Abstract: Systems and methods of utilizing a frequency modulation technique to determine an unknown distance between at least one source and at least one detector in an light scattering medium without knowing the optical properties of the medium are described. Modulated light is emitted from a light source to an optical scattering and absorbing medium and at least a portion of the modulated light is detected with a detector. A calibration factor is determined and then an unknown distance between at least one source and at least one detector can be determined, thereby providing a distance measurement.

Abstract: Levels of psoralen concentration in a biological detection target are determined so that an appropriate UVA light dose of PUVA therapy can be delivered to a biological treatment target. The appropriate therapy is determined by the product of the UVA light dose and psoralen concentration level. After determination of a baseline optical autofluoresence signal from the detection target, a first dosage of psoralen (preferably 8-methoxypsoralen ?8-MOP!) is administered. Thereafter, the detection target is irradiated under the same conditions as the pre-psoralen irradiation. Then, the optical return from the psoralen-treated detection target is analyzed. A computer (86) compares the pre-psoralen optical return and psoralen-treated optical return to calculate a real time determination of the concentration level of psoralen in the treatment target.

Abstract: An illuminator including a differential optical radiator and a laser fiber disposed within the differential optical radiator. The differential optical radiator includes a first region that has a first level of reflectivity and a first level of transmissivity and a second region that has a second, higher level of reflectivity and a second, lower level of transmissivity. The first and second regions are positioned such and their reflectivities and transmissivities are chosen such that the radiator produces a substantially uniform pattern of illumination from the first and second regions. In another embodiment, the illuminator includes an expandable radiator and a laser fiber disposed within the expandable radiator. The reflectivity of the expandable radiator is such that the illumination at the outer surface of the expandable radiator is substantially uniform.

Abstract: An illuminator including a differential optical radiator and a laser fiber disposed within the differential optical radiator. The differential optical radiator includes a first region that has a first level of reflectivity and a first level of transmissivity and a second region that has a second, higher level of reflectivity and a second, lower level of transmissivity. The first and second regions are positioned such and their reflectivities and transmissivities are chosen such that the radiator produces a substantially uniform pattern of illumination from the first and second regions.In another embodiment, the illuminator includes an expandable radiator and a laser fiber disposed within the expandable radiator. The reflectivity of the expandable radiator is such that the illumination at the outer surface of the expandable radiator is substantially uniform.

Abstract: Levels of psoralen concentration in a biological detection target are determined so that an appropriate UVA light dose of PUVA therapy can be delivered to a biological treatment target. The appropriate therapy is determined by the product of the UVA light dose and psoralen concentration level. After determination of a baseline optical autofluoresence signal from the detection target, a first dosage of psoralen (preferably 8-methoxypsoralen [8-MOP]) is administered. Thereafter, the detection target is irradiated under the same conditions as the pre-psoralen irradiation. Then, the optical return from the psoralen-treated detection target is analyzed. A computer (86) compares the pre-psoralen optical return and psoralen-treated optical return to calculate a real time determination of the concentration level of psoralen in the treatment target.