Automatic patient positioning within a laser eye surgery system

Patent metadata

Field	Value
Publication number	US-2016106581-A1
Application number	US-201514885824-A
Country	US
Kind code	A1
Filing date	Oct 16, 2015
Priority date	Oct 17, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

A laser eye surgery system produces a treatment beam that includes a plurality of laser pulses. An optical coherence tomography (OCT) subsystem produces a source beam used to locate one or more structures of an eye. The OCT subsystem is used to sense the distance between a camera objective on the underside of the laser eye surgery system and the patient's eye. Control electronics compare the sensed distance with a pre-determined target distance, and reposition a movable patient support toward or away the camera objective until the sensed distance is at the pre-determined target distance. A subsequent measurement dependent upon the spacing between the camera objective and the patient's eye is performed, such as determining the astigmatic axis by observing the reflection of a plurality of point source LEDs arranged in concentric rings off the eye.

First claim

What is claimed is:

1 . A method of positioning a patient with respect to a laser eye surgery system, comprising:
positioning an eye of a patient on a support below a camera objective within a laser eye surgery system containing an optical coherence tomography (OCT) scanner; sensing the distance between the camera objective and the patient's eye using the OCT scanner; transmitting the distance between the camera objective and the patient's eye to control electronics of the laser eye surgery system; and then performing a measurement function of the laser eye surgery system dependent on accurate knowledge of the distance between the camera objective and the patient's eye.

2 . The method of claim 1 , further including:
comparing the sensed distance with a pre-determined target distance; and repositioning the camera objective toward or away from the movable support until the sensed distance is within a threshold tolerance of the pre-determined target distance.

3 . The method of claim 1 , further including:
comparing the sensed distance with a pre-determined target distance; and repositioning the support toward or away from the camera objective until the sensed distance is within a threshold tolerance of the pre-determined target distance.

4 . The method of claim 1 , wherein the step of sensing the distance comprises performing a closed-loop iteration using the OCT scanner to produce an output graph indicative of the location of the patient's eye relative to the camera objective.

5 . The method of claim 4 , wherein the closed-loop iteration comprises taking a set of 2000 A-scans at 1000 Hz to measure the initial distance from the camera objective to the patient's eye, wherein a focus of the OCT scanner is placed as close as possible to a zero “Optical Path Distance” and the “Optical Path Distance” is continuously swept through a range of 20 mm to produce an inverted “V” on the output graph and a vertex of the inverted “V” identifies the location of the patient's eye.

6 . The method of claim 4 , further including displacing the patient's eye toward or away from the camera objective based on the location of the patient's eye determined from taking a set of 2000 A-scans, and then comprises taking a set of 1000 A-scans to refine the location of the patient's eye.

7 . The method of claim 4 , wherein the step of performing a closed-loop iteration using the OCT scanner is initiated automatically by pressing and maintaining pressed a control to start a controlled motion of a patient chair and stopping the chair motion when either the control is no longer pressed or one or more force sensors located at the camera objective transmits a signal indicating possible contact of the camera objective with the patient's eye.

8 . The method of claim 1 , wherein the measurement function comprises measuring an astigmatic axis or measuring the power or curvature of the cornea of the patient's eye.

9 . The method of claim 1 , wherein the measurement function comprises measuring an astigmatic axis by capturing an image of a reflection from a circular array of light sources off the cornea of the patient's eye.

10 . A method of positioning a patient with respect to a laser eye surgery system, comprising:
positioning an eye of a patient on a support below a camera objective within a laser eye surgery system containing an optical coherence tomography (OCT) scanner; sensing the distance between the camera objective and the patient's eye using the OCT scanner; comparing the sensed distance with a pre-determined target distance; adjusting the position between the support and the camera objective and sensing the distance again using the OCT scanner until the sensed distance is within a threshold tolerance of the pre-determined target distance; transmitting the sensed distance between the camera objective and the patient's eye to control electronics of the laser eye surgery system; and then performing a measurement function of the laser eye surgery system dependent on accurate knowledge of the sensed distance between the camera objective and the patient's eye.

11 . The method of claim 10 , wherein the step of sensing the distance comprises performing a closed-loop iteration using the OCT scanner to produce an output graph indicative of the location of the patient's eye relative to the camera objective.

12 . The method of claim 11 , wherein the closed-loop iteration comprises taking a set of 2000 A-scans at 1000 Hz to measure the initial distance from the camera objective to the patient's eye, wherein a focus of the OCT scanner is placed as close as possible to a zero “Optical Path Distance” and the “Optical Path Distance” is continuously swept through a range of 20 mm to produce an inverted “V” on the output graph and a vertex of the inverted “V” identifies the location of the patient's eye.

13 . The method of claim 11 , further including displacing the patient's eye toward or away from the camera objective based on the location of the patient's eye determined from taking a set of 2000 A-scans, and then comprises taking a set of 1000 A-scans to refine the location of the patient's eye.

14 . The method of claim 11 , wherein the step of performing a closed-loop iteration using the OCT scanner is initiated automatically by pressing and maintaining pressed a control to start a controlled motion of a patient chair and stopping the chair motion when either the control is no longer pressed or one or more force sensors located at the camera objective transmits a signal indicating possible contact of the camera objective with the patient's eye.

15 . The method of claim 10 , wherein the measurement function comprises measuring an astigmatic axis or measuring the power or curvature of the cornea of the patient's eye.

16 . The method of claim 10 , wherein the measurement function comprises measuring an astigmatic axis by capturing an image of a reflection from a circular array of light sources off the cornea of the patient's eye.

17 . A method of automatically positioning a patient with respect to a laser eye surgery system, comprising:
positioning an eye of a patient on a patient support below a camera objective within a laser eye surgery system containing an optical coherence tomography (OCT) scanner; sensing the distance between the camera objective and the patient's eye using a method selected from the group consisting of:
capturing an image of a reflection from a circular array of LEDs off the cornea of the patient's eye and detecting a contrast metric from the part of the video image that contains the reflection of the LEDs, moving the patient support in a first direction, toward or away from the camera objective, a short distance and the contrast metric detected again,
1. if the contrast improves, continuing to move the patient support in the first direction until the contrast gets worst, then moving the patient support in a second direction, opposite the first direction, to a previous maximum contrast location, and
2. if the contrast gets worst, then moving the patient support in the second direction until the contrast decreases, and then moving the patient support in the first direction to a previous maximum contrast location,
phase detection where a partial beam splitter picks off some light from the reflected image and directs it to a number of micro lens pairs which in turn project to small, independent sensors, comparing the output of the sensors,
capturing an image of an array of dots created by a reflection from a circular array of LEDs off the cornea of the patien

Assignees

• Optimedica Corp

Inventors

• Gonzalez Javier G
• Dewey David A
• Bareket Noah
• Campos Michael A
• Chen Yu-Tai Ray
• Scott David D

Classifications

• A61F2009/00851

  Optical coherence topography [OCT] · CPC title

• A61F2009/0087

  Lens · CPC title

• A61F2009/00846

  Eyetracking · CPC title

• A61F9/007

  Methods or devices for eye surgery · CPC title

• A61F9/009 Primary

  Auxiliary devices making contact with the eyeball and coupling in laser light, {e.g. goniolenses (apparatus for eye examination A61B3/0008)} · CPC title