Optical coherence tomography imaging

• US 8,144,336 B2
• Filed: 04/07/2008
• Issued: 03/27/2012
• Est. Priority Date: 05/05/2003
• Status: Active Grant

• Current Assignee: D4D Technologies L P (D4D Technologies)
• Original Assignee: D4D Technologies L P (D4D Technologies)
• Inventors: Quadling, Mark, Quadling, Henley, Blair, Alan
• Primary Examiner(s): Lyons, Michael A
• Application Number:
  US12/098,928
• Publication Number:
  US 20110058179A1
• Time in Patent Office: 1,450 Days
• Field of Search: 356/451, 356/477, 356/479, 356/511, 250/227.19, 250/227.27, 385/12
• US Class Current: 356/511
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0088 for oral or dental tissue
• CPC Class Codes: A61C 9/0073 Interferometric means or methods, e.g. creation of a hologram
• CPC Class Codes: G01B 2290/65 Spatial scanning object beam
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

Claims

1. A digitizer, comprising:

a light source configured to generate a beam of structured light;

a reference arm configured to generate a reference beam of light based on the beam of structured light;

a projector configured to project the beam of structured light toward an object and to detect a reflection of at least a portion of the beam, the beam being projected toward the object as a dot that traverses a two dimensional (2D) pattern across a three dimensional (3D) outer surface associated with the object to generate reflection data representing the 3D outer surface associated with the object;

a coupler configured to combine the reference beam and the reflection to generate a superimposed interference light pattern; and

a processor configured to generate a dataset representative of the three dimensional (3D) outer surface of the object based on the superimposed interference light pattern, wherein the dataset is generated from information consisting essentially of the reflection data;

where the object is one of;

an in-vivo oral structure, and an ex-vivo dental impression.

2. The digitizer of claim 1 where the projector comprises a hand-held intraoral probe configured to be manipulated in an oral cavity.

3. The digitizer of claim 2 where the intra-oral probe projects the beam of structured light toward in vivo dentition and detects light reflected from the dentition.

4. The digitizer of claim 1 where the reference arm generates a time-varying baseline pattern and the processor is configured to generate the dataset according to time domain data processing.

5. The digitizer of claim 1 where a signal comprises a shape, distribution and composition of the superimposed interference light pattern.

6. The digitizer of claim 1 where the reference arm generates a fixed reference baseline pattern and the digitizer further comprises:

a spectrometer configured to separate the superimposed interference light pattern to constituent components; and

a linear photosensor configured to detect the constituent components.

7. The digitizer of claim 1 where the processor is configured to generate the dataset according to Fourier domain data processing.

8. The digitizer of claim 6 where the spectrometer comprises a grating.

9. The digitizer of claim 6 where the photosensor comprises an array of light sensitive detectors.

10. The digitizer of claim 8 where the photosensor comprises a charge coupled device.

11. The digitizer of claim 1 where the light source comprises a beam splitter configured to split the beam of structured light into a first beam and a second beam.