title: Transthoracic defibrillation with chopping-modulated biphasic waveforms.
abstract: The superiority of different biphasic pulses for transthoracic defibrillation was proven by several studies. These efficient waveforms were implemented in some commercially available defibrillators. Recently we have devised and evaluated a biphasic waveform with a specially balanced ratio of the first-to-second phase voltages and with 5 kHz frequency 1:1 on-off chopping. It used less than half the energy for successful defibrillation in comparison with the 'classic' monophasic damped sinusoidal wave and showed considerably less post-shock negative effects. This experience led us to try several laws of chopping modulation. A pulse-width modulation, combining low energy with gradual upslope of the modelled transmembrane potential, proved to have better performance than the standard damped sinusoid wave and the non-chopped biphasic truncated exponential pulse. This waveform was tested in a series of animal experiments in comparison with other modulated pulses, with the non-modulated waveform and the standard damped sinusoid wave. The experiments demonstrated the superiority of the modulated waveform, assessed by combining the parameters of threshold defibrillation energy and of post-shock disturbances reduction.
authors.affiliation: Centre of Biomedical Engineering, Bulgarian Academy of Sciences, Sofia.
authors.forename: V
authors.initials: V
authors.lastname: Krasteva
authors.forename: A
authors.initials: A
authors.lastname: Cansell
authors.forename: I K
authors.initials: IK
authors.lastname: Daskalov
mesh_terms: D000818:Animals; D004285:Dogs; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D008564:Membrane Potentials; D008962:Models, Theoretical; D013997:Time Factors