Project Summary Volume overload (congestion) occurs in patients with heart failure (HF) and is the leading cause of hospitalization in the elderly worldwide. Unfortunately, clinical signs and symptoms; laboratory values; and existing diagnostic tools are unreliable in providing accurate assessment of volume status. Using a unique physiologic signal, Non-Invasive Venous waveform Analysis (NIVA), VoluMetrix has developed a proprietary device and algorithm designed for monitoring volume status in HF patients. Proof of concept data in humans and experimental animal models, demonstrate that NIVA provides a reliable indication of intravascular volume status (“pulmonary capillary wedge equivalent”). The work in this Phase IIB proposal will establish interface and usability studies to complete the process necessary for bridging the gap to commercialization.