Arthroscopy joint by a portal on the outer border of the patella. It is not clear if these examinations were of deceased or of living patients. Pioneering work began as early as the 1920s with the work of Eugen Bircher. He published several papers in the 1920s about his use of arthroscopy of the knee for diagnostic purposes. After diagnosing torn tissue, he used open surgery to remove or repair the damaged tissue. Initially, he used an electric Jacobaeus thoracolaparoscope for his diagnostic procedures, which produced a dim view of the joint. Later, he developed a double-contrast approach to improve visibility.
Effect of spaceflight on the human body space propulsion systems have been examined for over a century, and millions of man-hours of research have been spent on them. In recent years there has been an increase in research on the issue of how humans can survive and work in space for extended and possibly indefinite periods of time. This question requires input from the physical and biological sciences and has now become the greatest challenge (other than funding) facing human space exploration. A fundamental step in overcoming this challenge is trying to understand the effects and impact of long-term space travel on the human body. In October