2018
|
Ourak, M.; Smits, J.; Esteveny, L.; Borghesan, G.; Gijbels, A.; Schoevaerdts, L.; Douven, Y.; Scholtes, J.; Lankenau, E.; Eixmann, T.; Schulz-Hildebrandt, Hinnerk; Hüttmann, Gereon; Kozlovszky, M.; Kronreif, G.; Willekens, K.; Stalmans, P.; Faridpooya, K.; Cereda, M.; Giani, A.; Staurenghi, G.; Reynaerts, D.; Vander Poorten, E. B. Combined OCT distance and FBG force sensing cannulation needle for retinal vein cannulation: in vivo animal validation Journal Article In: International Journal of Computer Assisted Radiology and Surgery, vol. 13, no. 107, pp. 1-9, 2018. @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 = {},
pubstate = {published},
tppubtype = {article}
}
|
Malte Casper; Hinnerk Schulz-Hildebrandt; Michael Evers; Reginald Birngruber; Dieter Manstein; Gereon Hüttmann Optimized segmentation and characterization of capillary networks using OCT (Conference Presentation) Conference Proc. SPIE 10467, Photonics in Dermatology and Plastic Surgery 2018, vol. 10467, 2018. @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 = {},
pubstate = {published},
tppubtype = {conference}
}
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. |
Hinnerk Schulz-Hildebrandt; Michael Münter; Martin Ahrens; Hendrik Spahr; Dierck Hillmann; Peter König; Gereon Hüttmann Coherence and diffraction limited resolution in microscopic OCT by a unified approach for the correction of dispersion and aberrations Proceedings Article In: 2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources, pp. 105910O, 2018, ISBN: 9781510616745. @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 = {},
pubstate = {published},
tppubtype = {inproceedings}
}
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. |
Gianni Borghesan; Mouloud Ourak; Eva Lankenau; Gereon Hüttmann; Hinnerk Schulz-Hildebrant; Koen Willekens; Peter Stalmans; Dominiek Reynaerts; Emmanuel Vander Poorten Single Scan OCT-based Retina Detection for Robot-assisted Retinal Vein Cannulation Journal Article In: Journal of Medical Robotics Research, vol. 3, no. 02, pp. 184005, 2018. @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 = {},
pubstate = {published},
tppubtype = {article}
}
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 |
Hinnerk Schulz-Hildebrandt; Mario Pieper; Charlotte Stehmar; Martin Ahrens; Christian Idel; Barbara Wollenberg; Peter König; Gereon Hüttmann Novel endoscope with increased depth of field for imaging human nasal tissue by microscopic optical coherence tomography Journal Article In: Biomedical Optics Express, vol. 9, no. 2, pp. 636-647, 2018, ISBN: 10.1364/BOE.9.000636. @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 = {},
pubstate = {published},
tppubtype = {article}
}
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 – 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. |
2017
|
Jens Horstmann; Hinnerk Schulz-Hildebrandt; Felix Bock; Sebastian Siebelmann; Eva Lankenau; Gereon Hüttmann; Philipp Steven; Claus Cursiefen Label-Free In Vivo Imaging of Corneal Lymphatic Vessels Using Microscopic Optical Coherence Tomography Journal Article In: Investigative Ophthalmology & Visual Science, vol. 58, no. 13, pp. 5880-5886, 2017, ISBN: 1552-5783. @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 = {},
pubstate = {published},
tppubtype = {article}
}
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. |
Jens Horstmann; Sebastian Siebelmann; Hinnerk Schulz-Hildebrandt; I Glasunow; A Schadschneider; Gereon Hüttmann Understanding OCT – Part 2: State of the Practice Journal Article In: Klinische Monatsblatter fur Augenheilkunde, vol. 234, no. 2, pp. 233-247, 2017. @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 = {},
pubstate = {published},
tppubtype = {article}
}
Den Schwerpunkt dieses Artikels bildet die Vermittlung praktischen Wissens rund um die optische Kohärenztomografie (OCT). Während in Teil 1 [1] die physikalischen Grundlagen vorgestellt wurden, werden hier praktische Aspekte für den Anwender erläutert, unabhängig vom verwendeten Gerätetyp oder Hersteller.
Grundsätzliche Parameter und Einstellmöglichkeiten 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 Möglichkeiten der Vermeidung werden diskutiert. Zuletzt wird eine Übersicht über aktuelle Anwendungsfelder der OCT in der Augenheilkunde gegeben |
Jens Horstmann; Sebastian Siebelmann; Hinnerk Schulz-Hildebrandt; I Glasunow; A Schadschneider; Gereon Hüttmann Understanding OCT-Part 1: Basic Knowledge Journal Article In: Klinische Monatsblatter fur Augenheilkunde, vol. 234, no. 1, pp. 131-143, 2017. @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 = {},
pubstate = {published},
tppubtype = {article}
}
Die optische Kohärenztomografie (OCT) ist ein in vielen Bereichen der Augenheilkunde etabliertes Bildgebungsverfahren. Im 1. Teil zum Thema OCT werden technisch-physikalische Grundlagen zum Verständnis vermittelt. Die prinzipielle Arbeitsweise der OCT wird erläutert. Die zugrundeliegende Licht-Gewebe-Wechselwirkung sowie die OCT-Messtechnik werden beschrieben und verschiedene OCT-Verfahren vorgestellt. Komplexe physikalische Vorgänge werden dabei anschaulich dargestellt und Formeln weitgehend vermieden. Hintergrundboxen laden zu einem tieferen Verständnis ein. Ziel dieses Artikels ist ein Grundverständnis 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. |
Sarah Latus; Christoph Otte; Matthias Schlüter; Josua Rehra; Kevin Bizon; Hinnerk Schulz-Hildebrandt; Thore Saathoff; Gereon Hüttmann; Alexander Schlaefer An Approach for Needle Based Optical Coherence Elastography Measurements Conference Medical Image Computing and Computer-Assisted Intervention − MICCAI 2017, vol. 10434, Springer 2017, ISBN: 978-3-319-66185-8. @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 = {},
pubstate = {published},
tppubtype = {conference}
}
© 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 2–5 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 0.9–3.4 m/s agree with the expected values, illustrating that tissue elasticity estimates from within needle probes are feasible. |
Gianni Borghesan; Mouloud Ourak; Eva Lankenau; Richard Neffin; Peter Koch; Hinnerk Schulz-Hildebrandt; Koen Willekens; Peter Stalmans; Dominiek Reynaerts; Emmanuel Vander Poorten Probabilistic Principal Component Analysis and Particle Filtering for real-time retina detection from a single-fiber OCT Conference Proceedings of the 7th Joint Workshop on New Technologies for Computer/Robot Assisted Surgery, 2017. @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 = {},
pubstate = {published},
tppubtype = {conference}
}
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. |