The present invention relates to manufacturing processes for prosthetic implants and, more particularly, to a method of tracking an individual soft prosthetic implant component during its manufacturing history.
Soft implantable prostheses are commonly used to replace or augment body tissue. In the case of breast cancer, it is sometimes necessary to remove some or all of the mammary gland and surrounding tissue. This creates a void that can be filled with an implantable prosthesis. The soft implant serves to support surrounding tissue and to maintain the appearance of the body. The restoration of the normal appearance of the body has an extremely beneficial psychological effect on post-operative patients, eliminating much of the shock and depression that often follows extensive surgical procedures. Implantable prostheses are also used more generally for restoring the normal appearance of soft tissue in various other areas of the body.
Soft implantable prostheses typically include a relatively thin and flexible envelope or shell molded from silicone elastomer which is then vulcanized (cured). The shell is filled either with a fluid such as a silicone gel or a physiologic saline solution. Filling of the shell takes place before or after the shell is inserted through an incision. The present invention pertains to any type of fluid-filled prosthesis, but is especially beneficial for use with gel-filled shells.
A conventional dip-molding process for forming flexible implant shells for prostheses involves dipping a suitably shaped mandrel into a silicone elastomer dispersion. The shell is peeled from the mandrel and a shell hole resulting from the molding process is patched. The hollow interior of the shell is then filled with an appropriate filling material, for example a silicone gel, by means of an aperture in the patch. The aperture in the patch is then sealed with a silicone adhesive and the prosthesis is heat cured.
Another process for forming implant shells is rotational molding, such as the system and methods described in Schuessler, U.S. Pat. No. 6,602,452, the entire disclosure of which is incorporated herein by this reference.
Saline filled breast implants are typically constructed of an outer shell of several layers of silicone rubber and a valve. Saline implants are usually implanted in the breast cavity empty or only partially filled, and then inflated to their final size by one or more syringes or a disposable tube connected to a saline reservoir.
After manufacture, a batch of prostheses is labeled and packaged. Before packaging however, unfilled shells often remain unlabeled and in storage for a significant time before each shell is removed from its respective batch and further processed to create the final, assembled prosthesis. Although the assembled product itself may be labeled with identification information, each individual component of the implant is not easily traceable to its point of origin.
There is a need for processes that provide enhanced transparency about specific steps in the manufacture of individual prostheses, so that potential problems, for example, can be traced back to their origin and corrected.
In accordance with the invention, a process for forming a prosthesis, for example, a soft implant, for example, a breast implant, (hereinafter sometimes simply “implant”) is provided, the process generally comprising providing a fluid dispersion and molding the dispersion to form a hollow envelope or shell having an internal cavity. The cavity can subsequently be filled with a suitable filler material, for example, saline or silicone gel. The shell, with or without filling material, makes up the implant.
In accordance with one aspect of the invention, the process further comprises the step of providing an identifier, for example, indicia, on one or more components of the implant during the manufacture of that component. For example, an identifier is provided on the shell during the manufacture thereof, for example, during the steps of molding the shell. In one embodiment, the identifier is unique to the specific breast implant relative to other implants, even those other implants that have been made at the same time and/or in the same batch. The identifier remains with the shell during each subsequent implant manufacturing step and can be used to facilitate tracing the manufacturing history of the shell back to its original formation.
In one embodiment, the identifier is provided on the implant by providing a secondary component which includes the identifier, and securing the secondary component to the shell. The secondary component is secured to the shell during the process of molding the shell. For example, in accordance with one embodiment, the step of providing an identifier comprises forming a label or patch having the identifier thereon, and molding the label or patch to the shell, for example, while the shell itself is being molded. In one embodiment, the label or patch bearing the identifier is molded into the shell, for example, embedded between material layers which make up the shell.
In another aspect of the invention, a process for forming a soft implant generally comprises providing a starter material and forming the material into a first component; providing a second component including an identifier, and assembling the first and second component to form the implant having the identifier. In some embodiments, a second identifier is also provided, for example, on the first component, the second identifier being different from the first identifier. In addition, a third identifier may be provided on the assembled implant, the third identifier being different from the first and the second identifiers.
The starter material may comprise an elastomeric material, for example, a silicone elastomer. The step of forming the elastomeric material into a first soft component comprises one of dip-molding or rotational molding the material, for example, a dispersion of the material, on a molding surface, for example, a mandrel, thereby forming a flexible, fillable elastomeric shell. In a specific embodiment, the step of providing an identifier includes forming the identifier on the shell by molding the identifier into the shell during the dip molding or rotational molding of the shell itself, for example, by providing a negative imprint of the identifier on a molding surface, for example, the mandrel, for the shell.
In another aspect of the invention, a process for facilitating tracking one or more components of an implant, for example, a breast implant, is provided. In a specific embodiment, the process comprises forming components of a breast implant, providing an identifier on one or more of the components during the process of forming the components, assembling the components with one another to form an implant. In a specific embodiment, the process comprises the steps of molding an elastomeric shell having an internal cavity, providing a patch having a unique identifier thereon, and covering a hole in the shell with the patch to form a fillable breast implant. In one embodiment, one or more parameters of the breast implant manufacturing process are recorded and linked with the identifier. The recorded parameters may include information relating to the chemical and physical makeup of the shell, the date of manufacture, the place of manufacture, as well as other useful information.
Features and advantages of the present invention will be appreciated as the same become better understood with reference to the specification, claims, and appended drawings wherein:
The present application relates to assembled medical prosthetic implants. In accordance with a broad aspect of the invention, manufacturing processes are provided whereby the history of an assembled implant can be tracked or traced, for example, uniquely traced, to early points of manufacture.
In accordance with one embodiment of the invention, manufacturing processes generally comprise forming a component of an implant assembly and labeling the component with an identifier, for example, a unique identifier, for example, unique indicia specific to that particular component, during an early stage in the formation of the component. More specifically, the process may comprise forming a shell of a breast implant and labeling the shell with a unique identifier during molding of the shell. The identifier may comprise, for example, a serial number, bar code, indicia, transponder, or other means for human or machine-readable output. Consequently, in some embodiments, the unique identifier becomes integrated into an assembled breast implant including the shell, thereby facilitating tracing of the specific shell.
This aspect of the present invention can be contrasted with conventional manufacturing processes which place identification information on preformed or pre-molded shells that are each part of a batch of such shells, each shell not being individually distinguished from each other. Such shells remain unlabeled and in storage for a significant time before each shell is removed from the batch and further processed to make an assembled implant.
Although the assembled implant product itself may be labeled with identification information, each individual component of the implant is not easily traceable to its point of origin.
A shell of an implant in accordance with the invention is a flexible, elastomeric component that is typically dip-molded or rotational molded by applying a starter material, for example, an elastomeric material in a dispersion form, to a mandrel having the shape of the implant. Due to the nature of forming such a shell, a mandrel hole or sprue hole remains in the shell after the shell is removed from the mandrel. Prior to filling the shell with a filler material, such as silicone gel or saline, the hole is sealed with a patch. In one embodiment of the invention, the unique identifier is provided on the patch and the patch is molded in place onto the shell. In another embodiment, the unique identifier is located on the mandrel surface itself in the form of relief such that the identifier becomes molded into the shell. In another embodiment, the unique identifier is placed on the shell between dippings which form multiple layers of the shell such that the unique identifier is located between such layers.
In some embodiments of the invention, the unique identifier comprises an insert that is first placed in the mold before each and every part of the assembly is molded. In this way, the unique identifier becomes an integral part of the molded assembly.
In one embodiment of the invention, each component of the assembly receives a unique identifier upon its own formation. The presence of such identifying labels on each component from their inception provides maximum traceability of the component back to the point of manufacture. Alternatively, identifying labels may be placed on less than all of the components of the assembly, for example, on just the primary components of the assembly. For example, filled prosthetic implants of the invention may include an identifying label on the shell as soon as it is formed, or during process of formation, and may also be placed on the sprue hole patch and/or on a fill valve if the implant includes such a component.
A unique identifier in the form of a label may be provided within or on the shell 30. For instance, the identifier may be laser etched on a surface of the shell 30. The specific shell or assembly identification information, such as Part #, Lot #, Size, Style, Manufacturer, etc., as indicated at 40, could all be directly laser etched on the outside of the shell. Alternatively, or in addition, the same information may be incorporated into a bar code 42 that makes automatic identification though a scanner possible.
In one embodiment, the shell 30 includes a non-ferromagnetic or weakly ferromagnetic metal such as TiO2 blended therein that enhances the visibility of such a label, as the metal at the surface heats up and fuses to create visible lines. Moreover, the metallic quality of the label enables imaging thereof in vivo. See Yacoub et al., U.S. Provisional Patent Application Nos. 61/106,449 and 61/106,458, both filed on Oct. 17, 2008, and commonly assigned herewith. The entire disclosure of each of these patent applications is incorporated herein by this specific reference.
In another embodiment, the unique identifier comprises a semiconductor chip that can be read using a scanner or other radio frequency device.
Still with reference to
The shell identifier label 60 may be in two- or three-dimensional form. For example, an etched or printed bar code on the exterior of the shell 52 exemplifies a two-dimensional form. (Technically, an etched or laser-etched region is three-dimension on the miniscule level, but for all intents and purposes it appears as a printed 2-D region).
The mold 120 includes a relatively large circular opening 132 within a lower flange 134 into which projects a sprue tube (not shown) for passage of materials to enter into the mold 120, and for solvents or other gases to escape. Although the mold 120 may be used to form a multi-layered shell, in some embodiments, the mold is used to form a single layer shell. It should be understood, however, that a single layer shell may be formed in multiple steps by a sequence of thin layers such that the finished product exhibits no distinct layers and the entire shell wall is homogenous or uniform in composition.
A unique identifier 136 is shown positioned on an inner surface of the inner liner 130. Again, the unique identifier may be a label or plate that adheres to the exterior of the shell as it is being formed, or may be reverse image raised or indented regions that form in the shell an identifier such as the embossed area 64 or indented region 66 of
In one embodiment, a patch including the identifier is molded in place while the shell is being molded. The patch may be used to cover or patch a hole in the unfinished shell.
For instance,
The patch 142 provides a reinforced access region on the surface of the prosthesis 140 for passage of one or more implements from the exterior to the interior. For instance, a rotational mold process as described in co-pending U.S. Provisional Application Ser. No. 61/038,919, filed Apr. 28, 2008, entitled FLUSH PATCH FOR ELASTOMERIC IMPLANT SHELL and expressly incorporated by reference herein, desirably utilizes such a patch 142 as a reinforced conduit through which inserts two silicone dispersion tubes as well as a vent tube, and typically another tube for filling the implant with silicone gel.
Prior to molding the patch 142 in place with the shell 144, a unique identifier 148 is applied. The unique identifier 148 may be any of the configurations described herein, such as a separate label as shown, or an embossed or printed region. In some embodiments, the identifier comprises a laser-etched identifier. The information provided on the patch identifier 148 may include, as before, a serial number, a bar code, a transponder, or other means for human or machine-readable output. Once integrated with the shell 144 as a single unit (a hollow implant), the patch 142 provides information about the source materials and prior process steps, as well as provides subsequent traceability to the implant. For instance, the precise parameters of further finishing and gel-filling steps can be documented and linked to the unique identifier 148. In one scenario, the particular source, temperature, physical makeup (e.g., single layer, wall thickness), chemical makeup, etc. of silicone used to form one implant shell may differ from the next one, which can be traced by referencing process information recorded for the unique identifier 148.
The unique identifier 148 is shown in
By introducing the patch 142 during the process of molding the shell 144, rather than applying the patch to the shell aperture afterwards, the patch integrates with the casting material flowing over and around, thus producing a flush surface both inside and out. In particular, an external surface of the prosthesis including a circular interface line 170 at a flush butt joint between the patch 142 and shell 144 has no ridges or other surface irregularities. Likewise, an internal surface of the prosthesis in the area of the patch 142 has no surface irregularities, and in particular the boundary between the patch 142 and shell 144 is relocated to the radially inner end 172 of the stem 150.
In the shown embodiment, the shell 144 has a substantially contiguous and consistent wall except in an access region across which the patch 142 extends. That is, the access region interrupts the generally constant thickness shell wall. The patch 142 provides an access medium or port through which tubes or other instruments may be inserted into the inner cavity of the shell 144. In the access region, the material of the shell thins to form the ring 160 over the internal surface of the flange 152 and the tube 162 around the stem 150. Because the material of the shell 144 does not cover the open top of the stem 150, an aperture through the shell technically exists, though not the same type of aperture as previously seen with prior art shells. Indeed, in an alternative version in
The stem 150 of the patch 142 may be utilized to help prevent clogging of tubes inserted into the cavity of the mold. For example, a vent tube may extend through a channel 174 (
The unique identifier 148′ shown in
For breast implants, the formed implant of the shell 144 and patch 142 is ready for further assembly or processing consistent with the usual manner in creating a final breast implant product. For example, the implant is filled with a filler material of silicone gel or other biocompatible gel material well known to those of skill in the art, such as gel 146 shown in
Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the scope of the invention, as hereinafter claimed.
This application is a continuation application of U.S. patent application Ser. No. 13/128,497, filed on May 10, 2011, which is a national stage application under 35 U.S.C. §371 of PCT Patent Application No. PCT/US2009/063606, filed on Nov. 6, 2009, which claims the benefit of U.S. Provisional Patent Application No. 61/113,504, filed on Nov. 11, 2008, the entire disclosure of each of these applications being incorporated herein by this specific reference.
Number | Date | Country | |
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61113504 | Nov 2008 | US |
Number | Date | Country | |
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Parent | 13128497 | Jun 2011 | US |
Child | 14095892 | US |