Patent ID: 8535210

Claim:
An optical cell for a separation chamber of a density centrifuge blood processing system for separating fluid components, said optical cell being adapted to be mounted on a rotor of said blood processing system, said rotor having an axis of rotation, said optical cell having a radial dimension extending outwardly from said axis of rotation when said separation chamber is mounted on said rotor, said optical cell comprising: an extraction chamber adapted to transmit at least a portion of an incident optical beam; a first extraction port extending radially outwardly into said optical cell and being adapted to transmit at least a portion of the incident optical beam, said first extraction port having a bore for passing fluid components and an orifice; a red blood cell extraction port downstream from said first extraction port with respect to fluid flowing through said optical cell and having an orifice extending radially outwardly into said optical cell beyond said orifice of said first extraction port; a dam between said first extraction port and said red blood cell extraction port, said dam being generally radially perpendicular to fluid flowing through said optical cell, and having an upper edge and a lower edge, said lower edge being radially outward from said upper edge, a ramp at said lower edge of said dam, said a ramp extending from said lower edge of said dam upstream beyond said first extraction port, wherein said orifice of said first extraction port and said orifice of said red cell extraction port extend into said extraction chamber a sufficient distance to be radially between the radial positions of said upper edge and said lower edge of said dam, and a plate adjacent said orifice of said first extraction port, said plate being spaced away from said orifice of said first extraction port and being downstream of said ramp.