A cartridge and system involving a joint spectroscopic and biosensor bloodanalyzer for measurement of at least two hemoglobin species in a patient'sblood sample by spectroscopy, and measurement of at least pH of the bloodsample by biosensor, for assessing the patient's oxygenation and acid-basestatus. The cartridge comprises a housing having a first housing member anda second housing member bonded together by a gasket. The housingcomprises a cartridge inlet； a blood storage conduit； an optical chamber； abiosensor conduit ； a waste receptacle； a vent； an air bladder, an air bladderexit port； and, an optical window and an aligned optical member, the alignedoptical member being one of a reflecting member or a second optical window,and being positioned to align with at least a portion of the optical chamberandat least a portion of the optical window.
