0000000000001251

AUTHOR

Christian Hansen

showing 12 related works from this author

Augmented Reality Visualisation Concepts to Support Intraoperative Distance Estimation

2019

The estimation of distances and spatial relations between surgical instruments and surrounding anatomical structures is a challenging task for clinicians in image-guided surgery. Using augmented reality (AR), navigation aids can be displayed directly at the intervention site to support the assessment of distances and reduce the risk of damage to healthy tissue. To this end, four distance-encoding visualisation concepts were developed using a head-mounted optical see-through AR setup and evaluated by conducting a comparison study. Results suggest the general advantage of the proposed methods compared to a blank visualisation providing no additional information. Using a Distance Sensor concep…

Computer sciencebusiness.industry0206 medical engineeringAnatomical structuresHealthy tissue02 engineering and technology020601 biomedical engineeringBlank030218 nuclear medicine & medical imagingTask (project management)Visualization03 medical and health sciencesSpatial relation0302 clinical medicineComparison studyAugmented realityComputer visionArtificial intelligencebusiness25th ACM Symposium on Virtual Reality Software and Technology
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Virtual reality and 3D printing improve preoperative visualization of 3D liver reconstructions-results from a preclinical comparison of presentation …

2021

BACKGROUND: Preoperative three-dimensional (3D) reconstructions for liver surgery planning have been shown to be effective in reduction of blood loss and operation time. However, the role of the ‘presentation modality’ is not well investigated. We present the first study to compare 3D PDFs, 3D printed models (PR) and virtual reality (VR) 3D models with regard to anatomical orientation and personal preferences in a high volume liver surgery center. METHODS: Thirty participants, 10 medical students, 10 residents, 5 fellows and 5 hepatopancreatobiliary (HPB) experts, assigned the tumor-bearing segments of 20 different patient’s individual liver reconstructions. Liver models were presented in a…

medicine.medical_specialtyModalitiesModality (human–computer interaction)business.industryUsabilityStandardized testGeneral MedicineVirtual realitySurgical planningText miningUser experience designmedicineMedical physicsOriginal ArticlebusinessAnnals of translational medicine
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In Virtual Reality durch die Pandemie: Digitale Lehre mit modernster Technologie in der Leberchirurgie

2021

Viszeralmedizin 2021 Gemeinsame Jahrestagung Deutsche Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS), Sektion Endoskopie der DGVS, Deutsche Gesellschaft für Allgemein und Viszeralchirurgie (DGAV)
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An Interactive Demonstration of Collaborative VR for Laparoscopic Liver Surgery Training

2019

We introduce a collaborative virtual reality (VR) system for planning and simulation in laparoscopic liver surgery training. Patient image data is used for surgical model visualization and simulation. We developed two modes for training in laparoscopic procedures: exploration and surgery mode. Surgical joysticks are used in surgery mode to provide training for psychomotor skills and cooperation between a camera assistant and an experienced surgeon. Continuous feedback from our clinical partner comprised an important part of the development. Our evaluation showed that surgeons were positive about the usability and usefulness of the developed system. For further details, please refer to our f…

Laparoscopic surgeryLiver surgeryPsychomotor learning0209 industrial biotechnologymedicine.medical_specialtyComputer sciencebusiness.industrymedicine.medical_treatmentUsability02 engineering and technologyVisualization020901 industrial engineering & automation0202 electrical engineering electronic engineering information engineeringmedicine020201 artificial intelligence & image processingMedical physicsbusiness2019 IEEE International Conference on Artificial Intelligence and Virtual Reality (AIVR)
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Collaborative VR for Liver Surgery Planning using Wearable Data Gloves: An Interactive Demonstration

2021

Preoperative planning for liver surgery is a critical procedure to assess a potential resection and it supports surgeons to define the affected vessels and resection volume. Traditional surgical planning systems are widely used to support the planning with the usage of desktop-based 3D and 2D visualizations. However, desktop-based systems offer limited interactions and visualizations compared to virtual reality (VR) [3]. A suitable technique to support collaboration among surgeons is required. Our previous works [1], [2] illustrate that using collaborative VR is essential to enhance communication, teamwork, and over-distance collaboration. In this work, we present a collaborative VR prototy…

Liver surgeryTeamworkbusiness.industryComputer sciencemedia_common.quotation_subjectWearable computerInput devicePatient dataVirtual realitySurgical planningData visualizationHuman–computer interactionbusinessmedia_common2021 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW)
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A collaborative virtual reality environment for liver surgery planning

2021

Abstract Surgical planning software is a key component in the treatment of tumor diseases. However, desktop-based systems provide only limited visualization and interaction opportunities. Moreover, collaborative planning among members of a surgical team is only possible to a limited extent. In this work, a collaborative virtual reality (VR) environment to assist liver surgeons in tumor surgery planning is presented. Our aim is to improve virtual resection planning between surgeons in a remote or co-located environment. The system allows surgeons to define and adjust virtual resections on patient-specific organ 3D surfaces and 2D image slices. Changes on both modalities are synchronized, whi…

Liver surgerySurgical teamModalitiesComputer sciencebusiness.industryComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONGeneral EngineeringComputer Graphics and Computer-Aided DesignSurgical planningVisualizationHuman-Computer InteractionSoftwareHuman–computer interactionComponent (UML)Collaborative virtual realitybusinessComputers & Graphics
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3D-Druck, Virtual Reality oder regulärer Monitor? Vergleich unterschiedlicher Darstellungsmöglichkeiten dreidimensionaler Leberrekonstruktionen

2021

Viszeralmedizin 2021 Gemeinsame Jahrestagung Deutsche Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS), Sektion Endoskopie der DGVS, Deutsche Gesellschaft für Allgemein und Viszeralchirurgie (DGAV)
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Collaborative Virtual Reality for Laparoscopic Liver Surgery Training

2019

Virtual reality (VR) has been used in many medical training systems for surgical procedures. However, the current systems are limited due to inadequate interactions, restricted possibilities of patient data visualization, and collaboration. We propose a collaborative VR system for laparoscopic liver surgical planning and simulation. Medical image data is used for model visualization and manipulation. Additionally, laparoscopic surgical joysticks are used to provide an opportunity for a camera assistant to cooperate with an experienced surgeon in VR. Continuous clinical feedback led us to optimize the visualization, synchronization, and interactions of the system. Laparoscopic surgeons were …

Liver surgery0209 industrial biotechnologygenetic structuresbusiness.industryComputer scienceComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONUsability02 engineering and technologyVirtual realitySurgical planningVisualization020901 industrial engineering & automationHuman–computer interactionSynchronization (computer science)0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingCollaborative virtual realitybusiness2019 IEEE International Conference on Artificial Intelligence and Virtual Reality (AIVR)
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Head-Mounted Mixed-Reality Technology During Robotic-Assisted Transanal Total Mesorectal Excision

2019

INTRODUCTION Head-mounted mixed-reality technologies may enable advanced intraoperative visualization during visceral surgery. In this technical note, we describe an innovative use of real-time mixed reality during robotic-assisted transanal total mesorectal excision. TECHNIQUE Video signals from the robotic console and video endoscopic transanal approach were displayed on a virtual monitor using a head-up display. The surgeon, assistant, and a surgical trainee used this technique during abdominal and transanal robotic-assisted total mesorectal excision. We evaluated the feasibility and usability of this approach with the use of validated scales. RESULTS The technical feasibility of the rea…

MaleVisceral surgerymedicine.medical_specialtyRobotic assistedComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONTransanal approachAdenocarcinoma03 medical and health sciences0302 clinical medicineRobotic Surgical ProceduresHumansMedicineMesenteryMedical physicsAgedTransanal Endoscopic SurgeryProctectomyRectal Neoplasmsbusiness.industryVirtual RealityGastroenterologyTechnical noteUsabilityGeneral MedicineTotal mesorectal excisionMixed realityVisualization030220 oncology & carcinogenesis030211 gastroenterology & hepatologybusinessDiseases of the Colon & Rectum
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A VR/AR Environment for Multi-User Liver Anatomy Education

2021

We present a Virtual and Augmented Reality multi-user prototype of a learning environment for liver anatomy education. Our system supports various training scenarios ranging from small learning groups to classroom-size education, where students and teachers can participate in virtual reality, augmented reality, or via desktop PCs. In an iterative development process with surgeons and teachers, a virtual organ library was created. Nineteen liver data sets were used comprising 3D surface models, 2D image data, pathology information, diagnosis and treatment decisions. These data sets can interactively be sorted and investigated individually regarding their volumetric and meta information. The …

Iterative and incremental development020205 medical informaticsProcess (engineering)business.industryComputer scienceLearning environmenteducation020207 software engineeringUsabilityQualitative property02 engineering and technologyVirtual realityHuman–computer interaction0202 electrical engineering electronic engineering information engineeringAugmented realityUser interfacebusiness2021 IEEE Virtual Reality and 3D User Interfaces (VR)
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Artificial Versus Video-Based Immersive Virtual Surroundings: Analysis of Performance and User's Preference.

2018

Introduction. Immersive virtual reality (VR) laparoscopy simulation connects VR simulation with head-mounted displays to increase presence during VR training. The goal of the present study was the comparison of 2 different surroundings according to performance and users’ preference. Methods. With a custom immersive virtual reality laparoscopy simulator, an artificially created VR operating room (AVR) and a highly immersive VR operating room (IVR) were compared. Participants (n = 30) performed 3 tasks (peg transfer, fine dissection, and cholecystectomy) in AVR and IVR in a crossover study design. Results. No overall difference in virtual laparoscopic performance was obtained when comparing …

AdultMaleSurgeonsEducation Medicalbusiness.industryVirtual RealityMiddle Aged03 medical and health sciencesYoung Adult0302 clinical medicine030220 oncology & carcinogenesisSurveys and QuestionnairesLaparoscopic simulatorImmersion (virtual reality)MedicineHumans030211 gastroenterology & hepatologySurgeryFemaleLaparoscopyClinical CompetencebusinessVideo basedLetter to the EditorSimulationSurgical innovation
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A framework for identity and privacy management on mobile devices

2010

Masteroppgave i informasjons- og kommunikasjonsteknologi 2010 – Universitetet i Agder, Grimstad More and more online services require user identification. This increases time to fill out extensive forms and results in large amounts of login and identification data to remember. At the same time the number of users that need access to those service while roaming is equally increasing. However, unfortunately many users are not aware that there is a high risk of loosing privacy when disclosing information about oneself’s identity in an unregulated way. To counteract this and to help users in managing and maintaining related identity data, so-called Identity Management Systems have been develope…

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