Dose setting assembly for a medical injection device

Abstract

A dose setting assembly for a medical injection device, the medical injection device comprising a barrel defining a reservoir adapted to contain a medical injection fluid, an open proximal end and a distal end comprising a hub portion, a flange provided at the proximal end of the barrel, and an elongated plunger rod having a plunger flange at a proximal end and a stopper at a distal end, the plunger rod being slidable in motion within the barrel, the dose setting assembly comprising a rear stop attachable to the flange of the barrel, a distal dose setting member fixed on the rear stop and configured to hold the plunger rod at a distal predetermined position, the distal dose setting member being laterally removable from the rear stop to allow the plunger rod to move towards the rear stop and abut against the rear stop, and a proximal dose setting member fixed on the distal dose setting member and holding the plunger rod at a second predetermined position, the proximal dose setting member being laterally removable from the distal dose setting member to allow the plunger rod to move towards the distal dose setting member and abut against the distal dose setting member.

Description

Technical Field

[0001] The present invention relates to a dosage setting component for a medical injection device such as a syringe, which is capable of dispensing a precise dose of medical injection fluid. Background Technology

[0002] As is known in the art, medical injection devices such as syringes are used to administer medical injection fluids in liquid form to a patient.

[0003] Syringes typically include a barrel adapted to hold a medical injection fluid. A plunger rod is inserted through the distal end of the barrel's opening. Through its engagement with an elastomeric or rubber stopper fitted impermeably inside the barrel, a user can apply manual force to the proximal end of the plunger to deliver the medical injection fluid through a fluid channel located at the distal end of the barrel. A barrel flange, typically in the form of a finger rest, is provided around the proximal end of the syringe barrel opening to facilitate user manipulation of the medical injection device, and a plunger flange is also provided near the proximal end of the plunger rod, on which the user can apply finger pressure. The medical injection fluid is then dispensed by moving the plunger forward through the barrel.

[0004] Accurately dispensing precise volumes of medical injection fluid is crucial in cases such as injecting drugs into the eye. For this type of medication, the usual practice is to inject 50 microliters to 1 milliliter.

[0005] For this purpose, the syringe is usually marked with graduations that indicate the volume of medical injection fluid dispensed by the plunger's stroke. The required dose is determined by the distance between two graduations.

[0006] The graduations are often closely spaced and can be difficult to read, making it difficult to dispense accurate doses of medical injection fluid.

[0007] Furthermore, the release force (static friction) required to initiate plunger movement is greater than the sliding force (dynamic friction) required once the plunger has begun to move. Therefore, users are prone to exceeding the desired dosage setting when precise movement is required.

[0008] If not prefilled very carefully, syringe prefilling can also lead to the loss of precious medical fluids.

[0009] Therefore, when users are not very careful, too little or too much medical injection fluid can be delivered to the patient. Summary of the Invention

[0010] In this context, it is desirable to improve the accuracy of medical injection fluids dispensed from medical injection devices such as syringes.

[0011] This problem and other related problems are addressed by a dose setting assembly for a medical injection device, the medical injection device comprising: a cylinder defining a reservoir suitable for containing a medical injection fluid; an open proximal end and a distal end including a hub portion; a flange disposed at the proximal end of the cylinder; and an elongated plunger rod having a plunger flange at the proximal end and a plug at the distal end, the plunger rod being slidable within the cylinder, the dose setting assembly comprising:

[0012] - A rear stop that can be attached to the flange of the cylinder.

[0013] - A distal dose setting member fixed to the rear stop, the distal dose setting member being configured to hold the plunger rod in a predetermined distal position, the distal dose setting member being laterally removable from the rear stop to allow the plunger rod to move toward and abut against the rear stop, and

[0014] - A proximal dose setting member fixed to the distal dose setting member, the proximal dose setting member holding the plunger rod in a second predetermined position, the proximal dose setting member being laterally removable from the distal dose setting member to allow the plunger rod to move toward the distal dose setting member and abut against the distal dose setting member.

[0015] Other embodiments of the present invention may include the following features, which may be employed individually or in combination:

[0016] - The proximal dose setting member includes a locking device configured to hold the plunger flange in a concealed, locked position.

[0017] - The proximal dose setting member includes a proximal wall and two lateral walls, each lateral wall having an inwardly oriented intermediate rib, the intermediate rib together with the proximal wall defining a plunger flange locking cavity.

[0018] - The proximal dose setting member includes two inwardly oriented distal ribs defining two grooves.

[0019] - The proximal dose setting member includes an orifice defined by the intermediate rib, the orifice being configured and sized to allow the plunger rod to pass through and prevent the plunger flange from passing through.

[0020] - The distal dose setting member includes two legs connected by a transverse portion, each leg having an external groove defined between a proximal flange and a distal flange.

[0021] - The outrigger and the lateral portion define an orifice, which is constructed and sized to allow the plunger rod to pass through and prevent the plunger flange from passing through.

[0022] -The distal dose setting component includes a pull-tab.

[0023] - The rear stop includes a transverse wall and two lateral walls, the lateral walls of the rear stop defining an orifice, the orifice being configured and sized to allow the plunger rod to pass through and prevent the plunger flange from passing through.

[0024] - Each side wall of the rear stop includes two inwardly projecting parallel flanges defining a distal recess.

[0025] - Each side wall of the rear stop includes two inwardly projecting parallel flanges defining a proximal recess.

[0026] Another aspect of the present invention relates to a method of operating a medical injection device, the method comprising the following steps:

[0027] - Provide a medical device having the above-mentioned dosage setting components;

[0028] -Remove the proximal dose setting component from the distal dose setting component;

[0029] - Move the plunger rod toward the distal dose setting component into the syringe barrel until the plunger rod abuts against the distal dose setting component;

[0030] -Remove the distal dose setting component from the rear stop;

[0031] -Move the plunger rod toward the rear stop into the syringe barrel until the plunger rod abuts against the rear stop.

[0032] The public information described in this article is also limited by the following characteristics:

[0033] A dose setting assembly for a medical injection device includes: a cylinder defining a reservoir adapted to contain a medical injection fluid; an open proximal end and a distal end including a hub portion; a flange disposed at the proximal end of the cylinder; and an elongated plunger rod having a plunger flange at the proximal end and a plug at the distal end, the plunger rod being slidable within the cylinder. The dose setting assembly includes:

[0034] - A rear stop that can be attached to the flange of the cylinder; and

[0035] - A dose setting member removably fixed to the rear stop, the dose setting member being configured to hold the plunger rod in a predetermined position, the dose setting member being laterally removable from the rear stop to allow the plunger rod to move toward and abut against the rear stop.

[0036] This invention provides an add-on that can be readily applied to conventional medical injection devices such as plastic or glass syringes. The invention makes it possible to hold the syringe plunger rod in a predetermined position via a dose-setting member. After the dose-setting member is removed, the plunger advances freely distally. The distal movement of the plunger is restricted by a plunger flange abutting against a rear stop. Therefore, the plunger stroke is fully controlled, and the volume of medical injection fluid dispensed is independent of the scale on the user-read cartridge.

[0037] In one embodiment of the invention, the dose setting assembly includes a distal dose setting member fixed to a rear stop, the distal dose setting member being configured to hold a plunger rod in a predetermined distal position, the distal dose setting member being laterally removable from the rear stop to allow the plunger rod to move toward the rear stop and abut against the reversing member, and

[0038] A proximal dose setting member is fixed to the distal dose setting member, holding the plunger rod in a second predetermined position. The proximal dose setting member can be laterally removed from the distal dose setting member to allow the plunger rod to move toward and abut against the distal dose setting member. In this embodiment, the invention enables precise determination of the dosage of the drug injection fluid. It also ensures controlled pre-filling of the injection device.

[0039] In one embodiment, the proximal dose setting member includes at least one internal locking device configured to retain the plunger flange in a concealed, locked position. This embodiment of the invention ensures that the plunger rod does not move unintentionally during sterilization, storage, and transportation.

[0040] Other embodiments of the present invention may include the following features, which may be employed individually or in combination:

[0041] - The dosage setting component includes an elongated U-shaped wall that defines the housing.

[0042] - The dose setting component includes: a distal portion having at least one external groove oriented perpendicular to the longitudinal axis of the dose setting component; and a proximal portion having at least one internal groove oriented perpendicular to the longitudinal axis of the dose setting component.

[0043] - The dosage setting component includes an inner shoulder disposed in the U-shaped wall and an outer shoulder disposed in the U-shaped wall.

[0044] - The outer groove of the distal portion of the distal dose setting component is sized and configured to fit into the inner groove of the proximal portion of the proximal dose setting component.

[0045] - The rear stop includes a distal plate and a proximal funnel, both of which define the longitudinal housing.

[0046] - The rear stop includes a distal groove adjacent to the distal plate and two arcuate portions disposed on the distal plate.

[0047] - The rear stop includes a proximal groove provided in the proximal funnel portion.

[0048] - The distal plate extends radially from the funnel portion.

[0049] Another aspect of the present invention relates to a method of operating a medical injection device, comprising the following steps:

[0050] - Provides a medical injection device with a dosage setting component;

[0051] - Remove at least one dosage setting component from the medical injection device;

[0052] - Move the plunger rod toward the rear stop into the syringe barrel until the barrel flange abuts against the rear stop.

[0053] In another embodiment, the operation method may further include the following steps:

[0054] - Provides medical devices with dosage setting components;

[0055] -Remove the proximal dose setting component from the distal dose setting component;

[0056] - Move the plunger rod toward the distal dose setting member into the syringe barrel until the plunger rod abuts against the distal dose setting member;

[0057] -Remove the distal dose setting component from the rear stop;

[0058] - Move the plunger rod toward the rear stop into the syringe barrel until the plunger rod abuts against the rear stop.

[0059] In one embodiment of the invention, the dosage setting component is removed laterally from the medical injection device.

[0060] Other advantages and advantageous features of the invention are disclosed in the following description and dependent claims. Attached Figure Description

[0061] The invention will now be described in more detail with reference to the accompanying drawings, in which:

[0062] Figure 1 A perspective view shows a dosage setting assembly according to an exemplary embodiment of the present invention mounted to a conventional syringe;

[0063] Figure 2 yes Figure 1 Side view of the embodiment shown;

[0064] Figure 3 Shown in perspective Figure 1 The rear stop of the dosage setting component;

[0065] Figure 4 Shown in perspective Figure 1 The dose setting component of the dose setting assembly;

[0066] Figures 5 to 7 It shows the operation Figure 1 Dosage setting components;

[0067] Figure 8 A perspective view shows a dosage setting assembly according to an exemplary embodiment of the present invention mounted to a conventional syringe;

[0068] Figure 9 Shown at magnified scale Figure 8 Dosage setting components;

[0069] Figures 10 to 13 It shows the operation Figure 8 Dosage setting components;

[0070] Figure 14 Shown at magnified scale the contents included Figure 8 The distal setting component in the dose setting assembly. Detailed Implementation

[0071] As used herein, the term "proximal" and its derivatives refer to the end of the article or direction closest to the user during use of the invention. The term "distal" and its derivatives refer to the end of the article or direction facing the patient during use of the invention. As used herein, the term "medical injection fluid" and its derivatives refer to any substance intended to be injected into a patient, including but not limited to drugs, vaccines, therapeutic agents, etc. It will be apparent to those skilled in the art and from the disclosure provided herein that the invention is not limited or otherwise restricted to the type or class of substance administered using the dosing setting components of the invention.

[0072] In exemplary embodiments of the present invention, such as Figures 1 to 7 as well as Figures 8 to 13 As shown, the dose setting components 10 and 100 include rear stops 11 and 110, distal dose setting components 12 and 121, and proximal dose setting components 12' and 120.

[0073] Dosage setting components 10, 100 engage with a conventional syringe 15, which includes a barrel 16 and an elongated plunger rod 17.

[0074] The cylinder 16 includes an open proximal end with a flange 18 and a distal end with a channel 19.

[0075] The distal end of the tube 16 may be attached to the connecting hub 20. In other embodiments, the needle assembly 21 may be attached to the distal end of the tube 16.

[0076] A plunger rod 17 is inserted into a cartridge 16 at the proximal end of a syringe 15. A stopper 22 is located at the distal end of the plunger rod 17, the stopper serving to seal the cartridge 16 to form a reservoir 23 for medical injection fluid. The plunger rod 17 also includes a plunger flange 25 at its proximal end. The plunger flange 25 extends radially from the plunger rod 17. In the illustrated embodiment, the plunger flange 25 has a disc shape.

[0077] The dosage setting component 10 is located at the proximal end of the syringe 15.

[0078] Now turning more specifically Figure 3 One embodiment of the dose setting member 12 has an elongated single U-shaped wall 24 defining a housing 26; the housing 26 includes a lateral opening 29 defined by the free end of the U-shaped wall 24. In the illustrated embodiment, the dose setting member 12 has a square cross-section. The dose setting member 12 may also have a generally circular cross-section or any other cross-section shape.

[0079] The dose setting member 12 includes: a distal portion 27, which is sized and configured to connect to the rear stop 11; and a proximal portion 28, which is sized and configured to receive the proximal dose setting member 12′, as will be described in more detail below.

[0080] The distal portion 27 has a series of external grooves 30 formed on the outer surface of the U-shaped wall 24, while the proximal portion has a series of internal grooves 31 formed on the inner surface of the U-shaped wall 24. The external grooves 30 and internal grooves 31 are parallel and oriented perpendicular to the longitudinal axis of the dose setting member. The dose setting member 12 includes a section narrowing that makes the distal portion 27 narrower than the proximal portion 28. The section narrowing includes an internal shoulder 33 and an external shoulder 34 disposed in the U-shaped wall 24.

[0081] The internal groove 31 is constructed and sized to receive the plunger flange 25, as will be described in more detail below.

[0082] In order to allow the distal portion 27 of the distal dose setting member 12 to be inserted into the second dose setting member 12', the external groove 30 of the distal portion 27 is sized and configured to fit into the internal groove 31 of the proximal portion 28.

[0083] Now turning more specifically Figure 4 One embodiment of the rear stop 11 has a distal plate 37 and a proximal funnel portion 38, which together define a longitudinal housing 39. The distal plate 37 extends radially from the funnel portion 38. The housing 39 includes a longitudinal opening 40.

[0084] To allow insertion of the rear stop 11 into the syringe 15, as will be described in more detail below, the inner wall of the rear stop 11 is provided with a distal groove 41 adjacent to the distal plate 37. The distal plate 37 also includes two arcuate portions 42.

[0085] To allow insertion of the distal portion of the dose setting member 12, as will be described in more detail below, the dose setting member 12 includes a proximal groove 43 provided in the inner surface of the funnel portion 38.

[0086] Those skilled in the art will understand and appreciate that the rear stop 11 and the dosage setting member 12 can be formed by any of the conventional methods, such as injection molding. They can be made of suitable medical-grade plastics, hard rubber materials, glass, metals, etc.

[0087] Now turning more specifically Figure 1 or Figure 2 The dosage setting component 10 according to the invention is configured to engage with the syringe 15 via the syringe flange element 18. However, those skilled in the art will understand and appreciate that the dosage setting component 10 according to the invention can be applied to other medical delivery devices where it is desired to deliver precise and repeatable doses of medical injection fluid.

[0088] The syringe can be sold in pre-filled form, wherein a pre-defined dose of medical injection fluid is provided in the reservoir. In this configuration, the plunger rod 17 extends from the cylinder 16.

[0089] like Figure 2 As shown, the dosage setting assembly 10 includes a rear stop 11 engaged with a barrel flange 18. The barrel flange 18 engages in a distal recess 41, and the barrel 16 rests on an arcuate portion 42 provided in the rear stop 11. A longitudinal opening 29 of the rear stop 11 opening into the housing 26 forms a channel that allows the rear stop 11 to be mounted on the syringe flange 18 with the plunger rod 17 extending from the barrel 16.

[0090] The distal dose setting member 12 is engaged in the rear stop member 11. For this purpose, the distal portion of the dose setting member 12 is engaged in the groove 43 provided in the funnel portion 38 of the rear stop member.

[0091] Although Figure 2In the middle, the rear stop 11 and the distal dose setting member 12 face opposite directions, but it should be understood that the distal dose setting member 12 may be oriented differently relative to the rear stop 11 due to its square cross section.

[0092] The proximal dose setting member 12' is engaged with the distal dose setting member 12. For this purpose, the distal portion 27' of the second setting member 12' is engaged with the proximal portion 28 of the distal dose setting member 12.

[0093] It should be understood that in the illustrated embodiment, the distal dose setting member 12 and the proximal dose setting member 12′ are identical.

[0094] The rear stop 11 and the two dose setting components 12, 12' are attached to each other by friction engagement and to the barrel flange 18. Therefore, they can be secured or removed by hand relative to the syringe 15 without any tools or equipment. Thus, operating the dose setting assembly 10 proves easy and intuitive.

[0095] The longitudinal openings 40, 40' and 29, 29' in the rear stop 11, along with the two dose setting elements 12, 12', allow placement of the rear stop 11 and the two dose setting elements 12, 12' around the plunger rod 17 extending from the barrel 16. When the rear stop 11 and the two dose setting elements 12, 12' are close to the syringe 15, the barrel plunger rod 17 is accommodated within the housing of the rear stop 11 and the two dose setting elements 12, 12'.

[0096] like Figure 2 As shown, when the plunger flange 25 is surrounded within the internal groove 31 of the proximal dose setting member 12′, the plunger rod 17 is secured in its extended position. In the illustrated embodiment, the proximal dose setting member 12′ includes three internal grooves 31′, thereby providing three positions for securing the plunger flange 12.

[0097] Now turning more specifically Figures 5 to 7 The dosage setting component 10 is configured to control the standard operation of the syringe and thus provides a first medical injection fluid delivery stroke of the plunger (allowing for precise pre-filling) and a second medical injection fluid delivery stroke of the plunger (allowing for the dispensing of precise doses of medical injection fluid).

[0098] Syringe 15 in its Figure 3 The structure can be pre-filled and can be placed in a sterile package (not shown) together with the dosage setting component 10.

[0099] After removing the packaging, syringe 15 is ready for use. It can be noted that the plunger rod 17 is completely concealed within the proximal dose setting member 12', thus preventing accidental or unintentional movement of the plunger rod 17. Therefore, movement of the plunger stopper out of the sterile area is prevented during transport or storage of syringe 15. Furthermore, accidental or unintentional discharge of the medical product contained in the barrel 16 of syringe 15 is prevented.

[0100] The proximal dose setting member 12' can be removed from the injection device 15. To do this, the proximal dose setting member 12' is pulled laterally, which allows access to the plunger rod 17 previously hidden in the dose setting member 12'.

[0101] Understandably, the distal plate 37 of the rear stop 11 forms a type of finger rest, thereby allowing the user to easily manipulate the syringe 15 during use.

[0102] The user now advances the plunger rod 17 distally by applying finger pressure to the plunger flange 25. The distal movement of the plunger rod 17 is restricted by contact between the plunger flange 25 and the proximal region of the distal dose setting member 12. Therefore, with plunger movement, a dose of medical injection fluid is expelled from the reservoir 23. This allows for pre-filling of the syringe 15. In other words, the dose setting member allows for the dispensing of the required amount of medical injection fluid to pre-fill the syringe 15 without over-dispensing the medical injection fluid. This allows for the removal of potential air bubbles present in the medical injection fluid, thus preventing them from being injected into the patient.

[0103] The distal dose setting member 12 can now be removed from the rear stop 11. To do this, the distal dose setting member 12 is pulled laterally, which has the effect of releasing the plunger rod 17 that was previously abutting against the proximal region of the distal dose setting member 12.

[0104] The user can now advance the plunger rod 17 distally by applying finger pressure to the plunger flange 25. The distal movement of the plunger rod 17 is restricted by contact between the plunger flange 25 and the proximal region of the rear stop 11. Therefore, with the movement of the plunger rod, a predetermined dose of medical injection fluid is expelled from the reservoir 23. Preferably, the second dose is set to deliver a precise therapeutic dose.

[0105] Turn now Figures 8 to 14 One embodiment of the invention includes a static rear stop 110 and two removable dose setting members 120, 121. The two removable dose setting members 120, 121 define two controlled plunger strokes, which allows for the delivery of two precise doses of medical fluid.

[0106] One embodiment of the rear stop 110 has a U-shaped additional element, which includes a retaining wall connected to two lateral walls.

[0107] The rear stop 110 includes a transverse wall 111 and two lateral walls 112. An orifice 113 is defined between the transverse wall 111 and the lateral walls 112; the orifice 113 is sized to accommodate a channel for a syringe plunger 17. The width of the orifice 113 is configured to be greater than the diameter of the plunger rod 17 and smaller than the diameter of the plunger flange 25, as will be described in more detail below.

[0108] The inner surface of the rear stop 110 may be provided with a distal insertion groove 115 configured to removably connect the rear stop 110 to the syringe flange 18 and a proximal insertion groove 116 configured to removably connect the distal dose setting member 121 to the rear stop 110.

[0109] The distal groove 115 is formed between two inwardly projecting parallel overlapping flanges 118, 119. The overlapping flanges 118, 119 may include inclined insertion edges 124, 125.

[0110] The proximal groove 116 is formed between two inwardly protruding parallel flanges 127 and 126.

[0111] To enhance the locking retention of the rear stop 110 on the syringe barrel 16, the rear stop 110 may suitably include two lips 129 extending distally from the flange 119.

[0112] The rear stop 110 includes an external stepped construction that provides a finger rest surface 130.

[0113] More specifically turning Figure 14 The distal dose setting member 121 has a generally forked configuration that defines an orifice 132. The proximal dose setting member 121 includes two parallel legs 133 connected by a transverse portion 134. The orifice 132 is defined between the parallel legs 133 and the transverse portion 134; the orifice 132 is sized to accommodate a channel for the syringe plunger 16, and is sized such that the legs 133 and the transverse portion 134 serve as resting surfaces for the plunger flange 25. For this purpose, the width of the orifice 132 is configured to be greater than the diameter of the plunger rod 17 and smaller than the diameter of the plunger flange 25.

[0114] Each leg 133 is provided with an external insertion groove 136. The groove 136 is defined between a proximal flange 138 and an outwardly projecting distal flange 139.

[0115] The distal flange 139 is constructed and sized to removably engage with the proximal recess 116 provided in the rear stop 110.

[0116] The proximal flange 138 is constructed and sized to project laterally outward from the rear stop sidewall 112 when the distal dose setting member 121 is engaged with the rear stop 110.

[0117] The lateral portion 134 is provided with a pull tab 135 extending in the direction opposite to that of the leg portion 133. The pull tab 135 may be suitably provided with an outwardly oriented arrow mark 131 and may include at least one protrusion 137 to allow easy gripping of the pull tab 135.

[0118] The proximal dose setting member 120 is configured to be removably attached to the rear stop member 110.

[0119] Continue to refer to Figures 8 to 13 The proximal dose setting member 120 has a generally U-shaped structure, including a generally flat proximal wall 141 and two lateral stepped walls 143, the stepped walls including shoulders 142. Figure 9 As shown in the best example, the proximal lateral wall may have arrow marking 148.

[0120] The proximal dose setting member 120 includes two inwardly projecting intermediate ribs 147. The two intermediate ribs 147 face each other and define an orifice 144, which is sized to receive a channel for a syringe plunger 17 and is sized to serve as a resting surface for a plunger flange 18.

[0121] The internal dimensions between the intermediate rib 147 and the proximal sidewall 141 can be configured to accommodate the plunger flange 18, such that the plunger flange 18 is locked within the locking cavity 149 formed between the proximal sidewall 141 and the intermediate rib 147. In other words, once engaged between the intermediate rib 147 and the proximal rib 134, the plunger flange 18 is locked, and therefore the plunger rod 17 cannot move.

[0122] The proximal dose setting member 120 may further include two inwardly oriented distal ribs 145. The groove 146 defined between the intermediate rib 147 and the distal ribs 145 is sized and configured to removably receive the proximal end flange 138 of the distal dose setting member 121.

[0123] Those skilled in the art will understand and appreciate that the rear stop 110, the proximal dose setting member 120, and the distal dose setting member 121 can be formed in any of the conventional methods, such as injection molding. It can be made of suitable medical-grade plastics, hard rubber materials, glass, metals, etc.

[0124] Now turning more specifically Figure 8 or Figure 9The dosage setting component 10 according to the invention is configured to engage with the syringe 15 via the syringe flange element 18. However, those skilled in the art will understand and appreciate that the dosage setting component 10 according to the invention can be applied to other medical delivery devices where it is desired to deliver precise and repeatable doses of medical injection fluid.

[0125] The syringe can be sold in pre-filled form, wherein a pre-defined dose of medical injection fluid is provided in the reservoir. In this configuration, the plunger rod 17 extends from the cylinder 16.

[0126] like Figure 8 As shown, the rear stop 110 engages with the cylindrical flange 18. The cylindrical flange 18 engages with the distal groove 115 of the rear stop.

[0127] The distal dose setting member 121 is connected to the rear stop member 110; for this purpose, the distal flange 139 of the distal setting member 121 engages with the proximal groove 116 of the rear stop member 110.

[0128] The proximal dose setting member 120 is connected to the distal dose setting member 121; for this purpose, the groove 146 of the proximal dose setting member 120 engages with the proximal flange 138 of the distal dose setting member 121.

[0129] The rear stop 110, proximal dose setting member 121, and distal dose setting member 121 are attached to each other by friction engagement and to the barrel flange 18. Therefore, they can be secured or removed by hand relative to the syringe 15 without any tools or equipment. Thus, operating the dose setting assembly 100 proves easy and intuitive.

[0130] exist Figure 8 In the configuration of the present invention shown, the plunger flange 18 is enclosed within the space defined between the proximal dose setting member 120 and the distal dose setting member 121; this ensures that the plunger rod 17 is not accidentally pushed or pulled.

[0131] Now turning more specifically Figures 10 to 13 The dosage setting component 100 is configured to control the standard operation of the syringe and thus provides a first medical injection fluid delivery stroke of the plunger (allowing for precise pre-filling) and a second medical injection fluid delivery stroke of the plunger (allowing for the dispensing of precise doses of medical injection fluid).

[0132] In its Figure 8 The syringe 15 can be prefilled and placed in a sterile package (not shown) together with the dose setting component 100.

[0133] After removing the packaging, syringe 15 is ready for use. It can be noted that the plunger flange 18 is enclosed within the space defined between the proximal dose setting member 120 and the distal dose setting member 121; thus, accidental or unintentional movement of the plunger rod 17 is prevented. Therefore, movement of the plunger stopper out of the sterile area is prevented during transport or storage of syringe 15. Furthermore, accidental or unintentional discharge of the medical product contained in the barrel 16 of syringe 15 is prevented.

[0134] The proximal dose setting member 120 can be removed from the syringe 15. To do this, the proximal dose setting member 120 is pulled laterally in the direction of arrow 148; this has the effect of making access to the plunger flange 18 previously hidden within the proximal dose setting member 120.

[0135] The user now advances the plunger rod 17 distally by applying finger pressure to the plunger flange 25. The distal movement of the plunger rod 17 is restricted by the contact between the plunger flange 25 and the distal dose setting member 121. More specifically, the plunger flange 25 abuts against the leg 133. Therefore, with plunger movement, a dose of medical injection fluid is dispensed from the reservoir 23. This allows for pre-filling of the syringe 15. In other words, the dose setting member 100 allows the dispensed amount of medical injection fluid to pre-fill the syringe 15 without over-dispensing the medical injection fluid. This allows for the removal of potential air bubbles present in the medical injection fluid, thus preventing them from being injected into the patient.

[0136] The distal dose setting member 121 can now be removed from the rear stop 110. To do this, the user can grasp the pull tab 135, causing the distal dose setting member 121 to be pulled laterally in the direction of the arrow mark 131. This has the effect of releasing the plunger flange 25 that was previously abutting against the leg 133 of the distal dose setting member 121.

[0137] The user can now advance the plunger rod 17 distally by applying finger pressure to the plunger flange 25. The distal movement of the plunger rod 17 is restricted by the contact of the plunger flange 25 with the proximal flange 126 of the stop 110. Therefore, with the movement of the plunger rod, a dose of medical injection fluid is expelled from the reservoir 23. Preferably, the second dose is set to deliver a precise therapeutic dose.

[0138] It should be understood that the present invention is not limited to the embodiments shown above and in the accompanying drawings; rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of the appended claims.

Claims

1. A dosage setting component (100) for a medical injection device, the medical injection device comprising: A cylinder (16) defining a reservoir (23) adapted to contain a medical injection fluid; an open proximal end and a distal end including a hub portion; a flange (18) disposed at the proximal end of the cylinder (16); and an elongated plunger rod (17) having a plunger flange (25) at the proximal end and a plug (22) at the distal end, the plunger rod (17) being slidable within the cylinder (16), the dose setting assembly comprising: - A rear stop (110) that can be attached to the flange (18) of the cylinder (16). - A distal dose setting member (121) fixed to the rear stop (110), the distal dose setting member being configured to hold the plunger rod (17) in a distal predetermined position, the distal dose setting member (121) being laterally removable from the rear stop (110) to allow the plunger rod (17) to move toward and abut against the rear stop (110), the distal dose setting member (121) including a pull tab (135), and - A proximal dose setting member (120) fixed to the distal dose setting member (121) holds the plunger rod (17) in a second predetermined position. The proximal dose setting member (120) is laterally removable from the distal dose setting member (121) to allow the plunger rod (17) to move toward and abut against the distal dose setting member (121).

2. The dosage setting component (100) according to claim 1, characterized in that, The proximal dose setting member (120) includes a locking device configured to hold the plunger flange (25) in a concealed locked position.

3. The dosage setting component (100) according to claim 2, characterized in that, The proximal dose setting member (120) includes a proximal wall (141) and two lateral walls (143), each lateral wall having an inwardly oriented intermediate rib (147) that, together with the proximal wall, defines a plunger flange locking cavity (149).

4. The dosage setting component (100) according to claim 2 or 3, characterized in that, The proximal dose setting member (120) includes two inwardly oriented distal ribs (145) defining two grooves (146).

5. The dosage setting component (100) according to claim 3, characterized in that, The proximal dose setting member (120) includes an orifice (144) defined by the intermediate rib (147), the orifice (144) being configured and sized to allow the plunger rod (17) to pass through and prevent the plunger flange (25) from passing through.

6. The dosage setting component (100) according to any one of claims 1 to 3, characterized in that, The distal dose setting member (121) includes two legs (133) connected by a transverse portion (134), each leg (133) having an external groove (136) defined between a proximal flange (138) and a distal flange (139).

7. The dosage setting component (100) according to claim 6, characterized in that, The leg (133) and the transverse portion (134) define an orifice (132), which is constructed and sized to allow the plunger rod (17) to pass through and prevent the plunger flange (25) from passing through.

8. The dosage setting component (100) according to any one of claims 1 to 3, characterized in that, The rear stop (110) includes a transverse wall (111) and two lateral walls (112), the lateral walls of the rear stop defining an orifice (113), the orifice (113) defined by the lateral walls of the rear stop being configured and sized to allow the plunger rod (17) to pass through and prevent the plunger flange (25) from passing through.

9. The dosage setting component (100) according to claim 8, characterized in that, Each side wall (112) of the rear stop includes two inwardly projecting parallel flanges (118, 119) defining a distal recess (115).

10. The dosage setting component (100) according to claim 9, characterized in that, The lateral wall (112) of the rear stop includes two inwardly projecting parallel flanges (126, 127) defining a proximal groove (116).

11. A method of operating a medical injection device, comprising the following steps: - A medical device is provided, the medical device having a dose setting component according to any one of claims 1 to 10; - Remove the proximal dose setting member (120) from the distal dose setting member (121); - Move the plunger rod (17) toward the distal dose setting member (121) into the syringe barrel (16) until the plunger rod (17) abuts against the distal dose setting member (121); - Remove the distal dose setting member (121) from the rear stop (110); - Move the plunger rod (17) toward the rear stop (110) into the syringe barrel (16) until the plunger rod (17) abuts against the rear stop (110).

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