Patent Application
20230414316
Example embodiment of the present invention relate to an ophthalmological implant comprising an optically imaging element and for example comprising a haptic adjoining the optically imaging element, with a digital product identification being arranged on the optically imaging element. The present invention also relates to a corresponding method for producing same and a machine reading system for recording and decoding the digital product identification.
Ophthalmological implants, for example commercial intraocular lenses (IOL), are usually identified by labels on the primary and secondary packaging. In addition to other manufacturer information, it is possible to find the type of IOL and its refractive power on the label. The correct treatment of the patient therefore assumes that the packaged and supplied lens corresponds in terms of its properties to the specifications on the label. In this context, the user must rely on the manufacturer since an unambiguous identification and a check in the operating theater only on the basis of the visual lens features are difficult. This type of identification harbors the risk of mix-ups if an ophthalmological implant, for example an intraocular lens, is placed in the wrong packaging. Under certain circumstances, this may lead to explanations and product recalls as a consequence.
Intraocular lenses and other ophthalmological implants are medical devices where traceability is a key requirement. In current products, the lens or implant packaging contains a unique device identifier (UDI) in the form of a bar code, a data matrix code, or a radio-readable microchip. Once the ophthalmological implant has been introduced into the eye, it can no longer be identified accordingly.
Methods and devices have therefore been proposed for individually labelling the ophthalmological implants, for example in US 2006/0001828 A1, in which—outside an optically effective zone—ophthalmological lenses such as contact lenses or intraocular lenses are labelled by application of a matrix code, or other laser-engraved matrix codes in the haptic close to the lens or else farther away. However, labelling outside the optically effective zone is difficult to see in the case of ophthalmological implants once these have been implanted. Moreover, marking the haptic using a laser-engraved matrix code requires a corresponding laser system.
This geometric region of the code of ophthalmological implants, for example of intraocular lenses, according to the prior art is not visually accessible in the eye in the implanted state:
The iris, even when medically dilated, blocks the view of the haptic region. Here, it is desirable to render the code accessible, for example in biometrics or via a microscope (e.g., slit lamp or surgical microscope). According to the ISO 11979-2 standard, which describes the current requirements for ophthalmic lenses, markings on the optically imaging element of the IOL are permissible if a clear zone of 4.4 mm is observed. Thus, for example, a toric mark outside the 4.4 mm region is often used to align toric IOLs in the eye, and these marks are visually accessible with some effort.
In contrast, WO 2009/124838 A2 describes an ophthalmological implant with a marking that is also possible on an optically imaging element. However, a fluorescent dye with an emission maximum outside the light spectrum visible to humans or an absorbing dye with an absorption maximum outside the light spectrum visible to humans is used for marking in this case. However, the method used here is technically very complex and requires an additional biocompatible fluorescent dye or absorbing dye and a complex fluorescence excitation or detection system.
Both methods described here also need to be incorporated in the manufacturing chain in such a way that there is no possibility of incorrect labelling of the IOLs as a result of operating or programming errors. Both require additional manufacturing steps using additional tools to implement the markings.
Example embodiments of the invention include an ophthalmological implant, for example an intraocular lens, and a method for producing same, which allow a clear and complete product identification (UDI), for example type, refractive power, serial number, batch number on the intraocular lens, and verification of same using simple instruments and at any time.
An ophthalmological implant, for example an intraocular lens, comprises an optically imaging element, in particular a central optical lens, with an optically effective zone and for example with a haptic adjoining the optically imaging element. Ophthalmological implants usually comprise a haptic for the appropriate fixation of these implants in a patient's eye. In special cases, however, an ophthalmological implant is complete and implantable even without a haptic.
On the optically imaging element of the ophthalmological implant, for example within the optically effective zone, there is a digital product identification of the ophthalmological implant, in particular for example the type and the refractive power and/or a database key (i.e., a unique identifier).
If the digital product identification comprises a database key in the sense of a unique identifier, then the implant-specific product information has been assigned in advance in a database system to this database key. By reading out the database key on the ophthalmological implant (e.g., using the machine reading system described below, which in that case is for example connected directly to the database system), a database query of the implant-specific product information can be carried out. Using this procedure, comprehensive and clear product information can be made available with short coding lengths.
If a database key is arranged on the ophthalmological implant as a digital product identification for unique identification purposes, then usually only this database key is “stored” on the ophthalmological implant—since the database key ultimately provides access to unique information, stored or storable in great detail in the database system itself, about the specific ophthalmological implant.
The database system is for example made available in a data network or a data cloud. For example, the manufacturer stores the implant-specific product information for each database key, that is to say for each unique identifier, in this database system.
However, it is also conceivable that, in addition to this database key, the most important product information, such as type and refractive power, is arranged as digital product identification regardless, with the result that a treating physician, for example, can get hold of these most important product identifications even without a connection to the database system.
According to the invention, this digital product identification is implemented by use of a “coded marker” which is machine-readable in the visible light range and is realized here in the form of a coded point grid with pseudo-random irregular character made of marking points. In this case, “pseudo-random irregular” means that there are a number of different defined deviations of the marking points from a fixed reference point, which would produce a regular character of the point grid. As a result, it is possible to minimize grating diffraction effects which would exist in the case of a regular point grid and would lead to an impairment of imaging by use of such an ophthalmological implant, and hence, for example, to an impairment of vision with a corresponding intraocular lens.
In this case, the optically effective zone of the optically imaging element, in which the digital product identification is for example arranged, is a zone determined by the pupil opening under normal lighting conditions.
To begin with, a distinction should be made between two regions for the marking of the optically imaging element, in particular those of the optically effective zone:
The central optical zone is the central region with a diameter of 4.4 mm; marking in this region is currently not ISO-compliant.
The peripheral optical zone is the outer region of the optically imaging element, in the case of which the central optical zone with a diameter of 4.4 mm remains free; marking in this outer region is currently ISO-compliant. The optically effective zone of the optically imaging element is thus part of the central optical zone, in which marking has not been carried out/has not been allowed to date: This is because, to date, the use of markings according to the prior art has not rendered this possible without significantly impairing visual quality for the patient wearing the implant (the IOL).
Here, marking points of the machine-readable coded point grid are not points in the mathematical sense, but have a size: As a rule, they are round and characterized by a diameter. In an embodiment, however, they can assume an elliptical shape—that is to say they have a length that is significantly different from the width when viewed from above. Other geometric shapes, such as squares and rectangles, are also possible.
Thus, optical codes, for example data matrix codes, on or in the optically imaging element of an ophthalmological lens are described in this invention. The systems and methods outlined herein are based on an IOL equipped with a coded marker. However, the invention does not exclude other ophthalmological implants that need to be positioned in the eye, for example capsular tension rings, stents and ICLs.
Equipping the implant with a coded marker, also known as a “tag”, as an identifier offers various advantages. It supports the surgical workflow. However, it also allows traceability of the implant, from production, through logistics, implantation, in-vivo and, optionally, post-explanation for complaint management.
The focus here is therefore on, inter alia, the link to production and surgical equipment and to diagnostics. In order for this to be possible, the coded marker is made visually accessible even in the implanted state.
In an example embodiment of the ophthalmological implant according to the invention, the machine-readable coded point grid made of marking points is arranged centrally within the optically effective zone of the optically imaging element. As a result, it is visually accessible at all times, even in the implanted state, and rendered visible and readable by using an appropriate machine reading system.
Even if, for the coded point grid made of marking points, a central location within the optically effective zone of the optically imaging element is particularly advantageous in terms of accessibility, the coded point grid made of marking points can be located at any position within the optically effective zone or else outside of the optically effective zone.
The object is therefore achieved to the effect of the ophthalmological implant being associated with a digital identifier in the form of a machine-readable coded point grid that can be read in the visible light range, but which, contrary to the usual interpretation of the term “point grid”, precisely does not have any regularities in a form that could lead to grating diffraction effects. It is for this reason that this point grid is even arrangeable centrally within the optically effective zone of the IOL: By way of its structure, it is designed in such a way that the patient does not perceive any negative optical effect.
In a specific and particularly advantageous embodiment of the ophthalmological implant according to the invention, the coded point grid is constructed from marking points such that a virtual polar or Cartesian base lattice is arranged on the optically imaging element, for example on the optical zone of the optically imaging element, in such a way that this describes similar sectors or similar cells, each with a defined base lattice point of the sector or the cell, as a result. Such a (virtual) base lattice point of the virtual base lattice can be understood to be the center of the sector or cell.
By contrast, a real marking point of the point grid is arranged in each sector or each cell at a position which has an offset to this base lattice point, the offset in each sector or each cell being in one of four possible directions, which for example run pairwise opposite to each other, and having a defined distance to the base lattice point. Naturally, more than 4 directions of the offset are also possible, depending on the options for the creation of the coded point grid made of marking points and the resolution of a machine reading system intended to read out this coded point grid again. Therefore, this particularly advantageous example embodiment is intended to be read as “at least four possible directions of the offset of the marking point to the base lattice point”.
In an embodiment of the ophthalmological implant according to the invention as just described, a sector or cell with a base lattice point provides four states which are characterized by the respective location of the marking point in one of four positions around the base lattice point. The marking point of the sector or cell can thus in each case assume one of four possible positions around a base point of a sector or cell, as a result of which four different states can be described using this sector or cell.
In a development of this embodiment of the ophthalmological implant, a sector or cell with a base lattice point provides a further state, a fifth state, defined by the absence of a marking point at one of the four possible positions around a base lattice point. This results in five possible states for a sector or cell. This is advantageous in that the coding of a unique identification number into the five possible states of the sectors or cells leads, in the statistical average, to the absence of a marking point in this sector or cell in ⅕ of cases. Thus, the number of actually required marking points is reduced by−⅕. This further reduces potential optical effects of the coded point grid made of marking points.
In a further embodiment of the ophthalmological implant according to the invention, further states are defined in a sector or cell with a base lattice point by way of further possible offset directions and/or further possible defined distances of the offset of the marking point to the base lattice point.
The inventive concept therefore also comprises the additional arrangement of the marking points at further positions within a sector or cell on the base crossing points or further crossing points between the base lattice and offset lattice. By way of example, a sector or cell with a (virtual) base lattice point can generate up to nine geometric states if the base crossing points are also used. How many positions are clearly and reliably identifiable depends on the performance of the method for generating the machine-readable coded point grid made of marking points and on the performance of the machine reading system.
An ophthalmological implant according to the invention is advantageous in which the proportion of the area of the marking points to the total area of the optically imaging element is for example less than 2%, in another example less than 1%, and in a further example less than 0.5%, and/or wherein a proportion of the area of the marking points to the area of the optically effective zone of the optically imaging element is for example less than 8%, in another example less than 4%, and in a further example less than 2%. In this case, the total area of the optically imaging element is typically an area with a diameter of 6 mm, and the area of the optically effective zone of the optically imaging element is a zone determined by the pupil opening under normal lighting conditions, that is to say usually an area with a diameter of approximately 3 mm.
In addition to the option of using the absence of a marking point in a sector or cell to describe the state and thus “economizing” marking points, it is generally expedient to keep the proportion of the area of all marking points in the total area of the optically imaging element and in particular in the area of the optically effective zone of the optically imaging element as small as possible.
By way of its structure, the coded point grid made of marking points, according to the invention, is thus designed in such a way that the patient does not perceive any negative optical effect. To ensure this, the following conditions must be met:
In a further example embodiment of the ophthalmological implant according to the invention, the machine-readable coded point grid has structural marking points. In this case, structural marking points are marking points that are characterized by a topology, that is to say are physically raised or physically impressed, with the latter representing the more probable embodiment of these marking points.
These are advantageous for two reasons: Firstly, these points still ensure a certain transparency, that is to say they are not completely opaque absorbers. Secondly, the generation of such structural marking points is able to be integrated relatively easily into the manufacturing process of an ophthalmological implant.
Nevertheless, it is also possible to generate marking points by applying or introducing dyes in order to realize the ophthalmological implant according to the invention.
The contrast of, for example, laser-engraved marking points is usually given by scattering. With relatively recent technologies, a local optical change can be used to also achieve contrasts in addition to scattering and to generate the presented codes:
Such alternative approaches are advantageous as they reduce the amount of light which is scattered by the marking points and reaches the retina, causing side effects such as “star bursts” or other dysphotopsia. In the case of wavelength-selective reflection, absorption or refractive index changes, additional functions (chromatic filters, light polarizers and filters, lamps) may be required in the optical readout equipment. However, this is accompanied by a reduction in side effects on the visual impression of the patient. In addition, the markings are then not visible from the outside (which is cosmetically beneficial for the patient). This in turn allows the coded markers to be easily accommodated in the central optic and allows for easier optical access.
Moreover, it is very advantageous for example if the ophthalmological implant according to the invention contains a supplemented product identification which, in addition to the original product identification, has information for checksums and error correction methods.
On account of the huge number of representable states for clear product identification, there is sufficient representation reserve for checksums and error correction mechanisms, which represent additional safety when using such an ophthalmological implant.
The information-theoretical design of the coding schemes for example allows the coding of very long integers in order to enable a unique product identification of many (and different) implants over a long period of time. Due to the possible storage capacity, the coding itself can be protected against incorrect reading using known methods from information technology. These include, for example, checksum or error correction methods.
To improve the recognizability and referencing by a machine reading system, the ophthalmological implant has, in a further embodiment, one or more reference marks at a defined distance from the machine-readable coded point grid made of marking points. These one or more reference marks are therefore arranged in the vicinity of the coded point grid made of marking points and in a defined distance relationship to the latter and form the “control points” for a machine reading system, in relation to which the said machine reading system orientates itself and thereafter is able to very easily correctly localize and read the coded point grid made of marking points.
In different embodiments of the ophthalmological implant, its machine-readable coded point grid made of marking points, or more generally the coded marker, can be arranged on the optically imaging element (i.e., applied to its surface or introduced into its surface) or in the optically imaging element (i.e., in the volume of the optically imaging element) in the process. A combination of both embodiments is also possible.
An example embodiment of the ophthalmological implant according to the invention has an alignment aid. The alignment aid is likewise for example arranged within the optically effective zone. It is furthermore advantageous for example for the alignment aid to contain or consist of the machine-readable coded point grid made of marking points.
A further example embodiment of the ophthalmological implant according to the invention comprises a toric marker which is readable in the view from above and/or a toric marker which is readable in an axial view. The toric marker can likewise be arranged on the surface of the optically imaging element and/or in the volume thereof. Moreover, the toric marker may also contain or consist of the machine-readable coded point grid made of marking points.
A toric marker which is readable in the view from above allows access via camera in production and logistics and via surgical microscope, a slit lamp or biometric equipment in the implanted state. A toric marker which is readable in an axial view (that is to say in a side view) is accessible to tomographic measurements, for example. For example, it can be used with OCT (optical coherence tomography), CT (computed tomography) or MRI (magnetic resonance imaging).
Data matrix codes in the form of a toric marker serve to assist with in vivo lens alignment in the eye during surgery and with rotation traceability. To correct regular astigmatism, toric intraocular lenses have an optical cylinder arranged along a specific axis, the toric axis. The toric axis is indicated by the toric markers. Since the lens alignment in the eye during surgery is implemented with the surgical microscope using software such as Callisto, the necessary lens information can be automatically supplied in vivo. Furthermore, this function is intended not only for toric IOLs but also for monofocal IOLs, allowing for operative in-vivo and post-operative tracking of lens centering and rotation. Here, the data matrix code serves as an optical reference for tracking the lens alignment in vivo.
Thus, various embodiments of coded markers that differ from a standard code are presented here. In particular, the toric marker is visually accessible both in standard routines (biometric equipment, surgical microscopes, slit lamps) and/or in more advanced optical designs (pinhole concepts, central optic designs).
The embodiments with alignment aids and/or toric markers for all ophthalmological implants, in particular for intraocular lenses (toric and non-toric; modular lens alignment), also make it possible to detect postoperative changes in the implant position (inclination, decentering, rotation of all lenses).
Based on tests on an intraocular lens implanted in a human eye model, a marking point size (spot size) of ˜25 μm is preferred for example for the machine-readable coded point grid made of marking points, or more generally for the coded marker. It represents the best compromise between size and contrast visible in the surgical microscope. A conventional axial resolution of ˜5 μm is possible for OCT A. This would be a lower bound for the marking point size; a factor of 2 could be applied via resolution criteria.
Enabling traceability throughout the lifetime of the implant is advantageous in the case of a biomaterial code (thus a coded marker on an ophthalmological implant here). A greater distance between the marking points (lattice size>point size) reduces possible diffraction effects. The use of non-periodic data codes, not only at the level of the arrangement of individual marking points, but also with regard to the overall structure of the coded markers, is for example advantageous. Contrast enhancements such as laser-induced light traps or reflective structures or refractive index changes are likewise advantageous for example to reduce the risk of dysphotopsia.
A machine reading system according to the invention serves to capture and decode the digital product identification in the form of a coded point grid made of marking points, or in general the coded marker, on an ophthalmological implant described here.
The machine reading system comprises a camera system for recording structures of the machine-readable coded point grid made of marking points on the ophthalmological implant, and an analysis unit for capturing and evaluating a camera system recorded image of the structures of the machine-readable coded point grid made of marking points and for decoding the digital product identification of the ophthalmological implant, in particular for example the type and refractive power and/or the database key, for the identification thereof from this image.
Depending on the respective lighting conditions, such a machine reading system can have an illumination system for illuminating a digital product identification of an intraocular lens in the form of a machine-readable coded point grid made of marking points.
It is moreover advantageous for example if the machine reading system also comprises a display and/or output apparatus for displaying and/or outputting the decoded identification data of the ophthalmological implant. Otherwise, however, such a display or output can also be adopted by other apparatuses that can be connected to the machine reading system.
Especially if the digital product identification of the ophthalmological implant contains a database key, it is moreover advantageous for example if the machine reading system is connected to a database system. This database system assigns the implant-specific product information to a database key, which is a unique identifier. A database query of implant-specific product information can be carried out by the database key stored as the digital product identification of the ophthalmological implant being read by the machine reading system. Using this procedure, comprehensive and clear product information can be made available with short coding lengths. The database system is for example made available in a data network or a data cloud. For example, the manufacturer stores the implant-specific product information for each unique identifier in this database system.
In specific embodiments, the machine reading system according to the invention is part of a surgical microscope or a slit lamp.
In this case, the unique product identification can be stored and/or processed by the machine reading system, and can be made available digitally for other services. Such a machine reading system can be located in the production of the ophthalmological implant, for example in a production of intraocular lenses for quality monitoring and/or in the practice of the implanting and/or controlling ophthalmologist, for the purpose of checking the ophthalmological implant.
In a method according to the invention for producing an ophthalmological implant with a digital identifier as described above, the machine-readable coded point grid made of marking points is generated for digital product identification purposes on the ophthalmological implant, during or after the production of the latter.
The identifier is therefore connected to the ophthalmological implant, for example to an intraocular lens (IOL), during the manufacturing process and can then be read, stored, and processed by optical instruments during further subsequent steps in the cataract operation and in the implanted state.
In an example embodiment of the method according to the invention for producing an ophthalmological implant, the latter is labelled during the production of the ophthalmological implant
An embodiment of the method according to the invention for producing an ophthalmological implant, in which the machine-readable coded point grid made of marking points is introduced into the surface of the ophthalmological implant using a CNC-controlled drilling or milling tool during or after the production of the said implant, with the drilling or milling tool to this end for example having a tool diameter of less than 0.4 mm.
Usually, cutting turning methods, in particular diamond turning methods, are used for the production of ophthalmological implants themselves, that is to say CNC-controlled milling tools are used for this purpose. Ideally, the ophthalmological implant is now digitally labelled without the tool having to be changed for this purpose, since every change of machine and hence change of location of the ophthalmological implant can naturally be a source of mix-ups. However, if the ophthalmological implant can be digitally labelled with basically the same tool also used for the manufacture thereof, then this renders possible a method in which the data actively “collected” during the manufacturing process or used during the manufacturing process of the ophthalmological implant are also coded into this ophthalmological implant during or directly after manufacture. A mix-up of the data set or ophthalmological implant is thus precluded.
In this case, the machining for digital product identification is carried out with small tools (for example with a diameter <0.4 mm) in a surface-near region.
In an alternative embodiment of the method according to the invention for producing an ophthalmological implant, the machine-readable coded point grid made of marking points is applied either by use of laser processing by ablation or disruption or by application of printing methods, for example using biocompatible chromophores or pigments, which are usually situated in a matrix that bonds covalently to the lens material.
In an embodiment of the method according to the invention for producing an ophthalmological implant, a product identification or a supplemented product identification is in the process converted into grid coordinates for the physical product identification using a machine-readable coded point grid made of marking points.
The unique product identification is connected to the ophthalmological implant by use of the point grid made of marking points according to the invention. To this end, the unique product identification is initially supplemented with the information for checksum or error correction methods, if this is intended. The precise procedure here depends on the method selected. Thereafter, the supplemented unique product identification is converted into the grid coordinates for the physical product identification. The identification can now be transferred to the product, into the point grid made of marking points, using the grid coordinates.
Not least, a further embodiment of the method according to the invention provides, during or after the generation of the machine-readable coded point grid made of marking points for digital product identification, for the said machine-readable coded point grid to be stored in a manufacturer database system which can be linked to an electronic patient file and/or another data collection point for medical or official purposes.
The unique product identification is generally generated by the manufacturer himself or, if necessary, by a certification body during the manufacture of the ophthalmological implant.
According to the invention, this identification is then connected to the product and stored in a database system. This database system can be created in self-contained fashion by the manufacturer and/or at a public data collection point for medical or official purposes, or can be transferred from the manufacturer to a corresponding data collection point. This product identification can also be stored in an electronic patient file.
In an important embodiment of the method according to the invention for producing an ophthalmological implant, the product information of the ophthalmological implant is stored in a database system before the machine-readable coded point grid made of marking points for digital product identification is generated and a database key for this product information, which is contained in the digital product identification, is generated.
Such a method step can be implemented instead of the previously cited method step of storing the digital product identification in a database system during or post generation. However, it is also possible for a database key to be created in the database system prior to generation and for the database system to be write accessed during or post generation in order to confirm the actually generated digital product identification, for example the database key, which was generated by the machine-readable coded point grid as marking points on the ophthalmological implant. A comparison for example takes place in the process, and an incorrectly labelled ophthalmological implant is blocked in the event of deviations with respect to the database key.
The invention is explained in more detail below by way of example on the basis of the accompanying drawings, which also disclose features essential to the invention. In detail:
Firstly,
The polar base lattice shown here consists of three radial zones 52, each with twelve sectors 51. These generate the base lattice points 56, which are purely virtual in nature. The base lattice points are indexed consecutively from 0 to 35 in
In order to improve the recognizability and referencing by a machine reading system 200, a plurality of reference marks 58 are moreover arranged in the vicinity of the point grid 135 made of marking points 57.
In the example of
In this example embodiment, the single point size of a marking point 57 is approximately 0.0025 mm2. Hence, the proportion of the area of the marking points 57 to the total area of the optically imaging element 110 is 0.1059%.
In this example embodiment, the individual point size of a marking point 57 once again is approximately 0.0025 mm2, and hence the proportion of the area of the marking points 57 to the total area of the optically imaging element 110 is 0.1059%. Thus, although the possible storage capacity has increased, the proportion of the area of the marking points 57 to the total area of the optically imaging element 110 has remained the same in comparison with the second example embodiment.
In this example embodiment, the individual point size of a marking point 57 once again is approximately 0.0025 mm2, and hence the proportion of the area of the marking points 57 to the total area of the optically imaging element 110 is 0.2119%.
In the sixth example embodiment of
Finally,
This example embodiment of a machine reading system 200 according to the invention comprises an illumination system 210 for illuminating a digital product identification 130 of an intraocular lens in the form of a machine-readable coded point grid made of marking points 135, a camera system 220 for recording structures of the machine-readable coded point grid made of marking points 135 which have been rendered detectable by use of the illumination, and an analysis unit 230 for capturing and evaluating an image, recorded by the camera system 220, of the structures of the machine-readable coded point grid made of marking points 135 rendered detectable by use of the illumination and for decoding of the digital product identification 130 of the intraocular lens, for example the type and the refractive power, for identifying the ophthalmological implant 100 from this image, and also a display and/or output apparatus 240 for displaying and/or outputting the decoded identification data of the ophthalmological implant 100.
In this case, this example embodiment of the machine reading system 200 according to the invention can also decode intraocular lenses which have already been implanted in a patient's eye 300.
In general, a coded marker on an ophthalmological implant 100, for example on an IOL, can be any type of visually recognizable coded information that offers the above-described functions.
Examples of such coded information include, inter alia, (i) standard codes such as linear barcodes or matrix (2D) barcodes including point code, QR code, or (ii) advanced codes such as 3D matrix codes. The codes can differ in the number, size or width of the (individual) elements (e.g., pixels), the overall size of the code, the distances between the elements and the orientation of the elements within the code. The coded marker on an IOL is formed by a machine-readable pattern. Such a pattern can be recognized under different types of illumination, for example under normal white light illumination, fluorescent illumination or laser illumination.
The digital product identification 130 using coded markers is now attached to the IOL in such a way that it is recognizable during implantation and post operation. In the embodiments shown here, the coded marker is located at the edge of the optically imaging element 110 of an IOL, which is generally accessible by dilating the pupil. The coded marker, for example the machine-readable coded point grid made of marking points 135 contains information such as the specification data of the respective ophthalmological implant 100 (in the case of an IOL, for example diopter, type, manufacturer, model, material, toric axis). However, the specification data can also be represented by a unique identifier that enables the data to be retrieved from a database.
A coded marker as proposed in the invention not only enables a reliable identification of the IOL, but also, in example embodiments as illustrated in
To indicate the toricity of an intraocular lens or other lens characteristics (such as haptic or modular lens connection sites), the points can be extended in that direction. In addition, as shown in
The toric marker 160, 161 is located on the surface of the optically imaging element 110 of the ophthalmological implant 100, for example an intraocular lens, or in the volume of the optically imaging element 110 (i.e., in the material). The toric marker 160, here for example in the form of a QR code, is for example readable in the view from above, AO, as shown in
In general, toric markers 160 for toric IOLs are well established with no reports of dysphotopsia, which has the advantage that this shape and area can be used for a coded marker in the form of a data matrix code in the implanted state of an IOL with dilated pupils. This invention can be used for all IOLs, not just toric IOLs, and allows the rotation of the ophthalmological implant 100 to be tracked.
In this case,
In this case, the QR code designs are rectangular or square in UDI-compliant grid pattern, which is easier to generate than that of
The tables of
For the traceability of an ophthalmological implant 100 until production, in particular of the optically imaging element 110, within the scope of manufacture, coded markers, for example a machine-readable coded point grid made of marking points 135, can be applied in or on the material as a digital product identification 130 by laser engraving using a laser 190.
Another advantage is that a data matrix code in the interior of the material improves readout during production, logistics, and in the implanted state. For example, toric markers 160 on the surface of the optically imaging element 110, for example on a lens surface, at high diopters, and on the cornea, may appear deformed due to optical projection, making alignment during implantation of the ophthalmological implant 100 more difficult. Moreover, the toric markers 160 can also be used to align the material blank 180 during the production of the ophthalmological implant 100 in order to ensure toricity and haptic are on the correct axis.
It should be mentioned that the processing with regard to tilting and centering must be very precise, especially for the precisely timed alignment of a non-spherical intraocular lens. In the event of the lens not being perfectly aligned, this information must be linked to the serial number and stored both online (accessed via the database) and offline (box label).
Alternatively, the marker can also be attached directly after the processing or after the polishing of the ophthalmological implant 100. In this context, the marker can still be embedded into the material or applied to the surface.
In addition to conventional laser engraving, alternative techniques can also be used to produce the data matrix codes shown. One possibility would be the photochemical generation of metal (e.g., silver, gold) nanoparticles or silicon nanoparticles within the biomaterial matrix by way of two-photon absorption.
The code is clearly visible through a microscope. Modulation transfer function (MTF) values for 100 lp/mm are close to those of an IOL that has not been provided with a coded marker. Thus, only minor problems in terms of halo, glare and visual impairment can be determined in the case of this conventional laser-engraved code. Small lattice effects (small dysphotopsias) are visible due to the periodicity of the code. However, the test limits for such an ophthalmological implant 100 are met. These effects could be further minimized by positioning at the periphery of the optically imaging element 110 or further randomization of the pattern during the creation of the digital product identification 130.
Since the marking points are located in a Fourier plane, they are not projected onto the retina in focus. Here only visual acuity is reduced by the nature of the “blocking” of light rays in the central optical zone, which leads to a loss of contrast. About 0.5% of the light is blocked in an estimate for an M4 code (17×17) with a square marking point size of 25 μm and a central optical zone of 4.4 mm; this is negligible and has no impact on the MTF function. In order to reduce diffraction effects due to the periodicity of the point pattern of the code, the lattice spacing must be greater than the size of the marking points (sometime also called spot size). This is the case in the present example.
The aforementioned features of the invention, which are explained in various example embodiments, can be used not only in the combinations specified in an example manner but also in other combinations or on their own, without departing from the scope of the present invention.
A description of a piece of equipment relating to method features is analogously applicable to the corresponding method with respect to these features, while method features correspondingly represent functional features of the equipment described.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 214 126.6 | Nov 2020 | DE | national |
| 10 2021 206 092.7 | Jun 2021 | DE | national |
This application claims priority from Application PCT/EP2021/081210 filed Nov. 10, 2021, and claims priority from DE Patent Application No. 10 2021 206 092.7 filed Jun. 15, 2021 and DE Patent Application No. 10 2020 214 126.6 filed Nov. 10, 2020, each of which are incorporated by reference in their entireties in this application.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/081210 | 11/10/2021 | WO |
