Biomagnetism is the phenomenon of
magnetic field
A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...
s ''produced'' by living organisms; it is a subset of
bioelectromagnetism. In contrast, organisms' use of magnetism in navigation is
magnetoception
Magnetoreception is a sense which allows an organism to detect the Earth's magnetic field. Animals with this sense include some arthropods, molluscs, and vertebrates (fish, amphibians, reptiles, birds, and mammals). The sense is mainly used ...
and the study of the magnetic fields' ''effects'' on organisms is ''
magnetobiology''. (The word biomagnetism has also been used loosely to include magnetobiology, further encompassing almost any combination of the words magnetism, cosmology, and biology, such as "magnetoastrobiology".)
The origin of the word biomagnetism is unclear, but seems to have appeared several hundred years ago, linked to the expression "
animal magnetism
Animal magnetism, also known as mesmerism, is a theory invented by German doctor Franz Mesmer in the 18th century. It posits the existence of an invisible natural force (''Lebensmagnetismus'') possessed by all living things, including humans ...
". The present scientific definition took form in the 1970s, when an increasing number of researchers began to measure the magnetic fields produced by the human body. The first valid measurement was actually made in 1963, but the field of research began to expand only after a low-noise technique was developed in 1970.
[{{cite journal , last1=Cohen , first1=David , last2=Edelsack , first2=Edgar A. , last3=Zimmerman , first3=James E. , title=Magnetocardiograms taken inside a shielded room with a superconducting point contact magnetometer , journal=Applied Physics Letters , publisher=AIP Publishing , volume=16 , issue=7 , year=1970 , issn=0003-6951 , doi=10.1063/1.1653195 , pages=278–280, bibcode=1970ApPhL..16..278C ] Today the community of biomagnetic researchers does not have a formal organization, but international conferences are held every two years, with about 600 attendees. Most conference activity centers on the MEG (
magnetoencephalogram), the measurement of the magnetic field of the brain.
Prominent researchers
*
David Cohen
*
John Wikswo
*
Samuel Williamson
See also
*
Bioelectrochemistry
*
Human magnetism
*
Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...
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Magnetocardiography
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Magnetoception
Magnetoreception is a sense which allows an organism to detect the Earth's magnetic field. Animals with this sense include some arthropods, molluscs, and vertebrates (fish, amphibians, reptiles, birds, and mammals). The sense is mainly used ...
- sensing of magnetic fields by organisms
*
Magnetoelectrochemistry
Magnetoelectrochemistry is a branch of electrochemistry dealing with magnetic effects in electrochemistry.
History
These effects have been supposed to exist since the time of Michael Faraday.
There have also been observations on the existence of ...
*
Magnetoencephalography
Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electric current, electrical currents occurring naturally in the human brain, brain, using very sensitive magn ...
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Magnetogastrography
Magnetogastrography is the science of recording magnetogastrograms (MGGs). Magnetogastrograms are recordings of magnetic fields resulting from electrical currents in the stomach. The magnetic fields are typically recorded using SQUIDs.
See also
...
*
Magnetomyography
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SQUID
A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...
Notes
Further reading
* Williamson SH, Romani GL, Kaufman L, Modena I, editors. Biomagnetism: An Interdisciplinary Approach. 1983. NATO ASI series. New York: Plenum Press.
* Cohen, D. Boston and the history of biomagnetism. ''Neurology and Clinical Neurophysiology'' 2004; 30: 1.
History of Biomagnetism
Bioelectromagnetics
Magnetism