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US4159867A
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Device and method for measuring the curvature of the cornea
Assignee: Battelle-Institut
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Filing: 1977-09-09
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Granted: 1979-07-03
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Expires: 1997-09-09
Abstract
Abstract A device and method are disclosed for measuring the curvature of the cornea of the human eye. The device utilizes a continuous, curved surface plate positioned in front of the eye and having a telescope extending through the surface plate such that its optical axis is aligned with the eye. Several object points are generated on the surface plate within the field of vision of the eye and are formed also on the image plane of the eye. Detection devices, located within the telescope measure the positions of such image points in relation to the optical axis. The radius of curvature of the cornea can be determined from this measurement.
Inventors
- 👤 Manfred Achatz
- 👤 Rasmus Beck
- 👤 Werner Bockelmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:33
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/107
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
124 words
A device for measuring the curvature of a cornea comprising: (a) a continuous surface plate positioned in front of the cornea to be measured; (b) a telescope extending through said continuous surface plate having its optical axis located at the center of said surface; (c) means to generate a plurality of object points on said surface plate, the object points forming image points on the image plane of the cornea; (d) reflecting means in said telescope for reflecting incident light from the image plane of the cornea; (e) detecting and measuring means for detecting the light reflected by said reflecting means and for measuring the position of the image points with respect to the optical axis to thereby determine the curvature of the cornea.
Claim 2
Independent Claim
124 words
A device for measuring the curvature of a cornea comprising: (a) a continuous surface plate positioned in front of the cornea to be measured; (b) a telescope extending through said continuous surface plate having its optical axis located at the center of said surface; (c) means to generate a plurality of object points on said surface plate, the object points forming image points on the image plane of the cornea; (d) reflecting means in said telescope for reflecting incident light from the image plane of the cornea; (e) detecting and measuring means for detecting the light reflected by said reflecting means and for measuring the position of the image points with respect to the optical axis to thereby determine the curvature of the cornea.
Claim 3
Dependent Claim
12 words
The device according to claim 1 wherein the surface plate is curved.
Claim 4
Dependent Claim
15 words
The device according to claim 2 wherein the curved surface plate has a cardiod curvature.
Claim 5
Dependent Claim
18 words
The device according to claim 1 wherein the reflecting means is a mirror pivotally attached to the telescope.
Claim 6
Dependent Claim
16 words
The device according to claim 1 wherein the reflecting means is a partially light transmitting mirror.
Claim 7
Dependent Claim
74 words
The device according to claim 1 wherein the detecting and measuring means comprises: (a) a detector in said telescope positioned so as to receive incident light reflected by said reflecting means and to generate an output signal in response to the position of said light; and (b) a computer connected to said detector so as to receive said output signals therefrom and to calculate the curvature of said cornea in response to said signals.
Claim 8
Dependent Claim
22 words
The device according to claim 6 further comprising a temporary storage device interposed between and connected to said detector and said computer.
Claim 9
Dependent Claim
15 words
The device according to claim 6 wherein said detector is a position - sensitive detector.
Claim 10
Dependent Claim
29 words
The device according to claim 1 wherein the surface plate is sized so as to project object points to the eye at an angle of betweeen 3° and 45°.
Claim 11
Dependent Claim
35 words
The device according to claim 1 wherein the means to generate the object points comprises a laser light source and means to deflect the light generated by said laser light source onto said surface plate.
Claim 12
Independent Claim
86 words
A method of measuring the curvature of a cornea comprising the steps of: (a) generating a plurality of object points on a continuous surface plate positioned in front of the eye; (b) measuring the location of the reflections of said object points on the image plane of the cornea in relation to the optical axis of a telescope located in the center of said surface plate; and (c) determining the curvature of the cornea from the measured distance between the object points and the optical axis.
Claim 13
Independent Claim
86 words
A method of measuring the curvature of a cornea comprising the steps of: (a) generating a plurality of object points on a continuous surface plate positioned in front of the eye; (b) measuring the location of the reflections of said object points on the image plane of the cornea in relation to the optical axis of a telescope located in the center of said surface plate; and (c) determining the curvature of the cornea from the measured distance between the object points and the optical axis.
Claim 14
Dependent Claim
51 words
The method according to claim 11 comprising the additional steps of: (a) generating a plurality of light streaks on said continuous surface plate; and, (b) positioning said telescope by adjusting it such that the light streaks form two straight lines which cross each other on the image plane of the cornea.
Claim 15
Dependent Claim
22 words
The method according to claim 11 wherein the plurality of object points are produced in the form of a multi-beam Archimedean spiral.
References Cited (Backward Citations)
US3542458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |