Implantable defibrillator system employing capacitor switching networks

• US 5,199,429 A
• Filed: 05/23/1991
• Issued: 04/06/1993
• Est. Priority Date: 05/23/1991
• Status: Expired due to Fees

• Current Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Original Assignee: Angemed, Inc.
• Inventors: Kroll, Mark W., Adams, Theodore P.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US07/704,619
• Time in Patent Office: 684 Days
• Field of Search: 128/419 D, 128/419 PG, 128/419 R
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3906 characterised by the form of the shockwave
• CPC Class Codes: A61N 1/3912 Output circuitry therefor, e.g. switches
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

The present invention uses switching networks for the predetermined combination of capacitor-discharge waveforms in order to approximate a particular waveform for application to the heart muscle in a defibrillation procedure. These are usually biphasic waveforms, or waveforms exhibiting a positive pulse followed immediately by a negative pulse. Examples of the discharge-process possibilities are those of two capacitors in parallel, two in series, two in sequence, or a capacitor or capacitors with polarity inverted. Adding capacitors and switches expands the range of possibilities and provides waveforms "tailoring" under the guidance of a switching network that can be digitally programmed from an external programming console, much as in the digital programming of a pacemaker system. Digital signals are transmitted to the implanted system using infrared, visible, RF electromagnetic radiation, or ultrasound radiation. The use of multiple capacitors rather than just a single capacitor makes it possible to pack the components more densely, and in the case of some waveforms, to use less total capacitance than in the prior art, both factors contributing to very desirable size reduction for the implantable defibrillator. One or more implanted batteries are used to meet the heavy energy requirements of defibrillation, and these are recharged, one at a time, and after full discharge, by means of implanted series-array photovoltaic devices, preferably monolithic.

Claims

1. A device for energy delivery to a heart of a human during defibrillation comprising:

a. at least two capacitors;

b. electronic switching circuitry means for connecting said capacitors to the heart;

c. control means connected to the electronic switching circuitry to deliver the capacitor energy to the heart with at least one of said capacitors connected in parallel with another of said capacitors for a first phase of energy delivery; and

,

d. control means connected to the electronic switching circuitry to deliver the capacitor energy to the heart with at least one of said capacitors connected in series with another of said capacitors for a second phase of energy delivery whereby said second phase being either the same or opposite polarity of said first phase.

2. A device for energy delivery to a heart of a human during defibrillation comprising:

a. at least two capacitors;

b. electronic switching circuitry means for connecting said capacitors to the heart;

c. control means connected to the electronic switching circuitry to deliver the capacitor energy to the heart with at least one of said capacitors connected in series with another of said capacitors for a first phase of energy delivery; and

,

d. control means connected to the electronic switching circuitry to deliver the capacitor energy to the heart with at least one of said capacitors connected in parallel with another of said capacitors for a second phase of energy delivery whereby said second phase being either the same or opposite polarity of said first phase.