The microINR System is an in vitro diagnostics medical device, intended to monitor oral anticoagulation therapy (OAT) with vitamin K antagonist drugs. The microINR System refers to the reader (microINR Meter) and the analytic test strips (microINR Chips). The system provides quantitative determination of prothrombin time (PT) in INR (international normalized ratio) units with fresh capillary blood performed by fingersticking. The microINR Chip is a disposable plastic test strip that encloses 2 microcapillary channels which are of extremely simple construction and fully passive.