Long-term monitoring for discrimination of different heart rhythms

• US 8,798,727 B2
• Filed: 11/06/2012
• Issued: 08/05/2014
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Linker, David Thor
• Primary Examiner(s): DIETRICH, JOSEPH M
• Application Number:
  US13/670,246
• Publication Number:
  US 20130144146A1
• Time in Patent Office: 637 Days
• Field of Search: 600/509, 600515-519
• US Class Current: 600/509
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2560/0456 Apparatus provided with a docking unit
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/333 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A method, system, and device for detection of an arrhythmia, and discrimination between different types of arrhythmia, for example to determine whether to administer an electric shock to the heart, the device comprising a wearable monitor with electrodes that detect the electrical activity of a beating heart, attached to an embedded monitoring system having an amplifier, a microprocessor, a data storage device, and a power supply, all disposed on a substrate having large distal end portions that attach to the electrodes and a narrow intermediate portion that attaches to the monitoring system.

Claims

1. A wearable cardiac arrhythmia monitoring and detection device comprising:

a substrate having a first end incorporating a first electrode, a second end incorporating a second electrode, and an intermediate portion connecting the first and second ends, the intermediate portion incorporating an integrated monitoring device;

wherein the integrated monitoring device comprises;

(i) an amplifier configured to receive and amplify electrocardiography data from the first and second electrodes;

(ii) a programmable microprocessor configured to receive the electrocardiography data from the amplifier and to analyze the received data;

(iii) a data storage device configured to receive and store at least a portion of the electrocardiography data from the programmable microprocessor; and

(iv) a power supply; and

further

wherein the integrated monitoring device is configured to;

(v) determine the duration of heart beat intervals from the electrocardiography data for a selected analysis segment comprising a plurality of heart beat intervals;

(vi) calculate an instantaneous heart rate for each of the heart beat intervals in the analysis segment;

(vii) calculate a test result using the calculated instantaneous heart rates; and

(viii) compare the test result with a predetermined threshold to discriminate between different types of cardiac arrhythmia.

2. The wearable cardiac arrhythmia monitoring and detection device of claim 1, wherein the programmable microprocessor is configured to identify cardiac arrhythmia, and further wherein only electrocardiography data associated with detected cardiac arrhythmia is stored by the data storage device.

3. The wearable cardiac arrhythmia monitoring and detection device of claim 2, wherein the microprocessor compresses the electrocardiography data associated with detected atrial fibrillation prior to the data being stored by the data storage device.

4. The wearable cardiac arrhythmia monitoring and detection device of claim 2, wherein the cardiac arrhythmia comprises atrial fibrillation.

5. The wearable cardiac arrhythmia monitoring and detection device of claim 4, wherein the integrated monitoring device is configured to:

(i) determine the duration of heart beat intervals from the electrocardiography data for a selected analysis segment comprising a plurality of heart beat intervals;

(ii) calculate an instantaneous heart rate for each of the heart beat intervals in the analysis segment;

(iii) calculate a test result using the calculated instantaneous heart rates; and

(iv) compare the test result with a predetermined threshold to identify an event of atrial fibrillation.

6. The wearable cardiac arrhythmia monitoring and detection device of claim 4, wherein the integrated monitoring device is further configured to:

(v) calculate a mean instantaneous heart rate for the analysis segment;

(vi) calculate a deviation from the mean instantaneous heart rate for each heart beat interval in the analysis segment; and

(vii) determine a median deviation from the mean instantaneous heart rate in the analysis segment; and

wherein the test result is calculated using the mean instantaneous heart rate and the median deviation from the mean instantaneous heart rate.

7. The wearable cardiac arrhythmia monitoring and detection device of claim 6, wherein the test result is calculated as a linear combination of the mean instantaneous heart rate and the median deviation from the mean instantaneous heart rate.

8. The wearable cardiac arrhythmia monitoring and detection device of claim 1, wherein the analysis segment comprises between five and nineteen heart beat intervals.

9. The wearable cardiac arrhythmia monitoring and detection device of claim 1, wherein the integrated monitoring device further comprises a wave pattern detection device that is configured to receive electrocardiography data from the first and second electrodes.

10. The wearable cardiac arrhythmia monitoring and detection device of claim 9, wherein the wave pattern detection device is a QRS detector operable to detect a QRS complex signal from the received electrocardiography data, and to provide QRS information to the microprocessor.

11. The wearable cardiac arrhythmia monitoring and detection device of claim 9, wherein the wave pattern detection is performed by the microprocessor, and functions as a QRS detector operable to detect a QRS complex signal from the received electrocardiography data, and to provide QRS information to the microprocessor.

12. The wearable cardiac arrhythmia monitoring and detection device of claim 1, wherein the integrated monitoring device further comprises a wireless module configured to communicate data from the integrated monitoring device to an external computer.

13. A wearable atrial fibrillation monitoring and detection device comprising:

a substrate having a first end incorporating a first electrode, a second end incorporating a second electrode, and an intermediate portion with an embedded monitoring system;

wherein the embedded monitoring system comprises;

(i) a preamplifier configured to receive electrocardiography data from the first and second electrodes;

(ii) a microprocessor configured to receive the electrocardiography data from the amplifier and to analyze the received data;

(iii) a data storage device configured to receive and store at least a portion of the electrocardiography data from the microprocessor; and

(iv) a power supply; and

further

wherein the embedded monitoring system is configured to;

(v) determine the duration of heart beat intervals from the electrocardiography data for an analysis segment comprising a plurality of heart beat intervals;

(vi) calculate an instantaneous heart rate for each of the heart beat intervals in the analysis segment;

(vii) calculate a test result using the calculated instantaneous heart rates; and

(viii) compare the test result with a predetermined threshold to identify an atrial fibrillation event.

14. The wearable atrial fibrillation monitoring and detection device of claim 13, wherein the microprocessor is configured to detect atrial fibrillation, and further wherein only electrocardiography data associated with detected atrial fibrillation is stored on the data storage device.

15. The wearable atrial fibrillation monitoring and detection device of claim 14, wherein the microprocessor compresses the electrocardiography data associated with detected atrial fibrillation prior to the data being stored on the data storage device.

16. The wearable atrial fibrillation monitoring and detection device of claim 14, wherein the embedded monitoring system is further configured to:

(v) calculate a mean instantaneous heart rate for the analysis segment;

(vi) calculate a deviation from the mean instantaneous heart rate for each heart beat interval in the analysis segment; and

(vii) determine a median deviation from the mean instantaneous heart rate in the analysis segment; and

wherein the test result is calculated using the mean instantaneous heart rate and the median deviation from the mean instantaneous heart rate.

17. The wearable atrial fibrillation monitoring and detection device of claim 16, wherein the test result is calculated as a linear combination of the mean instantaneous heart rate and the median deviation from the mean instantaneous heart rate.

18. The wearable atrial fibrillation monitoring and detection device of claim 14, wherein the analysis segment comprises between five and nineteen heart beat intervals.

19. The wearable atrial fibrillation monitoring and detection device of claim 13, wherein the embedded monitoring system further comprises a wave pattern detection device that is configured to receive electrocardiography data from the first and second electrodes.

20. The wearable atrial fibrillation monitoring and detection device of claim 19, wherein the wave pattern detection device is a QRS detector operable to detect a QRS complex signal from the received electrocardiography data, and to provide QRS information to the microprocessor.

21. The wearable atrial fibrillation monitoring and detection device of claim 19, wherein the wave pattern detection is performed by the microprocessor, and comprises a QRS detector operable to detect a QRS complex signal from the received electrocardiography data, and to provide QRS information to the microprocessor.

22. The wearable atrial fibrillation monitoring and detection device of claim 13, wherein the embedded monitoring system further comprises a wireless module configured to communicate data from the integrated monitoring device to an external computer.