129 results about "Pulsed radiofrequency" patented technology

A cardiac assist device containing a device for connecting the cardiac assist device to a heart, for furnishing electrical impulses from the cardiac assist device to the heart, for ceasing the furnishing of electrical impulses to the heart, for receiving pulsed radio frequency fields, for transmitting and receiving optical signals, and for protecting the heart and the cardiac assist device from currents induced by the pulsed radio frequency fields. The cardiac assist device contains a control circuit comprised of a parallel resonant frequency circuit.

A medical device containing a device for connecting the medical device to a substrate, for furnishing electrical impulses from the medical device to the substrate, for ceasing the furnishing of electrical impulses to the substrate, for receiving pulsed radio frequency fields, for transmitting and receiving optical signals, and for protecting the substrate and the medical device from currents induced by the pulsed radio frequency fields. The medical device contains a control circuit comprised of a parallel resonant frequency circuit.

The present invention relates to a method for treating a nervous symptom or condition in a subject with a pulsed-radiofrequency stimulation system with a low voltage to overcome the disadvantages of the known related stimulation systems.

The present invention determines the resonant frequency of a wireless sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency. The system receives the ring down response of the sensor and determines the resonant frequency of the sensor, which is used to calculate a physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal. The system identifies false locks by detecting an unwanted beat frequency in the coupled signal, as well as determining whether the coupled signal exhibits pulsatile characteristics that correspond to a periodic physiological characteristic, such as blood pressure.

The present invention relates generally to a radiofrequency reactor for use in thermally recovering oil and related materials. The radiofrequency reactor includes a radiofrequency antenna configured to be positioned within a well, where the well is provided within an area in which crude oil exists in the ground. The radiofrequency antenna includes a cylindrically-shaped radiating element for radiating radiofrequency energy into the area in which crude oil exists. The cylindrically-shaped radiating element is configured to allow passage of fluids there through. The radiofrequency reactor also includes a radiofrequency generator electrically coupled to the radiofrequency antenna. The radiofrequency reactor is operable to control the radiofrequency energy generated.

An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

An apparatus and method for determining a parameter of interest of a formation composed of carbonate rock. A nuclear magnetic resonance (NMR) sensor assembly produces a pulsed RF field designed for obtaining measurements indicative of the parameter of interest of the formation. A downhole processor processes the measurements for obtaining BVI and BVM using a cutoff time based on classification of the carbonate. Further processing is done to estimate the permeability of the carbonate.

This invention relates to radiofrequency (rf) cavities and couplers that comprise metallic or dielectric rods to provide specified concentration of field patterns for the operating modes in the interaction region, for applications in particle accelerators, pulsed rf power sources, amplifiers, mode converters and power couplers.

A system for measuring a position and orientation of an object in flight relative to a reference coordinate system is provided. The system including: three or more illuminating sources, each disposed in a predefined position, the three or more illuminating sources together emitting a plurality of distinct polarized radio frequency signals to provide temporally synchronized, pulsed radio frequency signals that illuminate the object; one or more waveguide cavities disposed on the object for receiving the plurality of distinct polarized radio frequency signals from each of the three or more illuminating sources in flight; and a processor for measuring a time for the plurality of distinct polarized radio frequency signals to propagate from each of the three or more illuminating sources to the one or more waveguide cavities and the level of signal received at the waveguide cavities and to determine a position of the object relative to the three or more illuminating sources based on the measured times and the orientation of the object relative to the reference coordinate system based on the measure levels of received signals.

A method and apparatus for reducing chronic pain in animals by radio frequency (RF) neuromodulation of peripheral nerves of the animal is disclosed. The method, using the disclosed apparatus, comprises the steps of attaching active and dispersive percutaneous probes at respective active and dispersive locations relative to a peripheral nerve of the patient associated with the pain to be reduced; generating a first pulsed RF signal for coupling to the active and dispersive probes to verify the location of the peripheral nerve; and generating a second pulsed RF signal for coupling to the active and dispersive probes to modify propagation of pain sensation in the peripheral nerve without ablation thereof. In one embodiment of the apparatus, the active percutaneous probe includes an RF cannula having a conductive spatulate blade conformably attached to a dorsal side of a curved, blunt-ended tubular tip portion of the RF cannula. In another embodiment of the apparatus, a dispersive percutaneous probe includes a pair of 22 gauge needles connected to ground return conductors. In yet another embodiment of the apparatus, a pulsed RF generator is modified to provide specific outputs adapted to the neuromodulation of peripheral nerves in veterinary patients.

In one aspect, a method for imaging fluid flow and/or perfusion using spin labeling is provided. The method comprises applying a first magnetic gradient sequence at least to a labeling region, applying a first pulsed radio frequency (RF) sequence to the labeling region to label the fluid, the first pulsed RF sequence comprising a first plurality of pulses wherein an amplitude envelope is non-zero, the first plurality of pulses each separated by a respective first plurality of intervals wherein the amplitude envelope is substantially zero, and acquiring at least one first signal emitted from an imaging region a predetermined delay after applying the first pulsed RF sequence.

An apparatus and method for disinfestation of temperature sensitive and other commodities using short duration, high peak power radio frequency pulses and intense electric fields to preferentially induce drift of conduction charges, spot heating and other mortal damage to infesting insects and mites without raising the temperature of the host commodity. A low frequency mode is provided with a frequency range of approximately 10 Hz to 1 MHz and is particularly suited for large batch processing of pallets or field containers. A high frequency mode is also provided that is suited for continuous or small batch processing and uses a preferred frequency range of approximately 1 MHz to 150 MHz. Both modes preferably have an electric field strength of greater than approximately 5 kV/cm and pulse repetition rates of between one pulse and approximately 10 million pulses per second. The method is non-contact, residue free and effective with all biological stages of an infesting insect, mite or other biological pest including egg, pupa, larvae, juvenile and adult forms. The apparatus and methods of the invention are an effective alternative to methyl bromide fumigation that does not leave any toxic residues or damage the cosmetic appearance or flavor of the commodity.

This disclosure describes systems, methods, and apparatus for pulsed RF power delivery to a plasma load for plasma processing of a substrate. In order to maximize power delivery, a calibration phase using a dummy substrate or no substrate in the chamber, is used to ascertain a preferred fixed initial RF frequency for each pulse. This fixed initial RF frequency is then used at the start of each pulse during a processing phase, where a real substrate is used and processed in the chamber.

A method and system for injecting a pulsed radio frequency signal into a fluid-containing system in order to create and propagate an electromagnetic field throughout the fluid-containing system. The electromagnetic field may be used to prevent the formation and build-up of scale in the fluid-containing system and/or to prevent the proliferation of bacteria within the fluid-containing system. The method and system may also be used to inject a pulsed radio frequency signal at a number of points in a fluid-containing system, or to inject a pulsed radio frequency signal to a number of independent fluid-containing systems.

Sub-nanosecond single ion beam pulses are generated by means of one embodiment of the invention. In this embodiment, an ion source provides ions to a radio frequency quadrupole linear accelerator comprising electrodes. A power source is used to apply radio frequency alternating currents to the electrodes. A device is used to inject ions from the ion source to the accelerator, causing the accelerator to provide only a single sub-nanosecond output beam pulse at a time.

A flexible catheter includes two electrical contacts in a distal region of the catheter and a distal aperture of a hose line. The electrical contacts are connected to a high frequency pulse generator for applying pulsed radio frequency energy for nerve stimulation. A temperature sensor is located in the distal region of the catheter. The flexible catheter is inserted into a region in the spinal canal and the pulsed radio frequency generator is operated, thereby applying pulsed radio frequency energy to a localized region to be treated. The temperature at the distal region of the catheter can also be monitored, and the pulsed radio frequency energy is applied in dependence on the monitored temperature. With the catheter, pain and other medical conditions being related to and influenced by a nervous system are treated.

Methods for treatment of hyperhidrosis, Raynaud's phenomenon, cerebral ischemia and asthma and hypertension by nerve stimulation are disclosed. In particular, the invention relates to the improvement of these conditions by stimulating at least one ganglion selected from the group consisting of T-1 through T-4 ganglia, cervical ganglia, renal nerve or combinations thereof with an implantable, wireless, battery-less and lead-less stimulator. Stimulations of the ganglion may be carried out with pulsed radiofrequency, thermal energy or optical irradiation.

The present invention comprises methods and systems for treating a cardiac arrhythmia in a mammal by administering gated or pulsed radiofrequency current or other ablative energy to the mammal during one or more time periods of increased coronary blood flow. Preferred embodiments of the invention comprise, without limitation, the gated or pulsed administration of radiofrequency current in association with the formation of the dicrotic notch in the arterial blood pressure curve of the mammal. In accordance with the invention, the thermal effects of ablative energy application on the coronary artery are avoided or mitigated due to rapid coronary blood flow resulting in heat loss and minimization of damage to blood vessels.

A method of fabricating a gate of a transistor device on a semiconductor substrate, includes the steps of placing the substrate in a vacuum chamber of a plasma reactor and introducing into the chamber a process gas that includes oxygen while maintaining a vacuum pressure in the chamber. An oxide insulating layer on the order of several Angstroms in thickness is formed at the surface of the substrate by generating a plasma in a plasma generation region within the vacuum chamber during successive “on” times, and allowing ion energy of the plasma to decay during successive “off” intervals separating the successive “on” intervals, the “on” and “off” intervals defining a controllable duty cycle. During formation of the oxide insulating layer, the duty cycle is limited so as to limit formation of ion bombardment-induced defects in the insulating layer, while the vacuum pressure is limited so as to limit formation of contamination-induced defects in the insulating layer. A conductive gate electrode is formed over the insulating layer.

A dual channel downconverter that includes a two-channel heterodyne receiver architecture for downconverting two frequency-agile, pulsed RF signals to identical fixed IF signals without the use of a tunable local oscillator. This accomplishes downconversion while preserving, in the IF output signals, any amplitude modulations present in the RF signals. The device also preserves phase difference changes present in the RF signals while rejecting the phase modulations common to those input signals. The present device facilitates complex response measurements of pulsed two-port RF devices while operating in a target system such as a radar transmitter, including insertion gain, insertion phase, residual phase noise, error vector magnitude, AM noise, and group delay, all with increased accuracy, good repeatability, good dynamic range, and decreased measurement time.