Method and system for characterizing the quality of signals indicative of heart function

• US 5,967,994 A
• Filed: 03/26/1998
• Issued: 10/19/1999
• Est. Priority Date: 03/26/1998
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Wang, Jyh-Yun J.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/048,620
• Time in Patent Office: 572 Days
• Field of Search: 600/508, 600/509, 600/516, 600/517
• US Class Current: 600/509
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence

Abstract

A method and system for characterizing the quality of signals indicative of heart function, where such signals indicative of heart function are derived from electrocardiographic measurements. In the method and system, one or more signals indicative of heart function are measured. In response to the measuring, a noise metric, drawn upon physiologic and non-physiological sources, is created. In response to the creation of the noise metric, the quality of the measured one or more signals is designated.

Claims

1. A method for characterizing the quality of signals indicative of heart function, where such signals indicative of heart function are derived from electrocardiographic measurements, said method comprising the steps of:

measuring one or more signals indicative of heart function;

in response to said step of measuring, creating a noise metric drawn upon physiological and non-physiological sources; and

in response to said step of creating, designating the quality of the one or more signals indicative of heart function.

2. The method of claim 1, wherein said step of creating a noise metric further comprises the steps of:

calculating mismatch between successive QRS complexes in the one or more signals; and

in response to said step of calculating, maintaining a cumulative record of the mismatch between successive QRS complexes in the one or more signals.

3. The method of claims 2, wherein said step of calculating mismatch further comprises calculating area differences between directly in sequence QRS complexes in the one or more signals.

4. The method claim 2, wherein said step of calculating mismatch further comprises the step of calculating area differences between indirectly in sequence QRS complexes in the one or more signals.

5. The method of claim 2, wherein said step of maintaining a cumulative record further comprises the step of recording a histogram of the mismatch between successive QRS complexes in the one or more area signals.

6. The method of claim 5, wherein said step of recording a histogram of the mismatch between successive QRS complexes in the one or more signals further comprises the step of recording a cumulative histogram of the mismatch between successive QRS complexes in the one or more signals.

7. The method of claim 5, wherein said step of designating the quality of the one or more signals further comprises the step of:

comparing one or more distributions of the histogram of the mismatch between successive QRS complexes in the one or more signals; and

in response to said comparing, rank ordering the one or more measured signals.

8. The method of claim 7, wherein said step of rank ordering further comprises the step of ranking as higher quality those one or more signals whose distributions are centered about a smaller mean.

9. The method of claim 7, wherein said step of rank ordering further comprises the step of ranking as higher quality those one or more signals whose distributions are narrow.

10. The method of claim 1 further comprising the step of rank ordering the one or more signals.

11. A system for characterizing the quality of signals indicative of heart function, where such signals indicative of heart function are derived from electrocardiographic measurements, said system comprising:

means for measuring one or more signals indicative of heart function;

means, responsive to said means for measuring, for creating a noise metric drawn upon physiological and non-physiological sources; and

means, responsive to said means for creating, for designating the quality of the one or more signals indicative of heart function.

12. The system of claim 11, wherein said means for creating a noise metric further comprises:

means for calculating mismatch between successive QRS complexes in the one or more signals; and

means, responsive to said means for calculating, for maintaining a cumulative record of the mismatch between successive QRS complexes in the one or more signals.

13. The system of claim 12, wherein said means for calculating mismatch further comprises means for calculating area differences between directly in sequence QRS complexes in the one or more signals.

14. The system of claim 12, wherein said means for calculating mismatch further comprises means for calculating area differences between indirectly in sequence QRS complexes in the one or more signals.

15. The system of claim 12, wherein said means for maintaining a cumulative record further comprises the step of recording a histogram of the mismatch between successive QRS complexes in the one or more area signals.

16. The system of claim 15, wherein said means for recording a histogram of the mismatch between successive QRS complexes in the one or more signals further comprises means for recording a cumulative histogram of the mismatch between successive QRS complexes in the one or more signals.

17. The system of claim 15, wherein said means for designating the quality of the one or more signals further comprises:

means for comparing one or more distributions of the histogram of the mismatch between successive QRS complexes in the one or more signals; and

means, responsive to said means for comparing, for rank ordering the one or more measured signals.

18. The system of claim 17, wherein said means for rank ordering further comprises means for ranking as higher quality those one or more signals whose distributions are centered about a smaller mean.

19. The system of claim 17, wherein said means for rank ordering further comprises means for ranking as higher quality those one or more signals whose distributions are narrow.

20. The system of claim 11 further comprising means for rank ordering the one or more signals.