Abstract: Embodiments of the invention include an optical communications system including one or more optical transmission devices, one or more optical receiving devices, and at least one positive dispersion optical fiber coupled therebetween. The fiber includes a doped core region with an index of refraction n1, a cladding region with an index of refraction n2, and first and second annular rings or regions therebetween with indices of refraction n3 and n4, respectively. The various regions are manufactured in such a way that the refractive index value ranges are: 0.14<(n1−n2)/n2<0.31, −0.19<(n3−n2)/n2<−0.02, and −0.20<(n4−n2)/n2<−0.08. The fibers exhibit a chromatic dispersion greater than 20±2.0 ps/(nm-km) and a dispersion slope less than 0.062 ps/(nm2-km) at a wavelength of 1550 nm. Also, the fibers have a relatively large effective core area, Aeff, e.g., greater than 100.0 &mgr;m2, and a relative dispersion slope (RDS) less than 0.0032 nm−1.

Abstract: The present invention discloses a method of aligning scintillator crystalline structures for computed tomography imaging and a system of use. Crystal seeds are deposited inside a glass melt and are then grown to form a plurality of layer crystallites. While growing the crystallites, a field is applied to align each crystallite structure in a uniform orientation. As a result, the crystallites are configured to reduce light scattering and improve the overall efficiency of the CT system. A CT system is disclosed implementing a scintillator array having a plurality of scintillators, each scintillator being formed of a plurality of uniformly aligned crystallites. Each crystallite includes a receiving surface and an exiting surface configured perpendicular to an x-ray beam. Further, the receiving surface and the exiting surface are connected by a plurality of surface walls arranged parallel to the x-ray beam.

Abstract: A miniaturized, optically driven therapeutic radiation source operates at significantly reduced power levels. The apparatus includes a laser-driven thermionic cathode, a target element, a probe assembly, and a laser source. The probe assembly includes an optical delivery structure, such as a fiber optic cable, that directs a laser beam from the laser source to impinge upon a surface of the thermionic cathode, heating the surface to a temperature sufficient to cause thermionic emission of electrons. The emitted electrons form an electron beam along a beam path. The target element is positioned in the beam path, and includes means for emitting therapeutic radiation, such as x-rays, in response to incident accelerated electrons from the electron beam. Reflector elements may be included to reflect unabsorbed laser radiation back to the thermionic cathode.

Abstract: The present invention provides a detector for a multi-slice CT system. The detector includes a scintillator for receiving and converting high frequency electromagnetic energy directly to electrons. The detector is further configured to directly conduct the electrons. The detector comprises a compound formed of scintillator bulk and a conducting material capable of converting high frequency energy to electrons as well as conduct electrons. The CT system also provides for a gantry having an output for projecting high frequency electromagnetic energy toward the detector and a data acquisition system for receiving electrons directly from the detector. A method to provide imaging electrons to a CT system is also provided.

Abstract: An optical switch includes a core and a fluid reservoir. The core includes a base, a matrix controller substrate, and a planar lightwave circuit. The planar lightwave circuit has a plurality of waveguides and a plurality of trenches. Each trench is located at an intersection of two waveguides. The fluid reservoir supplies a fluid to the plurality of trenches of the core. The optical switch further includes a getter for removing atmospheric gases from the fluid. The getter may be a porous silica getter, a non-evaporable getter, or an evaporable getter. By removing atmospheric gases from the fluid, the getter improves the capacity and operation of the optical switch. The optical switch may further include a membrane to separate the getter in a getter chamber from the fluid in a fluid chamber.

Abstract: A bidirectional signal transmission device using light which adopts a photodiode-incorporated vertical cavity surface emitting laser (VCSEL) as light devices so that signal transmission and reception between facing light devices is achieved via the same channel, is provided. This bidirectional signal transmission device includes first and second light devices having a VCSEL part and a photodiode part incorporated with the VCSEL part, at least one optical fiber installed between the first and second light devices, and diffraction elements installed between the first light device and the input/output port of the optical fiber and between the second light device and the output port of the optical fiber, respectively, for selectively diffracting incident light so that light output from the optical fiber is received by the photodiode part, so that a received light signal having a high S/N ratio can be detected.

Abstract: In order to detect whether the center position of a subject is offset from a scan center and notify a human operator of the result of the detection, the subject center position is detected based on a projection profile of a parallel view at a view angle of 90° (S5). If the distance between the subject center position and the scan center exceeds a predefined range (e.g., 50 cm) (S6), a warning is displayed on a CRT to prompt the operator to adjust the position of the subject and repeat imaging (S7).

Abstract: A portable x-ray fluorescence spectrometer apparatus comprising a housing; a high voltage energized x-ray source operably secured within the housing; and an unheated electron cathode, operably linked to the high voltage energized x-ray source, thereby eliminating the need for a cathodic electron power supply for spectrometric analysis. Another embodiment comprises a portable x-ray fluorescence spectrometer having a housing, an integrated x-ray tube, a high voltage power supply operably linked to the integrated x-ray tube, and a mechanism for controlling the x-ray emissions of the x-ray tube and power supply including an electron suppression grid operably positioned between a filament cathode and a target anode of the x-ray tube.

Abstract: An automatic exposure control for an x-ray system using a large area solid state x-ray detector (26) includes an exposure control (36, 34) arranged to generate data of interest within the data generated by the detector and to adjust the dosage of x-rays to a predetermined level in response to data of interest so that an x-ray image of a patient is generated using the predetermined level.

Abstract: An optical fiber attenuator for adjusting the attenuation of a fiber optic cable, including a generally L-shaped housing with a spring clip positioned within the housing. The spring clip is adjustably positioned to change and hold the radius of curvature of a fiber optic cable wrapped around the spring clip. The fiber optic attenuator is fitted with a movable arm mounted to its housing which engages and adjusts the spring clip through a plurality of positions to adjust the position of the spring clip, thereby adjusting the attenuation of the fiber optic cable.

Abstract: Driving an X-ray imaging device by applying a high voltage signal to a photo-sensing layer, reading the stored charges that result from dark charges produced by the high voltage signal using a data reader such that stored charges are removed from the charging capacitors, performing X-ray irradiation such that X-ray induced charges are stored in a charging capacitor, and converting the stored charges to electrical signals, all while maintaining the high voltage on the photo-sensing layer. The driving method improves a contrast ratio caused by the dark charges and reduces signal variations caused by turning-off the high voltage before converting the stored charge into electrical signals. As the high voltage turned on and off only one once the driving time can be reduced.

Abstract: This invention concerns an apparatus to transilluminate objects. In known apparatus (1) there are two radiation sources (10, 20) in a transport path of a transport device (3), below to the right and left, as well as a third radiation source (30) arranged horizontal to the transport path (3), with the two radiation sources (10, 20) lying close together, one behind the other. Three detector apparatus (11, 14, 31) are arranged opposite these radiation sources (10, 20, 30). Thus, a so called multi-view from three beam directions is created, with beam paths (FX1.1, FX2.2, FX3) extending perpendicular to a transport direction. Contrary thereto, in the solution described herein, various radiation beam paths (FX1.1, FX1.2, FX2.1, FX2.2, FX3) cross so that not every beam radiation path extends perpendicular to the transport direction. This has the advantage that the apparatus can be structured in a space saving manner.

Abstract: The detector materials (8, 9) of a low energy detector (5) and a high energy detector (6) are coordinated with one another to permit better separation of lower and higher energy fractions of polychromatic X-ray (X′) radiation, and consequently, create a better determination of a material of an object through which the X-rays are passed. Thus, a negligible persistence in comparison with the integration time between two detector readings is achieved.

Abstract: The present invention is a fiber optic cable which uses pressure sensitive films or tactile films in order to detect areas on a fiber optic cable where excessive loads have been applied or experienced. In the present invention, a plurality of strips of tactile film or pressure sensitive film are inserted, at regular intervals, throughout the fiber optic cable structure in a fashion similar to that of swellable tape. The tactile film or pressure sensitive film used can be any color-changing stress sensor which is formed in the shape of a flat strip. The present invention uses strips of tactile or pressure sensitive film of different widths which are inserted periodically throughout the cable, both circumferentially and along the length of the cable. The films are located between the buffer tube(s) and the outer jacket of the cable or between the fibers and the outer jacket of the cable. This intermittent use decreases the overall cost and weight of the cable, over using a continuous length of tactile film.

Abstract: One embodiment of the present invention is a method for imaging an object with a computed tomographic (CT) imaging system that includes steps of scanning an object with a beam of radiation from a CT imaging system to produce a view stream including attenuation data for the object being scanned; sensing one or more dynamic parameters relating to at least one of the object being scanned and the CT imaging system; and integrating information relating to the one or more sensed dynamic parameters into the view stream. This embodiment integrates information necessary for compensating reconstructed images directly into the view stream, thereby making the necessary information more conveniently available for such compensation.

Abstract: A computed tomography system includes a gantry provided with an examination opening. The computed tomography system is provided with a position measuring system for measuring the position of the gantry. Preferably, an optical position measuring system which includes a camera unit is employed. The camera unit is suspended from a suspension point above the gantry.

Abstract: The present invention provides an improved thin layer nuclear density gauge comprising a gauge housing having a vertical cavity therethrough and a base, a first radiation detector located at a first position within said housing and adjacent to said base of said housing, a second radiation detector located at a second position within said housing and adjacent to said base of said housing, a vertically moveable source rod extending into said cavity of said gauge housing, a radiation source operatively positioned within a distal end of said source rod, at least one bearing operatively positioned to guide said source rod within said cavity, and means for vertically extending and retracting said source rod to a plurality of predetermined source rod positions so as to change the spatial relationship between said radiation source and said first and second radiation detectors. The source rod has a maximum radial movement of less than about 0.003 inch at each predetermined position.

Abstract: An apparatus and method for in-situ x-ray radiation treatment utilizes different types of miniature energy transducers to emit x-rays. Each type of energy transducer includes a transducer body, a cathode provided at one end of the transducer body, and an anode provided at another end of the transducer body. The transducer body, cathode and anode define a cavity that communicates with an evacuation opening. A desired vacuum is achieved and maintained by a dynamic pumping mechanism that draws a vacuum in the cavity via the evacuation opening.

Abstract: In radiotherapy, a high quality imaging array may be placed after the patient and opposite the radiation source to be used during radiation treatment to verify operation of a shutter system or similar device and/or to compute dose delivered to the patient. A model of the patient may be used and inverted in order to estimate values of energy fluence prior to absorption by the patient and overlapping of the various radiation beams passing through the patient. A test pattern of shutter excitation to illuminate a single ray at a time provides a simple method of obtaining the necessary model. The dose from this test pattern may be subtracted from the subsequent radiation treatment so as to provide limited or no increase in total dose to the patient.

Abstract: A CT scanner comprises an x-ray window mounted on an x-ray tube, a cooling fluid circulation line, and a cooling fluid return line. A cold-plate is operatively mounted on the x-ray tube around the x-ray window. The cold plate includes an elongated shell and corrugated fins for rapidly removing heat from the x-ray window. The circulation line is in fluid communication with an inlet of the cold-plate, a cooling fluid reservoir defined between the x-ray tube and a surrounding housing, and a heat exchanger. The return line is in fluid communication with an outlet of the cold-plate, the cooling fluid reservoir, and the heat exchanger. A pump circulates the cooling fluid through the heat exchanger, the suction and return lines, the cold-plate, and the x-ray tube housing.