While earlier work that played a part in the history of the
EKG
machine had been conducted, the first practical application of the EKG, or ECG
(electrocardiogram) machine came in 1903 through the efforts of a Dutch
doctor/physiologist named Willem Einthoven. He was later awarded the Nobel
Prize in Medicine (1924) for his discovery. The abbreviation EKG comes from the
German 'elektrokardiogramm', which was derived from the Greek electro, meaning
electrical; cardio, meaning heart; and graph, meaning 'to write'.
True uses of the EKG history is thought to have originated
in 1872 when Alexander Muirhead, while studying for his Doctor of Science in
Electricity, attached wires to the wrist of a patient in an effort to record
the person's heartbeat.
Nearly 40 years later, in 1911, British doctor Augustus Waller used a
Lippman capillary electrometer affixed to a projector to transfer the trace of
the heart's electrical output onto a photographic plate. His was the first
systematic approach to the heart as an organ of electrical impulses; however,
although he was able to make an actual recording of the heartbeat in real time,
he saw no practical application for his discovery.
Meanwhile Dr. Willem Einthoven, born in the Dutch
East Indies but now working in the Netherlands, invented a device called a
string galvanometer. This device was far more sensitive to transmitting
electrical impulses than the Lippman capillary electrometer that Waller used in
his experiments. Rather than using
electrodes as done today, Einthoven used
containers of salt solutions into which his test subjects would immerse their
limbs. From this configuration he was able to record the EKG in real time.
Einthoven was the first to use the letters P through T to describe the heart's
different electrical impulse deflections and how they pertain to various heart
disorders. The letters P, Q, R, S and T are still used today in the same way
when interpreting EKG traces on a screen or graph.
EKG history shows that it was known well before
Einthoven's breakthrough discovery that a beating heart produces electrical
impulses (currents) but earlier instruments were not sensitive enough to
measure these impulses without placing electrodes directly on the heart, which
required risky, invasive surgery.
With the 1901 invention of the string
galvanometer, the history of the EKG machine as it is known today was
galvanized. A thin, conductive wire running between large and powerful
electromagnets was charged, causing the 'string', or filament, to move. A light
projected on this moving string caused a shadow that was then captured on a
moving roll of photosensitive paper, forming a continual curve.
Although the
machine weighed close to 600 pounds and took five people to operate, it has
been developed through modern technology into a unit that can be small,
lightweight and portable. New units are fairly easy to use, take only a few
minutes for a complete test, and utilize computerized interpretation of
results. A wide variety of EKG machines utilizing the latest in medical technology are sold by
Medical Device Depot.