Detection of cardiac arrhythmia using mathematical representation of standard deltaRR probability density histograms

• US 20050004486A1
• Filed: 03/06/2003
• Published: 01/06/2005
• Est. Priority Date: 03/20/2002
• Status: Active Grant

• Current Assignee: McGill University, Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Katsumi Tateno, Leon Glass
• Inventors: Tateno, Katsumi, Glass, Leon
• Granted Patent: US 7,146,206 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 5/361 Detecting fibrillation

Abstract

A method and a system for detecting cardiac arrhythmias that includes detecting RR intervals of the patient wherein each RR interval is an interval between two heart beats, and simulating standard probability density histograms of ΔRRs by means of a suitable probability distribution calculated through at least one mathematical formulae, wherein ΔRR is a difference between two successive RR intervals. Test probability density histograms of ΔRRs of the patient are constructed from the detected RR intervals. Finally, the standard and test histograms are compared to detect whether the patient suffers from cardiac arrhythmia. As non limiting examples, the standard probability density histograms of ΔRRs are modeled by a mathematical equation selected from the group consisting of: the Lorentzian distribution, the Gaussian distribution, the Student'"'"'s t-distribution, and a probability distribution including a linear combination of the Lorentzian and Gaussian distribution.

Claims

1. A method for detecting cardiac arrhythmia of a patient, comprising:

detecting RR intervals of the patient wherein each RR interval is an interval between two heart beats;

constructing standard probability density histograms of Δ

RRs collected during cardiac arrhythmia of a plurality of subjects, wherein Δ

RR is a difference between two successive RR intervals;

modeling the standard probability density histograms of Δ

RRs by means of a suitable probability distribution calculated through at least one mathematical formulae;

constructing test probability density histograms of Δ

RRs of the patient from the detected RR intervals of said patient; and

comparing the standard modeled histograms and the test histograms to detect whether the patient suffers from cardiac arrhythmia.

2. A method for detecting cardiac arrhythmia as defined in claim 1, wherein simulating standard probability density histograms of Δ

RRs comprises modeling the standard probability density histograms of Δ

RRs by a mathematical equation selected from the group consisting of;

the Lorentzian distribution, the Gaussian distribution, the Student'"'"'s t-distribution, and a probability distribution including a linear combination of the Lorentzian and Gaussian distribution.

3. A method of for detecting cardiac arrhythmia as defined in claim 1, wherein said cardiac arrhythmia is atrial fibrillation.

4. A method for detecting cardiac arrhythmia as defined in claim 1, wherein comparison of the standard modeled histograms and the test histograms to detect whether the patient suffers from cardiac arrhythmia comprises performing a Kolmogorov-Smirnov test, said method further comprising eliminating premature ventricular contractions prior to performing the Kolmogorov-Smirnov test.

6. A system for detecting cardiac arrhythmia as defined in claim 3, wherein the simulator comprises a standard Δ

RR probability density histograms modeling unit using a mathematical equation selected from the group consisting of;

the Lorentzian distribution, the Gaussian distribution, the Student'"'"'s t-distribution, and a probability distribution comprising a linear combination of the Lorentzian and Gaussian distribution.

5. A system for detecting cardiac arrhythmia of a patient, comprising:

a detector of RR intervals of the patient, wherein each RR interval is an interval between two heart beats;

a standard probability density histogram storage unit in which are stored standard probability density histograms of Δ

RRs collected during cardiac arrhythmia of a plurality of subjects, said standard probability density histograms of Δ

RRs being modeled by means of a suitable probability distribution calculated through at least one mathematical formulae, and Δ

RR being a difference between two successive RR intervals;

a test Δ

RR histogram calculator supplied with the detected RR intervals from the detector and constructing test histograms of the Δ

RRs of the patient; and

a standard and test Δ

RR histograms comparator supplied with the standard modeled histograms and test histograms, this comparator comprising a detector of cardiac arrhythmia of the patient responsive to the comparison of the standard and test histograms.