Norman J. Holter

Norman Jefferis Holter (born February 1, 1914 in Helena (Montana) , USA ; † July 21, 1983 there ) was an American biophysicist .

family

He grew up in his birthplace as the son of a merchant family and the grandson of a well-known Montana pioneer.

education

After primary school, he began his academic training in 1931 at the University of California, Los Angeles and after graduating (AB 1937) went to Heidelberg University for a study visit . In 1939 he received a Masters' degree in chemistry (University of California) and in 1940 in physics ( University of Southern California ).

power

Norman J. Holter was a very versatile and creative basic researcher . He described the requirements for telemetry of biodata and developed for the first time a system for wireless continuous recording of the electrocardiogram ( long-term EKG ). In addition, he was an inventive developer of scientific process and measurement technology.

Telemetry

In addition to his professional work as a chemist (1937/38), Holter was involved as assistant to L. Detrick (University of California, 1940/1941) in experiments on the effect of vitamin C on fatigue of the frog muscle . He mainly dealt with questions relating to the production of suitable instruments and was interested in the well-known frog muscle preparation that Luigi Galvani had used in his historical work on "animal electricity" in 1771. In 1939 the collaboration with Joseph A. Gengerelli began with the idea of ​​producing frog muscle contractions without direct mechanical or electrical contact, which was achieved by stimulating nerves in a changing electrical field . This gave rise to the hypothesis that not only telemetric signal transmission but also telemetric signal reception is possible.

In 1947, Holter resumed his research on telemetry (together with Gengerelli) and founded the Holter Research Foundation with the aim of further developing telemetry as a tool in the life sciences. At first the transmission of electroencephalograms (EEG) was examined and in 1949 the EEG of a boy cycling was recorded wirelessly. Holter then turned to electrocardiography, since the surface potentials of the heart are ten times stronger than those of the brain.

Long-term ECG

Norman J. Holter

The first wireless transmission of an electrocardiogram (EKG) required a 45 kg machine that Holter carried on his back during physical exertion. The radioelectrocardiography (RECG) transmitter, which was then developed under laboratory conditions, used the amplification and power supply unit of a normal EKG machine as well as a transmitter and antenna system . The receiving unit with oscilloscope was housed on a cart.

The next step was the construction of a portable RECG transceiver, which was initially the size of a briefcase. When using a very thin magnetic tape , the recording of the electrocardiogram was possible over 24 hours. To evaluate the large amount of data, Holter developed the Audio-Visual Superimposed ECG Presentation (AVSEP) method , which made it possible to assess a continuous 24-hour ECG in less than 20 minutes. An improved, smaller multichannel model worked with very slow tape recording.

The first clinical application of the method proposed by Holter was carried out in 1954 by MacInnis, who radioelectrocardiographically (RECG) transmitted the bioelectrical potentials of a heart attack patient during a short walk. In Germany, the technology of continuous EKG recording with a Holter avionics system (Holter monitor) was first introduced in 1965. Today the long-term ECG is a standard diagnostic procedure in cardiology .

marine

From 1941 Holter served in the Navy as a senior physicist and was commissioned to research the behavior of ocean waves and their significance for military water-land operations. Among other things, he introduced a measuring method with which the submarine distance to the water surface could be determined, which later made it possible for the submarine Nautilus to cross under the North Pole .

Nuclear weapons tests

In 1946, Holter was the head of 33 scientists who were supposed to observe the oceanographic effects of the first post-war US nuclear weapons tests on Bikini Atoll . A 40-ton measuring device was used to record the wave movements and underwater turbulence caused by nuclear explosions. The destruction and deformation of one of these instruments by an atomic detonation later inspired Holter to produce a series of steel sculptures ( Geometry in Steel ), which were created by explosives and then shown in an exhibition.

radioactivity

Another project in the 1950s was the development of a method with which conclusions about natural uranium deposits could be drawn by measuring the radioactivity of the air and analyzing the wind direction . The company failed, but opened up the possibility of precisely determining the location of nuclear weapons tests (especially Russian tests) from the measured radioactivity in the air and precipitation . With this method, which a German scientist developed further, the identity and origin of radioactive fallout could be proven worldwide from the decay curves obtained . The procedure also improved knowledge of intercontinental meteorology and the nature of jet streams in the upper air layers.

Works

• Remote recording of physiological data by radio (with JA Gengerelli). Rocky Mountain Med J 46 (1949) 747
• Radioelectrocardiography: a new technique for cardiovascular studies . Ann NY Acad Sci 65 (1957) 913
• New Method for Heart Studies. Continuous electrocardiography of active subjects over long periods is now practical . Science 134 (1961) 1214
• Clinical observations using the electrocardiocorder-AVSEP continuous electrocardiographic system. Tentative standards and typical patterns (et al.). Am J Cardiol 14 (1964) 204
• The genesis of biotelemetry . Helena 1976

literature

• Eberhard J. Wormer : Syndromes of cardiology and their creators . Munich 1989, pp. 125-133
• WC Roberts, MA Silver: Norman Jefferis Holter and Ambulatory ECG Monitoring . Am J Cardiol 52 (1983) 903
• A. Cuppett: Norman J. Holter, DSc, the Father of the Holter Electrocardiograph . CVP 8 (1980) 46

Web links

• CE Rankin: Historical reflections. Montana: The Magazine of Western History 2000