Plasma separator assembly having interface-seeking piston with centrifugal valve

Claim 1

A SEPARATOR ASSEMBLY CAPABLE OF SEPARATING BLOOD INTO A PLASMA/SERUM ORLIGHT PHASE AND A CELLULAR OR HEAVY PHASE COMPRISING: A CONTAINER HAVING AT LEAST ONE OPEN ND WHICH IS ADAPTED TO RECEIVE BLOOD FOR SUBSEQUENT SEPARATION INTO A LIGHT PHASE AND A HEAVY PHASE, A CLOSURE SEALING THE OPEN END OF THE CONTAINER, THE CLOSURE BEING FORMED OF A SELF-SEALING, ELASTOMERIC MATERIAL EHICH IS PENETRABLE BY A CANNULA THROUGH WHICH BLOOD TO BE SEPARATED IS CONDUCTED INTO THE CONTAINER, AN INTERFACE-SEEKING PISTON HAVING A SPECIFIC GRAVITY RELATIVELY GREATER THAN BLOOD AND SLIDABLY MOUNTED IN THE CONTAINER ADJACENT ONE END THEREOF AND BEING MOVABLE DOWNWARDLY IN SAID CONTAINER DUE TO HE REFLUENCE OF CENTRIFUGAL FORCE AND HAVING MEANS ON AN OUTER SURFACE FOR PROVIDING SEALING ENGAGEMENT WITH AN INNER SURFACE OF THE CONTAINER, A VALVE ASSEMBLY MOUNTED ON THE PISTON AND DISPOSED AT THE LOWER END THEREOF, SAID ASSEMBLY COMPRISES A LOWER RESILIENT DIAPHRAGM MOUNTED ON THE LOWER END OF SAID PISTON AND HAVING APERTURES FORMED THEREIN, SAID APERTURES BEING NORMALLY CLOSED AND ADAPTED TO OPEN DURING THE DOWNWARD MOVEMENT OF THE PISTON, AN UPPER RESILIENT DIAPHRAGM MOUNTED ON THE UPPER END OF SAID PISTON, HAVING APERTURES FORMED THEREIN, SAID APERTURES BEING NORMALLY CLOSED AND ADAPTED TO OPEN DURING THE DOWNWARD MOVEMENT OF THE PISTON, A FILTER ASSEMBLY MOUNTED BETWEEN SAID VALVE ASSEMBLY AND SAID UPPER DIAPHRAGM AND BEING IN FLUID COMMUNICATION WITH THE VALVE ASSEMBLY, SAID FILTER ASSEMBLY INCLUDING A LOWER COARSE FILTER HAVING AN AVERAGE PORE OPENING LARGER THAN THE DIAMETER OF BLOOD CELLS, DISPOSED ADJACENT SAID VALVE ASSEMBLY AND AN UPPER FINE FILTER HAVING AN AVERAGE PORE OPENING SMALLER THAN THE DIAMETER OF BLOOD CELLS, SAID FINE FILTER DISPOSED BETWEEN THE UPPER IAPHRAGM SAID SAID COARSE FILTER, SAID FILTER ASSEMBLY BEING CAPABLE OF REMOVING SUBSTANTIALLY ALL SOLID MATERIAL FROM THE SEPARATED PLASMA/SERUM PHASE, AND SAID FINE FILTER PROVIDING PISTON STOP MEANS WHEN SAID PISTON IS AT THE PLASMA/SERUM-CELLULAR INTERFACE WHEREBY THE CELLULAR PHASE CLOGS THE FINE FILTER TO PREVENT FURTHER UPWARD FLOW OF FLUID THROUGH THE FINE FILTER SO THAT THE PISTON AUTOMATICALLY STOPS AT SAID INTERFACE AND THE UPPER DIAPHRAGM APERTURES CLOSE.