Haemodialysis (HD)-induced hypotension is still a severe complication in spite of all the progress in HD treatment. Because of its multifactor causes, HD-induced hypotension cannot be reliably prevented by conventional Ultrafiltration (UF) and sodium profiling in open-loop systems, as they are unable to adapt themselves to actual decreases in Blood Pressure (BP). Therefore, the ultimate goal of this paper is to build a biofeedback system dynamics software to provide automatic control of UF during HD. Furthermore, the treatment should improve patient comfort and be carried out without use of additional body sensors and without additional medication.