9412071 Murphy This equipment grant requests funds for an automatic six degree- of-freedom ultrasound scanning system to be assembled in the Mechanical Engineering Department at Louisiana State University. In situ, nondestructive measurement of the geometry of biological surfaces, including skin, skeletal, cartilage, and subchondral bone, will be possible with resolution on the order of 10-20 micrometers with the proposed system. This level of resolution is essential for developing mathematical models of the kinematics and dynamics of human joints. In the typical joint, short stiff ligaments and articular surfaces act as passive constraints, complementing the active constraint and control of the muscle system. Ligament elongations are thought to be on the order of one millimeter in normal movements of the knee joints and significantly less in finger joints. Thus surface geometry must be measured with high accuracy in order to develop meaningful mathematical models of passive constraint behavior of the articular surfaces and ligaments which form parallel systems. ***
