The goal of this project is the production of a low cost, portable 3-D ultrasound device capable of accurate measurement of left ventricle end-systolic and end-diastolic volumes and ejection fraction. The device will employ automatic boundary detection software, and will automatically construct 3-D endpoint endocardial surfaces with no or minimal operator interaction. As a result of this automation, this device can be operated by a technician with only moderate training, eliminating the need for a skilled radiographer. This, together with the low cost, would provide greater accessibility to quantitative measurements of ventricle function than is currently available. Locations that could benefit from this access include emergency rooms, cardiologists' offices, and chemotherapy centers. In addition, use of 3-D eliminates many of the geometric assumptions, which currently limit the accuracy 2-D echocardiographic methods. Use of automatic boundary detection methods further improve accuracy and repeatability over both 2-D and manually delineated 3-D boundaries. While Phase I will be limited to use of the apical view, as is the practice in 2-D echocardiography, there is no inherent limit on volume accuracy imposed by use of other views. Use of alternative views will allow measurements on a larger percentage of patients than is currently possible and will be pursued in Phase II.