公开(公告)号：EP0217642A3

公开(公告)日：1988-06-01

申请号：EP86307393

申请日：1986-09-25

申请人： DESIGN TEAM PARTNERS

发明人： Feldon, Steven ,  Mezack, Gary ,  Wallace, David ,  Monsour, Robert

IPC分类号： A61B03/16

CPC分类号： A61B3/16

摘要： 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.