Trocar Cannula with an Elastic Ring

Abstract

This invention provides a trocar cannula adapted to form a seal around a surgical instrument, the trocar cannula comprising: a housing for receiving the surgical instrument; an elastomeric septum seal disposed in the housing, the elastomeric septum seal comprising a septum seal defining an orifice having a diameter substantially no greater than the diameter of the surgical instrument so that during insertion of the surgical instrument, the septum seal forms a seal with the surgical instrument; a cannula tube connected to the housing; a zero closure valve disposed between the cannula tube and the housing; and an elastic ring disposed surrounding the elastomeric septum seal, the elastic ring being capable of changing its shape in accordance with the movement of the elastomeric septum seal so as to enable the septum seal to maintain a tight seal around the surgical instrument when the surgical instrument is moved.

Dependencies are inferred from the claim text.