The role of an engineering oriented medical research group in developing improved methods and devices for achieving...

Physical scientists and engineers have played important roles in helping to expand our understanding of the factors that influence the defibrillation process and in developing improved methods and devices for achieving cardiac ventricular defibrillation. The long-term experience of one engineering oriented group, based in a clinical department of a medical school, is summarized. Emphasized are the features of a series of research defibrillators that facilitated the generation of an extensive experimental database from studies in dogs and calves, the development of the first automatic implantable defibrillator to be successfully used in dogs, and studies that furnished the rationale for the widespread use of the uniphasic truncated exponential waveform and for the increasing interest in a variety of biphasic and multiphasic waveforms. Also considered are studies concerning the scaling of the defibrillatory shock with subject size and the role of compound units, defibrillation threshold, and contour graphs in the presentation and interpretation of data.