Abstract
The invention discloses a sterile syringe (100) comprising a barrel (1) having internal surfaces (2), a plunger (3) movable within the barrel, a non-sliding seal (7) between the barrel and the plunger defining a sealed volume (8) and at least one filter (9) allowing only filtered gases to enter the sealed volume such that the syringe maintains its sterility even after several uses. The filters could be positioned on different locations on the syringe like on the non-sliding seal, the barrel, the barrel flange or the plunger handle.
Claims
1. A syringe comprising: a barrel having internal surfaces; a plunger movable within the barrel; a non-sliding seal external to the barrel and extending between the barrel and the plunger defining a sealed volume; and at least one filter allowing only filtered gases to enter the sealed volume.
2. The syringe of claim 1, wherein the plunger and the barrel have a sliding seal therebetween.
3. The syringe of claim 1, wherein the non-sliding seal is attached to the barrel, the plunger or both.
4. The syringe of claim 1, wherein the non-sliding seal is in the form of bellows.
5. The syringe of claim 4, wherein the non-sliding seal is telescopic.
6. The syringe of claim 1, wherein the non-sliding seal is made of impermeable material such as silicone or plastics.
7. The syringe of claim 1, wherein at least a portion of the filter is located on or in the non-sliding seal, or the non-sliding seal and filter are integrally formed as one component.
8. The syringe of claim 1, wherein the filter is located on, or is integral with the barrel or the plunger.
9. The syringe of claim 8, wherein the filter comprises a porous material that prevents particulate material and pathogens from entering the sealed volume but permits the passage of gases including sterilizing gases into or out of said volume.
10. The syringe of claim 9, wherein the filter is made of plastics material heat sealable to the non-sliding seal.
11. A method of sterilizing a syringe, the syringe comprising a barrel having internal surfaces; a plunger movable within the barrel; a non-sliding seal external to the barrel and extending between the barrel and the plunger defining a sealed volume; and a filter allowing only filtered gases to enter the sealed volume; wherein the method comprises exposing the internal surfaces to ethylene oxide gas wherein the said gas entering the sealed volume via the filter.
12. A method of maintaining sterility in a syringe wherein the syringe comprises: a barrel having internal surfaces; a plunger movable within the barrel; a non-sliding seal external to the barrel and extending between the barrel and the plunger defining a sealed volume; and a filter allowing only filtered gases to enter the sealed volume; wherein the method comprises operating the syringe multiple times and maintaining sterility by avoiding the exposure of the internal surfaces other than to syringed liquids and the said filtered gases.
13. The syringe of claim 1, wherein the plunger extends between a proximal plunger end and a distal plunger end, wherein the barrel extends between a proximal barrel end and a distal barrel end, and wherein the non-sliding seal extends from the proximal barrel end toward a proximal plunger end.
14. The syringe of claim 13, wherein the proximal barrel end defines a handle, and wherein the non-sliding seal extends between the proximal barrel end and the handle.
15. The syringe of claim 1, wherein the at least one filter is external to the barrel.
Description
DRAWINGS
(1) The invention will now be described in more detail with reference to the appended drawings, wherein:
(2) FIG. 1A shows a first side view of an exemplary syringe 100 according to a first embodiment of the invention;
(3) FIG. 1B shows a second side view of the exemplary syringe 100 as illustrated in FIG. 1A;
(4) FIG. 2A shows a first side view of an exemplary syringe 200 according to a second embodiment of the invention;
(5) FIG. 2B shows a second side view of the exemplary syringe 200 as illustrated in FIG. 2A;
(6) FIG. 3A shows a first side view of an exemplary syringe 300 according to a third embodiment of the invention;
(7) FIG. 3B shows a second side view of the exemplary syringe 300 as illustrated in FIG. 3A;
(8) FIGS. 4A, 4B and 4C show side views of three further exemplary syringes 400-a, 400-b and 400-c, similar to the syringes shown in FIGS. 1A and 1B according to the first embodiment of the invention;
(9) FIGS. 5A and 5B show side views of two exemplary syringes 500-a and 500-b according to an alternate embodiment of the invention.
(10) FIG. 6 shows a side view of an exemplary syringe 600 according to another alternate embodiment of the invention.
DETAILED DESCRIPTION
(11) FIG. 1A shows a first side view of an exemplary syringe 100 according to a first embodiment of the invention. The syringe 100 comprises a barrel 1 and a plunger 3. The barrel 1 comprises internal surfaces 2 and a flange 11 extending outwards from the periphery of a proximal end of the barrel 1. The plunger 3 comprises a piston 4, a stem 5 and a handle 6. The piston 4 of the plunger 3 is connected to the internal surfaces 2 of the barrel 1 by a sliding seal 10. The piston 4 can be moved within the barrel 1 in a linear manner using the handle 6 of the plunger 3. When the handle 6 is pulled out, the piston 4 moves towards the proximal end of the barrel 1. When the handle 6 is pushed in, the piston 4 moves towards a distal end of the barrel 1. The syringe 100 also comprises a non-sliding seal 7 attached to the barrel 1 and the plunger 3, enclosing a sealed volume 8 within the syringe 100. As shown in FIG. 1A, the non-sliding seal 7 in the first embodiment of the invention, is in the form of bellows and is attached to the flange 11 of the barrel 1 and the handle 6 of the plunger 3, enclosing the sealed volume 8 within the syringe 100. The plunger 3 is always within the sealed volume 8 making the syringe 100 a closed system. Once the closed syringe 100 is sterilized using EtO for example before a first use, the sterility is maintained within it as there is no exposure to the atmosphere, this makes repeated use of the syringe 100 possible without compromising sterility. Thus, during the operation of the syringe 100, the syringed liquids are never exposed to non-sterile surfaces. The non-sliding seal 7 is made of flexible impermeable material for example, latex, silicone or flexible plastics. The syringe 100 further comprises one or more filters 9. In the exemplary syringe of FIG. 1A, the filters 9 are located on the bellows. The filter material allows gases such as Ethylene Oxide (EtO) to enter the otherwise sealed volume 8 for the purpose of sterilisation of that volume. The filter can be made of any material which allows the transfer of such sterilising gases, but inhibits the transfer of larger sized matter, as such macromolecules, bacteria, spores, viruses and the like. Suitable filter material is for example, nylon. Suitable filters include Tyvek® brand microbial bathers which are formed from continuous, randomly oriented, high-density polyethylene (HDPE) filaments. Suitable pore size of the filters is for example 0.2 μm. The filters 9 allow entry of sterile air in the sealed volume 8 to adjust the pressure in the syringe 100 when the plunger 3 is moved within the barrel 1, thus also maintaining sterility within the syringe 100. In the first view of the exemplary syringe as illustrated in FIG. 1A, the plunger 3 is pushed in such that the piston 4 is in a first position which is nearer to the distal end of the barrel 1. When the piston 4 is in the first position, the bellows 7 are in a folded configuration.
(12) FIG. 1B shows a second side view of the exemplary syringe 100 as illustrated in FIG. 1A. The plunger 3 is pulled out such that the piston 4 is in a second position which is nearer to the proximal end of the barrel 1. When the piston 4 is moved from the first position to the second position, the air behind the piston 4 is displaced and pushed into the folds of the bellows 7 thereby inflating the bellows 7. Thus, in the second position, the bellows 7 are in an inflated configuration. Due to change in the volume of the air within the syringe 100 due to movement of the plunger 3, some air may enter or escape through the filters 9 to maintain a suitable pressure inside the syringe 100.
(13) FIG. 2A shows a first side view of an exemplary syringe 200 according to a second embodiment of the invention. The syringe 200 comprises a barrel 201 and a plunger 203. The barrel 201 comprises internal surfaces 202 and a flange 211 extending outwards from the periphery of a proximal end of the barrel 201. The plunger 203 comprises a piston 204, a stem 205 and a handle 206. As illustrated in FIG. 2A, the stem 205 of the plunger 203 is exposed to the atmosphere and the contaminants contained therein. The piston 204 of the plunger 206 is connected to the internal surfaces 202 of the barrel 201 by a sliding seal 210. The piston 204 can be moved within the barrel 201 in a linear manner using the handle 206 of the plunger 203. When the handle 206 is pulled out, the piston 204 moves towards the proximal end of the barrel 201. When the handle 206 is pushed in, the piston 204 moves towards a distal end of the barrel 201. The syringe 200 also comprises a non-sliding seal 207 attached to the barrel 201 and the plunger 203 in a first configuration, enclosing a sealed volume 208 within the syringe 200. As shown in FIG. 2A, the non-sliding seal 207 in the second embodiment of the invention, is in the form of a flexible telescopic membrane and is attached to the flange 211 of the barrel 201 and the piston 204 of the plunger 203, enclosing the sealed volume 208 within the syringe 200. The non-sliding seal 207 seals off the internal surfaces 202 of the barrel 201 and prevents the transfer of any contaminants picked up by the stem 205 and the piston 204 during operation of the plunger 203 during which operation the plunger 203 is exposed to the atmosphere and the contaminants contained therein. Thus, once the syringe 200 is sterilized using EtO, for example before a first use, sterility is maintained within the syringe 200. When a sterile fluid is syringed using the syringe 200, the syringed fluid comes in contact with only the sterile surfaces of the syringe 200 and thus sterility of the syringed fluid is maintained. The non-sliding seal 207 is made of flexible impermeable material for example latex, silicone or flexible plastics. The syringe 200 further comprises one or more filters 209. The filters 209 allow entry of only sterile air in the sealed volume 208 to adjust the pressure in the syringe 200 when the plunger 203 is moved within the barrel 201, thus also maintaining sterility within the syringe 200. In the exemplary syringe of FIG. 2A, the filters 209 are located on the flange 211 of the barrel 201. In the first view of the exemplary syringe 200 as illustrated in FIG. 2A, the plunger 203 is pushed in such that the piston 204 is in a first position which is nearer to the distal end of the barrel 201. When the piston 204 is in the first position, the telescopic non-sliding seal 207 is in an extended configuration.
(14) FIG. 2B shows a second side view of the exemplary syringe 200 as illustrated in FIG. 2A. The plunger 203 is pulled out such that the piston 204 is in a second position which is nearer to the proximal end of the barrel 201. When the piston 204 is moved from the first position to the second position, the non-sliding telescopic seal 207 collapses onto itself and some of the air within the sealed volume 208 is expelled out of the syringe through the filters 209 to balance the pressure within the syringe 200. Thus, in the second position, the telescopic non-sliding seal 207 is in a collapsed configuration.
(15) FIG. 3A shows a first side view of an exemplary syringe 300 according to a third embodiment of the invention. The syringe 300 comprises a barrel 301 and a plunger 303. The barrel 301 comprises internal surfaces 302 and a flange 311 extending outwards from the periphery of a proximal end of the barrel 301. The plunger 303 comprises a piston 304, a stem 305 and a handle 306. As illustrated in FIG. 3A, the stem 305 of the plunger 303 is exposed to the atmosphere and the contaminants contained therein. The piston 304 of the plunger 306 is connected to the internal surfaces 302 of the barrel 301 by a sliding seal 310. The piston 304 can be moved within the barrel 301 in a linear manner using the handle 306 of the plunger 303. When the handle 306 is pulled out, the piston 304 moves towards the proximal end of the barrel 301. When the handle 306 is pushed in, the piston 304 moves towards a distal end of the barrel 301. The syringe 300 also comprises a non-sliding seal 307 attached to the barrel 301 and the plunger 303 in a second configuration, enclosing a sealed volume 308 within the syringe 300. As shown in FIG. 3A, the non-sliding seal 307 in the third embodiment of the invention, is in the form of a flexible telescopic sheet and is attached to the flange 311 of the barrel 301 and the stem 305 of the plunger 303, enclosing the sealed volume 308 within the syringe 300. The non-sliding seal 307 seals off the internal surfaces 302 of the barrel 301 and prevents the transfer of any contaminants picked up by the stem 305 during operation of the plunger 303 during which operation the plunger 303 is exposed to the atmosphere and the contaminants contained therein. Thus, once the syringe 300 is sterilized using EtO, for example before a first use, sterility is maintained within the syringe 300. When a sterile fluid is syringed using the syringe 300, the syringed fluid comes in contact with only the sterile surfaces of the syringe 300 and thus sterility of the syringed fluid is maintained. The non-sliding seal 307 is made of flexible impermeable material for example latex, silicone or flexible plastics. The syringe 300 further comprises one or more filters 309. The filters 309 allow entry of only sterile air in the sealed volume 308 to adjust the pressure in the syringe 300 when the plunger 303 is moved within the barrel 301, thus also maintaining sterility within the syringe 300. In the exemplary syringe of FIG. 3A, the filters 309 are located on the barrel 301. In the first view of the exemplary syringe 300 as illustrated in FIG. 3A, the plunger 303 is pushed in such that the piston 304 is in a first position which is nearer to the distal end of the barrel 301. When the piston 304 is in the first position, the telescopic non-sliding seal 307 is in an extended configuration.
(16) FIG. 3B shows a second side view of the exemplary syringe 300 as illustrated in FIG. 3A. The plunger 303 is pulled out such that the piston 304 is in a second position which is nearer to the proximal end of the barrel 301. When the piston 304 is moved from the first position to the second position, the non-sliding telescopic seal 307 collapses onto itself and some of the air within the sealed volume 308 is expelled out of the syringe through the filters 309 to balance the pressure within the syringe. Thus, in the second position, the telescopic non-sliding seal 307 is in a collapsed configuration.
(17) FIGS. 4A, 4B and 4C show side views of three further exemplary syringes 400-a, 400-b and 400-c, similar to the syringes shown in the first embodiment of the invention as described above in relation to FIGS. 1A and 1B. Each of the syringes 400-a, 400-b and 400-c comprise a barrel 401, a barrel flange 411, a plunger 403, a plunger handle 406, one or more filters 409 and a sealed volume 408. The syringes 400-a, 400-b and 400-c differ from each other in the positioning of their filters 409. Each of the filters 409 are positioned at different locations on the respective syringes such that the filters 409 are in fluid communication with the sealed volume 408 within the respective syringes and only allow sterile air or sterilizing gases such as EtO to pass through into the sealed volume 408. As illustrated in FIG. 4A, the filters 409 are located on the plunger handle 406 of the syringe 400-a. As illustrated in FIG. 4B, the filters 409 are located on the barrel flange 411 of the syringe 400-b. As illustrated in FIG. 4C, the filters 409 are located on the barrel 401 and on the barrel flange 411 of the syringe 400-c. The features not described are similar to those described in FIG. 1A and FIG. 1B above.
(18) FIGS. 5A and 5B show side views of two exemplary syringes 500-a and 500-b according to an alternate embodiment of the invention. Each of the syringes 500-a and 500-b comprise a barrel 501, a barrel flange 511, a plunger 503, a piston 504, a plunger stem 505, a plunger handle 506, a non-sliding seal 507 attached to the barrel 501 and the plunger 503, a sealed volume 508, one or more filters 509 and a sliding seal 510. In this alternate embodiment, the plunger stem 505 includes the piston 504, which provides an assembly that fits snugly within the barrel 501 and is slidably movable within the barrel 501 by using the plunger handle 506. The assembly provides the sliding seal 510 in the barrel 501. As illustrated in FIG. 5A, the filters 509 are located on the non-sliding seal 507 and on the barrel flange 511 of the syringe 500-a. As illustrated in FIG. 5B, the filters 509 are located on the plunger handle 506 of the syringe 500-b.
(19) FIG. 6 shows a side view of an exemplary syringe 600 according to another alternate embodiment of the invention. The syringe 600 comprises a barrel 601, a barrel flange 611, a plunger 603, a plunger handle 606, a non-sliding seal 607 attached to the barrel 601 and the plunger 603, and a sealed volume 608. The syringe 600 is similar to the syringes shown in the first embodiment of the invention as described above in relation to FIGS. 1A, 1B, 4A, 4B and 4C, but differ from them in that the non-sliding seal 607 is formed substantially wholly from a filtering material to allow only filtered or sterilising gases into the sealed volume 608. The filtering material could be for example the material sold under the brand name Tyvek® and can be heat sealed to the plunger 603 on one side and to the barrel 601 at the other side. The features not described are similar to those described in FIG. 1A and FIG. 1B above.
(20) The invention is not to be seen as limited by the embodiments described above, but can be varied within the scope of the appended claims as is readily apparent to the person skilled in the art. For example, in further alternate embodiments, the syringe could be of varying size and volumes. Similarly, the piston assembly could be of varying designs. The syringe could be operable manually or be part of an automatic or semi-automatic system like an auto sampler. The sliding seal could also vary in design and is not limited to bellows or telescopic membranes. The distal end of the syringe could be attached to a sterile tube or a needle through a luer connection or any other technique. The syringe could also be connected to other sterile devices or systems by using a sterile connection device (SCD).
