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MAGNETIC FIELDS BASICS
Basic Principles
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Why
Magnetic Therapy?
What is it?
Is there any value in it?
What is the evidence?
Magnetic
therapy is becoming recognized throughout the world as a
legitimate medical discipline. The roots of this bioscience come from the studies done
in biomagnetics, the study of the body’s own magnetic fields (MFs). The body’s fields are detectable only with suppression
of the earth’s fields. The physical body is germinated, develops as an embryo
and grows into the human adult totally immersed within the
earth’s magnetic fields. All
human activity is conditioned by the earth’s magnetic
environments. Once
the connection is made between the magnetic aspects of the
biophysical chemistry of the human bio-organism, in fact, all
planetary biology, then it becomes easier to conceive of the
body as a bioelectric/magnetic organism, subject to all the
physical laws of magnetism.
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Why
is it important to study Biomagnetism?
 Besides
the need to understand the potential impact internal and
environmental magnetism has on human functioning, we need to
know how they can be applied or directed therapeutically. In many areas of medicine, human and veterinary,
effective therapies are lacking, are inadequate, cost too much,
are invasive or cause harm.
Magnetic therapies offer the potential to create new
approaches in understanding the body and caring for people.
New
magnetic therapy uses are largely based on known principles. The basic principles of magnetism have been known and
identified by Maxwell before the turn of the 20th
century. Healers
have seen some of the effects of magnetic fields even in the 2nd
century BC in China, but only recently have we had a scientific basis to explain
their observations that magnetic fields can be used in
healing. Their observations were not systematically studied. Only in the past 30-40 years has there been more
systematic, concerted use, primarily in the former Soviet Union,
other parts of Europe and Asia.
Experience
in the English-speaking west to date, has been anecdotal and
unverified. The
information already available from other countries would be
extremely helpful so that the West wouldn't have to “reinvent
the wheel." A
substantial untranslated, non-English medical literature is
available. The
non-medical scientific literature on the biologic effects of
magnetic fields is already vast.
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I
have co-authored a book, with Dr. Jiri Jerabek
“Magnetic Therapy in
Eastern Europe
: a review of 30 Years of Research”.
What this book does is to provide in English a review of
the EXPERIENCE, not just theory and individual case histories or
testimonials, in the use of magnetics in the former Soviet
Union, that is,
Eastern Europe
. A
significant amount of research has also been performed in other
parts of Europe and
Japan
that supports much of the Eastern European experience.
After reviewing all this knowledge became very clear to
me that magnetic fields have important benefits in healing and
health-care and that they are not only effective but, used
properly, are also safe.
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There are many observed actions or effects on biologic processes,
including chemical reactions, ion movement, changes in charges
and electrical potentials, effects on lipids, starches and
proteins, hormones and the large molecules and fundamental
cellular processes, among others.
However, there is no accepted concept in physics yet of
how MFs affect these biologic activities. There are many
theories, but no single theory that explains all the phenomena
that have been observed. It is possible that no single theory or
model can. Names for these various theories include: cyclotron
resonance, parametric resonance, quantum mechanical, Larmor
precession, ion oscillation, solid-state, biologic closed
electric circuits and association-induction.
Despite
this lack of it will accepted theory of action, magnetic field
effects have definitely been observed and positive clinical
actions experienced. As in many other areas of science theories
often lag behind observed uses. Lack of a theory should not
prevent magnetic field from being used to help meet people's
health care needs. Magnetic field therapy can be effective in a
wide range of conditions.
Before
magnetic fields can be used in therapies, there is a need to
have some basic understanding of some of the physical
characteristics of magnetic fields, and some of their actions on
the body. To do this, we will cover some of the terms used,
basic characteristics of therapeutic fields, the body's own
fields and environmental fields.
We will also provide information on other aspects
important to consider in magnetic therapy, such as effects on
water and animals.
History
of magnetism
Much
of the history of magnetism is well covered on these websites:
www.phy6.org
www.newi.ac.uk
www.worldwideschool.org
www.ee.umd.edu
www-istp.gsfc.nasa.gov
For
our purposes here, it should be remembered that “magnetic
therapy”, even “electric therapy” had been
“discovered” and used to some extent going back to 2000-3000
BCE. The Chinese have even written protocols for using
lodestones on acupuncture points dating this far back. Even
ancient people and healers learned the practical value of using
magnets for healing. Our understanding today of how and why EMFs
work on biology is certainly much farther along, especially in
the 20th century. Clearly, there is much more to
learn and study.
The
magnetic field, physical characteristics
In
the space around moving electrical particles exist forces which
can affect other moving particles.
These forces are named magnetic fields.
The source of these forces can be electrons in wires
where electric current flows, ions in electrolyte solutions,
electrons in cathode ray tubes (television monitors), etc.
The static
magnetic field around permanent
magnets is based on the same principle.
In the permanent magnet, motion of electrons (spin
and orbital motion moment) is arranged such that “magnetic
field” forces are detectable outside the magnet.
Magnetic
fields have intensity, space, time and duration aspects.
Intensity applies to the strength of the field(s).
Space refers to the 3-dimensional shape of the field(s).
Time refers to whether the field(s) are fixed (static, DC or
permanent) or turned on or off or changed in intensity and/or
frequency over the period of use. Duration applies to the length
of time the MF is applied.
Some
facts about magnets
(from
the book 'Driving Force' by
James D. Livingston)
1.
North poles point north, south poles point south.
2.
Like poles repel, unlike poles attract.
3.
Magnetic forces attract only magnetic materials.
4.
Magnetic forces act at a distance.
5.
While magnetized, temporary magnets act like permanent magnets.
6.
A coil of wire with an electric current flowing through it
becomes a magnet.
7.
Putting iron inside a current-carrying coil increases the
strength of the electromagnet.
8.
A changing magnetic field induces an electric current in a
conductor.
9.
A charged particle experiences no magnetic force when moving
parallel to a magnetic field, but when it is moving
perpendicular to the field it experiences a force perpendicular
to both the field and the direction of motion.
10.
A current-carrying wire in a perpendicular magnetic field
experiences a force in a direction perpendicular to both the
wire and the field.
Space
Orientation
Regarding
space orientation, magnetic fields can be uniform or
non-uniform. Uniform
fields
are those where in every point
of the field area of interest the same value (strength
and sign) and direction is
found. Uniform
fields are rarely practical in treating humans and are usually
found in unique experimental situations. Not even the Earth’s
magnetic field is uniform. In non‑uniform fields,
orientation can vary but more
commonly the intensity varies and almost always decreases with
distance from the surface. The degree of non-uniformity can be
defined by mathematical calculations or by measurement using
magnetometers. Non‑uniform
fields are almost always the rule in magnetic therapy and
medical applications.
 This
diagram shows how the field density or strength decreases (the
field lines widen) with the distance from the surface of the
magnetic system. Also, because of the fact that field lines
close their loops, may change "their direction " or
polarity. This means, they tend to bend around and join with the
field lines coming out the opposite side of the magnetic
material. This gives the magnetic field a three-dimensional
structure around the material. The body or body part would
typically be enclosed by the three-dimensional field.
 Static
magnetic fields are similar to time-varied fields, in that they
have a 3-dimensional shape and decrease with distance from
the surface of the material. The only difference is that they
are stationary or static, and do not come and go in a frequency
pattern.
When
different types of static magnetic fields are combined into one
device or applicator, the three-dimensional field can become
very complicated and may determine the impact on the biologic
organism it contains (Holcomb Fields, picture below).
Fields
around coils: While
static magnetic fields can be made with some complexity, by
alternating their pole designs, time varied fields produced by
electrical coils can be much more complicated. Nevertheless,
intensity, shape, frequencies and the duration of use will
determine the biological effects.
Other
field configurations can be seen at these sites:
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Single
bar magnet
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Two
bar magnets end to end, N to S, with a gap between them
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Two
bar magnets end to end, N to N, with a gap between them
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Two
bar magnets end to end, S to S, with no gap between them
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Two
bar magnets side by side, N by N, with a gap between them
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Two
bar magnets side by side, N by S, with a gap between them
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DC
electromagnet with an air core
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DC
electromagnet with a soft iron core
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DC
electromagnet with a soft iron core, with a small permanent
magnet below it
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Single
donut magnet
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Group
of six donut magnets, three stuck together, three levitated
above
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Levitating
train platform above its magnetic tracks
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Two
disk magnets, stuck together, about to be slid apart
(sometimes this is the only way to pull two NIB magnets
apart)
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Two
hemispherical magnets,
with a gap between them
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A
spherical magnet,
like the earth's core
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Time
variation
Regarding
time distribution, magnetic fields can be static
and/or time varying.
A static magnetic field is one in which no change of
magnetic flux density or intensity can be found over the time
interval of use. In
time varying magnetic field
s, magnetic flux density or
intensity changes at specified frequencies, usually greater than
one cycle per second and typically up to the gigahertz level.
In other words, the time variation/frequency factor can
be theoretically or practically be the breadth of the
electromagnetic spectrum.
 Static
magnetic fields are found around permanent magnets or
electromagnets fed by direct (DC) current.
Time varying magnetic fields result from electromagnets
fed with non-constant currents, e.g. alternating (AC) currents.
The most common, everyday time varying fields are found
around electrical wires conducting AC current, e.g. to
electrical appliances. AC
current is typically used to generate other types of time-
varied fields. Current
(AC), the input current, is brought into a “box” where the
signal is modified to the specifications of the manufacturer and
then the “output current” is
directed onto the “coil(s)” or applicator used for
the MF therapy. The output current can be designed with various
frequencies, wave forms, field orientations and intensities.
Intensity
(H) and Magnetic Flux Density
(B)
Magnetic
fields are characterized by intensity (H) and magnetic flux
density (B). The
intensity of a magnetic field is directly proportional to the
current flowing through a wire and indirectly proportional to
the distance from the wire:
H = I/2pr
where I =
current intensity in amperes,
r = distance
from the wire in meters. The unit of H is ampere/meter
(A/m) that is defined as the intensity of magnetic field in a
distance
r
= 1/2p
from the wire where a current of 1 A is flowing.
Older terminology for H is in Oersteds where 1 Oersted
(Oe) = 79.6 A/m.
Science
measures magnetic flux density mostly in units of Tesla
(T).
This unit is defined as follows: if a force acting on a
wire 1 meter long, where 1 A is flowing in a uniform magnetic
field, is 1 N (newton
), this field has the magnetic
flux density of 1 T. Popular,
terminology uses gauss
(G), where 1 G = 10-4 T
(0.0001 T), 1 T = 104 G
or 100 mT (100 x 0.001T) = 1000G.
 The
relation between B and H is given by following equation:
B = mH,
where m
is the environment permeability
. Relation m
= mr .
m0 is
valid, where mr is
relative permeability
and m0 is
permeability of a vacuum.
Permeability of human tissues is effectively close to air
and therefore B ~= H in biologic systems.
Relative permeability is very limited with many metals,
e.g. aluminum, steel and coil systems designed to block external
MFs, ie, SQUIDS – Superconducting Quantum Interference
Devices.
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Since
magnetic fields typically decrease rapidly with distance, this
field intensity decline creates a “field gradient”, or
slope. The gradient is given in
units of strength over distance (T/m or mT/cm, etc). The
greater the number the higher the gradient.
It can be seen that the field drops
drastically at the edges of a static magnet.
Some
static field designs affect the strength of the fields produced
and how quickly the fields drop off in strength. Strong
individual static magnets incorporated into a magnetic product
will generally produce stronger fields, even if they placed in
alternating arrays.
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The
field patterns of alternating pole designs are very complex.
However, alternating pole designs may increase the field
strength of flat flexible materials. While flat flexible
materials may inherently have lower field strengths than
individual neodymium magnets, they offer the advantage of ease
of application.
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Measuring
field strength
 Magnetic
fields, static or time-varied, are measured using magnetometers
or gauss meters.
Different
meters may be necessary to measure AC fields in the home vs
permanent magnets. There are 3 basic approaches to measurement
devices using the Hall effect, Faraday’s law or nuclear
magnetic resonance (NMR). Meters
are available based on these designs. Hall meters are the most
common and vary significantly in price from simple home use
devices to engineering and scientific level systems.
This
site has good descriptions of magnetic fields and metering.
www.gaussbusters.com
Gaussmeters
are available from this site.
Gaussmeters at LessEMF.com
This
site allows you to convert units from cgs (gauss) to SI (Tesla)
and vice versa.
www.drusch.com
Actual
versus Advertised Field Strengths
Measuring
actual magnetic field strengths is important to knowing how much
magnetic energy is actually being delivered to the body. Many
advertised magnetic field strength numbers are really
theoretical and not actual. For permanent magnets, the field
strengths can be a third to half of the advertised strength. Few
manufacturers or retailers give the actual field strength at the
surface of the magnet. Since
most people do not have magnetometers or know how to properly
use them, for permanent magnets . you'll usually need to
subtract 50%, to be somewhere close to the real value. Often, if
a magnets is not working quickly for a problem, especially pain,
it is usually because the field strength is too low to have a
rapid benefit. Lower field strengths do not mean a lack of
benefit, benefits are just more likely to come more slowly.
Magnetic
field measurements around a magnet, even over the main surface
of the magnet, can vary tremendously depending on the quality of
the material and other factors related to the magnetizing
magnet. Most block or round, magnets have higher field strengths
at or over the edge than over the middle. Because of this
variability of measuring the field strength, this is why the
theoretical strengths are typically given. Using a magnetometer
one can determine the likely maximum field strength at the
surface of the magnet. With
larger magnets, this may be important in terms of determining
which part of the surface of the magnet should actually be
placed to treat the underlying problem.
Interaction
mechanisms
There
are three established physical mechanisms through which static
and time‑varying magnetic
fields interact with living matter.
[1]
Magnetic induction
- relevant to both static
and time varying magnetic
fields
and originates through the
following interactions:
a.
electrodynamic interactions with moving electrolytes are based
on Lorentz forces
on moving ionic charge
carriers, induce electric fields and currents in the tissue or
medium. This type of
interaction is the basis of magnetically induced blood flow
electrical charges or
potentials that have been studied with both static
and time varying magnetic field
s.
b.
Faraday
currents - relevant to time
varying magnetic field
s only.
Most scientists consider this interaction as the key
mechanism of magnetic therapy with time varying magnetic field
s.
[2]
Magnetomechanical effects
- relevant mainly to static
magnetic fields:
a.
in uniform magnetic fields, both diamagnetic (magnetically
non-susceptible) and paramagnetic (magnetically susceptible)
molecules experience torque, which tends to orientate them in a
configuration that minimizes their free energy within the field.
When the fields used for magnetic therapy are relatively
weak (10 to 100 mT – 100 to 1000 G), a magnetomechanical
action may not be practically significant for the effects found
from magnetic therapy.
b.
magnetomechanical action can be found in high gradient static
magnetic fields that leads to
the motion of either paramagnetic or ferromagnetic particles.
High gradient fields decrease steeply with distance.
Here again, this action may not be a significant cause of
the effects of magnetic therapy.
Some scientists believe that the slope of this
gradient may be important across tissues or cells, since
as a field crosses a tissue, each cell will experience a
different field strength and therefore this may contribute to
charge differentials across the tissue.
[3]
Electronic interactions
.
Some
chemical reactions are based on an action on free and non-free
radicals where static
magnetic fields exhibit an
effect on electronic spin states
.
It is possible that, although the lifetimes of the
intermediates
caused by this interaction are
short, they can still be a sufficiently strong influence on
biological matter via changed kinetics of dynamic chemical
reactions to create actions in tissue.
Faraday
’s
Law and current density
Time
varying magnetic field
s, versus static fields, have
been used most often for therapy since it is most commonly
believed that if the key mechanism of action is induction of
tiny electrical currents in tissue, time varied fields do this
more effectively than static magnetic fields. The better
approach to inducing currents is to use time varying magnetic
field.
Per
Faraday
’s law, magnetic fields that
vary in time will induce potentials and circulating currents in
biological systems, the human body included.
Current density is expressed in joules (J) or A/m2. E is used to
designate induced potentials
in V/m. It has been determined
that current density up to 100 mA/m2 is
safe. However, we
can’t calculate exactly the level of induced currents in the
complicated, non-homogeneous structures of the body.
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