Applanating tonometers
US6413214B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Apr 24, 2000 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Apr 24, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/16
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
There is provided a tonometer including an applanating element having a light-transmitting contact face engageable against the eye of a subject for projecting a light beam onto the eye and passing reflected light therefrom. There are also means responsive to the reflected illumination and means responsive to the force of engagement of the applanating element on the eye for obtaining data of changing values of reflected illumination and force as the element is applied to the eye. The contact face has an area larger than a predetermined area of engagement at which the applanting force is to be determined. The instant of applanation of the predetermined area is obtained by interpolation. The cornea is applanated over the contact face area, dependent upon the ratio of the predetermined and larger areas of applanation, in order to determine the force measured at the instant of applanation of the predetermined area. Preferably, means are provided for processing progressive measurements of the force and reflected illumination to derive a measure of acceleration of the applanating element at the moment of applanation, and preferably automatically correcting the applanating force measuremen…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.