Magnetocardiography (MCG) is a technique to measure the

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 electrical currents in the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

using extremely sensitive devices such as the superconducting quantum interference device (SQUID). If the magnetic field is measured using a multichannel device, a map of the magnetic field is obtained over the chest; from such a map, using mathematical

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

s that take into account the conductivity structure of the

torso The torso or trunk is an anatomical terminology, anatomical term for the central part, or the core (anatomy), core, of the body (biology), body of many animals (including human beings), from which the head, neck, limb (anatomy), limbs, tail an ...

, it is possible to locate the source of the activity. For example, sources of abnormal rhythms or

arrhythmia Arrhythmias, also known as cardiac arrhythmias, are irregularities in the cardiac cycle, heartbeat, including when it is too fast or too slow. Essentially, this is anything but normal sinus rhythm. A resting heart rate that is too fast – ab ...

may be located using MCG.

History

The first MCG measurements were made by Baule and McFee using two large coils placed over the chest, connected in opposition to cancel out the relatively large magnetic background. Heart signals were indeed seen, but were very noisy. The next development was by David Cohen, who used a magnetically shielded room to reduce the background, and a smaller coil with better electronics; the heart signals were now less noisy, allowing a magnetic map to be made, verifying the magnetic properties and source of the signal. However, the use of an inherently noisy coil detector discouraged widespread interest in the MCG. The turning point came with the development of the sensitive detector called the SQUID (superconducting quantum interference device) by James Zimmerman. The combination of this detector and Cohen's new shielded room at

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

allowed the MCG signal to be seen as clearly as the conventional electrocardiogram, and the publication of this result by Cohen et al. marked the real beginning of magnetocardiography (as well as

biomagnetism Biomagnetism is the phenomenon of magnetic fields ''produced'' by living organisms; it is a subset of bioelectromagnetism. In contrast, organisms' use of magnetism in navigation is magnetoception and the study of the magnetic fields' ''effects'' ...

generally). Magnetocardiography is used in various laboratories and clinics around the world, both for research on the normal human heart, and for

clinical diagnosis Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as a diagnosis with the medical context being implicit. The information ...

Clinical implementation

MCG technology has been implemented in hospitals in Germany. The MCG system, CS MAG II of Biomagnetik Park GmbH, was installed at Coburg Hospital in 2013. The CS-MAG III system was installed at the Dietrich Bonhoeffer Hospital, Neubrandenburg, and the Charité Hospital, Berlin, in 2017. The first MCG centre in Asia is set up in Hong Kong, adapting the same technology as Hamburg, and set up by the same team. Genetesis, a medical imaging company based in Mason, OH, is developing a device called the CardioFlux that leverages MCG technology to diagnose heart-related conditions.

References

{{Electrodiagnosis Bioelectromagnetics Diagnostic cardiology Electrodiagnosis Medical tests

History

Clinical implementation

See also

References