Patent CA-2475199-A1 (CA)
Title: System and method for using improved intravenous cannulas that solve the problem of blood spillage
Inventor: GADASSI HAIM
IPC: A61M39/10
Filed: 2004-08-02
Abstract: The introduction of indwelling cannulas into blood vessels (of humans or animals) (typically the veins) is one of the most common everyday actions of physician and nurses. Cannulas typically consist of a bending elastic thin plastic tunnel (typically with an inner diameter of about 1 mm) which can remain in the blood vessel for example up to 48 hours (after which it is typically replaced to avoid infections), and a rigid inner needle for puncturing the blood vessel, which is removed immediately after inserting the cannula into the blood vessel. However, one of the biggest problems of this technology is the problem of blood spillage when removing the needle and/or when switching devices that connect to the cannula (such as for example IV sets for infusion), which makes it almost impossible for the nurse or physician to avoid coming in contact with the patient's blood when removing the needle or when switching the connections. This entails for example the danger of catching various infections, for example if the physician's or nurse's skin is slightly broken or if he/she has wounds on the hands. Of course the nurse or physician can always use gloves for this but this is inconvenient many times, especially for example when there is a problem to find the veins and the physician has better control without the gloves. The present invention solves this problem by providing an improved device which automatically seals the cannula when removing the needle and when switching connections, preferably based on inserting the needle and any other connections thorough a preferably built-in self sealing rubber. Many other possible variations are also covered, such as for example: a. Letting the connecor itself push a self sealing rubber membrane towards a short needle within the cannula insertion device and/or push the inner needle towards the membrane, b. Using a sleeve or double funnel with a flexible strong material, which is held in at least one position in a closed state by rubber and/or springs, so that both the long needle and the internal rigid hollow pipe of the connector can alternately pass through it, c. Using a branch preferably on the wide side of the cannula insertion device, so that the long needle goes through a preferably self sealing rubber on one branch, and the connectors are screwed or otherwise connected to the other branch by any other known means for using automatic valves to prevent leakage, d. Using an inner cell or pipe preferably within the wide tube of the cannula insertion device (or for example in an even wider section in it), which preferably has a self sealing rubber at its edge so that first the long needle for the cannula insertion goes through it, and after the needle is removed, the other connectors work by pushing a valve which preferably opens one or more holes preferably at the side of the inner cell or pipe, e. Using a preferably even larger self sealing rubber in a preferably wider part within the wide tube of the cannula insertion device, wherein the rubber preferably has one or more cuts in the middle, so that both the long needle and the internal rigid hollow short pipe of the connectors can alternately pass through it, f. Using self sealing rubber within the wide tube of the cannula insertion device and using a preferably U-shaped by-pass flexible tube that goes through the external wall of the cannula insertion device, so that the external edge of the connector moves for example a spring or some other element which normally squashes the flexible by-pass tube.