Separation Apparatus and Method

Abstract

A separation apparatus and method are employed using a separation channel for rotation about an axis. Such channel includes radially spaced apart inner and outer side wall portions and an end wall portion. An inlet conveys fluid into the channel. A barrier is located in the channel intermediate of the inner and outer side wall portions. A first flow path communicates between upstream and downstream sides of the barrier. A collection region may be located downstream of the barrier for communication with the first flow path. An outer side wall section of the channel may be positioned radially outward of an upstream section thereof. The barrier may join the outer side wall portion along a substantial portion of an axial length of the channel. First and second exit flow paths may allow communication with the channel either upstream or downstream of the barrier or both.

1 - 70 . (canceled)  
     
     
         71 . A separation method comprising; 
 introducing a first fluid comprising first and second components having generally different density into a centrifugal field;    allowing an interface to form between at least portions of the first and second components;    removing a second fluid from one side of the interface; removing a third fluid from the other side of the interface;    combining at least a portion of the second fluid with the first or third fluid and re-introducing the combined fluids into the centrifugal field;    removing the second or third fluid from the centrifugal field.    
     
     
         72 . The method of  claim 71  in which the interface forms at a location within the centrifugal field and the method includes changing the location of the interface before reintroducing the combined fluids.  
     
     
         73 . The method of  claim 71  in which the first fluid comprises whole blood.  
     
     
         74 . The method of  claim 73  in which the second fluid substantially comprises plasma.  
     
     
         75 . The method of  claim 73  in which the third fluid substantially comprises red cells.  
     
     
         76 . The method of  claim 75  in which the combined second and first or third fluid have a hematocrit of between about 20% and 40%.  
     
     
         77 . The method of  claim 74  in which the plasma includes platelets.  
     
     
         78 . A separation method comprising: 
 introducing a first fluid comprising first and second components having generally different density into a centrifugal field;    allowing an interface to form between at least portions of the first and second components;    decreasing the force of the centrifugal field;    removing the first fluid component from the centrifugal field after the force of the centrifugal field is decreased.    
     
     
         79 . The method of  claim 78  wherein the step of removing is repeated more than once.  
     
     
         80 . The method of  claim 78  wherein the step of removing is repeated at least twice.  
     
     
         81 . The method of  claim 78  in which the first fluid comprises whole blood.  
     
     
         82 . The method of  claim 78  in which the first fluid component substantially comprises plasma.  
     
     
         83 . The method of  claim 82  in which the plasma includes platelets.  
     
     
         84 . A separation method comprising: 
 introducing a first fluid comprising first and second components having generally different density into a centrifugal field;    allowing an interface to form between at least portions of the first and second components;    sequentially and repeatedly removing fluid from the centrifugal field from one side of the interface and allowing the interface to reform.    
     
     
         85 . The method of  claim 84  in which the force of the centrifugal field is reduced during the removing and increased during restoring.  
     
     
         86 . The method of  claim 84  in which the first fluid comprises whole blood.  
     
     
         87 . The method of  claim 84  in which fluid is removed from the centrifugal field at least two times.  
     
     
         88 . The method of  claim 84  in which the removing includes passing the fluid through an aperture communicating with the centrifugal field on one side of the interface, and in which the interface is moved into proximity with said aperture for removing the fluid and moved away from the aperture for reforming the interface.  
     
     
         89 . The method of  claim 84  in which the fluid removed substantially comprises plasma and platelets.  
     
     
         90 . A method for collecting a blood component comprising: 
 connecting a source of blood to a blood separation device;    introducing the blood into in a centrifugal field created by the device;    allowing an interface to develop between at least two blood components;    removing a first fluid component from the centrifugal field from one side of the interface;    removing a second fluid component from the centrifugal field from the other side of the interface;    storing at least one of the first and second blood components;    returning at least in part the other of the first and second blood components to the blood source;    withdrawing additional blood from the blood source disconnecting the blood source;    repeating the steps of introducing and removing after the blood source has been disconnected; and    storing first and second blood components removed from the centrifugal field.    
     
     
         91 . (canceled)  
     
     
         92 . (canceled)  
     
     
         93 . The method of  claim 84  wherein the first fluid includes at least three fluid components of different density and includes removing portions of at least two of the three fluid components from the centrifugal field.  
     
     
         94 . (canceled)  
     
     
         95 . The method of  claim 78  wherein the removing includes removing portions of at least the first and second components from the centrifugal field.  
     
     
         96 . (canceled)  
     
     
         97 . (canceled)  
     
     
         98 . The method of  claim 71  wherein the removing includes removing portions of the first and second components from the centrifugal field.  
     
     
         99 . The method of  claim 71  wherein the first fluid includes at least three fluid components and includes removing portions of at least two of the three fluid components from the centrifugal field.  
     
     
         100 . The method of  claim 99  wherein portions of the three fluid components are removed from the centrifugal field.