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US 6,296,358 B1Granted
Ocular fundus auto imager
AssigneeVisual Pathways, Inc.
InventorsTom N. Cornsweet, Gary F. Buck
Life of this patent
Estimating the term…
Abstract
An ocular fundus imager automatically aligns fundus illuminating rays to enter the pupil and to prevent corneal reflections from obscuring the fundus image produced. Focusing the produced fundus image is automatically performed and is based upon the fundus image itself. A head restraint for the patient undergoing examination is in the form of a pair of spectacles which is not only easy to use accurately but significantly reduces the gross alignment between the optical system and the patient's pupil.
Claims41
Apparatus for imaging the ocular fundus, said apparatus comprising in combination:
- a) a source of illumination for illuminating at least a section of the ocular fundus of a patient;
- b) means for directing the illumination along an optical axis to enter the pupil of the patient;
- c) a video sensor responsive to an image reflected from the eye of the patient for depicting the alignment of the optical axis with the pupil of the patient;
- d) positioning means for aligning the optical axis in response to the depicted alignment;
- e) a focusing assembly for focusing the image of the ocular fundus as a function of the image itself;
- and
- f) a further video sensor for recording the focused image.
4 more elements
Apparatus for imaging the ocular fundus, said apparatus comprising in combination:
- a) a source of illumination for illuminating at least a section of the ocular fundus of a patient;
- b) means for directing the illumination along an optical axis to enter the pupil of the patient;
- c) a video sensor responsive to an image reflected from the eye of the patient for depicting the alignment of the optical axis with the pupil of the patient;
- d) positioning means for aligning the optical axis in response to the depicted alignment;
- e) a focusing assembly for focusing the image of the ocular fundus as a function of the image itself;
- f) a further video sensor for recording the focused image;
- and
- g) a head restraint for locating the patient's eye relative to said apparatus, said head restraint comprising at least a part of the frame of a pair of spectacles.
5 more elements
Apparatus for imaging the ocular fundus, said apparatus comprising in combination:
- a) a source of illumination for illuminating at least a section of the ocular fundus of a patient;
- b) means for directing the illumination along an optical axis to enter the pupil of the patient, said directing means including a fiber optic bundle for receiving illumination at one end from a source and transmitting the received illumination from the other end of said fiber optic bundle along the optical axis;
- c) a video sensor responsive to an image reflected from the eye of the patient for depicting the alignment of the optical axis with the pupil of the patient;
- d) positioning means for aligning the optical axis in response to the depicted alignment;
- e) a focusing assembly for focusing the image of the ocular fundus as a function of the image itself;
- and
- f) a further video sensor for recording the focused image.
4 more elements
Apparatus for imaging the ocular fundus, said apparatus comprising in combination:
- a) a source of illumination for illuminating at least a section of the ocular fundus of a patient;
- b) means for directing the illumination along an optical axis to enter the pupil of the patient;
- c) a video sensor responsive to an image reflected from the eye of the patient for depicting the alignment of the optical axis with the pupil of the patient;
- d) a beam splitter and a lens for directing the reflected image of the ocular fundus toward said video sensor and for creating a reflected image, respectively;
- e) positioning means for aligning the optical axis in response to the depicted alignment;
- f) a focusing assembly for focusing the image of the ocular fundus as a function of the image itself;
- g) a further beam splitter for reflecting the image to said focusing assembly;
- h) a further video sensor for recording the focused image;
- and
- i) the aerial focal plane of said lens being between said further beam splitter and said focusing assembly and wherein said focusing assembly includes:
- i) a lens located at its focal distance from the aerial focal plane, ii) an aperture located at the back focal plane of said lens, iii) a further lens for providing a further image, and iv) said further video sensor being located at the back focal plane of said further lens for receiving the image of the ocular fundus section under examination.
8 more elements
A method for imaging the ocular fundus, said method comprising the steps of:
- a) illuminating at least a section of the ocular fundus of a patient with a source of illumination;
- b) directing the illumination along an optical axis to enter the pupil of the patient;
- c) depicting the alignment of the optical axis with the pupil of the patient on a video sensor responsive to an image of the eye of the patient;
- d) aligning the optical axis in response to the depicted alignment;
- e) focusing the image reflected from the ocular fundus as a function of the image itself;
- and
- f) displaying the focused image.
4 more elements
A method for imaging the ocular fundus, said method comprising the steps of:
- a) restraining movement of a patient's head;
- b) initially positioning the patient's eye by exercising a step of locating the patient's head in at least a part of the frame of a pair of spectacles;
- c) illuminating at least a section of the ocular fundus of the patient with a source of illumination;
- d) directing the illumination along an optical axis to enter the pupil of the patient;
- e) depicting the alignment of the optical axis with the pupil of the patient on a video sensor responsive to an image of the eye of the patient;
- f) aligning the optical axis in response to the depicted alignment;
- g) focusing the image reflected from the ocular fundus as a function of the image itself;
- and
- h) displaying the focused image.
6 more elements
Apparatus for imaging the ocular fundus, said apparatus comprising in combination:
- a) a source of illumination for illuminating at least a section of the ocular fundus of a patient;
- b) a first lens for directing the illumination through a first aperture;
- c) a filter for controlling the bandwidth of the illumination emanating from said first aperture;
- d) a mirror for finely aligning the optical axis of the illumination, said mirror including means for repositioning said mirror in two axes;
- e) a first lens for collecting the illumination reflected from said mirror;
- f) a second lens for receiving the receiving the collected illumination and forming an image of said aperture in the pupil of the patient to illuminate a section of the ocular fundus of interest;
- g) a first beam splitter for receiving the image of the section of the ocular fundus of interest and reflecting the image to a second collecting lens;
- h) a third lens for focusing the image received from said first beam splitter upon a first video sensor;
- i) a second beam splitter for reflecting a part of the collected light to a fourth lens;
- j) a second aperture for passing the image from said forth lens to a third lens;
- k) a second video sensor for receiving the collimated image from said third lens;
- and
- l) means for relocating said apparatus in three axis to grossly align the optical axis of the ocular fundus illumination with the pupil of the patient.
10 more elements
Dependencies are inferred from the claim text.