Scanning ophthalmoscope for examining the fundus of the eye
AssigneeRetina Foundation
InventorsOleg Pomerantzeff, Robert H. Webb
Life of this patent
Estimating the term…
Abstract
A scanning ophthalmoscope for repeatedly scanning a selected portion of an eye fundus has a laser source which produces a directed narrow-beam output and means for scanning the fundus with at least one selected scanning sequence. The scanning beam passes through a pivot point located in a preselected plane, preferably within the eye, for providing a wide field of view. An optical system directs light reflected from the fundus to a detector, which produces an electrical output signal proportional to the detected light. An output element provides a visual representation of the magnitude of the output signal in a spatial distribution corresponding to the scanning sequence.
Claims14
A scanning ophthalmoscope for providing a visual representation of an eye fundus under scanned illumination, said ophthalmoscope having the improvement comprising
- A. scanning laser source means for projecting a fundus-illuminating laser beam which scans according to a selected scanning sequence,
- B. optical means
- for directing said scanning laser beam through a pivot point in a plane having a location selected relative to the laser beam for receiving the pupil of the eye being examined for introducing the scanning laser beam into an eye so located through a small portion only of the eye pupil, and
- for directing said scanning beam to travel from said pivot point onto a wide-angle region of the fundus of the eye located with the eye pupil at said selected plane,
- C. optical detecting means for receiving light reflected from the eye fundus in response to illumination with said scanning beam, said detecting means being arranged for receiving light which traverses from within the eye through at least a major portion of the eye pupil, and for producing an electrical signal in response to the received light and with correspondence to said scanning sequence, and
- D. output means for providing a fundus-imaging output representation in response to said electrical signal.
A scanning ophthalmoscope for providing a visual representation of the eye fundus under scanned illumination comprising
- a laser source having a directed, narrow beam, light output,
- first and second galvanometer drive members for rotating first and second light reflecting mirrors respectively,
- said first and second drive members being responsive to drive signals from a first synchronizing means for synchronizing the rotation of said mirrors with each other, according to a selected scanning sequence,
- said mirrors repeatedly varying the direction of said light output according to said selected scanning sequence for providing a scanning, narrow beam, laser light source,
- a turning mirror for directing the scanning narrow beam light source in a direction toward a preselected plane,
- means for optically providing said scanning light source with a pivot point in said plane through which the scanning, narrow beam, light source passes,
- detecting means for receiving light reflected from the eye fundus and for providing an electrical signal output related to the magnitude of light reflected from the received light,
- said scanning laser source and said reflected light being substantially coaxial between the selected plane and the turning mirror, and the scanning light source traversing a substantially smaller cross-sectional area than the reflected light source in a plane normal to said lights and positioned at said turning mirror, and
- output means connected to said detecting means for providing a visual output representation of the magnitude of the electrical signal in a spatial distribution corresponding to said scanning sequence,
- whereby an eye may be placed in optical alignment with the preselected plane and with the scanning light source for providing a visual representation of at least a portion of the fundus of the eye.
A scanning opthalmoscope for providing a visual representation of an eye fundus under scanned illumination, said ophthalmoscope having the improvement comprising
- A. a laser source producing a directed narrow light beam.
- B. means for generating primary timing signals,
- C. means for repeatedly varying the direction of said light beam according to at least one selected scanning sequence, said direction-varying means including
- first and second mirrors mounted for rotation, and
- first means responsive to said primary timing signals for synchronizing the extent and rate of rotation of said mirrors for varying the direction of said laser light beam according to said selected scanning sequence, including first and second galvanometer drive member for rotating said first and second mirrors respectively,
- D. means in optical alignment with said laser source and with said direction-varying means for directing said scanning beam through an optical pivot point lying in a plane having a selected location,
- E. detecting means for receiving light reflected from an eye fundus in response to illumination by said scanning beam and for producing an electrical signal proportional to the magnitude of the received reflected light, and
- F. output means connected with said detecting means for providing a visually perceptible output representation of the magnitude of said electrical signal in a spatial distribution corresponding to said scanning sequence,
- said output means including second means responsive to said primary timing signals for synchronizing the rotation of said mirrors with the detecting means output signal for providing said visual output representation,
- whereby said visual representation is of the fundus of an eye which is in optical alignment with said scanning laser beam and is selectively located relative to said plane.
Dependencies are inferred from the claim text.