U.S. patent application number 10/421543 was filed with the patent office on 2003-10-16 for prosthesis and method of making.
This patent application is currently assigned to Rocky Mountain Biosystems, Inc.. Invention is credited to Flock, Stephen T., Marchitto, Kevin S..
Application Number | 20030195623 10/421543 |
Document ID | / |
Family ID | 22746457 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030195623 |
Kind Code |
A1 |
Marchitto, Kevin S. ; et
al. |
October 16, 2003 |
Prosthesis and method of making
Abstract
The present invention provides a novel apparatus for measuring
the shape of various parts of anatomy, and alternatively capturing
and digitizing an image of the part for the purpose of creating
prosthetic or orthotic devices. Also provided are methods of
measuring anatomical profiles involving physical contact with the
body parts, and methods of manufacturing internal or external
prosthetic and orthotic articles which mimic natural body parts in
texture and motion characteristics, and in some cases,
appearance.
Inventors: |
Marchitto, Kevin S.; (Mt.
Eliza, AU) ; Flock, Stephen T.; (Mt. Eliza,
AU) |
Correspondence
Address: |
Benjamin Aaron Adler, Ph.D., J.D.
Adler & Associates
8011 Candle Lane
Houston
TX
77071
US
|
Assignee: |
Rocky Mountain Biosystems,
Inc.
|
Family ID: |
22746457 |
Appl. No.: |
10/421543 |
Filed: |
April 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10421543 |
Apr 23, 2003 |
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09847361 |
May 2, 2001 |
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6564086 |
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60201593 |
May 3, 2000 |
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Current U.S.
Class: |
623/7 ;
600/587 |
Current CPC
Class: |
A61B 5/1077 20130101;
A61F 2002/505 20130101; A61F 2/12 20130101; A61F 2310/00383
20130101; G01B 11/2518 20130101; G01B 11/2513 20130101; B33Y 80/00
20141201; A61F 2002/5053 20130101; A61F 2/52 20130101; G06T 17/00
20130101; A61B 5/0064 20130101; A61B 5/4312 20130101; A61F 2/5046
20130101 |
Class at
Publication: |
623/7 ;
600/587 |
International
Class: |
A61F 002/52 |
Claims
What is claimed is:
1. A method of imaging an object of an individual, comprising the
steps of: capturing perspective images in a fixed location relative
to the individual using multiple cameras; capturing images of a
calibration target; processing the data using a computer algorithm
into a processed digital image.
2. A method of imaging a breast or chest of an individual,
comprising the steps of: positioning said individual with exposed
breasts in front of a projection device such as a slide-projector,
said device facing said individual, is level and at the same height
as said individual's chest and at a known distance from the
individual; projecting an image of a pattern onto the breast and/or
chest; imaging the projected pattern on the chest of the individual
using an imaging device; digitizing and storing said image; and
calculating spatial coordinates of the pattern off the digitized
image and calculating the shape of the object on which the pattern
was projected.
3. The method of claim 2, wherein said imaging device is a
charge-coupled-device video camera.
4. The method of claim 2, wherein said digitizing is performed
using a frame-grabber.
5. The method of claim 2, wherein said image is stored on a
computer archival device such as a magnetic hard disk.
6. The method of claim 2, wherein said individual in an upright
position or a supine position.
7. The method of claim 2, wherein said breast are imaged from
several different directions, such as laterally, anterior-posterior
and coronary.
8. The method of claim 2, wherein said projection devices and image
capturing device rest on a movable track that rotates around the
patient in order to attain a three dimensional perspective.
9. The method of claim 2, wherein an increasingly fine pattern is
projected as one moves laterally or inferiorly further away from
the nipple.
10. The method of claim 2, wherein morphing software is used to
model the flow or motion characteristics of a prosthesis as the
individual assumes one position or another.
11. A method of measuring a three-dimensional profile of an object
of an individual, comprising the steps of: positioning said
individual upright and facing forwards with exposed breasts;
positioning a slide projector parallel to the floor of the
examination room and at the height of the patient's nipple;
projecting an image of a 64.times.64 matrix of small dots onto said
object; capturing and digitizing said matrix of points; determining
the real position in space of a point so as to provide a
three-dimensional profile of an object.
12. The method of claim 11, wherein volume of an anatomical
component is measured by using the three-dimensional information to
create a volume measurement either by comparison to an imaged
external standard or an internal standard which has been saved in
the devices memory.
13. A breast prosthesis, comprising an external shell, said shell
molded to fit the shape of a breast; and a hollow cavity defined by
the shell, said cavity filled with a viscoelastic material.
14. The breast prosthesis of claim 13, wherein said shell is a
single or multi-piece.
15. The breast prosthesis of claim 14, wherein said shell comprises
of an elastomeric material.
16. The breast prosthesis of claim 15, wherein said elastomeric
material is silastic.
17. The breast prosthesis of claim 13, further comprising viscous
low-density or viscoelastic materials contained within the
prosthesis.
18. The breast prosthesis of claim 13, wherein the walls of said
prosthesis are thin.
19. The breast prosthesis of claim 13, wherein the walls of the
breast prosthesis have a non-uniform thickness.
20. The breast prosthesis of claim 13, wherein the viscoelastic
material has (1) a low density), (2) has low thermal conductivity,
(3) has continuum-mechanical properties similar to human tissue,
and (4) is in a pourable form.
21. The breast prosthesis of claim 20, wherein the viscoelastic
material is selected from the group consisting of soybean oil,
agar, gelatin, silicone, and biologically inert polymers.
22. The breast prosthesis of claim 20, wherein the viscoelastic
material is silica-aerogel.
23. The breast prosthesis of claim 13, wherein the posterior aspect
of the prosthesis is composed of a plastic material having a
lattice-like structure.
24. The breast prosthesis of claim 13, further comprising an
antifungicide and/or an antibacteriocide incorporated in the shell.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional patent application claims benefit of
provisional patent application U.S. Serial No. 60/201,593, filed
May 3, 2000, now abandoned.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the fields of
imaging and biomedical devices. More specifically, the present
invention relates to prosthesis profilometry and manufacture.
[0004] 2. Description of the Related Art
[0005] In the United States, between 1990 and 1994, the incidence
of developing breast cancer stabilized at approximately 110 cases
per 100,000 women. Women who develop breast cancer have a 5-year
relative survival rate of 79-87%.
[0006] Often, women who have had breast cancer and receive a
mastectomy, choose to use a breast prosthesis to hide the loss of
one or both breasts, and to give an outward appearance to others
and themselves as aesthetically appealling. Today, there are about
1,000,000 women wearing external (i.e., not implanted) breast
prostheses, and about 100,000 new fittings are done every year.
Many more implants of internal breast prostheses are done every
year.
[0007] While there are several different models of external breast
prostheses, they are imperfect either because of a multitude of
reasons, such as having an unattractive shape, a shape different
from the remaining breast (if one remains), and because the color
does not match that of the patient's skin. The forms of internal
prostheses are typically only poor representations of the shape of
a real breast. While recent technological advances have led to the
development of hollow external breast prosthesis, there is still a
limitation in the ease at which these and other external prostheses
are fitted as they require that the patient visit a mold-maker
whereupon a negative impression of her breast(s) is made. Not only
is this inconvenient and potentially expensive, but by using
material such as plaster-of-paris to make the mold, and by having
the patient in a prone or other position during the molding
process, the shape obtained is not only unique to the shape of the
breast while the patient is in that position, but it is slightly
altered by the additional weight of the plaster.
[0008] The prior art is deficient in the lack of effective
apparatus and/or methods for measuring the shape of various parts
of anatomy. The present invention fulfills this long-standing need
and desire in the art.
SUMMARY OF THE INVENTION
[0009] The present invention provides a novel apparatus for
measuring the shape of various parts of anatomy that is quick,
non-contact, and results in digital contour information which can
be used to control computer-operated machines to make the mold for
an internal or external prosthesis or an orthotic. These devices
may alternatively be used for capturing and digitizing an image of
any anatomical part for the purpose of creating prosthetic or
orthotic devices which match previously existing parts, for
providing bilateral symmetry or for creating a new anatomical part
based on aesthetic or practical physical considerations. Other
applications include orthotic devices for the foot and facial
prostheses for reconstruction following cancer.
[0010] Also provided are methods of measuring anatomical profiles
involving physical contact with the breast or other body parts, and
methods of manufacturing internal or external prosthetic and
orthotic articles which mimic natural body parts in texture and
motion characteristics, and in some cases, appearance.
[0011] Other and further aspects, features, and advantages of the
present invention will be apparent from the following description
of the presently preferred embodiments of the invention given for
the purpose of disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the matter in which the above-recited features,
advantages and objects of the invention, as well as others which
will become clear, are attained and can be understood in detail,
more particular descriptions of the invention briefly summarized
above may be had by reference to certain embodiments thereof which
are illustrated in the appended drawings. These drawings form a
part of the specification. It is to be noted, however, that the
appended drawings illustrate preferred embodiments of the invention
and therefore are not to be considered limiting in their scope.
[0013] FIG. 1 is a diagram of the arrangement between the patient
and the projector/imaging device.
[0014] FIG. 2 is a diagram of one example of a projection pattern.
The lines connecting the dots are intended only to guide the
eye.
[0015] FIG. 3 is a diagram of the appearance of the pattern shown
in FIG. 2, projected on a breast.
[0016] FIG. 4 illustrates an example of a non-uniform grid
pattern.
[0017] FIG. 5 illustrates an example of a beam-splitter suitable
for creating a pattern to be projected on the breast.
[0018] FIG. 6 illustrates a diagram of a beam-scanning systems
suitable for creating a pattern to be projected onto the
breast.
[0019] FIG. 7 illustrates a diagram of an optical interferometer,
on an x-y translation stages, suitable for measuring breast
shape.
[0020] FIG. 8 is a diagram of an optical rangefinder for measuring
breast shape.
[0021] FIG. 9 is a diagram of an ultrasonic range finder for
measuring breast shape.
[0022] FIG. 10 is a diagram of a contact feeler gauge system to
measure breast shape.
[0023] FIG. 11 is a diagram of an arrangement to image the breast
from all angles with a single imaging device.
[0024] FIG. 12 is a diagram of a two-piece hollow breast prosthesis
filled with a viscoelastic material.
[0025] FIG. 13 illustrates a lateral view of the negative and
positive mold which is used to form the shell of an external breast
prosthesis.
[0026] FIG. 14 is a lateral view of a breast prosthesis with thick
walls (for a large breast) or relatively thin walls (for a small
breast).
[0027] FIG. 15 is a view of an external breast prosthesis with
walls of non-uniform thickness.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention provides a novel apparatus for
measuring the shape of various parts of anatomy, but most
importantly a woman's breast, that is quick,
non-contact/non-invasive, and results in digital contour
information which can b e used to control computer-operated
machines to make the mold for an internal or external prosthesis or
an orthotic. The device is "user-friendly" and can be shipped at
low cost to a medical practitioner or prosthesis consultant, who
can take the data of the breast contour on the patient without the
patient having to visit a fitting specialist or the prosthesis
manufacturer. The data can be obtained while the patient is in
several different positions (as, for example, the breast changes
shape when the patient is in different positions), and the data can
be sent back to the prosthesis manufacturer electronically. The
data then can be quickly transformed into a 3-dimensional form of
the breast through computer-aided manufacturing thus accelerating
the rate of manufacturing considerably so that the patient can
receive the prosthesis quickly and with minimal contact.
[0029] These devices may alternatively be used for capturing and
digitizing an image of any anatomical part for the purpose of
creating prosthetic or orthotic devices which match previously
existing parts, for providing bilateral symmetry or for creating a
new anatomical part based on aesthetic or practical physical
considerations. Other applications include orthotic devices for the
foot and facial prostheses for reconstruction following cancer.
[0030] The present invention also provides a method of measuring
anatomical profiles that has all the benefits described, except
that it involves physical contact with the breast or other body
part.
[0031] Furthermore, the devices may incorporate an optical color
detection system which is used to unambiguously measure the color
of the patient's skin (chest wall, pre-operative breast, remaining
breast, or other skin) as well as that of the nipple. This color
information is in the form of a set of standard color coordinates
(such as defined by the CIE chromaticity scale), which can also be
sent back to the prosthesis manufacturer by modem or through the
internet.
[0032] Further provided in the present invention are methods of
manufacturing internal or external prosthetic and orthotic articles
which mimic natural body parts in texture and motion
characteristics, and in some cases, appearance. Prosthetic articles
which move and feel like normal body parts are desirable for
various reasons. When patients assume different positions, a
prosthetic article that is rigid can be uncomfortable and
unappealing in appearance. This is particularly the case when
breast prostheses are worn. A more "life-like" breast prosthesis
that moves or "drapes" like a natural breast and is soft to the
touch will have a more natural appearance and feel than available
prosthetic devices currently.
[0033] The following examples are given for the purpose of
illustrating various embodiments of the invention and are not meant
to limit the present invention in any fashion.
EXAMPLE 1
[0034] Profilometry
[0035] In the present study, multiple cameras in a fixed location
relative to the patient can capture different perspective images.
Each module of two or more CCD cameras are first used to capture
several images of a specially designed calibration target and
corresponding images of an object such as a breast. In this way,
the cameras are used to first define a set reference range followed
by scanning of the object and precise determination of spatial
relationships between key attributes. Computer algorithms are used
to process the data and combine the attributes from different
perspectives into a processed digital image. The images are further
transformed digitally to extrapolate curvature and other
features.
[0036] Alternatively, greater resolution may be achieved by using
optical devices to first project an image, or pattern of images of
a known geometrical arrangement, at an object with a known
geometric position and orientation with respect to the optical
device. This step is followed by detection of the reflected image
of the pattern which now appears distorted as a consequence of
encountering irregular surfaces. Application of simple mathematics
may be used to measure the three-dimensional shape of an object, or
the orientation of an object of known shape based on the alteration
of the geometrical arrangement in three dimensions. These new
coordinates are then transformed into a digital reproduction with
extremely high resolution.
[0037] To measure the shape of a breast and other relevant anatomy
such as the chest wall, a patient with exposed breasts is
positioned in an upright position in front of a projection device
such as a slide-projector, which is set facing the patient and is
level and at the same height as the patient's chest and a known
distance from the patient (FIG. 1). The image-projector is used to
project an image of a pattern (see FIG. 2) onto the breast and/or
chest. Adjacent to the projector, and in a known geometric position
and orientation with respect to the projector, is an imaging device
such as a charge-coupled-device (CCD) video camera. The video
camera images the projected pattern on the chest of the patient
(FIG. 3). The video signal is sent to a digitizer, such as a
frame-grabber, which stores the image on a computer archival device
such as a magnetic hard disk. The computer can then calculate the
spatial coordinates of the pattern off the digitized image, and
then, calculate the shape of the object on which the pattern was
projected. An exemplary pattern would be a matrix of small spots
which are sited at the intersection of grids of a uniform x-y grid
(FIG. 2).
[0038] In order to establish the profile of the breasts and chest
wall when the patient is in various positions, the above procedure
could be repeated with the patient in other positions (supine, for
example). Improved information might result if the discussed
measurements are taken of the breast from several different
directions, such as laterally, anterior-posterior and coronary.
This information may be used to model prostheses which assume a
natural shape when the patient assumes different positions.
[0039] To further enhance resolution, the projection devices and
image capturing device may rest on a movable track that rotates
around the patient in order to attain a three dimensional
perspective (FIG. 11). In this case, multiple images are detected
over time while the apparatus is scanning. These images are then
combined through algorithms and reduced to a digital format.
[0040] Mathematical interpolation of data needs to be done to
establish the shape of the object in regions where no pattern was
projected, or where unusual distortion or glare is encountered.
This is of greater concern where an image is not projected and
cameras are used to capture planar images from different angles. In
the case where an image is projected, it is important to project a
fine enough pattern such that large gradients in the shape can be
measured. For breasts, this would mean that it would be beneficial
to project an increasingly fine pattern as one moves laterally or
inferiorly further away from the nipple (FIG. 4). Note also that
"morphing" software could be used at this stages to interpolate
data, and to allow the patient and prosthesis fitter to choose
shapes of the relevant anatomy different from the patient's.
[0041] In one application of morphing, images of a breast may be
collected while the patient is in two positions, for example,
pronate or supine. Morphing may be used to model the flow or motion
characteristics of the prosthesis as the patient assumes one
position or another. This information can then be used to predict
the physical characteristics which must be built into the
prosthetic to enable it to move in a natural manner.
[0042] There are manifold ways to project an image onto the
breasts. For example (FIG. 5), it is possible to project a visible
laser beam through a holographic diffraction pattern generator to
create a matrix of spots or a grid-pattern of lines. Alternatively
(FIG. 6), one can use a laser beam scanner (e.g. mirror on x-y
gimbals) which can scan a single laser beam rapidly in any
user-selectable pattern. The driver for the scanner can be made to
dwell at particular points for milliseconds, before moving rapidly
to other points; in this way, a human would perceive a pattern of
dots. The spacing of the spots is controllable by the
scanner-driver. The use of two or more lasers projecting a beam
from different angles will afford greater precision in capturing
the image.
[0043] There are other ways to measure the three-dimensional
profile of an object. For example, interferometry is a well
established technique of measuring distances. The use of lasers is
well established in interferometry because the laser is collimated,
monochromatic and highly directional, thus can be used to measure
distance with a high spatial resolution. In the case of measuring
breast profiles, it would be possible to set up a low-intensity
visible diode laser which is directed towards the breast, and which
is scanned either on an x-y scanner (FIG. 7), or is scanned in an
x-y pattern from a point. Interferometers have the advantage that
they can measure very small distances, but they are relatively
expensive. Alternatively, three-dimensional information may be
captured throughout the use of two or more cameras which capture
images with x-y-z coordinates thus enabling depth of field
measurements with greater precision where small differences are
expected between points or lines.
[0044] Another way to measure the three-dimensional profile of an
object is to use an optical rangefinder. These devices (FIG. 8)
typically use a laser, which can project the image of a spot or
other shape onto the breast, which is then imaged onto an position
sensitive detector (PSD); depending on where the image of the spot
falls on the detector, and using simple geometry based on distances
and angles, the distance "d" between the breast and the position
sensitive detector. This geometric rangefinder system can b e
scanned using mirror scanners or the detector/source itself can b e
scanned on an x-y scanner, as described above. Other optical
rangefinders which make use of Doppler interferometry would also be
useful, although they are typically more expensive than simple
geometric rangefinders.
[0045] Ultrasound can also be used to measure the distance between
an ultrasound transducer and an object. In this case (FIG. 9), a
focused ultrasonic detector positioned in a known orientation with
respect to, and a known distance from, the breast. The spot on the
breast to be investigated can be marked with a laser beam which is
collinear with the ultrasound transducer. The driver electronics of
the ultrasound transducer excites the transducer with a pulse,
thereby creating a brief pulse of ultrasound which travels to the
breast at the speed of sound. The reflected signal returns at the
speed of sound to a detector positioned a known distance from, and
orientation with respect to, the breast. Based on the time between
the incident and reflected pulses, and knowing the speed of sound
in the atmospheric conditions during which the measurement was
made, the distance "d" can be accurately calculated. Again, by
scanning this detector in an x-y plane, the x-y-z coordinates of
the breast can be measured.
[0046] While there are some disadvantages to a contact technique of
measuring anatomical shapes, especially breast and chest-wall
profiles, such an approach can be simple to use and inexpensive to
implement. In this case, a matrix of feeler-gauges, arranged in an
x-y matrix and with freedom of movement in the z-direction, are
brought into contact with the breast or chest wall (FIG. 10). Each
of the feeler gauges is calibrated with a scale, or each has a
potentiometer which translates the relative z-positions of the
gauges to resistance and ultimately to voltage, which can be read
out and analyzed serially with an analog-to-digital converter
housed in a microcomputer. These digital measurements can then be
transferred to a remote device composed of a similar matrix of
feeler gauges in contact with a contiguous flexible coating (e.g.
rubberized silicon) such that the change in movement of the gauges
corresponds to a reproduction of the shape in the flexible coating.
This "form" then becomes the element from which the anatomical
shape is molded. Such a device can provide either a negative or
positive impression of the original shape of the anatomical
component. Integration of these components into a continuous system
would therefor result in a completely integrated computer-aided
design and manufacturing (CAD/CAM) system for prosthesis
manufacture.
[0047] Using profilometry of a breast as an example, the patient is
first positioned upright and facing forwards with exposed breasts.
At a precisely measured distance from the patient (perhaps 6 feet
away), a slide projector is positioned parallel to the floor of the
examination room and at the height of the patient's nipple. The
projector projects an image of a 64.times.64 matrix of small dots.
This is done by taking a slide photograph of a black piece of paper
with a rectangular matrix of white dots. Adjacent to the slide
projector is a color CCD video camera, the output of which is
coupled to a frame-grabber in a microcomputer. The camera is the
same distance from the patient as the projector. With the room
lights dimmed, the matrix of points is captured and digitized.
Immediately afterwards, the same measurement is done on a flat
piece of paper positioned orthogonal to a line drawn from the
projector/camera and paper; this image of the array on paper serves
to verify calibration of the setup. Using mathematical formulas
that describe the real position in space of a point (x,y,z) which
based on the face that a uniform grid of points was projected, and
if the surface was flat and orthogonal, should be at (x',y',z').
This matrix can be expanded into an arbitrary number of elements by
mathematical interpolation or by using commercially available
morphing software.
EXAMPLE 2
[0048] Anatomically Correct Robotic Appendages and Masks
[0049] The methods and devices described herein are ideal for
creating life-like appendages for use in robotic systems. This
includes coverings for robotic prosthetic devices whereby the
robotic component is covered with a prosthesis that has the
appearance of a normal appendage. Furthermore, these devices can be
used to create a form in any shape or size that mimics other forms
such that a whole body or anatomical part can be created for
free-moving robots, robotic prosthetic devices or for masks to be
worn by individuals. This definition includes masks and forms of
animals, humans and inanimate objects used in the entertainment
industry, for medical purposes or other industrial purpose.
EXAMPLE 3
[0050] Volume Measurement
[0051] It is a further object of the present study to measure
volume of an anatomical component. For example, one may use the
three-dimensional information to create a volume measurement either
by comparison to an imaged external standard or an internal
standard which has been saved in the devices memory. One
application of this volume measurement is the measurement of chest
or abdomen volume in neonates. The volume of the chest or abdomen
will increase and decrease with inspiration and expiration,
respectively. Volume displacement can be measured by taking
multiple readings at various timepoints and extrapolating the
difference. This difference relates to lung volume.
EXAMPLE 4
[0052] Skin Color Measurement
[0053] When it is desirous to match the color of the prosthesis
with the skin color of the patient's chest and/or remaining breast,
a calibrated color imaging system can be employed to quantify the
color in terms of a standard color scale (e.g. Commission
Internationale de l'Eclairage (CIE) standard colorimetric scale).
The current invention involves imaging the breast and/or chest of
the patient with a CCD color camera, the output of which is
attached to a frame grabber in a microcomputer. Alternatively, the
patient can be photographed with a color digital still camera, or
with a black-and-white camera sequentially through red, green and
blue filters. The patient is illuminated with ambient room lights,
but more preferable with a xenon flashlamp or high-intensity
incandescent source such as a halogen lamp. A set of color
standards, such as produced by manufacturers of graphics arts color
systems, and a white and grayscale reflectance standards, such as
available from Kodak Inc., are held adjacent to the patient and
when a digital image is taken. The digital image can be analyzed
later and the color of the breast and nipple can be quantified on a
standard and universal color scale. The color standards in the
image are used to correct for the color of the illuminating light
source and the white and grayscale standards correct for light
intensity. This quantified color data can be used to match the
color of the prosthesis during manufacturing, to the color of the
patient's skin.
[0054] In all cases, electronic reproductions of the body part may
be transmitted to a manufacturing center in another location.
Digitized coordinates may be coded into computer aided machining or
manufacturing processes that can automatically generate model
reproductions of the body part. One method of achieving this is
through stereolithography. The model can then be used as a template
for creating the prosthetic device.
[0055] Digitized coordinates may also be developed based on models
or drawings. These coordinates can then be used to generate
machined or manufactured parts based on computer aided design. Use
of computer aided design, machining and manufacturing for
prosthetic and orthotic devices is highly desirable in terms of
speed and precision.
[0056] In this case, a xenon flashlamp is used to illuminate the
breast as the CCD camera captures an image. Color and illuminance
standards, available from Kodak for example, are held by the
patient in close proximity of the breast during the image capture.
With color analysis software commercially available (e.g. Adobe
Photoshop), the color of the breast and nipple is quantified using
a CIE chromaticity scale. The color and illuminance standards are
used to check on the accuracy of the measurement.
EXAMPLE 5
[0057] Manufacturing Prostheses
[0058] Application of the present invention is not intended to
limit to breast prostheses. Superior prostheses of other body parts
as well as improved orthotics are also applicable.
[0059] For manufacturing, the external shell can be a single or
multi-piece (FIG. 12) consisting of a material that is malleable
yet firm, such as silastic or other elastomeric material.
Optionally, viscous low-density or viscoelastic materials may be
contained within the prosthesis to give it shape and movement
similar to a real anatomical part. Alternatively, the prosthetic or
orthotic may be composed entirely of such viscoelastic material
with or without a n exterior coating. For breast prostheses worn
externally or used in implants, the shape of the shell is defined
by measurements taken of the remaining breast and chest wall after
surgery. Alternatively, the shape may be modeled after a selection
from a library of collected shapes or measurements. In the case of
a multi-piece shell, the anterior aspect of the external shell is
constructed by creating a negative mold of the breast shape,
applying the shell material in it's uncured form to the negative
mold, and then pressing in a positive mold of the breast that is
the same shape as the negative mold, but smaller in size (FIG. 13).
This process of using two molds ensures that the shell of the
prosthesis is of consistent thickness.
[0060] The desirable thickness depends on the shape and mass of the
breast. For example (FIG. 14), in order to get an aesthetically
appealing change in shape of a small breast when the patient
changes position from a supine to an upright position, it is
necessary to create relatively thin walls. Alternatively, a more
massive breast should have a thicker wall in order to avoid body
position changes that lead to an unattractive, pendulous breast.
Optionally, the walls of the breast prosthesis can be of
non-uniform thickness (FIG. 15) in order to give the prosthesis a
non-uniform rigidity thus resulting in shape and motions (when the
patient moves) similar to real breasts. For example, the skin at
the inferior aspect of a real breast is thicker than at the
superior aspect. This structure results in a mechanical motion to
the breast that is unique, recognizable and desirable. By adjusting
the thickness of the prosthetic device so that it varies in
different portions of the prosthesis, and by filling the prosthesis
with a viscoelastic or flowing material, one can manufacture a
prosthesis that is lifelike in its draping characteristics and soft
to the touch.
[0061] Once cured, the anterior shell surface is placed with the
nipple facing downwards and the hollow cavity defined by the shell
is filled with a viscoelastic material. The materials that would be
best suited for the internal cavity fill would be light (i.e. low
density), a poor conductor of heat (i.e. low thermal conductivity),
have continuum-mechanical properties (e.g. Young's modulus,
compressibility etc.) like tissue, would be cheap, non-toxic and in
a pourable form whereupon it subsequently takes on selectable
properties. Optionally, such materials may be used as filler in a
single piece prosthesis that is hollow or in multi-piece devices
that are sealed together.
[0062] Examples of suitable materials would be soybean oil, agar,
gelatin, silicone, biologically inert polymers, etc. These
materials could optionally be highly aerated in order to maintain
minimal weight. An example of such a material is that which is
incorporated into the children's toy called "Gak".TM..
Alternatively, a material, part of which has been photochemically
cross-linked in order to set suitable mechanical properties, can be
used (for example, acrylamide). A potentially suitable material
would be a silica-aerogel, which has exceptionally low density
(0.003-0.35 g/cm.sup.3) and low thermal conductivity (.about.0.017
W/mK). The material could be poured into the mold or directly into
the prosthesis in various stages, and each pouring could consist of
a filler with different properties (such as density) in order to
establish a non-uniform mechanical property of the breast as a
whole, thus making it more life-like in it's motional behavior.
Lattice structures and "aerogels" may also be used to form a solid
one piece design that provides such memory and shape
characteristics. Further, such lattice structures may be used to
provide compartments within the prosthesis that could be filled
appropriate liquids or gels.
[0063] The outer or anterior breast form may be molded of such
plastic material that has memory characteristics which facilitate
its return to its original shape following once the patient resumes
the supine position. When the patient assumes other positions, the
added viscoelastic material will allow the breast to assume a
different, natural shape, akin to a normal breast. Adjusting
density and elasticity will permit the shape to change gradually
and the rate of movement would be proportional to the adjusted
density. Further, such materials are compressible so that, when
density is matched to a normal breast, a natural, more life-like
feel is obtained. Following compression, or any physical event that
alters the form from the original shape, the memory characteristics
allow the breast to resume its original shape and form, provided
the patient is in such position after which the shape was
originally molded.
[0064] While taking care that no significantly large air bubbles
are trapped, the posterior and anterior surfaces are affixed
together using a permanent or detachable adhesive. The final result
is a breast that changes shape, like a real breast, with the
changing body positions of the patient and while fitted into
different articles of clothing. Weight and compressibility may be
adjusted through altering density of filler so as to mimic the
natural "feel" of a normal breast or as determined to optimize
patient comfort. In many cases, lighter weight prostheses are
desirable for patient comfort.
[0065] The posterior aspect of the prosthesis fits snugly against
the remaining chest wall. In order to minimize sweating and
associated problems such as the formation of fungal infections, the
posterior aspect of the prosthesis may optionally be composed of a
plastic material with lattice-like structure, such as aerogel, that
is a poor heat conductor and has good "breathing" properties. These
prostheses are compatible with common materials found in garments
such as cotton, nylon and wool. Antifungicides and
antibacteriocides can be incorporated in the shell in order to
minimize the formation of unwanted biological substances.
[0066] It may be of benefit to texture the external or internal
prosthesis for the purpose of life-like appearance (in the case of
the former) or for preventing significant adhesions (in the case of
the latter. This texturing can be done after the molding process,
but would be easier to do by texturing the negative or positive
mold prior to molding.
[0067] Finally, the color of the breast and nipple are matched to
the existing breast or pre-operative breast. The shell material can
be colored with the addition of compounds in order to match the
color of the patient's remaining skin. The nipple can take on it's
color, which is distinctive from the rest of the breast, by the
addition of a colorant or separate piece of wall material or darker
color, at this stage. Once the external shell has had time to cure
and achieve a consistency whereby it holds its integrity, then the
posterior aspect of the shell is constructed. This surface is
shaped to conform to the remaining chest wall of the patient, and
is formed in the same was as the anterior surface; by applying an
uncured material to a positive mold of the chest wall. As before, a
negative mold is used to ensure uniform thickness of the posterior
surface.
[0068] The technology is not limited to breast form development and
may be used to develop any orthotic or prosthetic devices where
motion and comfort issues are critical. For example, orthotic
devices for feet are generally composed of solid, firm materials
such as hard plastic or metals. The use of soft, pliable materials
provide the advantage of flexibility. Hollow orthotics provide the
characteristic of compressibility. Use of viscoelastic fillers
and/or layers of variable density can provide a means for the
orthotic to form to the foot with greater ease. Such applications
are particularly useful i n athletic footwear where flexibility and
responsivity are an issue.
[0069] Finally, a prosthesis or orthotic filled with a magneto- or
electro-rheological fluid (which are available commercially) would
allow the user to adjust the "stiffness" of the prosthesis by
applying a variable magnetic or electric field to the fluid. Such
technology has not been incorporated into prostheses or orthotics.
An penile implant or external penile prosthesis would benefit from
such a user-controllable mechanical effect.
[0070] One specific design in the case of a multi-piece external
breast prosthesis is as follows: the external shell is constructed
by creating a negative mold of the breast shape, based on
profilometric measurements taken of the existing breast or based on
a data base of breast shapes, applying an uncured "memory" polymer.
These materials are found in some children's toys, for example in
the outer surface of the toy called "Stretch Armstrong". An elastic
polymer with memory forms an outer shell, which is filled with corn
syrup. The color of the polymer is altered, with additives such as
dye, to match the color of the patient's skin. A piece of the
polymer, shaped and colored like the patient's nipple, is placed in
the bottom of the negative mold prior to the pouring in of the
remaining shell material. The wall thickness (for an average size
breast) would be about 5 mm thick on the inferior aspect of the
breast and 2 mm thick on the superior aspect.
[0071] Once cured, the anterior shell surface is placed with the
nipple facing downwards and the hollow cavity defined by the shell
is filled with corn syrup. A posterior prosthetic surface is
created as the anterior form, but based on the shape of the
patient's chest wall. Next, the posterior and anterior surfaces are
affixed together using a permanent adhesive such as silicone
sealant. A removable cotton fabric liner is affixed, with Velcro,
on the posterior aspect of the prosthesis.
[0072] Any patents or publications mentioned in this specification
are indicative of the levels of those skilled in the art to which
the invention pertains. These patents and publications are herein
incorporated by reference to the same extent as if each individual
publication was specifically and individually indicated to be
incorporated by reference.
[0073] One skilled in the art will readily appreciate that the
present invention is well adapted to carry out the objects and
obtain the ends and advantages mentioned, as well as those inherent
therein. The present examples along with the methods, procedures,
treatments, molecules, and specific compounds described herein are
presently representative of preferred embodiments, are exemplary,
and are not intended as limitations on the scope of the invention.
Changes therein and other uses will occur to those skilled in the
art which are encompassed within the spirit of the invention as
defined by the scope of the claims.
* * * * *