Bedside Monitor for the Measurement of Cardiac Output

Cardiac output measurements are one of the most important physiological indices ofcardiovascular function. Although there is interest in the measurement, there are no relativelyinexpensive, noninvasive cardiac output monitors available commercially. We are developing such amonitor, based on a new instrument which we call the Vector Doppler Ultrasound Velocimeter (VDUV).We have three specific aims which we believe will demonstrate the feasibility of our approach: (1) designand fabrication of a VDUV scanhead with one transmitter and two broad-beam receivers which view theaortiC blood velocity vector through the left parasternal-intercostal spaces, and design of a VDUVesophageal probe to measure aortic blood velocity from within the thoracic cavity, (2) testing in vitro(with steady and pulsatile laboratory flows) and in vivo (five normals and one ICU patient), and (3)preliminary assurance of clinical acceptance through interviews and reports of clinician's assessmentafter use of the VDUV prototype. Applications for the VDUV cardiac output monitor include use in theoperating room, intensive care unit, cardiac catheterization laboratory, and exercise and stress testingclinics.