U.S. patent application number 12/383580 was filed with the patent office on 2010-01-28 for external breast prosthesis.
Invention is credited to Aldo A. Laghi.
Application Number | 20100023123 12/383580 |
Document ID | / |
Family ID | 37830988 |
Filed Date | 2010-01-28 |
United States Patent
Application |
20100023123 |
Kind Code |
A1 |
Laghi; Aldo A. |
January 28, 2010 |
External breast prosthesis
Abstract
An external breast prosthesis includes an elastomeric skin in
the form of a human breast surrounding an inner material such as a
silicone gel or hydrogel. The inner material may be of a defined
shape or may be amorphous and conform to the shape of the
elastomeric skin. The elastomeric skin can be formed from a front
skin and a rear skin, and the skins can be made of a soft styrenic
elastomer having attributes similar to a gel. The elastomeric skin
can be substantially soft to the touch and have an elastic memory
that tends to maintain the skin in a pliable yet pre-defined
shape.
Inventors: |
Laghi; Aldo A.; (Clearwater,
FL) |
Correspondence
Address: |
Ronald A. Christaldi
101 East Kennedy Boulevard, Suite 2800
Tampa
FL
33602
US
|
Family ID: |
37830988 |
Appl. No.: |
12/383580 |
Filed: |
March 25, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11222288 |
Sep 8, 2005 |
|
|
|
12383580 |
|
|
|
|
Current U.S.
Class: |
623/7 ;
450/55 |
Current CPC
Class: |
Y10T 428/249953
20150401; A61F 2/52 20130101; A61F 2002/5053 20130101; A61F 2/5046
20130101 |
Class at
Publication: |
623/7 ;
450/55 |
International
Class: |
A61F 2/52 20060101
A61F002/52; A41C 3/10 20060101 A41C003/10 |
Claims
1. A kit, comprising in one or more containers: an external breast
prosthesis comprising a front skin configured and dimensioned in a
shape that approximates a form of a human breast, a rear skin
joined with said front skin and forming a cavity therebetween; and
a gel disposed in said cavity, wherein said front skin comprises an
elastomeric polymer; and a garment having a pocket adapted to hold
said external breast prosthesis against a user when the garment is
worn by a user.
2. The kit of claim 1, wherein said garment further comprises a
breast cup for supporting a breast of a user when the garment is
worn by a user.
3. The kit of claim 1, wherein the garment is a mastectomy bra.
4. The kit of claim 1, wherein said elastomeric polymer comprises:
a triblock copolymer comprising styrene and at least one of
ethylene, butadiene, butylene, isoprene, or propylene, and a
plasticizing agent.
5. The kit of claim 4, wherein the triblock copolymer is any of
polystyrene-b-poly(ethylene/propylene),
polystyrene-b-poly(ethylene/propylene)-b-polystyrene,
polystyrene-b-poly(ethylene/butylene)-b-polystyrene, or
polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene.
6. A garment, comprising: an external breast prosthesis comprising
a gel bounded by an elastomeric skin comprising a triblock
co-polymer, said elastomeric skin having a shape approximating a
human breast; at least one support attached with said external
breast prosthesis and configured to position said external breast
prosthesis against a user such that the shape of said external
breast prosthesis provides an appearance of a normal breast of the
user.
Description
[0001] This application is a divisional of U.S. nonprovisional
application Ser. No. 11/222,288, filed on Sep. 8, 2005, which is
herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to prosthetic devices, and in
particular to breast prostheses and methods of making such
prostheses.
BACKGROUND OF THE INVENTION
[0003] External breast prostheses are artificial breast forms that
can be worn after a surgery or other treatment in which the breast
has been altered or removed. For example, external breast
prostheses are available for women who have had a mastectomy or
lumpectomy to remove a breast cancer, and to those who have uneven
or unequal sized breasts resulting from radiation or reconstruction
procedures.
[0004] A mastectomy is a common treatment for breast cancer that
involves surgically removing the breast or a portion of the breast.
A modified radical mastectomy is the most common type of mastectomy
performed today. This procedure involves removing the breast,
nipple/areolar region, and often the axillary (underarm) lymph
nodes. Other types of mastectomies include simple mastectomy which
generally involves removing the breast but no lymph nodes, and
partial mastectomy which generally involves removing a cancerous or
otherwise abnormal portion of the breast tissue along with a margin
of normal breast tissue.
[0005] An external breast prosthesis can be worn to help replace
the appearance and feel of a breast removed or altered by surgery.
Such replacement is often not only for cosmetic, psychological and
emotional reasons, but also can provide physiological benefits as
well. For example, some breast prostheses are weighted as a
therapeutic measure to replace the weight of the lost breast. When
fitted with a breast prosthesis that approximates the size and
weight of the remaining breast, the weight equilibrium of the body
may be kept in balance following surgery to help avoid
musculoskeletal problems such as lower back and neck pain which are
common following a mastectomy.
[0006] Currently available external breast prostheses include
entire breast forms and partial forms. Partial breast prostheses
are commonly known as equalizers. Breast prostheses can be
symmetrical (i.e., they can be turned to fit either side of the
body) or asymmetrical (i.e., they fit only the right or the left
side). Prostheses can be attached to the skin using an adhesive or
other attachment mechanism. Alternatively, a breast prosthesis may
be worn inside of a garment such as a mastectomy bra which includes
a pocket or other feature to hold the prosthesis in place.
Prefabricated prostheses can come in various shapes, sizes and skin
tones and may be custom fabricated using a mold that is taken of
the breast and/or chest wall prior to or after surgery.
[0007] Most external breast prostheses available today are made of
a gel, either silicone or water based, contained in a plastic film
that acts as a skin to contain the gel. The film is generally made
of polyurethane and is substantially inelastic. Existing external
breast prostheses incorporating such plastic film have a number of
drawbacks and deficiencies. For example, the film has an unnatural,
relatively inflexible feel that is substantially different to the
touch from the feel of human skin. Also, the film forms hundreds of
wrinkles as the prosthesis is deformed from its original molded
shape. In fact wrinkles generally are always present on the
prosthesis skin even when such prosthesis is donned. Also, the
inner gel used in such a prosthesis must have its own shape, as the
film does not have the inherent ability to force the gel into a
predetermined shape.
[0008] Other available external breast prostheses consist of a
piece of foam in the shape of a human breast. Such foam prostheses
generally lack the consistency, feel, appearance and weight of
gel-filled prostheses and are therefore of limited functionality
and performance. In some cases, such prostheses are used
temporarily following surgery, for example to provide a basic
breast form that is light-weight to minimize discomfort during
healing of the surgical scars.
[0009] Some existing breast prostheses have two or more chambers
defined by polyurethane films, where each chamber is filled with a
gel of different consistency or firmness. Like existing
single-chambered prostheses, such multi-chambered prostheses employ
a thin polyurethane outer barrier that is substantially inelastic
and lacking characteristics that provide the look and feel of human
skin.
[0010] Accordingly, there is a need in the art to provide improved
external breast prostheses having the texture, appearance, and
elasticity of a normal human breast.
SUMMARY OF THE INVENTION
[0011] The present invention overcomes the disadvantages of the
current art and provides external breast prostheses and methods of
making such prostheses with improved skin and other features for
providing the texture, appearance, firmness and elasticity
approximating that of a normal human breast.
[0012] In one embodiment, an external breast prosthesis has one or
more elastomeric skins, which form the outer surface of the
prosthesis, and that define one or more inner chambers filled with
an inner material, for example a liquid or a gel. For example, such
an external breast prosthesis can have a front skin comprising an
elastomeric polymer configured and dimensioned to approximate the
shape of a human breast, wherein the skin surrounds a cavity filled
with a gel such as a hydrogel or a silicone gel. In certain
embodiments, the skin comprises a front portion, or front skin, and
a rear portion, or rear skin, wherein the front and rear skins are
joined about a perimeter of the prosthesis.
[0013] In some embodiments, one or more skins of an external breast
prosthesis comprise a triblock copolymer, for example a copolymer
comprising styrene and at least one of ethylene, butadiene,
butylene, propylene, or isoprene. For example, an external breast
prosthesis comprises a front and/or rear skin comprising a
hydrogenated poly(styrene-b-isoprene), a hydrogenated
poly(styrene-b-isoprene-b-styrene), a hydrogenated
poly(styrene-b-butadiene-b-styrene), a hydrogenated
poly(styrene-b-isoprene/butadiene-b-styrene), or combinations
thereof. In certain embodiments, the front and/or rear skin
comprises any of polystyrene-b-poly(ethylene/propylene) (SEP),
polystyrene-b-poly(ethylene/propylene)-b-polystyrene (SEPS),
polystyrene-b-poly(ethylene/butylene)-b-polystyrene (SEBS), or
polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene
(SEEPS), or any combination thereof.
[0014] The front and/or rear skins may also comprise selected
amounts of one or more plasticizing oils, for example, a paraffinic
oil, naphtenic oil, a mineral oil, or a synthetic oligomer of a
polybutene, a polypropene, or a polyterpene oil.
[0015] In other embodiments, a breast prosthesis with an outer skin
of a triblock copolymer, for example comprising a triblock
copolymer and a plasticizing oil, may further comprise one or more
additives to optimize the feel of the skin. Suitable additives are
described herein and, for example, in the applicant's co-pending
U.S. patent application Ser. No. 10/817,612 filed Apr. 2, 2004,
entitled Precipitation of Additives in Over-Saturated Triblock
Copolymer Elastomers, which is incorporated by reference herein in
its entirety.
[0016] External breast prostheses according to the present
invention can comprise a shaped gel or an amorphous gel, and such
gel may be, for example, silicone-based, water-based, and/or based
on other materials that do not act as a solvent of the elastomeric
skins. In some embodiments, the inner material has its own shape,
for example in the shape of a human breast, and can have
shape-memory properties. In other embodiments, the inner material
is substantially shapeless and conforms to a shape defined by the
skins or other barriers of the external breast prosthesis.
[0017] In other embodiments, an external breast prosthesis
comprises a front skin and a base, or rear, skin, wherein the front
and rear skins are of different thicknesses. For example, the base
skin may be thicker than the front skin to provide a desired amount
of firmness or structural support.
[0018] In other embodiments, an external breast prosthesis
comprises two or more internal cavities or chambers. Each chamber
may be defined, for example, at least in part by elastomeric skins
and may be filled with a liquid, a solid, or a gel having desired
characteristics. For example, such a prosthesis may include a front
chamber with a first filling material of a particular consistency
or firmness, and a rear chamber having a filling material of a
different consistency or firmness.
[0019] A method of making an external breast prosthesis according
to an embodiment comprises combining a polymer such as a styrene
triblock copolymer with a plasticizing agent, for example a mineral
oil, and processing the mixture into desired shapes to make front
and rear elastomeric skins of a prosthesis. Such processing can
involve, for example, heating and forming the material, e.g., by
molding or thermoforming or a combination thereof, into a desired
shape. In some embodiments, additives are used to provide desired
mechanical properties for the elastomeric skins. The skins can be
joined or sealed together, for example by an adhesive or a heat
seal. One or more cavities defined by the skins can then be filled
through an access site with an inner material such as a liquid or a
gel, for example a silicone gel or a hydrogel. The access site can
then be sealed and the excess material can be trimmed.
[0020] In other embodiments, an inner material such as a gel can
include microspheres or other particles or devices to optimize the
density and/or weight of the prosthesis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention and further developments of the invention are
explained in even greater detail in the following exemplary
drawings. The present invention can be better understood by
reference to the following drawings, wherein like references
numerals represent like elements. The drawings are merely exemplary
to illustrate certain features that may be used singularly or in
combination with other features and the present invention should
not be limited to the embodiments shown.
[0022] FIG. 1A is a front view illustration of an embodiment of an
external breast prosthesis according to the present invention;
[0023] FIG. 1B is a cross-sectional view illustration of an
embodiment of the external breast prosthesis of FIG. 1 taken along
line A-A;
[0024] FIG. 2 is a cross-sectional view illustration of another
embodiment of an external breast prosthesis having a front skin of
varying thickness and a low density inner material;
[0025] FIG. 3A is a cross-sectional view illustration of another
embodiment of an external breast prosthesis;
[0026] FIG. 3B is a cross-sectional view illustration of another
embodiment of the external breast prosthesis of FIG. 3A having
multiple chambers;
[0027] FIG. 4 is a cross-sectional view illustration of an external
breast prosthesis having a concave rear skin;
[0028] FIG. 5 is a flow diagram depicting a method of making an
external breast prosthesis according to an embodiment of the
present invention;
[0029] FIG. 6 is flow diagram depicting details of a processing
step of FIG. 5 according to an embodiment of the present
invention;
[0030] FIG. 7 is a flow diagram depicting details of a processing
step of FIG. 5 according to another embodiment of the present
invention; and
[0031] FIG. 8 is a schematic diagram depicting another embodiment
of a method of making an elastomer for use in an external breast
prosthesis.
DETAILED DESCRIPTION
[0032] FIGS. 1A and 1B depict front and cross-sectional views,
respectively, of an external breast prosthesis 10 according to an
embodiment of the present invention. Prosthesis 10 includes a base,
or rear skin 12, a front skin 14, and an inner material 20 disposed
within an inner cavity or chamber 21 between and confined by skins
12 and 14. Front skin 14 and/or rear skin 12 can be made of an
elastomer such as a soft elastomer. For example, elastomeric skins
12 and 14 can be substantially soft to the touch and have an
elastic memory that tends to maintain the skin in a pliable yet
pre-defined shape.
[0033] In some embodiments, rear skin 12 and/or front skin 14
comprise a triblock copolymer or combinations thereof. For example,
suitable elastomeric materials include styrenic triblock
copolymers, such as a hydrogenated poly(styrene-b-isoprene), a
hydrogenated poly(styrene-b-isoprene-b-styrene), a hydrogenated
poly(styrene-b-butadiene-b-styrene), a hydrogenated
poly(styrene-b-isoprene/butadiene-b-styrene), or combinations
thereof. In certain embodiments, the front and/or rear skin
comprises any of polystyrene-b-poly(ethylene/propylene) (SEP),
polystyrene-b-poly(ethylene/propylene)-b-polystyrene (SEPS),
polystyrene-b-poly(ethylene/butylene)-b-polystyrene (SEBS), or
polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene
(SEEPS), or any combination thereof.
[0034] An oil or other plasticizing agent (also referred to herein
as a plasticizer) can be added to the triblock copolymer in order
to provide desired mechanical properties, such as elasticity,
softness (or hardness), and elongation, tear and tensile strength
characteristics of the resulting elastomer. For example, in some
embodiments, suitable mechanical properties include: (a) hardness
between approximately 10 to 70 durometer on the Shore 00 scale,
more preferably about 25 durometer on the Shore 00 scale; (b)
ultimate elongation of approximately 300 to 2000 percent, more
preferably about 1500 percent; and/or (c) tensile modulus at 300
percent elongation of between about 5 to 300 psi, more preferably
about 30 psi. One or more other additives can also be included in
or added to such formulations in order to provide a desired tactile
feel, and/or to optimize mechanical properties or other
characteristics of the front 12 or rear 14 skin, or portions of
such skins.
[0035] Skins 12, 14 can be fused or joined in a seal 22, for
example by an adhesive or a heat seal, that confines inner material
20 within inner cavity or chamber 21 between skins 12 and 14. Seal
22 can be any desired width and/or thickness, e.g., between about 2
to 10 millimeters wide and about 0.5 to 5 millimeters thick, more
preferably between about 2 to 6 millimeters wide and about 1 to 2
millimeters thick. Seal 22 can be a single seal joining front skin
14 and rear skin 12 about a perimeter of prosthesis 10 as shown, or
can comprise multiple seals or joints in any desired configuration.
One skilled in the art will appreciate that, while some embodiments
described herein can include distinct front and rear skins 14 and
12 that are adhered, fused, or otherwise joined at a seal 22, other
embodiments of prosthesis 10 include a single contiguous skin
surrounding cavity or chamber 21, e.g., with no seam or seal 22,
and are intended within the scope of the present invention.
[0036] Elastomeric skins 12, 14 can be substantially thicker and
more elastic and resilient than polyurethane films used in existing
breast prostheses, thereby providing a more natural appearance. In
some embodiments, for example, front skin 14 has an average
thickness between about 0.1 to 3 mm, preferably about 1.5 mm; and
rear skin 12 has an average thickness between about 0.3 to 5 mm,
preferably about 3 mm. Skin 12 and/or skin 14 need not have a
uniform thickness. In some embodiments, front skin 14 near
perimeter seal 22 is relatively thick, e.g., between about 3 to 10
mm thick, preferably approximately 5 mm thick. Such increased
thickness may help to provide support for a more natural draping of
the prosthetic breast 10 when the bust of the patient is in the
erect position.
[0037] Elastomeric skins 12, 14 can be made substantially without
wrinkles, particularly compared with the wrinkles that are
prevalent in existing prostheses. Skins 12, 14 can have an
appearance, firmness, elasticity, texture and other characteristics
that approximate human skin. For example, a "natural" firmness and
feel can be represented by measurement of Shore 00 durometer, with
a desirable value of about 20 to 30 Shore 00 durometer, more
preferably about 25 Shore 00 durometer. In some embodiments, a
"natural" texture and smoothness can be obtained by precipitation
of additives, which provides a texture of having microscopic
craters similar to human skin.
[0038] Skins 12, 14 can be the same or different thickness as each
other and/or each can have a variable thickness, for example
depending upon the desired shape, firmness, weight, resiliency, or
other characteristics of prosthesis 10. Relative thicknesses of
skins 12, 14 can also be related to materials used in skins 12, 14
and in filling 20. For example, in some embodiments, rear skin 12
is thicker than front skin 14 as shown in FIG. 1B. In other
embodiments, front skin 14 may be thicker than rear skin 12. In
specific embodiments, front and rear skins 14 and 12 can comprise
different compositions of polymers, oils, additives and the like to
provide desired characteristics.
[0039] Determination of a desired amount and/or pattern of skin
thickness variations can depend upon the size of prosthesis 10 and
the weight of filling 20. For example, if filling 20 is of the
amorphous or shapeless-type that conforms to the shape of skins 12,
14, one should consider that the larger the breast the greater the
weight. (e.g., according to a factor "L" to the third power, where
"L" is an average linear dimension of the breast). Assuming the
modulus of elasticity of an elastomeric skin is kept constant, the
ability of such skin to hold its shape is a function of its
thickness and the "L" linear dimension of the skin to the single
power. Therefore, in general, larger breast prostheses may require
thicker skins for the same "draping". Also in the area near seal 22
where the front and the rear skin are joined, for example, front
skin 14 may be substantially thicker in order to help maintain a
desired shape, both when the patient is standing or sitting in an
upright position as well as when the patient is laying down in a
supine position.
[0040] Inner material 20 can be any type of suitable filling to
provide desired properties such as weight, consistency, resiliency,
firmness and feel, and to approximate such properties of a normal
human breast. Gels adequate for this purpose can include silicone
gels as well as water based gels, or hydrogels, for example gels
used in wound care or food applications. Other filling 20 material
may be used instead of or in addition to silicone gels or
hydrogels, including for example liquids or gels that are
chemically and physically compatible with the elastomer of the
skins 12, 14 of the prosthesis. In some embodiments, inner material
20 is substantially shapeless or amorphous, and the shape of
prosthesis 10 is defined by skins 12, 14. In other embodiments,
inner material 20 can have its own shape that helps define the
shape of prosthesis 10. Inner material 20 and/or skin 14 and/or
skin 12, can comprise one or more coloring agents to provide any
desired color or pattern of colors, e.g., a color approximating a
natural skin tone of a Caucasian user, an African-American user, an
Asian user, or any other potential or particular user. Suitable
coloring agents include, for example, dyes and pigments that are
commonly known and used in the industry for providing skin tone
coloring to silicone gels in cosmetic covers of hand and leg
prostheses. For hydrogels, pigments and dyes of the type used in
food coloring can be used.
[0041] The definition of "gel" can vary from one industry to the
next. As used herein, the term "gel" is intended to cover a variety
of materials that have a jelly-like consistency, and includes both
shaped and shapeless gels. As used herein, shaped gels can maintain
their own shape, for example a shape defined during a curing
process (e.g., in forming a silicone gel) or with the addition of a
thickening agent (e.g., in forming a hydrogel). Such gels generally
are self-healing when cut and, if deformed, will return to its
original shape (i.e., shape memory). As used herein, shapeless, or
amorphous, gels generally do not maintain their own shape when
deformed. Compared to shaped gels, shapeless gels do not exert
appreciable resisting force during or after deformation. Such gels
may in fact be liquids with a consistency approximating that of a
true gel. In some cases, when such gel-like liquids are rendered
lighter by the addition of hollow spheres or by the addition of
air, they can maintain their own shape under the effect of the
force or gravity, but can be easily deformed and maintain their new
shape after the deforming force is withdrawn.
[0042] Suitable gels include, for example, but are not limited
to:
[0043] (a) a polymer gel;
[0044] (b) a gel formed by a liquid plus a thickening agent;
and
[0045] (c) a gel formed by a liquid plus a high surface tension
agent.
[0046] Any of the above can be used alone or in combination, and
can be shaped or shapeless. An example of a suitable polymer for
filling 20 is a silicone gel. Examples of a gel that is a liquid
plus a thickening agent can include water plus carboxymethyl
cellulose (CMC) or polyvinylpyrrolidone (PVP) polyacrylates or
polyacrylamides. In this type of gel the thickening agents can
swell and trap the water. Examples of gels comprising a liquid plus
a high surface tension agent include fumed silica, where the gel
generally does not flow under the acceleration of gravity but it
can be shaped and reshaped without limitation. This effect can be
enhanced even more when the gel is lightened in weight by the
addition of fillers as discussed below with respect to other
embodiments.
[0047] Prosthesis 10 may also include a nipple 16. In some
embodiments, nipple 16 is a solid nipple formed or molded as an
area of increased thickness in elastomeric skin 14 as shown in FIG.
1B. In other embodiments, skin 14 can be of relatively uniform
thickness, with nipple 16 formed as an extended portion or shape of
skin 14 filled with gel 20. In some embodiments, a region 26 (also
referred to as areola 26) surrounding nipple 16 can be colored to
approximate the coloring and likeness of a human areola. This can
be achieved, for example, by coloring the areola 26 region of
elastomeric skin 14, coloring gel 20 in region underlying nipple
16, or both. In some embodiments, a desired coloring of areola 26
can be achieved by providing a darker color of gel 20 underneath
the nipple 16 and allowing it to diffuse into the lighter gel of
the surrounding areas. Such practice can result in an effect of
uneven fading around the center of areola 26 that closely resembles
the natural coloring pattern of the areola of a human breast. Such
coloring, in addition to color and additives that may be added to
gel 20 and/or skin 14 throughout prosthesis 10, can be used to
achieve a desirable depth of coloring overall to approximate the
appearance of normal human breast tissue.
[0048] Referring to FIG. 2, another embodiment of an external
breast prosthesis 210 can include a rear skin 212 and a front skin
214 joined by a seal 222. Front skin 214 can include regions of
different thickness, for example an upper region 228 and a base
region 230 that are substantially thicker or thinner, than a
central region 232 surrounding nipple 216 and areola 226. Such
variations in thickness of front skin 14 or rear skin 12 may be
used to optimize the elasticity of skin and the shape and feel of
prosthesis 210.
[0049] Like inner material 20 of prosthesis 10, inner material 220
may be a silicone gel, a hydrogel, or any other type of filling
suitable for providing desired properties such as weight,
resiliency, firmness, feel and appearance. Inner material 220 can
comprise or contain particles 224 such as microspheres or other
particles that affect the weight or density of prosthesis 210.
Particles 224 can be, for example, hollow microspheres such as
polymeric or glass beads or microspheres. Examples of suitable
microspheres can include acrylonitrile microspheres and glass or
ceramic microspheres. Other examples of microspheres may be found,
for example in U.S. Pat. No. 5,902,335 to Snyder, Jr., which is
incorporated by reference herein in its entirety.
[0050] In some embodiments, a fabric is adhered to, embedded
within, or otherwise bonded with rear skin 212 and/or front skin
214. For example, as shown in FIG. 2, a fabric 213 can be bonded to
rear skin 212. Such fabric 213 can be used, for example, to help
maintain a desired shape of the breast prosthesis 210 and limit
elongation due to the weight of filling 220. Fabric 213 may be
woven or knitted and can comprise polyester, nylon, acrylic,
cotton, rayon, or any other desired fabric.
[0051] Fabric 213 can be bonded with skin 212 in a variety of ways.
For example, in one embodiment, a sheet of fabric 213 is placed on
the skin 212 and heat is applied, e.g., using an iron or heated
plate, to soften or melt the underlying skin 212 and bind it with
the fabric. In another embodiment, an adhesive is used, with or
without heat, to apply the fabric. In another embodiment, a mixture
of a solvent and gel is used, with or without application of heat,
to adhere the fabric 213 to skin 212. In yet another embodiment,
fabric 212, is placed in an injection mold during the process of
forming skin 212, e.g., fabric 212 is placed in the mold prior to
injection of molten elastomer.
[0052] Referring to FIG. 3A, another embodiment of an external
breast prosthesis 310 includes a rear skin 312 that is dimensioned
to have a shape that is substantially thicker than front skin 314.
Skins 312 and 314 may be formed of a triblock copolymer as
described above. Rear skin 312 can have any desired thickness, for
example from 10-80 percent of the thickness of prosthesis from
outer surface 311 of rear skin 312 to nipple 316. In some
embodiments, rear skin 312 is configured and dimensioned to have a
varying thickness as shown in FIG. 3A.
[0053] Rear skin 312 can include, for example, a central portion
317 that bulges toward nipple 316 and is thicker than an upper, or
superior, portion 319 of skin 312. In such embodiments, skin 312
can be dimensioned to approximate the shape of outer skin 314 as
shown. In some embodiments, fasteners 313, 315 are integrated
within or adhered, fastened or otherwise attached to or with rear
skin 312. Such fasteners 313, 315 can be an adhesive material, a
hook and loop fastener (e.g., Velcro), or any other material or
device that facilitates attachment of prosthesis 310 against the
chest of a user (e.g., by direct attachment or adhering to the
user's skin, or by attachment to a shirt, bra or other garment or
device worn by the user).
[0054] Inner material 320 within chamber 321 defined by skins 312
and 314 can be, for example a silicone gel or hydrogel as described
above. Rear skin 312 can differ from front skin 314 in terms of
firmness and/or other characteristics in order to provide desired
firmness, feel, appearance or other properties of prosthesis
310
[0055] In another embodiment shown in FIG. 3B, prosthesis 310 can
include multiple chambers, such as a first chamber, or front
chamber 321 and a second chamber, or rear chamber 343, separated by
an inner barrier 346. Inner barrier 346 may be an elastomeric skin
such as skin 312 or 314, an elastic or inelastic film, e.g., a
polyurethane film, or any other compatible material. Inner material
320 in front chamber 321 can be a silicone gel, a hydrogel, a foam,
a liquid or other material of desired consistency. Inner material
342 in rear chamber 343 can also be a silicone gel, a hydrogel, a
foam, a liquid, a polymer or other material, and can be the same or
different than inner material 320. Inner material 320 can have a
consistency, firmness, or other characteristic that is the same or
different from that of material 342. Such differences between inner
materials 320 and 342, particularly when combined with
above-described characteristics of skins 312, 314, can be optimized
to provide any desired firmness, feel, weight, appearance or other
properties of prosthesis 310.
[0056] In specific embodiments according to the present invention,
external breast prosthesis 310 comprises inner barrier 346, which
is disposed between front skin 314 and rear skin 312 and separates
main cavity or chamber 21 into first chamber 321 and second chamber
343. Inner material 320 can be a first gel disposed in first
chamber 321, and inner material 342 can be a second gel disposed in
second chamber 343, wherein the second gel is the same as or
different than the first gel. Inner materials 320 and/or 342 can
be, for example, a silicone gel, a hydrogel, another gel, or any
combination of gels. For example, in some specific embodiments,
materials 320 and 342 are both silicone gels, but of differing
stiffness or consistency. In other embodiments, materials 320 and
342 are both hydrogels that may be the same or different. In other
embodiments, materials 320 and 342 are different types of gels,
e.g., one is a silicone gels and the other a hydrogel. In other
specific embodiments, material 320 is a foam and material 342 is a
gel.
[0057] Referring to FIG. 4, other embodiments that may have similar
components and characteristics to prostheses 10, 210 and 310 is an
external breast prosthesis 410 or partial prosthesis having a rear
skin 412 that is shaped and dimensioned to conform to the chest of
a patient. For example, rear skin 412 can include a concave rear
surface 450 dimensioned to accommodate and fit against the
remaining breast tissue or chest wall of a patient, e.g., a
mastectomy patient. In other embodiments, concave rear surface 450
can be dimensioned to accommodate, conform with and/or fit against
a user's normal breast, as a breast enhancer to augment the size
and/or shape of the user's bust. In specific embodiments,
prosthesis 410 can be attached to or against the user's breast, or
it may be worn within or attached to a brassiere or other
garment.
[0058] Skins 412 and 414 can be elastomeric skins such as those
described herein and each can have any desired shape and thickness
to provide desired properties of prosthesis 410. Front skin 414 may
comprise a solid nipple 416 with or without surrounding areola
coloring as 226 in FIG. 2. Inner material 420 can be a silicone
gel, hydrogel, foam or other material, and can contain microspheres
or other particles such as particles 224 of FIG. 2. In fact, one
skilled in the art will appreciate that breast prostheses according
to the present invention can include any combination of features
described with respect to the various embodiments herein.
[0059] In use, an external breast prosthesis such as 10, 210, 310
and 410 may be adhered or otherwise attached to the skin or
undergarment of a patient or other user, or may be integrated with
or worn within a bra or other garment or device. Prostheses 10,
210, 310 or 410, or any combination or variations thereof, can be
dimensioned and used as a partial breast prosthesis, a full breast
prosthesis, and/or a breast enhancer. Rear skin 12, 212, 312, 412
can include, for example, features such as embedded or otherwise
bonded fabric, adhesive portions, snap features, adhering features
or the like, or other fasteners to facilitate attachment to the
patient, garment or device. In some embodiments, the external
surface of rear skin 12, 212, 312, 412 and/or front skin 14, 214,
314, 414 is adhesive or partially adhesive, e.g., tacky, sticky or
gummy, to facilitate attachment of prostheses 10, 210, 310, 410,
respectively.
[0060] Kits comprising in a container a breast prosthesis of the
invention are also provided. In some embodiments, a kit according
to the present invention comprises in one or more containers an
external breast prosthesis 10, 210, 310 or 410 and a fastener for
adhering or otherwise attaching such prosthesis against a user
(e.g., by attachment directly or indirectly to the chest of the
user, or to a bra or other garment or device that may be worn by
the user and/or may be disposed between the prosthesis and the
user). In other embodiments, a kit according to the present
invention comprises in one or more containers an external breast
prosthesis 10, 210, 310 or 410 and a bra or other garment having
pockets or other features for holding such prosthesis in a desired
position against a user.
[0061] In some embodiments, a prosthesis 10, 210, 310 or 410 is
attached to or integrated within a bra or other garment. Such as
garment may comprise, for example, a brassiere or a tank top-like
undergarment having shoulder straps or other supports attached to a
prosthesis and/or to one or more cups or other features configured
to hold a prosthesis according to the present invention. Such
garments and related prosthesis may be used to replace or enhance
the appearance and feel of one or both breasts of a user, and may
include a liner, pocket or other feature for holding the
prosthesis.
[0062] Turning to FIG. 5, a method 500 of making an external breast
prosthesis according to an embodiment of the present invention can
include mixing a polymer and a plasticizing agent 502 and
processing the mixture into desired forms to make front and rear
skins such as the various elastomeric skin forms described
herein.
[0063] Suitable polymers may include, for example, triblock
co-polymers such as SEP, SEPS, SEBS, SEEPS, or combinations
thereof. Some such polymers are sold, for example, under the
trademarks SEPTON.RTM. and KRATON.RTM.. In some embodiments, 100
parts by weight of one or a mixture of two or more of a
hydrogenated styrene/isoprene/butadiene block copolymer are
used.
[0064] Suitable plasticizing agents include, for example, a
paraffinic oil, a naphtenic petroleum oil, a mineral oil, and a
synthetic oligomer of polybutene, polypropylene, polyterpene, and
the like.
[0065] In one example, a plasticizing oil such as CARNATION.RTM.
White Mineral Oil (Crompton Corporation, Tarrytown, N.Y.) can be
combined 502 with a styrenic block copolymer such as SEPTON.RTM.
TPR 4055 (Septon Company of America, Pasadena, Tex.), a
hydrogenated poly(styrene-b-isoprene/butadiene-b-styrene), or
polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene. The
polymer and oil are combined, for example, at a temperature of
about 130 to 165.degree. F. In some embodiments, approximately 100
pph of polymer and approximately 550 pph, or 300 to 1000 pph, of
plasticizing oil may be used. The plasticizing oil may be heated
prior to or after combination 502 with polymer, for example in an
extruder, a molding machine or other suitable heated vessel.
[0066] In some embodiments, a stabilizer or other additive may also
be included along with the polymer and/or oil. For example,
pentaerythritol
tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)
(IRGANOX.RTM. 1010, Ciba Specialty Chemicals, Inc.), provides a
silky smooth texture on the skin. In one embodiment, approximately
1 to 10 pph of a stabilizer (e.g., 3.85 pph, of SEPTON.RTM.) such
as IRGANOX.RTM. 1010 is added to the polymer and oil in step
502.
[0067] In step 504, the polymer/plasticizing agent mixture is
processed into desired forms to create rear and front skins, such
as rear skins 12, 212, 312, 412 and front skins 14, 214, 314, 414.
Different methods can be used to form the mixture into the desired
shapes, for example by molding or thermoforming as described in
more detail with respect to FIGS. 6 and 7, respectively.
[0068] Referring to FIG. 6, an embodiment of processing 504 the
skin material includes heating 602 the polymer and plasticizing
agent mixture in a device such as an injection molding screw. Such
heating 602 is performed at a sufficient temperature, e.g.,
385-410.degree. F. or more than 410.degree. F., and for a
sufficient duration, e.g., five to ten minutes or more than ten
minutes, to melt the polymer and plasticizing agent into a molten
mixture. Triblock copolymer elastomers melt at different
temperatures depending on the molecular weight of the polymer and
the amount of plasticizer used. The molding temperature therefore
can range from 300 to 450.degree. F. The time required is function
of the size of the melting apparatus. The process is generally
faster in machines such as reciprocating screw molding machines or
extruders, and it is slower in melting pots and kettles.
[0069] In step 604, the molten mixture is injected or otherwise
transferred into one or more molds of a desired shape of a front or
rear skin. For example, a suitable mold may be in the shape of
front skin 14 and include nipple 16 as shown in FIG. 1B. Another
mold may have a shape for creating rear skin 12. In other
embodiments, a single mold having one or more parts may be used to
create front 14 and/or rear skin 12. Color may be added to the
mixture or portions of the mixture before or after injection into
the mold. The mold(s) may be cooled (e.g., to 85-130.degree. F.)
prior to injecting 604 the molten mixture, and such injection can
be performed under vacuum or pressure to aid filling of mold
cavities. After injecting 604 the mixture, it can be allowed to
cool or cure 606 in the mold into the desired form, for example for
a duration of approximately 60 to 100 seconds.
[0070] Referring to FIG. 7, another embodiment of processing 504
the skin material for making an external breast prosthesis involves
thermoforming. For example, an initial step of such process 702 can
include forming the polymer/plasticizing oil mixture into one or
more sheets of desired thicknesses. Such forming 702, can be
accomplished, for example, by molding as described above or by
pouring a molten mixture into a mold or tray or onto a surface. The
mixture can be allowed to cure or cool into a sheet, e.g., an
elastomeric sheet, of desired thickness. To thermoform such sheets
into a desired shape, a sheet is first heated 704, for example to a
temperature of approximately 90.degree. C. The heated sheet is then
subjected to a vacuum over a desired form 706, such as a form of
front skin 14 of FIG. 1B.
[0071] Returning to FIG. 5, after front and rear skins are formed
in step 504, such skins are finished and sealed 506. In some
embodiments, finishing and sealing 506 can comprise heating front
and back skins to a suitable temperature, e.g., approximately
60.degree. C., and applying an adhesive to desired bonding areas on
both skins. An example of a suitable adhesive is toluene, although
various other adhesives are known and may be used. The bonding
areas can include, for example, circumferential edge portions 22 of
front 14 and rear 12 skins as shown in FIG. 1B. In multi-chambered
embodiments having an inner skin or barrier such as barrier 346 of
FIG. 3, such additional skin or barrier may be sealed along an edge
322 with front 314 and rear 312 skins.
[0072] After application of the adhesive, the bonding areas may be
pressed together for a period of time, e.g., for several minutes,
to create a seal between the front and rear skins. A powder, for
example talcum powder, may be applied to one both skins to provide
smooth surface characteristics. In some embodiments, the outer
surface of the front skin is powdered, which the outer surface of
the rear skin is not powdered and remains tacky to facilitate
placement or attachment of the prosthesis to the patient or within
a garment.
[0073] In other embodiments, finishing and sealing 506 can be
accomplished using heat sealing. For example, 506 can include
placing the front skin into a form having the desired shape of the
front skin, and overlaying the back skin to align the desired
bonding areas. Once the skins are aligned as desired, heat is
applied to the selected bonding areas to create a seal. Such heat
may be applied, for example, at 325-375.degree. F. for two to three
minutes. Again, one or both skins may be powdered as described
above.
[0074] In other embodiments, front and rear skins are not formed
separately and later joined. Rather, the front and rear skins can
be injection molded, thermoformed, or otherwise formed as a single
contiguous envelope or skin surrounding a central cavity into which
gel or other filling material is injected or otherwise deposited.
In a specific embodiment, a hollow envelope of elastomeric skin is
formed by injecting a molten elastomeric mixture as described
herein into a mold and cooling the mixture. Such a mold, can have
one or more parts, for example a first part configured to shape the
front of the prosthesis into a form approximating a human breast,
and a second part adapted to form the rear portion of the skin that
joins with the front portion to create and surround a central
cavity.
[0075] After the front and rear skins are finished and sealed in
506, the interior space or cavity between the sealed skins is
filled 508 with inner material, e.g., by injection through an
access site. As described above, inner material may be shapeless as
front and rear elastomeric skins can be molded or formed into the
desired breast shape that contains the inner material. Suitable
inner materials include, for example, silicone gels and hydrogels.
In one embodiment, a hydrogel filling includes approximately 100
pph water along with, for example, 2 pph of a gelling agent. An
example of a suitable gelling agent is an acrylamide such as
CARBOPOL.RTM. Ultrez 21 Polymer (Noveon, Inc., Cleveland, Ohio),
which is a hydrophobically modified crosslinked polyacrylate
polymer. Another example of a suitable gelling agent is a carboxy
methyl cellulose such as CARBOPOL.RTM. 940 (Noveon, Inc.,
Cleveland, Ohio). Color and/or a preservative may also be included
in the hydrogel or other filling as desired.
[0076] An example of a suitable silicone gel includes, for example,
RHODORSIL.RTM. Gel 4621 SLDA and Gel 4621 SLDB (Rhodia Silicone
GMBH, Lubeck), each at approximately 50 parts by weight, which form
into a two-component silicone elastomer that crosslinks at room
temperature by polyaddition reaction. Such polymerization can be
accelerated using heat up to 120.degree. C. Another example of a
suitable gel includes RHODORSIL.RTM. Gel 4723SLD A and B (Rhodia
Silicone GMBH, Lubeck), each at approximately 50 parts by
weight.
[0077] Continuing with FIG. 5, after the skins are filled with the
inner material in step 508, the hole or access site through which
the inner material was added is sealed in step 510. Such sealing
may be accomplished, for example, using adhesive or a heat seal as
described above, by using a patch, or by any other method that
effectively seals the skin(s) to prevent leakage of the inner
material. In step 512, excess skin material and/or inner material
can be trimmed away from the seal or bonding lines. The finished
prosthesis may also be cleaned, for example, using a water and
alcohol solution, checked using a suitable quality control
procedure, and packaged.
[0078] Referring to FIG. 8, a method of making an elastomer for use
in an external breast prosthesis according to an embodiment of the
present invention can include use of one or more additives to
provide desired surface characteristics of the front and/or rear
skins. Briefly, a process of making such an elastomer can include
mixing an additive 820, a plasticizing oil 830 and a polymer 840 to
form a mixture 850. For example, additives, e.g., such as one or
more of those additives listed in Table I below, may be used to
create a powder-like precipitate that diffuses to the surface of
the elastomer during and/or after forming or cooling of the
elastomer, thus reducing tackiness of the elastomer where such
surface characteristics are desired.
[0079] Plasticizing oil 830 may be heated prior to the addition of
polymer 840 and/or additive 820. Mixture 850 can be melted, for
example in an extruder, a molding machine or other suitable heated
vessel so that the additives become soluble in molten mixture 850
and remain in stable solution in the molten mixture 850.
[0080] Molten mixture 850 can then be molded 860 or otherwise
shaped into any desired shape or form, for example into a front or
rear prosthetic breast skin as described above. When allowed to
cool, the mixture can solidify and form elastomer 880. The
additives can begin to diffuse to the surface of elastomer 880 upon
completion of the solidification process. Precipitation may be
initiated by seeding the surface of elastomer 680 with fine powder
890 such as talcum powder, for example during the cooling process.
Elastomer 880 can then be cooled to solidify elastomer 898, whereby
additive 820 may precipitate to the surface of solidified elastomer
898, e.g., in the form of a dry powder.
[0081] If the plasticizing oil is heated, an appropriate
temperature range may be about 130 to 165.degree. F. As described
above with respect to FIG. 5, plasticizing oils such as paraffinic
oils, naphtenic petroleum oils, mineral oils, and synthetic liquid
oligomers of polybutene, polypropylene, polyterpene, and the like
may be used. Optionally, a seeding of the oil may also be effected,
with an insoluble fine powder such as talcum powder. Preferably,
300 to 1000 parts by weight of the plasticizing oil may be
used.
[0082] An additive can then be mixed in the plasticizing oil,
optionally with seed, for a defined time, e.g., approximately 10
minutes, at a temperature of preferably 130 to 165.degree. F. The
additive may also be added to the plasticizing oil with or after
the addition of the polymer. Table I discloses as examples some
additives that may be suitable in this process. TABLE-US-00001
TABLE I Chemical Name 1 Tetrakis (2,4-di-tert-butylphenyl)
[1,1-biphenyl]-4,4'-diylbisphosphonite 2 Tris
(2,4-ditert-butylphenyl) phosphate 3 Butanedioic acid,
dimethylester, polymer with
4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol 4
2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)
phenol 5
3,3',3',5,5',5'-hexa-tert-butyl-a,a',a'-(mesitylene-2,4,6-triyl)
tri-p-cresol 6 Pentaerythritol Tetrakis
(3-(3,5-di-tert-butyl-4-hydroxphenyl)propionate) 7 Phenol,
2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-methyl 8
Thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]
9 Calcium phosphonate 10 Dioctadecyl 3,3'-thiodipropionate 11
Didodecyl 3,3'-thiodipropionate 12
2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]-
methyl-4-methylphenyl acrylate 13
N,N'-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)-
)
[0083] The tris(2,4-ditert-butylphenyl) phosphate listed in Table I
is a white crystalline powder, commonly used as a phosphate
processing stabilizer for polycarbonate and polyolefins. It can be
used, for example, in combination with phenolic antioxidants and
can aid in color stability and polymer viscosity. The butanedioic
acid listed in Table I is also known as succinic acid. It is a
colorless crystalline solid with a melting point of 185-187.degree.
C., soluble in water, slightly dissolved in ethanol, ether, acetone
and glycerine, but not dissolved in benzene, carbon sulfide, carbon
tetrachloride and oil ether. A common method of synthesis of
succinic acid is the catalytic hydrogenation of maleic acid or its
anhydride.
[0084] In some embodiments, 0.5 to 10 parts of one or more
additives can be mixed with the plasticizing oil or with the
plasticizing oil and polymer mixture. The additives can be solid at
room temperature (25.degree. C.) and soluble in the molten mixture.
The additives can have higher solubility in the triblock copolymer
elastomers at higher temperatures than at room temperatures. The
addition of such additives can be in a predetermined proportion
that exceeds the solubility of the additives in the elastomer at
room temperature. The addition of such additives to the mixture of
polymers and plasticizing oil can be made either prior to the
melting of the mixture in a heated vessel or when the mixture is in
its molten state.
[0085] In a specific embodiment, a polymer or mixture of polymers
is added to the plasticizing oil or to the mixture of plasticizing
oil and additives for 30 minutes at 130.degree. F. to 165.degree.
F. starting temperature. As described above, suitable polymers may
be any triblock copolymer, including for example styrenic triblock
copolymers such as SEP, SEPS, SEBS or SEEPS. Preferably, 100 parts
by weight of one or a mixture of two or more of a hydrogenated
styrene/isoprene/butadiene block copolymer are used.
[0086] The mixture containing the plasticizing oil, the additive
and the polymer can be melted in an extruder, a reciprocating screw
molding machine, or a heated vessel at about 415.degree. F., for
example. As mentioned earlier, the additive may be added to the
mixture of polymers and plasticizing oils either prior to the
melting of the mixture or in the melt phase.
[0087] The mixture is maintained at or above melting temperature,
with or without mixing, for an amount of time necessary to ensure
adequate dissolution and dispersion of the additives in the
mixture. The time required to effect an adequate mixture can be a
function of the triblock copolymer used and the equipment used to
melt the mixture. For high molecular weight copolymers, such as
SEPTON.RTM. 4055, for example, the time at or above melting
temperature can be considerably higher than for a lower molecular
weight copolymer such as SEPTON.RTM. 4033. Also reciprocating screw
type injection molding machines or plastic extruders require less
time at or above melting temperature than melting pots or vats.
Also, when using melting pots and vats the time at or above melting
temperature can be dependent on the size of the pot. Thus, in some
embodiments utilizing high molecular weight polymers, a typical
time for processing the mixture is, for example, 10 to 30 minutes
in a reciprocating screw type injection molding machine or an
extruder, and 4 to 16 hours in a melting pot or vat. In embodiments
utilizing low molecular weight polymers, a typical time for
processing the mixture is, for example, 5 to 15 minutes in a
reciprocating screw, and 2 to 8 hours in a melting pot or vat.
[0088] After the expiration of such amount of time, the mixture can
be molded, extruded, cast or otherwise formed, and then allowed to
cool or can be actively cooled. In either event, the mixture may
undergo a phase change from liquid to semi-solid or solid. The
additives can remain dissolved in the molten mixture, where upon
solidification of the mixture, the mixture becomes an elastomer and
precipitation of the additives from the elastomer begins.
[0089] More particularly, where the mixture is first melted and
then cooled, at a controlled temperature profile, precipitation of
the additives can occur within the elastomer as the solubility
parameters of the additive in the elastomer are exceeded. The
solubility of the additives can decrease as the temperature of the
elastomer falls. Precipitation may be initiated by seeding the
surface of the elastomer with a fine powder such as talcum powder.
Precipitation may also be initiated by mechanical solicitation of
the elastomer, such as stretching or other deformation of the
elastomer.
[0090] The size of the particles of the precipitated phase can be a
function of the time temperature profile maintained during the
cooling period and of the mechanical stress to which the elastomer
is subjected. More particularly, the particles may increase in size
as the cooling rate is decreased and as the amount of mechanical
deformation is decreased. A faster cooling rate and greater
mechanical deformation can produce smaller particle sizes.
[0091] The diffusion rate of precipitate to the surface of the
liner can also increase as the stress to strain ratio decreases,
i.e., the diffusion rate increases as the modulus of the elastomer,
or elastic limit stress, decreases.
[0092] Molding, casting or extruding of the molten mixture can be
conducted at a mold temperature of, for example, 95-130.degree. F.
for 5-10 minutes. The molded elastomer can be removed from the mold
after the expiration of such period of time. Although stretching is
not required, stretching of the elastomer by about 50% may improve
the diffusion rate. Other mechanical deformation of the elastomer
may be substituted for or added to the stretching.
[0093] A step of aging at a controlled temperature profile may also
be performed. For example, such aging may be accomplished at a
temperature of 20-32.degree. F. for one (1) hour.
[0094] The precipitated phase can diffuse to the surface of the
elastomer and collect as a powder on its surface. After removal of
the surface powder, by wiping, washing, or the like, additional
powder can migrate to the surface of the elastomer. The process can
be repeated until the saturation level at room temperature of the
precipitate phase in the elastomer is reached. The process of
diffusion to the surface may then stop.
[0095] Details regarding suitable elastomers and additives, and
methods of making articles incorporating such elastomers, may also
be found in the applicant's co-pending U.S. patent application Ser.
No. 10/817,612, filed Apr. 2, 2004, entitled Precipitation of
Additives in Over-Saturated Triblock Copolymer Elastomers, which is
incorporated by reference herein in its entirety.
EXAMPLES
[0096] In a particular example, an external breast prosthesis
according to an embodiment of the present invention was made that
has front and rear skins comprising a mixture of styrenic block
copolymer (SEPTON.RTM. 4055, a SEEPS) at 100 pph, an additive
(IRGANOX.RTM. 1010, a pentaerythritol
tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)) at 2.9
to 3.85 pph, and plasticizing oil (CARNATION.RTM. 70) at 500 to 700
pph. The mixture was heated in an injection molding screw to
385-410.degree. F., injected into a cool mold (85-1 10.degree. F.),
and cured for 60 to 100 seconds. In this example, front and rear
skins were molded separately, and then bonded together to form a
perimeter seal using an adhesive as described above with respect to
FIG. 5. One skilled in the art will appreciate that other methods
of joining or sealing the skins may be used, or the front and rear
skins could have been formed in the same mold as a contiguous
skin.
[0097] In this example, front skin was molded in the shape of a
human breast and included an molded elastomeric nipple. Rear skin
included a fabric bonded with its exterior surface. After the front
and rear skins were sealed, a gel material was injected into the
cavity between the front and rear skins. In this particular
example, the gel was a hydrogel comprised of approximately 375 g of
water, 20 g of wet expanded microspheres, and 3 g of LUQUASORB.RTM.
101 (BASF), a super-absorbent polymer. In other examples, a
neutralized polyacrylate solution replaced the BASF solution. In
still other examples, various other hydrogels (e.g., a neutralized
polyacrylate, acrylamide, carboxylmethyl cellulose, or other
absorbent or super-absorbent polymers) and silicone gels were
used.
[0098] All references cited herein are incorporated herein by
reference in their entirety and for all purposes to the same extent
as if each individual publication or patent or patent application
was specifically and individually indicated to be incorporated by
reference in its entirety for all purposes.
[0099] Many modifications and variations of this invention can be
made without departing from its spirit and scope, as will be
apparent to those skilled in the art. The specific embodiments
described herein are offered by way of example only, and the
invention is to be limited only by the terms of the appended
claims, along with the full scope of equivalents to which such
claims are entitled.
* * * * *