An assembly of devices intended to be operated by a healthcare professional to continually measure patient blood glucose at the point of care in a healthcare facility. It is continuously connected to the patient during use and typically consists of a line-powered control unit, with user interface and rechargeable battery, containing a spectrometer to quantitatively measure glucose concentration in received plasma samples; a sterile, single-use cartridge connected to the patient via a venous catheter designed to withdraw a blood sample at intervals, convert it to plasma, and transport it to the control unit for analysis; a heparin syringe; and a sterile cap to protect the patient connector.