Medication infusion set

Abstract

An infusion set is provided for use in delivering fluid through a cannula, which is housed on a cannula housing, to a selected subcutaneous infusion site on a patient. The fluid is generally a medication, e.g., insulin. The cannula is in fluid communication with a fluid passageway surrounded by a projection on the cannula housing that includes one or more rail-like extensions acting as guides. A connector connects the cannula housing to a fluid delivery system, e.g., an infusion pump. The connector includes a needle, one or more guide arms that slide over the rail-like extensions to guide the needle into the self-sealing septum, and one or more locking arms, with barbs at the end, to connect with corresponding recesses in the cannula housing. An introducer having one or more similar guide arms and locking arms, and a longer needle, may be used to insert the cannula into the patient.

What is claimed is: 
     
         1 . A device for inserting a cannula for subcutaneous administration of fluid into a patient, comprising:
 a cannula housing defining a fluid passageway along a longitudinal axis thereof, the cannula housing including first and second guide rails and a cannula, said cannula being in fluid communication with the passageway, wherein, along substantially the entire length thereof, each of said guide rails has an outer longitudinal surface with an arcuate profile; and   an introducer configured to be detachably connected to the cannula housing, the introducer comprising separate first and second guide arms, each said guide arm being configured to mate with a respective one of the guide rails, and a longitudinally-extending needle that is parallel to said guide arms and has a distal tip that extends beyond respective distal ends of said first and second guide arms,   wherein the introducer is symmetrical about its longitudinal axis such that it is reversible, wherein each of the separate first and second guide arms has opposing inner and outer longitudinal sides, wherein, for each guide arm, the outer longitudinal side is flat along substantially the entire length thereof and the inner longitudinal side has an arcuate profile along substantially the entire length thereof, wherein the inner side of the first guide arm faces the inner side of the second guide arm, and wherein the cannula has a distal end for placement into the patient's skin, and, when the introducer is connected to the cannula housing, the needle's distal tip extends beyond the cannula's distal end.   
     
     
         2 . The device of  claim 1 , wherein the introducer further includes a locking arm having a barb, the cannula housing further defines a recess therein adjacent said fluid passageway, and said recess is configured to receive the barb when the introducer is connected to the cannula housing. 
     
     
         3 . The device of  claim 2 , wherein said locking arm includes a grip. 
     
     
         4 . The device of  claim 1 , wherein:
 the introducer includes a plurality of locking arms, each said locking arm having a barb associated therewith;   the cannula housing defines a plurality of recesses; and   each said recess is configured to receive a respective one of said barbs so as to detachably connect the introducer to the cannula housing.   
     
     
         5 . The device of  claim 1 , wherein at least one of the introducer and the cannula housing is made of material selected from the group consisting of polycarbonate and polypropylene. 
     
     
         6 . The device of  claim 1 , wherein the cannula housing further includes a self-sealing septum at an end of the fluid passageway opposite the cannula. 
     
     
         7 . The device of  claim 1 , wherein said arcuate profile of the outer longitudinal surface of each of said first and second guide rails is convex. 
     
     
         8 . The device of  claim 1 , wherein the needle is stationary at all times with respect to the first and second guide arms. 
     
     
         9 . A device for inserting a cannula for subcutaneous administration of fluid into a patient, comprising:
 a cannula housing defining a fluid passageway along a longitudinal axis thereof, the cannula housing including first and second guide rails and a cannula, said cannula being in fluid communication with the passageway, wherein, along substantially the entire length thereof, each of said guide rails has an outer longitudinal surface with an arcuate profile; and   an introducer configured to be detachably connected to the cannula housing, the introducer comprising separate first and second guide arms, each said guide arm being configured to mate with a respective one of the guide rails, a longitudinally-extending needle that is parallel to said guide arms and has a distal tip that extends beyond respective distal ends of said first and second guide arms, and a plurality of locking arms, each said locking arm having a barb associated therewith,   wherein each of the separate first and second guide arms has opposing inner and outer longitudinal sides, wherein, for each guide arm, the outer longitudinal side is flat along substantially the entire length thereof and the inner longitudinal side has an arcuate profile along substantially the entire length thereof, wherein the inner side of the first guide arm faces the inner side of the second guide arm, and wherein the cannula housing further defines a plurality of recesses therein, each said recess being configured to receive a respective one of said barbs so as to detachably connect the introducer to the cannula housing.   
     
     
         10 . The device of  claim 9 , wherein the cannula has a distal end for placement into the patient's skin, and, when the introducer is connected to the cannula housing, the needle's distal tip extends beyond the cannula's distal end. 
     
     
         11 . The device of  claim 9 , wherein each said locking arm includes a grip. 
     
     
         12 . The device of  claim 9 , wherein at least one of the introducer and the cannula housing is made of material selected from the group consisting of polycarbonate and polypropylene. 
     
     
         13 . The device of  claim 9 , wherein the cannula housing further includes a self-sealing septum at an end of the fluid passageway opposite the cannula. 
     
     
         14 . The device of  claim 9 , wherein said arcuate profile of the outer longitudinal surface of each of said first and second guide rails is convex. 
     
     
         15 . The device of  claim 9 , wherein the needle is stationary at all times with respect to the first and second guide arms. 
     
     
         16 . A method of inserting a cannula for subcutaneous administration of fluid into a patient, comprising:
 positioning a cannula housing at an insertion site on a patient, wherein the cannula housing defines a fluid passageway along a longitudinal axis thereof, wherein the cannula housing includes first and second guide rails and a cannula, said cannula being in fluid communication with the passageway, and wherein, along substantially the entire length thereof, each of said guide rails has an outer longitudinal surface with an arcuate profile;   connecting an introducer to the cannula housing, wherein the introducer includes separate first and second guide arms, each said guide arm being configured to mate with a respective one of the guide rails, and a longitudinally-extending needle that is parallel to said guide arms and has a distal tip that extends beyond respective distal ends of said first and second guide arms, and wherein the cannula has a distal end for placement into the patient's skin, and, when the introducer is connected to the cannula housing, the needle's distal tip extends beyond the cannula's distal end;   inserting the needle and the cannula into the insertion site; and   disconnecting the introducer from the cannula housing, whereby the needle is removed from the cannula.   
     
     
         17 . The method of  claim 16 , wherein the introducer further includes a plurality of locking arms, each said locking arm having a barb associated therewith, and the cannula housing further defines a plurality of recesses therein, each said recess being configured to receive a respective one of said barbs so as to detachably connect the introducer to the cannula housing. 
     
     
         18 . The method of  claim 16 , wherein each said locking arm includes a grip. 
     
     
         19 . The method of  claim 16 , wherein at least one of the introducer and the cannula housing is made of material selected from the group consisting of polycarbonate and polypropylene. 
     
     
         20 . The method of  claim 16 , wherein the cannula housing further includes a self-sealing septum at an end of the fluid passageway opposite the cannula. 
     
     
         21 . The method of  claim 16 , wherein said arcuate profile of the outer longitudinal surface of each of said first and second guide rails is convex. 
     
     
         22 . The method of  claim 16 , wherein the needle is stationary at all times with respect to the first and second guide arms. 
     
     
         23 . The method of  claim 16 , wherein the introducer is symmetrical about its longitudinal axis such that it is reversible. 
     
     
         24 . The method of  claim 16 , wherein the fluid is insulin. 
     
     
         25 . The method of  claim 16 , wherein the cannula housing further includes a base having an adhesive thereon for adhering the base to the patient's skin at said insertion site.