Abstract: A self-occluding cannula assembly comprising a generally tubular cannula sheath having a connecting hub formed on one end thereof and including an occluding means positioned within the inner bore of said connecting hub. The occluding means comprises (a) a generally frusto conical dilator projection; (b) an elastomeric valving member positioned transversely within the bore of the connecting hub proximal to said dilator projection. The elastomeric valving member is peripherally axially compressed so as to cause displacement, distortion and/or rheological flowing of the elastomeric material thereof in a radially inward direction. An elastically openable and closable aperture is formed in the mid-portion of the valving member and the valving member is alternately movable between an "occluding" position wherein the aperture is closed so as to prevent fluid flow through the cannula and a "non-occluding" position wherein the aperture is open to allow fluid flow through the cannula.

Abstract: Disclosed is a self-occluding cannula assembly comprising a cannula sheath having a connector hub formed on one end thereof. A self-actuating occluding means is formed within the cannula assembly so as to prevent back flow of body fluids from the cannula. In the cannulae wherein an introducer needle is initially axially positioned within the cannula lumen, the occluding means will permit desired withdrawal of the needle but will thereafter immediately occlude the cannula lumen to prevent back flow therethrough. The occluding means is further adapted to shift to a "non-occluded" configuration upon connection of a second infusion or monitoring tube to the proximal end of the cannula. If, during use, the infusion/monitoring tube should become disconnected, the occluding means will again shift to its "occluded" configuration so as to prevent back flow of fluids from the cannula until such time as the infusion/monitoring line is reconnected.