Method for quantitative measurement of fluorescent and phosphorescent drugs within tissue utilizing a fiber optic probe

摘要

A fiber optic based probe has been designed to sample the fluorescence or phosphorescence signal from animal or human tissues, such that the light intensity is not multiply scattered. This type of measurement allows a linear detection of the concentration of the luminescent compound non-invasively from the tissue. The basic principle of the fiber probe is to use fiber optics which are smaller in diameter that the average scattering length of the tissue. In order to increase the detected signal to a stronger level, multiple fibers are used by spacing them out on the surface of the tissue so that each fiber samples an isolated section of tissue. Each fiber delivers the excitation light to the tissue, and receives the emission light from the tissue. All fibers are coupled into the same detector to integrate the overall signal. Sampling of the scattered excitation signal intensity is also done to correct for changes in the scattering coefficient between tissues. This fiber bundle can be used to quantify the concentration of fluorescence or phosphorescent chemicals in vivo non-invasively. One application of this device is as a dosimetry tool, to monitor photosensitizer drug concentration within tissue for photodynamic therapy.