Diffuse reflectance spectroscopy

Diffuse reflectance spectroscopy (DRS) employs the diffusion approximation to transport theory to extract physical tissue parameters. White light reflectance is collected from the tissue via a small diameter fiber optic probe (see fastEEM page). A diffusion model (Zonios et al. Appl. Opt. 1999) is fit to the reflectance to extract three quantitative tissue parameters:

1) Hemoglobin concentration, [Hb] (mg/ml)
2) Oxygen saturation (%)
3) Reduced scattering coefficient, (1/mm)

Figure 1 shows white light reflectance spectra (black dots) from a tissue simulating phantom with varying amounts of physiologically relevant concentrations of hemoglobin. The model (red lines) is in good agreement with the data. Figure 2 shows that the estimated hemoglobin concentration extracted from the model is in good agreement with the actual Hb concentration.

Recent Publications

1. G. Zonios, L.T. Perelman, V. Backman, R. Manoharan, M. Fitzmaurice, J. Van Dam, and M. S. Feld, "Diffuse reflectance spectroscopy of human adenomatous colon polyps in vivo," Appl. Opt. 38, 6628-6637 (1999).