Stationary Optical Monitoring System For Blood Processing System

A blood processing system includes a centrifuge and an optical monitoring system mounted at a stationary radial position with respect to the centrifuge. A flow circuit may be mounted within the centrifuge, with an umbilicus of the flow circuit extending outside of the centrifuge. A midsection of the umbilicus is orbited around a rotational axis of the centrifuge at a uniform first speed, which causes the centrifuge to rotate at a non-uniform second speed that is approximately double the first speed. The monitoring system is configured to view the flow circuit through a radial window of the centrifuge to determine a characteristic of the flow circuit. The yoke and/or umbilicus may occasionally move into position between the monitoring system and the window, so a controller of the monitoring system is configured to determine when unobstructed light reflected through the window by the centrifuge is received by the monitoring system.