Patent ID: 7422693

Claim:
A system for processing blood by separating fluid components comprising: a density centrifuge blood processing system having a separation chamber rotating about a central rotation axis—and operable to extract and collect a separated, selected component from the chamber; a light source in optical communication with said density centrifuge blood processing system for providing an incident light beam for illuminating an observation region on said separation chamber of said density centrifuge blood processing system, thereby generating light transmitted, scattered or both from said observation region; a light collection element in optical communication with said density centrifuge blood processing system for collecting at least a portion of said light transmitted, scattered or both from said observation region and for directing at least a portion of said light transmitted, scattered or both from said observation region onto a two-dimensional detector; the two-dimensional detector position to receive and detect said light transmitted, scattered or both from said observation region provided by said light collection element, thereby measuring a two-dimensional distribution of intensities of said light transmitted, scattered or both from said observation region; said two-dimensional distribution of the intensities of said light transmitted, scattered or both from said observation region comprising an image of at least a portion of said density centrifuge blood processing system, said two-dimensional distribution of the intensities of said light transmitted, scattered or both providing a measurement of the positions of one or more phase boundary between optically differentiable blood components in said seperation chamber, and wherein said two-dimensional detector generates an output signal corresponding to said two-dimensional distribution of the intensities of said light transmitted, scattered or both from said observation; and a centrifugation device controller in communication with said two-dimensional detector for receiving said output signal, wherein said controller controls the positions of one or more phase boundary by adjusting a flow-related operating parameter of the density centrifuge blood processing system.