Laser fluence compensation of a curved surface
US6572606B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 2001 |
| Grant date | Jun 3, 2003 |
| Priority date | — |
| Expiry date | Jul 26, 2021 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2009/00882
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A laser system and techniques which compensate for laser fluence drop off or losses of irradiation as an ablating laser beam is traversed on a curved surface (e.g., on corneal tissue). The disclosed ablating laser system and techniques compensate for fluence differentials from pulse-to-pulse by adjusting an appropriate parameter of a laser beam. In the preferred embodiment, the number of pulses imparted in the periphery, the size or shape of the ablating laser beam is adjusted with, e.g., a variable aperture placed in the beam delivery path, by changing a magnification of relay optics in the beam delivery path, or by increasing a number of ablation spots in peripheral portions of an ablation zone as compared with the number of ablation spots in a central portion of the ablation zone. The fluence is compensated for using empirically measured or theoretical fluence correction factors given the angle of the laser beam, size and shape of the ablation spot, etc. In addition to magnification adjustment, the present invention also employs the technique of changing the size of the aperture that is imaged o the eye to provide uniform energy density (i.e., fluence) throughout the entire area…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.