Patent Number: 048333298
Section: description

DETAILED DESCRIPTION Referring to the drawings, first more particularly to FIG. 4, a system of this invention for generating and containerizing radioisotopes is shown to comprise a generator 1 containing a sterile pyrogen-free supply indicated at 3 of a parent radioisotope. As disclosed in the aforesaid U.S. Pat. No. 4,296,785, generally, this generator comprises an elongate cylindric glass tube having piercable closures indicated at 5 and 7 at its upper and lower ends (upper and lower as shown in FIG. 4) each constituted by a rubber stopper plugged in the respective end of the container. An aluminum crimp cap 9 is shown for each stopper with a central section of the cover removed. The parent radioisotope may be molybdenum-99, for example, adsorbed on an anion exchange medium, alumina or other medium (as in U.S. Pat. No. 3,655,981) for generating technetium-99M. The generator could be a tin/indium or germanium/gallium generator. Pierced through the rubber stopper at the upper end of the generator is the downturned end 11 of a relatively thin metal tube 13 constituting an eluant inlet for the generator. Pierced through the rubber stopper at the lower end of the generator is the upturned end 15 of a relatively thin metal tube 17 constituting an eluant outlet for the generator. At 19 is shown a reservoir for holding a supply of eluant indicated at 21 (e.g. saline solution). Preferably, this is a glass bottle having a rubber stopper 23 in its mouth with an aluminum foil cover 25 for the stopper, shown in FIG. 4 with a central circular section of the cover removed. Pierced through the stopper 23 is the downturned end 27 of a relatively thin metal tube 29 constituting an air inlet for the reservoir or bottle, for admission of air to the bottle to apply atmospheric air pressure on the eluant 21 in the bottle. Also pierced through the stopper 23 is the downturned leg 31 of a thin metal tube 33 constituting an eluant outlet for the bottle. The downturned leg 31 of the tube 33 extends down in the bottle nearly to the bottle of the bottle for the delivery of eluant upwardly through the leg 31. At 35 is indicated a tubular needle for piercing the rubber stopper 37 of a sealed sterile evacuated container or vial 39 (which may be placed in a lead shield as indicated at 40 in FIGS. 1 and 2). The tubular needle 35 extends down from the lower end of the valve body 41 of valve means of this invention which is designated in its entirety by the reference numeral 43. The valve body 41 is carried by a case indicated generally at 45 in FIGS. 1 and 2 corresponding generally to the case shown in U.S. Pat. No. 3,655,981, for movement downwardly from its raised retracted position of FIGS. 1 and 2 against the upward bias of a return spring 47 for causing the needle to pierce the rubber stopper or closure 37 of the vial 39, and for movement back upwardly to its raised retracted position by the spring. The case is shown as including an overhanging portion having top and bottom walls 49 and 51 and an outer wall 53 for mounting the body 41. A first flexible tube 55, constituted of a length of plastic tubing, which is resiliently compressible and thereby adapted to be pinched for closing it, is suitably connected at one end to the air inlet tube 29 for the eluant bottle or reservoir 19 and is in communication at its other end with the atmosphere upstream from the reservoir via a bacteriological filter 56 for precluding entry of bacteria from the atmosphere to the system. This tube is adapted to be pinched to close it, as will appear, to block communication between the head space 57 in the eluant reservoir above the eluant therein and the atmosphere. When the tube is open, the head space 57 is in communication with the atmosphere for subjecting the eluant in the eluant reservoir to atmospheric pressure for flow of eluant from the reservoir via the eluant outlet tube 33. A second flexible tube designated 59, also constituted by a length of resiliently compressible pinchable plastic tubing, is suitably interconnected between the eluant outlet tube 33 and the generator inlet tube 13. This tube 59 is adapted to be pinched closed, as will appear, to block communication between the eluant reservoir and the generator. When tube 59 is open, eluant may flow from the reservoir to the generator. A third flexible tube designated 61, also constituted by a length of resiliently compressible pinchable plastic tubing, is interconnected between the generator outlet tube 17 and the tubular needle 35. This tube is adapted to be pinched closed, as will appear, to block communication between the generator and the tubular needle. When the tube 61 is open, eluate may flow from the generator to the needle. Each of the tubes 55, 59, and 61 may be tubing made of plastic such as that sold under the trade name Silastic by Dow Corning Corp. of Midland, Michigan, of 0.156" outside diameter and 0.036" inside diameter. The tubes 13, 17, 29, 33 may be 19 gauge stainless steel tubes with beveled ends for piercing the respective stoppers and the connections to the tubes 13 and 17 may be by female luer fittings such as indicated at 63. The valve means 43 is provided for pinching the three tubes 55, 59 and 61 to close them and is operable on entry of the tubular needle 35 through the closure 37 of an evacuated container of vial 39 to open the tubes for venting of the eluant reservoir 19 to atmosphere via tube 55, for delivery of eluant from the reservoir to the generator via the tube 59, and for delivery of eluate from the generator via tube 61 to the needle 35 and thence to the evacuated container or vial 39. The body 41 of the valve means may be molded in one piece of a suitable plastic, such as polypropylene, with a generally elongate stem 65 which extends vertically as used in the system and which thereby has an upper end at 67 and a lower end at 69, and a head 71 at the upper end of the stem. The stem 65 is generally tubular so as to have an axial passage 73 for the tube 61. At its lower end 69 the stem is formed with an enlarged socket having an internal diameter somewhat larger than that of the passage 73, this socket having an internal annular groove 75. The passage 73 extends all the way down in the stem from its upper end to the socket, opening at its lower end into the socket. The stem is formed with an axial slot 77, flanges 79 being provided at opposite sides of the axial slot for stiffening the stem. The head 71 has a bottom 81 and spaced side walls each generally designated 83 extending up from the bottom, the side walls 83 defining a recess 85 in the head which is open at the top of the head. The side walls have portions 87 extending parallel to one another from a transverse wall 89 of the head, which may be referred to as the back wall of the head, and forward portions which converge to a relatively narrow wall 93 which may be referred to as the front wall of the head. Each of the forward portions 91 of the side walls 83 of the head has a slot 95 therein extending down from the top edge of the respective wall adjacent the rearward ends of said forward portions generally in a vertical plane parallel to and spaced from the narrow front wall 93 of the head. The slots have a width slightly greater than the diameter of the first, second and third tubes 55, 59 and 61, which are received in these slots one on top of another, tube 61 being the first to be placed in the slots and hence the lowest of the three tubes, tube 59 being next and hence being the intermediate tube in the slots, and tube 55 being the last to be placed in the slots and hence being the uppermost of the three tubes. Portions of the tubes, so lodged in the slots, extend across the head across the rearward edge of a back-up member 97 extending rearward from the front wall 93 of the head, being bent to some extent around the rearward edge of this back-up member. The latter is constituted by a vertical rib formed integrally with the head extending rearward from the narrow front wall 93 of the head slightly beyond the plane of the forward edges of the slots 95. The stated portions of the tubes also extend over vertical ribs 99 extending between wall 89 of the head and forward portions 91 of the head side walls 83 and a central vertical rib 101. The portions of the tubes 55, 59 and 61 which extend across the head 71 are adapted to be pinched or clamped closed against the rearward edge of the back-up member 97 by means comprising a pinch member 103 mounted for swinging movement on one of the side walls 83 of the head extending toward the other side wall above the ribs 99 and 101 and cam means 107 rotary in the head for swinging the pinch member into engagement with the portions of the tubes extending across the head to pinch or clamp them against the back-up member 97, and for releasing the pinch member to allow it to swing away from said portions of the tubes to allow them to open up. The pinch member is constituted by a flexible molded plastic plate member of generally rectagular shape having a flange 109 at one edge with a thickened bead 111 at the edge of the flange. The pinch plate 101 is mounted at said one side wall of the head by forming of that side wall with a vertical groove 113 on the inside and a flange 115 extending inwardly from that side wall at the rear of the groove with a lip 117 at the inner edge of the flange extending forward over the groove. The pinch plate is assembled with the head by sliding the bead 111 down into the recess defined by the groove 113, the flange 115 and the lip 117. The plate is adapted to flex adjacent the flange for the swinging of the plate generally on what is in effect an integral hinge adjacent its end with the bead 111. The rotary cam means 107 comprises a molded plastic (e.g. polypropylene) member formed to have a circular disk constituting a cap 119 for engagement with the top of the head 71, a cam shaft 121 extending down from the disk with a lug 123 extending radially outwardly from this shaft constituting the cam proper, the outer edge of the lug being rounded. The lug 123 extends down from the disk or cap 119 toward but terminates short of the lower end of the shaft 121. The latter is made tubular and is formed on its exterior with an annular snap ring formation or rib 125 located below the lower end of the lug 115. The lower end portion of the shaft, below the lower end of the lug, is rotatably fitted in a generally cylindric bearing 127 formed in the head, this bearing having an annular groove 129 in which the annular snap ring formation or rib 125 on the shaft is snap fitted. A hub 131 extends up from the disk 119 coaxial with the shaft 121, this hub being tubular as appears in FIG. 4 and having an axial external key 133 extending throughout its length. A knob or handle 135 has a stem 137 fitted in the hub 131, the stem 137 having a keyway 139 which interfits with a key 141 in the hub for keying the knob to the hub. Stem 137 also has a stop 143 engageable with the upper end of the hub. With the parts 41 and 107 disassembled, the upper end of the head 43 is open for insertion of the plate 103 in the head, also for insertion of the tubes 61, 59 and 55 (in that order) in the slots 95 in the side walls 83 of the head. The rotary member 107 may then be snap-fitted into assembly with the head. This makes for easy assebly. With member 107 so assembled with the head, the pinch plate 103 and the three tubes are held in place by the disk or cap 119 of member 107. The eluate tube 61 is connected at one end to the eluate outlet tube 17 for the generator 1. It extends in a loop from the head 71 of the valve body 41 and through the slot 77 in the stem into the passage 73 in the stem 65 and down in the passage 73 to a fitting 145, e.g. a luer fitting, accommodated in the socket 69 at the lower end of the stem to which the needle 35 is removably attached. The fitting 145 has an annular rib 147 snapped into the groove 75. The cam member 107 normally occupies the tubepinching position in which it is illustrated in FIG. 5 herein the cam lug 123 is in line with the back-up rib 97 and holds the pinch plate 103 against the tubes 55, 59 and 61 to pinch the tubes closed (see also FIG. 3). This tubepinching position of the cam member is generally determined by engagement of the lug 123 with the edge 149 of an upwardly extending portion of the bearing 127 in the head 71. The valve body 41 with the needle 35 extending down from its lower end, with the tubes 55, 59 and 61 in the slots 95, with the cam member 107 in place in the head 71 and in its tube-pinching position, and with knob 135 on the cam member, is movable downwardly against the bias of the spring 47 to drive the needle through the rubber stopper 37 of an evauated vial 39. The knob is then turned to turn the cam member to its tube-release position of FIG. 6 for opening the tubes for the flow of eluant from the bottle 19 via tube 59 to the generator 1 and for flow of eluate from the generator 1 via tube 61 to the needle 35 and thence into the vial. On delivery of the requisite amount of eluate into the vial, the knob is turned back to return the cam member 107 to its FIG. 5 tube-pinching position to cut off flow, and the valve body (with the needle and tubes) is released for return upward to its raised retracted position of FIGS. 1 and 2 awaiting filling of the next vial. The pinching of the tubes by the hinged pinch plate 103 is such as to avoid displacement ("walking") and stretching of the tubes, and also to avoid abrasion of the tubes. In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.