We have developed a high-bandwidth frequency-domain photon migration (FDPM) instrument which capable of noninvasively determining the optical properties of biological tissues in near-real-time. This portable, inexpensive, diode-based instrument is unique in the sense that we employ direct diode laser modulation avalanche photodiode detection. Diffusion models were used to extract the optical properties (absorption and transport scattering coefficients) of tissue-simulating solution from the 300 kHz to 1 GHz photon density wave data.

Hysterectomy is the most common major operation performed in the USA with dysfunctional uterine bleeding as one of the major indications. The clinical needs for simple and safe endometrial destruction are essential. Photodynamic therapy (PDT) may offer a simple and cost effective solution for the treatment of dysfunctional uterine bleeding. The dosimetry is discussed for the case of topical application of photosensitizer. This technique might be the method of preference because undesired side effects such as skin photosensitization that is typical for systemically injected photosensitizers, can be avoided. Effective PDT requires a sufficient amount of light delivered to the targeted tissue in a reasonable period of time. A trifurcated optical applicator consisting of three cylindrical diffusing fibers has been constructed, and this applicator can deliver a typical required optical dose of about 50-100 J/cm 2 to the full depth of the endometrium for an exposure time of 10-20 minutes.