Abstract: Detection systems for a syringe assembly that provide precision in monitoring the amount of fluid contained within the syringe barrel, detecting motion of the plunger within the syringe barrel, detecting the position of the plunger within the syringe barrel, and/or monitoring the volume received within or delivered by the syringe assembly are disclosed. A detection system of the present disclosure allows a sensor in communication with a portion of a plunger assembly to sense the motion of a plunger rod relative to a syringe barrel and thereby volume received within or delivered by the syringe by reading gradations having an identifier directly as the plunger rod with sensor moves past each respective gradation with identifier.

Abstract: A tube cassette (22) for receiving infusion tubing is shaped to define a locking surface (26). A pump (20) includes a latch (28) which engages with the locking surface and locks the cassette in a preset position with respect to the pump. A mechanical stop (38) in the pump stops motion of the cassette in a first direction, such that the cassette has moved past the preset position. Until motion of the cassette is stopped by the mechanical stop, the latch allows motion of the cassette past the preset position in the first direction. The latch automatically moves from an open position to a cassette-withdrawal-inhibiting position upon engagement of the latch with the locking surface, and subsequently locks the cassette in the preset position by pushing the cassette in a second direction, from past the preset position to the preset position. Other applications are also described.