nirs.modules.BeerLambertLaw
This module converts optical density data into oxy/deoxy-hemoglobin
parameters:
PPF: Partial Pathlength Factor. This is a combination of both the differential pathlength factor (DPF) and the Partial Volume Correction (PVC).
Default PPF = 0.1 which corresponds to a DPF=6 and PVC = 1/60
Example Usage:
raw = nirs.testing.simData;
job=nirs.modules.OpticalDensity;
job=nirs.modules.BeerLambertLaw(job);
Hb = job.run(raw);
PPF can be a single entry (applied to both/all wavelengths) or a vector for each wavelength (in order that they appear in probe.types
PPF can also be a function. This allows you to use age-corrected pathlength terms
job.PPF=PPF = @(lambda,data)nirs.media.frontal_DPF_model(lambda,data,‘age’);
% Note “age” must be a variable in the demographics of the data
This uses the model from:
Felix Scholkmann, Martin Wolf, “General equation for the differential pathlength factor of the frontal human head depending on wavelength and age,”J. Biomed. Opt. 18(10) 105004 (11 October 2013) https://doi.org/10.1117/1.JBO.18.10.105004
Age=21;
alpha=223.3;
beta=0.05624;
gamma=0.8493;
delta= -5.723E-7;
epsilon= 0.001245;
epsi= -0.9025;
DPF = alpha + beta*Age^gamma + delta*lambda.^3 + epsilon * lambda.^2 + epsi*lambda;