Abstract
Theoretical consideration of electrical shock hazards caused by medical equipment have been performed based on the electromagnetic theory and Hill's neurological theory. The isometric biological tissue having an active cell and a circular electrode on it are assumed for calculation. This model is feasible to application both to macro shock and micro shock. The characteristics of electrical shock hazards obtained were as follows;
1) The threshold of shock, when commercial frequency A. C. current is applied, is equivalent to a half-value of D. C. current.
2) From commercial frequency to nearly 100 kHz, the biological tissue has constant threshold value. However, it depends on relative resistance, time constant of active cell membrane, etc., of the biological tissue.
3) When any medical equipment with high-frequency current source is especially designed, it is important to consider the frequency characteristics of catheter or lead wire which connect the equipment and the biological tissue.
