Our Body also undergoes an electric activity of its own, which is very complex in nature. Physics says, “Wherever there is an electric activity there is also associated magnetic field”, so the case is same here also. These self-produced magnetic fields are too small and hence simply covered up by the environmental and planetary fields present in our surroundings. So, if we wish to study the characteristics of these magnetic fields alone, we need to block the surrounding fields. The indigenous magnetic & electric fields control all sorts of body processes and are interactive with each other. If properly researched we may unlock the secrets of such biomagnetic fields which may generate alternatives for diagnosis and treatment of the body.
Biomagnetometers
To measure the Electric field intensity a lot many devices are available which include Electrocardiograms (EKG) and Electroencephalograms (EEG), but this give only limited information, especially in the case of information at cellular level. In order to locate the minute areas of damage, only magnetic field measurements are helpful, not the Electric field ones. Only after probes are inserted into the body can the Electric field measurements become visual deep inside. Magnetic field measurements are physiologically more relevant as they capture total current or energy present rather than electric fields which capture voltage alone.
Bioelectric fields are also blocked by the tissues along their direction of propagation, unlike biomagnetic fields. Biomagnetometers can easily measure intracellular currents over the extracellular voltage charges as it doesn’t require placement or insertion of electrode. So for this type of measurements cell membrane charges can be measured without getting them penetrated. Its importance lies in the fact that it is a determinant of the cell’s health. So it is much easier to measure the electric current that is flowing (within someone) by simply associating them to the magnetic field measurements than measuring the electric charges at skin surface. It is very helpful in having a precise and non-invasive assessment of pathology or its function.
Magnetically isolated rooms
Using Magnetic isolations, we can finally use SQUID (Super-conducting Quantum Inference Devices), a device that can map out the magnetic field of the entire body and individual organs and also make precise measurements. For shielding, a combination of “mu” metals (new artificial metals) and other metals, so as to nullify the external magnetic effects. The Science behind their working is the phenomenon of “Josephson Junctions” observed in the super-conducting materials. Using these we can easily measure the smallest magnetic and electrical fields in any specific tissue or the entire body.
In terms of electric and magnetic fields a Laboratory is a very noise place. So is the remote natural surroundings and environment if compared to Human Body. The degree of isolation and SQUID sensitivity are the two determining factors for the smallest MF measurement that can be made.
Natural MF of body
Following is the comparison of Body’s MF with the Earth’s MF. It can be easily observed that Body’s magnetic field is almost negligible in comparison to earth’s magnetic field.
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Strengths of endogenous magnetic fields versus Earth’s field |
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|
Signal source |
FemtoTesla |
Gauss |
Earth’s field stronger by |
|
Earth’s field |
50,000,000,000 |
0.5 |
|
|
Skeletal Muscle |
~50,000 |
0.0000005 |
1 million times |
|
Physiologic “noise” |
50,000-5,000,000 |
0.0000005 0.00000005 |
1 – 10 million times |
|
Heart |
~500,000 |
0.000005 |
100,000 times |
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Science & Engineering imply that magnetic and electric fields, when externally applied always affect one another. Biomagnetic field of body also entails DC as well as time-varied components. To create an additional impact on body the DC field, externally applied has to be stronger than the geomagnetic field present in the surroundings. TMF (time-varied magnetic field) are much weak as compared to earth’s MF. As a fact, there is no as such lower limit specification for weak TMFs to affect the body biologically. Up to pico Tesla level or may be even up to Femto tesla level, TMFs competitively much weaker than Earth’s magnetic field have shown impacts on body. Most instruments used for treatments using EMF generate Magnetic fields of milli-tesla range, which are 1000 to 10,000 times more intense than Earth’s MF and further 10 to 100 million times intense than the body’s self-generated EMF. Body processes vary in energy requirements, some suffice by even tiny amounts, while others require much larger.
Diagnosis using Biomagnetic measurements
Apart from getting the measurements from the research in these endogenous fields, this also helps us in developing a brand new means of cellular function measurement without invasion. Already these have found technical applications in medicine field to measure natural biomagnetic field in a sensitive manner, like in MEG (Magnetoencephalography). This is useful for neurosurgeons in locating the elliptic seizures caused by enhanced electrical activity of the brain. Evaluation studies are being done for pathology and cardiologic function (magnetocardiography) too. Apart from these applications it can be used in measurement of iron loads in liver & lungs, where overload conditions exist. In future, measurement of muscle functioning along with other nerves shall be also possible.
