Defibrillation system

• US 6,427,083 B1
• Filed: 08/31/2000
• Issued: 07/30/2002
• Est. Priority Date: 03/07/1997
• Status: Expired due to Term

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Cardiac Science Operating Company (Cardica Incorporated)
• Inventors: Owen, James M., Totman, Mark H., Fincke, Randall W., OʼLeary, James P.
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US09/651,847
• Time in Patent Office: 698 Days
• Field of Search: 607/605, 607/115, 607/142, 607/148, 607/152, 607/133
• US Class Current: 607/5
• CPC Class Codes: A61N 1/0452 Specially adapted for transcutaneous muscle stimulation [TMS]
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/0468 Specially adapted for promoting wound healing
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 1/0476 Array electrodes (including any electrode arrangement with more than one electrode for at least one of the polarities)
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives
• CPC Class Codes: A61N 1/3904 External heart defibrillators [EHD]
• CPC Class Codes: A61N 1/3918 characterised by shock pathway, e.g. by electrode configuration
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/3937 Monitoring output parameters
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock
• CPC Class Codes: A61N 1/3993 User interfaces for automatic external defibrillators

Abstract

A method of treating a patient for ventricular tachycardia using a wearable defibrillator includes monitoring the patient for a predetermined condition via one or more electrodes on the defibrillator, sending a message to the patient in response to the predetermined condition, activating the defibrillator so that the defibrillator delivers defibrillation energy to the patient, and storing at least one of the results of the monitoring, sending and activating steps in a memory on the defibrillator. The method also includes downloading information stored in the memory of the defibrillator to a base station having an external interface, and transmitting the information downloaded from the memory of the base station to an external location via the external interface of the base station.

Claims

1. A method of treating a patient for cardiac arrhythmia using a defibrillator, the method comprising the steps of:

monitoring the patient for a predetermined condition via one or more electrodes on the defibrillator;

sending a message from said defibrillator to the patient in response to the predetermined condition;

activating the defibrillator so that the defibrillator delivers defibrillation energy to the patient;

storing information related to at least one of the results of the monitoring, sending and activating steps in a memory on the defibrillator; and

transmitting said information to an external location;

wherein at least one of the electrodes is used to monitor a transthoracic impedance of the patient; and

wherein the defibrilliation energy comprises an electrical signal having a bi-phasic waveform which varies in accordance with the transthoracic impedance of the patient.

2. A method according to claim 1, wherein the predetermined condition comprises abnormal heart activity.

3. A method according to claim 1, wherein the sending step comprises providing the patient with an auditory or visual indicator in response to the predetermined condition.

4. A method according to claim 3, further comprising the step of waiting for one or more replies from the patient in response to the auditory or visual indicator;

wherein the activating step activates the defibrillator only in a case that one or more replies is not received from the patient in response to the auditory or visual indicators.

5. A method according to claim 1 wherein the defibrillator delivers the defibrillation energy to the patient using a plurality of testing electrodes;

and

wherein at least one of the sensing electrodes is used to monitor the patient for a predetermined condition.

6. A method according to claim 1, wherein at least one of the electrodes is capable of transmitting a tactile stimulation signal to the patient;

and

wherein the tactile stimulation signal is transmitted to the patient in a case that the predetermined condition comprises a cardiac arrhythmia.

7. A method according to claim 1, wherein the bi-phasic waveform satisfies at least one of the following conditions:

(i) the bi-phasic waveform has a peak amplitude that is below 23 amperes in a case that the patient has a thoracic impedance of at least 40 ohms, and (ii) the bi-phasic waveform is comprised of two phases having substantially identical duration.

8. A method according to claim 1, wherein the transthoracic impedance of the patient is monitored by transmitting one of a DC and an AC electrical signal through the patient'"'"'s body.

9. A method according to claim 1, wherein at least one of the sensing electrodes is used to measure an electrode-to-skin impedance from the patient.

10. A method according to claim 1, further comprising the step of transmitting external information from the external location, via the external interface, to the base station and thence to the memory of the defibrillator.

11. A method according to claim 1, further comprising the steps of:

mating the defibrillator to the base station prior to the downloading step;

performing safety diagnostics on the defibrillator while the defibrillator is mated to the base station; and

transmitting results of the safety diagnostics to at least one of the defibrillator and the external location.

12. A method according to claim 1 further comprising sending within said message information regarding the status of the defibrillator.

13. A method according to claim 1

further comprising sending within said message information regarding the length of time that the defibrillator and/or electrodes were worn by the patient.

14. A method according to claim 1 further comprising sending within said message information descriptive of the operation of the defibrillator.

15. A method according to claim 1 further comprising sending within said message instructions for using the defibrillator.

16. A method according to claim 1 further comprising sending to said defibrillator information from a remote location.

17. The method of claim 1 further comprising downloading first said information to a base station having an external interface, and transmitting said information from said base station to said external location.