BC Biomedical DA-2006, Service Manual, Page: 51 / 171

Defibrillator Analyzer
44
The energy contained in a pulse is determined mathematically based on the fact that
the energy is defined as the integral of the power curve. The following formulas
describe the basic computation:
Energy = E = P dt
Power = P = V
2
/ R => E = V
2
/ R dt = V
2
dt / R
This computation is implemented digitally by taking timed samples of the voltage every
100 µsec for 100 msec (1000 readings). Each value is then squared and divided by the
resistance (50 ohms). The sum of these 1000 values times 10 is then the Energy in
Joules (Watt Seconds) contained in the pulse.