Advances in Biomedical Engineering, Volume 6, is a collection of papers that discusses the role of integrated electronics in medical systems and the usage of biological mathematical models in biological systems. Other papers deal with the health care systems, the problems and methods of approach toward rehabilitation, as well as the future of biomedical engineering. One paper discusses the use of system identification as it applies to biological systems to estimate the values of a number of parameters (for example, resistance, diffusion coefficients) by indirect means. More particularly, the indirect approach concerns the application techniques only in the respiratory system. Another paper describes the status of custom integrated electronics in medicine—that significant improvements in the quality, accessibility, and cost of health care can be achieved through innovating their applications in medicine. These integrated electronics include subcutaneous, supercutaneous, percutaneous, transcutaneous, and extracutaneous applications. One paper reviews the excitation and control of skeletal muscle such as in therapeutic electrical stimulation and suppression of undesired movement. An important part of electrical stimulation sensory feedback mechanism which will allow the investigator to have move functional control over the extremities or limbs being tested. The collection can prove valuable to micro-biologists, bio-chemists, physiologists, developmental biologists, and investigators involved in physical rehabilitation and biomaterials research.