An automated 3D ultrasound abdominal vessel monitor is capable of providing automated anatomical and physiological data on the large abdominal vessels, for example the Inferior Vena Cava (IVC). The 3D ultrasound abdominal vessel monitor includes one or more ultrasound transducers built into a housing or frame that in use sits on the upper abdomen, just below the ribcage. A disposable component can serve to secure the 3D ultrasound abdominal vessel monitor to the patient and provide a coupling medium between the 3D ultrasound abdominal vessel monitor and the skin of the patient.