Concentric needle device for transfer of liquids

Abstract

A concentric needle device for transfer of liquids from within a vial sealed with a septum. The concentric needle device for transfer of liquids includes two concentric needles. An outer needle is provided as a gas inlet and an inner needle is provided as a fluid outlet. An annulus is defined between the inner and outer needles, and through which gas enters the vial. Liquid exits through the inner needle once the terminal end is positioned in contact with or below the surface of the liquid in the vial and gas is forced through the annulus. The terminal end of the inner needle, or the fluid outlet, is disposed at a point lower than the terminal end of the outer needle, or the gas inlet. By disposing the needles concentrically, a smaller gauge needle is used for liquid transfer. When the inner needle is placed in contact with the vial septum and an axial force is placed thereon, bending of the inner needle is limited by the outer needle. By reducing the needle diameter, coring of the septum is reduced; closer monitoring of the flow rate of the fluid through the inner needle is effectuated; and the effect of sudden pressure changes is reduced, thus providing more control during the liquid delivery. Further, because the smaller gauge inner needle forms a pilot hole for the larger gauge outer needle, coring of the septum by the outer needle is also reduced.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Continuation-In-Part of Ser. No. 09/569,780, filed on May 12, 2000, and is related to the Ser. No. 09/xxx,xxx filed on Feb. 28, 2001 entitled "System and Method for Multi-Batch Production of FDG".

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable.

BACKGROUND OF THE INVENTION

[0003] 1. Field of Invention

[0004] This invention relates to the field of liquid transfer. More specifically, the present invention is related to a dual needle device for transferring liquids, and for particular use in a reagent delivery system for use in the production of radiopharmaceuticals such as 2-[.sup.18F]fluoro-2-deoxyglucose ([.sup.18F]FDG) for positron emission tomography (PET).

[0005] 2. Description of the Related Art

[0006] In the field of liquid transfer, it is well known that it is often desirable to withdraw a precise volume of fluid from a container. In the specific environment of PET radiopharmaceutical production, it is known that various reagents and solutions are used to effect the necessary chemical conversions. The reagents and solutions are stored in vials and withdrawn and delivered to a reaction vessel as needed. The volume of each must be precise to insure the desired final product is accomplished. A more detailed discussion of this type of delivery system is disclosed in the above-referenced patent application Ser. No. 09/569,780, filed on May 12, 2000, and in a related patent application Ser. No. 09/xxx,xxx filed on Feb. 28, 2001.

[0007] In such delivery systems, it is known to use two needles to accomplish fluid pick up and delivery. Illustrated in FIG. 1 is a prior art device for transferring liquid 16 using two needles 12A, 12B disposed parallel to each other. A first needle 12A extends lower than a second needle 12B. The first needle 12A is provided for the withdrawal of the fluid 16. The second needle 12B is provided for introducing a gas into the vial 14 from which the fluid 16 is being withdrawn. Both of the needles 12A, 12B are inserted through the septum 18 into the vial 14 until the lower end of the first needle 12A is below the surface of the liquid 16. With a gas being forced through the second needle 12B, the gas forces the liquid 16 into the first needle 12A until the fluid level is lowered below the first needle 12A.

[0008] In order to accurately and reproducibly dispense small quantities of reagents from the septum-sealed vials, the volume of reagent in the vial may be calculated from the diameter of the vial and the height of the liquid within the vial. For example, if the diameter of a vial is 2 cm and the height of the liquid is 1 cm, then the volume of the liquid is (.pi.r.sup.2.times.h), or 3.14 cm.sup.3. Different volumes may be dispensed from the reservoir by changing the depth of a needle used the remove the liquid.

[0009] It is known that needles inserted into a vial cause coring as a result of the diameter required and repeated insertion. Specifically, coring occurs when the needle annulus shreds small pieces of the septum material when inserted therein. The septum material pieces then lodge in the needle and block the flow of gas or liquid. Larger diameter needles are more likely to cause coring than smaller diameter needles. However, smaller diameter needles are more susceptible to structural failure when forced into a septum. When an axial force is applied to the needle, resistance from the septum causes the needle to flex to a degree relative to the diameter of the needle. Smaller diameter needles will yield a greater flex under similar forces, and is therefore more susceptible to breaking.

[0010] Another concern regarding the needle diameter is the flow rate of the fluid being withdrawn. As stated, it is essential that the amount of reagent being withdrawn be monitored in order to insure an accurate mixture of the various reagents. A smaller diameter needle permits monitoring to be accomplished more accurately.

[0011] Therefore, there are competing interests when selecting a needle diameter. Namely, coring of the septum and accurate flow rate monitoring versus structural integrity of the needle.

[0012] Another problem resulting from the use of parallel needles as described is the reduction of the target area within which the needles are inserted into the septum. Because the needles are separated, and because both needles must penetrate the septum, there is a need for greater accuracy when positioning the needles with respect to the septum.

[0013] Therefore, it is an object of the present invention to provide a concentric needle device for the transfer of liquids wherein the effects of coring are reduced.

[0014] Further, it is an object of the present invention to provide such a device wherein the structural integrity of each needle is enhanced.

[0015] Still another object of the present invention is to provide such a device whereby the flow rate of fluid being withdrawn using the device may be more closely monitored by reducing the needle diameter without increasing a risk of needle failure.

[0016] Another object of the present invention is to provide such a device wherein a greater effective target area for insertion of the needles into the septum is accomplished.

BRIEF SUMMARY OF THE INVENTION

[0017] Other objects and advantages will be accomplished by the present invention which serves to withdraw fluid from a vial sealed with a septum. The device of the present invention reduces coring of the septum, increases structural integrity of the needles, and enhances monitoring of the flow rate of fluid withdrawn through a fluid outlet. Moreover, the device is designed to increase the effective target area in which the needles may be inserted into the septum.

[0018] The device includes primarily two concentric needles. An outer needle is provided as a gas inlet and an inner needle is provided as a fluid outlet. An annulus is defined between the inner and outer needles, and through which gas enters the vial. Liquid exits through the inner needle once the terminal end is positioned in contact with or below the surface of the liquid in the vial and gas is forced through the annulus. The terminal end of the inner needle, or the fluid outlet, is disposed at a point lower than the terminal end of the outer needle, or the gas inlet.

[0019] By disposing the needles concentrically, a smaller gauge needle is used for liquid transfer. When the inner needle is placed in contact with the vial septum and an axial force is placed thereon, bending of the inner needle is limited by the outer needle. By reducing the needle diameter, coring of the septum is reduced. The reduced needle diameter also effectuates closer monitoring of the flow rate of the fluid through the inner needle. Reducing the needle diameter reduces the effect of sudden pressure changes and thus provides more control during the liquid delivery. Further, because the smaller gauge inner needle forms a pilot hole for the larger gauge outer needle, coring of the septum by the outer needle is also reduced.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE

DRAWINGS

[0020] The above mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:

[0021] FIG. 1 is an elevation view of a prior art device illustrating two needles disposed in parallel fashion;

[0022] FIG. 2 is an elevation view of the concentric needle device for transfer of liquids constructed in accordance with several features of the present invention;

[0023] FIG. 3 is an elevation view of the concentric needle device for transfer of liquids of FIG. 2 schematically illustrating a gas source and fluid receptacle in fluid communication with a vial;

[0024] FIG. 4 is an elevation view, in section, of a portion of the present invention illustrating the inner needle being bent and the outer needle limiting the degree of bend of the inner needle;

[0025] FIG. 5 is a plan view of a vial septum illustrating the effective target area of the prior art needle arrangement of FIG. 1; and

[0026] FIG. 6 is a plan view of a vial septum illustrating the effective target area of the needle arrangement of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0027] A concentric needle device for transfer of liquids incorporating various features of the present invention is illustrated generally at 10 in the figures. The concentric needle device for transfer of liquids, or device 10, is provided for withdrawing liquid 16 from within a vial 14 sealed with a septum 18. The device 10 is designed to reduce coring of the septum 18 into which the needles 12.sub.i, 12.sub.0 are inserted, increase structural integrity of the needles 12.sub.i, 12.sub.0, and enhance monitoring of the flow rate of fluid 16 withdrawn through the outer needle 12.sub.0. Moreover, in the preferred embodiment the device 10 is designed to increase the effective target area in which the needles 12.sub.i, 12.sub.0 may be inserted into the septum 18.

[0028] FIG. 2 illustrates the device 10 of the present invention. Shown, the device 10 is received through the septum 18 of a vial 14 such that an inner needle 12.sub.i is below the surface of the liquid 16 and an outer needle 12.sub.0 is above the liquid surface. The inner and outer needles 12.sub.i, 12.sub.0 of the device 10 are concentric. The outer needle 12.sub.0 is provided as a gas inlet and the inner needle 12.sub.i is provided as a fluid outlet. An annulus 20 is defined between the inner and outer needles 12.sub.i, 12.sub.0, and through which gas enters the vial 14. Liquid 16 exits through the inner needle 12.sub.i once the terminal end is positioned in contact with or below the surface of the liquid 16 in the vial 14 and gas is forced through the annulus 20, as illustrated in FIG. 3. In order to accomplish this flow pattern, the terminal end 22.sub.i of the inner needle 12.sub.i, or the fluid outlet, is disposed at a point lower than the terminal end 22.sub.0 of the outer needle 12.sub.0, or the gas inlet. Thus, the fluid outlet 22.sub.i forms a pilot hole for the gas inlet 22.sub.0 during insertion of the device 10 into a vial septum 18.

[0029] The inner and outer needles 12.sub.i, 12.sub.0 are mounted to a manifold 24. The manifold 24 defines a gas inlet channel 26 configured to allow fluid communication between a gas source 30 and the outer needle 12.sub.0. Further, the manifold 24 defines a fluid outlet channel 28 configured to allow fluid communication from the vial 14, through the inner needle 12.sub.i and to a further fluid receptacle 32. In the exemplary use for mixing reagents to produce a radiopharmaceutical, the further fluid receptacle 32 is a reaction chamber.

[0030] By disposing the needles 12.sub.i, 12.sub.0 concentrically, a smaller gauge needle 12.sub.i is used for liquid transfer. As illustrated in FIG. 4, when the inner needle 12.sub.i is placed in contact with the vial septum 18 and an axial force is placed thereon, bending of the inner needle 12.sub.i is limited by the outer needle 12.sub.0. By reducing the needle diameter, coring of the septum 18 is reduced. The reduced needle diameter also effectuates closer monitoring of the flow rate of the fluid through the inner needle 12.sub.i. Reducing the needle diameter reduces the effect of sudden pressure changes and thus provides more control during the liquid delivery. Further, because the smaller gauge inner needle 12.sub.i forms a pilot hole for the larger gauge outer needle 12.sub.0, coring of the septum 18 by the outer needle 12.sub.0. is also reduced.

[0031] As mentioned above, the outer needle 12.sub.0 serves to reinforce the inner needle 12.sub.i. Due to the reduced diameter of the inner needle 12.sub.i, it will tend to bend more than the fluid delivery needle 12A illustrated in FIG. 1. However, bending of the inner needle 12.sub.i is limited by the outer needle 12.sub.0. Therefore, even though the inner needle 12.sub.i diameter is reduced, its structural integrity is enhanced by the outer needle 12.sub.0. The added strength eliminates the need for a needle guide (not shown) or other means to prevent the bending of small gauge needles.

[0032] Illustrated in FIG. 5 is the effective target areas 34A, 34B within which the first needle 12A and the second needle 12B, respectively, must enter the septum 18 in order for both needles 12A, 12B to enter the septum 18. It will be seen that, depending upon the spacing of the needles 12A, 12B, the effective target area 34A, 34B may be half, or less, of the total septum area. However, as illustrated in FIG. 6, the effective target area 34 in which the inner needle 12.sub.i must enter the septum 18 is substantially the entire septum area. The limitation is the perimeter of the septum 18 for a width equal to approximately the difference of the radii (r.sub.0-r.sub.i) of the inner and outer needles 12.sub.i, 12.sub.0. Thus, it will be seen that a greater effective target area for insertion of the needles 12.sub.i, 12.sub.0 into the septum 18 is accomplished.

[0033] From the foregoing description, it will be recognized by those skilled in the art that a concentric needle device for transfer of liquids offering advantages over the prior art has been provided. Specifically, the device is provided for reducing the effects of coring, enhancing the structural integrity of each needle, and effectuating closer monitoring of the flow rate of fluid being withdrawn. Further, the device is provided for creating a greater effective target area for insertion of the needles into the septum is accomplished.

[0034] While a preferred embodiment has been shown and described, it will be understood that it is not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and the scope of the invention as defined in the appended claims.

Claims

Having thus described the aforementioned invention, we claim:

1. A device for transfer of liquids from a vial having a septum for sealing the vial, said device comprising: a manifold defining a gas inlet channel and a fluid outlet channel, said gas inlet and said fluid outlet being configured to prevent fluid communication therebetween; an inner needle carried by said manifold, said inner needle defining a proximal end and a distal end, said distal end defining a fluid outlet, said proximal end being mounted to said manifold in fluid communication with said fluid outlet channel; and an outer needle carried by said manifold and concentrically with inner needle, said outer needle defining a proximal end and a distal end, said distal end defining a gas inlet, said proximal end being mounted to said manifold in fluid communication with said gas inlet channel, said inner needle distal end extending beyond said outer needle distal end relative to said manifold.

2. A device for transfer of liquids from a vial having a septum for sealing the vial, said device comprising: a manifold defining a gas inlet channel and a fluid outlet channel, said gas inlet and said fluid outlet being configured to prevent fluid communication therebetween; a fluid outlet means including an inner needle carried by said manifold, said inner needle defining a proximal end and a distal end, said distal end defining a fluid outlet, said proximal end being mounted to said manifold in fluid communication with said fluid outlet channel; and a gas inlet means including an outer needle carried by said manifold and concentrically with inner needle, said outer needle defining a proximal end and a distal end, said distal end defining a gas inlet, said proximal end being mounted to said manifold in fluid communication with said gas inlet channel, said inner needle distal end extending beyond said outer needle distal end relative to said manifold.