Method and apparatus for monitoring electrocardiogram (ECG) signals

Apparatus for monitoring ECG signals, characterized in that it includes:

• detecting means for detecting successive ECG signal waves;
• filter means for filtering the detected ECG signal waves to pass a frequency band within a range of about 25-300 Hz;
• first and second storage devices;
• means for initially storing the first detected and filtered ECG signal wave in said first storage device, and for storing each successive filtered ECG signal wave in said second storage device;
• cross-correlation means for cross-correlating each signal wave stored in said second storage device with that stored in said first storage device, and for including means determlning whether the maximum cross-correlation coefficient exceeds a predetermined value;
• averaging means for averaging, with the signal wave stored in said first storage device, each of said successive signal waves having a maximum cross-correlation coefficient exceeding said predetermined value, and for storing the averaged signal wave in the first storage device in place of the signal wave previously stored therein;
• and display means for displaying the averaged signal wave stored in said first storage device.