Warnings Regarding Effects Of Electromagnetic Interference - Otto Bock Skippi Plus Service Manual

The interference (from radio wave sources) can cause the power wheelchair to release its
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brakes, move by itself, or move in unintended directions.
It can also permanently damage the power wheelchair control system.
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The intensity of the interfering EM energy can be measured in volts per meter (V/m). Each
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power wheelchair can resist EMI up to a certain intensity. This is called its "immunity level".
The higher the immunity level, the greater the protection. At this time, current technology is
capable of achieving at least a 20 V/m immunity level, which provides effective protection
from the more common sources of radiated EMI.
There are a number of sources of relatively intense electromagnetic fields in the everyday
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environment. Some of these sources are obvious and easy to avoid. Others are not apparent
and exposure is unavoidable. However, we believe that by following the warnings listed below,
your risk to EMI will be minimized.
The sources of radiated EMI can be broadly classified into three types:
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– Handheld portable transceivers (transmitters-receivers) with the antenna mounted directly on
the transmitting unit. Examples include: citizens band (CB) radios, "walkie talkie," security,
fire, and police transceivers, cellular telephones, and other personal communication devices.
INFORMATION
Some cellular telephones and similar devices transmit and receive signals while they are ON, even
when not being used;
– Medium-range mobile transceivers, such as those used in police cars, fire trucks, ambu-
lances, and taxis. These usually have the antenna mounted on the outside of the vehicle.
– Long-range transmitters and transceivers, such as commercial broadcast transmitters
(radio and TV broadcast antenna towers) and amateur (HAM) radios.
Because EM energy rapidly becomes more intense as one moves closer to the transmitting
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antenna (source), the EM fields from handheld radio wave sources (transceivers) are of special
concern. It is possible to unintentionally bring high levels of EM energy very close to the po-
wer wheelchair's control system while using these devices. This can affect power wheelchair
operation and braking.
Other types of handheld devices, such as cordless phones, laptop computers, AM/FM radios,
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TV sets, CD and cassette players as well as small appliances such as electric shavers and hair
dryers, as far as we know, are not likely to cause EMI problems with your power wheelchair.

2.7.2 Warnings regarding effects of electromagnetic interference

WARNING
Risk of accidents due to uncontrolled driving behaviour. Electromagnetic interference (EMI) from
sources such as radio and TV stations, amateur radio (HAM) transmitters, two-way radios, and
cellular phones can affect power wheelchairs and motorized scooters. Following the warnings listed
below should reduce the chance of unintended brake release or power wheelchair movement which
could result in serious injury.
Skippi Plus
Safety instructions
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