Multispectral measurement for improved biological signal acquisition

A functional near infrared (fNIR) system comprising:

• first, second, third, and fourth photo emitters;
• at least one photo detector;
• and
• at least one non-transitory storage medium having executable instructions stored thereon that, when executed, cause a processor of the system to:
• (a) emit first photo energy at first, second, third, and fourth wavelengths from the first, second, third, and fourth photo emitters during a first time period, (b) emit second photo energy at the first, second, third, and fourth wavelengths from the first, second, third, and fourth photo emitters during a second time period, (c) determine first, second, third, and fourth optical density changes based on emitting the first and second photo energies;
• (d) determine a first change in a first chromophore concentration and a second change in a second chromophore concentration based on the determined first, second, third, and fourth optical density changes;
• (e) determine first, second, third, and fourth absorption values based on determining the first and second changes in the first and second chromophores;
• (f) fit the first, second, third, and fourth absorption values to first and second absorption spectra datasets corresponding to the first and second chromophores;
• and (g) determine at least one confidence level based on fitting the first, second, third, and fourth absorption values to first and second absorption spectra datasets.