System and method for OCT depth calibration

• US 9,301,687 B2
• Filed: 03/12/2014
• Issued: 04/05/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Original Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Inventors: Kemp, Nathaniel J.
• Primary Examiner(s): Tabatabai, Abolfazl
• Application Number:
  US14/206,485
• Publication Number:
  US 20140270445A1
• Time in Patent Office: 755 Days
• Field of Search: 382/128, 382/129, 382/130, 382/131, 382/132, 382/13, 382/134, 378/4, 378/8, 378/901, 378 21- 27, 378/101
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/6852 Catheters

Abstract

The invention generally relates to methods for calibrating an OCT image by comparing a detected location of a feature within the image to an expected location of the feature, calculating a calibration value, and transforming the location of pixels within the image to provide a calibrated image.

Claims

1. A method of calibrating an imaging system, the method comprising:

using the processor for;

obtaining an image that includes a target and a reference item;

detecting a location of the reference item within the image;

determining a y-value of the location;

comparing the determined y-value to a stored reference y-value;

calculating a calibration value based on the comparison; and

providing a calibrated image by shifting pixels in a y-direction according to the calibration value;

wherein calculating the calibration value comprises taking a difference between the determined y-value and the stored reference y-value.

2. The method of claim 1, wherein the pixels are shifted by the difference.

3. A method of calibrating an imaging system, the method comprising:

using the processor for;

obtaining an image that includes a target and a reference item;

detecting a location of the reference item within the image;

determining a y-value of the location;

comparing the determined y-value to a stored reference y-value;

calculating a calibration value based on the comparison;

providing a calibrated image by shifting pixels in a y-direction according to the calibration value; and

removing a feature from the image;

wherein removing comprises cropping out the feature across its extent in the y direction at all x positions.

4. The method of claim 3, wherein removing comprises calculating an average value of pixels proximal to the cropped region and inserting the average values to replace the cropped pixels.