referring to the drawings in which like reference characters refer to like parts throughout the several views thereof , fig1 illustrates the invention as employed in a straight rod form of feed arrangement for the obturator rod of the invention . in fig1 the main body 12 of the catheter arrangement is shown having a fluid passage 44 therethrough . the front end surface 18 of main body 12 is tapered to cooperate with the tapered surface 16 of the catheter body 10 . a locking knob 14 is rotatable on main body 12 for joining the parts 10 , 12 together along their cooperating tapered surfaces 16 , 18 , respectively . as a more secure connection , the rear end of the locking knob may have an edge as shown which moves into place over the abutment 20 on the outer surface of main body 12 . extending forwardly from the catheter body 10 is the catheter 22 having a front end point 24 for insertion into the vein of a patient so as to communicate through lumen 46 of catheter 22 fluids fed to the catheter from a female luer connection 52 for feeding through the adapter 50 fluids to the lumen 49 of supply tube 48 for delivery of fluid through passage 42 to the passage 44 in main body 12 . cap 54 closes off female luer connection 52 until such time as a fluid supply is connected at which time the cap 54 is removed for such delivery . positioned in passage 44 is an obturator rod 32 which extends rearwardly out through an o - ring cap 28 having a sealing o - ring 26 , to a snap cap 36 for manipulating and feeding the obturator rod 32 to and through the lumen 46 in catheter 22 in order to occlude completely lumen 46 , as desired . rod 32 is surrounded by a bellows type film sleeve 30 which collapses , as shown in fig2 when cap 36 is moved to the right , as shown in fig1 for moving the front end 34 of rod 32 forwardly into the lumen 46 of catheter 22 . that is , when it is desired to seal off the in - place opening 24 of catheter 22 , cap 36 is moved to the right as shown in fig1 until such time as the forward annular locking ring 38 of snap - cap 36 snaps into place in annular groove 40 in o - ring cap 28 . when this happens , the front end portion , including point 34 , of rod 32 , because of the polyetherurethane coating on outer surface thereof , as discussed above , swells in contact with the aqueous environment of the blood in the vein of the patient because of the fact that the front end 24 of catheter 22 is in place in the vein of the patient . also , because of the heparin incorporated into the polyetherurethane which is at this point swelling for cooperating in a sealing engagement with the inner diameter or inner walls of lumen 46 the heparin which is gradually and slowly released prevents any clot formation at the point 24 . this positioning is shown clearly in fig2 . of course , any anti - infective agent present in the coating will also be released . consequently , if a nurse or other technician desires to administer a fluid to the patient through catheter 22 , the operator releases locking ring 38 from groove 40 and moves cap 36 to the left to a position which allows passage of fluid from supply tube 48 around the forward end of rod 32 in passage 44 . at this time , cap 54 is removed and a male luer connection is inserted into female luer connection 52 with the male luer connection being connected to a supply of the fluid to be administered . fig4 and 5 show an additional embodiment of the invention here for feeding a coated obturator rod through lumen 46 of catheter 22 . in this embodiment , a reel drive is utilized for feeding the obturator rod 64 through passage 48 and into lumen 46 of catheter 22 . reel 60 rotates around a shaft 62 in reel casing 61 for this purpose . as can be seen in fig5 knob 68 , positioned on one end of shaft 62 , rotates reel 60 for feeding rod 64 through passage 48 into catheter 22 to the end 24 thereof . the front end 66 of rod 64 extends in the occluded position slightly out the front end 24 of catheter 22 , in the same manner as front end 34 shown in fig2 . fig6 and 7 show a further arrangement of reel drive device for feeding an obturator rod 74 through passage 48 for occluding lumen 46 of catheter 22 in the same manner as the previous embodiments . in this embodiment , reel 70 is rotated around a shaft 72 through the action of a knob 73 . obturator rod 74 moves , under this action , in either direction for either feeding the front end 78 of rod 74 to the right hand end of catheter 22 out and through lumen 46 of catheter 22 to a point where point 78 of rod 74 extends slightly out of the front end 24 of catheter 22 . as can be seen in this embodiment , and particularly in the end view shown in fig7 the axis of catheter 24 is at the same level as the feed portion of reel 70 . in this connection , as shown in fig6 reel casing 71 is supported and suspended from a support 80 for feeding rod 74 at the position 76 shown in fig6 . as will be understood , with rod 74 in the position shown in fig6 fluids may be fed through the catheter lumen 46 from supply tube 48 and from luer connection 52 . it should be understood by practitioners - in - the - art that in molding plastic parts of the kind discussed here that molding design techniques may make it appropriate to combine two parts into a single molded part such as , for example , reel casing 71 and support 80 , as shown in fig6 . as discussed previously , in the extended position of rod 74 with the front end 78 extending slightly out the front end 24 of catheter 22 , because of the coating of polyetherurethane , as discussed above , in contact with an aqueous environment , swelling takes place so that there is a cooperating seal between the internal walls of lumen 46 and the outer walls of swollen rod 74 . also , because of the anti - thrombogenic and / or anti - infective agent bulk distributed in the coating , there is a constant slow release of these agents in this environment in order to maintain patency of the in - dwelling catheter during several medication changeovers , while at the same time maintaining a sterile condition . it should be understood that with each of the embodiments shown above , the main body 12 together with the catheter structure 22 itself and the fluid delivery structure 48 , 50 are substantially the same with the only change being the actual feed mechanism for the obturator rod which may be selected among the several embodiments described . referring to fig8 , 10 and 11 , a further obturator feed device is shown . this arrangement is somewhat different from the other embodiments , in that the feed arrangement , in the form of a reel , is positioned in the fluid delivery line , and g spaced from the catheter feed device . in fig8 catheter 22 is shown with front end 24 and catheter feed body 10 . a male luer adapter generally designated 90 is positioned on the rear end of body 10 and includes a fluid line connection 94 held in place by lock - nut 92 . a connection fluid supply 50 with female luer adapter 52 is positioned on one end of fluid delivery line 100 for delivering fluid shown as 102 in fig8 . a reel support 108 is positioned on line 100 for supporting reel casing 106 and reel 107 . as shown in fig8 the reel 107 has wound the flexible obturator rod 104 into the reel sufficiently to withdraw the distal end 110 of rod 104 to a point allowing fluid to pass through the lumen 46 of catheter 22 . in the position shown in fig9 the distal end 110 of rod 104 is moved forward to prevent fluid from passing through lumen 46 . in the open position , as shown in fig8 fluid passes from female luer connection 52 through line 100 and around obturator rod 104 . in this connection , fluid line 100 is made of a diameter large enough to accommodate this dual passage . fig1 and 11 show top and end views of the reel feed arrangement of this embodiment . that is , knob 112 , mounted on shaft 114 turns reel 107 in casing 106 to allow moving the distal end 110 of rod 104 forward to occlude , or rearward to allow fluid passage . in considering generally the conditions for carrying out the most enhanced results in connection herewith , which conditions have already been specifically discussed above and in connection with the above referred to co - pending application , the dimension of the obturator rod of the invention depends upon the dimension of the catheter being used in combination therewith . for example , for a rod used in conjunction with a 20 gauge catheter the diameter of the rod will be within the range of between about 0 . 050 and 0 . 028 inches , preferably 0 . 022 and 0 . 026 inches . most preferably , the tip for the rod has a diameter of 0 . 023 and is about 0 . 25 inches long with the remaining portion of the rod being 0 . 026 inches in diameter . the coating on the swollen rod increases the rod dimensions described above within the range of between about 0 . 002 and 0 . 027 inches , and preferably within the range of between about 0 . 003 and 0 . 008 inches and most preferably 0 . 004 inches . obviously , when the rod swells , the dimension of the rod with the coating increases and this has been found to be approximately an increase of one - half the thickness of the coating in place prior to any swelling . with a 16 gauge catheter , the preferred rod dimension is within the range of between about 0 . 040 and 0 . 050 inches with a similar coating dimension as described above . as a further treatment of the obturator rod and associated feeding device of the invention , the device is sterilized by gamma irradiation or ethylene oxide . it is placed in position for use as a sterile device since it will only be exposed to body fluids . the only way that it may become non - sterile would be with an exposure to contaminated infusates or from exposure to bacteremic blood . representative materials which may be used for the reel body include rigid polyvinyl chloride as the preferred material . alternative materials include acrylonitrile - butadiene - styrene terpolymer , styrene , polycarbonate or polyacrylate . the reel body may be transparent for observing the feed movement of the rod . however , it may also be comprised of a colored or opaque material . the bellows film sleeve 30 shown in the embodiment of fig1 may be comprised of , for example , polyethylene , polypropylene , polyvinyl chloride or polyesters . as an alternative to the bellows form of sleeve , a telescoping sleeve ( not shown ) may be provided comprised of a rigid polymer such as polystyrene . whereas , as discussed above , specific embodiments of obturator rod feed devices and associated connections have been shown , it should be understood that it is within the purview of this invention to provide other forms of feed arrangements or positioning of a reel feed , for example , connected to or spaced from the main body of the catheter . that is , the axis of the reel body for feeding the obturator rod may be positioned in several different placements around the axis of the catheter itself . while the forms of apparatus herein described constitute preferred embodiments of the invention , it is to be understood that the invention is not limited to these precise forms of apparatus , and that changes may ge made therein without departing from the scope of the invention which is defined in the appended claims .
an obturator is provided which allows for placing and withdrawing of a single catheter obturator over an extended period of time so as to allow spaced intervals of use , and non - use of a catheter while in place in the patient &# 39 ; s skin , while at the same time doing away with cumbersome , costly and time consuming administration and maintenance of saline and heparin locks . the device feeds the obturator in place for occluding the catheter lumen , when no fluids are being administered to the patient , and then may be retracted to a position allowing fluid feed through a supply tube connection to the catheter . the device includes a coating on the obturator rod which swells in contact with aqueous fluids to seal completely the catheter lumen which coating includes heparin to prevent clotting . moreover , the entire internal functioning arrangement remains sterile during the entire period of use , thus avoiding infection .