a, Simplified schematics of the perfusion machine with all main components included. b, Visual illustration of the perfusion loop. c, Representative illustration of hepatic-artery (HA) pressure pulse with the visible dicrotic notch (imitating in vivo aortic valve closure, red circle) created by variation of the rotation speed of the centrifugal pump. d, Representative bypass flow of fully oxygenated (arterial) perfusate to the portal vein (PV), automatically controlled according to the monitored oxygen saturation of the deoxygenized perfusate (vena cava (VC)) to generate a physiological portal vein oxygen saturation (bypass seen in a). e, Representative illustration of hepatic-artery flow variation in relation to the injection rate of vasodilator (Flolan (Epoprostenol)) when the limit of 0.25 l min−1 is undershot. f, Representative illustration of the hematocrit control by dialysis, where the system continuously measures the hematocrit level in the perfusate and determines the volume of dialysis fluid that is administered into, or removed from the perfusion loop through the dialysis filter. g, Representative illustration of the automated insulin injection shown for a 25 h section of perfusion where insulin is infused when the defined glucose target level is surpassed in the perfusate. h, Illustrative table showing features of the presented long-term perfusion machine as compared to the commercially available perfusion machines. ‘Liver4Life’ refers to the name of the research group.