Using the ECG Quiz Calipers

The Analysis Window of each type of ECG in the ECG Quiz displays the ECG in greater detail, allowing for precise measurements. You can use calipers in this window to measure intervals and amplitudes on the ECG. Two caliper modes are available:

• The Time Caliper: For measuring time intervals.
• The Voltage Caliper: For measuring amplitudes.

The active caliper mode is displayed in the lower-right corner of the Analysis Window, as shown in the inset figure to the right.

The following instructions are demonstrated using the Analysis Window of a 60-second single-lead telemetry ECG. The functionality of the calipers remains consistent regardless of the type of ECG being analyzed.

To activate the Time Caliper, press the 'T' key while the mouse is in the Analysis Window. When activated:

1. The Caliper Mode indicator in the lower-right corner updates.
2. The cursor changes to a caliper, as shown in Figure 1 between the 1st and 2nd QRS complexes..

Press the 'T' key again to deactivate the Timing Caliper.

To create a Time Caliper, follow these steps:

1. Move the left arm of the caliper cursor to the desired start location.
2. Press and hold the left mouse button, then drag the mouse left or right to begin measuring.
3. As you move the mouse, the Time Caliper Measurement comprising two lines and a measurement box will appear on the ECG.
4. Release the mouse button at the desired end location to finalize the measurement.

To measure a different region of the ECG when a Time Caliper Measurement is already present, repeat the steps outlined above but start the measurement outside the boundaries of the existing one.

To adjust the start or stop locations of an existing Time Caliper Measurement, follow these steps:

1. Place the mouse cursor over one of the two measurement lines. The cursor will change to , indicating the line can be moved.
2. Press and hold the left mouse button, then drag the line left or right to the desired position.
3. Release the mouse button to set the new location.

Alternatively, you can adjust the caliper using the keyboard.

You can reposition a Time Caliper Measurement within the Analysis Window. For example, to compare the RR intervals between different QRS complexes:

1. Place the mouse cursor between the two measurement lines. The cursor will change to , indicating the measurement can be moved.
2. Click and hold the left mouse button, then drag the measurement left or right to the desired location.
3. Release the mouse button to set the new position.

Alternatively, you can move the Time Caliper using the keyboard.

To clear a Time Caliper Measurement, you can

1. Click the mouse on the ECG in the Analysis Window outside of the Time Caliper Measurement
2. Toggle the caliper mode off and then on again by pressing the 'T' key twice
3. Pressing the 'Escape' key

To activate the Voltage Caliper, press the 'V' key while the mouse is in the Analysis Window. When activated:

1. The Caliper Mode indicator in the lower-right corner updates.
2. The cursor changes to a caliper, as shown in Figure 4 between the 3rd and 4th QRS complexes.

Press the 'V' key again to deactivate the Timing Caliper.

To create a Voltage Caliper, follow these steps:

1. Move the top arm of the caliper cursor to the desired start location.
2. Press and hold the left mouse button, then drag the mouse up or down to begin measuring.
3. As you move the mouse, the Voltage Caliper Measurement comprising two lines and a measurement box will appear on the ECG.
4. Release the mouse button at the desired end location to finalize the measurement.

To measure a different region of the ECG when a Voltage Caliper Measurement is already present, repeat the steps outlined above but start the measurement outside the boundaries of the existing one.

To adjust the start or stop locations of an existing Voltage Caliper Measurement, follow these steps:

1. Place the mouse cursor over one of the two measurement lines. The cursor will change to , indicating the line can be moved.
2. Press and hold the left mouse button, then drag the line up or down to the desired position.
3. Release the mouse button to set the new location.

Alternatively, you can adjust the caliper using the keyboard.

You can reposition a Voltage Caliper Measurement within the Analysis Window. For example, to compare the amplitudes of different QRS complexes:

1. Place the mouse cursor between the two measurement lines. The cursor will change to , indicating the measurement can be moved.
2. Click and hold the left mouse button, then drag the measurement up or down to the desired location.
3. Release the mouse button to set the new position.

Alternatively, you can move the Voltage Caliper using the keyboard.

To clear a Voltage Caliper Measurement, you can

1. Click the mouse on the ECG in the Analysis Window outside of Voltage Caliper Measurement
2. Toggle the caliper mode off and then on again by pressing the 'V' key twice
3. Pressing the 'Escape' key