摘要:
A cardiac lead for transmitting electric current to the heart and/or sensing and monitoring electrical activity of the heart has an elongated electrical conductor connected to a head. An electrode mounted on the head comprises a helical wire adapted to be turned into heart tissue. The helical wire is coated with platinum black particles which decrease electrical losses at the electrode-tissue interface. A plug impregnated with a drug located within the head is in contact with the helical wire and platinum black particles thereon. The drug migrates from the plug to the active outer end section of the electrode.
摘要:
A cardiac lead for transmitting electric current to the heart and/or sensing and monitoring electrical activity of the heart has an elongated electrical conductor connected to a head. An electrode mounted on the head comprises a helical wire adapted to be turned into heart tissue. A second electrode having an irregular or non-flat surface surrounds the helical wire. The non-flat surface may be a wire mesh, a segmented plate and an annular plate supporting one or more coiled wires.
摘要:
A bi-polar cardiac lead for transmitting electric current to the heart and/or sensing and monitoring electrical activity of the heart has elongated electrical conductors connected to a head. The lead has a first electrode mounted on the head having a helical wire connected to one conductor adapted to be turned into heart tissue. The helical wire is coated with platinum black particles which decrease electrical losses at the electrode-tissue interface. A second annular electrode having an irregular outer surface configuration is mounted on the head around the first electrode. A plug impregnated with a drug is located within a recess in the head adjacent the electrodes. The drug migrates from the plug to the stimulation site.
摘要:
A cardiac lead has an electrode and fixation assembly including a plurality of fixation members movable to extended positions into heart tissue to retain the electrode in intimate engagement with heart tissue. An elongated stylet is used to move the fixation members to their extended positions into the heart tissue and retract the fixation members into the fixation assembly to allow the lead to be removed from the heart and body of a person.
摘要:
A digital synthesizer is disclosed for generating complex waveforms of seted multiple frequencies and selected phases in the time domain. A plurality of independent frequency sources each produces square waves at its selected fundamental frequency and at frequencies which are integral multiples, such as twice, four times and eight times, that of the fundamental. A sampling clock whose frequency is at least the highest frequency produced by any frequency source, multiplied by the number of fundamentals used, provides a signal to a binary counter whose output is connected to a line decoder or multiplexer which multiplexes each frequency source's signals on a time-share basis via a system of AND and OR gates. The signal produced by the OR gates is provided to address a memory device which contains a predetermined waveform in a look-up table. The signal produced by the memory device is therefore the multiplexed combination of the signals that would have been produced therefrom had each frequency source alone been applied to address the memory. The complex waveform produced by the memory is provided to a plurality of serial in-parallel out shift registers whose outputs are applied to a plurality of digital-to-analog converters each producing identical waveforms time-delayed with respect to each other.
摘要:
A multi-activity drillship, or the like, method and apparatus having a single derrick and multiple tubular activity stations within the derrick wherein primary drilling activity may be conducted from the derrick and simultaneously auxiliary drilling activity may be conducted from the same derrick to reduce the length of the primary drilling activity critical path.
摘要:
Objects to be labelled with, for example, heat transfer labels, are initially stabilized by being positioned on freely movable platforms and conveyed to a station where the platforms are stabilized and the objects labelled.
摘要:
A smoke alarm activated portable light or lamp for providing emergency illumination in response to an alarm signal from a smoke alarm device includes a frequency selective microphone, several amplifier stages, a peak detector, an isolation or buffer stage, and a power stage comprising a pair of cascaded transistors and a light bulb. The lamp includes a bracket for positioning same in proximity to a smoke alarm and a switch which is closed upon removal of the lamp from the bracket. A power saving circuit includes a photoelectric cell and an amplifier and is operative to saturate or overdrive the first gain stage to override any signal from the microphone whereby the lamp is rendered unresponsive to the smoke alarm signal upon illumination of the photocell by daylight or artificial light.
摘要:
Nonionic surfactants, for automatic dishwasher detergents, are provided having specific alkoxylates bonded to block oxypropylene and oxyethylene/oxypropylene mixtures. These surfactants provide enhanced low-foaming and wetting, and compatibility with active chlorine compounds.
摘要:
Nonionic surfactants, for automatic dishwasher detergents, provide enhanced low-foaming and wetting, and compatibility with active chlorine compounds. The surfactants are specific block oxypropylene/oxyethylene adducts of alkylphenols.