Comparative in Vitro and Non-Invasive in Vivo Kromoscopic Measurements

Abstract

Non-invasive optical assay of trace analytes in vivo is a great challenge. Kromoscopic analysis™, invented for this purpose, uses real time correlations between measurements that are both spatially and temporally congruent and made with multiple detection channels having overlapping spectral sensitivities. This method permits the segregation of effects of the cardiac pulse from effects occurring in the background. We report here on results obtained for a subset of detection spectral sensitivities proposed for non-invasive glucose measurements. For this set, two different mathematical forms of pulsatile measurement both indicate that the pattern of relative responses (Kolors) of different fingers used as measurement sites in different subjects is largely unaffected by differences among subjects or among measurement sites on the same subject. Furthermore, for both pulsatile and non-pulsatile measurements, changes in responses between in vitro and in vivo data are shown to be predictably caused by scattering.