Wolfgang Draxinger

@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},
}

@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}
}

@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}
}

@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}
}

@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}
}

@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.},
}

@article{Klein2014,
   author = {Klein, Thomas and Draxinger, Wolfgang and Mohler, Kathrin and Kolb, Jan Philip and Wieser, Wolfgang and Kampik, Anselm and Neubauer, Aljoscha S. and Wolf, Armin and Huber, Robert},
   title = {Wide-field choroidal thickness and en-face maps of patients created with MHz-OCT},
   journal = {Investigative Ophthalmology & Visual Science},
   volume = {55},
   number = {13},
   pages = {1620-1620},
   abstract = { PurposeTo study the feasibility of simultaneous peripheral and central choroidal thickness measurement and en-face visualization in patients with a variety of diseases, using a single high-resolution wide-field MHz-OCT dataset spanning more than 50 degrees field of view.  MethodsIn this retrospective study, choroidal morphology of 29 patients imaged with MHz-OCT was assessed. MHz-OCT is a custom SS-OCT operating at 1060nm and an axial line rate of 1.68MHz. The high speed, more than 30 times faster than current commercial devices, enabled a very high resolution scan protocol of 2088x1024 A-scans over a wide field of ~60 degrees. However, due to the very high speed, signal strength is lower compared to slower devices. Hence, thickness and structure maps were only created for selected datasets: The positions of Bruch’s membrane and choroid sclera junction were determined manually by a trained observer a subset of all A-scans, from which thickness and intensity maps were created.  ResultsDespite relative low signal strength, the choroid sclera junction could be clearly observed over the entire unshadowed image area in 15 of 29 patients. Apart from shadowing, visibility of this junction shows strong variation even within a single dataset due to varying retinal thickness, eye-blinks, saccades and retinal curvature. Thus, thickness could be evaluated at least in some areas for all 29 patients, especially in the periphery. Moreover, choroidal thickness varied considerably intra- and interindividually. In two patients, abrupt changes of the choroid were observed in the temporal periphery, which may resemble morphology or imaging artifact. In addition to thickness, en-face choroidal structure maps were extracted from the segmented OCT datasets. Visibility of choroidal vasculature in these maps correlates with choroidal thickness.  ConclusionsChoroidal thickness and structure in patients could be visualized over large areas for the first time. Due to focal choroidal thickness changes with large thickness gradients, high-density scan protocols may be favorable for OCT-based investigations of the choroid. En-face images of the choroid can be extracted from these high-resolution datasets, but the influence of choroidal thickness on the image information should be taken into account. Choroidal en-face image (top), color-coded thickness map with superimposed structural image (middle) and OCT B-frame (bottom) for two eyes (A,B).},
   ISSN = {1552-5783},
   url = {http://dx.doi.org/},
   year = {2014},
keywords = {AG-Huber_OCT},
   type = {Journal Article}
}