Prismatic reflector for centrifugal separation chamber

A blood separation system, comprising:

• a fluid flow circuit including a centrifugal separation chamber having a rotational axis and comprising a channel defined between a low-g side wall portion and a high-g side wall portion;
• and
• a blood separation device including
• a centrifugal separator configured to receive at least a portion of the centrifugal separation chamber and rotate said at least a portion of the centrifugal separation chamber about the rotational axis, and
• an interface monitoring system including
• a light source configured to transmit a light along an initial path toward the rotational axis, into the centrifugal separation chamber, and through the channel of the centrifugal separation chamber, and
• a light detector configured to receive at least a portion of the light as the light exits the centrifugal separation chamber, wherein
• the centrifugal separation chamber includes a prismatic reflector associated with the low-g side wall portion, formed of a light-transmissive material, and comprising inner and outer walls and first and second end walls, with the inner wall being configured to receive light traveling along the initial path and transmit the light to the first end wall, the first end wall being configured to receive the light transmitted through the inner wall and direct the light toward the second end wall in a direction that is angled with respect to the initial path, and the second end wall being configured to receive the light from the first end wall and transmit the light out of the prismatic reflector and toward the light detector.

A method of detecting the location of an interface between separated fluid components within a channel of a centrifugal separation chamber having a rotational axis, the method comprising:

• separating fluid in a channel of a centrifugal separation chamber into at least two fluid components;
• directing a light along an initial path through the channel so as to intersect at least one of the fluid components;
• directing the light exiting the channel out of the centrifugal separation chamber;
• detecting at least a portion of the light exiting the centrifugal separation chamber;
• and
• generating a signal indicative of the location of an interface between the separated fluid components within the channel, wherein a prismatic reflector is associated with the channel, with the prismatic reflector being formed of a light transmissive material and comprising inner and outer walls and first and second end walls, with the first end wall being angled approximately 45° with respect to the second end wall, the inner wall being associated to a curved surface of the centrifugal separation chamber and having a curvature corresponding to a curvature of said curved surface of the centrifugal separation chamber and being configured to receive light traveling along the initial path and transmit the light to the first end wall, the first end wall being configured to receive the light transmitted through the inner wall and direct the light toward the second end wall in a direction that is angled with respect to the initial path, and the second end wall being configured to receive the light from the first end wall and transmit the light out of the prismatic reflector and out of the centrifugal separation chamber.