Patent · US Expired

Automatic applanation tonometer

US4621644A · kind A · utility

25Cited by
2References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 13, 1984
Grant dateNov 11, 1986
Priority date
Expiry dateApr 13, 2004

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA61B3/16
  • WIPO fieldMedical technology
  • WIPO sectorInstruments

Abstract

A portion of the cornea or similar flexible membrane is flattened by urging against the cornea a footplate with a measurable force and the magnitude of the applanated area of the cornea is sensed and compared to a threshold which corresponds to an area equal to a selected reference area of the planar footplate contacting the cornea. When the selected threshold is reached the force urging the footplate against the cornea is processed for scaling by another signal proportional to the reference area. In another embodiment signals proportional to both the applied force and the applanated area are digitized for averaging and/or storage and the two parameter functional dependence of area on the force or a selected region thereof is displayed and recorded for analysis.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.