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AssigneeMedtronic Physio-Control Manufacturing Corp.
InventorBarry F. Waltman
Estimating the term…
A circuit for generating both a biphasic defibrillation waveform and an external pacing waveform in an external defibrillator is provided. The output circuit of the device utilizes one or more SCR switches for applying energy to a patient. In one embodiment, the output circuit is in the form of an H-bridge, with three SCR legs and one IGBT leg. A drive circuit for one of the SCR legs is provided such that the SCR may be continuously driven on for either a high energy biphasic defibrillation pulse or a low energy pacing pulse. In one embodiment, the output circuit conducts the pacing waveform through a combination of one upper leg SCR of the H-bridge and a current source. The current source is configured to bypass a lower leg SCR of the H-bridge. The output circuit is capable of conducting pacing currents of as low as 10 mA. The output circuit is also capable of conducting a high energy biphasic defibrillation waveform of as high as 200 or more joules, and also a low energy defibrillation pulse of as low as 1 to 50 joules. The output circuit is also capable of conducting currents as high as approximately 200 amperes.
A circuit for use in an external unit that generates a defibrillation pulse in a defibrillation mode and a pacing pulse in a pacing mode, the circuit comprising:
A method of externally providing a defibrillation pulse or a pacing pulse to a patient from a single unit that includes one or more SCR switches, the method comprising:
An apparatus for externally providing to a patient a defibrillation pulse during a defibrillation mode and a pacing pulse during a pacing mode, the apparatus 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 output switches including one or more SCR switches, 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 output switches including one or more SCR switches, said external defibrillator further comprising a control circuit coupled to said plurality of output switches for controlling said output circuit 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:
Dependencies are inferred from the claim text.