User manual

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The trapezoidal pulse is also marked as MTE or BTE (Monophasic/Biphasic
Truncated Exponential pulse), Fig. 3.1 and Fig. 3.2.
Damped shape of the defibrillation pulse (DSW - Damped Sine Wave) is acquired via
the discharging of the capacitor past a coil, the so called choke, i.e. “choking” coil (from
blocking). Adding the choking coil into the capacitor’s circuit creates a serial oscillating
circuit with losses, Fig. 3.4. A damped oscillation is excited by means of this RLC circuit, the
parameters of which depend on the capacity of the capacitor (tens to hundreds of µF), the
inductivity of the choking coil (tens to hundreds of mH, the coil resistance in single units of
Ω), and the size of the idle resistance (resistance in the patient’s circuit, tens to hundreds of
Ω]. Damped defibrillation pulse is in some cases also time limited, just like the trapezoidal
pulse, this pulse then being marked as DMT or DBT (Damped Monophasic/Biphasic
Truncated pulse), Fig. 3.1 and Fig. 3.2.
Fig. 3.4: Equivalent electrical diagram of a final stage of a monophasic defibrillator with
damped (sine) defibrillation pulse. Position 1 - charging of the capacitor, position 2 -
discharging of the capacitor via a choking coil into the patient (DSW defibrillation pulse).
Damped shape of the pulse with delay is acquired by means of a circuit with delay line, Fig.
3.5. Thanks to the delay line, the pulse extends, compared to the pulse created by a capacitor
defibrillator with a choking coil. Extension of the pulse (increase in the area under the curve)
allows for reducing the amount of current of the defibrillation discharge, which passes
through the patient, thus reducing the stress on the patient’s tissue.
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