Waveform analysis of biphasic external defibrillators

Citation
U. Achleitner et al., Waveform analysis of biphasic external defibrillators, RESUSCITAT, 50(1), 2001, pp. 61-70
Citations number
26
Categorie Soggetti
Aneshtesia & Intensive Care
Journal title
RESUSCITATION
ISSN journal
03009572 → ACNP
Volume
50
Issue
1
Year of publication
2001
Pages
61 - 70
Database
ISI
SICI code
0300-9572(200107)50:1<61:WAOBED>2.0.ZU;2-W
Abstract
Background and Objective: All internal defibrillators and some external def ibrillators use biphasic waveforms. The study analysed the discharged wavef orm pulses of two manual and two semi-automated biphasic external defibrill ators. Methods and Results: The defibrillators were discharged into resisti ve loads of 25, 50 and 100 Ohm simulating the patient's transthoracic imped ance. The tested biphasic defibrillators differed in initial current as wel l as initial voltage, varying from 10.9 to 73.3 A and from 482.8 to 2140.0 V, respectively. The energies of the manual defibrillators set at 100, 150 and 200 J deviated by up to + 19.1 or - 28.9% from the selected energy. Imp edance-normalised delivered energy varied from 1.0 to 12.5 J/Ohm. Delivered energy, shock duration and charge flow were examined with respect to the t otal pulse, its splitting into positive and negative phases and their imped ance dependence. For three defibrillators pulse duration increased with the resistive load, whereas one defibrillator always required 9.9 ms. All test ed defibrillators showed a higher charge flow in the positive phase. Defibr illator capacitance varied between approximately 200 and 100 muF and intern al resistance varied from 2.0 to 7.6 Ohm. Defibrillator waveform tilt range d from - 13.1 to 61.4%. Conclusions: The tested defibrillators showed remar kable differences in their waveform. design and their varying dependence on transthoracic impedance. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.