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Lens that mIGHT be a Satisfactory Way Of Reducing age Degradation of Sight

Final Report Summary - LIGHTSWORDS (Lens that mIGHT be a Satisfactory Way Of Reducing age Degradation of Sight)

Executive Summary:
Ageing society is an issue of increasing importance for Europe. According to Eurostat, 36,5% of the European population is more than 50 years old and this percentage is constantly growing. In the next decades, Europe’s growth will increasingly depend on the ability to capitalise on the skills of ageing people: the goal set by EU for 2020 is to achieve an employment rate of 50% for older workers (55 to 64). One of the most common diseases associated with ageing is the decline in the quality of vision. In the framework of an ageing society and high retirement age more and more workers will require these problems to be addressed, particularly when wearing protective glasses. Protective glasses with prescription lenses exist, but they suffer several major drawbacks related to cost and usage, in particular related with difficulty to focus immediately or simultaneously on different distances. That exposes workers to potential risks. Number of different solutions exists as spectacles with lens of fixed depth of field, bifocal, pinhole or aspheric. LightSwords Optic Element (LSOE) is the optic structure, where the extended depth of field ranges from close distance to infinity. LSOE structure is created as rising /decreasing curvature radius with angular coefficient, where every subsequent angular segment in section has the shape of lens with optic power corresponding to actual angular coefficient. Obviously different possible geometries for such a structure exists. That in theory allow to compensate different presbyopia and myopia disorders with a one-solution-fits-all approach.

When LightSwords project was proposed, according to proposers knowledge, only theoretical model of such structure existed and one model elaborated in soft material by SME proposers in the past two years.

As the proposed LSOE structure is fixed for requested optic specification and extended depth of field is embedded in its structure, the prospected innovation is also dedicated for novel CCD camera lens, where focus mechanism could be eliminated.

According to the literature and market research performed by project proposers, this is the only optic element known up to date, which may create recognizable images of objects placed at any distances ranging between 33 cm and infinity in real operative conditions.

LightSWORDS project objective was to develop the mass production technology for that innovative asymmetric plastic lens. That strategy should lead to considerable less expensive with mass production, when compared to currently available ones.

When LSOE is to be manufactured, the main technology issue to solve, it is its complex geometry, where smoothly varying low curvature is combined with small steps of sharp edges - all within micron and submicron ranges. For tests three different LSOE structures were selected to check technology limits.
LightSwords Consortium developed technology, where finally dedicated moulds were manufactured and test series of considered optic structures were obtained. First samples were validated against theoretical assumptions. Also first ophthalmic tests confirmed the predicted features of LSOE structure. The status “ready to go” for pre-clinical testing was reached (TRL = 7).

Project Context and Objectives:
When project started, the market review was done for prospected project results placement. Two market segments were recognized: ophthalmic and CCD cameras. Considering further exploitation of project results - capability to produce short series of requested LSOE structures, they shall be observed in two different perspectives: short time, when novel production technology will be available – and long term, when matured LSOE solution will be available. When short term perspective is considered, the market is limited to prospected LSOE developers, where short series of different structure LSOE will be necessary for experimental assessment and validation process. Long term prospection is dedicated to the applications market. Safety eyewear is a mature, mostly SME-based market; there is still niche for newcomers and market is not necessary sensitive on the crisis impact. For further exploitation purposes, during GA2 the Consortium undertook decision to establish bilateral contacts with selected market players and relevant RTD to disseminate information about project results in limited way. Following meetings and demonstration of first results of LSOE samples optic tests, Partners noted deep interest on the considered LSOE solution inbetween ophthalmologists. That is particularly the possibility to integrate LightSwords optic structure with contact lens and intracoular lens, even it was out of project objectives - see also DoW. The secondary market for LightSWORDS technology is the optical instrumentation market, where multiple focal distances are appreciated and present electromechanical autofocus feature could be replaced with proposed optic structure. That market is highly demanding and narrow one.
Following, the evaluation of polymeric materials for LSOE mass production was done to select the polymer for hot embossing and injection moulding – D1.2. PMMA was selected as the most suitable for production testing phase.
Two subsequent tasks (T1.3 and T1.4) of WP1 were dedicated to document theoretical model of LSOE. That was assisted with numerical modelling and parameter sensitivity analysis for different optic structures. Analysis was concluded with selection of case study structures as well as with revision of tight manufacturing constrains listed in the DoW. The CAD documentation for case study was prepared for prospected case study set-up.
The WP2 were dedicated to selection and development of mass production technology. Finally following different approaches were tested:
- Direct machining of LSOE in PMMA material (5 different LSOES were finally machined and assessed) for micromachining applicability and test reference,
- LSOE production with plastic injection moulding technology, where:
o Mould insert was manufactured with micromachining technology
o Injections were done with PMMA
- LSOE production with hot embossing technology; two cases were analysed:
o Stamp was manufactured with micromachining and LSOE were embossed in PMMA sheet,
o Stamp was manufactured with novel technology: laser lithography in thick photoresist combined with replication process from developed photoresist to nickel galvanized plate; following LSOE were embossed in PMMA sheets.
Primary selected EDM technology was finally abandoned. It did not introduce any new elements to the technology quality. It had been found, that the micromachining had to be used anyway for electrodes manufacturing, and the same level of finishing could be reached with direct micromachining. Last but not least the process itself is expensive and long.
It was concluded, considering direct micromachining of LSOE, that it is not well suited for prospected application due to its timing and costs. However it was useful for first attempts of LSOEs assembly with goggles.
After first series of trials, the novel technology based on the thick photoresist, grey scale laser lithography combined with thick galvanization was found to be not matured on its details. Namely and in detail: thick photoresist availability and replication process from developed photoresist to galvanized plate. Nevertheless, applicability of that method to produce the complex geometries with sharp edges were confirmed and new front for research was defined and reached.
Finally micromaching with single point diamond turning method was found to be the most useful for mould production – at least for certain class of LSOE structures, where structure heights are high in comparison with tool radius.
The manufactured mould forming elements geometry was assessed against expected theoretical constrains. Following first serie of production, the embossed and injected LSOEs were assessed from geometry point of view. For mass production technology the best results were obtained for hot embossing. Injected samples exposed certain shrinkage and the process need further calibration (being a part of regular preproduction process).
Following, in the WP4 - Task 4.1 the procedure for LSOE assessment was elaborated, where exceptionality of LSOE structure were considered. Standard optics performance is evaluated in the best sharpness/focus plane. The idea behind LSOE is to not provide the best possible image quality at certain plane, but to provide the "acceptably" sharp vision across considered depth of field. Thus new provisional assessment criteria were created and a prototype of quality measure for prospected mass production was developed.
Following, in the Task 4.2 LSOE samples produced with different technologies were assessed from optical features point of view. The optic assessment gave similar result as the geometry assessment of LSOE samples: the best calibrated technology is the hot embossing, where the stamp was manufactured with direct machining. Detailed conclusions may be found in the Deliverables D3.6 and D4.2. Full documentation of optic measurements is stored in the private D4.2-Addition delivered on demand if necessary.
Since project startup, the dissemination and exploitation strategy plans were the object of permanent interest both from RTD and SME partners. The relevant plan was elaborated, where primary the pilot production of different optic structures is specified; that is aimed for wide optic structures parameters sensitivity analysis and selection of most promising for protection goggles and camera lens (machine vision) application. It is worth to note, that Military Institute of Medicine (contact lens - pre-clinic tests), Univ. de Antioquia UdeA form Colombia (the same application) and Ophthalmology and Ophthalmic Research Center for Intraocular Application in Poland expressed their deep interest in the clinic tests participation for contact lens application and Institute for Experimental Biology of Polish Academy of Science requested for LSOE samples for brain vision impact investigations. The website, necessary leaflets and communication on the availability of LSOEs for further tests were done in the form of EOS annual conference presentation and application of scientific article to Journal of American Optics Society.
Project Results:
The description is attached in the file "Scientific & Technology results and obtaineg foreground.
Potential Impact:
The primary market identified since proposal phase for the LightSWORDS Optical Element (LSOE) is its application to safety eyewear for workers, represented within the consortium by GAINIKA. Safety eyewear is a mature, mostly SME-based market, where there is still room for newcomers. The PPE market has been less affected by the economic crisis with respect to other market segments and it is projected to retain its value with potential growth in the short-medium term. Prescription safety glasses with progressive lenses exist for various applications, having prices in the range between 200 and 350 € for the majority of general purpose glasses, but rising up to 400 € and more for special purpose glasses. The market size for prescription safety eyewear suitable for combined myopia and presbyopia has been estimated in 4.1 million pairs per year. This number is expected to increase in the next decades due to the overall ageing of society and more specifically the projected ageing of workforce due to pension reforms.

The LightSWORDS concept is the extension of functionality of known optical structures such as multifocal lenses with smooth transition between different focus ranges; available medical literature and disputes on this topic made it possible to foresee since the beginning that the users could experience some degree of discomfort at first and there would need a settling time (variable from person to person) to train their eyes and brain for use of the device and get accustomed with it. In particular, as the LSOE make a favour of vision to the optic axis, tracing across the full scene of vision would need to be performed turning the whole head instead of just redirecting of eyes. LightSWORDS has very peculiar features such as the requirement for the eye to focus through the centre of the lens for any focal distance– as opposed to multifocals in which the eye needs to be trained to look through specific areas for short- medium- and long- range vision. At every instant “infinite” images belonging to each of the infinitesimal foci (“slices” of the lens) are formed on the retina. Early studies suggested that the brain would be able to accommodate this effect by automatically picking the image with the best sharpness, but confirmation of this ability of human brain was only possible to be acquired when specimens were available for testing.

The biomedical issues related with human perception of scene through LightSword structure was out of scope of project. Nevertheless from the beginning of LightSwords concept the Optic Researchers were obviously looking for the answer, would manufactured LSOES confirm the theoretical speculation. Some easy to proceed measurements confirmed the theoretical prediction:

YES – it is possible to manufacture the proposed LIGHTSWORDS structure with available fabrication hardware;
YES – the observed optic features are meeting the theoretical expectations.

However the detailed examination of medical acceptability of LightSWORDS concept are still waiting for pre clinic and clinic testing procedure. That includes brain vision acceptance and, when considering prospected contact lens or intraocular lens it demands for detailed testing of lens interaction with living tissue as well as fitting to different vision dysfunctions.
Nevertheless, the LightSwords project results opened the new path for medical tests on available LSOE samples.

From the experience gained via direct testing of the lenses, it was possible to state that the brain is able to adapt to select the sharpest image i.e. to select the right depth of focus among the “infinite” ranges available on the lens’s angular sectors. It appears that the brain is able to perform a fast scan of images from all areas and it chooses the area with highest contrast.
In order for this mechanism to work effectively, alignment between the pupil and the centre of the lens must be as exact as possible, which brings in the need of keeping the position of the pupil as close to the lens as possible. This means that side vision is not allowed: the user must always look through the centre of the lens, thus side vision is only allowed by turning the whole head when wearing LSOE-equipped goggles or glasses.

Perhaps this makes walking when wearing them uncomfortable. Moreover, the necessity of keeping a straight line of sight implies potential fatigue of ocular muscles, so that it is advisable to only wear the LSOE for limited periods of time. Already in the limited time available for the trial, it appeared evident that these drawbacks can be mitigated by training, as after ten minutes wearing the goggles volunteers reported better feeling and getting used to perform the head movements required. However, the discomfort makes it impractical to use LSOE as glasses for everyday use. Nonetheless, the concept is still valid for goggles, in particular working goggles but also swimming goggles and the like, that are used only specific activities and for limited periods of time.

Besides the proof-of-concept application, a very interesting market would be opened by extending the LightSWORDS principle beyond safety goggles to contact lenses and intraocular implants. The main benefit of applying the LSOE in such fields is the possibility of operating as close as possible to (and even inside) the eye. This is enormously beneficial due to the peculiarity of the LightSWORDS concept, i.e. working best when the alignment of the optical axis of the eye and the one of the lens is done. This condition is always satisfied, when implanting the LSOE as intraocular and it can be easily granted with contact lenses.

Obviously, when that application is compared regular glasses or goggles, the lens is practically integrated with LightSwords structure. The consequence is, the scene may be reviewed with eye without any limits following natural movement of eye.

The “universal” character of LightSWORDS is suitable for an extremely low cost mass production since the same model can be used by a wide range of users with different vision dysfunctions. It may also be an addon structure to regular corrective lenses. An estimation of the potential European consumer base, based on the simultaneous incidence of myopia and presbyopia among European citizens, gives a staggering 70 million potential customers. Especially when applied to the most sever cases, LSOE would provide a low-cost, high-diffusion means of providing satisfying vision (even if not perfect) to persons with serious impairment thus allowing a significant improvement of their living conditions.

This application of LightSWORDS would provide the bulk of correction (i.e. on focal distance), allowing to apply finer tuning of other defects (e.g. astigmatism) by means of regular glasses (in the case of contact lenses) or contact lenses (in the case of intraocular). This would help significantly cutting expenses, enabling high profile healthcare to reach also low income people.

None of the consortium members is involved in the business of contact lenses or intraocular implants; thus external partners are needed to pursue this way. Here contacts were made with the following companies for prospected exploitation:

Company field of interest status of contact
TS LAC(SME) custom contact lenses preliminary agreement in setting up a cooperation
HOYA (LE) mass produced contact lenses recognition
Abbott intraocular implants recognition

Since the theoretical calculations at the basis of the LightSWORDS optical element have been in public domain since many years ago, it is not possible to patent the concept. The advantage gained by project consortium over competition is in mastering the fabrication techniques. For this reason the consortium has been moving carefully when it came to addressing industrial partners, especially concerning large industries such as HOYA and Abbott.

HOYA expressed the availability to cooperate with the consortium in view of contact lens application; however at the moment the requests of HOYA for more information are being treated carefully in order to avoid drainage of IPR from their side.

Abbott on the other side has also expressed some interest for joint development. In this case, the preference goes towards performing the activities in a protected framework, such as in a follow-up innovation project. This way IPR and roles would be regulated since the beginning, while the large company would exploit a co-funding quota in the project, minimising its financial risk. To this end, CMS and DAPP are preparing a proposal together with Abbott to be submitted in the upcoming “Fast Track to Innovation” call (closing on 29/4/2015 or 29/09/2015)

Regarding other actions aimed at further research on the LSOE, the following institutes have expressed their interest: Polish Institute of Aviation Medicine (for contact lens application - pre clinic tests), Universidad de Antioquia from Colombia (same application) and Polish Ophtalmology and Ophtalmic Research Center for intraocular application.

Besides the main target of LightSwords concept – the correction of human vision, a second application is the machine vision. This market segment, assigned to SCAME, has been pursued in parallel to the first one. The main advantage is to exploit the focusing properties of the LSOE to build self-adjusting optics without the need of a moving objective. This is particularly important in applications where the following two requirements are needed: miniaturisation and stability. For instance, a great interest has been witnessed in the latest years for objective-less cameras for satellites, where every moving part needs to be counterbalanced in order to keep angular momentum constant.

The small, but remunerative, space niche market was introduced the concept to ESA by DAPP exploiting its role as official Italian broker of the Space Agency’s Technology Transfer Programme in two ways:
1. By proposing the technology as possible camera for rovers and/or EVAs under the call Space COMPET 6 2014 – outcome not successful.
2. By adding the LightSWORDS concept to ESA TTP Technology Exchange, a virtual marketplace where demand and offer for space technologies can meet.

A further very interesting application for LSOE in machine vision with the possibility of building 3D maps of the scene by processing the multiplicity of images collected simultaneously at different depths of field. In fact it is possible to distinguish and process objects captured in the image by mapping their contrast and focus. The characteristic relationship between sharpness and depth of field, which can be measured, makes it possible to express out-of-focus in terms of distance from the focal plane.

The principle can work quite straightforwardly for still images; however, when applying it to moving objects a further degree of freedom is added. A correlation algorithm thus would need to be developed between successive frames to cancel spurious out-of-focus effects. Another possibility would be to couple the lens with a high speed acquisition CCD, in order to work instantaneously still images.

The potential market applications of this enhanced version of the camera are still unexplored; however, it is possible to devise fields of interest for the application wherever miniaturisation and reduction of number of components is valuable. The prominent market for miniaturised 3D cameras in the coming years is projected to be the one of smartphones: according to “Research and Markets” the market for smartphone 3D cameras will exceed 2 billion $ worldwide in 2020.

The working principle of the camera-based application was demonstrated by field tests: the addition of a LSOE in front of a non-prepared regular camera is able to yield a recognisable image at all distances without the need of an objective.
However sharpness of objects at far distance is not satisfactory (as predicted by theoretical models): there is the clear need of programming a post-processing algorithm to fully exploit the potential of the lens. The work was still in its beginnings at the time of writing (due to specimens of suitable quality and diameter having been received quite late along project activities, at month 22) and will extend beyond the end of the project.

Besides the end products, a significant range of results is related to high precision manufacturing processes.

Even the direct micromachining gave perfect results and it make possible to produce requested LightSwords structures, some limits for that technology will limit the possible structural variations – mainly those which relate the lens thickness and overall diameter with demanded depth of field. The alternative method is the grey scale laser lithography exploitation. It is observed by Consortium Partners as an alternative tool for advanced mechanical elements mass production, and Laser lithography technology could be used for mould shaping without high precision geometry limits. The maturity of that method was overestimated on the beginning of the project and strategy for research had to be changed. Thanks to applied contingency plan CMS and SKA with WUT assistance improved that technology path to estimated TRL 4. That allow to prospect that within next two years Partners will be able to obtain the photoresist thick upto 40 µm with requested homogeneity and flatness of composition. Also, the grey scale laser lithography process programing on the prototype laser device (formerly used for holography) promises for elimination of stitching effect. Finally, still not discussed in detail the thick galvanization process needs calibration.
To proceed with progress, CMS and WUT extensively are preparing the relevant applications for national funds.

The direct micromachining of ADV were upgraded thanks to the project, making it possible for them to reach submicron precisions: their mould making offering is now extended to higher quality optical structures (e.g. Fresnel components for the automotive and solar energy industry).

A range of dissemination and exploitation activities was put in place in order to encourage market penetration of the LSOE concept (see section 4.2).

Meetings with industries were organised to introduce the LSOE principle, showcase the first prototypes and seek their cooperation for mass-producing and/or commercialising the related products.
DAPP visited the premises of two Italian industries, TS-LAC (contact lens producer) and Divel Italia (producer of lenses for fashion glasses). The first was very interested in the technology and the project partners are now evaluating a cooperation for adapting the concept to contact lenses, which will require changing material and redesign of the optical surface, while the second was not interested.
SKA contacted Abbott Medical and HOYA, to setup a potential cooperation scheme; however in the case of such large enterprises the need to avoid IPR drainage has slow down the pace of the contact.

List of Websites:
The relevant website, where project data are available is www.lightswords.eu

final1-lightswords-s-and-tx.pdf