A portable system and method for analyzing biological tissue samples and detecting analytes associated with tissue oxygenation using a conformal filter. A conformal filter, which may comprise a tunable filter, is configured to filter interacted photons conforming to a spectral shape correlated with an analyte of interest. Conformal filter configurations may be selected by consulting a modified look-up table associated with an analyte. An iterative methodology may be used to calibrate a conformal design for an analyte of interest, refine a previous conformal filter design for an analyte of interest, and/or generate a new conformal filter design for an analyte of interest.