Patent Application
20240024586
The invention relates to a medical syringe, in particular with needle protection, with a hollow body forming the syringe housing and intended to receive a medical active ingredient.
Medical syringes are used in a wide variety of applications, particularly therapeutic ones. They usually comprise a piston that can be moved in the interior of a syringe body via an actuating plunger.
To avoid or reduce the risk of contamination or injury after the use of medical syringes, and in particular to avoid multiple use of syringe needles by different users, syringes with so-called retraction systems for the syringe needle are increasingly being used. In such syringes, in particular medical syringes, also referred to as “syringes with (passive) needle protection”, the syringe needle is retracted into the syringe body after delivery of the active ingredient held in the syringe and is completely enclosed by the latter. Access to the syringe and thus a risk of injury, or even the risk of multiple use of the same needle, can thus be largely avoided.
Such syringes with passive needle protection are known, for example, from EP 1 284 769 B1, EP 0 720 491 B1, EP 0 680 347 B1 or EP 1 764 127 B1.
The needle of a medical syringe is usually held in a needle holder which is suitably connected to the syringe housing, in particular screwed or clipped onto the syringe. In the case of medical syringes in general, and thus also syringes with needle protection of the type mentioned, there is a need to deliver the active ingredient contained therein as completely as possible during use of the syringe and to minimize as far as possible the retention of unused residual amounts of the active ingredient within the syringe.
It is now an object of the invention to specify a syringe with needle protection of the type mentioned above, in which this need is taken into account even with a subsequently attached needle holder.
This task is solved according to the invention in that the connecting element has an inner channel provided for connection to the needle holder, which has an inner cross-section that widens continuously towards the distal end.
Advantageous embodiments of the invention are the subject of the subclaims and/or the following figure description.
The invention is based on the consideration that, particularly in the case of multi-component systems in which the needle holder is initially manufactured as a separate component and is only subsequently mounted on the syringe barrel, leaks could occur in the area of the connection between the needle holder and the syringe barrel, resulting in leakage. In order to counteract this and to ensure a particularly high level of system tightness even with this design, and thus to prevent the unintentional release of active ingredient due to leaks, the connection area in particular should be designed for a particularly high level of tightness. In order to make this possible, the use of a conical internal connection is now envisaged for the active substance-side connection of the needle holder and syringe housing. The internal channel provided for this purpose in the connection area of the syringe housing has a widening cross-section in the form of a cone. This means that the corresponding component on the needle holder can be inserted into this cone so that the desired tightness of the connection can be ensured, particularly if the contact pressure is sufficient.
Advantageously, the inner channel is designed in the form of a cone widening towards the distal end with a cone angle of about 2°.
In advantageous further development or in an embodiment regarded as independently inventive, the medical syringe is equipped with an RFID chip, for example for the purpose of setting up digitalized logistics, an automatable transport system for syringes, for quality or product control and/or for other recording or monitoring purposes. This advantageously has individualized, machine-readable coding. Preferably the RFID chip is arranged on a grip plate formed on the proximal end of the hollow body forming the syringe housing.
In a further alternative or additionally advantageous embodiment or also in an embodiment considered to be independently inventive, the medical syringe comprises an actuating plunger, on the shaft of which a number of stop and latching elements are arranged, preferably designed as adjusting rings running around the shaft.
In a particularly preferred embodiment, the syringe barrel is manufactured as a plastic part, preferably from cyclo-olefin polymer (COP) or cyclo-olefin copolymer (COC), with or without a barrier layer. This material is characterized by high break resistance and glass-like transparency. It also does not release any alkali ions, so that the risk of a pH shift in the active ingredient held in reserve is excluded. Thus, according to the invention, this material is considered and used as suitable even for primary packaging of even demanding drugs, especially for sensitive biotechnologically produced active ingredients. In addition, this material is suitable for production by injection molding and thus for particularly precise dimensioning.
An embodiment of the invention is explained in more detail with reference to a drawing. Therein show:
Identical parts are provided with the same reference signs in all figures. The embodiments have a plurality of features or feature groups regarded as independently inventive. In accordance with the invention, these can each be provided individually and independently of one another or also in any combination with one another.
The medical syringe 1 with needle retraction, which is shown in its entirety in longitudinal section in
In view of the concept that the syringe should be able to be used well and reliably in modern therapies and the sensitive, high-priced and, under certain circumstances, toxic active ingredients that may be used, the syringe and, in particular, the hollow body 6 forming the syringe housing are designed to be particularly leakproof so that, especially when used as a prefilled syringe, a certain shelf life of the active ingredient stored therein can also be achieved. For this purpose, on the one hand, the material for the syringe housing or the hollow body 6 forming it is suitably selected in a manner considered to be independently inventive, so that even high demands on the reliable temporary storage of the active medical ingredient are taken into account with a particularly high level of safety in the handling of the components. The injection body 6, which is designed as a cylindrical hollow body, can be made of PP or cyclo-olefin copolymer (COC), with or without a barrier layer, but in the embodiment considered to be in line with the invention it is particularly preferably made of the high-performance plastic cyclo-olefin polymer (COP). This material is characterized by high break strength and glass-like transparency. It also does not release any alkali ions, so that the risk of a pH value shift in the active ingredient being held is excluded. The syringe barrel 6 is preferably manufactured by injection molding, whereby, among other things, it is shaped in such a way that possible dead volumes in the interior are kept particularly low.
On the other hand, the hollow body 6 is also suitably designed for the intended high tightness and thus protection against unintentional loss of material by the geometric design and shaping of its components. This is taken into account in the area of the distal end 8 in particular by the design of the geometry of the connecting element 10 and the component connection formed by this together with the needle holder 12, which is considered to be independently inventive.
The needle holder 12 can be attached to the hollow body 6 forming the syringe housing or to the syringe cone, or alternatively it can be screwed on by means of a thread, for example a Luer thread. Both variants are regarded as equivalent alternatives, whereby the relevant design of the connection is regarded as interchangeable and freely selectable with regard to other boundary conditions, for example the intended subsequent handling. Accordingly, in the embodiment according to
Both variants have in common the design, which is regarded as independently inventive, that the connecting element 10 has in each case an inner channel 24 which is provided for connection to the needle holder 12 and has an inner cross section which widens continuously outwards, i.e. towards the distal end 8. In the embodiment example, the inner channel 24 is designed in each case in the manner of a cone widening towards the free end with an at least approximately circular cross-section. The angle of the cone is suitably selected with regard to the intended sealing effect, which is explained in more detail below; with regard to the preferably selected material pairing of the hollow body 6 and the needle holder 12, the angle of the cone is preferably about 2°.
The needle holder 12 carrying the hollow needle 14 is shown in detail in longitudinal section in
The design of the hollow needle 14 and its fixation in the bearing sleeve 30 essentially correspond to the design of the system described in EP 3 738 629 A1. Analogously, the bearing sleeve 30 is also provided here with a fixing lip 38 running around. The hollow needle 14 comprises a needle tube 40 made of metal, which forms a needle point 42, 44 at each of its two ends. The material for the needle tube 40 is preferably selected with regard to common requirements for medical applications, with particular preference being given to a stainless material that can also be used for standard needles, in particular stainless steel. In its central length region, the needle tube 40 is sheathed and surrounded or injection-molded by a plastic sheath 46. The material for the plastic jacket 46 is preferably a polyamide (PA12), most preferably the one commercially available under the designation Vestamid Care ML 17. In a particularly preferred embodiment, the plastic coating 46 is sprayed onto the needle tube 40 after the latter has been subjected to a plasma pretreatment in the manner of a surface activation. In this way, particularly good adhesion of the plastic forming the plastic jacket 46 to the needle 40 can be achieved.
A retaining groove 48 is formed in the plastic jacket 46, which serves to temporarily fix the needle 14 in the bearing sleeve 30 of the needle holder 12. In this case, the fixing lip 38 of the bearing sleeve 30 engages in the holding groove 48 when the needle 14 is mounted and properly pushed into the bearing sleeve 30 and fixes it in the longitudinal direction. The dimensions of the retaining groove 48 and the fixing lip 38 are selected such that, taking into account the deformability of the material of the plastic sheath 46, the overmolded needle 14 can be pushed into the bearing sleeve 30 and clipped or engaged therein. Furthermore, the plastic sheath 46 is designed in its end region facing the needle tip 42 on the inside to form a latching edge 50 or a number of latching elements, for example latching hooks or the like.
The drive or actuating plunger 4 shown in
The medical syringe 1 is provided with a needle protection in the form of a retraction system by the components and parts mentioned. The purpose of this is that after the syringe 1 has been used, i.e. after the active ingredient contained in the hollow body 6 forming the syringe housing has been dispensed via the needle 14, the latter is drawn into the syringe housing in such a way that it is completely enclosed by the syringe housing. This is intended to keep unintended contact with the used needle 14, for example by auxiliary or nursing personnel, and thus the risk of injury and contamination particularly low or, if possible, completely excluded. For this purpose, the medical syringe 1 is provided with a retraction system essentially corresponding to the design of the system described in EP 3 738 629 A1.
For this purpose, the gripping yoke 54 is provided centrally with a needle bearing 62 which forms a receiving hole for the needle 14 and into which the needle point 42 on the inside can be inserted and latched by means of the latching edge 50 or other suitable latching means. In this case, the needle bearing 62 is provided on the inside with an associated circumferential latching lip, analogous to the bearing sleeve 30 described above, which engages in the holding groove formed by the latching edge 50 when the needle tip 42 is inserted into the needle bearing 62 and thus fixes the needle 14 in the longitudinal direction. The dimensions of the retaining groove and of the latching lip in the needle bearing 62 associated therewith are selected in such a way that, taking into account the malleability of the material of the plastic sheath 46 and/or any adhesive force due to the material pairing of the material of the plastic sheath 46 and the material of the needle bearing 62 surrounding it, the retaining or breakaway force of the needle 14 thus latched in the longitudinal direction is greater than the corresponding retaining or breakaway force of the fixing lip 38 in the bearing sleeve 30, so that during a retraction movement of the piston 18 into the interior of the hollow body 6,6′, the needle 14 is retracted into the interior of the hollow body 6, 6′. The gripping yoke 54 is designed as a plastic part and, in the design example, with regard to the required holding forces and the mechanical loads expected during specific use, but also with regard to approval-related requirements, consists of the polypropylene available under the designation “Bormed™” (HD810MO, ISO 10993 Information (Biocompatibility)) or, alternatively, of other polyolefins suitable for pharmaceutical use with corresponding suitability.
Also analogous to the system described in EP 3 738 629 A1, the design of the gripper bow 54 in combination with the piston 18 surrounding it creates a free space 64 inside the piston 18 which, in the final phase of dispensing the active ingredient, when the needle tip 42 has already penetrated the needle bearing 62 and is thus no longer readily accessible to the active ingredient, allows the active ingredient to flow into the needle tube 40 via the needle tip 42 in the manner of a bypass. In this case, the inflow can occur on both sides of the gripping yoke 54 into the free space 64. The stopper 18, which thus functions as a piston jacket, is advantageously made of conventional rubber, particularly preferably of the material available from Kreiburg under the designation TM4RST (MC/RS Series), taking into account approval-related requirements. The stopper 18 is shaped in such a way that, when the gripper 54 is inserted, it leaves free inflow channels for the active ingredient on both sides of the gripper 54, so that the bypass for the desired zero-volume discharge is formed in the sense of avoiding or minimizing the dead volume.
To prevent injuries or the like when handling the medical syringe 1, it is further provided with a removable protective cap 70 for the needle 14, which is removed before the syringe 1 is used. This protective cap 70 shown in
The medical syringe 1 in its entirety, i.e. with the actuating plunger 4, the hollow body 6, 6′ forming the syringe housing and the attached tamper-evident closure, prior to its first use is shown in perspective view in
The first step is to remove the protective cap 70 by breaking it off. Thereafter, the syringe 1 is ready for use, as shown in
In the embodiment shown, however, it is intended that the syringe 1 be made ready for use when empty and filled with the active ingredient by drawing it on. For this purpose, the operator first presses the actuating plunger 4 so that the stopper 18 moves inside the hollow body 6 towards its distal end 8. As soon as a predetermined end position is reached in which the stopper 18 is still sufficiently far away from the needle tip 42 so that the detent edge 50 cannot penetrate the needle bearing 62 in the gripper bow 54, this movement is stopped by a stop. The syringe 1 in this position is shown in longitudinal section in
The detent receptacle 80, the exact design of which according to the embodiment example is clearly visible in the perspective view of the handle plate 17 of the hollow body 6 according to
When the stopper 18 is pushed into the interior of the hollow body 6, this abutment of the proximal setting ring 58 against the upper side 86 of the latching hook 84 is palpable for the user or operator, so that he can stop the insertion movement in the position shown in
After the syringe 1 has been made ready for use in one of the aforementioned ways and is accordingly in the state shown in
The actuating plunger 4 is then pressed by the operator so that the plunger or stopper 18 moves inside the hollow body 6 towards its distal end 8, thereby feeding the medical agent to the needle 14 and dispensing it via the latter. Shortly before complete dispensing of the active ingredient, i.e. shortly before complete emptying of the interior of the hollow body 6, the stopper 18 reaches the needle tip 42 of the needle 14 projecting into the interior in the vicinity of the distal end 8 of the hollow body 6, so that the latter penetrates into the receiving hole provided for this purpose in the needle bearing 62 of the gripper bar 54 as it moves further. The system thus again assumes the position already shown in
Unlike before, however, complete dispensing of the active substance is now provided. For this purpose, the operator applies a slightly increased force to further advance the stopper 18 in the hollow body 6, whereby the latching hooks 84 yield outwardly on the basis of suitable shaping and contouring on their surface, so that the adjusting ring 58 overcomes the aforementioned stop. Subsequently, as shown in the longitudinal section in
In this context, the combination of the free space formed in the stopper 18 by the interaction with the design of the gripping bow 54, i.e. the said bypass, with the inner channel 24 in the needle holder 12, which widens outwardly in the manner of a cone, is considered to be independently inventive. Through this combination, even in the final phase during the administration of the active ingredient, a continuous, uniform delivery of the active ingredient can be made possible while minimizing any dead volume, so that even for the residual quantities of the active ingredient to be administered, a continuous injection and highly accurate dosing of the active ingredient can be ensured without having to change the feed force required for further movement of the actuating plunger 4.
After the active ingredient has been administered and in particular after the hollow body 6 has been completely emptied, the operator retracts the pusher plate 52 and with it the actuating plunger 4 as a whole. This also takes along the stopper 18 arranged at the end of the shaft 56 and pulls it within the hollow body 6 away from the distal end 8 towards the proximal end 16. In turn, it takes the needle 14, which is enclosed and fixed in the gripping bow 54, with it and pulls it into the hollow body 6, so that it is completely positioned inside the hollow body 6 in the final position. This position is shown in longitudinal section in
In the mode of operation described, it is particularly important that, due to the suitable dimensioning of the components and/or a possible adhesive force due to the material pairing of the material of the plastic sheath 46 and the material of the bearing sleeve 30 surrounding it, the holding or break-away force of the needle 14 engaged in this way in the longitudinal direction is on the one hand sufficiently large, so that the needle 14 can be inserted into the patient's skin in accordance with the procedure described above, but on the other hand is also sufficiently small so that the described retraction movement of the needle 14 towards the interior of the hollow body 6 can be carried out.
In a further embodiment considered to be independently inventive, the medical syringe 1, in particular for the purpose of setting up digitalized logistics, an automatable transport system for syringes, for quality or product control and/or for other recording or monitoring purposes, is equipped with an RFID chip 90, which can have, for example, an individualized, machine-readable coding. As can be seen from the representation of the syringe 1 in
Such equipment of a medical syringe 1′ with an RFID chip 90 in the area of its grip plate 17 is considered to be independently inventive. In accordance with this,
The medical syringe 1 described above is equipped with a retraction system as explained, in which the operator can completely retract the needle 14 into the hollow body 6 forming the syringe housing after complete delivery of the active ingredient. For this purpose, in this embodiment, after the aforementioned “connecting”, the actuating plunger 4 together with the stopper 18 arranged at the end and the needle bearing 62 enclosed by the latter, in which the needle 14 is fixed after the “connecting”, must be retracted manually or in the manner of an active action by the operator until the distal adjusting ring 60 is locked with the hollow body 6 in the manner described. This type of retraction system is therefore also referred to as “active retraction”.
In an alternative embodiment, a medical syringe 1″ may also be equipped with a “passive” retraction system suitable for “passive retraction”, as known in its basic mode of operation, for example, from EP 3 738 628 A1. The combination of such a passive retraction system with one or more of the features or groups of features described above, in particular with the design of the connection to the needle holder 12, with the equipment with RFID chip 90, with the equipment of the actuating plunger 4 with the adjusting rings 58, 60 as detent or stop elements and/or with the equipment with a protective cap 70 designed as a tamper-evident closure, is considered to be independently inventive.
The components provided for forming such a passive retraction system of the medical syringe 1″ are shown in
Analogous to the design known from EP 3 738 628 A1, the retraction mechanism 104 is constructed according to the operating principle that a compressed spring 106 under pre-tension is locked by means of a locking element 108. The locking element 108 is unlocked at a given time as a result of the advance of the actuating plunger 4 and releases the spring 106 so that it can relax and thereby pushes back the actuating plunger 4.
The design of the locking mechanism for the spring 106 is considered to be independently inventive. The locking mechanism is essentially based on the interaction of a number of control pins arranged on the inner surface of the outer housing 102, each with an associated guide slot 110 in the outer jacket of the locking element 108. As can be clearly seen in the side view of
Unlocking can then be effected by turning the control pin 112 laterally by suitable actuation and moving it out of the bulge 114. This brings it to lie over a downwardly open channel 116 of the guide link 110, so that it can now deflect downwardly relative to the locking element 108 and is no longer blocked in a form conclusive manner by the guide link 110. In this position, the locking element 108 can thus be displaced upwards relative to the outer housing 102, i.e. away from the hollow body 6″, without being blocked by the control pin 112 by the spring 106, whereby the spring 106 relaxes.
Thus, in response, i.e., to the release of the spring 106, the latter relaxes, thereby moving the pusher plate 52 of the actuating plunger 4 away from the syringe body formed by the hollow body 6″. This also entrains the needle bearing 62 connected to the shaft 56 of the actuating plunger 4, in which the needle 14 is already located at this stage, and pulls it within the hollow body 6″ away from the distal end 8 towards the proximal end 16. At the same time, it in turn takes the encased needle 14 with it and pulls it into the hollow body 6″ so that it is positioned completely inside the hollow body 6″ in the final state.
A significant and considered inventive aspect here is that the spring 106 provided for carrying out the retraction movement of the needle 14 into the hollow body 6″ is arranged above the grip plate 17′ in the region of the shaft 56 of the actuating plunger 4 and acts on the actuating plunger 4 via the plunger plate 52 thereof. In contrast to conventional retraction systems, in which the retraction spring is arranged in the region of the tip or the distal end of the syringe within the syringe body and acts directly on the needle or its bearing body, the design now provided according to the invention means that the needle 14 is moved during retraction together with the actuating plunger 4 and, in particular, its pusher plate 52, so that the user or operator can recognize the position and, above all, the change in position of the needle 14 on the basis of the position of the pusher plate 52 relative to the handle plate 17′. This recognition is possible visually, but above all also haptically.
In other words, the retraction movement generates a movement of the pusher plate 52 that can be felt by the user, for example with the thumb, similar to an actuation button of a ballpoint pen. Thus, the user can conclude from the movement of the pusher plate 52 that can be felt with the thumb, on the one hand, that the needle 14 has now been retracted and that there is therefore no longer any risk of injury or contamination in the region of the distal end 8 of the syringe 1″. On the other hand, however, it can also conclude from this that the active ingredient has now been completely administered without having to monitor this visually, for example. The syringe 1″ thus enables significantly simplified handling when administering the active ingredient.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20212250.3 | Dec 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/084454 | 12/6/2021 | WO |
