Supplemental System for a Medical Device Utilizing Jet Transport Principles

Abstract

A jet-type fluid injection device, comprising: - a housing defining a fluid collection chamber and having a nozzle; - a connector for coupling the fluid injection device to a fluid container; - a piston head configured to be received in the housing and movable therein to increase and decrease its volume; - a piston rod coupled to the piston head and having an internal flow passage extending from the piston rod for penetrating the fluid container, the piston head including a valve made of an elastically deformable material and including a radial flow passage, the radial flow passage being opened when the piston head moves in a direction of increasing the volume of the fluid collection chamber, and the radial flow passage being closed by elastic deformation of the valve material when the piston head moves in a direction of decreasing the volume of the fluid collection chamber.

Description

[0001] Specification

[0002] The present invention relates to a fluid injection device of the type that uses a jet ejection principle to inject a fluid into a patient's skin, and a fluid injection assembly.

[0003] Traditionally, a fluid such as a drug or body fluid has been injected into the skin of a patient (human or non-human) using a needle. However, more recently, so-called "needleless" fluid injection devices have also entered the market. Such devices inject a fluid into the patient's skin by ejecting a jet of fluid from a tiny nozzle by applying a relatively high pressure. The jet is able to penetrate the patient's skin and successfully inject the liquid. Such a fluid injection device thus utilizes the jet ejection principle and is of the type that uses the jet ejection principle to inject a fluid into a patient's skin. One advantage of such a fluid injection device is that it overcomes the common "needle phobia" of patients, since there is no need to insert a needle into the patient's skin to allow the fluid to be introduced therein. Another advantage of such a device is that the fluid is absorbed by the patient's skin at a higher rate, which is desirable for certain types of fluids.

[0004] For example, US2005 / 0273048A1 describes a fluid injection device of this type that uses the jet ejection principle to inject a fluid into a patient's skin. A typical disadvantage of such fluid injection devices is that they require an additional adapter to allow the injection fluid to be sucked into the fluid injection device. Thus, before the fluid can be injected, the user (patient) first needs to use the adapter to suck the fluid from an external fluid container into the fluid injection device. This is rather cumbersome and user-unfriendly. It also introduces a risk associated with the contamination of the injection fluid. Devices similar to those described in US2005 / 0273048A1 are available on the market.

[0005] This patent document describes some solutions for coupling a fluid container to a fluid injection device of the type that uses the jet ejection principle to inject a fluid into a patient's skin.

[0006] For example, WO2005 / 051465A1 describes a jet ejection assembly that includes a reservoir and a pulse chamber assembly. A conduit is provided between the reservoir and the pulse chamber through which fluid can flow from the reservoir into the pulse chamber when a piston in the reservoir is moved. To prevent fluid from flowing back from the pulse chamber to the reservoir during fluid injection, in WO2005 / 051465A1, the conduit has a "flow resistance" that is "configured to allow" less than 15%, preferably less than 10%, more preferably less than 5%, and most preferably less than 1% of backflow. A first problem associated with WO2005 / 051465A1 is that it does not disclose technical features to achieve this desired result. A second problem with WO2005 / 051465A1 is that 1% of backflow is considered too much, and a backflow rate of 0% is desired.

[0007] WO01 / 89613A1 discloses a syringe device for delivering a liquid from a high-pressure source, the device comprising: a housing; a pressure chamber that includes a pressure cylinder for receiving at least one piston therein and has a front opening for ejecting the liquid, the pressure chamber having sufficient strength to maintain the liquid pressure; a piston inserted into the pressure cylinder; a storage chamber, separated from the pressure chamber, for a liquid or a liquid precursor component; a conduit between the pressure chamber and the storage chamber; a pressurizing mechanism in the housing that is arranged to apply a force directly or indirectly on the piston in the pressure cylinder to generate the liquid pressure, wherein at least a part of the pressure chamber, the piston, and the conduit are arranged as a unit, and wherein the unit and the housing have corresponding fitting parts that allow the unit to be releasably attached to the housing at a certain position to allow fluid connection between the storage chamber and the pressure chamber through the conduit and to allow the pressurizing mechanism to act on the piston.

[0008] US 3,507,276 discloses a subcutaneous jet injector comprising: a housing member defining an injection orifice disposed at its blunt end; a first one-way valve formed within said housing member and operable to provide a flow of liquid to be injected into said orifice and to prevent backflow through said valve; a member mounted for reciprocating movement relative to said housing member, one of said members forming a barrel and the other of said members forming a mating piston within said barrel to define a variable volume chamber of restricted cross-section, one of said members including a second one-way valve communicating with said chamber and arranged to provide free flow of liquid into said chamber, said last-mentioned member further defining an inlet passage for conveying liquid through said second valve into said chamber and including a connection for a liquid supply container, said last-mentioned member further defining a cartridge chamber for engaging and holding a pre-packaged liquid cartridge of the type having a pierceable seal at its outlet end and a slidable rubber stopper at its opposite end and serving as a liquid supply container, said connection for the supply container including a cannula having a hollow tip extending into the cartridge chamber adjacent said second valve to pierce the seal at the outlet end of the cartridge; and a quick-release compression means including: a spring engaging between said members and restrained by a latch supported by said housing member and engageable with said reciprocating member; a cocking lever pivotally mounted on said housing member and engaging said reciprocating member to move said reciprocating member against the pressure of said spring to expand said chamber, said compression means being operable upon release of said latch to cause said reciprocating member to move rapidly and forcefully in a direction to reduce the volume of said chamber, thereby causing liquid to be ejected from said chamber through said orifice with sufficient force to penetrate the skin of a patient.

[0009] EP 1 875 934 A1 discloses a pre-filled medical drug expelling device comprising: a first and a second drug chamber, a nozzle including at least one discharge opening, a plunger forming a barrier between the first and the second drug chamber, at least one passage between the first and the second drug chamber, a pre-filled drug being contained in said first chamber, wherein at least a rigid portion of said plunger contacts the second drug chamber, and wherein said plunger is adapted to move in a first direction, whereby said drug is transferred from said first drug chamber to said second drug chamber, and in a second direction, whereby the same drug is discharged through the discharge opening.

[0010] US2012 / 0059314A1, which is considered the closest prior art to the present invention, teaches an attachment for a standard injection device for needleless injection of fluids, which has a nozzle adapter and a piston unit. Regarding this disclosure Figure 1 and Figure 3 , the nozzle adapter includes a skin contact surface disposed at its distal end, which has an outlet opening, a first barrel portion connected proximally to the outlet opening, and a second barrel portion connected to the first barrel portion. The piston unit is movably mounted in the first barrel portion to form a piston-barrel unit, and the attachment has a fluid line for delivering fluid from the standard injection device to the outlet opening. More specifically, the fluid line includes a piston, a sealing element, and a lateral opening. The first barrel portion includes first and second expansion portions. By moving the fluid line into and out of the first barrel portion, fluid can be drawn into the chamber after the outlet opening and then discharged from the outlet.

[0011] The Figure 1 and Figure 3 first disadvantage of the device shown in US2012 / 0059314A1 is that the stroke length of the fluid line and thus the volume of fluid to be injected cannot be changed.

[0012] The Figure 1 and Figure 3 second disadvantage of the device shown in US2012 / 0059314A1 is that the barrel portion including two expansion portions is relatively difficult to manufacture and thus relatively expensive. In addition, when manufacturing the barrel portion with expansion portions and the fluid line with a piston and a sealing element, the margin of production error is very small because their dimensions must match closely.

[0013] In Figure 4 and Figure 6 of US2012 / 0059314A1, alternative solutions using a check valve and a ball valve are presented, and the check valve or the ball valve ensures a low reflux rate during fluid injection.

[0014] One disadvantage of these solutions is that a sufficiently low reflux rate cannot be obtained when testing these solutions. In addition, the solutions are relatively complex, resulting in a relatively high cost. It is also very difficult to match the shape of the plunger tip with the internal geometry of the nozzle, resulting in possible reflux and an inaccurate amount of injected fluid. To obtain a sufficiently reliable seal between the tip of the plunger and the internal geometry, extremely small tolerances would be required, resulting in very high costs. Regarding the ball valve solution in particular, when vibrations or sudden shocks are applied to the injection device during injection, its performance is a major problem.

[0015] Accordingly, it is an object of the present invention to provide an improved fluid injection device that at least partially eliminates one or more of the above disadvantages.

[0016] Accordingly, there is provided a fluid injection device of the type that injects a fluid into a patient's skin by ejecting a fluid jet. The fluid injection device comprises:

[0017] - a housing having an outlet nozzle, the housing defining a fluid collection chamber for collecting the fluid to be ejected, the fluid collection chamber being in fluid communication with the outlet nozzle;

[0018] - a coupler for coupling the fluid injection device to a fluid container, preferably in a releasable manner;

[0019] - a piston head configured to be received in the housing, the piston head being movable in the housing to increase and decrease the volume of the fluid collection chamber; and

[0020] - a piston rod coupled to the piston head and having an internal flow passage.

[0021] The flow passage of the piston rod extends relative to the piston rod for penetrating the fluid container, thereby providing a flow path from the fluid container to the piston head.

[0022] Furthermore, the piston head includes a valve having an open and a closed position, the valve being made of an elastically deformable material and including a radial flow passage that provides a flow path from the piston head to the fluid collection chamber. When the piston head and the piston rod move in a direction to increase the volume of the fluid collection chamber, the radial flow passage of the valve opens. When the piston head and the piston rod move in a direction to decrease the volume of the fluid collection chamber, the radial flow passage of the valve closes by elastic deformation of the elastically deformable valve material.

[0023] In an embodiment, the elastically deformable valve advantageously provides an injection device having a substantially 0% reflux rate, i.e., having a reflux rate of 0% or close to 0%, e.g., between 0.5% and 0.001%. Since the elastic deformation of the valve material ensures the closure of the radial flow passage, the operation of the fluid injection device is very safe and reliable.

[0024] In an embodiment, the elastically deformable valve further advantageously provides incremental dosing, allowing the user to select almost any amount of injection fluid between a minimum and a maximum value without limitation.

[0025] Advantageously, with the fluid injection device according to the invention, the fluid container and the injection nozzle are coupled and fluidly connected in the same assembly. It is no longer necessary to first use an adapter to draw the fluid from an external fluid container into the injection chamber, but the fluid can be drawn into the fluid injection chamber (fluid collection chamber) simply, for example, by turning a dial, switching a switch, pressing a button, or by performing other simple actions on the housing of the fluid injection device. When injecting the fluid, the fluid injection device and the fluid container are preferably kept coupled, and the fluid container is arranged at the rear side of the fluid injection device as compared to the position of the outlet nozzle.

[0026] The elastically deformable valve to be inserted into the fluid collection chamber of the housing before the fluid injection device can be used advantageously allows for a relatively large manufacturing tolerance for the housing and the valve, since it is deformable.

[0027] In an embodiment, the elastically deformable valve and other components of the fluid injection device are further advantageously of relatively simple and inexpensive construction, which provides a commercial advantage. In addition, the fluid injection device is easy to use since no separate adaptation is required.

[0028] As described above, the fluid injection device is of the type that injects fluid into the skin of a patient using the jet discharge principle. In other words, the nozzle of the fluid injection device is needleless.

[0029] The piston head of the fluid injection device includes a valve. In an embodiment, the piston head is formed as a valve and the entire piston head is made of an elastically deformable material. In other embodiments, the piston head includes a valve and, for example, a rigid front plate or other rigid components.

[0030] The piston can move in the fluid collection chamber, preferably along its longitudinal axis. Thus, the internal volume of the fluid collection chamber is variable. Preferably, after the fluid has been discharged from the fluid collection chamber and when the piston is closest to the nozzle outlet, the internal volume of the fluid collection chamber is substantially zero.

[0031] In the open position of the valve, fluid can flow out of the internal flow channel of the piston rod, through the radial flow channel of the valve, and into the fluid collection chamber. This flow is also referred to herein as "inflow". Preferably, there is a negative pressure in the fluid collection chamber relative to the fluid container to ensure that the fluid flows in the correct direction. The negative pressure can be achieved, for example, by increasing the pressure in the fluid container or by reducing the pressure in the fluid collection chamber. In the closed position of the valve, the radial flow channel of the valve is closed by the deformation (e.g., by its compression) of the elastically deformable material, closing the radial flow channel, for example, causing the walls of the radial flow channel to contact each other, and preventing fluid from flowing from the internal flow channel to the fluid collection chamber and back from the fluid collection chamber to the internal flow channel through the radial flow channel. This flow back from the collection chamber to the internal flow channel (and possibly back into the fluid container) is referred to herein as "backflow" and is undesirable because when there is backflow, the amount of injected fluid cannot be accurately determined, and because backflow can cause contamination of the injected fluid.

[0032] The valve is made of elastically deformable material. When the piston rod is moved towards the outlet nozzle, the material has sufficient deformability / flexibility to compress and close the radial flow outlet. For example, the rod can be pushed with a relatively large force of up to 2000 N, for example up to 1000 N, for example about 500 N. When the rod is a (relatively) rigid material and the valve is an elastically deformable material, this can cause the material of the valve to deform longitudinally and / or transversely to close the radial flow channel and prevent backflow of the fluid in the fluid collection chamber. As will be described below, this is particularly advantageous when forces are generated both in front of and behind the radial flow channel, for example due to friction between the components of the valve and the inner wall of the fluid container. However, while using the inventive concept on which the present invention is based, other principles that produce the same technical effect can also be considered.

[0033] A further advantage of using an elastically deformable valve material is that the valve and the injection device can be used multiple times for fluid injection and are not disposable.

[0034] When the piston head is assembled in the housing and moved in a direction away from the outlet nozzle, the volume of the fluid collection chamber increases and the radial flow channel of the valve opens. Fluid can flow from the fluid container into the fluid collection chamber. When the piston head is moved towards the outlet nozzle, the radial flow channel closes, and the fluid collected in the fluid collection chamber is discharged through the outlet nozzle in the form of a jet stream without any backflow.

[0035] In one embodiment of the fluid injection device, the valve is made of an elastomeric material or rubber, such as thermoplastic elastomer (TPE), synthetic rubber, or natural rubber. These materials are some examples of materials with the desired elastic deformation characteristics for allowing the fluid injection device to operate smoothly and safely simultaneously. However, many other materials are also suitable for this function. For example, the hardness of the valve material is between 70 and 100 Shore A, preferably between 80 and 100 Shore A, such as approximately 85 Shore A or approximately 90 Shore A or approximately 95 Shore A.

[0036] In one embodiment, the fluid injection device further includes a cap configured to be coupled to a syringe, such as to a housing, the cap including a seal for sealing the outlet nozzle. Preferably, the cap is releasably coupled to the syringe or the housing. The seal and the cap can, for example, protect and seal the outlet nozzle from external influences when the fluid injection device is not in use, for example, prevent dust from being introduced into the outlet nozzle and / or the fluid collection chamber. When the cap with the seal is coupled to the syringe, the seal covers the outlet nozzle, and the piston moves backward (backward: away from the outlet nozzle) in the fluid collection chamber, creating a relative negative pressure in the fluid collection chamber. Due to the negative pressure therein and the valve being in an open state when the piston moves backward, fluid can flow from the fluid container into the fluid collection chamber when the piston moves backward. This is one possible way to "load" the fluid injection device and make it ready for injection.

[0037] Preferably, when the cap is coupled to the syringe, the seal seals the outlet nozzle in a liquid-tight and gas-tight manner. The cap and / or the seal can be replaceable.

[0038] In an embodiment of the fluid injection device, the piston head and the piston rod are coupled to each other by a threaded connection. For example, the piston rod is made of a relatively hard material, such as molded polycarbonate plastic, possibly reinforced with glass fiber, or metal. The piston rod and the piston head are preferably connected in such a way that the force introduced on the piston rod can be transmitted to the piston head and the valve to open and / or close the valve. The threaded connection is one of the various options that can be used to couple the piston head and the piston rod to each other in this way. In other embodiments, the piston rod and the piston head are, for example, co-molded, such as by a 2K injection molding process.

[0039] In an embodiment of a fluid injection device, a piston head has a piston rod receiving cavity for receiving a piston rod therein, and when viewed in the longitudinal direction of the piston rod, an internal flow channel of the piston rod extends beyond the threaded connection. Thus, in this embodiment, the piston head is hollow to allow the piston rod to be received therein, for example, coupled by a threaded connection. The piston rod has an internal flow channel that preferably extends along the entire length of the rod and enters the piston head and / or the valve. The valve then includes a radially outflow opening through which fluid can flow from inside the piston rod to a radial position outside the piston rod.

[0040] In an embodiment of a fluid injection device, a piston head has a piston rod receiving chamber for receiving a piston rod therein, and when viewed in the longitudinal direction of the piston rod, an internal flow channel of the piston rod extends beyond the position of the radial flow channel. In such an embodiment, when fluid flows from a fluid container to a fluid collection chamber, it first flows through the internal flow channel of the piston rod in the longitudinal direction of the piston rod, then enters a recess in the piston head, moves radially outward to a position outside the piston rod, moves backward relative to the longitudinal direction of the piston rod outside the piston rod, and then further moves radially outward through the radial flow channel of the valve. The fluid can then flow again in the longitudinal direction of the piston rod, pass through the piston head, and flow into the fluid collection chamber.

[0041] In an embodiment of a fluid injection device, a tip configured to penetrate a septum of a fluid container is provided at a fluid container facing end of a flow channel. The septum is a standard seal for a fluid container containing a medical injection fluid. Such a septum can be easily pierced by a needle, for example. Thus, in the embodiment, the internal flow channel of the piston rod is defined by a needle with its tip facing the fluid container. Therefore, even if the outlet nozzle of the fluid injection device is needleless, this does not in itself mean that the fluid injection device as a whole does not have any needles. However, in such an embodiment, the needle is arranged at the rear end of the fluid injection device for piercing the septum of the fluid container, rather than at the front end of the fluid injection device for piercing the skin of a user / patient. The needle can be fixed to the piston rod by a variety of manufacturing methods, including but not limited to, for example, gluing, ultrasonic welding, or injection molding.

[0042] In an embodiment of a fluid injection device, a coupler between a housing of the fluid injection device and a fluid container includes snap fingers for receiving the fluid container therein. This advantageously allows the fluid container to be updated when it is emptied since it is a releasable connection. Then, when the fluid container is empty, only the fluid container needs to be updated, rather than the entire assembly of the fluid container and the fluid injection device.

[0043] In an embodiment of a fluid injection device, the connector between the housing of the fluid injection device and the fluid container includes a female Luer taper thread. The Luer taper thread provides a leak-proof connection and is commonly used to mount a container containing a medical injection fluid. To allow such a container to be coupled to the fluid injection device, in an embodiment, the connector may include a female Luer taper thread such that a container having a male Luer taper thread can be screwed into the connector. The Luer lock connection may be more robust and rigid compared to a connection using a snap finger. Of course, when the fluid container includes a female Luer taper thread, in an embodiment, the connector may include a male Luer taper thread.

[0044] In an embodiment of a fluid injection device, the valve further includes a sealing ring that, when viewed in the longitudinal direction of the piston rod, is located behind the radial flow channel of the valve and contacts the inner wall of the fluid collection chamber. When the piston head moves forward (i.e., towards the outlet nozzle) to eject fluid, the sealing ring advantageously prevents any backflow of fluid along the outer side of the piston rod. The sealing ring may be made of, for example, the same elastically deformable material as the valve, but this is not essential per se as long as the sealing ring fluidly seals the area between the inner wall of the fluid collection chamber and the valve to prevent the backflow.

[0045] In an embodiment of a fluid injection device, the valve includes an annular rim that contacts the inner wall of the fluid collection chamber with at least a portion of its outer circumference. The annular rim is made of an elastically deformable material and has one or more through flow openings. When the piston is disposed in the fluid collection device, the annular rim is located between the radial flow channel and the outlet nozzle. In use, due to the friction between the annular rim and the inner wall of the fluid collection chamber, the forward movement of the piston head causes the radial flow channel to close, and in use, due to the friction between the annular rim and the inner wall of the fluid collection chamber, the backward movement of the piston head causes the radial flow channel to open.

[0046] The annular rim has through flow openings to allow fluid to flow through the rim at least when "loading" the fluid injection device (i.e., when fluid flows from the fluid container to the fluid collection chamber). However, the through flow openings may also be open when injecting fluid because the valve closes at the radial flow channel. The through flow openings may be implemented as recesses at the outer circumference of the annular rim. In such an embodiment, the annular rim contacts the inner wall of the fluid collection chamber with only a portion of its outer circumference. However, in other embodiments, the through flow openings may be arranged more radially inwards, and then the annular rim contacts the inner wall of the fluid collection chamber with its entire outer circumference.

[0047] Since the outer circumference of the annular edge contacts the inner wall of the fluid collection chamber, there is friction between these two components of the fluid injection device when the piston rod and the piston head move. When the piston rod and the piston head move backward, this friction pulls open the radial flow opening. When the piston rod and the piston head move forward, this frictional force simultaneously compresses and closes the radial flow opening of the valve.

[0048] A second aspect of the present invention relates to a fluid injection assembly comprising a fluid injection device as described above and a fluid container, which is coupled to the fluid injection device by a coupler.

[0049] The container can be, for example, a syringe, a vial or a cartridge, and can be any known container that contains, for example, a medical injection fluid. An example of such a fluid is insulin, but many other fluids can be injected into a patient's skin using the fluid injection assembly according to the second aspect of the present invention.

[0050] In an embodiment of the fluid injection assembly, the fluid container includes a piston head. By moving the piston head in the direction towards the fluid injection device, for example, using an actuator, an overpressure can be obtained in the fluid container and the fluid therein can be forced into the fluid collection chamber of the fluid injection device. This is one way of loading the fluid injection assembly for use by the user / patient. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] These and other aspects of the present invention will now be further elucidated with reference to the drawings. The same reference numerals will be used in the drawings to denote similar or identical features. In these figures:

[0052] Figure 1 A longitudinal cross-sectional view of a fluid injection assembly according to the present invention is schematically shown;

[0053] Figure 2 Is schematically shown in an isometric view Figure 1 A detailed view of the piston head, piston rod and coupler of the fluid injection assembly of

[0054] Figure 3 Is schematically shown Figure 2 A longitudinal cross-sectional view of the piston head, piston rod and coupler of

[0055] Figure 4 Is schematically shown along Figure 1 A longitudinal cross-sectional view of the valve of the fluid injection device of

[0056] Figure 5 Substantially corresponds to Figure 4 And highlights the forces and fluid flow;

[0057] Figure 6AA front isometric view schematically showing the fluid flow around a valve of a fluid injection device and assembly according to the present invention, the valve being in its open position;

[0058] Figure 6B Substantially corresponding to Figure 6A , but omitting the fluid flow indication;

[0059] Figure 7 Schematically shows a view of a longitudinal section of the valve along Figure 4 , the valve being in the closed position;

[0060] Figure 8 Schematically shows a second embodiment of a fluid injection assembly according to the present invention in a longitudinal cross - sectional view;

[0061] Figure 9 Schematically shows a third embodiment of a fluid injection assembly according to the present invention in a longitudinal cross - sectional view; and

[0062] Figure 10 Schematically shows a possible manufacturing process of a valve of a fluid injection device and assembly according to the present invention. Detailed Description

[0063] Regarding those described simultaneously Figure 1 , Figure 2 and Figure 3 , Figure 2 shows a cross - sectional view along the longitudinal axis of the fluid injection assembly 100. Figure 2 An isometric view of a part of the injection assembly is shown, most importantly the connector 14, the piston rod 16, and the piston head 13 including the valve 131. Figure 3 Shows the same elements as Figure 3 , but in a cross - sectional view along the longitudinal direction.

[0064] The fluid container 3 and the fluid injection device 1 are connected by a connector 14. As shown herein, the fluid container 3 includes an injection fluid IF, a piston head 33 on its rear side, a diaphragm 31 for covering the outlet of the fluid container 3, and a cap 32 for sealing the diaphragm 31 relative to the fluid container 3.

[0065] It should be noted that this fluid container is a relatively standard fluid container. The present invention is in no way limited to the use of a specific fluid container. In fact, Figure 8 and Figure 9 show other embodiments of the fluid container, although the three shown embodiments are certainly not the only types of fluid containers that can be connected to the fluid injection device.

[0066] Figure 1 , Figure 2 and Figure 3The connector 14 herein includes latching fingers 141 for coupling the fluid container 3 to the fluid injection device 1. It should be noted that the present invention is in no way limited to the type of coupling used between the fluid container 3 and the fluid injection device 1. The use of the latching fingers 141 is just one exemplary choice among many. In fact, referring to Figure 8 and Figure 9 , for example, a luer connection is shown.

[0067] The connector 14 further includes a flange 142 that extends radially outward relative to the piston rod 16. The piston rod 16 and the piston head 13 can be moved, for example, by applying a force on the flange 142.

[0068] Herein, Figure 1 the fluid injection device 1 shown is coupled to a cap 11 that can protect the outlet 121 of the fluid injection device 1 when the fluid injection device 1 is not in use. The cap 11 includes a seal 111 for sealing the outlet 121 in an airtight and liquidtight manner. The cap 11 is coupled to the fluid injection device 1 via coupling mechanisms 112, 123 that include a male part 123 associated with the housing 12 and a female part 112 associated with the cap 11. In an embodiment, the cap 11 can be coupled to the housing 12 of the fluid injection device 1, for example.

[0069] Figure 1 The fluid injection device 1 shown in Figure 5 is more clearly visible and includes a housing 12. The housing 12 is hollow and defines a fluid collection chamber, for example. At the front end of the housing 12, there is a nozzle outlet 121. The nozzle outlet 121 and thus the fluid injection device 1 are of the type that allows fluid to be injected into a patient's skin by ejecting a fluid jet.

[0070] Figure 2 The fluid injection device 1 shown in Figures 4 - 7 also includes a piston head 13. In the assembled state of the fluid collection device 1, the piston head 13 is received in the fluid collection chamber. The piston head 13 can move in the forward F and backward B directions to respectively decrease and increase the volume of the fluid collection chamber. The front side of the piston head 13 matches the shape of the fluid collection chamber near the nozzle outlet 121, which allows the piston head 13 to reduce the volume of the fluid collection chamber to substantially zero in its foremost position. The piston head 13 includes a valve 131, which will be described in more detail with reference to Figures 4 - 7 .

[0071] Figure 1The fluid injection device 1 shown also includes a piston rod 16, which is coupled to the piston head 13 by a threaded connection 17 and is received in the fluid collection chamber of the housing 12. When the piston rod 16 moves, for example via the flange 142, both the piston head 13 and the piston rod 16 move in the fluid collection chamber. The piston rod 16 includes an internal flow channel 15, which extends relative to the piston rod 16 in the backward direction B and extends into the fluid container 3. The internal flow channel 15 provides a flow path from the fluid container 3 through the piston rod 16 and into the piston head 13. The flow channel 15 is here realized as a needle, having a tip on the side facing the fluid container 3, which allows the needle to penetrate the diaphragm 31 of the fluid container 3. Although the connection between the piston rod 16 and the piston head 13 is of the threaded type 17 here, many alternative connections between the piston rod 16 and the piston head 13 are known, and the present invention is not limited to a particular type of connection.

[0072] Also as regarding Figure 2 and Figure 3 shown, the coupler 14 and the piston rod 16 can be made as one piece.

[0073] Mainly referring to Figure 2 and Figure 3 , the piston head 13 includes a valve 131. The valve 131 shown here includes a sealing ring 134, a radial flow channel 133, and an annular rim 132 including a flow-through opening 137. The valve 131 is made of an elastically deformable material, such as an elastomeric material such as thermoplastic elastomer (TPE) or rubber such as synthetic rubber or natural rubber. For example, the elastically deformable material of the valve 131 has a hardness between 70 and 100 Shore A. In Figure 3 it, the radial flow channels 133 are shown in their closed position C. Due to the elastic deformability of the piston head 13 material, the parts of the piston head 13 in front of and behind the radial flow channels 133 can move relative to each other (and relative to the piston rod 16) to open and / or close the radial flow channels 133.

[0074] Now referring to Figures 4 - 8 describe the operation of the valve 131 in more detail, Figures 4 - 8 discussed together.

[0075] Figure 4Shown is a more detailed view of the piston head 13 including the valve 131, which is here in the open position O. The piston head 13 is connected to the piston rod 16 by a threaded connection 17. Inside the piston rod 16, a flow channel 15 is provided. The flow channel 15 extends between the two ends of the piston rod 16 as the piston rod 16 is hollow. When a fluid container is connected to the injection device, fluid can flow through the flow channel 15 as shown here. The piston head 13 includes a piston rod receiving chamber 135 in which the piston rod 16 is received when the piston rod 16 and the piston head 13 are connected. As shown here, the internal flow channel 15 extends along the entire length of the piston rod 16 and enters the piston rod receiving chamber 135 of the piston head 13 through a flow channel outlet provided on the front side of the flow channel 15. When viewed in the longitudinal direction of the piston rod, the flow channel outlet is provided further away than the position of the threaded connection 17 and is also provided further away than the radial flow channel 133.

[0076] Also as Figure 5 shown, the flow path of the fluid extends radially outwards from the piston rod receiving chamber 135 and extends backwards along the outer side of the piston rod 16 through the longitudinal flow channel 136 towards the radial flow channel 133. Then, the fluid flows radially outwards through the radial flow channel 133 (which is here in the open position O) and is forced through the recesses 137 arranged in the annular edge 132 (see Figure 6A and Figure 6B ), into the fluid collection chamber 122. The annular edge 132 of the piston head 13 includes recesses 137, which are here arranged on the radial outer side of the piston head 13 and which serve as axial flow channels to allow fluid to flow from the radial flow channel 133 to the fluid collection chamber 122. The sealing ring 134 prevents the fluid from flowing again in the backward direction B after flowing out of the radial flow channel 133.

[0077] As Figure 5 shown, when the piston head 13 and the piston rod 16 move in the backward direction B, i.e., away from the nozzle outlet 121 and increasing the volume of the fluid collection chamber 122, the valve 131 is in the open position O. Here the open position O is achieved by two forces acting in opposite directions. On the one hand, there is a frictional force F between the annular edge 132 of the valve 131 in contact with the inner wall 124 of the fluid collection chamber F . On the other hand, there is a backward pulling force F generated by the backward movement of the piston rod 16 B . The opposing forces cause the radial flow channel 133 to open, thus opening the valve 131.

[0078] Conversely, as Figure 7 shown, when the piston rod 16 and the piston head 13 move in the forward direction F, towards the outlet nozzle and reducing the volume of the fluid collection chamber, the valve is in the closed position C. The injection force F IDeform the part that connects the valve to the piston rod, and the frictional force F between the annular edge and the inner wall of the fluid collection chamber F Deform the front part of the valve. The combined effect of these deformations causes the radial flow channels to be compressed and closed. In addition, the flow path from the piston rod receiving chamber to the radial flow channels can be more or less compressed and closed by these mating forces. As shown, due to the injection force, the fluid is ejected from the fluid collection chamber through the outlet nozzle. As in the open position of the valve, the sealing ring 134 prevents the fluid from flowing radially outward along the piston rod in the backward direction when the injection force is applied to the fluid injection device, and ensures that all the fluid collected in the fluid collection chamber is extruded from the fluid injection device.

[0079] Figure 8 and Figure 9 Schematically shows two alternative embodiments of the fluid injection assembly 100. In Figure 8 , the coupler 14 of the fluid injection device 1 includes a male Luer connector 143. This allows the fluid injection device 1 to be coupled to the fluid container 3, which is provided with a female Luer connector 41. For example, the fluid container 3 can be attached to the adapter 4, which includes a female Luer connector 41.

[0080] In Figure 9 , the coupler 14 of the fluid injection device 1 includes a female Luer connector 41. This allows the fluid injection device 1 to be coupled to the syringe 5 provided with a male Luer threaded connector 51.

[0081] Figure 10 Shown is a possible way to manufacture the valve as described above. As Figure 10 shown, a pre-molded piston head 13 without radial flow channels can be fixed in the fixture 200. Then the cutting tools 201, 202 can cut off some material of the piston head 13 to create radial flow channels at the desired locations.

[0082] List of reference numerals

[0083] 1 Fluid injection device

[0084] 11 cap

[0085] 111 seal

[0086] 112 coupling mechanism (female)

[0087] 12 housing

[0088] 121 outlet nozzle

[0089] 122 fluid collection chamber Fluid collection chamber

[0090] 123 coupling mechanism(male) Coupling mechanism (male)

[0091] 124 inner wall of fluid collection chamber Inner wall of fluid collection chamber

[0092] 13 piston head Piston head

[0093] 131 valve Valve

[0094] 132 annular rim Annular rim

[0095] 133 radial flow channel Radial flow channel

[0096] 134 seal ring Seal ring

[0097] 135 piston rod receiving chamber Piston rod receiving chamber

[0098] 136 longitudinal flow channel Longitudinal flow channel

[0099] 137 throughflow opening Throughflow opening

[0100] 14 coupler Coupler

[0101] 141 snap finger Snap finger

[0102] 142 flange Flange

[0103] 143 male Luer connector Male Luer connector

[0104] 15 internal flow channel Internal flow channel

[0105] 151 fluid container facing end Fluid container facing end

[0106] 152 piston head facing end Piston head facing end

[0107] 16 piston rod Piston rod

[0108] 17 threaded connection Threaded connection

[0109] 3 fluid container Fluid container

[0110] 31 septum Septum

[0111] 32 cap Cap

[0112] 33 piston head Piston head

[0113] 4 fluid container adapter Fluid container adapter

[0114] 41 female Luer connector Female Luer connector

[0115] 42 container body Container body

[0116] 5 syringe Syringe

[0117] 51 male Luer taper thread Male Luer taper thread

[0118] 52 stopper Stopper

[0119] 100 assembly Assembly

[0120] 200 fixture Fixture

[0121] 201 knife Knife

[0122] 202 knife Knife

[0123] B backwards direction Backwards direction

[0124] C closed valve position Closed valve position

[0125] F forwards direction Forwards direction

[0126] F B force induced by movement in backwards direction Force induced by movement in backwards direction

[0127] F F friction force Friction force

[0128] F IForce induced by movement in injection direction

[0129] IF Injection fluid

[0130] L Longitudinal direction

[0131] O Open valve position

Claims

1. A fluid injection device (1) of the type for injecting a fluid into a patient's skin by means of a jet of fluid, said fluid injection device (1) comprising: - a housing (12) having an outlet nozzle (121), said housing (12) defining a fluid collection chamber (122) for collecting the fluid to be injected, said fluid collection chamber (122) being in fluid communication with said outlet nozzle (121); - a connector (14) for coupling said fluid injection device (1) to a fluid container (3, 5); - a piston head (13) configured to be received within said housing (12), said piston head (13) being movable within said housing (12) to increase and decrease the volume of said fluid collection chamber (122); - a piston rod (16) coupled to said piston head (13) and having an internal flow passage (15), characterized in that said flow passage (15) of said piston rod (16) extends relative to said piston rod (16) for piercing said fluid container (3, 5) so as to provide a flow path from said fluid container (3, 5) to said piston head (13), and said piston head (13) includes a valve (131) having open (O) and closed (C) positions, said valve (131) being made of an elastically deformable material and including a radial flow passage (133), said radial flow passage (133) providing a flow path from said piston head (13) to said fluid collection chamber (122), said radial flow passage (133) of said valve (131) being open when said piston head (13) and piston rod (16) are moved in a direction to increase the volume of said fluid collection chamber (122), and said radial flow passage (133) of said valve (131) being closed by elastic deformation of the elastically deformable valve material when said piston head (13) and said piston rod (16) are moved in a direction to decrease the volume of said fluid collection chamber (122).

2. The fluid injection device according to claim 1, wherein The connector (14) couples said fluid injection device (1) to the fluid container (3, 5) in a releasable manner.

3. The fluid injection device according to claim 1 or 2, wherein, Said valve (131) is made of an elastomeric material.

4. The fluid injection device according to claim 3, wherein, Said elastomeric material is a thermoplastic elastomer (TPE) or rubber.

5. The fluid injection device according to claim 4, wherein, Said rubber is synthetic rubber or natural rubber.

6. The fluid injection device according to claim 4, wherein Said thermoplastic elastomer material or said rubber has a hardness between Shore 70 and 100A.

7. The fluid injection device according to any one of claims 1 - 2 and 4 - 6, further comprising a cap (11) configured to be coupled to said fluid injection device (1), said cap (11) including a seal (111) for sealing said outlet nozzle (121).

8. The fluid injection device according to claim 7, wherein, When said cap (11) is coupled to said fluid injection device (1), said seal (111) seals said outlet nozzle (121) in a liquid - tight and gas - tight manner.

9. The fluid injection device according to any one of claims 1-2, 4-6 and 8, wherein, Said piston head (13) and said piston rod (16) are coupled to each other by a threaded connection (17).

10. The fluid injection device according to claim 9, wherein, The piston head (13) has a piston rod receiving chamber (135) for receiving the piston rod (16) therein, and wherein the internal flow channel (15) of the piston rod (16) extends beyond the threaded connection (17) when viewed in the longitudinal direction (L) of the piston rod (16).

11. The fluid injection device according to any one of claims 1-2, 4-6, 8, and 10, wherein, The piston head (13) has a piston rod receiving chamber (135) for receiving the piston rod (16) therein, and wherein the internal flow channel (15) of the piston rod (16) extends beyond the position of the radial flow channel (133) when viewed in the longitudinal direction (L) of the piston rod (16).

12. The fluid injection device according to any one of claims 1-2, 4-6, 8 and 10, wherein, The fluid container facing end (151) of the flow channel (15) has a tip configured to penetrate the diaphragm (31) of the fluid container (3, 5).

13. The fluid injection device according to claim 11, wherein, The fluid container facing end (151) of the flow channel (15) has a tip configured to penetrate the diaphragm (31) of the fluid container (3, 5).

14. The fluid injection device according to claim 12, wherein, The flow channel (15) is defined by a needle, the tip of which faces the fluid container (3, 5).

15. The fluid injection device according to claim 13, wherein, The flow channel (15) is defined by a needle, the tip of which faces the fluid container (3, 5).

16. The fluid injection device according to any one of claims 1-2, 4-6, 8, 10 and 13-15, wherein, The connector (14) includes a retaining finger (141) for receiving the fluid container (3, 5) therein.

17. The fluid injection device according to any one of claims 1-2, 4-6, 8, 10 and 13-15, wherein, The connector (14) includes a female Luer taper thread (143).

18. The fluid injection device according to any one of claims 1-2, 4-6, 8, 10 and 13-15, wherein, The valve (131) further includes a sealing ring (134) which, when viewed in the longitudinal direction (L) of the piston rod (16), is positioned behind the radial flow channel (133), and the sealing ring (134) contacts the inner wall (124) of the fluid collection chamber (122).

19. The fluid injection device according to claim 16, wherein, The valve (131) further includes a sealing ring (134) which, when viewed in the longitudinal direction (L) of the piston rod (16), is positioned behind the radial flow channel (133), and the sealing ring (134) contacts the inner wall (124) of the fluid collection chamber (122).

20. The fluid injection device according to claim 17, wherein, The valve (131) further includes a sealing ring (134) which, when viewed in the longitudinal direction (L) of the piston rod (16), is positioned behind the radial flow channel (133), and the sealing ring (134) contacts the inner wall (124) of the fluid collection chamber (122).

21. A fluid injection device according to any one of claims 1 - 2, 4 - 6, 8, 10, 13 - 15 and 19 - 20, wherein, The valve (131) includes an annular rim (132) that contacts an inner wall (124) of the fluid collection chamber (122) with at least a portion of its outer circumference. The annular rim (132) is made of the elastically deformable material and has a flow-through opening (137). In the assembled state of the fluid injection device (1), the annular rim (132) is located between the radial flow channel (133) and the outlet nozzle (121). Wherein, in use, due to the friction (F F ) between the annular rim (132) and the inner wall (124) of the fluid collection chamber (122), the forward movement (F) of the piston head (13) causes the radial flow channel (133) to close. In use, due to the friction (F F ) between the annular rim (132) and the inner wall (124) of the fluid collection chamber (122), the backward movement (B) of the piston head (13) causes the radial flow channel (133) to open.

22. A fluid injection assembly (100), comprising a fluid injection device (1) according to any one of claims 1 - 21 and a fluid container (3, 5), the fluid container (3, 5) being coupled to the fluid injection device (1) by the connector (14).

23. The fluid injection assembly according to claim 22, wherein, The fluid container (3, 5) includes a piston head.

24. The fluid injection assembly according to claim 23, comprising an actuator for moving the piston head of the fluid container (3) in a direction towards the fluid injection device (1), the movement causing fluid to flow from the fluid container (3) into and into the fluid collection chamber (122) of the fluid injection device (1).

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