U.S. patent application number 14/805023 was filed with the patent office on 2015-11-12 for artificial eyes and manufacture thereof.
The applicant listed for this patent is The Manchester Metropolitan University. Invention is credited to Thomas George Fripp, Lesley Elizabeth Gill, Lewis Green.
Application Number | 20150320546 14/805023 |
Document ID | / |
Family ID | 43639045 |
Filed Date | 2015-11-12 |
United States Patent
Application |
20150320546 |
Kind Code |
A1 |
Green; Lewis ; et
al. |
November 12, 2015 |
ARTIFICIAL EYES AND MANUFACTURE THEREOF
Abstract
A method of manufacturing an artificial eye for fitting as a
whole or partial replacement of a patient's original eye is
provided. The method includes providing a digitally acquired image
of an iris and transferring the image to a substrate comprising at
least the frontal region of an artificial eye.
Inventors: |
Green; Lewis; (South
Yorkshire, GB) ; Fripp; Thomas George; (South
Yorkshire, GB) ; Gill; Lesley Elizabeth; (Manchester,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Manchester Metropolitan University |
All Saints |
|
GB |
|
|
Family ID: |
43639045 |
Appl. No.: |
14/805023 |
Filed: |
July 21, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13978390 |
Aug 13, 2013 |
9101464 |
|
|
PCT/GB2012/050010 |
Jan 5, 2012 |
|
|
|
14805023 |
|
|
|
|
Current U.S.
Class: |
623/6.64 |
Current CPC
Class: |
A61L 27/025 20130101;
B29C 64/182 20170801; B33Y 80/00 20141201; A61L 2430/16 20130101;
A61L 27/16 20130101; A61L 27/34 20130101; A61F 2/141 20130101; B29C
64/165 20170801 |
International
Class: |
A61F 2/14 20060101
A61F002/14; A61L 27/34 20060101 A61L027/34; A61L 27/16 20060101
A61L027/16; A61L 27/02 20060101 A61L027/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 5, 2011 |
GB |
1100081.7 |
Claims
1. An artificial eye for fitting as a whole or partial replacement
of a patient's original eye comprising a powder material bound
together by a binder to form a shaped solid substrate, the binder
being selectively coloured in at least in a region thereof to
simulate at least an iris portion of an eye.
2. An artificial eye according to claim 1 wherein the substrate is
non-planar.
3. An artificial eye according to claim 2 wherein the substrate is
a dome-shaped, at least in the region that is selectively
coloured.
4. An artificial eye according to claim 1 wherein the substrate is
a shell-like structure.
5. An artificial eye according to claim 4 wherein the binder is
selectively coloured on the concave and convex surfaces of the
structure.
6. An artificial eye according to claim 5 wherein the selective
colouring is printed to a predetermined depth below a surface layer
of the substrate.
7. An artificial eye according to claim 6 wherein the predetermined
depth is between 0.2 mm and 1.0 mm below the surface.
8. An artificial eye according to claim 1 wherein the powder is a
silica based powder.
9. An artificial eye according to claim 1 wherein the powder is
substantially white.
10. An artificial eye according to claim 1 wherein the colouring or
ink further simulates a sclera portion of the eye.
11. An artificial eye according to claim 1 wherein the eye is
encapsulated in an acrylic material.
12. An artificial eye for fitting as a whole or partial replacement
of a patient's original eye comprising a shaped substrate upon at
least a region of which dye-sublimated ink is applied to simulate
at least an iris of an eye.
13. An artificial eye according to claim 12 wherein the substrate
is non-planar, preferably dome-shaped at least in the region where
ink is applied.
14. An artificial eye according to claim 12 further comprising an
adhesion promoter to enhance adhesion of the ink to the
substrate.
15. An artificial eye according to claim 12 further comprising a
lacquer covering at least the ink.
16. An artificial eye according to claim 12 wherein the substrate
comprises at least in part PMMA.
17. An artificial eye according to claim 12 wherein the substrate
is a bespoke blank shaped to conform to a particular patient's eye
socket.
18. An artificial eye according to claim 12 wherein the colouring
or ink further simulates a sclera portion of the eye.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a U.S. divisional patent application of
U.S. patent application Ser. No. 13/978,390 filed Jul. 4, 2013,
which is a 35 USC 371 application of International PCT Patent
Application No. PCT/GB2012/050010 filed on Jan. 5, 2012, and
further claims priority to GB 1100081.7 filed Jan. 5, 2011; the
entire contents of which are hereby incorporated by reference
herein in their entireties.
BACKGROUND
[0002] The present invention relates to artificial eyes (ocular
prostheses) and methods of manufacture thereof. More particularly,
the present invention relates to rapid manufacturing techniques for
artificial eyes and artificial eyes produced by such
techniques.
[0003] Artificial eyes have been prepared for patients whose eye(s)
have been damaged due to injury or disease for several centuries.
However, the techniques used remain skilled and labour intensive.
Commonly, the prosthesis is made from acrylic plastics such as
polymethylmethacrylate (PMMA) and this is encapsulated. Prior to
encapsulation, maxillofacial prosthetists and ocularists simulate
the colour of the iris and sclera using individual hand-painting
techniques with the patient present (or from an image of the
patient's eye). A variety of artists media are used which are
applied by pencils, crayons, cotton or a brush. This technique
requires inherent artistic ability and is time consuming and
expensive. The result is dependent upon operator ability and
experience.
[0004] Various proposals have been made to decrease the cost of
prosthesis manufacturing by utilising modern digital imaging and
CADCAM techniques. For example US20060173541 (Friel) discloses the
use of digital imaging of an iris in conjunction with use of
techniques such as selective laser sintering, stereo lithography to
manufacture a bespoke prosthesis. However, the approach disclosed
is still relatively complex requiring a number of separate
components to manufacture the finished artificial eye.
[0005] The present invention seeks to overcome or at least mitigate
the problems of the prior art.
SUMMARY
[0006] A first aspect of the present invention provides a method of
manufacturing an artificial eye for fitting as a whole or partial
replacement of a patient's original eye, the method comprising the
steps of: [0007] a) providing a digitally acquired image of an
iris; and [0008] b) transferring the image to a substrate
comprising at least the frontal region of an artificial eye.
[0009] Preferably there is a further step f) intermediate steps a)
and b) of overlaying the image onto a 3D CAD model of an artificial
eye.
[0010] In step b) the image is preferably transferred to the
substrate as an inherent part of the forming of the substrate in
the 3D printer. This has been found to be a particularly effective
way of producing artificial eyes in a cost-effective manner. The
colouration of the features of the eye (veins and/or iris) can
advantageously be improved (be better defined) if the coloured
features are configured to print to a predetermined depth below a
surface layer of the substrate.
[0011] A second aspect of the present invention provides an
artificial eye for fitting as a whole or partial replacement of a
patient's original eye comprising a powder material bound together
by a binder to form a shaped solid substrate, the binder being
selectively coloured in at least in a region thereof to simulate at
least an iris portion of an eye.
[0012] A third aspect of the present invention provides an
artificial eye for fitting as a whole or partial replacement of a
patient's original eye comprising a shaped substrate upon at least
a region of which dye-sublimated ink is applied to simulate at
least an iris of an eye.
[0013] The artificial eyes and the method of the present invention
have been found to provide a relatively low cost and effective
alternative to traditional manufacturing methods.
[0014] Preferred and/or optional features of the above three
aspects of the present invention are disclosed in the dependent
claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the present invention will now be described
in detail with reference to the accompanying drawings in which:
[0016] FIG. 1 is a perspective view of a domed artificial eye
(ocular prosthesis) according to a first embodiment of the present
invention;
[0017] FIG. 2 is a perspective view of the artificial eye of FIG. 1
from a different angle;
[0018] FIG. 3 is a perspective view of an artificial eye according
to a second embodiment of the present invention;
[0019] FIG. 4 is a captured digital image of an eye;
[0020] FIG. 5 is a digital image that has been manipulated and is
ready for subsequent use;
[0021] FIG. 6 is a flow chart illustrating a manufacturing method
according to another embodiment of the present invention for
manufacturing the prostheses of FIGS. 1, 2 and 3;
[0022] FIG. 7 is a plan view of a partially formed domed artificial
eye (ocular prosthesis) according to a third embodiment of the
present invention;
[0023] FIG. 8 is a perspective view of the partially formed domed
artificial eye of FIG. 7;
[0024] FIG. 9 is a perspective view of domed artificial eye
according of FIG. 7 at a later stage of manufacture; and
[0025] FIG. 10 is a perspective view of domed artificial eye
according of FIG. 7 at a still later stage of manufacture.
DETAILED DESCRIPTION
[0026] With reference to in particular FIG. 6, manufacturing
methods according to two embodiments of the present invention are
illustrated, in which certain steps are common, and other steps are
not as described below.
[0027] The method of both embodiments of the present invention
commences with the acquisition of an image of the visible portion
of an existing eye at step S200. This image is preferably taken
using a high quality digital camera such as a single lens reflex
(SLR) camera. The image may be of a particular patient's eye before
being replaced, may be of a patient's other eye that is not being
replaced (if the eye to be replaced is injured to the extent that
an image may not be acquired), or if the artificial eye is to be a
"stock" eye it may simply be of any person's eye in order to be
used with a collection that is representative of a number of
different general eye colours and sizes for subsequent "off the
shelf" use.
[0028] With reference to FIG. 4 the image 22 that is acquired is
incomplete since only a portion of the eye in situ can be made
visible at any time. The image 22 comprises a pupil 12, iris 14,
and sclera 15 having a particular pattern of veins 17 visible
thereon. At step S202 the image is edited using suitable photo
manipulation software such as Adobe Photoshop.RTM.. At this stage,
the iris 14 and pupil 12 are separated from the remainder of the
image and the image is colour corrected to remove a colour cast
that may be present due to the lighting conditions under which the
photograph is acquired. In addition, the image 22 is adjusted to
account for the particular colour profile of the printer upon which
the image will be output. In particular, the image is typically
acquired and stored as an RGB image whereas the printer prints
using a CYMK colour palette and appropriate corrections should be
made.
[0029] At step S204 simulated veins 16 are applied to the image and
the image canvas is extended to a sufficient area for subsequent
coverage of an artificial eye blank to provide a manipulated image
24 as illustrated in FIG. 5. In particular, a suitable Photoshop
brush may be used to apply the simulated veins. In a variant of the
process the veins 17 from the acquired image may be retained, and
simulated veins 16 may be matched thereto for the remainder of the
canvas.
[0030] At step S206 the manipulated image 24 is scaled to an
appropriate size. In selecting the size, it is preferable that
consideration is made for the apparent enlargement of the features
of the eye that will occur as a result of optical effects caused by
the subsequent encapsulation process, as well as a general desire
to have the iris 14 of the artificial eye appear slightly smaller
than the iris of the patient's "real" eye since this tends to draw
attention away from the artificial eye and it is therefore less
noticeable.
[0031] At this point, the process diverges dependent upon the type
of artificial eye that is required. Considering the first or
"stock" process:
[0032] This process is primarily to be used for the production of
stock or "off the shelf" eyes that may be produced in a range of
standard sizes and colours, and which may be used as a temporary
artificial eye, or a lower cost permanent eye, e.g. to be used in
developing countries. In addition to the entirely off the shelf
approach, a standard sized and shaped prosthesis may be used in
conjunction with an image which has been matched to a particular
patient by the acquisition process set out above. A finished stock
eye according to this embodiment is shown in FIGS. 1 and 2 and is
generally indicated by the numeral 10. The eye 10 is generally in
the shape of a hollow dome, having an outer convex surface 18 and
an inner concave surface 20.
[0033] Eyes 10 of this type may be used in conjunction with a
so-called "orbital implant". These are a substantially
hemispherical replacements for an eye that has been removed that
are manufactured from a natural porous material such as coral, or
an equivalent artificial material, which subsequently becomes
ingrown with the blood vessels and the tissue of the patient and is
therefore integrated into the body. An artificial eye 10 of the
type shown in FIGS. 1 and 2 can then be secured as the visible
"cover" over this orbital implant and mounted thereto by use of a
suitable small peg that locates within the orbital implant.
[0034] Further manufacture of this form of artificial eye 10 is as
follows:
[0035] At step S208 the scaled image produced at S206 is overlaid
on a CAD model of the required prosthesis and is positioned at an
appropriate location with pupil 12 at the frontal portion of the
model. In a preferred embodiment the image is also overlain on a
reverse (concave) face of the model in register the same image on
the convex face.
[0036] In a preferred embodiment, Magics rapid prototyping
software, produced by Materialise of Leuven, Belgium is used for
this stage of the process with the CAD model being in STL format.
In one variant, the scaling of the image 24 is undertaken at this
stage in Magics, rather than or in addition to the scaling that is
undertaken at step S206 in Photoshop. A close-up image of the
patient's real eye may be used at this stage to ensure that a size
and position good match is achieved for the artificial eye. The
Magics software may then export the finished model in a suitable
CAD file format for manufacturing on a 3D printer.
[0037] At step S210 in a preferred embodiment of the present
invention, a Z Corporation Spectrum model 510 3D printer is used
and Magics exports the CAD file in the proprietary ZPR or ZCP
format that is suitable for use with this type of printer.
[0038] Z Corporation produces a range of 3D printers that also
includes models 450 and 650, which function using a proprietary
process that builds up a 3D product in layers from powder material,
and are also suitable for use in the method of the present
invention. The printer has four print heads that "print" a binder
material into powder selectively in conjunction with coloured inks
(one head for each colour) to produce coloured 3 dimensional
objects, in a manner akin to a standard inkjet printer. The
printers have a resolution upwards of 300.times.300 dpi in the X
and Y direction and a layer thickness of as little as 0.1 mm (Z
direction). The way in which the colour is mixed in with the binder
means that the colour penetrates a distance into the eye itself and
is an intrinsic part of the finished eye, rather than a layer on
the surface.
[0039] In this embodiment, a silica powder having the designation
ZB150 and a binder having the designation ZB60 are used. Both are
supplied by Z Corporation. This powder is bleached to produce
objects that are by default white or substantially so. The
artificial eyes are preferably printed using this printer with the
outermost (anterior) portion of the eye 10 when fitted uppermost on
the print bed since this produces a strong finished eye. As the
print bed is substantially larger than a single artificial eye,
multiple eyes can be manufactured simultaneously in an X and Y
direction, and may also be stacked on top of each other in the Z
direction.
[0040] In a preferred embodiment, as a result of superimposing the
image 24 onto both the convex and concave faces of the CAD model
the image is printed on both faces 18 and 20 of the finished 3D
article, and in view of the degree of translucency of the material
at this thickness, the resultant artificial eye appears to have a
more vivid, realistic, colouring.
[0041] Once the printing process is complete, at step S212 the
artificial eyes 10 are removed from the bed of powder and are
cleaned using a stiff brush or by sand blasting and are then air
brushed with compressed air to remove any remaining dust and
particles.
[0042] At step S214 the artificial eye 10 is then immersed in a low
viscosity bonding agent that is substantially colourless, for
example cyanoacrylate, in this embodiment Procure PC08 produced by
Cyanotech of Dudley, UK. This product has the advantage of being an
approved substance for use in the manufacturing of medical
devices.
[0043] Once removed from the bonding agent and when curing is
complete, at step S216 the artificial eye 10 may then be
encapsulated in an acrylic material using a suitable known
technique of the type that has been employed for prior art PMMA
artificial eyes, before being fitted to a patient.
[0044] In the second embodiment, the manufacturing steps after S206
differ and are as follows:
[0045] At step S218 the scaled and colour corrected image is
printed onto a transfer material, which in this embodiment is dye
sublimation film using dye sublimation ink in an inkjet printer. A
preferred ink is Artrainium ink supplied by Sawgrass of Sheffield,
UK in CYMK and light cyan light magenta colours.
[0046] In this embodiment a cornea blank has the general solid
domed shape of the finished artificial eye 110 shown in FIG. 3, but
no colouring, is manufactured from PMMA using a known process. The
blank of this embodiment is termed "bespoke" because the rear
(anterior) thereof is shaped in accordance with a cast that has
been taken of a particular patient's eye socket, again using a
known process, and thus is specifically intended for use with that
patient.
[0047] The cornea blank is then pre-coated with an adhesion
promoter such as Digicoat as supplied by Octi-tech Limited of
Sheffield, UK, which is then wiped off and followed by application
of a sublimation coat that may also be supplied by Octi-tech
Limited in the Digicoat range. This process occurs at step
S220.
[0048] At step S222 the pre-treated cornea blank is then loaded at
a predetermined location into a vacuum press for the dye
sublimation ink to be transferred onto the blank. A suitable vacuum
press for this to be achieved is a Pictaflex PF480/6 model as
supplied by I-Sub of Kettering, UK. This press has a sufficiently
large bed that an array of blank prostheses may be arranged at
suitable locations that correspond to printed images on the
sublimation film, and the transfer may then simultaneously have
images transferred to them. In a preferred embodiment, a supporting
grid (e.g. of sheet metal with an array of apertures provided
therein) is preferably placed around the individual images to
prevent the sublimation film from sagging during the image
application process set out below.
[0049] In the vacuum press machine, the chamber is heated, the bed
supporting the blank prosthesis is raised and a vacuum is generated
in order to suck the sublimation film onto the blank. The heat
causes the sublimation ink to be transferred from the film onto the
prosthesis in an appropriate location. After an appropriate dwell
time, the vacuum is removed and the film and blank separated and
the press is allowed to cool.
[0050] Table 1 below sets out examples of various heat and dwell
time parameters that have been used. Example 5 has been found to
provide the best results.
TABLE-US-00001 TABLE 1 Standard Setting Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex.
5 Ex. 6 Pre-heat temp 120 no pre-heat no pre-heat no pre-heat no
pre-heat no pre-heat no pre-heat (.degree. C.) Pre-heat time 20 0c
0 0 0 0 0 (sec) Fill temp (.degree. C.) 135 135 135 145 135 135 135
Vacuum time 8 8 8 12 12 12 12 (sec) Air temp (.degree. C.) 190 190
200 220 180 190 200 Transfer 170 180 190 200 160 175 185 temp*
(.degree. C.) Print time 150 160 170 180 160 120 120 (sec) Release
time 15 15 15 20 15 5 5 (sec) Cooling time 15 15 30 35 30 30 30
(sec) Unload 60 60 60 60 35 35 35 (sec) *Transfer temp = ideal
temperature to transfer the image from film to eye
[0051] The blank is then removed from the vacuum press at step S224
and a clear lacquer is then applied to the image that has been
transferred so to minimise the bleeding of colours at step S226, to
produce the artificial eye 110 illustrated in FIG. 3 A currently
preferred lacquer is "Very high temperature lacquer" supplied by
Hycote of Oldham, UK.
[0052] Like features of this eye 110 are designated by like
numerals compared to FIGS. 1 and 2, but with the addition of the
prefix "1".
[0053] At step S216, the printed blank is then encapsulated at step
S216 in the same known manner as with the method of the first
embodiment, ready for the artificial eye to be fitted to a
patient.
[0054] FIGS. 7 to 10 illustrate an artificial eye and manufacturing
process according to a third embodiment of the present invention,
in which like parts are labelled by like numerals with the addition
of the suffix '.
[0055] The eye 10' and process of the third embodiment is a
variation of that of the first embodiment, so only differences from
the first embodiment are discussed in detail.
[0056] Referring to FIGS. 7 and 8 an alternative way of building up
the colouration of veins 16' is shown. In this embodiment, instead
of printing the vein colour on the surface layer of powder, a
predetermined depth of material (e.g. 0.2-1 mm) is coloured below
the surface parallel to the posterior-anterior axis, as the eye is
built up. This has been found to improve the colour and clarity of
the veins. A similar approach (not shown) is also used to improve
iris colouration. It will be appreciated that although the veins
are illustrated standing proud of the sclera 15' to explain this
approach, in reality, both would be built up together at the same
level.
[0057] It will also be noted in FIGS. 7 and 8 that the 3D printed
portion of the eye 10' has a regular domed shaped that is a full or
part hemisphere. Forming a part hemisphere enables a transparent
"skirt" portion 26' of poly methyl methacrylate (PMMA)
encapsulation material to be formed as part of the encapsulation
process as shown in FIG. 9.
[0058] This approach is advantageous in certain instances as it
then allows the perimeter free edge 28' of the skirt 26' to be
removed (e.g by milling or grinding) to customise the eye 10' to a
particular patient after encapsulation has been completed, as
illustrated in FIG. 10.
[0059] It will be appreciated that numerous changes may be made
within the scope of the present invention. For example certain
steps of the processes may be altered in their order; various steps
may be taken at different times and in different locations. Other
suitable 3D printers, dye sublimation materials, and vacuum
presses, and image manipulation techniques and software may be
used. The blanks/substrate used need not have a wholly domed shape.
For example, the iris region may be substantially flat, and the
finished domed shape built up from the encapsulation material.
[0060] It will be appreciated that terms such as front and rear,
upper and lower are used for ease of explanation, and should not be
regarded as limiting.
[0061] It will further be appreciated that the methods of both
embodiments of the present invention result in a cost effective way
in which artificial eyes may be produced at significantly less cost
than prior art techniques, which means that higher quality
artificial eyes may be supplied in developing countries where
previously the cost would be prohibitive. The resultant artificial
eyes have been found to be of at least similar or of higher quality
than those produced by prior art methods
* * * * *