Full-Field-OCT, Holoskopie und numerische Rekonstruktion in kohärent-optischer Bildgebung

Unter dem Forschungsschwerpunkt Holoskopie und Full-Field-OCT arbeiten wir in der AG Hüttmann an der Parallelisierung von OCT-Aufnahmen - sogenannten Full-Field-Systemen. Im Gegensatz zu konventionellen, scannenden OCT-Systemen werden bei Volumenaufnahmen die Messobjekte nicht abgerastert, sondern flächig beleuchtet.

Durch die Parallelisierung werden bei ausreichender Messgeschwindigkeit phasenstarre volumetrische Aufnahmen ermöglicht. Hierdurch können viele Probleme, die in der konventionellen OCT mit aufwendigen Aufbauten gelöst werden, nun während der Datenrekonstruktion numerisch gelöst werden, zum Beispiel die Korrektur einer Defokussierung oder anderer Aberrationen.

Im Gegensatz zu scannenden Systemen gibt es bei der Detektion kein konfokales Gating und rückgestreutes Licht aus allen Tiefen wird detektiert. Außerhalb des Fokus werden die lateralen Informationen zwar unscharf dargestellt, können aber durch eine Wellenfeldpropagation numerisch fokussiert werden. Auch bei hohen Auflösungen ist so kein zusätzliches Abrastern über die Tiefe notwendig. So kann eine hochaufgelöste volumetrische Bildgebung in einem Bruchteil der üblichen Messzeit umgesetzt werden.

Eine hochaufgelöste Abbildung der Probe ist oft nicht möglich, da Aberrationen aus dem optischen Aufbau oder aus der Probe selbst die Bildqualität beträchtlich beeinflussen. Üblicherweise kann die Bildqualität nur durch eine technisch aufwendige Wellenfrontkorrektur wieder hergestellt werden. Durch die phasenstarre Detektion in der Holoskopie ist eine numerische Aberrationskorrektur möglich. Dies ist insbesondere in der ophthalmologischen Bildgebung ein großer Vorteil. Das menschliche Auge erzeugt von sich aus sehr starke Aberrationen, die von Person zu Person stark variieren. Mit Hilfe der numerischen Aberrationskorrektur konnten wir erstmal die Augenaberrationen so gut korrigieren, dass Volumenaufnahmen der Retina mit vollständig beugungsbegrenzter Auflösung möglich waren.

OCT-Aufnahme der Retina (Photorezeptoren) vor und nach einer numerischen Aberrationskorrektur.
OCT-Aufnahme der Retina (Kapillaren) vor und nach einer numerischen Aberrationskorrektur.

Publikationen

2018

  • Hendrik Spahr and Clara Pfäffle and Peter Koch and Helge Sudkamp and Gereon Hüttmann and Dierck Hillmann: Interferometric detection of 3D motion using computational subapertures in optical coherence tomography. Opt. Express, no. 26, pp. 18803-18816, OSA, Jul, 2018
    BibTeX Link Link
    @article{Spahr:18,
    author = {Hendrik Spahr, Clara Pfäffle, Peter Koch, Helge Sudkamp, Gereon Hüttmann und Dierck Hillmann},
    journal = {Opt. Express},
    keywords = {Funktion, Fullfield},
    number = {15},
    pages = {18803--18816},
    publisher = {OSA},
    title = {Interferometric detection of 3D motion using computational subapertures in optical coherence tomography},
    volume = {26},
    month = {Jul},
    year = {2018},
    url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-26-15-18803},
    doi = {10.1364/OE.26.018803},
    abstract = {Doppler optical coherence tomography (OCT) quantifies axial motion with high precision, whereas lateral motion cannot be detected by a mere evaluation of phase changes. This problem was solved by the introduction of three-beam Doppler OCT, which, however, entails a high experimental effort. Here, we present the numerical analogue to this experimental approach. Phase-stable complex-valued OCT datasets, recorded with full-field swept-source OCT, are filtered in the Fourier domain to limit imaging to different computational subapertures. These are used to calculate all three components of the motion vector with interferometric precision. As known from conventional Doppler OCT for axial motion only, the achievable accuracy exceeds the actual imaging resolution by orders of magnitude in all three dimensions. The feasibility of this method is first demonstrated by quantifying micro-rotation of a scattering sample. Subsequently, a potential application is explored by recording the 3D motion vector field of tissue during laser photocoagulation in ex-vivo porcine retina.},
    }
    
    

2017

  • Pfäffle, Clara and Spahr, Hendrik and Hillmann, Dierck and Sudkamp, Helge and Franke, Gesa and Koch, Peter and Hüttmann, Gereon: Reduction of frame rate in full-field swept-source optical coherence tomography by numerical motion correction [Invited]. Biomedical Optics Express, no. 8, pp. 1499-1511, 2017
    BibTeX Link
    @article{Pfäffle2017,
       author = {Pfäffle, Clara and Spahr, Hendrik and Hillmann, Dierck and Sudkamp, Helge and Franke, Gesa and Koch, Peter and Hüttmann, Gereon},
       title = {Reduction of frame rate in full-field swept-source optical coherence tomography by numerical motion correction [Invited]},
       journal = {Biomedical Optics Express},
       volume = {8},
       number = {3},
       pages = {1499-1511},
       keywords = {Image reconstruction-restoration
    Optical coherence tomography},
       url = {http://www.osapublishing.org/boe/abstract.cfm?URI=boe-8-3-1499},
       year = {2017},
       type = {Journal Article}
    }
    

2016

  • Sudkamp, Helge and Koch, Peter and Spahr, Hendrik and Hillmann, Dierck and Franke, Gesa and Münst, Michael and Reinholz, Fred and Birngruber, Reginald and Hüttmann, Gereon: In-vivo retinal imaging with off-axis full-field time-domain optical coherence tomography. Optics Letters, no. 41, pp. 4987-4990, 2016
    BibTeX Link
    @article{Sudkamp2016,
       author = {Sudkamp, Helge and Koch, Peter and Spahr, Hendrik and Hillmann, Dierck and Franke, Gesa and Münst, Michael and Reinholz, Fred and Birngruber, Reginald and Hüttmann, Gereon},
       title = {In-vivo retinal imaging with off-axis full-field time-domain optical coherence tomography},
       journal = {Optics Letters},
       volume = {41},
       number = {21},
       pages = {4987-4990},
       abstract = {With a simple setup, mainly composed of a low coherence light source and a camera, full-field optical coherence tomography (FF-OCT) allows volumetric tissue imaging. However, fringe washout constrains its use in retinal imaging. Here, we present a novel motion-insensitive approach to FF-OCT, which introduces path-length differences between the reference and the sample light in neighboring pixels using an off-axis reference beam. The temporal carrier frequency in scanned time-domain OCT is replaced by a spatial carrier frequency. Volumetric in-vivo FF-OCT measurements of the human retina were acquired in only 1.3 s, comparable to the acquisition times of current clinically used OCT devices.},
       keywords = {Imaging systems
    Coherence imaging
    Optical coherence tomography
    Frequency filtering
    Interferometric imaging},
    DOI = {10.1364/OL.41.004987}
     url= {https://www.osapublishing.org/ol/abstract.cfm?uri=ol-41-21-4987}  
       year = {2016},
       type = {Journal Article}
    }
    
  • Hillmann, Dierck and Spahr, Hendrik and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon: In vivo optical imaging of physiological responses to photostimulation in human photoreceptors. PNAS Early Edition, pp. 1-6, 2016
    BibTeX Link
    @article{Hillmann2016,
       author = {Hillmann, Dierck and Spahr, Hendrik and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon},
       title = {In vivo optical imaging of physiological responses to photostimulation in human photoreceptors},
       journal = {PNAS Early Edition},
       pages = {1-6},
       abstract = {Noninvasive functional imaging of molecular and cellular processes of vision may have immense impact on research and clinical diagnostics. Although suitable intrinsic optical signals (IOSs) have been observed ex vivo and in immobilized animals in vivo, detecting IOSs of photoreceptor activity in living humans was cumbersome and time consuming. Here, we observed clear spatially and temporally resolved changes in the optical path length of the photoreceptor outer segment as a response to an optical stimulus in the living human eye. To witness these changes, we evaluated phase data obtained with a parallelized and computationally aberration-corrected optical coherence tomography system. The noninvasive detection of optical path length changes shows neuronal photoreceptor activity of single cones in living human retina, and therefore, it may provide diagnostic options in ophthalmology and neurology and could provide insights into visual phototransduction in humans.},
       url = {http://www.pnas.org/content/early/2016/10/10/1606428113.abstract},
       year = {2016},
       type = {Journal Article}
    }
    
  • Spahr, H. and Hillmann, D. and Hain, C. and Pfäffle, C. and Sudkamp, H. and Franke, G. and Koch, P. and Hüttmann, G.: Darstellung von Blutfluss und Pulsation in retinalen Gefäßen mit Full-Field-Swept-Source-OCT. Klin Monatsbl Augenheilkd, no. 233, pp. 1324-1330, 2016
    BibTeX Link
    @article{Spahr2016,
       author = {Spahr, H. and Hillmann, D. and Hain, C. and Pfäffle, C. and Sudkamp, H. and Franke, G. and Koch, P. and Hüttmann, G.},
       title = {Darstellung von Blutfluss und Pulsation in retinalen Gefäßen mit Full-Field-Swept-Source-OCT},
       journal = {Klin Monatsbl Augenheilkd},
       volume = {233},
       number = {12},
       pages = {1324-1330},
       ISSN = {0023-2165},
       DOI = {10.1055/s-0042-120279},
       year = {2016},
       type = {Journal Article}
    }
    
  • Hillmann, Dierck and Spahr, Hendrik and Hain, Carola and Sudkamp, Helge and Franke, Gesa and Pfäffle, Clara and Winter, Christian and Hüttmann, Gereon: Aberration-free volumetric high-speed imaging of in vivo retina. Scientific Reports, no. 6, pp. 1-11, 2016
    BibTeX Link
    @article{Hillmann2016,
       author = {Hillmann, Dierck and Spahr, Hendrik and Hain, Carola and Sudkamp, Helge and Franke, Gesa and Pfäffle, Clara and Winter, Christian and Hüttmann, Gereon},
       title = {Aberration-free volumetric high-speed imaging of in vivo retina},
       journal = {Scientific Reports},
       volume = {6},
       pages = {1-11},
       url = {http://dx.doi.org/10.1038/srep35209},
       year = {2016},
       type = {Journal Article}
    }
    

2015

  • Spahr, Hendrik and Hillmann, Dierck and Hain, Carola and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon: Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography. Optics Letters, no. 40, pp. 4771-4774, 2015
    BibTeX Link Link
    @article{Spahr2015,
       author = {Spahr, Hendrik and Hillmann, Dierck and Hain, Carola and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon},
       title = {Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography},
       journal = {Optics Letters},
       volume = {40},
       number = {20},
       pages = {4771-4774},
       abstract = {We demonstrate a new noninvasive method to assess biomechanical properties of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used to investigate retinal vascular dynamics at unprecedented temporal resolution. The motion of retinal tissue that is induced by expansion of the vessels therein is measured with an accuracy of about 10 nm. The pulse shapes of arterial and venous pulsations, their temporal delays, as well as the frequency-dependent pulse propagation through the capillary bed, are determined. For the first time, imaging speed and motion sensitivity are sufficient for a direct measurement of pulse waves propagating with more than 600 mm/s in retinal vessels of a healthy young subject.},
       keywords = {Optical coherence tomography
    Ophthalmology
    Time-resolved imaging
    Functional monitoring and imaging},
       DOI = {10.1364/OL.40.004771},
       url = {http://ol.osa.org/abstract.cfm?URI=ol-40-20-4771},
       year = {2015},
       type = {Journal Article}
    }
    
  • Spahr, Hendrik and Hain, Carola and Sudkamp, Helge and Franke, Gesa and Hillmann, Dierck and Huttmann, Gereon: Functional Microangiography of in vivo human retina by Full-Field OCT. Investigative Ophthalmology & Visual Science, no. 56, pp. 5974-5974, 2015
    BibTeX Link
    @article{Spahr2015,
       author = {Spahr, Hendrik and Hain, Carola and Sudkamp, Helge and Franke, Gesa and Hillmann, Dierck and Huttmann, Gereon},
       title = {Functional Microangiography of in vivo human retina by Full-Field OCT},
       journal = {Investigative Ophthalmology & Visual Science},
       volume = {56},
       number = {7},
       pages = {5974-5974},
       abstract = { PurposeOCT based functional microangiography of the retina requires high speed acquisition of a large number of volumetric datasets. Imaging speed of conventional scanning OCT devices is limited by the applicable radiant power and the mechanics used to scan the focused beam over the desired field of view. Full-Field Swept-Source OCT (FF-SS-OCT) resolves both issues, using an areal illumination, which dramatically increases the allowed amount of radiation, and an ultrafast camera for a highly parallelized acquisition.  MethodsThe retina of healthy volunteers was illuminated with wavelengths between 816 and 867 nm by the extended beam of a tunable laser (Broadsweeper, Superlum). Retinal irradiance was below the maximum permissable exposure (MPE). Light backscattered from the retina was imaged onto an ultrafast CMOS camera (SA-Z, Photron), where it interfered with an extended reference beam. From a series of interference images at different wavelengths, volumetric OCT images of the retina were reconstructed.  ResultsWe demonstrate in vivo retinal imaging at 9.9 billion voxels per second (40 million A-scans/s with 256 axial pixels). Sacrificing depth resolution by reducing the number of axial pixels, the A-scan rate was increased to more than 1 billion A-scans per second. FF-SS-OCT allowed imaging of all important retinal structures with good quality at unprecedented imaging speed (see fig. 1). Fast volumetric imaging at up to 3000 volumes/s was used to visualize small capillaries and to analyze the pulsation of retinal arteries and veins (see fig. 2). Imaging time for an area of 4 mm x 2 mm (896 x 368 A-scans) was only 316 µs. The high volume rate and the inherent phase stability enabled quantitative measurement of the change of retinal thickness due to blood pulsation with approx. 10 nm precision. A delay of the venous pulsation with respect to the arteries was observed (approx. 11 ms). The amplitudes of higher frequency components of the venous pulsation were considerably attenuated.  ConclusionsFF-SS-OCT provides fast volumetric imaging of the retina with good image quality. The capillary network can be analyzed with high spatial and temporal resolution. Analysis of retinal pulsation may provide information on pathological changes of vessels and capillaries. Angiographic OCT acquired with the FF-SS-OCT setup. Functional angiography showing the pulsation of retinal artery and vein.},
       ISSN = {1552-5783},
       url = {http://dx.doi.org/},
       year = {2015},
       type = {Journal Article}
    }
    

2013

  • Franke, Gesa Lilith and Hillmann, Dierck and Lührs, Christian and Koch, Peter and Wollenzin, Jörn and Hüttmann, Gereon: Towards microscopic resolution in holoscopy. pp. 85711O-85711O, 2013
    BibTeX Link Link
    @article{Franke2013,
       author = {Franke, Gesa Lilith and Hillmann, Dierck and Lührs, Christian and Koch, Peter and Wollenzin, Jörn and Hüttmann, Gereon},
       title = {Towards microscopic resolution in holoscopy},
       pages = {85711O-85711O},
       note = {10.1117/12.2006806},
       abstract = {Holoscopy is a new imaging approach combining digital holography and full-field Fourier-domain optical coherence tomography. The interference pattern between light scattered by a sample and a defined reference wave is recorded and processed numerically. During reconstruction numerical refocusing is applied, overcoming the limitation of the focal depth and thus a uniform, diffraction limited lateral resolution over the whole measurement depth can be obtained. The advantage of numerical refocusing becomes especially significant for imaging at high numerical apertures (NAs). We use a high-resolution setup based on a Mach-Zehnder interferometer with an high-resolution microscope objective (NA = 0.75). For reliable reconstruction of a sample volume the Rayleigh length of the microscope objective and the axial resolution, given by the spectral range of the light source, need to be matched. For a 0.75 NA objective a tunable light source with a sweeping range of ! 300nm is required. Here we present as a first step a tunable Ti:sapphire laser with a tuning range of 187 nm. By characterizing the spectral properties of the Ti:sapphire laser and determining the axial point spread function we demonstrate the feasibility of this light source for high-resolution holoscopy.},
       DOI = {10.1117/12.2006806},
       url = {http://dx.doi.org/10.1117/12.2006806},
       year = {2013},
       type = {Journal Article}
    }
    
  • Hillmann, Dierck and Franke, Gesa and Hinkel, Laura and Bonin, Tim and Koch, Peter and Hüttmann, Gereon: Off-axis full-field swept-source optical coherence tomography using holographic refocusing. pp. 857104-857104, 2013
    BibTeX Link Link
    @article{Hillmann2013,
       author = {Hillmann, Dierck and Franke, Gesa and Hinkel, Laura and Bonin, Tim and Koch, Peter and Hüttmann, Gereon},
       title = {Off-axis full-field swept-source optical coherence tomography using holographic refocusing},
       pages = {857104-857104},
       note = {10.1117/12.2006436},
       abstract = {We demonstrate a full-field swept-source OCT using an off-axis geometry of the reference illumination. By using holographic refocusing techniques, a uniform lateral resolution is achieved over the measurement depth of approximately 80 Rayleigh lengths. Compared to a standard on-axis setup, artifacts and autocorrelation signals are suppressed and the measurement depth is doubled by resolving the complex conjugate ambiguity. Holographic refocusing was done efficiently by Fourier-domain resampling as demonstrated before in inverse scattering and holoscopy. It allowed to reconstruct a complete volume with about 10μm resolution over the complete measurement depth of more than 10mm. Off-axis full-field swept-source OCT enables high measurement depths, spanning many Rayleigh lengths with reduced artifacts.},
       DOI = {10.1117/12.2006436},
       url = {http://dx.doi.org/10.1117/12.2006436},
       year = {2013},
       type = {Journal Article}
    }
    

2012

  • Hillmann, Dierck and Franke, Gesa and Lührs, Christian and Koch, Peter and Hüttmann, Gereon: Efficient holoscopy image reconstruction. Opt. Express, no. 20, pp. 21247-21263, 2012
    BibTeX
    @article{Hillmann2012,
       author = {Hillmann, Dierck and Franke, Gesa and Lührs, Christian and Koch, Peter and Hüttmann, Gereon},
       title = {Efficient holoscopy image reconstruction},
       journal = {Opt. Express},
       volume = {20},
       number = {19},
       pages = {21247-21263},
       abstract = {Holoscopy is a tomographic imaging technique that combines digital holography and Fourier-domain optical coherence tomography (OCT) to gain tomograms with diffraction limited resolution and uniform sensitivity over several Rayleigh lengths. The lateral image information is calculated from the spatial interference pattern formed by light scattered from the sample and a reference beam. The depth information is obtained from the spectral dependence of the recorded digital holograms. Numerous digital holograms are acquired at different wavelengths and then reconstructed for a common plane in the sample. Afterwards standard Fourier-domain OCT signal processing achieves depth discrimination. Here we describe and demonstrate an optimized data reconstruction algorithm for holoscopy which is related to the inverse scattering reconstruction of wavelength-scanned full-field optical coherence tomography data. Instead of calculating a regularized pseudoinverse of the forward operator, the recorded optical fields are propagated back into the sample volume. In one processing step the high frequency components of the scattering potential are reconstructed on a non-equidistant grid in three-dimensional spatial frequency space. A Fourier transform yields an OCT equivalent image of the object structure. In contrast to the original holoscopy reconstruction with backpropagation and Fourier transform with respect to the wavenumber, the required processing time does neither depend on the confocal parameter nor on the depth of the volume. For an imaging NA of 0.14, the processing time was decreased by a factor of 15, at higher NA the gain in reconstruction speed may reach two orders of magnitude.},
       keywords = {Image processing
    Optical coherence tomography
    Digital holography},
       year = {2012}
    }
    

2011

  • Hillmann, D. and Luhrs, C. and Bonin, T. and Koch, P. and Huttmann, G.: Holoscopy-holographic optical coherence tomography. Opt Lett, no. 36, pp. 2390-2, 2011
    BibTeX Link Link
    @article{Hillmann2011,
       author = {Hillmann, D. and Luhrs, C. and Bonin, T. and Koch, P. and Huttmann, G.},
       title = {Holoscopy--holographic optical coherence tomography},
       journal = {Opt Lett},
       volume = {36},
       number = {13},
       pages = {2390-2},
       abstract = {Scanning optical coherence tomography (OCT) is limited in sensitivity and resolution by the restricted focal depth of the confocal detection scheme. Holoscopy, a combination of holography and Fourier-domain full-field OCT, is proposed as a way to detect photons from all depths of a sample volume simultaneously with uniform sensitivity and lateral resolution, even at high NAs. By using the scalar diffraction theory, as frequently applied in digital holographic imaging, we fully reconstruct the object field with depth-invariant imaging quality. In vivo imaging of human skin is demonstrated with an image quality comparable to conventionally scanned OCT.},
       keywords = {Fingers
    Fourier Analysis
    Holography/*methods
    Humans
    Photons
    Tomography, Optical Coherence/*methods},
       ISSN = {1539-4794 (Electronic)
    0146-9592 (Linking)},
       DOI = {10.1364/OL.36.002390},
       url = {http://www.ncbi.nlm.nih.gov/pubmed/21725421},
       year = {2011},
       type = {Journal Article}
    }
    

2010

  • Bonin, T. and Franke, G. and Hagen-Eggert, M. and Koch, P. and Huttmann, G.: In vivo Fourier-domain full-field OCT of the human retina with 1.5 million A-lines/s. Opt Lett. 2010 Oct 15;35(20):3432-4. doi: 10.1364/OL.35.003432., 2010
    BibTeX
    @book{Bonin2010,
       author = {Bonin, T. and Franke, G. and Hagen-Eggert, M. and Koch, P. and Huttmann, G.},
       title = {In vivo Fourier-domain full-field OCT of the human retina with 1.5 million A-lines/s},
       publisher = {Opt Lett. 2010 Oct 15;35(20):3432-4. doi: 10.1364/OL.35.003432.},
       abstract = {In vivo full-field (FF) optical coherence tomography (OCT) images of human retina are presented by using a rapidly tunable laser source in combination with an ultra-high-speed camera. Fourier-domain FF-OCT provided a way to increase the speed of retinal imaging by parallel acquisition of A-scans. Reduced contrast caused by cross talk was observed only below the retinal pigment epithelium. With a 100Hz sweep rate, FF-OCT was fast enough to acquire OCT images with acceptable motion artifacts. FF-OCT allows ultrafast retinal imaging, boosting image speed by a lack of moving parts and a considerably higher irradiation power.},
      year={2010}
    }

  • Bonin, Tim and Hagen-Eggert, Martin and Franke, Gesa and Koch, Peter and Huttmann, Gereon: Ultra highspeed in-vivo Fourier domain full-field OCT of the human retina. no. 7889, pp. 788906, SPIE,
    BibTeX
    @inproceedings{Bonin2011,
       author = {Bonin, Tim and Hagen-Eggert, Martin and Franke, Gesa and Koch, Peter and Huttmann, Gereon},
       title = {Ultra highspeed in-vivo Fourier domain full-field OCT of the human retina},
       editor = {James, G. Fujimoto and Joseph, A. Izatt and Valery, V. Tuchin},
       publisher = {SPIE},
       volume = {7889},
       pages = {788906},
    
    }
  • Spahr, Hendrik and Hillmann, Dierck and Hain, Carola and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon: Imaging vascular dynamics in human retina using full-field swept-source optical coherence tomography (Conference Presentation). no. 9697, pp. 96970E-96970E-1,
    BibTeX Link
    @inproceedings{Spahr2016,
       author = {Spahr, Hendrik and Hillmann, Dierck and Hain, Carola and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon},
       title = {Imaging vascular dynamics in human retina using full-field swept-source optical coherence tomography (Conference Presentation)},
       volume = {9697},
       pages = {96970E-96970E-1},
       note = {10.1117/12.2214303},
       abstract = {We demonstrate a new non-invasive method to assess the functional condition of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used to investigate retinal vascular dynamics at unprecedented temporal resolution. Motion of retinal tissue, that is induced by expansion of the vessels therein, is measured with an accuracy of about 10 nm. The pulse shape of arterial and venous pulsation, their temporal delay as well as the frequency dependent pulse propagation through the capillary bed are determined. For the first time, imaging speed and motion sensitivity are sufficient for a direct measurement of pulse waves propagating with more than 600 mm/s in retinal vessels of a healthy young subject.},
       url = {http://dx.doi.org/10.1117/12.2214303},
       type = {Conference Proceedings}
    }
    
  • Hillmann, Dierck and Luhrs, Christian and Bonin, Tim and Koch, Peter and Vogel, Alfred and Huttmann, Gereon: Holoscopy: holographic optical coherence tomography. no. 8091, pp. 80911H, Proc. SPIE,
    BibTeX Link
    @inproceedings{Hillmann2011,
       author = {Hillmann, Dierck and Luhrs, Christian  and Bonin, Tim  and Koch, Peter and Vogel, Alfred  and Huttmann, Gereon },
       title = {Holoscopy: holographic optical coherence tomography},
       editor = {Rainer, A. Leitgeb and Brett, E. Bouma},
       publisher = {Proc. SPIE},
       volume = {8091},
       pages = {80911H},
       url = {http://link.aip.org/link/?PSI/8091/80911H/1
    http://dx.doi.org/10.1117/12.889485},
       type = {Conference Proceedings}
    }
    
  • Franke, Gesa Lilith and Hillmann, Dierck and Claussen, Thorsten and Luhrs, Christian and Koch, Peter and Huttmann, Gereon: High resolution holoscopy. no. 8213, pp. 821324, SPIE,
    BibTeX
    @inproceedings{Franke2012,
       author = {Franke, Gesa Lilith and Hillmann, Dierck and Claussen, Thorsten and Luhrs, Christian and Koch, Peter and Huttmann, Gereon},
       title = {High resolution holoscopy},
       editor = {Joseph, A. Izatt and James, G. Fujimoto and Valery, V. Tuchin},
       publisher = {SPIE},
       volume = {8213},
       pages = {821324},
    
    }
  • Bonin, Tim and Koch, Peter and Huttmann, Gereon: Comparison of fast swept source full-field OCT with conventional scanning OCT. no. 8091, pp. 80911K, SPIE,
    BibTeX
    @inproceedings{Bonin2011,
       author = {Bonin, Tim and Koch, Peter and Huttmann, Gereon},
       title = {Comparison of fast swept source full-field OCT with conventional scanning OCT},
       editor = {Rainer, A. Leitgeb and Brett, E. Bouma},
       publisher = {SPIE},
       volume = {8091},
       pages = {80911K},
    
    }