Patent ID: 6284142
Filing Date: 2001-09-04
Classification: A61M,B01D,G01N

Abstract:
A blood processing system comprisinga blood separation chamber constructed and arranged for rotation about an axis separate blood into a plasma layer and an adjoining region comprising different first and second cellular blood species arranged in layers according to density,a collection line including a pump to remove the plasma layer from the blood separation chamber, the pump operating to control flow through the collection line in response to pump control signals,a sensor assembly in the collection line to detect presence of the first or second cellular blood species in the collection line, the sensor assembly including a source of light at a first wavelength, a source of light at a second wavelength different than the first wavelength, the different first and second wavelengths being selected to possess substantially the same optical attenuation for the first cellular blood species and significantly different optical attentuations for the second cellular blood species, a sensor to sense attentuations of light at the first and second wavelengths in the collection line, and a module to analyze sensed attenuations of light at the two different wavelengths to differentiate between the presence of the first cellular blood species and the presence of the second cellular blood species in the collection line,a controller coupled to the sensor assembly and including an input to prompt selection of at least a first blood collection protocol, which harvests plasma substantially free of the first and second cellular blood species, and a second blood collection protocol which harvests plasma containing the first cellular blood species but which is substantially free of the second cellular blood component, the controller operating, when the first blood collection protocol is selected, to generate a pump control signal when the sensor assembly detects presence of the first cellular blood species in the collection line, the controller also operating, when the second collection protocol is selected, to generate a pump control signal when the sensor assembly detects presence of the second cellular blood species in the collection line.