Error analysis of finite-spectral-linewidth illumination in optical oximetry systems

Multi-spectral systems consisting of a small number of wavelengths are increasingly using light emitting diodes (LEDs) to reduce the overall costs of the system. However, LEDs typically have broad spectral bandwidths and cannot be modeled as having a single discrete wavelength. This paper puts forth a simple model to analyze the effects of using LEDs to illuminate a single layer of homogenous tissue. Monte Carlo simulations are used to approximate photon propagation through a semi-infinite turbid medium oximetry system using two light emitting diodes with broad spectra for varying oxygen saturations. The results are then compared against diffusion solutions for narrow-band illumination at the same two center wavelengths.