@article{singh2024virtual,
title = {Virtual Hall sensor triggered multi-MHz endoscopic OCT imaging for stable real-time visualization},
author = {Awanish Pratap Singh and Madita G\"{o}b and Martin Ahrens and Tim Eixmann and Berenice Schulte and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Mark Ellrichmann and Robert Huber and Maik Rahlves},
year  = {2024},
date = {2024-01-01},
journal = {Optics Express},
volume = {32},
number = {4},
pages = {5809\textendash5825},
publisher = {Optica Publishing Group},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@inproceedings{sieren2022strahlenfreie,
title = {Strahlenfreie Implantation eines thorakalen Aortenstentgrafts mittels faseroptischen und elektromagnetischen Trackings: Eine Phantomstudie},
author = {M Sieren and S Jaeckle and T Eixmann and H Schulz-Hildebrandt and M Preuss and V Garc\'{i}a-V\'{a}zquez and E Stahlberg and M Kleemann and J Barkhausen and J Goltz and others},
year  = {2023},
date = {2023-01-01},
urldate = {2022-01-01},
booktitle = {R\"{o}Fo-Fortschritte auf dem Gebiet der R\"{o}ntgenstrahlen und der bildgebenden Verfahren},
volume = {194},
number = {S 01},
pages = {ab83},
organization = {Georg Thieme Verlag},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{leichtle2023dynamic,
title = {Dynamic microscopic optical coherence tomography as a new diagnostic tool for otitis media},
author = {Anke Leichtle and Zuzana Penxova and Thorge Kempin and David Leffers and Martin Ahrens and Peter K\"{o}nig and Ralf Brinkmann and Gereon H\"{u}ttmann and Karl-Ludwig Bruchhage and Hinnerk Schulz-Hildebrandt},
year  = {2023},
date = {2023-01-01},
booktitle = {Photonics},
volume = {10},
number = {6},
pages = {685},
organization = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{Kohlfaerber:22,
title = {Dynamic microscopic optical coherence tomography to visualize the morphological and functional micro-anatomy of the airways},
author = {Tabea Kohlfaerber and Mario Pieper and Michael M\"{u}nter and Cornelia Holzhausen and Martin Ahrens and Christian Idel and Karl-Ludwig Bruchhage and Anke Leichtle and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
url = {http://opg.optica.org/boe/abstract.cfm?URI=boe-13-6-3211},
doi = {10.1364/BOE.456104},
year  = {2022},
date = {2022-06-01},
urldate = {2022-06-01},
journal = {Biomed. Opt. Express},
volume = {13},
number = {6},
pages = {3211--3223},
publisher = {OSA},
abstract = {In the imaging of airway tissue, optical coherence tomography (OCT) provides cross-sectional images of tissue structures, shows cilia movement and mucus secretion, but does not provide sufficient contrast to differentiate individual cells. By using fast sequences of microscopic resolution OCT (mOCT) images, OCT can use small signal fluctuations to overcome lack in contrast and speckle noise. In this way, OCT visualizes airway morphology on a cellular level and allows the tracking of the dynamic behavior of immune cells, as well as mucus transport and secretion. Here, we demonstrate that mOCT, by using temporal tissue fluctuation as contrast (dynamic mOCT), provides the possibility to study physiological and pathological tissue processes in\ vivo.},
keywords = {Full field optical coherence tomography; High nume},
pubstate = {published},
tppubtype = {article}
}
@misc{kohlfaerber2022dynamic,
title = {Dynamic microscopic optical coherence tomography to visualize morphological and functional micro-anatomy of the airways},
author = {Tabea Kohlfaerber and Mario Pieper and Michael M\"{u}nter and Cornelia Holzhausen and Martin Ahrens and Christian Idel and Karl Ludwig Bruchhage and Anke Leichtle and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
year  = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
@inproceedings{10.1007/978-3-658-36932-3_53,
title = {Abstract: 3D Stent Graft Guidance Based on Tracking Systems},
author = {Sonja J\"{a}ckle and Tim Eixmann and Florian Matysiak and Malte M Sieren and Marco Horn and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Torben P\"{a}tz},
editor = {Klaus Maier-Hein and Thomas M Deserno and Heinz Handels and Andreas Maier and Christoph Palm and Thomas Tolxdorff},
isbn = {978-3-658-36932-3},
year  = {2022},
date = {2022-01-01},
booktitle = {Bildverarbeitung f\"{u}r die Medizin 2022},
pages = {253},
publisher = {Springer Fachmedien Wiesbaden},
address = {Wiesbaden},
abstract = {In endovascular aneurysm repair (EVAR) procedures, the stent graft navigation and implantation is currently performed under a two-dimensional (2D) imaging-based guidance requiring X-rays and contrast agent. In [1], a novel three-dimensional (3D) stent graft guidance approach based on tracking systems is introduced. The method is based on a 3D guidance method which combines fiber optical shape sensing with electromagnetic tracking to obtain the 3D shape [2] of the tracked instrument, e.g., a stent graft system. In this work, the approach is extended to provide also the 3D stent graft shape.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{10.1167/tvst.11.5.28,
title = {Dynamic Contrast Microscopic Optical Coherence Tomography As a Novel Method for Assessing Corneal Epithelium During Exposure to Benzalkonium Chloride},
author = {Gwen Musial and Tabea Kohlfaerber and Martin Ahrens and Hinnerk Schulz-Hildebrandt and Philipp Steven and Gereon H\"{u}ttmann},
url = {https://doi.org/10.1167/tvst.11.5.28},
doi = {10.1167/tvst.11.5.28},
issn = {2164-2591},
year  = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Translational Vision Science \& Technology},
volume = {11},
number = {5},
pages = {28-28},
abstract = { Microscopic optical coherence tomography (mOCT) has an imaging resolution of 1 µm in all voxel dimensions, but individual epithelial cells are difficult to resolve due to lack of scattering contrast. Adding dynamic contrast processing to mOCT (dmOCT) results in color images that enable visualization of individual cells and possibly give information on cellular function via the calculation of a motility coefficient. We propose this technique as a novel method of evaluating the ocular surface after exposure to a toxic chemical, benzalkonium chloride (BAK). Ex vivo cross-section images were acquired with a custom-built, frequency-domain mOCT system. Eyes were explanted from healthy adult C57BL/6 mice and imaged every 30 minutes with five sets of dmOCT scans at each imaging time. Total epithelium and stroma thicknesses were measured from a single mOCT B-scan, and measures of color changes (hue) and the motility coefficient were acquired from dmOCT scans. After 30-minute exposures to 0.005% BAK, local motility decreased and total epithelium thickness increased compared to controls. For basal epithelium cells, local motility decreased after 60-minute exposures, and the hue shifted red after 90-minute exposures. Stroma thickness did not significantly swell until 150-minute exposures to BAK. dmOCT allows us to view the behavior of the cornea epithelium under toxic stress due to BAK, revealing parallel swelling of the extracellular matrix and changes in local subcellular motion. The evaluation of the cornea epithelium using dmOCT is helpful to our understanding of the toxic effects of BAK. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{pieper2022intravital,
title = {Intravital imaging of mucus transport in asthmatic mice using microscopic optical coherence tomography},
author = {Mario Pieper and Hinnerk Schulz-Hildebrandt and Inken Schmudde and Katharina M Quell and Yves Laumonnier and Gereon H\"{u}ttmann and Peter K\"{o}nig},
year  = {2022},
date = {2022-01-01},
journal = {American Journal of Physiology-Lung Cellular and Molecular Physiology},
volume = {323},
number = {4},
pages = {L423\textendashL430},
publisher = {American Physiological Society Rockville, MD},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Munter:21,
title = {Microscopic optical coherence tomography (mOCT) at 600 kHz for 4D volumetric imaging and dynamic contrast},
author = {Michael M\"{u}nter and Mario Pieper and Tabea Kohlfaerber and Ernst Bodenstorfer and Martin Ahrens and Christian Winter and Robert Huber and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
url = {http://www.osapublishing.org/boe/abstract.cfm?URI=boe-12-10-6024},
doi = {10.1364/BOE.425001},
year  = {2021},
date = {2021-10-01},
urldate = {2021-10-01},
journal = {Biomed. Opt. Express},
volume = {12},
number = {10},
pages = {6024--6039},
publisher = {OSA},
abstract = {Volumetric imaging of dynamic processes with microscopic resolution holds a huge potential in biomedical research and clinical diagnosis. Using supercontinuum light sources and high numerical aperture (NA) objectives, optical coherence tomography (OCT) achieves microscopic resolution and is well suited for imaging cellular and subcellular structures of biological tissues. Currently, the imaging speed of microscopic OCT (mOCT) is limited by the line-scan rate of the spectrometer camera and ranges from 30 to 250 kHz. This is not fast enough for volumetric imaging of dynamic processes in vivo and limits endoscopic application. Using a novel CMOS camera, we demonstrate fast 3-dimensional OCT imaging with 600,000 A-scans/s at 1.8\ textmum axial and 1.1 textmum lateral resolution. The improved speed is used for imaging of ciliary motion and particle transport in ex vivo mouse trachea. Furthermore, we demonstrate dynamic contrast OCT by evaluating the recorded volumes rather than en face planes or B-scans. High-speed volumetric mOCT will enable the correction of global tissue motion and is a prerequisite for applying dynamic contrast mOCT in vivo. With further increase in imaging speed and integration in flexible endoscopes, volumetric mOCT may be used to complement or partly replace biopsies.},
keywords = {CMOS cameras; Full field optical coherence tomogra},
pubstate = {published},
tppubtype = {article}
}
@article{https://doi.org/10.1002/rcs.2327,
title = {Instrument Localization for Endovascular Aneurysm Repair \textendash Comparison of two methods based on Tracking Systems or using Imaging},
author = {Sonja J\"{a}ckle and Annkristin Lange and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Tim Eixmann and Florian Matysiak and Malte Maria Sieren and Marco Horn and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Floris Ernst and Stefan Heldmann and Torben P\"{a}tz and Tobias Preusser},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/rcs.2327},
doi = {https://doi.org/10.1002/rcs.2327},
year  = {2021},
date = {2021-09-04},
journal = {The International Journal of Medical Robotics and Computer Assisted Surgery},
volume = {n/a},
number = {n/a},
pages = {e2327},
abstract = {Abstract Background In endovascular aortic repair (EVAR) procedures, medical instruments are currently navigated with a two-dimensional imaging based guidance requiring X-rays and contrast agent. Methods Novel approaches for obtaining the three-dimensional instrument positions are introduced. First, a method based on fiber optical shape sensing, one electromagnetic sensor and a preoperative computed tomography (CT) scan is described. Second, an approach based on image processing using one 2D fluoroscopic image and a preoperative CT scan is introduced. Results For the tracking based method, average errors from 1.81 to 3.13 mm and maximum errors from 3.21 to 5.46 mm were measured. For the image-based approach, average errors from 3.07 to 6.02 mm and maximum errors from 8.05 to 15.75 mm were measured. Conclusion The tracking based method is promising for usage in EVAR procedures. For the image-based approach are applications in smaller vessels more suitable, since its errors increase with the vessel diameter. This article is protected by copyright. All rights reserved.},
keywords = {2D/3D registration, 3D localization, computer assisted surgeryS, electromagnetic tracking system, endovascular procedures, fiber optical shape sensing},
pubstate = {published},
tppubtype = {article}
}
@inproceedings{10.1117/12.2575733,
title = {Endo-microscopic optical coherence tomography (emOCT) with dynamic contrast},
author = {Hinnerk Schulz-Hildebrandt and Martin Ahrens and Michael M\"{u}nter and Elisa Wilken and Tabea Kohlf\"{a}rber and Cornelia Holzhausen and Peter K\"{o}nig and Gereon H\"{u}ttmann},
editor = {Guillermo Tearney J M.D. and Thomas D Wang and Melissa J Suter},
url = {https://doi.org/10.1117/12.2575733},
doi = {10.1117/12.2575733},
year  = {2021},
date = {2021-01-01},
booktitle = {Endoscopic Microscopy XVI},
volume = {11620},
publisher = {SPIE},
organization = {International Society for Optics and Photonics},
keywords = {dynamic OCT, Endoscopy, intravital imaging, microscopic OCT, OCT},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{10.1117/12.2583811,
title = {Comparison between dynamic microscopic OCT and autofluorescence multiphoton microscopy for label-free analysis of murine trachea},
author = {Tabea Kohlfaerber and Michael M\"{u}nter and Mario Pieper and Peter K\"{o}nig and Ramtin Rahmanzadeh and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
editor = {Joseph A Izatt and James G Fujimoto},
url = {https://doi.org/10.1117/12.2583811},
doi = {10.1117/12.2583811},
year  = {2021},
date = {2021-01-01},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXV},
volume = {11630},
publisher = {SPIE},
organization = {International Society for Optics and Photonics},
keywords = {autofluorescence multiphoton imaging, dynamic contrast, microscopic OCT, murine airways, Optical coherence tomography, spectral domain},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{10.1117/12.2578787,
title = {Voice coil based endomicroscopic optical coherence tomography probe for in vivo mucosa examination},
author = {Martin Ahrens and Christian Idel and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
editor = {Guillermo Tearney J M.D. and Thomas D Wang and Melissa J Suter},
url = {https://doi.org/10.1117/12.2578787},
doi = {10.1117/12.2578787},
year  = {2021},
date = {2021-01-01},
booktitle = {Endoscopic Microscopy XVI},
volume = {11620},
publisher = {SPIE},
organization = {International Society for Optics and Photonics},
keywords = {endomicroscopic, Endoscopy, in vivo, intranasal, mucosa, Optical coherence tomography, sidewards, voice coil},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{10.1117/12.2577822,
title = {Novel method to assess the impact of aging and sun exposure on skin morphology by optical coherence tomography},
author = {Felix Hilge and Michael Evers and Malte Casper and Joshua Zev Glahn and Weeranut Phothong M.D. and Garuna Kositratna M.D. and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Dieter Manstein M.D.},
editor = {Bernard Choi and Haishan Zeng},
url = {https://doi.org/10.1117/12.2577822},
doi = {10.1117/12.2577822},
year  = {2021},
date = {2021-01-01},
booktitle = {Photonics in Dermatology and Plastic Surgery 2021},
volume = {11618},
publisher = {SPIE},
organization = {International Society for Optics and Photonics},
keywords = {Optical coherence tomography, Skin roughness, Skin topology},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{Jaeckle2021c,
title = {3D Stent Graft Guidance based on Tracking Systems for Endovascular Aneurysm Repair:},
author = {Sonja J\"{a}ckle and Tim Eixmann and Florian Matysiak and Malte Maria Sieren and Marco Horn and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Torben P\"{a}tz},
url = {https://doi.org/10.1515/cdbme-2021-1004},
doi = {doi:10.1515/cdbme-2021-1004},
year  = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Current Directions in Biomedical Engineering},
volume = {7},
number = {1},
pages = {17--20},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{CEREDA2021100085,
title = {Clinical Evaluation of an Instrument-Integrated OCT-Based Distance Sensor for Robotic Vitreoretinal Surgery},
author = {Matteo Giuseppe Cereda and Salvatore Parrulli and Y G M Douven and Koorosh Faridpooya and Saskia Romunde and Gereon H\"{u}ttmann and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Gernot Kronreif and Maarten Beelen and Marc D Smet},
url = {https://www.sciencedirect.com/science/article/pii/S2666914521000750},
doi = {https://doi.org/10.1016/j.xops.2021.100085},
issn = {2666-9145},
year  = {2021},
date = {2021-01-01},
journal = {Ophthalmology Science},
volume = {1},
number = {4},
pages = {100085},
abstract = {Purpose 
To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.). 
Design 
Single-center interventional study. 
Participants 
Patients requiring vitreoretinal surgery. 
Methods 
Five patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively. 
Main Outcomes Measures 
The feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe. 
Results 
Surgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epithelium\textendashBruch's membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCT-based sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration. 
Conclusions 
This iiOCT-based sensor was tested successfully and promises reliable use during robot-assisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.},
keywords = {OCT, OCT distance sensor, Robotic vitreoretinal surgery},
pubstate = {published},
tppubtype = {article}
}
@article{SIEREN2021,
title = {Radiation-free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance:A Phantom Study},
author = {Malte Maria Sieren and Sonja J\"{a}ckle and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Florian Matysiak and Mark Preuss and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Erik Stahlberg and Markus Kleemann and J\"{o}rg Barkhausen and Jan Goltz and Marco Horn},
url = {https://www.sciencedirect.com/science/article/pii/S1051044321016079},
doi = {https://doi.org/10.1016/j.jvir.2021.12.025},
issn = {1051-0443},
year  = {2021},
date = {2021-01-01},
journal = {Journal of Vascular and Interventional Radiology},
abstract = {Purpose 
The purpose of this study was to evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent-graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom. 
Materials and Methods 
An anthropomorphic phantom was manufactured based on computed tomography angiography (CTA) data from a patient. An aortic stent-graft application system was equipped with a fiber Bragg gratings fiber and three electromagnetic sensors. The stent-graft was navigated in the phantom by three interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and pre- and post-interventional CTA. Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent-graft application system and the tip/end of the stent-graft. 
Results 
The procedure resulted in technical success with a mean error below 3 mm for the entire application system and \<2 mm for the position of the tip of the stent-graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on a par with comparable, routinely used stent-graft application systems. 
Conclusion 
Our study demonstrates successful stent-graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent-grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.},
keywords = {Electromagnetic fields, endovascular navigation, Endovascular surgery, Fiber optic technology, Radiation, Three dimensional},
pubstate = {published},
tppubtype = {article}
}
@article{Schneider2020,
title = {An Intraoral OCT Probe to Enhanced Detection of Approximal Carious Lesions and Assessment of Restorations},
author = {Hartmut Schneider and Martin Ahrens and Michaela Strumpski and Claudia R\"{u}ger and Matthias H\"{a}fer and Gereon H\"{u}ttmann and Dirk Theisen-Kunde and Hinnerk Schulz-Hildebrandt and Rainer Haak},
url = {https://www.mdpi.com/852930},
doi = {10.3390/JCM9103257},
year  = {2020},
date = {2020-10-01},
journal = {Journal of Clinical Medicine 2020, Vol. 9, Page 3257},
volume = {9},
number = {10},
pages = {3257},
publisher = {Multidisciplinary Digital Publishing Institute},
abstract = {Caries, the world\’s most common chronic disease, remains a major cause of invasive restorative dental treatment. To take advantage of the diagnostic potential of optical coherence tomography (OCT) in contemporary dental prevention and treatment, an intraorally applicable spectral-domain OCT probe has been developed based on an OCT hand-held scanner equipped with a rigid 90\°-optics endoscope. The probe was verified in vitro. In vivo, all tooth surfaces could be imaged with the OCT probe, except the vestibular surfaces of third molars and the proximal surface sections of molars within a "blind spot" at a distance greater than 2.5 mm from the tooth surface. Proximal surfaces of 64 posterior teeth of four volunteers were assessed by intraoral OCT, visual-tactile inspection, bitewing radiography and fiber-optic transillumination. The agreement in detecting healthy and carious surfaces varied greatly between OCT and established methods (18.2-94.7%), whereby the established methods could always be supplemented by OCT. Direct and indirect composite and ceramic restorations with inherent imperfections and failures of the tooth-restoration bond were imaged and qualitatively evaluated. The intraoral OCT probe proved to be a powerful technological approach for the non-invasive imaging of healthy and carious hard tooth tissues and gingiva as well as tooth-colored restorations.},
keywords = {caries diagnosis, carious lesions, dental restorations, intraoral probe, OCT},
pubstate = {published},
tppubtype = {article}
}
@article{Munter:20,
title = {Dynamic contrast in scanning microscopic OCT},
author = {Michael M\"{u}nter and Malte vom Endt and Mario Pieper and Malte Casper and Martin Ahrens and Tabea Kohlfaerber and Ramtin Rahmanzadeh and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
url = {http://ol.osa.org/abstract.cfm?URI=ol-45-17-4766},
doi = {10.1364/OL.396134},
year  = {2020},
date = {2020-09-01},
journal = {Opt. Lett.},
volume = {45},
number = {17},
pages = {4766--4769},
publisher = {OSA},
abstract = {While optical coherence tomography (OCT) provides a resolution downto 1 textmum, it has difficulties in visualizing cellular structures due to alack of scattering contrast. By evaluating signal fluctuations, asignificant contrast enhancement was demonstrated using time-domainfull-field OCT (FF-OCT), which makes cellular and subcellular structuresvisible. The putative cause of the dynamic OCT signal is thesite-dependent active motion of cellular structures in a sub-micrometerrange, which provides histology-like contrast. Here we demonstrate dynamiccontrast with a scanning frequency-domain OCT (FD-OCT), which we believehas crucial advantages. Given the inherent sectional imaging geometry,scanning FD-OCT provides depth-resolved images across tissue layers, aperspective known from histopathology, much faster and more efficientlythan FF-OCT. Both shorter acquisition times and tomographicdepth-sectioning reduce the sensitivity of dynamic contrast for bulktissue motion artifacts and simplify their correction in post-processing.Dynamic contrast makes microscopic FD-OCT a promising tool for thehistological analysis of unstained tissues.},
keywords = {Full field optical coherence tomography; Image processing; Image quality; Line scan cameras; Optical coherence tomography; Tomography, mOCT, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@article{Wertheimer2020,
title = {Refractive Changes After Corneal Stromal Filler Injection for the Correction of Hyperopia},
author = {Christian M Wertheimer and Katharina Brandt and Steffen Kaminsky and Carolin Elhardt and Stefan A Kassumeh and Linh Pham and Hinnerk Schulz-Hildebrandt and Siegfried Priglinger and Rox R Anderson and Reginald Birngruber},
doi = {10.3928/1081597X-20200429-01},
year  = {2020},
date = {2020-06-14},
journal = {Journal of Refractive Surgery},
volume = {36},
number = {6},
pages = {406--413},
abstract = {PURPOSE: To evaluate a new non-ablative and adjustable procedure for laser ablative refractive corneal surgery in hyperopia using the injection of a biocompatible liquid filler material into a stromal pocket.
METHODS: A total of 120 stromal pockets were created using a clinical femtosecond laser system in 96 rabbit corneoscleral discs and 24 whole globes. Pockets were cut at a depth of 120 or 250 μm below the epithelial surface. Hyaluronic acid was injected manually into the pocket. To determine the refractive changes, three-dimensional optical coherence tomography images and a specifically developed picture recognition Mat- lab (The Mathworks) routine were used.
RESULTS: After injection, a steepening of the anterior and flattening of the posterior corneal surface was observed, which led to hyperopic correction. The two main factors de- termining the amount of correction were the pocket depth and the injected volume. After the pocket was homogeneously filled, an initial refractive increase was observed, followed by a linear relation between the injected volume and the re- fraction increase.
CONCLUSIONS: This possible clinical protocol for controlled refraction correction of hyperopia suggests a potential readjustable clinical application.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{doi:10.1002/cyto.a.24012,
title = {Coregistered Spectral Optical Coherence Tomography and Two-Photon Microscopy for Multimodal Near-Instantaneous Deep-Tissue Imaging},
author = {Asylkhan Rakhymzhan and Lucie Reuter and Raphael Raspe and Daniel Bremer and Robert G\"{u}nther and Ruth Leben and Judith Heidelin and Volker Andresen and Sergey Cheremukhin and Hinnerk Schulz-Hildebrandt and Maria G Bixel and Ralf H Adams and Helena Radbruch and Gereon H\"{u}ttmann and Anja E Hauser and Raluca A Niesner},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/cyto.a.24012},
doi = {10.1002/cyto.a.24012},
year  = {2020},
date = {2020-04-14},
journal = {Cytometry Part A},
volume = {97},
number = {5},
pages = {515-527},
abstract = {Abstract Two-photon microscopy (2PM) has brought unique insight into the mechanisms underlying immune system dynamics and function since it enables monitoring of cellular motility and communication in complex systems within their genuine environment\^{a}€”the living organism. However, use of 2PM in clinical settings is limited. In contrast, optical coherence tomography (OCT), a noninvasive label-free diagnostic imaging method, which allows monitoring morphologic changes of large tissue regions in vivo, has found broad application in the clinic. Here we developed a combined multimodal technology to achieve near-instantaneous coregistered OCT, 2PM, and second harmonic generation (SHG) imaging over large volumes (up to 1,000\^{a}€‰\~{A}—\^{a}€‰1,000\^{a}€‰\~{A}—\^{a}€‰300\^{a}€‰\^{I}\OEm3) of tendons and other tissue compartments in mouse paws, as well as in mouse lymph nodes, spleens, and femurs. Using our multimodal imaging approach, we found differences in macrophage cell shape and motility behavior depending on whether they are located in tendons or in the surrounding tissue compartments of the mouse paw. The cellular shape of tissue-resident macrophages, indicative for their role in tissue, correlated with the supramolecular organization of collagen as revealed by SHG and OCT. Hence, the here-presented approach of coregistered OCT and 2PM has the potential to link specific cellular phenotypes and functions (as revealed by 2PM) to tissue morphology (as highlighted by OCT) and thus, to build a bridge between basic research knowledge and clinical observations. \^{A}© 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{jackle20b,
title = {Three-dimensional guidance including shape sensing of a stentgraft system for endovascular aneurysm repair},
author = { Sonja J\"{a}ckle and Ver\'{o}nica Garc{'i}a-V\'{a}zquez and Tim Eixmann and Florian Matysiak and Felix von Haxthausen and Malte Maria Sieren and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Floris Ernst and Markus Kleemann and Torben P\"{a}tz},
url = {https://doi.org/10.1007/s11548-020-02167-2},
doi = {10.1007/s11548-020-02167-2},
isbn = {1861-6429},
year  = {2020},
date = {2020-04-06},
journal = {International Journal of Computer Assisted Radiology and Surgery},
abstract = {During endovascular aneurysm repair (EVAR) procedures, medical instruments are guided with two-dimensional (2D) fluoroscopy and conventional digital subtraction angiography. However, this requires X-ray exposure and contrast agent is used, and the depth information is missing. To overcome these drawbacks, a three-dimensional (3D) guidance approach based on tracking systems is introduced and evaluated.},
keywords = {endovascular aneurysm repair, endovascular navigation, fiber Bragg gratings},
pubstate = {published},
tppubtype = {article}
}
@misc{mnter2020dynamic,
title = {Dynamic contrast in scanning microscopic OCT},
author = {Michael M\"{u}nter and Malte vom Endt and Mario Pieper and Malte Casper and Martin Ahrens and Tabea Kohlfaerber and Ramtin Rahmanzadeh and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},
url = {https://arxiv.org/pdf/2003.00006.pdf},
year  = {2020},
date = {2020-03-01},
abstract = {While optical coherence tomography (OCT) provides a resolution down to 1 μm it has difficulties to visualize cellular structures due to a lack of scattering contrast. By evaluating signal fluctuations, a significant contrast enhancement was demonstrated using time-domain full-field OCT (FF-OCT), which makes cellular and subcellular structures visible. The putative cause of the dynamic OCT signal is ATP-dependent motion of cellular structures in a sub- micrometer range, which provides histology-like contrast. Here we demonstrate dynamic contrast with a scanning frequency-domain OCT (FD-OCT). Given the inherent sectional imaging geometry, scanning FD-OCT provides depth-resolved images across tissue layers, a perspective known from histopathology, much faster and more efficiently than FF-OCT. Both, shorter acquisition times and tomographic depth-sectioning reduce the sensitivity of dynamic contrast for bulk tissue motion artifacts and simplify their correction in post-processing. The implementation of dynamic contrast makes microscopic FD-OCT a promising tool for histological analysis of unstained tissues.},
howpublished = {ARXIV:Preprint},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
@article{pieper2020intravital,
title = {Intravital microscopic optical coherence tomography imaging to assess mucus mobilizing interventions for muco-obstructive lung disease in mice},
author = {Mario Pieper and Hinnerk Schulz-Hildebrandt and Marcus A Mall and Gereon H\"{u}ttmann and Peter K\"{o}nig},
doi = {10.1152/ajplung.00287.2019},
year  = {2020},
date = {2020-02-26},
journal = {American Journal of Physiology-Lung Cellular and Molecular Physiology},
volume = {318},
number = {3},
pages = {518-524},
publisher = {American Physiological Society Rockville, MD},
abstract = {Pieper and Schulz-Hildebrandt contributed equally

Airway mucus obstruction is a hallmark of chronic lung diseases such as cystic fibrosis, asthma and COPD, and the development of more effective mucus mobilizing therapies remains an important unmet need for patients with these muco-obstructive lung diseases. However, methods for sensitive visualization and quantitative assessment of immediate effects of therapeutic interventions on mucus clearance in vivo are lacking. In this study, we determined if newly developed high-speed microscopic optical coherence tomography (mOCT) is sensitive to detect and compare in vivo effects of inhaled isotonic saline, hypertonic saline and bicarbonate on mucus mobilization and clearance in Scnn1b-transgenic mice with muco-obstructive lung disease. In vivomOCT imaging showed that inhaled isotonic saline-induced rapid mobilization of mucus that was mainly transported as chunks from the lower airways of Scnn1b-transgenic mice. Hypertonic saline mobilized a significantly greater amount of mucus that showed a more uniform distribution compared to isotonic saline. Addition of bicarbonate to isotonic saline had no effect on mucus mobilization, but also led to a more uniform mucus layer compared to treatment with isotonic saline alone. mOCT can detect differences in response to mucus mobilizing interventions in vivo, and may thus support the development of more effective therapies for patients with muco-obstructive lung diseases.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@inproceedings{10.1007/978-3-658-29267-6_58,
title = {Abstract: 3D Catheter Guidance Including Shape Sensing for Endovascular Navigation},
author = {Sonja J\"{a}ckle and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Felix von Haxthausen and Tim Eixmann and Malte Maria Sieren and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Floris Ernst and Markus Kleemann and Torben P\"{a}tz},
editor = {Thomas Tolxdorff and Thomas M Deserno and Heinz Handels and Andreas Maier and Klaus H Maier-Hein and Christoph Palm},
url = {https://link.springer.com/chapter/10.1007/978-3-658-29267-6_58},
isbn = {978-3-658-29267-6},
year  = {2020},
date = {2020-02-12},
booktitle = {Bildverarbeitung f\"{u}r die Medizin 2020},
pages = {261--261},
publisher = {Springer Fachmedien Wiesbaden},
address = {Wiesbaden},
abstract = {In endovascular aortic repair (EVAR) procedures fluoroscopy and conventional digital subtraction angiography are currently used to guide the medical instruments inside the patient. Drawbacks of these methods are X-ray exposure and the usage of contrast agents. Moreover, the fluoroscopy provides only a 2D view, which makes the guidance more difficult. For this reason, a catheter prototype including an optical fiber for shape sensing and three electromagnetic (EM) sensors, which provide the position and orientation information, was built to enable a 3D catheter guidance.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{10.1007/978-3-658-29267-6_70,
title = {Abstract: Fiber Optical Shape Sensing of Flexible Instruments},
author = {Sonja J\"{a}ckle and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Torben P\"{a}tz},
editor = {Thomas Tolxdorff and Thomas M Deserno and Heinz Handels and Andreas Maier and Klaus H Maier-Hein and Christoph Palm},
isbn = {978-3-658-29267-6},
year  = {2020},
date = {2020-02-12},
booktitle = {Bildverarbeitung f\"{u}r die Medizin 2020},
pages = {314--314},
publisher = {Springer Fachmedien Wiesbaden},
address = {Wiesbaden},
abstract = {For minimal invasive procedures like endovascular aortic repair procedures the instruments are navigated with 2D fluoroscopy imaging and digital subtraction angiography, which have several disadvantages. Optical fibers with fiber Bragg gratings (FBG), which allow to sense local strain respectively local curvature and bending angles, can be used for the guidance of medical tools to reduce the X-ray exposure and the used contrast agent. However, FBG-based shape sensing of flexible and long instruments is challenging and the computation includes many steps.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{10.1117/12.2548094,
title = {3D catheter guidance including shape sensing for endovascular navigation},
author = {Sonja J\"{a}ckle and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Felix von Haxthausen and Tim Eixmann and Malte Maria Sieren and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Floris Ernst and Markus Kleemann and Torben Paetz},
editor = {Baowei Fei and Cristian A Linte},
url = {https://doi.org/10.1117/12.2548094},
doi = {10.1117/12.2548094},
year  = {2020},
date = {2020-01-01},
booktitle = {Medical Imaging 2020: Image-Guided Procedures, Robotic Interventions, and Modeling},
volume = {11315},
pages = {21 -- 29},
publisher = {SPIE},
organization = {International Society for Optics and Photonics},
abstract = {Currently, uoroscopy and conventional digital subtraction angiography are used for imaging guidance in endovascular aortic repair (EVAR) procedures. Drawbacks of these image modalities are X-ray exposure, the usage of contrast agents and the lack of depth information. To overcome these disadvantages, a catheter prototype containing a multicore fiber with fiber Bragg gratings for shape sensing and three electromagnetic (EM) sensors for locating the shape was built in this study. Furthermore, a model for processing the input data from the tracking systems to obtain the located 3D shape of the first 38 cm of the catheter was introduced: A spatial calibration between the optical fiber and each EM sensor was made in a calibration step and used to obtain the located shape of the catheter in subsequent experiments. The evaluation of our shape localization method with the catheter prototype in different shapes resulted in average errors from 0.99 to 2.29 mm and maximum errors from 1.73 to 2.99 mm. The experiments showed that an accurate shape localization with a multicore fiber and three EM sensors is possible, and that this catheter guidance is promising for EVAR procedures. Future work will be focused on the development of catheter guidance based on shape sensing with a multicore fiber, and the orientation and position of less than three EM sensors.},
keywords = {catheter guidance, electromagnetic tracking, endovascular aneurysm repair, endovascular navigation, fiber Bragg gratings, shape sensing},
pubstate = {published},
tppubtype = {inproceedings}
}
@proceedings{Horn2019b,
title = {First Steps into Catheter Guidance Including Shape Sensing for Endovascular Aneurysm Repair Procedures},
author = {Marco Horn and Sonja J\"{a}ckle and Felix von Haxthausen and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Juljan Bouchagiar and Florian Matysiak and Mark Kaschwich and Markus Kleemann and Floris Ernst and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Torben P\"{a}tz},
doi = {10.1016/J.EJVS.2019.09.091},
issn = {1078-5884},
year  = {2019},
date = {2019-12-13},
journal = {European Journal of Vascular and Endovascular Surgery},
volume = {58},
number = {6},
pages = {e610--e611},
publisher = {W.B. Saunders},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
@article{Casper2019b,
title = {Capillary Refill - The Key to Assessing Dermal Capillary Capacity and Pathology in Optical Coherence Tomography Angiography},
author = {Casper, M. J. and Glahn, J. and Evers, M. and Schulz-Hildebrandt, H. and Kositratna, G. and Birngruber, R. and H\"{u}ttmann, G. and Manstein, D.},
doi = {10.1002/lsm.23188},
year  = {2019},
date = {2019-11-22},
journal = {Lasers in Surgery and Medicine},
abstract = {Background/Objectives Standard optical coherence tomography angiography (OCTA) has been limited to imaging blood vessels actively undergoing perfusion, providing a temporary picture of surface microvasculature. Capillary perfusion in the skin is dynamic and changes in response to the surrounding tissue's respiratory, nutritional, and thermoregulatory needs. Hence, OCTA often represents a given perfusion state without depicting the actual extent of the vascular network. Here we present a method for obtaining a more accurate anatomic representation of the surface capillary network in human skin using OCTA, along with proposing a new parameter, the Relative Capillary Capacity (RCC), a quantifiable proxy for assessing capillary dilation potential and permeability. Methods OCTA images were captured at baseline and after compression of the skin. Baseline images display ambient capillary perfusion, while images taken upon capillary refill display the network of existing capillaries at full capacity. An optimization-based automated vessel segmentation method was used to automatically analyze and compare OCTA image sequences obtained from two volunteers. RCC was then compared with visual impressions of capillary viability. Results Our OCTA imaging sequence provides a method for mapping cutaneous capillary networks independent of ambient perfusion. Differences between baseline and refill images clearly demonstrate the shortcomings of standard OCTA imaging and produce the RCC biometric as a quantifiable proxy for assessing capillary dilation potential and permeability. Conclusion Future dermatological OCTA diagnostic studies should implement the Capillary Refill Methods over standard imaging techniques and further explore the relevance of RCC to differential diagnosis and dermatopathology. 
\textbf{Lasers Surg. Med. © The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.}},
keywords = {optical coherence angiography, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@proceedings{Kohlfaerber2019b,
title = {Investigation of cell dynamics in 3D cell spheroids and cell interaction with 3D printed scaffolds by mOCT},
author = {Tabea Kohlfaerber and Shujun Ding and Ramtin Rahmanzadeh and Thomas J\"{u}ngst and J\"{u}rgen Groll and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann},
doi = {10.18416/AMMM.2019.1909S03P19},
year  = {2019},
date = {2019-11-21},
journal = {Transactions on Additive Manufacturing Meets Medicine},
volume = {1},
number = {1},
abstract = {Optical coherence tomography is a non-invasive and label-free imaging modality based on the detection of backscattered light in samples. As microscopic OCT (mOCT) combines high axial and lateral resolution, an investigation of biological and printed samples at subcellular level is feasible.  The additional excellent depth resolution enables mOCT to be a suitable quality control of 3D printed samples. The use of speckle variance adds information about cell viability. Here we present the feasibility of investigating cell viability within a cell spheroid and monitoring the cell interaction with bioprinted scaffolds using mOCT.},
keywords = {Optical coherence tomography, optical sensing},
pubstate = {published},
tppubtype = {proceedings}
}
@article{J\"{a}ckle2019,
title = {Fiber optical shape sensing of flexible instruments for endovascular navigation},
author = {Sonja J\"{a}ckle and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Torben P\"{a}tz},
url = {https://doi.org/10.1007/s11548-019-02059-0},
doi = {10.1007/s11548-019-02059-0},
issn = {1861-6429},
year  = {2019},
date = {2019-09-01},
journal = {International Journal of Computer Assisted Radiology and Surgery},
abstract = {Endovascular aortic repair procedures are currently conducted with 2D fluoroscopy imaging. Tracking systems based on fiber Bragg gratings are an emerging technology for the navigation of minimally invasive instruments which can reduce the X-ray exposure and the used contrast agent. Shape sensing of flexible structures is challenging and includes many calculations steps which are prone to different errors. To reduce this errors, we present an optimized shape sensing model.},
keywords = {fiber probes, optical sensing},
pubstate = {published},
tppubtype = {article}
}
@article{Casper2019,
title = {Optimization-based vessel segmentation pipeline for robust quantification of capillary networks in skin with optical coherence tomography angiography},
author = {Malte Casper, Hinnerk Schulz-Hildebrandt, Michael Evers, Reginald Birngruber, Dieter Manstein, Gereon H\"{u}ttmann},
doi = {10.1117/1.JBO.24.4.046005},
year  = {2019},
date = {2019-04-30},
journal = {Journal of Biomedical Optics},
volume = {24},
number = {4},
pages = {46005 - 1 - 11},
abstract = {We present an endoscopic probe for optical coherence tomography (OCT) equipped with a miniaturized hollow ultrasonic motor that rotates the objective lens and provides an internal channel for the fiber to pass through, enabling 360 deg unobstructed circumferential scanning. This probe has an outer diameter of 1.5 mm, which is ultra-small for motorized probes with an unobstructed view in distal scanning endoscopic OCT. Instead of a mirror or prism, a customized aspheric right-angle lens is utilized, leading to an enlargement of the numerical aperture and thus high transverse resolution. Spectral-domain OCT imaging of bio-tissue and a phantom are demonstrated with resolution of 7.5 μm(axial) × 6.6 μm (lateral) and sensitivity of 96 dB.},
keywords = {optical coherence angiography, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@inproceedings{Munter2019,
title = {4D microscopic optical coherence tomography imaging of ex vivo mucus transport},
author = {Michael M\"{u}nter and Hinnerk Schulz-Hildebrandt and Mario Pieper and Peter K\"{o}nig and Gereon H\"{u}ttmann},
url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11078/2527138/4D-microscopic-optical-coherence-tomography-imaging-of-ex-vivo-mucus/10.1117/12.2527138.full},
doi = {10.1117/12.2527138},
isbn = {9781510628496},
year  = {2019},
date = {2019-01-01},
booktitle = {Proc. SPIE 11078, Optical Coherence Imaging Techniques and Imaging in Scattering Media III},
volume = {11078},
number = {11},
pages = {1--5},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{Ahrens2019,
title = {An endomicroscopic OCT for clinical trials in the field of ENT (Invited)},
author = {Martin Ahrens and Christian Idel and Adam Chaker and Barbara Wollenberg and Peter K\"{o}nig and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann},
url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11073/2527099/An-endomicroscopic-OCT-for-clinical-trials-in-the-field-of/10.1117/12.2527099.full},
doi = {10.1117/12.2527099},
isbn = {9781510628397},
year  = {2019},
date = {2019-01-01},
booktitle = {Proc. SPIE 11073, Clinical and Preclinical Optical Diagnostics II},
number = {110730U},
pages = {1--4},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{Haak2019,
title = {Handheld OCT probe for intraoral diagnosis on teeth},
author = {Rainer Haak and Martin Ahrens and Hartmut Schneider and Michaela Strumpski and Claudia Rueger and Matthias Haefer and Gereon H\"{u}ttmann and Dirk Theisen-Kunde and Hinnerk Schulz-Hildebrandt},
url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11073/2527185/Handheld-OCT-probe-for-intraoral-diagnosis-on-teeth/10.1117/12.2527185.full},
doi = {10.1117/12.2527185},
isbn = {9781510628397},
year  = {2019},
date = {2019-01-01},
booktitle = {Proc. SPIE 11073, Clinical and Preclinical Optical Diagnostics II},
number = {110730W},
pages = {1--4},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{Schulz-Hildebrandt2019,
title = {Monitoring temperature induced phase changes in subcutaneous fatty tissue using an astigmatism corrected dynamic needle probe},
author = {Hinnerk Schulz-Hildebrandt and Naja Meyer-Schell and Malte Casper and Michael Evers and Reginald Birngruber and Dieter Manstein and Gereon H\"{u}ttmann},
url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11073/2527087/Monitoring-temperature-induced-phase-changes-in-subcutaneous-fatty-tissue-using/10.1117/12.2527087.full},
doi = {10.1117/12.2527087},
isbn = {9781510628397},
year  = {2019},
date = {2019-01-01},
booktitle = {Proc. SPIE 11073, Clinical and Preclinical Optical Diagnostics II},
number = {110730L},
pages = {1--3},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
@inproceedings{Smits2018,
title = {Development and Experimental Validation of a Combined FBG Force and OCT Distance Sensing Needle for Robot-Assisted Retinal Vein Cannulation},
author = {Jonas Smits and Mouloud Ourak and Andy Gijbels and Laure Esteveny and Gianni Borghesan and Laurent Schoevaerdts and K. Willekens P. Stalmans E. Lankenau Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Dominiek Reynaerts and Emmanuel B. Vander Poorten},
url = {https://doi.org/10.1109/ICRA.2018.8460983},
doi = {10.1109/ICRA.2018.8460983},
year  = {2018},
date = {2018-09-20},
journal = {2018 IEEE International Conference on Robotics and Automation (ICRA)},
pages = {129-134},
abstract = {Retinal Vein Occlusion is a common retinal vascular disorder which can cause severe loss of vision. Retinal vein cannulation followed by injection of an anti-coagulant into the affected vein is a promising treatment. However, given the scale and fragility of the surgical workfield, this procedure is considered too high-risk to perform manually. A first successful robot-assisted procedure has been demonstrated. Even though successful, the procedure remains extremely challenging. This paper aims at providing a solution for the limited perception of instrument-tissue interaction forces as well as depth estimation during retinal vein cannulation. The development of a novel combined force and distance sensing cannulation needle relying on Fiber Bragg grating (FBG) and Optical Coherence Tomography (OCT) A-scan technology is reported. The design, the manufacturing process, the calibration method, and the experimental characterization of the produced sensor are discussed. 
The functionality of the combined sensing modalities and the real-time distance estimation algorithm are validated respectively on in-vitro and ex-vivo models.},
keywords = {fiber probes, Medical optics instrumentation, Optical coherence tomography, Robotic},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{Schulz-Hildebrandt2018b,
title = {High-speed fiber scanning endoscope for volumetric multi-megahertz optical coherence tomography},
author = {Hinnerk Schulz-Hildebrandt and Tom Pfeiffer and Tim Eixmann and Sabrina Lohmann and Martin Ahrens and Josua Rehra and Wolfgang Draxinger and Peter K\"{o}nig and Robert Huber and Gereon H\"{u}ttmann},
url = {https://www.osapublishing.org/ol/abstract.cfm?uri=ol-43-18-4386#Abstract},
doi = {10.1364/OL.43.004386},
year  = {2018},
date = {2018-09-05},
journal = {Optics Letters},
volume = {43},
number = {18},
pages = {4386-4389},
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 μm 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.

© 2018 Optical Society of America},
keywords = {Endoscopic imaging., fiber probes, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@article{Ourak2018,
title = {Combined OCT distance and FBG force sensing cannulation needle for retinal vein cannulation: in vivo animal validation},
author = {Ourak, M. and Smits, J. and Esteveny, L. and Borghesan, G. and Gijbels, A. and Schoevaerdts, L. and Douven, Y. and Scholtes, J. and Lankenau, E. and Eixmann, T. and Schulz-Hildebrandt, Hinnerk and H\"{u}ttmann, Gereon and Kozlovszky, M. and Kronreif, G. and Willekens, K. and Stalmans, P. and Faridpooya, K. and Cereda, M. and Giani, A. and Staurenghi, G. and Reynaerts, D. and Vander Poorten, E. B.},
url = {http://link.springer.com/10.1007/s11548-018-1829-0},
doi = {10.1007/s11548-018-1829-0},
year  = {2018},
date = {2018-07-28},
journal = {International Journal of Computer Assisted Radiology and Surgery},
volume = {13},
number = {107},
pages = {1-9},
keywords = {fiber probes, Medical optics instrumentation, OCT, Optical coherence tomography, Robotic},
pubstate = {published},
tppubtype = {article}
}
@conference{Casper2018,
title = {Optimized segmentation and characterization of capillary networks using OCT (Conference Presentation)},
author = {Malte Casper and Hinnerk Schulz-Hildebrandt and Michael Evers and Reginald Birngruber and Dieter Manstein and Gereon H\"{u}ttmann},
url = {https://doi.org/10.1117/12.2292005},
doi = {10.1117/12.2292005},
year  = {2018},
date = {2018-03-14},
booktitle = {Proc. SPIE 10467, Photonics in Dermatology and Plastic Surgery 2018},
journal = {Proc.SPIE},
volume = {10467},
abstract = {The ability to image the physiology of microvasculature with high spatial resolution in three dimensions while investigating structural changes of skin, is essential for understanding the complex processes of skin aging, wound healing and disease development. Further, the quantitative, automatic assessment of these changes enables to analyze large amounts of image data in an abstract but comprehensive manner. 
However, previous work using OCT with methods of angiography was imaging less scattering, hence more challenging tissue than skin, such as brain and retina tissue. The published methods for capillary segmentation were mostly non-automatic, poorly benchmarked against state-of-the-art methods of computer vision and not applied to investigate medical processes and studies in a comprehensive fashion. 
Here, segmentation of capillaries in skin is reported and its efficacy is demonstrated in both, a 
longitudinal mouse study and a preliminary study in humans. By combining state-of-the-art image 
processing methods in an optimized way, we were able to improve the segmentation results and analyze the impact of each post-processing step. 
Furthermore, this automatic segmentation enabled us to analyze big amounts of 
datasets automatically and derive meaningful conclusions for the planning of clinical studies. 
With this work, optical coherence tomography is combined with methods of computer vision to a diagnostic 
tool with unique capabilities to characterize vascular diversity and provide extraordinary 
opportunities for dermatological investigation in both, clinics and research.},
keywords = {optical coherence angiography, Optical coherence tomography},
pubstate = {published},
tppubtype = {conference}
}
@inproceedings{Schulz-Hildebrandt2018a,
title = {Coherence and diffraction limited resolution in microscopic OCT by a unified approach for the correction of dispersion and aberrations},
author = {Hinnerk Schulz-Hildebrandt and Michael M\"{u}nter and Martin Ahrens and Hendrik Spahr and Dierck Hillmann and Peter K\"{o}nig and Gereon H\"{u}ttmann},
doi = {10.1117/12.2303755},
isbn = {9781510616745},
year  = {2018},
date = {2018-03-05},
booktitle = {2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources},
volume = {10591},
pages = {105910O},
abstract = {Optical coherence tomography (OCT) images scattering tissues with 5 to 15 μm resolution. This is usually not sufficient for a distinction of cellular and subcellular structures. Increasing axial and lateral resolution and compensation of artifacts caused by dispersion and aberrations is required to achieve cellular and subcellular resolution. This includes defocus which limit the usable depth of field at high lateral resolution. OCT gives access the phase of the scattered light and hence correction of dispersion and aberrations is possible by numerical algorithms. Here we present a unified dispersion/aberration correction which is based on a polynomial parameterization of the phase error and an optimization of the image quality using Shannon’s entropy. For validation, a supercontinuum light sources and a costume-made spectrometer with 400 nm bandwidth were combined with a high NA microscope objective in a setup for tissue and small animal imaging. Using this setup and computation corrections, volumetric imaging at 1.5 μm resolution is possible. Cellular and near cellular resolution is demonstrated in porcine cornea and the drosophila larva, when computational correction of dispersion and aberrations is used. Due to the excellent correction of the used microscope objective, defocus was the main contribution to the aberrations. In addition, higher aberrations caused by the sample itself were successfully corrected. Dispersion and aberrations are closely related artifacts in microscopic OCT imaging. Hence they can be corrected in the same way by optimization of the image quality. This way microscopic resolution is easily achieved in OCT imaging of static biological tissues.},
keywords = {mOCT, OCT theory},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{borghesan2018single,
title = {Single Scan OCT-based Retina Detection for Robot-assisted Retinal Vein Cannulation},
author = {Gianni Borghesan and Mouloud Ourak and Eva Lankenau and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrant and Koen Willekens and Peter Stalmans and Dominiek Reynaerts and Emmanuel Vander Poorten},
editor = {World Scientific},
url = {https://www.worldscientific.com/doi/abs/10.1142/S2424905X18400056},
doi = {10.1142/S2424905X18400056},
year  = {2018},
date = {2018-02-12},
journal = {Journal of Medical Robotics Research},
volume = {3},
number = {02},
pages = {184005},
abstract = {Vitreoretinal surgery concerns a set of particularly demanding minimal invasive micro-surgical interventions at the retina. Micro-surgeons are targeting sub-millimeter-sized structures here. Tiny vessels or wafer-thin membranes are to be cannulated or need to be peeled off. The greatest care is to be displayed not to damage these fragile structures or to inadvertently injure the underlying retina. Damage to the latter is mostly irreparable and might cause permanent loss of vision. Despite the availability over excellent stereo microscopes, wide-angle lenses and powerful light source visualization remains a problem. Especially, the limited depth perception is still perceived as a major bottle-neck whereas efforts have been conducted to integrate sensing capability in today’s state-of-the-art instruments, so far, little effort has been paid to process the obtained sensor data and turns this into a reliable source of information upon which robot assistive guidance schemes could be endowed upon. This paper proposes a number of processing techniques tailored to Optical Coherence Tomography (OCT) measurements. The first results of the proposed algorithms show that it is feasible to extract good and reliable distance estimates from this otherwise rather noisy signal and from a fairly limited dataset. The used data are the so-called A-scans. These are OCT measurements consisting of a single-line image that could be captured by an instrument-mounted fiber through which the OCT signal passes back-and-forth. However, in this work, we perform a pilot study whereby the employed A-scans are extracted from B-scans that are captured by a microscope-mounted OCT scanner, rather than obtained from a probe. The performance of a first embodiment of the algorithm that is based on an Unscented Kalman Filter (UKF) is compared to the performance of a second embodiment that relies on a Particle Filter (PF), focusing on the issues in filter initialization and the tracking quality. Finally, results of UKF and PF executions on a validation dataset are presented. 
Read More: https://www.worldscientific.com/doi/abs/10.1142/S2424905X18400056},
keywords = {estimation, fiber probes, Optical coherence tomography, Robotic, vitroretinal surgery},
pubstate = {published},
tppubtype = {article}
}
@article{schulz2018novel,
title = {Novel endoscope with increased depth of field for imaging human nasal tissue by microscopic optical coherence tomography},
author = {Hinnerk Schulz-Hildebrandt and Mario Pieper and Charlotte Stehmar and Martin Ahrens and Christian Idel and Barbara Wollenberg and Peter K\"{o}nig and Gereon H\"{u}ttmann},
editor = {Optical Society of America},
url = {https://www.osapublishing.org/abstract.cfm?URI=boe-9-2-636
https://www.osapublishing.org/boe/viewmedia.cfm?uri=boe-9-2-636\&seq=0},
doi = {10.1364/BOE.9.000636},
isbn = {10.1364/BOE.9.000636},
year  = {2018},
date = {2018-01-16},
journal = {Biomedical Optics Express},
volume = {9},
number = {2},
pages = {636-647},
abstract = {Intravital microscopy (IVM) offers the opportunity to visualize static and dynamic changes of tissue on a cellular level. It is a valuable tool in research and may considerably improve clinical diagnosis. In contrast to confocal and non-linear microscopy, optical coherence tomography (OCT) with microscopic resolution (mOCT) provides intrinsically cross-sectional imaging. Changing focus position is not needed, which simplifies especially endoscopic imaging. For in-vivo imaging, here we are presenting endo-microscopic OCT (emOCT). A graded-index-lens (GRIN) based 2.75 mm outer diameter rigid endoscope is providing 1.5 \textendash 2 μm nearly isotropic resolution over an extended field of depth. Spherical and chromatic aberrations are used to elongate the focus length. Simulation of the OCT image formation, suggests overall a better image quality in this range compared to a focused Gaussian beam. Total imaging depth at a reduced sensitivity and lateral resolution is more than 200 μm. Using a frame rate of 80 Hz cross-sectional images of concha nasalis were demonstrated in humans, which could resolve cilial motion, cellular structures of the epithelium, vessels and blood cells. Mucus transport velocity was determined successfully. The endoscope may be used for diagnosis and treatment control of different lung diseases like cystic fibrosis or primary ciliary dyskinesia, which manifest already at the nasal mucosa.},
keywords = {emOCT, Endoscopic imaging., Imaging systems, Medical optics and biotechnology, Medical optics instrumentation, mOCT, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@article{Horstmann2017,
title = {Label-Free In Vivo Imaging of Corneal Lymphatic Vessels Using Microscopic Optical Coherence Tomography},
author = {Jens Horstmann and Hinnerk Schulz-Hildebrandt and Felix Bock and Sebastian Siebelmann and Eva Lankenau and Gereon H\"{u}ttmann and Philipp Steven and Claus Cursiefen},
editor = {The Association Research for in Vision and Ophthalmology},
url = {http://iovs.arvojournals.org/article.aspx?articleid=2664271},
doi = {10.1167/iovs.17-22286},
isbn = {1552-5783},
year  = {2017},
date = {2017-12-25},
journal = {Investigative Ophthalmology \& Visual Science},
volume = {58},
number = {13},
pages = {5880-5886},
abstract = {Purpose: Corneal neovascularization, in particular lymphangiogenesis, is a limiting factor in corneal transplant survival. Novel treatment approaches focus on (selective) inhibition and regression of lymphatic vessels. Imaging clinically invisible corneal lymphatic vessels is a prerequisite for these strategies. Using a murine model, this study investigates whether corneal lymphatic vessels can be imaged using microscopic optical coherence tomography (mOCT). 
 
Methods: Corneal neovascularization was induced by intrastromal placement of 11.0 nylon sutures in one eye of BALB/c mice. After 2 weeks, cross-sectional images and volumes of the corneas with a 0.5 mm lateral and axial field of view were acquired using a custom-built mOCT system enabling a resolution of 1 μm at a B-scan rate of 165/s. Three of the six animals received an additional intrastromal injection of India ink 24 hours before the measurement to stain the corneal lymphatic system in vivo. Immunohistochemistry using CD31 and LYVE-1 was used to validate the mOCT findings. 
 
Results: Using mOCT, lymphatic vessels were visible as dark vessel-like structures with the lumen lacking a hyperreflective wall and mostly lacking cells. However, individual, slowly moving particles, which most likely are immune cells, occasionally could be observed inside the lumen. In lymphatic vessels of ink-stained corneas, hyperreflection and shadowing underneath was observed. Ink-filled lymphatic vessels were colocalized in consecutive corneal flat mounts of the same specimen. 
 
Conclusions: Corneal lymphatic vessels can be imaged using mOCT. This novel approach opens new options for noninvasive clinical imaging of corneal lymphatic vessels for diagnostic and therapeutic indications.},
keywords = {cornea, diagnostic imaging, lymphatic vessel, mOCT, Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@article{Horstmann2017c,
title = {Understanding OCT \textendash Part 2: State of the Practice},
author = {Jens Horstmann and Sebastian Siebelmann and Hinnerk Schulz-Hildebrandt and I Glasunow and A Schadschneider and Gereon H\"{u}ttmann},
editor = {Thieme},
doi = {10.1055/s-0033-1358249},
year  = {2017},
date = {2017-11-21},
journal = {Klinische Monatsblatter fur Augenheilkunde},
volume = {234},
number = {2},
pages = {233-247},
abstract = {Den Schwerpunkt dieses Artikels bildet die Vermittlung praktischen Wissens rund um die optische Koh\"{a}renztomografie (OCT). W\"{a}hrend in Teil 1 [1] die physikalischen Grundlagen vorgestellt wurden, werden hier praktische Aspekte f\"{u}r den Anwender erl\"{a}utert, unabh\"{a}ngig vom verwendeten Ger\"{a}tetyp oder Hersteller. 
 
Grunds\"{a}tzliche Parameter und Einstellm\"{o}glichkeiten werden vorgestellt. Es wird hinterfragt, was ein OCT-Bild eigentlich zeigt und wann bei der Interpretation und Auswertung Vorsicht geboten ist. Typische Artefakte sowie deren Ursachen und M\"{o}glichkeiten der Vermeidung werden diskutiert. Zuletzt wird eine \"{U}bersicht \"{u}ber aktuelle Anwendungsfelder der OCT in der Augenheilkunde gegeben},
keywords = {Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@article{Horstmann2017b,
title = {Understanding OCT-Part 1: Basic Knowledge},
author = {Jens Horstmann and Sebastian Siebelmann and Hinnerk Schulz-Hildebrandt and I Glasunow and A Schadschneider and Gereon H\"{u}ttmann},
doi = {10.1055/s-0042-119126},
year  = {2017},
date = {2017-11-02},
journal = {Klinische Monatsblatter fur Augenheilkunde},
volume = {234},
number = {1},
pages = {131-143},
abstract = {Die optische Koh\"{a}renztomografie (OCT) ist ein in vielen Bereichen der Augenheilkunde etabliertes Bildgebungsverfahren. Im 1. Teil zum Thema OCT werden technisch-physikalische Grundlagen zum Verst\"{a}ndnis vermittelt. Die prinzipielle Arbeitsweise der OCT wird erl\"{a}utert. Die zugrundeliegende Licht-Gewebe-Wechselwirkung sowie die OCT-Messtechnik werden beschrieben und verschiedene OCT-Verfahren vorgestellt. Komplexe physikalische Vorg\"{a}nge werden dabei anschaulich dargestellt und Formeln weitgehend vermieden. Hintergrundboxen laden zu einem tieferen Verst\"{a}ndnis ein. Ziel dieses Artikels ist ein Grundverst\"{a}ndnis der Methode zu vermitteln, das helfen soll, die OCT und ihre Aufnahmen zu verstehen. Die praktische Anwendung der OCT ist in Teil 2 [1] dargestellt.},
keywords = {Optical coherence tomography},
pubstate = {published},
tppubtype = {article}
}
@conference{Latus2017,
title = {An Approach for Needle Based Optical Coherence Elastography Measurements},
author = {Sarah Latus and Christoph Otte and Matthias Schl\"{u}ter and Josua Rehra and Kevin Bizon and Hinnerk Schulz-Hildebrandt and Thore Saathoff and Gereon H\"{u}ttmann and Alexander Schlaefer},
editor = {Springer International Publishing},
url = {https://link.springer.com/chapter/10.1007/978-3-319-66185-8_74},
doi = {https://doi.org/10.1007/978-3-319-66185-8_74},
isbn = {978-3-319-66185-8},
year  = {2017},
date = {2017-09-01},
booktitle = {Medical Image Computing and Computer-Assisted Intervention − MICCAI 2017},
volume = {10434},
pages = {655--663},
organization = {Springer},
abstract = {© Springer International Publishing AG 2017. 
While navigation and interventional guidance are typically based on image data, the images do not necessarily reflect mechanical tissue properties. Optical coherence elastography (OCE) presents a modality with high sensitivity and very high spatial and temporal resolution. However, OCE has a limited field of view of only 2\textendash5 mm depth. We present a side-facing needle probe to image externally induced shear waves from within soft tissue. A first method of quantitative needle-based OCE is provided. Using a time of flight setup, we establish the shear wave velocity and estimate the tissue elasticity. For comparison, an external scan head is used for imaging. Results for four different phantoms indicate a good agreement between the shear wave velocities estimated from the needle probe at different depths and the scan head. The velocities ranging from 0.9\textendash3.4 m/s agree with the expected values, illustrating that tissue elasticity estimates from within needle probes are feasible.},
keywords = {fiber probes, Interventional imaging, Optical coherence elastography},
pubstate = {published},
tppubtype = {conference}
}
@conference{Borghesan2017,
title = {Probabilistic Principal Component Analysis and Particle Filtering for real-time retina detection from a single-fiber OCT},
author = {Gianni Borghesan and Mouloud Ourak and Eva Lankenau and Richard Neffin and Peter Koch and Hinnerk Schulz-Hildebrandt and Koen Willekens and Peter Stalmans and Dominiek Reynaerts and Emmanuel Vander Poorten},
year  = {2017},
date = {2017-06-02},
booktitle = {Proceedings of the 7th Joint Workshop on New Technologies for Computer/Robot Assisted Surgery},
abstract = {Vitreo-retinal surgery concerns a set of particularly demanding micro-surgical interventions that take place at the back of the eye. Examples of such procedures are retinal vein cannulation (where the surgeon aims to insert a needle in a vein of the size of human hairs) and epiretinal membrane peeling (where a detached membrane must be removed from the retina). As severe retinal damage can be caused by undesired collisions, good instrument to retina distance perception would be very useful. We propose to use an OCT-fiber instrumented tool, and purposefully designed algorithms to interpret the measurements and extract a reliable real-time distance estimate. This abstract describes the progress that was made and includes a test conducted with a robotic platform on a synthetic eye mockup.},
keywords = {Optical coherence tomography, vitroretinal surgery},
pubstate = {published},
tppubtype = {conference}
}
@conference{Casper2017,
title = {Imaging cold-induced vasodynamic behaviour in skin using OCT for microangiography (Conference Presentation)},
author = {Malte Casper and Hinnerk Schulz-Hildebrandt and Michael Evers and Cuc Nguyen and Reginald Birngruber and Gereon H\"{u}ttmann and Dieter Manstein},
editor = {Spie},
doi = {doi: 10.1117/12.2251485},
year  = {2017},
date = {2017-04-19},
booktitle = {Proceedings Volume 10037, Photonics in Dermatology and Plastic Surgery},
volume = {10037OS},
abstract = {In dermatology the reflexes of vasoconstriction and vasodilation are known as important mechanisms of thermoregulation of the inner body. Imaging the physiology of microvasculature of the skin with high spatial resolution in three dimensions while reacting to changes in temperature is crucial for understanding the complex processes of vasodynamics, which result in constriction and dilation of vessels. However, previous studies using Laser-Doppler flowmetry and -imaging could not provide reliable angiographic images which allow to quantify changes in blood vessel diameter. Here, we report a different approach for angiographic imaging of microvasculature of a anaesthetized rodent model using speckle variance optical coherence tomography (svOCT) during and after localized cooling. Therefore a commercial OCT with a center wavelength of 1.3 μm and a spatial resolution of 13µm was used in combination with a custom built cooling device to image such reflexes at the mouse ear pinna and dorsal skinfold. Cooling was applied in steps of 2−5◦ C starting at the baseline temperature of 27◦ C down to −10◦ C. To our surprise and in contrast to the general opinion in literature, we were able to observe that the majority of vessels with a diameter larger than 20 μm maintain perfused with a constant diameter when the tissue is cooled from baseline to subzero temperatures. However, vasoconstriction was observed very rarely and only in veins, which led to their occlusion. The results of this experiment lead us to reconsider essential aspects of previous understanding of temperature-induced vasodynamics in cutaneous microvasculature.},
keywords = {optical coherence angiography, Optical coherence tomography},
pubstate = {published},
tppubtype = {conference}
}
@conference{Schulz-Hildebrandt2017,
title = {Improving imaging of the air-liquid interface in living mice by aberration-corrected optical coherence tomography (mOCT) (Conference Presentation)},
author = {Hinnerk Schulz-Hildebrandt and Benjamin Sauer and Fred Reinholz and Mario Pieper and Markus Mall and Peter K\"{o}nig and Gereon Huettmann},
doi = {doi: 10.1117/12.2252558},
year  = {2017},
date = {2017-04-17},
booktitle = {Proceedings Volume 10041, Optical Techniques in Pulmonary Medicine II},
volume = {1004105},
keywords = {Optical coherence tomography},
pubstate = {published},
tppubtype = {conference}
}
@conference{Schulz-Hildebrandt2016,
title = {Towards automated evaluation of mucus transport measured by microscopic OCT (mOCT) during hypertonic saline treatment of Cystic Fibrosis},
author = {Hinnerk Schulz-Hildebrandt and Mario Pieper and J Kasper and Nadine Traulsen and Markus Mall and Peter K\"{o}nig and Gereon H\"{u}ttmann},
url = {http://www.schulz-hildebrandt.com/wp-content/uploads/2018/04/SchulzHildebrandt2016.jpg},
doi = {10.1055/s-0036-1584651},
year  = {2016},
date = {2016-07-01},
booktitle = {Pneumologie},
volume = {70},
number = {07},
pages = {48},
abstract = {Effective mucus transport in the airways is essential for infection defense. Malfunction caused by diseases like cystic fibrosis (CF) can result in severe and even life threatening complications. Time resolved imaging of mucus transport in vivo is essential to get mechanistic insight in factors influencing the transport and for developing and testing therapeutic interventions to increase mucus transport. 
 
Microscopic OCT (mOCT) was used successfully to image mucus transport in trachea of spontaneous breathing mice. Image series over more than 2 hours containing 35,000 frames were captured in wild type (WT) and βENaC overexpressing mice, which served as a model for CF. In order to evaluate these large amount of data an automatic quantitative evaluation is need. This has to include an efficient correction of tissue motion and an automatic identification and rejection of non-evaluable frames. 
 
In this study we compared two algorithms for motion correction. A pairwise correlation of the different frame for calculation of the motion vector was matched to a maximization of the overlap of segmented images. Image series were evaluated with both algorithms and bench marked against a manual motion correction. 
 
Due to the dominating speckle noise in the OCT images and tissue motion perpendicular to the plane of the cross-sectional images, the correlation algorithms was not able to correctly determine a correct tissue motion in all cases. Results of the optimization algorithms were more reliable after dedicated preprocessing of the images. In cases of strong motion both algorithms failed. 
 
In conclusion, automatic motion correction of mOCT image series taken from mice trachea is possible. However, at the current stage manual supervision is still necessary.},
keywords = {Optical coherence tomography},
pubstate = {published},
tppubtype = {conference}
}
@conference{Pieper2016,
title = {Intravital microscopy of mucus transport in mice provides mechanistic insight into hypertonic saline treatment of Cystic Fibrosis},
author = {Mario Pieper and Hinnerk Schulz-Hildebrandt and Marcus A Mall and Gereon H\"{u}ttmann and Peter K\"{o}nig},
editor = {Thieme},
doi = {10.1055/s-0036-1584654},
year  = {2016},
date = {2016-07-01},
booktitle = {Pneumologie},
volume = {70},
pages = {SOP2},
keywords = {Optical coherence tomography},
pubstate = {published},
tppubtype = {conference}
}
@article{Guder2015,
title = {Microanatomy of the tympanic membrane in chronic myringitis obtained with optical coherence tomography},
author = {Ellen Guder and Eva Lankenau and Felix Fleischhauer and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and HW Pau and Tino Just},
editor = {Springer Berlin Heidelberg},
url = {https://link.springer.com/article/10.1007/s00405-014-3373-z},
doi = {doi.org/10.1007/s00405-014-3373-z},
issn = {1434-4726},
year  = {2015},
date = {2015-11-11},
journal = {European Archives of Oto-Rhino-Laryngology},
volume = {272},
number = {11},
pages = {3217-3223},
abstract = {© 2014, Springer-Verlag Berlin Heidelberg. A microscope-based optical coherence tomography (OCT) device was used to assess the microanatomy of the tympanic membrane in patients with chronic myringitis. A prospective study was designed for this purpose. OCT measurements of the tympanic membrane were done on 11 patients with myringitis with a microscope-based spectral domain OCT system. The in vivo findings were compared with those findings of a control group consisting of 36 patients with retraction pockets or atrophic tympanic membranes (n = 13), myringosclerosis (n = 12) and perforations (n = 11). In active chronic myringitis, the thickness of the tympanic membrane is increased compared to healthy membranes and to other pathological conditions of the tympanic membrane. Consistent changes of the microanatomy of the tympanic membrane were found in chronic myringitis with OCT. Serial OCT measurements revealed no biofilm suspicious findings in all patients with active chronic myringitis. Intraoperative and in vivo OCT measurements may help to detect microanatomical changes of the tympanic membrane in chronic myringitis and in other conditions of the tympanic membrane.},
keywords = {Chronic myringitis, Optical coherence tomography, Tympanic membrane},
pubstate = {published},
tppubtype = {article}
}
@conference{Fleischhauer2013,
title = {Polarization-sensitive optical coherence tomography on different tissues samples for tumor discrimination},
author = {Felix Fleischhauer and Hinnerk Schulz-Hildebrandt and Tim Bonin and Gereon H\"{u}ttmann },
url = {http://www.bmo.uni-luebeck.de/fileadmin/files/publications/Fleischhauer__2013_Polarization-sensitive_optical_coherence_tomography.pdf},
year  = {2013},
date = {2013-07-01},
booktitle = {Student Conference Medical Engineering Science 2013: Proceedings},
volume = {2},
pages = {38},
publisher = {GRIN Verlag},
abstract = {ptical coherence tomography (OCT) is now state of the art in ophthalmology. Other medical departments, such as otolaryngology, could also benefit from this imaging modality. Polarization is a property which is a benefit to conventional OCT. It can be used in particular to detect birefringent tissue layers. To evaluate possible OCT applications in Ear, Nose and Throat (ENT) department, a fiber-based polarization-sensitive OCT (PS- OCT) is used to measure human ex-vivo tissue biopsies. A total of 58 samples from 20 different tissues were measured.
The measurements show that small biopsies lose their birefrin- gent property, this leads to the assumption that tissue-matrices lose tension and molecular order. Larger samples show phase retardation and are used to detect different birefringent layers of tissue. We also show a method of verifying cancer diagnosis by displaying the tissue layer structure.
As a conclusion, PS-OCT may improve cancer diagnosis in ENT.},
keywords = {OCT, Optical coherence tomography, PS-OCT},
pubstate = {published},
tppubtype = {conference}
}
@book{Jurgens2012,,
title = {Introduction to Micro- and Nanooptics},
author = {J\"{u}rgen Jahns and Stefan Helfer},
url = {http://www.wiley-vch.de/de/fachgebiete/ingenieurwesen/introduction-to-micro-and-nanooptics-978-3-527-40891-7},
isbn = {9783527408917},
year  = {2012},
date = {2012-05-01},
publisher = {WILEY-VCH},
abstract = {This first textbook on both micro- and nanooptics introduces readers to the technological development, physical background and key areas.The opening chapters on the physics of light are complemented by chapters on refractive and diffractive optical elements. The internationally renowned authors present different methods of lithographic and nonlithographic fabrication of microoptics and introduce the characterization and testing of microoptics.The second part of the book is dedicated to optical microsystems and MEMS, optical waveguide structures and optical nanostructures, including photonic crystals and metamaterials. Each chapter includes exercises illustrating a sample approach to new and complex topics, making the textbook suitable for lectures on optics as part of a physics or electrical engineering course.
},
keywords = {Book, PageSimulation},
pubstate = {published},
tppubtype = {book}
}