Method and apparatus for facilitating physiological coherence and autonomic balance

• US 20070021675A1
• Filed: 09/27/2006
• Published: 01/25/2007
• Est. Priority Date: 03/02/1999
• Status: Active Grant

• Current Assignee: Quantum Intech, Inc.
• Original Assignee: Quantum Intech, Inc.
• Inventors: McCraty, Rollin, Atkinson, Michael, Childre, Doc
• Granted Patent: US 7,462,151 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/4047 afferent nerves, i.e. nerves that relay impulses to the central nervous system
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence

Abstract

Method and apparatus for determining the state of entrainment between biological systems which exhibit oscillatory behavior such as heart rhythms, respiration, blood pressure waves and low frequency brain waves based on a determination of heart rate variability (HRV) and an evaluation of the power spectrum thereof. Entrainment reflects a harmonious balance between the two branches of the autonomic nervous system within the body. This internal state of heightened physiological efficiency enhances health and promotes optimal performance. According to one embodiment a method is used to determine the entrainment level based on an entrainment parameter related to HRV, The method first determines the power distribution spectrum (PSD) and then calculates an entrainment parameter (EP), which is a measure of the power distribution in the HRV spectrum. High EP values occur when this power is concentrated within a relatively narrow range of frequencies, and lower values when the power is distributed over a broader range of frequencies. In one embodiment, an apparatus is provided for monitoring the heart beat and presenting this information via a personal computer, handheld device, or other processing means.

Claims

1. A method, characterized by:

sampling a heart beat of a subject;

determining a heart rate variability (HRV) of the heart rate as a function of time (HRV(t));

expressing HRV(t) as a function of frequency (HRV(f));

determining a distribution of frequencies in HRV(f);

selecting a peak frequency of HRV(f);

determining the energy in said peak frequency (E_peak);

determining the energy in frequencies below said peak frequency (E_below) and above said peak frequency (E_above);

determining a ratio of E_peak to E_below and E_above; and

providing to the subject, in a first presentation format, a representation of a first parameter related to said ratio.

2. The method as in claim 1, wherein the ratio is characterized as:

3. The method as in claim 2, wherein the first parameter is characterized by an entrainment parameter (EP).

4. The method as in claim 3, further characterized by the step of:

demeaning and detrending the HRV(t).

5. The method as in claim 2, wherein the frequency distribution determining step is further characterized as:

determining a power spectrum distribution (PSD) of frequencies in HRV(f);

6. The method as in claim 1, wherein the method is practiced in a data processing system including a display, wherein the method is further characterized by the steps of:

determining an entrainment parameter (EP), related to the ratio;

in response to a first EP value, providing a first image on the display; and

in response to a second EP value, different from the first EP value, altering the first image on the display.

7. The method as in claim 6, further characterized as:

wherein the first image includes a graphic element in a first position;

wherein if the second EP value is greater than the first EP value, the graphic element transitions toward a goal; and

wherein if the second EP value is less than the first EP value, the graphic element transitions away from the goal.

8. A software program performing the method of claim 1.

9. The method as in claim 1, further characterized by the steps of:

digital signal processing the HRV to provide a plurality of bins corresponding to frequencies;

selecting the peak within a first predetermined range of the frequencies;

calculating the power in the bins corresponding to the peak;

calculating the power in the bins below those corresponding to the peak; and

calculating the power in the bins above those corresponding to the peak.

10. An apparatus, characterized by:

sampling means adapted to sample a heart beat of a subject for a first predetermined time period;

a display unit;

a processing unit coupled to the sampling means and the display unit, wherein the processing unit is adapted to;

determine a heart rate variability (HRV) of the heart beat as a function of time by measuring the interval between each beat during the first predetermined time period;

determine a frequency distribution of the HRV, the frequency distribution having at least one peak including a first number of frequencies;

calculate a first parameter of the frequency distribution of the HRV, wherein the first parameter is a ratio of the area under the at least one peak to the area under the rest of the frequency distribution; and

output the first parameter to the display unit for presentation to the subject.

11. A method, comprising the steps of:

receiving heart rate variability (HRV) information, the HRV information comprising the time intervals between each heart beat of a subject during a first predetermined time period;

expressing the HRV as a function of frequency;

determining the power in said HRV over a first range of frequencies;

selecting a power peak in said first range of frequencies;

calculating a first parameter relating the power in said selected power peak to the power in said HRV over a second range of frequencies;

presenting the first parameter to the subject.