In the active versions, the leaflets are constructed such that they provide minimal resistance to the flow with {TAIL ~ minimal rise} in the pressure across {HEAD ~ the valve}, similar to the disclosed valves in the aforementioned patents 
In the active versions , the leaflets are constructed such that they provide minimal resistance to the flow with { TAIL ~ minimal rise } in the pressure across { HEAD ~ the valve } , similar to the disclosed valves in the aforementioned patents
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH