I I I . E M I / R F I
EMI/RFI—FREQUENTLY ASKED QUESTIONS (FAQS)
The following FAQs summarize what you should know about EMI/RFI. Use this information to minimize the risk that EMI/RFI will affect your power chair.
WARNING! Radio waves may interfere with the control of power chairs.
Where do radio waves come from?
Radio waves are emitted from the antennas of cellular phones, mobile
Are all power chairs susceptible to EMI?
Each make and model of chair differs in its ability to resist electromagnetic interference. That is, each has a particular level of “immunity” to interference, measured in volts per meter (V/m).Ahigher immunity level offers greater protection. In other words, a power chair with a high immunity level is less likely to be affected by a strong radio source than one with a low immunity level.
What is the FDA doing about the problem?
The FDA has written to the power chair manufacturers and requested that they test their new products to be sure that they provide a reasonable degree of immunity against EMI. The letter states that power chairs should have an immunity of at least 20 V/m. This provides a reasonable degree of protection against the common sources of EMI/RFI.
The FDA has also requested that these manufacturers clearly label their products with the immunity level, or state that the immunity level is not known. The labeling and informational material supplied with the power chair must explainwhattheimmunitylevelmeans,andthelabelingorinformationalmaterialmustwarnusersaboutthepossibility of EMI/RFI and how to avoid it. In addition, the FDA has recommended that manufacturers establish an educational program to inform power chair users and their caregivers about the problems associated with EMI/RFI, and the actions they can take to minimize the risk.
If my power chair is affected by EMI/RFI, what kind of motion should I expect? This is hard to predict. It depends on a number of factors:
νStrength of the radio waves
νConstruction of the power chair
νPosition of the power chair (whether it is on level ground or on an incline)
νWhether or not the power chair is in motion
An affected power chair’s movement can be erratic. It may move by itself or come to a sudden stop. Furthermore, it is possible for EMI/RFI to unexpectedly release the brakes on a power chair. Some intense sources of EMI/RFI can even damage the control system of your Jazzy.
14 | www.pridemobility.com | US Jazzy 1113/Rev I/Feb03 |