Download Electrodes for stimulation

ELECTRODES FOR STIMULATION
Cardiac Pacemakers and Defibrillators
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The heart is a natural example of a critical
Bioelectromagnetic system.
An electrocardiogram (ECG), which is used to diagnose the
control signals of the heart, is a mapping of the electrical
voltages produced by the heart on the surface of the body.
External electrodes are placed on the body’s surface
to receive these electrical signals.
As with any voltage, the surface potentials must be
measured relative to a reference (or ground)
electrode.
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Cardiac electrical signals sometimes malfunction.
During a heart attack, for instance, the heart may go into
fibrillation where the electrical signals become confused and
don not progress the heart in the correct order, thus not allowing
the heart contract properly for pumping of blood.
Then an external defibrillator may be used.
The defibrillator uses a pair of electrodes (paddles) that are
placed of the chest.
One of these electrodes is ground , and the other has a large
voltage, producing a shock across the heart that attempts to
restart the normal electrical activity of heart.
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Defibrillators can also be implanted internal to the body.
In that case, the battery pack is placed in the shoulder or
chest cavity of the patient..
The metal case (usually titanium) of the battery pack is left
in contact with body and a metal wire is surgically
attached near an electrically sensitive point on the heart.
A very similar device can be used for cardiac pacing.
A pacemaker typically works continuously, controlling most
if not all of the heart’s beats, where as a defibrillator
typically works only occasionally when needed
Pulsed Electromagnetic Fields
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Pulsed electromagnetic fields (PEMFs) have been used
for a number of medical applications.
Electrodes on the surface of the body are most often
used for these applications, although internal electrodes
can be used in isolated applications.
It is used to stimulate the body for pain control, bone and
tissue healing, and nerve stimulation.
Pulsed electromagnetic fields have been found to be
highly effective for healing fractures and soft tissue
injuries, particularly those that do not respond to
ordinary healing methods.
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Another application of pulsed electromagnetic fields is
for controlling pain in the knee, back and shoulder.
Pulsed electromagnetic fields are also used for a wide
variety of needleless drug delivery applications.
Direct Nerve Stimulation
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An electrodes used for neural stimulation.
Deep brain stimulators for treatment of Parkinson’s
disease currently use a device very similar to a cardiac
pacemaker.
A battery pack is embedded in the shoulder, and a wire
lead is run up the neck to the brain, where an implanted
can stimulate the brain to relieve tremors.
Both external electrodes and invasive needle electrodes
are used for stimulation of nerves and muscles for
therapy and diagnostic purpose.
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Stimulation of the optical nerve for retinal implants and
the auditory nerve for cochlear implants, as well as
bypassing a damaged spinal cord, have all been
demonstrated in the laboratory
Treatment of urinary, rectal, and erectile dysfunction has
also been proposed using implantable neural stimulators.
Ablation
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Ablation refers to using large amounts of localized heat
(burning) to treat medical conditions.
Cardiac ablation uses this localized heat to destroy illconducting pathways in heart muscles.
In coronary arteries, it is used to break up plaque and
clear the arteries.
All ablation applications require very precise control of
the localized heating.