Publications

@article{Schrempf2026a,

title = {A model-based approach for B/A estimation using the finite amplitude insertion-substitution method},

author = {Andreas Schrempf and Lisa Stefely and Thomas Thurner and Harald Weichenberger},

doi = {10.1121/10.0042448},

issn = {0001-4966},

year  = {2026},

date = {2026-02-02},

journal = {Journal of the Acoustical Society of America},

volume = {159},

number = {2},

pages = {1416–1429},

publisher = {Acoustical Society of America},

abstract = {An enhanced, model-based framework is presented for estimating the acoustic nonlinearity parameter B / A using the finite amplitude insertion-substitution (FAIS) method in transmission mode. The proposed approach advances harmonic amplitude modeling by eliminating the restrictive plane wave assumption and introducing shape functions that accurately account for transducer diffraction and wave superposition. Additionally, a correction term for secondharmonic attenuation is incorporated, enabling precise characterization across a wide range of attenuation exponents. The framework supports both iterative and direct B / A estimation methods, each validated through comprehensive simulations and experimental measurements. Compared to conventional FAIS methods, this method significantly improves accuracy and robustness in B / A estimation, reduces sensitivity to experimental setup and transducer geometry, and provides practical guidance for optimizing experimental parameters such as sample thickness, distance between source, sample, and receiver, and attenuation measurement.},

note = {Publisher Copyright: © 2026 Author(s).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gmeiner2025a,

title = {Development and external validation of a mixed-reality aneurysm clipping simulator},

author = {Matthias Gmeiner and Andreas Schrempf and Thomas Thurner and Wolfgang Fenz and Bertram Sabrowsky-Hirsch and Michael Giretzlehner and Robert Prückl and Stefan Schaffelhofer and Zoltan Major and Sebastian Lämmermann and Melanie Baumgartner and Lukas Drabauer and Jozsef Nagy and Giuseppe Esposito and Elisa Colombo and Nico Stroh-Holly and Andreas Gruber},

doi = {10.1007/s10143-025-03846-x},

issn = {0344-5607},

year  = {2025},

date = {2025-12-01},

journal = {Neurosurgical Review},

volume = {48},

number = {1},

publisher = {Springer},

abstract = {Nowadays, surgical treatment of cerebral aneurysms remains one of the most demanding disciplines in neurosurgery. The increasing shift toward endovascular interventions leads to a decline in open surgical cases. This fact leaves residents and young neurosurgeons with fewer training opportunities and limited to complex and high-risk aneurysms. There is a growing need for realistic simulation tools to enhance neurosurgical training and preoperative planning. We developed and externally validated a patient-specific mixed-reality simulator for cerebral aneurysm clipping, during the research project "Medical EDUcation in Surgical Aneurysm Clipping (MEDUSA)". Our approach combines physical phantoms of the skull and brain tissue with virtual intracranial blood vessels, including a virtual intracranial aneurysm. Real surgical instruments provide an immersive training environment featuring integrated blood flow simulation for evaluating clipping strategies. A life-sized skull with silicone brain lobes is mounted in a standard neurosurgical head clamp. Optical tracking synchronizes the position of a real clip applier and an emulated surgical microscope with the corresponding virtual environment, allowing true mixed-reality interaction. After aneurysm clipping, blood flow is automatically simulated to assess residual aneurysms or stenoses of the parental vessels. We conducted an external validation with 40 neurosurgeons at two international events. Participants completed a 32-item questionnaire evaluating face and content validity on a 5-point Likert scale. Participants' surgical experience ranged from novice to expert (> 15 years). Average ratings for simulator realism and educational value were high, with mean scores between 3.13 and 4.25. The highest ratings were for the blood flow simulation (4.25) and the simulator's potential for preoperative planning (4.20). Most participants agreed that the physical and virtual components were valuable and that the simulator should be integrated into neurosurgical training and standard surgical workflows. Our mixed-reality simulator achieved robust face and content validity among a diverse group of neurosurgeons. Combining real surgical instruments with a deformable virtual aneurysm model, including blood flow simulation, offers a high level of realism and immediate objective feedback.},

note = {Publisher Copyright: © The Author(s) 2025.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurner2024b,

title = {Dynamic Tactile Synthetic Tissue: from Soft Robotics to Hybrid Surgical Simulators},

author = {Thomas Thurner and Julia Maier and Martin Kaltenbrunner and Andreas Schrempf},

doi = {10.1002/aisy.202400199},

issn = {2640-4567},

year  = {2024},

date = {2024-12-01},

journal = {Advanced Intelligent Systems},

volume = {6},

number = {12},

publisher = {Wiley},

abstract = {Surgical simulators are valuable educational tools for physicians, enhancing their proficiency and improving patient safety. However, they typically still suffer from a lack of realism as they do not emulate dynamic tissue biomechanics haptically and fail to convincingly mimic real-time physiological reactions. This study presents a dynamic tactile synthetic tissue, integrating both sensory and actuatory capabilities within a fully soft unit, as a core component for soft robotics and future hybrid surgical simulators utilizing dynamic physical phantoms. The adaptive surface of the tissue replica, actuated via hydraulics, is assessed by an embedded carbon black silicone sensor layer using electrical impedance tomography to determine internally or externally induced deformations. The integrated fluid chambers enable pressure and force measurements. The combination of these principles enables real-time tissue feedback as well as closed loop operation, allowing optimal interaction with the environment. Based on the concepts of soft robotics, such artificial tissues find broad applicability, demonstrated via a soft gripper and surgical simulation applications including a dynamic, artificial brain phantom as well as a synthetic, beating heart. These advancements pave the way toward enhanced realism in surgical simulators including reliable performance evaluation and bear the potential to transform the future of surgical training methodologies.},

note = {Publisher Copyright: © 2024 The Author(s). Advanced Intelligent Systems published by Wiley-VCH GmbH.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurner2024a,

title = {Carbon black silicone composite in surgical simulation - A detailed electromechanical characterization},

author = {Thomas Thurner and Roland Pruckner and Julia Maier and Martin Kaltenbrunner and Andreas Schrempf},

doi = {10.1016/j.sna.2024.115262},

issn = {0924-4247},

year  = {2024},

date = {2024-03-01},

journal = {Sensors and Actuators, A: Physical},

volume = {370},

pages = {115262},

publisher = {Elsevier},

abstract = {The integration of advanced materials into surgical simulators has revolutionized medical training. In this study, a detailed characterization of carbon black silicone composites specifically designed as soft sensor material in hybrid surgical simulators including a hyper visco plasto elastic model is performed. Carbon black-silicone composites offer unique properties such as flexibility, softness and electrical conductivity, making them ideal for integration into synthetic tissue imitations in simulators. These sensors provide real-time feedback on tissue deformation, improving the realism and evaluation capability of surgical simulations. The comprehensive, closed-form material model enables detailed analysis of the composite's mechanical and electrical behavior, accounting for viscoelasticity, plasticity and hyperelasticity. The application of this model provides insights into the behavior of the conductive composite in different sensory scenarios, which facilitates the development of more realistic simulators.},

note = {Publisher Copyright: © 2024 The Authors},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurner2023a,

title = {Open Source Sensor Interface for Soft Detectors in Surgical Simulators},

author = {Thomas Thurner and Roland Pruckner and Martin Kaltenbrunner and Andreas Schrempf},

doi = {10.1109/ACCESS.2023.3276444},

issn = {2169-3536},

year  = {2023},

date = {2023-01-01},

journal = {IEEE Access},

volume = {11},

pages = {49650–49664},

publisher = {Institute of Electrical and Electronics Engineers Inc.},

abstract = {Surgical simulation is an emerging area of research and development, making new developments of especially hybrid simulators highly relevant. In this context, soft sensors enable low-cost position or force detection in haptically realistic synthetic tissue imitations to link the physical and virtual components of a patient phantom. To accelerate and facilitate the development of such simulators, an open-source sensor interface module optimized for use with soft carbon black silicone composite based sensors is presented. The module can measure complex voltages and impedances between multiple measurement channels at various frequencies. This enables up to three-dimensional tool tracking of conductive surgical instruments in patient phantoms as well as force or deformation detection at relevant structures. Several application scenarios are presented. Disruptive influences on the sensors are minimized by evaluating the signals based on discrete Fourier transform. Higher frequency signal coupling avoids contacting problems with soft sensors, which are often highly piezoresistive. Compensation functions or favorable sensor structures can largely avoid the influence of parasitic capacitances, which are particularly prevalent in low-cost electronics. The universally applicable module provides all the necessary electronics, including firmware and software interface for the subsequent processing computer. The handy module offers 17 measuring channels as well as digital inputs and outputs and is operated via USB. In addition to the evaluability of various sensor types relevant for surgical simulation, electroimpedance tomography is also supported, as demonstrated by the examples.},

note = {Publisher Copyright: © 2013 IEEE.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurner2023b,

title = {Smart Artificial Soft Tissue - Application to a Hybrid Simulator for Training of Laryngeal Pacemaker Implantation},

author = {Thomas Thurner and Andreas Schrempf and Benjamin Esterer and Marianne Hollensteiner and Sabrina Sandriesser and Peter Augat and Roland Pruckner and David Fürst and Daniela Wirthl and Martin Kaltenbrunner and Andreas Müller and Gerhard Förster and Claus Pototschnig},

doi = {10.1109/TBME.2022.3201613},

issn = {0018-9294},

year  = {2023},

date = {2023-01-01},

journal = {IEEE Transactions on Biomedical Engineering},

volume = {70},

number = {2},

pages = {735–746},

publisher = {IEEE Computer Society},

abstract = {Surgical simulators are safe and evolving educational tools for developing surgical skills. In particular, virtual and hybrid simulators are preferred due to their detailedness, customization and evaluation capabilities. To accelerate the revolution of a novel class of hybrid simulators, a Smart Artificial Soft Tissue is presented here, that determines the relative position of conductive surgical instruments in artificial soft tissue by inverse resistance mappings without the need for a fixed reference point. This is particularly beneficial for highly deformable structures when specific target regions need to be reached or avoided. The carbon-black-silicone composite used can be shaped almost arbitrarily and its elasticity can be tuned by modifying the silicone base material. Thus, objective positional feedback for haptically correct artificial soft tissue can be ensured. This is demonstrated by the development of a laryngeal phantom to simulate the implantation of laryngeal pacemaker electrodes. Apart from the position-detecting larynx phantom, the simulator uses a tablet computer for the virtual representation of the vocal folds' movements, in accordance with the electrical stimulation by the inserted electrodes. The possibility of displaying additional information about target regions and anatomy is intended to optimize the learning progress and illustrates the extensibility of hybrid surgical simulators.},

note = {Publisher Copyright: © 1964-2012 IEEE.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wittner2021a,

title = {Thickness accuracy of virtually designed patient-specific implants for large neurocranial defects},

author = {Claudia Wittner and Markus Borowski and Lukas Pirl and Johann Kastner and Andreas Schrempf and Ute Schäfer and Klemens Trieb and Sascha Senck},

doi = {10.1111/joa.13465},

issn = {0021-8782},

year  = {2021},

date = {2021-10-01},

urldate = {2021-10-01},

journal = {Journal of Anatomy},

volume = {239},

number = {4},

pages = {755–770},

publisher = {Wiley},

abstract = {The combination of computer-aided design (CAD) techniques based on computed tomography (CT) data to generate patient-specific implants is in use for decades. However, persisting disadvantages are complicated design procedures and rigid reconstruction protocols, for example, for tailored implants mimicking the patient-specific thickness distribution of missing cranial bone. In this study we used two different approaches, CAD- versus thin-plate spline (TPS)-based implants, to reconstruct extensive unilateral and bilateral cranial defects in three clinical cases. We used CT data of three complete human crania that were virtually damaged according to the missing regions in the clinical cases. In total, we carried out 132 virtual reconstructions and quantified accuracy from the original to the generated implant and deviations in the resulting implant thickness as root-mean-square error (RMSE). Reconstructions using TPS showed an RMSE of 0.08–0.18 mm in relation to geometric accuracy. CAD-based implants showed an RMSE of 0.50–1.25 mm. RMSE in relation to implant thickness was between 0.63 and 0.70 mm (TPS) while values for CAD-based implants were significantly higher (0.63–1.67 mm). While both approaches provide implants showing a high accuracy, the TPS-based approach additionally provides implants that accurately reproduce the patient-specific thickness distribution of the affected cranial region.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Esterer2020a,

title = {Characterization of tissue properties in epidural needle insertion on human specimen and synthetic materials},

author = {Benjamin Esterer and Marianne Hollensteiner and Andreas Schrempf and Martin Winkler and Stefan Gabauer and David Fürst and Robert Merwa and Stephanie Panzer and Klaus Püschel and Peter Augat},

doi = {10.1016/j.jmbbm.2020.103946},

issn = {1751-6161},

year  = {2020},

date = {2020-10-01},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

volume = {110},

publisher = {Elsevier},

abstract = {The force experienced while inserting an 18-gauge Tuohy needle into the epidural space or dura is one of only two feedback components perceived by an anaesthesiologist to deduce the needle tip position in a patient's spine. To the best of the authors knowledge, no x-ray validated measurements of these forces are currently available to the public. A needle insertion force recording during an automated insertion of an 18-gauge Tuohy needle into human vertebral segments of four female donors was conducted. During the measurements, x-ray images were recorded simultaneously. The force peaks due to the penetration of the ligamentum supraspinale and ligamentum flavum were measured and compared to the measurements of an artificial patient phantom for a hybrid patient simulator. Based on these force peaks and the slope of the ligamentum interspinale, a mathematical model was developed. The model parameters were used to compare human specimens and artificial patient phantom haptics. The force peaks for the ligamenta supraspinale and flavum were 7.55 ± 3.63 N and 15.18 ± 5.71 N, respectively. No significant differences were found between the patient phantom and the human specimens for the force peaks and four of six physical model parameters. The patient phantom mimics the same resistive force against the insertion of an 18-gauge Tuohy needle. However, there was a highly significant (p < 0.00},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2019b,

title = {Development of open-cell polyurethane-based bone surrogates for biomechanical testing of pedicle screws},

author = {Marianne Hollensteiner and Benjamin Esterer and David Fürst and Andreas Schrempf and Peter Augat},

doi = {10.1016/j.jmbbm.2019.05.038},

issn = {1751-6161},

year  = {2019},

date = {2019-09-01},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

volume = {97},

pages = {247–253},

publisher = {Elsevier},

abstract = {Artificial bones made of polyurethane are frequently used as an alternative to human bone for biomechanical testing. However, the biomechanical characteristics of these materials are often not validated against those of human bones. Thus, synthetic bone surrogates reflecting procedure-specific biomechanical properties of human bones are necessary for reliable implant design and testing. The aim of this study was to evaluate novel custom made open- and close-cell bone surrogates through morphometry assessment and pedicle screw pullout tests as an alternative to human bone for biomechanical testing. Bone surrogates created from polyurethane resin, mineral fillers and varying amounts of blowing agent were customized to various densities. Pedicle screws were manually inserted and pullout tests with a feed rate of 1 mm/min were conducted until failure. Load and displacement curves were recorded and analyzed in terms of maximum pullout forces. The resulting pullout forces of open- (1437 ± 665 N)and close-cell surrogates (951 ± 578 N)showed comparable results to human bone (1417 ± 812N)used as a reference. Furthermore, structural morphometric parameters were in accordance with human vertebral cancellous bone. In conclusion, the customized bone surrogates provide a new opportunity to design and test pedicle screws and further study the relationship between biomechanical properties and apparent density of artificial spongy bone.},

note = {Funding Information: The Research Group for Surgical Simulators Linz (ReSSL) acknowledges the financial support by the Austrian Research Promotion Agency (FFG) within the program line Cooperation & Innovation (COIN) and project number 845436. Publisher Copyright: © 2019 Elsevier Ltd Copyright: Copyright 2019 Elsevier B.V., All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Glinz2019b,

title = {IN-SITU COMPRESSION TEST OF ARTIFICIAL BONE FOAMS IN CONTROLLED ENVIRONMENT USING X-RAY MICRO-COMPUTED TOMOGRAPHY},

author = {Jonathan Glinz and Daniel Kytýř and Tomáš Fíla and Jan Šleichrt and Andreas Schrempf and David Fürst and Johann Kastner and Sascha Senck},

doi = {10.14311/APP.2019.25.0048},

issn = {1805-2363},

year  = {2019},

date = {2019-06-06},

journal = {Acta Polytechnica},

pages = {48–51},

publisher = {Czech Technical University in Prague},

abstract = {In this study, we investigated specimens of artificial bone foams, developed by the research group for surgical simulators at the UAS Linz, which are used to mimic the haptic feedback of physiologic and pathologic bone for more realistic surgery training. Specimens with two kinds of mineral filler material as well as different amounts of foaming agent were tested in an environmental in-situ loading stage developed by the ITAM CAS and scanned via X-ray micro-computed tomography. In this in-situ stage, specimens can be immersed in liquid and tested under temperature-controlled conditions. Consequently, a total amount of 12 specimens was subjected to compression loading; half of them immersed in water at 36.5◦C and half in dry condition. Results showed that there is no significant influence of liquid immersion to the compression outcome. However, foams with less amount of foaming agent appeared to have smaller pores resulting in higher compression strength.},

note = {Funding Information: The research has been supported by the European Regional Development Fund in frame of the projects Competence Center for High-Resolution 3D X-ray Imaging (ATCZ38) in the Interreg V-A Austria - Czech Republic programme and by Operational Programme Research, Development and Education in project INAFYM (CZ.02.1.01/0.0/0.0/16_019/0000766). Publisher Copyright: © Czech Technical University in Prague, 2019; 17th Youth Symposium on Experimental Solid Mechanics, YSESM 2019 ; Conference date: 06-06-2019 Through 09-06-2019},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2019a,

title = {Bone surrogates provide authentic onlay graft fixation torques},

author = {Marianne Hollensteiner and Peter Augat and David Fürst and Falk Schrödl and Benjamin Esterer and Stefan Gabauer and Andreas Schrempf},

doi = {10.1016/j.jmbbm.2018.12.013},

issn = {1751-6161},

year  = {2019},

date = {2019-03-01},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

volume = {91},

pages = {159–163},

publisher = {Elsevier},

abstract = {Onlay graft bone augmentation is a standard practice to restore the loss of height of the alveolar ridge following loss of a tooth. Cranial grafts, lifted from the parietal bone, are sandwiched and used to bridge the bony defect in the jaw by means of small screws. During the elevation of the covering gum and subsequent screw placement, care has to be taken in order to preserve underlying nerves. Therefore, to avoid harm to the patient, a solid education of surgeons is essential, which requires training and experience. A simulator for cranial graft-lift training was already developed and shall be expanded to train the augmentation of the lifted implants. Therefore, in this study, synthetic bones for onlay block graft screw placement with realistic haptics for the screw application training were evaluated and compared with human specimens. Six different polyurethane based bone surrogate composites, enriched with varying amounts of calcium-based mineral fillers and blowing agents, were developed. The haptical properties of these synthetic bones were validated for screw placement and compared with human parietal bone specimens. For that, bones were pre-drilled, screws were automatically inserted using a customized testbench and the slope of the screw-insertion torques were analyzed. The slope of the screw insertion torques of the human reference bones was 56.5 ± 14.0 * 10-3 Nm/deg, Surrogates with lower amounts of mineral fillers and blowing agents showed lower torques than the human bone. Synthetic bones, validated for drilling, milling and sawing in an earlier study, also achieved significantly lower torques, which were only the half of the human parietal bones. Two intermediate stages of the aforementioned material compositions, consisting of 75% mineral filler with 0.75% blowing agent and 100% mineral filler with 1.00% blowing agent revealed results comparable with human bone (57.4 ± 10.2 *10-3 Nm/de},

note = {Publisher Copyright: © 2018 Elsevier Ltd Copyright: Copyright 2019 Elsevier B.V., All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2018b,

title = {Characterization of polyurethane-based synthetic vertebrae for spinal cement augmentation training},

author = {Marianne Hollensteiner and Melanie Botzenmayer and David Fürst and Martin Winkler and Peter Augat and Sabrina Sandriesser and Falk Schrödl and Benjamin Esterer and Stefan Gabauer and Klaus Püschel and Andreas Schrempf},

doi = {10.1007/s10856-018-6161-2},

issn = {1573-4838},

year  = {2018},

date = {2018-09-29},

journal = {Journal of Materials Science: Materials in Medicine},

volume = {29},

number = {10},

pages = {153},

publisher = {Springer},

abstract = {Vertebral augmentation techniques are used to stabilize impacted vertebrae. To minimize intraoperative risks, a solid education of surgeons is desirable. Thus, to improve education of surgeons as well as patient safety, the development of a high-fidelity simulator for the surgical training of cement augmentation techniques was initiated. The integrated synthetic vertebrae should be able to provide realistic haptics during all procedural steps. Synthetic vertebrae were developed, tested and validated with reference to human vertebrae. As a further reference, commercially available vertebrae surrogates for orthopedic testing were investigated. To validate the new synthetic vertebrae, characteristic mechanical parameters for tool insertion, balloon dilation pressure and volume were analyzed. Fluoroscopy images were taken to evaluate the bone cement distribution. Based on the measurement results, one type of synthetic vertebrae was able to reflect the characteristic parameters in comparison to human vertebrae. The different tool insertion forces (19.7 ± 4.1, 13.1 ± 0.9 N, 1.5 ± 0.2 N) of the human reference were reflected by one bone surrogate (11.9 ± 9.8, 24.3 ± 3.9 N, 2.4 ± 1.0 N, respectively). The balloon dilation pressure (13.0 ± 2.4 bar), volume (2.3 ± 1.5 ml) of the synthetic vertebrae were in good accordance with the human reference (10.7 ± 3.4 bar, 3.1 ± 1.1 ml). Cement application forces were also in good accordance whereas the cement distribution couldn’t be reproduced accurately. Synthetic vertebrae were developed that delivered authentic haptics during transpedicular instrument insertion, balloon tamp dilation and bone cement application. The validated vertebra model will be used within a hybrid simulator for minimally invasive spine surgery to educate and train surgeons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2018d,

title = {Validation of a Simulator for Cranial Graft Lift Training: Face, Content, and Construct Validity},

author = {Marianne Hollensteiner and Peter Augat and David Fürst and Benjamin Esterer and Stefan Gabauer and Michael Malek and Stefan Hunger and Falk Schrödl and Andreas Schrempf},

doi = {10.1016/j.jcms.2018.05.036},

year  = {2018},

date = {2018-08-01},

journal = {Journal of Cranio-Maxillo-Facial Surgery},

volume = {46},

number = {8},

pages = {1390–1394},

abstract = {Purpose: Surgical skills can be improved through practical exercise. The use of specimens, human as well as animal, or live animals for surgical training is limited due to ethical concerns. Drawbacks of simulators are costs, fidelity and creditibility. Thus, simulators must be evaluated objectively to determine their validity before they can be used as teaching modalities. The aim of this study was to verify the face content and construct validity of a novel model-based simulator for lifting tabula externa transplants from the parietal skull. Materials and Methods: Participants were invited to perform a tabula externa graft lift during a training session on the simulator. Task performance was analyzed with a standardized assessment tool evaluating realism and appropriateness. Specialist ratings were used to evaluate the performance of the participants. This was an exploratory study using a questionnaire, a t Kepler University Hospital, Linz, Austria, a university hospital. According to their expertise in craniomaxillofacial surgery, 17 participants were subdivided into 3 groups: 8 novices, 7 experts and 2 raters. Results: The face validity (realism) obtained an average score of 4.2 of a maximum of 5 points. Likewise, the content validity (appropriateness as a teaching modality) obtained an average score of 4.8 of maximum 5 points. No differences were found between experts and novices concerning the recorded surgery completion times (p=0.418) or the sizes of the lifted grafts (p=0.110). During the evaluation of task performance, the expert surgeons (46.9 ± 3.7) were graded significantly better than the novices (36.4 ± 8.5), which proved the construct validity of the simulator (p=0.001). Conclusion: All investigated validities were confirmed and approved the simulator as a valid training tool for parietal graft lift.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2018c,

title = {Procedure-specific validation of artificial vertebrae},

year  = {2018},

date = {2018-01-01},

abstract = {Objective: The development of a novel hybrid patient simulator was initiated to provide a safe training possibility for novice surgeons. Integrated artificial vertebrae should be able to realistically mimic the haptics of transpedicular vertebroplasty instrument insertion and pedicle screw placement. Therefore, new open-celled material compositions were developed, tested, and validated with reference to elderly human vertebrae. Methods: Vertebroplasty tool insertion force and pedicle screw torque measurements were performed. To validate the new bone surrogates for transpedicular tool insertion, a novel parametric model of the procedure was developed identifying three characteristic insertion parameters (weighting factors, cutting, and clamping forces). Furthermore, the slope of the insertion torque was used to validate the new materials against the human vertebrae for pedicle screw placement. Results: A relative error less than 6% confirmed the suitability of the parametric model for validation. The weighting factors (28.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2018a,

title = {Transpedicular Approach on a Novel Spine Simulator: A Validation Study},

author = {David Fürst and Marianne Hollensteiner and Stefan Gabauer and Benjamin Esterer and Klemens Trieb and Felix Eckstein and Andreas Schrempf},

doi = {10.1016/j.jsurg.2018.01.002},

issn = {1931-7204},

year  = {2018},

date = {2018-01-01},

journal = {Journal of Surgical Education},

volume = {75},

number = {4},

pages = {1127–1134},

publisher = {Elsevier},

abstract = {Objective: The popularity of simulation in the medical field has increased dramatically over the last decades. However, the majority of studies focused on laparoscopic or other endoscopic procedures. In this study, participants performed an image-guided surgery task on a novel spine simulator. Face, content, construct, and concurrent validity were examined. Design: A surgical access through both pedicles (transpedicular) into the vertebral body of artificial L3 vertebrae was performed. Questionnaires, a simulation-based performance score, and a specialist rating were used to evaluate the various forms of validity. Setting: Klinikum Wels-Grieskirchen, Wels, Austria; tertiary hospital Participants: According to their expertise in image-guided surgery and pedicle tool insertions, 43 participants were subdivided into 3 groups: 22 novices, 12 intermediates, and 9 experts. Results: Of the novice group, the vast majorities were impressed with the attractiveness and the general appearance of the simulator. The majority of intermediates (92%) and experts (89%) would recommend the simulator to others. According to a simulation-based performance score, experts performed significantly better than novices (p = 0.00},

note = {Publisher Copyright: © 2018 Association of Program Directors in Surgery},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Esterer2017b,

title = {A hybrid, low-cost tissue-like epidural needle insertion simulator},

author = {Benjamin Esterer and Stefan Gabauer and Robert Pichler and Daniela Wirthl and Michael Drack and Marianne Hollensteiner and Gerald Kettlgruber and Martin Kaltenbrunner and Siegfried Bauer and David Fuerst and Robert Merwa and Jens Meier and Peter Augat and Andreas Schrempf},

year  = {2017},

date = {2017-01-01},

journal = {Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society},

abstract = {Epidural and spinal anesthesia are mostly performed “blind” without any medical imaging. Currently, training of these procedures is performed on human specimens, virtual reality systems, manikins and mostly in clinical practice supervised by a professional. In this study a novel hybrid, lowcost patient simulator for the training of needle insertion into the epidural space was designed. The patient phantom provides a realistic force feedback comparable with biological tissue and enables sensing of the needle tip position during insertion. A display delivers the trainee a real-time feedback of the needle tip position.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2017,

title = {Characterization of synthetic foam structures used to manufacture artificial vertebral trabecular bone},

author = {David Fuerst and Sascha Senck and Marianne Hollensteiner and Benjamin Esterer and Peter Augat and Felix Eckstein and Andreas Schrempf},

doi = {10.1016/j.msec.2017.03.158},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Materials Science and Engineering C},

abstract = {Artificial materials reflecting the mechanical properties of human bone are essential for valid and reliable implant testing and design. They also are of great benefit for realistic simulation of surgical procedures. The objective of this study was therefore to characterize two groups of self-developed synthetic foam structures by static compressive testing and by microcomputed tomography. Two mineral fillers and varying amounts of a blowing agent were used to create different expansion behavior of the synthetic open-cell foams. The resulting compressive and morphometric properties thus differed within and also slightly between both groups. Apart from the structural anisotropy, the compressive and morphometric properties of the synthetic foam materials were shown to mirror the respective characteristics of human vertebral trabecular bone in good approximation. In conclusion, the artificial materials created can be used to manufacture valid synthetic bones for surgical training. Further, they provide novel possibilities for studying the relationship between trabecular bone microstructure and biomechanical properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Esterer2017,

title = {Development of Validated Methods to Generate Haptic Feedback in Interventional and Therapeutical Needle Insertions},

author = {Benjamin Esterer and David Fuerst and Marianne Hollensteiner and Stefan Gabauer and Peter Augat and Robert Merwa and Andreas Schrempf},

year  = {2017},

date = {2017-01-01},

journal = {Proceedings of the IAUP Triennial Conference},

abstract = {Nowadays, surgical education still follows the Halstedian approach of “see one, do one, teach one” which is already over 100 years old [1]. Anaesthetist novices gather fi rst hands-on experience directly on the patient assisted by a medical expert. Training anaesthetic procedures on simulators constitutes a safer alternative. The one way to learn is by making mistakes. By practicing on a simulator, a medical novice is allowed to make mistakes, learn from them, gather new information and to acquire surgical skills [2]. On the other hand, by learning from mistakes while performing a procedure on a patient can lead to major complications [3, 4]. Simulators on the market are categorized in low fi delity/high fi delity or virtual reality, manikins or hybrid simulators. A hybrid simulator combines artifi cial structures that provide realistic haptic feedback with a computer model [5]. One of these simulators is currently under development in the Research Group for Surgical Simulators Linz (ReSSL), which is department of the Upper Austrian University of Applied Sciences in Linz.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2017,

title = {Novel bone surrogates for cranial surgery training},

author = {Marianne Hollensteiner and David Fuerst and Benjamin Esterer and Peter Augat and Falk Schroedl and Stefan Hunger and Michael Malek and Daniel Stephan and Andreas Schrempf},

year  = {2017},

date = {2017-01-01},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

abstract = {Parietal graft lifts are trained on human or animal specimens or are directly performed on patients without extensive training. In order to prevent harm to the patient resulting from fast rotating machinery tools, the surgeon needs to apply appropriate forces. Realistic haptics are essential to identify the varying parietal bone layers and to avoid a penetration of the brain. This however, requires experience and training. Therefore, in this study, bone surrogate materials were evaluated with the aim to provide an anatomically correct artificial skull cap with realistic haptic feedback for graft lift training procedures. Polyurethane composites made of calcium carbonate and calcium phosphate were developed and were used to create customized bone surrogates, imitating both cancellous and cortical bone. Mechanical properties of these surrogates were validated for drilling, milling and sawing by comparison with human parietal bones. For that, surgical tool tips were automatically inserted into artificial and human bones in a customized test bench and the maximum axial insertion forces were analyzed. Axial tool insertion measurements in human parietal bones resulted in mean maximum forces of 1.8±0.5 N for drilling, 1.7±0.3 N for milling and 0.9±0.1 N for sawing. Calcium carbonate-based materials achieved higher forces than the human bone for drilling and milling, and lower forces for sawing. The calcium phosphate-based bone surrogates showed comparable axial insertions forces for all investigated tools and were identified as a suitable surrogate for drilling (p=0.87 and 0.41), milling (p=0.92 and 0.63) and sawing (p=0.11 and 0.76) of the cortical layer and the cancellous bone, respectively. In conclusion, our findings suggest, that a suitable material composition for artificial parietal bones has been identified, mimicking the properties of human bone during surgical machinery procedures. Thus, these materials are suitable for surgical training and education in simulator training.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2017b,

title = {Novel Simulator for Cranial Graft Lift Training},

author = {Marianne Hollensteiner and David Fuerst and Benjamin Esterer and Stefan Gabauer and Peter Augat and Falk Schroedl and Andreas Schrempf},

year  = {2017},

date = {2017-01-01},

journal = {Proceedings of the IAUP Triennial Conference},

abstract = {Cranial grafts are used for the reconstruction of skeletal defects after trauma, tumor, infection or congenital pseudarthrosis [1] and due to their biocompatibility are more favored [2]. A common method to harvest parietal grafts is the split thickness graft method which is characterized by fast rotating surgical drives. To avoid accidents, appropriate thrust forces and drilling speeds have to be applied. Thus extensive training of novice surgeons is necessary. One training modality are model simulators, which provide a physical phantom with realistic anatomy and haptic feedback. Studies have shown that, in contrast to visual guided training only, simulators with haptic feedback have higher surgical skill-transfer to novel surgeons [3]. The aim of this study was to validate artifi cial parietal bones for graft lift training. Structural parameters of all bony layers were measured and characteristic forces during surgical machinery procedures were recorded [4]. Further, a simulator prototype was developed and tested by two experienced surgeons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2017a,

title = {Novel synthetic vertebrae provide realistic haptics for pedicle screw placement},

author = {Marianne Hollensteiner and Peter Augat and David Fuerst and Benjamin Esterer and Stefan Gabauer and Klaus Pueschel and Falk Schroedl and Andreas Schrempf},

year  = {2017},

date = {2017-01-01},

journal = {Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society},

abstract = {During vertebral surgery, misplaced pedicle screws can harm vital neural and vascular structures. Haptic distinction between cortical and cancellous bone structures is therefore essential for correct screw placement. This tactile experience during pedicle screw placement can be obtained by training on human or animal specimens even if expensive or ethically questionable. In this study, novel synthetic vertebrae were evaluated within a hybrid simulator to provide realistic haptics for the training of spine surgeries. Synthetic vertebrae were custommade of calcium powder-based composites imitating both, cancellous and cortical bone. The mechanical properties of synthetic surrogates were validated for pedicle screw placement and cement augmentation and were compared with those obtained from human vertebrae and insertion torques were analyzed. In human vertebrae pedicle screw torque measurements resulted in mean torque slopes of 8233Nm=m. Calcium carbonate-based materials achieved lower torques than the human bone whereas calcium phosphate-based bone surrogates showed comparable results. A further differentiation of the calcium phosphate-based vertebrae revealed, that synthetic vertebrae with lower amounts of blowing agent, achieved suitable torques (83  28Nm=m) in comparison to the human reference (p = 0:39). Cement application and subsequent fluoroscopy images confirmed, that the cancellous core of the synthetic vertebrae enabled cement augmentation. In conclusion, our findings suggest, that the artificial bone samples mimic the properties of human bone during pedicle screw placement and cement augmentation and are therefore suitable as synthetic vertebrae in a hybrid surgical simulator.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2018a,

title = {Characterization of an Artificial Skull Cap for Cranio-Maxillofacial Surgery Training},

author = {Marianne Hollensteiner and David Fürst and Peter Augat and Falk Schrödl and Benjamin Esterer and Stefan Gabauer and Stefan Hunger and Michael Malek and Daniel Stephan and Andreas Schrempf},

doi = {10.1007/s10856-018-6143-4},

issn = {0957-4530},

year  = {2017},

date = {2017-01-01},

journal = {JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE},

volume = {29},

number = {9},

publisher = {Springer},

abstract = {Cranial grafts are favored to reconstruct skeletal defects because of their reduced resorption and their histocompatibility. Training possibilities for novice surgeons include the “learning by doing” on the patient, specimens or simulators. Although the acceptance of simulators is growing, the major drawback is the lack of validated bone models. The aim of this study was to create and validate a realistic skull cap model and to show superiority compared to a commercially available skull model. Characteristic forces during machinery procedures were recorded and thickness parameters from the bony layers were obtained. The thickness values of the bone layers of the developed parietal bone were comparable to the human ones. Differences between drilling and sawing forces of human and artificial bones were not detected using statistical analysis. In contrast the parameters of the commercially available skull model were significantly different. However, as a result, a model-based simulator for tabula externa graft lift training, consisting of a brain, skull bone cap and covering soft tissues was created. This simulator enables the training of all procedural steps of a “split thickness graft lift”. In conclusion, an artificial skull cap suitable for parietal graft lift training was manufactured and validated against human parietal bones.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Esterer2016,

title = {Development of artificial tissue-like structures for a hybrid epidural anesthesia simulator},

author = {Benjamin Esterer and Johannes Razenboeck and Marianne Hollensteiner and David Fuerst and Andreas Schrempf},

year  = {2016},

date = {2016-01-01},

journal = {Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society},

abstract = {Puncturing the epidural space and lumbar puncture are common procedures in anesthesia. They are carried out blind, where a needle is advanced from posterior between two adjacent vertebrae. Two different approaches are common practice for this technique, the midline and the paramedian one. The learning curve characteristics of both approaches significantly depends on the number of punctures carried out by a medical novice. For the training of these blind procedures a hybrid simulator requires artificial structures imitating the tissues which are penetrated by the needle. Within this work a patient phantom for spinal needle insertion procedures was developed and validated successfully against literature as well as by a study carried out with medical experts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2017c,

title = {Development of parietal bone surrogates for parietal graft lift training},

author = {Marianne Hollensteiner and David Fuerst and Benjamin Esterer and Stefan Hunger and Michael Malek and Peter Augat and Falk Schroedl and Daniel Stephan and Andreas Schrempf},

year  = {2016},

date = {2016-01-01},

journal = {Current Directions in Biomedical Engineering},

abstract = {Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2016a,

title = {Druckeigenschaften synthetischer Knochenmodelle zur Nachbildung des trabekul¨aren Knochens von humanen Wirbelk¨orpern},

author = {David Fuerst and Marianne Hollensteiner and Benjamin Esterer and Andreas Schrempf},

year  = {2016},

date = {2016-01-01},

journal = {Proceedings of the DWG Hannover 2016},

abstract = {K¨unstliche Knochenmodelle aus Polyurethan (PU) sind f¨ur das Testen von orthop¨adischen Produkten sowie f¨ur die Ausbildung angehender Chirurgen sehr popul¨ar. Geschlossenzellige Hartsch¨aume sind dabei in der Lage, die Druckeigenschaften von humanem, trabekul¨arem Knochen nachzubilden. Das Ziel dieser Studie war die Untersuchung der Druckeigenschaften von eigens entwickelten, synthetischen Knochenmodellen mit offener Zellstruktur.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2016b,

title = {Inexpensive bone cement substitute for vertebral cement augmentation training},

author = {Marianne Hollensteiner and Markus Samrykit and Michael Hess and David Fuerst and Benjamin Esterer and Andreas Schrempf},

year  = {2016},

date = {2016-01-01},

journal = {Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society},

abstract = {Vertebral compression fractures are treated surgically for approximately 25 years. In percutaneous cement augmentation techniques bone cement is applied to a fractured vertebra under fluoroscopic evidence to stabilize the bone fragments. Complications due to leakage of the low viscosity bone cement are reported in 5 to 15% of all routine cases. During the intraoperative application of bone cement surgeons rely on visiohaptic feedback and hence need to be familiar with the cement’s rheology properties. Therefore, training is necessary. A hybrid simulator for cement augmentation training was developed but the usage of expensive real cement limits its purpose as a training modality. Twentythree inexpensive bone substitutes were developed and tested with the objective to mimic real bone cement. Cement application measurements were conducted and a mathematical model of the measurement setup was created. Compared with real bone cement, a cement substitute based on Technovit 3040 in combination with radical catchers and additional additives was identified as an appropriate substitute for cement augmentation training.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2015a,

title = {Assessment Parameters for a Novel Simulator in Minimally Invasive Spine Surgery},

author = {David Fuerst and Marianne Hollensteiner and Andreas Schrempf},

year  = {2015},

date = {2015-01-01},

journal = {Conf Proc IEEE Eng Med Biol Soc},

institution = {Department of Medical Device Engineering, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Linz, Austria.},

abstract = {Surgical simulators provide a safe environment where novice surgeons can acquire their surgical skills. Although the number of patients with diseases of the muscu- loskeletal system is growing, the development of orthopedic simulators is still in it's infancy. The aim of this work was to identify simulation-based assessment parameters for a novel simulator in minimally invasive spine surgery. Apart from parameters targeting the duration and the surgeon's economy of motion during percutaneous bone access, parameters characterizing the movement smoothness during stroke recovery were also examined in respect to their suitability. The results indicated, that the overall duration, the number of instrument movements, the number of velocity peaks and the Movement Arrest Period Ratio are the most promising predictors of expertise. Targeting performance improvement, the overall duration (p = 0.001), the number of instrument movements (p = 0.003) and the traveled instrument path length (p = 0.009) detected significant differences between subsequent trials. Using these parameters, a study can be designed targeting the validity and reliability of the simulation-based assessment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2015a,

title = {Development of Trabecular Bone Surrogates for Kyphoplasty-Balloon Dilatation Training},

author = {Marianne Hollensteiner and Markus Samrykit and Michael Hess and David Fuerst and Andreas Schrempf},

year  = {2015},

date = {2015-01-01},

journal = {Conf Proc IEEE Eng Med Biol Soc},

abstract = {Vertebral compression fractures can limit quality of life. Cement augmentation techniques show good results in attaining pain relief. Kyphoplasty enables a better restoration of vertebra height due to a dilatateable ballon tamp, which is inflated in the fractured vertebra. Surgical training of vertebral cement augmentation techniques is currently performed on patients or specimens. To enable another training possibility for surgical residents, a new hybrid patient simulator was developed. Artificial vertebrae allocate a realistic haptic feedback during needle insertion. Based on these results, new polyurethane foam recipes were developed to either enable a realistic needle insertion as well as a balloon tamp dilatation. Needle insertion forces of the newly developed foams were compared against the formerly used polyurethane trabeculae and balloon tamp dilatations were performed in manufacured materials. Based on the matching needle insertion forces, two suitable material compositions for needle insertion and balloon dilatation training were found. This investigation is considered as a prior study before evaluation on human specimen.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2014a,

title = {A Novel Augmented Reality Simulator for Minimally Invasive Spine Surgery},

author = {David Fuerst and Marianne Hollensteiner and Andreas Schrempf},

url = {http://dl.acm.org/citation.cfm?id=2685617.2685645},

year  = {2014},

date = {2014-01-01},

journal = {Proceedings of the 2014 Summer Simulation Multiconference},

pages = {28:1–28:5},

publisher = {Society for Computer Simulation International},

address = {Monterey, California},

series = {SummerSim '14},

abstract = {Currently the surgical training of kyphoplasty and vertebroplasty is performed on patients or specimens. To improve patient safety, a project was initiated to develop an Augmented Reality simulator for the surgical training of these interventions. Artificial vertebral segments should be integrated to provide realistic haptic feedback. To reach this, resulting forces during needle insertions (trans- and extrapedicular) into formalin-fixed vertebral specimens were measured. The same insertion procedure was also performed on six customized polyurethane blocks with varying mechanical parameters. Based on the results of these measurements, a specific foam phantom was generated and the insertion force measured. Additionally a parametric model for the needle insertion into bone was designed calculating three characteristic parameters for all insertion measurements. The resulting insertion force for the foam phantom was comparable to the specimen measurements and the parametric model provided comprehensible characteristic parameters. Based on the resulting force during needle insertion into human vertebrae, a possible foam recipe for manufacturing artificial segments was found. Furthermore, the parametric model provides characteristic parameters for the assessment of phantoms as well as the development of its production process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2014a,

title = {Artificial muscles for a novel simulator in minimally invasive spine surgery.},

author = {Marianne Hollensteiner and David Fuerst and Andreas Schrempf},

year  = {2014},

date = {2014-01-01},

journal = {Conf Proc IEEE Eng Med Biol Soc},

pages = {506-509},

abstract = {Vertebroplasty and kyphoplasty are commonly used minimally invasive methods to treat vertebral compression fractures. Novice surgeons gather surgical skills in different ways, mainly by ?learning by doing? or training on models, specimens or simulators. Currently, a new training modality, an augmented reality simulator for minimally invasive spine surgeries, is going to be developed. An important step in investigating this simulator is the accurate establishment of artificial tissues. Especially vertebrae and muscles, reproducing a comparable haptical feedback during tool insertion, are necessary. Two artificial tissues were developed to imitate natural muscle tissue. The axial insertion force was used as validation parameter. It appropriates the mechanical properties of artificial and natural muscles. Validation was performed on insertion measurement data from fifteen artificial muscle tissues compared to human muscles measurement data. Based on the resulting forces during needle insertion into human muscles, a suitable material composition for manufacturing artificial muscles was found.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hollensteiner2013a,

title = {Artificial Vertebrae for a Novel Simulator in Minimally Invasive Spine Surgery.},

author = {Marianne Hollensteiner and David Fuerst and Andreas Schrempf},

url = {http://dx.doi.org/10.1515/bmt-2013-4409},

doi = {10.1515/bmt-2013-4409},

year  = {2013},

date = {2013-09-01},

journal = {Biomed Tech (Berl)},

abstract = {Currently the surgical training of vertebral augmentation techniques is performed on patients or specimens. To improve patient safety, the development of a novel patient simulator was initiated. Artificial vertebrae should be integrated to provide realistic haptic feedback. In a previous study, resulting forces during transpedicular needle insertions into formalin-fixed vertebral specimens were measured. Based on these results, a specific polyurethane foam recipe was covered by different resin shells. The resulting insertion forces for the artificial vertebrae were comparable to the specimen measurements. Based on the resulting force during needle insertion into human vertebrae, a suitable material composition for manufacturing artificial vertebral segments was found.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2012a,

title = {Foam phantom development for artificial vertebrae used for surgical training.},

author = {David Fuerst and Daniel Stephan and Peter Augat and Andreas Schrempf},

url = {http://dx.doi.org/10.1109/EMBC.2012.6347306},

doi = {10.1109/EMBC.2012.6347306},

year  = {2012},

date = {2012-01-01},

journal = {Conf Proc IEEE Eng Med Biol Soc},

volume = {2012},

pages = {5773–5776},

institution = {Department of Medical Device Engineering, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Linz, Austria.},

abstract = {Currently the surgical training of kyphoplasty and vertebroplasty is performed on patients or specimens. To improve patient safety, a project was initiated to develop an Augmented Reality simulator for the surgical training of these interventions. Artificial vertebral segments should be integrated to provide realistic haptic feedback. To reach this, resulting forces during needle insertions (trans- and extrapedicular) into formalin-fixed vertebral specimens were measured. The same insertion procedure was also performed on six customized polyurethane blocks with varying mechanical parameters. Based on the results of these measurements, a specific foam phantom was generated and the insertion force measured. Additionally a parametric model for the needle insertion into bone was designed calculating three characteristic parameters for all insertion measurements. The resulting insertion force for the foam phantom was comparable to the specimen measurements and the parametric model provided comprehensible characteristic parameters. Based on the resulting force during needle insertion into human vertebrae, a possible foam recipe for manufacturing artificial segments was found. Furthermore, the parametric model provides characteristic parameters for the assessment of phantoms as well as the development of its production process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fuerst2012b,

title = {PatientSIM - Development of an augmented reality simulator for surgical training of vertebroplasty and kyphoplasty.},

author = {David Fuerst and Andreas Schrempf},

doi = {10.2316/P.2012.764-078},

year  = {2012},

date = {2012-01-01},

journal = {BioMed 2012, Innsbruck Austria},

abstract = {Surgical interventions have become more complex over the last years and the number of new surgical technologies is still rising. Surgical simulators represent safe and reliable training environments were novice surgeons can acquire the surgical skills required for new or complex procedures. Augmented reality or hybrid simulators combine the advantage of a detailed visualization with haptic feedback to make complex interventions as realistic as possible. As common treatment options for vertebral compression fractures, which are characterized by high incidence rates, kyphoplasty and vertebroplasty represent such complex interventions. Currently the training for both procedures is performed on cadavers with fluoroscopic guidance which results in two serious problems. First, the need for cadavers and second the radiation exposure limiting the duration of the surgical training. This paper reports the current stage of development of an augmented reality simulator which allows novice surgeons to train kyphoplasty and vertebroplasty without having these two disadvantages. We describe how surgical instruments are modified to allow position and force tracking during insertion into artificial vertebrae, and present a first concept for a processing and visualization unit. Preliminary data provide requirements for manufacturing patient specific vertebral phantoms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}