Method for eliminating error in tonometric measurements
US6817981B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Oct 26, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/165
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A novel tonometry method wherein measured intraocular pressure corresponding to inward applanation of the cornea and corneal hysteresis derived from a pressure differential associated with inward and outward applanation events in the same measurement pulse allows comparison with a predetermined population normality function to avoid corneal effects so that the actual status of intraocular pressure can be ascertained. A dual mode non-contact tonometer allows selection between a standard measurement mode for patient comfort and an alternate measurement mode wherein pressure-time characteristics of the fluid pulse are varied to allow additional observation of corneal hysteresis associated with the dynamic measurement process for carrying out the novel tonometry method. Corresponding tonometry method embodiments include a method adapted for a contact tonometer and a method based on a pair of non-contact tonometer measurements taken using different air pulse pressure ramp rates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.