A computer model was used to predict thresholds for 532 mm scanned retinal exposure for different retinal beam profile geometries, including rectangles and ring shaped profiles. The image analysis method described in IEC 60825-1 Edition 1.2 - maximizing the ratio of power within a rectangle over the value of a for this rectangle - was applied to the different profiles to determine a and the fractional power that would be compared to the MPE value. The predicted thresholds for these special types of retinal exposure were compared with the predicted damage theshold for top hat profiles for the value of a that resulted from the image analysis method. The comparison shows that the most restrictive power/a ratio method produces appropriate results, provided that a time dependent amax is used, as was proposed at BIOS 2006.
|Fachzeitschrift||Ophthalmic Technologies XVIII, Proc. of SPIE|
|Publikationsstatus||Veröffentlicht - 2008|
- Biosensor Technologies
- laser safety; ICNIRP; computer model; retinal thermal injury; threshold; MPE; IEC60825-1; ANSI Z136.1