Abstract: An optical tomography system has a group of lasers for generating light of multiple distinct wavelengths within a first wavelength band. Light from these lasers is directed into mammalian tissue at laser-specific locations on the tissue, and light from the mammalian tissue is collected at a plurality of reception points. Collected light from each reception point is separated according to its wavelength, and received by a photodetector to produce path attenuation signals representing attenuation along paths between the laser-specific locations on the tissue and the reception points. Image construction apparatus generates a tomographic image of heme concentrations in the mammalian tissue from the path attenuation signals. In an alternative embodiment, there is a second group of lasers operating in a second wavelength band, and the image construction apparatus can generate an image of heme oxygenation In the mammalian tissue.

Abstract: A diffuse optical tomography system incorporating a mode-locked, tunable laser produces pulsed light that may be used to interrogate tissue with high spatial and spectral resolution. The detection signal may be heterodyne shifted to lower frequencies to allow easy and accurate measurement of phase and amplitude. Embodiments incorporating wavelength-swept, tunable, lasers and embodiments using broadband photonic fiber lasers with spectrally-sensitive detectors are described.

Abstract: Optical tomography systems that provide light of multiple distinct wavelengths from a plurality of sources are described. The systems direct light into mammalian tissue, and light from the mammalian tissue is collected at a plurality of reception points. Collected light from each reception point is separated according to its wavelength, and received by a photodetector to produce path attenuation signals representing attenuation along paths between the source locations and the reception points. An image construction system generates a tomographic image of the mammalian tissue from the path attenuation signals. One embodiment of an optical imaging system includes an optical coherence tomography-near infrared probe. The systems and methods may utilize a spectral derivative approach that provides insensitivity to the boundary and boundary artifacts in the signal, thereby improving the quality of the reconstructed images.

Abstract: 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.