function [val_UWattsPerCm2,limit_UWattsPerCm2] = ISO2007MPEComputeType1ContinuousAntConvrgUnweightedValue(S,irradiance_UWattsPerCm2,stimulusDurationSecs) % [val_UWattsPerCm2,limit_UWattsPerCm2] = ISO2007MPEComputeType1ContinuousAntConvrgUnweightedValue(S,irradiance_uWattsPerCm2,stimulusDurationSecs) % % Compute the unweighted radiation for anterior segment convergent beam value, for Type 1 instruments as given on page 8, Table 2, % 5.4.1.5. This limit applies only to convergent beams, whatever they are. I'm guessing this is what a Maxwellian view produces, % however, as in that case the beam is brought to a waist inside the eye. In this case, the limit applies to the irradiance % at the beam waist over the 1 mm diameter aperture with the highest irradiance. % % Unlike all the other routines in this suite, the key quantity is probably not best passed as stimulus radiance. Rather, for % this type of optical system, the relevant irradiance should be measured directly. % % NOTE: This routine has not been tested, since I (DHB) don't have any instrument currently that produces the relevant type of % stimulus. I added it as a placeholder for convenience. There is an error statement to keep it from being used % until it is tested. % % Input spectrum is radiance in units of UWatts/[m2-wlinterval]. % % Also return the exposure limit for this quantity. % % See page 6 for a definition of a Type 1 instrument. As far as I can tell, the key % criterion is that it doesn't put out more light that exceeds the Type 1 limits. % % If the exposure time is longer than 2 hours the specified limits should be reduced by % 1/exposureDuration in hours. This routine implements that adjustment for its returned % limit value. It does not implement a further reduction of of the limit (by a factor of 2) % for microscopes and endoilluminators. % % **************************************************************************** % IMPORTANT: Before using the ISO2007MPE routines, please see the notes on usage % and responsibility in PsychISO2007MPE/Contents.m (type "help PsychISO2007MPE" % at the Matlab prompt. % **************************************************************************** % % 6/28/13 dhb Wrote it. %% Error statement to indicate draft status of this routine. fprintf('\tISO2007MPEComputeType1ContinuousAntConvrgUnweightedValue\n'); fprintf('\t\tThis routine has been drafted but not tested. It might\n'); fprintf('\t\tbe correct. Or it might not. Develop a reasonable\n'); fprintf('\t\ttest before using.\n'); error('Not yet ready for use'); %% Specify the limit (from table) % % Limit in table is in Watts, we convert to uWatts % for consistency with the weighted routine. exposureDurationHours = stimulusDurationSecs/3600; if (exposureDurationHours <= 2) limit_UWattsPerCm2 = 4*(10^6); else limit_UWattsPerCm2 = 4*(10^6)/(exposureDurationHours/2); end %% Get sum betwen 380 and 1200. wls = SToWls(S); index = find(wls >= 380 & wls <= 1200); if (isempty(index)) error('Should not call this routine with no spectral sampling between 380 and 1200'); end val_UWattsPerCm2 = sum(irradiance_UWattsPerCm2(index));