Patent attributes
A cannula system (1) comprising a tubular housing (7) having a front and a rear end. A slider (6) is displaceably mounted inside the housing (7) between a front and a rear limit position. A tear end (5) of a cannula (3) is rigidly joined to the slider (6), the front end of said cannula being fitted with a front end (4) having a tip to pierce biological tissue and extending into the front end of the housing (7) when the slider (6) is in the rear limit position. Means are provided to move the cannula (3) back. A catheter (2) is affixed to the rear end of the housing (7) in the direction opposite the direction of piercing and extends at least in part through the slider (6) and into the cannula (3), preferably as far as the front end of said cannula, when the slider (6) is in its front limit position and the cannula (3) projects from the front end of the housing (7). This cannula system offers the advantage that the catheter can be sealed at the tip and also may consist of several ducts without incurring any danger of leaks anywhere.
