Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR THE PRODUCTION OF OTOPLASTICS AND
CORRESPONDING OTOPLASTIC
FIELD OF THE INVENTION
The present invention relates to a method for the production of otoplastics
and to an
otoplastic obtained by such method.
BACKGROUND OF THE INVENTION
The present invention starts out from problems which
have arisen in the production of in-the-ear hearing
devices. However, the solution which has been found to
these problems can be applied in general to otoplastics
whose definition is referred to further below.
In the production of shells for in-the-ear hearing
devices, the customary practice followed at present by
the audiologist is to make a mold in the shape of the
individual auditory canal, by taking an impression,
usually of silicone.
This mold is subsequently sent to the producer of the
hearing devices where the hearing device shell is
molded from a plastic on the basis of this mold.
This procedure is problematic from various aspects:
= In the production method based on the
aforementioned impression, polymer materials which
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lead to relatively hard, dimensionally stable
shells have to be used. This virtually always
leads to the shell having to be re-worked on
account of remaining pressure points when the
finished in-the-ear hearing device is fitted into
the individual ear.
= The aforementioned procedure no doubt permits the
resulting relatively hard shell to have an outer
shape corresponding to the impression, but it does
not permit complex internal/external shapes to be
formed, as would be desirable, for example, in
order for functional parts of the hearing device
to be received in an optimized way in terms of
fitting. In this respect, we understand functional
parts as meaning all units which are responsible
for picking up, processing and reproducing the
audio signals, that is to say of microphones,
digital processors, loudspeakers and the
associated auxiliary units, such as for remote
controls, binaural signal transmissions,
batteries, etc. In this respect, it must be
pointed out that optimum packing of these
functional parts in a way which utilizes the
available space- can only be carried out on an
individual basis, since the geometry of the
auditory canal may vary greatly individually.
The procedure described is, on the one hand, highly
labor-intensive, and the resulting hearing device
usually remains less than optimum with respect to its
wearing comfort and space utilization. The materials
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used in said conventional production method also entail
a relatively great wall thickness of the shell of the
in-the-ear hearing device, which reduces the space
available for said functional parts more than is the
case anyway.
SUMMARY OF THE INVENTION
The present invention has the purpose of overcoming
these stated disadvantages. For this purpose, it is
characterized by the fact that the at least one mold is
digitized three-dimensionally to obtain a set of data,
and the otoplastic or its shell is created by an
additive construction method, controlled using the set
of data. Although this production method is suitable
particularly for in-the-ear hearing devices, it can
also be used with similar advantages for hearing
devices worn outside the ear, and also for other
otoplastics, for example for the production of
headphones of all types, inserts for protecting against
water, inserts for protecting against noise, etc. In a
preferred embodiment of the method according to the
invention, account is taken of the fact that the site
of application of otoplastics, particularly of in-the-
ear otoplastics, is routinely subject to considerable
dynamics, for example the auditory canal is subject to
the dynamics of chewing movements. Taking a single
impression of the application site, as it were like an
instantaneous image, it is not possible for these
dynamics to be taken into account when producing the
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otoplastic. Therefore, in a preferred embodiment of the
method according to the invention, it is proposed to
take a plurality of impressions of the individual
application site in natural movement or in positions of
the natural movement and record the dynamics of the
application site like a film and thus control the
additive construction method as a function of the set
of data thereby obtained.
The present invention, as claimed, more particularly concerns a method for the
production of otoplastics, in which at least one mold of the individual
application site
is digitized three-dimensionally to obtain a set of data (p. 8, 1. 1) and the
otoplastic is
created as follows:
(a) deposition of a layer of material (p. 12, 1. 10);
(b) solidification of a sectional layer with the individual shape of the
individual otoplastic, controlled using the set of data;
(c) application of a further layer of the material over the solidified
sectional
layer and repetition of steps (b) and (c),
characterized in that sectional layers with individual shapes of a plurality
of
otoplastics, controlled by respective sets of data, are solidified in the
layer.
The present invention, as claimed, is also directed to a method for the
production of
otoplastics, in which at least one mold of the individual application site is
digitized
three-dimensionally to obtain a set of data, and the otoplastic is constructed
as
follows:
(a) application of a sectional layer with the individual shape of the
individual otoplastic;
(b) solidification of the applied sectional layer;
(c) application of a further sectional layer over the solidified layer and
repetition of steps (a) to (c),
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characterized in that sectional layers of a plurality of individual
otoplastics are
deposited in a common operation, controlled by means of the sets of data, and
are
then solidified before further sectional layers are deposited on the
solidified layers.
The present invention, as claimed, further concerns an otoplastic produced
according
to the method as described above, characterized in that at least its covering
consists
of thermoplastic material solidified in layers.
The present invention, as claimed, is also directed to the use of the method
as
described above for the production of in-the-ear hearing devices, hearing
devices
worn outside the ear, headphones, ear inserts protecting against noise or
water.
The present invention, as claimed, further concerns a method for manufacturing
ear
devices individualized for individuals comprising the steps of:
providing data of the three-dimensional shape of each individual's area of
application for a hearing device;
construing individual shells for said ear devices by respectively depositing
commonly a layer of one of a liquid and of a powderous material and
solidifying by a
laser arrangement in said layer individually shaped layers of said individual
sheRls,
thereby controlling said laser arrangement with said data.
The present invention, as claimed, is also directed to a method for
manufacturing ear
devices individualized for individuals comprising the steps of:
providing data of the three-dimensional shape of each individual's area of
application for a hearing device;
construing individual shells for said ear devices by providing a layer of
powderous or liquid material and solidifying at least two individually shaped
layers of
said individual shells by a common laser arrangement subsequently operating
for
solidifying one of said individually shaped layers and then the other of said
individually shaped layers, thereby controlling said laser arrangement by said
data.
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Furthermore, the present invention, as claimed, concerns a method for
manufacturing ear devices individualized for individuals comprising the steps
of:
providing data of the three-dimensional shape of each individual's area of
application for a hearing device;
simultaneously depositing individually shaped layers of fluidic material in a
predetermined plane;
solidifying said deposited individually shaped layers of fluidic material in
said
plane and depositing further individually shaped layers upon said solidified
individual
layers, thereby controlling said simultaneous deposition of layers of said
fluidic
material by said data.
The present invention, as claimed, also concerns a method for simultaneously
manufacturing a plurality of ear devices, each ear device individualized to a
person,
the method comprising:
providing data for each ear device, the data including three-dimensional shape
data of the area of application for the associated person; and
simultaneously construing shells for each ear device, with each shell being
construed at a respective location, the step of construing the shells includes
providing, at each respective location, a layer of solidifiable material, and
solidifying,
by a solidifying aspect that sequentially proceeds to each respective
locationõ a
portion of the material to provide a portion of the respective shell utilizing
the
provided data.
BRIEF DESCRIPTION OF THE DRAWINGS
The production method according to the invention, and
otoplastics realized using this method, are also
explained below with reference to the figures, in which
for example:
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Fig. 1 shows a simplified diagram of a production
installation for optimizing the industrial
production of otoplastics which operates in
accordance with the method according to the
invention;
Fig. 2 shows a further installation concept, in a
view analogous to that in Fig. 1;
Fig. 3 shows yet another installation concept in a
view analogous to that in Figures 1 and 2;
Fig. 4 shows a diagrammatic view of an in-the-ear
hearing device, with an earwax protection cap
fitted in a known manner;
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Fig. 5 shows, in a view analogous to Fig. 4, an in-
the-ear hearing device produced with an
earwax protection cap in accordance with the
method according to the invention;
Fig. 6 shows an in-the-ear hearing device with a
ventilation groove formed in it in a known
manner;
Figures 7 (a) through (f) show,
with the aid of perspective views of cutouts
of otoplastic shell surfaces, ventilation
grooves produced by the method according to
the invention;
Fig. 8 shows, based on a diagrammatic cutout of an
otoplastic surface, a ventilation groove
produced by the method according to the
invention with a cross section and cross-
sectional shape varying along its
longitudinal extent;
Fig. 9 shows a diagrammatic view of an in-the-ear
otoplastic with lengthened ventilation groove
processed in accordance with the method
according to the invention;
Fig. 10 shows, in a view analogous to Fig. 9, an in-
the-ear otoplastic with a plurality of
ventilation grooves produced in accordance
with the invention;
Figures 11 (a) through (e) show
cutouts of otoplastic shells with ventilation
channels of different cross-sectional shapes
and dimensions formed in accordance with the
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method according to the invention;
Fig. 12 shows, in a view analogous to that in Fig. 8,
a ventilation channel produced in accordance
with the method according to the invention in
an otoplastic shell with a cross-sectional
shape and cross-sectional surface varying
along its longitudinal extent;
Fig. 13 shows, diagrammatically in analogy to the
view in Fig. 9, an in-the-ear otoplastic with
a lengthened ventilation channel formed in
accordance with the method according to the
invention;
Fig. 14 shows, in a view analogous to Fig. 10, an in-
the-ear otoplastic with a plurality of
ventilation channels produced in accordance
with the method according to the invention;
Fig. 15 shows a diagrammatic view, in longitudinal
section, of an in-the-ear otoplastic with
ribbed inner surface;
Fig. 16 shows a cutout of the otoplastic according to
Fig. 15 in cross section, the ribs having
different cross-sectional surfaces;
Fig. 17 shows a perspective view of the cutout of an
otoplastic shell with inner ribbing according
to Fig. 15 or 16, the ribs having different
cross-sectional shapes and dimensions along
their longitudinal extent;
Fig. 18 shows, in a view analogous to Fig. 15, an in-
the-ear otoplastic with outer ribbing
produced in accordance with the invention;
Fig. 19 shows a diagrammatic view of a cutout of a
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ribbed otoplastic shell according to Fig. 18,
with ribs having different cross-sectional
surfaces;
Fig. 20 shows a diagrammatic view of a cross section
through an otoplastic with outer ribbing, or
inner ribbing, and an interior at least
partly filled with filler material;
Fig. 21 shows a diagrammatic cutout, in longitudinal
section, of an otoplastic shell produced in
accordance with the invention with a part
which is flexible upon bending and
compression;
Fig. 22 shows a diagrammatic view, in longitudinal
section, of an in-the-ear otoplastic produced
in accordance with the invention with a
receiving space for an electronic module;
Fig. 23 shows the otoplastic according to Fig. 22
being pushed on over an electronic module;
Fig. 24 shows a perspective and diagrammatic view of
an in-the-ear otoplastic, such as in
particular an in-the-ear hearing device, with
a two-part, separable and connectable
otoplastic shell produced in accordance with
the invention;
Fig. 25 shows, in a diagrammatic and cutaway view,
the integration of acoustic leads and adapter
members to an acoustic/electric or
electric/acoustic transducer, in an
otoplastic produced in accordance with the
invention;
Fig. 26 shows, in a view analogous to that in Fig.
25, the arrangement of two or more acoustic
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leads in the shell of an otoplastic shell
produced in accordance with the invention,
and
Fig. 27 shows, in a simplified signal flow chart and
functional block diagram, a novel procedure,
and a novel arrangement for carrying out the
procedure, where the dynamics of the
application area of an otoplastic are taken
into consideration when configuring the
latter.
The embodiments of otoplastics which are described
following the production method are preferably all
produced by this described production method.
DETAILED DESCRIPTION OF THE INENTION
Definition
An otoplastic is to be understood here as being a
device which is fitted directly outside the auricle
and/or on the auricle and/or in the auditory canal.
These include hearing devices worn outside the ear, in-
the-ear hearing devices, headphones, inserts protecting
against noise and inserts protecting' against water,
etc.
1. Production method
In the production method preferably used to produce the
otoplastics described in detail hereinafter, the shape
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of an individual application area for an intended
otoplastic is three-dimensionally digitized, and the
otoplastic or its shell is then constructed by an
additive construction method. Additive construction
methods are also known by the term "rapid prototyping".
With regard to additive methods which have already been
used in rapid prototyping, reference is made for
example to:
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Wohlers Report 2000, Rapid Prototyping
& Tooling State of the industry
From the group of these additive methods known today
for rapid prototyping, it appears that laser sintering,
laser lithography or stereolithography, or the
thermojet method are particularly well suited for
constructing otoplastics or their shells, and.in this
case in particular the specific embodiments described
hereinafter. Therefore, specifications of these
preferably= used additive- construction methods will be
discussed here, only in a brief summary:
Laser sintering: Hot-melt powder is applied in a
thin layer on a powder bed, for example by means
of a roller. The powder. layer is solidified by
means of a laser beam, said laser beam being
guided, inter alia according to a cutting layer of
the otoplastic or otoplastic shell, by means of
the 3-D shape information of the individual
application area. A solidified cutting layer of
the otoplastic or of its shell is obtained in the
otherwise loose powder. This layer is lowered from
the powder plane, and a new layer of powder is
applied over it, and this layer of powder is in
turn solidified by laser according to a cutting
layer, etc.
Laser lithography or stereolithocTraphy: A first
cutting layer of an otoplastic or of an otoplastic
shell is solidified by means of UV laser on the
surface of liquid photopolymer. The solidified
layer is lowered and is again covered by liquid
polymer. By means of said UV laser, the second
cutting layer of the otoplastic or of its shell is
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solidified on the already-solidified layer. Once
again, the laser positioning is controlled inter
alia by means of the 3-D data or information from
the individual, previously recorded application
area.
Thermojet method: The contour formation in
accordance with a cutting layer of the otoplastic
or of the otoplastic shell is carried out, in the
same way as in an ink-jet printer, by liquid
application inter alia according to the digitized
3-D shape information, in particular also the
individual application area. The deposited cutting
"picture" is then solidified. Once again,
according to the principle of the additive
construction methods, the otoplastic or its shell
is built up by depositing layer after layer.
As regards additive construction methods, and the
preferred ones mentioned above, reference may be made
to the following further publications:
"Selective Laser Sintering (SLS) of Ceramics",
Muskesh Agarwala et al., presented at the
Solid Freeform Fabrication Symposium, Austin,
Texas, August 1999,
Donald Klosterman et al., "Direct Fabrication of
Polymer Composite Structures with Curved LuM",
Solid Freeform Fabrication Symposium, University
of Texas at Austin, August 1999,
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In principle, therefore, in additive construction
methods, a thin layer of material is in each case
deposited on a surface, either over the whole surface
as in laser sintering or stereolithography, or, as in
the thermojet method, already in the contour of a cut
of the otoplastic or of its shell under construction.
The desired cut shape is then stabilized and
solidified.
Once a layer has been solidified, a new layer is
10 deposited over this, as has been described, and this
new layer is in turn solidified and connected to the
already solidified layer lying below it. The otoplastic
or its shell is thus constructed layer by layer by
additive layer-by-layer application.
For industrial production, it is preferable not just
for the cutting layer of one individual otoplastic or
otoplastic shell to be deposited and solidified in each
case, but for a plurality to be deposited and
solidified simultaneously per individual. In laser
sintering, for example, the one laser, normally under
mirror control, successively solidifies the cutting
layers of a plurality of otoplastics or their shells,
before all the solidified cutting layers are lowered in
unison. Then, after a new layer of powder has been
deposited over all the already solidified and lowered
cutting lavers, the plurality of further cutting layers
are formed in turn. Despite this parallel production,
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the respective otoplastics or their shells are produced
individually by digital control.
In this case, in order to solidify the plurality of
cutting layers, a single laser beam is used and/or
several beams are operated and controlled in parallel.
In an alternative to this procedure, a cutting layer is
solidified with one laser, while at the same time the
layer of powder is being deposited for the formation of
a further otoplastic or otoplastic shell. Thereafter,
the same laser will solidify the prepared layer of
powder according to the cutting layer for the next
otoplastic, while the previously solidified layer is
lowered and a new layer of powder is deposited there.
The laser then operates intermittently between two or
more otoplastics or otoplastic shells under
construction, and so the idle time of the laser
occasioned by the deposition of powder for the
formation of one of the shells is exploited for
solidification of a cutting layer of another otoplastic
under construction.
Fig. 1 shows, in a diagrammatic view, how, in one
embodiment, a plurality of otoplastics or their shells
are produced industrially in a parallel process by
means of laser sintering or laser lithography or
stereolithography. The laser with control unit 5 and
beam 3 is mounted above the material bed 1 for powder
or liquid medium. At position 1, it solidifies the
layer S1 of a first otoplastic or its shell, controlled
by the first individual set of data D1. Thereafter, it
is displaced on a displacement device 7 to a second
position where, with the individual set of data D2, it
prepares the layer S2 according to a further individual
contour. Of course, a plurality of the lasers can be
displaced as a unit and in each case several individual
otoplastic layers are prepared simultaneously. It is
only when the lasers 5 provided have prepared the
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respective individual layers at all the intended
positions that a new layer of powder is deposited, in
the case of laser sintering, by the powder delivery
means represented in general at 9, whereas in laser
lithography and stereolithography (not shown) the
solidified layers S are lowered in the liquid bed.
According to Fig. 2, layers of individual otoplastics
or their shells are solidified simultaneously on one or
more liquid or powder beds 1 by a plurality of lasers 5
which are controlled individually and simultaneously.
Once again, after this solidification phase has been
completed and after the lasers have been stopped, the
powder delivery unit 9 deposits a new layer of powder,
whereas, in the case of laser lithography or
stereolithography, the layers which have just
solidified, or already solidified structures, are
lowered in the liquid bed.
According to Fig. 3, the laser 5 solidifies the layer
S,, on a powder or liquid bed la and is then transferred
(broken line) to the bed ib, so that, during the
solidification phase at the bed la, the powder
application device 9b removes powder from above a
previously solidified layer S1_ or, in laser lithography
or stereolithography, the layer S1_ is lowered. It is
only when the laser 5 is active at the bed lb that the
powder delivery device 9a deposits a new layer of
powder over the layer S1 which has just solidified at
the bed la, or the layer Sl is lowered in the liquid
bed la.
When using the thermojet methods, and to similarly
increase productivity, cutting layers of more than one
otoplastic or its shell are deposited simultaneously,
in practice through one application head or, in
parallel, through several in one go.
By means of the method described, it is possible to
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obtain extremely complex shapes of otoplastics or their
shells, specifically as regards both their outer shape,
with individual adaptation to the application area, and
also, in the case of a shell, as regards their inner
shape. Overhangs and inward and outward protrusions can
be readily achieved.
Moreover, materials for additive construction methods
are known which can be shaped to give a rubber-elastic
and yet dimensionally stable shell, which, if so
desired, can be given local differences and even an
extremely thin wall and yet remain resistant to
tearing.
In a presently preferred embodiment, the digitization
of the individual application area, in particular the
application area for a hearing device, in particular an
in-the-ear hearing device, is undertaken in a
specialized institute, in the latter case by an
audiologist. The individual shape recorded there as
digital 3-D information is, particularly in connection
with hearing devices, sent to a production center,
either by transfer of a data carrier or via an Internet
link, etc. The otoplastic or its shell,- in the present
case the shell of the in-the-ear hearing device, is
shaped individually at the production center, in
particular using the abovementioned methods. The
fitting of the hearing device with the functional
component groups is preferably also carried out there.
On account of the fact that, as has been mentioned, the
thermoplastic materials used generally lead to a
relatively elastic, conformable outer shape, the
shaping with respect to pressure points in otoplastics
or their shells is also much less critical than was
hitherto the case, which is of huge importance in
particular for in-the-ear otoplastics. Thus, in-the-ear
otoplastics, for example as ear protectors, headphones,
devices protecting against water, but in particular
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also for in-the-ear hearing devices, can be used
similarly to rubber-elastic plugs, and their surface
conforms optimally to the application area, i.e. the
auditory canal. One or more ventilation channels can be
easily incorporated in the in-the-ear otoplastic so
that, with the resulting and possibly relatively tight
fit of the otoplastic in the auditory canal, it is
possible to guarantee unimpaired ventilation as far as
the eardrum. The individual 3-D data from the
application area can also be used during production to
optimize the interior of the otoplastic and utilize
this optimally, including individually with respect to
the individual array of components which this interior
is possibly intended to receive, as in the case of a
hearing device.
Particularly in the case of otoplastics in the form of
hearing devices, centralized production of their shells
permits central storing and administration of
individual data, both with respect to the individual
application area and also to the individual functional
parts and their settings. If, for whatever reasons, a
shell has to be replaced, it can be newly prepared
without any problem by calling up the individual sets
of data, without the need for laborious readaptation,
as has hitherto been the case.
On account of the fact that the methods described for
the production of otoplastics are known and described
in the literature, albeit only for prototyping, it is
not necessary at this point to reproduce all the
technical details of these methods.
At any rate, taking these technologies previously known
from prototyping and using them for industrial and
commercially feasible production of otoplastics
surprisingly affords very considerable advantages,
specifically for reasons which in themselves are not
critical in prototyping, for example the elasticity of
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the thermoplastic materials which can be used, the
possibility of individual construction with extremely
thin walls, etc.
In summary, by using said additive construction methods
for the production of otoplastics or their shells, it
is possible to integrate various functional elements on
them, which functional elements are prepared on
computer during the planning of the otoplastic and
which are generated with the construction of the
otoplastic or its shell. Hitherto, functional elements
of this kind were typically fitted into or onto the
otoplastic or its shell only after the latter had been
produced, which is recognizable from material
interfaces or from lack of homogeneity of the material
at the connection points.
For said otoplastics, in particular those with
electronic inserts, for example for hearing devices,
and in particular for in-the-ear hearing devices,
examples of elements which can be fitted directly into
the otoplastic shell by the proposed technique are:
seats and holders for structural parts, earwax
protection systems, ventilation channels in the case of
in-the-ear otoplastics, and support elements which hold
the in-the-ear otoplastic in the auditory canal, for
example channel locks.
Fig. 4 shows, in diagrammatic form, an example of an
in-the-ear otoplastic 11, for example an in-the-ear
hearing device in which the acoustic outlet 13 to the
eardrum is protected by means of an earwax protection
cap 15. This protection cap 15 has hitherto been
produced as a separate part and attached to the shell
16 of the otoplastic 11 and fixed, for example, by
adhesion or welding. As Fig. 5 shows in the same view,
by using said additive construction methods, the earwax
protection cap 15a is integrated directly on the shell
16a of the otherwise identical in-the-ear otoplastic
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lla. At the connection points indicated schematically
at P in Fig. 4, where in conventional methods there is
necessarily a lack of homogeneity of the material or a
material interface, there are no such interfaces
according to Fig. 5, and the material of the shell 16a
merges homogeneously into that of the earwax protection
cap 15a.
This is just an example of how known earwax protection
systems and other functional elements can be integrally
incorporated by using said production method.
A number of specific, novel otoplastics are presented
below:
2. In-the-ear otoplastics with ventilation
In the case of in-the-ear otoplastics, in particular
in-the-ear hearing devices, it is known to provide a
ventilation groove on the outside, as is shown
diagrammatically in Fig. 6. Such ventilation grooves,
as they are used today, are not by any means optimal,
and for different reasons:
- As regards acoustics: The ventilation grooves
known today are not really adapted to the
particular acoustic requirements. Thus, in active
otoplastics, for example in-the-ear hearing
devices, they can do little to help effectively
solve the problems of feedback from electro-
mechanical output transducer to acoustic/electric
input transducer. In the case of passive in-the-
ear otoplastics too, for example ear protectors,
they are not able to support the desired
protective action and simultaneously maintain the
desired ventilation properties.
- Earwax sensitivity: The ventilation grooves used
today in the outer surfaces of in-the-ear
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otoplastics are extremely sensitive to formation
of earwax. Depending on its intensity, the earwax
formation can quickly impair the ventilation
properties of the ventilation grooves provided, if
not completely obstruct them.
Ventilation measures are proposed below for in-the-ear
otoplastics, in particular for in-the-ear hearing
devices or ear protectors, but also for otoplastics
which extend only partially into the auditory canal,
for example headphones, these ventilation measures at
least partly avoiding the abovementioned disadvantages
of known measures.
In this connection, a distinction is made below between
ventilation systems which
- are groove-like and at least partially open toward
the wall of the auditory canal,
- are completely closed off from the wall of the
auditory canal..
2a) Ventilation systems open toward the wall of the
auditory canal
In Figures 7(a) through (f), which are perspective
diagrammatic views of cutouts of the outer wall 18 of
in-the-ear otoplastics which bears against the auditory
canal, novel ventilation groove profiles are shown in
cutaway view. According to Fig. 7(a), the profile of
the ventilation groove 20a is rectangular or square
with predetermined and exactly observed dimensional
relationships. According to Fig. 7(b), the profile of
the ventilation groove 20b is in the shape of a sector
of a circle or ellipse, again with an exactly
predetermined cross-sectional edge curve 21b. By exact
determination and execution of the cross-sectional
shape of the ventilation grooves 20 provided, it is
already possible to a certain extent to predict and
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influence the acoustic transmission conditions along
this groove, upon bearing against the inner wall of the
auditory canal. Of course, the acoustic behavior also
depends on the length by which the groove 20 extends
along the outer wall 18 of the otoplastic.
Figures 7(c) through (f) show further ventilation
groove profiles which are additionally protected
against earwax. The profile of the groove 20c according
to Fig. 7(c) is T-shaped.
Regarding the wide cross-sectional surface of the
groove at 27c, the inwardly jutting portions 23c and
the resulting constriction 25c, toward the wall of the
auditory canal, already give a considerable protective
action against earwax. Even if earwax penetrates into
the constriction 25c and hardens there, this does not
cause any real constriction or even blockage of the
ventilation groove, which now becomes an enclosed
ventilation channel. In Figures 7(d) through 7(f),
which follow the principle of Fig. 7(c) already
explained, the cross-sectional shape of the wide groove
portion 27d through 27f is designed with different
shapes: in Fig. 7(d) in the shape of a sector of a
circle or the sector of an ellipse, in Fig. 7(e) in the
shape of a triangle, and in Fig. 7(f) in the shape of a
circle or ellipse.
By specific configuration of the cross-sectional
surface of the groove, shown simply by way of example
in Figures 7(a) through 7(f), it is already possible to
achieve a considerably improved effect, both with
respect to the acoustic properties and also with
respect to the protection against earwax, compared to
conventional ventilation grooves which have more or
less random profiles. In this case, the profiles are
first computer-modeled, taking into consideration said
protection against earwax and the acoustic effect, and
are integrated exactly into the finished otoplastics.
CA 02412934 2002-12-16
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The additive construction methods discussed above are
very particularly suitable in this respect. In order
now to further optimize the acoustic effect of the
ventilation groove, a very wide variety of acoustic
impedances can be obtained along the length of the
novel ventilation grooves, which results, for example
as in Fig. 8, in ventilation grooves 29 defining
different profiles along their longitudinal extent,
which in Fig. 8 are made up of profiles according to
Fig. 7.
Like the configuring of passive electrical networks,
the acoustic transmission behavior of the groove which
bears on the auditory canal can thus be computer-
modeled and checked and then integrated into the in-
the-ear otoplastic or its shell.
More areas protected against earwax can be specifically
provided on exposed portions for this purpose, as is
indicated at A in Fig. 8.
Moreover, with a view to optimizing the acoustic
conditions, it may be entirely desirable for the
provided ventilation grooves to be made longer than is
permitted in principle by the longitudinal extent of a
given in-the-ear otoplastic. As is shown in Fig. 9,
this is achieved by the fact that such grooves 31,
designed in the manner shown for example in Figures 7
and 8, are guided in predetermined curves along the
surface of the otoplastic, for example as is shown in
Fig. 9, in practice as grooves running round the
otoplastic like a thread. Further optimization
flexibility is achieved by the fact that not just one
ventilation groove, but a plurality are guided across
the surface of the otoplastic, as is shown
diagrammatically in Fig. 10. The high degree of
flexibility of the groove design means that, depending
on the application area in the auditory canal,
differently dimensioned ventilation grooves
CA 02412934 2002-12-16
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specifically optimized in each case with respect to
earwax protection and acoustic transmission. behavior
can be formed along the surface of the otoplastic.
2b) Ventilation svstems with fully integrated channels
This alternative embodiment of the novel ventilation
systems is based on ventilation channels which are
fully integrated into the otoplastic, at least in some
areas, and closed off from the wall of the auditory
canal. This system is explained below on the basis of
its design on an otoplastic shell. It should be
stressed, however, that when no other units are to be
integrated on the otoplastic in question and the latter
is designed as a solid otoplastic, the following
explanations naturally relate also to a channel passage
in any form right through said solid otoplastic.
Fig. 11 shows, in analogy to Fig. 7, different cross-
sectional shapes and surface relationships of the
proposed ventilation channels 33a through 33e.
According to Fig. 11(a), the ventilation channel 33a
built into the otoplastic shell 35a has a rectangular
or square cross-sectional shape. In the embodiment
according to Fig. 11(b), it has, at 35b, a channel
cross-sectional shape in the form of a sector of a
circle or sector of an ellipse. In the embodiment
according to Fig. 11(c), the ventilation channel 33c
provided has a circular or elliptic cross section, and,
in the embodiment according to Fig. 11(d), it has a
triangular cross-sectional shape.
In the embodiment according to Fig. 11(e), the
otoplastic shell has a complex inner shape, for example
a retention part 37 integrated thereon. For optimal
utilization of space, the ventilation channel 35e
provided here is designed with a cross-sectional shape
which also makes use of complex shapes of the
otoplastic shell. Accordingly, its cross-sectional
CA 02412934 2002-12-16
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shape extends in a complicated manner partially into
the retention strip 37 built onto the shell 35e.
Looking back at the variant embodiment in accordance
with section 2a), it should be noted that these complex
cross-sectional shapes optimally utilizing the
available space can also be realized on ventilation
grooves which are open toward the auditory canal, and,
conversely, channel passages as shown for open grooves
in Figures 9 and 10 can be realized on closed
ventilation channels.
Fig. 12 shows, finally, an alternative embodiment of a
fully integrated ventilation channel 39 which has
different cross-sectional shapes and/or cross-sectional
dimensions along its longitudinal extent, as is
represented for example in the otoplastic shell 41, in
which case the acoustic transmission behavior can be
optimized in the sense of executing different acoustic
impedance elements. In this connection, and with
reference to subsequent section 5), it may also be
noted that, because of the possibility of realizing
complex acoustic impedance conditions, ventilation
channels, in particular of the closed configuration
presented in this section, can at the same time be
used, at least in some sections, as acoustic lead
sections on the output side of active electromechanical
transducers, for example on the output side of
microphones, for example in in-the-ear hearing devices.
Figures 13 and 14, in analogy to Figures 9 and 10,
show, on the one hand, how the integrated ventilation
channels discussed in this section are lengthened on
the respective otoplastic 43 by appropriate guiding of
their course, and, on the other hand, how two and more
of said channels, if appropriate with different and/or
varying channel cross sections, in analogy to Fig. 12,
are integrated on the otoplastic.
CA 02412934 2002-12-16
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The possibilities which are presented in sections 2a)
and 2b), and which can also be combined in any desired
manner, afford the skilled person a countless number of
design variants of the novel ventilation systems and in
particular, because of the different independently
dimensionable parameters, a large degree of freedom in
creating optimum earwax protection and optimum acoustic
transmission conditions for the respective individual
otoplastic. In all the embodiment variants, the
specific individual configuration of the system is
preferably calculated or computer-modeled, taking the
stated requirements into account. The individual
otoplastic is then made. Once again, the production
method with the additive construction principle, which
is known from prototyping and which is explained in the
introduction, is suitable for this purpose, which
method is then controlled with the optimized model
result.
3. Otoplastics with optimized shape stability
This section deals with providing novel otoplastics
which are optimally adapted to the dynamics of the
application areas. It is known, for example, that
conventional in-the-ear otoplastics are unable to
accommodate the relatively great dynamics of the
auditory canal, for example during chewing, because
their shape stability is substantially identical in all
parts. Similarly, for example, the acoustic leads
between hearing devices worn outside the ear, and the
auditory canal are unable to freely follow the dynamics
of the application area. The same problem arises with
in-the-ear otoplastics, to a slightly lesser extent,
and also with ear protectors, headphones, inserts
protecting against water, etc.
In particular, their intrinsic function, for example
their protective action, in this case partially
deteriorates if the stated dynamics of the application
CA 02412934 2002-12-16
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area are increasingly taken into consideration. By way
of example, reference may be made in this connection to
known ear protectors which are made of elastically
deformable plastics and which indeed take considerable
account of the stated dynamics of the application area,
but at the expense of their acoustic transmission
behavior.
Fig. 15 shows a diagrammatic view of a longitudinal
section of an in-the-ear otoplastic, and Fig. 16 shows
a diagrammatic cross-sectional view of a portion of
this otoplastic. The otoplastic, for example for
receiving electronic components, has a shell 45 which
is made, like a pair of tights, as a thin wall of
elastic material. The shape stability of the shell
skin, which is smooth on the outside in the
illustrative embodiment shown, is ensured, where so
desired, by ribs 47 which are applied integrally on the
inside of the shell and which are made of the same
material as the shell skin.
Depending on the required dynamics of the in-the-ear
otoplastic on the one hand, in order for example to
take account of the dynamics of the auditory canal, and
the requirements in respect of the support and
protection of built-in components, as in an in-the-ear
hearing device, the course of the wall thickness of
shell skin 45 and the density and configuration of the
ribs 47 are calculated in advance, and the otoplastic
is thereafter constructed according to the calculated
data. Once again, the above-discussed production method
using additive construction methods is outstandingly
suitable for this purpose. Of course, the design of the
in-the-ear otoplastic just discussed can be readily
combined with a ventilation system of the kind
discussed with reference to Figures 7 through 14. In
particular, the ribs provided to influence the shape
stability or bendability can also be designed with
different cross-sectional profile in certain areas of
CA 02412934 2002-12-16
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the otoplastic, if appropriate also advancing from one
cross section to the other in their longitudinal
extent.
In the form of a perspective view, Fig. 17 shows purely
by way of example and diagrammatically the design of
the outer skin 45 with ribs 47 having varying cross-
sectional surfaces along their longitudinal extent.
Instead of or in addition to the specific wall
strengthening and the specific configuration of the
bending and torsion behavior, in short of the shaping
behavior of the in-the-ear otoplastic, it is possible,
as has been mentioned, in addition to the internal
ribbing pattern as is shown in Figures 17 and 18, also
to provide an external ribbing pattern. According to
Figures 18 and 19, a pattern of ribs 51 is worked on
the outer surface of the otoplastic 49, if appropriate
with different density, orientation and profile shape
in different areas.
According to Fig. 19, this can be used for the
otoplastics in question here which have a hollow
cavity, but also for otoplastics with no hollow cavity,
that is to say, for example, with no electronic
components, e.g. for ear protector devices and devices
protecting against water. One such otoplastic is shown
diagrammatically in a cross-sectional view in Fig. 20.
Here, the interior 53 is made, for example, from
extremely compressible absorption material and is
surrounded by a shape-giving skin shell 55 with rib
pattern 57. Here, the "skin" 55 and the rib pattern 57
are integrally produced together. The production method
discussed in the introduction and using additive
construction methods is once again suitable for this
purpose. How far these additive construction methods
will be able to be used, in the near future, on a
workpiece with changing of the processed materials
remains to be seen. Should this become possible, then
CA 02412934 2002-12-16
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the way is clear, for example in the illustrative
embodiment according to Fig. 20, to sequentially also
construct the filler 53 at the same time as the shell
skin 55 and the ribs 57 in respective construction
layers.
Looking back in particular to Figures 18 and 19, it
will be seen that ventilation channels or free spaces
can at the same time be formed with the aid of the
external ribbing pattern, as is shown purely
schematically and by way of example by the path P.
Returning once more to Fig. 20, it is entirely
possible, if so required, and as is shown by broken
line 571 in Fig. 20, to provide an internal ribbing
pattern 57i on the shell skin 55 even if the in-the-ear
otoplastic is filled with material, that is to say if
it is not intended to receive further components, such
as electronic components.
As is also shown by the broken line 59 in Fig. 20,
otoplastics can also be created which indeed leave free
a hollow cavity to receive units such as electronic
components, but in which the interspace, between such a
hollow cavity 59, is designed specifically to the
necessary volumes and shapes of the units additionally
to be received, and the shell skin 55 is filled for
example with a resilient or sound-damping material, or
components to be incorporated are surrounded by such a
material as far as the shell skin 55.
The shell skin 55 or 45 according to Figures 15, 16 and
17 can be made entirely of electrically conductive
material, by which means an electrical screening effect
is at the same time created for electronic components
lying on the inside. This also applies, if appropriate,
to the filling 53 according to Fig. 20.
Figures 15 through 20 have shown an example of an
CA 02412934 2002-12-16
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otoplastic in the form of an in-the-ear otoplastic
whose shell is shape-stabilized with ribs lying on the
inside and/or outside, resulting in an extraordinarily
light and deliberately formable structure. if
necessary, this structure can of course also be used
for otoplastics worn outside the ear.
Fig. 21 shows a further alternative embodiment of an
in-the-ear otoplastic which is deliberately bendable or
compressible in one area. For this purpose, the shell
61 of an otoplastic, such as in particular the shell of
an in-the-ear hearing device, has an undulated or
creased configuration 63 at one or more predetermined
regions where, in accordance with the particular
requirements, it is bendable or compressible. Although
Fig. 21 shows this measure on the basis of the shell of
an in-the-ear otoplastic, it is entirely possible, if
necessary, to provide this measure also for an
otoplastic worn outside the ear. For this purpose, the
production method discussed in the introduction is once
again preferably used.
In this illustrative embodiment too, it is possible, as
was explained with reference to Fig. 20, for the
internal volume of the otoplastic to be filled with
filler material in accordance with the requirements,
and built-in components integrated therein can be
embedded in such filler material, resulting in a higher
degree of stability of the appliance and improved
acoustic conditions.
4. Modular housing/built-in comnonents
Particularly in the case of in-the-ear hearing devices,
the problem is that the application area, i.e. the
auditory canal, changes its shape. This is obviously
the case when a person is growing up. In adults too,
however, the auditory canal changes, sometimes
considerably, and in most cases in the sense of
CA 02412934 2002-12-16
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narrowing (e.g. what is called diver's ear).
In the case of in-the-ear hearing devices, the problem
thus generally arises that, even if the components
built into the hearing device could themselves be
maintained over long periods of the user's life, for
example with only the transmission behavior of the
hearing device having to be readjusted to the
particular hearing conditions, new hearing devices
nevertheless have to be constantly designed, simply
because of the fact that the previous ones no longer
fit satisfactorily into the auditory canal.
The measures discussed in section 3 already make it
possible to improve this, on account of the fact that
automatic shape adjustment of the otoplastic to the
changing application areas is thus permitted. In this
section, further measures in this connection will be
discussed, particularly with reference to in-the-ear
otoplastics. However, it should be noted that also in
the case of otoplastics worn outside the ear, for
example hearing devices worn outside the ear, this
opens up the possibility of changing the "housing", and
of doing so not only when this is necessary for reasons
of wearing comfort, but also as and when desired, for
example in order to change the esthetic appearance of
such hearing devices worn outside the ear.
Fig. 22 shows a diagrammatic view of an in-the-ear
otoplastic 65 in longitudinal section, the design of
the interior 67 corresponding substantially to the
shape of the electronic module 69 to be received, which
is shown diagrammatically in Fig. 23. The otoplastic 65
is made of rubber-elastic material and, as is shown in
Fig. 23, can be pushed on over the electronic modules
69. The shaping of the interior 67 is such that the
module or the plurality of modules to be received are
positioned and held directly with a form fit by the
otoplastic 65. By means of this measure, it is easily
CA 02412934 2002-12-16
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possible to provide one and the same electronic modules
69 with different otoplastics 65, for example in order
thereby to take account of the changing shape of the
auditory canal in a growing child. The otoplastic in
practice becomes an easily exchangeable throw-way
accessory for the in-the-ear hearing device. The
otoplastic 65 can be easily changed not only to take
account of changing conditions in the application area,
namely the auditory canal, but also simply for reasons
of soiling. This concept can even be used, if
appropriate, for example in cases of inflammation of
the auditory canal, to apply medicines, for example by
application of medicines to the outer surface of the
otoplastic, or at least in order to use sterilized
otoplastics at regular intervals.
The concept shown with reference to Figures 22 and 23
can of course be combined with the concepts set out in
sections 2) and 3), and the otoplastic 65 is preferably
produced using the production method discussed in
section 1), which permits the design of highly complex
internal shapes for receiving the module 69 in a manner
free from play and vibration.
As can be seen from Figures 22 and 23, the phase plate
1 otherwise provided in conventional in-the-ear hearing
devices is built integrally with the otoplastic, for
example as part of the module holder. The same applies
to other holders and receiving seats for electronic
components of the hearing device. If the layer-by-layer
construction method set out in section 1) is carried
out, as is indicated by broken lines in Fig. 22 and in
the direction shown by the arrow AB, then it ought to
be easily possible to produce the otoplastic from
different materials in said construction direction AB,
according to the requirements in the respective areas.
This applies also to the otoplastics set out in
sections 2) and 3), and to those discussed in sections
5), 6) and 7) below. Taking the example in Fig. 22, it
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is thus quite possible to produce the area 65a using
rubber-elastic material, and by contrast the outlet
area 65b using more shape-stable material.
Fig. 24 shows a further embodiment of an otoplastic,
again taking the example of an in-the-ear hearing
device, which allows the internal built-in components
to be easily and quickly changed. In principle it is
proposed here that the otoplastic shell of an in-the-
ear otoplastic with buil~-in components is designed in
a plurality of parts which can be fitted together, as
is shown in Fig. 24. By means of quick-acting
couplings, such as snap-in couplings, catches or even
bayonet-like couplings, it is possible for housing
parts 73a and 73b of the in-the-ear otoplastic to be
quickly separated from one another, for the built-in
components such as electronic modules to be removed,
and for these to be inserted again into a new shell, if
appropriate with different outer shape, or in principle
into a new shell even when this is necessary, for
example, for cleaning reasons, sterility reasons, etc.
If provision is made,for the already used shell to be
disposed of, it is easily possible to design the
connections of the shell parts in such a way that the
shell can only be opened by destroying it, for example
by providing locking members, such as catches, which
are not accessible from the outside and by the shell
being cut open in order to remove them.
This embodiment can of course also be combined with the
alternative embodiments described above and those still
to be described.
5. Integra.;nn nf acousatir 1 ads in o oplast;r-G and
their shells
In hearing devices worn outside the ear, and also in
in-the-ear hearing devices, it is customary for the
provided acoustic/electric transducers or electro-
CA 02412934 2002-12-16
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acoustic output transducers to be coupled, on the input
side or output side, to the environment of the hearing
device via acoustic leads assembled as independent
parts, namely tube-like structures, or, in particular
with acoustic/electric transducers on the input side,
to place these with their receiving surface immediately
in the area of the surfaces of the hearing device, if
appropriate separated from the environment only by
small hollow spaces and protective measures.
In the design of such hearing devices, there is
therefore a relatively large join where the actual
transducers are to be provided in the hearing device
and where the actual coupling openings to the
environment are to be provided on said hearing device.
As regards the arrangement of coupling openings to the
environment and the arrangement of said transducers
inside the hearing device, it would be highly desirable
to have the greatest possible design freedom.
This is in principle achieved by the fact that said
acoustic leads - at the input side of acoustic/electric
transducers or output side of electric/acoustic
transducers - are integrated into the otoplastic or
into the wall of otoplastic shells.
This is shown purely schematically in Fig. 25. A
transducer module 75 has an acoustic input/output 77.
The shell 79 of the otoplastic of an in-the-ear hearing
device, or of a hearing device worn outside the ear, or
of headphones, has an acoustic lead 81 integrated
within it. This lies at least partially within the wall
of the otoplastic shell 79, as is shown in Fig. 25. The
respective acoustic impedance of the acoustic lead 81
is preferably adapted by means of acoustic stub lines
or line sections 83. This concept, taking the example
of hearing devices worn outside the ear, makes it
possible to provide acoustic input openings 85
staggered along the hearing device and at desired
CA 02412934 2002-12-16
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locations, and to couple said inlet openings 85 to the
provided acoustic/electric transducers 91 via acoustic
leads 89 integrated in the otoplastic or its shell 87,
and largely irrespective of where these transducers 91
are built into the hearing device. Thus, Fig. 26 shows,
only by way of example, how two transducers are
centralized into one module and their inputs are
connected to the desired receiving openings 85 via said
path of the acoustic leads 89. In the light of Figures
25 and 26 and the statements in section 2) regarding
the novel ventilation systems, it will be evident that
it is quite possible to use ventilation channels also
as acoustic lead channels, especially if, as is shown
diagrammatically in Fig. 25, the acoustic impedance
conditions are specifically configured by means of
acoustic adapter members 83.
6. Identification of otoplastics
In the production of otoplastics, in particular of in-
the-ear otoplastics, each one is individually adapted
to its respective wearer. For this reason, it would be
highly desirable to identify each finished otoplastic,
as mentioned in particular each in-the=ear otoplastic,
and very particularly each in-the-ear hearing device.
It is therefore proposed to provide an individual
identification in the otoplastic or its shell by means
of indentations and/or embossings, which
identification, in addition to giving the individual
orderer, for example manufacturer, can contain the
product serial number, left/right application, etc.
Such an identification is created in a much preferred
manner during the production of the otoplastic using
the removal method described under 1) This ensures
that any mix-up of the otoplastics is ruled out
starting from the time of production. This is
particularly important in the subsequent and possibly
automatic fitting with further modules, for example the
fitting of in-the-ear hearing devices.
CA 02412934 2002-12-16
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This measure can of course be combined with one or more
of the aspects described under sections 2) through 5).
7. Optimization of otonlastics with resnect to the
dynamics of the application area
When molding otoplastics for in-the-ear application,
for example for in-the-ear hearing devices, it is at
present customary to take an impression of the auditory
canal, for example using silicone. If one now considers
the quite substantial dynamics of movement of the
auditory canal, for example during chewing, it is
evident that basing the shape of the in-the-ear
otoplastic on an impression, which corresponds in
practice to a momentary record, can scarcely yield a
result which will be entirely satisfactory in use. As
is now shown in Fig. 27, which is a simplified
functional block diagram/signal flow chart, a mold is
taken from the dynamic application area, represented by
the block 93, at several of the positions corresponding
to the dynamics occurring in practice, or the dynamics
of the application area are recorded per se in the
manner of a film. The resulting data sets are stored in
a memory unit 95. Also in the conventional procedure
with impression-taking, this can be readily done by
taking impressions, corresponding to the practical
dynamics, of the application area at two or more
positions.
These impressions are then scanned and the respective
digital data sets are stored in the memory unit 95. As
a further possibility, the dynamics of the application
area can be recorded by X-ray, for example.
Thus, depending on the accuracy which is to be
achieved, a number of "images" or even in practice a
"film" of the pattern of movement of the application
area in question are recorded. The data recorded in the
CA 02412934 2002-12-16
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memory unit 95 are then fed to a computer unit 97. At
its output, the computer unit 97 controls the
production process 99 for the otoplastic. If, for
example, as is still customary today, in-the-ear
otoplastics are produced with a relatively hard shell,
the computer unit 97 uses the dynamics data stored in
the memory unit 95 and, if appropriate, further
production parameters as shown schematically at K, to
calculate the best matching shape for the otoplastic,
so that optimum wearing comfort in everyday use is
achieved while maintaining its functionality. If the
otoplastic to be produced is realized using the
principle set out in section 3), the computer unit 97
determines which otoplastic areas are to be configured
and how in terms of their flexibility, bendability,
compressibilty, etc. At its output, the computer unit
97, as has been stated, controls the production process
99, preferably in this case the production process as
was set out in section 1) as the preferred process.
