1428 results about "Pulse waveform" patented technology

A system for minimizing neuromuscular stimulation includes a converter, an inverter, and a controller. The converter is configured to output a dc waveform and includes at least one first switching element operated at a first duty cycle. The inverter is coupled to the converter and includes at least one second switching element operated at a second duty cycle. The inverter is configured to invert the DC waveform to generate an electrosurgical pulse waveform. The controller is coupled to the converter and the inverter, and is configured to control the first duty cycle to adjust a magnitude of the electrosurgical pulse waveform and the second duty cycle to adjust at least one property of the electrosurgical pulse waveform to minimize neuromuscular stimulation.

An acoustic transmitter produces a pulsed ultrasound waveform which is transmitted through body tissues to an implanted receiver-stimulator device. The waveform has an acoustic amplitude, pulse width, and pulse repetition period, which corresponds to a pacing pulse electrical amplitude, pacing pulse width, and pacing cycle length, respectively. The receiver-stimulator device intercepts at least a portion of the transmitted acoustic energy and coverts that acoustic energy into electrical energy using piezoelectric or other devices. This electrical energy is applied to circuitry, which produces a desired stimulating pulse waveform, which is then applied to tissue-contacting electrodes.

An object of the invention is to provide a method for delivery of macromolecules into biological cells in the tissues of a patient and includes the steps of: (a) providing electrodes (16) in an electrode assembly (12), wherein the electrodes have fixed electrode surfaces (42) which are coated with at least one static layer of electrode releasable molecules (44) to be delivered; (b) providing a waveform generator (15) for generating electric fields; (c) establishing electrically conductive pathways between the electrodes (16) and the waveform generator (15); (d) locating the electrodes (16) such that the biological cells are situated therebetween, and (g) providing electric fields in the form of pulse waveforms from the waveform generator (15) to the electrodes (16), such that molecules in the at least one static layer of the electrode releasable molecules (44) on the electrodes (16) are delivered into the biological cells. The electrode releasable molecules (44) can be either electric field separable molecules and / or solvent separable material. Another object of the invention is to provide an apparatus for carrying out the method of the invention. The static-coated electrode assembly (12) can be provided in a sterile package (24), from which the electrode assembly (12) is removed prior to use. The statically-coated electrode assembly (12) can be in a form of a disposable assembly (12) which is removable and replaceable from an electrode assembly holder (13).

A method comprises conveying a pulsed waveform between an electrode and a stimulation site of a spinal cord, thereby evoking the antidromic propagation of action potentials along a first sensory neural fiber creating a therapeutic effect in the tissue region, evoking the orthodromic propagation of action potentials along the first sensory neural fiber potentially creating paresthesia corresponding to the tissue region, and evoking the antidromic propagation of action potentials along a second sensory neural fiber potentially creating a side-effect in another tissue region. The method further comprises conveying electrical energy between an electrode and a blocking site rostral to the stimulation site, thereby blocking the action potentials propagated along the first sensory neural fiber and reducing the paresthesia, and conveying electrical energy between an electrode and a blocking site caudal to the stimulation site, thereby blocking the action potentials propagated along the second sensory neural fiber and reducing the side-effect.

A digital transmit beamformer system with multiple beam transmit capability has a plurality of multi-channel transmitters, each channel with a source of sampled, complex-valued initial waveform information representative of the ultimate desired waveform to be applied to one or more corresponding transducer elements for each beam. Each multi-channel transmitter applies beamformation delays and apodization to each channel's respective initial waveform information digitally, digitally modulates the information by a carrier frequency, and interpolates the information to the DAC sample rate for conversion to an analog signal and application to the associated transducer element(s). The beamformer transmitters can be programmed per channel and per beam with carrier frequency, delay, apodization and calibration values. For pulsed wave operation, pulse waveform parameters can be specified to the beamformer transmitters on a per firing basis, without degrading the scan frame rate to non-useful diagnostic levels. Waveform parameters can be specified to the transmitters by an external central control system which is responsible for higher level flexibility, such as scan formats, focusing depths and fields of view. The transmit pulse delay specified per-channel to each transmitter is applied in at least two components: a focusing time delay component and a focusing phase component. The carrier frequency can be specified for each transmit beam, to any desired frequency within a substantially continuous predefined range of frequencies, and a beam-interleaved signal processing path permits operation in any of several predefined processing modes, which define different parameter sets in a trade-off among (1) the number of beams produced; (2) per-beam initial waveform sample interval; and (3) transmit frequency.