A damped sine wave defibrillator that is capable of delivering a constant peak discharge current over a wide range of patient thoracic impedance is shown to be theoretically possible. This is realized in practice by the technique of storing an amount of energy above that required for delivery, and dumping the excess charge when the discharge current has reached a predetermined level, the dumping being triggered by a current sensor. A larger than normal inductance assists in swamping the effect of varying impedance and produces a smooth waveform. The preselected peak current can be delivered with a variation of about +/- 6% to 95% of a normal patient population. The energy expended in a simulated patient circuit is somewhat lower than for conventional defibrillators.
The laboratory's main working bench is arranged round the walls and has been designed for a comfortable working position. The shelf above the bench is of sufficient width and strength to accommodate all but the largest instruments. The power supplies to the bench consist of a generous number of 240V a.c. shuttered socket outlets and a smaller number of 240V d.c. switched socket outlets. There are also coaxial sockets connected to the main radio and TV antennae. In general it has been found most convenient to use small individual stabilised power supplies for separate experiments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.