@article{Detrez:26,
author = {Nicolas Detrez and Sazgar Burhan and Jessica Kren and Jakob Matschke and Christian Hagel and Steffen Buschschl\"{u}ter and Dirk Theisen-Kunde and Matteo Mario Bonsanto and Robert Huber and Ralf Brinkmann},
journal = {Biomed. Opt. Express},
keywords = {Clinical applications; Deep learning; Elastography; Phase noise; Phase unwrapping; Tissue characterization},
number = {3},
pages = {1335--1358},
publisher = {Optica Publishing Group},
title = {Processing pipeline for large optical coherence elastography datasets with quasi-static air-jet excitation: application to human brain tumor tissue},
volume = {17},
month = {Mar},
year = {2026},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-17-3-1335},
doi = {10.1364/BOE.584263},
abstract = {Optical coherence elastography (OCE) is a powerful imaging modality for assessing the mechanical properties of biological tissues. We employed an OCE system based on an Optores OMES 3.2 MHz OCT platform combined with an in-house developed air-jet excitation source to characterize healthy and tumorous (meningioma) human brain tissue. This paper presents a comprehensive software framework for processing large OCE datasets, enabling robust extraction of characteristic features from phase-derived displacement data and calculation of mechanical proxy parameters for detailed tissue characterization. Feature detection is achieved using a modified triangle threshold algorithm applied to the displacement curves from the OCE phase data. Extensive pre- and post-processing steps, including percentile-based filtering and adaptive histogram equalization, are applied to mitigate phase unwrapping errors and enhance visualization of the high dynamic range of OCE data. Exemplary measurements on human brain tumor samples demonstrate the framework's ability to differentiate between tissue types, highlighting its potential for future clinical and research applications.},
}

@Article{dj14020084,
AUTHOR = {Kuhl, Julie-Jacqueline and Schlenz, Maximiliane Amelie and Wöstmann, Bernd and Grill, Christin and Brinkmann, Ralf and Moos, Christoph},
TITLE = {Discrepancy Between Surface Wear and Subsurface Fatigue Damage in CAD/CAM Composite Crowns: A Comparative Study of Intraoral Scans and Optical Coherence Tomography},
JOURNAL = {Dentistry Journal},
VOLUME = {14},
YEAR = {2026},
NUMBER = {2},
ARTICLE-NUMBER = {84},
URL = {https://www.mdpi.com/2304-6767/14/2/84},
ISSN = {2304-6767},
ABSTRACT = {Objectives: This study aimed to determine whether surface wear, identified through the superimposition of intraoral scans (IOS), can predict subsurface damage progression detected by optical coherence tomography (OCT) during fatigue testing of computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns. Methods: Monolithic CAD/CAM composite crowns (Brilliant Crios; n=8) were adhesively luted to standardized prepared human teeth and artificially aged by cyclic loading in a mouth-motion simulator (50–500 N, 2 Hz, 37 °C). Under phantom-head condition, IOS (surface wear) and handheld swept-source (SS)-OCT (subsurface damage) were performed before loading and after every 250,000 cycles. OCT crack depth/width were normalized to local thickness and cusp-tip distance; correspondence between IOS- and OCT-derived metrics at each timepoint was assessed with Spearman’s rank correlation coefficient (ρ) to test whether surface wear can predict subsurface damage under the given conditions. Results: All specimens survived without catastrophic failure, and both modalities revealed progressive damage from the earliest observation interval. OCT consistently showed higher defect percentages and larger dispersion (e.g., mean vertical defects (25.47 ± 4.97)% OCT vs. (4.36 ± 0.91)% IOS at T1 and (66.79 ± 19.53)% OCT vs. (7.78 ± 3.19)% IOS at T5). Across all timepoints, no statistically significant associations between IOS and OCT were observed (p = 0.146 to 0.955). Conclusions: Within the limitations of this exploratory, single-material in vitro study, restricted to a CAD/CAM composite (Brilliant Crios), surface-based monitoring alone did not reliably reflect subsurface damage progression. Clinically, this suggests that surface wear assessment may underestimate subsurface fatigue damage. Intraoral OCT may provide complementary, non-invasive information alongside routine IOS for individualized monitoring, but its added value needs to be confirmed in larger studies and other CAD/CAM composite materials and additional restorative material classes.},
DOI = {10.3390/dj14020084}
}

@inproceedings{10.1117/12.3080934,
author = {Henrik Volkens and Christin Grill and Florian Denk and Philipp Lamminger and Sebastian Freidank and Norbert Linz and Hendrik Husstedt and Robert Huber and Ralf Brinkmann},
title = {{A home-built flexible fiber laser to investigate optimal parameters for stimulating the tympanic membrane}},
volume = {13849},
booktitle = {Optical Interactions with Tissue and Cells XXXVII},
editor = {Joel N. Bixler and Alex J. Walsh and Norbert Linz},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1384904},
abstract = {This work investigates optimizing optoacoustic stimulation of tympanic membrane models as a non-occlusive alternative to conventional acoustic drivers. We used a home-built, ytterbium-based master oscillator power amplifier (MOPA) operating at 1064 nm to stimulate an artificial tympanic membrane within a simplified middle ear model. The MOPA system can generate single laser pulses with 200 ps minimum pulse duration as well as concatenating multiple single pulses to MHz-bursts with burst durations up to 100 ns. Burst durations and burst energies were systematically varied between 30 and 100 ns and from 10 to 40 μJ. The laser-induced displacement of the membrane model was measured using phase-sensitive optical coherence tomography. Simultaneously the sound pressure level within a 0.4 ccm volume that mimics the middle ear cavity was measured. The results indicate that the membrane displacement and sound pressure increases both with higher burst energies at the same burst duration and longer burst durations at the same burst energy. Specifically, at a low burst repetition rate of 16 Hz, 100-ns pulse bursts yielded the most efficient stimulation. Furthermore, we demonstrated the system's capability for sound transmission up to 5 kHz by operating the MOPA at a repetition rate of 10 kHz. Using an acousto-optic modulator (AOM) for pulse amplitude modulation, we transmitted a speech signal onto the artificial membrane. The resulting acoustic signal was clearly audible and measurable within the middle ear model. These findings validate the feasibility of using tailored infrared laser pulses for middle ear stimulation. The ability to modulate complex audio signals via flexible, fiber-based laser architecture is a promising approach for developing next-generation hearing restoration technologies that avoid the occlusion effects and discomfort associated with traditional hearing aids.},
keywords = {Master oscillator fiber amplifier, Tympanic membrane, Temporal pulse shaping, Flexible fiber laser, Thermoelastic bending, Parameter optimization, Optical tissue stimulation},
year = {2026},
doi = {10.1117/12.3080934},
URL = {https://doi.org/10.1117/12.3080934}
}

@inproceedings{10.1117/12.3080401,
author = {Henrik Volkens and Sebastian Freidank and Philipp Lamminger and Alfred Vogel and Robert Huber and Ralf Brinkmann and Norbert Linz},
title = {{Dynamic shockwave photography using a home-built MOFA laser system with flexible repetition rate up to 5 GHz}},
volume = {PC13849},
booktitle = {Optical Interactions with Tissue and Cells XXXVII},
editor = {Joel N. Bixler and Alex J. Walsh and Norbert Linz},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {PC1384903},
abstract = {Laser-induced ablation in liquids (LAL) is widely used for nanoparticle generation, yet its underlying mechanisms are not completely understood. We investigate interactions between shockwave, cavitation bubble and target material by multi exposure imaging with high temporal and spatial resolution. Our home-built Yb-based master oscillator fiber amplifier system delivers 170 ps pulses at 2 µJ and tunable burst rates up to 5 GHz, ideal for capturing transient events. Speckle-free imaging is achieved using a fiber-based rapid optical mode mixing approach combining spectral broadening with optical delay and spatial mode mixing of frequency-doubled 532 nm pulses.},
keywords = {Laser Ablation in Liquids (LAL), Shockwave Photography, High-Speed Imaging, Multi-Exposure Illumination, Master Oscillator Fiber Amplifier (MOFA), Speckle-Free Imaging, Cavitation Bubble, Nanoparticle Generation},
year = {2026},
doi = {10.1117/12.3080401},
URL = {https://doi.org/10.1117/12.3080401}
}

@inproceedings{10.1117/12.3080520,
author = {Henrik Volkens and Philipp Lamminger and Norbert Linz and Sebastian Freidank and Robert Huber and Ralf Brinkmann},
title = {{Towards optoacoustic transient shaping using a flexible fiber laser system}},
volume = {13851},
booktitle = {Photons Plus Ultrasound: Imaging and Sensing 2026},
editor = {Alexander A. Oraevsky and Lihong V. Wang},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {138511F},
abstract = {We aim to increase the efficiency of optoacoustic signal generation for precise, in vivo, real-time tissue temperature monitoring during thermal retinal interventions, by matching the timing of multiple laser excitation events to the acoustic response of the examined specimen. To achieve this goal, we utilized a home-built Ytterbium-based master oscillator power amplifier (MOPA) fiber laser system that provides unprecedented control over the temporal pulse structure, allowing for pulse-burst durations from picoseconds to nanoseconds and arbitrary repetition rates for investigating the influence of the excitation duration on the amplitude of the resulting optoacoustic transients. Methodologically, experiments were performed on ex vivo explants of porcine retinal pigment epithelium (RPE) consisting of the RPE, choroid, and sclera embedded in a cuvette filled with saline solution. Optoacoustic transients were detected using a piezoelectric ring transducer (fres = 1 MHz, Medical Laser Center Lübeck, Germany) integrated into a standard ophthalmic contact glass with a distance of 24 mm to the specimen. We systematically investigated the influence of pulse-burst durations between 10 and 100-ns with the total burst energy of 3 μJ matching a typical probe pulse energy. Each burst was produced with a repetition rate of 500 MHz. Results demonstrate that, at typical pulse energies of 3 μJ, shorter pulse-burst durations down to 30 ns significantly increase the amplitude of the generated acoustic transients compared to longer pulse-bursts. While higher burst energy consistently results in stronger signals, signal generation efficiency is highly dependent on the temporal burst width. With decreasing burst durations, the amplitude of the resulting transients decreases lower than that of the 30-ns burst. We hypothesize that shorter excitation bursts result in a signal consisting of higher-frequency components that are stronger attenuated in water. These findings highlight that tailoring the temporal excitation profile is essential for maximizing signal-to-noise ratio. The compact and scalable fiber-based MOPA architecture offers a versatile alternative to traditional bulk lasers, providing the necessary degrees of freedom for optimized optoacoustic tissue characterization and in future real-time monitoring.},
keywords = {Master Oscillator Fiber Amplifier (MOFA), Optoacoustics, Transient shaping, Temperature measurement, Tailored optoacoustic excitation, Flexible fiber laser, Retinal laser treatment, Multi-GHz repetition rate},
year = {2026},
doi = {10.1117/12.3080520},
URL = {https://doi.org/10.1117/12.3080520}
}

@article{Enzian2026,
  title = {Precise ablation of cholesteatoma using a 445-nm diode laser},
  volume = {16},
  ISSN = {2045-2322},
  url = {http://dx.doi.org/10.1038/s41598-026-47908-6},
  DOI = {10.1038/s41598-026-47908-6},
  number = {1},
  journal = {Scientific Reports},
  publisher = {Springer Science and Business Media LLC},
  author = {Enzian,  Paula and Detje,  Ann Marina and Lange,  Birgit and Penxová,  Zuzana and Leffers,  David and Rahmanzadeh,  Ramtin and Bruchhage,  Karl-Ludwig and Leichtle,  Anke and Brinkmann,  Ralf},
  year = {2026},
  month = May 
}

@article{Enzian2026LaserAblation,
author = {Enzian, Paula and Lühring, Kimberley and Lange, Birgit and Leffers, David and Bruchhage, Karl-Ludwig and Leichtle, Anke and Brinkmann, Ralf},
title = {Enhancing the Efficacy of Noncontact Laser Ablation of Weakly Absorbing Cholesteatoma Tissue Using a Blood Layer},
journal = {Lasers in Surgery and Medicine},
keywords = {blood absorption layer, blue laser, cholesteatoma, laser ablation, otorhinolaryngology},
doi = {https://doi.org/10.1002/lsm.70145},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lsm.70145},
eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/lsm.70145},
abstract = {ABSTRACT Objectives The 445 nm diode lasers have already been used successfully and safely for cholesteatoma surgery. However, the ablation of low absorbing and strongly scattering anemic tissue, such as keratinizing squamous epithelium of the cholesteatoma becomes challenging with low laser power. The initiation of ablation often occurs abruptly and not reproducibly with a noticeable acceleration after the start of carbonization. This study investigates whether a thin layer of blood on an adequate tissue model can improve light absorption and ablation. Materials and Methods Porcine aortic tissue served as a model for pale, weakly absorbing tissue. Blood volumes of 2.5–110 μL were pipetted onto punch samples with a diameter of 12 mm. Tissue ablation was performed with a 445 nm diode laser at continuous wave powers of 1 W and 4 W at working distances of 1 mm and 2 mm to the distal tip of the transmitting multimode optical fiber, being moved with a speed of 5 mm/s across the tissue. Ablation depths and blood layer thicknesses were measured using optical coherence tomography (OCT). A theoretical model was used to estimate the optimal amount of blood to achieve the deepest ablation. Results Different blood layer thicknesses were examined, ranging from 17 μm to 1.3 mm. With the blood layer thickness of 50–100 μm the maximum ablation depth of approximately 370 μm was measured with a power of 4 W. Without blood, no ablation was achieved. However, it could be shown that the optimal blood layer thickness depended on the selected parameters, such as laser power and working distance. The experimental results closely matched model predictions, confirming the model's validity in estimating the ablation outcomes. Conclusion A thin blood layer enhances laser ablation of low-absorbing tissue with 445 nm laser radiation, such as cholesteatoma, allowing precise tissue removal.}
}

@article{https://doi.org/10.1002/jbio.70304,
author = {Lühring, Kimberley and Lange, Birgit and Brinkmann, Ralf},
title = {Ho:YAG and Thulium Fiber Laser Radiation Transmission Through Vapor Channels in Laser Lithotripsy},
journal = {Journal of Biophotonics},
volume = {19},
number = {6},
pages = {e70304},
keywords = {laser lithotripsy, laser therapy, urinary stones, urolithiasis},
doi = {https://doi.org/10.1002/jbio.70304},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jbio.70304},
eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/jbio.70304},
note = {e70304 4077416},
abstract = {ABSTRACT The efficiency of energy deposition during laser lithotripsy is strongly influenced by the interaction between laser radiation and the water layer between fiber tip and stone. This study investigates the transmission of holmium:YAG (Ho:YAG) and thulium fiber laser (TFL) radiation through vapor channels under varying fiber-to-target distances (0.5–3 mm). Both lasers were set to deliver pulses of 1 J. The fiber was positioned in a water-filled cuvette on top of an integrating sphere to measure transmittance through different water layer thicknesses. A 580 μs, high-power (up to 7 kW) Ho:YAG laser pulse creates a vapor channel that enables continuous transmission of the laser energy to the target surface for standoff distances > 0.5 mm. With the TFL's longer (2 ms), lower peak power (500 W) pulses, repeated cycles of vaporization and bubble collapse occur, resulting in a reduced energy transmission efficiency compared to the Ho:YAG laser pulses.},
year = {2026}
}

@Article{bioengineering13070808,
AUTHOR = {Moos, Christoph and Kuhl, Julie-Jacqueline and Wöstmann, Bernd and Grill, Christin and Brinkmann, Ralf and Schlenz, Maximiliane Amelie},
TITLE = {Prediction of Subsurface Fatigue Damage in Dental CAD/CAM Restorations: Intraoral Scanning vs. Optical Coherence Tomography},
JOURNAL = {Bioengineering},
VOLUME = {13},
YEAR = {2026},
NUMBER = {7},
ARTICLE-NUMBER = {808},
URL = {https://www.mdpi.com/2306-5354/13/7/808},
ISSN = {2306-5354},
ABSTRACT = {This study extended a previously established intraoral scanning (IOS) and optical coherence tomography (OCT) dual-modality monitoring workflow for computer-aided design/computer-aided manufacturing (CAD/CAM) restorations to three additional crown material classes alongside a resin composite (RECO) reference. Four material classes were investigated (n=8 each): RECO, polymer-infiltrated ceramic network (PICN), lithium disilicate ceramic (LDSC), and zirconia-reinforced lithium silicate ceramic (ZLSC). Monolithic crowns were adhesively luted to standardized human molar abutment teeth and aged by cyclic loading (50500N, 2Hz, 37 2∘C, up to 1250000 cycles) in a mouth-motion simulator. IOS and handheld OCT were performed at baseline and after every 250000 cycles under phantom-head conditions; correspondence was assessed using Spearman’s rank correlation coefficient (exploratory, uncorrected for multiple comparisons). OCT consistently showed higher defect extents than IOS across all material classes and timepoints. While no significant IOS-OCT associations were found for RECO and the PICN, OCT detected full-thickness vertical subsurface damage propagation from the earliest timepoint in LDSC and ZLSC, with IOS-derived surface wear remaining markedly lower. Surface-based monitoring alone did not reliably reflect subsurface damage propagation, a dissociation most pronounced in the vertical dimension and silicate-based materials. Intraoral OCT may provide complementary, non-invasive subsurface information to support individualized recall scheduling and minimally invasive repair decisions.},
DOI = {10.3390/bioengineering13070808}
}

@conference {KupplerSD26DGNC77,
author       = {Patrick Kuppler and Paul Strenge and Wolfgang Draxinger and Jakob Matschke and Sonja Spahr-Hess and Dirk Theisen-Kunde and Ralf Brinkmann and Robert Huber and Neureen Keric and Matteo Mario Bonsanto},
title        = {{Automatisierte Tumorranddiagnostik in vivo mittels mikroskopintegrierter MHz-OCT Technologie}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Neuroonkologie 15},
number       = {V269},
pages        = {456},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@conference {KrenRK26DGNC77,
author       = {Jessica Kren and Maximilian Rixius and Niclas Hinselmann and Patrick Kuppler and Nicolas Detrez and Dirk Theisen-Kunde and Thies Hörcher and Ralf Brinkmann and Matteo Mario Bonsanto},
title        = {{Handgeführter Assistenzroboter zur Stabilisierung diagnostischer Sonden bei Hirntumoroperationen}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Technik und Innovation 9 -- klinisches Monitoring},
number       = {RC301},
pages        = {744},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@conference {DetrezBM26DGNC77,
author       = {Nicolas Detrez and Sazgar Burhan and Jakob Matschke and Robert Huber and Ralf Brinkmann},
title        = {{Luftstrahl-basierte optische Kohärenz-Elastografie zur Abgrenzung von Hirntumorgewebe und
Grundlagenforschung in der Gewebemechanik}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Technik und Innovation 1},
number       = {V073},
pages        = {122},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@conference {DetrezDT26DGNC77,
author       = {Nicolas Detrez and Wolfgang Draxinger and Dirk Theisen-Kunde and Jessica Kren and Isabelle Skambath and Patrick Kuppler and Niclas Hinselmann and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
title        = {{Vom Labor in den Operationssaal: Intraoperative Luftstrahl-Optische Kohärenz-Elastographie, unterstützt durch
ein Roboterarmsystem in der Neurochirurgie}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Technik \& Innovation 6 -- Robotik},
number       = {V148},
pages        = {194},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@conference {DraxingerSK26DGNC77,
author       = {Wolfgang Draxinger and Sonja Spahr-Hess and Patrick Kuppler and Matteo Mario Bonsanto and Robert Huber and Nicolas Detrez and Veit Danicke and Dirk Theisen-Kunde and Paul Strenge and Ralf Brinkmann},
title        = {{Oberflächliche transdurale in-vivo Bildgebung mittels in ein OP-Mikroskop integrierter MHz-OCT in klinischer
Umgebung: Ein Baustein für die autonome robotegestützte Neurochirurgie}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Technik und Innovation 1 -- Bildgebung},
number       = {RC048},
pages        = {453},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@conference {KrenRK26DGNC77,
author       = {Jessica Kren and Maximilian Rixius and Niclas Hinselmann and Patrick Kuppler and Nicolas Detrez and Dirk Theisen-Kunde and Thies Hörcher and Ralf Brinkmann and Matteo Mario Bonsanto},
title        = {{Handgeführter Assistenzroboter zur Stabilisierung diagnostischer Sonden bei Hirntumoroperationen}},
booktitle    = {77. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie},
series       = {Technik und Innovation 9 -- klinisches Monitoring},
number       = {RC301},
pages        = {744},
year         = 2026,
month        = jun,
address      = {Aachen},
organization = {Deutsche Gesellschaft für Neurochirurgie},
}

@ARTICLE{10726870,
  author={Detrez, Nicolas and Burhan, Sazgar and Rewerts, Katarina and Kren, Jessica and Buschschlüter, Steffen and Theisen-Kunde, Dirk and Bonsanto, Matteo Mario and Huber, Robert and Brinkmann, Ralf},
  journal={IEEE Transactions on Biomedical Engineering}, 
  title={Flow-controlled air-jet for in vivo quasi steady-state and dynamic elastography with MHz optical coherence tomography}, 
  year={2024},
  volume={},
  number={},
  pages={1-12},
  keywords={Force;Biomedical measurement;Pressure measurement;In vivo;Steady-state;Generators;Elastography;Valves;Force measurement;Optical coherence tomography;Air-Jet;Air-Puff;Optical Coherence Elastography;Stiffness;Tissue Mechanics;Young's Modulus},
  doi={10.1109/TBME.2024.3484676}}

@inproceedings{10.1117/12.3041264,
author = {Kimberley L{\"u}hring and Birgit Lange and Lion Sch{\"u}tzeck and Ralf Brinkmann},
title = {{Laser lithotripsy: the impact of beam profile and wavelength on stone ablation}},
volume = {13293},
booktitle = {Advanced Photonics in Urology 2025},
editor = {Hyun Wook Kang and Ronald Sroka and Jian J. Zhang},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1329306},
abstract = {Thulium fiber lasers (TFL) with a peak power of 500W were introduced a few years ago for clinical use in laser lithotripsy of urinary stones. To compare the TFL with the current gold standard, the Ho:YAG laser, single pulse experiments were performed at 1.5J from different working distances using a 365μm fiber. For evaluation of the fragmentation properties of both laser systems, cuttlefish bone samples and glued BegoStone cylinders were ablated at 1.5J using different pulse durations. It was found that the TFL produced up to two times higher stone ablation compared to the Ho:YAG laser but showed significantly poorer results in fragmentation which might be explained by its lower peak power. Furthermore, the increase in the ablation efficiency of laser lithotripsy by adjusting the beam profile was investigated in this study. A series of measurements with annular and circular beam profiles of the same beam diameter was performed with the TFL. At a pulse energy of 1J the annular beam profile has removed 90% more stone volume with a single pulse.},
keywords = {laser lithotropsy, thulium fiber laser, beam profile, urolithiasis},
year = {2025},
doi = {10.1117/12.3041264},
URL = {https://doi.org/10.1117/12.3041264}
}

@inproceedings{10.1117/12.3047226,
author = {Paul Strenge and Birgit Lange and Wolfgang Draxinger and Dirk Theisen-Kunde and Sonja Spahr-Hess and Matteo M. Bonsanto and Robert Huber and Ralf Brinkmann and Heinz Handels},
title = {{Enhancing brain tumor detection using optical coherence tomography and variational autoencoders}},
volume = {13410},
booktitle = {Medical Imaging 2025: Clinical and Biomedical Imaging},
editor = {Barjor S. Gimi and Andrzej Krol},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {134101P},
abstract = {Neurosurgical intervention is critical in brain tumor treatment, with long-term survival closely linked to the extent of tumor resection. The goal is to completely remove tumor tissue while preserving healthy tissue, a challenging task due to the diffuse nature of some brain tumors, such as glioblastoma, which infiltrate healthy tissue in ways that are difficult to distinguish histologically. Current intraoperative imaging techniques, including MRI and fluorescence microscopy, are limited in reliably identifying tumor tissue. Optical coherence tomography (OCT) offers a promising alternative, providing non-invasive, high-resolution cross-sectional images. This study investigates the use of a variational autoencoder (VAE) in combination with an evidential learning framework to enhance the classification of brain tissues in OCT images. The classification approach, applied to ex vivo OCT images captured at a wavelength of 1300 nm, achieved an average precision of 0.87 and a recall of 0.88 for the discrimination of healthy and tumorous brain tissue with consideration of prediction uncertainties. This method demonstrated improved discrimination between healthy white matter and tumor-infiltrated white matter compared to previous studies.},
keywords = {brain tumor, OCT, variational autoencoders, glioblastoma, classification, medical imaging, brain, evidential learning},
year = {2025},
doi = {10.1117/12.3047226},
URL = {https://doi.org/10.1117/12.3047226}
}

@inproceedings{Detrez:25,
author = {Nicolas Detrez and Dirk Theisen-Kunde and Wolfgang Draxinger and Thies H\"{o}rcher and Veit Danicke and Sazgar Burhan and Jessica Kren and Matteo Mario Bonsanto and Robert Huber and Ralf Brinkmann},
booktitle = {European Conferences on Biomedical Optics 2025},
journal = {European Conferences on Biomedical Optics 2025},
keywords = {Coherence and statistical optics; Elastography; Modes; Optical coherence tomography; Phase; Phase measurement},
pages = {M3A.36},
publisher = {Optica Publishing Group},
title = {Co-Robot Supported Air-Jet Based Optical Coherence Elastography Towards In-Situ Brain Tumor Tissue Delineation},
year = {2025},
url = {https://opg.optica.org/abstract.cfm?URI=ECBO-2025-M3A.36},
doi = {10.1364/ECBO.2025.M3A.36},
abstract = {Accurate tumor delineation in neurosurgery is challenging. We developed an in-situ optical coherence elastography system using air-jet excitation and phase based full-range OCT. The challenges in transitioning from ex vivo to in-situ application are presented.},
}

@inproceedings{Seifert:25,
author = {Eric Seifert and Leonie Hoffmann and Xi Zhang and Lisa-Marie Fr\"{u}hauf and Yoko Miura and Ralf Brinkmann},
booktitle = {European Conferences on Biomedical Optics 2025},
journal = {European Conferences on Biomedical Optics 2025},
keywords = {Absorption coefficient; Fluorescence; Laser energy; Laser light; Multimode fibers; Nd:YLF lasers},
pages = {S1E.2},
publisher = {Optica Publishing Group},
title = {Validating optoacoustic temperature determination for retinal laser treatments with the fluorescence dye ERthermAC},
year = {2025},
url = {https://opg.optica.org/abstract.cfm?URI=ECBO-2025-S1E.2},
doi = {10.1364/ECBO.2025.S1E.2},
abstract = {Temperature dependent fluorescence of the dye ERthermAC was used to measure laser induced temperature rise on RPE/choroid/sclera explants during simultaneous optoacoustic temperature determination, already being in clinical approval. Both methods didn't show significant differences.},
}

@article{https://doi.org/10.1002/jbio.202500430,
author = {Lange, Birgit and Kren, Christopher and Brinkmann, Ralf},
title = {Autofluorescence of Renal Tissue and Its Impact on Fluorescence-Guided Lithotripsy},
journal = {Journal of Biophotonics},
volume = {n/a},
number = {n/a},
pages = {e202500430},
keywords = {autofluorescence, fluorescence guided lithotripsy, laser lithotripsy, renal tissue},
doi = {https://doi.org/10.1002/jbio.202500430},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jbio.202500430},
eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/jbio.202500430},
note = {e202500430 jbio.202500430.R1},
abstract = {ABSTRACT When illuminated with green light, tissue shows negligible autofluorescence in comparison to urinary stones. In automatically controlled lithotripsy, this property is utilized to prevent the laser from being triggered if the fiber is mispositioned: the fluorescence signal is compared to a set threshold before each pulse. However, previous studies have shown that tissue damage cannot be completely ruled out. We are investigating this phenomenon and its impact on fluorescence guidance. An experiment with porcine calyx (with the automatic control switched off) shows that single Ho:YAG laser pulses are sufficient to coagulate tissue, resulting in an increase in autofluorescence. During lithotripsy of fluorescent artificial stones embedded in renal cortex, thermal damage occurs despite automatic laser control. Maximum fluorescence values measured on those tissue places were above the control's set threshold for laser emission. Therefore, an increase in autofluorescence in the event of denaturation must be considered when using automatically controlled lithotripsy.}
}

@article{Burhan:24,
author = {Sazgar Burhan and Nicolas Detrez and Katharina Rewerts and Paul Strenge and Steffen Buschschl\"{u}ter and Jessica Kren and Christian Hagel and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {High speed imaging; Imaging systems; In vivo imaging; Magnetic resonance imaging; Phase noise; Phase shift},
number = {2},
pages = {1038--1058},
publisher = {Optica Publishing Group},
title = {Phase unwrapping for MHz optical coherence elastography and application to brain tumor tissue},
volume = {15},
month = {Feb},
year = {2024},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-15-2-1038},
doi = {10.1364/BOE.510020},
abstract = {During neuro-oncologic surgery, phase-sensitive optical coherence elastography (OCE) can be valuable for distinguishing between healthy and diseased tissue. However, the phase unwrapping process required to retrieve the original phase signal is a challenging and critical task. To address this issue, we demonstrate a one-dimensional unwrapping algorithm that recovers the phase signal from a 3.2\&\#x2005;MHz OCE system. With a processing time of approximately 0.11 s per frame on the GPU, multiple 2\&\#x03C0; wraps are detected and corrected. By utilizing this approach, exact and reproducible information on tissue deformation can be obtained with pixel accuracy over the entire acquisition time. Measurements of brain tumor-mimicking phantoms and human ex vivo brain tumor samples verified the algorithm\&\#x0027;s reliability. The tissue samples were subjected to a 200\&\#x2005;ms short air pulse. A correlation with histological findings confirmed the algorithm\&\#x0027;s dependability.},
}

@article{10.1167/tvst.13.1.24,
    author = {Sonntag, Svenja Rebecca and Klein, Britta and Brinkmann, Ralf and Grisanti, Salvatore and Miura, Yoko},
    title = "{Fluorescence Lifetime Imaging Ophthalmoscopy of Mouse Models of Age-related Macular Degeneration}",
    journal = {Translational Vision Science & Technology},
    volume = {13},
    number = {1},
    pages = {24-24},
    year = {2024},
    month = {01},
    abstract = "{   To investigate fluorescence lifetime of mouse models of age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO).    Two AMD mouse models, apolipoprotein E knockout (ApoE−/−) mice and NF-E2-related factor-2 knockout (Nrf2−/−) mice, and their wild-type mice underwent monthly ophthalmic examinations including FLIO from 3 months of age. After euthanasia at the age of 6 or 11 months, blood plasma was collected to determine total antioxidant capacity and eyes were enucleated for Oil red O (ORO) lipid staining of chorioretinal tissue.    In FLIO, the mean fluorescence lifetime (τm) of wild type shortened with age in both spectral channels. In short spectral channel, τm shortening was observed in both AMD models as well, but its rate was more pronounced in ApoE−/− mice and significantly different from the other strains as months of age progressed. In contrast, in long spectral channel, both model strains showed completely opposite trends, with τm becoming shorter in ApoE−/− and longer in Nrf2−/− mice than the others. Oil red O staining at Bruch's membrane was significantly stronger in ApoE−/− mice at 11 months than the other strains. Plasma total antioxidant capacity was highest in ApoE−/− mice at both 6 and 11 months.    The two AMD mouse models exhibited largely different fundus fluorescence lifetime, which might be related to the different systemic metabolic state. FLIO might be able to indicate different metabolic states of eyes at risk for AMD.    This animal study may provide new insights into the relationship between early AMD-associated metabolic changes and FLIO findings.  }",
    issn = {2164-2591},
    doi = {10.1167/tvst.13.1.24},
    url = {https://doi.org/10.1167/tvst.13.1.24},
    eprint = {https://arvojournals.org/arvo/content\_public/journal/tvst/938660/i2164-2591-13-1-24\_1706520239.75643.pdf},
}

@article{RN5472,
   author = {Kren, Jessica;Skambath, Isabelle;Kuppler, Patrick;Buschschlüter, Steffen;Detrez, Nicolas;Burhan, Sazgar;Huber, Robert;Brinkmann, Ralf and Bonsanto, Matteo Mario},
   title = {Mechanical characteristics of glioblastoma and peritumoral tumor-free human brain tissue},
   journal = {Acta Neurochirurgica},
   volume = {166},
   number = {1},
   pages = {102},
   ISSN = {0942-0940},
   DOI = {10.1007/s00701-024-06009-x},
   url = {https://doi.org/10.1007/s00701-024-06009-x},
   year = {2024},
   type = {Journal Article}
}