Switched capacitor defibrillation circuit

Abstract

A defibrillator circuit for generating a rectangular waveform across a patient from capacitively stored energy and employing a plurality of capacitors initially chargeable to a common voltage and thereafter sequentially switchable into parallel relation with one another so as to raise the voltage supplied to an H-bridge circuit from a point of decay back to said common voltage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of co-pending U.S. application Ser. No. 10 / 011,952, filed Nov. 5, 2001, the disclosure of which is incorporated herein by reference. [0002] The present invention may find application in systems such as are disclosed in the U.S. patent application entitled “SUBCUTANEOUS ONLY IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR AND OPTIONAL PACER,” having Ser. No. 09 / 663,607, filed Sep. 18, 2000, now U.S. Pat. No. 6,721,597, and U.S. patent application entitled “UNITARY SUBCUTANEOUS ONLY IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR AND OPTIONAL PACER,” having Ser. No. 09 / 663,606, filed Sep. 18, 2000, now U.S. Pat. No. 6,647,292, of which both applications are assigned to the assignee of the present application, and the disclosures of both applications are hereby incorporated by reference. [0003] Applications related to the foregoing applications include U.S. application Ser. No. 09 / 940,283 entitled “DUCKBILL-SHAPED IMPLANTA...

AI Technical Summary

Benefits of technology

"The invention provides circuitry that can create a rough estimate of a rectangular waveform from energy stored in devices like a capacitor."

Problems solved by technology

This system is far more complicated to use than current ICD systems using transvenous lead systems together with an active can electrode, and therefore, it has no practical use.

It has, in fact, never been used because of the surgical difficulty of applying such a device (3 incisions), the impractical abdominal location of the generator and the electrically poor sensing and defibrillation aspects of such a system.

ICDs are very effective at treating V-Fib, but are therapies that still require significant surgery.

In addition, chronic transvenous lead systems, their reimplantation and removals, can damage major cardiovascular venous systems and the tricuspid valve, as well as result in life threatening perforations of the great vessels and heart.

Consequently, use of transvenous lead systems, despite their many advantages, are not without their chronic patient management limitations in those with life expectancies of ≦5 years.

The problem of lead complications is even greater in children where body growth can substantially alter transvenous lead function and lead to additional cardiovascular problems and revisions.

Moreover, transvenous ICD systems also increase cost and require specialized interventional rooms and equipment as well as special skill for insertion.

However, an AED must be used by another individual, not the person suffering from the potential fatal rhythm.

Because >75% of cardiac arrests occur in the home, and over half occur in the bedroom, patients at risk of cardiac arrest are often alone or asleep and cannot be helped in time with an AED.

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