A system for determining a condition of a tissue of a patient body is described. The tissue is illuminated with an illumination wavelength by a light source. In response to the illumination, the tissue emits light. This emitted light is received at a detector that includes multiple diode sensors. The diode sensors detect intensities of associated wavelengths of the emitted light. A spectral analysis is performed with the detected intensities. The spectral analysis includes initial coefficients. A composite function associated with the initial coefficients is minimized so as to determine wavelength coefficients. The wavelength coefficients are used to compute a score. Based on the score, the condition of the tissue is determined. Related methods, techniques, apparatus, and articles are also described.
