Abstract: Methods of forming thin nitride dielectric layers for semiconductor devices are provided. Additionally, methods of forming capacitor structures utilizing thin nitride dielectric layers are provided. The thin nitride layers are formed by nitridizing the surface of a doped or undoped semiconductor substrate using a remote plasma nitridization or a rapid thermal nitridization to form a first growth of silicon nitride. A self-limiting second growth of silicon nitride is formed using a remote plasma nitridization. The resulting silicon nitride layers exhibit improved dielectric and leakage characteristics.

Abstract: A system for delivering ultrasound energy to a treatment section in a vessel is disclosed. The system includes a sheath with a utility lumen and an energy delivery section at least partially constructed from a material which transmits ultrasound energy. The system also includes a drug delivery member having a plurality of drug delivery ports which are positioned adjacent the energy delivery section. The system further includes an elongated body including at least one ultrasound element and configured to be movably positioned within the utility lumen to transmit the ultrasound energy from the ultrasound element through the energy delivery section.

Abstract: The invention relates to a catheter system. The system comprises a catheter body having a chamber containing a low acoustic impedance medium. The catheter body includes an elongated body with an external surface and an ultrasound transducer having an external side between a first end and a second end. The ultrasound transducer is positioned over the external surface of the elongated body such that the first end is adjacent to the chamber.

Abstract: The invention relates to a catheter system. The system comprises a catheter body having a chamber containing a low acoustic impedance medium. The catheter body includes an elongated body with an external surface and an ultrasound transducer having an external side between a first end and a second end. The ultrasound transducer is positioned over the external surface of the elongated body such that the first end is adjacent to the chamber.

Abstract: The invention relates to a catheter system. The system comprises a catheter body having a chamber containing a low acoustic impedance medium. The catheter body includes an elongated body with an external surface and an ultrasound transducer having an external side between a first end and a second end. The ultrasound transducer is positioned over the external surface of the elongated body such that the first end is adjacent to the chamber.

Abstract: A drill bit is disclosed which includes a bit body having a plurality of ports therein arranged to provide a flow path between an interior of a drill string and the exterior of the bit body. At least one flow relief is disposed in one of the ports. The at least one flow relief is adapted to provide an increase in total flow area of the bit upon application to the bit of a selected fluid flow condition. A method for is also disclosed changing a total flow area of a drill bit, which includes pumping drilling fluid through the drill bit and operating a flow relief disposed in the bit to change the total flow area of the bit.

Abstract: A method is provided for fabricating ceramic microstructures, i.e., microcomponents of micron or submicron dimensions. A polymer composition is prepared containing a polymer, typically a thermally or chemically curable polymer, and nanometer size (1 to 1000 nm in diameter) ceramic particles. A mold, such as a lithographically patterned mold, preferably a LIGA mold, is filled with the polymer composition and the polymer is then cured or otherwise hardened. The elevated segments of the mold are then removed. The surface-attached ceramic microstructures so provided may then be removed from the substrate and, if desired, pyrolyzed and sintered.

Abstract: A catheter assembly comprising two elements each having a hub disposed at the proximal end thereof. The hubs are constructed so as to be complementary and rotatably engageable as the result of a plurality of threads disposed on the hubs of the two catheter introducer elements. When the threads of the hubs of the two catheter elements are engaged axial disengagement of the hubs is inhibited. The catheter assembly also comprising a means of securing against accidental rotational disengagement. The size and location of the threads and the rotational securement means permits the catheter assembly to have a lower profile because the distance to the hemostasis gasket is reduced thus permitting easier access to the hemostasis gasket.

Abstract: Method and apparatus for estimating a line bias for a signal received from a common signal source at each of two or more GPS signal receivers. Single difference solutions are obtained for angular orientation of an antenna array and for antenna location, using a two-thread or two-procedure process for determining and updating line bias variation within each of a sequence of time intervals.

Abstract: A sinusoidal acceleration trajectory controller is used in positioning a transducer at high speed to minimize vibration and acoustic noise. The controller reduces vibration and acoustic noise without sacrifice of seeking time by using a sinusoidal waveform as the actuator input. This sinusoidal waveform is a function of target track position and the seeking terminal time. When the velocity of the read/write head on the transducer reaches a maximum velocity, the sinusoidal waveform becomes a segment sinusoidal waveform, including a zero value waveform between two half sinusoidal waveforms. The amplitude of the sinusoidal waveforms and the coast period are minimized to obtain the minimum harmonic content in the segment sinusoidal waveform.

Abstract: A catheter introducer assembly includes an introducer sheath mounted on a dilator. The distal end of the dilator protrudes beyond the distal end of the sheath and defines an arrowhead having a proximally facing surface that cooperates with the distal end of the sheath to reduce the risk of tissue trauma while facilitating smooth entry into and through tissue. The proximal hubs of the dilator and sheath are configured with respect to the relation between the distal end of the dilator and sheath to provide smooth controlled withdrawal of the dilator through the sheath. The sheath is attached, at its proximal end, to a housing with a mechanical connection that does not require the use of adhesives, welding or other bonding techniques. The connection also may incorporate an integral strain relief for the proximal end of the sheath.

Abstract: Methods for estimation of the relative locations (baseline vectors) of two or more GPS signal antennas relative to each other and for estimation of line biases associated with each signal processing channel associated with each GPS signal antenna. Double difference carrier phase signal measurements are formed, using floating integer and fixed integer solutions for the phase integer ambiguities, and baseline vectors between the GPS signal antennas are estimated. Single difference phase integer ambiguities are obtained and approximations for line biases are computed. Single difference carrier phase measurements are used to estimate baseline vectors and line biases, using fixed phase integer ambiguities with the estimated baseline vectors and line biases as initial conditions, and are processed by Kalman filtering or other suitable signal processing. Angular orientation or attitude of a vehicle body on which the GPS signal antennas are placed is determined from the baseline vectors.

Abstract: A catheter assembly comprising two elements each having a hub disposed at the proximal end thereof. The hubs are constructed so as to be complementary and rotatably engageable as the result of a plurality of threads disposed on the hubs of the two catheter introducer elements. When the threads of the hubs of the two catheter elements are engaged axial disengagement of the hubs is inhibited. The catheter assembly also comprising a means of securing against accidental rotational disengagement. The size and location of the threads and the rotational securement means permits the catheter assembly to have a lower profile because the distance to the hemostasis gasket is reduced thus permitting easier access to the hemostasis gasket.

Abstract: A processing system (210) subdivides (302) a voice message into a plurality of portions, and estimates (304) a plurality of preferred pitch periods corresponding to the plurality of portions. The processing system calculates (314) a plurality of segment sizes corresponding to the plurality of preferred pitch periods, and compresses (316) each of the plurality of portions by utilizing a corresponding one of the plurality of segment sizes in a speech compression algorithm, thereby generating a compressed message. The processing system determines (326) from the plurality of segment sizes a preferred segment size for decompressing the compressed message; and sends (328) the preferred segment size, along with the compressed message, to a receiver (122) for use in decompressing the compressed message in a speech decompression algorithm.

Abstract: A self-sealing hemostatic valve for use in a catheter apparatus is disclosed, comprising a proximal valve element having a sealing hole, a distal valve element having a flap and biasing means to enhance the force with which the flap bears against the distal side of the proximal valve element to normally seal the hole. The sealing hole seals about an instrument passed through the valve and the flap seals the valve when no instrument is present. The proximal face of the proximal valve element is provided with discontinuities that increase the flexibility of the proximal valve element in a distal direction.

Abstract: A nitride material comprises C.sub.2 N. A method of forming a covalent carbon material includes forming an atomic nitrogen source, forming an elemental reagent source and combining the atomic nitrogen, elemental reagent to form the covalent carbon material and annealing the covalent carbon material. The elemental reagent is reactive with the atomic nitrogen of the atomic nitrogen source to form the covalent carbon material. Annealing the covalent carbon material produces the C.sub.2 N. In one embodiment, essentially all carbon nitride chemical bonds are single or double bonds.

Abstract: An improved self-sealing gasket provides hemostasis while reducing the force required to move a catheter or guidewire positioned within the gasket. Slits formed on one surface of the gasket intersect with a central aperture formed on the opposite face of the gasket. An annular ring formed on the gasket assists in retaining the gasket within a catheter introducer. An annular shelf may be provided distally of the gasket to prevent dislodgement of the gasket if an instrument is inserted into the introducer off axially.

Abstract: An improved self-lubricating catheter and guidewire introducer is provided with a reservoir containing lubrication fluid located proximally of a sealing gasket in a modified end cap. An improved self-sealing gasket provides hemostasis while reducing the force required to move a catheter or guidewire positioned within the gasket.

Abstract: An improved self-sealing gasket provides hemostasis while reducing the force required to move a catheter or guidewire positioned within the gasket. Slits formed on one surface of the gasket intersect with a central aperture formed on the opposite face of the gasket. An annular ring formed on the gasket assists in retaining the gasket within a catheter introducer. An annular shelf may be provided distally of the gasket to prevent dislodgement of the gasket if an instrument is inserted into the introducer off axially.