US 5,470,341 AGranted

High voltage switch drive for implantable cardioverter/defibrillator

AssigneeMedtronic, Inc.

InventorsKevin P. Kuehn, Martin A. Rossing, William C. Berg

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Abstract

A battery powered cardioverter or defibrillator employing a DC-DC converter for charging high voltage output capacitors and for delivering biphasic cardioversion or defibrillation pulses through a bridge circuit including high and low side drive circuits under the control of a microprocessor controlled arrhythmia detection system. Upon the detection of an arrhythmia and the selection of cardioversion/defibrillation therapy, the charging of the high voltage output capacitors is commenced and the capacitor voltage enables a regulated voltage source for the high and low side drive circuits for the high power IGTs of each branch of the bridge circuit. High voltage switching transients are suppressed from re-triggering or otherwise affecting operation of the drive circuits. Fail safe circuitry disables operation of the drive circuits in the event that the first and second control signals are inadvertently provided simultaneously or overlap.

Claims11

Dependent claims

A medical device for electrical termination of an arrhythmic condition of a patient's heart of the type comprising:

a battery;
means for detection of an arrhythmic condition of a patient's heart;
a high voltage capacitor;
controller means responsive to detection of an arrhythmic condition of said patient's heart, for initiating charging of said capacitor and for providing a discharge control signal;
converter means, responsive to said controller means, for providing charging current from said battery to said capacitor;
and
discharge circuit means for delivering voltage stored on said capacitor to said patient's heart in response to said discharge control signal, said discharge circuit means comprising:
high voltage switch means for connecting said capacitor to said patient's heart to discharge said capacitor through said patient's heart;
voltage regulating means coupled to said capacitor for sensing voltage stored on said capacitor and for generating a regulated voltage upon charging of said capacitor to a predetermined voltage;
drive circuit means powered by said regulated voltage and triggerable responsive to said discharge control signal for in turn triggering said high voltage switch means to discharge said capacitor;
and
means for inhibiting transient high voltage signals generated during switching of said high voltage switch means from re-triggering said drive circuit means.

9 more elements

A medical device for electrical termination of an arrhythmic condition of a patient's heart by delivery of biphasic stimulation pulses sequentially in opposing directions through said patient's heart comprising:

a battery;
means for detection of an arrhythmic condition of said patient's heart;
a high voltage capacitor;
controller means responsive to detection of an arrhythmic condition of said patient's heart for initiating a charging of said high voltage capacitor and for providing first and second discharge control signals in sequence;
converter means, responsive to said controller means, for providing charging current from said battery to said high voltage capacitor;
and
high voltage discharge means for delivering voltage stored on said high voltage capacitor to said patient's heart in response to said first and second discharge control signals, said high voltage discharge means further comprising:
first high and low side drive circuit means for providing first high and low side trigger signals in response to said first discharge control signal;
second high and low side drive circuit means for providing second high and low side trigger signals in response to said second discharge control signal;
first discharge circuit means having first high and low side voltage discharge switches switchable into conduction by said first high and low side trigger signals for connecting said high voltage capacitor with said patient's heart, for discharging high voltage through said patient's heart in a first direction;
second discharge circuit means having second high and low side voltage discharge switches switched into conduction by said second high and low side trigger signals for connecting said high voltage capacitor means with said patient's heart, for discharging high voltage through said patient's heart in a second direction;
and
wherein said first and second high side drive circuit means further comprise means for inhibiting transient high voltage signals generated during switching of said first and second high side voltage discharge switches and coupled back to said first and second high side drive circuit means from re-triggering said first and second high side voltage discharge switches.

10 more elements

Dependencies are inferred from the claim text.