The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 1999
Filed:
Apr. 21, 1998
R Daniel Ferguson, Melrose, MA (US);
Physical Sciences, Inc., Andover, MA (US);
Abstract
Apparatus and methods for tracking a feature on a target surface and continually providing analog corrections to tracking mirrors in real time by utilizing a low-power incoherent tracking beam to detect the movements of a reference feature on the target and confocal reflectometry to monitor the reflection from the tracking beam's current position are described. The apparatus includes a dithering device for dithering the tracking beam in a first and a second direction with an oscillatory motion, a tracking device for controlling the position of a therapeutic beam relative to a target and for controlling the position of the tracking beam relative to a reference feature, a reflectometer for providing an output signal with a phase corresponding to a phase of the reflected tracking beam, and a signal processor for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion and for controlling the tracking device so that the therapeutic beam to tracks relative to the reference feature.