Product Manual

www.heartway.com.tw
6
the overall immunity of the powered wheel-chair).
5. Report all incidents of unintended movement or brake release to the powered wheelchair manufacturer,
and note whether there is a radio wave source nearby. Power wheelchairs and motorized scooters (in
this section, both will be referred to as powered wheelchairs) may as susceptible to electromagnetic
interference (EMI), which is interfering electromagnetic energy emitted from sources such as radio
stations, TV stations, amateur radio (HAN) transmitter, two-way radios and cellular phones. The
interference (from radio wave sources) can cause the powered wheelchair to release its brakes, move
by itself or move in unintended directions. It can also permanently damage the powered wheelchairs
control system.
6. The intensity of the EM energy can be measured in volts per meter(V/m).Each powered wheelchair can
resist EMI up to a certain intensity. This is called “immunity level”. The higher the immunity level, the
greater the protection. At this time, current technology is capable of providing at least 20 V/m of
immunity level, which would provide useful protection against common sources of radiated EMI.
Following the warnings listed below should reduce the chance of unintended brake release or powered
wheelchair movement that could result in serious injury:
Do not turn on hand-held personal communication devices such as citizens band (CB) radios and
cellular phones while the powered wheelchair is turned on.
TURN OFF YOUR POWERED WHEELCHAIR AS SOON AS POSSIBLE WHEN EXPERIENCING THE
FOLLOWING:
Unintentional motions
Unintended or uncontrollable direction.
Unexpected brake release
The FDA has written to the manufacturers of power wheelchairs asking them to test new products to be
sure they provide a reasonable degree of immunity against EMI. The FDA requires that a powered
wheelchair should have an immunity level at least 20 V/m, which provides a reasonable degree of
protection against more common sources of EMI.
The higher the immunity level, the greater the protection. Your powered wheelchair has an immunity
level of 20 V/m which should protect against common sources of EMI.