Gas injection device, assembly and associated process

Abstract

Gas injection device, assembly and associated method. The present invention relates to a gas injection device (16) for subcutaneous gas injection, comprising a fluidic system for delivering a dose of gas, including: - a gas reservoir (18) having a predefined reservoir volume V1, the reservoir being configured to receive gas at a given reservoir pressure P1; - a delivery module (20) comprising a gas injection line (30) connected upstream to the gas delivery outlet (24), the gas injection line being equipped with an injection valve (34), and a gas outlet line (32), the gas injection line being connected downstream to the gas outlet line, the injection valve being actuable to allow the passage of gas to the outlet line. Figure for the abstract: Figure 1

Description

Title of the invention: Gas injection device, assembly and associated method

[0001] The present invention relates to a gas injection device, particularly for carbon dioxide, intended for subcutaneous gas injection, comprising a fluidic system for delivering a dose of gas having a determined volume, comprising:

[0002] - a gas tank having a predefined tank volume V1, the tank having a gas delivery outlet and configured to receive pressurized gas at a given PI tank pressure;

[0003] - a delivery module comprising a connected gas injection line upstream at the gas delivery outlet, the gas injection line is equipped with an injection valve, and a gas outlet line is outside the fluidic system, the gas injection line is connected downstream to the gas outlet line, the injection valve is actuable from a closed rest configuration, in which it blocks the passage of gas from the tank to the gas outlet line, and an open configuration, in which it allows the passage of gas to the outlet line.

[0004] Such a device is intended to inject a specific volume of gas under the skin, and particularly to perform self-injection. The gases that can be injected are notably chosen from among biocompatible gases such as carbon dioxide, nitrous oxide, nitric oxide, oxygen, or hydrogen. Advantageously, the injected gas is carbon dioxide.

[0005] The injection of gas, in particular carbon dioxide, under the skin is a cosmetic procedure used in the aesthetic treatment of various skin problems, in particular the reduction of dark circles.

[0006] Dark circles are a common facial feature. The appearance of dark circles, exacerbated by the physiological aging of the face, affects men and women of all ages and is often a significant aesthetic concern due to the tired appearance they give to the eyes.

[0007] To this end, the injection of gas, in particular carbon dioxide, into the stratum corneum, which is the outer part of the epidermis, contributes in particular to the improvement of the oxygenation of the skin and promotes better blood circulation, which improves the aesthetic appearance of the skin in the treated areas.

[0008] Carbon dioxide injection also stimulates collagen production and provides anti-inflammatory properties. The observed cosmetic benefits Clinically, the benefits include improved pigmentation of the under-eye circle and brightening of the eye contour.

[0009] Injected into the skin layers, the gas acts advantageously on the physical, mechanical and / or optical characteristics of the skin, in particular of dark circles, both inside and outside, in particular on elasticity, volumetric suppleness, tone, firmness, luminosity, radiance, but also on the appearance of the skin surface, by improving its softness, relief, radiance and / or color.

[0010] Since such injections aim to introduce gas into the outermost layer of the skin, the injection depth is therefore very shallow. Generally, such procedures are carried out by injection using a short needle, known as a microneedle, having, for example, a length between 0.1 mm and 10 mm.

[0011] In order to produce the desired aesthetic effects, and to avoid risks to the user, it is necessary that the injection device delivers a precisely and reproducibly calibrated volume of gas.

[0012] The invention aims in particular to provide a device having a fluidic system without an active component to deliver a calibrated volume of gas at a given flow rate.

[0013] To this end, the invention relates to a device of the aforementioned type, characterized in that the delivery module comprises an injection pressure regulator mounted on the outlet line, the injection pressure regulator being configured to open spontaneously when the pressure in the outlet line between the injection line and the injection pressure regulator is greater than a predetermined threshold pressure P3, the predetermined threshold pressure P3 being less than the tank pressure PI, the injection pressure regulator being configured to close spontaneously when the pressure in the outlet line between the injection line and the injection pressure regulator is less than or equal to the predetermined threshold pressure P3.

[0014] The injection pressure regulator on the outlet line ensures in a purely passive manner, without the need for active components, and in a reproducible manner the delivery of a calibrated quantity of gas.

[0015] The use of such a regulator simplifies the fluidic system and therefore reduces its cost. The volume of gas delivered by the fluidic system can also be adjusted by sizing the pressures PI and P3, in order to ensure the delivery of the appropriate quantity of gas.

[0016] According to one variant, the delivery module comprises a purge generation line, connected upstream to the gas injection line, and connected downstream to the outlet line, the purge generation line being equipped with a purge regulator, the purge pressure regulator being configured to open spontaneously when the pressure in the purge generation line between the injection line and the purge pressure regulator is greater than a predetermined intermediate pressure P2, the predetermined intermediate pressure being less than the tank pressure PI and being greater than the predetermined threshold pressure P3, the purge pressure regulator being configured to close spontaneously when the pressure in the purge generation line between the injection line and the purge pressure regulator is less than the predetermined intermediate pressure P2.

[0017] The purge line, equipped with a purge regulator, ensures the cleaning of the fluidic system, prior to the injection of gas under the skin, by ejecting any dust present in the gas delivery outlet, or residues from a previous injection.

[0018] The choice of pressures PI, P2 and P3 makes it possible in particular to size the volume of gas intended for purging and to make it reproducible thanks to the presence of the purge regulator.

[0019] According to one variant, the device comprises the following feature: - the purge generation line includes a purge valve actuable between a closed rest configuration, in which it blocks the passage of gas from the tank to the outlet line, and a flow configuration in which it permits the passage of gas to the outlet line, the purge valve being located between the tank and the purge pressure regulator.

[0020] The presence of a purge valve on the purge line allows purging to be triggered only when the purge valve is in the open position. This purge valve therefore saves gas compared to a system in which purging would be performed continuously.

[0021] According to one variant, the device comprises the following feature: - the purge valve is actuated separately from the injection valve, between a first state of the fluidic system in which the purge valve occupies the passage configuration and the injection valve occupies its closed configuration and a second state of the fluidic system in which the injection valve occupies its open configuration, the purge valve advantageously occupying its passage configuration.

[0022] Actuating the purge valve when the injection valve is in the closed configuration allows, in particular, purging to be carried out following the injection, in order to eliminate residues resulting from the injection.

[0023] According to one variant, the device comprises the following feature: - the purge generation line lacks an actuable valve between the tank and the outlet line.

[0024] The absence of a purge valve simplifies the system and ensures that purging is carried out continuously, as long as the tank can supply enough gas at pressure P2. Thus, there can be no deposit, for example of dust, at the gas outlet line.

[0025] According to one variant, the device comprises the following feature: - the volumes defined by the purge generation line upstream and downstream of the purge pressure regulator are configured to be constant between the predetermined threshold pressure P3 and the given reservoir pressure PI.

[0026] Maintaining the aforementioned volumes constant over the defined pressure range ensures that the quantity of gas ejected during purging is repeatable and easily determinable, without having to take into account a variation in volumes.

[0027] According to one variant, the device comprises the following feature: - the volumes defined by the gas injection line upstream and downstream of the injection valve and the volume defined by the outlet line upstream of the injection pressure regulator are configured to be constant between the predetermined threshold pressure P3 and the given tank pressure PI:

[0028] Thus, the quantity of gas ejected following the actuation of the activation valve is repeatable and easily determinable, without having to take into account a variation of volumes.

[0029] According to one variant, the device comprises the following feature: - the outlet pipe includes a microneedle attachment device defining an orifice for delivering the gas dose.

[0030] The fixing element of a microneedle ensures the passage of the quantity of gas delivered through a microneedle, in order to perform a subcutaneous injection of gas.

[0031] According to one variant, the device comprises the following feature: - it includes a microneedle mounted detachably on the fixation device.

[0032] The fixing element is thus adapted for the replacement of the microneedle, in particular to change the microneedle between several uses, thus improving safety.

[0033] In addition, detaching the microneedle allows the device to be handled and stored while avoiding unintentional punctures.

[0034] According to one variant, the device comprises the following feature: - the tank has a filling nozzle intended to be connected to a gas refilling device.

[0035] The fluidic system can thus be easily recharged between several uses, without needing to have a removable reservoir.

[0036] The invention also relates to an assembly comprising:

[0037] - a device as described above, the reservoir comprising a nozzle filling and

[0038] - a gas loading device having a gas delivery head,

[0039] wherein the gas delivery head is configured to connect to the filling nozzle, to fill the predefined tank volume VI of the gas fluidic system tank to the given tank pressure PL

[0040] The user thus has a simple refilling option for the tank, ensuring that the tank of volume V1 is filled with gas at the tank pressure PI, the pressure and volume being sized for the ejection of the desired volume of gas.

[0041] According to one embodiment, the device comprises a gas capacity defining an internal volume containing gas at a capacity pressure PO greater than the given tank pressure PI, and a gas capacity pressure regulator interposed between the gas capacity and the gas delivery head, the gas capacity pressure regulator being configured to deliver gas at the given tank pressure PI to the gas delivery head.

[0042] The pressure regulator allows gas loading to be carried out in a purely passive manner, without an active component, which contributes to the simplicity and robustness of the assembly.

[0043] The invention also relates to a method for injecting a dose of gas comprising the following steps:

[0044] - input by a user of a device as described above, the volume predefined tank VI receiving a pressurized gas at the given tank pressure PI;

[0045] - actuation of the injection valve from the closed rest configuration in which it blocks the passage of gas from the tank to the outlet pipe and the open configuration in which it allows the passage of gas to the outlet pipe;

[0046] - spontaneous opening of the injection pressure regulator by establishment in the outlet line between the injection line and the injection pressure regulator of a pressure greater than the predetermined threshold pressure P3 and delivery of the dose of gas having a predefined volume by the fluidic system through the outlet line;

[0047] - spontaneous closure of the injection pressure regulator when the pressure in the outlet line between the injection line and the injection pressure regulator is less than the predetermined threshold pressure P3.

[0048] The method according to the invention ensures the injection of a determined quantity of gas through a passive system, in particular without the addition of active electronic components with respect to regulation in the fluidic system.

[0049] According to one variant, the method comprises the following feature: - the delivery module includes a purge generation line, connected upstream to the gas injection line, and connected downstream to the outlet line, the purge generation line being equipped with a purge pressure regulator, the process comprising, before the actuation of the injection valve, the spontaneous opening of the purge pressure regulator by the establishment of a pressure in the purge generation line between the injection line and the purge pressure regulator greater than the predetermined intermediate pressure P2, then the spontaneous opening of the injection pressure regulator by the establishment in the outlet line between the injection line and the injection pressure regulator of a pressure greater than the predetermined threshold pressure P3, optionally by opening a purge valve disposed between the tank and the purge pressure regulator,and the delivery of a volume of purge gas by the fluidic system through the outlet line before the spontaneous closure of the injection pressure regulator when the pressure in the outlet line between the injection line and the injection pressure regulator is less than the predetermined threshold pressure P3, - - spontaneous closure of the purge pressure regulator when the pressure in the purge generation line between the injection line and the purge pressure regulator is less than the predetermined intermediate pressure P2.

[0050] The generation of a purge improves the hygiene of the device; it can be carried out continuously in order to maximize safety or only by opening a purge valve, in order to save gas.

[0051] According to one variant, the method comprises the following feature: - the tank has a filling nozzle, the process comprising, after the delivery of the dose of gas having a predefined volume, the connection of a gas delivery head of a gas loading device to the filling nozzle and the filling of the predefined tank volume VI of the gas fluidic system tank to the tank pressure PI

[0052] The user can thus easily recharge the device following a gas injection, to fill the tank to the desired PI tank pressure. The process therefore makes it possible to deliver the same quantity of gas several times.

[0053] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0054] [Fig-1] [Fig. 1] is a schematic representation of the pneumatic circuit of a first gas injection assembly according to the invention, and

[0055] [Fig.2] [Fig.2] is a schematic representation of the pneumatic circuit of a second gas injection assembly according to the invention, different from that of [Fig.1].

[0056] In all that follows, pressures are expressed in absolute bars. The terms "upstream" and "downstream" are generally understood with respect to the normal direction of fluid flow in the injection assembly 10.

[0057] A first set 10 of gas injection according to the invention is illustrated in [Fig.1].

[0058] The assembly 10 is in particular intended to deliver a calibrated quantity of gas through a microneedle in order to perform a subcutaneous injection, for example of carbon dioxide for aesthetic treatment purposes.

[0059] Gases that can be injected under the skin are chosen in particular from among biocompatible gases such as carbon dioxide, nitrous oxide, nitric oxide, oxygen, or hydrogen. Advantageously, the injected gas is carbon dioxide.

[0060] With reference to [Fig.1], the assembly 10 comprises a gas injection device 12, configured to be operated by a user, and a gas recharging device 14 configured to be made to communicate fluidically with the device 12.

[0061] The assembly 10 is particularly suitable for delivering a precise quantity of gas in a reproducible manner using the device 12, the device 12 being rechargeable by connecting to the recharging device 14.

[0062] The device 12 is thus mobile relative to the charging device 14 between a charging configuration connected to the charging device 14 and a usage configuration disconnected from the charging device 14.

[0063] The device 12 includes a gas reservoir 18 and a fluidic system 16 for ejecting a determined quantity of gas from the reservoir 18. The device 12 here includes a housing (not shown) containing the reservoir 18 and the fluidic system 16. The housing is configured to allow the combined movement of the reservoir 18 and the fluidic system 16 towards a body surface of the user.

[0064] For this purpose, the fluidic system 16 includes a delivery module 20 which allows the quantity of gas to be delivered from the reservoir 18 to the outside of the device 12 and, in this example, a fixing element 22 for a microneedle.

[0065] The fixing member 22 defines a gas outlet orifice outside the delivery module 20. Alternatively, the delivery module 20 is without a fixing member 22, while still defining a gas outlet orifice.

[0066] The tank 18 defines a volume intended to receive the gas subjected to a tank pressure PL. For example, the tank pressure PI is between 3 bar and 4 bar, in particular equal to 3.4 bar. The volume of the tank 18 is constant at least up to the pressure PI, for example due to the rigidity of its walls.

[0067] The tank 18 includes a gas delivery outlet 24, placed in fluidic communication with the delivery module 20, and a filling nozzle 26, intended to be put in fluidic communication with the recharging device 14, in order to recharge the tank 18 with pressurized gas.

[0068] The delivery module 20 includes a gas injection line 30 connected upstream to the delivery outlet 24 of the tank 18 and a gas outlet line 32, the gas injection line 30 being connected downstream to the gas outlet line 32.

[0069] The delivery module 20 further includes a purge generation line 44, parallel to the gas injection line 30, connected upstream to the delivery outlet 24 of the tank 18 and connected downstream to the gas outlet line 32.

[0070] The gas injection line 30 is equipped with an injection valve 34, actuable between a closed rest configuration and an open configuration in which the tank 18 and the gas outlet line 32 are put into fluidic communication via the injection line 30.

[0071] The gas injection line 30 has an upstream portion 35, located between the reservoir 18 and the injection valve 34 and a downstream portion 36, located between the injection valve 34 and the gas outlet line 32.

[0072] The upstream portion 35 is fluidly connected to the reservoir 18, it is thus intended to receive the gas at the pressure of reservoir PI from the reservoir 18.

[0073] In the closed configuration of the injection valve 34, the downstream portion 36 is fluidically isolated from the upstream portion 35.

[0074] The outlet conduit 32 leads to the fixing member 22, which defines the gas outlet out of the device 12 via the outlet orifice.

[0075] The fastening member 22 is advantageously configured to receive in a removable manner a microneedle having an internal conduit allowing the gas passing through the outlet conduit 32 to pass through it, for the purpose of its injection under the user's skin.

[0076] Examples of microneedles are described in documents EP 2 594 313 or US 8,236,368.

[0077] The outlet pipe 32 is equipped with an injection pressure regulator 38, located upstream of the fastening member 22.

[0078] The injection pressure regulator 38 is configured to regulate the upstream pressure to a threshold pressure value P3, for example between 1 bar and 2 bar, in particular equal to 1.7 bar. This pressure regulation is carried out passively, without the use of active electronic components. To this end, the injection pressure regulator 38 is configured to open when the upstream pressure is greater than P3 and to close when the upstream pressure is less than or equal to P3. Thus, the pressure in the portion of the outlet line 32 located upstream of the injection pressure regulator 38 and in the downstream portion 36 of the injection line 30 is maintained less than or equal to P3.

[0079] The threshold pressure P3 is sized to be lower than the tank pressure PL. Thus, the actuation of the injection valve 34 to put it in the open configuration causes the downstream portion 36 and the upstream portion 35 to be connected. The pressure in the downstream portion 36 is then greater than the threshold pressure P3, and the injection pressure regulator 38 opens to regulate the pressure in the downstream portion 36 to the threshold pressure P3.

[0080] The portion of the outlet pipe 32 located upstream of the injection pressure regulator 38 and the downstream portion 36 of the gas injection pipe 30 together define a volume V3.

[0081] The volume V3 is advantageously constant at least up to the pressure P3, which is ensured by a rigidity of the gas injection line 30 and the gas outlet line 32 sufficient so that their walls do not deform when a threshold pressure P3 is applied to them.

[0082] The purge generation line 44 is here connected upstream to the gas injection line 30 at an upstream connection point 46 and downstream to the gas outlet line 32 at a downstream connection point 48.

[0083] The purge generation line 44 is intended to circulate a quantity of purge gas from the reservoir 18 to the fastening member 22, the quantity of purge gas being intended to clear the outlet line 32 of impurities that may be present there.

[0084] The purge generation line 44 is equipped with a purge pressure regulator 50 which regulates the upstream pressure to an intermediate pressure P2, for example between 2 and 3 bar, in particular equal to 2.35 bar. This pressure regulation is carried out passively, without the use of active electronic components.

[0085] The operation of the purge pressure regulator 50 is analogous to that of the injection pressure regulator 38. It opposes the passage of fluid by being closed when the upstream pressure is less than or equal to the intermediate pressure P2, and allows the fluid to pass through and it opens when the upstream pressure is greater than the intermediate pressure P2.

[0086] In the embodiment shown in [Fig.1], the purge generation line 44 is provided with a purge valve 51 located upstream of the purge pressure regulator 50. The purge valve 51 defines an intermediate portion 49 of the purge generation line 44 between the purge valve 51 and the purge pressure regulator 50 which has a volume V2.

[0087] The volume V2 is advantageously constant at least up to the pressure P2, which is ensured by a rigidity of the purge generation line 44 sufficient so that its walls do not deform when a pressure P2 is applied to them.

[0088] The fluid intended to be received in volume V2 of the intermediate portion 49 is subjected to a pressure less than or equal to P2, due to the purge pressure regulator 50. The intermediate pressure P2 is lower than the threshold pressure P3, and higher than the reservoir pressure PL

[0089] The purge valve 51 is actuable between a closed rest configuration in which it blocks the passage of gas from upstream to the purge pressure regulator 50 and an open passage configuration in which the tank 18 and the intermediate portion 49 are in fluidic communication.

[0090] The reservoir 18, the upstream portion 35 of the gas injection line 30, and the upstream portion of the purge generation line 44 upstream of the purge valve 51 are in fluidic communication and define a volume VI of gas.

[0091] The volume V1 is advantageously constant at least up to the pressure PI, which is ensured by a rigidity of the tank 18, of the gas injection line 30, of the purge generation line 44 sufficient so that their walls do not deform when a pressure PI is applied to them.

[0092] With reference to [Fig. 1], the recharging device 14 is intended to supply the tank 18 with gas so that it reaches the tank pressure PL

[0093] For example, it forms a docking station intended to accommodate the injection device 12.

[0094] For this purpose, the recharging device 14 includes a gas capacity 52, a gas delivery head 54 and a recharging line 56 placing the gas capacity 52 and the gas delivery head 54 in fluidic communication.

[0095] The gas capacity 52 has a volume V0 of gas subjected to a capacity pressure PO. It is configured to supply the gas necessary to fill the tank 18 of the device 12. The capacity pressure PO is greater than the tank pressure PI, in particular greater than 5 times the tank pressure PI, for example between 30 and 70 bar, in particular equal to 50 bar.

[0096] The gas capacity 52 is for example received in the recharging device 14 in a removable manner, so that it can be easily replaced when it no longer contains enough gas to perform its function of recharging the tank 18.

[0097] The gas delivery head 54 is configured to be removably connected with the filling nozzle 26 of the tank 18 to establish fluid communication between the refilling line 56 and the tank 18.

[0098] The recharging line 56 is equipped with a gas capacity pressure regulator 58, located between the gas capacity 52 and the gas delivery head 54. The gas capacity pressure regulator 58 is configured to impose a downstream tank pressure PI.

[0099] Thus the recharging device 14 is suitable for imposing a reservoir pressure PI in the volume VI of the reservoir 18 by connecting the gas delivery head 54 and the filling nozzle 26.

[0100] A method for injecting a dose of gas using an assembly 10 according to the embodiment illustrated in [Fig.1] will now be described.

[0101] The user wishing to distribute the dose of gas grasps the device 12 in an initial state.

[0102] In the initial state of the fluidic system 16, the injection valve 34 and the purge valve 51 are in their closed rest position and block the passage of gas. Volumes V2 and V3 receive gas subjected to a threshold pressure P3 and volume VI receives gas at the tank pressure PI from tank 18.

[0103] The user first activates the purge valve 51 to switch it to its flow configuration. The fluidic system 16 is then in a first state, establishing fluidic communication between volumes VI and V2.

[0104] The gas contained in the volume VI + V2 is characterized by a pressure Pjnt:

[0105] pp / V^v-rint~ V^V,

[0106] The values ​​of the pressures PI, P2 and P3 and of the volumes VI and V2 are dimensioned so that the pressure P^t is greater than the intermediate pressure P2.

[0107] The purge pressure regulator 50 then opens spontaneously until the pressure Pint is equal to the intermediate pressure P2. The volume of purge gas Vp2, at the intermediate pressure P2, which passes through the purge pressure regulator 50 then satisfies the following relationship:

[0108]

[0109] The purge gas volume can therefore be expressed as a constant that depends on predefined pressures and constant volumes of the fluidic system:

[0110] v _ UiMWMy vp2“ P2

[0111] The gas received in volume V3 is then subjected to a pressure higher than the threshold pressure P3 due to the passage of gas through the purge volume Vp2 to the intermediate pressure P2. Consequently, the injection pressure regulator 38 opens in order to regulate the gas pressure in volume V3 to the threshold pressure P3.

[0112] Indeed, the gas contained in the volume V3 in the initial state is at the threshold pressure P3, the additional volume Vp2 of gas passes through the injection pressure regulator 38 downstream and is distributed through the fixing member 22, thus purging the gas outlet line 32.

[0113] When the actuation of the purge valve 51 stops, it then returns to its closed rest configuration.

[0114] Consequently, to perform a subcutaneous gas injection, the user activates the injection valve 34, which switches to its open position. The reservoir 18 is then in fluidic communication with the outlet line 32 via the gas injection line 30 and the purge generation line 44.

[0115] The purge valve 51 is in the closed configuration and the injection valve is in the open configuration, the fluidic system 16 is then in a second state.

[0116] The injection pressure regulator 38 opens to regulate the pressure of the volume V1 + V2 + V3 to the threshold pressure P3. A volume of injection gas Vi then flows through the gas outlet line 32 and passes through the retaining member 22. The volume of injection gas Vi that passes through the retaining member 22 is then equal to:

[0117]

[0118] The quantity of gas ejected is therefore known and dimensioned using the pressures imposed by the injection pressure regulator 38 and the purge pressure regulator 44.

[0119] At the end of the sequence, the fluidic system 16 contains gas at the uniform threshold pressure P3.

[0120] The device 12 is then recharged, using the recharging device 14, in order to fill the tank 18 to the tank pressure PL

[0121] To do this, the user connects the filling nozzle 26 of the device 12 with the delivery outlet 24 of the recharging device 14.

[0122] The gas tank pressure regulator 58 switches to the open configuration, since the gas tank pressure PO in the gas tank 52 is greater than the threshold pressure P3 in the tank 18. As a result, the gas tank 52 and the tank 18 are in fluidic communication, and the tank 18 is filled with gas until it reaches the tank pressure PL

[0123] The gas capacity pressure regulator 58 switches to the closed configuration when the gas in the tank 18 is subjected to the tank pressure PL

[0124] The user can then detach the device 12 from the recharging device 14, and the fluidic system 16 is in its previously described initial state, ready to be used to deliver the quantity of purge and / or injection gas again.

[0125] The assembly 10 shown in [Fig. 2] differs from that shown in [Fig. 1] in that the purge generation line 44 lacks a purge valve 51. The reservoir 18, the upstream portion 35 of the gas injection line 30, and the upstream portion of the purge generation line 44 upstream of the purge pressure regulator 50 are in fluidic communication and define a constant volume VI + V2. In this embodiment, the gas contained in the volume VI + V2 is subjected to a pressure less than or equal to P2, due to the purge pressure regulator 50.

[0126] A method for injecting a dose of gas using the device 12 according to the embodiment illustrated in [Fig.2] will now be described.

[0127] In this embodiment, the absence of a purge valve 51 puts the reservoir 18 and the purge generation line 44 in fluidic communication. The volume VI + V2 is at a pressure higher than P2. Thus, purging is carried out continuously until the volume VI + V2 reaches the intermediate pressure P2 imposed by the purge pressure regulator 50.

[0128] Once the purging has been carried out, the user can freely operate the injection valve 34 in order to expel the volume Vi of injection gas, which is expressed as:

[0129]

[0130] Consequently, the gas contained in the fluidic system 16 is at the threshold pressure P3, and the user can recharge the tank with gas at the pressure PI via the recharging device 14, similarly to what has been described previously.

[0131] The device 12 according to the invention allows for the injection of a predetermined quantity of gas in a very simple manner, using a fluidic system devoid of active components, in particular purely mechanical ones. The refilling device 14 ensures easy repeatability of gas delivery to the reservoir 18, guaranteeing reproducibility of the delivered dose. Thanks to the attachment member 22, which is configured to receive a microneedle, the device 12 is particularly well-suited for subcutaneous gas injection.

Claims

1.

2. Demands A gas injection device (12), in particular a carbon dioxide device, intended for subcutaneous gas injection, comprising a fluidic system (16) for delivering a dose of gas having a determined volume, comprising: - a gas tank (18) having a predefined tank volume VI, the tank (18) having a gas delivery outlet (24) and being configured to receive a pressurized gas at a given tank pressure PI; - a delivery module (20) comprising a gas injection line (30) connected upstream to the gas delivery outlet (24), the gas injection line (30) being equipped with an injection valve (34), and a gas outlet line (32) outside the fluidic system (16), the gas injection line (30) being connected downstream to the gas outlet line (32), the injection valve (34) being actuable from a closed rest configuration, in which it blocks the passage of gas from the reservoir (18) to the gas outlet line (32) and an open configuration, in which it allows the passage of gas to the outlet line (32), characterized in that the delivery module (20) comprises an injection pressure regulator (38) mounted on the outlet line (32),the injection pressure regulator (38) being configured to open spontaneously when the pressure in the outlet line (32) between the injection line (30) and the injection pressure regulator (38) is greater than a predetermined threshold pressure P3, the predetermined threshold pressure P3 being less than the tank pressure PI, the injection pressure regulator (38) being configured to close spontaneously when the pressure in the outlet line between the injection line (30) and the injection pressure regulator (38) is less than or equal to the predetermined threshold pressure P3. Device (12) according to claim 1, wherein the delivery module (20) comprises a purge generation line (44), connected upstream to the gas injection line (30), and connected downstream to the outlet line (32), the purge generation line (44) being equipped with a purge regulator (50), the regulator purge pressure regulator (50) being configured to open spontaneously when the pressure in the purge generation line (44) between the injection line (30) and the purge pressure regulator (50) is greater than a predetermined intermediate pressure P2, the predetermined intermediate pressure being less than the tank pressure PI and greater than the predetermined threshold pressure P3, the purge pressure regulator (50) being configured to close spontaneously when the pressure in the purge generation line (44) between the injection line (30) and the purge pressure regulator (50) is less than the predetermined intermediate pressure P2.

3. Device (12) according to claim 2, wherein the purge generation line (44) includes a purge valve (51) actuable between a closed rest configuration, in which it blocks the passage of gas from the reservoir (18) to the outlet line (32) and a pass configuration in which it permits the passage of gas to the outlet line (32), the purge valve (51) being located between the reservoir (18) and the purge pressure regulator (50).

4. Device (12) according to claim 3, wherein the purge valve (51) is actuable separately from the injection valve (34), between a first state of the fluidic system (16) in which the purge valve (51) occupies the passage configuration and the injection valve (34) occupies its closed configuration and a second state of the fluidic system (16) in which the injection valve (34) occupies its open configuration, the purge valve (51) advantageously occupying its passage configuration.

5. Device (12) according to claim 2, wherein the purge generation line (44) is devoid of an actuable valve between the reservoir (18) and the outlet line (32).

6. Device (12) according to any one of claims 2 to 5, wherein the volumes defined by the purge generation line (44) upstream and downstream of the purge pressure regulator (50) are configured to be constant between the predetermined threshold pressure P3 and the given reservoir pressure PI.

7. Device (12) according to any one of the preceding claims, wherein the volumes defined by the gas injection line (30) upstream and downstream of the injection valve (34) and the volume defined by the outlet line (32) upstream of the injection pressure regulator (38) are configured to be constant between the predetermined threshold pressure P3 and the given tank pressure PI.

8. Device (12) according to any one of the preceding claims, wherein the outlet conduit (32) comprises a microneedle attachment element (22) defining a gas dose delivery orifice,

9. Device according to claim 8, comprising a microneedle mounted detachably on the fixation member (22).

10. Device (12) according to any one of the preceding claims, wherein the reservoir (18) has a filling nozzle (26), intended to be connected to a gas recharging device (14).

11. Injection assembly (10) comprising: - a device (12) according to any one of the preceding claims, the reservoir (18) having a filling nozzle (26), and - a gas loading device (14) having a gas delivery head (54), in which the gas delivery head (54) is configured to connect to the filling nozzle (26), to fill the predefined reservoir volume VI of the reservoir (18) of the fluidic system (16) with gas at the given reservoir pressure PI.

12. Assembly (10) according to claim 11, comprising a gas capacitance (52) defining an internal volume containing gas at a capacitance pressure PO greater than the given tank pressure PI, and a gas capacitance pressure regulator (58) interposed between the gas capacitance (52) and the gas delivery head (54), the gas capacitance pressure regulator (52) being configured to deliver gas at the given tank pressure PI to the gas delivery head (54).

13. Gas injection method comprising the following steps: - user grasping a device (12) according to any one of claims 1 to 10, the predefined tank volume V1 receiving a gas under pressure at the given tank pressure PI;

14. - actuation of the injection valve (34) from the closed rest configuration in which it blocks the passage of gas from the tank (18) to the outlet line (32) and the open configuration in which it allows the passage of gas to the outlet line (32); - spontaneous opening of the injection pressure regulator (38) by establishing in the outlet line (32) between the injection line (30) and the injection pressure regulator (38) a pressure greater than the predetermined threshold pressure P3 and delivery of the dose of gas having a predefined volume by the fluidic system (16) through the outlet line (32); - spontaneous closure of the injection pressure regulator (38) when the pressure in the outlet line between the injection line and the injection pressure regulator is less than the predetermined threshold pressure P3. A method according to claim 13, wherein the delivery module (20) comprises a purge generation line (44), connected upstream to the gas injection line (30), and connected downstream to the outlet line (32), the purge generation line (44) being equipped with a purge pressure regulator (50), the method comprising, before the actuation of the injection valve (34), the spontaneous opening of the purge pressure regulator (50) by establishing a pressure in the purge generation line (44) between the injection line (30) and the purge pressure regulator (50) greater than the predetermined intermediate pressure P2, then the spontaneous opening of the injection pressure regulator (38) by establishing in the outlet line (32) between the injection line (30) and the injection pressure regulator (38) a pressure greater than the predetermined threshold pressure P3,optionally by opening a purge valve (51) disposed between the reservoir (18) and the purge pressure regulator (50), and the delivery of a volume of purge gas by the fluidic system (16) through the outlet line (32) before the spontaneous closure of the injection pressure regulator (38) when the pressure in the outlet line (32) enters the line, injection (30) and the injection pressure regulator (38) is less than the predetermined threshold pressure P3 - spontaneous closure of the purge pressure regulator (50) when the pressure in the purge generation line (44) between the injection line and the purge pressure regulator (50) is less than the predetermined intermediate pressure P2.

15. A method according to any one of claims 13 or 14, wherein the reservoir (18) has a filling nozzle (26), the method comprising, after the delivery of the dose of gas having a predefined volume, connecting a gas delivery head (54) of a gas loading device (14) to the filling nozzle (26) and filling the predefined reservoir volume VI of the fluidic system reservoir (16) with gas at the reservoir pressure PI.

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