SYSTEM AND METHOD FOR PRECISE BEAM POSITIONING IN OCULAR SURGERY

• US 20080177256A1
• Filed: 01/19/2007
• Published: 07/24/2008
• Est. Priority Date: 01/19/2007
• Status: Active Grant

• Current Assignee: Technolas Perfect Vision GMBH (Bausch Health Cos., Inc.)
• Original Assignee: Technolas Perfect Vision GMBH (Bausch Health Cos., Inc.)
• Inventors: Pape, Ulrich von, Loesel, Frieder, Glasmacher, Mathias
• Granted Patent: US 8,088,124 B2
• Time in Patent Office: Days
• US Class Current: 606/4
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61F 2009/00844 Feedback systems
• CPC Class Codes: A61F 2009/00851 Optical coherence topography [OCT]
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00825 for photodisruption

Abstract

A system and method for ocular surgery includes a delivery system for generating and guiding a surgical laser beam to a focal point in a treatment area of an eye. Additionally, a contact device is employed for using the eye to establish a reference datum. Further, an optical detector is coupled to the beam path of the surgical laser to create a sequence of cross-sectional images. Each image visualizes both the reference datum and the focal point. Operationally, a computer then uses these images to position and move the focal point in the treatment area relative to the reference datum for surgery.

Claims

1. An apparatus for directing a surgical laser beam onto tissue in a treatment area of an eye of a patient during ocular surgery, the apparatus comprising:

a beam delivery system for generating and guiding the surgical laser beam along a beam path to a desired focal point in the treatment area;

a means for using the eye to establish a reference datum;

an optical detector for creating a cross-sectional image wherein the image includes visualizations of the reference datum and the treatment area; and

a means, connected to the beam delivery system and to the optical detector, for positioning the focal point in the treatment area relative to the reference datum in the image, for guiding the beam during surgery.

2. An apparatus as recited in claim 1 wherein the surgical laser beam comprises a sequence of femtosecond pulses.

3. An apparatus as recited in claim 1 wherein the using means is a contact device mounted on the beam delivery system for engagement with the eye to establish the reference datum.

4. An apparatus as recited in claim 3 wherein the contact device is a contact lens and the reference datum is an interface between an external surface of the eye and the contact lens.

5. An apparatus as recited in claim 1 wherein the reference datum is selected from a group consisting of an anterior surface of a cornea, a posterior surface of a cornea, a boundary of a crystalline lens, and a fundus of an eye.

6. An apparatus as recited in claim 1 wherein the optical detector is an optical coherence tomograph (OCT) and the positioning means is a computer.

7. An apparatus as recited in claim 6 wherein the image is planar, and wherein a portion of the beam path is in the plane of the image.

8. An apparatus as recited in claim 1 further comprising:

a means for sequentially creating a plurality of images with the optical detector;

a means for continuously monitoring the reference datum with the computer;

a means for using the reference datum to determine a delta for each image, wherein the delta is a distance between an actual position of the focal point and the position of the desired focal point; and

a means in the beam delivery system for maintaining the delta at a substantial null.

9. An apparatus as recited in claim 1 wherein the beam delivery system, in sequence along the beam path, comprises:

a laser source for generating the surgical laser beam;

a scanning unit for moving the focal point of the surgical laser beam in orthogonal x, y and z directions; and

a focusing lens for establishing the focal point.

10. An apparatus as recited in claim 9 wherein the optical detector includes a secondary scanning unit and is positioned to couple a diagnostic beam onto the beam path of the surgical laser beam at a point between the scanning unit and the focusing lens.

11. An apparatus as recited in claim 10 wherein the wavelength of the surgical laser beam is approximately one thousand nanometers (λ

_s=1000 nm), and the wavelength of the diagnostic beam is approximately one thousand three hundred nanometers (λ

_d=1,300 nm).

12. An apparatus for directing a surgical laser beam onto a treatment area of a substantially transparent material, wherein the transparent material includes a first portion having a first refractive index and a second portion having a second refractive index to establish an interface therebetween, the apparatus comprising:

a means for generating and guiding the surgical laser beam along a beam path to a desired focal point in the treatment area;

a means for using the interface to establish a reference datum;

an optical means for creating a cross-sectional image wherein the image includes visualizations of the reference datum and the treatment area; and

a means for positioning the focal point in the treatment area relative to the reference datum in the image, for guiding the beam during surgery.

13. An apparatus as recited in claim 12 wherein the surgical laser generating means comprises:

a laser source for generating the surgical laser beam;

a primary scanning unit for moving the focal point of the surgical laser beam in orthogonal x, y and z directions; and

a focusing lens for establishing the focal point.

14. An apparatus as recited in claim 13 wherein the optical means includes a secondary scanning unit, and wherein the optical means is positioned to couple a diagnostic beam onto the beam path of the surgical laser beam at a point between the primary scanning unit and the focusing lens.

15. An apparatus as recited in claim 12 further comprising:

a means for sequentially creating a plurality of images with the optical detector;

a means for continuously monitoring the reference datum with the computer;

a means for using the reference datum to determine a delta for each image, wherein the delta is a distance between an actual position of the focal point and the position of the desired focal point; and

a means for maintaining the delta at a substantial null.

16. An apparatus as recited in claim 12 wherein the transparent material is in an eye and the using means is a contact lens mounted on the beam delivery system for engagement with the eye to establish the reference datum, and wherein the reference datum is an interface between an external surface of the eye and the contact lens.

17. An apparatus as recited in claim 12 wherein the optical means is an optical coherence tomograph (OCT) and the positioning means is a computer.

18. A method for directing a surgical laser beam onto tissue in a treatment area of an eye of a patient during ocular surgery which comprises the steps of:

generating a surgical laser beam;

guiding the surgical laser beam along a beam path to a desired focal point in the treatment area;

using the eye to establish a reference datum;

creating a cross-sectional image wherein the image includes a visualization of the reference datum and a visualization of the treatment area; and

positioning the focal point of the surgical laser beam in the treatment area, relative to the reference datum in the image, for guiding the beam during surgery.

19. A method as recited in claim 18 further comprising the steps of:

scanning the focal point of the surgical laser beam in orthogonal x, y and z directions; and

focusing the surgical laser beam for establishing the focal point.

20. A method as recited in claim 19 further comprising the steps of:

sequentially creating a plurality of cross-sectional images;

continuously monitoring the reference datum and the focal point;

using the reference datum to determine a delta for each image, wherein the delta is a distance between an actual position of the focal point and the position of the desired focal point; and

maintaining the delta at a substantial null.