Patent ID: 6173204
Filing Date: 2001-01-09
Classification: A61N

Abstract:
In an external defibrillator for applying a multiphasic defibrillation pulse to a patient, said external defibrillator including an energy storage capacitor having first and second leads, said external defibrillator also having first and second output terminals for applying a biphasic defibrillation pulse to a patient when said first and second output terminals are coupled to a patient, said external defibrillator also including an output circuit for switchably coupling the energy storage capacitor to the first and second output terminals, said external defibrillator also including a control circuit for controlling the operation of said output circuit, the improvement comprising an improved defibrillator with an improved output circuit and an improved control circuit, said improved output circuit comprising:(a) a switching element coupled between the energy storage capacitor and the output terminals, said switching element being configured to stop the flow of energy between the energy storage capacitor and the output terminals in order to end the first phase of a multiphasic defibrillation pulse;(b) a non-semiconductor relay circuit coupled between the energy storage capacitor and the output terminals; andsaid improved control circuit controlling the non-semiconductor relay circuit and the switching element such that:(i) the non-semiconductor relay circuit is placed in a first configuration and the switching element is placed in a conducting state for a first period to electrically couple the first lead of the energy storage capacitor to the first output terminal and to also electrically couple the second lead of the energy storage capacitor to the second output terminal so as to complete a circuit path between the energy storage capacitor and the first and second output terminals when the first and second output terminals are coupled to a patient, so as to conduct energy from the energy storage capacitor to the patient in the form of a first phase of a multiphasic defibrillation pulse; and(ii) the non-semiconductor relay circuit is placed in a second configuration and the switching element is placed in a conducting state for a second period to electrically couple the first lead of the energy storage capacitor to the second output terminal and to also electrically couple the second lead of the energy storage capacitor to the first output terminal to complete a circuit path between the energy storage capacitor and the first and second output terminals when the first and second output terminals are coupled to a patient, so as to conduct energy from the energy storage capacitor to the patient in the form of a second phase of a multiphasic defibrillation pulse.