The operation of the filter device has been described as applied to {HEAD ~ the filtration} of {TAIL ~ blood}  
The operation of the filter device has been described as applied to { HEAD ~ the filtration } of { TAIL ~ blood }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH