Science News, Vol. 156, No. 20, November 13, 1999, p. 316.
Medicinal EMFs -- Harnessing electric and
magnetic fields for healing and health
By Janet Raloff
<snip>
Over the past 20 years, FDA has approved EMF generators for two
medical uses. The devices are used frequently to treat bone
fractures that have stopped healing. EMF treatment is also
increasingly being applied to fuse spinal vertebrae in people
with intractable back pain.
<snip>
More recent techniques enable fields to be delivered without
electrodes touching the body. This is the most important
therapeutic advance in recent years, suggests Arthur A. Pilla. A
biophysicist at the Mount Sinai School of Medicine in New York
City, he explains that the newer devices transfer a field's energy
into the body from wire coiled around, but not touching, the
injured area.
For EMFs to penetrate the body, the coils must carry a pulsing
electric current, he explains -- not the simpler direct currents
associated with electrode-generated fields. In designing the
waveform for these oscillating fields -- their shape, amplitude,
and frequency -- "we were guided by measurements people were making
of natural, mechanically induced voltages in bone," Pilla recalls.
The waveforms of these therapeutic EMFs differ dramatically from
those generated by power lines and indoor wiring.
His group won FDA approval in 1979 for the use of a pulsing EMF
device for fusing broken bones. Pilla adds that the major
manufacturers of EMF-generating bone-growth stimulators still rely
on this basic waveform. Twenty years later, researchers still argue
whether therapeutic benefits trace to the electric fields or the
magnetic fields that these devices induce.
<snip>
EMF therapy also helps people with established joint disease, Aaron
says. This month, he's completing a clinical trial of EMF therapy
for men and women with advanced osteoarthritis in their knees.
Two previous studies had found that EMFs reduce pain and swelling.
EMFs also have that effect in his new trial -- presumably, he says,
"by changing the chemistry of the joint." Studies by his team and
others indicate that these fields can increase a joint's production
of natural anti-inflammatory agents, such as transforming growth
factor-beta.
Not surprisingly, Aaron notes, medical supply companies are now
developing products, such as a glove with coils, to deliver EMFs to
arthritis-savaged joints.
Softer tissues also respond to these fields. For instance, Pilla
observes that many people with bone breaks experience significant
pain in muscles around their injuries. Shortly after EMF therapy
begins, however, that pain disappears.
Though the mechanism remains elusive, Pilla says, the treatment
seems to affect swelling, which can cause pain. If this proves
true, he says, EMFs might benefit people with carpal tunnel
syndrome, where swelling in the wrist pinches nerves going to
the fingers.
<snip>
Despite some exploration of EMFs to heal nerves and other soft
tissue, the majority of studies continue to focus on bone.
James T. Ryaby, vice president of OrthoLogic, a medical devices
company in Tempe, Ariz., has been using what he calls combined
fields -- oscillating magnetic fields superimposed on a static
magnetic field. They appear to spur bone growth more quickly than
the older type of pulsed EMFs, Ryaby says.
What's more, the combined-field devices require just a small
percentage of the power used by typical pulsed EMF generators. This
means the combined-field devices can run on conventional batteries,
Ryaby says. His company is testing such a device for fusing
vertebrae in patients with back pain.
<snip>
At the BioElectromagnetics Society meeting last June, Sisken's
group reported on test-tube experiments showing that pulsed EMFs
can turn on a gene in damaged nerves. That gene plays a role in
triggering growth-related repair.
Brighton is also working to elucidate which genes are altered by
EMFs. "This is to me what's most exciting," he says. "We can turn
genes on and off with this stuff."
McLeod and his group tend to focus on physical effects of fields on
cells. Their data indicate that EMFs may bias the movement of cell
structures that are otherwise jostled by the random pushes and
pulls of chemical and physical processes, McLeod says. He also
finds that EMFs can alter the environment in which cells grow and
move within the body. For instance, electric fields may alter the
stickiness of surrounding proteins. Indeed, he argues that changes
in a cell's behavior may trace as much to environmental alterations
as to the cell's gene activity or membrane effects.
Changes in cellular behavior may not be limited to the fields being
used in therapy today, however. Aaron, for instance, has examined
effects of the 60-Hz fields generated by power lines and home
wiring.
In the August Bioelectromagnetics, his group reports that field
strengths similar to those in the home and workplace increased
production of a protein that regulates proliferation and
development of cells destined to become bone. The EMFs also
stimulated some maturation in cells.
Aaron concludes that fields associated with electric power may
exert a beneficial influence on such tissues rather than harm them.
All this basic research may add up to more effective devices and
ubiquitous applications. For instance, Pilla says he believes
generators might one day be miniaturized to the size of a dime and
cost next to nothing.
He envisions disposable bandages incorporating a tiny EMF device
that would treat problems ranging from ankle sprains to bedsores.
References:
<snip>
Copyright =A9 1999 Science Service. All rights reserved.
=1A
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