A dual one-way check valve arrangement (300) that may be used for assessing anoperating condition of at leastone of first and second check valves (304, 308) situated in seriesalong/within a section of a patient-specific section of tubing(244). A pressure sensor (332) may be associated with at least part of theflow path between the first and second check valves(304, 308) and may be operable to provide an indication of a failed conditionof at least one of the first and second check valves(304, 308). In one embodiment, the pressure sensor (332) may change from afirst state to a second state upon fluid pressure withinthe flow path between the first and second check valves (304, 308) fallingbelow a predetermined level. For instance, the prede-termined level may be a cracking pressure of at least one of the first andsecond check valves (304, 308). The change in state maybe visually discernible on an exterior of the pressure sensor (332).
