Staged energy concentration for an implantable biomedical device

• US 5,674,248 A
• Filed: 06/07/1995
• Issued: 10/07/1997
• Est. Priority Date: 01/23/1995
• Status: Expired due to Fees

• Current Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Original Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Inventors: Donohoo, Ann M., Kroll, Mark W., Brumwell, Dennis A.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US08/486,760
• Time in Patent Office: 853 Days
• Field of Search: 607/2, 607/4, 607/5, 607/7, 607/9, 607/11, 607/12, 607/34, 607/35, 607/75, 607/45, 600/16, 623/3, 604/65
• US Class Current: 607/5
• 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: A61N 1/3975 Power supply A61N1/378 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 6/16 with organic electrolyte H01M6/18 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A staged energy storage system provides electrical energy to an implantable biomedical device by using the combination of a first stage energy source and a second stage energy concentration system. The second stage energy concentration system allows a lower density and/or lower voltage energy source to be used as the first stage energy source, thereby decreasing the battery cost, size and weight. In one embodiment, the second stage energy concentration system comprises a rechargeable battery. In another embodiment, the second stage energy capacitor system comprises a high energy density capacitor system. The staged energy storage system is ideal for internally charging a pulse-generating capacitor system within an implantable cardioverter defibrillator. In this embodiment, a high voltage transformer has a secondary side that is electrically connected to the pulse-generating capacitor system. A second stage concentration system is electrically connected between a first stage energy source and a primary side of the high voltage transformer to store at least a portion of an electrical charge that is delivered from the first stage energy source and to the high voltage transformer.

Claims

1. A staged energy storage system for providing low voltage energy to an implantable biomedical device comprising:

a first stage energy source means for providing a long-term, low-voltage, low-current source of an electrical current of less than 10 milliamperes;

a second stage energy concentration means comprising a capacitor system for storing the electrical current delivered from the first stage energy source means; and

switch means electrically connected to the second stage energy concentration means and to at least two implanted electrodes for selectively discharging the electrical current in the second stage energy concentration means through the at least two implanted electrodes as at least one short-term, low-voltage, high-current discharge of greater than 0.5 A,

wherein the first stage energy source means is capable of delivering at least 1 joule/second and the second stage energy concentration means stores at least 15 J and wherein the first stage energy source means, the second stage energy concentration means and the switch means for selectively discharging are all contained within the implantable biomedical device.

2. The staged energy storage system of claim 1 further comprising a trickle charge system electrically connected between the first stage energy source means and the second stage energy concentration means wherein the first stage energy source means constantly recharges the second stage energy concentration means.

3. The staged energy storage system of claim 1 wherein the first stage energy source means is a low current battery selected from the set consisting of:

a lithium iodide battery, a Li-CF_x battery, a radioisotope-activated battery, a nuclear battery, or a thermo-electric battery.

4. An improved implantable cardioverter defibrillator for producing a truncated capacitor-discharge countershock pulse, the implantable cardioverter defibrillator being a self-contained human implantable device including a pulse-generating capacitor means for storing an electrical charge, energy storage means for internally charging the pulse-generating capacitor means, and means for selectively discharging the electrical charge in the pulse-generating capacitor means through a plurality of electrodes implanted in a human patient in response to a means for sensing of a cardiac dysrhythmia in the human patient, the improvement comprising:

the energy storage means for internally charging the pulse-generating capacitor means including;

a first stage battery energy source;

a high voltage transformer having a primary side and a secondary side, the secondary side being electrically connected to the pulse-generating capacitor means; and

a second stage energy concentration capacitor system means electrically connected between the first stage battery energy source and the high voltage transformer for storing an electrical charge that is delivered from the first stage battery energy source and is applied to the transformer in response to the means for sensing of a cardiac dysrhythmia,

wherein the second stage energy concentration means charges the pulse-generating capacitor means to a maximum charging voltage in less than 6 seconds.

5. The implantable cardioverter defibrillator of claim 4 further comprising a trickle charge system electrically connected between the first stage energy source means and the second stage energy concentration means wherein the first stage energy source means constantly recharges the second stage energy concentration means.

6. The implantable cardioverter defibrillator of claim 4 wherein the first stage energy source means is a low current battery selected from the set consisting of:

a lithium iodide battery, a Li-CF_x battery, a radioisotope-activated battery, a nuclear battery, or a thermo-electric battery.

7. An improved implantable cardioverter defibrillator for producing a truncated capacitor-discharge countershock pulse, the implantable cardioverter defibrillator being a self-contained human implantable device including a pulse-generating capacitor means for storing an electrical charge, energy storage means for internally charging the pulse-generating capacitor means, and means for selectively discharging the electrical charge in the pulse-generating capacitor means through a plurality of electrodes implanted in a human patient in response to a means for sensing of a cardiac dysrhythmia in the human patient, the improvement comprising:

the energy storage means for internally charging the pulse-generating capacitor means including;

a first stage battery energy source;

a high voltage transformer having a primary side and a secondary side, the secondary side being electrically connected to the pulse-generating capacitor means; and

a second stage energy concentration capacitor system means electrically connected between the first stage battery energy source and the high voltage transformer for storing an electrical charge that is delivered from the first stage battery energy source and is applied to the transformer in response to the means for sensing of a cardiac dysrhythmia,

wherein the second stage energy concentration means stores an energy required for a therapy regimen consisting of multiple countershocks to be delivered in the event that an initial countershock is unsuccessful in converting the cardiac dysrhythmia without need for recharging from the first stage battery energy source.

8. The implantable cardioverter defibrillator of claim 7 further comprising a trickle charge system electrically connected between the first stage energy source means and the second stage energy concentration means wherein the first stage energy source means constantly recharges the second stage energy concentration means.

9. The implantable cardioverter defibrillator of claim 7 wherein the first stage energy source means is a low current battery selected from the set consisting of:

a lithium iodide battery, a Li-CF_x battery, a radioisotope-activated battery, a nuclear battery, or a thermo-electric battery.