Numerous experts in hospitals, universities, research institutes, industry and health agencies responded to the call of the commission of the European Communities for project proposals in the field of research and development of medical informatics, the AIM Exploratory Action. AIM is the acronym for Advanced Informatics in Medicine. The main objective of the AIM Programme is to further the usage of information technology and telecommunications in health care in the Community. The subjects of the projects comprised: information generation and coding; communication networks; workstations; image and signal processing; decision support systems; integration of instrumentation; regulatory aspects; and standardization. This book introduces the state of art, current thinking and trends in the field of health care informatics. Surveys and results are presented by the project managers andexperts directly concerned with the 42 AIM projects and 3 main accompanying activities on data protection and confidentiality, patient data cards and standardization.