Device and method for injecting a flexible tissue under a living organ

Abstract

A device (1) for injecting a flexible tissue under a living organ, the device (1) comprising a removable injection cartridge (30) comprising a receptacle (31) adapted to receive the flexible tissue, and a cannula (32) arranged downstream from the receptacle (31) in an injection direction (S) and being adapted to be inserted at least partially under the organ, the cannula (32) having an internal diameter (D1) smaller than an internal diameter (D2) of the receptacle (31), a first pushing means (10) adapted to transfer the flexible tissue from the receptacle (31) to the cannula (32) when the injection cartridge (30) is attached to the first pushing means (10), and a second pushing means (20) adapted to transfer the flexible tissue from the cannula (32) to the organ when the injection cartridge (30) is attached to the second pushing means (20).

Description

DescriptionTitle of the invention: Device and method for injecting a flexible tissue under a living organTECHNICAL FIELD

[0001] The present disclosure relates to a device for injecting flexible tissue under a living organ, in particular, but not limited, to a retina, and to a method of injecting flexible tissue using such a device.TECHNOLOGICAL BACKGROUND

[0002] In the medical field, recent techniques have made it possible to implant flexible biological or artificial tissues into living organs, with these flexible tissues containing the cells that can reconstitute cells from a diseased organ or prosthesis for the reason to restore the functionality, or any other substrate and contents.

[0003] Typically, these flexible tissues are in the form of a plate, in particular a membrane comprising living stem-derived cells. The membrane may be an agar plate comprising the cells.

[0004] These cells should make it possible to regenerate diseased cells in a given organ. For example, in the case of degeneration of the retinal pigment epithelium, implantation of these stem-derived cells under the retina could limit this degeneration and improve the condition of the diseased organ.

[0005] Nevertheless, the injection and implantation of these flexible tissue plates into the organ to be treated is delicate and complex, especially when the target is situated at a distance from the accessible entry point. Moreover, these tissues have a polarization direction that must be respected and maintained during implantation. However, there is currently no device or method for injecting these flexible tissues efficiently and systematically.

[0006] Therefore, there is a real need for a device and a method for injecting flexible tissues which are free, at least in part, from the aforementioned disadvantages, and has certain advantages.SUMMARY

[0007] In this respect, the present disclosure relates to a device for injecting a flexible tissue under a living organ, the device comprising :- a removable injection cartridge comprising a receptacle adapted to receive the flexible tissue, and a cannula arranged downstream from the receptacle in an injection direction and being adapted to be inserted at least partially under the organ, the cannula having an internal diameter smaller than an internal diameter of the receptacle,- a first pushing means adapted to transfer the flexible tissue from the receptacle to the cannula when the injection cartridge is attached to the first pushing means, and- a second pushing means adapted to transfer the flexible tissue from the cannula to the organ when the injection cartridge is attached to the second pushing means.

[0008] In the present disclosure, the term “flexible” means that the tissue is able to be rolled and unrolled after being released, by recovering its initial shape. In particular, a flexible tissue may be defined as such when it fulfills the bending and recovery test as described below in the detailed description.

[0009] In the present disclosure, the term "tissue" does not only designate biological tissues as cells, for example, but also artificial tissue, such as prosthesis for example.

[0010] In the present disclosure, the term "under" encompasses cases where the tissue is actually injected under a given organ, but also cases where it is injected into an organ, but under a given portion of that organ. For example, when the living organ is an eye, the flexible tissue is injected into the eye, but under the retina.[001 l]In the present disclosure, the terms "downstream" and "upstream" refer to a direction of injection of the flexible tissue, from the device to the organ. In other words, when the first pushing means is an injector, like a syringe for example, the direction of injection is the direction of displacement of the syringe's piston to proceed to the injection.

[0012] In the present disclosure, the terms "internal", "external" and their derivatives relate to the main axis of the device, which is a longitudinal axis. In other words, when the first pushing means is an injector, like a syringe for example, the main / longitudinal axis corresponds to the direction of injection, which is also the direction of displacement of the syringe's piston. Thus, an internal surface (or diameter) is a surface closer to the main / longitudinal axis than an external surface (or diameter).

[0013] The living organ may be an eye's retina, but the invention is not limited to that example. The flexible tissue may be a plate membrane embedded in agarlike substance comprising the cells of the organ to be cured, or any flexible substrate with any contents.

[0014] In addition, in the present disclosure, a component is considered "removable" when it is possible to separate the component from the rest of the device without the use of special tools.

[0015] It is thus understood that the removable injection cartridge may be alternatively and selectively attached (or detached) to (or from) the first and the second pushing means.

[0016] While the cannula has typically a small diameter so as to allow injection in a living organ, which makes it difficult to suitably dispose the tissue inside, the internal diameter of the receptacle being greater than that of the cannula allows to more easily and suitably disposing the flexible tissue in the receptacle. In particular, this makes it possible to position the tissue taking into account its polarization direction, which may be for example identified by making the flexible tissue asymmetrical, for example by cutting a corner of the flexible tissue.

[0017] Additionally, the device of the present disclosure allows to suitably transferring the flexible tissue from the receptacle to the cannula by the first pushing means, and then to suitably transfer the flexible tissue from the cannula to the organ by the second pushing means. In particular, the use of two distinct pushing means allows taking into account the different internal diameters of the receptacle and of the cannula, thereby properly transfer the flexible tissue in two times, namely from the receptacle to the cannula at first, and secondly from the cannula to the organ.

[0018] Also, this device allows providing a packaging by delicate wrapping of the tissue in the receptacle, and offers the opportunity to minimize invasiveness by using a small incision ensuring structural integrity of the delivered tissue. This device also allows transferring the sensible biological tissue while minimizing the time during which the tissue is squeezed, which limits the risk of deteriorating the cells. The short time interval between folding, and delivery also allows the flexibility of the tissue to be used in an optimized manner.

[0019] Thus, the device of the present disclosure allows injecting and implanting flexible tissues under living organs such as a retina, in a more efficient and systematic way, including the cases where the target is located at a distance from the accessible entry point.

[0020] In some embodiments, the injection cartridge further comprises a junction portion between the receptacle and the cannula, the junction portion having an internal diameter decreasing from the internal diameter of the receptacle to the internal diameter of the cannula.

[0021] In some embodiments, the receptacle is movable between an opened position for insertion of the flexible tissue, and a closed position for enclosing the flexible tissue.

[0022] In some embodiments, the injection cartridge comprises two tabs able to be brought closer to each other or moved away from each other in order to move the receptacle between the opened position and the closed position, the tabs including locking means able to maintain the receptacle in the closed position.

[0023] In some embodiments, the first pushing means is a first injector one end of which comprises a first housing adapted to accommodate the injection cartridge, the first injector comprising a piston having a first pushing end adapted to push the flexible tissue from the receptacle towards the cannula, the first pushing end having a diameter smaller than the internal diameter of the receptacle, and greater than the internal diameter of the cannula.

[0024] In some embodiments, the second pushing means is a second injector, one end of which comprises a second housing adapted to accommodate the injection cartridge, the second injector comprising a pushing rod adapted to push the flexible tissue from the cannula towards the organ, the pushing rod comprising a second pushing end having a diameter smaller than the internal diameter of the cannula.

[0025] In some embodiments, the second pushing end has a length at least equal to a length of the cannula.

[0026] In some embodiments, the second pushing end has flexibility greater than that of the cannula.

[0027] In some embodiments, the pushing rod comprises a displacement portion upstream from the second pushing end, the displacement portion comprising a rack adapted to cooperate with teeth of a thumbwheel of the second pushing means.

[0028] In some embodiments, the cannula is at least partly curved.

[0029] In some embodiments, the cannula is straight.

[0030] In some embodiments, a curvature of the cannula is included in an axial plane of symmetry of the second pushing means when the injection cartridge is attached to the second pushing means.

[0031] In some embodiments, the cannula is oriented such that a downstream end of the cannula points to a same side of the second pushing means as the side to which wheels of the thumbwheel protrude outward from a casing of the second pushing means.

[0032] In some embodiments, a downstream end of the cannula is beveled.

[0033] The present disclosure also relates to a method of injecting flexible tissue under a living organ using a device according to any one of the preceding embodiments, the method comprising :- placing the flexible tissue in the receptacle of the removable injection cartridge,- transferring the flexible tissue from the receptacle to the cannula by the first pushing means when the injection cartridge is attached to the first pushing means, then- transferring the flexible tissue from the cannula to the organ by the second pushing means when the injection cartridge is attached to the second pushing means.

[0034] In some embodiments, the method comprises :- opening the receptacle so that the receptacle is in an opened position, then placing the flexible tissue in the receptacle,- closing the receptacle so that the receptacle has an internal diameter higher than the internal diameter of the cannula,- fixing the injection cartridge to the first pushing means,- pushing the flexible tissue towards the cannula by the first pushing means and via a junction portion having decreasing internal diameter,- detaching the injection cartridge from the first pushing means and fixing the injection cartridge to the second pushing means, and- pushing the flexible tissue from the cannula towards the organ by the second pushing means.

[0035] In some embodiments, the method comprises the placement of a piece of additional protective substance behind the tissue in the receptacle before closing the injection cartridge. This reinforces the protection of the tissue during the transfer from the cartridge to the cannula, and from the cannula to the organ.BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention and advantages thereof will be better understood upon reading the detailed description which follows, of embodiments given as non-limiting examples. This description refers to the appended drawings, wherein:

[0037] Fig. 1 is a side view and in transparency of an injection cartridge of the device of the present invention,

[0038] Fig. 2 is a perspective view of the injection cartridge of Fig. 1 in an opened position,

[0039] Fig. 3 is a perspective view of a first pushing means of the device of the present invention, to which the injection cartridge of Fig. 1 is fixed,

[0040] Fig. 4 is a side view and in transparency of the first pushing means of Fig. 3,

[0041] Fig . 5 is a perspective view of a second pushing means of the device of the present invention, to which the injection cartridge of Fig. 1 is fixed,

[0042] Fig . 6 is a perspective view, with a different orientation, of the second pushing means of Fig. 5 from which an upper casing has been removed,

[0043] Fig. 7 is a top view of the second pushing means of Fig. 6,

[0044] Fig. 8 is a perspective and detailed view of a downstream portion of the second pushing means of Fig. 6,

[0045] Fig. 9 is a top view of a portion of a pushing rod of the second pushing means,

[0046] Fig. 10 is a perspective overview of the device of the present invention,

[0047] Fig. 11 schematically represents the steps of a method of the present invention of injecting flexible tissue under a living organ.DETAILED DESCRIPTION OF EMBODIMENTS

[0048] A device 1 for injecting a flexible tissue under a living organ is described below, in reference to Figs. 1 to 10. An overview of the device 1 is illustrated in Fig. 10.

[0049] The device 1 described in this embodiment is adapted to inject a flexible tissue, namely a membrane embedded in agar-like substance comprising stem cells, under an eye's retina. However, the invention is not limited to that example; the device 1 could also be adapted to inject a flexible tissue in another living organ.

[0050] As mentioned above, the term "flexible" means that the tissue is able to be rolled and to recover its initial shape after releasing. The flexible property may be measured by a bending and recovery test, which allows measuring the ability of a fabric to recover its shape after being bent or rolled.

[0051] In this test, a fabric sample is firstly rolled with a specific device and held in that position for a specified time. Then, the bending force is released. Finally, the return position, which is the open position at which the fabric returns after being released, is observed immediately and after a certain resting time.

[0052] Fig. 1 represents a side view of an injection cartridge 30 of the device 1. The injection cartridge 30 comprises a receptacle 31 adapted to receive a flexible tissue (not illustrated), and a cannula 32, which is in other words a tube, arranged downstream from the receptacle 31 in an injection direction S. The injection direction S is the direction of injection of the flexible tissue from the receptacle 31 to the organ (not illustrated), via the cannula 32.

[0053] The cannula 32 is adapted to be inserted at least partially under the retina. In particular, the cannula 32 may be made of Hexafluoropropylene (FEP, which is a copolymer of tetrafluoroethylene and hexafluoropropylene), and has an internal diameter D1 depending on the size of the tissue to be injected (for example, D1 may be between 1 and 2 mm for the injection under a retina). In particular, the diameter D1 must match to the width of injected tissue. The external diameter of cannula must also match to the incision’s sizes, both of entry point of organ and entry point for insertion under the retina.

[0054] Preferably, a downstream end 321 of the cannula 32 is beveled in order to facilitate penetration of this downstream end 321, and of the cannula 32 accordingly, into an incision formed under the retina. The beveled downstream end 321 also allows facilitating the injection and the disposition under the retina.

[0055] In the side view of the cartridge 30 (Fig. 1), an angle 0 between a plane Pl including the beveled downstream end 321, and a plane P2 which would include the downstream end 321 if it was not beveled, may be between 0° and 80°, preferably between 40° and 50°, for example equal to 45°.

[0056] However, this example is not limitative, and the downstream end 321 may also be not beveled and be simply straight cut, without departing from the scope of the invention. In this respect, the type of cut of the downstream end 321 of the cannula defines the direction of release of the transferred object, namely the tissue. For example, a straight cut directs the object straight out, and the beveled downstream end directs the tissue to exit in the desired direction depending on the angle of the bevel.

[0057] Preferably, the cannula 32 may be curved as detailed later in the description, in order to take into account the global round form of an eye and thus facilitate injection under the retina. Of course, the cannula 32 may also be straight without departing from the scope of the invention, especially in applications other than injection under a retina, where no curvature is necessary.

[0058] The receptacle 31 may be made of polypropylene, preferably with an additive, for example distilled monoglyceride, giving sliding property to the receptacle 31. The receptacle 31 and forms an internal housing in which the flexible tissue can be disposed. More specifically, the receptacle 31 may be movable between an opened position for insertion of the flexible tissue, and a closed position for enclosing the flexible tissue.

[0059] In particular, the cartridge 30 may include two tabs 34 which can be manually manipulated in order to move the receptacle 31 from the opened position to the closed position, and conversely. The position illustrated in Figs. 1 and 3 to 8 is the closed position, and the position illustrated in Fig. 2 is the opened position.

[0060] For example, the receptacle 31 may have two portions 311, 312 linked by a hinge 35, one portion 312 being able to be moved away from the other portion 311 by pulling on one tab 34 so as to pivot the portion 312 about the hinge 35, and thus reaching the opened position of the receptacle 31, as shown in the perspective view of Fig.2.

[0061] When the receptacle 31 is in the opened position, the receptacle 31 has an enlarged opening which facilitates disposition of the flexible tissue. In particular,it is possible to properly deposit the flexible tissue in the receptacle 31 and to choose its orientation of polarization.

[0062] By manually bringing the tabs 34 back together, the receptacle 31 moves in the closed position. By doing that, when the two portions 311, 312 are brought and locked together, the internal enclosure of the receptacle 31 forms a closed cylindrical housing having a given internal diameter D2, which is greater than the internal diameter DI of the cannula 32.

[0063] It is noted that the tabs 34 may include a locking means allowing maintaining the receptacle 31 in the closed position, for example via clips 37 which may be forcibly assembled.

[0064] Furthermore, the tabs 34 may have an increased height allowing facilitating manual gripping of the injection cartridge 30, in order to more easily move it, attached it (or detached) it to (or from) the pushing means as detailed below. For example, a height of the tabs 34 in a direction perpendicular to the injection direction S may be at least twice the diameter D2 of the receptacle 31.

[0065] In addition, the injection cartridge 30 comprises preferably a junction portion 33, between the cannula 32 and the receptacle 31.

[0066] More specifically, the junction portion 33 may extend downstream from the receptacle 31, and an upstream end 322 of the cannula 32 is inserted and fixed into the junction portion 33. The junction portion 33 may optionally form a single part with the receptacle 31, and be formed in the same material.

[0067] Preferably, an internal diameter D3 of the junction portion 33 decreases from upstream to downstream, in order to link the receptacle 31 to the cannula 32. More specifically, at an upstream end of the junction portion 33, the diameter D3 is equal to the internal diameter D2 of the receptacle 31, and at a downstream end of the junction portion 33, the diameter D3 is equal to the internal diameter DI of the cannula 32.

[0068] The decreasing diameter D3 of the junction portion 33 allows continuously and progressively linking the internal diameter D2 of the receptacle 31 to theinternal diameter DI of the cannula 32, which facilitates the transfer of the flexible tissue from the receptacle 31 to the inside of the cannula 32.

[0069] In addition, while the membrane of flexible tissue is partially rolled up in the receptacle 31, the decreasing diameter D3 leads the flexible tissue to further rollup when moving from the receptacle 31 to the cannula 32. The membrane of flexible tissue can thus be properly disposed inside the cannula 32, in particular, properly rolled-up and oriented.

[0070] This proper displacement and positioning of the flexible tissue is allowed by the pushing means as detailed below.

[0071] The device 1 comprises a first pushing means 10, represented in perspective in Fig. 3 and in a side view in Fig. 4. In the present embodiment, the first pushing means 10 is a first injector 10 having the form of a syringe extending longitudinally along a main (or longitudinal) axis X. The first injector 10 includes a casing 11 into which a piston 14, for example made of Polyoxymethylene (POM) can translate. The first injector 10 may be manually operated via an enlarged end 17 of the piston 14 and a gripping portion 15 of the casing 11. A spring 18 may be disposed around the piston 14 inside the casing 11 to facilitate manipulation.

[0072] A downstream end of the casing 11 has a first housing 12, into which the above described injection cartridge 30, which is removable, may be inserted. In particular, the first housing 12 may include an opening formed in the casing as a chicane such that the cartridge 30 may be axially inserted into the first housing 12, and the cartridge 30 may be locked by a slight rotation around the main axis X inside the first housing 12. For example, a locking means (not illustrating) as a clamp or an slight elastically deformation of the tabs 34 may allow to maintain the cartridge 30 into the first housing 12 after rotation around the main axis X.

[0073] A downstream end of the piston 14 comprises a first pushing end 16 adapted to push the flexible tissue disposed in the receptacle 31. In particular, the first pushing end 16 may be an enlarged portion of the downstream region of the piston 14, so that the first pushing end 16 has a diameter lower than the internaldiameter D2 of the receptacle 31, but greater than the internal diameter DI of the cannula 32.

[0074] Preferably, the first pushing end 16 has almost the same diameter as the internal diameter D2 of the receptacle 31, but slightly lower than said internal diameter D2. This allows properly pushing the whole flexible tissue by keeping its orientation unchanged, while allowing displacement of the first pushing end 16 inside and along the receptacle 31.

[0075] In this respect, we understand that if the diameter of the first pushing end 16 were too small, for example the diameter DI of the cannula 32 or lower, the flexible tissue lying on the lateral wall of the receptacle 31 would not be properly pushed, but would rather be crushed or damaged.

[0076] 0ptionally, the first pushing end 16 may be elastically deformable, by being made of rubber or foam for example, so that an initial diameter of the first pushing end 16 may be equal to the internal diameter D2 of the receptacle 31 or slightly lower, and so that the first pushing end 16 may be compressed when moving downstream inside the junction portion 33 having a decreasing diameter D3.

[0077] This allows moving the first pushing end 16 until the downstream end of the junction portion 33, and thus correctly and entirely positioning the flexible tissue inside the cannula 32. In this respect, the first pushing end 16 may be made of thermoplastic elastomer (TPE).

[0078] The device 1 further comprises a second pushing means 20, represented in perspective in Figs. 5 and 6, in a top view in Fig. 7, and in a detailed view in Fig. 8. In the present embodiment, the second pushing means 20 is a second injector 20 extending longitudinally along a main (or longitudinal) axis Y. The second injector 20 includes a casing 21 into which a pushing rod 24 can translate. The casing 21 may include a removable upper casing 211 (which is removed in Figs.6, 7 and 8), which forms a hood of the casing 21. The casing 21, including the upper casing 211, may be made of polycarbonate (PC).[0079JA downstream end of the casing 21 has a second housing 22, into which the above described injection cartridge 30, which is removable, may be inserted. The second housing 22 may have the same characteristics as the first housing 12.

[0080] As visible in Figs. 6, 7 and 8 in which the upper casing 211 has been removed, the pushing rod 24 comprises a displacement portion 25, and a second pushing end 26 (which is hidden in Figs. 6 and 8, and partially hidden in Fig. 7) extending downstream from the displacement portion 25. It is noted that a portion of the pushing rod 24 is illustrated alone in Fig. 9.

[0081] The displacement portion 25 comprises a rack 251 which cooperates with teeth of a thumbwheel 28 of the second injector 20. More specifically, the thumbwheel 28 is movably fixed to the casing 21, such that the thumbwheel 28 can rotate with respect to the casing 21 around an axis perpendicular to the main axis Y.

[0082] The thumbwheel 28 may be made of polyoxymethylene (POM) and include two wheels 28a manually operable, between which extends a third wheel 29 having smaller diameter than the two wheels 28a and comprising the teeth cooperating with the rack 251. The thumbwheel 28 is formed such that when the casing 21 is closed by the upper casing 211, the two wheels 28a protrude outward from the casing 21, more specifically from the upper casing 211, so as to be accessible and operable by a user (Fig. 5).

[0083] Thus, a user holding the second injector 20 by the casing 21 can operate one of the two wheels 28a, for example with his thumb, so as to rotate the third wheel 29 accordingly. The rotation movement of the thumbwheel 28 involves the translation of the pushing rod 24, due to the cooperation of the teeth of the third wheel 29 with the rack 251 of the displacement portion 25.

[0084] Thus, the use of the second injector 20 allows for, firstly, not only providing the proper diameter of the second pushing end 26 to correctly displace the rolled tissue, but also enabling control of the injection process at a microsurgical level, comfortably for the surgeon, thanks to its wheel system for both the lefty and righty.

[0085] It is noted that an inside housing of the casing 21 may comprise a plurality of guiding walls 210 having notches 211 into which the displacement portion 25 may be accommodated. The guiding walls 210 thus allow proper guidance of the pushing rod 24 along the main axis Y during injection of the flexible tissue. The displacement portion 25 may further includes an enlarged portion 252 having sensibly the same width as the notches 211 of the guiding walls 210, in order to further improve efficiency of the guidance.

[0086] The second pushing end 26 may be made of the same material as the rest of the pushing rod 24, namely high density polyethylene (HDPE). The second pushing end 26 is a narrowed portion of the pushing rod 24 and has a diameter smaller than the internal diameter DI of the cannula 32. The second pushing end 26 has typically the shape of a thin elongated and flexible stem.

[0087] Preferably, the second pushing end 26 has a downstream end 261 which is larger than the rest of the second pushing end 26, but slightly smaller than the internal diameter DI of the cannula 32, so that the second pushing end 26 can properly push downward the flexible tissue disposes in the cannula 32.

[0088] Preferably, the second pushing end 26 has a length at least equal to a length of the cannula 32, so that the whole flexible tissue may be more easily ejected outside from the cannula 32, under the retina. In this respect, a length of the cannula 32 (in the present case a curvilinear length) and of the second pushing end 26 accordingly, is determined so as to allow delivering the tissue at a right distance, depending on the application and on the injection site in the organ. In the case of injection under a retina for example, this length may be between 1 and 5 cm.

[0089] Furthermore, the second pushing end 26 has preferably flexibility, in other words elasticity, which is greater than that of the cannula 32. Thus, when the cannula 32 is curved as in the present embodiment, the second pushing end 26 may bent during its displacement inside the cannula 32 without causing deformation of the cannula 32. This allows facilitating the downstream displacement of the second pushing end 26 inside the cannula 32, and therefore facilitating the use of the second injector 20.

[0090] Moreover, as mentioned previously, the cannula is curved. For example, when the cartridge 30 is fixed to the second injector 20, an angle a between the downstream portion of the cannula 32 and the main axis Y may be between 15° and 25°, for example equal to 20° (Fig. 1).

[0091] In addition, the curvature of the cannula 32 is included in an axial plane of symmetry of the second injector 20 when the injection cartridge 30 is attached to the second injector 20. The axial plane of symmetry is a plane including the main axis Y, parallel to the two wheels of the thumbwheel 28 for example, and disposed at a mid-distance of these two wheels.

[0092] Furthermore, the cannula 32 is oriented such that the downstream end 321 of the cannula 32 points to a same side of the second injector 20 as the side to which the thumbwheel 28 is attached. In other words, in the spatial reference of Fig. 5 for example, the downstream end 321 points upwardly, in the same manner as the protruding portions of the two wheels 28a of the thumbwheel 28. The alignment of the curvature with the main axis Y, and the orientation of the cannula 32 thus allow facilitating the process of injection of the flexible tissue under the retina by a user.

[0093] A method of injecting flexible tissue under a living organ, namely a retina, using the above described device 1, will now be described, in reference to Fig. 11.

[0094] The method comprises three main steps, namely a first step S100 of placing the flexible tissue in the receptacle 31 of the removable injection cartridge 30, a second step S200 of transferring the flexible tissue from the receptacle 31 to the cannula 32 by the first injector 10, and a third step S300 of transferring the flexible tissue from the cannula 32 to the organ by the second injector 20.

[0095] More specifically, the first step S100 of placing the flexible tissue in the receptacle 31 includes a step SI 10 of opening the receptacle 31, so that the receptacle 31 is in the opened position. For example, the tabs 34 may be detached and moved away from each other, thus enlarging the opening of the receptacle 31. This position allows to more easily placing the flexible tissue in thereceptacle 31, in particular by appropriately orienting the polarization of the flexible tissue. In order to visually recognize the correct orientation of the polarization, the flexible tissue may be previously cut at a corner, indicating the correct direction of orientation, like the "SIM" card principle.

[0096] Then, the method includes a step S120 of closing the receptacle 31, so that the receptacle 31 has the internal diameter D2. For example, the tabs 34 may be brought closer to each other, and locked together via the locking means 37. Since the internal width of the receptacle 31 is decreased until the internal diameter D2, the flexible tissue is thus partially rolled up in the receptacle 31.

[0097] The second step S200 of transferring the flexible tissue from the receptacle 31 to the cannula 32 includes a step S210 of fixing the removable injection cartridge 30 to the first injector 10, more specifically in the first housing 12, and a step S220 of pushing the flexible tissue towards the cannula 32.

[0098] During step S220, the piston 14 is operated via the enlarged end 17, which involves translation of the first pushing end 16. The first pushing end 16 comes into contact with the flexible tissue which is partially rolled up in the receptacle 31, and pushed the flexible tissue downstream. While going through the junction portion 33, the flexible tissue progressively further roll up on itself, due to the decreasing internal diameter D3 of the junction portion 33. The flexible tissue is thus pushed by the first injector 10 until it is completely disposed inside the cannula 32, wherein the flexible tissue is rolled up to a higher extent as compared to when it was disposed in the receptacle 31.

[0099] By the junction portion 33, the transfer of the flexible tissue can thus be made smoothly and properly, while keeping its orientation of polarization and its global positioning unchanged.

[0100] The third step S300 of transferring the flexible tissue from the cannula 32 to the organ includes a step S310 detaching the removable injection cartridge 30 from the first injector 10, and fixing the removable injection cartridge 30 to the second injector 20. More specifically, the injection cartridge 30 is detached fromthe first housing 12 of the first injector 10, and then fixed to the second housing 22 of the second injector 20.

[0101] The method then includes a step S320 of pushing the flexible tissue towards the organ, more specifically under the retina, by the second injector 20. During this step S320, the user inserts the downstream end 321 of the cannula 32 in the desired location, for example under the retina, and then manually operates the wheels 28a of the thumbwheel 28.

[0102] By doing that, the pushing rod 24 is translated via the rack 251 of the displacement portion 25 cooperating with the teeth of the thumbwheel 28. The second pushing end 26 comes into contact with the flexible tissue disposed in the cannula 32, and the flexible tissue is thus pushed downstream by second pushing end 26, which bents during its displacement so as to follow the curvature of the cannula 32.

[0103] When reaching the downstream end 321 of the cannula 32, the flexible tissue is expelled outside the injection cartridge 30 in the desired location, for example under the retina. At this moment, the flexible tissue is free to unfold in the appropriate position and orientation of polarization.

[0104] Although the present disclosure refers to specific exemplary embodiments, modifications may be provided to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual characteristics of the different illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and the drawings should be considered in an illustrative rather than in a restrictive sense.

Claims

Claims

1. A device (1) for injecting a flexible tissue under a living organ, the device (1) comprising :- a removable injection cartridge (30) comprising a receptacle (31) adapted to receive the flexible tissue, and a cannula (32) arranged downstream from the receptacle (31) in an injection direction (S) and being adapted to be inserted at least partially under the organ, the cannula (32) having an internal diameter (DI) smaller than an internal diameter (D2) of the receptacle (31),- a first pushing means (10) adapted to transfer the flexible tissue from the receptacle (31) to the cannula (32) when the injection cartridge (30) is attached to the first pushing means (10), and- a second pushing means (20) adapted to transfer the flexible tissue from the cannula (32) to the organ when the injection cartridge (30) is attached to the second pushing means (20).

2. The device (1) according to claim 1, in which the injection cartridge (30) further comprises a junction portion (33) between the receptacle (31) and the cannula (32), the junction portion (33) having an internal diameter (D3) decreasing from the internal diameter (D2) of the receptacle (31) to the internal diameter (DI) of the cannula (D3).

3. The device (1) according to claim 1 or 2, in which the receptacle (31) is movable between an opened position for insertion of the flexible tissue, and a closed position for enclosing the flexible tissue.

4. The device (1) according to claim 3, in which the injection cartridge (30) comprises two tabs (34) able to be brought closer to each other or moved away from each other in order to move the receptacle (31) between the opened position and the closed position, the tabs (34) including locking means (37) able to maintain the receptacle (34) in the closed position.

5. The device (1) according to any one of claims 1 to 4, in which the first pushing means (10) is a first injector one end of which comprises a first housing (12) adapted to accommodate the injection cartridge (30), the first injector comprising a piston (14) having a first pushing end (16) adapted to push the flexible tissue from the receptacle (31) towards the cannula (32), the first pushing end (16) having a diameter smaller than the internal diameter (D2) of the receptacle (31), and greater than the internal diameter (DI) of the cannula (32).

6. The device (1) according to any one of claims 1 to 5, in which the second pushing means (20) is a second injector, one end of which comprises a second housing (22) adapted to accommodate the injection cartridge (30), the second injector comprising a pushing rod (24) adapted to push the flexible tissue from the cannula (32) towards the organ, the pushing rod (24) comprising a second pushing end (26) having a diameter smaller than the internal diameter (DI) of the cannula (32).

7. The device (1) according to claim 6, in which the second pushing end (26) has a length at least equal to a length of the cannula (32), and flexibility greater than that of the cannula (32).

8. The device (1) according to claim 6 or 7, in which the pushing rod (24) comprises a displacement portion (25) upstream from the second pushing end (26), the displacement portion (25) comprising a rack (251) adapted to cooperate with teeth of a thumbwheel (28) of the second pushing means (20).

9. The device (1) according to any one of claims 1 to 8, in which the cannula (32) is at least partly curved.

10. The device (1) according to claim 9, in which a curvature of the cannula (32) is included in an axial plane of symmetry of the second pushing means (20) when the injection cartridge (30) is attached to the second pushing means (20), the cannula (32) being oriented such that a downstream end (321) of the cannula (32) points to a same side of the second pushing means (20) as the side to which wheels (28a) of the thumbwheel (28) protrude outward from a casing (21) of the second injector (20).

11. A method of injecting flexible tissue under a living organ using a device (1) according to any one of the preceding claims, the method comprising :- placing (S100) the flexible tissue in the receptacle (31) of the removable injection cartridge (30),- transferring (S200) the flexible tissue from the receptacle (31) to the cannula (32) by the first pushing means (10) when the injection cartridge (30) is attached to the first pushing means (10), then- transferring (S300) the flexible tissue from the cannula (32) to the organ by the second pushing means (20) when the injection cartridge (30) is attached to the second pushing means (20).

12. The method according to claim 11, comprising :- opening (S110) the receptacle (31) so that the receptacle (31) is in an opened position, then placing the flexible tissue in the receptacle (31),- closing (S120) the receptacle (31) so that the receptacle (31) has an internal diameter (D2) higher than the internal diameter (DI) of the cannula (32),- fixing (S210) the injection cartridge (30) to the first pushing means (10),- pushing (S220) the flexible tissue towards the cannula (32) by the first pushing means (10) and via a junction portion (33) having decreasing internal diameter (D3),- detaching (S310) the injection cartridge (30) from the first pushing means (10) and fixing the injection cartridge (30) to the second pushing means (20),and- pushing (S320) the flexible tissue from the cannula (32) towards the organ by the second pushing means (20).

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