Abstract Koronis Biomedical Technologies (KBT) proposes to develop and fully evaluate a renal replacement therapy (RRT) machine specifically targeted for critically-ill small children and neonates with acute kidney injury (AKI), fluid overload, and kidney failure. In recent years, continuous renal replacement therapy (CRRT) has emerged as the preferred method for providing kidney support to these patients, especially those who are hemodynamically unstable. Continuous veno-venous hemofiltration (CVVH) is a form of CRRT built on hemofiltration: waste products and fluid in plasma are removed from the blood by a pressure gradient over a filter, while a replacement fluid is infused to maintain fluid balance. Unfortunately, neonates infrequently receive renal replacement therapy due to the technical challenges of traditional CRRT machines that make therapy initiation very difficult, even at experienced tertiary children’s hospitals. Machines designed for adult- sized patients, but commonly used in pediatric care, require large catheters, tubing, and filters. This results in a high extracorporeal volume (ECV, the total volume of blood in the external circuit—the tubing and hemofilter) relative to a small patient’s size, as well as higher blood flows, higher clearance rates, and higher risks. Numerous medical centers do not even offer CRRT to infants, let alone for critically-ill neonates or premature infants, due to the inherent risks. At therapy initiation, a volume of fluid roughly equivalent to the ECV must be injected into the blood circuit to “prime” the pump. For CRRT in larger children and adults, the priming fluid is simply saline. If, however, the amount of fluid required to prime the circuit is greater than 10% of the patient’s total blood volume, the saline fluid could significantly dilute the patient’s blood, leading to hemodynamic instability. To avoid this outcome, a donor “blood prime” is used, though it is not without risks, such as hypocalcemia, acidosis, hyperkalemia, and a loss of platelets and coagulation functions. KBT’s Phase II SBIR project proposes to bring a new CRRT device with a lower ECV to market that is specifically targeted for small children and neonates, eliminating the need for blood primes. The performance and safety of the proposed highly integrated CRRT system will be evaluated in a clinical trial.