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AssigneeMedtronic Physio-Control Manufacturing Corp.
InventorsJoseph L. Sullivan, Lawrence A. Borschowa, Richard C. Nova
Estimating the term…
An external defibrillator with an output circuit having four legs arrayed in the form of an “H” (an “H-bridge”) is disclosed. The output circuit is designed to be able to conduct a range of defibrillation pulse energies, from below 50 joules to above 200 joules. Each leg of the output circuit contains a solid-state switch. By selectively switching on pairs of switches in the H-bridge, a biphasic defibrillation pulse may be applied to a patient. The switches in three of the legs of the H-bridge output circuit are preferably silicon controlled rectifiers (SCRs). Gate drive circuits are coupled to the SCRs to bias the SCRs with a voltage that allows the SCRs to remain turned-on even when conducting low current. The switch in the fourth leg is preferably a pair of insulated gate bipolar transistors (IGBTs) coupled in series. A gate drive circuit is coupled to the gate of the IGBTs to provide a slow turn-on and a fast turn-off of the IGBTs. The gate drive circuit also biases the IGBTs with a sufficient voltage to allow the IGBTs to withstand a shorted discharge of the external defibrillator through the output circuit. The circuit also includes a protective component that has both inductive and resistive properties. An internal energy dump may be performed by biasing on two legs on the same side of the H-bridge output circuit, thus eliminating the need for a separate energy dump circuit. Methods for testing the H-bridge and verifying its integrity are also disclosed.
In an external defibrillator for applying a multiphasic defibrillation pulse to a patient through first and second electrodes when said first and second electrodes are coupled to a patient, said external defibrillator including one or more energy storage devices having first and second leads and a charging system for charging said one or more energy storage devices, said external defibrillator also including one or more output circuits with a plurality of output switches for switchably coupling the one or more energy storage devices to the first and second electrodes in order to conduct the energy stored in the one or more energy storage devices to a patient, said external defibrillator further comprising a control circuit coupled to said plurality of output switches for controlling said output switches, said control circuit switching the plurality of output switches so as to generate a multiphasic defibrillation pulse for application to a patient, the improvement comprising:
In an external defibrillator for applying a multiphasic defibrillation pulse to a patient through first and second electrodes when said first and second electrodes are coupled to a patient, said external defibrillator including one or more energy storage devices having first and second leads and a charging system for charging said one or more energy storage devices, said external defibrillator also including one or more output circuits with output switches for switchably coupling the one or more energy storage devices to the first and second electrodes in order to conduct the energy stored in the one or more energy storage devices to a patient, said one or more output switches being coupled in a circuit path between the one or more energy storage devices and the first and second electrodes, said external defibrillator further comprising a control circuit coupled to said one or more output switches for controlling said one or more output switches, the control circuit switching said one or more output switches so as to generate a multiphasic defibrillation pulse for application to a patient, the improvement comprising:
A method for applying a multiphasic defibrillation pulse to a patient through first and second electrodes of an external defibrillator when said first and second electrodes are coupled to a patient, said external defibrillator including one or more energy storage devices having first and second leads and a charging system for charging said one or more energy storage devices, said external defibrillator also including one or more output circuits with output switches for switchably coupling the one or more energy storage devices to the first and second electrodes in order to conduct the energy stored in the one or more energy storage devices to a patient, said one or more output switches being coupled in a circuit path between the one or more energy storage devices and the first and second electrodes, said external defibrillator further comprising a control circuit coupled to said one or more output switches for controlling said one or more output switches, the control circuit switching said one or more output switches so as to generate a multiphasic defibrillation pulse for application to a patient, the method comprising:
Dependencies are inferred from the claim text.