Detection of a movable object when 3D scanning a rigid object

Patent metadata

Field	Value
Publication number	US-9629551-B2
Application number	US-201214232363-A
Country	US
Kind code	B2
Filing date	Jul 12, 2012
Priority date	Jul 15, 2011
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method for detecting a movable object in a location includes —providing a first 3D representation of at least part of a surface by scanning; —providing a second 3D representation of at least part of the surface by scanning; —determining for the first 3D representation a first excluded volume; —determining for the second 3D representation a second excluded volume; —if a portion of the surface in the first 3D representation is located in space in the second excluded volume, the portion of the surface in the first 3D representation is disregarded, and/or —if a portion of the surface in the second 3D representation is located in space in the first excluded volume, the portion of the surface in the second 3D representation is disregarded.

First claim

The invention claimed is:

1. A method for detecting a movable object in a location, when scanning a rigid object in the location by means of a 3D scanner for generating a virtual 3D model of the rigid object, wherein the method comprises:
providing a first 3D representation of at least part of a surface by scanning at least part of the location;
providing a second 3D representation of at least part of the surface by scanning at least part of the location;
determining for the first 3D representation a first excluded volume in space where no surface can be present in both the first 3D representation and the second 3D representation;
determining for the second 3D representation a second excluded volume in space where no surface can be present in both the first 3D representation and the second 3D representation;
if a portion of the surface in the first 3D representation is located in space in the second excluded volume, the portion of the surface in the first 3D representation is disregarded in the generation of the virtual 3D model, and/or
if a portion of the surface in the second 3D representation is located in space in the first excluded volume, the portion of the surface in the second 3D representation is disregarded in the generation of the virtual 3D model.

2. The method according to claim 1 , wherein the rigid object is a patient's set of teeth, and the location is the mouth of the patient.

3. The method according to claim 1 , wherein the movable object is a soft tissue part of a patient's mouth.

4. The method according to claim 1 , wherein the movable object is a dentist's instrument or remedy which is temporarily present in a patient's mouth.

5. The method according to claim 1 , wherein the movable object is a finger.

6. The method according to claim 1 , wherein at least part of the surface captured in the first representation and at least part of the surface captured in the second representation are overlapping the same surface part on the rigid object.

7. The method according to claim 1 , wherein the first representation of at least part of the surface is defined as the first representation of at least a first part of the surface, and the second representation of at least part of the surface is defined as the second representation of at least a second part of the surface.

8. The method according to claim 1 , wherein the method comprises determining a first scan volume in space related to the first representation of at least part of the surface, and determining a second scan volume in space related to the second representation of at least part of the surface.

9. The method according to claim 1 , wherein the scan volume is defined by the focusing optics in the 3D scanner and the distance to the surface which is captured.

10. The method according to claim 1 , wherein the first scan volume related to the first representation of at least part of the surface is the volume in space between the focusing optics of the 3D scanner and the surface captured in the first representation; and the second scan volume related to the second representation of at least part of the surface is the volume in space between the focusing optics of the 3D scanner and the surface captured in the second representation.

11. The method according to claim 1 , wherein the first excluded volume and second excluded volume in space where no surface can be present corresponds to the first scan volume and the second scan volume, respectively.

12. The method according to claim 1 , wherein the volume of the 3D scanner itself is defined as an excluded volume.

13. The method according to claim 1 , wherein a near threshold distance is defined, which determines a distance from the captured surface in the first representation and the second representation, where a surface portion in the second representation or the first representation, respectively, which is located within the near threshold distance from the captured surface and which is located in space in the first excluded volume or in the second excluded volume, respectively, is not disregarded in the generation of the virtual 3D model.

14. The method according to claim 1 , wherein a far threshold distance is defined, which determines a distance from the captured surface, where the volume outside the far threshold distance is not included in the excluded volume of a representation.

15. The method according to claim 1 , wherein the first representation of at least part of a surface is a first subscan of at least part of the location, and the second representation of at least part of the surface is a second subscan of at least part of the location.

16. The method according to claim 1 , wherein the first representation of at least part of a surface is a provisional virtual 3D model comprising the subscans of the location acquired already, and the second representation of at least part of the surface is a second subscan of at least part of the location.

17. The method according to claim 1 , wherein acquired subscans of the location are adapted to be added to the provisional virtual 3D model concurrently with the acquisition of the subscans.

18. The method according to claim 1 , wherein the movable object is an inside of a cheek, a tongue, lips, gums and/or loose gingival.

19. The method according to claim 1 , wherein the movable object is a dental suction device, cotton rolls, and/or cotton pads.

20. The method according to claim 1 , where in the method includes:
disregarding the portion of the surface in the first 3D representation that is located in space in the second excluded volume in the generation of the virtual 3D model, and
disregarding the portion of the surface in the second 3D representation that is located in space in the first excluded volume in the generation of the virtual 3D model.

21. The method according to claim 1 , wherein:
the first excluded volume is determined to be a space where no surface of the rigid object is present, and
the second excluded volume is determined to be a space where no surface of the rigid object is present.

22. A nontransitory computer readable medium encoded with a computer program product comprising program code for causing a data processing system to perform the method of claim 1 , when said program code is executed on the data processing system.

23. A system for detecting a movable object in a location, when scanning a rigid object in the location by means of a 3D scanner for generating a virtual 3D model of the rigid object, wherein the system comprises a hardware processor configured to:
provide a first 3D representation of at least part of a surface by scanning at least part of the location;
provide a second 3D representation of at least part of the surface by scanning at least part of the location;
determine for the first 3D representation a first excluded volume in space where no surface can be present in both the first 3D representation and the second 3D representation;
determine for the second 3D representation a second excluded volume in space where no surface can be present in both the first 3D representation and the second 3D representation;
disregard the portion of the surface in the first 3D representation in the generation of the virtual 3D model, if a portion of the surface in the first 3D representation is located in space in the second excluded volume, and/or
disregard the portion of the surface in the second 3D representation in the generation of the virtual 3D model, if

Assignees

• Fisker Rune
• Vinther Michael
• Öjelund Henrik
• 3Shape As

Inventors

• Fisker Rune
• Vinther Michael
• Öjelund Henrik

Classifications

• A61C19/04

  Measuring instruments specially adapted for dentistry ({A61C5/44 takes precedence; testing vitality of teeth A61B5/0534;} radiation diagnosis specially adapted for dentistry A61B6/51) · CPC title

• A61B5/0088

  for oral or dental tissue · CPC title

• G06T7/55 Primary

  from multiple images · CPC title

• G06T2200/04

  involving 3D image data · CPC title

• A61B5/0062 Primary

  Arrangements for scanning · CPC title