FIG 10 shows {HEAD ~ ball check valve} 310 comprising {TAIL ~ electrodes} 340 and 342 and conducting ball 345 
comprising
FIG 10 shows { HEAD ~ ball check valve } 310 comprising { TAIL ~ electrodes } 340 and 342 and conducting ball 345
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH