Apparatus and method for reading and analyzing ECG images

• US 20020172404A1
• Filed: 05/17/2001
• Published: 11/21/2002
• Est. Priority Date: 05/17/2001
• Status: Active Grant

• Current Assignee: AMPS, LLC
• Original Assignee: AMPS, LLC
• Inventors: Badilini, Fabio F.
• Granted Patent: US 6,580,817 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/36 Detecting PQ interval, PR interval or QT interval
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes

Abstract

A method of analyzing an electrocardiogram (ECG) paper chart includes the steps of scanning the ECG chart, to thereby create a computer-readable ECG image file representative of the ECG chart, storing the ECG image file in a memory of a computer, opening the ECG image file and displaying on a computer display an ECG plot corresponding to the ECG image file, calibrating the x-axis and y-axis of the displayed ECG plot with an x-axis scale and a y-axis scale, identifying characteristics of the ECG plot by using an input device connected to the computer, and measuring the identified characteristics.

Claims

1. A computerized method of analyzing an electrocardiogram (ECG) paper chart, comprising the steps of:

scanning the ECG chart to thereby create a computer-readable ECG image file representative of the ECG chart;

storing said ECG image file in a memory of a computer;

opening said ECG image file;

displaying an ECG plot of said ECG image file on a display of the computer;

calibrating an x-axis and a y-axis of said ECG plot;

identifying characteristics of said ECG plot by using at least one input device connected to the computer; and

measuring said identified characteristics.

2. The method of claim 1, wherein said scanning step comprises scanning the ECG chart with an optical scanner.

3. The method of claim 1, wherein said storing step comprises storing said ECG image file in a memory of the computer, said memory comprising one of a random access memory, a read only memory, a hard disk and a floppy disk.

4. The method of claim 1, wherein said calibrating step comprises:

scaling the x-axis of said ECG plot; and

scaling the y-axis of said ECG plot.

5. The method of claim 4, wherein each of said scaling steps comprise:

accessing a tool bar displayed on the computer display;

selecting a button of said toolbar corresponding to one of the x-axis and the y-axis of said ECG plot to thereby select one of the x-axis and y-axis for calibration; and

drawing a calibration line for one or both axes and assigning a calibrated scale to the length of the line and to the axes;

drawing a feature line with a first end point at one feature and second end point at a second feature; and

automatically finding the distance between the two end points as projected upon one or both axes of said ECG plot.

6. The method of claim 5, wherein said drawing step comprises:

drawing a calibration line of a predetermined length, said predetermined length corresponding to a default value; and

assigning said default value to a portion of the selected one of the x-axis and the y-axis, said portion having a portion length equal to said predetermined length.

7. The method of claim 6, comprising the further step of calculating a magnitude of a projection of said feature line onto one of the calibrated axes, said projection being substantially parallel to the selected axis, said magnitude corresponding to the product of the scale of the axis and the length of the projected line.

8. The method of claim 5, further comprising the step of inputting a value corresponding to a projection of said calibration line, said projection being substantially parallel to the selected one of the x-axis and the y-axis, said value being assigned to an equal length of the selected one of the x-axis and the y-axis.

9. The method of claim 1, wherein said identifying step comprises selecting with an input device at least one of an RR interval, a QT interval, a PR interval, a QRS interval, a baseline, a tangent line, and an onset of a QRS interval.

10. The method of claim 9, wherein said identifying step further comprises selecting a first point on the ECG plot that corresponds to a beginning of a selected one of an RR interval, a QT interval, a PR interval, a QRS interval, a baseline, a tangent line, and an onset of a QRS interval, and selecting with an input device a second point on the ECG plot that corresponds to an end of the selected one of an RR interval, a QT interval, a PR interval a QRS interval, a baseline, a tangent line, and an onset of a QRS interval.

11. The method of claim 10, further comprising the step of labeling the selected one of an RR interval, a QT interval and a QRS interval, a baseline and a tangent line.

12. The method of claim 11, wherein said labeling step comprises selecting with an input device a label from a menu displayed on the display of the computer, said label corresponding to the selected one of an RR interval, a QT interval, a PR interval, a QRS interval, a baseline, a tangent line, and an onset of a QRS interval.

13. The method of claim 1, wherein said measuring step comprises calculating a duration of at least one of an RR interval, a QT interval, a PR interval and a QRS interval identified in said identifying step.

14. The method of claim 1, comprising the further step of calculating and displaying a baseline of said ECG plot.

15. The method of claim 14, wherein said calculating and displaying a baseline step is performed separately for each QRS interval of the ECG plot to thereby establish a respective baseline for each QRS interval.

16. The method of claim 1, comprising the further step of calculating with the tangent method a QT interval identified in said identifying step.

17. The method of claim 16, wherein said calculating with the tangent method step comprises:

accessing a tool bar displayed on the computer display;

selecting a button of said toolbar corresponding to said calculating with the tangent method step; and

displaying on the display the calculated QT interval.

18. The method of claim 1, comprising the further steps of:

calculating an average of the RR intervals identified in said identifying step and measured in said measuring step; and

calculating an average QT interval of the QT intervals identified in said identifying step and measured in said measuring step.

19. The method of claim 17, wherein each of said calculating an average of the RR intervals and said calculating an average QT interval comprises selecting a corresponding command form a dialog box displayed on the display.

20. The method of claim 1, comprising the further step of:

exporting the results of said measuring step to a computer-readable file.

21. The method of claim 19, wherein said exporting step further comprises storing data representative of the ECG plot in said data file, storing data representative of said calibrating step, and storing data representative off said identifying step, to thereby enable subsequent display and analysis of the analyzed ECG plot.

22. A computerized method of analyzing an electrocardiogram (ECG) paper chart, comprising the steps of:

scanning the ECG chart to thereby create a computer-readable ECG image file representative of the ECG chart;

storing said ECG image file in a memory of a computer;

opening said ECG image file;

displaying an ECG plot of said ECG image file on a display of the computer;

scaling each of an x-axis and a y-axis of said ECG plot by accessing a toll bar displayed on the computer display, selecting a button of said toolbar corresponding to one of the x-axis and the y-axis to thereby select one of the x-axis and y-axis for calibration, and drawing a line generally parallel with the selected one of the x-axis and the y-axis of said ECG plot;

identifying characteristics of said ECG plot by selecting with an input device connected to the computer at least one of an RR interval, a QT interval, a PR interval, a QRS interval, a baseline, a tangent line, and an onset of a QRS interval; and

drawing a feature line between two feature points and finding a projected axial distance between the two feature points by calculating a duration each of the RR intervals, QT intervals, PR intervals and QRS intervals identified in said identifying step.

24. The system of claim 22, wherein said application software includes:

a scanning module enabling a user to control said scanner to scan the ECG chart and thereby create a computer-readable ECG image file representative of the ECG chart;

a storing module saving said ECG image file in a memory of a computer;

a file open module to enable a user to open said ECG image file;

a display module displaying an ECG plot of said ECG image file on a display of the computer;

a calibrating module to calibrate an x-axis and a y-axis of said ECG plot;

an identifying module to identify characteristics of said ECG plot by using at least one input device connected to the computer;

a measuring module measuring said identified characteristics; and

a calculating module calculating parameters of said ECG plot based upon said identified characteristics.

23. A system for analyzing an ECG paper chart, comprising:

a computer having a display, keyboard and mouse;

a scanner electrically interconnected with said computer; and

application software stored in a memory of said computer and being executable thereon, said application software configured for displaying, identifying, measuring and calculating characteristics of an image file representing said ECG chart, said image file created by scanning with said scanner the ECG chart.