The past decade has witnessed a vigorous growth in activities toward the development of a variety of biomedical devices ranging from the simple A-V shunt to the complex artificial heart. Re- search and development teams have been created comprising engi- neers, material scientists and clinicians and, perhaps for the first time, such groups are collaboratively bringing their respec- tive talents to bear on problems associated with defects in the human organism. These collaborations have resulted in a prolifera- tion of new information and a rapid and continuing redefinition of the frontiers of...