Charging and safety control for automated external defibrillator and method

• US 6,029,085 A
• Filed: 04/08/1998
• Issued: 02/22/2000
• Est. Priority Date: 04/09/1997
• Status: Expired due to Term

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: SurVivaLink Corporation (Cardica Incorporated)
• Inventors: Olson, Kenneth F., Gilman, Byron L.
• Primary Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US09/057,277
• Time in Patent Office: 685 Days
• Field of Search: 607/5, 607/63, 607/6, 607/8, 607/7
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3931 Protecting, e.g. back-up systems
• CPC Class Codes: A61N 1/3981 High voltage charging circuitry

Abstract

A fail-safe safety circuit for a portable automated external defibrillator allows earlier charging of capacitors. In turn, the earlier charging of the capacitors allows quicker release of a defibrillation shock than prior art method of automatically detecting the appropriateness of administering a defibrillation shock and subsequently preparing the shock.

Claims

1. An automated external defibrillator comprising:

a charging circuit for preparing and temporarily storing a defibrillation shock;

a manually actuated trigger switch mechanism for generating a defibrillation shock release request signal;

monitoring and analysis means operably communicatively coupled to the trigger switch mechanism for pre-qualifying release of a defibrillation shock in response to the defibrillation shock release request signal from the trigger switch mechanism; and

a safety switch mechanism operably communicatively coupled to the trigger switch mechanism, separately responsive to the defibrillation shock release request signal from the monitoring and analysis means, for connecting a pre-qualified release of a defibrillation shock to patient electrode terminals.

2. The automated external defibrillator of claim 1, wherein the manually actuated trigger switch is a single pole switch providing a single defibrillation shock release request signal for response from both the monitoring and analysis circuit and from the safety switch.

3. The automated external defibrillator of claim 1, wherein the manually actuated trigger switch is a double pole switch providing a first defibrillation shock release request signal to the monitoring and analysis circuit and a second, separate defibrillation shock release request signal to the safety switch.

4. The automated external defibrillator of claim 1 wherein the monitoring and analysis means is responsive to the defibrillation shock release signal produced by manually closing the trigger switch.

5. The automated external defibrillator of claim 1, wherein the monitoring and analysis circuit is responsive to a signal generated by a change of state of circuit closure at the manually operated trigger switch.

6. The automated external defibrillator of claim 1 wherein the charging circuit comprises a plurality of capacitors, connected in series and controllable by solid state relays.

7. The automated external defibrillator of claim 6, wherein the safety switch includes a solid state relay.

8. The automated external defibrillator of claim 1 and wherein the monitoring and analysis means pre-qualifies a defibrillation shock release based upon at least one monitored factor selected from the group consisting of:

acceptable impedance between the patient electrode terminals; and

detection of a cardiac rhythm predefined as indicative of ventricular fibrillation.

9. An automated portable external defibrillator comprising:

a charging circuit for preparing and temporarily storing a defibrillation shock;

a manually actuated double pole trigger switch mechanism for generating a defibrillation shock release request signal; and

a safety switch mechanism, responsive to the defibrillation shock release request signal, for connecting a defibrillation shock to patient electrode terminals; and

monitoring and analysis means prequalifying the generation of the defibrillation shock release request signal.

10. The automated external defibrillator of claim 9 wherein the monitoring and analysis means pre-qualifies a defibrillation shock release based upon at least one monitored factor selected from the group consisting of:

acceptable impedance between the patient electrode terminals, and

detection of a cardiac rhythm predefined as indicative of ventricular fibrillation.

11. An automated external defibrillator comprising:

switch means for electrical interconnection to the electrical power supply;

a charging circuit, connected to the switch means for electrical interconnection, for preparing and temporarily storing a defibrillation shock;

a manually actuated trigger switch mechanism for generating a defibrillation shock release request signal;

monitoring and analysis means for pre-qualifying release of a defibrillation shock in response to the defibrillation shock release request signal from the trigger switch mechanism;

a switch mechanism, controlled by the monitoring and analysis means, for releasing a defibrillation shock; and

patient electrode terminals for connection and conveyance of a released defibrillation shock.

12. The automated external defibrillator of claim 11 and wherein the switch means for electrical interconnection of the power supply is independent of pre-qualification activity of the monitoring and analysis means.

13. A method for providing automated external defibrillation shocks, comprising the steps of:

providing an electrical power supply, a charging circuit capable of preparing and temporarily storing a defibrillation shock, and a switched interconnection therebetween;

providing a monitoring and analysis circuit to automatically prevent release of a defibrillation shock in the absence of a pre-qualified situation, and a manually actuated trigger switch to request a pre-qualified defibrillation shock release by the monitoring and analysis circuit;

activating the switched interconnection to begin preparing and storing a defibrillation shock; and

subsequent to activating the switched interconnection, manually actuating the trigger switch to request the monitoring and analysis circuit to release a pre-qualified defibrillation shock.

14. A method for providing automated external defibrillation shocks, comprising the steps of:

providing a monitoring and analysis circuit to automatically prevent release of a defibrillation shock in the absence of a pre-qualified situation, and a manually actuated trigger switch mechanism to request a pre-qualified defibrillation shock release by the monitoring and analysis circuit;

manually actuating the trigger switch mechanism to request the monitoring and analysis circuit to release a pre-qualified defibrillation shock;

providing a safety switch mechanism, separately responsive to the trigger switch mechanism from the monitoring and analysis circuit, to connect the pre-qualified defibrillation shock to patient electrode terminals, thereby separately assuring that the trigger switch mechanism was manually actuated.

15. A method for providing a defibrillation shock using an automated external defibrillator (AED) having AED circuitry including an electrical power supply interconnected to a charging circuit capable of preparing and temporarily storing a defibrillation shock, a pair of electrodes connected to the charging circuit, a processor for controlling operation of the AED, an analysis circuit connected to the processor, and a trigger switch operably coupled to the AED circuitry for initiating generation of a defibrillating shock, the method including the steps of:

turning the AED on;

activating the charging circuit to prepare and store a defibrillation shock;

instigating the analysis circuit after the charging circuit has been activated, and

generating the defibrillating shock, deliverable to a patient.

16. A method for providing a defibrillation shock using an automated external defibrillator having AED circuitry including an electrical power supply interconnected to a charging circuit capable of preparing and temporarily storing a defibrillation shock, a pair of electrodes connected to the charging circuit, a processor for controlling operation of the AED, an analysis circuit connected to the processor, and a trigger switch operably coupled to the AED circuitry for initiating generation of a defibrillating shock, the method including the steps of:

turning the AED on;

activating the charging circuit to prepare and store a defibrillation shock;

instigating the analysis circuit simultaneously to the actuation of the charging circuit, and

generating the defibrillating shock, deliverable to a patient.