US005098426A
United States Patent [19] [11] Patent Number: 5,098,426
Sklar et al. [45] Date of Patent: Mar. 24, 1992
[54] METHOD AND APPARATUS FOR PRECISION LASER SURGERY
[75] Inventors: H. Alfred Sklar, San Francisco; Alan M. Frank, Livermore, both of Calif.; Olga M. Ferrer, Miami, Fla.; Charles F. McMillan, Livermore, Calif.; Stewart A. Brown, Livermore, Calif.; Fred Rienecker, Pleasanton, Calif.; Paul Harriss, Livermore, Calif.; Steven Schiffer, San Francisco, Calif.
[73] Assignee: Phoenix Laser Systems, Inc., San Francisco, Calif.
[21] Appl. No.: 307,315
[22] Filed: Feb. 6, 1989
[51] Int. CI.' A61N 5/02
[52] U.S. CI 606/5; 606/4;
606/10; 606/13; 128/630; 128/395; 364/413.02;
364/413.13; 351/209; 219/121.60; 219/121.62;
219/121.85
[58] Field of Search 128/630, 633, 653, 664,
128/665, 395; 606/2, 4, 5, 6, 10, 12, 13; 364/413.01, 413.02, 413.13; 351/200, 205, 209, 209-215; 219/121.60, 121.62, 121.67, 121.69, 121.73, 121.74, 121.75, 121.78, 121.79, 121.81,
121.83, 121.85
[56] References Cited
U.S. PATENT DOCUMENTS
4,538,608 9/1985 L'Esperance 128/345
4,579,430 4/1986 Bille 351/206
4,669,466 6/1987 L'Esperance 606/5
4,743,771 5/1988 Sacks et al 250/560
4,848,340 7/1989 Bille et al 606/4
FOREIGN PATENT DOCUMENTS
8707165 12/1987 World Int. Prop. 0 606/4
Primary Examiner—David Shay
Attorney, Agent, or Firm—Thomas M. Freiburger
[57] ABSTRACT
A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device. The imaging system of the invention enables the surgeon to have before him abundant visual information on the video screen with indication of precisely where, in three dimensions, a focused surgical laser beam is directed at any time. The system also includes tracking system for following the movements of the subject tissue, for example an eye during surgery. The tracking system is fast enough to track such movement, preferably at the maximum repetition rate of the laser plus a sufficient margin for safety, but at all times faster than the frame rate for the video displays at which the video screen is retraced.
44 Claims, 12 Drawing Sheets
