US 12,076,574 B2
Cardiac beat classification to avoid delivering shock during ventricular repolarization
Venugopal Allavatam, Saratoga, CA (US); Benjamin Speakman, Eagan, MN (US); and Leanne M. Eberle, Mahtomedi, MN (US)
Assigned to CARDIAC PACEMAKERS, INC.
Filed by CARDIAC PACEMAKERS, INC., St. Paul, MN (US)
Filed on Oct. 7, 2021, as Appl. No. 17/496,511.
Claims priority of provisional application 63/089,152, filed on Oct. 8, 2020.
Prior Publication US 2022/0111220 A1, Apr. 14, 2022
Int. Cl. A61N 1/39 (2006.01)
CPC A61N 1/3987 (2013.01) [A61N 1/3956 (2013.01); A61N 1/3981 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method of delivering a defibrillation shock in a defibrillator having electrodes for sensing cardiac signals, analysis circuitry for analyzing the sensed cardiac signals, therapy delivery capacitors for storing energy for the defibrillation shock, a charger configured to charge the therapy delivery capacitors, and therapy output circuitry for issuing the defibrillation shock using energy stored on the therapy delivery capacitors;
the method comprising:
determining a need for the defibrillation shock and charging the therapy delivery capacitors for defibrillation shock delivery to a predetermined shock threshold;
after completing charging of the therapy delivery capacitors to the predetermined shock threshold:
sensing an Nth cardiac electrical event;
characterizing the Nth cardiac electrical event as either an R-wave or a T-wave; and:
in response to a determination that the Nth cardiac electrical event is characterized as an R-wave, issuing the defibrillation shock according to a first shock protocol; and
in response to a determination that the Nth cardiac electrical event is characterized as a T-wave, issuing the defibrillation shock according to a second shock protocol;
further comprising sensing a N-1 cardiac electrical event preceding the Nth cardiac electrical event, wherein the step of characterizing the Nth cardiac electrical event as either an R-wave or a T-wave comprises:
determining an interval from the N-1 cardiac electrical event to the Nth cardiac electrical event;
comparing the interval to an R-T interval range; and
in response to a determination that the interval is in the R-T interval range, characterizing the Nth sensed cardiac electrical event as a T-wave;
else characterizing the Nth cardiac electrical event as an R-wave.