Imaging-controlled laser surgical system

1. An imaging-based laser system, comprising:

a laser engine configured to generate a beam of laser pulses;

an imaging-based laser-controller configured to:

determine z-depths of a sequence of points in a scan-pattern that correspond to a layer of the eye imaged by an imaging system;

generate a tracking band within the scan pattern defining the incision to be made in the eye, wherein a lower boundary of the tracking band has a non-uniform z-depth that varies according to the determined z-depths of the sequence of points corresponding to the imaged layer;

cause a beam scanner to scan the beam of laser pulses to the points of the scan-pattern, and

cause a beam attenuator to control the laser-power parameter of the laser pulses such that a laser power parameter of laser pulses in the tracking band is above a photo-disruption threshold, and a laser power parameter of laser pulses outside the tracking band is below the photo-disruption threshold.

2. The system of claim 1 , wherein: the layer of the eye imaged by the imaging system is tilted relative to a z-axis of the incision to be made in the eye.

3. The system of claim 2 , wherein the imaging system comprises a timedomain optical coherence tomography (OCT) system, a frequency-domain OCT system, or a spectrometer-based OCT system.

4. The system of claim 2 , wherein the imaging-based laser-controller is configured to determine the z-depths of the sequence of points in the scan-pattern that correspond to the layer of the eye imaged by the imaging system by performing a feature-cognition analysis of an image of the imaged layer.

5. The system of claim 2 , wherein: the imaged layer is a lens capsule between a lens of the eye and an aqueous chamber of the eye; and the tracking band corresponds to an intended capsulotomy cut intersecting the lens capsule.

6. The system of claim 1 , wherein the beam attenuator comprises at least one of a Pockels cell, a polarizer-assembly, a mechanical shutter, an electro-mechanical shutter, and an energy wheel.

7. A method, comprising:

generating an image, with an imaging system, of a layer of an eye that is tilted relative to a z-axis of an incision to be made in the eye;

determining, with an imaging-based laser-controller, z-depths of a sequence of points in a scan-pattern that correspond to the image of the layer;

generating, with the imaging-based laser-controller, a tracking band within the scan pattern defining the incision to be made in the eye, wherein a lower boundary of the tracking band has a non-uniform z-depth that varies according to the determined z-depths of the sequence of points corresponding to the image of the layer;

directing, with the imaging-based laser-controller, a beam of laser pulses to the points of the scan-pattern to create the incision defined by the tracking band.

8. The method claim 7 , further comprising: associating a photodisruptive laser-power parameter with points in the scan pattern that are inside the tracking band; and associating a non-photodisruptive laser-power parameter with points in the scan pattern than are outside the tracking band.

9. The method of claim 7 , wherein determining z-depths of the sequence of points in the scan pattern that correspond to the imaged layer in the eye comprises performing a feature-recognition analysis to identify the imaged layer.

10. The method of claim 9 , comprising: generating coordinates of the imaged layer corresponding to the scan pattern and the tracking band; signaling the coordinates to a beam scanner; and signaling laser-power parameters to a beam attenuator.

11. The method of claim 10 , wherein signaling laser-power parameters to a beam attenuator comprises: signaling a photodisruptive laser-power parameter associated with points in the scan pattern that are inside the tracking band; and signaling a non-photodisruptive laser-power parameter associated with points in the scan pattern than are outside the tracking band.

12. The method of claim 7 , wherein the incision defined by the tracking band results in a capsulotomy.

13. A non-transitory computer-readable medium storing instructions that, when executed, cause a processor of an imaging-based laser system to:

analyze an image of a layer of an eye that is tilted relative to a z-axis of an incision to be made in the eye;

determine z-depths of a sequence of points in a scan-pattern that correspond to the layer;

generate a tracking band within the scan pattern defining the incision to be made in the eye, wherein a lower boundary of the tracking band has a non-uniform z-depth that varies according to the determined z-depths of the sequence of points corresponding to the image of the layer;

generate signals to cause an imaging-based laser-controller system to direct a beam of laser pulses to the points of the scan-pattern to create the incision defined by the tracking band.

14. The computer-readable medium of claim 13 , wherein the stored instructions, when executed, cause the processor to: associate a photodisruptive laser-power parameter with points in the scan pattern that are inside the tracking band; and associate a non-photodisruptive laser-power parameter with points in the scan pattern than are outside the tracking band.

15. The computer-readable medium of claim 13 , wherein the stored instructions, when executed, cause the processor to perform a feature-recognition analysis to identify the imaged layer.

16. The computer-readable medium of claim 13 , wherein the stored instructions, when executed, cause the processor to: generate coordinates of the imaged layer corresponding to the scan pattern and the tracking band; signal the coordinates to a beam scanner; and signal laser-power parameters to a beam attenuator.

17. The computer-readable medium of claim 13 , wherein the stored instructions, when executed, cause the processor to signal the laser-power parameters to a beam attenuator by: signaling a photodisruptive laser-power parameter associated with points in the scan pattern that are inside the tracking band; and signaling a non-photodisruptive laser-power parameter associated with points in the scan pattern than are outside the tracking band.