Patent ID: 9056207
Filing Date: 2015-06-16
Classification: A61N

Abstract:
1. A biphasic defibrillation circuit for supplying a biphasic pulse to a patient when connected to defibrillation electrodes of an automated external defibrillator, comprising: a switching circuit comprising a first switch, a second switch, a third switch, and a fourth switch, wherein a first output terminal and a second output terminal from the switching circuit are respectively coupled to the defibrillation electrodes, wherein a first phase pulse and a second phase pulse in an opposite direction to the first phase pulse are applied to the defibrillation electrodes by the switching circuit; a first energy storage device coupled to the defibrillation electrodes by the switching circuit for delivering a first phase current to the defibrillation electrodes during the first phase pulse and delivering a second phase current in an opposite direction to the first phase current to the defibrillation electrodes during the second phase pulse, wherein the first energy storage device is a high voltage energy storage device, a first lead of the first energy storage device is coupled with the switching circuit directly and a second lead of the first energy storage device is coupled with the switching circuit through an eighth switch; a second energy storage device coupled to defibrillation electrodes during at least one of the first and second phase pulses for respectively delivering at least one of the first phase current and the second phase current in conjunction with the first energy storage device, wherein the second energy storage device is a low voltage energy storage device, a first lead of the second energy storage device is coupled with the switching circuitry through a sixth switch and with the second lead of the first energy storage device through a seventh switch and a second lead of the second energy storage device is coupled with the switching circuit directly; and a charging circuit coupled to the first and second energy storage devices for charging the first and second energy storage devices, wherein charging of the first and second energy storage devices is controlled by a fifth switch; wherein a serial branch formed by the sixth switch and the second energy storage device connects in parallel to a serial branch formed by the first energy storage device and the eighth switch; and wherein a difference between a first length of a first discharging time of the first phase pulse and a second length of a second discharging time of the second phase pulse is less than 40 percent of the first length of the first discharging time.