LUMENIS SELECTA - Laser Safety Eyewear Requirements

Selecta
PBL200051, Rev J
10  Safety and Regulatory
Laser Safety Eyewear
Laser safety eyewear is routinely required with most lasers. When using the
laser system, the Laser Safety Officer should determine the need for safety
eyewear based on the Maximum Permissible Exposure (MPE), Nominal
Hazard Zone (NHZ), the Nominal Ocular Hazard Distance (NOHD), and
the optical density (OD) for each of the available laser emissions and the
configuration of the treatment room (usually within the controlled area). For
additional information, refer to ANSI Z136.1-2000, ANSI Z136.3-2005, or
International Standard IEC 60825-1: 2001.
The following formula was used to calculate the worst case NOHD for
Lumenis Selecta lasers and compatible delivery systems:
where,
Z = the distance of the beam waist from the laser system;
a = the beam waist diameter (1/e
2
of axial irradiance for
gaussian beam);
 = minimum full angle beam divergence (1/e
2
of axial
irradiance for gaussian beam);
e  2.7182818285, the base of natural logarithms;
 = maximum energy of one laser pulse or maximum
CW laser power;
Pf = the profile correction factor (1 for uniform profile or
2 for gaussian irradiance profile);
MPE = Maximum Permissible Exposure, in energy density
units (energy per unit area), or power density units
(power per unit area);
NOHD = the Nominal Ocular Hazard Distance (measured
from laser aperture);
= the distance required to reduce the energy density or
power density to the MPE.
NOHD =
1
θ
4
π
Φ
MPE
Pf - a
2
Z +