Method and apparatus for tear film measurement
US7771353B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 11, 2006 |
| Grant date | Aug 10, 2010 |
| Priority date | — |
| Expiry date | Mar 4, 2028 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/101
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Tear film is measured without contacting the eye by comparing reflectance from the eye when the tear film is undisturbed with reflectance from the eye when the when the tear film is disturbed. If the reflectance levels differ somewhat, it is an indication that a healthy tear film exhibiting good specular reflection was present initially and was disturbed by the air pulse. However, if the reflectance levels are close to one another, it is an indication that a less-than-normal tear film was present initially (dry eye). In a described embodiment, tear film is disturbed by an air pulse directed at the eye, and a photosensitive detector is positioned to receive light from an illumination beam after the beam is reflected by the eye to generate a reflectance signal. The reflectance signal is evaluated to calculate a tear film index.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.