Editing Defibrillation (section)

=== Closed-chest method ===
Until the early 1950s, defibrillation of the heart was possible only when the chest cavity was open during surgery. The technique used an alternating voltage from a 300 or greater [[volt]] source derived from standard AC power, delivered to the sides of the exposed heart by "paddle" electrodes where each electrode was a flat or slightly concave metal plate of about 40&nbsp;mm diameter. The closed-chest defibrillator device which applied an alternating voltage of greater than 1000 volts, conducted by means of externally applied electrodes through the chest cage to the heart, was pioneered by Dr V. Eskin with assistance by A. Klimov in Frunze, USSR (today known as [[Bishkek]], [[Kyrgyzstan]]) in the mid-1950s.<ref name="Kirg" /> The duration of AC shocks was typically in the range of 100–150 milliseconds.<ref name="patent1" />