Syringe device

Abstract

A syringe device 10 comprising a tubular barrel 4 having an open first end 4a and a narrower tip 4b at the other end, and a plunger 1 slidably disposed within the barrel, the plunger having a plunger tip 1c at its distal end having, or being configured to receive, thereon a hypodermic needle, the barrel comprising an integral backfill port 3 close to said open end and comprising an opening in the barrel, in or over which is disposed a sealing means, said sealing means being arranged and configured to fluidly couple another syringe to the inside of the barrel so as to allow fluid from the barrel of said another syringe to be transferred into said barrel, in use, and to automatically seal said opening when said another syringe is removed from said backfill port. The backfill port may be located between the maximum fill level of the barrel and the open end thereof.

Description

Field of the Invention This invention relates generally to a syringe device for the hypodermic application of medicaments and, more particularly, but not necessarily exclusively, to a hypodermic syringe for introducing dermal fillers (and other substances) just beneath a patient’s skin for cosmetic enhancement and / or tissue reconstruction purposes. Background of the Invention In the field of cosmetic enhancement, it is well known to inject dermal filler products under the skin of a patient to, for example, enhance facial features and plump and fill lines, grooves and sunken areas. The location of the injections depends on the particular application, and the dermal filler material must usually be injected in very small amounts, very precisely, in multiple locations in order to achieve the desired result. Accordingly, a small syringe, with a very fine needle, is typically used. Dermal filler products are usually gel-like substances, often made up, primarily, of hyaluronic acid, and are often supplied in a predetermined quantity in a sealed, sterile syringe, ready for application. However, there are often circumstances in which it may be beneficial to add small quantities of other substances to the dermal filler material in order to enhance results and / or patient comfort. For example, an anaesthetic substance may substantially improve patient comfort, and additives such as vitamins or antioxidants can provide other clinical benefits. In certain cases, the filler and the additive cannot be mixed until a few minutes prior to the injection, for example, in cases where mixing of the two fluid will cause instability or degradation of one or the other. Therefore, the mixture cannot be supplied in pre-filled syringes and, in order to add certain additives to the dermal filler material, the dermal filler material has to be decanted from the pre-filled sterile syringe into another syringe, and the additive can then be added to the material in the syringe immediately prior to injection. In other cases, it may be required to use a smaller syringe and needle than that supplied by the manufacturer of the pre-filled dermal filler syringes; for example, where very small quantities of filler material are required to be injected at each location on the patient’s body, with a relatively low injection force, and where very fine precision is required. In both of these circumstances, the dermal filler material has to be decanted from the pre-filled, sterile syringe in which it is supplied, into another syringe where an additive can also be added immediately prior to treatment. Currently, this would require the dermal filler to be decanted, and (optionally) an additive to be introduced, into another syringe via the open end of the barrel (with the plunger removed). As a result, the sterility of the contents cannot be maintained, which means that bacteria from the surroundings could be introduced into the patient’s dermal layer and cause infection. This is clearly undesirable, and it is an object of aspects of the present invention to address at least one or more of these issues. Statements of Invention According to an aspect of the invention, there is provided a syringe device comprising a tubular barrel having an open first end and a narrower tip at the other end, and a plunger slidably disposed within the barrel, the plunger having a plunger tip at its distal end having, or being configured to receive, thereon a hypodermic needle, the barrel comprising an integral backfill port close to said open end and comprising an opening in the barrel, in or over which is disposed a sealing means, said sealing means being arranged and configured to fluidly couple another syringe to the inside of the barrel so as to allow fluid from the barrel of said another syringe to be transferred into said barrel, in use, and to automatically seal said opening when said another syringe is removed from said backfill port. The term “close to said open end” is intended to mean at any point over about halfway between the end of the barrel having the tip and its open end, but in a preferred embodiment, the backfill port is located at least % of the way up the length of the barrel (nearest the open end thereof), and, beneficially (but necessarily), immediately adjacent the distal end of the plunger tip when the plunger is fully retracted within the barrel. This allows the maximum proportion of the barrel volume to be used for dermal filler and, optionally, additive materials. Unit markers may, beneficially, be provided on the side wall of the barrel, at intervals along its length, to indicate, in use, a volume of material contained in the barrel, the unit markers ascending in value from a location near the tip of the barrel to a location near the open end of the barrel, wherein the backfill port is located in a gap between the distal end of the plunger tip when the plunger is fully retracted within the barrel and the highest value unit marker. In an embodiment a maximum fill level and the backfill port is located on the barrel between said maximum fill level and said open end thereof. The plunger is slidable within the barrel between a fully retracted position, wherein a proximal end of the plunger tip is substantially adjacent to the open end of the barrel, and a fully inserted position, wherein a distal end of the plunger is substantially adjacent to the tip of the barrel, and wherein said backfill port is optionally located on the barrel between said maximum fill level and the location of the distal end of the plunger tip when the plunger is in the fully retracted position. As stated above, the syringe device may comprise at least one unit marker on a side wall of the barrel, to indicate said maximum fill level. More preferably, the syringe device may comprise a plurality of unit markers on the side wall of the barrel to, in use, indicate the volume of a liquid or gel contained in said barrel, the unit markers extending at intervals, and ascending in value, from a location substantially adjacent to the tip of the barrel and said maximum fill level. The needle may be permanently affixed to the tip of said barrel. In an embodiment, the syringe device may further comprise a removable needle cap for covering the needle when it is not in use. For example, the needle cap may comprise a generally tubular sleeve which is closed at its distal end and open at its proximal end so as to, in use, receive the needle longitudinally therein. In an embodiment, the closed end of said needle cap may be laterally planar so that the syringe device can be stood up on its end, if required. In an embodiment, the backfill port may comprise a generally tubular collar that extends around the edge of said opening, the collar extending from an external side all of the barrel at an angle to the longitudinal axis thereof. The collar may extend at substantially 90 degrees to the longitudinal axis of the barrel. In another example, the collar may extend at an acute angle relative to the longitudinal axis of the portion of the barrel between the backfill port and the open end of the barrel. In an embodiment, the sealing means may comprise a self-sealing, resiliently elastic bung disposed within said collar. In another embodiment, the sealing means may comprise a male luer lock port disposed on said collar. In this case, the syringe device may further comprise a removable luer cap disposed over said male luer lock port. In an embodiment, the syringe device may further comprise means for preventing the plunger from being completely removed from the barrel. For example, the syringe device may comprise a plunger cap for preventing the plunger from being completely removed from said barrel, the plunger cap comprising a generally tubular collar affixed to the barrel adjacent the open end thereof, said tubular collar having a longitudinal through-hole within which the stem of the plunger is slidably disposed, the through-hole being of a size and shape such that the stem of the plunger can slide therethrough but the plunger tip is prevented from passing therethrough. In this case, the size and shape of the through-hole may be substantially the same as the lateral cross-sectional shape of the plunger stem. In an embodiment, the syringe device may further comprise a barrel flange that extends around the open end of the barrel, said barrel flange having an elongate oval shape, wherein its length is greater than its width so as to provide a pair of diametrically opposing finger flanges defining the respective sides of the barrel, when in use. Beneficially, the backfill port may be located on the front or rear of the barrel, between, and substantially orthogonal to, said finger flanges. Beneficially, the length of said barrel flange may be at least twice its width; and / or the barrel flange may be curved, with its concave surface facing the barrel. In an embodiment, a thumb loop may be integrally coupled to the proximal end of the plunger stem, for improved handling and manipulation of the syringe device, in use, which improves safety and control of the device. The syringe device could be provided in any required size. For example any size / volume between 0.2 and 1ml. These and other aspects of the invention will be apparent from the following detailed description. Brief Description of the Drawings Embodiments of the invention will now be described, by way of examples only, and with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a syringe device according to an exemplary embodiment of the invention; Figure 1 is a schematic perspective view of the needle portion of the syringe device of Figure 1; Figure 2 is a schematic partial perspective view of a syringe device according to an exemplary embodiment of the invention; Figure 2A is a schematic partial side view of the syringe device of Figure 2; Figure 3B is a schematic perspective view of a syringe device according to an exemplary embodiment of the invention; Figure 3B is a schematic partial side cross-sectional view of the syringe device of Figure 3A; and Figure 4 is a schematic side view of a syringe device according to an exemplary embodiment of the present invention. Detailed Description Referring to Figure 1 of the drawings, an example syringe device 10 comprises an elongate, generally tubular barrel 4 having an open first end 4a and a narrower integral tubular tip 4b at the second, opposite, end, the distal end of the barrel tip 4b being open such that a fluid flow path is defined through the barrel 4, from the open first end 4a to the distal end of the barrel tip 4b. A needle 5 is permanently affixed, and fluidly coupled, to the distal end of the barrel tip 4b. The needle 5 beneficially features a short bevel, for enhanced safety and may, for example, comprise a 30g, 10mm needle, which would have a diameter of approximately 0.32mm, for optimum patient comfort. A removable cap 6 is provided over the needle 5 such that the needle 5 cannot pierce its packaging and cause inadvertent injury. The cap 6 is elongate and generally tubular, having a diameter sufficient to receive the needle 5 via a first open end. The opposite end of the cap 6 is closed and, beneficially, has a flat surface such that the syringe device 10 can stand up on its end. The internal diameter of the barrel 4 (between the open end 4a and the proximal end of the tip 4b) may be relatively narrow, say approximately 2mm, such that the injection force exerted during use is lower than that of many conventional (and larger) pre-filled dermal filler syringes, thereby, once again, improving patient comfort. Referring additionally to Figure 1A of the drawings, units 7, indicating fluid volume in the syringe device 10, are printed or etched along the length of the barrel 4 (ascending from the proximal end of the barrel tip 4b to a maximum, at a point near the open end 4a of the barrel 4). The syringe device 10 further comprises a plunger 1, consisting of an elongate stem 1a having a thumb rest 1 b at one end, and a plunger tip 1 c at the other end. The plunger tip 1c, which would normally be formed of rubber or the like, has a diameter substantially equal to the inner diameter of the barrel 4. The plunger 1 is slidably disposed within the barrel 4 (from its open end 4a) such that the plunger tip 1c engages with the inner side walls of the barrel 4 and creates a fluid tight seal. The plunger is permanently disposed within the barrel 4 (as will be described hereinafter), and can be slidably moved therethrough such that the distal end of the plunger tip 1 c can, in use, move from a fully retracted position, where the proximal end of the plunger tip 1c is substantially adjacent to the open end 4a of the barrel 4, to a fully inserted position, wherein the distal end of the plunger tip is adjacent the proximal end of the barrel tip 4b. In this example, a fixed plunger cap (not shown in Figure 1) may be provided over the open end 4a of the barrel 4. The cap defines a through-hole that has a similar diameter to the stem 1 a of the plunger (but smaller than that of the plunger tip 1 c). The plunger stem 1a extends through the plunger cap into the barrel 4 and the plunger cap thus acts to prevent the plunger tip 1 c from being pulled completely out of the barrel. Other methods of achieving this are possible, and one such alternative method is described hereinafter. There is a longitudinal gap 4c between the distal end of the plunger tip lewhen the plunger 1 is in the fully retracted position and the final (highest value) unit marker 7 on the side wall of the barrel 4. An integral backfilling port 3 is provided on the side wall of the barrel 4 within that gap 4c. The backfilling port 3 comprises a generally tubular housing 3a that extends from the side wall of the barrel 4, substantially orthogonally to the longitudinal axis thereof. The housing 3a is fluidly coupled, at its proximal end, to the inside of the barrel 4 and has an open distal end 3b. The diameter of the housing may be substantially similar to, or even less than, that of the barrel 4. In this example, the opening 3b at the distal end of the backfilling port housing 3a is sealed by a self-sealing rubber (or similar material) generally cylindrical bung 2, having a diameter substantially the same as the inner diameter of the backfilling port housing 3a such that it fits snugly and sealingly within the backfilling port housing 3a. A flange 8 is provided around open end 4a of the barrel 4. Conventional syringes tend to include a circular or oval shaped flange around the open end of the barrel. However, in the example syringe device 10, the flange 8 is of a much more elongated (longer) oval shape, to allow for greater fine control, in use. The width of the oval shaped flange 8 may be similar to, or slightly larger than, the outer diameter of the open end 4a of the barrel 4, whereas its length may be 2 or even 3 times its width. The flange 8 may be curved, with its concave surface facing the barrel In use, when the syringe device 10 is removed from the packaging, the needle cap 6 will be in place over the needle and the plunger 1 would typically be in the fully retracted position, with the proximal end of the plunger tip 4c adjacent the open end 4a of the barrel 4 (although, if not, the user can simply retract the plunger 1 to that position). The needle of another syringe (not shown) containing a fluid or gel to be transferred into the syringe device 10 is used to puncture the self sealing bung 2 and, thus, create a fluid flow path from the other syringe into the barrel 4 of the syringe device 10. A required quantity of the fluid or gel is transferred into the barrel 4 of the syringe device 10, and then the needle of the other syringe is withdrawn and the resiliently elastic nature of the bung 2 causes it to close back over the puncture hole and, thereby, seal the barrel 4. Another syringe, containing another substance can then be used, if required, to add, for example, an additive of the type described above, into the fluid / gel that has already been transferred into the barrel 4 of the syringe device 10. Once the desired substances in the desired quantities have been placed in the barrel 4, the syringe device 10 can be used in the normal manner to inject the substance / mixture at desired locations on a patient’s body (e.g. face or hands). Assuming that the fluids / gel placed into the barrel 4 have come from pre-filled and sealed (i.e. sterile) syringes, the contents of the barrel 4 will remain sterile throughout the transfer and injection processes. Referring now to Figure 2 of the drawings, in an alternative example syringe device 100, many of the features are the same as, or very similar to, those described in relation to Figure 1 above and, as such, the same reference numerals will be used hereinafter to refer to those similar features. Some of these features are omitted from Figure 2 (which is a partial view). In the example syringe device 100 of Figure 2, the self sealing rubber bung of the example syringe device described with reference to, and illustrated in Figure 1, is replaced by a male luer lock port 20. A luer lock is known in the art as a mechanism for enabling a hypodermic needle to be attached to the end of a syringe. In such arrangements, the male luer lock port is typically provided at the top of a short sleeve or collar provided at the proximal end of a hypodermic needle, whilst the female luer lock port is typically provided around the tip of the syringe barrel. The luer lock mechanism, in conventional syringe devices, allows a hypodermic needle to be removably affixed to the distal end of the barrel tip by screwing it on by rotating the needle clockwise, and can achieve a very tight fit bond between the needle and the syringe as the male and female luer lock ports engage with each other. In this example, the male luer lock port 20 is provided within the housing 3a of the integral backfilling port 3. A removable luer cap 23 is provided over the male luer lock port 20 to seal the barrel and maintain its sterility. In use, the luer cap 23 can be removed, and another syringe 24 (having a female luer lock port 26 around the distal end of the barrel tip) can be fluidly coupled to the barrel 4 of the syringe device 100 to allow the contents thereof to be transferred into the barrel 4 of the syringe device 100. Once the transfer has been completed, the other syringe can simply be unscrewed from the backfilling port 2 and the luer cap 22 replaced to, once again, seal the barrel 4. In the example illustrated in Figure 2 of the drawings, a plunger cap 12, for preventing the plunger 1 from being completely removed from the barrel 4, is illustrated schematically. The plunger cap 12 comprises a generally tubular sleeve 12a and a concentric cap portion 12b. A generally central channel or through-hole 12c extends from the cap portion 12b and through the sleeve 12a, and the plunger stem 1a extends through the through-hole 12c. The through-hole 12c is beneficially of substantially the same shape and size as the cross-sectional shape of the plunger stem 1a such that the plunger stem 1a can slide longitudinally through the through-hole 12c, in use, but there is no gap between the outer edges of the plunger stem 1 a and the inner edge of the through-hole 12c, thus ensuring that no bacteria can enter the barrel 4 therethrough. The plunger cap 12 is affixed, at the distal end of the sleeve 12a, to the barrel 4, over its open end 4a, and the size of the through-hole, 12c whilst large enough to allow the plunger stem 1 a to slide through it, is smaller than the dimeter of the plunger tip 1 c, such that, in use, the plunger 1 can be slidably moved through the barrel 4, between the fully retracted and fully inserted positions, but the plunger cannot be fully removed from the barrel 4 because it is prevented from doing so by the plunger tip 4c against the edge of the through hole 12c at the distal end of the tubular sleeve 12a. In the examples described above, the housing 2a of the backfilling port 2 extends substantially orthogonally from the barrel 4 of the syringe device 10, 100. However, and referring to Figure 2Aof the drawings, the housing 2a could, instead, extend at an acute angle relative to the longitudinal axis of the barrel 4 (the acute angel, in this example being relative to the portion of the barrel 4 nearest the open end 4a), and the present invention is not necessarily intended to be limited in this regard. Referring now to Figures 3A and 3B of the drawings, in yet another example syringe device 200, instead of the plunger cap described above for preventing the plunger 1 from being completely removed from the barrel 4, a plunger lock 202 may be provided for this purpose. The plunger lock 202 comprises a flange cap portion 202a, shaped and configured to fit (beneficially permanently affixed) over the flange 8 of the syringe device 200 and has a generally central through-hole of diameter sufficient to allow the plunger stem 1 a to slidably pass therethrough, but less than the diameter of the plunger tip 1c. A generally tubular, concentric collar portion 202b is provided integrally with the flange cap portion 202, and has a similar through-hole such that the collar sits around the plunger stem 1a. In an alternative embodiment, the flange 8 could be replaced entirely with a plunger lock 202 of the type described above, with the cap portion 202a thereof permanently affixed over the open end 4a of the barrel 4. Referring to Figure 4 of the drawings, an alternative example syringe device comprises most of the same features as that described and illustrated with reference to Figures 3A and 3B. However, in this embodiment, the thumb rest 1b is replaced by a thumb loop 300 for improved handling and manipulation of the syringe device during use. In the example shown, the thumb loop 300 comprises a base 301 that has parallel opposing end edges 301a and side edges 301b (only one can be seen in Figure 4) curve or bow outwardly, such that the width of the base at its centre is greater than the width of the end edges 301a. The base 301 is curved about the lateral axis, such that the base 301 is concave when viewed from the ‘top’ of the syringe plunger, towards its tip. A generally C-shaped handle portion 52b is integrally coupled, via curved coupling segments 303 at the end edges 301a, to the base 301 so as to form a loop therewith. The width of each coupling segment 303 tapers from the respective end edge 301a of the base 301 (i.e. so that it is narrower at the distal end), and the width of the handle portion 302 being substantially equal to the width of distal end of the coupling segments 303. It will be appreciated by a person skilled in the art, from the foregoing description, that modifications and variations can be made to the described embodiment, without departing from the scope of the invention as defined by the appended claims.

Claims

1. A syringe device comprising a tubular barrel having an open first end and a narrower tip at the other end, and a plunger slidably disposed within the barrel, the plunger having a plunger tip at its distal end having, or being configured to receive, thereon a hypodermic needle, the barrel comprising an integral backfill port close to said open end and comprising an opening in the barrel, in or over which is disposed a sealing means, said sealing means being arranged and configured to fluidly couple another syringe to the inside of the barrel so as to allow fluid from the barrel of said another syringe to be transferred into said barrel, in use, and to automatically seal said opening when said another syringe is removed from said backfill port.

2. A syringe device according to claim 1, wherein said barrel has a maximum fill level and the backfill port is located on the barrel between said maximum fill level and said open end thereof.

3. A syringe according to claim 2, wherein said plunger is slidable within the barrel between a fully retracted position, wherein a proximal end of the plunger tip is substantially adjacent to the open end of the barrel, and a fully inserted position, wherein a distal end of the plunger is substantially adjacent to the tip of the barrel, and wherein said backfill port is located on the barrel between said maximum fill level and the location of the distal end of the plunger tip when the plunger is in the fully retracted position.

4. A syringe device according to claim 2 or claim 3, comprising at least one unit marker on a side wall of the barrel, to indicate said maximum fill level.

5. A syringe device according to claim 4, comprising a plurality of unit markers on the side wall of the barrel to, in use, indicate the volume of a liquid or gel contained in said barrel, the unit markers extending at intervals, and ascending in value, from a location substantially adjacent to the tip of the barrel and said maximum fill level.

6. A syringe device according to any of the preceding claims, wherein the needle is permanently affixed to the tip of said barrel.

7. A syringe device according to any of the preceding claims, further comprising a removable needle cap for covering the needle when it is not in use.

8. A syringe device according to claim 7, wherein said needle cap comprises a generally tubular sleeve which is closed at its distal end and open at its proximal end so as to, in use, receive the needle longitudinally therein.

9. A syringe device according to claim 8, wherein said closed end of said needle cap is laterally planar.

10. A syringe device according to any of the preceding claims, wherein said backfill port comprises a generally tubular collar that extends around the edge of said opening, the collar extending from an external side all of the barrel at an angle to the longitudinal axis thereof.11 .A syringe device according to claim 10, wherein said collar extends at substantially 90 degrees to the longitudinal axis of the barrel.

12. A syringe device according to claim 10, wherein said collar extends at an acute angle relative to the longitudinal axis of the portion of the barrel between the backfill port and the open end of the barrel.

13. A syringe device according to any of claims 10 to 12, wherein said sealing means comprises a self-sealing, resiliently elastic bung disposed within said collar.

14. A syringe device according to any of claims 10 to 12, wherein said sealing means comprises a male luer lock port disposed on said collar.

15. A syringe device according to claim 14, further comprising a removable luer cap disposed over said male luer lock port.

16. A syringe device according to any of the preceding claims, further comprising means for preventing the plunger from being completely removed from the barrel.

17. A syringe according to claim 16, comprising a plunger cap for preventing the plunger from being completely removed from said barrel, the plunger cap comprising a generally tubular collar affixed to the barrel adjacent the open end thereof, said tubular collar having a longitudinal through-hole within which the stem of the plunger is slidably disposed, the through-hole being of a size andshape such that the stem of the plunger can slide therethrough but the plunger tip is prevented from passing therethrough.

18. A syringe device according to claim 17, wherein the size and shape of the through-hole is substantially the same as the lateral cross-sectional shape of the 5          plunger stem.

19. A syringe device according to any of the preceding claims, further comprising a barrel flange that extends around the open end of the barrel, said barrel flange having an elongate oval shape, wherein its length is greater than its width so as to provide a pair of diametrically opposing finger flanges defining the respective io          sides of the barrel, when in use.

20. A syringe device according to claim 19, wherein said backfill port is located on the front or rear of the barrel, between, and generally orthogonal to, said finger flanges.21 .A syringe device according to claim 19 or claim 20, wherein the length of said 15           barrel flange is at least twice its width.

22. A syringe device according to any of claims 19 to 21, wherein said barrel flange is curved, with its concave surface facing the barrel.

23. A syringe device according to any of the preceding claims, wherein a thumb loop is integrally coupled to the proximal end of the plunger stem.

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