System and method for evaluating cardiovascular performance in real time and characterized by conversion of surface potential into multi-channels

• US 8,571,645 B2
• Filed: 04/13/2012
• Issued: 10/29/2013
• Est. Priority Date: 12/20/2011
• Status: Active Grant

• Current Assignee: National Taiwan University (Government of The Republic of China)
• Original Assignee: National Taiwan University (Government of The Republic of China)
• Inventors: Wu, Chau-Chung, Lin, Chii-Wann, Liu, Chien-Sheng
• Primary Examiner(s): DIETRICH, JOSEPH M
• Application Number:
  US13/445,985
• Publication Number:
  US 20130158421A1
• Time in Patent Office: 564 Days
• Field of Search: 600/515, 600/516, 600/517
• US Class Current: 600/516
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/327 Generation of artificial ECG signals based on measured signals, e.g. to compensate for missing leads
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats

Abstract

A system and method for evaluating cardiovascular performance in real time and characterized by conversion of a surface potential into multi-channels are introduced. The system includes an electrocardiographic signal measuring unit, a reconstruction unit, and a parameter computation and assessment unit. The reconstruction unit reconstructs electrocardiographic signals (ECG signals) recorded by the electrocardiographic signal measuring unit, such that the ECG signals are reconstructed as ones located at different spatial positions but actually not having a channel. The method includes calculating a variation manifested spatially during an interval between a Q wave and a T wave of an ECG signal against time with a parameter computation and assessment algorithm, to evaluate its discreteness degree and thereby diagnose cardiovascular diseases (CVD) and locate lesions thereof.

Claims

1. A system for evaluating cardiovascular performance in real time and characterized by conversion of a surface potential into multi-channels, the system comprising:

an electrocardiographic signal measuring unit comprising at least one channel located at different spatial positions, the electrocardiographic signal measuring unit recording electrocardiographic signals (ECG signals) measured with the channels, the ECG signals each comprising a P wave, a Q wave, a R wave, a S wave, and a T wave;

a reconstruction unit electrically connected to the electrocardiographic signal measuring unit, the reconstruction unit having a reconstruction algorithm for calculating eigenvectors of the ECG signals and using the eigenvectors as a base for calculating an eigenvalue matrix, the reconstruction unit calculating at least one reconstructed ECG signal at other different spatial positions with the eigenvalue matrix and the ECG signals of the channels, the at least one reconstructed ECG signal comprising a reconstructed P wave, a reconstructed Q wave, a reconstructed R wave, a reconstructed S wave, and a reconstructed T wave; and

a parameter computation and assessment unit electrically connected to the reconstruction unit and having a parameter computation and assessment algorithm,

wherein the parameter computation and assessment unit receives the ECG signals and the at least one reconstructed ECG signal, calculates an interval from a starting point of the Q wave to an ending point of the T wave of the ECG signals, calculates variation in a reconstruction interval from a starting point of the reconstructed Q wave to an ending point of the reconstructed T wave of the at least one reconstructed ECG signal against time at different spatial positions, and evaluates the degree of discreteness of the ECG signals and the at least one reconstructed ECG signal with the parameter computation and assessment algorithm;

wherein the parameter computation and assessment algorithm is;

SI_QTc=(1/S)

2. The system for evaluating cardiovascular performance in real time of claim 1, wherein a multi-dimension space defined by an interval of the ECG signals and a reconstruction interval of the at least one reconstructed ECG signal is calculated by equation:

3. The system for evaluating cardiovascular performance in real time of claim 1, wherein the electrocardiographic signal measuring unit further comprises a signal buffer, an amplifier, and a filter, the signal buffer being electrically connected to the channels for receiving the ECG signals measured with the channels and protecting the electrocardiographic signal measuring unit, the amplifier being electrically connected between the signal buffer and the filter for receiving and amplifying the ECG signals, and the filter filtering out interference noise of the ECG signals.

4. The system for evaluating cardiovascular performance in real time of claim 1, further comprising a communication unit electrically connected to the electrocardiographic signal measuring unit, the reconstruction unit, and the parameter computation and assessment unit, the communication unit being connected to a service platform at a remote end by means of wireless or wired communication for transmitting the ECG signals, the at least one reconstructed ECG signal, and data related to the degree of discreteness thereof synchronously.

5. The system for evaluating cardiovascular performance in real time of claim 1, wherein the reconstruction algorithm is implemented by a physical circuit.

6. The system for evaluating cardiovascular performance in real time of claim 1, wherein the parameter computation and assessment algorithm is implemented by a physical circuit.

7. The system for evaluating cardiovascular performance in real time of claim 1, wherein the parameter computation and assessment unit determines whether the ECG signals are attributable to a cardiovascular disease based on the degree of discreteness.

8. A method for evaluating cardiovascular performance in real time and characterized by conversion of a surface potential into multi-channels, the method comprising the steps of:

measuring, by the electrocardiographic signal measuring unit, electrocardiographic signals (ECG signals) at different spatial positions with at least one channel, the ECG signals each comprising a P wave, a Q wave, a R wave, a S wave, and a T wave;

calculating, by a reconstruction unit, eigenvectors of the ECG signals with a reconstruction algorithm, an eigenvalue matrix with the eigenvectors being used as a base, and at least one reconstructed ECG signal at other different spatial positions with the eigenvalue matrix and the ECG signals of the channels, the at least one reconstructed ECG signal comprising a reconstructed P wave, a reconstructed Q wave, a reconstructed R wave, a reconstructed S wave, and a reconstructed T wave; and

receiving the ECG signals and the at least one reconstructed ECG signal by a parameter computation and assessment unit, calculating an interval from a starting point of the Q wave to an ending point of the T wave of the ECG signals, calculating variation in a reconstruction interval from a starting point of a reconstructed Q wave to an ending point of a reconstructed T wave of the at least one reconstructed ECG signal against time at different spatial positions, and evaluating a degree of discreteness of the at least one reconstructed ECG signal and the ECG signals with the parameter computation and assessment algorithms;

wherein the parameter computation and assessment algorithm is;

SI_QTc=(1/S)

9. The method for evaluating cardiovascular performance in real time of claim 8, wherein a multi-dimension space defined by the interval of the ECG signals and the reconstruction interval of the at least one reconstructed ECG signal is calculated by equation:

10. The method for evaluating cardiovascular performance in real time of claim 8, wherein the electrocardiographic signal measuring unit further comprises a signal buffer, an amplifier, and a filter, the signal buffer being electrically connected to the channels for receiving the ECG signals measured with the channels and protecting the electrocardiographic signal measuring unit, the amplifier being electrically connected between the signal buffer and the filter for receiving and amplifying the ECG signals, and the filter filtering out interference noise of the ECG signals.

11. The method for evaluating cardiovascular performance in real time of claim 8, wherein a communication unit is electrically connected to the electrocardiographic signal measuring unit, the reconstruction unit, and the parameter computation and assessment unit, the communication unit being connected to a service platform at a remote end by means of wireless or wired communication for transmitting the ECG signals, the at least one reconstructed ECG signal, and data related to the degree of discreteness thereof synchronously.

12. The method for evaluating cardiovascular performance in real time of claim 8, wherein the reconstruction algorithm is implemented by a physical circuit.

13. The method for evaluating cardiovascular performance in real time of claim 8, wherein the parameter computation and assessment algorithm is implemented by a physical circuit.

14. The method for evaluating cardiovascular performance in real time of claim 8, wherein the parameter computation and assessment unit determines whether the ECG signals are attributable to a cardiovascular disease based on the degree of discreteness.