AU2024236170A1

AU2024236170A1 - A device for use in intravenous medicine

Info

Publication number: AU2024236170A1
Application number: AU2024236170A
Authority: AU
Inventors: Madhukar THAKKALPALLI
Original assignee: Thane Pty Ltd
Current assignee: Thane Pty Ltd
Priority date: 2023-03-10
Filing date: 2024-03-08
Publication date: 2025-09-25
Also published as: WO2024187222A1

Abstract

A single-use device for use in administering a fluid substance to a patient via an intravenous catheter or cannula is disclosed. The device has a body with a hollow interior inside at least part of the body, and the device is manufactured with the fluid substance that is to be administered to the patient contained within the hollow interior of the body. The device also has a connecting portion for connecting the device to the intravenous catheter or cannula, and an opening in the connecting portion which leads into the hollow interior of the body, which opening is initially closed but which can be opened, or, a portion of the connecting portion in which an opening into the hollow interior of body can be formed. Once the opening is opened or formed, the fluid substance is able to exit the hollow interior of the body through the opening. There is also a deformable portion of the body which, after the opening into the hollow interior has been opened or formed, is able to be deformed, or its shape is able to change, upon application of force. The deformation of, or the change in shape of, the said deformable portion caused by the application of force reduces the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening. The volume of the hollow interior can be reduced substantially to zero such that substantially all of the fluid substance that was originally contained within the hollow interior is expelled. Also, if the application of force which deforms the deformable portion, or causes the shape thereof to change, is stopped or paused, the state/extent of the deformation of, or the change in shape of, the deformable portion will remain as it was at that point and the deformable portion does not return or re-expand.

Description

A DEVICE FOR USE IN INTRAVENOUS MEDICINE

TECHNICAL FIELD

[0001] The present invention relates generally to the field of intravenous medicine. It is envisaged that one particular application in which the invention may often find use is for “flushing” intravenous catheters and cannulas, and the invention is described below mainly with reference to its use in that application. However, the invention may also be used or employed in other applications or in other ways.

BACKGROUND

[0002] In the medical (and also veterinary) fields, the words “catheter” and “cannula” are both often used to describe flexible tubes (or the like) that can be inserted into veins or other body cavities, for example, to introduce or remove fluids, to enable medication to be administered, etc. These two terms, i.e. “catheter” and “cannula”, are often used interchangeably. However, there is also sometimes a distinction drawn between the terms “catheter” and “cannula”. Where a distinction is drawn between them, the word “cannula” is often used to refer to the kinds of smaller flexible tubes that are inserted into a part of the body of a patient (human or animal), generally a vein, with the aid of a needle that initially penetrates the skin and also punctures the vein or other vessel into which the cannula is to be inserted. The needle is then removed, but the cannula remains in place (i.e. it remains inserted in the vein or other vessel) for the purpose of enabling substances to be administered into, or withdrawn from, the vessel through the cannula. In contrast (where a distinction is drawn between the meanings of “catheter” and “cannula”) the term “catheter” is often used to refer to the kinds of larger flexible tubes or conduits that can be inserted into an area of the body that already has an opening, but which needs assistance in draining (or removing fluids therefrom), such as e.g. the bladder or an open wound or the like. Despite these slightly different meanings that are sometimes given to the terms “cannula” and “catheter” respectively, for the purposes of this specification, these terms may be considered interchangeable. Nevertheless, to help minimise confusion arising from the fact that these terms are sometimes considered to have slightly different meanings, for the remainder of this specification reference will mainly be made to the term “cannula” (and “cannulas”).

[0003] As indicated above, in the field of intravenous medicine, a cannula is typically inserted into the vein of a patient (the patient may be human or an animal) in order to be used, for example, to administer medication in fluid form, or to administer other fluids as may be required, as a part of the medical management of the patient. Such intravenous cannulas must be “flushed” regularly, typically with saline solution (i.e. a solution comprising sodium chloride (NaCI) dissolved in water at a concentration of 0.90% weight per volume). More specifically, an intravenous cannula must generally be flushed at the following times (at least): immediately after initial insertion of the cannula; after every drug administration via the cannula; and in any event at least twice a day (i.e. even if the intravenous device is not used more frequently than that for any period). Regular flushing of the intravenous cannula helps to ensure patency of the device (i.e. it helps to ensure that it remains open and not blocked or obstructed) and it also helps to reduce peripheral intravenous cannula related infections or thrombophlebitis. [0004] Traditionally, a “flush” (i.e. a quantity of saline solution that is to be used in performing a single flush of an intravenous cannula) is typically either: made up at the time of performing the flush by drawing up an appropriate quantity of the flush fluid (typically saline solution) from an ampoule into a single use syringe, and the flush is then performed by administering that drawn up quantity of the flush solution from the single use syringe into the patient via the intravenous cannula (thereby flushing the cannula); or pre-made as a prefilled single use disposable flush syringe (for example, such prefilled single use disposable flush syringes are sold by Becton Dickinson (BD) under the trade mark PosiFlush™) - and (again) the flush is performed by administering the quantity of flush solution contained within the pre-filled syringe to the patient via the intravenous cannula (thereby flushing the cannula).

[0005] In both cases above, the single use syringe used normally has a standardised fitting (which is typically the male portion of a luer lock or luer slip connector), and the intravenous cannula also has a standardised fitting (which is typically the female portion of a luer lock or luer slip connector, as applicable), so that when a flush is to be administered, the single use syringe can be connected via a fluid-tight (leak- free) connection to the cannula (this leak free connection is provided by the luer lock or luer slip connector) in order for the flush solution to be transferred into the patient via the cannula, flushing the cannula as it passes through.

[0006] Given how many hospitals (both human and animal/veterinary, and also other clinics and similar facilities) there are throughout the world, the number of times per day that a “flush” of an intravenous cannula is required to be performed is enormous. Indeed, it is believed that the number of times the procedure of flushing an intravenous canula is undertaken around the world (even if one only considers human patients) is likely well over one million per day. The resultant cost of this to hospitals, health authorities, and ultimately to patients or taxpayers (who must fund these facilities), is high, particularly given the cost of producing single use syringes (either standard single use syringes or specifically designed pre-filled single use flush syringes), and especially when also taking into account costs associated with their disposal after use.

[0007] One problem associated with the way in which flushing of intravenous cannulas is currently performed (as outlined above) is related to the fact that a single use syringe containing flush solution is generally extremely similar in appearance to, and may sometimes be almost indistinguishable from, a syringe containing some other medication or substance. (This can be the case even for specifically designed, pre-made single use flush syringes, but it is especially so for standard single use syringes into which flush solution has been drawn up from an ampoule). As a result of the fact that a single use syringe containing flush solution often looks extremely similar to (if not identical to I indistinguishable from) a syringe containing some other medication or substance, there can be a risk of medical error in that a syringe containing a medication or other substance might accidentally be administered to a patient by mistake, for example, if a clinician, meaning to perform a flush of a patient’s intravenous cannula, accidentally mistakes / confuses a syringe containing medication or other substance for the (intended) syringe containing the flush solution and administers the medication to the patient in error instead of the flush. The reverse situation is also possible, i.e. there may be a risk that, for example, a clinician might accidentally administer a flush to a patient in error instead of administering the required and intended medication. Furthermore, the current method described above for performing a flush that involves drawing up the flush solution into a conventional single use syringe may also be subject to the potential risk of tampering.

[0008] International Patent Application Publication No WO. 2020/055960 A1 discloses a device, described therein as a pre-filled collapsible syringe assembly, which is provided (i.e. it comes prefilled) with flush solution and which is intended for flushing intravenous cannulas and the like. The prefilled collapsible syringe assembly described in WO. 2020/055960 A1 has a manually deformable barrel portion inside which the flush solution is initially contained. The outer wall of the deformable barrel portion is corrugated, and this allows the barrel portion to deform in the manner of a bellows (i.e. in an accordionlike manner). Therefore, when the deformable barrel portion of the collapsible syringe assembly in WO. 2020/055960 A1 is compressed, e.g. by pressing one end of the deformable barrel portion (e.g. using the thumb) towards the other end in which the fluid outlet is formed, the deformable barrel portion collapses/compresses and the corrugated portions of its outer wall come together (accordion-style), such that the internal space I volume within the barrel portion is reduced and the fluid therein is forced out through the fluid outlet. The collapsible syringe assembly in WO. 2020/055960 A1 has a locking protrusion on one of the outer corrugated surfaces of the deformable barrel body, and there is a locking cavity on the adjoining outer corrugated surface. That is, the locking cavity is formed on the outer surface of the corrugated portion which the first mentioned corrugated surface (the one that has the locking protrusion on it) folds into contact with when the corrugated body is fully compressed. Thus, in WO. 2020/055960 A1 , when the deformable corrugated body is fully compressed and the two said corrugated surfaces come together and are pressed into contact with one another, the locking protrusion on the one said surface inserts into/engages with the locking cavity in the other said surface thereby securing those two surfaces together (i.e. preventing them from separating from one another again). This prevents the deformable body (which is now in a fully compressed/collapsed state) from re-expanding from this fully compressed/collapsed state. When the locking protrusion on the one corrugated surface engages in the locking cavity in the adjoining corrugated surface, this is also said to cause a “click” and/or provide tactile feedback thereby confirming to the user that as much of the flush fluid as can be dispensed from within the deformable barrel portion, has been dispensed. A problem with the collapsible syringe assembly described in WO. 2020/055960 A1 is that the locking protrusion on the one corrugated surface only engages with the locking cavity in the other adjoining corrugated surface once the body has been fully collapsed/compressed. Consequently, with the collapsible syringe assembly in WO. 2020/055960 A1 it appears that, if the deformable barrel were to be compressed/collapsed only part of the way, but if the pressure I force that is required to continue compressing/collapsing the deformable barrel is then stopped or released/removed (i.e. at a point before the barrel has been fully compressed and therefore before the locking protrusion engages in the locking cavity), the inherent resilience of the corrugated barrel’s outer wall may cause the barrel to re-expand (possibly including due to the resilient properties of the material from which the barrel is made and also due to the corrugated or accordion-like configuration of the barrel’s outer wall, which has a natural tendency to re-open or re-expand towards its original state if not prevented from doing so). This kind of re-expansion of the deformable barrel, if it occurs while the collapsible syringe assembly is connected to an intravenous cannula (such as while a flush is being performed) would cause some of the flush fluid that has already been dispensed/expelled from within the barrel body, and possibly also some bodily fluids of the patient, to be sucked or aspirated back into the collapsible syringe assembly. This is thought to be undesirable because, as mentioned above, the reason for flushing an intravenous cannula is to help ensure that it remains open and not blocked or obstructed and it also to helps reduce peripheral intravenous cannula related infections or thrombophlebitis. If some of the flush fluid that is initially dispensed/expelled from the device is subsequently sucked or aspirated back in, this may reduce the effectiveness of the flush in helping to ensure that the cannula remains open and unobstructed. Furthermore, if some bodily fluids (e.g. blood) of the patient is also sucked or aspirated back into the device, this may increase (rather than reduce) the possibility for infection or thrombophlebitis.

[0009] International Patent Application Publication No WO. 86/05989 A1 discloses a device which is similar in many ways to (and indeed it functions and is used in much the same way as) the device disclosed in WO. 2020/055960 A1 discussed above. The device disclosed in WO. 86/05989 A1 (like the device in WO. 2020/055960 A1 above) has a manually deformable barrel portion. The outer wall of the deformable barrel portion is also again corrugated (it has a concertina like configuration), and this (again) allows the barrel portion to deform in an accordion- or concertina-like manner. Therefore (similar to WO. 2020/055960 A1 discussed above) when the deformable barrel portion of the device in WO. 86/05989 A1 is compressed, e.g. by pressing one end of the deformable barrel portion (e.g. using the thumb) towards the other end in which the fluid outlet is formed, the deformable barrel portion (again) collapses/compresses and the corrugated portions of its outer wall come together (accordion-style) such that the internal space I volume within the device’s barrel portion is reduced and the fluid therein is forced out through the fluid outlet. The device in WO. 86/05989 A1 also has a locking arrangement for preventing the device from re-expanding after it is completely/fully compressed. Two possible configurations for this locking arrangement are disclosed in WO. 86/05989 A1. In one configuration disclosed therein, there is a projection (referred to as a projecting peg or stud) formed in the end of the barrel that is pressed by the user’s thumb. This peg or stud extends in an inward direction, that is, it projects into the interior of barrel and therefore extends axially into the space inside the barrel, and it points towards the fluid outlet which is in the opposite end of the barrel. In this first configuration of the locking arrangement in WO. 86/05989 A1 , the projecting peg or stud is configured to be lockingly received within the inside of the fluid outlet in the opposite end of the barrel once the device has been completely/fully compressed. Therefore, for the device of WO. 86/05989 A1 which has this first configuration of the locking arrangement disclosed therein, when the compressible barrel of the device has been fully compressed/collapsed, the projecting peg or stud (which extends into the inside of the device from the end of the device which is pressed by the user’s thumb) inserts into and it becomes lockingly received (secured) in the inside of the fluid outlet at the opposite end of the barrel, thereby securing the device in the fully compressed/collapsed state and preventing the device from re-expanding. In the other (second) configuration of the locking arrangement disclosed in WO. 86/05989 A1 , there is an annular flange that extends around the outside of the device at the end of the barrel which is pressed by the user’s thumb, and this flange also projects forward from that end a short distance towards the opposite end of the device, i.e. this flange projects towards the other end of the device which has the fluid outlet. The annular flange also has catches formed thereon which are configured to engage with complimentary formations at the opposite end of the barrel near the fluid outlet. Therefore, for the device of WO. 86/05989 A1 which has this second configuration of the locking arrangement, when the compressible barrel of the device is fully compressed/collapsed, the catches on the flange (which are near the end of the barrel that is being pressed by the user’s thumb) engage with the complimentary formations (which are at the other end of the device near the fluid outlet), thereby securing the device in the fully compressed/collapsed state and preventing the device from re-expanding. A problem with the device in device in WO. 86/05989 A1 , which is similar to the problem described above with reference to WO. 2020/055960 A1 , is that the locking arrangement (in both possible configurations disclosed) only engages once the device is fully collapsed/compressed. Consequently, as for WO. 2020/055960 A1 above, it appears that, if the device in WO. 86/05989 A1 were to be compressed/collapsed only part of the way, but if the pressure I force that is required to continue compressing/collapsing the device is then stopped or released/removed (i.e. at a point before the device is fully compressed and therefore before the locking arrangement (in either of the configurations) has engaged), then the inherent resilience of the corrugated outer wall of the device may cause the device to re-expand towards its original state. As mentioned above, this kind of re-expansion, if it occurs while the device is connected to an intravenous cannula (such as while a flush is being performed) would cause some of the flush fluid that has already been dispensed/expelled from within the formal body, and possibly also some bodily fluids of the patient, to be sucked or aspirated back into the device. As mentioned above, this is undesirable.

[0010] European Patent Application Publication No EP 0 701 833 A1 discloses a device which it describes as a plungerless syringe. The device in EP 0 701 833 A1 has a body at one end (the rearward end) that comprises a hollow, collapsible bellows, and it also has a “cannula portion” at the other (forward) end. The cannula portion is the device’s fluid outlet and its rearward end is connected to the forward end of the bellows portion I body. The cannula portion has a passageway inside it through which fluid can flow from within the bellows portion I body (when the bellows portion is compressed to cause this). A problem with the device in EP 0 701 833 A1 , which is again similar to the problem described above with reference to WO. 2020/055960 A1 and WO. 86/05989 A1 , is that if the device in EP 0 701 833 A1 were to be compressed/collapsed only part of the way (and in particular if the device having the particular configuration shown in the figures of EP 0 701 833 A1 were to be depressed less than halfway in, such that the end of the device which is pressed by the user’s thumb has not yet passed through the widest point on the collapsible bellows portion I body), and if the pressure that is required to continue compressing/collapsing the device is then stopped or released/removed, then the inherent resilience of the outer wall of the body I bellows would likely cause the body I bellows to re-expand towards its original state. Furthermore, it is expressly stated in EP 0 701 833 A1 that at least a portion of the body I bellows is specifically configured to enable such re-expansion (including by the user back pulling on the same end of the body/bellows that is pressed inwards by the thumb in order to pull that end back out) and thereby intentionally cause some of the fluid that has already been dispensed/expelled (and also some bodily fluids of the patient) to be sucked or aspirated back into the device.

[0011] US Patent No 5,509,906 discloses a device which it describes as a plungerless syringe. The device in US 5,509,906 has a rearward collapsible chamber and a forward dispensing assembly. The dispensing assembly is the device’s fluid outlet and the rearward end of the dispensing assembly is connected to the forward end of the collapsible chamber. The dispensing assembly also has a passageway inside it through which fluid can flow from within the collapsible chamber (when the collapsible chamber is compressed/collapsed to cause this). Somewhat similar to EP 0 701 833 A1 discussed above, it is expressly explained in US 5,509,906 that the collapsible chamber is configured to enable it to be re-expanded after having been compressed. In US 5,509,906 this is done by the user pulling back on a tab, which is the same tab located on the rear end of the collapsible chamber that the user presses on with theirthumb to compress the collapsible chamberto expel the fluid. Pulling backwards on the tab causes the collapsible chamber to re-expand, thereby causing suction at the fluid outlet, which in turn (if done while the device is still connected to an intravenous cannula) may cause some of the fluid that has been dispensed/expelled, and also some bodily fluids of the patient, to be sucked or aspirated back into the device.

[0012] US Patent No 5,538,506 discloses a device which is similar to the device in US 5,509,906 in that it is also specifically configured to be able to re-expand after having been compressed. In US 5,538,506 this is (again) done by the user pulling back on a tab, which is the same tab located on the rear end of the device’s collapsible reservoir portion that the user presses on with theirthumb to compress the reservoir portion to expel the fluid. Pulling backwards on the tab causes the reservoir portion to re-expand, thereby causing suction at the fluid outlet, which in turn causes some of the fluid that has been dispensed/expelled and also some bodily fluids of the patient to be sucked or aspirated back into the device.

[0013] US Patent Application Publication No. US 2013/0345673 A1 discloses a number of (what it describes as) pre-filled delivery devices, which are intended for use in intravenous medicine. One particular configuration of device is shown in Figures 3-17 of US 2013/0345673 A1 , and in this particular device configuration, the device has a thumb press at the proximal end and a fluid outlet at the opposite I distal end, and device’s body (which contains the fluid before it is dispensed) comprises a plurality of portions/stages, each with a collapsible side wall, wherein the sidewalls of the respective portions/stages are concentric with one another but the diameters of the respective concentrically-arranged walls decrease moving from the distal end (where the fluid outlet is) to the proximal end (where the thumb press is). This configuration shown in Figures 3-17 of US 2013/0345673 A1 is said to allow the body to fold in onto itself thereby dispensing (i.e. forcing out) the fluid contents contained therein. However, it is thought that, because the body in this configuration comprises (i.e. the body, before it is compressed, is made up of) a number of discrete portion/sections, which decrease in size (diameter) moving from the distal end to the proximal and, consequently when pressure/force is applied to compress/collapse the device, the said discrete portions/sections will collapse, one after another, in stages, rather than collapsing all together smoothly and continuously. Consequently, when fluid is dispensed from the device in Figures 3-17 of US 2013/0345673 A1 , it may be dispensed jerkily or in pulses or “squirts” as each discrete portion/section of the device compresses individually, and the successive portion/sections compress one after another, rather than compressing all together to provide relatively continuous or at least smoother and less varying flow rate exiting the device. It is also thought that the configuration shown in Figures 3-17 of US 2013/0345673 A1 may make it difficult for the user to stop or pause the delivery of fluid at times (or at stages) during the collapsing of the device when one of the portions/sections is only partially collapsed. In other words, with devices that have the configuration shown in Figures 3-17 of US 2013/0345673 A1 , it may be difficult to pause at points (or stages) during the collapsing of the device except at those points I stages where one of the portions/sections has been fully collapsed but the next is yet to begin to be compressed. A further problem with devices that have the configuration shown in Figures 3-17 of US 2013/0345673 A1 is that, even when the device is collapsed fully (i.e. collapsed as much as it can be), there is still a considerable amount of fluid (i.e. a relatively large proportion of the original amount of fluid that the device was supplied with) that remains in the device and is not (and is not able to be) dispensed because a considerable volume of space remains (i.e. it remains open, and therefore fluid remains therein) inside the device even when the device is fully compressed.

[0014] European Patent Application Publication No. 0490 857 A1 and US Patent No 6,383,166 both discloses plungerless syringes. However, because of the configurations of the plungerless syringes in EP 0 490 857 A1 and US 6,383,166 (which are quite similar), a problem again arises that, even when the plungerless syringe is collapsed fully (i.e. collapsed as much as it can be), there is still a considerable amount of fluid (i.e. a relatively large proportion of the original amount of fluid that the device was supplied with) that remains inside the device and is not (and is not able to be) dispensed because a considerable volume of space remains (i.e. it remains open, and therefore fluid remains therein) inside the device even when the plungerless syringe is fully compressed. Another problem that may affect the plungerless syringes of EP 0 490 857 A1 and US 6,383,166 is that if the plungerless syringe were to be compressed/collapsed only part of the way (and in particular if it were to be depressed less than halfway in, such that the end of the device which is pressed inwards, e.g. by the user’s thumb, has not yet passed through the widest point on the collapsible container portion), and if the pressure that is required to continue compressing/collapsing the plungerless syringe is then stopped or released/removed, then the inherent resilience of the outer wall of the container portion of the plungerless syringe may cause the container portion to re-expand towards its original state, sucking or aspirating flush fluid and/or bodily fluid back into the plungerless syringe.

[0015] It is to be clearly understood that mere reference anywhere in this specification to any previous or existing devices, apparatus, products, methods, practices, publications, patents, or indeed to any other information, orto any problems or issues, does not constitute an acknowledgement or admission that any of those things, whether individually or in any combination, formed part of the common general knowledge of those skilled in the field or is admissible prior art.

SUMMARY OF THE INVENTION [0016] In one form, albeit not necessarily the only or even the broadest form, the invention resides in a single-use device for use in administering a fluid substance to a patient via an intravenous catheter or cannula, the device having:

■ a body with a hollow interior inside at least part of the body, and the device is manufactured (i.e. it is provided pre-made or pre-filled) with the fluid substance that is to be administered to the patient contained within the hollow interior part of the body;

■ a connecting portion (which may be part of the body) for connecting the device to the intravenous catheter or cannula; o an opening in the connecting portion which leads into the hollow interior of the body, which opening is initially closed (sealed) but which can be opened, or, o a portion of the connecting portion in which an opening into the hollow interior of body can be formed; wherein once the opening is opened or formed, the fluid substance is able to exit the hollow interior part of the body through the opening (and if the device is connected to the intravenous catheter or cannula via the connecting portion when this happens, the fluid substance flows into the patient via the intravenous catheter or cannula); and

■ a deformable portion of the body which, after the opening into the hollow interior has been opened or formed, is able to be deformed, or its shape is able to change, upon application of force, wherein the deformation of, or the change in shape of, the said deformable portion caused by the application of force reduces the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening, wherein the volume of the hollow interior can be reduced substantially to (i.e. to almost if not exactly) zero (i.e. to almost if not completely nil volume) such that substantially all of the fluid substance that was originally contained within the hollow interior is expelled, and if the application of force which deforms the deformable portion, or causes the shape thereof to change, is stopped or paused (or reduced to below a level needed to cause further deformation or change in shape of the deformable portion), the state/extent of the deformation of, or the (change in) shape of, the deformable portion will remain as it was at that point (i.e. as it was at the point when the application of the force was stopped or paused) and the deformable portion does not return or re-expand (even partially, in a way that would cause an amount of the fluid substance to be sucked or drawn back in).

[0017] In some embodiments, it may be that (and it is thought that this may be preferable) the deformation of, or the change in shape of, the deformable portion may occur smoothly/continuously, i.e. not jerkily or in stages. For instance, it may be that (and it may be preferable that) the rate of flow of the fluid substance exiting the device may remain substantially (or at least approximately/roughly) constant if/while the application of force by the user that causes this is kept approximately constant.

[0018] Also, a user may be able to stop or pause the delivery/expulsion of the fluid substance out of the hollow interior at any point after the deformation or change in shape of the deformable portion has commenced, but before the deformation or change in shape thereof is complete, by ceasing the application of the force (or reducing the amount of force applied to below the level required to continue the deformation or change in shape of the deformable portion).

[0019] As explained above, the device may have an opening in the connecting portion which leads into the hollow interior of the body, which opening is initially closed but which can be opened. In some embodiments which have this opening, the opening may be initially closed and sealed by a cap, but the opening may be opened and unsealed by removing the cap. In some such embodiments, the connecting portion of the device may include a luer lock connector portion, and the cap may be initially attached to, and it may seal the device, via the luer lock connector portion.

[0020] However, as also explained above, the connecting portion of the device may have a portion in which an opening into the hollow interior part of body can be formed (i.e. even if there is no opening formed therein initially). In such embodiments, the device may initially be provided with a removable tab attached to the connecting portion, and the removable tab may be able to be separated from the connecting portion, and separating the removable tab from the connecting portion may cause the opening into the hollow interior part of the body to be formed. The removable tab may initially be integrally formed with the connecting portion of the device. Furthermore, in some particular embodiments, the body, connecting portion and removable tab may be unitary being initially formed from a single piece of material.

[0021] In the above embodiments in which the device is initially provided with a removable tab attached to the connecting portion, and the removable tab is able to be separated from the connecting portion, and separating the removable tab from the connecting portion causes the opening into the hollow interior part of the body to be formed, when the removable tab is separated from the connecting portion (i.e. once the removable tab has been separated from the connecting portion), the connecting portion may be configured as either a male portion of a luer slip connector or a male portion of a luer lock connector.

[0022] The device may be manufactured (i.e. it may be provided pre-made or pre-filled) with the fluid substance completely filling, or at least almost completely filling, the hollow interior part of the body.

[0023] Once the above-mentioned opening in the connecting portion is opened or formed, and with the connecting portion oriented generally upwards, but before the device is connected to the intravenous catheter or cannula, the device may be able to be “primed”. In some embodiments, this may be done by causing a small quantity of the fluid substance to be forced out through the opening, such that the level of the surface of the fluid substance is (or it becomes) substantially level with the opening in the connecting portion (i.e. to help ensure that no air remains inside the hollow interior of the body, including in or near the rim of the opening, before the device is connected to the intravenous catheter or cannula). [0024] In some embodiments, the device may include an auxiliary depressible portion, and the device may be able to be “primed” (once the opening is opened or formed, and with the connecting portion oriented generally upwards, but before the device is connected to the intravenous catheter or cannula) by depressing the auxiliary depressible portion which causes a small quantity of the fluid substance to be forced out through the opening, such that the level of the surface of the fluid substance is (or it becomes) substantially level with the opening in the connecting portion.

[0025] In other embodiments, the device may be able to be “primed” by applying force to the deformable portion of the body which (after the opening into the hollow interior of the device has been opened or formed) is able to be deformed, or the shape of which is able to change, upon the application of such force, wherein “priming” the device in this way involves applying sufficient force that the deformation of, or the change in shape of, the said deformable portion caused by the application of the force reduces the volume of the hollow interior of the body by a sufficiently small amount that only a correspondingly small quantity of the fluid substance is forced out of the hollow interior through the opening.

[0026] There may also be a relatively more non-deformable portion of the body which, even after the opening into the hollow interior part of the device has been opened or formed, is not substantially deformed, or the shape of which remains substantially unchanged, upon the application of force to the device. The connecting portion may be part of this more non-deformable portion of the body. The body of the device may be sized to be grasped by a user in one hand. (Once the above-mentioned opening is opened or formed, and) With the connecting portion oriented generally upwards, the device may be able to be grasped by a user in one hand with one or more fingers pressing generally downwards from above on the more non-deformable portion of the body and with the thumb simultaneously pressing generally upward against the deformable portion of the body.

[0027] The more non-deformable portion of the body may include a first conical portion that tapers (i.e. it may have an outer diameter that decreases) from a widest point to a narrowest point in a first direction, and the deformable portion of the body may include a second (initially) conical portion extending from at or near the widest point of the first conical portion, and the second (initially) conical portion may (initially) taper (i.e. before it is deformed it may have an outer diameter that decreases) from a widest point to a narrowest point in a direction opposite to the first direction. Force may be applied to the second conical portion in the first direction causing the second conical portion to deform/collapse in the first direction, towards (and possibly also into) the first conical portion, and the deformation, or the change in shape, of the second conical portion caused by this, may reduce the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening.

[0028] The second conical portion may include an indent or groove, or a series of indents or grooves, that initially (before the deformation of the second conical portion commences) extend(s) around, and also up/down, the second conical portion. The configuration of said indent(s) or groove(s), and the way it/they deform(s) when second conical portion deforms, may help to ensure that if or when the application of force which deforms the second conical portion, or causes the shape thereof to change, is stopped or paused (or reduced to below a level needed to cause further deformation or change in shape), the state/extent of the deformation of, or the change in shape of, the deformable second conical portion will remain as it was at that point (i.e. as it was at the point when the application of the force was stopped or paused) and the deformable second conical portion does not return or re-expand (even partially, in a way that would cause an amount of the fluid substance to be sucked or drawn back in).

[0029] In certain other embodiments, the deformable portion of the body may include a concertinashaped portion extending from a portion of the non-deformable portion. In these embodiments, after the opening into the hollow interior part of the device has been opened or formed, force may be applied to the concertina-shaped portion causing the concertina-shaped portion to deform and collapse (i.e. causing it to squash) towards the non-deformable portion, which reduces the volume of the hollow interior part of the body such that the fluid substance is forced out of the hollow interior through the opening. In these embodiments, there may be parts of, or points on, the deformable portion of the body which progressively engage with one or more parts of, or points on, the non-deformable portion as the deformable portion is progressively deformed, or as its shape is caused to progressively change, by the application of force, such that if the application of force is stopped or paused (or reduced to below a level needed to cause further deformation or change in shape), the state/extent of the deformation of, orthe change in shape of, the deformable portion will remain as it was at that point (i.e. as it was at the point when the application of the force was stopped or paused) and the deformable portion does not return or re-expand (even partially, in a way that would cause an amount of the fluid substance to be sucked or drawn back in).

[0030] Other features and aspects of the present invention will be made evident from the Detailed Description below.

BRIEF DESCRIPTION OF THE FIGURES

[0031] Features, embodiments and/or variations of the invention may be discerned from the following Detailed Description which (together with Background section above) provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the invention, whether as summarised in the preceding Summary of the Invention or as set out in the appended Claims (if any) or otherwise. The Detailed Description below makes reference to a number of Figures as follows:

[0032] Figure 1 is a perspective view of a prefilled single use flush device (a device) in accordance with a first embodiment of the present invention.

[0033] Figure 2 is a top view (i.e. from above) of the device in Figure 1 .

[0034] Figure 3 is a side view of the device in Figure 1 in an orientation where the device’s dome is visible from side on. [0035] Figure 4 is a side view of the device in Figure 1 in an orientation where the device’s dome is not visible because it is hidden from view in this orientation (i.e. the device’s dome is on the side of the device that is hidden from view in this Figure).

[0036] Figure 5 is an underside view (i.e. from below) of the device in Figure 1 .

[0037] Figure 6 contains a number of views, referred to hereafter as Figure 6(i) - Figure 6(iv), of a device like the one in Figure 1 on which certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 6(i) - Figure 6(iv) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 1 to Figure 5 etc) may have different dimensions and/or relative proportions to those shown in Figure 6.

[0038] Figure 7 contains a number of views, referred to hereafter as Figure 7(i) - Figure 7(iv), which help to illustrate some (but not all) aspects of the way a device like the one in Figure 1 can be produced.

[0039] Figure 8 contains a number of views, referred to hereafter as Figure 8(i) - Figure 8(v), of a prefilled single use flush device (a device) in accordance with a second possible embodiment of the present invention. Note that there may be features of the invention which, even though not shown/depicted in Figure 8 (or Figure 9 or Figure 10), may nevertheless be part of and/or used in and/or incorporated into this embodiment.

[0040] Figure 9 is similar to Figure 8 in that it also contains a number of views, referred to hereafter as Figure 9(i) - Figure 9(v), and the images in these are actually the same as in Figure 8(i) - Figure 8(v) respectively, except that in Figure 9(i) - Figure 9(v) certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 9(i) - Figure 9(v) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 8) may have different dimensions and/or relative proportions to those shown in Figure 9.

[0041] Figure 10 contains a number of views, referred to hereafter as Figure 10(i) - Figure 10(iii), illustrating certain steps in the use of the device in this embodiment.

[0042] Figure 11 contains a number of views, referred to hereafter as Figure 11 (i) - Figure 11 (vii), of a prefilled single use flush device (a device) in accordance with a third possible embodiment of the present invention.

[0043] Figure 12 is similarto Figure 11 in that it also contains a number of views, referred to hereafter as Figure 12(i) - Figure 12(vii), and the images in these are actually the same as in Figure 11 (i) - Figure 11 (vii) respectively, except that in Figure 12(i) - Figure 12(vii) certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 12(i) - Figure 12(vii) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 1 1) may have different dimensions and/or relative proportions to those shown in Figure 12.

[0044] Figure 13 contains a number of views, referred to hereafter as Figure 13(i) - Figure 13(iii), illustrating steps in the use of the device in this embodiment.

[0045] Figure 14 contains a number of views, referred to hereafter as Figure 14(i) - Figure 14(v), of a prefilled single use flush device (a device) in accordance with a fourth possible embodiment of the present invention

[0046] Figure 15 is similarto Figure 14 in that it also contains a number of views, referred to hereafter as Figure 15(i) - Figure 15(v), and the images in these are actually the same as in Figure 14(i) - Figure 14(v) respectively, except that in Figure 15(i) - Figure 15(v) certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 15(i) - Figure 15(v) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 14) may have different dimensions and/or relative proportions to those shown in Figure 15.

[0047] Figure 16 contains a number of views, referred to hereafter as Figure 16(i) - Figure 16(iii), illustrating steps in the use of the device in this embodiment

[0048] Figure 17 through Figure 22 contain various views of a prefilled single use flush device (a device) in accordance with a fifth possible embodiment of the present invention. Figure 17 is a first perspective view of the device in this embodiment, Figure 18 is a side view of the device, Figure 19 is a top view (i.e. from above) of the device, Figure 20 is a second perspective view of the device in this embodiment, Figure 21 is a cross-sectional view of the device in this embodiment taken in a vertical plane extending through the centre of the device, and Figure 22 is an underside view (i.e. from underneath) of the device. Note that there may be features of the invention which, even though not shown/depicted in any of Figure 17 through Figure 22 may nevertheless be part of and/or used in and/or incorporated into this embodiment.

[0049] Figure 23 is a perspective view of a prefilled single use flush device (a device) in accordance with a sixth embodiment of the present invention, which is mainly similar to the first embodiment shown in Figure 1 to Figure 6 except that it has a longer neck portion.

[0050] Figure 24 is a top view (i.e. from above) of the device in Figure 23.

[0051] Figure 25 is a side view of the device in Figure 23 in an orientation where the device’s dome is visible from side on.

[0052] Figure 26 is a side view of the device in Figure 23 in an orientation where the device’s dome is visible front-on. [0053] Figure 27 is an underside view (i.e. from below) of the device in Figure 23.

[0054] Figure 28 contains a number of views, referred to hereafter as Figure 28(i) - Figure 28(v), of a device like the one in Figure 23 on which certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 28(i) - Figure 28 (v) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 23 to Figure 27 etc) may have different dimensions and/or relative proportions to those shown in Figure 28.

[0055] Figure 29 is a perspective view of a prefilled single use flush device (a device) in accordance with a seventh embodiment of the present invention, which is similar to the sixth embodiment shown in Figure 23 except that, whereas the upper end of the neck portion in the sixth embodiment shown in Figure 23 provides the male portion of a luer slip connector, in contrast, the structure at the upper end of the neck portion in the seventh embodiment functions like a luer lock connector.

[0056] Figure 30 is a top view (i.e. from above) of the device in Figure 29.

[0057] Figure 31 is a side view of the device in Figure 29 in an orientation where the device’s dome is visible from side on.

[0058] Figure 32 is a side view of the device in Figure 29 in an orientation where the device’s dome is visible front-on.

[0059] Figure 33 is an underside view (i.e. from below) of the device in Figure 29.

[0060] Figure 34 contains a number of views, referred to hereafter as Figure 34 (i) - Figure 34(v), of a device like the one in Figure 29 on which certain dimensions (in millimetres) and features of the device are shown and labelled. It is to be clearly understood that the dimensions shown in Figure 34 (i) - Figure 34 (v) are given by way of example only, and the invention (even in embodiments having a configuration like the one shown in Figure 29 to Figure 33) may have different dimensions and/or relative proportions to those shown in Figure 34.

DETAILED DESCRIPTION

[0061] As indicated above, Figure 1 through Figure 6 illustrate a device 100 in accordance with a first possible embodiment of the present invention. The device 100 in this embodiment is a prefilled single use flush device for use in flushing an intravenous cannula. In other words, it is a device that is manufactured and supplied (i.e. it comes pre-made) containing a quantity of flush solution ready to be used to perform a flush of an intravenous cannula.

[0062] The device 100 may (and typically will) be supplied in a sterile condition. For example, the device 100 may be supplied inside a sterile packet or envelope or container or the like (i.e. in a similar manner to the way in which e.g. syringes and other such medical devices are often supplied). The same applies to the devices in the various other embodiments discussed further below. All explanations given below assume that the device has initially been removed from any sterile packaging or container in which it may have been supplied, i.e. the explanations below explain the device (in various different embodiments) after it has been removed from any sterile packaging or container in which it may have been supplied.

[0063] Typically, the flush solution will be saline solution, i.e. a solution comprising sodium chloride (NaCI) dissolved in water at a concentration of 0.90% weight per volume, although it is to be noted that there is no strict limitation on the particular type of flush solution used and the device 100 could therefore be prefilled with a quantity of any solution that is suitable for use in flushing intravenous cannulas.

[0064] As shown e.g. in Figure 3, the device 100 includes a body 110 and a removable tab 170. The body 110 includes an upper portion 120 and a lower portion 150. The way (or possible ways) that the device 100 may be made will be discussed further below. However, before discussing the way(s) in which the device 100 may be made, it is useful to initially explain how the device 100 can be used.

[0065] In order for the use of the device 100 to be understood, it should first be noted that the body 110 of the device is hollow. In particular, all parts of the body 110, including the upper portion 120 (which itself includes the body portions 130 and 135 and the neck portion 140) and also the lower portion 150, are hollow, and the device 100 comes pre-filled (i.e. it is supplied) with flush solution (typically saline solution) contained within the hollow interior of the body 110 (mainly inside 130 and 150). The device 100 comes pre-filled with flush solution completely filling (or at least almost completely filling) the entire volume of the hollow interior of the body (mainly inside 130 and 150). In embodiments where the device is configured like the device 100 (and also in other embodiments discussed below), the volume of flush solution provided (i.e. which comes pre-filled) inside the body will often be about 2 mL to about 10 mL. However, it will be appreciated that the size and shape of the body, and hence the volume of the hollow interior inside the body, can be varied in order to enable the device to be used to supply smaller or larger quantities of flush solution (as may be required). The same applies to devices in other embodiments, discussed further below.

[0066] In any case, in general terms, the size of the body 110 of the device 100 is such that, firstly, the volume of the hollow interior inside the body 110, and hence the volume/quantity of flush solution contained therein (i.e. the amount of flush solution that comes pre-filled in the device 100 and which almost, if not completely, fills the hollow interior of the body 110 prior to use), is sufficient (i.e. the device contains enough flush solution) to be used in performing a single flush of an intravenous cannula. However, in addition to this, the body 110, and in particular the “bulbous” part of the body 110, which comprises the portions of the body 110 located at the lower end of the device (in Figure 1 through Figure 6 this “bulbous” bottom part of the body includes the body portions identified by reference numerals 130 and 150), is sized so that it can be grasped by a user in one hand, and the user can also simultaneously grasp the tab 170 at the top of the device in the other hand.

[0067] Although the body 110, and also the tab 170, of the device 100 in this embodiment are both formed together as a single unitary piece initially (as will be discussed further below), at the location 147 where the tab 170 joins to the top of the body 1 10 (i.e. where the tab 170 joins to the top of the neck portion 140, which neck portion 140 is shaped/configured as a male part of a standard luer slip connector) the material connecting the tab 170 to the top of the male luer slip connector part 140 is a “frangible” or “breakable”. The frangibility or breakability of the material at this location 147 may be achieved, for example, by giving the material at this location 147 a reduced thickness (i.e. making it thinner) compared to other parts of the body 1 10, or the frangibility or breakability of the material at 147 may be due to the way the material at this location is indented (e.g. as shown in the figures - this indentation can in turn lead to localised stress concentrations and earlier/easier failure of the material at this location 147 when the tab 170 is twisted or bent relative to the body, as discussed below), or this frangibility or breakability of the material at this location 147 may be achieved in any other suitable way.

[0068] In any case, a user (who will typically be a nurse or clinician or other healthcare professional) can twist and/or bend the tab 170 relative to the body 110, thereby causing the material connecting these two parts (i.e. the material at location 147) to break, and consequently allowing the tab 170 to become separated (torn away) from the top of the body 110 (specifically the tab 170 becomes separated and torn away from the top of the male luer slip connector (“neck”) part 140). When the tab 170 is torn free and separates from the top of the body 110 (and specifically from the top of the male luer slip connector (neck) part 140), the removal of the tab 170 creates (or this causes to be revealed) an opening (not shown) in the top of the body 110. More specifically, the removal of the tab 170 creates an opening (not shown) in the top of the male luer slip connector (neck) part 140. This opening (not shown) in the top of the male luer slip connector (neck) part 140 (which is only created when the tab 170 is removed) is the opening which the flush solution inside the device 100 can flow out through in use, as discussed further below.

[0069] It should next be noted that, because removing the tab 170 (tearing it away) from the top of the device 100 causes the opening (not shown) to be formed in the top of the device body 110 (i.e. it creates the opening (not shown) in the top of the male luer slip connector (neck) part 140), consequently the device should be oriented with the tab 170 and the male luer slip connector (neck) part 140 pointed generally vertically or upwards when the tab 170 is being removed. If the device is not oriented with the tab 170 and the male luer slip connector (neck) part 140 pointed generally upwards when the tab 170 is being removed (and immediately thereafter), i.e. if the tab 170 were to be removed while the device is oriented with the male luer slip connector (neck) part 140 pointed somewhat sideways/horizontally or downwards, then in that case some of the flush solution contained inside the device would likely spill out through the opening immediately after the tab 170 is removed. Orienting the device 100 with the tab 170 and the male luer slip connector (neck) part 140 pointed generally upwards immediately before, when, and after the tab 170 is removed can help prevent such accidental spillage of flush solution from occurring when (and after) the tab 170 is removed.

[0070] Thus, when the device 100 is to be used, the user can initially “open” the device 100 by grasping the body 110 of the device (i.e. the “bulbous” bottom portion of the device) in one hand, and simultaneously grasping the tab 170 in the other hand, and with the tab and the male luer slip connector (neck) part 140 pointed upwards, the user can twist and/or bend the tab 170 relative to the body 110 so that the material connecting the tab 170 to the top of the male luer slip connector (neck) 140 breaks at location 147 and the tab 170 breaks/tears away and separates from the top of the body 110, thereby revealing the opening (not shown) in the top of the male luer slip connector (neck) 140. After the device 100 has been “opened”, i.e. once the tab 170 has been removed, the tab 170 can be discarded.

[0071] However, even after it has been “opened”, before the device 100 is connected to an intravenous cannula for the flush solution therein to be administered via the cannula for the purpose of performing a flush of the cannula, it is generally important for the user to first (i.e. before connecting the device 100 to the cannula) make sure that any air (or possibly other gas(es)) that may be present inside the device 100, or as much of this as possible, is removed. In other words, it is important to ensure that any air (and/or other gas), which may be contained inside the device’s body (e.g. this may be present as small bubbles in the flush fluid and/or as air/gas pockets inside the hollow body of the device 110), is removed and the device contains none, or as little as possible, of this, before the device is connected to the intravenous cannula for use. This is to prevent any (or as much as possible) of such air or gas from being administered into the patient with the flush solution when the flush of the cannula is performed. The way in which this (removal of air/gas from within the device) can be done with the device 100 is as follows.

[0072] Firstly, the (now “open”) device 100 can be held (by holding the “bulbous” portion in one hand and) with the male luer slip connector (neck) part 140 (and the open opening in the top end thereof (not shown)) pointed vertically upwards, and the device can then be tapped or flicked (or otherwise vibrated, etc) in order to dislodge or shake free any air or other gas bubbles that may, for example, be trapped in corners inside the hollow interior of the device, or temporarily stuck/adhered to the inside walls or surfaces of the device, etc. The purpose of tapping or flicking (or otherwise vibrating) the “open” device is to cause any such bubbles to become dislodged from the walls or corners inside the device against or in which they may have been trapped, such that those bubbles then float upwards through the flush fluid towards the top of the device and ultimately exit/leave the device through the “open” opening in the top of the male luer slip connector (neck) part 140. Thus, any (or as many as possible of) such air/gas bubbles are allowed to escape, and they are thereby removed (i.e. no longer present) in the flush solution or inside the device.

[0073] After the above-mentioned initial “vibration” step has been performed to dislodge and remove (as many as possible of the) air/gas bubbles that might have been present inside the device, the next step, still with the device oriented with the male luer slip connector (neck) part 140 pointing generally upwards, is for a small quantity of the flush solution to be forced up and out (i.e. a small quantity of the flush solution should be deliberately dispensed/ spilt out) through the opening (not shown) in the top of the male luer slip connector (neck) part 140. This is called “priming” the device. The reason this is done is so that, after this small quantity of flush solution has flowed/spilled up out through the opening top of the male luer slip connector part 140 (i.e. after the device has been “primed”), the level of the surface of the flush fluid still remain in the device will then be level with the very top of the male luer slip connector (neck) part 140 (i.e. level with the very rim of the opening in the male luer slip connector (neck) part 140). This, in turn, ensures that no air remains anywhere inside the neck 140 including that there is no air gap remaining just inside the very top of the male luer slip connector (neck) part 140. (A small air gap would still be present just inside the very top of the male luer slip connector (neck) part 140, just below the opening, if the level of the surface of the remaining flush fluid inside the device were to be below the level of the very upper rim of the opening in the male luer slip connector (neck) part 140. However, “priming” the device by causing a small quantity of the flush solution to be forced up and out through the opening in the top of the male luer slip connector (neck) part 140 ensures that, after this has been done, the level of the surface of the flush fluid then remaining is level with the very top of the rim of the opening in the male luer slip connector part 140, such that no air gap remains.)

[0074] With the embodiment shown in Figure 1 through Figure 6 (after the tab 170 has been removed, and with the body 110 still held upright, and after air/gas bubbles have been removed by the tapping/vibration step explained above), the way in which the user can next “prime” the device (i.e. deliberately cause a small quantity of the flush solution to be forced up and out through the opening (not shown) in the top of the male luer slip connector (neck) part 140) is by pressing on (e.g. with a thumb or finger), and depressing, the dome portion (“priming dome”) 160 which is present on the upwardly-facing conical face of the body portion 130. Importantly, it should be noted that, as can be appreciated from e.g. Figure 6(ii) the dome portion (priming dome) 160 (like all other parts of the portions 130 and 150 of the body of the device 100) is hollow. Accordingly, the space inside the priming dome 160 is initially filled with flush solution. Consequently, when the user presses on and depresses the dome portion 160, this causes the dome portion 160 to deform and collapse inwards towards the inside of the body. This, in turn, causes the flush solution that was in the hollow interior region of space inside of the dome portion 160 to also be pushed inwards, i.e. into the main volume inside the conical portions 130 and 150. In other words, when the user depresses the dome portion 160 inwards, the total internal volume inside the body of the device is reduced due to the change in shape of (and hence the reduced or eliminated, or possibly inverted, internal volume within) the priming dome portion 160. And this, in turn, causes the required small quantity of flush solution (i.e. a small quantity of the flush solution having a volume equivalent to the amount by which the internal volume of the device is changed by the depression of the priming dome portion 160) to be forced up and out through the opening (not shown) in the top of the male luer slip connector (neck) part 140. Thus, the device 100 can be “primed” by depressing the dome portion 160 and causing it to collapse inwards, which forces a small amount of fluid out through the opening.

[0075] It is important to note that, when the user presses on the priming dome portion 160 to depress it in order to “prime” the device 100, the deformation of the dome portion 160 is permanent and irreversible. In other words, the dome portion 160 does not (and cannot) pop back out, or re-expand, or otherwise deform further in a way that might cause some of the flush solution to be drawn or sucked back into any part of the space inside the dome portion 160 that was occupied with fluid before the device was “primed” (but which fluid was forced out of that region when dome portion 160 was pressed in). This is important because, if any fluid were to be drawn or sucked back into this region, this could also cause an air gap to be created (or recreated or reformed) at the very top of the device near or in the opening in the male luer slip connector (neck) part 140. [0076] Once the device 100 has also been “primed”, such that all air/gas (or as much as possible) has been removed (including from within the opening (or the rim of the opening) at the very top of male luer slip connector (neck) part 140), the “open” device 100 can next be connected to an intravenous cannula in order for the flush solution contained therein to be administered to the patient to flush the cannula.

[0077] It should be noted at this point that, although it is explained above that the “priming” step can be performed with the device 100 after the tab 170 has been removed, it is also possible for the “priming” step to be performed just before the tab 170 has been removed (but preferably still after the above “vibration” step has been performed). In other words, in some cases, a user may “prime” the device 100 by depressing the dome portion 160 and causing it to collapse inwards (after the “vibration” step has been performed and) just before the tab 170 is removed. If this is done, i.e. if the device 100 is “primed” by depressing the dome portion 160 (preferably after the “vibration” step and) just before the tab 170 is removed, this will temporarily create or cause an increase in pressure inside the (still closed/sealed) device. Then, when (or as) the tab 170 is subsequently removed, the increased pressure will cause the required small quantity of flush solution to flow/spill up out through the open top of the male luer slip connector part 140, as required. Also, in this situation, because the “vibration” step will preferably have been performed before the device is “primed” and the tab 170 removed, any (or at least most of the) air or gas bubbles that may have been present in the device should have already floated up to the top, so that they are already present at or near or in the top of the luer slip connector part 140 at the time when the tab 170 is removed. Consequently, the increased pressure caused by “priming” the device before the tab 170 is removed will also mean that these are air bubbles (which are then present at or near or in the top of the luer slip connector part 140) will also be expelled through the opening formed when the tab 170 is removed. It should also be noted that the same may be done with other embodiments discussed further below. That is, the action of priming the device may be formed before, rather than after, the tab or cap which initially closes/seals the device is removed (but preferably still after the “vibration” step has been performed), even though this possibility of removing the tab or cap is not expressly discussed in connection with any of the other embodiments below.

[0078] With the embodiment shown in Figure 1 through Figure 6, the way in which the “open” device 100 (i.e. after it has been “primed”, as explained above) can be connected to an intravenous cannula (not shown) is that the male luer slip connector (neck) part 140 is inserted into a correspondingly sized and shaped female luer slip connector part (not shown) on the end of the intravenous cannula. These male/female luer slip connections are standardised and widely used on many forms of intravenous medical devices, so the means by which the device 100 can be connected to an intravenous cannula via such a standard male/female luer slip connection should be readily apparent. Nevertheless, by way of brief explanation, the male luer slip connector (neck) part 140 is generally elongate in shape and its outer surface tapers/n arrows in an upward direction (i.e. the outer diameter of the male (neck) part 140 is greater at its base than at its upper end). The corresponding female luer slip connector part (not shown), into which the male connector part 140 is inserted when the device 100 is connected to the cannula, has a closely corresponding internal shape. That is, the female luer slip connector part (not shown) would have an opening that is widest at its outer end and which tapers/n arrows in a direction moving into the female connector. The diameter and taper of the internal surface of the female connector part would be substantially identical to the diameter and taper of the outer surface of the male connector part 140. Consequently, in order to connect the device 100 to the cannula, the male connector (neck) part 140 is inserted into the corresponding female connector part (not shown), and when this is done, the outer surface of the male connector (neck) part 140 fits snugly into and it presses firmly against the internal surface of the female connector part, thus forming a fluid tight seal between the two when they are connected together.

[0079] It should be noted that, although most or all of the outer surface of the male part 140 is inserted into the corresponding female part (not shown) of the luer slip connector when the device 100 is connected to the cannula, the joint part 135 of the device 100, which connects the male (neck) part 140 to the top of the upwardly-facing conical portion 130 of the device, does not insert into the inside of the female portion of the cannula’s luer slip connector.

[0080] It should also be noted that, in a possible variant of the device 100, the neck portion 140 of the device could instead be configured like the female portion of a conventional luer slip connector. Such a configuration might be useful where it is a male portion of a luer slip connector that is provided on the end of the cannula to which the device is to be connected. The same applies to the other embodiments discussed below. That is, although the various embodiments discussed below are described as devices which have (or which have portions that functions as) the male portion of a conventional luer slip or luer lock connector, the devices could alternatively have (or they may be provided with portions that function as) the female portion of a conventional luer slip or luer lock connector, so as to enable them to connect with a cannula having a corresponding male connector portion thereon.

[0081] After the device 100 has been opened, primed, and connected to the cannula, as all described above, the device 100 is then ready to be used to perform a flush of the cannula. To do so, the user of the device 100 (typically a nurse or clinician or other healthcare professional) will typically first grasp the body 110 of the device in one hand. More specifically, the user will typically hold the device in one hand with two fingers pressing on the outer conical surface 130 of the body, i.e. with those fingers pressing on the upper surface of the conical portion 130 (typically with one finger positioned to either side of the male luer slip connector (neck) part 140), and the user’s thumb will simultaneously press against the substantially flat base of the body’s lower conical part 150. Thus, the user will initially hold the device with the thumb pressing against the substantially flat base of conical part 150 such that the thumb is applying pressure in a direction generally opposite to the direction in which their fingers are simultaneously pressing against (and applying pressure to) the conical surface 130. Thus, the “bulbous” part of the device’s body (which comprises body portions 130 and 150) is held/grasped between the user’s thumb and fingers.

[0082] Then, when it is desired to intentionally dispense the flush fluid from the device, i.e. when it is desired to cause the flush fluid to be expelled out through the opening in the top of the male connector (neck) part 140 and into the cannula (i.e. to administer the flush fluid into the patient via the cannula to thereby flush the cannula), the user increases the force applied between their thumb and fingers, i.e. they squeeze the “bulbous” part of the device between their thumb and fingers more tightly or with greater force, and more specifically, with sufficient force to begin deforming the lower conical portion 150. This initially causes the lower conical portion 150 of the body to begin to deform and collapse inward ly/upwardly towards (and ultimately into) the underside (i.e. towards and into the concave inside) of the upwardly- facing conical portion 130. As will be appreciated, when the lower conical portion 150 of the body begins to deform and collapse in this way, the flush fluid contained inside the body, between the portions 130 and 150 of the body, begins to be forced up and out and therefore dispensed from (i.e. it begins to be forced out through) the opening in the top of the male connector (neck) part 140. With continued application of such force by the user (i.e. while the user continues to squeeze the bulbous part of the device between the thumb and fingers with sufficient force) the lower conical portion 150 continues to deform and collapse upwards towards and then into the inside of the conical portion 130. The effect of the progressive deformation/collapsing of the lower conical portion 150 (which is caused by the deliberate initiation, and then the continued application, of sufficient force by the user) is that the material of the (originally) conical lower portion 150 (i.e. the material from which this part of the device is made) moves upwards as it deforms and collapses and, ultimately, when the material of the lower conical portion 150 has been depressed (i.e. pressed in by the user) as far as it will go, the material of the (originally convex) conical portion 150 comes to be mostly (if not entirely/completely) inverted (into a concave shape) so that it conforms to, and so that it’s inside (interior) surface is close to or in contact with, the concave interior/inside surface of the conical portion 130.

[0083] This deformation of the (originally conical) lower portion 150 (which deformation, for reasons discussed below, is permanent and non-reversible at all stages after it has begun), ultimately causes the lower portion 150 to become (mostly if not fully) inverted and pressed (mostly if not fully) into close conformity (or even conforming contact) with the underside (inside surface) of the conical body portion 130, and this, in turn, means that once the lower portion 150 has been fully compressed in this way, all of the flush solution that was previously (after the device had been “primed”) contained inside the body in the hollow space between the inside/underside of the conical portion 130 and the inside surface of the (originally) conical lower portion 150 will have been forced out of the device through the opening in the top of the male connector (neck) part 140. In other words, after the user has pressed the lower portion 150 in as far as it can go, the volume of the space between the inside surfaces of the conical portion 130 and the (now substantially inverted) portion 150 is reduced substantially (i.e. nearly if not absolutely or completely) to zero - i.e. there is little if any space left between them, and therefore there is also little if any remaining flush fluid left in between them. (There may still be a little fluid remaining inside the neck portion, but the amount of this would be small or negligible. This is also true if the length of the neck portion is made longer, as in certain other embodiments discussed below. That is, even if the length of the neck portion is made longer, the amount of fluid remaining therein after the user has pressed the lower portion 150 in as far as it can go will still be small or negligible.)

[0084] Because the device 100 is connected to the intravenous cannula when this is done, the quantity of flush fluid that is forced up and out of the device (which is substantially all of the flush solution that was previously (after the device had been “primed”) contained inside the body in the hollow space between the inside/underside of the conical portion 130 and the inside surface of the (originally) conical lower portion 150) is consequently administered to the patient via the cannula, thereby flushing the cannula. Consequently, if the volume of flush fluid that comes prefilled within the device is known (which it generally will be, and it will generally be the volume of fluid that is required to be delivered to perform an effective flush), then once the flush has been performed and the lower portion 150 has been fully depressed, so that substantially all of the fluid originally contained within the device is expelled, the user can be confident that the amount of flush fluid required to be delivered to perform an effective flush, has been delivered.

[0085] It is important to note that, the reason why it is the lower portion 150 of the device that deforms and collapses when the bulbous portion of the device’s body 110 is squeezed firmly between the user’s thumb and fingers is because the lower portion 150 of the device is specifically designed/con figured to be more deformable/collapsible than the more upper portions of the device’s body 1 10 (e.g. the upper conical portion 130 is more rigid and less deformable, whereas the lower conical portion 150 is less rigid and more deformable). This helps to ensure that it is the lower conical portion 150 that deforms when the user squeezes the “bulbous” portion of the body to perform the flush. In fact, the device is configured to ensure that the lower portion 150 of the device deforms and collapses in a particular (permanent and non- reversible) way.

[0086] With the device 100 in the first embodiment shown in Figure 1 to Figure 5 (etc), one of the ways in which the lower conical portion 150 is made to be more deformable than other portions of the device is through the provision of an elongate indent or groove 156 which extends circumferentially around, and also vertically up/down, the lower conical portion 150 (when the portion 150 is considered in its original, non-deformed, configuration). In other words, this elongate groove 156 is curved to form a spiral or helix shape that extends around, and also up/down, the lower portion 150 (when the portion 150 is considered in its non-deformed configuration). The spiral/helical groove 156 extends from near the top (or widest point) on the conical portion 150 down to close to the substantially flat base of the lower conical portion 150.

[0087] One function of this elongate helical indent or groove 156 is that it causes the lower conical portion 150 to be more deformable compared to the upwardly-facing conical portion 130. The reason why it is believed to do this is because the polymer material (from which the body of the device 100 is made) is believed to have a greater tendency to bend/fold (and therefore deform) at the edges and ridges (surface discontinuities) created by the side edges, and in the trough, of this helical indent/groove 156. More specifically, it is believed that the material has a greater tendency to bend/fold (and therefore deform) at points along the continuous (unbroken) edges and ridges which define the sides of, and which form the trough in, the helical indent/groove 156. Thus, the provision of the helical indent or groove 156 makes the lower portion 150 more deformable (i.e. gives it a greater tendency to deform and collapse when pressure is applied) compared to the upwardly-facing conical portion 130 which is more rigid due the general absence of such edges or curved portions at which the material of the conical portion 130 might have a tendency to deform or bend. (The upwardly-facing conical portion 130 does include the priming dome 160, but the priming dome 160, due to its shape and configuration, has little tendency to cause the upwardly- facing conical portion 130 overall to deform or collapse or become more deformable. In fact, the priming dome 160, given its shape and configuration, may even add to the rigidity (and therefore resistance to deformation) of the upwardly-facing conical portion 130).

[0088] The elongate helical indent I groove 156 in this embodiment is also thought to serve another function (i.e. in addition to just making the lower conical portion 150 more deformable compared to the upwardly-facing conical portion 130). Specifically, it is thought that the elongate helical indent I groove 156 also functions to ensure that all deformation of the lower portion 150, after the deformation thereof has initially commenced by the application of sufficient force by the user, is permanent and irreversible. Therefore, as explained above, when the user squeezes the “bulbous” part of the device between their thumb and fingers with sufficient force to begin deforming the lower conical portion 150, this initially causes the lower conical portion 150 of the body to begin to deform and collapse inwardly/upwardly towards the underside of the upwardly-facing conical portion 130, which in turn causes flush fluid to begin to be dispensed from (i.e. it begins to be forced out through) the opening in the top of the male connector (neck) part 140. More specifically, when the lower conical portion 150 begins to deform and collapse as a result of sufficient force being applied thereto by the user, the locations where the material of the portion 150 begins to deform (i.e. to bend and increase) includes, in particular, at points on (i.e. on and the long the surface discontinuities created by) the edges and ridges which define the sides of, and trough in, the helical indent/groove 156. Even more specifically, when the conical portion 150 begins to deform and collapse, the initial deformation of the material will include deformation or bending or creasing of the material at the edge/ridge points on the helical indent/groove 156 that are near the lowermost end of the helical groove 156. Then, with continued deformation of the portion 150 (i.e. as it is pressed generally more or further inwards), the location(s) where bending/creasing of the edge/ridge points of the indent/groove 156 is caused to occur will move progressively along the continuous unbroken edges and ridges of the indent/groove 156. However, if at any point the user releases the force that is causing the deformation to occur (or reduces the amount of force applied to below the level required to cause further deformation), the way in which the material of the portion 150 will have creased, in particular, at points along the edges of (and in) the helical indent/groove 156 will prevent any parts of the portion 150 that have already been deformed from moving or springing back the other way or re-expanding.

[0089] Thus, because of the way the indent/groove 156 functions, as explained above, it is possible for user to cease (i.e. to stop or pause) the application of force (or even move their thumb out of contact with the portion 150 completely) at any point, and if this is done at any time/point/ stage after the deformation of the portion 150 commences, the portion 150 will remain deformed in the state (shape) that it was in when the force was removed, but it will not move or spring or expand back in any way, so the space inside the device does not re-expand, so no fluid is drawn or sucked or aspirated back in through the opening in the top of the male (neck) portion 140. It is in this sense that the deformation of the portion 150 is said to be permanent and irreversible. [0090] The continuous shape of the helical groove 156 may also, it is thought, allow the dispensing of flush fluid from the device 100 to be smooth and continuous, if desired, and it may also allow the flow rate of fluid being dispensed from the device to be more easily controlled. That is, it is thought that the continuous shape of the helical groove 156 may help to allow fluid to be dispensed from the apparatus (if desired) with a smooth and continuous flow rate (i.e. with a flow rate that does not substantially vary), except if the amount of force applied to expel the fluid from the device is varied (increased or decreased intentionally) by the user to intentionally vary (increase or decrease) the rate of flow of fluid being expelled). The continuous shape of the helical groove 156 may also, it is thought, help to allow the device to provide a degree of user “feedback”. This is because, if at any point the pressure required to be applied by the user to continue dispensing fluid at the same rate increases, or decreases, this should not be caused by a change in the amount of force required to be applied to continue causing deformation of portion 150 (and dispensing of the fluid) at the same rate. On the contrary, the amount of force required to be applied by the user to continue dispensing fluid at the same or a constant rate should remain approximately the same at all times, and so the reason why the amount of pressure required to be applied may change (go up or down) is if something else exterior to device occurs. For example, if a kink or blockage forms in the cannula, or if the cannula becomes “Tissued”, this could lead to a (possibly sudden or abrupt) increase in the pressure required to continue dispensing the fluid from the device at the same rate, and this would likely be felt by the user (as they would immediately feel it become harder, or require more force, to continue expelling the fluid), and the user may therefore be alerted by this and know to stop and investigate the cause rather than simply attempting to apply significantly increased force just to continue forcing fluid out. Alternatively, if there is a rapid decrease in the pressure required to continue deforming the device (and to continue dispensing the flush fluid), this could indicate, for example, that the connection between the device and the cannula has become loose or the two have become disconnected (partially or fully separated), and in this case also, this may again alert the user to stop the application of force (i.e. and stop attempting to perform the flush) and take whatever action may be needed.

[0091] Although a continuous helical indent or groove 156 is used in the device 100 corresponding to the first embodiment, and is thought to serve the purposes and functions discussed above, these functions could also potentially be achieved in other ways. For example, instead of providing a single continuous helical indent or groove 156, a series of curved or helical indents or grooves could be provided, rather than just one. As a further possible alternative, one or more indents/grooves which simply extend in straight lines (or possibly wavy or curved lines) could extend from near the flat base of the portion 150 in an upward and radially outward direction so that it/they end closer to the widest point where portion 150 joins portion 130. One or more such indents/grooves could potentially serve the same or similar purposes and functions to the single helical indent/groove 156 discussed above.

[0092] As a possible further alternative, instead of having the spiral or helix shaped indent or groove 156, the device 100 could be provided with a series of concentric circular indents or grooves at spaced locations vertically up and down the conical lower portion 150. Such circular indents or grooves could also have a similar effect to the helical indent/groove 156 (described above) because these could also provide edges and ridges and curved portions about which the material in the lower conical portion 150 would have a tendency to bend/fold. Furthermore, provided these are spaced relatively close enough to one another such that only a small amount of deformation is required in order for the deformation to move from one such concentric groove to the next (i.e. such that the deformation moves from one point where it cannot spring back or re-expanded, to the next such point where it cannot spring back or re-expand), this could also serve to make the deformation, effectively or practically, permanent and irreversible.

[0093] The device 100 in the embodiment shown in Figure 1 through Figure 6 may be made from any suitable plastic or polymer material. Generally, the polymer material from which the device 100 is made should be of a kind/type that is (not only able to be moulded or otherwise formed into the required shape, and filled with flush fluid, and sealed, etc, but which is also) suitable for, and permitted to be used use in, manufacturing medical devices (i.e. it should be a medical grade material). The material should preferably also be of a kind that is able to be sterilised. It is believed that polyethylene and polypropylene are examples of materials which may be suitable; however there may well be other suitable (or even more preferable) materials.

[0094] It is thought that one way (and possibly an advantageous or preferable way) that the device 100 may be made is by using a so-called blow-fill-seal (BFS) manufacturing process. According to the Wikipedia article for blow-fill-seal manufacturing (https://en .wikiped j fill seal) : “Blow-Fill- Seal, also spelled as Blow/Fill/Seal, in this article abbreviated as BFS, is an automated manufacturing process by which plastic containers, such as bottles or ampoules are, in a continuous operation, blow- formed, filled, and sealed. It takes place in a sterile, enclosed area inside a machine, without human intervention, and thus can be used to aseptically manufacture sterile pharmaceutical or nonpharmaceutical liquid/semiliquid unit-dosage forms. BFS is an advanced aseptic processing technology that is typically used for filling and packaging of certain sterile liquid formulations like liquid ophthalmics, inhalational anesthetics, or lavaging agents, but can also be used for injectables, parenteral medicines, and several other liquid or semiliquid medications, with fill volumes ranging from 0. 1... 1000 cm³”. Further information on this blow-fill-seal manufacturing technique can be obtained from the above Wikipedia webpage.

[0095] The views in Figure 7 illustrate certain steps, but not all steps, that may be performed in the manufacture of the device 100. For example, Figure 7 does not illustrate any of the steps that take place prior to the point where the body of the device has assumed the form shown in these images, nor does it illustrate the processing steps where the device is filled with the flush fluid, orthe process where the device is sealed, or sterilised, etc. Thus, this Figure should not be considered to fully illustrate the manufacturing process for the device 100. There are numerous other steps in its manufacture that are not illustrated in this Figure.

[0096] It is thought that manufacturing the device using blow-fill-seal manufacturing may assist to bring down or reduce the overall production cost compared to the production costs associated with manufacturing traditional ampoules and single use syringes.

[0097] Whilst it is thought that one way (and possibly an advantageous or preferable way) that the device 100 might be made is through blow-fill-seal manufacturing, it is to be clearly understood that this is not necessarily the only way in which the device 100 could be made and, therefore, no limitation is to be understood or implied as to the way in which the device 100 is made. Equally, there is no limitation on the method or means by which devices in accordance with other embodiments of the invention may be manufactured.

[0098] Another benefit associated with the device 100 (and this also applies for the devices in the other embodiments described below) is that the device 100 looks completely different to a traditional single use syringe (or indeed any traditional syringe). It is therefore virtually impossible that the device 100, which is used to perform a flush of an intravenous cannula, could inadvertently be mixed up or mistaken for a single use or other syringe containing some other substance or medication. Accordingly, there is virtually no possibility that a mistake could be made whereby a flush of a patient’s cannula is inadvertently performed instead of an intended action of administering a required medication. Similarly, there is virtually no possibility that a medication (contained in a syringe) could be accidentally I wrongly administered instead of performing an intended action of simply performing a flush of the patient’s cannula using a device according to this invention.

[0099] Another significant benefit associated with the device 100 (and, again, this also applies for the devices and the other embodiments described below) is that the device is initially completely sealed. It is therefore virtually impossible that the contents of the device could be tempered with.

[00100] Yet another possible benefit associated with at least some embodiments of the present invention is that the amount of plastic/polymer material(s) (e.g. polyethylene, polypropylene or other appropriate polymer material(s)) used in the manufacture of each device may be less than the amount of material (including plastic/polymer materials, but also other material such as rubber, etc) used in making the kinds of devices conventionally used for performing flushes of intravenous cannulas, such as syringes, ampoules and the like. It is thought that this advantage may be realised, in particular, where the device(s) according to the present invention is/are manufactured using blow fill seal technology, because that manufacturing method, by its nature, can reduce the amount of material required to be used compared with other manufacturing techniques. The fact that devices in accordance with at least some embodiments of the present invention may be able to be made using less material than the devices (like e.g. syringes, ampoules and the like) conventionally used for performing flushes of intravenous cannulas may, in turn, mean that there may be less waste material required to be discarded. In other words, even though devices in accordance with the present invention may (like the conventional syringes and the like) need to be treated as medical waste after use, and they may therefore need to be e.g. incinerated or treated and discarded in landfill after use (or it may not be possible to recycle them due to restrictions on the recycling of medical waste in many jurisdictions), nevertheless the amount of material required to be disposed of in this way may be less than the amount of material that would otherwise be required to be disposed of if conventional devices were used instead (because more material is used in making those conventional devices). [00101] Turning now to Figure 8 and Figure 9, as mentioned above, these Figures illustrate a device 200 in accordance with a second possible embodiment of the invention. The device 200 in this second embodiment is (again - like the device 100 in the previous embodiment described above) a prefilled single use flush device for use in flushing an intravenous cannula. In other words, the device 200 is manufactured and supplied (i.e. it comes pre-made) containing a quantity of flush solution ready to be used to perform a flush of an intravenous cannula. As for the first embodiment described above, the device 200 may be prefilled with a quantity of any solution that is suitable for use in flushing intravenous cannulas.

[00102] As shown in Figure 8, the device 200 includes a body 210. The device 200 in this second embodiment could also have a removable tab 270; however such a removable tab 270 is not shown in any of the images in Figure 8 and Figure 9. A dashed outline indicating where the removal tab 270 would or could connect is, however, illustrated in Figure 8(ii). The purpose of the removable tab 270 (if it is used), i.e. the way the removable tab 270 may initially be present to close/seal device but may also be twisted/torn away from the body 210 in order to “open” the device 200, is the same as for the first embodiment described above. This therefore need not be explained (again). However, for the avoidance of doubt, it should be noted that all of the views shown in Figure 8 and Figure 9 (with the exception of Figure 8(ii), which shows a dashed outline representing the removable tab 270) illustrate the device 200 without the tab 270, i.e. as if the tab 270 had already been removed, assuming a tab 270 was initially used to seal the device.

[00103] Alternatively, for the embodiment in Figure 8 and Figure 9, instead of having a removable tab 270 which initially closes/seals the device, the device may instead come sealed (i.e. it may be provided initially with the opening in the device closed/sealed) by a cap (not shown) in the form of a conventional luer lock cap installed on the top portion 240 of the body (i.e. similarto the kind of cap often used to initially seal a syringe that has a luer lock connector). As discussed below, the top portion 240 of the body 210 in this embodiment forms the male part of a luer lock connector. The way a luer lock connector works is discussed below, and it will be evident from the explanation below how this can be used to allow a luer lock cap (not shown) to be installed that initially closes and seals the device 200.

[00104] As shown by certain text labelling in Figure 9, the body 210 of the device 200 in this embodiment comprises two separate (separately-formed) sections, which are subsequently joined to one another. The first section 220 forms the upper outer portion of the body 210. This first section 220, which includes the top portion 240 at the top and a generally conical portion which tapers outwards moving down from the top portion 240, may be made from a plastic or polymer material that is relatively more rigid than the material used for the second section (see below). The first section 220 may (it is thought) be formed by injection moulding (although no limitation is to be inferred from this and other manufacturing methods may also be used). The second section 225 of the body includes a lower portion 250 which initially extends below the bottom of the first section 220. The lower portion 250 of the second section 225 also has a generally conical shape which tapers inwards moving down until it reaches and joins with the substantially flat base portion at the bottom. The second section 225 also has an upper portion which extends up into (i.e. it is received into) the interior / inside of the first section 220. This upper portion of the second section 225 includes the device’s priming dome 260, which projects out through an opening/hole in the side wall of the first section 220, as shown in these Figures. The second section 225, and in particular the lower portion 250 thereof, is relatively more deformable than the first section 220. The second section 225 may (it is thought) be formed by blow moulding (although, again, no limitation is to be inferred from this and other manufacturing methods may also be used to form the second section 225).

[00105] Although not shown in any of the images in Figure 8 and Figure 9, in the device 200, the second section 225, and in particular its lower portion 250, may be provided with a spiral/helical groove (not shown) which extends from near the top (or widest point) on the lower portion 250 down to close to the substantially flat base of the lower portion 250. Alternatively, as for the first embodiment discussed above, instead of providing a single continuous helical indent or groove, a series of curved or helical indents or grooves could be provided on the lower portion 250, rather than just one. As a further possible alternative, one or more indents/grooves which simply extend in straight lines (or possibly wavy or curved lines) could extend from near the flat base of the portion 250 in an upward and radially outward direction so that it/they end closer to the widest point where portion 250 meets the bottom of the upper section 220. One or more such indents/grooves may serve the same or similar purposes and functions in the second embodiment as discussed in connection with the first embodiment above, including making the deformation of the lower portion 250 permanent and irreversible.

[00106] The size of the body 210 of the device 200 is such that, firstly, the volume of the hollow interior inside the body 210 (in this embodiment it is actually mainly only the second section 225 that has an enclosed interior containing flush fluid, except for a small opening in the top thereof that leads to the outlet 241), and hence the volume/quantity of flush solution contained therein (i.e. the amount of flush solution that comes pre-filled in the device 200 and which almost, if not completely, fills the hollow interior of the second section 225 prior to use), is sufficient (i.e. the device contains enough flush solution) to be used in performing a single flush of an intravenous cannula. However, in addition to this, the body 210 is again sized so that it can be grasped by a user in one hand, and the user can also simultaneously grasp the tab 270, or the cap (not shown), at the top of the device in the other hand. Thus, the user can: twist and/or bend the tab 270 relative to the body 210, thereby causing the material connecting the tab 270 to the very top of the body 210 to break, and consequently allowing the tab 270 to become separated (torn away) from the very top of the body 210, or unscrew the cap (not shown) which is initially screwed onto (and thereby seals) the luer lock connector 240 on the top of the body, thereby removing the cap and unsealing/opening the device.

[00107] Importantly, as mentioned above, the top portion 240 of the body 210 in this second embodiment (which is the top of the first section 220) is different to the top portion of the body 110 in the previous device 100. Indeed, as explained above, the top (neck) portion 140 of the body 110 of the device 100 above formed the male part of a luer slip connector. In contrast, the upper portion 240 of the body 210 of the device 200 in this second embodiment forms the male part of a luer lock connector. Such male/female luer lock connections are standardised and widely used on many forms of intravenous medical devices, so the means by which the device 200 may be connected to an intravenous cannula (and also the way in which a cap (not shown) may initially be installed to close/seal the device) via such a standard male/female luer lock connection should be readily apparent.

[00108] When the tab 270, or the cap (not shown), is removed from the body 210 of the device 200 in this embodiment, the device should be held with the upper male luer lock connector part 240 pointed upwards. This is to prevent accidental spilling of the flush fluid, as explained in connection with the first embodiment above.

[00109] Thus, when the device 200 is to be used, the user can initially “open” the device 200 by grasping the body 210 of the device in one hand, and simultaneously: grasping the tab 270 in the other hand, and with the tab and the male luer lock connector part 240 pointed upwards, the user can twist and/or bend the tab 270 relative to the body 210 so that the material connecting the tab 270 to the top of the male luer lock connector 240 breaks and the tab 270 breaks/tears away and separates from the top of the body 210, thereby revealing an opening 241 in the top of the inner part of the male luer lock connector part 240, or grasping the cap (not shown) in the other hand, and with the male luer lock connector part 240 pointed upwards, the user can unscrew the cap (not shown) from the body 210 so that the cap unseals and separates from the body 210, thereby (again) revealing the opening 241 in the top of the inner part of the male luer lock connector part 240.

After the device 200 has been “opened”, the tab 270, or the cap (not shown), can be discarded.

[00110] However, as explained in connection with the device 100 above, even after the device 200 has been “opened”, before the device 200 is connected to an intravenous cannula for the flush solution therein to be administered via the cannula for the purpose of performing a flush of the cannula, it is important for the user to first (i.e. before connecting the device 200 to the cannula) make sure that any air (or possibly other gas(es)) that may be present inside the device 200, or as much of this as possible, is removed. The way in which this can be done is essentially same as for the device 100 described above. That is, the device 200 (after it has been “opened”) can initially be tapped or flicked (or otherwise vibrated) in order to dislodge any air or gas bubbles and enable them to float up to the surface and escape through the opening 241 in the luer lock connector part 240.

[0011 1] After that, the device 200 must be “primed”. The way in which the device 200 is “primed” is essentially the same as described for the device 100 above. That is, the way in which the user can “prime” device 200 (i.e. cause a small quantity of the flush solution to be forced up and out through the opening 241 in the top of the male luer lock connector part 240) is by pressing on (e.g. with a thumb or finger), and depressing, the priming dome portion 260. When the user presses on and depresses the priming dome 260, this causes the dome portion 260 to deform and collapse inwards (once again, permanently and irreversibly). This, in turn, causes the flush solution that was in the hollow interior region of space inside of the dome portion 260 to also be pushed inwards, i.e. into the main volume inside the second section 225. In other words, when the user depresses the dome portion 260 inwards, the total internal volume inside the device is reduced due to the change in shape of (and hence the reduced or eliminated or inverted internal volume within) the priming dome portion 260. And this, in turn, causes the required small quantity of the flush solution (i.e. a small quantity of the flush solution having a volume equivalent to the amount by which the internal volume of the device is changed by the depression of the priming dome portion 260) to be forced up and out through the opening 241 in the top of the male luer lock connector 240. Thus, the device 200 can be “primed” by depressing the dome portion 260 and causing it to collapse inwards.

[00112] As was the case for the device 100 in the first embodiment described above, it is also the case for the device 200 in this second embodiment that when the user presses on the dome portion 260 to depress it in order to “prime” the device 200, the deformation of the dome portion 260 is permanent. In other words, the dome portion 260 does not pop back out, or re-expand, or otherwise deform further in a way that might cause some of the flush solution to be drawn back into any part of the space inside the dome portion 260 that was occupied with fluid before the device was primed. This is important for the same reason as described above in connection with the device 100.

[00113] Once the device 200 has been “primed”, such that all air/gas (or as much as possible) has been removed, including within the rim of the opening 241 , the “open” device 200 can next be connected to an intravenous cannula in order for the flush solution contained therein to be administered to the patient to flush the cannula.

[00114] With the embodiment shown in Figure 8 and Figure 9, the way in which the “open” device 200 (after it has been “primed”) can be connected to an intravenous cannula (not shown) is that the male luer lock connector part 240 is connected to a corresponding female luer lock connector part (not shown) on the end of the intravenous cannula. Such male/female luer lock connections are standardised and widely used on many forms of intravenous medical devices, so the means by which the device 200 may be connected to an intravenous cannula via such a standard male/female luer lock connection should be readily apparent. Nevertheless, by way of brief explanation, the male luer lock connector part 240 has an internal portion (on the inside of which the opening 241 is formed) that is generally elongate in shape and the outer surface of this internal portion of the male luer lock connector part 240 tapers/n arrows slightly in an upward direction. The corresponding female luer lock connector part (not shown) has an inner surface with a shape closely corresponding to the shape of the outer surface of the inner portion of the male luer lock connector part 240. That is, the female luer lock connector part (not shown) would have an opening that is widest at its outer end and which tapers/narrows in a direction moving into the female connector. The diameter and taper of the internal surface of the female connector part would be substantially identical to the diameter and taper of the outer surface of the inner portion of the male luer lock connector part 240. To this extent, the luer lock connector used on the device 200 in Figure 8 and Figure 9 is similar to the luer slip connector used by the device 100 in the previous embodiment. However, in addition, the male portion of the luer lock connector part 240 on the device 200 also has an outer cylindrical portion which is internally threaded (the threads on the inside of this cylindrical portion are not shown in Figure 8 and Figure 9). The outer surface of the female connector on the cannula (not shown) would have a corresponding thread or ridge which engages with the thread on the cylindrical outer portion of the male connector 240. Consequently, in order to connect the device 200 to the cannula, the female connector part is screwed into the male connector part, and when this is done, the internal portion of the male connector part 240 comes to be inserted into the corresponding opening in the female connector part (not shown), and the outer surface of the inner portion of the male connector part 240 fits snugly into and it presses firmly against the internal surface of the female connector part, thus forming a fluid tight seal between the two when the two are connected together. The flush fluid contained inside the device 200 can then flow (when it is forced out by the user) out of the device through the opening 241 , and into the patient via the intravenous cannula thereby flushing the intravenous cannula.

[00115] It should be noted that the above-mentioned luer lock cap (not shown), which may be used (rather than a removable tab 270) to initially close and seal the device 200 can be initially connected to the top portion 240 of the device 200 (i.e. as part of the manufacturing process, after the device 200 has been filled) in the same way as the intravenous cannula is connected, as described above.

[00116] With reference to Figure 10, after the device 200 has been opened, primed, and connected to the cannula, as described above, the device 200 is then ready to be used to perform a flush of the cannula. To do so, the user of the device 200 (typically a nurse or clinician or other healthcare professional) will typically first grasp the body 210 of the open device in one hand. More specifically, the user will typically hold the open device in one hand with two fingers pressing on the top of the first section 220 of the body (typically with one finger to either side of the male luer lock connector part 240), and the user’s thumb will simultaneously press against the flat bottom I base of the lower portion 250 of the body’s second section 225. Thus, the user will initially hold the device with the thumb pressing against the base of the portion 250 in a direction generally opposite to the direction in which fingers are simultaneously pressing against the top of the first section 220, such device’s body 210 is held/grasped between the user’s thumb and fingers.

[00117] Then, when it is desired to intentionally dispense the flush fluid from the device 200, i.e. when it is desired to cause the flush fluid to be expelled out through the opening 241 in the top of the male luer lock connector part 240 and into the cannula (i.e. to administer the flush fluid into the patient via the cannula to thereby flush the cannula), the user increases the force applied between their thumb and fingers, i.e. they squeeze the device between their thumb and fingers more tightly or with greater force, and more specifically, with sufficient force to begin deforming the lower portion 250. This initially causes the lower portion 250 of the second section 225 to begin to deform and collapse inwardly/upwardly towards (and ultimately into) the concave inside of the upper region of the second section 225 itself. As will be appreciated, when the lower portion 250 of the second section 225 begins to deform and collapse in this way, the flush fluid begins to be forced up and out through the opening 241 . With continued application of such force by the user (i.e. while the user continues to squeeze the device between the thumb and fingers with sufficient force) the lower portion 250 continues to deform and collapse upwards into the concave inside of the upper region of the second section 225. The effect of the progressive deformation/collapsing of the lower portion 250 (which is caused by the deliberate initiation, and then the continued application, of sufficient force by the user) is that the material of the (originally convex conical) lower portion 250 (i.e. the material from which this part of the second section 225 is made) moves upwards as it deforms and collapses and, ultimately, when the material of the lower portion 250 has been depressed (i.e. pressed in by the user) as far as it will go, the material of the (originally convex conical) portion 250 comes to be mostly (if not entirely/completely) inverted so that it conforms to, and so that it’s inside (interior) surface is close to or in contact with, the concave interior/inside surface of the upper region of the second section 225. This is what is shown in Figure 10(iii).

[00118] Once the lower portion 250 has been fully compressed in this way, all of the flush solution that was previously (after the device had been “primed”) contained inside the second section 225 will have been forced out of the device through the opening 241. In other words, after the user has pressed the lower portion 250 in as far as it can go, the volume of the space inside the second section 225 (i.e. with the lower portion 250 thereof now substantially pressed up into the inside of the first section 220 so that the lower portion 250 is inverted and substantially conforms to the inside of the upper region thereof) is reduced substantially (i.e. nearly if not absolutely or completely) to zero - i.e. there is little if any space left therein, and therefore there is also little if any remaining flush fluid left therein. And, because the device 200 is connected to the intravenous cannula when this is done, this (substantially full or entire) quantity of flush fluid (that is contained within the device after it is “primed”) is forced up and out of the device 200 and is consequently administered to the patient via the cannula, thereby flushing the cannula.

[00119] One reason why it is the lower portion 250 of the device 200 that deforms and collapses when the device’s body 210 is squeezed between the user’s thumb and fingers is because, as explained above, the second section 225 of the body (which includes the lower portion 250) is made from a material that is softer/more deformable than the first section 220.

[00120] When the user squeezes the body 210 of the device 200 thereby causing the lower portion 250 to deform and collapse dispensing the flush fluid up and out of the device 200, the deformation of the lower portion 250 may once again be permanent and irreversible. In other words, it may be that the lower portion 250 does not pop back out, or re-expand, or deform further or back in a way that might cause some of the flush solution to be drawn back into the device. As explained in connection with the first embodiment above, it is preferably also the case in the second embodiment that all deformation of the lower portion 250, after the deformation thereof has initially commenced by the application of sufficient force by the user, is permanent and irreversible This is important for the same reasons as described above in connection with the device 100. The way in which this may be achieved in the second embodiment may also be the same as or similar to that described above in connection with the first embodiment. For example, the lower portion 250 may be provided with a spiral/helical indent or groove (not shown) or a series of curved or helical indents or grooves (not shown) or one or more indents/grooves (not shown) which simply extend in straight lines (or possibly wavy or curved lines) which extend from near the flat base of the portion 250 upward and radially outward to near the widest point where portion 250 meets the bottom of the upper section 220, etc, as described above. [00121] Turning now to Figure 11 and Figure 12, these Figures illustrate a device 300 in accordance with a third possible embodiment of the invention. The device 300 in this third embodiment is (once again) a prefilled single use flush device for use in flushing an intravenous cannula. The device 300 is manufactured and supplied (i.e. it comes pre-made) containing a quantity of flush solution ready to be used to perform a flush of an intravenous cannula. As for the first and second embodiments described above, the device 300 may be prefilled with a quantity of any solution that is suitable for use in flushing intravenous cannulas.

[00122] As shown in Figure 11 , the device 300 includes a body 310. The device 300 in this third embodiment could again have either a removable tab or a luer lock cap that initially closes and seals the device; however neither the removable tab nor the luer lock cap is shown in any of the images in Figure 11 and Figure 12. Nevertheless, the purpose of the removable tab or luer lock cap (whichever one is used) in this embodiment, i.e. the way this initially seals the device closed, but can be twisted/torn away from, or unscrewed from, the body 310 in order to “open” the device 300, is the same as for e.g. the second embodiment 200 described above. This therefore need not be explained further. Forthe avoidance of doubt, it should be noted that all of the views shown in Figure 11 and Figure 12 show the device 300 without the tab or cap, i.e. as if this (whichever one is used) has already been removed.

[00123] As shown by e.g. certain of the labelling in Figure 12, the body 310 of the device 300 in this third embodiment comprises a number of separate (separately-formed) sections, which are subsequently joined to one another. A first section 320 has a pair of vertically extending sides which are connected to one another at their bottom ends by a semicircular portion, i.e. to form a U-shape, and the first section 320 also has a portion which extends across the top between the respective top ends of the vertically extending sides. As shown in Figure 1 1 (vii), this top portion of the first section 320 (which extends across the top between the tops of the respective sides) is generally circular, and a second section 305 of the device’s body is mounted/secured in an opening that extends through the centre of the top part of the first section 320. This second section 305 of the device’s body, in addition to being secured in the opening in the top of the first section 320, also includes a male luer lock connector part 340. The body 310 of the device 300 also includes a third section 325 which generally resembles the bellows used the musical instrument called a concertina. It is this third section 325 that initially contains the flush fluid (within its hollow inside) in this embodiment.

[00124] The first section 320, and also the second section 305 (including the male luer lock connector 340), may be made from a plastic or polymer material that is relatively more rigid than the material used forthe third section 325 (see below). The first section 320 and second section 305 may (it is thought) each be formed by injection moulding (although no limitation is to be inferred from this and other manufacturing methods may also be used). The third section 325 of the body 310 may be formed from a plastic or polymer material that is relatively softer or more deformable than the first section 320 and second section 305. The third second section 325 may (it is thought) be formed by blow moulding (although, again, no limitation is to be inferred from this and other manufacturing methods may also be used to form the third section [00125] In the device 300, the size of the third section 325 of the device’s body is such that, firstly, the volume of the hollow interior inside this third section 325 (it is only the third section 325 that has a hollow interior in this embodiment, except for an opening that leads from the top thereof to the outlet 341), and hence the volume/quantity of flush solution contained therein (i.e. the amount of flush solution that comes pre-filled in the device 300 and which almost, if not completely fills, the hollow interior of the third section 325 prior to use), is sufficient (i.e. the device contains enough flush solution) to be used in performing a single flush of an intravenous cannula. However, in addition to this, the body of the device 300 is again sized so that it can be grasped by a user in one hand, and the user can also simultaneously grasp the tab (not shown) or cap (not shown) at the top of the device in the other hand.

[00126] Notably, in this embodiment, the very top portion of the second section 305 comprises the male part 340 of a conventional luer lock connector. The male luer lock connector 340 used in the device 300 has the same configuration as the male luer lock connector 240 used on the device 200. That is, it operates the same way, and this therefore need not be explained again.

[00127] When the device 300 is to be used, the user can initially “open” the device 300 by grasping the body 310 of the device in one hand, and simultaneously: if a removable tab is used, grasping the tab (not shown) in the other hand, and with the tab and the male luer lock connector part 340 pointed upwards, the user can twist and/or bend the tab relative to the body 310 so that the material connecting the tab to the top of the male luer lock connector 340 breaks and the tab breaks/tears away and separates from the top of the body 310, thereby revealing an opening 341 in the top of the inner part of the male luer lock connector part 340, or if a luer lock cap is used, grasping the cap (not shown) in the other hand, and with the male luer lock connector part 340 pointed upwards, the user can unscrew the cap (not shown) from the body 310 so that the cap unseals and separates from the body 310, thereby (again) revealing the opening 341 in the top of the inner part of the male luer lock connector part 340.

After the device 300 has been “opened”, the tab (not shown), or the cap (not shown), can be discarded.

[00128] However, as explained in connection with the devices 100 and 200 above, even after the device 300 has been “opened”, before the device 300 is connected to an intravenous cannula, it is important for the user to first (i.e. before connecting the device 300 to the cannula) make sure that any air (or possibly other gas(es)) that may be present inside the device 300, or as much of this as possible, is removed. To do this, the device 300 (after it has been “opened”) can initially be tapped or flicked (or otherwise vibrated) in order to dislodge any air or gas bubbles and enable them to float up to the surface and escape through the opening 341 in the luer lock connector part 340. Next, the device 300 must be “primed”.

[00129] The way in which the device 300 is “primed” is different to the devices 100 and 200 described above. For the device 300, the way that the device is “primed” is that the user first grasps the body 310 of the device in one hand. More specifically, the user will typically hold the device in one hand with two fingers pressing on the top of the first section 320 of the body (typically with one finger to either side of the male luer lock connector part 340), and the user’s thumb will simultaneously press against the base/bottom of the concertina shaped third portion 325. Thus, the user will initially hold the open device 300 with the thumb pressing against the base of the third portion 325 in a direction generally opposite to the direction in which fingers are simultaneously pressing against the top of the first section 320, such device’s body 310 is held/grasped between the user’s thumb and fingers. Then, in order to force a small initial quantity of the flush fluid out through the opening 341 in the top of the male luer connector part 340 for the purpose of priming the device, the user increases the force applied by their thumb enough to cause a small amount of initial deformation of the third section 325, and this causes the concertina-shaped third section 325 to begin to deform and collapse (i.e. it is squashed) upwardly towards the top of the first section 320. This, in turn, reduces the internal volume inside the concertina-shaped third section 325, meaning that fluid is forced out through the opening 341 in the top of the male luer lock connector 340. The user continues to push upward with their thumb against the bottom of the third section 325, thereby deforming and squashing the third section 325 (and causing flush fluid to be dispensed from the top of the male luer lock connector 340) until two small ridges 327, each one located in a channel 326 on respective opposite outer sides of the third section 325 (incidentally these channels 326 also prevent sideways movement of the third section 325 relative to the sides of the first section 320), have moved up and ridden over a respective pair of small ledges 321 that are inwardly extending from the insides of the respective vertical sides of the first section 320, as illustrated in Figure 11 (iii). After the two small ridges 327 have ridden up and over the respective ledges 321 , a sufficient quantity of flush fluid will then have been dispensed in order for the device to be properly “primed”. Also, the respective small ridges 327 cannot move back downwards again (i.e. they cannot then move back the other way) past the small ledges 321 because the shape and configuration of the ledges 321 prevents this. Thus, the concertina-shaped third section 325 is prevented from re-expanding after it has been “primed” so that flush fluid is not drawn back into the device after it has been primed.

[00130] Once the device 300 has been “primed”, such that all air/gas (or as much as possible) has been removed, the “open” device 300 can next be connected to an intravenous cannula in order for the remaining flush solution contained therein to be administered to the patient to flush the cannula. The way in which the “open” device 300 can be connected to an intravenous cannula is the same as for the device 200 described above (and indeed the male luer lock connector used is identical in this configuration to the one used on the device 200).

[00131] With reference to Figure 13, after the device 300 has been opened, primed, and connected to the cannula, as described above, the device 300 is then ready to be used to perform a flush of the cannula. To do so, the user will once again hold the open device 300 with the thumb pressing against the base of the third portion 325 (which is now in the “primed” position - see above) in a direction opposite to the direction in which fingers are simultaneously pressing against the top of the first section 320. Then, in order to force the quantity of flush fluid remaining within the third portion 325 (which is the amount that remains after the device is primed and should be the amount required for the flush) out through the opening 341 in the top of the male luer connector part 340, the user once again applies additional force with their thumb, and this again causes the concertina-shaped third section 325 to begin to deform and collapse further upwardly towards the top of the first section 320. This, in turn, progressively reduces the internal volume inside of the concertina-shaped third section 325, meaning that fluid is again forced out through the top of the male luer lock connector 340 and into the cannula to which the device is now connected, thereby flushing the cannula.

[00132] This further deformation of the third section 325 to dispense all (or substantially all) of the remaining flush fluid out through the opening 341 to flush the cannula may again be substantially permanent and irreversible. One way in which this may be achieved, although this is not shown in any of the Figures that depict the device 300, is that, in addition to the above-mentioned ridges 327 in the channels 326 on either side of the third section 325 (recall that those above-mentioned ridges 327 ride over the respective small ledges 321 when the device is “primed”), there may be a number of further ridges (not shown but similar to the ridges 327) at spaced locations down the third section 325, within each of the channels 326 on either side there. The way in which these further ridges (not shown), which are located at spaced locations down the sides of the third section 325 (within the channels 326 on either side) work is in much the same way as the above-mentioned ridges 327 which function to prevent the third section 325 from re-expanding after it has been “primed”. Thus, when the user applies additional force with their thumb thereby causing the concertina-shaped third section 325 to deform and collapse further upwardly towards the top of the first section 320, this in turn causes the respective further ridges (not shown) on each respective side of the third section 325 to progressively (i.e. one after another) move/ride up and over the above-mentioned small ledges 321 that are inwardly extending from the insides of the respective vertical sides of the first section 320. After each of these further ridges (not shown) has ridden up and over the respective ledges 321 , the third section 325 of the device may be prevented from reexpanding in a way that would cause the ridges that have just passed the ledges 321 (from time to time) to move back downwards again past the small ledges 321 because (as mentioned above) the shape and configuration of the ledges 321 prevents this. In this way, the further deformation of the third section 325 which dispenses flush fluid out through the opening 341 to flush the cannula may be made substantially permanent and irreversible.

[00133] Turning next to Figure 14 and Figure 15, these Figures illustrate a device 400 in accordance with a fourth possible embodiment of the invention. The configuration of the device 400 in these figures, although slightly different to the configuration of the device 300, nevertheless works in mostly the same way as the device 300. This will be readily apparent to those skilled in this area from a comparison of the Figures illustrating the device 400 with the earlier Figures illustrating the device 300, and therefore the configuration and use of the device 400 will not be explained in as much detail as the previous embodiment.

[00134] The way in which the device 400 is “primed” is slightly different to the device 300 described above. For the device 400, the way that the device is “primed” is that the user first grasps the body 410 of the device in one hand. More specifically, the user will typically hold the device in one hand with two fingers pressing on the top of the first section 420 of the body (typically with one finger to either side of the male luer lock connector part 440), and the user’s thumb will simultaneously press against the base/bottom of the concertina-shaped portion 425. Thus, the user will initially hold the open device 400 with the thumb pressing against the base of the portion 425 in a direction generally opposite to the direction in which fingers are simultaneously pressing against the top of the section 420, such device’s body 410 is held/grasped between the user’s thumb and fingers. Then, in order to force a small initial quantity of the flush fluid out through the opening 441 in the top of the male luer lock connector part 440 for the purpose of priming the device, the user increases the force applied by their thumb, and this causes the concertinashaped section 425 to begin to deform and collapse (i.e. it is squashed) upwardly towards the top of the section 420. This, in turn, reduces the total internal volume inside the concertina-shaped section 425, meaning that fluid is forced out through the top of the male luer lock connector 440. The user continues to push upward with their thumb against the bottom of the section 425, thereby deforming and squashing the section 425 (and causing flush fluid to be dispensed from the top of the male luer lock connector 440) until one of the ridges 427A of the concertina-shaped section 425, which ridge 427A is larger (i.e. it has a larger outer diameter than) than the other ridges 426 above it, has moved up and ridden over/past a respective pair of small ledges 421 that are inwardly extending from the insides of the vertical sides of the first section 420, as illustrated in Figure 16(ii) and (iv). After the larger ridge 427A has ridden past the respective ledges 421 , a sufficient quantity of flush fluid will have been dispensed and the device will be “primed”. Also, the large ridge 427A cannot then move back downwards again past the small ledges 421 . Thus, the concertina-shaped section 425 is prevented from re-expanding after it has been “primed” so that flush fluid is not drawn back into the device after it has been primed.

[00135] It should also be noted that, although not illustrated this way in the Figures, the ridges on the concertina-shaped section 425 which are indicated as “Y”, i.e. the ridges located in between the large ridges 427A and 427B, can also be made as large as (i.e. these ridges “Y” can have the same outer diameter as) the larger ridges 427A and 427B. If so, the effect of this may be that, in use, the concertinashaped section 425 is also prevented from re-expanding after each of the ridges “Y” has ridden past the respective ledges 421 . And, of course, the size of the large ridge 427B at the bottom means that, after the device has been used (i.e. after the concertina-shaped section 425 has been fully depressed and this final large ridge 427B at the bottom has ridden up past the respective ledges 421), the concertina-shaped section 425 is also prevented from re-expanding after it has been fully compressed. In this way, the deformation of the concertina-shaped section 425 which dispenses flush fluid out through the opening 441 to flush the cannula may be made substantially permanent and irreversible.

[00136] In Figure 14 and Figure 15, the first section 420 of the device 400 is shown as having a pair of vertical portions, with each one of the vertical portions extending approximately half the way down the length of the (uncompressed) concertina-shaped section 425. The inwardly pointing ledges 421 are located at the lower ends on the inside of these vertical portions. In a possible variant of the device 400, these vertical portions of the first section 420 could instead extend down for most of the length of the (uncompressed) concertina-shaped section 425. In such a variant, there would again be an inwardly- pointing ledge 421 located at or near the lower end on each of these vertical cautions, just above the location where the larger ridge 427B is before the concertina-shaped section 425 begins to be compressed. In such a variant, the device could be “primed” by pressing on the bottom of the concertinashaped section 425 enough to cause the ridge 427B to ride up past the ledges 421 on or near the bottom of the vertical portions, thereby causing a sufficient quantity of the flush fluid to be forced up and out of the device to prime the device. There could also be a number of additional inwardly-pointing ledges (similar to ledges 421) provided at spaced locations extending up the inside face of each of the vertical portions of the first section 420. Thus, when the user applies additional force with their thumb, thereby causing the concertina-shaped section 425 to deform and collapse further upwardly, this in turn would cause the ridges on the concertina-shaped section 425 (427A, Y, 427B) to progressively move/ride up and over these further ledges that are inwardly pointing from the insides of the respective vertical sides of the first section 420. After the further ridges have ridden up and over the respective ledges (or as they progressively do so), the concertina-shaped section 425 of the device may be prevented from reexpanding in a way that would cause the ridges that have just passed the ledges (from time to time) to move back downwards again past the ledges. In this way, the further deformation of the concertinashaped section 425 which dispenses flush fluid out through the opening to flush the cannula may be made substantially permanent and irreversible.

[00137] Turning to Figure 17 through Figure 22, the device 500 shown in these Figures is similar to the device 100 shown in Figure 1 to Figure 6. Importantly, the device 500 is shown in Figure 17 through Figure 22 without a removable tab; however (as for the device 100 described above) the device 500 would initially be provided with a removable tab in the same way as the device 100. One difference between the device 500 and the earlier device 100 described above is that, unlike the device 100, the device 500 is not shown having a priming dome (like the priming dome 160 of the device 100) for priming the device. The device 500 could, however, have such a dome, and the way it would work would be the same as for the device 100 above.

[00138] It should also be noted that variations on the devices 100, 200, 600 and 700 could be provided which do not have a priming dome. If so, those devices would need to be primed in the manner discussed for device 500 below.

[00139] The way in which the device 500 would work (i.e. the way in which it could be used) would be generally much the same as for the device 100, except that, for example, if the device 500 does not have a priming dome portion like the dome 160 of the device 100, then in that case it is not possible with the device 500 to simply press the dome in to prime the device 500. Therefore, to prime the device 500 (if it does not have a priming dome), the user might instead need to press upward slightly on the conical lower portion 550 of the body of the device 500 to prime it. The user may then also need to hold the device in this “primed” position while connecting it to the cannula via the upper luer slip connector 540 of the device 500, before squeezing the rest of the flush fluid out in order to perform the flush.

[00140] Another difference between the device 500 and the device 100 described above is that, with the device 500, once the device has been used (i.e. once the (initially convex conical) lower portion 550 of the device has been depressed and collapsed fully up into the inside of the (concave conical) upper portion 530 of the device), the indented cup-shaped portion 502 in the base portion of the device 500, and in particular the outer cylindrical surface thereof (which is on the inside of the device), inserts into the inside of the cylindrical portion 504 near the top of the device (in the centre at the top of the top portion 530). More specifically, the outer cylindrical surface of the cup-shaped portion 502 is designed to become snugly received by the internal wall of the cylindrical portion 504, so that once the device has been used (i.e. once the lower portion 550 of the device has been depressed and collapsed fully up into the inside of the upper portion 530 of the device), the outer cylindrical surface of the cup-shaped portion 502 on the inside of the device is received into the inside of the cylindrical portion 504 in a friction fit which holds it there and prevents the (then substantially inverted) material of the lower portion 550 from moving or reexpanding back downwards.

[00141] In addition to this (although this is not shown in any of Figure 17 through Figure 22 which depict the device 500), the device 500, and in particular its lower portion 550, may once again be provided with a spiral/helical groove (not shown) which extends from near the top (or widest point) on the lower portion 550 down to close to the bottom of the outer perimeter of the cup-shaped portion 502 at the base. Alternatively, as for other embodiments above, instead of providing a single continuous helical indent or groove, a series of curved or helical indents or grooves could be provided on the lower portion 550, rather than just one. As a further possible alternative, one or more indents/grooves which simply extend in straight lines (or possibly wavy or curved lines) could extend from near the bottom of the outer perimeter of the cup-shaped portion 502 at the base in an upward and radially outward direction so that it/they end closer to the widest point where portion 550 meets the upper section 530. One or more such indents/grooves may serve the same or similar purposes and functions as discussed in connection with the first and second embodiments above, including making the deformation of the lower portion 550 permanent and irreversible.

[00142] Turning to Figure 23 through Figure 28, the device 600 shown in these Figures is very similar to (in fact it is really just a variant of) the device 100 shown in Figure 1 to Figure 6. Therefore, the way in which the device 600 works is mostly the same as for the device 100 and therefore need not be explained again. The main difference between the device 600 and the device 100 is that the neck portion 640 of the device 600 is longerthan then neck portion 140 of the device 100. (There are also a number of reinforcing ribs 643 which extend up for a portion of the length of the neck portion 640 from its base on four sides thereof. These reinforcing ribs 643 serve to reinforce/strengthen the (longer) neck portion 640, i.e. they help to prevent undue or excessive bending or creasing or twisting of the neck portion 640 (which it has a greater tendency to do (compared to the shorter neck portion 140 of the device 100) due to its longer length.) It will be recalled that, in the device 100 discussed above, substantially the whole (i.e. the whole length) of the neck portion 140 forms and functions as the male part of a standard luer slip connector. However, in the device 600, the overall length of the neck portion 640 is much greater than the length of a standard luer slip connector. Accordingly, in the device 600, it is only the upper part 642 of the overall neck 640 that forms and functions as the male part of a standard luer slip connector. In other words, it is only this upper portion 642 that inserts into the corresponding female portion of a standard luer slip connector when the device 600 is connected to an intravenous cannula.

[00143] One possible benefit of the device 600, compared to the device 100, is that greater length of the neck portion 640 of the device 600 (compare to the much shorter neck portion 140 of the device 100) relates the way in which the device can be handled when initially removing the removable tab 670. As explained above, with the device 100, the user can initially “open” the device 100 by grasping the body 110 of the device in one hand, and simultaneously grasping the tab 170 in the other hand, and with the tab and the neck part 140 pointed upwards, the user can twist and/or bend the tab 170 relative to the body 110 so that the material connecting the tab 170 to the top of the neck 140 breaks and the tab 170 breaks/tears away and separates from the top of the body 110. One possible problem is that, when this is done with the device 100, the user is required to grasp the body 110 in one hand. Therefore, they must generally hold body 110 (in particular the “bulbous” part of the body 130 and 150) in that one hand by applying at least some pressure in order to maintain sufficient grip on it. The problem with this is that, when the removable tab 170 comes away and the opening in the top of the neck 140 is opened, there is a possibility that the pressure being applied to the body by the user’s hand may cause some deformation of the body which may in turn cause some of the flush fluid contained therein to be unintentionally dispensed/expelled. The configuration of the device 600 may allow this problem to be avoided or reduced. The reason is because, with the device 600, the user is not required to hold the “bulbous” portion of the body of the device 600 in one hand while removing the tab 670 with their other hand. Instead, with the device 600, the user can instead grasp the neck 640 of the device in one hand while simultaneously grasping the tab 670 in the other hand, and with the tab and the neck part 640 pointed upwards, the user can twist and/or bend the tab 670 relative to the firmly-grasped neck portion 640 so that the material connecting the tab 670 to the top of the neck 640 breaks and the tab 170 breaks/tears away and separates from the top of the neck portion 640. Accordingly, with the device 600, because the user is able to hold the neck 640 of the device (rather than having to grasp and apply pressure to the “bulbous” portion of the device that contains the flush solution) when removing the tab 670, consequently there is little or no risk that pressure will be applied to the bulbous portion of the body causing flush fluid to be unintentionally dispensed/expelled when (or just after) the tab is removed.

[00144] Another thing that is depicted (albeit only very roughly I schematically by dashed lines) in Figure 23, Figure 24 and Figure 26 is that the device 600 can also be provided with an additional dome portion 665 (or possibly multiple such additional dome portions 665 could be provided, although only one is shown in the above-mentioned Figures). These are in addition to the main priming dome 660. The configuration of the (or each) such additional dome portion 665 may be similar to, or the same as, that of the main priming dome 660. The function of the (or each) additional dome portion 665 may also be generally similar to that of the main priming dome 660. By way of further explanation, the main priming dome 660 may be used to “prime” the device before it is connected to an intravenous cannula. However, sometimes, a short extension tube is used in between the flush device and the intravenous cannula. In other words, such a short extension tube is sometimes used/placed in between the intravenous cannula and the flush device, such that in order to perform the flush, the device is actually connected to the intravenous cannula via the extension tube. In situations where this is done, the flush device will generally be connected to the extension tune only after the device itself has been initially primed, which can be done using the main priming dome 660. Therefore, the device 600 may be connected to the extension tube after the device 600 has been primed using the main priming dome 660. However, before the other end of the extension tube is then connected to the cannula, it may be necessary or desirable to perform an additional prime and/or flush of the extension tube (so that it is also primed and/or flushed before it is connected to the cannula). This can be done (after the device 600 itself has been primed and then connected to one end of the extension tube) by (then) depressing the (or each) additional dome portion 665 in order to dispense further fluid to prime and/or flush the extension tube. And, once this further step of priming and/or flushing the extension tube has been completed, the other end of the extension tube may be connected to the cannula, thereby connecting the device 600 to the cannula via the extension tube.

[00145] It should be noted that, although the possible one or more additional dome portions 665 are only described and shown with reference to the device 600, such additional dome portions may also be provided with the devices in other embodiments, including in particular the devices 100, 200, 500 and 700, for similar reasons.

[00146] Turning to Figure 29 through Figure 34, the device 700 shown in these Figures is very similar to (in fact it is really just a further variant of) the device 600 shown in Figure 23 through Figure 28. Therefore, the way in which the device 700 works, and the way it is used, etc, is mostly the same as for the device 600 (which was itself mostly the same as for the device 100) and therefore need not be explained again. The main difference between the device 700 and the device 600 is that, whereas the upper portion 642 of the neck 640 of the device 600 forms and functions as the male part of a standard luer slip connector, in contrast to this, in the device 700, the upper portion 742 of the neck 740 of the device 700 forms and functions as the male part of a luer lock connector. This is because, the upper portion 742 of the neck 740 of the device 700 has a pair of upstanding projections 743 extending parallel to and on either side of the main/central (male) part of the upper portion 742. Each of these upstanding projections 743 has a number of “teeth” projecting from the inwardly-facing surface thereof. The size, shape and spacing of these teeth is configured to enable the teeth to engage with the threads that are formed in the outside of the female part of a standard luer lock connector. Accordingly, with the device 700, after the removable tab 770 has been removed (and after the device 700 has been vibrated and “primed” etc), the device 700 can be connected to a cannula by attaching (screwing) the female luer lock connector on the end of the cannula into engagement with the male luer lock connector formed by the upper portion 742 of the neck 740 of the device 700.

[00147] In the present specification and claims, the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ are intended to denote the inclusion of a stated integer or integers, but not necessarily the exclusion of any other integer, depending on the context in which the term is used.

[00148] It is to be understood that the present invention is not necessarily limited to specific features shown or described herein since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

1. A single-use device for use in administering a fluid substance to a patient via an intravenous catheter or cannula, the device having:

■ a body with a hollow interior inside at least part of the body, and the device is manufactured with the fluid substance that is to be administered to the patient contained within the hollow interior of the body;

■ a connecting portion for connecting the device to the intravenous catheter or cannula; o an opening in the connecting portion which leads into the hollow interior of the body, which opening is initially closed but which can be opened, or, o a portion of the connecting portion in which an opening into the hollow interior of body can be formed; wherein once the opening is opened or formed, the fluid substance is able to exit the hollow interior of the body through the opening; and

■ a deformable portion of the body which, after the opening into the hollow interior has been opened or formed, is able to be deformed, or its shape is able to change, upon application of force, wherein the deformation of, or the change in shape of, the said deformable portion caused by the application of force reduces the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening, wherein the volume of the hollow interior can be reduced substantially to zero such that substantially all of the fluid substance that was originally contained within the hollow interior is expelled, and if the application of force which deforms the deformable portion, or causes the shape thereof to change, is stopped or paused, the state/extent of the deformation of, or the (change in) shape of, the deformable portion will remain as it was at that point and the deformable portion does not return or re-expand.

2. The device as claimed in claim 1 , wherein the deformation of, or the change in shape of, the deformable portion can occur smoothly/continuously.

3. The device as claimed in claim 1 or 2, wherein a user can stop or pause the delivery/expulsion of the fluid substance out of the hollow interior at any point after the deformation or change in shape of the deformable portion has commenced and before the deformation or change in shape thereof is complete by ceasing the application of said force.

4. The device as claimed in any preceding claim, wherein the device has an opening in the connecting portion which leads into the hollow interior of the body, which opening is initially closed and sealed by a cap, but the opening can be opened and unsealed by removing the cap.

5. The device as claimed in claim 4, wherein the connecting portion of the device includes a luer lock connector portion, and the cap is initially attached to, and it seals the device via the luer lock connector portion.

6. The device as claimed in any one of claims 1-3, wherein the connecting portion of the device has a portion in which an opening into the hollow interior part of body can be formed.

7. The device as claimed in claim 6, wherein the device is initially provided with a removable tab attached to the connecting portion, and the removable tab is able to be separated from the connecting portion, and separating the removable tab from the connecting portion causes the opening into the hollow interior part of the body to be formed.

8. The device as claimed in claim 7, wherein the body, connecting portion and removable tab are unitary being initially formed from a single piece of material.

9. The device as claimed in any one of claim 6, 7 or 8, wherein, with the removable tab separated from the connecting portion, the connecting portion is configured as either a male portion of a luer slip connector or a male portion of a luer lock connector.

10. The device as claimed in any one of the preceding claims, wherein the device is manufactured with the fluid substance completely filling, or at least almost completely filling, the hollow interior part of the body.

11. The device as claimed in any one of the preceding claims, wherein once the opening is opened or formed, and with the connecting portion oriented generally upwards, but before the device is connected to the intravenous catheter or cannula, the device is able to be “primed” by causing a small quantity of the fluid substance to be forced out through the opening, such that the level of the surface of the fluid substance is substantially level with the opening in the connecting portion.

12. The device as claimed in claim 1 1 , wherein the device includes an auxiliary depressible portion, and the device is able to be “primed” by depressing the auxiliary depressible portion which causes the small quantity of the fluid substance to be forced out through the opening, such that the level of the surface of the fluid substance is substantially level with the opening in the connecting portion.

13. The device as claimed in any one of the preceding claims, wherein there is a relatively more non- deformable portion of the body which, even after the opening into the hollow interior part of the device has been opened or formed, is not substantially deformed, or the shape of which remains substantially unchanged, upon the application of force to the device.

14. The device as claimed in claim 13, wherein the connecting portion is part of the more non- deformable portion of the body.

15. The device as claimed in any one of the preceding claims, wherein the body of the device is sized to be grasped by a user in one hand.

16. The device as claimed in claim 14, or claim 15 when dependent on at least claim 14, wherein with the connecting portion oriented generally upwards, the device is able to be grasped by a user in one hand with one or more fingers pressing generally downwards from above on the more non- deformable portion of the body and with the thumb simultaneously pressing generally upward against the deformable portion of the body.

17. The device as claimed in claim 13, or any one of claims 14-16 when dependent on at least claim 13, wherein the more non-deformable portion of the body includes a first conical portion that tapers from a widest point to a narrowest point in a first direction, and the deformable portion of the body includes a second (initially) conical portion extending from at or near the widest point of the first conical portion, and the second conical portion (initially) tapers from a widest point to a narrowest point in a direction opposite to the first direction.

18. The device as claimed in claim 17, wherein, after the opening into the hollow interior part of the device has been opened or formed, force can be applied to the second conical portion in the first direction causing the second conical portion to deform/collapse in the first direction, towards (and possibly also into) the first conical portion, wherein the deformation, or the change in shape, of the second conical portion caused by this, reduces the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening.

19. The device as claimed in claim 18, wherein the second conical portion includes an indent or groove which initially is curved into a spiral or helix shape that extends around, and also up/down, the second conical portion, wherein the configuration of said indent or groove, and the way it deforms when second conical portion deforms, helps to ensure that if the application of force which deforms the second conical portion, or causes the shape thereof to change, is stopped or paused, the state/extent of the deformation of, or the change in shape of, the deformable second conical portion will remain as it was at that point and the deformable second conical portion does not return or re-expand.

20. The device as claimed in any one of claims 13-16, wherein the deformable portion of the body includes a concertina-shaped portion extending from a portion of the more non-deformable portion.

21. The device as claimed in claim 20, wherein, after the opening into the hollow interior part of the device has been opened or formed, force can be applied to the concertina-shaped portion causing the concertina-shaped portion to deform and collapse towards the non-deformable portion, which reduces the volume of the hollow interior of the body such that the fluid substance is forced out of the hollow interior through the opening.

22. The device as claimed in claim 20 or 21 , wherein there are parts of, or points on, the deformable portion of the body which progressively engage with one or more parts of, or points on, the non- deformable portion as the deformable portion is progressively deformed, or as its shape is caused to progressively change, by the application of force, such that if the application of force is stopped or paused, the state/extent of the deformation of, orthe change in shape of, the deformable portion will remain as it was at that point and the deformable portion does not return or re-expand.