Defibrillator waveform generator for generating waveform of long duration
First Claim
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1. A system for generating a defibrillation waveform including a defibrillator and an electrode structure, the system comprising:
- a single capacitor having a capacitance of at least 200 microfarads;
means for charging said capacitor to a maximum voltage of less than 400 volts;
switch means for connecting said capacitor to said electrode structure; and
switch control means for controlling said switch means to connect said capacitor to said electrode structure for discharge via said electrode structure in a first polarity for a first phase of a biphasic waveform, and to connect said capacitor to said electrode structure in a polarity opposite said first polarity for a second phase of said biphasic waveform;
the first phase having duration equal to or greater than said second phase, the total duration of the first and second phases being at least 15 milliseconds, a trailing edge voltage of said first phase being greater than fifty percent of a leading edge voltage of the first phase and the biphasic waveform having a fixed tilt so as to produce a fixed low tilt biphasic waveform.
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Abstract
An implantable defibrillator/cardioverter which generates a biphasic waveform having a duration of at least 15-80 msec and a small "tilt" between the leading edge and trailing edge voltages of each phase. In one embodiment, two capacitors are connected in parallel to create an effectively large capacitance to generate a slowly decaying waveform. In another embodiment, a high capacitance bipolar capacitor is used, which capacitance is at least 200 microFarads.
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Citations
8 Claims
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1. A system for generating a defibrillation waveform including a defibrillator and an electrode structure, the system comprising:
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a single capacitor having a capacitance of at least 200 microfarads; means for charging said capacitor to a maximum voltage of less than 400 volts; switch means for connecting said capacitor to said electrode structure; and switch control means for controlling said switch means to connect said capacitor to said electrode structure for discharge via said electrode structure in a first polarity for a first phase of a biphasic waveform, and to connect said capacitor to said electrode structure in a polarity opposite said first polarity for a second phase of said biphasic waveform; the first phase having duration equal to or greater than said second phase, the total duration of the first and second phases being at least 15 milliseconds, a trailing edge voltage of said first phase being greater than fifty percent of a leading edge voltage of the first phase and the biphasic waveform having a fixed tilt so as to produce a fixed low tilt biphasic waveform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification