Abstract: An apparatus and method for determining the level of cross-talk between scintillating fibers and the secondary attenuation length corresponding to a desired level of cross-talk and for utilizing cross-talk adjusted scintillating fibers in a medical imaging system is provided by the present invention. An input device receives a secondary attenuation length, which is then stored by a memory device. A central processing unit determines a level of cross-talk between scintillating fibers by calculating an average number of visible light photons produced within the fibers due to simulated interaction of an energized particle within the fibers. An output device displays the level of cross-talk. The central processing unit may also determine a plurality of levels of cross-talk for a plurality of secondary attenuation lengths and select a desired secondary attenuation length corresponding to a desired level of cross-talk.

Abstract: An NMR clinical chemistry analyzer includes a shield (20) having a plurality of elongate ferromagnetic bars (22) disposed around an NMR magnet (10) and aligned with its axis (13). A probe arm (28) is disposed within the axial bore (12) of the magnet (10) and is articulable in an axial direction to position any one of a plurality of sample modules (32) within the magnetic field "sweet spot" (144) such that tests may be performed on at least one fluid sample within the chosen sample module (32). Counterrotating conductive, nonferromagnetic cylinders (122, 124) are disposed within the axial bore (12) to assure magnetic field homogeneity. Robotics (50, 30, 34) are provided to automatically test fluid analytes without the need for manual changeout of the fluid testing vessel (102) or per-sample electronic shimming.

Abstract: A method and apparatus which assesses the mechanical properties of a material by launching an ultrasound signal at the material while varying the angle of incidence and analyzing the amplitude of the ultrasound wave reflected by the material. The method and apparatus correlates extrema (maxima or minima inflection points) in the reflected angle with the angle of incidence of the transmitted signal to identify critical angles of incidence. The velocity of the pressure wave in the material has been found to be a function of a first critical angle corresponding to a first maxima as the angle of incidence is increased in the range 0.degree.-90.degree.. The velocity of the shear wave in the material has been found to be a function of a second critical angle corresponding to a second maxima following the first maxima. Young's modulus of elasticity, Poisson's modulus, and density can be approximated using the velocity of the pressure wave and shear wave for isotropic materials.

Abstract: A diverging template (18) for radioactive therapy of cancer within an internal tumor volume by interstitial implants through the skin (78) comprises a proximal surface (34) for positioning adjacent the skin and a distal surface (36) opposite the proximal surface (34). An axis (32) of the template (18) is substantially perpendicular to the proximal surface (34). A plurality of holes (24'-30') are formed in the template (18) from the distal surface (36) to the proximal surface (34) for guiding respective needles (24-30) through the skin (78) and into the tumor volume. The holes comprise at least a first group (28) and a second group (26), each hole of the first group (28) spaced from the axis (32) and forming a first angle therewith that diverges from the distal surface (36) to the proximal surafce (34). Each hole (26) of the second group is spaced from the axis (32) and diverges from the distal surface (36) to the proximal surface (34) at a second angle greater than the first angle.