[Safety problems during the use of electromedical apparatus in man].
The stimulating action of an electric current on the human body is determined by the strength of the current, the direction, frequence and duration of action of the current. Measurements of sensation have shown that even with strengths of currents of about 15 to 20 mA (50 Hz), a complete cramp of the arm musculature occurs, whereby a voluntary relaxation of the part under tension is no longer possible. The inner resistance of the human body (without skin resistance) is between 650 and 1300 Ohm, according to the direction of the current. Electric field strengths on the heart have shown that disturbances of heart action always occur when the electric field produced by an outer circle of current round the heart is in the order of 80 mV/cm. This means that currents passed through the heart of even 80 muA can produce lethal ventricular fibrillation. On the basis of practical examples from clinical cases, the danger of micro shocks is shown. The question of a security check list is discussed.
D000818:Animals; D004597:Electroshock; D006041:Goats; D006801:Humans; D007362:Intensive Care Units; D008991:Monitoring, Physiologic / Q000009:adverse effects; D012756:Sheep; D013552:Swine; D014693:Ventricular Fibrillation / Q000209:etiology
Sicherheitsfragen bei der Anwendung elektromedizinischer Geräte am Menschen