Difference in electrotherapy Lifepak 12
I read now that the pacing control is to emulate a pacemaker with repetitive pulses say after the defib is used to get the heart started but with a weak response.
&quot;Controlled&quot; Current does not depend on variations in contact pad resistance which causes some skin burns and reduces the charge voltage energy in Joules. So pacing uses an estimate then quickly adjusts voltage automatically to settle on the current setpoint by measuring the impulse current peak.
Pacing control offers consistent muscle force that is proportional to the current setpoint.
The defib uses impulse energy based on experience with pads and patient response which measures the energy that is the square of the voltage actually being adjusted.
The energy is E=1/2 CV^2 (Joules) so the charge voltage is varied manually to set the Joules before discharge.
The pacer method is more accurate but requires multiple readings to obtain feedback for adjusting the next voltage to achieve the current setting, whereas setting the Joules is more direct but can vary between machines with different C values.