4. Defibrillator Mode Testing
This chapter describes QA-45 defibrillator mode testing.
4.1 Introduction
The defibrillator function of the QA-45 measures the energy output,
and ensures that the defibrillator complies with specified require-
ments. QA-45 has a built-in load resistance of 50 ohm, which
roughly corresponds to the impedance of the human body. The de-
fibrillator pads are placed on the QA-45 contact plates. Thus, the de-
fibrillator is connected through the load resistance. When the defib-
rillator is discharged, QA-45 will calculate and display the energy
delivered.
Defibrillator energy is defined as an integral of the moment of the
discharged energy from the defibrillator. The energy is equal to the
square of the voltage, divided by the load resistance.
QA-45 measures and records the voltage pulse every 100 µs, 1000
times, for a total time of 100 ms. The squares of the voltages are
then summed, multiplied by 100 µs, and divided by the load resis-
tance, 50 ohms.
The unit for energy is 'joule', which is equal to Ws (Watt second).
4.2 Test Preparation
1. If checking ECG monitoring, prompting, or triggering from the
ECG, connect the low level or high level ECG connectors to the
ten 4 mm AHA color-coded safety terminals or standard phone
jack, as appropriate.
2. Switch the QA-45 on. The following will be displayed in the
LCD display for about two seconds:
3. The following main menu will then appear. It will show LO-
CAL, indicating that the testing is not remotely controlled by
PRO-Soft QA-40M/45 test automation software.
1000 1000
E = (V
2
) • dt / R = (V
2
) • 100 µs / 50 ohms
0 0
E = p dt = V
2
/ R dt = V
2
dt / R
1
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