WO2014057286A1

WO2014057286A1 - Injector device

Info

Publication number: WO2014057286A1
Application number: PCT/GB2013/052666
Authority: WO
Inventors: George Perkins; Lasse Mogensen; Lai Chiu Tang; Eugene VAN WYK; Archie LODGE; William HARBORNE; James Mclean
Original assignee: Cambridge Consultants Limited
Priority date: 2012-10-12
Filing date: 2013-10-11
Publication date: 2014-04-17
Also published as: GB201218393D0; GB2506918A

Abstract

A spring driven auto injector device (200) for receiving a syringe (150) for use in an injection procedure, having a deformable needle shield (201) and an internal heater (221) for heating the contents of the syringe (150) prior to injection.

Description

!sijector Device

Technical FseSd

The present invention relates to injector devices and, in particular, automatic injector devices. The invention has particular relevance to injector devices that house and discharge a syringe, allowing drugs to be delivered by the syringe to a delivery area. In particular, the present invention relates to such devices which are reusable and adapted for self-administration of drugs.

Background

Self-administration of drugs can be awkward, intimidating (particularly to needie-phobics) and potentially hazardous if not executed correctly. Auto-injector delivery devices address these issues, to a certain extent, by providing assemblies that are easier to hold and operate than a syringe, particularly if the injection site is in an awkward position, such as the upper buttock.

As an example, women undergoing fertility treatment such as in vito fertilisation (IVF) may have to self-administer multiple drug doses every day. An example of this is Progesterone-in-Oil (PiO), a treatment designed for women to improve their chances of sustaining their pregnancy to full term. Typically women who are prescribed PiO injections will have a history of unsuccessful fertility treatments, and attach high value to these injections. The PiO injection itself is a daunting daily intramuscular injection of up to 2ml of an oil and drug suspension into the upper buttock or thigh. The injections are commonly taken for the first 12 weeks of pregnancy; however, some patients need to take this throughout their pregnancy. Fertility treatments are commonly expensive and stressful, yet many patients are willing to accept these injections because of their strong desire to have a child.

A number of usability issues have been identified where an auto injector delivery device could significantly improve the patient experience in administering drugs such as PiO. Firstly, the large and long needle is often intimidating, regardless of whether the actual injection is painful. Secondly, given the size of the needle (22G), most patients are advised by healthcare professionals only to inject into the upper buttock, which is an awkward position into which to self-administer a drug. Thirdly, it can take a significant time (typically over one minute) to inject 2ml of PiO into the body which adds to the discomfort of manually injecting in an already difficult to reach position. Further, the suspension in oil results in a higher drug viscosity to typical intramuscular injections, resulting in slower than ideal delivery and a higher force requirement.

The present invention seeks to overcome or at least partially alleviate one or more of the above issues.

According to an aspect of the present invention, there is provided an injector device for use with a syringe holding a fluid to be injected, said injector device comprising: a housing for receiving the syringe; means for heating the fluid held by the syringe whilst housed in said housing; and means for operating the syringe, whilst housed in said housing, to expel fluid held by the syringe that has been heated by the heating means.

The syringe may comprise a needle, and the housing may be arranged such that the needle extends from the housing when the syringe is housed in the housing. The device may further comprise means for shielding the needle of the syringe, when the syringe is housed in the housing, said shielding means comprising a shield that is movable between a first position in which the needle is shielded and a second position in which the needle is unshielded.

The shielding means may comprise a shield formed of a deformable material whereby said shield is deformable between said first position and said second position by deformation of said deformable material.

According to another aspect of the present invention, there is provided an injector device for use with a syringe holding a fluid to be injected and comprising a needle from which said fluid is expelled in operation, said injector device comprising: a housing for receiving the syringe such that the needle extends from the housing; means for shielding the needle of the syringe, when the syringe is housed within the housing, said shielding means comprising a shield formed of a deformable material whereby said shield is deformable, by deformation of said deformable material, between a first position in which the needle is shielded and a second position in which the needle is unshielded; and means for operating the syringe, whilst housed in said housing, to expel fluid held b the syringe. The device may further comprise means for heating the fluid held by the syringe when whilst housed said housing.

The heating means may comprise a heater element, said heating element arranged to be located proximate to a barrel of said syringe when the syringe is housed in said housing.

The heater element may comprise at least one of a resistive heater and a dielectric heater. The heater element may be configured to surround substantially an entire perimeter of the barrel of the syringe when the syringe is housed in said housing.

The heater element may be configured to be in contact with the barrel of the syringe when the syringe is housed in said housing.

The heating means may be configured to heat the fluid held by the syringe, whilst the syringe is housed in said housing, to a predetermined temperature.

The device may further comprise means for inhibiting heat generated by said heating means propagating away from the barrel of the syringe when the syringe is housed in said housing.

The inhibiting may comprise an insulating layer surrounding at least a portion of the barrel of the syringe, whilst the syringe is housed in said housing. The device may further comprise means for transferring power from an external source of power to said heating means to drive said heating means.

The device and power transferring means may be configured such that power is transferred from said external source of power to the heating means when the device is connected to a docking device. The power transferred from the external source of power to the device may be electrical power. The power may be transferred from the external source of power to the device via a direct electrical connection.

The power may be transferred from the external source of power to the device via an inductive connection. The shield may be formed as a rolling diaphragm. The shield may be formed from an elastic polymer material (e.g. an elastomer). The shield may be formed from a silicone rubber, or from a natural rubber.

The shield may be moveable, in operation, from said first position, to said second position and back to said first position. The shield may be moveable, in operation, from said first position, to said second position and back to a further position in which the needle is shielded, said further position being different to said first position.

The device may further comprise means for maintaining said deformab!e shield rigid when in said first position. The device may further comprise resilient means (e.g. a spring) arranged to bias said shield towards said first position.

The housing may comprise means for receiving said shield as it moves into said second position.

The device may further comprise means for storing energy for driving the syringe operating means.

The syringe operating means may be configured to automatically operate the syringe using the energy stored by the energy storing means.

The energy storing means may comprise a resilient means.

The energy storing means may comprise a spring.

The device ma further comprise means for triggering the operating means to operate the syringe.

The triggering means may be operable to trigger said operating means when the injector device is in a predefined state relative to a skin surface of a user.

The device may further comprise means for inhibiting triggering of operation of the syringe operating means when the inhibiting means is in a first state, and for allowing triggering of operation of the syringe by the syringe operating means when the inhibiting means is in a second state.

The first state of said inhibiting means may be a default state and said inhibiting means may be operable to change to said second state under an action of a user.

The device may further comprise means for priming the syringe operating means.

The priming means may be adapted to prime the syringe operating means as part of a process for securing the syringe in said housing. The priming means may be adapted to cause the energy storing means to store said energy for operating the syringe.

The priming means may be adapted to prime the triggering means as part of the process for securing the syringe in the housing. The housing may comprise a first part and a second part, said first part and said second part being separable to allow insertion of the syringe into the housing, and being reconnectabie to secure the syringe in place within the housing.

The priming means may be adapted to prime said syringe operating means and/or said triggering means as part of a process of separating the first part and the second part of the housing to allow insertion of the syringe into the housing and reconnection of the first part and the second part of the housing.

The device may further comprise means for indicating when the heating means has heated the fluid held by the syringe to a predetermined temperature or temperature range.

The device may be reusable. According to another aspect of the present invention, there is provided a docking device for receiving an injector device as described above, said device comprising means for transferring power to said heating means to drive said heating means, said transferring means being configured to transfer said power when the device is received by the docking device.

According to another aspect of the present invention, there is provided a method of preparing an injector device for use, said injector device being an injector device as described above, said method comprising: inserting the syringe into the device; providing a source of power for driving the heating means to heat the fluid held by the syringe; receiving an indication that the heating means has heated the fluid held by the syringe to a predetermined temperature or temperature range; and removing the device from said power source in response to receiving said indication. According to another aspect of the present invention, there is provided an injector device for use with a syringe holding a fluid to be injected, said injector device comprising: a housing for receiving the syringe, wherein said housing comprises a first part and a second part, said first part and said second part being separable to allow insertion of the syringe into the housing, and being reconnectabie to secure the syringe in place within the housing; means for operating the syringe, whilst housed in said housing, to expel fluid held by the syringe; means for storing energy for driving the syringe operating means; and means for priming the syringe operating means to cause the energy storing means to store said energy for operating the syringe as part of a process for securing the syringe in the housing.

The present invention will now be described by way of example only with reference to the attached figures in which:

Figures la and lb illustrate a simplified depiction of an exemplary syringe for use with the injector device described herein; Figure 2 is a simplified illustration of an embodiment of an injector device for use with the syringe as illustrated in Figure 1;

Figure 3a is a simplified illustration of an embodiment of an injector device for use with the syringe as illustrated in Figure 1; Figure 3b is a simplified illustration of the a trigger plate forming part of the injector device;

Figure 4 illustrates a simplified cross sectional view of the injector device;

Figure 5 is a simplified illustration of a default state of the injector device;

Figure 6a is a simplified illustration of the injector device in its default state;

Figure 6b is a simplified illustration of a section through the injector device of Figure 6a; Figure 6c is a simplified illustration of a locking ring forming part of the injector device;

Figures 7a and 7b are simplified illustrations of the injector device in a disassembled state;

Figure 8 is a simplified illustration of the loading of a syringe into the injector device;

Figures 9a and 9b are simplified illustrations of reassembly of the injector device;

Figures 10a and 10b are simplified illustrations of a docking station for use with the injector device; Figure 11 illustrates a simplified view of the injector device;

Figures 12a, 12 and 12c are simplified illustrations of the process of delivering the syringe contents to an injection site using the injector device.

Overview

Figures la and lb illustrate a simplified depiction of an exemplary syringe 150 for use with an injector device as described herein. Figures 2 and 3a illustrate an injector device 200 for use with the syringe 150 as illustrated in Figure 1.

Referring to Figures 1 to 3, the injector device beneficially addresses or at least partially alleviates the issues discussed above by providing an easy to use auto injector device 200 for use with a syringe 150 having a bore 107, a hollow needle 110 in fluid connection with the bore 107, and a plunger 113 movable within the bore 107 in a manner that those skilled in the art would immediately understand. The auto injector device 200 comprises a housing 205 (referred to herein as a 'chassis'} for holding the syringe 150. As described in more detail below, the injector device 200 has a portion 227 for applying a force to the plunger 113 of the syringe 150, in operation, to drive the plunger 150 along the bore 107 and towards the needle 110, thereby forcing the contents of the syringe 150, disposed within the bore 107, to be expelled from the syringe 150 via the needle 110.

The auto-injector device 200 beneficially includes a heating element 221 located within the housing 205 which is arranged to heat the contents of the syringe 150 to a desired temperature, before the contents of the syringe 150 is expelled under the action of the force application portion 227. The auto injector device 200, of the present embodiment, is adapted for use on human patients, and therefore the heating element 221 is configured to heat the contents of the syringe 150 to an average human body temperature ^■· approximately 38°C. Heating the syringe contents when the syringe is located within the housing of device is particularly advantageous because patient discomfort caused by a relatively cold liquid entering their body can be minimised. Accordingly, heating the drug contained in a syringe 150 immediately prior to delivery can be seen to provide a number of benefits over a room temperature delivery. This is particularly advantageous for the intramuscular administration of drugs with a higher viscosity than typical intramuscular administered drugs. As an example, the injector device is particularly beneficial in the case of the Progesterone-in-Qil (PiO) treatment designed for women to improve their chances of sustaining their pregnancy to full term when undergoing fertility treatment such as in vitro fertilisation (IVF). As explained above, higher drug viscosities result in longer delivery times due to the greater resistance encountered in expelling the drug from the syringe via the needle. Therefore, heating the drug contained in a syringe prior to delivery of the drug leads to lower resistance during delivery and increased delivery speed, which minimises user strain and discomfort, particularly in situations where users are self-administering the drug in awkward to reach positions such as the upper buttock, it has been found, for example, that pre-warming of PiO can result in approximately a 30% reduction in injection duration. Also, decreased drug viscosity results in a lower force required to be exerted by the plunger moving means on the plunger in order to expel the drug from the syringe and deliver the drug to the patient via the needle. In addition, reducing the viscosity of the contents of the syringe provides the potential for the size of the needle to be reduced (which can have a beneficial psychological effect). Furthermore, pre-warming syringe contents in the device may provide faster dissipation of the drug in the body, reducing discomfort post injection.

A flexible safety shroud 201 is also provided for protecting a user from needle stick injuries whilst preparing the injector. The shroud 201 is arranged in the form of a 'rolling diaphragm' to flex (or '^"roll"^') between an extended position (shown in Figures 2 and 3a), in which the shroud shields the needle 110 of a syringe 150 that is in position in the injector device 200 prior to injection, and a fully retracted position (shown in Figures 12b and 12c) when the needle 110 is fully inserted into a user's body. As the shroud travels (or 'rolls') towards the fully retracted position the shroud 201 is beneficially received into a 'shroud' cavity 235 thereby keeping the flexible material of the shroud awa from the injection site and preventing it from interfering with the injection process. The shroud 201 and corresponding components of the injector are also beneficially arranged such that when the shroud has travelled a predetermined distance towards its fully retracted position, the auto-injector device 200 is triggered to start the injection process.

The various components of the auto-injector device 200 and the syringe will now be described in more detail, by way of example only.

Syrirtge

Referring to Figures la and lb, which illustrate a simplified depiction of an exemplary syringe 150, the syringe 150 includes a body, or "barrel" portion 105 in which the bore 107 is disposed and to which the hollow needle 110 is coupled. An opening 109 is provided in the body portion to provide a fluid connection between the bore 107 and the needle 110, thus allowing fluid communication between the bore 107 and the needle 110. The piunger 113 is slidable within the bore 107 between an extended position, as illustrated in Figure la, in which a cavity is defined in the bore 107 which can accommodate fluid contents, and an enclosed position, as illustrated in Figure lb, in which the plunger abuts an end of the bore proximate to the syringe opening 109 (essentially filling, or at least partially filling, the cavity). The plunger 113 is thus slidable towards the syringe body 105 opening 109 in order to expel any fluid contents of the syringe 150, held within the bore 107, from the syringe 150 via the needle 110, until the plunger 113 is in the enclosed position.

The plunger 113 maintains a substantially sealed contact with the inner surface of the bore 107 as it moves along the bore 107, which helps to ensure that all of the contents of the syringe held within the bore 107 is expelled from the syringe via the syringe opening 109 and the needle 110.

!rijector

Referring to Figures 2 and 3a, which illustrate the injector device 200, Figures 2 and 3a each show the injector device 200 from a different respective axial cutaway view of the device. In addition, Figure 3b is a simplified illustration of the trigger plate 223. As shown in Figures 2 and 3a, the injector device 200 includes a main chassis portion 205 in which a syringe 150 is housed in operation. The main chassis portion 205 (referred to as a 'housing' above) is operable to be releasabiy connected to a further chassis portion 225 via a locking ring 207.

The main chassis portion 205 has a cavity for receiving the syringe 150 and an opening 231, disposed at a front (or 'injecting') end 262 of the injector through which the needle 110, and possibly a section of the syringe body 105 adjacent to the needle 110, extends when the syringe 150 is received within the chassis 205. The opening 231 is configured such that the majority of the needle 110 extends beyond the front end 262 of the chassis, allowing the majority of the needle 110 to be inserted through the skin of a user before the skin of the user comes into close proximity to (or contact with) the main chassis portion 205. in operation to load the syringe 150 into the main chassis portion 205, when the main and further chassis portions 205, 225 are engaged with one another, the locking ring 207 can be moved from a locked position into an unlocked position, which releases the connection between the main chassis portion 205 and the further chassis portion 225 and allows separation of the two elements. With the chassis separated from the further chassis portion 225, the syringe can be inserted into the associated cavity of main chassis portion 205 with the needle extending from the injector device. Separation of the chassis 205 and the further chassis portion 225 and insertion of the syringe into the chassis is described in more detail below with reference to Figures 6a, 6b, 7a and 7b.

As explained in overview above, the injector device 200 includes a heating element 221 disposed, within the main chassis portion 205, around the cavity for receiving the syringe 150 such that when the syringe 150 is in place the heating element 221 substantially surrounds the syringe body 105. An insulating layer 219 is provided that substantially surrounds the heating element 221 and the syringe body 105 thereby inhibiting heat from the heater element 221 from conducting towards the outside of the injector device. These elements of the device are described in more detail below with reference to Figure 4. The main chassis portion 205 also includes the shroud cavity 235 into which the shroud 201 is received during an injection process. The shroud cavity 235 comprises a chamber having a generally annular cross-section that is substantially co-axial with the needle opening 231.

An outer surface of the main and further chassis portions 205, 225 are each substantially covered by a respective external chassis skin 203, 211 which protects the chassis portions 205, 225 and other elements included within the device 200, The external chassis skin 203 of the main chassis portion 205 continues towards a rear end of the device and partially covers the further chassis portion, as shown in Figure 10b thereby providing overlapping main and further chassis skins 203, 211.

Shroud The shroud 201 is coupled to the main chassis portion 205 at the injecting end 262 of the main chassis portion 205, where the needle opening 231 is located. In this embodiment, the shroud 201 has a general frustoconical shape. In Figures 2 and 3a the shroud 201 is shown in a fully extended position in which the shroud extends away from the chassis 205 for a distance sufficient to extend beyond the needle 110 of the syringe 150 when the syringe 150 is housed within the chassis 205. When the shroud 201 is fully extended, it surrounds the needle 110 and extends beyond the needle 110, protecting it from debris and preventing the needle 110 from coming into unintended contact with a user and resulting in needle stick injury.

The shroud 201 is formed from a flexible/deformabie material, such as an elastomer or polymer material, for example silicone rubber, natural rubber, latex, or a similar material, in order to allow the shroud to retreat, with a rolling action, into the shroud cavity 235 of the main chassis portion 205, as explained further below in relation to Figures 12a to 12c,

A contact plate 215 is disposed within the shroud 201, at a 'contact' end 237 of the shroud 201, distal from the chassis 205, that makes contact with a user's skin during an injection process. The contact end 237 of the shroud 201 extends over the contact plate 215 such that, in operation, the contact plate 215 does not make direct contact with a user's skin (thereby improving the comfort of the injection process).

The contact plate 215 is partially or fully formed from a material with a higher rigidity than the shroud 201 and therefore increases the rigidity and reinforces the distal end of the shroud. The shape of the contact plate 215 is generally annular, conforming to a corresponding annular cross section of the contact end 237 of the shroud 201. The contact plate 215 and shroud end are coaxial with one another, and with the needle opening 231, and thus have common central apertures through which the needle 110 can pass, in operation, as the shroud retracts into the shroud cavity 235 of the main chassis portion 205, thus allowing the needle 110 to extend beyond the distal end of the shroud to enter into the skin of a user when being deployed in a drug administration procedure. A recoil spring (not shown) is provided within the shroud 201, coaxiaily with the contact plate 215, and the needle opening 231, to softly bias the contact plate 215 away from the end of the main chassis portion 205, and hence the shroud towards its extended position. Accordingly when, in operation, a syringe needle 110 is removed from a user's body after an injection, the shroud returns from its retracted position to its extended position under the recoil spring's bias. An interior surface of the contact plate 215 (facing the injection end of the main chassis portion 205), and the injection end 262 of the main chassis portion 205, are each provided with a respective annular spring cavity 271-1 and 271-2 for receiving respective ends of the recoil spring.

A further advantage of using silicone rubber, or similar material, for forming the shroud is that the surface of this materia! exhibits a relatively high coefficient of friction, which reduces the risk of slippage of the shroud when placed in contact with a user's skin. Furthermore, whilst an infiexibie material could potentially be used in a retractable shroud having many of the above benefits, using a flexible shroud is particularly beneficial because it allows the depth of the shroud cavity to be minimised as a result of the shroud effectively folding over on itself in the cavity.

Guide Rods

The injector device 200 further includes a plurality of guide rods 217 (one of which can be seen in Figure 2, and two of which can be seen in Figure 3a) which are coupled to the contact plate 215 and are s!idabiy received within complementary guide channels within the main chassis portion 205 of the injector device 200 to allow the guide rods 217 to retract into the main chassis portion 205 as the shroud 201 travels towards its retracted position in operation. In this embodiment, three guide rods extend away from the contact plate 215 towards the main chassis portion in a direction perpendicular to the plane of the contact plate 215, and are spaced apart equally in a radial manner. Such a configuration provides good support to the contact plate and the shroud.

Accordingly, as the shroud retreats into the main chassis portion 205, the guide rods 217 also retract into the chassis in unison with the shroud and each other, following a path which is linear and parallel to the axis of the needle 110. The provision of the guide rods 217 coupled to the rigid contact plate in this manner helps to ensure that, as the shroud retreats towards the main chassis portion 205, the needle 110 passes cleanly through the aperture at the contact end 237 of the shroud to enter the user's skin cleanly at an angle substantially perpendicular to the plane of the user's skin. Each guide rod 217 has a trigger end, opposite the end coupled to the contact plate 215, that is configured to engage with a trigger plate 223 provided in the main chassis portion 205, when the shroud 201 is approaching its fully retracted position. As will be explained in more detail below with reference to Figures 12a to 12c, the trigger end of each guide rod 217 and the trigger plate 223 are arranged such that when, in operation, the trigger end of each guide rod 217 engages with the trigger plate 223, the trigger plate 223 moves (e.g. rotating through approximately 6 degrees) to trigger the start of the injection process. As shown, the trigger ends of the guide rods 217 are pointed, for example having a conical, chamfered or bevelled end.

Trigger Piate

Figure 3b is a simplified illustration of the trigger plate 223. As shown, the trigger plate 223 includes guide rod interface edges 657 for interfacing with the trigger end of each guide rod 217, a push rod interface 655 for interfacing with a push rod 209, retention slots 651 for retaining the trigger plate 223 whilst allowing rotational movement, recesses 659 for use in assembling the device and a central void having a chamfered edge 653 for receiving the syringe 150.

In this embodiment, the guide rod interface edges 657 are defined by cylindrical voids passing through the trigger piate 223. The trigger plate is rotationally biased towards a position in which each pointed trigger end is aligned with a corresponding cylindrical void, but offset from the central axis of the cylindrical void. As the guide rods 217 move into the main chassis portion 205, the trigger ends approach and enter the corresponding cylindrical voids. By virtue of their offset nature, the pointed trigger ends engage with the guide rod interface edges 657, causing the trigger plate 223 to rotate through a predefined angle to trigger the start of the injection process.

Force Application Portion

The further chassis portion 225 houses the force application portion 227 used to drive the plunger 113 of the syringe 150 during an injection procedure. The force application portion 227 comprises a plunger pusher which is slidably mounted within a correspondingly shaped cavity in the further chassis portion 225 in order to allow slidable movement towards and away from the injection end

262 of the main chassis portion 205. The plunger pusher 227 is shaped to engage with the plunger 113 of the syringe 150 and is configured to exert a force on the plunger 113 in order to cause it to move along the bore 107 and towards the syringe opening 109 to cause any contents of the syringe, such as a drug for delivery into a user, to be expelled from the syringe via the syringe opening 109 and the needle 110. The plunger pusher 227 includes a power spring cavity 261 for housing a power spring (not shown) which is configured, when primed and triggered, to exert a force on the plunger pusher 227 to drive the plunger pusher 227 in a direction towards the front end of the chassis. The power spring engages with an inner surface of the further chassis portion 225 at the rear 'non- injecting' end of the further chassis portion 225 and therefore, when primed, the power spring exerts equal at opposite forces on the inner surface of the further chassis portion 225 and the plunger pusher 227. Thus, when the plunger pusher 227 is not prevented from moving towards the injection end 262 of the chassis by any other means (e.g. when the injection process has been triggered by means of the guide rods and trigger plate), the power spring acts to drive the plunger pusher 227 towards the front end of the chassis and, as a result the plunger 113 will be driven along the bore 107 of the syringe, delivering the contents of the syringe to a user.

Priming Mechanism

The injector device 200 also beneficially includes a priming mechanism for priming the injector for performing an injection. The priming mechanism comprises a push rod 209 which is slidably received within a corresponding push rod spring cavity 263 located within the main chassis portion 205. The push rod 209 is biased by a push rod spring (not shown) disposed within the push rod spring cavity

263 towards an extended position in which the push rod extends beyond a rear end of the main chassis portion 205. . The push rod 209 is configured to retreat into the push rod spring cavity 263 when a force, having magnitude greater than the force exerted by the push rod spring, is exerted on the push rod 209 in a direction towards the front end 262 of the main chassis portion 205. The priming mechanism is arranged such that when the push rod 209 is fully extended the push rod engages with the push rod interface 655 of the trigger plate 223 to lock the push rod 209 in the fully extended position thereby inhibiting it from being pushed back into the push spring cavity 263. in order to facilitate engagement, the trigger plate is biased towards a position in which the push rod interface 655 interfaces with the push rod 223. When the trigger plate 223 is moved under the action of the guide rods 217, as described previously, this action releases the push rod 209 and hence the push rod is free to move back into the push spring cavity 263 when a sufficient force is applied to overcome the resilient force of the push rod spring. The end of the push rod 263 that extends out of the push rod spring cavity 263 is arranged to engage with the plunger pusher 227 of the further chassis portion 225, when the further chassis portion 225 is coupled to the main chassis portion 205, via the locking ring 207. The push rod 263 and plunger pusher 227 are configured to mutually co-operate with one another such that when the plunger pusher 227 exerts a force on the plunger 113, under the action of the power spring, the plunger pusher 227 also exerts a similar force on the push rod 263, The power spring is configured such that when, in operation, the plunger pusher 227 exerts a force on the push rod 209, the force is greater than the force exerted by the push rod spring in the opposite direction.

Accordingly, during operation to assemble the injector 200, when the push rod 209 is locked in its extended position, and the further chassis portion 225 is brought together with the main chassis portion 205, the push rod 209 pushes against the plunger pusher 227 towards the non-injecting end of the injector thereby compressing, and hence priming, the power spring. When the trigger plate 223 is moved under the action of the guide rods 217, as described previously, this action triggers release of the push rod 209 and hence the push rod 209 is pushed back into the push rod spring cavity by the plunger pusher 227 under the influence of the power spring. Thus, if a syringe 150 is in position in the main chassis portion 205 with its plunger 113 extended when the triggering occurs, then the plunger 113 is also driven by the plunger pusher under the influence of the power spring, thereby initiating the expulsion of the contents of the syringe by the plunger 113.

Heating Arrangement Figure 4 illustrates a simplified cross sectional view of the injector device 200, showing the heating element 221 and the insulating layer 219 in greater detail. As described above, the syringe receiving cavity in the main chassis portion 205 is configured to accommodate and support the syringe when the syringe is inserted into the main chassis portion 205. Accordingly, the syringe receiving cavity is shaped to conform to the shape of the syringe, being linearly elongate as shown in Figures 2 and 3a, and having a generally circular cross section as shown in Figure 4.

The insulating layer 219 is disposed around an inner surface of the syringe receiving cavity and the heating element 221 is disposed around an inner surface of the insulating layer 219, so that the insulating layer 219 lies between the heating element 221 and the inner surface of the syringe receiving cavity and therefore insulates the heating element 221 from the main chassis portion 205. Figure 4 shows a syringe present in the syringe receiving cavity of the main chassis portion 205. As shown, the heating element 221 is positioned to make contact with (or at least be in close proximity to) the syringe body 105. Therefore, when the syringe is housed within the syringe receiving cavity, the heating element 221 is sandwiched between the syringe body 105 and the insulating layer 219. This configuration is advantageous because good thermal contact is formed between the heating element 221 and the syringe body 105, allowing heat energy generated by the heating element 221 to be conducted through the syringe body 105 and to the contents of the syringe bore 107, causing the contents of the syringe to increase in temperature. The provision of the insulating layer 219 helps to minimise conduction of the heat generated by the heating element 221 into the main chassis portion 205, as this represents an energy loss and thus decreases the heat energy transferred into the syringe contents. In this embodiment, the insulating layer 219 is made from a foam-like material which includes a large number of small air pockets, giving the insulating layer 219 good thermal insulating properties. The heating element 221 is preferably flexible in order to allow it to conform to the curved inner surface of the insulating layer 219, and to help accommodate the syringe within the syringe well and encourage close contact between the heating element 221 and the syringe body 105.

As also shown in Figure 4, the heating element 221 and the insulating layer 219 extend radially around the majority of the curved surface of the syringe receiving cavity. Provision of a gap in the insulating layer 219 and in the heating element 221 can beneficially allow space for electrical connections to the heating element 221. The heating element 221 may comprise a resistive heater, a dielectric heater or any other heating means.

Locking Mechanism

Figure 5 illustrates a default state of the injection device, where no syringe is present within the syringe, and the chassis and further chassis portion 225 are securely connected to one another by virtue of the locking ring 207 which is positioned in the locked position.

A simplified illustration of a cross section through the injector device 200 along the section A-A' (as indicated in Figure 6a) is illustrated in Figure 6b. Figure 6c is a simplified illustration of the locking ring. in Figure 5, the plunger pusher 227 occupies a "fired" position with the plunger pusher 227 at its maximum - or close to maximum - level of travel towards the injection end 262 of the main chassis portion 205. As seen in Figure 5 when the plunger pusher 227 is in the fired position, the plunger pusher 227 is in engagement with the distal end of the push rod 209, and substantially all of the push rod 209 is located within the push rod cavity 263. As explained previously, this position is maintained because the biasing force exerted on the plunger pusher 227 by the power spring is of a greater magnitude than the biasing force acing in the opposite direction by the push rod spring on the push rod 209, and because the chassis 205 and the further chassis portion 225 are secured together by the locking ring 207.

Referring to Figures 6a to 6c, the locking ring 207 is generally cylindrical and has a first edge 631 which, when assembled, faces the further chassis portion 225 and a second edge 632 which faces the main chassis portion 225. A first series of inward facing lips 601 is disposed around the locking ring 207 proximate to the first edge 631, and a second series of inward facing lips 603 is disposed around the locking ring 207 proximate to the second edge 632.

The first series of lips 601 is adapted to provide releasable connection of the locking ring 207 to complementary features of the further chassis portion 225. The second series of lips 603 is adapted to provide rotatabie coupling of the locking ring 207 to the main chassis portion 205 when the injector is assembled. In this embodiment, each of the first and second series of lips comprises three lips spaced substantially equidistantiy around the locking ring 207 in a radial manner in order to provide secure connection to further chassis portion 225 and main chassis portion 205 respectively. The lips of the first series are relatively short when compared to the the lips of the second series. The relatively short length of the lips of the first series allow the lips of the first series to be disengaged from connection to the further chassis portion 225 with a relatively short rotation (e.g. between 7° and 15°, typically ^'"10°) of the locking ring. Contrastingly, the longer length of the lips of the second series ensures that the lips of the second series do not disengage from the main chassis portion 205 when the locking ring is rotated to disengage the further chassis portion 225. The complementary locking feature provided on the further chassis portion 225, in this embodiment, are bayonet-style retention features, which the lips 601 of the first series are adapted to co-operate with to secure the two chassis portions together.

The locking ring is sprung such that as the further chassis portion 225 is pushed into it, it rotates against a locking ring spring to accommodate the three bayonet style retention features. Once sufficient engagement has been achieved, the locking ring spring is free to drive the locking ring back to a locked' position and the further chassis portion 225 is 'locked' to the main chassis portion 205. in this state, only manually rotating the locking ring (against the locking ring spring) will release the two chassis portions from one another. The second series of lips 603 do not directly attach main chassis portion 205, but do so via movable attachment to the trigger plate 223. Each lip of the second series of lips 603 is located within a groove provided between the trigger plate 223 and the main chassis potion 205. Engagement of the second series of lips 603 with the trigger plate 223 in this manner prevents separation of the locking ring 207 from the main chassis portion whilst allowing rotation of the locking ring about the longitudinal axis of the injector.

Thus, when the injector device 200 is in the state shown in Figure 6a, the first series of lips 601 are positioned in engagement with the complementary locking features provided on the further chassis portion 225, and the locking ring 207 is in a locked state. In order to unlock the locking ring 207 and release the connection between the main chassis portion 205 and the further chassis portion 225, the locking ring 207 is rotated in the direction indicated by the arrow in Figure 6b in order to disengage the first series of lips 601 from the complementary locking features provided on the further chassis portion 225. As described above, this rotation is approximately 10 degrees in this example although different rotations may be beneficial depending on requirements. After disengagement, the further chassis portion can be separated from the main chassis portion 205. As described above, when the injector device 200 is in the state shown in Figure 6a, the push rod 209 is substantially or fully contained within the push rod spring cavity 263, and therefore the push rod spring is compressed. Rotation of the locking ring 207 from its locked state to its unlocked state therefore beneficially causes the main chassis portion 205 and the further chassis portion 225 to be inclined to separate from one another, under the bias of the push rod spring, as the push rod 209 presses against the plunger pusher 227.

Other features

The injector 200 also includes an interlock mechanism 265. The interlock mechanism 265 comprises a stop element 265-1 in at least one of the guide channels that is arranged to inhibit movement of the guide rod 217 in the channel, thereby inhibiting the contact plate 215 (and hence the shroud end 237} from being depressed towards the injection end 262 of the main chassis portion and the needle 110 becoming exposed inadvertently. As seen in Figure 5, the interlock mechanism 265 also comprises a button 265-2 at an externa! surface of the main chassis portion 205 which is arranged to co-operate with the stop element 265-1 such that when the button 265-2 is depressed by a user the stop element 265-1 is moved out of the guide channel thereby allowing movement of the guide rod 217 in the channel and the contact plate 215 (and hence the shroud end 237) to be depressed towards the injection end 262 of the main chassis portion to perform an injection.

A stroke limiting pin 313 is attached to each of the guide rods 217, the stroke limiting pin 313 is arranged for limiting the path of travel of the guide rods 217 within the guide channels of the main chassis portion 205. The stroke limiting pins 313 are configured to engage with an abutment of the main chassis portion 205 when the guide rod to which the stroke limiting pin 313 is connected reaches its maximum desirable distance of travel towards the main chassis portion 205, i.e. the point at which the trigger end of the guide rod 217 triggers release of the triggering plate's locking engagement with the push rod 209. Engagement of the stroke limiting pin 313 with the corresponding abutment prevents further movement of the guide rod towards the main chassis portion 205. This prevents possible damage caused by the guide rods to other elements of the injection device due to the guide rods 217 being pushed too far into the main chassis portion. Similarly, a stroke limiting pin 313 is attached to the plunger pusher 227 in order to limit movement of the plunger pusher 227 towards the injection end 262 of the device 200, by engagement of the stroke limiting pin 313 with an abutment of the further chassis portion 225.

Operation Figures 7 to 10 illustrate the process of using the injector device 200 to administer a dosage of drug, either by one user administering the drug to a second user, such as a doctor on a patient, or more particularly where one user is administering the drug themselves.

Disassembled State

Figures 7a and 7b illustrate the injector device 200 in an initial, disassembled, state in which the main chassis portion and the further chassis portion 225 are separated from one another. As seen in Figure 7a, when these two parts are fully separated, the push rod 209 extends fully from the chassis 205 in its extended position. The push rod is locked in the extended position by virtue of engagement of the trigger plate 223 with complementary features of the push rod 209.

Syringe insertion With the injector device 200 is in the disassembled state, access is provided to the syringe receiving cavity in the main chassis portion 205. A syringe 150 containing a drug to be administered is loaded axialiy into the syringe receiving cavity, as shown in Figure 8, in the direction of arrow 'X'. Specifically, the syringe is inserted into the syringe receiving cavity via an opening 801 at a rear 'non- injecting' end of the external chassis skin 203 such that it abuts the end of the syringe receiving cavity proximate to the needle opening 231, with the needle 110 extending through the needle opening inside the shroud 201, as illustrated in Figure 9a.

Reassembly

Figures 9a and 9b illustrate reassembly of the injector device 200 by reconnection of the main chassis portion 205 and the further chassis portion 225. A user guides the further chassis portion 225 towards the main chassis portion 205, and the further chassis portion 225 is received by the externa! chassis skin 203. As this is done, the push rod 209, which is locked in its extended position, interfaces with the plunger pusher 227 and as the two chassis portion are pushed together the plunger pusher 227 is driven towards the non-injecting end of the further chassis portion 225 by the push rod 209. As a result the power spring is compressed thereby 'priming' the injector device 200 for drug delivery.

As the further chassis portion 225 encounters the locking ring 207, an inclined surface on the chassis portion invokes rotation of the locking ring 207 (of 10 degrees in the preferred embodiment), thereby moving the locking ring 207 from the locked position towards which it is biased into an unlocked position. In the unlocked position, the first series of lips 601 of the locking ring 207 enter a complementary recess on the further chassis portion 225, as the further chassis portion 225 moves further towards the main chassis portion 205. The locking ring then returns to the locked position, under the locking ring bias, to secure the further chassis portion 225 to the main chassis portion 205 by means of the lips 601 and the complementary features of the further chassis portion 225. Thus, when the locking ring 207 returns to the locked position, the main chassis portion 205 and the further chassis portion 225 are held in secure connection by the locking ring 207.

Primed State

Figure 9b shows the injector device 200 in a primed state, holding a syringe containing a drug for delivery, and with the plunger pusher 227 fully retracted within the power pack ready for release when the trigger plate 223 triggers unlocking of the push rod.

Heating

Figures 10a and 10b illustrate a docking station 500 used to provide power to the heating element 221 for the procedure of warming the syringe contents. In operation, the injector device 200 is docked with the docking cradle by inserting the shroud 201 into a docking cavity 510 until the front end 262 of the chassis 205 abuts against a top of a wall 520 defining the cavity 510. The docking station 500 contains control circuitry on a printed circuit board (PCB) which connects to and controls an induction coil disposed within the wall 520.

Figure 11 illustrates a simplified schematic of the injector device 200. As shown, the injector device 200 includes a temperature sensor 901 in contact with the syringe body 105. The temperature sensor 901 is connected to a monitoring circuit 903 which monitors the temperature of the syringe body 105 and therefore obtains an indication of the temperature of the syringe contents. The monitoring circuit 903 controls a heating circuit 905 which is configured to supply power to the heating element 221, in turn heating the contents of the syringe 150 to a desired temperature. The action of placing the injector device 200 in the docking station 500 initiates the control circuitry on the PCB to activate the induction coil and commence the heating operation. The induction coil in the docking station 500 is configured to inductively power the heating circuit, in turn heating the contents of the syringe 150.

The monitoring circuit 903 monitors the temperature of the syringe body 105 until a target temperature is achieved (preferably human body temperature, approximately 38C). At this point the monitoring circuit continues to monitor the temperature of the syringe body 105 and controls the heating circuit 905 to only apply power to the heating element 221 in order to maintain the target temperature.

During the heating phase, before the target temperate is achieved, a Light Emitting Diode (LED) disposed on the outer surface of the device 200 is controlled by the monitoring circuit 903 to blink. Once target temperature is reached, the monitoring circuit 903 controls the LED to remain constantly lit.

In a preferred embodiment, the heating procedure takes approximately 30s, during which time the user can prepare the injection site.

When prompted by the visual indication of the LED to remaining constantly lit, the user can remove the device 200 from the docking station 500 and position it proximate to the injection site, and at an approximate 90 degree angle to the surface of the skin, such that shroud 201 is in contact with the skin (skin contact with the flat surface of the shroud end beneficially providing an indication of when the correct injection angle has been reached).

Once the device is removed from the docking station 500, no power is provided to the device by the induction circuit. This is advantageous because the risk of electrical faults causing harm to the user while delivering the drug is minimised. The insulating layer 219 serves to slow the temperature drop of the syringe contents after the device is lifted from the docking station.

Drug delivery

Figures 12a, 12 and 12c illustrate the process of delivering the pre-warmed syringe contents to an injection site.

Once the user has positioned the device 200 proximate to the injection site, the user can depress the button 265-2 of the interlock mechanism in order to release the guide rods and allow the shroud 201 to be retracted. With the device 200 at an approximate 90 degree angle to the surface of the skin, and shroud 201 in contact with the skin, the user pushes the chassis towards the skin, and the shroud 201 progressively retreats with the shroud cavity 235, causing the guide rods to retreat through the chassis and causing the needle 110 to be driven through the skin surface. At approximately 90% of shroud retraction into the shroud cavity 235, the guide rods interface with the trigger plate 223 and cause the trigger plate 223 to rotate (in a preferred embodiment by 6 degrees). This rotation unlocks the push rod. The push rod is compressed against the push rod spring by the force of the power spring. As the push rod moves, so does the plunger pusher 227 and the plunger is driven within the bore of the syringe, delivering the drug to the injection area via the needle 110.

Once delivery is complete the user removes the device by pulling it away from their skin. As this happens the shroud automatically advances to surround the needle 110 under the bias of the associated recoil spring, safely shielding the needle 110. Once the shroud is fully extended the safety interlock button 265 can be released. The user then once again separates the chassis 205 and further chassis portion 225 and removes the syringe for disposal. As the device separates, the push rod resets to its extended position and the system is reset. The user positions the device back in the dock for storage. Modifications arsd Alternatives

Detailed embodiments have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein. in alternative embodiments, the contact plate 215 and/or guide rods 217 may not be included in the injector device 200.

Although a plurality of guide rods are described, and preferably the auto injector device 200 comprises three guide rods, only one guide rod (or more than three guide rods) may be provided.

The shroud may, alternatively, not extend over the contact plate 215 such that the contact plate makes direct contact with a user's skin. The surface of the contact plate which makes contact with the user's skin may be designed to have relatively high friction to reduce risk of slippage.

The shroud 201 may retract within the chassis 205 using an alternative method. For example, the shroud 201 may be rigid or semi-rigid and may be movably mounted within the shroud cavity 235, allowing the shroud to retreat into or advance out from the shroud cavity without deformation. The shroud may be biased towards the advanced position using additional, or alternative, means, such as a spring located within the shroud cavity and configured to engage with the shroud. In alternative embodiments the shroud may not retreat into a cavity but may instead be collapsible (e.g. along predefined fold lines in a concertina fashion).

Furthermore, in an alternative embodiment the shroud may be configured to retract along the outside of the chassis 205. When the syringe needle 110 is removed from a user's body after an injection, the shroud 201 may be configured to return, under the recoil spring's bias, from its retracted position to an extended position being a different position than its original extended position which it occupied before the injection was administered. Specifically, the shroud 201 may return to an extended position where the contact end 237 is located further from the injection end 262 of the main chassis portion 205 than it did before the injection was administered.

it will be appreciated that while several springs have been disclosed any appropriate resilient means may be used for example leaf springs, compressible/stretchable rubber or the like.

The plunger pusher 227 is described as having a power spring cavity for housing a power spring which exerts a force on the plunger pusher 227 in a direction towards the front end of the chassis. However, it will be appreciated that the plunger pusher 227 may not include a power spring cavity, and the power spring may be replaced with other means suitable for exerting a force on the plunger pusher 227. In alternative embodiments the heating element 221 and the insulating layer 219 may extend radially around the whole of the syringe receiving cavity. The insulating layer 219 may extend only partially around the syringe receiving cavity.

In place first series and a second series of inward facing lips disposed on the locking ring, each series may instead comprise only a single lip (or more than three lips), or alternatively the locking ring may use any means for connecting to the main chassis portion 205 (or the locking ring 207) and any means for connecting to the further chassis portion 225. Furthermore, the locking ring 207 may be irremovably and rotationally mounted to the further chassis portion 225 and releasably connectable to the main chassis portion 205. in an alternative embodiment, the temperature sensor 901 may not be in contact with the syringe but be located in close proximity to the syringe. in an alternative embodiment, the heating element may be powered by means of a direct electrical contact to the docking station 500, or to another power source, rather than using an inductive coil.

Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

Claims

An injector device for use with a syringe holding a fluid to be injected, said injector device comprising:

a housing for receiving the syringe;

means for heating the fluid held by the syringe whilst housed in said housing; and means for operating the syringe, whilst housed in said housing, to expel fluid held by the syringe that has been heated by the heating means .

A device according to claim 1, wherein the syringe comprises a needle, and the housing is arranged such that the needle extends from the housing when the syringe is housed in the housing.

A device according to claim 2, further comprising means for shielding the needle of the syringe, when the syringe is housed in the housing, said shielding means comprising a shield that is movable between a first position in which the needle is shielded and a second position in which the needle is unshielded.

A device according to claim 3, wherein said shielding means comprises a shield formed of a deformable material whereby said shield is deformable between said first position and said second position by deformation of said deformable material.

An injector device for use with a syringe holding a fluid to be injected and comprising a needle from which said fluid is expelled in operation, said injector device comprising:

a housing for receiving the syringe such that the needle extends from the housing; means for shielding the needle of the syringe, when the syringe is housed within the housing, said shielding means comprising a shield formed of a deformable material whereby said shield is deformable, by deformation of said deformable material, between a first position in which the needle is shielded and a second position in which the needle is unshielded; and

means for operating the syringe, whilst housed in said housing, to expel fluid held by the syringe.

A device according to claim 5, further comprising means for heating the fluid held by the syringe when whilst housed said housing.

A device according to any of claims 1 to 3 or 6, wherein the heating means comprises a heater element, said heating element arranged to be located proximate to a barrel of said syringe when the syringe is housed in said housing.

A device according to claim 7, wherein said heater element comprises at least one of a resistive heater and a dielectric heater.

9. A device according to any of claims 7 to 8. wherein said heater element is configured to surround substantially an entire perimeter of the barrel of the syringe when the syringe is housed in said housing. 10. A device according to any of claims 7 to 9, wherein said heater element is configured to be in contact with the barrel of the syringe when the syringe is housed in said housing.

11. A device according to any of claims 7 to 10, wherein said heating means is configured to heat the fluid held by the syringe, whilst the syringe is housed in said housing, to a predetermined temperature.

12. A device according to any of claims 7 to 11, further comprising means for inhibiting heat generated by said heating means propagating away from the barrel of the syringe when the syringe is housed in said housing.

13. A device according to claim 12, wherein said inhibiting means comprises an insulating layer surrounding at least a portion of the barrel of the syringe, whilst the syringe is housed in said housing. 14. A device according to any of claims 7 to 13, further comprising means for transferring power from an external source of power to said heating means to drive said heating means.

15. A device according to claim 14, wherein the device and power transferring means are configured such that power is transferred from said external source of power to the heating means when the device is connected to a docking device.

16. A device according to claim 14 or 15, wherein the power transferred from the external source of power to the device is electrical power. 17. A device according to claim 16, wherein the power is transferred from the external source of power to the device via a direct electrical connection.

18. A device according to claim 16, wherein the power is transferred from the external source of power to the device via an inductive connection.

19. A device according to any of claims 4 to 6, or any of claims 7 to 18 when dependent on any of claims 4 to 6, wherein said shield is formed as a rolling diaphragm.

20. A device according to any of claims 4 to 6 or 19, or any of claims 7 to 18 when dependent on any of claims 4 to 6, wherein said shield is formed from an elastic polymer material (e.g. an elastomer).

21. A device according to claim 20 wherein said shield is formed from a silicone rubber. 22. A device according to claim 20 wherein said shield is formed from a natural rubber.

23. A device according to any of claims 4 to 6 or 19 to 22, or any of claims 7 to 18 when dependent on any of claims 4 to 6, wherein said shield is moveable, in operation, from said first position, to said second position and back to said first position.

24. A device according to any of claims 4 to 6 or 19 to 22, or any of claims 7 to 18 when dependent on any of claims 4 to 6, wherein said shield is moveable, in operation, from said first position, to said second position and back to a further position in which the needle is shielded, said further position being different to said first position.

25. A device according to any of claims 4 to 6 or 19 to 22, or any of claims 7 to 18 when dependent on any of claims 4 to 6, further comprising means for maintaining said deformab!e shield rigid when in said first position. 26. A device according to any of claims 3 to 6 or 19 to 25, or any of claims 7 to 18 when dependent on any of claims 3 to 6, further comprising resilient means (e.g. a spring) arranged to bias said shield towards said first position.

27. A device according to any of claims 3 to 6 or 19 to 26, or any of claims 7 to 18 when dependent on any of claims 3 to 6, wherein said housing comprises means for receiving said shield as it moves into said second position.

28. A device according to any preceding claim, further comprising means for storing energy for driving the syringe operating means.

29. A device according to claim 28, wherein said syringe operating means is configured to automatically operate the syringe using the energy stored by the energy storing means.

30. A device according to any of claims 28 to 29, wherein said energy storing means comprises a resilient means.

31. A device according to any of claims 28 to 30, wherein said energy storing means comprises a spring. 32. A device according to any preceding claim, further comprising means for triggering the operating means to operate the syringe.

33. A device according to claim 32 wherein said triggering means is operable to trigger said operating means when the injector device is in a predefined state relative to a skin surface of a user.

34. A device according to claim 32 or 33, further comprising means for inhibiting triggering of operation of the syringe operating means when the inhibiting means is in a first state, and for allowing triggering of operation of the syringe by the syringe operating means when the inhibiting means is in a second state.

35. A device according to claim 34, wherein said first state of said inhibiting means is a default state and said inhibiting means is operable to change to said second state under an action of a user.

36. A device according to any preceding claim, further comprising means for priming the syringe operating means.

37. A device according to claim 36, wherein said priming means is adapted to prime the syringe operating means as part of a process for securing the syringe in said housing.

38. A device according to any of claims 36 to 37 when dependent on any of claims 29 to 31, wherein said priming means is adapted to cause the energy storing means to store said energy for operating the syringe.

39. A device according to any of claims 36 to 38 when dependent on any of claims 32 to 35, wherein the priming means is adapted to prime the triggering means as part of the process for securing the syringe in the housing.

40. A device according to any preceding claim, wherein the housing comprises a first part and a second part, said first part and said second part being separable to allow insertion of the syringe into the housing, and being reconnectable to secure the syringe in place within the housing.

41. A device according to claim 40 when dependent on any of claims 36 to 39, wherein the priming means is adapted to prime said syringe operating means and/or said triggering means as part of a process of separating the first part and the second part of the housing to allow insertion of the syringe into the housing and reconnection of the first part and the second part of the housing.

42. A device according to any preceding claim, further comprising means for indicating when the heating means has heated the fluid held by the syringe to a predetermined temperature or temperature range.

43. A device according to any preceding claim, wherein the device is reusable.

44. A docking device for receiving an injector device according to any preceding claim, said device comprising means for transferring power to said heating means to drive said heating means, said transferring means being configured to transfer said power when the device is received by the docking device.

45. A method of preparing an injector device for use, said injector device being an injector device according to claim 1, said method comprising:

inserting the syringe into the device; providing a source of power for driving the heating means to heat the fluid held by the syringe;

receiving an indication that the heating means has heated the fluid held by the syringe to a predetermined temperature or temperature range; and

removing the device from said power source in response to receiving said indication.

46. An injector device for use with a syringe holding a fluid to be injected, said injector device comprising:

a housing for receiving the syringe, wherein said housing comprises a first part and a second part, said first part and said second part being separable to allow insertion of the syringe into the housing, and being reconnectable to secure the syringe in place within the housing;

means for operating the syringe, whilst housed in said housing, to expel fluid held by the syringe;

means for storing energy for driving the syringe operating means; and

means for priming the syringe operating means to cause the energy storing means to store said energy for operating the syringe as part of a process for securing the syringe in the housing.