Improvement of defibrillators for EMS use: a problem in engineering and medicine

Recent improvement in defibrillators has been limited mostly to decreased size and weight of portable units. An overview of the scientific literature indicates that the main limitation to further improvement in defibrillators is the lack of medical and physiologic information. Technology probably exists to change defibrillators if the manufacturers know what changes would be desirable. Clinical studies are needed for determining (a) more accurate quantitation of electrical dose for human use, (b) the relative effectiveness of different waveforms, (c) the toxicity and damage of electrical shocks to the heart, (d) the effects of drugs upon defibrillation threshold, (e) improvement of defibrillation techniques, (f) optimal placement and size of electrodes, and (g) the effects of cardiac disease on defibrillation threshold. Most of the needed studies are not technically difficult to carry out but they will be moderately expensive. In some cases special equipment may be needed or special techniques may have to be developed. The experimental animal studies appropriate as background for these clinical studies have been completed. With limited resources available, it is important to ask the most important questions first in order to develop improved defibrillation techniques and defibrillators.