Preliminary studies on the use of modulation sensing for noninvasive monitoring of drug compliance

摘要

Presently two methods in concert, a marker method and an electronic monitoring method, have been emphasized for an objective monitoring of drug compliance in ambulatory care. While the marker method proves dose ingestion, the electronic monitoring method provides continuous record of timing of presumptive drug doses. The marker method is however time intensive with associated safety problems, and the electronic monitoring method is easily defeated. We here present preliminary results on modulation sensing, a new method that could be used to non-invasively monitor patient compliance. Measurement is based on observing the amplitude modulation of the emission from both a short lifetime marker fluorophore of interest and a long lifetime reference fluorophore contained in the monitoring device. At some intermediate frequencies, the observed modulation of the combined emission is nearly equivalent to the fractional intensity of the marker fluorophore. This method precludes problems associated with measuring fluorescence intensities in highly scattering media. Using this method we measured the presence of rhodamine 800 (Rh800) in intralipid suspensions and chicken tissue. Rh800 is excited at long wavelengths not absorbed by tissues. Micromolar concentrations of this dye were detected in intralipid and chicken muscle covered with a layer of chicken skin.