Note: Descriptions are shown in the official language in which they were submitted.
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METHODS OF MAKING A NEGATIVE HEARING AID MOLD
FIELD OF THE INVENTION
The present invention relates to methods to make a negative hearing aid mold
and more particularly to methods to use rapid prototyping such as stereo
lithography,
fused deposition modeling, and laser sintering to make a negative hearing aid
mold.
BACKGROUND OF THE INVENTION
Hearing aids have been made utilizing various techniques including using
vacuum forming to create a negative mold for the hearing aid and the creation
of the
hard solid hearing aid bodies directly from stereo lithography techniques.
Many hearing aids are designed for insertion in the auditory canal which
includes the portion of the ear defined by parts of the pinna and the external
ear canal.
The external ear canal includes the cartilaginous portion and the bony
portion.
In the vacuum forming process, an impression of the auditory canal is used to
create a hard cast which is then used to create the negative mold through
vacuum
lamination, e.g. the impression by itself cannot be used directly. The
negative mold is
then filled with silicon or other suitable soft material. Before filing with
silicone, the
hearing electronics and transducers are installed. This construction technique
results in
a soft solid hearing aid.
Vacuum forming has the distinct draw back that auditory canal shapes and
dimensions are not faithfully reproduced. The vacuum forming techniques do not
have
the ability to faithfully reproduce the topology of the auditory canal due to
surface
undulations and curves that exceed the limits of tlus technology. This
situation creates
a potentially uncomfortable or irntating hearing aid because of misfit and
audio
feedback. These discomforts arise directly from the nonconforming aspects of
the
resulting hearing aid. The nonconforming aspects of the resulting hearing aid
are a
direct result of a low fidelity mold.
A misfit hearing aid is uncomfortable due to the tender nature of the pinna
and
external auditory canal. A nonconforming hearing aid creates an auditory
feedback
pathway from the canal tip region, through the space between the hearing aid
body and
microphone input. Audio feedback directly interferes with the functioning of
the
hearing aid and is uncomfortable.
During the creation of the hard solid hearing aid bodies directly from stereo
lithography techniques, a shell hearing aid body is directly created using
rapid
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prototyping such as stereo lithography. Directly creating the shell hearing
aid body
does not utilize a negative mold and thus cannot be used to create soft solid
hearing
aids.
Therefore, there is a need for a novel method of creating a high fidelity
negative hearing aid mold that is useful for the creation of a soft solid
hearing aid.
Therefore, there is a need for such a novel method of creating a negative
hearing aid mold that is useful for the creation of a soft solid hearing aid
using rapid
prototyping such as stereo lithography, fused deposition modeling, and laser
sintering.
SUMMARY
The present invention solves these needs and other problems in the field of
negative hearing aid mold creation by first processing auditory canal
dimension
measurement data representing dimensions of the auditory canal to generate
outside
auditory canal dimension data that represents outside dimensions of the
auditory canal.
Next, the outside auditory canal dimension data is processed to generate
outside mold
data. Then, a negative hearing aid mold is created from the outside mold data
using
rapid prototyping such as stereo lithography, fused deposition modeling,
Digital light
processing, such as Perfactory TM DLP teclmology, and laser sintering, with
the
negative hearing aid mold having an inside surface representing the outside
dimensions
of the auditory canal from the outside mold data, with the negative hearing
aid mold
suitable for receipt of a soft solid during the formation of a soft solid
hearing aid.
In other aspects of the present invention, the methods provide that the soft
solid
is silicone or any other suitable materials available to create the soft
solid.
In other aspects of the present invention, the methods provide that the
auditory
canal dimension measurement data representing internal dimensions of an
auditory
canal includes measuring the outside dimensions of an impression of an
auditory canal
to generate the outside auditory canal dimension data.
In other aspects of the present invention, the methods provide measuring the
outside dimensions of the impression of an auditory canal by measuring the
outside
dimensions of the impression of an auditory canal with a laser to generate
laser
measured auditory canal data and then generating point cloud/STL data from the
laser
measured auditory canal data.
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In other aspects of the present invention, the methods process the outside
auditory canal dimension data to generate the outside mold data in the form of
point
cloud/STL data.
In other aspects of the present invention, the methods further include
generating stereo lithography data from the point cloud/STL data.
In other aspects of the present invention, the methods analyze the impression
to
generate auditory canal point cloud/STL data using a laser to measure a
plurality of
surface positions on the impression to generate the auditory canal point
cloud/STL
data.
In other aspects of the present invention, the methods create a negative
hearing
aid mold from the outside mold data using stereo lithographic techniques. The
negative hearing aid mold is suitable for use as an outside mold for the
construction of
a hearing aid.
In other aspects of the invention, a soft solid negative hearing aid mold is
created from the outside mold data using stereo lithographic techniques, with
the soft
solid negative hearing aid mold suitable for use as an outside mold for the
construction
of a soft solid hearing aid.
In other aspects of the present invention, the methods create a negative
hearing
aid mold from the outside mold data using rapid prototyping such as stereo
lithography, fused deposition modeling, Digital light processing, and laser
sintering
with the addition of making an hearing aid mold from the outside mold data
using
rapid prototyping such as stereo lithography, fused deposition modeling,
Digital light
processing, and laser sintering.
In other aspects of the present invention, the methods create a negative
hearing
aid mold from the outside mold data using rapid prototyping such as stereo
lithography, fused deposition modeling, digital light processing, and laser
sintering
with the addition of making an epoxy based hearing aid mold from the outside
mold
data using rapid prototyping such as stereo lithography, fused deposition
modeling,
Digital light processing, and laser sintering with SLA Epoxy Resin Si, medical
grade
acrylonitrile butadiene styrene (ABS), or with powdered nylon.
In other aspects of the present invention, the methods further include
mounting
the negative hearing aid mold on a faceplate and placing a soft solid in the
negative
hearing aid mold.
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In other aspects of the present invention, the methods place a soft solid in
the
form of silicone in the negative hearing aid mold.
In other aspects of the present invention, the methods include installing
hearing
aid transducers and electronics in the negative hearing aid mold.
In other aspects of the present invention, the methods process, with a
computer
processor, the auditory canal dimension measurement data representing
dimensions of
an auditory canal to generate outside auditory canal dimension data that
represents
outside dimensions of the auditory canal.
In other aspects of the invention, the methods process, with a computer
processor, the outside auditory canal dimension data to generate outside mold
data.
In other aspects of the invention, the methods further comprising measuring
auditory canal dimension measurement data representing dimensions of an
auditory
canal directly from the auditory canal to generate outside auditory canal
dimension
data that represents outside dimensions of the auditory canal.
In other aspects of the invention, the methods provide creating a negative
hearing aid mold from the outside mold data using rapid prototyping further
comprises
creating the negative hearing aid mold from the outside mold data using rapid
prototyping such as stereo lithography.
In other aspects of the invention, the methods provide creating a negative
hearing aid mold from the outside mold data using rapid prototyping further
comprises
creating the negative hearing aid mold from the outside mold data using fused
deposition modeling.
W other aspects of the invention, the methods provide creating a negative
hearing aid mold from the outside mold data using rapid prototyping further
comprises
creating the negative hearing aid mold from the outside mold data using laser
sintering.
In other aspects of the invention the methods provide for making a negative
hearing aid mold comprising the steps of processing laser measured auditory
canal
dimension measurement data representing dimensions of an auditory canal to
generate
outside auditory canal dimension data that represents outside dimensions of
the
auditory canal, with the laser measured auditory canal dimension measurement
data
obtained with a laser measurement system; processing the outside auditory
canal
dimension data to generate outside mold data; and creating a negative hearing
aid mold
from the outside mold data using rapid prototyping, with the negative hearing
aid mold
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having an inside surface, with the inside surface representing the outside
dimensions of
the auditory canal from the outside mold data, with the negative hearing aid
mold
suitable for receipt of a soft solid.
These and ftu-ther objects and advantages of the present invention will become
clearer in light of the following detailed description of an illustrative
embodiment of
this invention described in comzection with the drawings.
DESCRIPTION OF THE DRAWINGS
The illustrative embodiment may best be described by reference to the
accompanying drawings where:
Figure 1 shows a negative hearing aid mold created following the preferred
methods according to the teachings of the present invention.
Figure 2 diagrammatically shows preferred methods according to the teachings
of the present invention.
Figure 3 shows an impression taken from the auditory canal.
Figure 4 shows a schematic diagram of a laser measuring system measuring the
impression following the preferred methods according to the teachings of the
present
invention.
Figure 5 shows point cloud/STL data representing the impression following the
preferred methods according to the teachings of the present invention.
Figure 6 shows the point cloud/STL data representing the impression after
being processed into outside auditory canal data for use in malting a stereo
lithography,
fused deposition modeling, and laser sintering based negative hearing aid mold
following the preferred methods according to the teachings of the present
invention.
Figure 7 shows the negative hearing aid mold being created in a stereo
lithography machine following the preferred methods according to the teachings
of the
present invention.
Figure 8 shows the negative hearing aid mold created following the preferred
methods according to the teachings of the present invention being filled with
a soft
solid and hearing aid electronics to create a soft solid hearing aid.
All figures are drawn for ease of explanation of the basic teachings of the
present invention only; the extensions of the figures with respect to number,
position,
relationship, and dimensions of the parts to form the preferred embodiment
will be
explained or will be within the slcill of the art after the following
description has been
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read and understood. Further, the exact dimensions and dimensional proportions
to
conform to specific force, weight, strength, and similar requirements will
likewise be
within the skill of the art after the following description has been read and
understood.
Where used in the various figures of the drawings, the same numerals designate
the same or similar parts. Furthermore, when the terms "side," "end,"
"bottom,"
"first," "second," "laterally," "longitudinally," "row," "column," and similar
terms are
used herein, it should be understood that these terms have reference only to
the
structure shown in the drawings as it would appear to a person viewing the
drawings
and are utilized only to facilitate describing the illustrative embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A negative hearing aid mold produced according to the preferred teachings of
the present invention is shown in the drawings and generally designated 10.
Figure 1
shows a negative hearing aid mold 10 created following the preferred methods
according to the teachings of the present invention. The negative hearing aid
mold 10
is used as a mold to create a soft solid hearing aid 16; the hearing aid 16 is
shown
being created in Figure 8.
An inside surface 15 of the negative hearing aid mold 10 conforms to an
outside surface 24 of an impression 22 taken of an auditory canal 21. The
impression
22 is shown in Figure 3. The negative hearing aid mold 10 according to the
teachings
I
of the present invention provides a negative impression of the auditory canal
21, so
that when the negative hearing aid mold 10 is filled with a soft solid 12 from
a soft
solid applicator 19, the soft solid hearing aid 16 may be produced that fits
well in the
auditory canal 21.
When the soft solid hearing aid 16 is constructed, a bowl end 17 of the
negative
hearing aid mold 10 is mounted on a faceplate 18. In one embodiment according
to the
preferred teachings of the present invention, a helix area 47 of the negative
hearing aid
mold 10 maybe used to insert the soft solid 12 from a soft solid applicator 19
to create
the body of the hearing aid 16. Those skilled in the art will recogivze that
other areas
of the hearing aid mold 10, other than the helix area 47, can be used for the
insertion of
the soft solid 12, such as in smaller hearing aid molds having various shapes.
The
faceplate 18 is shown in Figure 8. The bowl end 17 is open to allow insertion
of
hearing aid electronics and transducers 14, also shown in Figure 8. The
negative
hearing aid mold 10 also has an outside surface 41 and a canal tip portion 43.
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The negative hearing aid mold 10 is designed to create the hearing aid 16 that
fits in the auditory canal 21 but other types of negative hearing aid molds 10
may be
created with the preferred methods of the present invention and are within the
spirit
and scope of the invention. Undercuts and undulations in the topology of the
auditory
canal 21 make it difficult for prior art methods to produce a mold that
conforms. The
construction methods for the negative hearing aid mold 10 according to the
preferred
teachings of the invention are not affected by such undercuts and undulations.
A
nonconforming mold may create a hearing aid 16 that is uncomfortable or
impossible
to wear.
The hearing aid 16 that can be constructed with the negative hearing aid mold
10 according to the teachings of the present invention has a high degree of
conformance to the impression 22. Thus, the hearing aid 16 is comfortable to
wear
because it does not unduly impinge on the auditory canal 21. Since the hearing
aid 16
fits well in the auditory canal 21, no direct air pathways are created between
the
receiver and the microphone of the hearing aid 16. This conforming fit reduces
or
eliminates audio pathways available to create audio feedback. Therefore, a
much better
performing hearing aid 16 can be created with the negative hearing aid mold 10
produced according to the teachings of the present invention.
Figure 2 shows a diagram 20 diagrammatically illustrating the preferred
methods of the present invention.
As diagrammatically shown by box 29 and Figure 3, the impression 22 of the
auditory canal 21 is taken. The impression 22 provides a model of the auditory
canal
21 and is obtained with conventional means. Those slcilled in the art will
recognize
that other methods of obtaining the impression 22 of the auditory canal 21 are
within
the spirit and scope of the invention such as direct inner ear scanning using
optical or
MRI (magnetic resonance imaging) with direct transmission of measurement data
of
the auditory canal 21 for mold production. Arrow 23 indicates that the
impression 22
is made available to a topology characterization device, such as a laser
topology
system 26.
As diagrammatically shown by box 30 and in a preferred form, dimensions are
taken from the outside surface 24 of the impression 22. In a most preferred
form, a
laser topology system 26 is utilized to measure the outside dimensions of the
impression 22 with a laser beam 33. Those spilled in the art will appreciate
that other
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technologies can be used to measure the outside dimensions of the impression
such as
white light and digital imagining. The impression 22 is mounted in the laser
topology
system 26 in a way that permits reliable and consistent measurement. For some
systems, the impression 22 is mounted on a three-pronged mount 44 in an
orientation
that facilitates an analysis methodology, conventionally known as a path plan.
For
example, the canal faces the laser and the tragus portion of the impression
faces a
consistent way from impression to impression. Other laser topology systems
require
that the impression 22 be positioned perpendicular to the mount 44. Other
scanners do
not require such orientations. The laser topology system 26 captures complex
geometry through laser line scanning and translating of X, Y, Z data.
Conformance
utilizing prior methods is thus hit or miss. The present invention therefore
avoids the
hit and miss techniques of the prior art by producing a high fidelity negative
hearing
aid mold 10. The laser topology system 26 outputs the three-dimensional
measurement of the outside dimensions of the impression 22 as point cloud/STL
data
28. The point cloud data may be converted to a file type used for stereo
lithography
data also known as STL data. The laser topology system 26 analyzes the
impression
22 to generate point cloud/STL data 28 from the auditory canal 21 using the
laser beam
33 to measure surface positions on the outside surface 24 of the impression 22
to
generate the auditory canal point cloud/STL data 28.
According to the preferred teachings of the present invention, auditory canal
dimension measurement data representing dimensions of the auditory canal 21
are
processed by the laser topology system 26 to generate outside auditory canal
dimension data, such as the point cloud/STL data 28, that represents outside
dimensions of the auditory canal 21. The outside dimension data represents the
boundary of the auditory canal 21 such that, when the negative hearing aid
mold 10 is
used to create the hearing aid 16, the inside surface 15 of the negative
hearing aid mold
10 conforms to the outside dimension of the auditory canal 21 as represented
by the
impression 22. Thus, the resultant hearing aid 16 will conform well to the
auditory
canal 21.
Figure 4 shows a schematic diagram of the laser topology system 26 measuring
the impression 22 with the laser beam 33. To obtain the outside dimensions 28
of the
impression 22, which represent the dimensions of the auditory canal 21, the
laser
topology system 26 scans the impression with the laser beam 33 and detects
reflected
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laser signals and converts this data into measurements of the outside 24 of
the
impression 22. Laser based measurement of the impression 22 has the advantage
of
providing a rapid and accurate measurement of the impression 22. The laser
topology
system 26 which can be utilized with the methods of the present invention is
available
from either Laser Design, Inc. or ThreeShape of Copenhagen, Denmark. Those
skilled
in the art will recognize that other methods, both automated and manual, of
obtaining
the dimensions of the auditory canal 21 may be used such as mechanical
measurement
or other laser based methods such as efforts of workers in the art to directly
measure
the auditory canal 21 without the need for the impression 22, without
deviating from
the spirit and scope of the invention. According to the preferred teachings of
the
present invention, the laser topology system 26 is computer processor based.
Figure 5 shows the point cloud/STL data 28 representing the impression 22.
The point cloud/STL data 28 is diagrarnlnatically shown being provided to a
computer
processor 31 in Figure 2. The point cloudJSTL data 28 is the result of
processing the
laser measurements of the impression 22. The point cloud/STL data 28 is
provided in
three-dimensional format representing the spatial measurements of the
impression 22
by the laser topology system 26. Arrow 25 indicates that the point cloud/STL
data 28
is provided for further processing as diagrammatically shown by box 32.
The provision of the point cloudlSTL data 28 could either be through a local
connection or a remote connection such as the Internet. Other communication
methods
may be used without deviating from the spirit and scope of the present
invention.
Also, as diagrammatically shown by box 32, the point cloudlSTL data 28 is
converted to stereo lithography data such as auditory canal shell data 38 by
the
computer processor 31. The computer processor 31 receives the point cloud/STL
data
28 from the laser topology system 26. The computer processor 31 outputs the
stereo
lithography data such as auditory canal shell data 38. According to the
preferred
teachings of the present invention, the computer processor 31 processes the
outside
auditory canal dimension data, such as the point cloud/STL data 28, to
generate outside
mold data, such as the auditory canal shell data 38.
Figure 6 shows a graphical representation of the point cloud/STL data 28,
representing the impression 22, after being processed into auditory canal
shell data 38
for use in making a stereo lithography based negative hearing aid mold 10 and
follow
techniques used in the either the shell design software called Shell Designer
from
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3Shape of Copenhagen, Denmark or the software called E-Shell from RainDrop
Geomagic of North Carolina, USA. The computer processor 31 utilizes detailing
software from RainDrop Geomagic or 3Shape and establishes well known customer
features and parameters such as shell thickness, hole dimension, engraving,
and
surface editing. Other data conversion techniques and customization methods
that
produce an auditory canal shell design from measurement of the impression 22
are
within the spirit and scope of the present invention.
The provision of the auditory canal shell data 38 could either be through a
local
connection or a remote connection such as the Internet. Other communication
methods
may be used without deviating from the spirit and scope of the invention.
As diagrammatically shown by box 34, the negative hearing aid mold 10 is I
created from the auditory canal shell data 38. Figure 7 shows a partially
formed
negative hearing aid mold 11 being created in a stereo lithography machine 36.
Other
production technologies could be used such as fused deposition modeling and
laser
sintering. In fused deposition modeling the article is created out of medical
grade ABS
acrylonitrile butadiene styrene. In laser sintering the article is made out of
powdered
nylon. The partially formed negative hearing aid mold 11 is made using
standard
stereo lithography techniques. According to the preferred teachings of the
present
invention, the stereo lithography machine 36 is, and, utilizes an epoxy, from
3D
Systems of Valencia, California known as part description: SLA Epoxy Resin Si-
10.
Other stereo lithographic construction materials can be used without deviating
from the
spirit and scope of the invention, such as any other rapid prototype material
suitable for
stereo lithography. The resulting negative hearing aid mold 10 functions as a
form for
the construction of a hearing aid 16. According to the preferred teachings of
the
present invention, the stereo lithography machine 36 creates the negative
hearing aid
mold 10 from the outside mold data, such as the auditory canal shell data 38,
using
rapid prototyping such as stereo lithography, fused deposition modeling,
Digital light
processing, and laser sintering, with the negative hearing aid mold 10 having
the inside
surface 15 rapid prototyping is also known as concept modeling or rapid
manufacturing systems. The inside surface 15 represents the outside dimensions
of the
auditory canal 21 from the outside mold data, such as the auditory canal shell
data 38.
The negative hearing aid mold 10 is suitable for receipt of a soft solid 12
from a soft
solid applicator 19. The 3D Systems makes use of Light Year software and Build
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Station software to create a multi part-multi slice database as is
conventionally used in
the stereo lithography art. More than one negative hearing aid mold 10 may be
created
at a time. For example, up to 120 or more negative hearing aid molds 10 may be
made
in a run.
As diagrammatically illustrated by box 35, the negative hearing aid mold 10 is
further processed to create the hearing aid 16. Figure 8 shows the negative
hearing aid
mold 10 being filled with the soft solid 12 and hearing aid electronics and
transducers
14 to create the soft solid hearing aid 16. The negative hearing aid mold 10
is
designed to receive the soft solid 12 and hearing aid electronics and
transducers 14.
The soft solid 12 is made from silicone, as the principal material used to
ultimately form the body of the hearing aid 16. Silicones are materials that
exhibit
physiological inertness and thermal stability. Those skilled in the art will
recognize
that these examples are provided by way of example and not limitation and any
other
hearing aid application compatible material may be used without deviating from
the
spirit and scope of the invention. The hearing aid electronics and transducers
14 are
those well known in the art but other electronic and transducer combinations
may be
used that are compatible with the applied soft solid 12. The negative hearing
aid mold
10 is filled with the soft solid 12 after being placed on faceplate 18, as
diagrammatically illustrated by arrow 27, and after having the hearing aid
electronics
and transducers 14 installed, preferably by being attached to the faceplate 18
before the
negative hearing aid mold 10 is placed on the faceplate 18.
Thus since the invention disclosed herein may be embodied in other specific
forms without departing from the spirit or general characteristics thereof,
some of
which forms have been indicated, the embodiments described herein are to be
considered in all respects illustrative and not restrictive. The scope of the
invention is
to be indicated by the appended claims, rather than by the foregoing
description, and
all changes which come within the meaning and range of equivalency of the
claims are
intended to be embraced therein.
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