@article{Jakober2025b,

title = {Design, development, and evaluation of an immersive augmented virtuality training system for transcatheter aortic valve replacement},

author = {Jorik Jakober and Matthias Kunz and Robert Kreher and Matteo Pantano and Daniel Braß and Janine Weidling and Christian Hansen and Rüdiger Braun-Dullaeus and Bernhard Preim},

doi = {https://doi.org/10.1016/j.cag.2025.104414},

year  = {2025},

date = {2025-09-12},

journal = {Computers & Graphics},

volume = {133},

abstract = {Strong procedural skills are essential to perform safe and effective transcatheter aortic valve replacement (TAVR). Traditional training takes place in the operating room (OR) on real patients and requires learning new motor skills, resulting in longer procedure times, increased risk of complications, and greater radiation exposure for patients and medical personnel. Desktop-based simulators in interventional cardiology have shown some validity but lack true depth perception, whereas head-mounted display based Virtual Reality (VR) offers intuitive 3D interaction that enhances training effectiveness and spatial understanding. However, providing realistic and immersive training remains a challenging task as both lack tactile feedback. We have developed an augmented virtuality (AV) training system for transfemoral TAVR, combining a catheter tracking device (for translational input) with a simulated virtual OR. The system enables users to manually control a virtual angiography system via hand tracking and navigate a guidewire through a virtual patient up to the aortic valve using fluoroscopic-like imaging. In addition, we conducted a preliminary user study with 12 participants, assessing cybersickness, usability, workload, sense of presence, and qualitative factors. Preliminary results indicate that the system provides realistic interaction for key procedural steps, making it a suitable learning tool for novices. Limitations in angiography system operation include the lack of haptic resistance and usability limitations related to C-arm control, particularly due to hand tracking constraints and split attention between interaction and monitoring. Suggestions for improvement include catheter rotation tracking, expanded procedural coverage, and enhanced fluoroscopic image fidelity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Allgeier2025,

title = {Impact of Input and Output Devices on a Virtual Ultrasound Training},

author = {Mareen Allgaier and Eric-Morten Dangszat and Florentine Huettl and Laura Isabel Hanke and Tobias Huber and Bernhard Preim and Christian Hansen},

doi = {10.1109/VRW66409.2025.00191},

year  = {2025},

date = {2025-03-08},

journal = {2025 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW)},

pages = {937-941},

abstract = {Performing ultrasound requires mental skills that have to be trained hands on. Virtual simulations can be employed to provide novice surgeons with a safe training environment prior to performing ultrasound on the patient. For both input and output there is a wide range of devices that are used in existing ultrasound simulations. Because the devices have their limitations and benefits regarding realism, costs, and access, we compared three technical setups: desktop with mouse interaction, desktop with a haptic device, and virtual reality with a haptic device. In a user study with 19 participants we investigated the usability and assessed qualitative user feedback in a semi-structured interview. Significant differences regarding usability and training time were found between both versions with the haptic device and the desktop with mouse version. Based on the feedback, using a haptic device seems to be more relevant than the two output devices in this training case.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Razavizadeh2025,

title = {A virtual patient authoring tool for transcatheter aortic valve replacement},

author = {Seyedsina Razavizadeh and Markus Kofler and Matthias Kunz and Joerg Kempfert and Ruediger Braun-Dullaeus and Janine Weidling and Bernhard Preim and Christian Hansen},

doi = {https://doi.org/10.1007/s11548-024-03293-x},

year  = {2025},

date = {2025-02-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {20},

number = {2},

pages = {379-389},

abstract = {Purpose

Computer-based medical training scenarios, derived from patient’s records, often lack variability, modifiability, and availability. Furthermore, generating image datasets and creating scenarios is resource-intensive. Therefore, patient authoring tools for rapid dataset-independent creation of virtual patients (VPs) is a pressing need.



Methods

An authoring tool and a virtual catheterization laboratory environment were developed. The tool allows customised VP generation through a real-time morphable heart model and Euroscore parameters. The generated VP can be examined inside the vCathLab using a fluoroscopy and monitoring device, both on desktop and immersive virtual reality. Seven board-certified experts evaluated the proposed method from three aspects, i.e. System Usability Scale, qualitative feedback, and its performance in VR.



Results

All participants agreed that this method could provide the necessary information and is anatomically correct within an educational context. Its modifiability, variability, and simplicity were well recognised. The prototype achieved excellent usability score and considerable performance results.



Conclusion

We present a highly variable VP authoring tool that enhances variability in medical training scenarios. Although this work does not aim to explore didactic aspects, the potential of using this approach in an educational context has been confirmed in our study. Accordingly, these aspects can benefit from a thorough investigation in the future. In addition, our tool can be improved to provide more realistic parameter ranges for procedure-specific cases.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Huber2024,

title = {Virtual Reality in der Leberchirurgie – Planen, Weiterbilden, Prüfen},

author = {Tobias Huber and Florentine Huettl and Lukas Vradelis and Verena Tripke and Danny Schott and Vuthea Chheang and Patrick Saalfeld and Mareen Allgaier and Sylvia Saalfeld and Bernhard Preim and Christian Hansen and Laura Isabel Hanke and Hauke Lang},

doi = {https://doi.org/10.1007/s00104-024-02216-5},

year  = {2024},

date = {2024-12-17},

journal = {Die Chirurgie},

abstract = {Bereits seit über 20 Jahren können anatomische Strukturen der Leber aus präoperativen Schnittbildgebungen dreidimensional rekonstruiert werden. Diese dreidimensionale (3D) Darstellung optimiert nicht nur die präoperativen Planungsmöglichkeiten, auch die Vermittlung spezifischer, operationsrelevanter Strukturen kann durch 3D-Modelle verbessert werden. Die disruptive Technologie der virtuellen Realität (VR) kann neben einer plastischen und interaktiven Visualisierung dreidimensionaler Organmodelle auch eine Möglichkeit zur strukturierten Aus- und Weiterbildung hinsichtlich leberchirurgischer Anatomie und Operationsplanung liefern. Prüfungen in virtueller Realität erscheinen dadurch ebenfalls greifbar. Neueste Prototypen ermöglichen sogar eine patientenindividuelle Simulation der intraoperativen Sonographie. Dieser Artikel stellt einen Überblick über den gegenwärtigen Stand der verfügbaren Technologien für Aus- und Weiterbildung mittels VR am Beispiel der Leberchirurgie dar.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chheang_CGF,

title = {A collaborative virtual reality environment for liver surgery planning},

author = {Vuthea Chheang and Patrick Saalfeld and Fabian Joeres and Christian Boedecker and Tobias Huber and Florentine Huettl and Hauke Lang and Bernhard Preima and Christian Hansen},

doi = {https://doi.org/10.1016/j.cag.2021.07.009},

year  = {2024},

date = {2024-01-22},

journal = {Computers & Graphics},

pages = {in print},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ALLGAIER2022105429,

title = {A comparison of input devices for precise interaction tasks in VR-based surgical planning and training},

author = {Mareen Allgaier and Vuthea Chheang and Patrick Saalfeld and Vikram Apilla and Tobias Huber and Florentine Huettl and Belal Neyazi and Erol I Sandalcioglu and Christian Hansen and Bernhard Preim and Sylvia Saalfeld},

url = {https://www.sciencedirect.com/science/article/pii/S0010482522002219},

doi = {https://doi.org/10.1016/j.compbiomed.2022.105429},

issn = {0010-4825},

year  = {2022},

date = {2022-01-01},

journal = {Computers in Biology and Medicine},

volume = {145},

pages = {105429},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Huettl_2021_ATM,

title = {Virtual Reality and 3D Printing Improve Preoperative Visualization of 3D Liver Reconstructions - Results from a Preclinical Comparison of Presentation Modalities and User`s Preference},

author = {Florentine Huettl and Patrick Saalfeld and Christian Hansen and Bernhard Preim and A Poplawski and Werner Kneist and Hauke Lang and Tobias Huber},

year  = {2021},

date = {2021-01-01},

journal = {Annals of Translational Medicine},

pages = {1-11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Boedecker_2021_LAS,

title = {Using Virtual 3D-models in Surgical Planning: Workflow of an Immersive Virtual Reality Application in Liver Surgery},

author = {Christian Boedecker and Florentine Huettl and Patrick Saalfeld and Marcus Paschold and Werner Kneist and J Baumgart and Bernhard Preim and Christian Hansen and Hauke Lang and Tobias Huber},

year  = {2021},

date = {2021-01-01},

journal = {Langenbeck`s Archives of Surgery},

pages = {911-915},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{WAGNER202170,

title = {iVRoad: Immersive virtual road crossing as an assessment tool for unilateral spatial neglect},

author = {Sebastian Wagner and Julia Belger and Fabian Joeres and Angelika Thöne-Otto and Christian Hansen and Bernhard Preim and Patrick Saalfeld},

url = {https://www.sciencedirect.com/science/article/pii/S009784932100128X},

doi = {https://doi.org/10.1016/j.cag.2021.06.013},

issn = {0097-8493},

year  = {2021},

date = {2021-01-01},

journal = {Computers & Graphics},

volume = {99},

pages = {70-82},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{CHHEANG2021234,

title = {A collaborative virtual reality environment for liver surgery planning},

author = {Vuthea Chheang and Patrick Saalfeld and Fabian Joeres and Christian Boedecker and Tobias Huber and Florentine Huettl and Hauke Lang and Bernhard Preim and Christian Hansen},

url = {https://www.sciencedirect.com/science/article/pii/S0097849321001400},

doi = {https://doi.org/10.1016/j.cag.2021.07.009},

year  = {2021},

date = {2021-01-01},

journal = {Computers & Graphics},

volume = {99},

pages = {234-246},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Heinrich_2021_CG,

title = {Estimating Depth Information of Vascular Models: A Comparative User Study Between a Virtual Reality and a Desktop Application},

author = {Florian Heinrich and Vikram Apilla and Kai Lawonn and Christian Hansen and Bernhard Preim and Monique Meuschke},

url = {https://isgwww.cs.ovgu.de/~meuschke/wp-content/uploads/2025/09/Heinrich_2021_CG.pdf},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Computer & Graphics},

volume = {98},

pages = {210–217},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chheang_2020_JCARS,

title = {Toward interprofessional team training for surgeons and anesthesiologists using virtual reality},

author = {Vuthea Chheang and Virve Fischer and Holger Buggenhagen and Tobias Huber and Florentine Hüttl and Werner Kneist and Bernhard Preim and Patrick Saalfeld and Christian Hansen},

url = {https://www.vismd.de/wp-content/uploads/legacy/chheang_2020_jcars.pdf, PDF Download},

year  = {2020},

date = {2020-01-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chheang_2019_AIVR,

title = {Collaborative Virtual Reality for Laparoscopic Liver Surgery Training},

author = {Vuthea Chheang and Patrick Saalfeld and Tobias Huber and Florentine Hüttl and Werner Kneist and Bernhard Preim and Christian Hansen},

url = {https://www.youtube.com/watch?v=hDwiy0i5uFM, YouTube},

year  = {2019},

date = {2019-01-01},

journal = {Proceedings of IEEE International Conference on Artificial Intelligence and Virtual Reality (AIVR)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{wagner_2019_cg,

title = {Difficulty Factors for VR Cognitive Rehabilitation Training – Crossing a Virtual Road},

author = {Sebastian Wagner and Fabian Joeres and Mareike Gabele and Christian Hansen and Bernhard Preim and Patrick Saalfeld},

url = {http://www.sciencedirect.com/science/article/pii/S0097849319301037

https://www.youtube.com/watch?v=PZK_MMKcNOw, YouTube},

doi = {https://doi.org/10.1016/j.cag.2019.06.009},

issn = {0097-8493},

year  = {2019},

date = {2019-01-01},

journal = {Computers & Graphics},

volume = {83},

pages = {11--22},

abstract = {Patients with cognitive or visual impairments have problems in dealing with complex situations. During the rehabilitation process, it is important to confront the patient with (everyday) tasks that have increasing degrees of difficulty to improve their performance. Immersive virtual reality training offers the potential to create a better transfer to daily life than non-immersive computer training. In cooperation with two neuropsychologists, an immersive virtual environment (VE) was developed in which cognitive training in the form of safe road crossing decisions can be performed. We present the experimental exploration and evaluation of difficulty factors within such a VR-based cognitive rehabilitation program. Four difficulty factors were identified and compared (number of relevant traffic lanes, speed of vehicles, distance between vehicles, and number of vehicles). The combination of these difficulty factors resulted in 36 training scenarios. The impact of the factors on participant performance and subjective perception of scenario difficulty were evaluated with 60 healthy participants to estimate the impact of the four factors to a situation’s difficulty level. For the factors Relevant Lanes and Traffic Speed a clear influence on the perceived task difficulty could be determined. No clear influence could be found for the Gap Size. The Number of Vehicles had almost no effect on the perceived task difficulty. Finally, we asked two experienced neuropsychologists about the applicability of our developed system to patients, and they stated that the system is ready for a study on patients.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hettig_2018_IJCARS,

title = {AR in VR: assessing surgical augmented reality visualizations in a steerable virtual reality environment},

author = {Julian Hettig and Sandy Engelhardt and Christian Hansen and Gabriel Mistelbauer},

doi = {10.1007/s11548-018-1825-4},

year  = {2018},

date = {2018-07-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {13},

number = {11},

pages = {1717--1725},

publisher = {Springer Nature America, Inc},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mewes2016,

title = {A gesture-controlled projection display for CT-guided interventions},

author = {André Mewes and Patrick Saalfeld and Oleksandr Riabikin and Martin Skalej and Christian Hansen},

url = {http://dx.doi.org/10.1007/s11548-015-1215-0},

doi = {10.1007/s11548-015-1215-0},

issn = {1861-6429},

year  = {2016},

date = {2016-01-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {11},

number = {1},

pages = {157--164},

abstract = {The interaction with interventional imaging systems within a sterile environment is a challenging task for physicians. Direct physician--machine interaction during an intervention is rather limited because of sterility and workspace restrictions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mewes_2015_JCARS,

title = {A Gesture-Controlled Projection Display for CT-Guided Interventions},

author = {André Mewes and Patrick Saalfeld and Oleksandr Riabikin and Martin Skalej and Christian Hansen},

url = {https://www.vismd.de/wp-content/uploads/legacy/mewes_2015_jcars.pdf, PDF Download},

year  = {2015},

date = {2015-01-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {10},

pages = {1--8},

publisher = {Springer Berlin Heidelberg},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hansen_2014_JCARS,

title = {Impact of Model-based Risk Analyses for Liver Surgery Planning},

author = {Christian Hansen and Stephan Zidowitz and Bernhard Preim and Karl-Jürgen Oldhafer and Horst Hahn},

url = {https://www.vismd.de/wp-content/uploads/legacy/hansen_2014_jcars.pdf, PDF Download},

year  = {2014},

date = {2014-05-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {9(3)},

pages = {473--480},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Moench_2013_JCARS,

title = {The LiverSurgeryTrainer: training of computer-based planning in liver resection surgery},

author = {Jeanette Mönch and Konrad Mühler and Christian Hansen and Karl-Jürgen Oldhafer and Gregor Stavrou and Christian Hillert and Christoph Logge and Bernhard Preim},

url = {https://www.vismd.de/wp-content/uploads/legacy/moench_2013_jcars.pdf, PDF Download},

doi = {10.1007/s11548-013-0812-z},

year  = {2013},

date = {2013-09-01},

journal = {International Journal of Computer Assisted Radiology and Surgery},

volume = {8(5)},

pages = {809--818},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ritter_2006_TV,

title = {Real-Time Illustration of Vascular Structures for Surgery},

author = {Felix Ritter and Christian Hansen and Bernhard Preim and Volker Dicken and Olaf Konrad-Verse},

url = {https://www.vismd.de/wp-content/uploads/legacy/ritter_2006_tv.pdf, PDF Download},

year  = {2006},

date = {2006-01-01},

journal = {IEEE Transactions on Visualization},

volume = {12},

pages = {877--884},

keywords = {},

pubstate = {published},

tppubtype = {article}

}