i-Check is a handheld blood gas electrolyte analyzer based on microfluidic and electrochemical detection technology that needs only 95 μL of blood for measuring pH, PCO2, PO2, K, Na, iCa, Hct etc. in just one minute. Its single-use cartridge includes a plastic substrate, a multi-biosensor array, a calibrator pouch, a sample injection port and a waste chamber.