GB2520080A

GB2520080A - Apparatus for transferring fluid

Info

Publication number: GB2520080A
Application number: GB1319852.8A
Authority: GB
Inventors: Amy Scott
Original assignee: POOLE HOSPITAL NHS FOUNDATION TRUST
Current assignee: POOLE HOSPITAL NHS FOUNDATION TRUST
Priority date: 2013-11-11
Filing date: 2013-11-11
Publication date: 2015-05-13
Also published as: GB201319852D0

Abstract

A syringe comprising a barrel 106 defining a central longitudinal axis, a needle mount 104 formed at a first end of the barrel 106, eccentrically relative to the longitudinal axis A, and a shield 302 displaceable between a first configuration, in which the shield 302 substantially surrounds the barrel 106, and a second configuration, in which the shield 302 extends beyond said first end of the barrel 106. The shield 302 is formed such that a needle mounted on said needle mount 104 may be inserted into a fluid transfer container whilst the shield 302 is in said second configuration. The shield 302 may be frusto-conical, or have a elliptical or oval second end. The second end of the shield 302 may be laterally displaceable relative to the needle.

Description

APPARATUS FOR TRANSFERRING FLUID

TECHNICAL FIELD OF THE INVENTION

This invention relates to an apparatus for transferring fluid.

BACKGROUND TO THE INVENTION

Syringes are used regularly by medical practitioners to take fluid, particularly blood, from patients and to store and transfer fluid to containers such as blood bottles.

A typical apparatus for taking blood from a patient is shown in Figure 1. The apparatus, labeled generally as 100, includes a syringe 102 and a needle 104. The syringe 102 includes a barrel 106 for containing fluid, and a plunger 108 which fits snugly within the barrel and is moveable along substantially the length of the barrel.

The barrel 106, which is generally cylindrical in shape, defines an axis A, denoted by a dashed line in the drawings. A first end 108a of the plunger remains outside the barrel 106, and includes a flange 110 to allow a user to apply pressure to the plunger, for example using his or her thumb, to move the plunger along the barrel. A second end I 08b ofthc plunger includes a rubber piston 112 which forms a seal with an inner surface of the barrel 106.

A pair of fins 1 14a, 1 14b extend outwardly from a first end 106a of the barrel to provide a surface opposing the flange 110, and against which the user can apply pressure with his or her fingers when activating the plunger 108. A needle mount 116 extends from a second end 106b of the barrel, and acts as a mount to which the needle 104 can be connected.

In Figure 1, the needle mount 116 is located in the centre of the end 106b of the barrel 106. In some known apparatus, such as a apparatus 200 shown in Figure 2, the needle mount 116 of the syringe 102 is located in an offset, or eccentric position at the end 106b of the barrel 106. In other words, the needle mount 116 is positioned non-centrally, close to an edge of the barrel 106, rather than in the centre of the end 106b of the barrel as is shown in Figure 1.

An apparatus 200 having an eccentric or offset needle mount 116, such as a hypodermic needle, is particularly advantageous when taking blood from a patient as the needle 104 should enter the patient at an acute angle relative to the patient's skin.

In order to draw Mood from a patient, the medical practitioner would connect a new S needle 104 to the needle mount 116 of the syringe 100, 200. Once blood has been drawn from the patient and is contained within the barrel 106, the medical practitioner might need to transfer the blood to a suitable container, such as a blood bottle (not shown). Such a procedure typically requires the medical practitioner to hold a blood bottle in one hand and the syringe 100, 200 in his or her other hand, and feed the needle 104 into one end of the blood bottle. Syringes and blood bottles are typically manufactured to standard sizes. When performing a blood transfer procedure, the medical practitioncr must bc careful when inserting the needlc 104 into the blood bottle because, if the needle misses the blood bottle, the medical practitioner runs the risk of injuring their self by stabbing his or her finger or thumb with the needle.

Such an injury is known as a needlestick injury (NSI), and can expose the medical practitioner to a blood-borne pathogen which could lead to a disease such as Hepatitis B, Hepatitis C or Human Immunodeficiency Virus (HIV).

It is desirable, therefore, to improve the safety of needle use by medical practitioners, and to reduce the risk of an NSl occurring.

SUMMARY OF INVENTION

According to a first aspect, the present invention provides a syringe comprising: a barrel defining a central longitudinal axis; a needle mount formed at a first end of the barrel, eccentrically relative to the longitudinal axis, for mounting a needle on the syringe; and a shield moveable between a first configuration, in which the shield substantially surrounds the barrel, and a second configuration, in which the shield extends beyond said first end of the barrel.

When a needle is mounted on the syringe, the shield, in the second configuration, may be configured to permit said needle to engage a fluid transfer container through an end ofthe shield.

The shield may have a first end having a generally cireuar cross section of a first diameter and a second end having a generally circular cross section of a second diameter, the second diameter being larger than the first diameter. The shield may be frusto-conical in shape.

The shield may have a first end and a second end, the first end having a substantially circular cross section, and the second end having a non-circular cross section.

The cross sectional shape of the second end may be selected from a group comprising: elliptical, oval and oviform.

The shield may have a fir st end and a second end and the second end of the shield may be displaceable laterally with respect to the longitudinal axis of the barrel. The shield may comprise a flexible portion.

The syringe may include an attachment portion for attaching to the barrel, the attachment portion being relatively more rigid than the flexible portion.

The syringe may include a protrusion formed either: i) on an outer surface of the barrel for engaging with a complementary recess formed on an inner surface of the shield; or ii) on an inner surface of the shield for engaging with a complementary recess formed on an outer surface of the barrel. The protrusion may be a ridge formed around a circumference of the barrel.

The shield may be rotatable about the barrel of the syringe.

The syringe may include a retaining member extending either from an inner surface of the shield or from an outer surface of the barrel, for retaining the shield in said second configuration. The retaining member may comprise an arm connected to, or formed integrally with, an inner surface of the shield at first end, and biased inwardly from the shield such that, when the shield is moved into said second configuration, a second end of the arm springs away from the shield, thereby preventing movement of the shield back into said first configuration.

The syringe may include a helical track formed on an outer surface of the barrel, arranged to engage a complementary helical track formed on an inner surface of the shield.

According to a second aspect, the present invention provides a syringe as described above, wherein either: i) the helical track formed on the barrel comprises a helical protrusion and the helical track formed on the shield comprises a complementary helical recess; or ii) the helical track formed on the barrel comprises a helical recess and the helical track formed on the shield comprises a complementary helical protrusion.

The helical track formed on the barrel may extend only partially along the length of the barrel so as to restrict movement of the shield beyond the first end of the barrel.

The barrel may be substantially cylindrical.

According to a third aspect, the present invention provides a fluid sampling apparatus comprising: a syringe as described above; and a needle attached to the needle mount; wherein the shield, in the second configuration, permits access to the needle through an end of the shield.

The apparatus may comprise a hypodermic needle for sampling blood.

The shield, in the second configuration, may permit access of a blood bottle to the needle through an end of the shield. The shield, in the second configuration, may extend beyond the length of the needle.

According to a fourth aspect, the present invention provides a bodily fluid sampling kit comprising: a syringe as described above; a needle attachable to the syringe; and a fluid transfer container for engaging with the needle and for containing fluid transferrable to and/or from the syringe.

According to a fifth aspect, the present invention provides a method of transferring fluid from a syringe to a fluid transfer container, the syringe comprising a syringe as described above and a needle attached to the syringe, the method comprising: moving the shield into said second configuration; engaging the needle with the fluid transfer container; and transferring the fluid from the syringe to the fluid transfer container.

The method may include: prior to engaging the needle with the fluid transfer container, displacing an end of the shield laterally with respect to the longitudinal axis of the barrel.

Other advantageous features will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, strictly by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a known apparatus for drawing blood, with a needle positioned centrally with respect to the syringe; Figure 2 is a perspective view of a known apparatus for drawing blood, with a needle positioned in an off-centre position with respect to the syringe; Figure 3A is a sectional view of a first configuration of a fluid transfer apparatus constructed in accordance with a first embodiment of the invention; Figure 3B is a sectional view of a second configuration of the fluid transfer apparatus of Figure 3A; Figure 4A is a sectional view of a first configuration of a fluid transfer apparatus constructed in accordance with a second embodiment of the invention; Figure 4B is a sectional view of a second configuration of the fluid transfer apparatus of Figure 4A; Figure 5A is a sectional view of a first configuration of a fluid transfer apparatus constructed in accordance with a third embodiment of the invention; Figure 5B isa sectional view of a second configuration of the fluid transfer apparatus of Figure 5A; Figure 6A is a sectional view of a first configuration of a fluid transfer apparatus constructed in accordance with a fourth embodiment of the invention; Figure 6B is a sectional view of a second configuration of the fluid transfer apparatus of Figure 6A; Figure 6C is a sectional view of a third configuration of the fluid transfer apparatus of Figurc6A Figure 7A is a sectional view of a first configuration of a fluid transfer apparatus constructed in accordance with a fifth embodiment of the invention Figure 713 is a sectional view of a second configuration of the fluid transfer apparatus of Figure 7A; Figure 8A is a perspective view of a first portion of a fluid transfer apparatus constructed in accordance with a sixth embodiment of the invention; Figure 8B is a perspective view of a second portion of the fluid transfer apparatus of Figure 8k Figure 9A is a perspective view of a first portion of a fluid transfer apparatus constructed in accordance with a seventh embodiment of the invention; and Figure 9B is a perspective view of a second portion of the fluid transfer apparatus of Figure 9A.

DESCRIPTION OF TilE EMBODIMENTS

Referring to the drawings, Figures 1 and 2 show known fluid transfer apparatus 100, which do not include means for reducing the risk of a user of the apparatus suffering an NSI.

Figures 3A and 3B show sectional views of a fluid transfer apparatus 300 constructed in accordance with a first embodiment of the invention. The apparatus 300 includes the syringe 102 having the barrel 106 and the plunger 108 movable within and along substantially the length of the bane!. The barrel 106 defines a longitudinal axis A, denoted by a dashed line along the centre of the barrel. The barrel is shown having a genera!!y cylindrical shape, with a circular cross section. However, it will be appreciated that the barrel may alternatively have a cross section having a different shape. The needle 104 is shown connected to the needle mount 116 in a position which is eccentric with respect to the longitudinal axis A of the barrel 106. That is to say, the needle 104 is connected to the barrel 106 in an offset position relative to the centre of the second end 106b of the barrel. It will be clear, therefore, that the apparatus 300 shown in Figures 3A and 3B has a similar arrangement to the apparatus shown in Figure 2.

The apparatus 300 further includes a sleeve, sheath or shield 302 which, in the configuration shown in Figure 3A, substantially surrounds the barrel 106 of the syringe 102. In this embodiment, the shield 302 is formed of relatively rigid plastics material, such that the shield is able to maintain its shape and position relative to the bane! 106 of the syringe 102. In some embodiments, the shield 302 is formed from the same material as the bane! 106 of the syringe 102.

Protrusions are formed around the bare! 106 in the form of circumferential ridges 304 and 306. The ridges 304, 306 form a raised profile around the circumference of the bane! 106, and are arranged to engage with complementary notches or recesses 308 and 310 formed in an inner surface of the shield 302. While, in this embodiment, the ridges 304, 306 form a ring around the entire circumference of the barrel 106, in other embodiments, the ridges may be formed only partially around the barrel in the form of individual protrusions. Similarly, the recesses 308, 310 formed in the shield 302 may be formed as partial recesses or notches, to complement the form of the protrusions.

Additionally, the ridges 304, 306 in this embodiment are formed integrally with the bane! 106 of the syringe 102. In other embodiments, the ridges 304, 206 may take the form of a plastic or rubber ring positioned and secured to the barrel 106, for examp!e by adhesive. Alternatively or additionally, one or more of the ridges 304, 306 may be formed on an inner surface of the shield, configured to interface and engage with one or more comp!ementary recesses formed in an outer surface of the barrel 106.

In a first configuration, as shown in Figure 3A, the ridge 304 of the barrel 106 engages the recess 308 of the shield 302, forming a frictiona! engagement between the shie!d and the barrel, thereby retaining the shie!d in its first configuration around the barrel. Similarly, the ridge 306 of the barrel 106 engages the recess 310 of the shield 302 in the first configuration, he!ping to retain the shic!d in position.

While the barrel 106 has a substantially cylindrical shape, with a substantially circular cross scction, the shic!d 302 has a cross section that varies along its length. At a first end 302a, the shield 302 has a substantially circular cross section, matching that of the barrel 106. At the first end 302a, the diameter of the cross section of the shield 302 is very simi!ar to, but s!ightly!argcr than the diameter of the cross section of the barrel 106, so that the shield is able to fit around the outside of the bane!. However, at a second end 302b, the shield 302 has a cross section which is different to that of the barrel 106. In one embodiment, the cross section of the second end 302b of the shield 302 is circular, but has a diameter which is larger than the diameter of the cross section of the first end 302a of the shield. The shie!d 302 may be frusto-conica!. In other embodiments, the cross section at the second end 302b is non-circular, such as elliptical, oviform or oval. An effect of a larger circular cross section of a non-circular cross section of the shield 302 at the second end 302b is that a portion of the shie!d is spaced apart from the syringe 106. The purpose of this arrangement will be made clear with reference to Figure 3B below.

The shield 302 is movable along substantially the length of the barrel 106. In order to move the shield 302 from its first configuration, as shown in Figure 3A, into its second configuration, as shown in Figure 3B, a user holds the syringe 102 in one hand, for examp!e by grasping the fins 1 14a, 1 14b between his or her finger and thumb, and slides the shield 302 along the length of the barrel 106. It will be clear that, in order to overcome the retaining force generated by the engagement of the ridges 304, 306 of the barrel 106 and the recesses 308, 310 of the shield, the user would have to apply a greater initial force to the shield. When the shield has been moved along substantially the length of the barrel 106, the recess 308 at the first end 302a of the shield 302 engages the ridge 306 formed at the second end 106b of the barrel 106. When the recess 308 engages with the ridge 306, the shield 302 "clicks" into place, and its further movement along the barrel 106 is restricted.

In Figure 3B, the shield 302 is shown in its second configuration, with the recess 308 engaged with the ridge 306. The second end 302b of the shield 302 extends beyond the needle 104, thereby shielding the needle and reducing the risk of a user suffering an NSI by inadvertently bringing his or her hand into contact with thc nccdlc.

It will be noted that, as shown in Figure 3A, the lower portion of the barrel 106 is substantially parallcl with the shield 302 and thc uppcr portion of thc barrel 106 is spaced apart from the second end 302b of the shield 302. In its second configuration, as shown in Figure 3B, the upper portion of the barrel 106 is parallel with the shield 302, and the lower portion of the barrel 106 is spaced apart from the second end 302b of the shield 302.

In addition to being moveable along substantially the length of the barrel 106, the shield 302 can be rotated about the axis A of the barrel 106. The shield 302 as shown in Figure 3B is rotated 180 degrees about the axis A of the barrel 106 with respect to its position in Figure 3A. By rotating the shield 302 into the configuration shown in Figure 3B, the needle 104, while shielded generally by the shield 302, is accessible via the end 302b of the shield. Accordingly, a user is able to access the needle 104, for example to insert the needle into a blood bottle (not shown) or other container to allow blood to be transferred from the barrel 106 of the syringe to the blood bottle or the container.

Figures 4A and 4B show a fluid transfer apparatus 400 constructed according to a second embodiment of the invention. In the apparatus 400, a shield 402 is movable between a first configuration, shown in Figure 4A, and a second configuration, shown in Figurc 4B. The shield 402 differs from the shield 302 shown in Figurcs 3A and 3B only in that the shield 402 includes a first end portion 404 towards a first end 402a of the shield, a second end portion 406 towards a second end 402b of the shield, and an intermediate portion 408 connecting the first and second end portions 404 and 406.

The intermediate portion 408 of the shield 402 extends outwardly from the barrel 106 such that the second end portion 406 is at least partly spaced apart from the barrel.

The cross section of the second end 402b of the shield 402 may be circular or non-circular, such as oval, elliptical or egg-shaped.

As with the embodiments shown in Figures 3A and 3B, the effect of having a portion of the shield 402 spaced apart from the barrel 106 is that, in its second configuration, as shown in Figure 4B, once the shield has been rotated through 180 degrees about the axis A ofthe barrel 106, a uscr is abic to acccss thc necdlc 104 using a blood bottle or container (not shown) to aid transfer of fluid or blood to and from the barrel 106.

In use, a user of the fluid transfer apparatus 300 or 400 (shown in Figures 3 and 4) uses the apparatus with the shield 302, 402 in its first configuration to draw fluid from a patient or from another fluid source, such as a container. Once the fluid is within the barrcl 106, thc uscr slidcs the shicld 302, 402 from its first configuration to its second configuration in which the shield sibstantia1ly surrounds the needle 104. With the shield 302, 402 in the second configuration, the user is at less risk of sustaining an NSI from the needle 104. In order to transfer fluid from the barrd 106 to another container, such as a blood bottle, the user rotates the shield 302, 402 through 180 degrees about the longitudinal axis A of the band 106 so that the portion of the end 302b, 402b of the shield 302, 402 that is spaced apart from the barrel 106 is the same side of the barrel as the needle 104. That way, the user is able to fit a container into the opening at the end 302b, 402b of the shield 302, 402 to engage with the needle 104 for transfening fluid to and/or from thc syringc 102.

Figures 5A and SB show a fluid transfer apparatus 500 constructed according to a third embodiment of the invention. In this embodiment, a shield 502 is identical to the shield 402 shown in Figures 4A and 4B. In this embodiment, however, the shield 502 further includes a locking arm 504. In the first configuration, shown in Figure 5A, the locking arm 504 fits snugly between an inner surface of the shield 502 and an outer surface of the barrel 106. The locldng arm 504 is biased in the direction of the central axis A of the barrel such that, when the sleeve 502 is moved into its second configuration, a first end 504a of the locking arm is urged towards the central axis A. A second end 504b of the locking arm 504 is connected to the sleeve 502 by a pivot or hinge (not shown). By arranging the locking arm 504 in such a spring-loaded way, the locking arm forms a latch which prevents the sleeve 502 from being moved back along the length of the barrel 106 towards its position in the first configuration. Thus, when the locking arm 504 is in its outwardly-extended position as shown in Figure SB, the user is prevented from inadvertently moving the shield 502 back onto the barrel 106, which could inadvertently reveal the needle 104 upon which the user could sustain anNSI.

Whilc, in this embodiment, the means for prcvcnting thc retum of the shield 502 from its sccond configuration to its first configuration takes the form of a locking arm 504, those skilled in the art will appreciate that other suitable means could be used.

Specifically, any latch which is caused to move into the path of the shield when the shield is in its second configuration, and which prevents the shield from being moved back into its first configuration, could suitably replace the locking arm 504. For example, in an alternative embodiment, a spring-loaded latch or protrusion (not shown) which provides the same function as the locking arm 504, may be connected to the barrel 106 of the syringe 102, such that, when the shield 502 is moved beyond the latch or protrusion, the latch or protrusion is extended outwardly, preventing the shield from being moved back into its first configuration.

A fourth embodiment of the invention is shown in Figures 6A, 6B and 6C. In this embodiment, a fluid transfer apparatus 600 includes the syringe 102 and the needle 104 connectable to the syringe in an off-centre position. In this embodiment, the apparatus 600 includes a shield 602 formed of an attachment portion, or retaining ring 604, and a flexible member 606. The retaining ring 604, located at a first end 602a of the shield 602, is formed of ridged plastics material, and includes a recess 608 on an inner surface of the retaining ring. When the shield 602 is in its first configuration, the recess 608 of the retaining ring 604 engages the ridge 304 formed around the barrel 106. As with the embodiments shown in Figures 3 to 5, the engagement of the ridge 304 with the recess 608 serves to attach the shield to the barrel 106 and to retain the retaining ring 604 and shield in its first configuration shown in Figure 6A.

An outer surface of the retaining ring 604 is formed with a number of barbs 610 for engaging with, and forming an interference fit with, the flexible portion 606 of the shield 602.

The flexible portion 606 of the shield 602 is wedged onto the barbs 610 of the retaining ring 604 such that the barbs engage the flexible portion of the shield.

Towards a second end 602b of the shield 602, the shield flexes around the ridge 306 of the barrel 106. Thus, when the shield 602 is in its first configuration, as shown in Figure 6A, the an inner surface of the shield engages with the ridge 306 of the barrel 106 so as to retain the shield 602 in the first configuration. A user of the apparatus 600 is able to slide the shield 602 along substantially the length of the barrel 106 in a manner similar to that described above with reference to Figures 3 to 5. Figure 6B shows the apparatus 600 with the shield 602 in its second configuration. That is to say, in Figure 6B, the shield 602 is shown extended beyond the second end I 06b of the barrel 106, thereby shielding the needle 104.

In this embodiment, the flexible portion 606 of the shield 602 is formed from a material that is more flexible than the material from which the retaining ring 604 is formed. The flexible portion 606 may, for example, be formed from plastics material.

The flexibility of the flexible portion 606 of the shield enables it to be bent or flexed away from the axis A, while the relative rigidity of the retaining ring 604 serves to retain the shield 602 in the second configuration, attached to the syringe 102. In Figure 6C, the flexible portion 606 of the shield 602 is shown flexed downwards relative to the syringe 102. In this position, the shield 602, while still generally shielding the needle 104, allows access to the needle through the second end 602b of the shield, so that fluid such as blood can be transferred to and/or from the syringe 102, but the risk of the user sustaining an NSI is reduced.

In use, the user of the fluid transfer apparatus 600 (shown in Figures 6) uses the apparatus with the shield 602 in its first configuration to draw fluid from a patient or from another fluid source, such as a container. Once the fluid is within the barrel 106, the user slides the shield 602 from its first configuration to its second configuration in which the shield substantially surrounds the needle 104. With the shield 602 in the second configuration, the user is at less risk of sustaining an NSI from the needle 104.

In order to transfer fluid from the barrel 106 to a container, such as a blood bottle, the user flexes the flexible portion 606 of the shield 602 so that the needle 104 becomes more accessible through the opening at the end 602b of the shield 602. The user is then able to insert a container into the opening at the end 602b of the shield 602 to engage with the needle 104 in order to transfer fluid from the syringe 102 into the container.

Figures 7A and 7B show an embodiment in which a fluid transfer apparatus 700 has a shield 702 which is similar to the shield 602 dcscribcd above with reference to Figures 6A, 6B aild 6C. In this embodiment, the shield 702 includes a rctaining ring 704 and a flexible portion 706. The retaining ring 704 illcludes a locking member 708 which takes the form of a spring-loaded latch. When the shield 702 is in its first configuration, as shown in Figurc 7A, the locking member 708 is in a closcd, compressed position, between the shield and the barrel 106. However, when the shield 702 is moved into its second configuration, as shown in Figure 7B, an end of the locking member 708 springs away from the shield, forming a latch preventing movement of the shield back into its first configuration. The locking member 708 ifinctions in a similar way to the locking arm 504 described above with reference to Figures 5A and SB.

In this embodiment, the means for preventing the return of the shield 702 from its second configuration to its first configuration takes the form of a locking member 708. However, those skilled in the art will appreciate that other suitable means could bc uscd. Specifically, any latch which is caused to move into thc path of the shicld when the shield is in its second configuration, and which prevents the shield from being moved back into its first configuration, could suitably replacc thc locking member 708. For exampic, in an altcrnative embodiment, a spring-loadcd latch or protrusion (not shown) which provides the same firnetion as the locking member 708, may be coimected to the barrel 106 of the syringe 102, such that, when the shield 702 is moved beyond the latch or protrusion, the latch or protrusion is extended outwardly, preventing the shield from being moved back into its first configuration.

In thc cmbodimcnts describcd above, the shields 302, 402, 502, 602, 702 have been clcscribcd as being movable along the barrel 106 of the syringe 102 by sliding the S shield along the barrel in the direction of the axis A. An alternative means of moving the shield 302, 402, 502, 602, 702 from its first configuration, substantially surrounding the barrel 106, to its second configuration, extending beyond the needle 104, is shown in Figures SA, SB, 9A and 9B.

In Figures 8A and SB, a spiral or helical guide rail 804 is formed around an outer surface of the barrel 106 of the syringe 102, extending along the length of the barrel.

The guide rail 804 may take the form of a protrusion or ridge formed integrally with the barrel 106, or of a separate member, for example of rubber or plastics material, attached and adhcrcd to the barrel.

A shicld 802, shown in Figure 8B, is similar to the shield 602 shown in Figures 6A, 6B and 6C in that it is formed of a retaining ring 806 and a flexible portion 808, connectable to the retaining ring 806 by one or more barbs 810 formed around an outer surface of the retaining ring 806. In this embodiment, howcvcr, a spiral or helical recess 812 which is complementary to the guide rail 804 is formed on an inner surface of the retaining ring 806 of the shield 802. The helical recess 812 is arranged to engage with the guide rail 804 such that the retaining ring 806 can screw onto the barrel 106. Thus, a user is able to move the shield 802 from a first configuration, where the shield substantially surrounds the barrel 106 into a second configuration, where the shield extends beyond the second end 1 06b of the barrel, substantially shielding the needle 104, by twisting the shield relative to the syringe 102.

Figures 9A and 9B show an embodiment similar to the embodiment shown in Figures SA and SB. However, in the embodiment shown in Figures 9A and 9B, a helical or spiral recess 904 is formed in an outer surface of the barrel 106 of the syringe 102, and a complementary protrusion 912 is formed on an inner surface of a retaining ring 906 of a shield 902. The shield 902 can be moved along substantially the length of the barrel 106 by screwing the retaining ring 906 onto the barrel engaging the helical recess 904 with the complementary protrusion 912.

An alternative embodiment (not shown in the drawings), the spiral recess 904 formed in the barrel 106 does not extend to the second end I 06b of the barrel, but ends a short distance from the second end. In this arrangement, the retaining ring 906 and shield 902 are prevented from moving beyond the second end 106b of the barrel 106, thereby reducing the chance of the shield being removed from the syringe 102.

While the embodiments shown in Figures 8A, 8B, 9A and 9B are described with a shield having a retaining ring and a flexible portion, both embodiments could alternatively have shields similar to those shown in Figures 3A, 3B, 4A and 4B, with a second end having a cross section that differs in shape from a first end, and the shape of which allows access to the needle 104 for transferring fluid to and from the syringe 102.

Thc fluid transfer apparatus 300, 400, 500, 600, 700 described above may form part of a fluid sampling kit including a syringe, a needle, a shield, and a fluid transfer container such as a blood bottle.

So far, the invention has been described in terms of individual embodiments.

However, those skilled in the art will appreciate that various embodiments of the invention, or features from one or more embodiments, may be combined as required.

For example, the shield or syringe of any of the embodiments may be provided with means, for example the locking arm 504, for preventing movement of the shield back into its first configuration. It will be appreciated that various modifications may be made to these embodiments without departing from the scope of the invention, which is defined by the appended claims.

Claims

CLAIMS1. A syringe comprising: a barrel defining a central longitudinal axis; a needle mount formed at a first end of the barrel, eccentrically relative to the longitudinal axis, for mounting a needle on thc syringe; and a shicld moveablc bctwccn a fir st configuration, in which the shield substantially surrounds the barrel, and a second configuration, in which the shield extends beyond said first end of the barrel.
2. A syringe according to claim 1, wherein, when a needle is mounted on the syringe, the shield, in the second configuration, is configured to permit said needle to engage a fluid transfer container through an end of the shield.
3. A syringe according to claim I or claim 2, wherein the shield has a first end having a generally circular cross section of a first diameter and a second end having a generally circular cross section of a second diameter, the second diameter being larger than the first diameter.
4. A syringe according to any of claims I to 3, wherein the shield is frusto-conical in shape.
5. A syringe according to claim 1 or claim 2, wherein the shield has a first end and a second end, the first end having a substantially circular cross section, and the second end having a non-circular cross section.
6. A syringe according to claim 5, wherein the cross sectional shape of the second end is selected from a group comprising: elliptical, oval and oviform.
7. A syringe according to claim 1 or claim 2, wherein the shield has a first end and a second end, and wherein the second end of the shield is displaceable laterally with respect to the longitudinal axis of the barrel.
8. A syringe according to claim 1 or claim 2, wherein the shield comprises a flexible portion.
9. A syringe according to claim 8, further comprising an attachment portion for attaching to the barrd, the attachment portion being rdativc!y more rigid than the flexible portion.
10. A syringe according to any of the preceding claims, further comprising a protrusion formed either: i) on an outer surface of the bane! for engaging with a comp!ementary recess formed on an inner surface of the shi&d; or ii) on an inner surface of the shield for engaging with a complementary recess formed on an outer surface of the barrel.
11. A syringe according to claim 10, wherein the protrusion is a ridge formed around a circumference of the barrel.
12. A syringe according to any of the preceding c!aims, wherein the shield is rotatable about the barrel of the syringe.
13. A syringe according to any of the preceding claims, further comprising a retaining member extending either from an inner surface of the shield or from an outer surface of the barrel, for retaining the shield in said second configuration.
14. A syringe according to claim 13, wherein the retaining member comprises an arm connected to, or formed integrally with, an inner surface of the shield at first end, and biased inwardly from the shield such that, when the shield is moved into said second configuration, a second end of the arm springs away from the shield, thereby preventing movement of the shield back into said first configuration.
15. A syringe according to any of claims 1, 2 or 7 to 14, further comprising a helical track formed on an outer surface of the barrel, arranged to engage a complementary hc!ical track formed on an inner surface of the shield.
16. A syringe according to daim 15, wherein either: i) the helical track formed on the bare! comprises a helical protrusion and the helical track formed on the shield comprises a complementary he] ical recess; or ii) the helical track formed on the barrel comprises a helical recess and the helical track formed on the shield comprises a complementary helical protrusion.
17. A syringe according to c!aim 15 or claim 16, wherein the he!ica! track formed on the barrel extends on!y partially a!ong the!ength of the barrel so as to restrict movement of the shield beyond the first end of the barrel.
18. A syringe according to any of the preceding claims, wherein the barrel is substantially cylindrical.
19. A fluid sampling apparatus comprising: a syringe according to any of the preceding c!aims; and a needle attached to the needle mount; wherein the shield, in the second configuration, permits access to the needle through an end of the shield.
20. A fluid samp!ing apparatus according to claim 19, wherein the apparatus comprises a hypodermic needle for sampling blood.
21. A fluid samp!ing apparatus according to claim 19 or claim 20, wherein the shield, in the second configuration, permits access of a blood bottle to the needle through an end of the shield.
22. A fluid sampling apparatus according to claim 20, wherein the shield, in the second configuration, extends beyond the length of the needle.
23. A bodi!y fluid sampling kit comprising: a syringe according to any of claims Ito 18; a needle attachable to the syringe; and a fluid transfer container for engaging with the needle and for containing fluid transferrable to and/or from the syringe.
24. A method of transferring fluid from a syringe to a fluid transfer container, the syringe comprising a syringe according to any of claims I to 18 and a needle attached S to the syringe, the method comprising: moving the shield into said second configuration; engaging the needle with the fluid transfer container; and transferring the fluid from the syringe to the fluid transfer container.
25. A method according to claim 24, further comprising: prior to engaging the needle with the fluid transfer container, displacing an end of the shield laterally with respect to the longitudinal axis of the barrel.
26. A syringe substantially as hereinbefore described, with reference to, or as shown in, Figures 3 to 9.
27. A fluid sampling apparatus substantially as hereinbefore described, with reference to, or as shown in, Figures 3 to 9.
28. A body fluid sampling kit substantially as hereinbefore described, with reference to, or as shown in, Figures 3 to 9.
29. A shield substantially as hereinbefore described, with reference to, or as shown in, Figures 3 to 9.