Project title, ESR4: Supercontinuum generation in specific windows for versatile OCT investigations and spectroscopic OCT
Aiming towards broadening the usability of optical coherence tomography by adding functional information that can be crucial for medical diagnoses.
Current projects and research areas
- Ultra-wide optical coherence tomography in different wavelengths regions using a supercontinuum source
- Spectroscopic visible-light optical coherence tomography for oxygenation detection
- Different wavelength scanning laser ophthalmoscope (SLO) combined with adaptive optics for spectral analysis of samples
Motivation
To this date medical doctors try to improve their diagnosis for severe diseases using optical imaging technology, which can be further improved to give more precise results. Our aim is to help developing and improving existing imaging modalities such as optical coherence tomography or scanning laser ophthalmoscope and provide additional, functional information, which will enable the medical staff to diagnose diseases with a higher accuracy.
Many eye diseases can be related to the oxygenation of the back of the eye, by improving the possibility in measuring the oxygen saturation many diseases can be diagnosed earlier and damage can be prevented. This will improve the patient’s life and reduce causes of blindness.
Professional Experience
2016 – present
Canterbury, UK
University of Kent
Researcher / PhD student
Accomplishment
- Integrating a supercontinuum source in an adaptive optics SLO set-up for different wavelength SLO imaging
2014 – 2016
Birkerød, Denmark
NKT Photonics A/S
Researcher / PhD student
Accomplishment
- Optical coherence tomography combined with supercontinuum source in different wavelength regions
- Spectroscopic optical coherence tomography in near infrared and visible wavelength
Education
2011 – 2014
University of Lübeck, Germany
Masters of Science in Biomedical / Medical Engineering
With focus on: Laser physics and optics
2008 – 2011
University of applied Sciences Bremerhaven, Germany
Bachelor of Engineering in Medical Engineering
With focus on: Computational sciences
PublicationsList of publications
- Demonstration of visible light swept-source for high resolution spectroscopic optical coherence microscopy with complex Master-Slave interferometry
- Status: In progress
- Authors: Felix Fleischhauer, Thomas Feuchter, Frederik Nielsen, Adrian Bradu, Lasse Leick, Peter Moselund and Adrian Podoleanu
- Journal: To be submitted to the Journal of Optics
List of peer review conferences:
- Danish Optical Society annual meeting 2014, Organiser: Danish Optical Society, Venue: DTU Risø, 13 – 14. November 2014, Website: http://dops.dk/
- Status: Accepted
- Title: Optical coherence microscopy with extended depth of focus
- Authors: Felix Fleischhauer, Hinnerk Schulz-Hildebrand and Gereon Hüttmann
- Abstract: The increase of lateral resolution leads to a decreased imaging depth, which destroys the benefit of Spectral domain OCT of measuring all depth information at once compared to Time-domain OCT. By using an axicon lens or a ring illumination the imaging depth can be increased by obtaining high lateral resolution.
- Danish Opening Ceremony of the International Year of Light, Organiser: Danish Physics Society, Venue: DTU Lyngby, 22 – 23 January 2015, Final report web page http://unesdoc.unesco.org/images/0024/002460/246088e.pdf
- Status: Accepted
- Title: Optical coherence microscopy with extended depth of focus
- Authors: Felix Fleischhauer, Hinnerk Schulz-Hildebrand and Gereon Hüttmann
- Abstract: The increase of lateral resolution leads to a decreased imaging depth, which destroys the benefit of Spectral domain OCT of measuring all depth information at once compared to Time-domain OCT. By using an axicon lens or a ring illumination the imaging depth can be increased by obtaining high lateral resolution.
- Biophotonics 15 Summer school abstract,
- Status: Accepted Organiser: DTU and Lund university, Venue: Backafallsbyn on the Island of Ven, 06 – 13 June 2015, Website: http://www.biop.dk/
- Title: Spectroscopic optical coherence tomography in combination with a broadband supercontinuum light source
- Authors: Felix Fleischhauer, Thomas Feuchter, Lasse Leick and Adrian Gh. Podoleanu
- Abstract: Spectroscopic OCT is a tool to add additional information about tissue properties, such as absorption to conventional OCT data. By using the spectral information the image contrast can be enhanced or functional information about concentration can be added to the depth information. The broadband supercontinuum light source is a promising light source for spectroscopic OCT because it covers a wide range of absorption lines of dyes and chromophores.
- Danish Optical Society annual meeting 2015, Organiser: Danish Optical society, Venue: Odense university, 19 – 20. November 2015, Website: http://dops.dk/
- Status: Accepted
- Prize: Best poster award
- Title: Spectroscopic low coherence interferometry using a supercontinuum source and an ultra broadband spectrometer
- Authors: Felix Fleischhauer, Sophie Caujolle, Thomas Feuchter, Ranjan Rajendram, Lasse Leick and Adrian Gh. Podoleanu
- Abstract: The need for functional imaging in medicine is one of the biggest needs from clinicians in the last years. Optical coherence tomography (OCT) is a relatively new optical imaging technique, which uses interferometry for non-contact, non-invasive and non-toxic measuring of depth information [1]. Spectroscopic optical coherence tomography (SOCT) combines the imaging capability of OCT with spectroscopic absorption information [1, 2]. Recent papers have shown the usefulness of SOCT in the visible wavelength range for oxygen saturation estimation in the eye [3, 4, and 5]. We demonstrate a SOCT system working in the visible spectral range from 490 to 730 nm by combining a supercontinuum light source, a Linnik interferometer and a commercial available broadband spectrometer. This wavelength range is chosen because it covers a range of useful absorbers, including that of human proteins. SOCT requires a large bandwidth combined with a broadband spectrometer, due to the fact that reconstruction of SOCT data requires dividing the measured spectrum in spectral bands. The number of bands determines the spectral resolution, while the axial resolution depends on the spectral width of each window. A supercontinuum source with its broad spectrum allows a sufficient number of windows combined with a reasonable axial resolution. The system is tested with a laser dye rhodamine B for calibration and verification. Rhodamine B is dissolved in ethanol in a cuvette and placed in one of the interferometer arms. It has an absorption peak at around 542 nm, which resembles the absorption spectrum of several proteins in the globin group. The results show that the absorption spectrum of rhodamine B can be reconstructed and show varying spectroscopic information retrieved from different concentration.
5. Photonics West 2016
- Status: Published, SPIE Proceedings Vol. 9697, Website: http://spie.org/Publications/Proceedings/Paper/10.1117/12.2214691, DOI: 1117/12.2214691
- Title: Spectroscopic low coherence interferometry using a supercontinuum source and an ultra broadband spectrometer
- Authors: Felix Fleischhauer, Sophie Caujolle, Thomas Feuchter, Lasse Leick, Ranjan Rajendram and Adrian Gh. Podoleanu
- Abstract: Spectroscopic optical coherence tomography (SOCT) combines the imaging capability of OCT with spectroscopic absorption information. We demonstrate a SOCT system working in the visible spectral range from 510 to 730 nm by combining a supercontinuum light source, a Linnik interferometer and a commercial available broadband spectrometer. This wavelength range is chosen because it covers a range of useful absorbers, including that of human proteins. SOCT requires a large bandwidth combined with a broadband spectrometer, due to the fact that reconstruction of SOCT data requires dividing the measured spectrum in spectral bands. The number of bands determines the spectral resolution, while the axial resolution depends on the spectral width of each window. A supercontinuum source with its broad spectrum allows a sufficient number of windows combined with a reasonable axial resolution. The system is tested with a laser dye rhodamine B for calibration and verification. Rhodamine B is dissolved in ethanol in a cuvette and placed in one of the interferometer arms. It has an absorption peak at around 560 nm, which resembles the absorption spectrum of several proteins in the globin group. The results show that the absorption spectrum of rhodamine B can be reconstructed and show varying spectroscopic information retrieved from different concentration.
6. ARVO
Status: Presented by co-author, Investigative Ophthalmology & Visual Science September 2016, Vol.57, 472, Website: http://iovs.arvojournals.org/article.aspx?articleid=2557797&resultClick=1 DOI: not available;
Title: Localized absorption measurements for possible oxygen saturation using visible-light spectroscopic optical coherence tomography
Authors: Ranjan Rajendram, Felix Fleischhauer, Sophie Caujolle, Michael Maria, Thomas Feuchter, Lasse Leick and Adrian Gh. Podoleanu
Abstract: Spectroscopic optical coherence tomography (SOCT) combines the imaging of optical coherence tomography (OCT) with localized absorption information, which are used as functional information. By covering the wavelength range from 490 to 730 nm a powerful tool to measure localized (de-)oxygenated haemoglobin for oxygen saturation estimation, which can be used in several applications, such as retinal venous and arteriolar occlusions, diabetic retinopathy, glaucoma or assessment of central venous and arteriolar oxygen saturation is being developed. We can show that using SOCT can be used to find the absorption maximum of Rhodamine B and the signal degrades with thinner solutions.
7. Impact of absorption in the top layer of a two layer sample on spectroscopic spectral domain interferometry of the bottom layer
Status: Proc. SPIE 10591, 2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources, 105910H (5 March 2018), 6-8 Sept 2017; doi: 10.1117/12.2281928; https://doi.org/10.1117/12.2281928
Authors: Felix Fleischhauer, Thomas Feuchter, Ranjan Rajendram and Adrian Podoleanu
Abstract: Spectroscopic spectral domain interferometry and spectroscopic optical coherence tomography combine depth information with spectrally-resolved localised absorption data. These additional data can improve diagnostics by giving access to functional information of the investigated sample. One possible application is measuring oxygenation levels at the retina for earlier detection of several eye diseases.
Here measurements with different hollow glass tube phantoms are shown to measure the impact of a superficial absorbing layer on the precision of reconstructed attenuation spectra of a deeper layer.
Measurements show that a superficial absorber has no impact on the reconstructed absorption spectrum of the deeper absorber. Even when diluting the concentration of the deeper absorber so far that an incorrect absorption maximum is obtained, still no influence of the superficially placed absorber is identified.
List of further attended conferences
- Marie Skłodowska-Curie Action ESOF Satellite conference,
- Title: UBAPHODESA – Ultrawide Bandwidth Photonics Devices, Sources and Applications
- Authors: Magalie Bondu, Sophie Caujolle, Felix Fleischhauer, Michael Maria, Lasse Leick, Thomas Feuchter and Adrian Podoleanu
- Postgraduate Festival, 05.2017
- Organiser: University of Kent, Venue: SPS
- Presentation: Poster
- Title: Visible light spectroscopic low coherence interferometry using a supercontinuum source
- Authors: Felix Fleischhauer, Thomas Feuchter, Lasse Leick, Ranjan Rajendram and Adrian Podoleanu
- Abstract: Spectroscopic low coherence and spectroscopic optical coherence tomography are combining depth information with spectrally-resolved localized absorption data. These additional data can improve diagnostic by giving access to functional information of the investigated tissue. One possible application is measuring oxygenation levels at the retina for earlier detection of several severe eye diseases, such as diabetic retinopathy and glaucoma, which are under the main causes of blindness and visual loss in the world.
- Maximise Your Research Impact
- Organiser: University of Kent, Venue: Woolf college, Website: https://www.kent.ac.uk/campusonline/news.html?view=8182, Date: 17 May 2017
- Presentation: Poster
- Title: Visible light spectroscopic low coherence interferometry using a supercontinuum source
- Authors: Felix Fleischhauer, Thomas Feuchter, Lasse Leick, Ranjan Rajendram and Adrian Podoleanu
- Abstract: Spectroscopic low coherence and spectroscopic optical coherence tomography are combining depth information with spectrally-resolved localized absorption data. These additional data can improve diagnostic by giving access to functional information of the investigated tissue. One possible application is measuring oxygenation levels at the retina for earlier detection of several severe eye diseases, such as diabetic retinopathy and glaucoma, which are under the main causes of blindness and visual loss in the world.