Abstract: A system for measuring oxygen consumption uses a chamber holding culture medium with a biological material. A resistively gas-permeable membrane has a first side contacting culture medium in the chamber and a first sensor for measuring oxygen in the culture medium. A second sensor measures oxygen in gas adjacent a second side of the membrane. The sensors provide data to a processor having a memory with machine readable instructions for determining oxygen consumption from the data. Alternatively, a method of measuring oxygen flux begins with placing biological material, with fluid, in the chamber; exposing the fluid to a resistively-permeable membrane with oxygen-containing gas on a second side of the membrane; measuring oxygen in the fluid; measuring oxygen in the gas, and calculating the oxygen flux of the biological material from an oxygen permeability constant of the membrane and a difference between the oxygen concentrations of the fluid and gas.

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: 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.