Method and system for controlling a digital mircomirror device for laser refractive eye surgery

• US 6,413,251 B1
• Filed: 05/09/2000
• Issued: 07/02/2002
• Est. Priority Date: 03/13/2000
• Status: Expired due to Fees

• Current Assignee: Memphis Eye & Cataract Associates Ambulatory Surgery Center
• Original Assignee: Memphis Eye & Cataract Associates Ambulatory Surgery Center
• Inventors: Williams, Roy E.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): FARAH, AHMED M
• Application Number:
  US09/567,155
• Time in Patent Office: 784 Days
• Field of Search: 606/4-6, 606/10-13, 606/17, 606/18, 356/2, 356/4.09, 356/24, 356/27, 128/898
• US Class Current: 606/5
• CPC Class Codes: A61F 2009/00846 Eyetracking
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 2009/0088 based on wavefront
• CPC Class Codes: A61F 2009/00882 based on topography
• CPC Class Codes: A61F 9/00806 Correction of higher orders
• CPC Class Codes: A61F 9/00817 Beam shaping with masks

Abstract

A laser eye surgery system includes a laser for producing a laser beam capable of making refractive corrections, an optical system for shaping and conditioning the laser beam, a digital micromirror device (DMD) for reflecting the shaped and conditioned beam toward the eye, and a computer system for controlling the mirrors of the DMD. The computer system generates one-bit resolution images corresponding to ablation layers defining a correction for the eye. The images are then transferred to the DMD for appropriate reflection of the laser beam toward the eye such that the shape of the cornea of the eye is corrected.

Claims

1. A method of directing mirrors of a digital micromirror device (DMD) used in a laser eye surgery system having a computer, comprising:

a) inputting eye refraction data into the computer;

b) generating with the computer spherical and cylinder refraction correction profiles from said eye refraction data;

c) creating a sequence of layer image data for at least one of a spherical and a cylinder correction profile;

d) transferring said sequence of layer image data to the DMD; and

e) directing a broadbeam laser to the DMD.

2. A method according to claim 1, wherein:

for each of said spherical and said cylinder correction profiles, said layer image data is created, and said layer image data is combined.

3. A method according to claim 1, wherein:

said layer image data is divided into spot-sized portions.

4. A method according to claim 1, wherein:

said inputting eye refraction data includes inputting corneal topography data into the computer,

said method further comprising,

f) modifying said at least one of said spherical and cylinder refraction correction profiles relative to said corneal topography data, wherein said sequence of layer image data is created for said modified refraction correction profile.

5. A method according to claim 4, wherein:

said layer image data includes corneal height information.

6. A method according to claim 5, wherein:

said layer image data is divided into a series of 1 bit images.

7. A method according to claim 6, wherein:

each 1 bit image corresponds to an etch depth of a pulse of said laser.

8. A laser surgery system for reshaping the cornea of the eye, said system comprising:

a) means for generating a spherical correction profile and a cylinder correction profile;

b) means for determining iris size data for each of a plurality of slices through said spherical correction profile and slit size data for each of a plurality of slices through said cylinder correction profile;

c) means for merging said iris size data and said slit size data for each said respective plurality of slices into a data array;

d) means for creating a plurality of one-bit resolution images from said data array;

e) a digital micromirror device (DMD) having a plurality of mirrors and adapted to modulate said mirrors into patterns corresponding to said one-bit resolution images; and

f) a laser adapted to direct a broadbeam laser beam at said DMD such that a laser beam produced by said laser is shaped into said patterns and redirected by said DMD to the eye.

9. A laser surgery system according to claim 8, wherein:

each of said one-bit resolution images corresponds to a particular etch depth in the cornea.