Patent ID: 8708950

Claim:
A tubing state detector for detecting the presence or absence of a tubing segment, comprising: a first light emitter positioned next to a side wall of a channel and located at a pre-determined point longitudinally along the channel, the channel configured to receive and hold a tubing segment, the first light emitter having a first optical axis directed toward a center of a tubing segment positioned in the channel; a second light emitter positioned next to the side wall of the channel and located at approximately the same point longitudinally along the channel as the first light emitter, the second light emitter having a second optical axis directed toward the channel, the second light emitter being positioned next to the first light emitter and having an optical axis approximately parallel to but spaced apart from the first optical axis; and an optical sensor positioned on a side of the channel opposite the first and second light emitters and arranged to receive light emitted by the first and second light emitters to determine a presence or absence of a tubing segment in the space.