From GHN  Jump to: navigation, search  Author: David Geselowitz
In the modern world, electrocardiography is a medical technology
that is used every day in doctors' offices, clinics, and
hospitals around the world. The technology grew out of
investigations beginning in the late 18th century of electrical
phenomena in living systems. Nerve and muscle are electrically
active, and the heart produces currents and voltages that can be
recorded in what is called the electrocardiogram (ECG). In the
course of the 20th century, scientists and engineers elucidated
the medical significance of ECGs, set standards for recording
ECGs, and helped make the technology invaluable to medical
practitioners.   1791 Luigi Galvani reports that an electric
spark can cause muscle to twitch 1853 Hermann von Helmholtz
develops the physics of the volume conductor problem 1856 R.A.
von Kölliker and Heinrich Müller discover that a frog's heart
generates electric currents 1887 A.D. Waller records a human
electrocardiogram (ECG) 1901 Wille