A variety of devices could be powered selectively from a single-power source carried on the body via multiple power supply signals at different frequencies, according to the patent abstract.
a single power source cannot power a variety of devices. 
( z1 possible :polarity - :ARG1 ( z2 power :ARG0 ( z3 source :ARG0-of ( z4 power ) :ARG1-of ( z5 single ) ) :ARG1 ( z6 device :mod ( z7 variety ) ) ) )