Process and apparatus for ophthalmic surgery
OwnerDaniele S. Aron nee Rosa, Michele-Gabrielle R. Griesemann nee Laporteinventors
Life of this patent
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Abstract
Process and apparatus for ophthalmological surgery, wherein the apparatus includes a laser having a beam of power greater than 10.sup.12 Watts/cm.sup.2 in one or more very short pulses of duration between 20 and 400 picoseconds. The laser beam is focussed by a strong conveying lens on tissue to be cut and has such low total energy that an optical puncture is produced without any notable thermal action. The apparatus employs a Q-switched YAG laser, with a helium-neon laser producing a registering or alignment beam. The laser beams are applied to a conventional slit lamp to enable them to be aligned at the target tissue, an electronic pulse selector may be included to select the exact number of pulses to be applied to the target.
Claims12
A process for cutting biological tissue including transparent tissue in ophthalmic surgery, comprising bombarding tissue to be cut with a focussed pulsed laser beam, wherein the power density of the laser beam is greater than 10.sup.12 Watts/cm.sup.2, and the duration of each pulse being between 20 and 400 picoseconds, the pulses being in the form of a train of from 5 to 9 spikes having a total energy of from 2 to 5 millijoules, the beam being passed through an optical focussing system having a strong converging effect.
Apparatus for producing a directed and focussed laser beam suitable for cutting biological tissue including transparent tissue in optical surgery, comprising a laser oscillator producing a pulsed beam, the power density of which is greater than 10.sup.12 Watts/cm.sup.2 and an optical focussing system having a strong converging effect aligned in the path of the beam of the laser oscillator between the oscillator and the tissue to be cut, and the laser oscillator including a rod of yttrium aluminum garnet (YAG) doped with neodymium emitting short trains of light pulses at a wavelength of 10645 A.
Apparatus according to any of claims 4 or 7 further including optical means downstream of the laser oscillator for enlarging the diameter of the laser beam to reduce the intensity of the beam.
Dependencies are inferred from the claim text.