fig1 through 3 depict an insertion aid 2 according to the present invention in a perspective schematic view . the insertion aid 2 comprises a cylindrical grip section 4 and , anchored on this , a guide needle 6 for stabilizing and guiding a soft cannula 8 of a catheter head of which , in the view shown in fig1 , only a plaster 10 and a guide section 42 can be seen . when the catheter head is in the applied position , the plaster 10 lies on the skin of the organic tissue . the cannula 8 is intended to puncture the skin and permit delivery and / or removal of fluid into and out of the organic tissue . after removal of the insertion aid 2 , an infusion set or the like can be placed on the guide section 42 and anchored there . the guide needle 6 has an external diameter which substantially corresponds to an internal diameter of the soft cannula 8 . by means of the stiffening and stabilizing of the cannula 8 and a beveled tip of the guide needle 6 , this can easily penetrate the tissue and be applied at the intended infusion site . the grip section 4 has a cylindrical outer circumferential surface 26 with two grip surfaces 28 lying opposite one another and intended for gripping with two fingers . on the lower end face of the grip section 4 from which the guide needle 6 also protrudes , first and second shields 16 , 18 are secured in a pivotable manner via film or living hinges 14 . other suitable hinge forms or connectors which enable a relative folding movement may be used . when the insertion aid 2 is removed , the shields can be pivoted over the guide needle 6 and can shield the latter from contact from outside . the first and second shields 16 , 18 each have a disk - shaped contour , with a tab 38 formed on the second shield 18 . the tab 38 indicates to the user , among other things , in which orientation the connection element is connected to the cannula housing of the catheter head . when the two shields 16 , 18 are joined and locked together , the tab 38 points vertically downward ( cf . fig6 and 7 ). in a plan view , the shields 16 and 18 each have an approximately mushroom - shaped silhouette , with a narrower section 44 being anchored at one end on the grip section 4 via the hinges 14 . at its opposite end , the narrower section 44 is adjoined by a roof - like wider section 46 which has a straight main face pointing toward the narrow section 44 , and , lying away from this , a curved face . at the sides , the straight main face merges into the curved face via a radius of curvature . the curved faces of the wide section 46 each point downward when the two parts are locked together . the grip tab 38 points vertically downward ( cf . fig6 and 7 ) from the curved face of the second shield 18 . the narrow sections 44 have a width which approximately corresponds to the diameter of the outer circumferential surface 26 of the grip section 4 . the wide sections 46 are approximately double or slightly less than double the width of the narrow sections 44 . on the undersides of the first and second shields 16 , 18 facing away from the grip section 4 when the needle guard 12 is in the folded - out state , there are in each case web sections 20 , 22 which follow the arc of the outer edge contours of the wide sections 46 of the shields 16 , 18 and which , through engagement and interlocking of the two shields , permit a labyrinthine enclosure . the first web section 20 has a slightly larger contour engaging round the second web section 22 , with the result that the second web section 22 is completely enclosed by the first web section 20 when the shields are engaged in one another ( cf . fig6 and 7 ). the second web section 22 of the second shield 18 does not , however , follow the contour of the grip tab 38 , but instead only the contours of the wide section 46 . on the sides of the narrower section 44 facing toward the grip section 4 , the web sections 20 , 22 are in each case open , so that they do not collide with the guide needle 6 . the web sections 20 , 22 thus do not follow the narrow section 44 , but instead end at this . thus , the web sections 20 , 22 in each case as a whole have a mushroom - like profile which follows an area of the outer contour of the shields 16 , 18 . the contour and profile of the web sections 20 , 22 can be seen in fig3 and 4 . provided around the guide needle 6 , and spaced apart from it , there is a centering web 24 which comprises two webs in the shape of generally semicircular segments and which is used to ensure correct and accurate placement of the insertion aid 2 on the catheter head ( not shown ). this centering web 24 is likewise illustrated in fig3 and 4 . to ensure that the shields 16 , 18 do not collide with the centering web 24 when folded together , their film hinges 14 are in two parts and are arranged on both sides of the centering web 24 , i . e ., at the edges of the lower end face of the grip section 4 . the two short film hinges of each of the two shields 16 , 18 are continued in each case by a narrow connecting section . the two connecting sections of each shield 16 , 18 thus form the narrow sections 44 thereof and each open into the wider section 46 . the shields have corresponding catch connections , a recess on the first shield 16 being provided with catches 32 arranged on the first web section 20 . on the second shield 18 , at its second web section 22 , there are corresponding undercuts 36 into which the catches 32 each engage and thus ensure locking of the two parts . the two undercuts 36 in the second web section 22 of the second shield 18 adjoin two recesses 34 in the flat upper face of the shield . the catches 32 adjoin a first recess 30 on the upper face of the first shield 16 . as is illustrated in fig5 , the guide needle 6 is secured with its upper section in an anchor 40 in the grip section 4 . in a preferred embodiment , the grip section 4 , and the shields 16 , 18 anchored thereon via the hinges 14 , can be made of plastic in an injection molding process . the guide needle 6 can in this way be easily secured in the grip section 4 or in its anchor 40 during the injection molding process . the hinges 14 too can be produced by an injection molding process , with the result that they can be produced along with the other components in a joint operation . the two shields 16 , 18 can be moved toward one another and pivoted relative to one another , via the hinges 14 at the lower end face of the grip section 4 , until the catches 32 lock in the undercuts 36 . the second web section 22 is at the same time substantially completely enclosed by the first web section 20 ( cf . fig6 ). as is illustrated in fig7 , the guide needle 6 in this case is suitably completely shielded and enclosed by the two shields 16 , 18 and by the web sections 20 , 22 engaged in one another . in this way , when the insertion aid 2 is removed from the catheter head and disposed of , there is no risk of injury posed by the guide needle 6 . while various embodiments , including preferred embodiments , of the present invention have been described herein , it is contemplated that various modifications could be made without deviating from the spirit of the present invention . accordingly , it is intended that the scope of the present invention be dictated by the appended claims .
an insertion aid for inserting a cannula of a catheter head into organic tissue , in particular a catheter head for administering a liquid active substance , wherein the insertion aid includes a guide needle that is fixed to a grip section for removably inserting and stabilising the cannula during insertion into the organic tissue and a needle shield , having at least two sections , which is secured in a pivotable manner to the grip section and which encases and shields the guide needle when the insertion aid is separated from the catheter head .