed, for
example, in U.S. Patent 5,102,597 (Roe et al), issued April 7, 1992.
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d. Optional Fibrous Layer
An optional component for inclusion in the absorbent cores according to the
present invention is a fibrous layer adjacent to, and typically underlying the
storage layer. This underlying fibrous layer would typically provide the same
function as the secondary fluid distribution layer.
e. Other Optional Components
The absorbent cores according to the present invention can include other
optional components normally present in absorbent webs. For example, a
reinforcing scrim can be positioned within the respective layers, or between
the
respective layers, of the absorbent cores. Such reinforcing scrims should be
of
such configuration as to not form interfacial barriers to fluid transfer,
especially if
positioned between the respective layers of the absorbent core. Given the
structural integrity that usually occurs as a result of thermal bonding,
reinforcing
scrims are usually not required for the absorbent structures according to the
present invention.
Another component which can be included in the absorbent core according
to the invention and preferably is provided close to or as part of the primary
or
secondary fluid distribution layer are odor control agents. Typically active
carbon
coated with or in addition to other odor control agents, in particular
suitable
zeolite, silica or clay materials, are optionally incorporated in the
absorbent core.
Physical characteristics of absorbent cores
Absorbent cores are usually non extensible and non-elastic, however, they
can be rendered extensible and depending on the selected materials can also be
made to have elastic characteristics. The term "extensible" as used
hereinafter
refers to a structure which under external forces such as those occurring
during
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use extends in the direction of the forces or in the direction of a component
of the
forces in cases where only mono directional extensibility is provided.
The term "elastic" as used hereinafter refers to extensible structures which
return at least partially to their initial state after the forces causing the
extension
seize to be excerpted. Absorbent cores can be corrugated or pleated in one or
several directions to provide a certain extensibility while selection of
elastic fibers
for the structure can provide elasticity.
If intended for use in panty liners the absorbent cores should preferably be
thin. A thickness of less than 5 mm, preferably less than 3 mm and even more
preferable between 0.8 and 1.8 mm is desirable such that the resulting panty
liners can also have a low thickness. As with the topsheet or the backsheet
transparency of or tinting of the materials forming the core can be
particularly
desirable to allow easy inspection of the detector status.
Non-limiting examples of sanitary napkin, panty liners which may be
provided with a detection means include those manufactured by The Procter &
Gamble Company of Cincinnati, Ohio as: ALLDAYS~ Panty Liners with
DriWeaveO manufactured according to U.S. Patents 4,324,246; 4,463,045; and
6,004,893; (ALWAYSO Ultrathin Slender Maxi with Wings manufactured
according to U.S. Patents 4,342,314, 4,463,045, 4,556,146, B1 4,589,876,
4,687,478, 4,950,264, 5,009,653, 5,267,992, and Re. 32,649; ALWAYS~
Regular Maxi; ALWAYSO Ultra Maxi with Wings; ALWAYS~ Maxi with Wings;
ALWAYS~ Ultra Long Maxi with Wings; ALWAYS~ Long Super Maxi with
Wings; and ALWAYSO Overnight Maxi with Wings). However most other
commercially available sanitary napkin or panty liners could also serve as an
example for the potential use in the context of the present invention.
Non-limiting examples of interlabial devices which may be provided with a
detection means are described in U.S. Patents 5,762,644; 5,885,265; 5,891,126;
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5,895,381; 5,916,205; 5,951,537; 5,964,689; 5,968,026; Des. 404,814; and Des.
413,669.
Detectors/Sensors
According to the present invention at least one sensor for the detection of
menstruation selected from blood sensors, pH-sensors and progesterone and/or
estrogen hormone sensors is used in the manufacturing of sanitary napkins,
panty liners or interlabial articles/inserts. As used herein, the term
"sensor" is
defined as a component comprising one or more reactive means being adapted
to detect one or more target substances (also referred to as analytes) such as
microorganisms or related (bio-)molecules (e.g., an enzyme sensor, organelle
sensor, tissue sensor, microorganism sensor, immunosensor, and chemical or
electrochemical sensor), additionally having the capability to provide a
signal of
said detection to the wearer, caretaker, or an actuator. The term "reactive"
is
defined as having the capability to selectively interact with such target
substances.
There are 2 categories of sensors which have different sensitivity:
biosensors and chemical-/electro-chemicall sensors. Generally biosensors
function by providing a means of specifically binding, and therefore
detecting, a
target biologically active analyte. In this way, the biosensor is highly
selective,
even when presented with a mixture of many chemical and biological entities,
such as present in vaginal discharge. Electrochemical and chemical sensors, on
the other hand, which rely on chemically reactive means, generally do not have
either the high selectivity or the amplification properties of biosensors but
are
highly reliable, inexpensive, i.e. useful in the context of commodity
products, and
often very well established, i.e. proven to be save for use on human skin.
Often
the target analyte is a minor component of a complex mixture comprising a
multiplicity of biological and other components. Thus, in many biosensor
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applications, detection of target analytes to the parts-per-billion, parts-per-
trillion,
or even lower levels is necessary.
Blood sensor
According to the present invention a blood sensor can be used. There are
many blood sensors commercially available which can be used provided their
sensitivity is sufficient to detect blood at quantities which are not visually
discernible to the human eye. However according to the present invention a
specifically selected chemical composition as blood sensor is preferred. When
referring to blood herein a typical component of blood, such as hemoglobin or
iron, can of course also be used as analyte.
The preferred chemical composition comprises a color indicating
component selected from Gum Guaiac or tetra-methyl-benzidine or combinations
thereof which reacts when oxidized and an oxidizing component selected from a
peroxide or a per-acid or combinations thereof. In particular the following
combinations have been found useful as blood sensors in the context of this
invention:
- Gum Guaiac with a peroxide and optionally cyclo-dextrin
- Gum Guaiac with , epta-phtalimido-peroxy-hexanoic acid
- tetra-methyl benzidine with a peroxide and optionally cyclo-dextrin
- tetra-methyl benzidine with epta-phtalimido-peroxy-hexanoic acid
The Gum Guaiac is a resin found from wood of Guaiacum officinale or
Guaiacum santum (mainly found in Mexico or West India). Gum Guaiac is
historically used as flavoring agent for food(and hence has a long record of
save
usage by humans) and is known for its ability to indicate the presence of
blood or
hemoglobin, especially in feces. According to the present invention the Gum
Guaiac wood resin is preferred, however one or all of the active components,
whether naturally or artificially derived, can be used in stead of the wood
resin.
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The best known active components are guaiacol (OHC6H40CH3, CAS 90-05-1 ),
guaiaconic acid and (furo)-guaiacine.
The cyclo-dextrin used this composition is useful to improve stability of the
peroxide and help carry the peroxide into aqueous solution upon wetting.
Alternatively to or in combination with cyclo-dextrin also metal-chelants,
such as
EDTA (ethylene di-amino tetra acetic acid or its salt) can also be used. In
general
the oxidizing component needs to be stable and insensitive to storage
conditions
usual for such articles (e.g. in a warm and high humidity environment of a
bathroom). If the oxidizing component is a hydro peroxide then physio-chemical
stabilization e.g. by use of cyclo-dextrin is desirable. For per-acids such
stabilization has been found to be less necessary, in particular for the
preferred
epta-phthalimido-peroxy-hexanoic acid. It is also desirable that the oxidizing
component is not activated by the conventional components in sanitary articles
and the humidity introduced during wearing (e.g. sweat) or absorption of
vaginal
discharges without blood component. The same applies of course also to the
color indicator.
Not only stabilization of each component but also premature and accidental
reaction of the 2 components should preferably be prevented. This can be
achieved by separating them physically in that one is applied on one surface
of
one layer in the article according to the present invention and the other
component is applied on the other side of that layer. Alternatively one
component
can be applied on one surface of one layer and the other component on the
surface facing the same direction of another layer. Finally one component can
be
applied so that it is located inside a layer e.g. inside the central absorbent
core
layer while the other component is located on at least part of the surface of
that
layer. Application of both components on the same layer can be done in an
alternate pattern such as stripes, dots or different shapes. The sensor can be
provided in discrete parts of a surface of a layer or as full surface coverage
of the
layer (both components or one alone). The components can be provided either
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one or both as powder, liquid or as components in an adhesive admixture for
better coating.
It is also possible to separate the 2 components by providing at least one,
e. g. the oxidizing component, completely separate from the article (and hence
from the other component) e. g. in the form of a spray or liquid or powder,
which
is applied to the article after use to provide the desired detection. Such
detection
systems could be especially desirable in the context of articles which are
worn in
close proximity and can be flushed into the toilet (e.g. interlabial
articles/inserts).
Such systems would address concerns of stability for the separate component
but also of concerns with materials coming into close contact with the
regenerative organs of a woman.
The color indicator and the oxidizing material both are reactive only in
aqueous solution. Hence they will only start to react once they have dissolved
in
the vaginal discharges and are activated by the presence of blood. In order to
accelerate and promote the dissolution it is preferred to include a
tensioactive
material, such as a surfactant, preferably a non-ionic surfactant, or
polyethylene-
glycol or a combination thereof. The tensioactive should preferably be located
such that it is wetted first before the liquid reaches the 2 components.
pH Sensors
In addition or alternatively to the blood sensor a signal of the approach of
menstruation in the form of a change of the pH of vaginal discharges can be
detected and used to provide a desired signal. pH electrodes or pH color
indicators are well known and have been used for the detection of vaginal
infections or at least as indications of occurrences of vaginal flora changes
implicating some health concern.
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According to the present invention, and under the assumption of a healthy
vaginal flora, a change in the vaginal pH is also indicative of a time
proximity to
the start of menstruation.
Hence any commercially available pH indicator composition which is
indicative of the menstruation related increase in pH to values between pH 4
and
pH 7 can be used in the present invention. Such pH sensors undergo a color
change due to a pH change in the range between pH 4 and pH 7 and are
commercially available e.g. from The Merck Company, Darmstadt, Germany. A
highly preferred pH sensor, having a well established safety profile in this
context
is carminic acid, which is used as a food dye, but undergoes a color change in
the range between pH 4 and pH 7. Carminic acid is a tricyclic compound which
has the compound formula C22-H20-013.
Hormone Sensors
In addition or alternatively the presence of certain hormones, especially
progesterone or estrogen can be used as tracers in vaginal discharges to
provide
prediction of the time until start of menstruation.
The cyclic nature of the hormones of the menstrual cycle (i.e., the full 28
day cycle) make them particularly useful in understanding, the position of an
individual during her cycle. This has historically been used in the assessment
of
fertility, but the use according to the present invention goes beyond current
uses
of hormones to predict ovulation and pregnancy. For example, progesterone
peaks and then drops just prior to menstruation. Estrogen also declines just
prior
to menstruation. Thus, alone or in combination with other predictors, such as
blood detection or pH indication, assay for either of these two hormones will
allow reliable prediction of the onset and the presence of menstruation. The
timing of the peak of these hormones, along with their subsequent drop, allows
a
highly accurate marking of the time before menstruation.
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The only potential drawback of such hormone sensors is the associated
cost and complexity due to lack of simple and cheep visualization systems.
This
makes their use especially for medical purposes highly attractive. Hence the
use
of hormone detection in order to predict menstruation is preferably provided
in
conjunction with blood detection and/or pH detection to improve the accuracy
of
such predictions. Such systems are particularly useful in the context of a
medical
scheme to serve an individual having health related issues relating to the
start of
menstruation. Such combined systems are discussed below in greater detail but
can be provided as partially integral with the absorbent sanitary napkin,
panty
liner or interlabial article/insert according the present invention or even as
a
completely separate system.
Use of hormones may also be developed for other points of interest in the
cycle. Follicle Stimulating Hormone (FSH) exhibits a peak about one week prior
to ovulation, giving more advance timing for pregnancy planning than assays
for
the luteinizing hormone, which exhibits a sharp peak at the time of ovulation.
Two
to three days of fertility may be missed when relying only on assay of the
luteinizing hormone. Thus, in a diagnostic for ovulation herein, it is highly
preferred to measure for both the Follicle Stimulating Hormone and the
luteinizing hormone along with estrogen.
A rise in Follicle Stimulating Hormone to a near constant amount signals the
approach of menopause. This may be of use in planning healthy approaches to
menopause, such as Hormone Replacement Therapy, nutritional changes, and
checks for osteoporosis.
Additional Sensors
The sanitary article according to the present invention can be provided with
several additional sensor and detector systems which allow e.g. indications or
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23
predictions of health related issues of the individual. Such additional sensor
systems are primarily useful for articles which are used in a care taker
situation.
In general such additional systems or biosensors comprise a recognition
element, or molecular recognition element, that provides detection for a
particular
analyte. The recognition element may be a biologically derived material such
as
an enzyme or sequence of enzymes; an antibody; a membrane receptor protein;
DNA; an organelle, a natural or synthetic cell membrane; an intact or partial
viable or nonviable bacterial, plant or animal cell; or a piece of plant or
mammalian tissues, and generally functions to interact specifically with a
target
analyte. The recognition element is responsible for the selective recognition
of
the analyte and creates a physical-chemical signal that provides the basis for
the
output signal.
Biosensors may include biocatalytic biosensors, and bioaffinity biosensors.
In biocatalytic biosensor embodiments, the bio-recognition element is
"biocatalytic" and may comprise an enzyme, organelle, piece of plant or
mammalian tissue, or whole cells, the selective binding sites "turn over"
(i.e., can
be used again during the detection process), resulting in a significant
amplification of the input signal. Biocatalytic sensors such as these are
generally
useful for real-time, continuous sensing.
Bioaffinity sensors are generally applicable to bacteria, viruses, and toxins
and include chemoreceptor-based biosensors and/or immunological sensors (i.e.
immunosensors). Chemoreceptors are complex biomolecular macroassemblies
responsible, in part, for a viable organism's ability to sense chemicals in
its
environment with high selectivity. Chemoreceptor-based biosensors comprise
one or more natural or synthetic chemoreceptors associated with a means to
provide a signal (visual, electrical, etc.) of the presence or concentration
of a
target biological analyte. Chemoreceptors may include whole or partial nerve
bundles (e.g., from antennae or other sensing organs) and/or whole or partial
natural or synthetic cell membranes. On the other hand, the bio-recognition
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24
elements of immunosensors are generally antibodies. Antibodies are highly
specific and can be made toward bacteria, viruses, fragments of microorganisms
(e.g., bacterial cell walls, parasite eggs or portions thereof, etc.), and
large
biomolecules. Suitable antibodies may be monoclonal or polyclonal. In any
case,
bioaffinity biosensors are generally irreversible because the receptor sites
of the
biosensor become saturated when exposed to the target biological analyte. In
certain embodiments biocatalytic and bioaffinity biosensors may be combined.
Biocatalytic and bioaffinity biosensor systems are described in more detail in
Journal of Chromatography, 510 (1990) 347-354 and in the Kirk-Othmer
Encyclopedia of Chemical Technology, 4t" ed. (1992), John Wiley & Sons, NY.
The biosensors of the present invention preferably also detect biologically
active analytes related to impending (i.e., future presentation of symptoms is
likely) or current human systemic disease states, including pathogenic
bacteria,
parasites, viruses, fungi such as Candida albicans, antibodies to pathogens,
and/or microbially produced toxins. Additionally, the biosensor may target
biologically active analytes related to impending or current localized health
issues, such as stress proteins (e.g., cytokines) and IL-1a (interleukin 1-
alpha)
that may precede the clinical presentation of skin irritation or inflammation.
In
preferred embodiments, the biosensor functions as a proactive sensor,
detecting
and signaling the wearer or caretaker of the impending condition prior to the
presentation of clinical symptoms. This allows time to administer prophylactic
or
remedial treatments to the wearer which can significantly reduce, if not
prevent,
the severity and duration of the symptoms. Further, the biosensor by detecting
the presence of a target biological analyte in the wearer's bodily waste, may
detect residual contamination on a surface, such as skin, in contact with the
biosensor, and provide an appropriate signal.
The signal generated by the recognition element or elements is
communicated visually to the wearer or caretaker, e.g. via a color change
visible
to the human eye. The signal may be qualitative (e.g., indicating the presence
of
WO 00/65096 CA 02367588 2001-10-16 pCT/US00/11206
the target biological analyte) or quantitative (i.e., a measurement of the
amount
or concentration of the target biological analyte). In any case, the signal is
preferably durable i.e., stable and readable over a length of time (typically
at
least of the same magnitude as the usage period of the article). Further, the
sensor may be adapted to detect and/or signal only concentrations of the
target
biological analyte above or below a predefined threshold level (e.g., in cases
wherein the target biological analyte is normally present in the bodily
waste).
As described above, the target analyte that the biosensors of the present
invention are adapted to detect is pathogenic microorganisms such as the
pathogenic microorganisms implicated in human gastrointestinal diseases,
especially those resulting in diarrhea. It has been found that severe chronic
diarrhea may result in weight loss and permanent physical and mental
retardation. A non-limiting list of pathogenic bacteria that the biosensor 60
may
detect include any of the various pathogenic strains of Escherichia coli
(commonly known as E. Coli); Salmonella strains, including S. typhi, S.
paratyphi,
S. enteriditis, S. typhimurium, and S. heidelberg; Shigella strains such as
Shigella sonnei, Shigella flexneri, Shigella boydii, and Shigella dysenteriae;
Vibrio cholerae; Mycobacterium tuberculosis; Yersinia enterocolitica;
Aeromonas
hydrophila; Plesiomonas shigelloides; Campylobacter strains such as C. jejuni
and C. coli; 8acteroides fragilis; and Clostridia strains, including C.
septicum, C.
perfringens, C. botulinum, and C. difficile. A non-limiting example of a
commercially available biosensor adapted to detect E. coli is available from
AndCare, Inc. of Durham, NC, as test kit #4001. ABTECH, Scientific, Inc., of
Yardley, PA offers "bioanalytical biotransducers", available as BB Au-1050.5-
FD-
X, which may be rendered biospecific (for microorganisms or other target
biological analytes as described herein) by covalently immobilizing
polypeptides,
enzymes, antibodies, or DNA fragments to their surfaces. Other suitable
microbial biosensors are described in US Patents 5,869,272 (gram negative
organisms); 5,795,717 (Shigella); 5,830,341; 5,795,453; 5,354,661; 5,783,399;
5,840,488; 5,827,651; 5,723,330; and 5,496,700.
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The target analytes that the biosensors of the present invention are adapted
to detect may also be viruses. These may include diarrhea-inducing viruses
such
as rotavirus, or other viruses such as rhinovirus and human immunodeficiency
virus (HIV). An exemplary biosensor adapted to detect HIV is described in US
Patents 5,830,341 and 5,795,453, referenced above.
In alternative embodiments, the target analytes that the biosensors of the
present invention are adapted to detect may also be parasites, especially
those
which inhabit the gastrointestinal tract during some point in their life-
cycle. Such
parasites may include protozoans, worms, and other gastrointestinal parasites.
Other examples of parasites which may be detected include entamoeba
histolytica (which cause amoebic dysentery), trypana cruzi (which causes
Chagas disease), and plasmodium falciparum.
In yet other embodiments, the target analytes the biosensors of the present
invention are adapted to detect fungi such as Candida albicans. In addition to
pathogenic bacteria, certain beneficial colonic bacteria may be detected
and/or
measured as a health indicator, such as 8ifidobacteria and Lactobacillus
strains.
The target analytes that the biosensors of the present invention are adapted
to detect may also be proteins or antigens related to skin distress.
Preferably,
these analytes are detectable on or at the skin surface, preferably prior to
the
presentation of clinically observable skin irritation. These may include
stress
proteins such as cytokines, histamine, and other immune response factors
including interleukins (such as IL-1a, IL-2, IL-3, IL-4, and IL-8) and
interferons
(including interferons a and g). Again, these are preferably detectable by the
biosensor 60 prior to the onset of clinically observable redness, irritation,
or
dermatitis. Additionally, the biosensors of the present invention may be
adapted
to detect enzymes, or other biological factors, implicated in skin irritation
(e.g.,
diaper dermatitis), including tryspin, chymotrypsin, and lipase.
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The biosensors of the present invention may also comprise bio-recognition
systems, including enzymes or binding proteins such as antibodies immobilized
onto the surface of physico-chemical transducers. For example, a specific
strain
of bacteria may be detected via biosensors employing antibodies raised against
that bacterial strain. Alternatively, a target bacteria may be detected by a
bio-
recognition element (including antibodies and synthetic or natural molecular
receptors) specific to extracellular products of the target bacteria, such as
toxins
produced by that strain (e.g., E. coli). Exemplary enzyme electrodes that may
be
used to detect phenols (e.g. in urine or feces) include tyrosinase based
electrodes or polyphenol oxidase enzyme electrodes described in U.S. Patent
No. 5,676,820 entitled "Remote Electrochemical Sensor," issued to Joseph
Wang et al. on October 14, 1997 and U.S. Patent No. 5,091,299 entitled "An
Enzyme Electrode For Use In Organic Solvents," issued to Anthony P. F. Turner
et al. on February 25, 1992, respectively
In any of the foregoing examples, the specific microorganism may be
directly detected or may be detected by binding a toxin, enzyme, or other
protein
produced by the organism or an antibody, such as a monoclonal antibody,
specific to the organism. Exemplary biosensors adapted to detect proteolytic
enzymes described in US Patent 5,607,567 and toxins in US Patents 5,496,452;
5,521,101; and 5,567,301.
The biosensor of the present invention may comprise one or more
"proactive sensors". This is especially useful in embodiments where the
detection
of the target biologically reactive analyte precedes the onset of clinically
observable health symptoms. As used in this application, the term "proactive
sensor" refers to a sensor that is capable of detecting changes or signals on
the
body of the wearer (i.e., skin) or in the waste, i.e., inputs, that directly
relate or, at
a minimum, correlate to the occurrence of an impending or potential health or
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skin related even. Proactive sensors may respond to one or more specific
inputs
as described above.
A proactive sensor may detect an impending event or detect a parameter
that directly relates, or at a minimum correlates to the occurrence of an
impending event, particularly a systemic or skin health event or condition
(i.e., the
presentation of clinically observable indications or symptoms). An impending
event that may be detected or predicted by a proactive sensor of the present
invention may include diarrheal disease, skin irritation or rash (including
candidiasis), and/or other types of illness or medical conditions of the
wearer
such as a parasitic infestation. The detected biological analyte may be one or
more steps removed from the actual presentation of clinical symptoms. For
example, the biosensor may detect potential precursors to the above conditions
(e.g., fecal contamination of the skin that may precede the elicitation of
stress
proteins which may, in turn, precede clinically observable skin irritation. A
parameter that correlates to an event is any measurable input, signal such as
one or more of the potential inputs listed above, that correlates with the
occurrence of the event within the frame of reference of the system (i.e., a
signal
caused by the waste or the wearer). Proactive sensors in an article may
measure
one or more different inputs in order to predict an event. For example, the
proactive sensor may monitor for Candida albicans in vaginal discharges and
residual colonic bacteria on the skin (i.e., detecting residual contamination)
both
of which are signals that may precede skin irritation.
In biosensor embodiments wherein the bio-recognition element does not
produce an easily visible signal (e.g., a color change), the biosensor may
include
a transducer in communication with the bio-recognition element in order to
convert the physico chemical signal from the bio-recognition element into a
usable signal to the wearer, caretaker, or component of the article (e.g., and
actuator). Exemplary transducers may include electrochemical transducers
(including potentiometric, amperometric, and conductimetric transducers),
optical
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transducers (including fluorescence, bioluminescence, total internal
reflective
resonance, and surface plasmon resonance), thermal transducers, and acoustic
transducers, as known in the art. A power source, such as a miniature 3 volt
watch battery or printed thin film lithium battery, may be connected with the
biosensor to provide any required power.
Combinations of sensors
In one particularly preferred embodiment of the present invention the article
comprises in addition to one sensor another separately activated and
independently functioning sensor to detect the approach of menstruation.
E.g. it is clear that the detection of blood in particular to allow prediction
of
menstruation cannot be considered to be one hundred percent accurate. First of
all, the indicator itself needs to be provided with a high degree of accuracy
for
only detecting blood, i. E. it should be insensitive to other materials to
which it is
exposed. On the other hand, the sensitivity should be high to allow detection
of
low quantities of blood, i.e. prior to its visual recognition. These two
competing
interests need to be balanced.
Further the presence of blood is well known as an indication of the
approach of menstruation. However also injuries or pathological situations may
cause the presence of low levels of blood in vaginal discharges. It is
therefore
desirable to provide the sanitary article with an additional sensor selected
from
pH sensors or progesterone and/or estrogen hormone sensors providing a
second independent signal of the approach of menstruation. it is then of
course
necessary to use the resulting signal in combination to identify the time
delay
until start of menstruation.
E.g. if additional sensors are provided as color change indicators they can
be provided separately, for example in a different region of the article (of
course,
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such that they will be exposed to vaginal discharges). Alternatively they can
be
provided together with the color indicator providing a multicolor indication
as
explained in an example below.
For example, in the context of Gum Guaiac, which provides a color change
to blue and a pH sensor providing e.g. a color change to red, the mixed color
sensor (blue and red) would need to turn purple in order to provide an
indication
with high accuracy of the time until the start of menstruation. A different
color
change (such as only blue or only red) would indicate that the menstruation is
still
some more time away or that there is the potential of a health issue (a pH
change alone can be indicative - but does not have to - of infections, while
blood
indication alone can - but does not have to - indicate a wound). Of course the
absence of a color change would indicate that there is still time until the
next
menstruation. Preferably such sensors are provided separately next to each
other such that 2 color indications are indicative of menstruation approaching
and
a single color change is indicative as explained above.
Examples
A panty liner was provided with a blood indicator and provided consistent
indication of the approach of menstruation more than 4 hours advance on
different women. The panty liner was a conventional panty liner with a
topsheet a
secondary topsheet layer between the topsheet and the core, a core layer and a
polyethylene film as backsheet.
The blood indicator comprised 2 components, a first component being a
composition of 0.1 g of polyethylene-glycol as carrier and tensioactive
component with 0.04 g of epta-phtalimido-peroxy-hexanoic acid. The second
component was a composition of 0.2 g of polyethylene-glycol as carrier and
tensioactive component with 0.02 g of Gum Guaiac. The first component was
spread over a 20 mm wide and 130 mm long strip onto the garment facing
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surface of the secondary topsheet layer. The second component was spread
over a 20 mm wide and 130 mm long strip onto the garment facing surface of the
absorbent core.
Alternatively a commercially available blood detector strip was inserted into
a
panty liner as exemplified above between the topsheet and the backsheet also
having acceptable results. Such strips are available e.g. as Chroma 6 T"' from
the
Menarini Company, Florence Italy, Arkray Aution Sticks TM, by KDK Corporation
of Kyoto, Japan. In another alternative a pH indicator strip was used in the
same
fashion as the blood indicator strip, again with acceptable results. Such pH
indicator strips are available as Spezial Indikator, code 109542, from the
Merck
Company mentioned above.
