PCT
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`WO 99/25536
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`(51) International Patent Classification 6 :
`B29C 45/16, A61F 2/52, GOlB 7/04
`
`(11) International Publication Number:
`
`Al
`
`(43) International Publication Date:
`
`27 May 1999 (27.05.99)
`
`(21) International Application Number:
`
`PCT/US98/24353
`
`(22) International Filing Date:
`
`13 November 1998 (13.11.98)
`
`(81) Designated States: CA, JP, European patent (AT, BE, CH, CY,
`DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT,
`SE).
`
`(30) Priority Data:
`60/065,245
`
`13 November 1997 (13.1 l.97)
`
`US
`
`Published
`With international search report.
`
`(71) Applicant: COLOPLAST CORPORATION [US/lJSJ; 1995
`West Oak Circle, Marietta, GA 30062 (US).
`
`(72) Inventors: FUNT. Stephen, Carlyle; 1995 Azalea Circle, De(cid:173)
`catur, GA 30033 (US). HODGKINS, Diane, Taryn-Leigh;
`208 South Forest Street, Bellingham, WA 98225 (US). LIT(cid:173)
`MAN, Jennifer, Kay; Apartment 2, 2846 North Calvert
`Street, Baltimore, MD 21218 (US). HALLEY, Robert,
`James; 922 Myrtle Street #4, Atlanta, GA 30309 (US).
`
`(74) Agents: WITHERS, James, D. et al.; Jones & Askew, LLP,
`37th floor, 191 Peachtree Street, N.E., Atlanta, GA 30303
`(US).
`
`(54) Title: DESIGNING AND MANUFACTURING A CUSTOM BREAST PROSTHESIS
`
`(57) Abstract
`
`The present invention is directed to custom-fitted
`breast prostheses, and more particularly relates to systems
`and methods for disigning and manufacturing custom-fitted
`breast prostheses. One method (100) involves the creation
`of a visual mandrel using three-dimensional scanning equip(cid:173)
`ment and computer aided design software. The visual man(cid:173)
`drel may be stored in a computer and later reused and/or
`modified as needed by a custom breast prosthesis wearer, A
`funher method involves the creation of a physical mandrel
`by an interactive sculpting process (110), wherein a patient
`and a designer develop the shape of the physical mandrel
`through the exchange of information including comfort, feel,
`and fit of the mandrel, as well as prior prostheses.
`
`1CO
`
`I
`
`EX1081
`Yita v. MacNeil
`IPR2020-01139
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
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`AL
`AM
`AT
`AU
`AZ
`BA
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`CI
`CM
`CN
`cu
`CZ
`DE
`DK
`EE
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`Albania
`Armenia
`Austria
`Australia
`Azerbaijan
`Bosnia and Herzegovina
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Cote d'Ivoire
`Cameroon
`China
`Cuba
`Czech Republic
`Germany
`Denmark
`Estonia
`
`ES
`Fl
`FR
`GA
`GB
`GE
`GH
`GN
`GR
`HU
`IE
`IL
`IS
`IT
`JP
`KE
`KG
`KP
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`KR
`KZ
`LC
`LI
`LK
`LR
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`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People's
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
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`LS
`LT
`LU
`LV
`MC
`MV
`MG
`MK
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`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`L~sotho
`Lithuania
`Luxembourg
`Latvia
`Monarn
`Republic of Moldova
`Madagascar
`The former Yugoslav
`Republic of Macedonia
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
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`SI
`SK
`SN
`sz
`TD
`TG
`TJ
`TM
`TR
`TT
`UA
`UG
`us
`uz
`VN
`YU
`zw
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`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
`
`

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`PCT /US98/24353
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`DESIGNING AND MANUFACTURING A CUSTOM BREAST PROSTHESIS
`
`FIELD OF THE INVENTION
`This invention relates in general to external breast prostheses, and more
`particularly relates to systems and methods for designing and manufacturing custom-fitted
`breast prostheses.
`
`BACKGROUND OF THE INVENTION
`It is an unfortunate fact that many women are diagnosed with breast cancer and
`must have the affected breast removed. After removal of one or both of her breasts, most
`mastectomy patients in today's society seek a prosthetic replacement to feel whole, and
`present a normal appearance beneath clothing. Another goal of breast prostheses is to
`maintain the balance of the body and to assist in reducing stress on the spine. Early fabric
`prostheses were never satisfactory, and surgically implanted prostheses are expensive and
`involve health risks. Therefore, external silicone breast prostheses have become
`extremely popular with mastectomy patients.
`Mastectomy patients may choose from a variety of "off the shelf' external silicone
`prostheses. Each of the different types of prostheses employ various features in an
`attempt to provide an acceptable level of comfort and to duplicate the form, feel, weight
`distribution, fullness, and softness of the natural breast.
`The first external silicone breast prostheses included a single volume of a two(cid:173)
`component cross-linked silicone material contained within a cavity formed by two pieces
`of polyurethane film. The silicone material is cured in a mold that determines the shape of
`the prosthesis. Such prostheses were designed to be worn inside a brassiere. An
`example of such a prosthesis and a mold are described in U.S. Patent Nos. 4,172,298
`and 4,247,351 to Rechenberg.
`Later, prosthesis designers determined that certain advantages could be obtained
`by forming a prosthesis of two volumes of silicone rubber materials having different
`softness. Such prostheses include three pieces of polyurethane film, which are welded
`together along a common peripheral edge to form front and rear chambers.
`In some
`products, the firmer silicone is in the front chamber. In others, the firmer silicone is in
`the rear chamber.
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`U.S. Patent No. 4,950,291 to Mulligan describes a two-chamber prosthesis in
`which the front chamber is relatively thin. The silicone rubber in the larger rear chamber,
`which is placed next to the chest wall, is softer than that in the front chamber. The softer
`silicone conforms to the shape of the chest wall and moves with the body, thereby
`providing a natural appearance. The softer silicone helps redistribute the weight of the
`prosthesis across and against the chest wall and away from the brassiere shoulder strap,
`which reduces stress on the shoulder. The firmer silicone in the front chamber supports
`the soft rear chamber, prevents the prosthesis from collapsing, and gives shape to the
`product.
`As mentioned above, other two-chamber prostheses place the firmer silicone in the
`rear chamber. An example of a two-chamber prosthesis of this type is sold by the
`assignee of the present invention under the trademark "DELTA PERSONALLY." In this
`prosthesis, the rear chamber, which contains the firmer silicone, is relatively thin. The
`larger front chamber contains the softer silicone material. This configuration is
`advantageous because the firmer rear chamber simulates the pectoralis chest muscles
`while the softer front chamber moves like a natural breast. This prosthesis provides a
`significant natural drape with softness to fill and mold to a brassiere cup completely and
`naturally. The overall softness of the prosthesis helps the prosthesis mold to the chest
`wall contributes to redistributing the weight of the prosthesis across and against the chest
`wall and away from the brassiere shoulder strap.
`Subsequent developments led to the introduction of attachable prostheses, which
`could be attached to the skin of the wearer. Like the earlier silicone prostheses, the
`attachable products included a single volume of a two-component cross-linked silicone
`material contained within a cavity formed by two pieces of polyurethane film. The
`prosthesis is held in place on the wearer's chest by a skin support or fastening slab,
`which has a skin-friendly adhesive on one side and attachment members on the other side.
`The prosthesis is attached to the skin support by complementary attachment members.
`U.S. Patent Nos. 5,071,433 to Naestoft et al. and 5,352,307 to Wild describe attachable
`prostheses that employ hook-and-loop fasteners, where the hook material is on the
`prosthesis and the loop materials forms one side of the skin support.
`Although many women are able to be fitted with the types of products described
`above, there are many mastectomy patents who, due to variations in their surgery, their
`size, or other factors, are more difficult to properly fit with off the shelf external
`prostheses. This has resulted in the introduction of custom fitted external breast
`prostheses.
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`The custom breast prostheses that have been previously available suffer from
`several drawbacks. First, the fitting requires that a plaster cast be made of the patient's
`entire chest. Second, the finished product is fairly rigid, and does not look or feel like a
`natural breast under clothing.
`In addition, custom breast prostheses are relatively
`expensive. Despite these drawbacks, custom breast prostheses provide the best
`alternative for some mastectomy patients.
`Therefore, there is a need in the art for an improved system and method for fitting,
`designing, and manufacturing custom external breast prostheses. The improvement
`should provide a custom breast prosthesis that duplicates the form, feel, weight
`distribution, fullness, and softness of the patient's natural breast as closely as possible,
`while remaining affordable to the majority of mastectomy patients.
`
`SUMMARY OF THE INVENTION
`The present invention provides a system and method for designing and
`manufacturing a custom breast prosthesis. The invention employs novel methods,
`materials, and apparatus to improve the design and manufacturing processes associated
`with the production of custom breast prostheses. The invention results in a custom breast
`prosthesis that provides mastectomy patients with a viable alternative to surgery while
`duplicating as much as possible the look and feel of the natural breast under clothing. The
`present invention provides a method of design and manufacture that allows significant
`involvement of the patient in order to ensure optimum customer satisfaction while also
`keeping costs down. The resulting custom breast prosthesis is highly durable and will
`retain satisfactory fit and appearance even when the patient experiences typical seasonal
`body changes. Finally, a custom breast prosthesis in accordance with the present
`invention duplicates the form, feel, weight distribution, fullness, and softness of the
`natural breast more closely than any other products currently on the market.
`The various aspects of the present invention may be more clearly understood and
`appreciated from a review of the following detailed description of the disclosed
`embodiments and by reference to the appended drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`Fig. 1 is a flow chart of an exemplary method of designing and manufacturing a
`custom breast prosthesis.
`Fig. 2 illustrates an exemplary blank, which is used to form a mandrel.
`Fig. 3 illustrates a mandrel formed from the blank of Fig. 2.
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`Fig. 4, consisting of Figs. 4a and 4b, illustrates a base for the mandrel of Fig. 3,
`and the base/mandrel combination, respectively.
`Fig. 5 is a cross-sectional view of a compensated and uncompensated mandrel.
`Fig. 6 illustrates a wax dam that is used to form a mold cavity.
`Fig. 7 illustrates the back side of a mandrel after it has been compensated.
`Fig. 8 illustrates a polycarbonate floating plate used to form the back side of a
`prosthesis.
`Fig. 9 illustrates a bag sealing die.
`Fig. 10 illustrates a bag attached to the mold.
`Fig. 11 illustrates a clamp assembly used to hold the mold during the curing
`process.
`Fig. 12 is a flow chart of an alternative method of designing and manufacturing a
`custom breast prosthesis using computer aided design techniques.
`
`DBT AILED DESCRIPTION OF THE INVENTION
`The present invention will now be described with reference to the drawings, in
`which like numerals represent like elements throughout the several views. A custom
`breast prosthesis designed and manufactured in accordance with the present invention
`employs an improved process to provide an external breast prosthesis that duplicates the
`form, feel, weight distribution, fullness, and softness of a patient's breast as closely as
`possible, while remaining affordable to the majority of mastectomy patients. In general,
`the advantages of the present invention result from both the materials and processes
`employed in the design and manufacture of the custom breast prosthesis.
`The process of producing a custom breast prosthesis in accordance with the
`present invention comprises two processes, a design process and a manufacturing
`process. In one embodiment of the present invention, the design process may be based
`upon the use of a two-part silicone modeling compound that can be shaped, worked, and
`sculpted much like modeling clay, but which then cures at room temperature to a hard
`rubber-like material that can then be carved, sanded, drilled, or machined to provide a
`final model, or mandrel, of the finished prosthesis. Desirably, the material is non-toxic,
`hypo-allergenic, and non-irritating when applied to the skin. The use of this type of
`material allows the designer to sculpt a "physical" mandrel on-site in the presence of the
`patient, which results in an interactive design process that ensures the best possible fit and
`appearance. Once a satisfactory mandrel shape is decided upon, the mandrel is sent to the
`manufacturer. At this point, the design process continues with the mandrel being
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`compensated for fullness, drape, shrinkage, weight distribution, and attachment system
`(if any is used).
`In this embodiment of the present invention, the manufacturing process begins
`with the finished mandrel. A mold may be cast from the mandrel using an off-the-shelf
`silicone molding compound for the cavity, and a backside floating plate thermoformed
`from a material, such as polycarbonate. The footprint of the mandrel is traced from the
`mold cavity outline, then converted to a pattern for forming a custom heat sealing die.
`The heat sealing die is used to make a polyurethane bag, which encloses a silicone gel.
`The fill weight for the prosthesis is determined by multiplying the weight of the
`finished mandrel by a factor. The bag is placed in a filling/sealing jig and filled with
`uncured silicone gel at the correct softness, color, and volume. The final heat seal is
`added, and the bag is removed from the jig. The bag is then fastened to the cavity side of
`the mold, taking care to line the bag seal edge to the edge of the mold cavity. The mold is
`placed on the mold clamp assembly, and a vacuum is drawn through a tiny hole at the
`lowest point in the mold to ensure good nipple and undercut detail through the cure. The
`floating plate, with or without attachment tabs, is placed on the top of the cavity side of
`the mold; the mold clamp assembly is closed; and the entire assembly is heated in an oven
`to ·cure the silicone and chemically adhere the silicone to the bag. A vacuum is applied
`throughout the cure. When the curing period is over, the mold assembly is removed from
`the oven and cooled on a ventilated cooling grate. The prosthesis is carefully removed
`from the mold, trimmed, inspected, and then sent to the retailer to be fitted on the patient.
`In a further embodiment of the present invention, the design process may be based
`upon computer data acquired by scanning the patient's chest using a three-dimensional
`scanner. In this process, three-dimensional data representing the shape of the patient's
`chest is acquired and stored in a computer. The physical mandrel mentioned above is
`replaced by a "virtual mandrel," which is derived from data representing the contour of
`the chest wall and represents a mirror image of the patient's natural breast. Once this data
`is acquired, the virtual mandrel is compensated for fullness, drape, shrinkage, weight
`distribution, and attachment system (if any is used).
`In this embodiment of the present invention, the manufacturing process begins
`with the finished virtual mandrel. A mold insert may be machined directly from the data
`associated with the virtual mandrel. Preferably, the mold is machined from a reusable
`metal material in order to increase efficiency and economy. Because the mold is metal,
`the prosthesis may be cured in normal ovens with other products. Similarly, because the
`mold is a reusable metal, the mold may be melted down, recast, and eventually machined
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`again. The data representing each patient's prosthesis is stored electronically, so that the
`mold itself need not be stored.
`Turning now to the flow chart of Fig. 1, the design and manufacturing process
`employing a physical mandrel will be described in additional detail. As depicted in Fig.
`1, an exemplary method 100 begins at step 105 with the manufacture of a "blank,"
`which is modified to form the physical mandrel. The size and shape of the blank may be
`based on the style and size of the patient's currently worn breast prosthesis. The blank
`may be made in the same style as the currently worn breast prosthesis, but is typically one
`size smaller. The blank serves as a starting point for the sculpting session, and is usually
`prepared prior to traveling to the sculpting site. Two exemplary blanks are illustrated in
`Fig. 2.
`
`Step 110 represents the on-site sculpting session, which typically takes place at a
`retailer's shop. At the sculpting site, a designer meets with the patient and discusses the
`patient's complaints with previous breast prostheses, her preferences regarding fit and
`appearance, her expectations, etc. This information helps the designer visualize how the
`finished prosthesis should look, how it will be mated with the chest wall, etc. The patient
`puts on a bra that best represents the type of bra the patient will typically wear. Those
`skilled in the art will appreciate that bra selection is very important because the custom
`prosthesis is designed to fit not only the patient's chest wall, but also to fit a specific type
`of bra. Therefore, the selected bra style should be the style that best fits the shape of the
`patient's natural breast, is most flattering to her figure, and provides the best comfort.
`After a bra is selected, the patient puts on the bra and remains standing during the
`sculpting session. A blank is placed in the bra and inspected by the designer and patient.
`The designer then modifies the blank and places it back in the bra. The blank is modified
`by adding additional sculpting material to the blank, or by removing sculpting material
`with a knife, sandpaper, etc. The process of modifying and evaluating the blank may be
`repeated several times to form a physical mandrel having a satisfactory shape and
`"footprint." As used herein, the term "footprint" refers to the outline of the prosthesis,
`which contacts the chest wall. The bra is then removed.
`A cosmetic pencil is used to draw an outline of the mandrel's footprint on the chest
`wall. A release agent, such as petroleum jelly, is applied to the chest wall. An
`impression material is mixed and applied to the back of the mandrel, which is then lightly
`pressed against the chest wall and oriented to correspond to the footprint. Any
`impression materials may be used as long as the material conforms to a patient's chest
`wall when pressed against the chest wall. The impression material typically cures in five
`to ten minutes to yield an accurate imprint, or impression, of the chest wall on the back of
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`the mandrel. The marked footprint outline on the chest wall transfers to the impression
`material providing a guide for cutting the mandrel to the correct footprint shape.
`At this point, the patient again puts on the bra, and the mandrel is placed in the
`bra. The mandrel is inspected and fine tuned by the designer until a satisfactory shape
`and fit are achieved. Those skilled in the art will appreciate that the dialogue that takes
`place with the patient throughout the sculpting session helps ensure the best possible fit
`and appearance. Because the designer works directly with the patient, anatomical
`asymmetries, which may be natural or the result of surgery, can be taken into account and
`Traditional plaster casts do not provide sufficient anatomical
`compensated for.
`information to facilitate this type of compensation. This interaction is an important
`advantage of on-site design and greatly contributes to the finished product being
`satisfactory to the patient.
`Finally, the mandrel is marked for orientation and nipple placement, and nipple
`measurements are recorded. Color and softness are matched and recorded. The mandrel
`is then returned to the manufacturing facility. A typical finished mandrel is illustrated in
`Fig. 3.
`
`The design process continues once the mandrel is returned to the manufacturer.
`As shown in Fig. 1 at step 115, a base may be made for the mandrel to provide a support
`for working on the mandrel. The base also preserves the anatomical curves of the
`footprint and serves as the base for pouring the mold cavity. The base is illustrated in
`Fig. 4a. Fig. 4b illustrates the base with the mandrel positioned thereon.
`At step 120 of Fig. 1, the mandrel undergoes a compensation process, wherein
`the mandrel is compensated for a variety of factors. Those skilled in the art will
`appreciate that the custom breast prosthesis is typically made from a soft silicone gel
`encased in a polyurethane shell. These materials yield a prosthesis that closely mimics the
`suppleness and weight of human tissues. However, one drawback is that the final
`prosthesis will usually deform under the force of gravity as a function of its softness,
`orientation, fullness, and weight distribution, just as a natural breast does. Also, silicone
`gel typically shrinks 5-8% during the curing process. Therefore, the mandrel is typically
`compensated so that the finished prosthesis retains the fit and appearance of the on-site
`sculpture.
`To perform the compensation process, the cup side of the mandrel may be
`digitized and stored for analysis in a computer aided design (CAD) surfacing program.
`Designers then determine how the mandrel may be modified to best translate into the
`finished prosthesis. As before, modification of the mandrel involves adding material to or
`removing material from the mandrel. Curves which tend to flatten under gravity are given
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`greater convexity, the projection (how far the prosthesis protrudes) is increased to
`compensate for "sag" and shrinkage, and fullness is added to regions which might
`collapse when under the strain of bra fabric. All of these compensations, as well as
`others, may be done in such a way as to preserve the anatomical contours of the patient's
`natural breast.
`Fig. 5 illustrates the nature of the compensation that may be applied to the
`mandrel. The dashed line 510 illustrates a cross-sectional view of the mandrel before it
`has been compensated. The solid line 520 illustrates a cross-sectional view of the
`mandrel after it has been compensated. The compensation 530 increases the projection
`(P) of the mandrel by approximately 8 per cent in order to allow for shrinkage and
`backside hollowing. Drape compensation 540 adds fullness to compensate for the effects
`of gravity. The back side of the mandrel may be hollowed in order to reduce and
`redistribute the weight of the prosthesis. A fit gasket 550 may be used to provide a
`uniform transition to the chest wall. An attachment shelf 560 may be used to provide for
`placement of an attachment system. The compensation of the back side is discussed
`below in conjunction with step 130.
`After the mandrel is compensated by adding or removing material, the finished
`mandrel cup side may be digitized and compared with the original digitized data. After the
`comparison, additional adjustments may be made to the mandrel if necessary. Once the
`final cup side appearance is determined, the mandrel is sanded to a smooth surface, and
`the nipple is added.
`After the cup side of the mandrel is finished, the mandrel may be used to create a
`mold cavity, as shown in step 125 of Fig. 1, which will then be used to form the
`prosthesis. To form the mold cavity, the mandrel is first sealed to the base with a heavy
`silicone grease, and covered with a thick layer of a suitable release agent (e.g., petroleum
`jelly). Wax sheeting with a low softening temperature is softened, and then fashioned
`around the mandrel/base assembly to provide walls of a "vessel," which is illustrated in
`Fig. 6. Additional sealing grease is applied where necessary, and a molding compound is
`mixed and poured into the vessel. Suitable molding compounds include, but are not
`limited to, a room temperature vulcanization (RTV) silicone molding compound such as
`Vi-Sil V-242, manufactured by Rhone-Poulenc and available from Medford Silicones,
`Medford, NJ. The molding compound may be cured for up to about eighteen hours.
`Following the curing process, the wax is removed the mold is inverted, and the mandrel
`and base are removed from the cavity. A hole is drilled at the lowest point of the cavity to
`allow subsequent application of a vacuum. Desirably, the hole is about 1/16 inch in
`diameter. The cavity side of the mold is now complete, and may be used as a support for
`the mandrel while the back side (chest wall side) compensation is added.
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`As shown in Fig. 1, the back side of the prosthesis is compensated at step 130.
`First, the back side of the mandrel may be carefully hollowed to reduce weight while
`maintaining the fit and appearance. Additionally, the weight distribution may be
`optimized by removing or adding sculpting material to the hollowed areas to ensure that
`the prosthesis will drape and "flow" just like the natural breast under normal body
`movements and positions. If an attachment system, such as hook and loop fasteners, is
`desired, the back side may be modified to accommodate the tabs of hook material. All
`back side modifications may be done in the way which ensures that the anatomical curve
`corresponding to the chest wall is preserved, so that the fit of the prosthesis will not be
`adversely affected. An example of a mandrel with back side compensation completed is
`illustrated in Fig. 7.
`At step 135 of Fig. 1, the "floating plate" is made. As used herein, the term
`"floating plate" refers to the mold surface that is used to form the back side of the
`prosthesis. The floating plate usually undergoes a series of modification steps to improve
`the fit and appearance of the finished prosthesis. For this reason, the floating plate is
`desirably formed from a thermoformable material. Suitable thermoformable materials
`include, but are not limited to, polycarbonates, polyimides, and polyamides. Desirably,
`the thermoformable material is a polycarbonate in order to minimize the cost of materials
`and labor. In order to form the floating plate, vacuum channels are carved in the surface
`of the cup side of the mandrel. The vacuum channels extend to the edges of the footprint.
`The mandrel is placed in the mold cavity, which is then placed on the thermo former platen
`so that the vacuum hole in the cavity lines up with the vacuum port of the thermoformer.
`A thermoformable material, such as polycarbonate sheeting having a thickness of 1/16
`inch, is then placed in the thermoformer frame, and subjected to heat and vacuum forces.
`Thermoforming conditions may vary depending on the materials used and
`the
`thermoformer type. For polycarbonate sheeting, desirably the polycarbonate sheeting is
`dried at about 120°C for a period of about thirty minutes prior to thermoforming, to
`remove bubbles from the sheeting. Once formed, the floating plate may be trimmed and
`bead-blasted to prevent adhesion to a prosthesis bag material, such as polyurethane. For
`illustrative purposes, a polycarbonate floating plate and mold cavity are illustrated in Fig.
`8. Thermoforming the floating plate enables fast and inexpensive modifications, if
`necessary, of the floating plate and ultimately, the final custom breast prosthesis.
`In one embodiment of the present invention, a floating plate cover is formed, as
`shown in step 140 of Fig. 1. The floating plate cover is used in combination with the
`floating plate to provide support thereto. In the case of larger prostheses, thermoformable
`In these cases, an additional
`materials, such as polycarbonate, may flex or distort.
`support may be added in the form of a floating plate cover. The floating plate cover may
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`be formed from a molding compound, such as the silicone molding compounds discussed
`above.
`
`While the floating plate and/or floating plate cover is being formed, a bag for
`forming the outer surf ace of the prosthesis may also be fabricated, as shown in step 14 5
`of Fig. 1. The bag may comprise a variety of materials including, but not limited to,
`polyurethane and silicone polymers. Desirably, the bag material comprises one or more
`layers of a thin polyurethane film, which has a matte finish on the cup side. The edges of
`the bag are heat sealed to form a shape defined by a custom sealing die, which is made for
`each custom prostheses. The outline of the mold cavity may be used as a guide to trace
`the sealing die pattern, which is then reduced by 3-5% to produce a bag which may be
`stretched to fit the mold (to prevent wrinkles in the resulting prosthesis). From the
`pattern, the die may be formed from a material, such as an aluminum stock sheet having
`dimensions 1/8 x 3/4 inches, on a bending jig so that the 1/8 inch edge forms the seal.
`The die may be clamped to an universal die mounting plate and the seal edge milled flat.
`The mounting plate is then mounted into existing bag sealing equipment to form a bag as
`shown in step 150 of Fig. 1. Numerous bags are typically made to accommodate any
`iterations, which may be required to produce an acceptable prosthesis. A bag sealing die
`is illustrated in Fig. 9.
`In step 155 of Fig. 1, a bag is fitted with a fill tube and clamped into a
`filling/sealing jig. The fill weight of the prosthesis is determined by weighing the mandrel,
`then multiplying by a factor taking into account various factors including the density of the
`sculpting material, the density of the impression material, and the density of the uncured
`silicone gel material. Typically, a factor of about 0.7 is used to get the fill weight. From
`the patient data, the color and softness is referenced, and the bag is filled with an uncured
`silicone gel. The choice of a particular uncured silicone gel may be made by one of
`ordinary skill in the art given a patient's particular needs. Suitable silicone gels are well
`known in the art of making external breast prosthesis, and any one may be used in the
`present invention. An appropriate silicone rubber material is described in detail in Patzke
`and Wohlfarth, "Vernetzungssyteme beim Siliconkautschuk," in CHEMIKERZEITUNG
`97th year (1973) No. 4, pages 176-180, which is incorporated herein by reference. Once
`the bag is filled with the uncured silicone gel material, a heat seal is applied to the fill port,
`and the bag is removed from the jig.
`In step 160 of Fig. 1, the mold cavity is preheated to a desired temperature
`depending on the uncured material used. For uncured silicone, the mold cavity is heated to
`a temperature of about 160°C. The bag is then fastened to the mold using staples or some
`other attachment means. While staples are inserted, the bag is stretched around the
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`perimeter of