1 µm axial resolution polarisation sensitive OCT system delivered by GALAHAD project with a range of new OCT products

Ilminster, 17 February 2020

G&H announces that the EU GALAHAD project has now been completed. GALAHAD (Glaucoma – Advanced, LAbel-free High resolution Automated OCT Diagnostics; was funded by the European Union through its Horizon 2020 programme. Co-ordinated by G&H Torquay, the project brought together ten partners from across Europe with the common objective of developing hardware, software and know-how to improve the early screening of glaucoma.

UHR-PS-OCT device imaging a human volunteer.
UHR-PS-OCT device imaging a human volunteer.

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 fiber 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.
1 µm axial resolution images of a human volunteer taken with a GALAHAD PS OCT device. The scale bar shows a depth of 100 µm. The images are single circular scans (i.e. no averaging).
1 µm axial resolution images of a human volunteer taken with a GALAHAD PS OCT device. The scale bar shows a depth of 100 µm. The images are single circular scans (i.e. no averaging).

This document outlines the material available in the public domain. More detail may be found at the project website.  For further information, please contact Bruce Napier.

This project has received funding from Horizon 2020, the European Union’s Framework Programme for Research and Innovation, under grant agreement No. 732613.