A future "vascular" (vascular-like machine) would replace human blood with about 500 billion nanorobots distributed through the vasculature of the body as a coating. It could eradicate heart disease, stroke, and other vascular problems; Eliminate parasites, bacteria, viruses and metastases from cancer cells to limit the spread of the disease transmitted by the blood; Move lymphocytes more rapidly to improve immune response; Reduce susceptibility to chemical, biochemical and parasitic poisons; Improve physical endurance and endurance; And partially protect from various accidents and other physical damage. With the availability of mature molecular nanotechnology we could replace the blood with a single complex robot. This robot would duplicate all essential functions of thermal and biochemical transport of blood, including the circulation of respiratory gases, glucose, hormones, cytokines, waste products and all necessary cellular components. The device would fit! The shape of existing blood vessels. Ideally, it would replace the natural blood so completely that the rest of the body would remain, essentially unaffected.
In fact a mechanical redesign of the human circulatory system that attempts to integrate itself as an intimate personal apparatus with minimal adaptation by the host human body. Molecular nanotechnology has been defined as the three-dimensional positional control of molecular structure to create molecular precision materials and devices. The human body is made up of molecules, so the availability of molecular nanotechnology will allow for dramatic progress in human medical services. Nanomedicine will employ molecular machine systems to address medical problems and will use molecular knowledge to maintain and improve human health on a molecular scale. Nanobots will have extraordinary and powerful implications for the medical profession, for the definition of disease, for diag. Nose and treatment of medical conditions, including aging and, ultimately, for the improvement and extension of the natural human biological structure and function.