The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1988
Filed:
Sep. 27, 1985
Steven E Feldon, San Marino, CA (US);
David A Wallace, Beverly Hills, CA (US);
Gary Mezack, Norco, CA (US);
Robert A Monsour, Pasadena, CA (US);
Design Team Partners, Glendale, CA (US);
Abstract
Disclosed is a battery powered, hand-held self-contained electronic tonometer with a digital readout for displaying pressure in millimeters of mercury. The tonometer includes a transducer which is a solid state pressure sensitive element and which produces a voltage proportional to intraocular pressure. An electrical waveform is produced by gently bringing the transducer in contact with the cornea. The waveform is converted to a digital signal and processed by a single chip microprocessor. The baseline of a reference signal is nulled by equalizing the charges on two capacitors on the inputs of two differential amplifiers. Equalizing the differential inputs of the two amplifier stages results in a gain of zero and removes any carrier signal. Microprocessor software detects the baseline condition established by equalizing the differential inputs. The microprocessor then looks for a series of valid measurements and calculates the average intraocular pressure along with an estimate of reliability. This average value and the reliability indicator are displayed on a liquid crystal display.