Abstract
The present invention relates to an encapulated hearing device (50), e.g. for long-term wear, in which an electronics module (10) is encapsulated into a thermoformed hull (30) by means of an appropriate adhesive (41). This thermoformed hull (30) acts as an improved barrier between the electronics module (10) and the environment of the inner ear, reducing the risk of moisture reaching electrical components.
Claims
1. An in-the-ear hearing device, comprising: a single-piece thermoformed hull with a first opening and a second opening; an electronics module comprising a microphone, a battery, and a loudspeaker, wherein the electronics module is disposed in the single-piece thermoformed hull, wherein the microphone is communication with the first opening, wherein the first opening is configured to provide sound to the microphone, wherein the loudspeaker is in communication with the second opening, wherein the second opening is configured enable the output of sound, wherein the entire electronics module is encapsulated by the single-piece thermoformed hull, wherein the battery is hardwired to the electronics module without a battery compartment separate from the single-piece thermoformed hull, and wherein the single-piece thermoformed hull is configured to be positioned within an ear canal; adhesive that adheres to the single-piece thermoformed hull, and wherein the adhesive fills gaps between the electronics module and the single-piece thermoformed hull.
2. The hearing device of claim 1, wherein a tube is attached to the second opening.
3. The hearing device of claim 2, wherein the tube protrudes through the second opening in to the single-piece thermoformed hull.
4. The hearing device of claim 2, wherein the tube is substantially cylindrical or hollow-truncated-conical.
5. The hearing device of claim 1, wherein the electronics module is physically coupled to an extraction loop proximate to the first opening.
6. The hearing device of claim 1, further comprising a silicone ear mold or a compressible seal disposed around the hull.
7. The hearing device of claim 1, wherein the hull is sized such that it is deformed by the electronics module.
8. The hearing device of claim 1, further comprising a vent tube inside the hull and having a first end in communication with first opening.
9. A method of manufacturing an in-the-ear hearing device comprising: providing a sheet of thermoformable material; thermoforming and separating a hull blank from the sheet of thermoformable material, said hull blank comprising an open end and a closed end; forming at least one opening in the closed end of the hull blank, thereby forming a hull; providing an electronics module comprising a microphone in communication with a sound inlet, a battery, and a loudspeaker in communication with a sound outlet; inserting the entire electronics module into the hull such that the sound outlet is in communication with the opening; filling the hull and the electronics module with the exception of at least part of the sound inlet and at least part of the sound outlet into the hull with an adhesive, wherein: the battery is hardwired to the electronics module without a battery compartment separate from the hull; the adhesive adheres to the hull, the adhesive fills gaps between the electronics module and the hull, and wherein the hull is configured to be positioned within an ear canal.
10. The method according of claim 9, further comprising: attaching a tube to the sound outlet.
11. The method to claim 10, wherein the hull at least partially prevents moisture from entering the electronics module.
12. The method of claim 9, further comprising: forming an additional opening on the closed end of the hull blank; and inserting a vent tube into the hull blank.
13. The method of claim 12, further comprising: trimming excess vent tube material such that the vent tube is flush with or protrudes less than or equal to 2 mm from the hull.
14. The method of claim 9, wherein the hull blank is separated from the sheet of thermoformable material by laser cutting or hot-wire cutting, and wherein the at least one opening is formed by laser cutting or die cutting.
15. The method of claim 9, wherein the thermoformable material includes at least one of the following: BAREX, PET-GAG, COP, PEEK, or any combination thereof.
16. The method of claim 9, wherein, the adhesive is applied by means of a cannula.
17. The method of claim 9, wherein the adhesive is a UV- or light-curable epoxy, and wherein the adhesive is cured by UV radiation or light.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Non-limiting exemplary embodiments of the present invention will now be described with reference to the following figures, which show:
(2) FIG. 1—a perspective view of an electronics module of a hearing device;
(3) FIG. 2—a perspective view of the electronics module of FIG. 1 fitted with a tube;
(4) FIG. 3—a perspective view of the stages of manufacturing the hull of a hearing device according to the invention;
(5) FIG. 4—a perspective view of an assembled hearing device;
(6) FIG. 5—a perspective view of a fully assembled and encapsulated hearing device according to the invention;
(7) FIG. 6—a flowchart of a method of manufacturing a hearing device according to the invention;
(8) FIG. 7—a perspective view of a fully assembled and encapsulated hearing device according to a further embodiment of the invention; and
(9) FIG. 8—a flowchart of a method of manufacturing a hearing device according to the further embodiment of the invention.
(10) In the figures, like reference signs refer to like parts.
DETAILED DESCRIPTION OF THE DRAWINGS
(11) FIG. 1 shows an electronics module 10 comprising, as is conventional, an acoustic hybrid comprising a microphone 17 in communication with a sound inlet 11, a sound outlet 12 leading from a loudspeaker 15 (also referred to in the industry as a receiver) and a battery 16. In the illustrated example, the sound outlet 12 forms a cylindrical spout, although other forms are possible. The layout of the electronics module 10 is conventional, and thus need not be discussed further. An extraction loop 13 is provided at the end of the electronics module 10 proximate to the sound inlet 11, and serves to facilitate extraction of the hearing device from the ear canal by means of a tool.
(12) FIG. 2 shows the electronics module 10 as in FIG. 1, with the addition of a tube 14 attached to the sound outlet 12 by means of an appropriate adhesive. This tube has several functions: firstly, it acts as an aid to insertion of the electronics module 10 into the hull (see below) by helping to align the electronics module 10 with the opening in the hull; secondly, it protects the loudspeaker 15 of the electronics module 10 from the encapsulation material by virtue of preventing said encapsulation material from being able to enter the sound outlet 12 and thereby reach the loudspeaker 15; thirdly, it seals against the hull, permitting a very low viscosity adhesive to be used for encapsulation; and fourthly it acts as a wax guard during insertion of the hearing device into the auditory canal of the wearer. The tube 14 may be of any convenient shape such as cylindrical or truncated conical, and may be made from any convenient material, such as soft thermoplastic or silicone rubber. However, tube 14 is not essential and could for instance be simply omitted. Alternatively, the sound outlet spout 12 could be configured so as to perform the same functions, e.g. by being extended such that it will protrude from the hull and form a tight seals with the hull when assembled.
(13) FIG. 3 illustrates the steps for manufacturing a hull 30 for a hearing device according to the invention. Firstly, a sheet 20 of an appropriate thermoformable material with an appropriate thickness to achieve the desired final wall thickness of the hulls (e.g. a final sidewall thickness of 20-100 μm) is provided. The hull 30 may thus equally be described as a hull with a sidewall thickness of 20-100 μm. Suitable materials include but are not limited to BAREX, PET-GAG, COP and PEEK, which are used in the food and drug packaging and medical industries. These materials not only have the required thermoforming properties, but also serve as effective barrier materials to moisture, for instance from cerumen, sweat, soapy water and so on, and also to metal ions such as nickel released from module components.
(14) A plurality of hull blanks 21 are then formed by conventional thermoforming. This process generically entails taking the sheet 20 of thermoformable material, placing it over a vacuum-forming mould, which may define the outer or inner contour of the hull blanks, heating the thermoformable material, and moulding it by means of a vacuum. Alternatively, a two-part mould defining both the inner and outer contours and operated with or without vacuum may be used. After ejection of the thus moulded sheet from the mould, the hull blanks 21 are separated from the sheet 20 e.g. by laser cutting or die cutting. Finally, the hull blanks 21 are trimmed to length e.g. by laser cutting or hot-wire cutting, and an opening 31 for the sound outlet 12 and/or tube 14 is created in the closed-end of the whole blank 21, again e.g. by laser cutting or die-cutting.
(15) It should be noted that the use of a mould which defines the inner contour of the hull blanks 21, whether used alone or in combination with a corresponding outer-contour mould, presents the advantage that the interior contour and interior volume of the hulls, in which the electronics module will be placed, are essentially constant with a high tolerance independent of variations in sheet material thickness, thus the relationship between the size of the electronics module and the hulls is likewise kept to within high tolerances, giving excellent consistency between individual hearing devices.
(16) These thermoformed hulls 30 are easily distinguishable from hulls or shells produced by other processing techniques such as injection moulding. Firstly, thermoforming enables the wall thickness of the hull 30 to be significantly thinner (approximately 50-100 μm, or even 20-100 μm) than those produced e.g. by injection moulding: injection moulded hulls are typically 3 to 5 times thicker due limitations of the process. As a result, they are relatively rigid, and either exhibit visible seams and/or sprues, or must be created as two half-shells, such as that described in U.S. Pat. No. 7,092,543. Since the thermoformed hulls have significantly thinner walls than injection moulded hulls, or hulls produced by other methods, they are relatively elastic and flexible. Secondly, the orientation of the crystal structure of the plastic material is identifiably different in a thermoformed hull compared with an injection moulded hull.
(17) FIG. 4 illustrates an assembled hearing device 40. Electronics module 10, complete with tube 14, has been inserted into hull 30 such that the tube 14 protrudes through the opening 31 (not visible on FIG. 4). Since the tube 14 protrudes from the electronics module 10, it assists in insertion and alignment of the electronics module 10 into the hull 30. To ensure that the outer dimensions are kept to a minimum, the fit between the electronics module 10 and the hull 30 can be so tight that the electronics module 10 deforms the hull 30 and leaves an impression therein. Alternatively, the fit can be looser, which enables a greater quantity of encapsulant material such as UV-curable epoxy to be distributed between electronics module 10 and hull 30.
(18) As illustrated in FIG. 5, the electronics module 10 is encapsulated into the hull 30 by means of appropriate adhesive 41, represented in FIG. 5 by dots, resulting in a fully assembled and encapsulated hearing device 50. This adhesive may be applied with a cannula 43 in the gaps between the electronics module 10 and the hull 30, for instance via open end 32 of the hull 30, or by any other convenient means. The entire electronics module 10 is encapsulated into the hull 30 with the exception of the sound inlet and the sound outlet, which in the case of the embodiment of FIG. 5 is protected by the tube 14. In the case in which the adhesive is a UV-curable or light-curable epoxy, the applied adhesive is then cured by means of light in an appropriate wavelength range. If required, the thus assembled hearing device 50 can then be provided with a silicone sleeve and other attributes as is standard (not illustrated).
(19) FIG. 6 illustrates the overall process in block-diagram form. In block 51, the electronics module 10 is provided, and in block 52, tube 14 (if required) is applied and bonded (if necessary) to the sound outlet 12 of the electronics module 10. In block 53, a sheet 20 of thermoformable material is provided, and in block 54 the sheet 20 is thermoformed into hull blanks 21, which are separated from the sheet, trimmed (if required), and pierced with opening 31 e.g. by means of laser cutting, thereby resulting in hull 30. In block 55, the electronics module 10 is inserted into the hull 30, creating an assembled hearing device 40. In block 56, the electronics module 10 is encapsulated into the hull 30 by means of an appropriate adhesive, e.g. a UV or light-curable epoxy, which may be applied by a cannula 41 and cured by means of a UV light source 42, and in block 57 the fully assembled and encapsulated hearing device 50 is complete.
(20) FIG. 7 shows a further embodiment of the hearing device according to the invention, which differs from that described above in that a vent tube 60 is additionally encapsulated into the hull 30. For clarity, this vent tube has been illustrated in solid line even though it is situated inside the hull 30. The vent tube is inserted at the same time or before insertion of the electronics module 10 into the hull 30. The vent tube 60 extends from an additional opening 33, pierced in the same step as opening 31, proximate to the opening 31 in what was the closed-end of the hull blank 21 to outside of the encapsulated adhesive proximate to the open end 32 of the hull 30, near to the hull 30, although this may naturally be situated anywhere desired. As illustrated, the vent tube 60 protrudes from each end of the hull 30, for instance by no more than 2 mm. However, it can also be cut off substantially flush with both the hull 30 and the encapsulation material 41. The vent tube may, for instance, have an interior diameter of 0.20-0.30 (e.g. 0.25 mm), have a wall thickness of 0.05-0.10 mm and be made of polyimide (PI) or any other suitable material. Such dimensions do not result in a critical feedback between the sound output and the sound input since such a tube is acoustically opaque above 50 Hz. It does, however, permit equalization of pressure within approximately 0.05 seconds during rapid changes in ambient pressure.
(21) FIG. 8 illustrates the overall process of manufacturing the second embodiment hearing device of FIG. 7 in block-diagram form. In block 51, the electronics module 10 is provided, and in block 52, tube 14 (if required) is applied and bonded (if necessary) to the sound outlet 12 of the electronics module 10. In block 59, a length of vent tube 60 is provided. In block 53, a sheet 20 of thermoformable material is provided, and in block 54 the sheet 20 is thermoformed into hull blanks 21, which are separated from the sheet, trimmed (if required), and pierced with opening 31 and further opening 33 e.g. by means of laser cutting, thereby resulting in hull 30. In block 55, the electronics module 10 is inserted into the hull 30 along with vent tube 60 which protrudes from further opening 33, creating an assembled hearing device 40. In block 56, the electronics module 10 and vent tube 60 are encapsulated into the hull 30 by means of an appropriate adhesive, e.g. a UV or light-curable epoxy, which may be applied by a cannula 41 and cured by means of a UV light source 42, and in block 57 the fully assembled and encapsulated hearing device 50 is completed by trimming the loose ends of the vent tube 60 to the desired length or flush with the encapsulation material and the hull 30 by means of trimming device 44, resulting in a completed hearing device 50 in block 58.
(22) Although the invention has been described in terms of specific embodiments, variations therefrom are possible without departing from the scope of the invention as defined by the appended claims.
