Method and apparatus for precision laser surgery

An instrument and system for high precision ophthalmic laser surgery at a surgical site, comprising,

• a laser pulsed source for producing a visible light laser beam having a power capable of effecting a desired type of surgery in an eye,
• laser firing control means for enabling a surgeon/user to control the aim, depth, and timing of the firing of the laser to effect the desired surgery,
• three dimensional mapping means directed at a patient's eye, for obtaining data representing the location and shapes of features on and inside the eye,
• microprocessor means for receiving data from the three dimensional mapping means and for converting the data to a format presentable on a screen and useful to the surgeon/user in precisely locating features of the eye and the aim and depth of the laser beam within those features, and
• display means for displaying microprocessor-generated images representing the topography of the eye and the aim and depth of the laser beam before the next pulse of the laser is fired to the surgeon/user in preparation for and during surgery, with display control means for enabling the surgeon/user to select areas of the eye for display, including images of cross sections of portions of the eye.

A system for facilitating precisely controlled surgery using a focused laser beam, comprising,

• user interface means for presenting information to a surgeon/user and for enabling control of the surgical procedure by the surgeon/user, including video display means for presenting precise information to the surgeon/user relating to the location in a patient's tissue at which the system is targeted, and the three-dimensional topography and contours of features of the subject tissue and including means for displaying images of cross sections of portions of the patient's tissue, and including means in the control of the surgeon/user for scanning across the tissue to change the information on the video display means as desired by the surgeon/user and for enabling control of the firing of a surgical laser beam by the surgeon/user,
• an imaging system connected to the video display means, including three-dimensional mapping means for generating, reading, and interpreting data to obtain information regarding the location in three dimensions of significant features of the tissue to be operated upon, and including microprocessor means for interpreting the data and presenting the data to the video display means in a format useful to the surgeon/user,
• a short pulse visible light laser power source for generating a laser beam capable of effecting the desired laser surgery in the patient's tissue, including within transparent tissue of the patient,
• optical path means for receiving the laser beam and redirecting the laser beam and focusing it as appropriate toward a desired target in the tissue to be operated upon,
• surgical microscope means positioned to intercept and to be coaxial with the optical path means, for taking surgical microscopic images of said target along the optical path means and for feeding video image information to the video display means, and
• tracking means in the optical path means and associated with the microprocessor means, for tracking movements of the subject tissue at which the system is targeted without damaging the subject tissue before the next pulse of the laser is fired and shifting the optical path means accordingly before the next pulse of the laser is fired, such that information and images generated by the three dimensional mapping mans and by the surgical microscope means, as well as the aiming and position of the laser beam, follow changes in position of the tissue.

A system for use in ophthalmic laser surgery, comprising,

• a laser source for producing a pulsed visible light laser beam having a power capable of effecting a desired type of surgery at targeted tissue at a selected surgical site in the ocular tissues,
• optical path means for delivering the laser beam, including beam directing means for controlling aim and depth of focus of the laser beam,
• three dimensional mapping means for sensing locations, shapes and features on and in a patient's eye in three dimensions, and for generating data and signals representing such locations, shapes and features,
• display means receiving signals from the three dimensional mapping means, for presenting to a surgeon user images representative of said locations, shapes and features of the eye including at depths in the eye selectable by the surgeon,
• position analysis means associated with and receiving signals from the three dimensional mapping means, for recognizing the occurrence of changes of position of features of targeted tissue of the eye,
• target tracking means associated with the position analysis means, for searching for a feature of targeted tissue and finding the feature's new position after such a change of position, and for generating a signal indicative of the new position of the targeted feature tissue, and
• tracking positioning means for receiving said signal from the target tracking mean and for executing a change in the aim of the three dimensional mapping means to the new position of a targeted tissue feature to thereby follow the feature and stabilize the images on the display means, and for simultaneously and accordingly adjusting the aim of the laser beam to be directed at a new position of the targeted feature.

A method for conducting laser surgery, comprising,

• providing a system for imaging a patient's tissue in three dimensions, displaying images is selected formats on a display screen in front of a surgeon, delivering a visible light laser beam at the patient's tissue and firing the laser in accordance with a surgical path in three dimensions as selected by the surgeon directing the laser and for tracking the patient's tissue so as to stabilize images presented on the display screen and to essentially immobilize the subject target tissue on the display screen in spite of actual movements of the tissue,
• placing a patient adjacent to the system,
• under control of the surgeon, reviewing the patient's tissue at different locations and along different cross-sections by selection of desired images on the display screen,
• under control of the surgeon, selecting a surgical path in three dimensions for surgery on the subject tissue and comprising a series of locations for targeting the focal point of and firing the laser beam to effect the surgery, and entering the precise surgical path as selected by the surgeon into a computer and memory of the system,
• under control of the surgeon, initiating the firing of the laser along the programmed surgical path selected by the surgeon, and
• automatically interrupting the surgery along the programmed surgical path whenever the tracking device of the system has failed to relocate a moved tissue feature within a pre-selected period of time.

A method for conducting ophthalmic laser surgery using an imaging system which displays for the surgeon precise information as the location and configuration of features of the patient's eye and as to the aim and depth of focal point of a surgical laser beam, comprising,

• generating with a laser source a visible light laser beam having a power capable of effecting a desired type of surgery in the eye,
• delivering the laser beam along an optical path,
• controlling aim and depth of focus of the laser beam with a beam directing means associated with the laser optical path,
• sensing locations, shapes and features on and in a patient's eye in three dimensions with a three dimensional mapping means, and generating data and signals representing such locations, shapes and features,
• presenting to a surgeon user images representative of said locations, shapes and features of the eye at the target site, on a display mans which receives signals from the three dimensional mapping means including images of cross sections of portions of the eye,
• recognizing the occurrence of changes of position of features of the at the targeted site, with a position analysis means associated with and receiving signals from the three dimensional mapping means,
• searching for a target site feature and finding the target site feature's new position after such a change of position ,and generating a signal indicative of the new position, with a target tracking means associated with the position analysis means, and
• automatically executing a change in the aim of the three dimensional mapping means to the new position of the feature with a tracking positioning means receiving said signal from the target tracking means, to thereby follow the target site feature and stabilize the images on the display means, and simultaneously and accordingly adjusting automatically the aim and depth of the focus of the laser beam to be directed at the new position of a feature targeted.