Non-contact instrument for measurement of internal optical pressure
AssigneeThe Ohio State University
InventorEric K. Walton
Life of this patent
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Abstract
A method and apparatus for measuring the intraocular pressure of a cornea includes an interferometer directing a beam of a coherent light along a path to the cornea, a sensor for sensing the reflected light from the cornea, an air supply device for directing puffs of air to the cornea in alignment with the beam to cause the surface of the cornea to be artificially displaced and means for measuring variations of light intensity reaching the sensor.
Claims12
A method for measuring the intraocular pressure of a cornea of an eye, the cornea having an outwardly facing surface comprising the steps of:
- (a) directing at least one coherent light beam along a path to the cornea surface;
- (b) directing puffs of air or other gaseous fluid to the cornea surface at puff rates of between 5 hertz to 100 hertz to cause the cornea surface to be displaced;
- (c) reflecting the beam from the cornea surface to a sensor;
- (d) measuring variations of light intensity reaching the sensor and ascertaining therefrom the induced deflection of the cornea;
- (e) separating signals based upon the displacement of the cornea from the puffs of air set forth in step (b) from signals based upon displacement of the cornea from random human motion;
- and
- (f) calculating therefrom the intraocular pressure.
Apparatus for measuring intraocular pressure of a cornea of an eye, comprising in combination
- (a) an interferometer directing a beam of coherent light along a path to the cornea;
- (b) a sensor for sensing reflections of the beam from the cornea;
- (c) an air supply device for directing puffs of air or other gaseous fluid to the cornea at puff rates of between 5 hertz to 100 hertz to cause the surface of the cornea to be displaced;
- and
- (d) means for measuring variations of light intensity reaching the sensor and ascertaining therefrom the speed of movement of the cornea.
Dependencies are inferred from the claim text.