Automated signal detection

...

HOW CAN I MOVE QRS PEAK EVENT MARKS FROM THE BOTTOM OF S WAVES TO THE TOP OF R WAVES?

Missing markers

Manually add placeholder markers where systoles are missing

To add markers, select the flag tool and click above each R peak where the qrs marker is missing. Do all qrs markers at once. We have to place these placeholders roughly on the peaks, and subsequently use their locations to place qrs markers at the exact peaks of the signal.

...

Place qrs markers

Then go to Analysis → Find cycle

...

Under the Cycles/Peaks tab, select “Events”, then “Start event” → “Notes” → “Flag”

...

Under “End event”, also select the flag and under both “located on”, select CH9 ECG.

Go to the selection tab. Since we used eye balling to place the flag markers, we now want to select an area around the flag in which we can tell the software to place the correct markers exactly on the maximum signal of each R peak.

We have to provide a range to the left of the flag (“Left edge”) and to the right of the flag (“Right edge”).

The left requires you to add a “-” in the “seconds” box, followed by a number. Try something like -0.2 and under right edge, try 0.2. On the bottom of the window, you will see the selection range appear in blue. Make sure all peaks are included by the selection.

...

Go to the Output tab → Events. Check the “Output events” box. Here we tell the software to output new markers (Events) onto our ECG signal. Select “Maximum”, i.e. top of the peak. The top dropdown channel is where the software will look for signal peaks. The Output type is “Hemodynamics → qrs”, i.e. we want to output qrs markers. The “Output channel” is where the qrs markers will be placed. If this seems confusing, you can technically find peaks on the ECG channel and output markers onto a different channel. Under “Event 2” on the bottom, select “None”.

Click “Find all cycles” on the bottom.

...

The software will ask where you want to start looking for markers. Click “Set to origin”.

...

Remove flags

The software now places qrs markers on the peaks on the peaks around each flag.

We now have to remove all flags. Right-click on any marker and click “Edit event”. In the new window, check the first two boxes. Select “Flag” under type and select the ECG channel. Be careful here, this action cannot be undone. If you have flags saved in other channels, they will be removed if you don’t check the second box. In the “Events” window, click “Clear” towards the bottom. In the box that opens, select “are of type” and find “Flags” under “Notes”. If you want to make sure you do not accidentally remove flags in other channels, you can also check “are defined on” and find “CH9, ECG”.

...

In the next box, the warning says “this action cannot be undone”. Click ok. The flags are now removed.

Repeat the Find cycle steps as briefly summarized below.