Manufacturing methods and systems for rapid production of hearing-aid shells

• US 7,328,080 B2
• Filed: 06/03/2002
• Issued: 02/05/2008
• Est. Priority Date: 10/06/2000
• Status: Active Grant

• Current Assignee: Phonak Incorporated USA (Sonova Holding AG)
• Original Assignee: Phonak Incorporated USA (Sonova Holding AG)
• Inventors: Fu, Ping, Fletcher, G. Yates, Nekhayev, Dmitry, Gloth, Tobias, Edelsbrunner, Herbert
• Primary Examiner(s): Bahta; Kidest
• Assistant Examiner(s): Lee; Douglas S
• Application Number:
  US10/162,434
• Publication Number:
  US 20030074174A1
• Time in Patent Office: 2,073 Days
• Field of Search: 700/118, 700/163, 700/182, 345/420, 715/700, 703/13
• US Class Current: 700/118
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/32189 Compare between original solid model and measured manufactured object
• CPC Class Codes: G05B 2219/45172 Prosthesis
• CPC Class Codes: G05B 2219/49008 Making 3-D object with model in computer memory
• CPC Class Codes: H04R 2225/77 Design aspects, e.g. CAD, of hearing aid tips, moulds or housings
• CPC Class Codes: H04R 2460/11 Aspects relating to vents, e.g. shape, orientation, acoustic properties in ear tips of hearing devices to prevent occlusion
• CPC Class Codes: H04R 25/652 Ear tips; Ear moulds hybrid ear moulds or post-processing thereof for their customisation H04R25/659
• CPC Class Codes: H04R 25/658 Manufacture of housing parts
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Methods, apparatus and computer program products provide efficient techniques for designing and printing shells of hearing-aid devices with a high degree of quality assurance and reliability and with a reduced number of manual and time consuming production steps and operations. These techniques also preferably provide hearing-aid shells having internal volumes that can approach a maximum allowable ratio of internal volume relative to external volume. These high internal volumes facilitate the inclusion of hearing-aid electrical components having higher degrees of functionality and/or the use of smaller and less conspicuous hearing-aid shells. A preferred method includes operations to generate a watertight digital model of a hearing-aid shell by thickening a three-dimensional digital model of a shell surface in a manner that eliminates self-intersections and results in a thickened model having an internal volume that is a high percentage of an external volume of the model. This thickening operation preferably includes nonuniformly thickening the digital model of a shell surface about a directed path that identifies a location of an undersurface hearing-aid vent. This directed path may be drawn on the shell surface by a technician (e.g., audiologist) or computer-aided design operator, for example. Operations are then preferably performed to generate a digital model of an undersurface hearing-aid vent in the thickened model of the shell surface, at a location proximate the directed path.

Claims

1. A method of manufacturing an in-the-ear shell, comprising the steps of:

automatically generating a first three-dimensional digital model of a surface that describes a shape of an ear canal of a subject as a 2-manifold surface having zero or nonzero functional boundary, from captured three-dimensional data;

generating a second three-dimensional digital model of a thickened in-the-ear shell from the first three-dimensional digital model;

printing the second three-dimensional digital model as an in-the-ear shell; and

performing quality assurance by comparing at least two of the first three-dimensional digital model, the second three-dimensional digital model and a third three-dimensional digital model derived from the printed in-the-ear shell.

2. The method of claim 1, wherein said step of performing quality assurance comprises comparing at least two of the first three-dimensional digital model, the second three-dimensional digital model and a third three-dimensional digital model derived from a scan of the printed in-the-ear shell.

3. The method of claim 2, wherein said step of generating a first three-dimensional digital model comprises:

generating a point cloud representation of a non star-shaped surface that describes the shape of an ear canal of a subject, from multiple point sets that described respective portions of the non star-shape surface; and

automatically wrapping the point cloud representation into a non star-shaped surface triangulation.

4. The method of claim 3, wherein said step of automatically wrapping the point cloud representation into a non star-shaped surface triangulation comprises the steps of:

determining a plurality of stars from a plurality of points in the point cloud by projecting the plurality of points onto planes that are each estimated to be tangent about a respective one of the plurality of points; and

merging the plurality of stars into the surface triangulation.

5. The method of claim 3, wherein said step of generating a second three-dimensional digital model comprises:

cutting and/or trimming the non star-shaped surface triangulation into a three-dimensional digital model of a star-shaped in-the-ear shell surface; and

thickening the digital model of the star-shaped in-the-ear shell surface.

6. The method of claim 5, wherein said thickening step is followed by the steps of:

defining a receiver hole and/or vent in the thickened digital model; and

fitting a digital faceplate to the thickened digital model.

7. The method of claim 6, wherein said printing step comprises printing an in-the-ear shell with integral faceplate from the thickened digital model.

8. The method of claim 6, wherein said printing step comprises printing an in-the-ear shell with integral faceplate using a printing tool selected from the group consisting of a stereolithography tool and a rapid prototyping apparatus.

9. A method of manufacturing an in-the-ear shell, comprising the steps of:

generating a three-dimensional digital model of an in-the-ear shell surface from scan data; and

generating a thickened model of the in-the-ear shell from the three-dimensional digital model of an in-the-ear shell surface.

10. The method of claim 9, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface from scan data comprises the steps of:

determining a plurality of stars from a plurality of points in the scan data by projecting the plurality of points onto planes that are each estimated to be tangent about a respective one of the plurality of points; and

merging the plurality of stars into a surface triangulation.

11. The method of claim 9, wherein said step of generating a thickened model comprises generating a thickened model of the in-the-ear shell having a digital representation of a receiver hole therein, from the three-dimensional digital model of an in-the-ear shell surface.

12. The method of claim 9, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface is preceded by the step of generating the scan data as a point cloud representation of a non star-shaped surface that describes a shape of an ear canal.

13. The method of claim 12, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface comprises generating a three-dimensional digital model of an in-the-ear shell surface as a 2-manifold surface having a nonzero functional boundary.

14. The method of claim 12, wherein said step of generating a three-dimensional digital model of ah in-the-ear shell surface comprises processing the point cloud representation of a non star-shaped surface using an automated wrap function that, independent of information in excess of the Cartesian coordinates of the points in the point cloud representation, converts the point cloud representation into the three-dimensional digital model of an in-the-ear shell surface.

15. The method of claim 13, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface comprises processing the point cloud representation of a non star-shaped surface using an automated wrap function that, independent of information in excess of the Cartesian coordinates of the points in the point cloud representation, converts the point cloud representation into the three-dimensional digital model of an in-the-ear shell surface.

16. The method of claim 12, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface comprises processing the point cloud representation of a non star-shaped surface using an automated wrap function that, independent of connectivity information linking points in the point cloud representation by edges and triangles, converts the point cloud representation into the three-dimensional digital model of an in-the-ear shell surface.

17. The method of claim 13, wherein said step of generating a three-dimensional digital model of an in-the-ear shell surface comprises processing the point cloud representation of a non star-shaped surface using an automated wrap function that, independent of connectivity information linking points in the point cloud representation by edges and triangles, converts the point cloud representation into the three-dimensional digital model of an in-the-ear shell surface.

18. A method of manufacturing a hearing-aid, shell, comprising the steps of:

generating scan data as a point cloud representation of a non star-shaped surface that describes a shape of an ear canal;

generating a three-dimensional digital model of a hearing-aid shell surface from scan data by;

processing the point cloud representation using a wrap function that, independent of connectivity information linking points in the point cloud representation by edges and triangles, automatically converts the point cloud representation into a surface triangulation; and

converting the surface triangulation into the three-dimensional digital model of a hearing-aid shell surface, by cutting, trimming and/or otherwise detailing the surface triangulation; and

generating a thickened model of the hearing-aid shell from the three-dimensional digital model of a hearing-aid shell surface.

19. The method of claim 18, wherein said step of processing the point cloud representation comprises the steps of:

determining a plurality of stars from a plurality of points in the scan data by projecting the plurality of points onto planes that are each estimated to be tangent about a respective one of the plurality of points; and

merging the plurality of stars into the surface triangulation.

20. The method of claim 18, wherein said step of generating a thickened model comprises generating a thickened model of the hearing aid shell having a digital representation of a receiver hole therein.

21. A method of manufacturing a hearing-aid shell, comprising the steps of:

generating a three-dimensional digital model of a hearing-aid shell surface from scan data; and

generating a thickened model of the hearing-aid shell that comprises a digital representation of a receiver hole therein and a digital representation of a mounting flange that surrounds the receiver hole and extends into an interior of the thickened model, from the three-dimensional digital model of a hearing-aid shell surface.

22. The method of claim 21, wherein said step of generating a three-dimensional digital model of a hearing-aid shell surface comprises generating a surface triangulation from the scan data and generating a digital hill ear cast from the surface triangulation.

23. The method of claim 22, wherein said step of generating a digital full car cast comprises subtracting a volume bounded by the surface triangulation from a digital model of a cast form using a Boolean operation.

24. The method of claim 21, wherein said step of generating a thickened model of the hearing-aid shell comprises generating a thickened digital model of the hearing-aid shell with integral faceplate and vent hole extending through the faceplate.

25. The method of claim 21, further comprising the step of generating a trim curve that identifies a shape of a rim of the thickened model of the hearing-aid shell.

26. The method of claim 25, further comprising the step of cutting a faceplate form along a path defined by the trim curve.

27. A method of manufacturing a hearing-aid shell, comprising the steps of:

generating a point cloud representation of a non star-shaped surface that describes a shape of an car canal, from multiple partial scans of the non star-shape surface; and

generating a three-dimensional digital model of a hearing-aid shell surface from the point cloud representation by;

processing the point cloud representation using a wrap function that, independent of connectivity information linking points in the point cloud representation by edges and triangles, automatically

converts the point cloud representation into a surface triangulation; and

converting the surface triangulation into the three-dimensional digital model of a hearing-aid shell surface.

28. The method of claim 27, wherein said step of processing the point cloud representation comprises the steps of:

determining a plurality of stars from a plurality of points in the point cloud representation by projecting the plurality of points onto planes that are each estimated to be tangent about a respective one of the plurality of points; and

merging the plurality of stars into the surface triangulation.

29. The method of claim 27, wherein said converting step comprising digitally cutting and/or digitally trimming the surface triangulation at least until the three-dimensional digital model of a hearing-aid shell surface is star-shaped.

30. The method of claim 27, wherein said step of generating a point cloud representation of a non star-shaped surface comprises filtering the point cloud representation to remove high frequency noise and outliers.

31. The method of claim 27, wherein said step of generating a point cloud representation of a non star-shaped surface comprises generating a plurality of partial point cloud representations from the multiple partial scans of the non star-shape surface and registering the plurality of partial point cloud representations into a single, cohesive a point cloud representation.

32. A method of manufacturing a hearing-aid shell, comprising the steps of:

generating a point cloud representation of a non star-shaped surface that describes a shape of an car canal, from multiple overlapping scans of the non star-shape surface; and

generating a three-dimensional digital model of a hearing-aid shell surface from the point cloud representation by;

processing the point cloud representation using a wrap function that converts the point cloud representation into a surface triangulation; and

converting the surface triangulation into the three-dimensional digital model of a hearing-aid shell surface that is star-shaped.

33. The method of claim 32, wherein said step of processing the point cloud representation comprises the steps of:

determining a plurality of stars from a plurality of points in the point cloud representation by projecting the plurality of points onto planes that are each estimated to be tangent about a respective one of the plurality of points; and

merging the plurality of stars into the surface triangulation.

34. The method of claim 32, wherein said step of generating a point cloud representation of a non star-shaped surface comprises filtering the point cloud representation to remove high frequency noise and outliers.

35. The method of claim 32, wherein said step of generating a point cloud representation of a non star-shaped surface comprises:

generating a plurality of partial point cloud representations from the multiple overlapping scans of the non star-shape surface; and

registering the plurality of incomplete point cloud representations into a cohesive a point cloud representation.

36. A method of manufacturing a hearing-aid shell, comprising the steps of:

generating a point cloud representation of a non star-shaped surface that describes a shape of an ear canal, from multiple partial scans of the non star-shape surface;

wrapping the point cloud representation into a non star-shaped surface triangulation;

cutting and/or trimming the non star-shaped surface triangulation into a three-dimensional digital model of a star-shaped hearing-aid shell surface;

thickening the digital model of the star-shaped hearing-aid shell surface;

printing the thickened digital model of the star-shaped hearing-aid shell surface as a hearing-aid shell; and

performing quality assurance by comparing two or more of a digital model derived from a scan of the printed hearing-aid shell, the three-dimensional digital model of a star-shaped hearing-aid shell surface, the non-star shaped surface triangulation and a digital full-ear cast.