Wavefront measuring method for adaptive optics system

Patent metadata

Field	Value
Publication number	US-10052018-B2
Application number	US-201615092073-A
Country	US
Kind code	B2
Filing date	Apr 6, 2016
Priority date	Apr 6, 2016
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A method, a controller, and a non-transitory medium for controlling an optical-image pickup apparatus. Receiving quality data representative of quality of wavefront data. Comparing the quality data to a threshold. Performing normal adaptive optics feedback if the wavefront data is of sufficient quality. Performing an initial adjustment if the wavefront data is not of sufficient quality. The initial adjustment comprising sending control information to modify the optical path in which light is radiated onto a subject. After the initial adjustment, receiving new quality data that is based on new wavefront data after the optical path has been modified. Performing the normal adaptive optics feedback if the quality information indicates that the wavefront data is of sufficient quality. Re-performing the initial adjustment if the new quality information indicates that the wavefront data is not of sufficient quality.

First claim

What is claimed is:

1. A method for controlling an optical-image pickup apparatus configured to radiate measurement light onto a subject, to measure a wavefront aberration generated at the subject with a wavefront measurement device, to correct the aberration with a wavefront correction device, and to acquire an optical image of the subject, the method comprising:
receiving a first set of quality data that is representative of a quality of wavefront data, wherein the wavefront data is an estimation of wavefront aberrations generated at the subject;
comparing the first set of quality data to a first threshold;
in a first case wherein the comparison of the first set of quality data indicates that the wavefront data is of sufficient quality then performing normal adaptive optics feedback comprising:
sending a first set of control information to the optical-image pickup apparatus instructing the optical-image pickup apparatus to compensate for aberrations based on an estimated shape of the wavefront based on the received wavefront data; and
re-estimating the shape of the wavefront based on re-acquired wavefront data and sending a new first set of control information to the optical-image pickup apparatus instructing the optical-image pickup apparatus to compensate for aberrations based on the re-estimated shape of the wavefront; and

in a second case wherein the comparison of the first set of quality data indicates that the wavefront data is not of sufficient quality then performing an initial adjustment comprising:
sending a second set of control information to the optical-image pickup apparatus instructing the optical-image pickup apparatus to modify the optical path in which measurement light is radiated onto the subject;
receiving a new first set of quality data, to replace the previously received first set of quality data, that is based on new wavefront data after the optical path has been modified; and
re-comparing the new first set of quality data to the first threshold;

in a third case wherein the comparison of the first set of quality data that is based on the new wavefront data indicates that the new wavefront data is of sufficient quality then performing the normal adaptive optics feedback in which the optical path has been adjusted based on the second set of control information; and
in a fourth case wherein the comparison of the first set of quality data that is based on the new wavefront data indicates that the new wavefront data is not of sufficient quality then re-performing the initial adjustment based on a new second set of control information.

2. The method according to claim 1 , wherein before receiving the first set of quality data the wavefront correction unit compensates for the known optical aberrations based on optical prescription data associated with the subject.

3. The method according to claim 1 , wherein modifying the optical path include adjusting a position of a second correction unit other than the wavefront correction unit.

4. The method according to claim 3 , wherein:
a second correction unit includes as least one or more focusing optical components selected from a group including a lens and a mirror; and
the second set of control information includes instructions for the optical-image pickup apparatus to move the at least one or more focusing optical components.

5. The method of claim 1 , wherein the wavefront correction device is one of a deformable mirror or a spatial light phase modulator.

6. The method of claim 5 wherein the wavefront measurement device is a Shack-Hartman sensor that detects a plurality of Hartmann spots.

7. The method of claim 6 wherein the first set of quality data is based on a numerical count of the plurality of Hartmann spots.

8. The method of claim 6 wherein the first set of quality data is based on a plurality of diameters of the plurality of Hartmann spots.

9. The method of claim 6 wherein the first set of quality data is based on signal intensity data of the plurality of Hartmann spots.

10. The method of claim 1 , wherein the normal adaptive optics feedback is done repeatedly so as to form a feedback loop.

11. The method of claim 10 , further comprises:
controlling the image pickup apparatus so as to acquire the optical image of the subject by scanning a spot in parallel with continuous use of the normal adaptive optics feedback.

12. The method of claim 1 , wherein the initial adjustment is performed repeatedly until the comparison of the first set of quality data with the first threshold indicates that the wavefront data is of sufficient quality and controlling the image pickup apparatus so as to acquire the optical image of the subject by scanning a spot in parallel with continuous use of the normal adaptive optics feedback after the comparison of the first set of quality data with the first threshold indicates that the wavefront data is of sufficient quality.

13. The method of claim 1 , wherein:
the initial adjustment is performed repeatedly, wherein the initial adjustment includes:
a first part of modifying the optical path by adjusting a position of one or more focusing optical components to change the focus until the comparison of the first set of quality data with the first threshold indicates that the wavefront data is of sufficient quality; and
a second part, of modifying the optical path by adjusting a position of one or more focusing optical components to change the astigmatism until the comparison of the first set of quality data with a second threshold indicates that the wavefront data is of sufficient quality; and

controlling the image pickup apparatus so as to acquire the optical image of the subject by scanning a spot in parallel with continuous use of the normal adaptive optics feedback after the comparison of the first set of quality data with the first threshold and the second threshold indicates that the wavefront data is of sufficient quality.

14. The method of claim 1 , wherein:
the first set of quality data includes multiple elements which represent different qualitative aspects of the wavefront data;
the first threshold include multiple elements which provide different thresholds for different qualitative aspects of the wavefront data; and
comparing the first set of quality data to the first threshold includes comparing those elements of the first set of quality data associated with particular qualitative aspects of the wavefront data with thresholds associated with those qualitative aspects of the wavefront data.

15. A non-transitory computer readable medium encoded with instructions for controlling an optical-image pickup apparatus configured to radiate measurement light onto a subject, to measure a wavefront aberration generated at the subject with a wavefront measurement device, to correct the aberration with a wavefront correction device, and to acquire an optical image of the subject, the instructions comprising:
receiving a first set of quality data that is representative of a quality of wavefront data, wherein the wavefront data is an estimation of wavefront aberrations generated at the subject;
comparing the first set of quality data to a first threshold;
in a first case wherein the comparison of the first set of quality data indicates that the wavefront data is of sufficient quality then performing normal adaptive optics feedback comprising:
sending a first set of control information to the optical-image pickup apparatus instructing the optical-image pickup apparatus to compensate for aberrations based on an estimated shape of the wavefront based on the received wavefront data; and
re-estimating

Assignees

• Canon Kk

Inventors

• Nozato Koji

Classifications

• A61B3/1015 Primary

  for wavefront analysis · CPC title

• G02B27/0068

  having means for controlling the degree of correction, e.g. using phase modulators, movable elements (controlling the phase of light using moving or deformable elements G02B26/06) · CPC title

• A61B3/12

  for looking at the eye fundus, e.g. ophthalmoscopes (A61B3/13 takes precedence) · CPC title

• A61B3/158

  of corneal reflection · CPC title