text: 1. Field of the Invention
  The present invention relates to biomedical apparatus, and particularly to a sterile covering for a surgical camera used in arthroscopic operations.
  2. Description of the Prior Art
  Arthroscopy involves the use of filamentary probes, such as an endoscope, which is a filamentary tube particularly adapted for transmitting an optical image of a remote surgical site. The image can be seen through the endoscope with the naked eye, but it is more typically picked up by a television camera and enlarged for display on a video screen. A typical coupling between an endoscope and a camera is shown by Makepeace, et al., U.S. Pat. No. 3,900,021.
  Although endoscopes are designed to be autoclaved for sterilization, it is impractical sterilize a television camera and its coupling. Therefore, once an endoscope has been connected to the coupling, that portion of the endoscope coming into contact with the coupling is regarded as contaminated according to surgical practice. The contaminated endoscope must then be resterilized before reuse, or a separate, sterilized endoscope used in its place.
  In prior art practice, a sterile plastic covering or bag is placed over the camera to form a sterile barrier between the camera and the operating environment. Typically, the bag is tied off tightly around that end of the endoscope nearest the camera.
  Several endoscopes are typically used during an operation, each endoscope having a different shape or characteristic. Each time an endoscope is attached or detached from the camera coupling, the end of the sterile bag must be untied and retied to uncover and recover the endoscope-to-camera coupling. However, as discussed above, once an endoscope is decoupled from the camera, it is treated as contaminated and cannot be reused unless resterilized.
  What is needed is some means for providing a sterile covering for a camera which allows a succession of endoscopes to be attached and detached from the camera coupling without contamination from the camera or its coupling, and without destroying the sterility of the camera covering.