Abstract: A non-invasive medical imaging technique capable of evaluating, in situ, the oxygenation state of body tissues (e.g., by measuring the spectral properties of heme proteins) is described. The technique is based on the measurement of scattered radiation in the near-infrared region (NIR), where significant penetration into body tissues occurs. The disclosed technique employs a multi-wavelength collimated source and a collimated receiver and performs a positional and angular scan of the scattered radiation for each position of the incident beam. The resultant data is evaluated by employing imaging schemes which give differential weights to the contribution of various volume elements (voxels) in the medium to the detector response. A three-dimensional spectroscopic image of the target medium is determined by considering the contribution of the various volume elements for each source-detector configuration and position of the incident beam at various frequencies.

Abstract: A furnace tray for supporting tooth pegs used in the manufacture of false teeth, dental prostheses and the like comprises a refractory tray base member having a carbon plate receiving recess in its upper surface. A carbon plate is positioned in the recess and dental prostheses supported by tooth pegs are placed on the upper surface of the plate. The tray with the carbon plate and the dental prostheses thereon are then placed in a furnace and the teeth are fired. During the firing process the interior of the furnace is simultaneously purged by the carbon.