Jack Wasserman

Biomechanics of the normal and abnormal hip joint

Static analysis of the canine hip has given some insight to the nature and trend of the force and subsequent stress that is normally applied to the joint. Using the static model, the magnitude and direction of force and stress worsens in the hip with the anatomic and stability changes associated with CHD. More sophisticated dynamic models that take into account unbalanced forces and moments with the resultant motion are needed to better understand the mechanics of the hip joint.

Recording and processing aneurysmal vibration signals in dogs

A specially designed computerized acoustic aneurysm detection system has been developed and used for recording the acoustic signal produced by aneurysms in dogs. Two transducer types, a modified horn-coupled microphone and a microvascular intra-operative Doppler flowmeter have been used. The results show that the aneurysm signal is time-varying and that a stronger vibration signal can be obtained if a proximal stenosis presents. With direct contact recording, the acoustic signals from aneurysms and parent arteries show different characteristics that can be easily distinguished. The aneurysm signals are processed by spectrograms, and a smoothing technique for suppressing noise is introduced.

Automobile/Motorcycle Impact Research Using Human Legs and Tibias

It has been widely reported that injury to the leg is the most common form of non-fatal trauma associated with motorcycle accidents. Furthermore, it has also been reported that the majority of motorcycle leg injuries resemble those experienced by pedestrians in that they do not involve crush. Rather, these injuries appear to involve only a direct impact between the leg and an opposing rigid object. Often the soft tissue of the limb is injured from the inside out in that sharp bone fragments and jagged ends lacerate the soft tissue as relative motion occurs. The complexity of understanding these results is due to a combination of impact effects, biological material properties and human geometric considerations. Our ongoing research, underway for several years, is providing the fundamental data for cadaver leg and bone impact response. To conduct this research a unique test facility has been developed that simulates collisions between automobiles and pedestrians, motorcycles, or bicycles. Results are presented and discussed for the purposes of understanding fracture behavior of the human leg and tibia. For the covering abstract see IRRD 853578.

Technology enhanced cooperative learning

The University of Tennessee has initiated a yearlong set of projects related to Wireless Instructional Initiatives. The project has provided a set of wireless laptops for student use in several classes. The courses for this paper have been organized into structured groups for both in class and out of class projects. During class, the groups may be required to develop approaches to problems, answer and present solutions, and assess the work of other groups. The use of wireless laptops combined with a Blackboard course web site provides an opportunity to have an available documented group solution for discussions. The initial applications were with junior - senior course, where the students provide approaches to realistic problems, which were available to all groups. The students reported that they gained significant insight from reading other groups. The next course will be a sophomore course with over 9-10 student groups and a more general application.