The vibration device 24, wherein a change in the direction of the combined vibration force corresponds to a change in {HEAD ~ the direction} of {TAIL ~ a simulated motion} in the computer simulation 
of
The vibration device 24 , wherein a change in the direction of the combined vibration force corresponds to a change in { HEAD ~ the direction } of { TAIL ~ a simulated motion } in the computer simulation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH