Book excerpt: This book gathers 30 papers presented at the 21st PCBBE, which was hosted by the University of Zielona Góra, Poland, and offered a valuable forum for exchanging ideas and presenting the latest developments in all areas of biomedical engineering. Biocybernetics and biomedical engineering are currently considered one of the most promising ways to improve health care and, consequently, the quality of life. Innovative technical solutions can better meet physicians' needs and stimulate the development of medical diagnostics and therapy. We are currently witnessing a profound change in the role of medicine, which is becoming ubiquitous in everyday life thanks to technological advances. Further, the development of civilization manifests itself in efforts to unlock the secrets of the human body, and to mimic biological systems in engineering. The biannual Polish Conference on Biocybernetics and Biomedical Engineering (PCBBE) has been held for nearly four decades and has attracted scientists and professionals in the fields of engineering, medicine, physics, and computer science. Gathering the outcomes of this conference, the book introduces the reader to recent developments and achievements in biocybernetics and biomedical engineering.