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:
Jun. 01, 1999
Filed:
Apr. 10, 1997
James E Brewer, Cottage Grove, MN (US);
Gary B Stendahl, Crystal, MN (US);
SurVivaLink Corporation, Minneapolis, MN (US);
Abstract
A method and apparatus for delivering a stepped truncated damped sinusoidal external defibrillation waveform which, when applied through a plurality of electrodes positioned on a patient's torso will produce a desired response in the patient's cardiac cell membranes is provided. Further, the method and apparatus sufficiently approximates a constant current defibrillation shock pulse. The method includes the steps monitoring a patient-dependent electrical parameter and determining a duration based on the parameter determined. First and second charge storage components are then charged. A first truncating switch is then closed to discharge the first charge storage component. After a predetermined delay, a second truncating switch is closed to discharge the second charge storage component. Then, after the duration period that was calculated has expired the switches are opened to truncate the waveform. The computation of discharge duration is made as a function of the desired cardiac membrane response function, a patient model and a defibrillator circuit model.