User's Manual Part 1

viii
EMI Avoidance
The VitalSense system is intended as a short range wireless device. The
maximum distance at which the capsule sensor can be used is 1 m, and the
maximum distance at which the patch can be used is 2 m. If transmissions
appear to be lost, bring the monitor closer to the sensors. Move the system
away from any devices you suspect may be emitting electrical radiation.
The VitalSense system is intended to be an ambulatory system worn on
the body, with the monitor placed at or near the waist. Because of its low
power, it is not recommended for use in electrically noisy environments.
Although protected by filtering, the VitalSense system is susceptible to
frequencies other than the channel band. The VitalSense system has been
tested for RF immunity between 2 MHz and 1800 MHz. Generally, the
system can still be used when the maximum field strength of the
interfering signal is 10 V/m. Table 1.1 lists those frequencies which may
cause interference at levels below 10 V/m.
Table 1.1 Frequencies where RF Immunity is less than 10 V/m
Frequency
Dermal Patch RF
Immunity Level
Capsule RF
Immunity Level
17 MHz - 26 MHz 7 V/m 3 V/m
56 MHz - 83 MHz 5 V/m 3 V/m
678 MHz -782 MHz 5 V/m 3 V/m