Optical cohrence tomography (OCT)

Application and development of ultrafast MHz OCT systems

OCT is a noninvasive Imaging modality which is typically used for high resolution (~10µm), three dimensional imaging of scattering tissue. By using home built FDML laser technology we achieve imaging speeds of several million depth scans per second, which is one to two orders of magnitude higher than current commercially available systems (MHz-OCT).

These high imaging speeds already proved to be very useful in clinical applications, by reducing acquisition times and therefore reducing motion artifacts. But the high speed also gives access to the phase of the detected light and will thus allow the use of new numerical approaches for image quality enhancement and functional imaging with Swept-Source-OCT.

Our working group is conducting research in the field of OCT to develop new technologies and to identify possible fields of application.

The focus areas are:

  • MHz-OCT - Ultra-fast OCT imaging with several million depth scans per second
  • LARA-OCT - Large area robotically assisted OCT
  • VR-OCT - Real-time computation and rendering of entire OCT volumes in a virtual environment
  • Eye OCT - application of MHz-OCT to the eye for visualization of the retina or the anterior segment of the eye
  • Phase sensitive OCT - enhancement of the information content of an OCT image by adding phase contrast
  • Multispectral OCT - combination of RGB and OCT images for improved visualization of morphological structures

related Publications

2018

Hinnerk Schulz-Hildebrandt, Tom Pfeiffer, Tim Eixmann, Sabrina Lohmann, Martin Ahrens, Josua Rehra, Wolfgang Draxinger, Peter König, Robert Huber, and Gereon Hüttmann,
High-speed fiber scanning endoscope for volumetric multi-megahertz optical coherence tomography, Opt. Lett. , vol. 43, no. 18, pp. 4386-4389, Sep. 2018. Optica Publishing Group.
DOI:10.1364/OL.43.004386
Bibtex: BibTeX
@article{Schulz-Hildebrandt:18,
author = {Hinnerk Schulz-Hildebrandt and Tom Pfeiffer and Tim Eixmann and Sabrina Lohmann and Martin Ahrens and Joshua Rehra and Wolfgang Draxinger and Peter K\"{o}nig and Robert Huber and Gereon H\"{u}ttmann},
journal = {Opt. Lett.},
keywords = {Fiber optics imaging; Endoscopic imaging; Medical and biological imaging; Optical coherence tomography; Fourier domain mode locking; Image quality; Optical coherence tomography; Single mode fibers; Step index fibers; Three dimensional imaging},
number = {18},
pages = {4386--4389},
publisher = {Optica Publishing Group},
title = {High-speed fiber scanning endoscope for volumetric multi-megahertz optical coherence tomography},
volume = {43},
month = {Sep},
year = {2018},
url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-43-18-4386},
doi = {10.1364/OL.43.004386},
abstract = {We present a forward-viewing fiber scanning endoscope (FSE) for high-speed volumetric optical coherence tomography (OCT). The reduction in size of the probe was achieved by substituting the focusing optics by an all-fiber-based imaging system which consists of a combination of scanning single-mode fibers, a glass spacer, made from a step-index multi-mode fiber, and a gradient-index fiber. A lateral resolution of 11 $\mu$m was achieved at a working distance of 1.2 mm. The newly designed piezo-based FSE has an outer diameter of 1.6 mm and a rigid length of 13.5 mm. By moving the whole imaging optic in spirals for scanning the sample, the beam quality remains constant over the entire field of view with a diameter of 0.8 mm. The scanning frequency was adjusted to 1.22 kHz for use with a 3.28 MHz Fourier domain mode locked OCT system. Densely sampled volumes have been imaged at a rate of 6 volumes per second.},
}
Jan Philip Kolb, Tom Pfeiffer, Matthias Eibl, Hubertus Hakert, and Robert Huber,
High-resolution retinal swept source optical coherence tomography with an ultra-wideband Fourier-domain mode-locked laser at MHz A-scan rates, Biomed. Opt. Express , vol. 9, no. 1, pp. 120-130, Jan. 2018. Optica Publishing Group.
DOI:10.1364/BOE.9.000120
Bibtex: BibTeX
@article{Kolb:18,
author = {Jan Philip Kolb and Tom Pfeiffer and Matthias Eibl and Hubertus Hakert and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Medical optics instrumentation; Lasers, fiber; Medical and biological imaging; Ophthalmic optics and devices ; Optical coherence tomography; Adaptive optics; Image quality; In vivo imaging; Mode locking; Ophthalmic imaging; Three dimensional imaging},
number = {1},
pages = {120--130},
publisher = {Optica Publishing Group},
title = {High-resolution retinal swept source optical coherence tomography with an ultra-wideband Fourier-domain mode-locked laser at MHz A-scan rates},
volume = {9},
month = {Jan},
year = {2018},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-9-1-120},
doi = {10.1364/BOE.9.000120},
abstract = {We present a new 1060 nm Fourier domain mode locked laser (FDML laser) with a record 143 nm sweep bandwidth at 2\&\#x2219;\&\#x202F;417 kHz\&\#x202F; $=$ \&\#x202F;834 kHz and 120 nm at 1.67 MHz, respectively. We show that not only the bandwidth alone, but also the shape of the spectrum is critical for the resulting axial resolution, because of the specific wavelength-dependent absorption of the vitreous. The theoretical limit of our setup lies at 5.9 \&\#x00B5;m axial resolution. In vivo MHz-OCT imaging of human retina is performed and the image quality is compared to the previous results acquired with 70 nm sweep range, as well as to existing spectral domain OCT data with 2.1 \&\#x00B5;m axial resolution from literature. We identify benefits of the higher resolution, for example the improved visualization of small blood vessels in the retina besides several others.},
}

2017

Tianshi Wang, Tom Pfeiffer, Min Wu, Wolfgang Wieser, Gaetano Amenta, Wolfgang Draxinger, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Thermo-elastic optical coherence tomography, Optica Publishing Group, Sep.2017. pp. 3466-3469.
DOI:10.1364/OL.42.003466
Bibtex: BibTeX
@article{Wang:17,
author = {Tianshi Wang and Tom Pfeiffer and Min Wu and Wolfgang Wieser and Gaetano Amenta and Wolfgang Draxinger and Antonius F. W. van der Steen and Robert Huber and Gijs van Soest},
journal = {Opt. Lett.},
keywords = {Imaging systems; Medical and biological imaging; Optical coherence tomography; Lasers, pulsed ; Fourier domain mode locking; Functional imaging; Laser beams; Nanosecond pulses; Optical coherence tomography; Phantom studies},
number = {17},
pages = {3466--3469},
publisher = {Optica Publishing Group},
title = {Thermo-elastic optical coherence tomography},
volume = {42},
month = {Sep},
year = {2017},
url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-42-17-3466},
doi = {10.1364/OL.42.003466},
abstract = {The absorption of nanosecond laser pulses induces rapid thermo-elastic deformation in tissue. A sub-micrometer scale displacement occurs within a few microseconds after the pulse arrival. In this Letter, we investigate the laser-induced thermo-elastic deformation using a 1.5 MHz phase-sensitive optical coherence tomography (OCT) system. A displacement image can be reconstructed, which enables a new modality of phase-sensitive OCT, called thermo-elastic OCT. An analysis of the results shows that the optical absorption is a dominating factor for the displacement. Thermo-elastic OCT is capable of visualizing inclusions that do not appear on the structural OCT image, providing additional tissue type information.},
}
Jan Philip Kolb, Julian Klee, Tom Pfeiffer, and Robert Huber,
1060nm FDML laser with centimeter coherence length and 1.67 MHz sweep rate for full eye length and retinal ultra-widefield OCT, in Optical Coherence Imaging Techniques and Imaging in Scattering Media II , Maciej Wojtkowski and Stephen A. Boppart and Wang-Yuhl Oh, Eds. SPIE, Aug.2017. pp. 104160J.
DOI:10.1117/12.2286854
Bibtex: BibTeX
@inproceedings{10.1117/12.2286854,
author = {Jan Philip Kolb and Julian Klee and Tom Pfeiffer and Robert Huber},
title = {{1060nm FDML laser with centimeter coherence length and 1.67 MHz sweep rate for full eye length and retinal ultra-widefield OCT}},
volume = {10416},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media II},
editor = {Maciej Wojtkowski and Stephen A. Boppart and Wang-Yuhl Oh},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {104160J},
abstract = {We present a new design of a 1060nm Fourier Domain Mode Locked-Laser (FDML-Laser) that combines 1.67 MHz A-scan rate with a centimeter scale coherence length. The extended coherence length is achieved by synchronizing the cavity roundtrip time over the 75 nm sweep with a relative accuracy of 10<sup>-7</sup>. We will show that this requires careful combination of multiple fiber types in the cavity with a gradient heated chirped Fiber Bragg grating.},
keywords = {optical coherence tomograhy, OCT, tunable laser, Fourier domain mode locking, FDML, MHz OCT},
year = {2017},
doi = {10.1117/12.2286854},
URL = {https://doi.org/10.1117/12.2286854}
}
Tom Pfeiffer, Wolfgang Draxinger, Christin Grill, and Robert Huber,
Long-range live 3D-OCT at different spectral zoom levels, in Optical Coherence Imaging Techniques and Imaging in Scattering Media II , Maciej Wojtkowski and Stephen A. Boppart and Wang-Yuhl Oh, Eds. SPIE, Aug.2017. pp. 104160L.
DOI:10.1117/12.2287484
Bibtex: BibTeX
@inproceedings{10.1117/12.2287484,
author = {Tom Pfeiffer and Wolfgang Draxinger and Christin Grill and Robert Huber},
title = {{Long-range live 3D-OCT at different spectral zoom levels}},
volume = {10416},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media II},
editor = {Maciej Wojtkowski and Stephen A. Boppart and Wang-Yuhl Oh},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {104160L},
abstract = {We demonstrate that the 3.2 MHz a-scan rate and the improved coherence of our new low noise FDML laser enables live 3D-OCT with different spectral zooms and up to 10 cm of imaging range.},
keywords = {Optical coherence tomography, Fourier Domain Mode Locking, FDML, OCT},
year = {2017},
doi = {10.1117/12.2287484},
URL = {https://doi.org/10.1117/12.2287484}
}
Josef Maertz, Kathrin J. Mohler, Jan Philip Kolb, Thomas Klein, Aljoscha Neubauer, Anselm Kampik, Siegfried Priglinger, Wolfgang Wieser, Robert Huber, and Armin Wolf,
INTRAPAPILLARY PROLIFERATION IN OPTIC DISK PITS: Clinical Findings and Time-Related Changes, Retina , vol. 37, no. 5, pp. 906-914, May 2017.
DOI:10.1097/iae.0000000000001260
Bibtex: BibTeX
@article{Maertz2017,
   author = {Maertz, J. and Mohler, K. J. and Kolb, J. P. and Klein, T. and Neubauer, A. and Kampik, A. and Priglinger, S. and Wieser, W. and Huber, R. and Wolf, A.},
   title = {INTRAPAPILLARY PROLIFERATION IN OPTIC DISK PITS: Clinical Findings and Time-Related Changes},
   journal = {Retina},
   volume = {37},
   number = {5},
   pages = {906-914},
   DOI = {10.1097/iae.0000000000001260},
   year = {2017},
keywords = {AG-Huber_OCT},
   type = {Journal Article}
}
Max-Heinrich Laves, Andreas Schoob, Lüder A. Kahrs, Tom Pfeiffer, Robert Huber, and Tobias Ortmaier,
Feature tracking for automated volume of interest stabilization on 4D-OCT images, in Medical Imaging 2017: Image-Guided Procedures, Robotic Interventions, and Modeling , Robert J. Webster III and Baowei Fei, Eds. SPIE, Mar.2017. pp. 101350W.
DOI:10.1117/12.2255090
Bibtex: BibTeX
@inproceedings{10.1117/12.2255090,
author = {Max-Heinrich Laves and Andreas Schoob and L{\"u}der A. Kahrs and Tom Pfeiffer and Robert Huber and Tobias Ortmaier},
title = {{Feature tracking for automated volume of interest stabilization on 4D-OCT images}},
volume = {10135},
booktitle = {Medical Imaging 2017: Image-Guided Procedures, Robotic Interventions, and Modeling},
editor = {Robert J. Webster III and Baowei Fei},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {101350W},
abstract = {A common representation of volumetric medical image data is the triplanar view (TV), in which the surgeon manually selects slices showing the anatomical structure of interest. In addition to common medical imaging such as MRI or computed tomography, recent advances in the field of optical coherence tomography (OCT) have enabled live processing and volumetric rendering of four-dimensional images of the human body. Due to the region of interest undergoing motion, it is challenging for the surgeon to simultaneously keep track of an object by continuously adjusting the TV to desired slices. To select these slices in subsequent frames automatically, it is necessary to track movements of the volume of interest (VOI). This has not been addressed with respect to 4DOCT images yet. Therefore, this paper evaluates motion tracking by applying state-of-the-art tracking schemes on maximum intensity projections (MIP) of 4D-OCT images. Estimated VOI location is used to conveniently show corresponding slices and to improve the MIPs by calculating thin-slab MIPs. Tracking performances are evaluated on an in-vivo sequence of human skin, captured at 26 volumes per second. Among investigated tracking schemes, our recently presented tracking scheme for soft tissue motion provides highest accuracy with an error of under 2.2 voxels for the first 80 volumes. Object tracking on 4D-OCT images enables its use for sub-epithelial tracking of microvessels for image-guidance.},
keywords = {4D imaging, maximum intensity projection, optical coherence tomography, feature tracking},
year = {2017},
doi = {10.1117/12.2255090},
URL = {https://doi.org/10.1117/12.2255090}
}
Tianshi Wang, Tom Pfeiffer, Min Wu, Wolfgang Wieser, Wolfgang Draxinger, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Short pulse laser induced thermo-elastic deformation imaging, in Optical Interactions with Tissue and Cells XXVIII , E. Duco Jansen and Hope Thomas Beier, Eds. SPIE, Feb.2017. pp. 100620C.
DOI:10.1117/12.2251502
Bibtex: BibTeX
@inproceedings{10.1117/12.2251502,
author = {Tianshi Wang and Tom Pfeiffer and Min Wu and Wolfgang Wieser and Wolfgang Draxinger and Antonius F. W. van der Steen and Robert Huber and Gijs van Soest},
title = {{Short pulse laser induced thermo-elastic deformation imaging}},
volume = {10062},
booktitle = {Optical Interactions with Tissue and Cells XXVIII},
editor = {E. Duco Jansen and Hope Thomas Beier},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {100620C},
abstract = {Absorption of nanosecond laser pulses induces rapid thermo-elastic deformation in tissue, i.e. a sub-micrometer scale displacement happens within a couple of microseconds. In this study, we initially investigate the depth-resolved deformation using a 1.5 MHz phase-sensitive optical coherence tomography (OCT) system. Functional images can be reconstructed based on the detected deformation, which enables a new imaging modality called thermo-elastic deformation imaging (TDI). Our results show that the associated displacement is related to the optical absorption of the short laser pulses. The TDI images can provide tissue type information in addition to the conventional OCT images.},
keywords = {thermal-elastic deformation, optical coherence tomography},
year = {2017},
doi = {10.1117/12.2251502},
URL = {https://doi.org/10.1117/12.2251502}
}
Thomas Klein, and Robert Huber,
High-speed OCT light sources and systems [Invited], Biomed. Opt. Express , vol. 8, no. 2, pp. 828-859, Feb. 2017. Optica Publishing Group.
DOI:10.1364/BOE.8.000828
Bibtex: BibTeX
@article{Klein:17,
author = {Thomas Klein and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Imaging systems; Optical coherence tomography; Lasers and laser optics; Lasers, tunable; Optical coherence tomography; Full field optical coherence tomography; High speed imaging; Image quality; Imaging systems; Light wavelength; X ray imaging},
number = {2},
pages = {828--859},
publisher = {Optica Publishing Group},
title = {High-speed OCT light sources and systems \[Invited\]},
volume = {8},
month = {Feb},
year = {2017},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-8-2-828},
doi = {10.1364/BOE.8.000828},
abstract = {Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.},
}
Tom Pfeiffer, Wolfgang Draxinger, Wolfgang Wieser, Thomas Klein, Markus Petermann, and Robert Huber,
Analysis of FDML lasers with meter range coherence, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXI , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 2017. pp. 100531T.
DOI:10.1117/12.2254792
Bibtex: BibTeX
@inproceedings{10.1117/12.2254792,
author = {Tom Pfeiffer and Wolfgang Draxinger and Wolfgang Wieser and Thomas Klein and Markus Petermann and Robert Huber},
title = {{Analysis of FDML lasers with meter range coherence}},
volume = {10053},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXI},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {100531T},
abstract = {FDML lasers provide sweep rates in the MHz range at wide optical bandwidths, making them ideal sources for high
speed OCT. Recently, at lower speed, ultralong-range swept-source OCT has been demonstrated using a tunable
vertical cavity surface emitting laser (VCSEL) and also using a Vernier-tunable laser. These sources provide relatively
high sweep rates and meter range coherence lengths. In order to achieve similar coherence, we developed an extremely
well dispersion compensated Fourier Domain Mode Locked (FDML) laser, running at 3.2 MHz sweep rate and 120 nm
spectral bandwidth. We demonstrate that this laser offers meter range coherence and enables volumetric long range OCT
of moving objects.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz OCT},
year = {2017},
doi = {10.1117/12.2254792},
URL = {https://doi.org/10.1117/12.2254792}
}

2016

Tianshi Wang, Tom Pfeiffer, Evelyn Regar, Wolfgang Wieser, Heleen van Beusekom, Charles T. Lancee, Geert Springeling, Ilona Krabbendam-Peters, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Heartbeat OCT and Motion-Free 3D In Vivo Coronary Artery Microscopy, JACC: Cardiovascular Imaging , vol. 9, no. 5, pp. 622-623, 2016.
DOI:10.1016/j.jcmg.2015.08.010
Bibtex: BibTeX
@article{WANG2016622,
title = {Heartbeat OCT and Motion-Free 3D In Vivo Coronary Artery Microscopy},
journal = {JACC: Cardiovascular Imaging},
volume = {9},
number = {5},
pages = {622-623},
year = {2016},
issn = {1936-878X},
doi = {https://doi.org/10.1016/j.jcmg.2015.08.010},
url = {https://www.sciencedirect.com/science/article/pii/S1936878X15006713},
author = {Tianshi Wang and Tom Pfeiffer and Evelyn Regar and Wolfgang Wieser and Heleen {van Beusekom} and Charles T. Lancee and Geert Springeling and Ilona Krabbendam-Peters and Antonius F.W. {van der Steen} and Robert Huber and Gijs {van Soest}}
}
Jan Philip Kolb, Thomas Klein, Matthias Eibl, Tom Pfeiffer, Wolfgang Wieser, and Robert Huber,
Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX , Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin, Eds. SPIE, 2016. pp. 969703.
DOI:10.1117/12.2214758
Bibtex: BibTeX
@inproceedings{10.1117/12.2214758,
author = {Jan Philip Kolb and Thomas Klein and Matthias Eibl and Tom Pfeiffer and Wolfgang Wieser and Robert Huber},
title = {{Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm}},
volume = {9697},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX},
editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {969703},
abstract = {We present a new design of a Fourier Domain Mode Locked laser (FDML laser), which provides a new record in sweep
range at ~1&mu;m center wavelength: At the fundamental sweep rate of 2x417 kHz we reach 143nm bandwidth and 120nm
with 4x buffering at 1.67MHz sweep rate. The latter configuration of our system is characterized: The FWHM of the
point spread function (PSF) of a mirror is 5.6&mu;m (in tissue). Human in vivo retinal imaging is performed with the MHz
laser showing more details in vascular structures. Here we could measure an axial resolution of 6.0μm by determining
the FWHM of specular reflex in the image. Additionally, challenges related to such a high sweep bandwidth such as
water absorption are investigated.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz OCT},
year = {2016},
doi = {10.1117/12.2214758},
URL = {https://doi.org/10.1117/12.2214758}
}

2015

Tianshi Wang, Tom Pfeiffer, Evelyn Regar, Wolfgang Wieser, Heleen van Beusekom, Charles T. Lancee, Geert Springeling, Ilona Krabbendam, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography, Biomed. Opt. Express , vol. 6, no. 12, pp. 5021-5032, Dec. 2015. Optica Publishing Group.
DOI:10.1364/BOE.6.005021
Bibtex: BibTeX
@article{Wang:15,
author = {Tianshi Wang and Tom Pfeiffer and Evelyn Regar and Wolfgang Wieser and Heleen van Beusekom and Charles T. Lancee and Geert Springeling and Ilona Krabbendam and Antonius F.W. van der Steen and Robert Huber and Gijs van Soest},
journal = {Biomed. Opt. Express},
keywords = {Fiber optics imaging; Three-dimensional image acquisition; Medical optics instrumentation; Scanners; Endoscopic imaging; Medical and biological imaging; Optical coherence tomography; Image quality; Image registration; Imaging techniques; Laser modes; Mode locking; Optical coherence tomography},
number = {12},
pages = {5021--5032},
publisher = {Optica Publishing Group},
title = {Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography},
volume = {6},
month = {Dec},
year = {2015},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-6-12-5021},
doi = {10.1364/BOE.6.005021},
abstract = {Cardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging system that we called \&\#x201C;Heartbeat OCT\&\#x201D;, combining a fast Fourier Domain Mode Locked laser, fast pullback, and a micromotor actuated catheter, designed to examine a coronary vessel in less than one cardiac cycle. We acquired in vivo data sets of two coronary arteries in a porcine heart with both Heartbeat OCT, working at 2.88 MHz A-line rate, 4000 frames/s and 100 mm/s pullback speed, and with a commercial system. The in vivo results show that Heartbeat OCT provides faithfully rendered, motion-artifact free, fully sampled vessel wall architecture, unlike the conventional IV-OCT data. We present the Heartbeat OCT system in full technical detail and discuss the steps needed for clinical translation of the technology.},
}
Kathrin J. Mohler, Wolfgang Draxinger, Thomas Klein, Jan Philip Kolb, Wolfgang Wieser, Christos Haritoglou, Anselm Kampik, James G. Fujimoto, Aljoscha Neubauer, Armin Wolf, and Robert Huber,
Combined 60° Wide-Field Choroidal Thickness Maps and High-Definition En Face Vasculature Visualization Using Swept-Source Megahertz OCT at 1050 nm60° High-Definition MHz-OCT Imaging of the Choroid, Investigative Ophthalmology & Visual Science , vol. 56, no. 11, pp. 6284--6293, Oct. 2015.
DOI:10.1167/iovs.15-16670
Bibtex: BibTeX
@article{10.1167/iovs.15-16670,
    author = {Mohler, Kathrin J. and Draxinger, Wolfgang and Klein, Thomas and Kolb, Jan Philip and Wieser, Wolfgang and Haritoglou, Christos and Kampik, Anselm and Fujimoto, James G. and Neubauer, Aljoscha S. and Huber, Robert and Wolf, Armin},
    title = "{Combined 60° Wide-Field Choroidal Thickness Maps and High-Definition En Face Vasculature Visualization Using Swept-Source Megahertz OCT at 1050 nm}",
    journal = {Investigative Ophthalmology & Visual Science},
    volume = {56},
    number = {11},
    pages = {6284-6293},
    year = {2015},
    month = {10},
    abstract = "{   To demonstrate ultrahigh-speed swept-source optical coherence tomography (SS-OCT) at 1.68 million A-scans/s for choroidal imaging in normal and diseased eyes over a ∼60° field of view. To investigate and correlate wide-field three-dimensional (3D) choroidal thickness (ChT) and vascular patterns using ChT maps and coregistered high-definition en face images extracted from a single densely sampled Megahertz-OCT (MHz-OCT) dataset.    High-definition, ∼60° wide-field 3D datasets consisting of 2088 × 1024 A-scans were acquired using a 1.68 MHz prototype SS-OCT system at 1050 nm based on a Fourier-domain mode-locked laser. Nine subjects (nine eyes) with various chorioretinal diseases or without ocular pathology are presented. Coregistered ChT maps, choroidal summation maps, and depth-resolved en face images referenced to either the retinal pigment epithelium or the choroidal–scleral interface were generated using manual segmentation.    Wide-field ChT maps showed a large inter- and intraindividual variance in peripheral and central ChT. In only four of the nine eyes, the location with the largest ChT was coincident with the fovea. The anatomy of the large lumen vessels of the outer choroid seems to play a major role in determining the global ChT pattern. Focal ChT changes with large thickness gradients were observed in some eyes.    Different ChT and vascular patterns could be visualized over ∼60° in patients for the first time using OCT. Due to focal ChT changes, a high density of thickness measurements may be favorable. High-definition depth-resolved en face images are complementary to cross sections and thickness maps and enhance the interpretation of different ChT patterns.  }",
    issn = {1552-5783},
    doi = {10.1167/iovs.15-16670},
    url = {https://doi.org/10.1167/iovs.15-16670},
    eprint = {https://arvojournals.org/arvo/content\_public/journal/iovs/934564/i1552-5783-56-11-6284.pdf},
}
Lukas Reznicek, Jan Philip Kolb, Thomas Klein, Kathrin J. Mohler, Wolfgang Wieser, Robert Huber, Marcus Kernt, Josef Märtz, and Aljoscha Neubauer,
Wide-Field Megahertz OCT Imaging of Patients with Diabetic Retinopathy, Journal of Diabetes Research , vol. 2015, pp. 305084, Jul. 2015. Hindawi Publishing Corporation.
DOI:10.1155/2015/305084
Bibtex: BibTeX
@article{Reznicek2015,
   author = {Reznicek, Lukas and Kolb, Jan P. and Klein, Thomas and Mohler, Kathrin J. and Wieser, Wolfgang and Huber, Robert and Kernt, Marcus and Märtz, Josef and Neubauer, Aljoscha S.},
   title = {Wide-Field Megahertz OCT Imaging of Patients with Diabetic Retinopathy},
   journal = {Journal of Diabetes Research},
   volume = {2015, Article ID 305084},
   pages = {1-5},
   DOI = {10.1155/2015/305084},
   url = {http://dx.doi.org/10.1155/2015/305084},
   year = {2015},
keywords = {AG-Huber_OCT},
   type = {Journal Article}

}

Jan Philip Kolb, Thomas Klein, Wolfgang Wieser, Wolfgang Draxinger, and Robert Huber,
High definition in vivo retinal volumetric video rate OCT at 0.6 Giga-voxels per second, in Optical Coherence Imaging Techniques and Imaging in Scattering Media , Brett E. Bouma and Maciej Wojtkowski, Eds. SPIE, Jul.2015. pp. 95410Z.
DOI:10.1117/12.2183768
Bibtex: BibTeX
@inproceedings{10.1117/12.2183768,
author = {Jan Philip Kolb and Thomas Klein and Wolfgang Wieser and Wolfgang Draxinger and Robert Huber},
title = {{High definition in vivo retinal volumetric video rate OCT at 0.6 Giga-voxels per second}},
volume = {9541},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media},
editor = {Brett E. Bouma and Maciej Wojtkowski},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {95410Z},
abstract = {We present full volumetric high speed OCT imaging of the retina with multiple settings varying in volume size and volume rate. The volume size ranges from 255x255 A-scans to 160x40 A-scans with 450 samples per depth scan with volume rates varying between 20.8 V/s for the largest volumes to 195.2 V/s for the smallest. The system is based on a 1060nm Fourier domain mode locked (FDML) laser with 1.6MHz line rate. Scanning along the fast axis is performed with a 2.7 kHz or 4.3 kHz resonant scanner operated in bidirectional scanning mode, while a standard galvo scanner is used for the slow axis. The performance is analyzed with respect to various potential applications, like intraoperative OCT.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz-OCT},
year = {2015},
doi = {10.1117/12.2183768},
URL = {https://doi.org/10.1117/12.2183768}
}
Wolfgang Wieser, Thomas Klein, Wolfgang Draxinger, and Robert Huber,
Fully automated 1.5 MHz FDML laser with more than 100mW output power at 1310 nm, in Optical Coherence Imaging Techniques and Imaging in Scattering Media , Brett E. Bouma and Maciej Wojtkowski, Eds. SPIE, Jul.2015. pp. 954116.
DOI:10.1117/12.2183431
Bibtex: BibTeX
@inproceedings{10.1117/12.2183431,
author = {Wolfgang Wieser and Thomas Klein and Wolfgang Draxinger and Robert Huber},
title = {{Fully automated 1.5 MHz FDML laser with more than 100mW output power at 1310 nm}},
volume = {9541},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media},
editor = {Brett E. Bouma and Maciej Wojtkowski},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {954116},
abstract = {While FDML lasers with MHz sweep speeds have been presented five years ago, these devices have required manual control for startup and operation. Here, we present a fully self-starting and continuously regulated FDML laser with a sweep rate of 1.5 MHz. The laser operates over a sweep range of 115 nm centered at 1315 nm, and provides very high average output power of more than 100 mW. We characterize the laser performance, roll-off, coherence length and investigate the wavelength and phase stability of the laser output under changing environmental conditions. The high output power allows optical coherence tomography (OCT) imaging with an OCT sensitivity of 108 dB at 1.5 MHz.},
keywords = {OCT, optical coherence tomography, swept laser, wavelength-swept laser, fiber laser, MHz-OCT, Fourier-domain mode-locking, FDML},
year = {2015},
doi = {10.1117/12.2183431},
URL = {https://doi.org/10.1117/12.2183431}
}
Robert Huber,
4-D Real-Time Optical Coherence Tomography, Opt. Photon. News , vol. 26, no. 6, pp. 32-39, Jun. 2015. Optica Publishing Group.
DOI:10.1364/OPN.26.6.000032
Bibtex: BibTeX
@article{Huber:15,
author = {Robert Huber},
journal = {Opt. Photon. News},
keywords = {Image processing; Optical coherence tomography; Lasers, tunable; Medical optics and biotechnology; Optical coherence tomography; Image processing; Imaging techniques; Line scan cameras; Medical imaging; Optical coherence tomography; Three dimensional imaging},
number = {6},
pages = {32--39},
publisher = {Optica Publishing Group},
title = {4-D Real-Time Optical Coherence Tomography},
volume = {26},
month = {Jun},
year = {2015},
url = {https://www.optica-opn.org/abstract.cfm?URI=opn-26-6-32},
doi = {10.1364/OPN.26.6.000032},
abstract = {Advances in OCT techniques, combined with the processing power of moderncomputer hardware, are adding a new dimension---time---to a familiar 3-D imaging method.The result could be new applications in research and the biomedicalclinic.},
}
Jan Philip Kolb, Thomas Klein, Corinna L. Kufner, Wolfgang Wieser, Aljoscha Neubauer, and Robert Huber,
Ultra-widefield retinal MHz-OCT imaging with up to 100 degrees viewing angle, Biomed. Opt. Express , vol. 6, no. 5, pp. 1534--1552, May 2015. Optica Publishing Group.
DOI:10.1364/BOE.6.001534
Bibtex: BibTeX
@article{Kolb:15,
author = {Jan Philip Kolb and Thomas Klein and Corinna L. Kufner and Wolfgang Wieser and Aljoscha S. Neubauer and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Medical optics instrumentation; Lasers, fiber; Medical and biological imaging; Ophthalmic optics and devices ; Optical coherence tomography; Adaptive optics; Full field optical coherence tomography; Image quality; Imaging techniques; Laser scanning; Three dimensional imaging},
number = {5},
pages = {1534--1552},
publisher = {Optica Publishing Group},
title = {Ultra-widefield retinal MHz-OCT imaging with up to 100 degrees viewing angle},
volume = {6},
month = {May},
year = {2015},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-6-5-1534},
doi = {10.1364/BOE.6.001534},
abstract = {We evaluate strategies to maximize the field of view (FOV) of in vivo retinal OCT imaging of human eyes. Three imaging modes are tested: Single volume imaging with 85{\textdegree} FOV as well as with 100{\textdegree} and stitching of five 60{\textdegree} images to a 100{\textdegree} mosaic (measured from the nodal point). We employ a MHz-OCT system based on a 1060nm Fourier domain mode locked (FDML) laser with a depth scan rate of 1.68MHz. The high speed is essential for dense isotropic sampling of the large areas. Challenges caused by the wide FOV are discussed and solutions to most issues are presented. Detailed information on the design and characterization of our sample arm optics is given. We investigate the origin of an angle dependent signal fall-off which we observe towards larger imaging angles. It is present in our 85{\textdegree} and 100{\textdegree} single volume images, but not in the mosaic. Our results suggest that 100{\textdegree} FOV OCT is possible with current swept source OCT technology.},
}
Tom Pfeiffer, Wolfgang Wieser, Thomas Klein, Markus Petermann, Jan Philip Kolb, Matthias Eibl, and Robert Huber,
Flexible A-scan rate MHz OCT: computational downscaling by coherent averaging, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX , Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin, Eds. SPIE, Apr.2015. pp. 96970S-96970S-5.
DOI:10.1117/12.2214788
Bibtex: BibTeX
@inproceedings{10.1117/12.2214788,
author = {Tom Pfeiffer and Wolfgang Wieser and Thomas Klein and Markus Petermann and Jan-Phillip Kolb and Matthias Eibl and Robert Huber},
title = {{Flexible A-scan rate MHz OCT: computational downscaling by coherent averaging}},
volume = {9697},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX},
editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {96970S},
abstract = {In order to realize fast OCT-systems with adjustable line rate, we investigate averaging of image data from an FDML based
MHz-OCT-system. The line rate can be reduced in software and traded in for increased system sensitivity and image
quality. We compare coherent and incoherent averaging to effectively scale down the system speed of a 3.2 MHz FDML
OCT system to around 100 kHz in postprocessing. We demonstrate that coherent averaging is possible with MHz systems
without special interferometer designs or digital phase stabilisation. We show OCT images of a human finger knuckle joint
in vivo with very high quality and deep penetration.},
keywords = {Optical coherence tomography, OCT, Fourier domain mode locking, FDML, MHz OCT, averaging, tunable laser},
year = {2016},
doi = {10.1117/12.2214788},
URL = {https://doi.org/10.1117/12.2214788}
}
Jan Philip Kolb, Philipp Schwarz, Thomas Klein, Wolfgang Wieser, and Robert Huber,
Dual parametric compounding approach for speckle reduction in OCT, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, Mar.2015. pp. 93123G.
DOI:10.1117/12.2077659
Bibtex: BibTeX
@inproceedings{10.1117/12.2077659,
author = {Jan Philip Kolb and Philipp Schwarz and Thomas Klein and Wolfgang Wieser and Robert Huber},
title = {{Dual parametric compounding approach for speckle reduction in OCT}},
volume = {9312},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {93123G},
abstract = {OCT as a coherent imaging technique inherently suffers from speckle. We present a new dual parametric compounding approach to reduce speckle. The approach is to acquire several OCT volumes with different numerical apertures (NAs). Then in post processing, a first spatial compounding step is performed by averaging of adjacent B-frames. In a second step data from the different volume is averaged. Retinal imaging data comparing this idea with standard spatial compounding is presented and analyzed and necessary parameters such as the required variation of the NA and number of different NAs are discussed},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode lockng, FDML, MHz OCT},
year = {2015},
doi = {10.1117/12.2077659},
URL = {https://doi.org/10.1117/12.2077659}
}
Jan Philip Kolb, Thomas Klein, Wolfgang Wieser, Wolfgang Draxinger, and Robert Huber,
Full volumetric video rate OCT of the posterior eye with up to 195.2 volumes/s, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, Mar.2015. pp. 931202.
DOI:10.1117/12.2077147
Bibtex: BibTeX
@inproceedings{10.1117/12.2077147,
author = {Jan Philip Kolb and Thomas Klein and Wolfgang Wieser and Wolfgang Draxinger and Robert Huber},
title = {{Full volumetric video rate OCT of the posterior eye with up to 195.2 volumes/s}},
volume = {9312},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {931202},
abstract = {Full volumetric high speed OCT imaging of the retina with multiple settings varying in volume size and volume rate is
presented. The volume size ranges from 255x255 A-scans to 160x40 A-scans with 450 samples per depth scan. The
volume rates vary between 20.8 V/s for the largest volumes to 195.2 V/s for the smallest. The system is based on a
1060nm Fourier domain mode locked (FDML) laser with 1.6MHz line rate. Scanning along the fast axis is performed
with a 2.7 kHz or 4.3 kHz resonant scanner operated in bidirectional scanning mode, while a standard galvo scanner is
used for the slow axis. The performance is analyzed with respect to various potential applications, like intraoperative
OCT.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode lockng, FDML, MHz OCT},
year = {2015},
doi = {10.1117/12.2077147},
URL = {https://doi.org/10.1117/12.2077147}
}

2014

Wolfgang Wieser, Wolfgang Draxinger, Thomas Klein, and Tom Pfeiffer,
A 4-D OCT Engine with 1 GVoxel/s, Optics and Photonics News , vol. 25, no. 12, pp. 36, Dec. 2014. OSA.
Weblink: https://www.optica-opn.org/home/articles/volume_25/december_2014/extras/a_4-d_oct_engine_with_1_gvoxel_s/#.VcH21Pl5raw
Bibtex: BibTeX
@Article{HU_2014_Wieser_b,
  Title                    = {{A 4-D OCT Engine with 1 GVoxel/s}},
  Author                   = {Wieser, Wolfgang and Draxinger, Wolfgang and Klein, Thomas and Karpf, Sebastian and Pfeiffer, Tom and Huber, Robert},
  Journal                  = {Optics and Photonics News},
  Year                     = {2014},

  Month                    = dec,
  Number                   = {12},
  Pages                    = {36 },
  Volume                   = {25},
keywords = {AG-Huber_FDML, AG-Huber_OCT},

  Publisher                = {OSA},
  Url                      = { http://www.osa-opn.org/home/articles/volume_25/december_2014/extras/a_4-d_oct_engine_with_1_gvoxel_s/#.VcH21Pl5raw}
}
Yaokun Zhang, Tom Pfeiffer, Marcel Weller, Wolfgang Wieser, Robert Huber, Jörg Raczkowsky, Jörg Schipper, Heinz Wörn, and Thomas Klenzner,
Optical coherence tomography guided laser cochleostomy: towards the accuracy on tens of micrometer scale, BioMed research international , vol. 2014, pp. 251814, Sep. 2014. Hindawi Publishing Corporation.
DOI:10.1155/2014/251814
Bibtex: BibTeX
@Article{HU_2014_Zhang_a,
  Title                    = {{Optical coherence tomography guided laser cochleostomy: towards the accuracy on tens of micrometer scale}},
  Author                   = {Zhang, Yaokun and Pfeiffer, Tom and Weller, Marcel and Wieser, Wolfgang and Huber, Robert and Raczkowsky, J\"{o}rg and Schipper, J\"{o}rg and W\"{o}rn, Heinz and Klenzner, Thomas},
  Journal                  = {BioMed research international},
  Year                     = {2014},
  Month                    = jan,
  Pages                    = {251814--24},
  Volume                   = {2014},
  Doi                      = {10.1155/2014/251814},
  ISSN                     = {2314-6141},
keywords = {AG-Huber_OCT},
  Url                      = {http://www.hindawi.com/journals/bmri/2014/251814/}
}
Wolfgang Wieser, Wolfgang Draxinger, Thomas Klein, Sebastian Karpf, Tom Pfeiffer, and Robert Huber,
High definition live 3D-OCT in vivo: design and evalution of 4D-OCT engine with 1 GVoxel/s, Biomed. Opt. Express , vol. 5, no. 9, pp. 2963--77, Sep. 2014. Optica Publishing Group.
DOI:10.1364/BOE.5.002963
Bibtex: BibTeX
@article{Wieser:14,
author = {Wolfgang Wieser and Wolfgang Draxinger and Thomas Klein and Sebastian Karpf and Tom Pfeiffer and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Optical coherence tomography; Lasers, tunable; Optical coherence tomography; Endoscopic imaging; Full field optical coherence tomography; Functional imaging; Image quality; Ophthalmic imaging; Vertical cavity surface emitting lasers},
number = {9},
pages = {2963--2977},
publisher = {Optica Publishing Group},
title = {High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s},
volume = {5},
month = {Sep},
year = {2014},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-5-9-2963},
doi = {10.1364/BOE.5.002963},
abstract = {We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin.},
}