Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/12—Mammary prostheses

Definitions

• the present invention relates to the technical field of artificial devices, of the implant or prosthesis type, intended to reshape the shape of a part of the human body, for aesthetic and / or therapeutic purposes.
• the present invention relates more particularly, but not exclusively, to the field of breast implants intended to ensure breast reconstruction in the event of mastectomy, or to carry out breast augmentation of an aesthetic nature.
• the present invention relates to a plastic surgery implant intended to be implanted in the body of a patient, said implant comprising at least one flexible pocket delimiting a predetermined internal volume, said flexible pocket being formed of at least one envelope made of a material elastomer.
• the present invention also relates to a method of manufacturing a plastic surgery implant.
• prosthesis or “implant”
• 'A filling material such as silicone gel or physiological saline for example
• These implants are generally introduced subcutaneously, through an incision made near the final implantation area of the implant.
• breast implants In the particular case of breast implants, these are generally introduced subcutaneously at the level of the patient's thorax, on or under the pectoral muscle, by an incision which can be made near the hollow of the armpit, depending on the groove under the breast, or according to the contour of the areola of the breast.
• Such plastic surgery implants are generally made by dipping.
• the dipping process consists in dipping a nucleus having the desired shape for the implant (for example hemisphere, ovoid, ellipsoid) in a silicone bath dispersed in a solvent, to dry the film formed at the surface of the core by this soaking, then “unmolding” it from the core, in order to obtain a flexible pocket.
• Each layer may be different from the others, the surface layer having in particular texture properties favoring its implantation.
• this method implements a multitude of tasks justifying in particular the use of a conveyor carousel, and which make the cycle time for obtaining an implant relatively long.
• the dipping process generally does not allow precise control of the thickness of the implant shell. Implants obtained by dipping, while generally satisfactory, however sometimes suffer from insufficient dimensional accuracy, which can lead to over-thicknesses in certain areas of the implant, which increases the costs of producing the implant, or to under-thicknesses in other places, which can possibly cause embrittlement of the implant.
• the objects assigned to the invention therefore aim to remedy the various drawbacks listed above and to propose a new plastic surgery implant having improved resistance and regularity.
• Another object of the invention is to propose a new method for manufacturing a plastic surgery implant allowing the manufacture of implants in a safer, simpler manner and at a lower cost.
• Another object of the invention is to propose a new method for manufacturing a plastic surgery implant which enables implants to be manufactured quickly with excellent dimensional regularity.
• Another object of the invention is to propose a new method for manufacturing a plastic surgery implant, the number of steps of which is reduced.
• the objects assigned to the invention are achieved using a process for manufacturing a plastic surgery implant, characterized in that it comprises an injection step in which one injects using a press injection, an elastomeric material in a mold to obtain a flexible envelope intended to participate in the formation of a pocket (2).
• a plastic surgery implant intended to be implanted in the body of a patient, said implant being capable of being obtained by a manufacturing process in accordance with one of claims 1 to 5, characterized in that said implant comprises at least one flexible pocket delimiting a predetermined internal volume, said flexible pocket being formed of at least one envelope made of an elastomeric material, the dimensional tolerance of the thickness of said at least one envelope being between 1% and 20%.
• FIG. 1 illustrates, in a side view, a mold in the closed position allowing the implementation of the method according to the invention.
• Figure 2 illustrates, in a side view, the mold of Figure 1 in the open position, as well as in the release position.
• FIG. 3 illustrates, in a schematic view, a plastic surgery implant with multi-layer pocket according to the invention.
• Figures 4 and 5 illustrate, schematically respectively in a top view and a side view, a first embodiment of a breast implant according to the invention.
• FIG. 6 and 7 illustrate, schematically respectively in a top view and a side view, a second embodiment of a breast implant according to the invention.
• FIG. 8 and 9 illustrate, schematically respectively in a top view and a side view, a third embodiment of a breast implant according to the invention.
• Figures 3 to 9 show a plastic surgery implant 1 according to the invention.
• plastic surgery is meant in what follows surgery intended to modify the shape of an organ, or part of the body, in order to correct a congenital or acquired anomaly, and / or in order to modify the aesthetic of the body of a patient, in the sense for example of an increase in volume.
• Plastic surgery notably includes a branch called "cosmetic surgery" which is mainly concerned with the remodeling of body parts for an essentially aesthetic purpose.
• the present invention therefore relates to plastic surgery, and preferably to cosmetic surgery.
• the plastic surgery implant 1 is intended to be inserted under the skin of a patient to reconstruct, and / or reshape, and / or increase the volume of a part of the body, for example a breast, insofar as said implant, which has a predetermined functional volume, comes to increase or replace the biological tissues, for example and preferably the breast tissues.
• the insertion of the plastic surgery implant 1 according to the invention is generally and preferably carried out by introducing said implant 1 subcutaneously through an incision made beforehand by the surgeon.
• the implant 1 is a breast implant (cf. FIGS. 4 to 9)
• said breast implant may in particular be implanted by axillary, submammary, periareolar or even transareolar route.
• the plastic surgery implant 1 may also be, for example, an arm (forearm, biceps), leg (calves, thighs), buttock, or chest (implant) implant. breast for women, breast implant for men). Among all these examples of plastic surgery implants which fall within the scope of the invention, the breast implant will be preferred.
• the plastic surgery implant 1 conventionally comprises at least one flexible pocket 2 delimiting, thanks to its external walls, a predetermined internal volume.
• Said at least one flexible bag 2 is preferably made from elastomeric materials, for example based on one or more silicones.
• the flexible pocket 2 can be produced according to a single-layer construction, that is to say that it is formed by a single envelope (not shown), or according to a multi-layer mode, in which the flexible pocket. 2 is formed of the stack of different envelopes 2A, 2B possibly having different compositions and / or properties.
• the flexible pocket 2 may be a complex formed by a stack of layers 2A, 2B secured to one another, preferably on all of their respective surfaces.
• the flexible pocket 2 therefore preferably has a unitary and monobloc character.
• Such a multi-layer construction makes it possible to obtain a gradient of properties depending on the thickness of the pocket 2, that is to say for example an excellent seal imparted by the internal layer 2A, and a "velvet" texture imparted by the outer layer 2B.
• the implant 1 may comprise two pockets of different volumes (not shown), one being contained in the other and each containing a different filling material.
• the flexible bag 2 may include a greater number of layers, for example three, four, five or more.
• the predetermined internal volume defined by the flexible pocket 2 contains a filling material 3, which makes it possible to give the implant 1 the desired consistency, as well as its functional volume.
• the filling material 3 can be a liquid, a gel, or even a gas.
• the filling material 3 could be a silicone gel, a saline solution, a physiological liquid, soybean oil, polyvinylpyrrolidone (PVP) or even a hydrogel.
• the dimensional tolerance T of the nominal thickness e n0 m of at least one of the envelopes 2A, 2B participating in the formation of the pocket 2 is between 1% and 20%, c ' that is to say that the real thickness e rée i of the envelope 2A can vary between e n0 m (1 - T) and e n0 m (1 + T).
• the general concept of the invention is based on the presence of an envelope 2A, 2B having a tolerance T of between 1% and 20%, whether this envelope alone constitutes the pocket 2, or that it is associated with other envelopes in a multi-layer structure.
• one or more, or even all of the envelopes 2A, 2B may have the dimensional tolerance characteristic according to the invention.
• the real thickness e r ean can vary, for the envelope 2A, 2B considered, between e n0 m (1 - 0.1 ) and e n0 m (1 + 0.1), i.e. between 0.9 e n0 m and 1, 1 e n0 nv
• the thickness measurement can be carried out using a mechanical thickness comparator, and for example with the Mitutoya NO7304 mechanical comparator.
• the set of N measurement points must of course be chosen so that all the points correspond to the same category of material. Thus, it will be ensured that in general no measurement point is positioned on a singularity of the envelope 2A, 2B, that this singularity is constituted by a plane of joints, a reinforcement (for example at the level of a valve ) or any other element.
• the dimensional tolerance of the thickness of the envelope 2A, 2B is within a range from 15% to 20%.
• envelope 2A, 2B made of silicone, or based on silicone. It is however entirely conceivable that this envelope is made of any other material, in particular elastomer, without departing from the scope of the invention.
• the invention also relates to a method for manufacturing a plastic surgery implant 1, said implant 1 being intended to be implanted subcutaneously in the body of a patient.
• the invention relates to a process for manufacturing a plastic surgery implant taken from the following group: - breast implant, - pectoral implant, - leg implant, - arm implant, - buttock implant.
• the manufacturing process comprises an injection step in which an elastomeric material, of the silicone type, is injected, using an injection press, into a mold to obtain an envelope.
• flexible 2A, 2B intended to participate in the formation of the pocket 2 of the implant 1.
• the manufacturing process is therefore an injection molding process, carried out using an injection molding machine, that is to say an injection molding press.
• injection must therefore be understood here as relating to the operation carried out using a press, and not to a simple transfer of material, of the casting type, which could be carried out without an injection press.
• the injected elastomeric material is substantially non-foaming or foamy, and is rather in substantially “full” form.
• the method according to the invention is designed to aim at substantially eliminating air bubbles which could become trapped within the elastomeric material.
• the method thus makes it possible to obtain a regular and homogeneous flexible envelope, which can in particular be used to form the external shell of a surgical implant.
• the mold comprises: - an upper cavity 40 comprising a concave conformation 40A defining in hollow a portion of the surface of the flexible envelope which it is sought to obtain, - a lower cavity 41, comprising a . concave conformation 41 B which defines in hollow a surface complementary to that of the upper cavity 40, so that when the upper cavity 40 and the complementary lower cavity 41 are pressed against each other, one obtains a closed internal volume, substantially sealed, delimited by a surface 40A, 41A whose shape corresponds to that of the flexible envelope 2A, 2B which it is desired to obtain.
• the mold also comprises a core 42 formed by a convex body whose external surface is substantially complementary to that of the internal volume defined by the upper 40 and lower 41 cavities, except for a change of scale.
• the external surface of the core 42 is thus a reduced uniformity of the surface of the internal volume defined by the upper 40 and lower 41 cavities.
• the core 42 is intended to be positioned within the internal volume, preferably equidistant from the walls defining the volume internal. The arrangement described in FIG.
• the upper 40 and lower 41 indentations include the core 42, so as to define a gap or air gap 43, which is a free space delimited on the one hand by the external surface 42A of the core 42, and on the other hand by the internal surface 40A, 41A of the internal volume defined by the upper cavity 40 associated with the complementary lower cavity 41.
• the injection method thus comprises, prior to the injection step, a mold preparation step in which an upper cavity 40 of generally hemispherical shape and a lower cavity 41 of generally hemispherical complementary shape are pressed against each other, so as to obtain an internal volume substantially in the form of a sphere, having previously positioned between the two indentations 40, 41, concentric with said internal volume, a spherical core 42 whose diameter is less than that of said internal volume defined by the upper indentations 40 and lower 41.
• step d injection in which an elastomeric material is injected, which may for example be gum silicone or liquid silicone, into the interstitial space between the core 42 and the upper 40 and lower 41 cavities, so as to obtain an envelope 2A, 2B of generally spherical shape intended to participate in the formation of the pocket 2 of the implant.
• the upper imprint 40 is secured to an upper sole 44, so that the interior space 40B defined by the concave conformation 40A of the imprint 40 is in fluid communication with the upper sole 44, which itself the same carries the means for injecting elastomeric material, which are themselves in communication with the injection press (not shown).
• the injection means preferably comprise three injection nozzles distributed angularly in a regular manner (spaced apart by 120 °) around or at the level of the apex 45 of the internal volume defined by the upper 40 and lower 41 indentations.
• the apex 45 thus corresponds substantially to the point of the concave conformation 40A of the upper imprint 40 closest to the upper sole 44.
• the injection nozzles all have an identical flow rate.
• the method also implements a lower sole 46 on which is fixed a centering pin 47 of the core 42.
• the core 42 which is for example, as shown in FIGS. 11 and 12, under the shape of a solid sphere, comprises a bore 48 whose shape is complementary to that of the centering axis 47, so as to be able to fit the core 42 on the axis 47, through the lower cavity 41 which comprises for this purpose a passage light 41 B for the centering axis 47.
• the bore 48 and the centering axis 47 are designed so as to limit any risk of seizure between the core 42 and the centering axis 47.
• the steels constituting the core 42 and the centering axis 47 preferably have different hardnesses, for example 49 or 50 HRc for the centering axis 47, and 35 HRc for the core 42 (Rockwell hardness). It is also envisaged to provide the centering axis 47 with a base 47A of generally substantially frustoconical shape, as well as an opposite engagement end 47B of general shape also substantially frustoconical.
• the bore 48 formed in the core 42 comprises, at each of its ends, a lower recess 48B, the shape of which is complementary to that of the base 47A, as well as an upper recess 48A, the shape of which is complementary to that of the engagement end 47B, said centering axis 47 and bore 48 being arranged so as to promote an annular support between the base 47A of the centering axis 47 and the core 42, said annular support contributing to control the positioning of the core 42 relative to the centering axis 47.
• a demolding axis 49 is implemented, one of the ends of which is integral with the lower sole 46, while the other end, or the leading end 49A, is intended to engage the lower recess 48B of the core 42, and has for this purpose a conformation allowing the abutment of the lower end 48B of the bore 48.
• the core 42 is extracted from the cavity lower 41 as follows: - the upper 40 and lower 41 imprints are separated, - then the lower imprint 41 is subjected to a vertical translational movement in the direction in which the centering axis 47 extends, so to drive the core 42 out of the centering axis 47, - then the subset formed by the lower recess 41 is threaded supporting the core 42 on the demolding axis 48, so as to extract the core 42 out of the concave conformation 41A of the lower impression 41. Lastly, the actual removal of the silicone envelope from the surface of the core 42 is carried out.
• the core 42 will advantageously be covered with a surface treatment coating limiting the adhesion of the elastomers, by example of a uniform layer of Teflon®, a few micrometers thick.
• the method according to the invention makes it possible to rapidly produce (a cycle time can be of the order of 5 minutes), using a single machine and according to a limited number of operations, an envelope. flexible with great regularity in wall thickness.
• a silicone envelope 2A, 2B of nominal thickness equal to 0.5 mm with a tolerance of less than ⁇ 0.08 mm and up to ⁇ 0.05 mm.
• the method according to the invention comprises, after the injection step, a complexing step in which the flexible envelope 2A obtained at the end of the injection step is covered with a surface envelope 2B by a soaking operation, which makes it possible to obtain a flexible bag 2 similar to that illustrated in FIG. 3.
• This dipping operation preferably takes place in the following manner: - the flexible envelope 2A obtained by injection is threaded onto a soaking core, - the assembly formed by the core covered with the flexible envelope 2A is soaked in a suitable bath , according to any well-known soaking technique, so as to cover the flexible envelope 2A with a surface envelope 2B, for example made of silicone.
• a suitable bath according to any well-known soaking technique, so as to cover the flexible envelope 2A with a surface envelope 2B, for example made of silicone.
• a flexible bag 2 is thus obtained which is in the form of a multi-layer complex, that is to say of a material formed by the stack of different layers of material.
• each of the envelopes 2A, 2B forming the pocket 2 is obtained by injection, without however departing from the scope of the invention.
• the invention finds its industrial application in the manufacture of plastic surgery implants.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Cardiology (AREA)
• Transplantation (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Prostheses (AREA)
• Materials For Medical Uses (AREA)

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• 2003
  • 2003-07-24 FR FR0309102A patent/FR2857852B1/fr not_active Expired - Fee Related
• 2004
  • 2004-07-16 WO PCT/FR2004/001890 patent/WO2005009711A2/fr not_active Ceased
  • 2004-07-16 CN CNA2004800213816A patent/CN1829484A/zh active Pending
  • 2004-07-16 EP EP04767714A patent/EP1651143A2/de not_active Withdrawn
  • 2004-07-16 BR BRPI0412841-9A patent/BRPI0412841A/pt not_active IP Right Cessation
  • 2004-07-16 CA CA002533676A patent/CA2533676A1/en not_active Abandoned
  • 2004-07-16 US US10/565,613 patent/US20070276485A1/en not_active Abandoned

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