Electromagnetic Interference - Heartway Medical Products S19F User Manual

18
ELECTROMAGNETIC INTERFERENCE (EMI)
The rapid development of electronics, especially in the area of communications, has
saturated our environment with electromagnetic (EM) radio waves that are emitted by
television, radio and communication signals. These EM wave are invisible and their
strength increases as one approach the source. All electrical conductors act as
antennas to the EM signals and, to varying degrees, all power scooters and scooters
are susceptible to electromagnetic interference (EMI). The interference could result in
abnormal, unintentional movement and/or erratic control of the vehicle. The United
States Food and drug Administration (FDA) suggests that the following statement be
incorporated to the user's manual for all power scooter like the S19F. Power scooters
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, cellular phones and alarm systems
of shops. The interference (from radio wave sources) can cause the power scooter to
release its brakes, move by itself or move in unintended directions. It can also
permanently damage the powered scooter's control system. The intensity of the EM
energy can be measured in volts per meter (V/m).Each powered scooter 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 scooter movement that could result in serious injury:
1. Do not turn on hand‐held personal communication devices such as citizens band
(CB) radios and cellular phones while the powered scooter is turned on.
2. Be aware of nearby transmitters such as radio or TV stations and try to avoid
coming close to them.
3. If unintended movement or brake release occurs, turn the powered scooter off as
soon as it is safe.
4. Be aware that adding accessories or components, or modifying the powered
scooter, may make it more susceptible to interference from radio wave sources
(Note: It is difficult to evaluate the effect on the overall immunity of the powered
scooter).
5. Report all incidents of unintended movement or brake release to the powered
scooter manufacturer, and note whether there is a radio wave source nearby.
TURN OFF YOUR POWERED SCOOTER AS SOON AS POSSIBLE WHEN
EXPERIENCING THE FOLLOWING:
Unintentional scooter movements.
Unintended or uncontrollable direction.
Unexpected brake release.