Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection

• US 7,539,535 B1
• Filed: 01/26/2006
• Issued: 05/26/2009
• Est. Priority Date: 07/12/2001
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: DePalma, Jude L., Schlegel, Todd T., Moradi, Saeed
• Primary Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US11/345,687
• Time in Patent Office: 1,216 Days
• Field of Search: None
• US Class Current: 600/517
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle

Abstract

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as “RAZs”. RAZs are displayed as “go, no-go” signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

Claims

1. A process of operating a computer, comprised of a general purpose data processor of known type and a display device, to enable the data processor to execute a plurality of steps in an object program, such that the same results will be produced when using the same given data, comprising the steps of:

a. inputting a patient'"'"'s electrocardiograph signal to the computer via a communications channel, the signal comprising a succession of waves;

b. using the data processor to independently isolate the QRS interval from each of the waves of the signal;

c. using the data processor to independently analyze data within each of the isolated

QRS intervals relating to cardiac function of a patient in real-time, the step of analyzing including band-pass filtering the data between about 150 Hz and about 250 Hz; and

d. using the display device to display the analyzed data, the signal, the waves of the signal, the QRS intervals, or any combination beat-by-beat in real-time.

2. The process of claim 1, wherein the step of analyzing the data within the QRS interval further comprises the steps of:

using the data processor to generate an initial template of the signal using the first QRS interval from the first wave of the signal;

using the data processor to cross-correlate each subsequent independently isolated QRS interval against predetermined criteria wherein accepted QRS intervals are incorporated into the initial template to create a running template in real-time;

using the data processor to align each independently isolated QRS interval with the running template in real-time; and

using the data processor to calculate predetermined, selectable characteristics of each QRS interval in a beat-by-beat, real-time manner.

3. The process of claim 2, wherein the step of using the data processor to calculate is comprised of calculating a reduced amplitude zone,

wherein the reduced amplitude zone occurs when at least two local maxima or at least two local minima are present in the filtered data;

and

wherein each local maximum or each local minimum is a peak or a trough, respectively and wherein the absolute value of each peak or trough'"'"'s voltage exceeds that of a predetermined number of sample points within the filtered data immediately preceding and following each peak or trough.

4. The process of claim 3, wherein the absolute value of the amplitude of the smallest of the at least two local maxima or the smallest of the at least two minima is at least a predetermined percentage relative to the largest of the at least two maxima or the largest of the at least two minima, respectively.

5. The method of claim 3, wherein the absolute value of the amplitude of the smallest of the at least two local maxima or the smallest of the at least two local minima is at least a predetermined multiple of the high frequency noise level of a predetermined iso-electric portion.

6. The method of claim 2, wherein the step of using the data processor to calculate is comprised of calculating a skewness, kurtosis, or both of the filtered data.

7. The process of claim 1, wherein the step of using the data processor to independently analyze is further comprised of using the data processor to compute the presence or absence of reduced amplitude zones from the high frequency filtered data associated with the QRS interval.

8. A process of operating a computer, comprised of a general purpose data processor of known type, to enable the data processor to execute a plurality of steps in an object program, such that the same results will be produced when using the same given data, comprising the steps of:

a. inputting a patient'"'"'s electrocardiograph signal to the computer via a communications channel, the signal comprising a succession of waves;

b. using the data processor to independently isolate the QRS interval from each of the waves of the signal;

c. using the data processor to independently analyze data within each of the QRS intervals relating to cardiac function of a patient in real-time, the step of analyzing including band-pass filtering the data between about 150 Hz and about 250 Hz;

d. connecting a storage device to the data processor; and

e. using the storage device to store the analyzed data, the signal, the waves of the signal, the QRS intervals, or any combination.

9. An electronic storage database of the analyzed data, the signal, the waves of the signal, the QRS intervals, or any combination resulting from the process described in claim 8 wherein the database is stored in the storage device.