Unit dose syringe shield and measuring applicator

[0002] This application is a continuation-in-part to U.S. patent application Ser. No. 10/401,183 entitled “Improvement For Unit Dose Syringe Shield And Measuring Applicator”, filed Mar. 27, 2003, which is a continuation in part of U.S. patent application Ser. No. 10/241,418 entitled “Improvement For Unit Dose Syringe Shield And Measuring Applicator”, filed Sep. 11, 2002 now U.S. Pat. No. 6,717,163, and is itself a continuation in part of U.S. patent application Ser. No. 10/167,025, filed Jun. 11, 2002, now U.S. Pat. No. 6,614,040 entitled “Unit Dose Syringe Shield And Measuring Applicator,” issued Sep. 2, 2003, the entire disclosure of which is hereby incorporated by reference.

[0003] This invention relates to an apparatus for transporting and administering radiopharmaceuticals, and more particularly to a radionuclide syringe shield and dose measuring applicator.

[0004] Radiopharmaceuticals are radioactive materials that are widely used in the diagnosis and treatment of various diseases and body disorders. Radiopharmaceuticals are typically injected into the body of a patient by means of a hypodermic syringe. The repeated exposure to radioactive materials may over time present serious health hazards to the person preparing and administering the injection. This hazard is a result of radiation emanating from radioactive material which is to be injected.

[0005] Nuclear medicine technologists may receive significant radiation exposure when repeatedly handling radiopharmaceuticals, particularly high-energy radionuclides such as, for example, F-18 fluorodeoxyglucose. The technologists are particularly at risk when preparing the dose prior to injection and following injection from direct exposure to the patient. However, the latter risk can be avoided by increasing the distance from the patient while injecting the dose and decreasing time spent near the patient after the injection.

[0006] The exposure during the dose measuring procedure occurs when the dose is removed from the shipping container, when the dose is placed into and removed from the well counter and when the dose is inserted into the syringe shield. For example, the technologist's upper extremities receive a significant dose of radiation during the time the dose is unshielded. The prior art syringe shields (pigs) do not allow for measurement unless the syringe is removed from them resulting in direct exposure to the technologist's upper extremities.

[0007] Existing devices that provide radiation shielding when the hypodermic syringe is being used to inject the patient, offer only limited radiation shielding. In Applicant's co-pending application Ser. No. 10/241,418, there is no radiation shielding at the piston end of the hypodermic syringe when the injection is being administered. This exposes the individual performing the injection to undesirable radiation. Furthermore, such devices require additional time to administer the injection because the protective shielding must be removed from the piston end of the hypodermic syringe before the injection can be administered.

[0008] What is needed is an apparatus that will allow the measuring procedure to be carried out without the technologist being exposed to radiation from the radionuclide contained in the syringe. What is further needed is the ability of the same apparatus to act as a syringe shield to prevent escape of radiation from the radionuclide in the syringe, while it is being transported to the patient for injection. What is further needed is the ability of the same apparatus to be used to inject the patient while preventing radionuclide exposure through the piston end of the syringe.

[0009] It is an aspect of the present invention to shield the technologist from radionuclide exposure while inserting the hypodermic syringe into a well counter.

[0010] It is another aspect of the present invention to allow a measuring procedure to be carried out without the technologist being directly exposed to the radionuclide in the hypodermic syringe.

[0011] It is another aspect of the present invention to provide improved radiation shielding when the hypodermic syringe is being used to inject the patient.

[0012] It is yet another aspect of the present invention to provide an improved mechanism for securing a radionuclide-containing hypodermic syringe in a protective container while measuring the radioactivity of the radionuclide.

[0013] To accomplish these and other aspects of the present invention an apparatus that transports radiopharmaceuticals and protects individuals from radioactivity during measurement and injection includes a first body with a first hollow core open on a first edge and a second edge. The first hollow core surrounds an insert containing a hypodermic syringe. The apparatus further includes a second body with a second hollow core open on a first edge and a third body with a third hollow core open on a first edge. The second hollow core surrounds the insert with the hypodermic syringe. The third hollow core surrounds the insert with the hypodermic syringe.

[0014] The second body includes means for compressing the piston of the hypodermic syringe to eject the radiopharmaceutical from the hypodermic syringe and providing protection from the radioactivity. In the preferred embodiment, the means for compressing comprises a piston actuator that includes a sliding sleeve, guides and a disk for activating the piston of the hypodermic syringe to eject the radiopharmaceutical from the hypodermic syringe when the third body is removed and providing protection from radioactivity.

[0015] The third body includes extension means that allow the insert containing the hypodermic syringe to be extended from the first and third bodies when the second body has been removed. In the preferred embodiment, the extension means comprises a dose applicator that includes a nut, a telescoping rod attached to the nut, and means for releasably attaching the telescoping rod to the hypodermic syringe. The extension means is for positioning the hypodermic syringe into and out of the first and third bodies whereby said individuals easily measure and transport the radiopharmaceutical in the hypodermic syringe. The extension means includes means for selectively securing the telescoping rod in the first and third bodies so that the hypodermic syringe can be conveniently lowered into a well counter for radiation measurement and thereafter raised into the first and third bodies so that the second body can be attached for transport and administration of the radiopharmaceutical.

[0016] A first connection means releasably communicates the first body with the third body and a second communication means releasably communicates the first body with the second body for providing protection from radioactivity.

[0017] These and other aspects of the present invention will become apparent from the following description, the description being used to illustrate the preferred embodiment of the invention when read in conjunction with the accompanying drawings.

[0018] The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:

[0019] FIG. 1 illustrates the cross-section view of the double-ended syringe shield without the dose applicator.

[0020] FIG. 2 illustrates the cross-section of the dose applicator used in the double-ended syringe shield.

[0021] FIG. 3 illustrates the cross-section view of the insert device.

[0022] FIG. 4 illustrates the end-view of the insert device.

[0023] FIG. 5 illustrates the cross-section view of the single-ended syringe shield without the dose applicator.

[0024] FIG. 6 illustrates the cross-section of the dose applicator used in the single-ended syringe shield.

[0025] FIG. 7 illustrates the cross-section view of the dose applicator used in the single-ended syringe shield with a hypodermic syringe positioned in a well counter.

[0026] FIG. 8 illustrates the cross-section view of the double-ended syringe shield, transporter and dose applicator with hypodermic syringe.

[0027] FIG. 9 illustrates the cross-section of the double-ended syringe shield with the double piece insert and hypodermic syringe ready to be injected into a patient.

[0028] FIG. 10 illustrates the cross-section of the piston actuator.

[0029] FIG. 11 illustrates another cross-section of the piston actuator, rotated 90° from FIG. 10.

[0030] FIG. 12 illustrates an end view of the piston actuator.

[0031] FIG. 13 illustrates an end view of the piston actuator viewed from the opposite direction of FIG. 12.

[0032] FIG. 14 illustrates the cross-section of the dose applicator, incorporating the piston actuator.

[0033] FIG. 15 illustrates the cross section view of the syringe shield with a latch to secure the dose applicator.

[0034] FIG. 16 illustrates an end view of the latch mechanism, with portions of the syringe shield cut away for a more complete view.

[0035] While the present invention is described below with reference to a syringe shield, a practitioner in the art will recognize the principles of the present invention are applicable elsewhere.

[0036] FIG. 1 illustrates the cross-section of a double-ended syringe shield apparatus 10. The double-ended syringe shield is used to transport a hypodermic syringe 25 with a radioactive pharmaceutical 26 (FIG. 8). The first body 11 releasably communicates with the second body 12 and the first body 11 releasably communicates with the third body 13. The third body 13 releasably communicates with the nut 15. The hypodermic syringe and a one-piece insert are positioned inside the apparatus 10 as shown in FIG. 8. The first body 11 has a first hollow core 23athat is formed all the way through the first body 11 from the first body first edge 11fto the to the first body second edge 11e. The diameter of the first hollow core 23athat is formed by the first body inner surface 11bis a variety of sizes depending on the size of the hypodermic syringe and insert to be used. The first body 11 shape is defined by the first body outer surface 11aand is typically machined. However, as is known by the practitioner in the art, the machining of the first body inner surface 11band the first body outer surface 11ais substitutable for casting the first body 11. Furthermore, the first body first edge 11fand the first body second edge 11eare typically formed in parallel planes.

[0037] The first connection means 34 located at the first body first edge 11fis usually a first male thread 11d. It is formed starting at the first body first edge 11fwith a diameter that is smaller than the first outer surface 11aand larger than the diameter of the first inner surface 11b. Typically, the first male thread 11ddiameter is formed in the range of about 70% to 85% of the diameter of the first outer surface 11a. It is machined back from the first body first edge 11fto the first body fourth edge 11hfor a depth of about 15% of the overall length of the first body 11. The first male thread 11dis usually a unified fine thread or a unified coarse thread.

[0038] The second connection means 33 at the first body second edge 11ethat is usually a second male thread 11c. It is formed starting at the first body second edge 11ewith a diameter that is smaller than the first outer surface 11aand larger than the diameter of the first inner surface 11b. Typically, the second male thread 11cdiameter is formed in the range of about 70% to 85% of the diameter of the first outer surface 11a. It is machined back from the first body second edge 11eto the first body third edge 11gfor a depth of about 15% of the overall length of the first body 11. The second male thread 11cis typically a unified fine thread or a unified coarse thread.

[0039] In other applications, the male thread connections are substitutable for female threads, a locking nut arrangement or a compression flange arrangement as is known by the practitioner in the art. The first outer surface 11ais cylindrical in shape but is readily substitutable for any circular or polyhedron shape. Finally, the wall thickness between the first outer diameter 11aand the first inner diameter 11bmust contain enough radiation shielding material to provide adequate protection against radiation exposure. The radiation is from the radiopharmaceutical 26 contained within the hypodermic syringe.

[0040] The second body 12 has a second hollow core 23bthat is formed by starting from the second body third edge 12eto a depth that is about 75% to 85% of the length of the second body 12. The diameter of the second hollow core 23bthat forms the second inner surface 12bis a variety of sizes depending on the size of the hypodermic syringe and insert to be positioned in the second hollow core 23b. The second hollow core 23bis formed before the formation of the third inner surface 12cand the first female thread 12f. The second body 12 shape is defined by the second body tapered first outer surface 12aand a second body second outer surface 12g, wherein both are typically formed by machining and cylindrically shaped. Typically, the second body second outer surface 12gis machined. However, as is known by the practitioner in the art, machining is substitutable for casting the second body 12. Alternately, the second body second outer surface 12gcan have the same tapered plane as the second body tapered first outer surface 12a.

[0041] The second body second outer surface 12gat the second body third edge 12eis usually flush with the first body first outer surface 11a. Furthermore, the second body first edge 12h, the second body second edge 12dand the second body third edge 12eare all typically formed in parallel planes. The cylindrical shape of the second body 12 is substitutable for any circular or polyhedron shape. Finally, the wall thickness between the second outer surface 12g, the second body tapered first outer surface 12aand the second inner surface 12bmust contain enough radiation shielding material to provide adequate protection against radiation exposure.

[0042] The second connection means 33 at the second body third edge 12eis usually a first female thread 12fthat is formed by machining either a unified fine thread or a unified coarse thread. The first female thread 12fis formed starting at the second body third edge 12ewith a diameter that is smaller than the second body second outer surface 12gand larger than the diameter of the second inner surface 12b. Typically, the first female thread 12fdiameter is formed in the range of about 70% to 85% of the diameter of the second body tapered first outer surface 12aor the second body second outer surface 12g. The first female thread 12fis machined back from the second body third edge 12eto the second body first edge 12hfor a depth that is about 10% to 15% the distance of the overall length of the second body 12. Alternately, the first female thread 12fis substitutable for a male thread, a locking nut arrangement or a compression flange arrangement as is known by the practitioner in the art.

[0043] There is a second body annular ridge 23ethat is formed to provide a means for the insert (FIG. 3) to be coaxially secured to the third inner surface 12c. The diameter of the third inner surface 12cdepends upon the diameter of the insert second outer surface 21f(FIG. 3). Typically, the third inner surface 12cis the size to fit an insert that accepts 3 cc or 5 cc hypodermic syringes.

[0044] The third body 13 has a third hollow core 23cthat is formed by starting from the third body third edge 13eto a depth that is about 75% to 85% the length of the third body 13. The diameter of the third hollow core 23cthat is formed at the fourth inner surface 13bis a variety of sizes depending upon the size of the insert and hypodermic syringe to be used. The cylindrical shape of the third body 13 is defined by the third body tapered second outer surface 13aand the third body first outer surface 13g, wherein both are typically machined. However, machining the fourth inner surface 13b, the third body tapered second outer surface 13aand the third body first outer surface 13gis substitutable for casting the entire third body 13. Alternately, the third body first outer surface 13gcan have the same tapered plane as the third body tapered second outer surface 13a. The third body first outer surface 13gthat is formed at the third body third edge 13eis flush with the first outer surface 11a. Furthermore, the third body first edge 13j, the third body second edge 13iand the third body third edge 13eare all typically formed in parallel planes. The cylindrical shape of the third body 13 is substitutable for any circular or polyhedron shape. Finally, the wall thickness between the third body first outer surface 13g, the third body tapered second outer surface 13aand the fourth inner surface 13bmust contain enough radiation shielding material to provide adequate protection against radiation exposure.

[0045] The first connection means 34 at the third body third edge 13eis usually a second female thread 13hthat is formed by machining either a unified fine thread or a unified coarse thread. The second female thread 13his formed starting at the third body third edge 13ewith a diameter that is smaller than the third body first outer surface 13gand smaller than the second tapered outer surface 13a. The second female thread 13his formed at a diameter that is larger than the fourth inner surface 13b. Typically, the second female thread 13hdiameter is formed in the range of about 70% to 85% of the diameter of the third body first outer surface 13gor the third body tapered second surface 13a. The second female thread 13his machined back from the third body third edge 13eto the third body first edge 13jfor a depth that is about 15% to 25% the length of the third body 13. As is known in the art, the second female thread 13his substitutable for a male thread, a locking nut arrangement or a compression flange arrangement.

[0046] The third connection means 35 that is located at the third body second edge 13iis a releasable wrap 15cthat releasably secures the third body 13 to the nut 15. Typically, the releasable wrap 15sis a fabric hook or loop fastener, but is substitutable for any fastener that is easy to use. For example, the first telescoping rod 16hand second telescoping rod 16gcan be sized to form a snug but releasable fit in the first hollow stem 13land second hollow stem 13k, allowing the nut 15 to be secured to the third body 13 by friction.

[0047] The first hollow stem 13land the second hollow stem 13kthat are located in the third body 13 are both formed by either machining or drilling. The third hollow core 23cfixedly communicates with the two hollow stems. The two hollow stems are open on the third body second edge 13iand the third hollow core 23c. The first hollow stem 13land the second hollow stem 13kare symmetrically positioned around the center of the third body second edge 13i. The first hollow stem 13lis formed large enough to allow the positioning of the first telescoping rod 16h(FIG. 2). Furthermore, the second hollow stem 13kis formed large enough to allow the positioning of the second telescoping rod 16g(FIG. 2). Typically the first hollow stem 13land the second hollow stem 13kare drilled. However, drilling is substitutable for casting the hollow stems into the third body.

[0048] The nut 15 has a nut outer surface 15athat is radially formed for a flush-fit with the third body tapered second outer surface 13a. The nut outer edge 15f, the nut inner edge 15hand the third body second edge 13iare all formed in parallel planes. This allows the nut 15 to fit snugly against the third body 13 when the third connection means 35 is used. Finally, the thickness of material required between the nut outer edge 15fand the nut inner edge 15his enough to adequately prevent radiation from leaking through the nut 15 in any direction.

[0049] The first hollow slot 12jand the second hollow slot 12kthat are located in the second body 12 are both formed by either machining, casting or drilling. The second hollow core 23bfixedly communicates with the two hollow slots. The two hollow slots are open on the second body second edge 12dand the second hollow core 23b. The first hollow slot 12jand the second hollow slot 12kare symmetrically positioned around the center of the second body second edge 12d. The first hollow slot 12jis formed large enough to allow the positioning of the first arm of the internal sleeve 37b(FIG. 13). Furthermore, the second hollow slot 12kis formed large enough to allow the positioning of the second arm of the internal sleeve 37c. Typically the first hollow slot 12jand the second hollow slot 12kare machined.

[0050] In one embodiment, the actuator cap 36 outer surface is radially formed for a flush-fit with the second body second 12e. The actuator cap 36 fits snugly against the second body 12. Finally, the thickness of the actuator cap 36 is enough to adequately prevent radiation from leaking through the actuator cap 36 in any direction.

[0051] The double-ended syringe shield apparatus 10, as illustrated in FIG. 1, shows the nut 15 communicating with the third body 13 by the third connection means 35. The third body 13 communicates with the first body 11 by the first connection means 34. The first body 11 communicates with the second body 12 by the second connecting means 33. The first body first edge 11f, the first body second edge 11e, the first body third edge 11g, the first body fourth edge 11h, the second body first edge 12h, the second body third edge 12e, the third body third edge 13eand the third body first edge 13jare formed in parallel planes. The forming in parallel planes allows the first connection means 34 to be a snug fit between the first body 11 and the third body 13, when they are securely connected by axially threading the first body 11 and third body 13. The forming in parallel planes allows the second connection means 33 to be a snug fit between the first body 11 and the second body 12, when they are securely connected by axially threading the first body 11 and second body 12.

[0052] FIG. 2 illustrates the cross-section of the dose applicator 18aused in the double-ended syringe shield apparatus 10 in the preferred embodiment of the invention. The dose applicator 18acommunicates with and is releasably secured to the third body 13 by using a releasable wrap 15c. The dose applicator 18ais used, for example, when it is desired to load the hypodermic syringe 25 (FIG. 7) into a well counter allowing radiation shielding. The dose applicator 18aconsists of a nut 15, a first telescoping rod 16h, a second telescoping rod 16gand an insert holder 16i. The first telescoping rod 16his positioned into the first hollow stem 13land communicates with the nut 15. The second telescoping rod 16gis positioned into the second hollow stem 13kand communicates with the nut 15. The first telescoping rod 16hfurther consists of a first telescoping rod first section 16lthat is larger in diameter and slides around a first telescoping rod second section 16mthat is larger in diameter and slides around a first telescoping rod third section 16n. Furthermore the second telescoping rod 16gconsists of a second telescoping rod first section 16othat is larger in diameter and slides around a second telescoping rod second section 16pthat is larger in diameter and slides around a second telescoping rod third section 16q. The insert holder 16isecurely fastens to the first telescoping rod first section outer end 16rand the second telescoping rod first section outer end 16s. The nut 15 securely fastens to the first telescoping rod third section outer end 16tat the nut inner edge 15h. The nut 15 securely fastens to the second telescoping rod third section outer end 16uat the nut inner edge 15h. Finally, the first telescoping rod 16hand the second telescoping rod 16gare symmetrically positioned inside the third hollow core, wherein the insert 20 (FIG. 3) can be positioned between them and be releasably secured by the insert holder 16i.

[0053] The first hollow stem 13lis sized providing a first gap 19abetween the first hollow stem circumferential surface 16jand the first telescoping rod first section 16l. The first gap 19ais large enough to allow the first telescoping rod 16hto completely extend or retract inside the first hollow stem 13l. The second hollow stem 13kis sized providing a second gap 19bbetween the second hollow stem circumferential surface 16kand the second telescoping rod first section 16o. The second gap 19bis large enough to allow the second telescoping rod 16gto completely extend or retract inside the second hollow stem 13k.

[0054] The third connection means 35 comprises the nut 15 that releasably communicates with the third body 13 and the releasable wrap 15c. Typically, the releasable wrap 15cis a fabric hook or loop fastener but the fabric can be substitutable for any connection that is easy to use. The nut outer edge 15f, the nut inner edge 15hand the third body second edge 13iare all formed in parallel planes. The edges formed in parallel planes allow the nut 15 and the third body 13 to releasably communicate with a snug fit when the dose applicator 18ais retracted. The releasable wrap 15cis positioned around the third body tapered second outer surface 13aand the nut outer surface 15ato releasably secure the nut 15 to the third body 13. The nut outer surface 15aand the third body tapered second outer surface 13aare formed by machining to produce a flush-fit when the nut inner edge 15hand the third body second edge 13icommunicate with each other. Alternately, the nut can be cast and its edges machined to produce a flush-fit when it communicates with the third body 13. The nut outer surface 15ais usually formed at the same diameter as the diameter of the third body tapered second outer surface 13aat the third body second edge 13i.

[0055] Those skilled in the art will recognize that other means of extending the hypodermic syringe 25 from the first body 11 and third body 13 are within the scope of the present invention. For example, a chain or cable can be substituted for the telescoping rods 16hand 16gto lower the hypodermic syringe 25 into a well counter and then to raise the hypodermic syringe into the first body 11 and third body 13.

[0056] The first telescoping rod 16hand the second telescoping rod 16gare substitutable for one telescoping rod. The single telescoping rod is circumferentially mountable on the holder inside edge 16was long as the insert 20 can be positioned and freely movable inside the third hollow core 23c, the second hollow core 23band the first hollow core 23a.

[0057] FIG. 3 is a cross-section illustration of the one piece insert 20. The insert 20 consists of a first section 21 and a cover 30. Alternately, the insert 20 may consist of a first and second section with a cover. The second section 22 is removable from the first section 21 along a perforation 21bbetween the first and second section (FIG. 9). The first section inner surface 21dhas a diameter large enough to allow a 3 cc or 5 cc hypodermic syringe to be placed inside the insert 20. Alternately, the first section first inner surface 21ddiameter is substitutable for various sizes allowing different sizes of the hypodermic syringe to be placed inside 21ithe insert 20. The first section first outer surface diameter 21ais small enough to fit between the first telescoping rod 16h(FIG. 2) and second telescoping rod 16g(FIG. 2). The first section first end 21gis usually rounded to the same size as the radius of the first section inner surface 21dso that the insert 20 will easily fit into the insert holder 16i(FIG. 7) when, for example, the hypodermic syringe 25 is being transported to a well counter 28. The diameter of the first section second outer surface 21fis larger than the diameter of the first section first outer surface 21a. The transition from the first section first outer surface 21adiameter to the first section second outer surface 21fdiameter is in the shape of a tapered cylinder or a cone. This shape allows the insert 20 to be positioned and releasably secured by the insert holder 16i(FIG. 7). Alternately, the cone shape is substitutable for any polyhedron shape.

[0058] The first section second end annular lip 21hprotrudes slightly from the first section second outer surface 21fso that the cover 30 is secured to the first section second end 22dby a snap fit. Also, the first section inner annular lip 21eallows the hypodermic syringe 25 (FIG. 7) to snugly fit into the insert 20. The first section inner annular lip 21eis integrally a part of the first section 21 where the first section first outer surface 21abegins transitioning to the first section second outer surface 21f. Finally, the first section 21 is typically a clear molded plastic. However, any material is suitable as long as it is can be seen through after being molded.

[0059] The cover 30 is defined by the cover outer end 30a, the cover inner end 30b, the cover first outer surface 30d, the cover tapered outer surface 30eand the cover second outer surface 30h. The cover 30 is further defined by the cover annular lip 30c, the cover lip annular ridge 30fand the cover tapered inner surface 30g. The cover 30 is removably attached to the first insert second end 22dby a snap fit. The cover annular lip 30cthat is integrally a part of the cover 30 is positioned so as to communicate with the first section second end annular lip 21h, at the second end annular lip inner end 21k, and the cover annular lip inner end 30j. The cover tapered inner surface 30gdiameter is normally larger at its narrowest diameter than the diameter of the first section second inner surface 21j. Furthermore, the cover lip annular ridge 30fis formed allowing the cover annular lip 30cto snap fit around the first section second end annular lip 21h. Finally, the cover 30 is typically a clear molded plastic. However, any material is suitable as long as it can be seen through after being molded. The cover 30 would not normally be attached to the insert 20 after the hypodermic syringe 25 has been filled with radiopharmaceutical 26.

[0060] Alternatively, in uses where a covered syringe is not required by medical protocol, the syringe shield can operate without a syringe insert 21. This would be the case, for example, when a syringe will not be in contact with a patient's blood, such as when the radiopharmaceutical 26 will be injected into an intravenous fluid delivery system rather than directly into a patient's body. In such a case, the third inner surface 12cwould be sized to the hypodermic syringe 25 rather than to the syringe insert 20. In addition, the insert holder 16iwould be sized to securely hold the hypodermic syringe 25 rather than the syringe insert 20.

[0061] FIG. 4 shows the end view of the insert 20 with the cover second outer surface 30h, the first insert second end 22dand the first section inner annular lip 21e.

[0062] FIG. 5 illustrates the cross-section view of the single ended syringe shield 10awithout the dose applicator 18a(FIG. 6). The single-ended syringe shield is used to transport a hypodermic syringe 25 with a radioactive pharmaceutical 26 (FIG. 8). The first body 11 releasably communicates with the second body 12 and the first body 11 releasably communicates with the nut 15. The hypodermic syringe and a one-piece insert are positioned inside the apparatus 10aas shown in FIG. 8. The first body 11 has a first hollow core 23athat is formed all the way through the first body 11 from the first body first edge 11fto the to the first body second edge 11e. The diameter of the first hollow core 23a, that is formed by the first body inner surface 11b, is a variety of sizes depending on the size of the hypodermic syringe and insert to be used. The first body 11 shape is defined by the first body first outer surface 11aand the first body tapered second outer surface 11i. All the surfaces of the first body 11 are usually machined. As is known by the practitioner in the art, the machining of the first body inner surface 11b, the first body first outer surface 11aand the first body tapered second surface 11iis substitutable for casting the first body 11. Furthermore, the first body first edge 11fand the first body second edge 11eare typically formed in parallel planes.

[0063] The first connection means 34aat the first body first edge 11fis usually a releasable wrap 15c. Typically, the releasable wrap 15sis a fabric hook or loop fastener, but is substitutable for any fastener that is easy to use.

[0064] The second connection means 33 at the first body second edge 11eis usually a second male thread 11c. It is formed starting at the first body second edge 11eat a diameter that is smaller than the first body first outer surface 11aand larger than the diameter of the first body inner surface 11b. Typically, the second male thread 11cdiameter is formed in the range of about 70% to 85% the diameter of the first body first outer surface 11a. It is machined back from the first body second edge 11eto the first body third edge 11gfor a depth of about 5% the overall length of the first body 11. The second male thread 11cis typically a unified fine thread or a unified coarse thread.

[0065] In other applications, the male thread connections are substitutable for female threads, a locking nut arrangement or a compression flange arrangement as is known by the practitioner in the art. The first body first outer surface 11ais cylindrical in shape but is readily substitutable for any circular or polyhedron shape. Also, the first body 11, the second body 12 and the nut 15 can be cast with machining the ends and the connections. Finally, the wall thickness between the first body first outer diameter 11aor the first body tapered second outer surface 11iand the first inner diameter 11bmust contain enough radiation shielding material to provide adequate protection against radiation exposure.

[0066] At the first connection means 34athe first body first edge 11fcontains a first hollow stem 11land a second hollow stem 11k. The first and second hollow stems are large enough to have positioned inside them the first telescoping rod 16h(FIG. 6) and the second telescoping rod 16g(FIG. 6). The first and second hollow stems are typically drilled in the first body 11 from the first body first edge 11fthrough to the first hollow core 23a.

[0067] The second body 12 has a second hollow core 23bthat is formed starting from the second body third edge 12eto a depth that is about 75% to 85% of the length of the second body 12. The second hollow core 23bis usually machined. The diameter of the second hollow core 23bthat is formed by the second inner surface 12bis a variety of sizes depending on the size of the hypodermic syringe and insert to be positioned in the second hollow core 23b. The second body 12 shape is defined by the second body tapered first outer surface 12aand a second body second outer surface 12g, wherein both are typically machined and cylindrically shaped. The second body second outer surface 12gdiameter usually is flush with the first outer surface 11a. Alternately, the second body second outer surface 12gcan have the same tapered plane as the second body tapered first outer surface 12a. Typically, the second body second outer surface 12gat the second body third edge 12eis flush with the first outer surface 11a. Furthermore, the second body first edge 12h, the second body second edge 12dand the second body third edge 12eare all typically formed in parallel planes. The cylindrical shape of the second body 12 is substitutable for any circular or polyhedron shape. Finally, the wall thickness between the second outer surface 12g, the second body tapered first outer surface 12aand the second inner surface 12bmust contain enough radiation shielding material to provide adequate protection against radiation exposure. The radiation is from the radiopharmaceutical 26 contained within the hypodermic syringe 25 placed inside the second hollow core 23b.

[0068] The second connection means 33 at the second body third edge 12eis usually a first female thread 12fthat is formed by machining either a unified fine thread or a unified coarse thread. The first female thread 12fis formed starting at the second body third edge 12eat a diameter that is smaller than the second body second outer surface 12gand larger than the diameter of the second inner surface 12b. Typically, the first female thread 12fdiameter is formed in the range of about 70% to 85% of the diameter of the second body tapered first outer surface 12aor the second body second outer surface 12g. The first female thread 12fis machined back from the second body third edge 12eto the second body first edge 12hfor a depth that is about 15% the distance of the overall length of the second body 12. Alternately, the first female thread 12fis substitutable for a male thread, a locking nut arrangement or a compression flange arrangement as is known by the practitioner in the art.

[0069] There is a second body annular ridge 23ethat is formed to provide a means for the insert (FIG. 3) to be coaxially and releasably secured to the third inner surface 12c. The diameter of the third inner surface 12cdepends upon the diameter of the insert second outer surface 21f(FIG. 3). The third inner surface 12cis typically the size to fit an insert that accepts 3 cc or 5 cc hypodermic syringes.

[0070] The nut 15 has a nut outer surface 15adiameter that is flush with the diameter of the third body tapered second outer surface 13aat the first body first edge 11f. The nut 15 has a length of about 10% to 15% the length of the first body 11 and extends from the nut outer edge 15fto the nut inner edge 15h. A first connection means 34ais a releasable wrap 15cthat is typically a fabric hook or loop fastener. Finally, the thickness of material required between the nut outer edge 15fand the nut inner edge 15his enough to adequately prevent radiation of leaking through the nut 15 in all directions.

[0071] The single-ended syringe shield apparatus 10aas illustrated in FIG. 5 shows the nut 15 releasably communicating with the first body 11 by the first connection means 34a. The first body 11 releasably communicates with the second body 12 by the second connecting means 33. The first body first edge 11f, the first body second edge 11e, the first body third edge 11g, the second body first edge 12hand the second body third edge 12eare formed in parallel planes. Additionally, the nut inner edge 15hand the nut outer edge 15fare formed in parallel planes with the first and second body edges. The forming in parallel planes allows the first connection means 34ato be a snug fit between the first body 11 and the nut 15 when they are securely connected by the releasable wrap 15c. The forming in parallel planes allows the second connection means 33 to be a snug fit between the first body 11 and the second body 12 when they are securely connected by axially threading the first body 11 and second body 12.

[0072] In the preferred embodiment of the invention the radiation shielding material is typically lead. However, in many applications although lead is an excellent radiation shielding material it is unsuitable because it is too heavy and insufficiently flexible. Other materials include, but are not limited to, tungsten. Consequently, the radiation shielding material is any material that will attenuate the photons released from the radioactive agent. For example, a radiation shielding material is obtainable from lead acrylate or lead methacrylate combined by polymerizing it at a temperature above the melting point in a mixture with a copolymerizable monomer such as methyl methacrylate. Alternately, another radiation shielding material comprises an elastomeric or rubbery plastics material filled with lead particles. These materials combine the excellent radiation shielding properties of lead with other materials that weigh less than lead to provide a good radiation shield that is flexible and not too heavy.

[0073] Another commonly utilized radiation shielding material is tungsten. When tungsten, a tungsten compound or a tungsten based alloy is used as the material with high radiation absorptivity, when the γ-ray absorption coefficient of tungsten is not less than about 1 when the energy of the γ-ray is 511 KeV or greater, there is provided a safe radiation shielding material. For example, one such tungsten compound with high radiation absorptivity is a tungsten powder that is not less than 80% by weight or greater than 95% by weight combined with vulcanized rubber. The tungsten powder in combination with the vulcanized rubber has particle sizes in the range of about 4μ to 100 μm. When a tungsten alloy is used for the radiation shielding material a typical combination includes but is not limited to a hard-find grained internally stressed material of tungsten and carbon or tungsten, carbon and oxygen.

[0074] The insert holder 16imaterial is non-attenuating typically a plastic, a fiberglass or a polyethylene that is easily formed into the shape required to hold the insert 20 as shown in FIG. 2 and FIG. 6. In another embodiment the insert holder 16iis shaped so that it can directly position and hold the hypodermic syringe 25 without using the insert 20. The first telescoping rod 16hand the second telescoping rod 16gare typically constructed from a light weight material, preferably a non-attenuating material.

[0075] FIG. 6 illustrates the cross-section of the single-ended syringe shield 10awith the dose applicator 18a. The dose applicator 18acommunicates with and is releasably secured to the first body 11. The dose applicator 18ais used, for example, when it is desired to load the hypodermic syringe 25 (FIG. 7) into a well counter 28, wherein individuals are shielded from radiation emanating from the radiopharmaceutical 26 in the hypodermic syringe 25. The dose applicator 18aconsists of a nut 15, a first telescoping rod 16h, a second telescoping rod 16gand an insert holder 16i. The first telescoping rod 16his positioned into the first hollow stem 11land communicates with the nut 15. The second telescoping rod 16gis positioned into the second hollow stem 11kand communicates with the nut 15. The first telescoping rod 16hfurther consists of a first telescoping rod first section 16lthat is larger in diameter and slides around a first telescoping rod second section 16mthat is larger in diameter and slides around a first telescoping rod third section 16n. Furthermore the second telescoping rod 16gconsists of a second telescoping rod first section 16othat is larger in diameter and slides around a second telescoping rod second section 16pthat is larger in diameter and slides around a second telescoping rod third section 16q. The insert holder 16isecurely fastens to the first telescoping rod first section outer end and the second telescoping rod first section outer end. The nut 15 securely fastens to the first telescoping rod third section outer end and the second telescoping rod third section outer end at the nut inner edge 15h. The first telescoping rod 16hand the second telescoping rod 16gare symmetrically positioned inside the third hollow core, wherein the insert 20 can be positioned between them and be releasably secured by the insert holder 16i.

[0076] The first hollow stem 11lis sized providing a first gap 19abetween the first hollow stem circumferential surface 16jand the first telescoping rod first section 16l. The first gap 19ais large enough to allow the first telescoping rod 16hto completely extend or retract within the first hollow core 23a. The second hollow stem 11kis sized providing a second gap 19bbetween the second hollow stem circumferential surface 16kand the second telescoping rod first section 16o. The second gap 19bis large enough to allow the second telescoping rod 16gto completely extend or retract within the first hollow core 23a. The first body inner surface 11bis formed large enough to allow a slideable movement of the insert holder inside the hollow core 23a.

[0077] The first connection means 34acomprises the nut 15 with a releasable wrap 15cthat is releasably secured to the first body 11. Typically, the releasable wrap 15cis a fabric hook or loop fastener, but is substitutable for any fastener that is easy to use. The nut outer edge 15f, the nut inner edge 15hand the first body first edge 11fare all formed in parallel planes. The edges formed in parallel planes allow the nut 15 and the first body 11 to be releasably secured with a snug fit between the nut inner edge 15hand the first body first edge 11fwhen the releasable wrap 15cis used. The nut outer surface 15adiameter is formed flush with the first body tapered second outer surface 11iat the first body first edge 11f. However, the nut outer surface 15acan have a diameter that is either larger or smaller than the diameter of the first body tapered second outer surface 11iat the first body first edge 11f. Typically, the nut edges and surfaces and the first body edges and surfaces are formed by machining to produce a snug-fit at the edges and a flush-fit at the surfaces. Alternately, the nut and first body can be cast with their edges machined to produce a snug fit when they are connected together.

[0078] In the preferred embodiment of the invention the first body first outer surface 11ais typically formed as a straight cylinder while the first body tapered second outer surface 11iis formed as a cone. Alternately, the first body first outer surface 11ais substitutable for a tapered surface that matches the first body tapered second outer surface 11i.

[0079] The first telescoping rod 16hand the second telescoping rod 16gare substitutable for one telescoping rod. The single telescoping rod is circumferentially mountable on the holder inside edge 16was long as the insert 20 can be positioned and freely movable inside the third hollow core 23c, the second hollow core 23band the first hollow core 23a.

[0080] FIG. 7 illustrates the single-ended apparatus 10abeing loaded into a well counter 28. The well counter 28 typically has a well counter liner 27 that the apparatus 10ais set into to allow the hypodermic syringe 25 containing a radiopharmaceutical 26 to be loaded and measured at the well counter 28. The dose applicator 18apositions the insert 20 by the insert holder 16iand the first telescoping rod 16hand the second telescoping rod 16g. The well counter liner gap 27ais large enough so that the first body second male thread 11ccan easily fit into the well counter liner 27 allowing the first body 11 to set on top of the well counter liner. In this illustration the second body 12 (FIG. 5) has been removed and the first body 11 is positioned into the well counter liner 27 in the direction of the arrow 31. The nut 15 is extended as the insert 20 rests in the first hollow core 23 to be pushed into the well counter 28 in the direction of the arrow 31.

[0081] FIG. 8 illustrates the doubled-ended apparatus 10 with the dose applicator 18a. The apparatus 10 transports a hypodermic syringe 25 containing a radiopharmaceutical 26 and protects individuals from radiation generated therefrom. A first body 11 releasably communicates with a second body 12 and the first body 11 releasably communicates with a third body 13. The third body 13 releasably communicates with a nut 15. Attached to the nut 15 is the first telescoping rod 16hand the second telescoping rod 16gof the dose applicator 18a. The first telescoping rod 16his positioned in the first hollow stem 13land sized to allow all of the sections of the first telescoping rod 16hto move freely within the first hollow stem 13l. Likewise, the second telescoping rod 16gis positioned in the second hollow stem 13kand sized to allow all of the sections of the second telescoping rod 16gto move freely within the second hollow stem 13k. Finally, the first connection means 34 releasably secures the first body 11 to the third body 13, the second connection means 33 releasably secures the first body 11 to the second body 12 and the third connection means 35 releasably secures the third body 11 to the nut 15.

[0082] The dose applicator is positioned in the first hollow core 23a, the second hollow core 23band the third hollow core 23c. This allows the hypodermic syringe 25 with the radiopharmaceutical 26 to be positioned inside the insert 20 wherein the insert is releasably secured to the dose applicator 18aby the insert holder 16i. Radiation leakage around the dose applicator 18ais significantly reduced by releasably securing the third body 13 and the nut 15 with the releasable wrap 15c. For example, when the nut 15 is not releasably secured by the releasable wrap 15cthe nut can be moved away from the third body 13 exposing the first hollow stem 13land the second hollow stem 13k. When there is radiation emanating from the radiopharmaceutical 26 located in the third hollow core 23cthe radiation leakage is possible out of the first hollow stem 13land second hollow stem 13k. A snug-fit between the third body 13 and nut 15 using the releasable wrap 15cas the third connection means 35 prevents this radiation leakage.

[0083] FIG. 9 illustrates one view of the preferred embodiment of the invention, including the first body 11 and second body 12 (with the piston actuator 17) of the double-ended apparatus 10 with the hypodermic syringe 25 and the radiopharmaceutical 26 wherein the radiopharmaceutical can be injected into a patient or intravenous delivery system. The first body 11 and second body 12 are the radionuclide shield surrounding the insert 20 and are constructed of various materials including, but not limited to tungsten and lead. The insert holder 16i(FIG. 8) has been removed from the first hollow core 23aalong with the dose applicator 18a(FIG. 8). When the radiopharmaceutical 26 is going to be injected into a patient the second section 22 of the insert 20 is removed from the first section 21 at the perforation 21b. The piston actuator 17 is partially withdrawn from the second body 12 and the actuator cap 36 is rotated to the engaged position, causing the internal sleeve engagement tooth 37ato engage the disk 39, which in turn engages the piston of the syringe 25. This is accomplished without exposing anyone to the radiation emanating from the radiopharmaceutical 26. The hypodermic syringe 25 is ready to be injected into the patient or intravenous delivery system once the needle cover 32 is removed. The radiopharmaceutical 26 is injected by depressing the actuator cap 36 which in turn compresses the syringe 25.

[0084] FIG. 10 illustrates the cross-section of the piston actuator 17 used in the double-ended syringe shield apparatus 10 in the preferred embodiment of the invention. The piston actuator 17 communicates with and is slidably secured to the second body 12. The piston actuator 17 is used, for example, to inject the contents of the hypodermic syringe 25 (FIG. 7) into a patient or intravenous tubing.

[0085] In the preferred embodiment, the means for compressing includes piston actuator 17 that comprises an actuator cap 36, a disk 39, at least one guide 38, and an internal sleeve 37, having a first arm 37b, a second arm 37c, a retainer lip 37dand an engagement tooth 37a. The internal sleeve 37 is a hollow cylinder, sized to allow it to slide within the second hollow core 23bwithout contacting the insert 20 or hypodermic syringe 25. The internal sleeve first arm 37bis positioned in the first hollow slot 12jand communicates with the actuator cap 36. The internal sleeve second arm 37cis positioned in the second hollow slot 12kand communicates with the actuator cap 36. The actuator cap 36 and the internal sleeve 37 are fixedly connected. The first hollow slot 12jand second hollow slot 12kare of sufficient width to allow the internal sleeve arms 37band 37cto slide in the hollow slots 12jand 12k, allowing the internal sleeve 37 to slide longitudinally relative to the second body 12. FIG. 11 illustrates the cross section of the second body 12 with the actuator cap 36 and internal sleeve arms 37band 37cextended from the second body 12.

[0086] The first hollow slot 12jand second hollow slot 12kare of sufficient length relative to the width of the internal sleeve arms 37band 37cthat the actuator cap 36 is capable of rotating less than a full rotation, preferably approximately a quarter rotation, relative to the second body 12. In the preferred embodiment, the limit of rotation of the actuator cap 36 in one direction would be the engaged position and the limit of rotation of the actuator cap 36 in the opposite direction would be the disengaged position.

[0087] The disk 39 consists of at least one guide notch 39aand at least one engagement notch 39b. In the preferred embodiment there are two guide notches 39aand two engagement notches 39b, corresponding to two guides 38 and two engagement teeth 37a. The disk 39 is sized so that it can slide within the internal sleeve 37. The at least one engagement notch 39bis slightly larger than the internal sleeve engagement tooth 37a. The at least one guide notch 39ais approximately the same size as the diameter of the at least one guide 38. The at least one guide 38 is fixedly attached to the inside of the second body 12, opposite the second body second surface 12dand extends to the second body first surface 12e. The at least one guide notch 39aslidably communicates with the at least one guide 38, allowing the disk 39 to slide within the internal sleeve 37. The at least one guide 38 prevents the disk 39 from rotating relative to the second body 12. The internal sleeve retainer lip 37d, retains the disk 39 inside of the internal sleeve.

[0088] The internal sleeve engagement tooth 37ais positioned on the inside surface of the internal sleeve 37. The location of the internal sleeve engagement tooth is selected such that depressing the actuator cap when it is in the engaged position will completely compress the syringe piston into the syringe 25. The internal sleeve engagement tooth must be of sufficient size that it will engage the disk 39 when the disk 39 slides within the internal sleeve 37. The disk engagement notch 39bis positioned such that when the actuator cap 36 is rotated to the disengaged position and is extended from the second body, the internal sleeve engagement tooth 37apasses through the engagement notch 39a.

[0089] When the actuator cap 36 is then rotated to the engaged position and compressed into the second body 12, the disk engagement notch 39bengages the disk 39 and causes the disk 39 to engage the piston of a syringe 25 contained within the double ended syringe shield apparatus 10. The actuator cap 36 is usually sized to the same diameter as the diameter of the second body 12 at the second body second edge 12d.

[0090] As shown in FIG. 15, in the most preferred embodiment the apparatus includes a single telescoping rod 16z. The telescoping rod 16zcontacts and secures a radiopharmaceutical-containing hypodermic syringe 25 directly, without an interposed insert. Alternatively, when accepted medical protocols dictate use of a syringe cover or insert, for example in the case of radiopharmaceuticals to be administered directly from the syringe into the patient's body, the telescoping rod 16zcontacts and secures the insert 20 (FIG. 3).

[0091] To facilitate lowering the hypodermic syringe 25 into a well counter, the telescoping rod 16zis fixedly attached to nut 15 and selectively secured in the first body 11 and third body 13. Preferably, the single telescoping rod 16zis selectively secured by means of a releasable latch in the third body 13 that engages near the telescoping rod 16z. The releasable latch is activated by a button 14don the outside of the third body 13 which, when pressed, disengages the latch from the telescoping rod 16z, allowing it to be extended out of the third body 13. Preferably the latch is spring loaded so that a portion of the latch is urged into position against the telescoping rod 16zand engages rod detent 16x, except when button 14dis pressed.

[0092] In the most preferred embodiment, the third connection means 35 comprises a threaded connection to allow the nut 15 to releasably engage the third body 13. To operate the apparatus to lower a hypodermic syringe 25 into a well counter, second body 12 is removed from first body 11 and the apparatus is placed over the well counter (see FIG. 7). The nut 15 is then disengaged from third body 13 and raised to fully extend telescoping rod 16z. The button 14dis activated to release the latch and the nut 15 is lowered, along with the extended telescoping rod 16z, causing the hypodermic syringe 25 to be lowered into the well counter. After measurement is complete, nut 15 is raised, along with extended telescoping rod 16z, until the latch engages the telescoping rod 16z. The nut 15 is then lowered, causing the telescoping rod 16zto collapse. The nut 15 is then secured to third body 13 and second body 12 may be reattached to first body 11 for transporting the hypodermic syringe 25 in the apparatus 10.

[0093] As shown in FIG. 16, in the most preferred embodiment the releasable latch comprises a yoke 14, a spring 14e, a button 14dand a rod detent 16x. The yoke 14 comprises a spring arm 14athat communicates with the spring 14e. Spring arm 14ais partially contained within and slides within a spring channel 13nformed in the third body 13. The spring 14eis positioned such that it engages the spring arm 14aand urges the yoke 14 away from the spring channel 13n. A guide arm 14bof the yoke 14 is partially contained within and slides within a guide arm channel 13oformed in the third body 13. A release arm 14cof the yoke 14 extends through a release arm channel 13pformed in the wall of the third body 13. The release arm 14cof the yoke slides within the release arm channel 13p. Preferably, the end of the release arm 14cof the yoke 14 that extends outside the third body 13 communicates with a release button 14dand, further, extends a sufficient distance out of the third body 13 that, when the release button 14dis pressed, the yoke 14 completely disengages from a rod detent 16xformed in the telescoping rod 16z. Typically, the detent 16xis positioned approximately 0.5 to 1.5 cm from the telescoping rod insert holder 16i. The detent 16xis sufficiently wide to allow the yoke 14 to engage it, thereby preventing the telescoping rod 16zfrom extending out of the third body 13 into the first body 11.

[0094] The yoke 14 is preferably Y-shaped and made of metal, but other shapes and other materials may be substituted as is known in the art. The width and length of the arms of the yoke 14 may vary provided that the yoke 14 is capable of limited travel along the longitudinal axis of the spring arm channel 13n, allowing the yoke 14 to selectively engage and disengage from the rod detent 16x. The semicircular interior portion of he yoke 14 must be sized to allow the telescoping rod 16zto pass easily when the yoke 14 is disengaged from the rod detent 16x.

[0095] Preferably, the rod detent 16xcompletely encircles the telescoping rod 16z, so that the telescoping rod 16zcan be engaged by the yoke 14 without regard to rotation of the telescoping rod 16zrelative to the yoke 14. Preferably, the rod detent 16xis created by an increase in the diameter of the telescoping rod 16zboth below and above the rod detent 16x(FIG. 15a). Preferably, diameter of the telescoping rod 16zgradually increases as it approaches the rod detent 16xfrom either side and drops sharply at the rod detent 16xto form a s shoulder for engaging the yoke 14. Alternatively, the rod detent 16xcan be formed by uniformly decreasing the diameter of the telescoping rod 16z, to form a shoulder for engaging the yoke 14.

[0096] In another embodiment, the yoke 14 may be fashioned without a guide arm 14b, provided that the release arm 14cand spring arm 14aare capable of retaining the yoke 14 in position in the third body 13 and also allow the yoke 14 to slide in the channels 13nand 13pwithout excessive binding. For example, the yoke 14 may have a generally oval or circular shape that completely encircles the telescoping rod 16z, with the release arm 14cand spring arm 14apositioned opposed to each other around the circle or oval's perimeter.

[0097] In yet another embodiment, the yoke 14 comprises high friction material for engaging the telescoping rod 16z. According to this embodiment, the telescoping rod 16zdoes not require a rod detent 16x. According to this embodiment the high friction material, for example rubber, of the yoke 14 is urged by the spring 14einto contact with the telescoping rod 16z, which is thereby prevented from sliding in or out of the third body 13, except when button 14dis depressed to disengage the high friction material.

[0098] The spring arm channel 13n, guide arm channel 13oand release arm channel 13pmay be formed in the third body 13 by molding or drilling and filling or other methods known in the art. The channels 13n13o13pmust be sufficiently large to allow the respective arms 14a14b14cto move freely. The channels 13n13o13p, however, should be small enough to prevent undesired release of radiation from the hypodermic syringe 25 through the channels 13n13o13p. In normal orientation, the channels 13n13o13pwill be perpendicular to the axis of third hollow core 23cand will therefore not provide a path for release of radiation.

[0099] Release arm channel 13ppasses completely through the wall of third body 13 so that release arm 14ccan extend out of third body 13 and communicate with release button 14d. Preferably, spring arm channel 13nand guide arm channel 13odo not pass completely through the wall of third body 13. Alternatively, spring arm channel 13nand guide arm channel 13ocan pass completely through the wall of third body 13, provided that means are provided for securing and retaining spring 14ein spring arm channel 13n.

[0100] While there has been illustrated and described what is at present considered to be the preferred embodiment of the invention, it should be appreciated that numerous changes and modifications are likely to occur to those skilled in the art. It is intended in the appended claims to cover all those changes and modifications that fall within the spirit and scope of the present invention.