GALAHAD finished on schedule at the end of November 2019. Over the last 36 months the project has had a major impact on the development of ultra-high resolution polarisation sensitive optical coherence tomography (UHR-PS-OCT), from advances in components to automated algorithms to process the results. GALAHAD has been very successful in developing components, sub-systems, operational systems (1 µm axial resolution), processes and software related to OCT and has achieved some important results in applying them to glaucoma screening. The key advances include:
Hardware for UHR-PS-OCT
-Components (already available as products from G&H)
-G&H has set the new state-of-the-art in both SM and PM broadband fused fibre components and has a wide range of new products already on the market
-PM and SM collimators
-SM and PM delay lines
-Motorised polarization controller
-Variable dispersion compensator
-Sources (products planned to be released in 2020 by NKT)
-NKT Photonics has developed the first polarised supercontinuum source with a long lifetime and robust polarisation extinction ratio (>25 dB PER for >2200 h successful operation)
-Technical University of Denmark (DTU) made fundamental advances in the understanding of noise processes in supercontinuum sources
-Spectrometers (customized products available from Ibsen Photonics)
-Ibsen has improved its technology from the large area etch process for its gratings to improved thermal stability for its spectrometers
Software for UHR-PS-OCT
-DTU developed numerical all-depth OCT dispersion compensation software
-Universitat Politècnica de València (UPV) developed algorithms which set the new state-of-the-art in several areas:
-Retinal layer segmentation algorithms for in vivo and ex vivo rodent OCT images
-Computer-aided diagnosis algorithms for glaucoma from human OCT images
-Epidermis and hair follicle segmentation algorithms for human skin OCT images
-Gloucestershire Hospitals NHS Foundation Trust has made available a large anonymised human glaucoma OCT database
-Standards for UHR-PS-OCT
-University of Münster (WWU) delivered permanent tissue-like test standards for UHR-PS-OCT testing
-WWU reported the first measurement of retinal refractive index as a function of wavelength
-Systems for UHR-PS-OCT
-Optos assembled two final systems which were characterised with axial resolutions of 1.25 µm (GALAHAD-1) and 1.39 µm (GALAHAD-2)
-Preliminary observations with the GALAHAD UHR-PS-OCT systems
->150 OCT measurements from various glaucoma models were performed
-GALAHAD standard mouse retina models at WWU
-Standard test targets and in vivo rodent retina models at the Rigshospitalet, Copenhagen
-Thanks to excellent progress and efforts at Optos, it was possible to demonstrate the systems on a human volunteer
-This work has already contributed to analytical procedures for the refined analysis prediction of visual field characteristics by Rigshospitalet
-Demonstration of GALAHAD UHR-PS-OCT system
-This live demonstration, on a human volunteer, formed part of the workshop on 8 January 2020 to an audience of researchers and clinicians
-This went significantly beyond the planned project scope and was a highly satisfactory conclusion to the project.
More detail may be found at the project website:
https://galahad-project.eu(s’ouvre dans une nouvelle fenêtre)
