AN IMPRESSION-TAKING PAD, A METHOD OF IMPRESSION-TAKING, AN IMPRESSION, A METHOD OF MANUFACTURING A CUSTOM EAR CANAL SHELL, A CUSTOM EAR CANAL SHELL AND A HEARING DEVICE

Abstract

An impression-taking pad is proposed for impression-taking of an ear canal. The impression-taking pad includes an elastic body having a hollowed dome-shaped contour, wherein the inner surface includes axially aligned scallops.

Claims

1. An impression-taking pad (10) used for impression-taking of an ear canal (26), said impression-taking pad (10) comprises an elastic body (12) having a hollowed dome-shaped contour, wherein the inner surface (16) comprises axially aligned scallops (18).

2. The impression-taking pad (10) according to claim 1, wherein the outer surface (14) comprises a smooth material.

3. The impression-taking pad (10) according to claim 1, wherein the dome-shaped contour is elliptic in cross-section.

4. The impression-taking pad (10) according to claim 1, wherein the inner surface (16) material comprises a larger contact area than the outer surface (14) material.

5. The impression-taking pad (10) according to claim 4, wherein the inner surface (16) material comprises porous material, in particular foam.

6. The impression-taking pad (10) according to claim 1, further comprising an interface part (20) adapted to be connected with at least one of an insertion tool, a removal yarn (22) and a ventilation tube.

7. The impression-taking pad (10) according to claim 6, wherein the interface part (20) is connected to the distal end of the inner surface (16).

8. The impression-taking pad (10) according to claim 1, comprising a flat plane at the medial distal end of the outer surface (14).

9. A method of impression-taking of an ear canal (26) by means of an impression-taking pad (10) according to one of the preceding claims, the method comprising: inserting the impression-taking pad (10) into the ear canal (26); filling impression-taking material into the ear canal (26) such to fill the ear canal (26) in addition to the hollowed part of the impression-taking pad (10); curing the filled impression-taking material; and removing the cured impression (28) from the ear canal (26).

10. The method according to claim 9, wherein the insertion step comprises placing the impression-taking pad (10) a predetermined distance from the tympanic membrane.

11. The method according to claim 9, further comprising a step of measuring the ear canal (26) length before the inserting step.

12. An impression (28) comprising an impression-taking material and an impression-taking pad (10) according to claim 1, adhered to the impression-taking material by curing during deep insertion into the ear canal (26).

13. A method of manufacturing a custom ear canal shell, comprising: scanning the impression (28) according to claim 12, said impression (28) including the impression-taking pad (10), by means of an impression scanner resulting in ear canal impression model data; and manufacturing the custom ear canal shell by means of at least one subtractive and/or additive production step using the ear canal impression model data.

14. A custom ear canal shell manufactured by the method according to claim 13, configured for deep insertion into the ear canal (26).

15. A hearing device comprising the custom ear canal shell according to claim 14, the hearing device configured as Invisible-in-Canal hearing device for deep insertion into the ear canal (26).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described with reference to the accompanying drawings jointly illustrating various exemplary embodiments, which are to be considered in connection with a following detailed description. What is shown in the Figures is the following:

[0030] FIGS. 1A-C depict an impression-taking pad according to the invention in different views;

[0031] FIG. 2 is a schematically cross-section view showing the impression-taking pad surface;

[0032] FIG. 3 is a schematically view showing the impression-taking pad positioned inside an ear canal;

[0033] FIGS. 4A-B are schematically views showing an impression obtained according to the present invention; and

[0034] FIGS. 5A-B depict impressions obtained according to the prior art.

[0035] In order to allow for manufacturing of a best fitting shell of a hearing device for proper insertion into the human ear canal, a high quality impression of said ear canal is required. Should the quality of the impression be insufficient, information is missing which is required to produce the hearing device shell in the desired size and quality for best fitting. An insufficient impression results in the impression-taking procedure has to be repeated which produces high costs in terms of material and time and which is inconvenient for the customer as well as the audiologist.

[0036] A conventional impression according to the prior art lacks the ability of a complete reproduction of the concha as well as the complete reproduction of the ear canal, in particular beyond the second bend. A further problem is that common impression-taking pads lack the complete reproduction of sealing zones Tragus, Antitragus and aperture plane.

[0037] FIGS. 5A-B show conventional impressions 100 obtained according to the prior art. In the state of the art, in order to acquire the impressions 100, a standard impression pad 110 comprising polymer foam is positioned inside an ear canal. In a further step, liquid impression-taking material is filled into the ear canal. A problem in the prior art is that, after curing of the liquid impression-taking material, the foam 110 often lacks the ability to proper connect to the impression-taking material. Resulting from this inability, holes (refer to portions encircled in the drawings) can emerge between the foam 110 and the impression-taking material. Due to this, important information about the ear canal features in this region gets lost.

[0038] FIG. 5A shows an impression 100 according to the prior art, which extension is too short since it does not extend beyond the second bend of the ear canal. This impression demonstrates the shortage of the prior art with respect to insufficient length. The example shown in FIG. 5A is not suitable to completely reproduce the ear canal beyond the second bend.

[0039] While the impression 100 as shown in FIG. 5B may allow for reproduction of the ear canal beyond the second bend, this reproduction is nevertheless too short as well. Further, the pathway of the ear canal cannot be reproduced proper due to the shortage of the impression 100. In the prior art, the modeler of a hearing device shell often has to guess the best way of the ear canal as well as the sound output direction which is unsatisfactory.

[0040] Further, in the prior art, customers often object that the insertion of prior art foam pads 110 is uncomfortable and the foam would crackle in the ear canal. A further disadvantage of the foam pads 110 in the state of the art is the requirement that the foam has to be cut back to provide a good adaptation to the ear canal. This work is time and material consuming. Standard impression pads 110 according to the prior art need to be inserted with a sturdy illuminated bar. Hence, insertion is difficult and can result in injuries. Further, the insertion depth is vague and often depends on the decision of the audiologist. An additional disadvantage of cotton or foam pads 110 is that they do not perfectly merge with the impression-taking material and gaps can occur at the transition area. Therefore they always have to be removed for the impression gets followed up and scanned.

[0041] FIGS. 1A-C show different views of an impression-taking pad 10 according to the present invention. The impression-taking pad 10 comprises an elastic body 12 having a hollowed dome-shaped contour. The elastic body 12 comprises an outer surface 14 made of a smooth material. The elastic body 12 further comprises an inner surface 16 made of a material comprising a larger contact area than that of the outer surface 14. Further, the inner surface 16 comprises scallops 18 axially aligned in lengthwise direction of the elastic body 12. The material of the inner surface 16 comprises porous material, for example foam. The dome-shaped contour of the elastic body 12 is elliptic in cross-section. This allows optimized conformity with the ear canal wall. Further, the provision of said axially aligned scallops 18 advantageously provides an even pressure distribution and conformity with the ear canal wall. Furthermore, the scallop shape provides increased specific surface area for enhanced bonding to the impression-taking material. Since the inner surface 16 comprises porous material such as foam, a further improved bonding to the impression-taking material can be exhibited. Summarized, the inventive impression-taking pad 10 advantageously provides a combination of a smooth outer surface 14 to comply with the ear canal skin and an inner surface 16 having a macroscopic structure given by the scallops 18 as well as a microscopic structure given by the nature of the porous material, for example foam.

[0042] The outer surface 14 in combination with the inner scallops 18 provides an impression-taking pad 10 being allowed to conform to the geometry of the ear canal without causing any wrinkles. In addition to this, the inventive impression-taking pad 10 is available in different sizes in order to comply with all different ear canal sizes. By way of preventing the impression-taking pad 10 to cause any wrinkles, the liquid impression-taking material is sealed against flowing along the impression-taking pad 10 and leaking into the volume between the eardrum and the impression-taking pad 10.

[0043] The impression-taking pad 10 further comprises an interface part 20 (refer to FIGS. 1A-B) adapted to be connected with an insertion tool (not shown). This agile interconnection allows the audiologist to safely place the impression-taking pad deeply into the ear canal by means of the insertion tool, for example a forceps tool. This allows for deep and safe insertion of the impression-taking pad 10 to a specified depth in the ear canal. The interface part 20 is also adapted to be connected with a removal yarn 22 (refer to FIG. 1C). This removal yarn 22 can be threaded such to run through a penetrating aperture 24 formed into the interface part 20. The removal yarn 22 serves as removal safety, if necessary. For example, the removal yarn can be embodied by means of a ventilation tube (not shown).

[0044] In an exemplary embodiment, the removal yarn 22 can be made integral with the ventilation tube. For example, the removal yarn 22 is molded with the material of the ventilation tube. This feature allows to more stiffen the ventilation tube in axial direction thereof. Therefore, stretching of the ventilation tube can be prevented in the course of drawing-out the impression-taking pad 10 out of the ear canal. This feature allows to combine two functions resulting in an easy and simple configuration as well as in reduced costs as a whole.

[0045] FIG. 2 shows an enlarged cross sectional view of the elastic body 12 of the impression-taking pad taken along a plane perpendicular to the center axis thereof. The outer surface 14 of the elastic body 12 comprises a smooth material allowing to touch the thin-skinned ear canal wall of the customer very softly. The material of the inner surface 16 comprises porous material, in particular foam, comprising a larger contact area than that of the outer surface 14. This highly porous foam structure ensures good compliance and conformity with the ear canal wall. In other words, the open porosity ensures a large contact area providing enhanced engagement with the impression-taking material. This engagement feature in combination with the inner scallop structure (refer to FIGS. 1A-C) advantageously provides the ability to retain the impression-taking pad in its deformed position once the impression-taking material is cured. Further advantageously, additional information relating to the contour of the ear canal can be provided allowing to obtain a very good reproducibility.

[0046] FIG. 3 shows the impression-taking pad 10 inserted into the ear canal 26 in a schematically view. The impression-taking pad 10 exhibits high compliance and exerts minimal pressure to the wall of the ear canal 26. Further, due to its conformity with the geometry of the wall of the ear canal 26, a tight seal is formed, preventing liquid impression-taking material leaking into the volume between the impression-taking pad 10 and the eardrum (not shown). This conformity with the ear canal 26 geometry is facilitated by the inner scallop structure of the dome-shaped impression-taking pad 10 allowing an even pressure distribution to the wall of the ear canal 26. Therefore, formation of any wrinkles is prevented, which otherwise could adversely cause liquid impression-taking material leaking into the volume between the impression-taking pad 10 and the ear drum. In addition to this, the inventive impression-taking pad is available in different sizes in order to cover all different ear canal sizes.

[0047] Additionally, the scallop structure forms a large surface area, whichonce filled with the liquid impression-taking material and cured afterwardskeeps the impression-taking pad 10 in its deformed position for the moment it is needed to make a scan of the impression. It is to be noted that the impression comprises the cured impression-taking material as well as the impression-taking pad bonded to the impression-taking material.

[0048] An exemplary workflow for impression-taking of the ear canal can comprise steps as follows. In an initially step, the ear canal length is measured using a depth sizer. For example, the aperture plane can be used as reference. In a further step, the corresponding insertion length on an insertion tool is adjusted accordingly. Afterwards, a correct insertion taking pad 10 size can be identified. Further, a tight sealing of the impression-taking pad 10 around the wall of the ear canal 26 is verified via an otoscope. This step comprises a verification in order to ensure that the impression-taking pad 10 does not create any wrinkles. In case of tight sealing against the ear canal 26 wall cannot be assured due to wrinkles, for example, an impression-taking pad 10 of a different size should be selected and used. In a further step, the impression-taking pad 10 is placed a distance before the tympanic membrane. The distance between the distal end of the impression-taking pad 10 and the tympanic membrane can be 6 mm, for example. The removal yarn 22 should be adhered during the impression-taking process. In a final step, impression-taking material, for example a silicone based impression material, is inserted or rather filled into the ear canal 26.

[0049] FIG. 4 shows an impression 28 comprising cured impression-taking material 30 and the impression-taking pad 10 according to the present invention fixedly engaged with the cured impression-taking material 30. The impression 28 exhibits a perfect transition between surfaces of the impression-taking material 30 and the impression-taking pad 10. This allows the impression 28 to reproduce the ear canal completely by exhibiting a neat surface. Advantageously, the impression 28 is free of any holes between the impression-taking material 30 and the impression-taking pad 10 allowing to gather all important information relating to the ear canal anatomy. The inventive impression-taking pad 10 perfectly conjoins with the impression-taking material 30 seamlessly.

[0050] Due to the hollowed dome-shaped contour of the elastic body of the impression-taking pad 10 (refer to FIGS. 1A-B), the impression-taking material 30 perfectly occupies said hollowed contour without running into danger that liquid impression-taking material, during filling thereof into the ear canal, will flow past the impression-taking pad 10. Due to the flexibility and perfect connection between the impression-taking pad 10 and the impression-taking material 30, the exterior of the impression-taking pad 10 supplies additional information relating to the ear canal anatomy. Additionally and contrary to the prior art, the sound output direction can be determined in a high precision. Further, contrary to the prior art, the impression-taking pad 10 is left on the impression 28 after impression-taking by the acoustician.

[0051] Advantageously, the surface of the impression-taking pad 10 can be easily recognized by an impression scanner. Therefore, the hearing device manufacturer is able to produce a high quality custom ear canal shell by scanning the impression 28. This scanning results in precise ear canal impression model data. In a subsequent step, the custom ear canal shell can be manufactured by means of a subtractive and/or additive production step(s) using the ear canal impression model data. This allows to obtain a custom ear canal shell configured for deep insertion into the ear canal of the customer. The obtained custom ear canal shell can be used as a shell of a hearing device configured for example as Invisible-in-Canal hearing device for deep insertion into the ear canal. Advantageously, a plane at the medial distal end of the outer surface of the impression-taking pad 10 uniquely indicates the sound exit and orientation towards the tympanic membrane.

[0052] Hence, the obtained impression 28 extends deeper into the ear canal exhibiting more details. By means of information relating to the ear canal length as retrieved from length measurement before impression-taking, additional information can be gathered comprising the position of the sound output plane. Further, the residual volume of the ear canal can be determined exactly. Furthermore, due to the tight sealing between the impression-taking pad 10 and the wall of the ear canal, manufacturing of the impression 28 is safe. Therefore, repeated manufacturing procedures as known in the prior art can be omitted. This results in increased customer satisfaction as well as reduced costs.