ACKNOWLEDGEMENTS 
The editor would like to express his deep 
appreciation to the authors for their excellent 
scientific manuscripts and for their generous 
contribution of time and energy in manuscript 
preparation, delivery and review for publica- 
tion. A special word of thanks is extended to 
the scientists who served on the manuscript 
review board and as session chairmen for their 
outstanding contribution to the conference and 
publication. 
The editor is grateful to many members of the 
National Heart and Lung Institute's staff, in 
particular the staff of the Medical Devices Pro- 
gram, for their unfailing support and assist- 
ance. They worked diligently in their planning 
and organizing activities for the conference, and 
carried a significant burden in making arrange- 
ments for the conference. 
The editor wants to acknowledge and express 
sincere appreciation to the Peat, Marwick, 
Mitchell Company and their supporting per- 
sonnel for their excellent support and coopera- 
tion in assisting with the papers and discussions 
of the conference. 
Further, the editor wants to thank all those 
who read and commented on the many scien- 
tific manuscripts at the various stages of 
publication. 
