Dynatronics Dynatron 550 Plus, Service Manual

Page: 97 / 153

Dynatron
®
850plus & 550plus
Ultrasound Technical Information
89
Electrotherapy Usage Cautions
The following are general cautions to be observed during interferential, premodulated, Russian,
biphasic, and high voltage pulsed stimulation. For microcurrent electrotherapy, see separate
“Microcurrent Usage Cautions” following this section.
Electrical stimulation, by its very nature, has the ability to irritate the patient’s skin. Certain
precautions should be observed to assure maximum safety and comfort for patients. A
patient’s tendency to have adverse reactions is dependent upon several factors. These factors
are:
Current Density. This is the amount of current being delivered to the patient divided by the
area through which the current is being delivered (the surface area of the electrodes being
used).
Electrode Condition. Worn or dried out electrodes cause the current to concentrate in small
areas of the electrode instead of going into the skin distributed evenly throughout the entire
electrode surface. This has the effect of increasing the current density, since the current is
being delivered through a smaller area.
Patient Susceptibility. Some patients’ skin is more sensitive to electrotherapy currents.
This can cause a reaction similar to a heat rash.
Electrotherapy treatment can result in a rash, burn, or blister. The tendency to do this is
dependent upon the factors listed above and can be minimized by applying the following
guidelines:
1. Use only moderate current. It is not always necessary to raise the treatment intensity to
just short of the patient’s pain threshold to achieve adequate results. Suggested
maximum treatment levels for different electrode sizes are given below (for interferential
or premodulated therapy). These values are not intended to be inflexible, but they should
be a guideline. If your treatment goes beyond these intensities, you should examine the
treatment to discover why such a high intensity setting is required.
Use as large an electrode as is practical for the application. Note that the current density in a
1.25” square electrode is FIVE TIMES the current density in a 1.75” by 3.75” electrode for
the same intensity setting. Using larger electrodes allows current to be delivered over a
larger area of the body, keeping the current density to be as low as possible and minimizing
the possibility for adverse reactions.
Interferential / Premodulated
Electrode Size Maximum Recommended Intensity
Carbon Electrodes 3” round 25-30
3” x 5” 30-40
Self-adhesive Electrodes 1.75” square 10-15
1.75” x 3.75” 25-30
1.25” round 10-12
2” round 10-20
3” round 25-30