Hand-held apparatus for determining the eccentricity of a cornea
Abstract
Abstract THERE IS PERESENTED A UNITARY HAND-HELD APPARATUS FOR DETERMINING THE SHAPE OF THE ANTERIOR SURFACE OF THE HUMAN CORNEA IN TERMS OF THE ECCENTRICITY OF CONICOIDS OF REVOLUTION WHICH APPROXIMATE THE SHAPE F THE CORNEA, IN WICH AN ILLUMINATED CIRCULAR TARGET IS PRESENTED TO A NONAPICAL PORTION OF SAID CORNEA, ROTATED A GIVEN ANGLE, AND THE REFLECTED IMAGE OF SAID TARGET IS OBSERVED TROUGH A TELESCOPE WHOSE OPTICAL AXIS FORMS A GIVE ANGLE WITH THE OPTICAL AXIS OF SAID CORNEA, THE CENTER OF SAID CIRCULAR TARGET LYING ON THE OPTICAL AXIS OF SAID TELESCOPE. AND SAID CIRCULAR TARGET BEING ROTATABLE ABOUT A DIAMETER THEREOF WHICH IS PERPENDICULAR TO THE OPTICAL AXIS OF SAID TELESCOPE, SAID TARGET BEING ROTATED ABOUT SAID DIAMETER UNTIL SAID IMAGE APPEARS SUBSTANTIALLY AS A CIRCLE, AND USING THAT ANGLE OF ROTATION OF SAID TARGET TO DETERMINE THE ECCENTRICITRY OF THE CORNEA.
Inventors
- 👤 David Volk
Bibliographic Details
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |