Separation apparatus

Abstract

A method for centrifugally separating whole blood into red blood cells and a plasma constituent rotates about a rotational axis a separation zone having radially spaced apart walls with a high-G side and a low-G side located closer to the rotational axis than the high-G side. Whole blood enters the rotating separation zone in an entry region to begin separation. Separation is halted by a terminal wall that is circumferentially spaced from the entry region. The whole blood separates into red blood cells toward the high-G side and plasma constituent toward the low-G side. The method directs red blood cells separated in the separation zone in a circumferential flow direction toward the terminal wall. The method directs separated red blood cells from the rotating separation zone through a second path that extends, at least in part, radially beyond the high-G wall.

1 - 7 . (canceled)  
     
     
         8 . A separation channel for rotation about an axis to separate a biological fluid including: 
 radially spaced apart inner and outer side wall portions and an end wall portion,    an inlet to convey fluid into the channel;    a barrier located in the channel intermediate the side wall portions and having upstream and downstream sides;    a single flow path communicating between the upstream and downstream sides of the barrier;    the outer wall portion including a section in the vicinity of the barrier, such section of the outer wall portion being located radially outward of the outer wall portion of the channel upstream of such section.    
     
     
         9 . The separation channel of  claim 8  wherein the barrier extends to a radial position inward of the inner wall portion.  
     
     
         10 . The separation channel of  claim 8  wherein the barrier extends at least between the radial locations of the inner and outer wall portions.  
     
     
         11 . The separation channel of  claim 8  wherein a surface of the single flow path includes the outer wall portion.  
     
     
         12 . The separation channel of  claim 8  further comprising a first exit path communicating with the channel upstream of the barrier, and a second exit path communicating with the channel downstream of the barrier.  
     
     
         13 . A separation channel for rotation about an axis to separate a biological fluid including: 
 radially spaced apart inner and outer side wall portions and an end wall portion,    an inlet to convey fluid into the channel;    a barrier located in the channel intermediate the side wall portions and having upstream and downstream sides;    a first flow path communicating between the upstream and downstream sides of the barrier; and    a fluid outlet from the channel defined upstream of the barrier terminating at the inner wall portion.    
     
     
         14 . The separation channel of  claim 13  further comprising a first exit path communicating with the fluid outlet from the channel upstream of the barrier, and a second exit path communicating with the channel downstream of the barrier.  
     
     
         15 . The separation channel of  claim 13  wherein at least a portion of the first flow path is defined by an axially disposed surface of the barrier, which surface forces at least one blood component in an axial direction of the channel.  
     
     
         16 . The separation channel of  claim 13  wherein a surface of the first flow path includes the outer wall portion.