Ophthalmic testing unit and ophthalmic testing equipment
US7393104B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2005 |
| Grant date | Jul 1, 2008 |
| Priority date | — |
| Expiry date | Apr 1, 2026 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/028
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
When a Landolt ring optotype is presented in a visual acuity testing unit, an examinee answers a position of a slit of the optotype through an operation of a joystick lever or the like. If an examinee gives a right answer within a standard time at a first presentation of optotype, examination at a higher visual acuity grade is executed by presenting a smaller Landolt ring optotype. In case of a right answer over the standard time, reexamination at the same visual acuity grade is executed twice at the most. If a right answer is given at least once, examination at a higher visual acuity grade is executed. In case of a wrong answer within the standard time at a first presentation of optotype, reexamination at the same visual acuity is executed only once. If the right answer is given at this reexamination, examination at a higher visual acuity grade is executed. Reexamination is thus executed, so that the result of the examination is correct. In addition, the examination time can be shortened since necessary number of times of reexaminations is minimum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.