The occurrence of hypotension during ultrafiltration (UF) necessitates termination of the UF procedure and is commonly considered as a sign that DW has been reached. However, although intradialytic hypotension is commonly considered to be a sign of hypovolemia, this is not always correct, because too rapid removal of large amounts of fluid within a few hours causes a temporary state of disequilibrium. It has been shown that achievement of DW by volume control in fact decreases the number of hypotensive episodes (5) Therefore, there is a need for objective methods to estimate the body fluid volumesThis prospective, randomized, controlled study aims to evaluate the usefulness of the new BCM device as a method to improve volume control dialysis patients and compare the results with those obtained by conventional volume control modalities. To our knowledge such an investigation has not been done elsewhere.