Objective quality metric for ocular wavefront measurements
View Patent ↗A system and method for determining an objective quality metric for image data collected by a wavefront aberrometer. The method may include quantifying a plurality of characteristics of the image data and calculating the objective quality metric based on the quantified characteristics of the image data. The objective quality metric can be a weighted sum of the quantified characteristics of the image data. The weightings for the weighted sum can be determined based on subjective quality metrics assigned to a set of training image data by a human expert.
1. An ophthalmic device, comprising:
a wavefront aberrometer; and
a processing module enabled to execute computer-executable instructions for,
receiving an indication of a plurality of wavefront aberrometer images indicative of ocular aberrations of an eye of a patient;
determining a plurality of quantitative quality metrics respectively for each of the wavefront aberrometer images, wherein each of the quantitative quality metrics is based on a characteristic of a respective wavefront aberrometer image;
selecting at least a subset of the wavefront aberrometer images based on values of the quantitative quality metrics; and
determining ocular aberration measurements using at least the subset of the wavefront aberrometer images.
2. The ophthalmic device of claim 1 , wherein the subset of wavefront aberrometer images consists of a first wavefront aberrometer image.
3. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
calculating a first quantitative quality metric using a parameter determined from a plurality of training images representative of ocular aberrations.
4. The ophthalmic device of claim 3 , further comprising computer-executable instructions for:
determining the parameter based on qualitative quality metrics assigned to the plurality of training images by a human expert.
5. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristic of a second wavefront aberrometer image by analyzing a spatial-domain representation of the second wavefront aberrometer image.
6. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristic of a third wavefront aberrometer image by analyzing a frequency-domain representation of the third wavefront aberrometer image.
7. The ophthalmic device of claim 1 , further comprising computer-executable instructions for: quantifying the characteristic of a fourth wavefront aberrometer image as an output of a mathematical function that receives the fourth wavefront aberrometer image as an input.
8. The ophthalmic device of claim 7 , further comprising computer-executable instructions for:
determining a quantitative quality metric for the fourth wavefront image based on a combination of outputs of a plurality of mathematical functions.
9. The ophthalmic device of claim 8 , further comprising computer-executable instructions for:
calculating the combination of the outputs of the mathematical functions based on a weighted sum of the outputs calculated using respective weightings of the mathematical functions.
10. The ophthalmic device of claim 9 , further comprising computer-executable instructions for:
selecting the weightings based on qualitative quality metrics assessed to a plurality of test images by a human expert.
11. The ophthalmic device of claim 10 , further comprising computer-executable instructions for:
selecting the weightings based on a difference between the quantitative quality metrics calculated for the test images and the qualitative quality metrics for the test images.
12. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristic of a fifth wavefront aberrometer image based on a degree of centration of the fifth wavefront aberrometer image.
13. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristics of the subset of wavefront aberrometer images based on a first variance of the ocular aberration measurements.
14. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristic of a sixth wavefront aberrometer image based on a width of a spectral peak identified in a spatial frequency-domain representation of the sixth wavefront aberrometer image.
15. The ophthalmic device of claim 14 , further comprising computer-executable instructions for:
determining the characteristic of the sixth wavefront aberrometer image based on a second variance of the width of the spectral peak based on a direction across the spectral peak.
16. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
determining the characteristic of a seventh wavefront aberrometer image based on an image contrast value for the seventh wavefront aberrometer image.
17. The ophthalmic device of claim 16 , further comprising computer-executable instructions for:
determining the image contrast value from a region of interest within the seventh wavefront aberrometer image.
18. The ophthalmic device of claim 1 , wherein an eighth wavefront aberrometer image comprises a Moiré fringe pattern.
19. The ophthalmic device of claim 1 , wherein a ninth wavefront aberrometer image comprises a Shack-Hartmann spot pattern.
20. The ophthalmic device of claim 1 , wherein the ocular aberration measurements include measurements selected from: a spherical power of the eye, a cylindrical power of the eye, and a cylindrical axis of the eye.
21. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
based on the ocular aberration measurements, selecting an intraocular lens for implantation in the eye.
22. The ophthalmic device of claim 1 , further comprising computer-executable instructions for:
outputting the ocular aberration measurements for positioning an intraocular lens during cataract surgery.
23. A computer-implemented method for execution in a wavefront aberrometer system, the method comprising:
receiving an indication of a plurality of wavefront aberrometer images indicative of ocular aberrations of an eye of a patient;
determining a plurality of quantitative quality metrics respectively for each of the wavefront aberrometer images, wherein each of the quantitative quality metrics is based on a characteristic of a respective wavefront aberrometer image;
selecting at least a subset of the wavefront aberrometer images based on values of the quantitative quality metrics; and
determining ocular aberration measurements using at least the subset of the wavefront aberrometer images.
24. A computer-readable medium storing instructions executable by a computer for:
receiving an indication of a plurality of wavefront aberrometer images indicative of ocular aberrations of an eye of a patient;
determining a plurality of quantitative quality metrics respectively for each of the wavefront aberrometer images, wherein each of the quantitative quality metrics is based on a characteristic of a respective wavefront aberrometer image;
selecting at least a subset of the wavefront aberrometer images based on values of the quantitative quality metrics; and
determining ocular aberration measurements using at least the subset of the wavefront aberrometer images.
25. The ophthalmic device of claim 1 , wherein the quantitative quality metrics comprise scalar values.