| 摘要 |
Access devices to facilitate the introduction of various surgical instruments into vessels, conduits, cavities, and other interior regions of the body are disclosed, which include a "duck bill" valve having at least three flexible fold sections or leaflets subtending 360 DEG degrees of the cylindrical wall portion. The valve is configured to provide reduced friction forces when an instrument is inserted, as well as zero closure characteristics when the instrument is removed. |
