a machine for extracorporeal blood treatment comprises a device for ultrafiltration of a liquid through a semi - permeable membrane of a blood treatment device , a first sensor for ultrafiltration rate through the membrane , a second group of sensors for measuring a trans - membrane pressure , an infusion line with an infusion pump and a programmed controller for calculating a maximum infusion rate as a function of the transmembrane pressure . the machine is suitable for kidney failure treatments , such as hemofiltration and hemodiafiltration . in a relatively short time the machine enables a large quantity of corporeal blood to be removed from the patient .