Spire Corporation

Gas Research Institute

Anton C Greenwald

Ward D Halverson

Vinod Jalan, Deceased

Bobby L Buchanan

Nader Montazernezam Kalkhoran

The present invention provides a catheter having an x-ray generator unit at its tip which generates x-ray radiation having a wavelength in a range effective for treating biological tissue. In one embodiment, the x-ray generator unit includes a miniature x-ray generator and a miniature transformer that form, in combination, a monolithic device. The transformer includes a primary winding that receives an input voltage in a range of 100 V to 4 kV from a power source, via a flexible cable that runs from the proximal end of the catheter body to its distal end. The transformer further includes a secondary winding that up-converts the input voltage to generate an output voltage in a range of 10 kV to 40 kV to be applied to a cathode of the x-ray generator. The cathode emits electrons in response to the applied voltage, and an extraction electrode guides the emitted electrons to an anode, which is preferably formed of a high-Z refractory metal. The impact of the electrons with the anode effects generation of x-ray radiation, a portion of which is transmitted via an x-ray transmissive window to the outside environment. One significant advantage of the device of the invention is that by employing a lower voltage in the body of the catheter and confining a higher voltage to a short, rigid section at the distal end of the catheter, the device provides enhanced mechanical flexibility and lowers the likelihood of electrical breakdown.

Catheter tip x-ray source

The present invention provides methods and apparatus for creating insulating layers in Group III-V compound semiconductor structures having aluminum oxide with a substantially stoichiometric compositions. Such insulating layers find applications in a variety of semiconductor devices. For example, in one aspect, the invention provides vertical insulating layers separating two devices, such as photodiodes, formed on a semiconductor substrate from one another. In another aspect, the invention can provide such insulating layers as buried horizontal insulating layers of semiconductor devices.

Formation of insulating aluminum oxide in semiconductor substrates

A catalyst material of carbon black powder having nitrogen affixed to its surface and process for its production by contacting carbon black powder particles with a plasma or low energy beam of nitrogen containing ions affixing the nitrogen ions to the surface of the particles in a concentration of about 0.1 to about 10 percent, based upon the total number of surface atoms. The catalysts are particularly suited for use in phosphoric acid fuel cells.

Process for producing carbon black having affixed nitrogen

A stream of gaseous source compounds and their ranges of relative ratios useful in the deposition of thin film ferroelectric materials by CVD are disclosed. The stream of gaseous source compounds are used in combination with a CVD reactor flushed with an inert gas and maintained at a predetermined internal pressure and, a substrate disposed within the CVD reactor and maintained at a predetermined temperature. The steam of gaseous source compounds include a Zr source compound, a Ti source compound, a Pb source compound, an oxidizing agent compound, and an inert gas, as well as their ranges of relative ratios to deposit lead-zirconate-titanate, related ferroelectrics, specifically including lead-lanthanum-zirconium-titanate.

CVD thin film compounds

An improved process of making a ferroelectric electronic component, such as a non-volatile RAM or an electro-optic switching array, is disclosed. The process essentially includes the separate formation of two subassemblies and then connecting them by placing one on top of the other. Electrical contacts are made by 'bumping' or other 'flip chip' techniques.

Growing community of inventors

North Andover, MA, United States of America

Anton C Greenwald