The complete volume 12 of Medical Progress through Techlogy is devoted to the work of colleagues in Japan. Additionally, whole authority and responsibility both for the election of topics and for the reviewing procedure had been delegated to Guest Editors from Japan. What are the objectives of this special issue and why has Japan been elected to present itself in this way? International journals such as Medical Progress through Techlogy usually contain papers from authors all over the world. Such issues provide a rather comprehensive survey on different scientific projects but do t reflect the standard and extent of medical techlogy in a certain country. I think that issues like the present one give far better information on the actual state of research and development in a country than an irregular sequence of scientific reports. It is t intended that all future issues of Medical Progress through Techlogy will concern only national issues. The present issue is an exception. However, if the readers appreciate such an approach, then other national issues may be published. There are several reasons in favor of Japan preparing the first national issues. We all admire the history, tradition and culture of this country, but we are also impressed by the high standard of research, develop- ment and technical realisation achieved in nearly all high techlogy fields. There is doubt, that Japan is among the leading nations in the field of medical techlogy.