Alignment system for an ophthalmic instrument
US6669340B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 2001 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Feb 6, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/1208
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An alignment system for an ophthalmic instrument comprises an optical axis along which an operator can directly view the patient's eye and the patient can fixate on a dark fixation target surrounded by a bright background that helps to illuminate the eye for operator viewing. A position detection system utilizing stored geometrical relationships determined by multiple regression during instrument calibration computes X-Y-Z alignment status of the instrument relative to a patient's eye based on local x-y position information from a pair of lateral detectors receiving corneally reflected light from a corresponding pair of lateral light sources. A heads-up display image is provided along an optical axis of the instrument for supplying instructive cues to an operator for moving the instrument to achieve alignment based on signal information from the position detection system, whereby the operator sees both a direct macro-image of the patient's eye and the display image. The alignment system is particularly suitable for use in hand-held ophthalmic instruments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.