Method of motion correction in optical coherence tomography imaging

An optical coherence tomography (OCT) device comprising:

• a light source for generating a beam of radiation;
• a beam divider for directing a first portion of the light into a reference arm and a second portion of the light into a sample arm;
• optics for scanning the beam in the sample arm over a set of transverse locations on a sample;
• a detector for measuring light radiation returning from the sample and reference arms and generating output signals in response thereto;
• and
• a processor for converting the output signals into three dimensional image information;
• said processor for controlling the scanning optics in a manner to acquire a first set of longitudinal scans at a first plurality of transverse locations within the sample;
• said processor for controlling the scanning optics in a manner to acquire a second set of longitudinal scans at a second plurality of transverse locations in a two-dimensional pattern across the sample, wherein at least some of the second plurality of transverse locations on the sample correspond to at least some of the first plurality of transverse locations in the sample;
• said processor matching certain ones of said second plurality of scans to certain ones of said first plurality of scans to define matched pairs, said matching being based on an evaluation of whether the associated optical scattering profiles of the scans are substantially similar;
• said processor determining a displacement between coordinates associated with each of said matched pairs;
• said processor adjusting the coordinates associated with at least some of the scans of the second set based on the determined displacements in order to reduce any inaccuracies created by relative movement of the sample during the acquisition of the second set of scans.

An optical coherence tomography (OCT) device for use generating images of any eye comprising:

• a light source for generating a beam of radiation;
• a beam divider for directing a first portion of the light into a reference arm and a second portion of the light into a sample arm;
• optics for scanning the beam in the sample arm over a set of transverse locations on an eye;
• a detector for measuring light radiation returning from the eye and reference arms and generating output signals in response thereto;
• and
• a processor for converting the output signals into three dimensional image information;
• said processor for controlling the scanning optics in a manner to acquire a first set of A-scans over a region of interest of the eye, said first set having a first resolution and being obtained during a first time period;
• said processor for controlling the scanning optics in a manner to acquire a second set of A-scans over the region of interest, said second set having a second resolution, said second resolution being higher than the first resolution and being obtained over a second time period longer than the first time period;
• said processor comparing A-scans in the first set to A-scans in the second set to find substantially matching pairs;
• said processor analyzing the matched pairs to determine eye movement;
• said processor adjusting the originally assigned coordinates of the second set of A-scans based on the determined eye movement.

An optical coherence tomography (OCT) device for generating images of the eye comprising:

• a light source for generating a beam of radiation;
• a beam divider for directing a first portion of the light into a reference arm and a second portion of the light into a sample arm;
• optics for scanning the beam in the sample arm over a set of transverse locations on an eye;
• a detector for measuring light radiation returning from the sample and reference arms and generating output signals in response thereto;
• and
• a processor for converting the output signals into three dimensional image information;
• said processor for controlling the scanning optics in a manner to acquire a first set of A-scans over a region of interest of the eye, said first set having a first resolution and being obtained during a first time period;
• said processor for controlling the scanning optics in a manner to acquire a second set of A-scans of the region of interest, said second set having a second resolution, said second resolution being higher than the first resolution and being obtained over a second time period longer than the first time period;
• said processor comparing A-scans in the first set to A-scans in the second set to find substantially matching pairs by computing the cross-correlation between pairs;
• said processor analyzing the axial shift between the matched pairs to determine eye movement along the axis of the A-scan and determining eye movement perpendicular to the axis of the A-scan by analyzing which of the A-scans in the first set matched an A-scan in the second set and determining the displacement of the coordinates therebetween;
• said processor adjusting the originally assigned coordinates of the second set of A-scans based on the determined eye movement.