Artificial eye model for medical-surgical training and production method thereof

Abstract

An artificial eye model (1) for medical-surgical training, even of an advanced type, is described, consisting of a front segment (100) and a rear segment (200) defining an eyeball, wherein said front segment (100) comprises a region (110) intended to simulate the sclera and a region (120) intended to simulate the crystalline lens, and wherein said rear segment (200) is in the shape of a spherical cap comprising at least one first layer (210) intended to simulate the sclera, a second layer (220) intended to simulate the choroid, a third layer (230) intended to simulate the retina and a region (240), inside the retina layer (230), intended to simulate the vitreous humour.

Description

[0001] " ARTIFICIAL EYE MODEL FOR MEDICAL-SURGICAL TRAINING AND PRODUCTION METHOD THEREOF"

[0002] *****

[0003] DESCRIPTION

[0004] The present invention relates to an artificial anatomical model intended for the practice of medical and surgical techniques. In particular, the invention relates to an artificial eye model, its use for ophthalmic medical-surgical training practices, even of advanced type, and a production method thereof.

[0005] Background of the invention

[0006] In the surgical field, artificial physical models made of various materials, very often innovative materials, are well known and widely used to carry out training practices. These artificial models, also referred to by the term phantom, are used in almost every field of surgery and therefore also in the ophthalmic surgery one, in which phantoms capable of reproducing the structure of the eye are used.

[0007] As known, the structure of an eye can be represented by an eyeball made up of a front segment and a rear segment.

[0008] The front segment extends from the inside of the cornea, which can be understood as the surface lens of the eye, to the front surface of the crystalline lens, which instead is the inner lens.

[0009] The rear segment extends from the rear surface of the crystalline lens to the rear sclera. It contains a gelatinous substance defined vitreous humour and is made up of a series of layers.

[0010] The retina is the innermost layer of the rear segment in contact with vitreous humour and has the fundamental function of receiving light. The sclera, which is the outermost layer,constitutes most of the tunic of the eyeball. Between the sclera and retina is the choroid, a pigmented and vascularised layer.

[0011] To date, in ophthalmic surgery there are several eye phantoms used for training, even advanced training, but none can replicate the mechanical properties of all the anatomical sections that make it up. The limitations of these phantoms lie in the difficulty of mimicking the actual structure of the eye and, in particular, the possible interactions between the various layers that make up the rear segment (vitreous humour, retina, choroid and sclera).

[0012] US9437119B1, for example, describes an artificial surgical eye model designed for the practice of ophthalmic surgery techniques, comprising a front ocular segment and a detachable base, both created with multi-material 3D printing processes.

[0013] The front segment comprises at least two structures with different hardness levels: a structure with hardness lower than Shore A 95 and another structure with hardness higher than Shore D 20. The front ocular segment further contains a lens capsule filled with supporting material.

[0014] The model described in said document is formed in such a way that it does not faithfully replicate the structure of the eyeball layers. In particular, the material is made up of materials with physical properties that do not allow for adequate modelling of the eye to be used in the medical-surgical training field, not permitting, for example, the simulation of complex operations, such as the induction of subretinal blebs to create an actual gap between the neuroretina and the retinal-choroidal pigmented epithelium complex, simulating the inj ection of subretinal drugs.In general, intraocular ophthalmic medicine and surgery have a slower learning curve than others, as they are performed on microscopic structures, which can only be viewed at high magnification. Training in this field therefore requires models that adequately represent biometric measurements, resistances and mechanical responses of tissues to manipulation.

[0015] Summary of the invention

[0016] From what has just been set forth, the disadvantages of the artificial or phantom eye models currently used in the practice of ophthalmic medicine and surgery techniques are clear.

[0017] Obj ect of the invention is to provide an artificial eye model capable of overcoming the limitations of models currently on the market, by adequately simulating biometric measurements and mechanical responses during the simulation of medical-surgical procedures.

[0018] In particular, obj ect of the present invention is to provide an artificial eye model whose structure allows the simulation of even complex medical-surgical procedures such as, for example, the induction of subretinal bleb to create a real gap between the neuroretina and the retinal-choroidal pigmented epithelium complex.

[0019] Another obj ect of present invention is to provide an artificial eye model for medical-surgical training, even advanced training, that is simple and quick to implement, from mixtures of polymeric materials.

[0020] These and other obj ects are achieved by an artificial eye model having the characteristics listed in claim 1, as well as by a method for the production of that model having the characteristics listed in claim 11.Advantageous implementations of the invention become apparent from the dependent claims.

[0021] Essentially, the present invention relates to an artificial eye model for medical-surgical training, consisting of a front segment and a rear segment joined together in an assembly defining an eyeball, wherein said front segment comprises a region intended to simulate the sclera and a region intended to simulate the crystalline lens, and wherein said rear segment is in the form of a spherical cap comprising at least one first layer intended to simulate the sclera, a second layer intended to simulate the choroid, a third layer intended to simulate the retina and a spherical region, inside the retinal layer, intended to simulate vitreous humour, wherein said front segment and said sclera, choroid and retina layers of said rear segment are made from mixtures of polymeric materials through 3D printing or additive manufacturing processes and wherein between said sclera layer and said choroid layer, there is a first division layer and between said choroid layer and said retina layer, there is a second division layer, and wherein said division layers are made from a material, which can also be polymerised through 3D printing or additive manufacturing processes. Preferably, said material constituting the division layers is an inert material.

[0022] The artificial eye model according to the invention is an eye of a mammal, preferably a human eye.

[0023] Brief description of the drawings

[0024] Further characteristics of the invention will become clearer from the detailed description below, which refers to a purely exemplary, and therefore non- limiting, embodiment shown in the accompanying drawings, wherein:• Figure 1 is an isometric view of an artificial eye model according to the invention;

[0025] • Figure 2 is an isometric view of a front segment of an artificial eye model according to the invention;

[0026] • Figure 3 is an isometric view of a rear segment of an artificial eye model according to the invention;

[0027] • Figure 4 is a front proj ection view of the rear segment of Figure 3;

[0028] • Figure 5 is a photograph of a bleb induced with a red liquid in the artificial model of the invention;

[0029] • Figure 6 is a photograph of a section of the model of Figure 5;

[0030] • Figure 7 is an isometric view of an alternative embodiment of a rear segment of an artificial eye model according to the invention;

[0031] • Figures 8A- 8D are views showing an alternative embodiment of a front segment of an artificial eye model according to the invention from various angles.

[0032] Detailed description of the invention

[0033] An artificial eye model according to the present invention will now be described in greater detail, which is configured to allow training in all fields of vitreoretinal medicine and surgery, with a particular focus on subretinal inj ections to induce blebs.

[0034] It will be understood that the artificial model of the invention is adapted to any training in the ophthalmic field, whether of the medical, surgical, diagnostic or pharmacological type, which is herein generally referred to as "medical-surgical" training or, for ease of reading, even only "surgical" training. That training therefore includes, but is not limited to, actual surgical exercises, as well asexercises in invasive or mini-invasive medicine techniques, e. g. the administration of drugs within the eye or the induction of subretinal blebs.

[0035] Following an analysis of the ocular anatomy, a model (or phantom) was made that recreated the main functional structures of the eye, i. e. sclera, choroid, retina and vitreous humour for the rear segment; sclera and crystalline lens for the front segment.

[0036] The model according to the present invention, denoted in its entirety by reference numeral 1 in Figure 1, consists of a front segment 100 and a rear segment 200 joined together to form an eyeball.

[0037] The front segment 100 is shown separately in the isometric view of Figure 2, whereas the rear segment 200 is shown in the isometric view of Figure 3 and in the frontal proj ection of Figure 4.

[0038] The front segment 100, which is essentially in the shape of a spherical cap, consists of a region 110 intended to simulate a portion of the sclera and a region 120 intended to simulate the crystalline lens.

[0039] In order to best mimic the anatomical structure of the rear segment 200 of the eye and the mechanical interaction between its inner structures, this rear segment 200 is made of a plurality of layers.

[0040] In particular, the rear segment 200 is in the shape of a spherical cap or section consisting of a plurality of layers in the shape of portions of concentric spherical shells, as shown in the isometric view of Figure 3. The composition of the layers will be clearer from the proj ection view of Figure 4. The term "spherical shell portion" or simply "spherical shell" means herein not a complete sphere, but a partialshell structure.

[0041] With reference to these figures, an outermost layer 210 simulating the sclera, an innermost layer 230 simulating the retina, and an intermediate layer 220 simulating the choroid between the sclera and the retina, are emphasised. The volume of the eyeball 240 inside the retina 230, which defines a spherical segment, is the vitreous humour.

[0042] In order to achieve the intended purposes, a first division layer 215 is provided between the sclera layer 210 and the choroid layer 220, whereas a second division layer 225 is provided between the choroid layer 220 and the retina layer 230. The division layers 215, 225 are necessary to allow bleb formation.

[0043] According to a preferred implementation of the invention, the front and rear segments of the artificial model are produced using 3D printing processes or, more generally, additive manufacturing processes, using different mixtures of photosensitive resins, polymerised by UV light.

[0044] The artificial eye model made according to a preferred embodiment advantageously represents an eyeball with a diameter of 27 mm, whereas the two front and rear segments have the geometric characteristics set forth herein below. The region defining the sclera, for both the layer 110 of the front segment 100 and the layer 210 of the rear segment 200, has a thickness of 1.5 mm. The layer 220 defining the choroid has a thickness of 0.5 mm, whereas the layer 230 defining the retina has a thickness of 0.4 mm.

[0045] The division layers 215, 225 each have a thickness of 0.2 mm. In this configuration, the region 240 inside the retina, representing the vitreous humour, is defined by a spherical segment with a diameter of 20.8 mm.As regards the front segment 100, in addition to the sclera layer 110, a circular region 120 defining the crystalline lens with a diameter of 12 mm is provided.

[0046] Although in the just described implementation the eyeball has a diameter of about 27 mm (where "about 27 mm" means that the diameter may be 26 -28 mm), the obj ects and purposes to be achieved according to the present invention can generally be achieved with a phantom, wherein the eyeball has a diameter between 25 and 32 mm.

[0047] As a result, the thicknesses of the layers may vary slightly from the measurements set forth above with reference to the implementation shown. In particular, the final thickness identified for the layer 230 defining the retina may range from 0.4 mm and a maximum value of 0.6 mm.

[0048] As mentioned, the front and rear segments of the artificial model are made by means of additive manufacturing. Preferably, the eye model is produced by means of 3D printing and advantageously using a PolyJet J850 printer marketed by the Stratasys company.

[0049] All layers and regions that make up the phantom have been specifically designed and made of materials suitable for accurately reproducing their interactions.

[0050] These materials are preferably selected from acrylic components that can be polymerised or mixtures thereof, optionally in combination with photoinitiators and / or other additives conventionally used for the polymerisation of acrylic components, such as, e. g., photosensitising agents, co- initiators and the like.

[0051] Such acrylic components that can be polymerised are preferably liquid mixtures suitable for 3D printing.

[0052] According to an advantageous embodiment, the layercorresponding to the sclera has an elastic modulus value ranging from 650 to 1, 400 kPa, preferably from 800 to 1, 200 kPa.

[0053] According to an advantageous embodiment, the layer corresponding to the choroid has an elastic modulus value of 140 to 220 kPa, preferably 150 to 200 kPa.

[0054] According to an advantageous embodiment, the layer corresponding to the retina has an elastic modulus value of 50 to 90 kPa, preferably 60 to 80 kPa.

[0055] According to an advantageous embodiment, each division layer has an elastic modulus value of 2. 80 to 4.20 kPa, preferably 3.0 to 4.0 kPa.

[0056] These values were measured with a Bioindenter UNHT3 Bio instrument, by Anton Paar (Bioindenter: UNHT3Bio | Anton Paar), particularly adapted to measure the mechanical properties of soft and biological samples. For the tests carried out according to the present invention, a long shaft, safe link BALL D1MM RUBY bit was used.

[0057] According to an embodiment, to

[0058] LAYER AVERAGE STANDARD VALUE [kPa] DEVIATION [kPa] Sclera 1024.4 355.8 Choroid 178.6 38 Retina 69.4 19.3 Division layers 3.5 kPa 0.62 kPa The characteristics of the layers defined above can be obtained through 3D printing of acrylic components, generally an acrylic resin or mixtures of acrylic resins, well known to the person skilled in the art and commercially available. With specific reference to the use of the 3D printer set forth above (PolyJet J850), the compositions ofthe materials used to make the layers of the rear segment 200 are summarised in Table 1 below.

[0059] [Table 1]

[0060] LAYER COMPOSITION

[0061] Outer layer: 0.3 mm

[0062] Agilus30™ Clear

[0063] Background: digital material Agilus30™ Sclera

[0064] Clear 45%

[0065] (layer 210)

[0066] TissueMatrix™ 25%

[0067] GelMatrix™ 20%

[0068] VeroPure™ White 10%

[0069] Division 1

[0070] Stratasys preset: PureGel™ Support (layer 215)

[0071] Outer layer: 0.3 mm

[0072] Agilus30Clear™ 50%

[0073] Choroid

[0074] Agilus™ Magenta™ 30%

[0075] (layer 220)

[0076] GelMatrix™ 20%

[0077] Background: n / a

[0078] Division 2

[0079] Stratasys preset: PureGel™ Support (layer 225)

[0080] Outer layer: 0.3 mm

[0081] Retina GelMatrix™ 20%

[0082] (layer 230) TissueMatrix™ 80%

[0083] Background: n / a

[0084] Vitreous Printing in progress

[0085] humour Stratasys preset: PureGel™ Support (region 240 ) Final material: Solution of water and

[0086] glycerol

[0087]

[0088] According to an alternative embodiment, the rear segment 200 has an additional layer representing an epiretinal membrane235 (see Fig. 7 ). This epiretinal membrane 235 is formed on the retinal layer 235 inside the eyeball 240 and appears as a substantially circular layer with irregular contours. The epiretinal membrane layer has a thickness of 0.2 mm and an average elastic modulus value of 413. 15 kPa, with a standard deviation of 59.52 kPa.

[0089] This layer is also made of materials that can be polymerised through additive manufacturing processes and, preferably, through 3D printing. With reference to the 3D printer set forth above (PolyJet J850 ), the composition of the materials used in the implementation of the layer is as follows: 50% Agilus30 Clear, 50% TissueMatrix (Shore 20A).

[0090] As regards the front segment 100, also with reference to the aforesaid 3D printer, the compositions of the materials used to make the layers and regions are summarised in Table 2 below.

[0091] [Table 2]

[0092] LAYER COMPOSITION

[0093] Outer layer: 0.3 mm

[0094] Agilus30Clear

[0095] Background: digital material Sclera

[0096] Agilus30Clear 45%

[0097] (layer 110)

[0098] Tissue Matrix 25%

[0099] Gel Matrix 20%

[0100] VeroPureWhite 10%

[0101] Crystalline

[0102] lens VeroClear

[0103] (layer 110)

[0104]

[0105] With regard to what is set forth in the tables, the followingis noted.

[0106] When defining resin recipes, it is necessary to define the outermost layer ("outer layer" ), which has a minimum thickness of 0.3 mm, and the inner material ("background" ), which defines the obj ect being sent to print.

[0107] The outer layer shall be considered for both "sides" of printed obj ects. Actually, an outer layer of 0.3 mm actually results in a thickness of 0.6 mm (0.3 mm on one side and 0.3 mm on the other side). As a result, for thicknesses of less than 0.6 mm - as in the case of the retina and choroid - it is not possible to define a background layer, whose value in the table is specified as " N / A", not available.

[0108] " Digital material", on the other hand, means the method of mixing the materials that constitute the recipe (which are mixed randomly according to the specified percentages). With regard to the division layers, they can be made of any inert material that allows the sclera / choroid / retina layers to remain separate, e. g. by ensuring that said layers do not chemically bond together.

[0109] According to a preferred embodiment, said division layers are prepared through 3D printing from the product " Pure Gel Support" which is currently marketed by Stratasys company. It should be noted that there are no division layers in the eye, but the layers are naturally detached.

[0110] It is understood that in the recipes of materials, the Agilus30 Clear material can be replaced with Agilus which are coloured in order to obtain different colours, thereby differentiating the structures more clearly.

[0111] Furthermore, it will be understood that, in order to obtain the same result, slight variations in the materials used may be provided (within a delta of + / - 10% of the percentages),without thereby departing from the scope of the present invention.

[0112] According to a further advantageous embodiment, the front segment 100 has a crystalline layer produced by 3D printing using a mixture comprising between 60% and 70% VeroClear and between 40% and 30% Agilus30 Clear (Shore 70A), instead of a formulation comprising only VeroClear. This mixture allows precise adjustment of the optical transparency and mechanical compliance of the lens, thus improving the realism during cataract procedure simulation.

[0113] Also advantageously, a structure representing the iris is introduced into the front segment 100 of the artificial eye model, which is produced by means of 3D printing using a mixture comprising between 45% and 55% VeroClear and between 55% and 45% Agilus30 Clear (Shore 70 A).

[0114] The artificial eye model may further comprise elements that represent extra-ocular muscles intended to simulate anatomical anchorage and mechanical interaction between the eyeball and surrounding muscles. These elements are also made by means of 3D printing with a preferred mixture consisting of:

[0115] • VeroClear: 40-30%

[0116] • Agilus30 Clear: 60-70%

[0117] Representations of these elements are depicted with the numerals 151, 152, 153, 154 in Figures 8A-8D. In these figures, which show the front segment from different angles, four extra-ocular muscles, the front sclera, the cornea and, particularly in the rear view of Fig. 8A, the iris 140 are visible.

[0118] The muscles 151, 152, 153, 154 are essentially in the shape of portions of spherical spindle, are arranged at 90°intervals from the base of the cap defining the sclera layer 110 and ending in pointed ends at the pole opposite to that in which the crystalline lens 120 is provided.

[0119] Advantageously, the muscles 151, 152, 153, 154 are suturable. The term "suturable" means a technical characteristic of printed anatomical structures, which are made of materials and geometries designed to withstand suturing without tearing or mechanical failure during surgical training procedures.

[0120] The additional layers and elements of the front segment 100 are then formed from materials that can be polymerised through additive manufacturing processes and, preferably, through 3D printing.

[0121] Also with reference to the use of the PolyJet J850 3D printer, these additional layers have the following elastic modulus values:

[0122] LAYER AVERAGE STANDARD AVERAGE VALUE [kPa] DEVIATION [kPa] Iris 2889.26 1007. 01 Crystalline lens 573. 04 330.72 Muscles 1455.09 549.17 The front 100 and rear 200 segments, having the aforesaid geometric characteristics and made of the materials set forth above, are j oined together in an assembly to form the artificial eye model to be used in medical-surgical training practices.

[0123] Preferably, the two segments are joined through the laying of a thin layer of liquid resin adapted to polymerise under UV light.

[0124] By way of example, a preferred method for making an artificial eye model according to the present invention willnow in fact be described.

[0125] The method will be described in particular with reference to the use of the already mentioned PolyJet J850 printer which is capable of creating a highly detailed and precise model in a single printing session, but it will be understood that other types of printers capable of obtaining the same results can be applied.

[0126] The method begins with the creation, by means of 3D printing, of the rear segment 200 of the eyeball, preferably with a diameter of about 27 mm.

[0127] The outermost layer 210, representing the sclera, is made with a thickness of 0. 9 mm and consists of 45% Agilus30 Clear digital material, 25% Tissue Matrix, 20% Gel Matrix and 10% VeroPure White made by Agilus30 Clear.

[0128] The sclera layer 210 also has a 0.3 mm outer layer made of Agilus30Clear.

[0129] Subsequently, a first division layer 215 is made toward the inside of the eye by using the pre-set Pure Gel Support material from Stratasys, with a thickness of 0.2 mm.

[0130] A 0.5 thick spherical shell layer is then printed using a mixture of materials consisting of 50% Agilus30 Clear, 30% Agilus Magenta and 20% GelMatrix, constituting a layer 220 representing the choroid.

[0131] Preferably, a second division layer 220 is added, also with a thickness of 0.2 mm and made of PureGel Support.

[0132] A layer 230 corresponding to the retina is then arranged, which has a thickness of 0.4 mm with an outer layer of 0.3 mm and consists of a mixture of 20% Gel Matrix and 80% Tissue Matrix.

[0133] The volume inside the retina, corresponding to the vitreous humour region 240, which is essentially a spherical segmentwith a diameter of 20.8 mm, is made using the pre-set PureGel™ Support material by Stratasys. After printing, the polymeric material of the vitreous humour region is removed, and the volume is filled with liquid adapted to mimic the physical characteristics of the vitreous humour, e. g. with a solution of water and glycerol.

[0134] Advantageously, the method can be implemented by eliminating the printing of the region corresponding to the vitreous humour and making the eye model in two halves, which are subsequently j oined. According to an embodiment, the two parts can be joined by applying, by means of a needle, a thin layer of Agilus3 0 resin between the two parts and polymerising with UV light, at room temperature.

[0135] This way, the model is made without the need to print the vitreous humour, which has essentially the supporting function during the printing step. The region corresponding to the actual vitreous humour is subsequently made by introducing a solution of water and glycerol.

[0136] In an alternative implementation, there is also an epiretinal membrane layer 235, the laying of which takes place after the laying of the retinal layer 230.

[0137] In this implementation, a layer with irregular contours with a thickness of about 0.2 mm is laid, consisting of a mixture of 50% Agilus30 Clear and 50% Tissue Matrix (Shore 20A). In the optimised version of the production process, which does not provide for printing vitreous humour, the epiretinal membrane 235 is laid as an intermediate layer between the retina and the vitreous cavity, so as to more accurately reflect the application intended for surgical training, while improving printing efficiency.

[0138] In a second step, which can also precede or coincide withthe implementation of the rear segment 200, the front segment 100 of the eye phantom is produced. This segment is also part of an eyeball having a diameter of 27 mm.

[0139] A layer 110 representing the sclera is then produced, having the same composition and thickness as the layer 210 described above and a circular region, such as that shown in Figure 2 with the reference numeral 120, with a diameter of 12 mm and made of VeroClear material.

[0140] As mentioned, the front segment 100 of the artificial eye model may further comprise a layer corresponding to the iris and representations of the extra-ocular muscles. Including an iris layer does not require a separate production step, since this layer is laid simultaneously with the printing of the front segment, thus ensuring a correct anatomical positioning and ideal integration with the surrounding structures.

[0141] This way, all the components of the front segment, including the sclera, crystalline lens and iris, are made with the same printing process and are structurally anchored to the front segment.

[0142] Advantageously, the extra-ocular muscles 151, 152, 153, 154 are also made in the same production method as the front segment 100, providing an additional 3D printing step consisting of laying layers composed of a mixture of Vero Clear (40-30%) and Agilus30 Clear (60-70%) to form the spindle- like structures described above.

[0143] Subsequently, a thin layer of polymerising material, e. g. a layer of Agilus3 OClear resin, is applied between the front segment 100 and the rear segment 200 thus made, and a polymerisation step is performed by means of UV irradiation to achieve a precise and secure coupling between twosegments, thus obtaining an artificial eye model 1 ready to be used in medical-surgical training practices.

[0144] Clearly, as already mentioned, the thicknesses of the layers above refer to an exemplary implementation and should not be understood as limiting the implementation of an eye model according to the present invention, as the thicknesses may vary within ranges such as to create a phantom capable of achieving the pre-set obj ects.

[0145] Additionally, material variations are also possible. For example, Agilus3 OClear can be replaced with Agilus coloured to obtain different colours, making the structures more distinguishable. Slight variations (+ / - 10%) in the percentages of material used do not constitute a different recipe and allow the same result to be obtained.

[0146] The artificial eye model having the characteristics just described is capable of replicating the ocular characteristics of the front and rear segments of the eye, with particular interest in the definition of the three tunics of the eye (neuro-glial, vascular and sclerocorneal ). In particular, an artificial model made according to the method described herein is capable of recreating the main functional structures of the eye: sclera, choroid, retina and vitreous humour for the rear segment; sclera and crystalline lens for the front segment.

[0147] The artificial eye model according to the invention has been tested by executing a medical-surgical procedure that is currently not reproducible on other available models, i. e. an intraocular procedure consisting of the following steps: central and peripheral vitrectomy, subretinal bleb induction such as to create a real gap between neuroretina and pigmented epithelium-choroid complex, simulating inj ectionof subretinal drugs.

[0148] In particular, the main characteristic of an eye model according to the present invention is that to perfectly recreate the adhesion force between the retina and choroid. The structure of the retina layer consisting of a deformable material as defined above and preferably having a thickness of about 0.4 mm, as well as the presence of a division layer interposed between the retina and choroid layers, advantageously allow the formation of bleb when a pressure of 6 to 12 psi, e. g. 8 psi, is applied to the inj ector. This faithfully reproduces the structure of an eye intended for medical-surgical practice, bearing in mind that there are no division layers in the eye but the layers are naturally detached.

[0149] The photographs of Figures 5 and 6 show a bleb induced with a red liquid in the artificial model of the invention.

[0150] In particular, in the section of Figure 6, the sclera (thick outer layer) and choroid (layer placed between the sclera and retina) can be clearly seen, while the retina (innermost layer) is very thin and transparent and therefore poorly visible.

[0151] The results showed that the artificial model is suitable for medical-surgical simulation. It was possible to successfully perform the different steps of vitrectomy, managing to induce the formation of the subretinal bleb.

[0152] It can therefore be stated that the artificial model according to the invention is capable of reproducing mechanical geometries and properties suitable for realistically simulating ocular medical and surgical procedures and, particularly, vitreoretinal procedures, for the purposes of surgical training, even of advanced type.Obviously, the present invention is not limited to the particular embodiments previously described and illustrated in the accompanying drawings, but numerous detailed changes can be made to it by the technician of the field, without thereby departing from the scope of the invention itself, as defined in the accompanying claims.

[0153] According to another aspect thereof, subj ect-matter of the invention is also using artificial eye model, as defined and claimed herein, for medical-surgical training.

[0154] Subj ect-matter of the invention, according to another aspect thereof, is also a medical-surgical training method that comprises carrying out practical exercises on the artificial eye model as defined and claimed herein.

Claims

CLAIMS1. An artificial eye model (1 ) for medical-surgical training, consisting of a front segment (100 ) and a rear segment (200 ) joined to each other in an assembly defining an eyeball, wherein said front segment ( 100) comprises a region (110) intended to simulate the sclera and a region ( 120) intended to simulate the crystalline lens and wherein said rear segment (200) is in the shape of a spherical cap comprising at least one first layer (210 ) intended to simulate the sclera, a second layer (220 ) intended to simulate the choroid, a third layer (230 ) intended to simulate the retina and a region (240), inside the retina layer (230 ), intended to simulate the vitreous humour, characterised in that said front segment (100) and said sclera (210 ), choroid (220) and retina (230) layers of said rear segment (200 ) are made from mixtures of materials which can be polymerised through 3D printing or additive manufacturing processes, and in that between said sclera layer (210) and said choroid layer (220 ), a first division layer (215) is provided and, between said choroid layer (220) and said retina layer (230 ), a second division layer (225) is provided, wherein said division layers (215, 225) are made of a material which also can be polymerised through 3D printing or additive manufacturing processes.

2. The artificial model ( 1) according to claim 1, wherein the layers of said rear segment (200 ) are made in a single 3D printing process.

3. The artificial model (1 ) according to claim 1 or 2, comprising a thin layer of resin, which is polymerised between said front segment (100) and said rear segment (200 ), to ensure the union of the two segments.

4. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said assembly def ining the eyeball has a diameter between 25 mm and 32 mm and advantageously equal to about 27 mm.

5. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said sclera layer (210 ) of the rear segment (200 ) has a thickness of 1.5 mm, said choroid layer ( 220 ) has a thickness of 0.5 mm and said retina layer ( 230 ) has a thickness between 0.4 mm and 0.6 mm.

6. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said layer ( 210 ) corresponding to the sclera has an elastic modulus value of 650 to 1,400 kPa, preferably 800 to 1,200 kPa.

7. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said layer ( 220 ) corresponding to the choroid has an elastic modulus value of 140 to 220 kPa, preferably 150 to 200 kPa.

8. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said layer ( 230 ) corresponding to the retina has an elastic modulus value of 50 to 90 kPa, preferably 60 to 80 kPa.

9. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said division layers (215, 225 ) each have an elastic modulus value of 2.80 to 4.20 kPa, preferably 3.0 to 4.0 kPa.

10. The artif icial model ( 1 ) according to any one of the preceding claims, wherein said front segment ( 100 ) comprises a layer (235 ) representing an epiretinal membrane which is made of a material that can be polymerised through 3D printing or additive manufacturing processes, formed on the retinal layer (230 ) inside the eyeball, said layer (235 )representing an epiretinal membrane preferably having an irregular contour with a thickness of 2 mm and an average elastic modulus value of 413.15 kPa.

11. The artificial model (1 ) according to any one of the preceding claims, wherein said front segment (200 ) comprises, at said region (120) intended to simulate the crystalline lens, a structure representing the iris also made of a material that can be polymerised through 3D printing or additive manufacturing processes and having an average elastic modulus value of 2889.26 kPa.

12. The artificial model (1 ) according to any one of the preceding claims, wherein said front segment (200 ) comprises elements intended to simulate extra-ocular muscles ( 151, 152, 153, 154 ) made of materials that can be polymerised through 3D printing or additive manufacturing processes and which are in the shape essentially of portions of spherical spindle that extend from the base of said front segment (200 ) and loosening therefrom.

13. The artificial model (1 ) according to any one of the preceding claims, characterised by being a model of human eye.

14. A method for producing an artificial eye model ( 1) for medical-surgical training, comprising:a step of producing, by means of an additive manufacturing process, a front segment (100) made from a mixture of polymeric materials and comprising a region ( 110) corresponding to the sclera and a region ( 120) corresponding to the crystalline lens;a step of producing, by means of an additive manufacturing process, of a spherical cup-shaped rear segment (200 ) made from a mixture of polymeric materials andcomprising a first layer (210 ) intended to simulate the sclera, a first division layer (215 ), a second layer (220) intended to simulate the choroid, a second division layer (225), a third layer (230) intended to simulate the retina, wherein said layers and regions are made in one continuous step;a step of making a region (240) intended to simulate the vitreous humour, consisting of filling the region inside the third layer (230 ), corresponding to the retina with a solution of water and glycerol;a step consisting of placing a layer of polymeric resin between the two previously made segments (100, 200 ) and polymerising the resin, preferably by means of UV, in order to accurately and securely join the two segments into an assembly (1 ) defining an eyeball.

15. The method according to claim 15, wherein said step of producing, by means of additive manufacturing process, a front segment (100 ) comprises, at the same step, producing a layer intended to simulate the iris and / or producing elements intended to simulate extra-ocular muscles ( 151, 152, 153, 154 ), and / or wherein said step of producing, by means of additive manufacturing process, a rear segment (200) comprises, at the same step, laying a layer (235) intended to simulate an epiretinal membrane, the laying of which takes place after the laying of said third layer intended to simulate the retina (230).

16. The method according to claim 14 or 15, wherein said additive manufacturing process is a 3D printing process.

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