WEEK 5: NEAR-INFRARED

Detection of Glucose Level Using Non-Invasive Method project involves the use of near-infrared (NIR).

so, I'll explain about NIR today.

The NIR defines the range of wavelengths from 650nm to 2500nm where light has its maximum depth of penetration in tissue. Within the NIR, scattering is the most dominant light-tissue interaction, and therefore the propagating light becomes diffused rapidly. Since scattering increases the distance traveled by photons within tissue, the probability of photon absorption also increases. Because scattering has weak dependence on wavelength, the NIR is primarily limited by the light absorption of blood at short wavelengths and water at long wavelengths.

Molar absorption for the solute of hemoglobin (black) and glucose (red)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675860/