HEART RATE VARIABILITY SENSOR

• US 20120197148A1
• Filed: 08/02/2011
• Published: 08/02/2012
• Est. Priority Date: 08/05/2010
• Status: Active Grant

• Current Assignee: Lev-El Diagnostics of Heart Diseases, Ltd.
• Original Assignee: Lev-El Diagnostics of Heart Diseases, Ltd.
• Inventors: LEVITAN, JACOB, Kobo, Roi
• Granted Patent: US 8,798,732 B2
• Time in Patent Office: Days
• US Class Current: 600/515
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• 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
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/3962 in combination with another heart therapy
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: G16H 40/60 for the operation of medical equipment or devices

Abstract

A system for measuring heart rate variability (HRV) comprising 3 sub-systems: a data collection sub-system, a data analysis sub-system, and an output sub-system. A patient is connected to a heart monitoring device such as an ECG and the data collection sub-system records the patients heart beats, and an ECG chart is produced from which the patient'"'"'s HRV value is derived by the data analysis sub-system. The present invention obtains the HRV value through calculation of a new parameter called relative density (RD). In accordance with the inventive method, data points are generated from the peak interval data of measured heart beats and the HRV relative density parameter (RD) is calculated by correlation between two subsets of data points.

Claims

1. A method for measuring heart rate variability (HRV), the method comprising:

recording electrocardiograph measurements for a series of heartbeats;

determining peak interval data from the electrocardiograph measurements;

generating a plurality of data points from the peak interval data;

identifying two subsets of data points from the plurality of data points, each subset having a maximum number of data points; and

calculating an HRV relative density parameter (RD) by dividing the maximum number of data points in one of the two subsets of data points by the maximum number of data points in the other one of the two subsets of data points.

2. The method for measuring HRV according to claim 1,

wherein each data point has a first coordinate on a first axis and a second coordinate on a second axis;

and wherein the two subsets of data points comprise a first subset having a first maximum number of data points in a first data interval on the first axis, and a second subset having a second maximum number of data points in a second data interval on the second axis.

3. The method for measuring HRV according to claim 1, wherein determining peak interval data includes discarding peak intervals greater than 2500 msec.

4. The method for measuring HRV according to claim 2, wherein generating a plurality of data points includes translating each data point to a new data point having a new first coordinate and a new second coordinate according to the formula:

new first coordinate=cos 45 (first coordinate plus second coordinate), and

new second coordinate=cos 45 (second coordinate minus first coordinate).

5. The method for measuring HRV according to claim 2, wherein identifying a first data interval and a second data interval includes selecting a data interval length

6. The method for measuring HRV according to claim 5, wherein the data interval length is in the range of 10 to 20.

7. The method for measuring HRV according to claim 1, further including detrending the peak interval data,

wherein the RD calculated is applicable for general health prognosis.

8. The method for measuring HRV according to claim 7, wherein detrending a peak interval comprises subtracting an average value from the peak interval.

9. The method for measuring HRV according to claim 8, wherein the average value is calculated by obtaining a sum of a predetermined number of peak intervals and dividing the sum by the predetermined number.

10. The method for measuring HRV according to claim 1, further including measuring a pulse level and calculating RD upon the pulse level exceeding a predetermined threshold,

wherein the RD calculated is applicable for determining a pending incident of ventricular tachycardia (VT) or ventricular fibrillation (VF)

11. The method for measuring HRV according to claim 10, wherein the predetermined threshold is a pulse level of 10 consecutive heartbeats occurring at a rate of at least 120 beats per second.

12. A method for providing heart treatment in real time, the method comprising:

recording an electrocardiograph measurement of a current heartbeat;

measuring an interval between the current heartbeat and a preceding heartbeat;

adding the measured interval to a record of a series of intervals corresponding to a series of preceding heartbeats;

calculating a heart rate variability (HRV) parameter based upon a predetermined number of recorded intervals; and

applying a heart treatment if the HRV parameter exceeds a threshold.

13. The method for providing heart treatment according to claim 12, further including, after measuring an interval, applying a test to a predetermined number of recorded intervals and obtaining test results;

repeating the previous steps if the test results fail within a first predetermined range of values; and

calculating the heart rate variability (HRV) parameter if the test results fall within a second predetermined range of values.

14. The method for providing heart treatment according to claim 13, wherein the test comprises comparing a pulse rate corresponding to the predetermined number of recorded intervals to a threshold pulse rate, and wherein the first range of values are pulse rates below the threshold pulse rate and the second range of values are pulse rates above the threshold pulse rate

15. The method for providing heart treatment according to claim 12, wherein the treatment comprises at least one of applying a mild warning shock, injecting a drug, and applying a voltage to pace the heart.

16. A system for measuring heart rate variability (HRV), the system comprising:

a data collector, to record heart beats and detect a series of heart beat intervals,

a data analyzer, to analyze the series of heart beat intervals and obtain an HRV value based on a relative density parameter; and

an output device, to output the HRV value.

17. The system for measuring heart rate variability (HRV) according to claim 16, wherein the output device is at least one of a screen, to display the HRV value, a printer, to print the HRV value, an alarm, to raise an audible sound, and an injector, to deliver an injection to a patient.