Operator's Manual

6.1 Electrocardiography (ECG)
Tempus Pro User/Operator Manual - 41-2001EN-00 – Page 73
The Tempus Pro presents the user ST elevation (+) and depression (-) measurements as well as QT
duration measurements for the electrocardiogram (ECG) monitoring waveform and displays it in numeric
format on the results screen.
The Tempus makes ST and QT measurements on the 2 waveforms which are viewed on the home screen.
These waveforms can be changed using the Lead Waveform selection option on the ECG menu. These
measurements can be performed on any of the lead types available from the ECG cable being used. An ST
measurement for each of the 2 waveforms is reported along with a single global QT measurement value.
The ST measurement is taken between the ECG isoelectric line (PR segment) and a point in the ST
segment. The point taken for measurement is 80 milliseconds after the J point if the heart rate does not
exceed 115 bpm and 60 milliseconds after the J point if the heart rate exceeds 115 bpm. The ST
measurement value is updated every 10s. If the measurement is not available, the display will show “- - - “.
The ST value measured is a voltage; by convention the value is displayed as the equivalent measurement
height for a standard ECG gain of 10mm/mV. In this convention 0.1mV will be displayed as 1.0mm. The ST
measurement height gain is fixed at 10mm/mV and does not depend on the ECG gain setting.
A medium priority alarm will be triggered if the ST alarm limit is exceeded for more than 1 minute and the
value will flash to indicate it is in alarm.
The QT interval is a measurement of the time between the start of the Q wave and the end of the T wave in
the heart’s electrical cycle. The Tempus Pro shows this measurement on the results screen. The QT value is
reported in milliseconds (ms).
A medium priority alarm will be triggered if the QT alarm limit is exceeded for more than 1 minute and the
value will flash to indicate it is in alarm.