11.5 Frequency Filters

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Functionality is available in the Pro edition
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If an ECG is recorded with distorsions, use filters to correct the graphs.

When filters are used, graphs are changed. To establish a diagnosis, you need to use original data.

These filters remove the components those frequency is higher than 35 Hz (the Low pass filter 35 Hz button) or 75 Hz (the Low pass filter 75 Hz button). To apply the filter, click the corresponding button. To cancel filtering, click the corresponding button again. Only one filter can be applied at a time.

To remove power line interference from the ECG signal, use the Notch filter. The tool has 2 predefined values (50 Hz and 60 Hz). To select a filter value, click on the arrow on the right side of the Notch filter button. The current value is marked with a flag. If you need to set a different value, select the Custom... item in the button menu and set the value in the dialog that opens. To use the filter with the current value, click on the Notch filter button. To cancel filtering, click the button again.

To remove the walks of the baseline of the graph, use a High pass filter 1Hz. To apply the filter, click the High pass filter 1Hz button. To cancel filtering, click the button again.