Biomedical engineering, application of principles of engineering to biology and medicine, usually involving collaboration between engineers and biological scientists. There are a number of specialty areas in the field. Bioinstrumentation is the use of electronic measuring devices to monitor, diagnose, and treat diseases; biomechanics is the study of effects of various forces on the body, such as gravity. The development of appropriate materials that can be implanted inside the human body is the province of biomaterials, and systems physiology aims at an integrated understanding of living organisms. Clinical engineering involves the development of computer instruments in hospitals, and rehabilitation engineering develops devices and procedures to expand the capabilities of disabled people.