Project Overview G laucoma – A dvanced, LA bel-free H igh resolution A utomated OCT D iagnostics GALAHAD Jul-2017 This project has received funding from the European Union's Horizon 2020 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Presentation outline • Project key facts • Motivation • Project objectives • Project technology • Photonic sources • Components and sub-systems • Automated algorithms • Demonstration • Summary This project has received funding from the European Union's Horizon 2020 Page 2 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Presentation outline • Project key facts • Motivation • Project objectives • Project technology • Photonic sources • Components and sub-systems • Automated algorithms • Demonstration • Summary This project has received funding from the European Union's Horizon 2020 Page 3 www.galahad-project.eu research and innovation programme under grant agreement 732613.
GALAHAD key facts • Horizon 2020 project funded by the European Union • ICT-29-2016: Photonics KET • Project No. 732613 • Budget: c. 4 M€ • Ten partners • 4 four industrial, 3 academic, 2 clinical, 1 management • Start date: 01-Dec-2016 • Duration: 36 months • Coordinator: Gooch & Housego (Torquay) • Project public website: www.galahad-project.eu This project has received funding from the European Union's Horizon 2020 Page 4 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Consortium Main role in project Partner Optical components and sub-systems for OCT [Coordinator] OCT systems integrator Supercontinuum sources Diffraction gratings and spectrometers Supercontinuum source design and simulation Algorithm development Data collection (new lab data) and analysis Data collection (existing patient data) and analysis Data collection (existing patient data) and analysis Project management and admin This project has received funding from the European Union's Horizon 2020 Page 5 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Presentation outline • Project key facts • Motivation • Project objectives • Project technology • Photonic sources • Components and sub-systems • Automated algorithms • Demonstration • Summary This project has received funding from the European Union's Horizon 2020 Page 6 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Motivation: potential for glaucoma screening • Glaucoma is the second leading cause of blindness globally (after cataracts) • Increased intra-ocular pressure • Slow onset and gradual degeneration • Irreversible damage to the optic nerve head • Universal screening could save 4M cases of blindness p.a. worldwide Vertical transfoveal OCT of an eye with epiretinal fibrosis • Cost-effective testing is not possible with existing Image courtesy of Rigshospitalet (Copenhagen) technology OCT • A candidate screening technology is optical coherence tomography • Offers non-contact label-free high-resolution retinal imaging BUT… technical developments are required for glaucoma screening This project has received funding from the European Union's Horizon 2020 Page 7 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Presentation outline • Project key facts • Motivation • Project objectives • Project technology • Photonic sources • Components and sub-systems • Automated algorithms • Demonstration • Summary This project has received funding from the European Union's Horizon 2020 Page 8 www.galahad-project.eu research and innovation programme under grant agreement 732613.
UHR-PS OCT • Ultra-high resolution (UHR-) OCT • Leading commercial systems achieve c. 3-5 µm axial resolution • Glaucoma screening requires an axial resolution of c. 1 µm � This requires broader bandwidth source and components • Polarisation sensitive (PS-) OCT • Can identify birefringent retinal features • These may improve glaucoma diagnosis � This requires polarisation maintaining (PM) components GALAHAD hardware objective To develop ultra-high resolution polarisation sensitive OCT This project has received funding from the European Union's Horizon 2020 Page 9 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Automated algorithms • Automated image analysis based on artificial intelligence • Could allow cost-effective glaucoma screening • Intelligent algorithms will be developed useable by non-experts • Automatically process and analyse OCT images • Identification of patients requiring closer expert examination GALAHAD software objective Automated algorithms to identify high risk patients from OCT images This project has received funding from the European Union's Horizon 2020 Page 10 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Presentation outline • Project key facts • Motivation • Project objectives • Project technology • Photonic sources • Components and sub-systems • Automated algorithms • Demonstration • Summary This project has received funding from the European Union's Horizon 2020 Page 11 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Supercontinuum sources • Pulsed fibre lasers are coupled with supercontinuum (SC) generating fibres • Allows fibre delivery of output spectrum • Broadband light from UV to near-IR • In GALAHAD, NKT will develop two different sources: 1. Low risk option 6 - To ensure project delivery Extreme Red - Randomly polarised, low noise, 5 P=500mW incoherent SC source 4 power [mW/nm] 2. High risk option 3 - New state-of-the-art source 2 - Linearly polarised, ultra-low noise, 1 coherent SC source 0 450 550 650 750 850 950 1050 1150 1250 1350 1450 1550 1650 1750 wavelength [nm] This project has received funding from the European Union's Horizon 2020 Page 12 www.galahad-project.eu research and innovation programme under grant agreement 732613.
SC sources (SCSs) competition • The resolution of an OCT system depends largely on the spectral bandwidth of the interrogating source • SCSs can comfortably provide sufficient optical power across the 600- 900 nm window suitable for ocular OCT • Other options: • Lamps: brightness is too low for OCT SLD* and ASE † sources have relatively narrow bandwidths • • Ti:sapphire lasers are large, expensive and not rugged enough • Swept sources mainly access the 1300 nm band • The noise level of the OCT source is a critical consideration in the GALAHAD project: • Ti:sapphire and the incoherent SCS can provide similar results • Coherent SCSs provide the lowest possible noise for any OCT technology. * Super Luminescent Diode † Amplified Spontaneous Emission This project has received funding from the European Union's Horizon 2020 Page 13 www.galahad-project.eu research and innovation programme under grant agreement 732613.
State-of-the-art SCSs The normally-pumped, linearly polarised, ultra-low noise, coherent SCS is the best available source for OCT. • New SCSs are pumped with all- normal dispersion fibre. • This produces temporally coherent pulses • Temporal coherence reduces shot- to-shot noise • Background noise of OCT measurement is reduced • Linearly polarised SCSs allow for polarisation sensitive OCT • New image information available Figure shows the strong birefringence of blebs. (a) Intensity OCT, (b) polarisation- on birefringent objects and features sensitive OCT, and (c) highly birefringent • Features (like “blebs”) can be regions from (b) overlaid on (a). observed This project has received funding from the European Union's Horizon 2020 Page 14 www.galahad-project.eu research and innovation programme under grant agreement 732613.
Femtosecond laser sources available at DTU Laser description Max. Pulse Rep rate/ Wavelength/ OCT viability Average length/ fs MHz nm power/ W Picosecond mode-locked laser 1 255 80 1036 Yes, but max SC band: 800- compressed with a hollow-core fiber 1300 nm Fianium femtosecond laser 5 170 80 1064 Yes (Commercially available) Max SC band 650-1450 nm Optical parametric amplifier 0.23 250 21 1064 No (bulky) Measured supercontinua from 1 m (red) and 9 m (black) fibre Bandwidth (black) from 950 nm at -10 dB w.r.t. 800 nm Calculated (dashed red) with 100 kW and 170 fs pumped at 1064 nm vs average power measured at the fiber output. Inset: Microscope image of the ANDi (all normal dispersion) fibre. Estimated average power (blue) from 650-950 nm. Pumping with 170 fs at 1064 nm. This project has received funding from the European Union's Horizon 2020 www.galahad-project.eu research and innovation programme under grant agreement 732613.
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