The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 1995
Filed:
Mar. 24, 1992
Mark W Kroll, Minnetonka, MN (US);
Charles G Supino, Arden Hills, MN (US);
Theodore P Adams, Edina, MN (US);
Dennis A Brumwell, Bloomington, MN (US);
Angeion Corporation, Plymouth, MN (US);
Abstract
The first embodiment of the present invention repositions the shunt thyristor used in the monophasic-waveform generator of the prior art so that it discharges the main capacitor through a series thyristor, thus increasing current through it briefly, rather than reducing current through it. The result of this arrangement is that the node between the series thyristor and the heart is pulled rapidly to a low voltage, causing the shunt switch to discharge the cardiac capacitance, as well as the main capacitance. The consequence is that discharging the cardiac capacitance requires a reversal of current in the heart, which enhances the heart-stimulating effect of the defibrillating waveform. The resulting true-voltage-pulse waveform has an efficacy approximating that of a biphasic waveform and is achieved with a circuit no more complex than that used to generate a monophasic waveform. A second and alternative embodiment of the present invention is a defibrillation system comprising a switching-bridge circuit, augmented by a zener diode and a rectifier diode, that is capable of delivering on demand any one of the waveforms known as monophasic, biphasic, and true-voltage-pulse waveforms.