METHOD AND DEVICE FOR MEASURING THE RSA COMPONENT FROM HEART RATE DATA

• US 20110301477A1
• Filed: 06/01/2011
• Published: 12/08/2011
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Zinc Software Limited
• Original Assignee: Zinc Software Limited
• Inventors: Hughes, Darran John
• Granted Patent: US 8,882,676 B2
• Time in Patent Office: Days
• US Class Current: 600/500
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: A61B 5/744 Displaying an avatar, e.g. an animated cartoon character

Abstract

A device for providing biofeedback information to a subject, including a receiver for receiving heart rate data from a sensor, said heart rate data corresponding to a human subject, a storage device for storing a time series of the received heart rate data, a display, and a processor that is programmed to enable access to the storage device and to perform actions including estimating an RSA strength of the subject'"'"'s heart from the time series of the received heart rate data, calculating an accumulated RSA strength from a designated starting time until the present time, determining a motion by a virtual agent based on the accumulated RSA strength at the present time, said virtual agent being a graphical object or character that represents the subject, and displaying the motion of the virtual agent determined by said determining on the display.

Claims

1. A device for providing biofeedback information to a subject, comprising:

a housing;

a receiver, in said housing, for receiving heart rate data from a sensor, said heart rate data corresponding to a human subject;

a storage device, in said housing, for storing a time series of the received heart rate data;

a display, mounted on a surface of said housing; and

a processor, in said housing, that is programmed to enable access to the storage device and to perform actions comprising;

estimating an RSA strength of the subject'"'"'s heart from the time series of the received heart rate data;

calculating an accumulated RSA strength from a designated starting time until the present time;

determining a motion by a virtual agent based on the accumulated RSA strength at the present time, said virtual agent being a graphical object or character that represents the subject; and

displaying the motion of the virtual agent determined by said determining on the display.

2. The device of claim 1 wherein said received heart rate data includes inter heart beat interval information for the subject'"'"'s heart.

3. The device of claim 1 wherein the virtual agent is a virtual plant.

4. The device of claim 3 wherein said processor is programmed to perform actions further comprising displaying water flowing into the virtual plant where the volume of water displayed at a specified time is based on the value of said accumulated RSA strength at the specified time.

5. The device of claim 1 wherein the virtual agent is a monk or spiritual guide.

6. The device of claim 1 in which the virtual agent is a virtual pet, wherein said processor is programmed to perform actions further comprising displaying food for the virtual pet, where the quantity of food displayed at a specified time is based on the value of said accumulated RSA strength at the specified time.

7. The device of claim 1 wherein specified time intervals are designated as sessions, and the value of the accumulated RSA strength at the end of a session is converted into a number of points and said number of points are accumulated for each session, wherein said processor is programmed to perform actions further comprising displaying the accumulated number of points.

8. The device of claim 7 wherein said displaying the accumulated number of points includes displaying coins whose total value is equal to the accumulated number of points.

9. The device of claim 1 wherein said processor is programmed to perform actions further comprising:

designating, by the subject, a target breathing rate; and

displaying a plurality of concentric circles that move at a rate related to the target breathing rate.

10. A computer-implemented method for calculating RSA from heartbeat sensor data comprising:

(a) sampling a subject'"'"'s heart beat during a window of time by a sensor to obtain heart beat sensor data;

(b) transmitting, by the sensor, heart beat sensor data corresponding to each sample during the window to a computing device;

(c) calculating, by the computing device, the inter beat intervals from the heart beat sensor data;

(d) determining, by the computing device, an all-pole filter model that best fits the inter beat interval data;

(e) calculating, by the computing device, positions of the filter model poles;

(f) identifying, by the computing device, the pole with the largest modulus within a pre-specified sector of the unit circle; and

(g) specifying, by the computing device, a value of RSA based on the identified pole.

11. The method of claim 10 wherein said specifying specifies the component strength, designated as S_RSA, according to the equation,

12. The method of claim 10 wherein the sensor is a transducer device selected from the group consisting of an electrocardiogram, a photoplethysmograph, a pressure sensor, and a microphone.

13. The method of claim 10 wherein the calculated inter beat intervals are resampled at a uniform rate.

14. The method of claim 10 further comprising de-meaning and de-trending, by the computing device, the samples in a window.

15. The method of claim 10 wherein the Burg method is used to calculate the best fit all-pole model filter coefficients.

16. The method of claim 10 wherein the pre-specified sector of the unit circle is defined by

17. The method of claim 10 wherein the pole with the largest modulus in the sector of interest is used to calculate the user'"'"'s current breathing rate according to the equation,

18. A system for presenting biofeedback information to a plurality of human subjects comprising:

a plurality of sensors, each sensor taking samples of heart rate data for a subject and transmitting heart rate data corresponding to the samples to a computing device;

a computing device comprising;

a receiver for receiving the heart rate data from each sensor;

a storage device for storing a time series of the received heart rate sensor data for each sensor;

speakers for playing a piece of music;

a processor programmed to enable access to the storage device and to perform actions comprising;

estimating an RSA strength of each subject'"'"'s heart from the time series of received heart rate data for the sensor corresponding to the subject;

calculating an accumulated RSA strength from a designated starting time until the present time for each subject;

playing a piece of music on the speakers wherein the piece of music comprises parts for a plurality of musical instruments and wherein each user corresponds to one of said instruments;

determining the volume of each instrument based on the most recent value of accumulated RSA strength for the corresponding user; and

modulating the volume of each instrument based on the determined volume for the instrument.