Publications

2017

• M. Hollensteiner, M. Malek, S. Hunger, D. Fuerst, B. Esterer, P. Augat, F. Schroedl, D. Stephan, and A. Schrempf, “Validierung eines modell-basierten Simulators für das Training in der CMF Chirurgie,” Proceedings of the 3rd Kepler Science Day, 2017.
  [BibTeX] [Abstract]
  

  Das Heben von Tabula Externa Transplantaten aus der parietalen Schädelkalotte ist eine anerkannte Praxis zur Behandlung von knöchernen Deformitäten. Um Risiken zu minimieren, müssen während des chirurgischen Eingriffs entsprechende Kräfte und Geschwindigkeiten der chirurgischen Instrumente angewendet werden. Um diesen Eingriff zu trainieren, wurde ein modell-basierter Simulator entwickelt. Um zu beweisen, dass dieser neue Simulator für das Training und die Ausbildung von Novizen geeignet ist, wurde eine Validierungsstudie im Kepler Universitätsklinikum Linz durchgeführt.

  @Article{Hollensteiner2017e,
  Title = {{Validierung eines modell-basierten Simulators für das Training in der CMF Chirurgie}},
  Author = {Marianne Hollensteiner and Michael Malek and Stefan Hunger and David Fuerst and Benjamin Esterer and Peter Augat and Falk Schroedl and Daniel Stephan and Andreas Schrempf},
  Journal = {{Proceedings of the 3rd Kepler Science Day}},
  Year = {2017},
  Abstract = {Das Heben von Tabula Externa Transplantaten aus der parietalen Schädelkalotte ist eine anerkannte Praxis zur Behandlung von knöchernen Deformitäten. Um Risiken zu minimieren, müssen während des chirurgischen Eingriffs entsprechende Kräfte und Geschwindigkeiten der chirurgischen Instrumente angewendet werden. Um diesen Eingriff zu trainieren, wurde ein modell-basierter Simulator entwickelt. Um zu beweisen, dass dieser neue Simulator für das Training und die Ausbildung von Novizen geeignet ist, wurde eine Validierungsstudie im Kepler Universitätsklinikum Linz durchgeführt.},
  Volume = {},
  Number = {},
  Pages = {},
  Url = {}
  }

• B. Esterer, S. Gabauer, R. Pichler, D. Wirthl, M. Drack, M. Hollensteiner, G. Kettlgruber, M. Kaltenbrunner, S. Bauer, D. Fuerst, R. Merwa, J. Meier, P. Augat, and A. Schrempf, “Needle position tracking in a hybrid low-cost tissue-like epidural needle insertion simulator,” Proceedings of the 3rd Kepler Science Day, 2017.
  [BibTeX] [Abstract]
  

  Epidural needle insertion is mostly carried out without any imaging modality. The advancement of a needle into the epidural space is part of different therapeutic and/or diagnostic interventions, e.g. lumbar puncture or epidural anesthesia. The latter is done with an 18-gauge Tuohy needle mounted on a loss of resistance (LOR) syringe. During the procedure the anesthesiologist experiences two haptic feedback components to deduce the position of the needle tip: the force needed for the advancement of the needle into the body and the counter pressure acting on the thumb while trying to compress the air or saline inside the syringe. For the training of this procedure, a novel hybrid epidural needle insertion simulator offers the possibility of real-time quantification of the successful needle placement in a patient phantom.

  @Article{Esterer2017c,
  Title = {{Needle position tracking in 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 },
  Journal = {{Proceedings of the 3rd Kepler Science Day}},
  Year = {2017},
  Abstract = {Epidural needle insertion is mostly carried out without any imaging modality. The advancement of a needle into the epidural space is part of different therapeutic and/or diagnostic interventions, e.g. lumbar puncture or epidural anesthesia. The latter is done with an 18-gauge Tuohy needle mounted on a loss of resistance (LOR) syringe. During the procedure the anesthesiologist experiences two haptic feedback components to deduce the position of the needle tip: the force needed for the advancement of the needle into the body and the counter pressure acting on the thumb while trying to compress the air or saline inside the syringe. For the training of this procedure, a novel hybrid epidural needle insertion simulator offers the possibility of real-time quantification of the successful needle placement in a patient phantom. },
  Volume = {},
  Number = {},
  Pages = {},
  Url = {}
  }

• M. Hollensteiner, D. Fürst, B. Esterer, P. Augat, F. Schrödl, S. Hunger, M. Malek, D. Stephan, and A. Schrempf, “Novel bone surrogates for cranial surgery training,” Journal of the Mechanical Behavior of Biomedical Materials, vol. 72, iss. Supplement-C, p. 9 – 51, 2017.
  [BibTeX] [Abstract] [Download PDF]
  

  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±0.5N for drilling, 1.7±0.3N for milling and 0.9±0.1N 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.

  @Article{Hollensteiner2017d,
  Title = {{Novel bone surrogates for cranial surgery training}},
  Author = {Marianne Hollensteiner and David Fürst and Benjamin Esterer and Peter Augat and Falk Schrödl and Stefan Hunger and Michael Malek and Daniel Stephan and Andreas Schrempf},
  Journal = {{Journal of the Mechanical Behavior of Biomedical Materials}},
  Year = {2017},
  Abstract = {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±0.5N for drilling, 1.7±0.3N for milling and 0.9±0.1N 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.},
  Volume = {72},
  Number = {Supplement-C},
  Pages = {9 -- 51},
  Url = {http://www.sciencedirect.com/science/article/pii/S1751616117301741}
  }

• B. Esterer, S. Gabauer, R. Pichler, D. Wirthl, M. Drack, M. Hollensteiner, G. Kettlgruber, M. Kaltenbrunner, S. Bauer, D. Fuerst, R. Merwa, J. Meier, P. Augat, and A. Schrempf, “A hybrid, low-cost tissue-like epidural needle insertion simulator,” Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2017.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @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 },
  Journal = {{Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society}},
  Year = {2017},
  Url = {https://doi.org/10.1109/EMBC.2017.8036758},
  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.}
  }

• B. Esterer, D. Fuerst, M. Hollensteiner, S. Gabauer, P. Augat, R. Merwa, and A. Schrempf, “Development of validated methods to generate haptic feedback in interventional and therapeutical needle insertions,” Proceedings of the IAUP Triennial Conference, 2017.
  [BibTeX] [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 fidelity/high fidelity 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.

  @Article{Esterer2017a,
  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},
  Journal = {{Proceedings of the IAUP Triennial Conference}},
  Year = {2017},
  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 fidelity/high fidelity 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.}
  }

• M. Hollensteiner, D. Fuerst, B. Esterer, S. Gabauer, P. Augat, F. Schroedl, and A. Schrempf, “Novel simulator for cranial graft lift training,” Proceedings of the IAUP Triennial Conference, 2017.
  [BibTeX] [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.

  @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},
  Journal = {{Proceedings of the IAUP Triennial Conference}},
  Year = {2017},
  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.}
  }

• M. Hollensteiner, P. Augat, D. Fuerst, B. Esterer, S. Gabauer, K. Pueschel, F. Schroedl, and A. Schrempf, “Novel synthetic vertebrae provide realistic haptics for pedicle screw placement,” Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2017.
  [BibTeX] [Abstract] [Download PDF]
  

  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 82+/-33Nmmm. 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+/-28Nmm) 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.

  @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},
  Journal = {{Proceedings of the 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society}},
  Year = {2017},
  Url = {https://doi.org/10.1109/EMBC.2017.8036759},
  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 82+/-33Nmmm. 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+/-28Nmm) 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.}
  }

• D. Fuerst, S. Senck, M. Hollensteiner, B. Esterer, P. Augat, F. Eckstein, and A. Schrempf, “Characterization of synthetic foam structures used to manufacture artificial vertebral trabecular bone,” Materials Science and Engineering C, 2017.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Fuerst2017a,
  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},
  Journal = {{Materials Science and Engineering C}},
  Year = {2017},
  Url = {https://doi.org/10.1016/j.msec.2017.03.158},
  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.}
  }

2016

• M. Hollensteiner, D. Fuerst, B. Esterer, S. Hunger, M. Malek, P. Augat, F. Schroedl, D. Stephan, and A. Schrempf, “Development of parietal bone surrogates for parietal graft lift training,” Proceedings of the 2nd Kepler Science Day, 2016.
  [BibTeX] [Abstract]
  

  Taking split thickness bone grafts from the skull is an accepted standard practice in facialskeletal surgery to treat traumatic or reconstructive deformities. However, the lift of cranial grafts also harbors risks such as subdural hematomas, intracranial injury or even the death of the patient. To minimize these risks, appropriate forces and speeds of the hand drives have to be applied during the surgical procedure. Currently the surgical training of parietal bone graft techniques is performed on patients or specimens but modelbased simulators would provide a safe and unrestricted training opportunity. Thus customized parietal skull surrogates were developed for surgical training purposes.

  @Article{Hollensteiner2016c,
  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},
  Journal = {{Proceedings of the 2nd Kepler Science Day}},
  Year = {2016},
  Abstract = {Taking split thickness bone grafts from the skull is an accepted standard practice in facialskeletal surgery to treat traumatic or reconstructive deformities. However, the lift of cranial grafts also harbors risks such as subdural hematomas, intracranial injury or even the death of the patient. To minimize these risks, appropriate forces and speeds of the hand drives have to be applied during the surgical procedure. Currently the surgical training of parietal bone graft techniques is performed on patients or specimens but modelbased simulators would provide a safe and unrestricted training opportunity. Thus customized parietal skull surrogates were developed for surgical training purposes.},
  Volume = {},
  Number = {},
  Pages = {},
  Url = {}
  }

• B. Esterer, J. Razenboeck, M. Hollensteiner, D. Fuerst, and A. Schrempf, “Development of validated methods to generate haptic feedback in interventional and therapeutical needle insertions“,” Proceedings of the 2nd Kepler Science Day, 2016.
  [BibTeX] [Abstract]
  

  Nowadays, surgical education still follows the Halstedian approach of “see one, do one, teach one” which is already over 100 years old. Anaesthetist novices gather first hands-on experience directly on the patient assisted by a medical expert. Training anaesthetic procedures on simulators constitutes a safer alternative. The best 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. On the other hand, by learning from mistakes while performing a procedure on a patient can lead to major complications. Simulators on the market are categorized in low fidelity/high fidelity or virtual reality, manikins or hybrid simulators. At the moment there is no hybrid simulator for the training of epidural or spinal anesthesia available.

  @Article{Esterer2016b,
  Title = {{Development of validated methods to generate haptic feedback in interventional and therapeutical needle insertions“}},
  Author = {Benjamin Esterer and Johannes Razenboeck and Marianne Hollensteiner and David Fuerst and Andreas Schrempf},
  Journal = {{Proceedings of the 2nd Kepler Science Day}},
  Year = {2016},
  Abstract = {Nowadays, surgical education still follows the Halstedian approach of “see one, do one, teach one” which is already over 100 years old. Anaesthetist novices gather first hands-on experience directly on the patient assisted by a medical expert. Training anaesthetic procedures on simulators constitutes a safer alternative. The best 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. On the other hand, by learning from mistakes while performing a procedure on a patient can lead to major complications. Simulators on the market are categorized in low fidelity/high fidelity or virtual reality, manikins or hybrid simulators. At the moment there is no hybrid simulator for the training of epidural or spinal anesthesia available.},
  Volume = {},
  Number = {},
  Pages = {},
  Url = {}
  }

• M. Hollensteiner, D. Fuerst, B. Esterer, S. Hunger, M. Malek, P. Augat, F. Schroedl, D. Stephan, and A. Schrempf, “Development of parietal bone surrogates for parietal graft lift training,” Current Directions in Biomedical Engineering, 2016.
  [BibTeX] [Abstract] [Download PDF]
  

  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

  @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},
  Journal = {{Current Directions in Biomedical Engineering}},
  Year = {2016},
  Url = {https://doi.org/10.1515/cdbme-2016-0140},
  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}
  }

• D. Fuerst, M. Hollensteiner, B. Esterer, and A. Schrempf, “Druckeigenschaften synthetischer Knochenmodelle zur Nachbildung des trabekulaeren Knochens von humanen Wirbelkoerpern,” Proceedings of the DWG Hannover 2016, 2016.
  [BibTeX] [Abstract]
  

  Kuenstliche Knochenmodelle aus Polyurethan (PU) sind fuer das Testen von orthopaedischen Produkten sowie fuer die Ausbildung angehender Chirurgen sehr populaer. Geschlossenzellige Hartschaeume sind dabei in der Lage, die Druckeigenschaften von humanem, trabekulaerem Knochen nachzubilden. Das Ziel dieser Studie war die Untersuchung der Druckeigenschaften von eigens entwickelten, synthetischen Knochenmodellen mit offener Zellstruktur.

  @Article{Fuerst2016a,
  Title = {{Druckeigenschaften synthetischer Knochenmodelle zur Nachbildung des trabekulaeren Knochens von humanen Wirbelkoerpern}},
  Author = {David Fuerst and Marianne Hollensteiner and Benjamin Esterer and Andreas Schrempf},
  Journal = {{Proceedings of the DWG Hannover 2016}},
  Year = {2016},
  Abstract = {Kuenstliche Knochenmodelle aus Polyurethan (PU) sind fuer das Testen von orthopaedischen Produkten sowie fuer die Ausbildung angehender Chirurgen sehr populaer. Geschlossenzellige Hartschaeume sind dabei in der Lage, die Druckeigenschaften von humanem, trabekulaerem Knochen nachzubilden. Das Ziel dieser Studie war die Untersuchung der Druckeigenschaften von eigens entwickelten, synthetischen Knochenmodellen mit offener Zellstruktur.}
  }

• B. Esterer, J. Razenboeck, M. Hollensteiner, D. Fuerst, and A. Schrempf, “Development of artificial tissue-like structures for a hybrid epidural anesthesia simulator,” Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2016.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Esterer2016a,
  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},
  Journal = {{Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society}},
  Year = {2016},
  Url = {https://doi.org/10.1109/EMBC.2016.7591142},
  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.}
  }

• M. Hollensteiner, M. Samrykit, M. Hess, D. Fuerst, B. Esterer, and A. Schrempf, “Inexpensive bone cement substitute for vertebral cement augmentation training,” Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2016.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @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},
  Journal = {{Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society}},
  Year = {2016},
  Url = {https://doi.org/10.1109/EMBC.2016.7591166},
  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.}
  }

2015

• D. Fuerst, M. Hollensteiner, and A. Schrempf, “Assessment parameters for a novel simulator in minimally invasive spine surgery,” Conf Proc IEEE Eng Med Biol Soc, 2015.
  [BibTeX] [Abstract] [Download PDF]
  

  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 its 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 surgeons 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.

  @Article{Fuerst2015a,
  Title = {Assessment Parameters for a Novel Simulator in Minimally Invasive Spine Surgery},
  Author = {Fuerst, David and Hollensteiner, Marianne and Schrempf, Andreas},
  Journal = {{Conf Proc IEEE Eng Med Biol Soc}},
  Year = {2015},
  Url = {https://doi.org/10.1109/EMBC.2015.7319541},
  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 its 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 surgeons 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.}
  }

• M. Hollensteiner, M. Samrykit, M. Hess, D. Fuerst, and A. Schrempf, “Development of trabecular bone surrogates for kyphoplasty-balloon dilatation training,” Conf Proc IEEE Eng Med Biol Soc, 2015.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Hollensteiner2015a,
  Title = {Development of Trabecular Bone Surrogates for Kyphoplasty-Balloon Dilatation Training},
  Author = {Hollensteiner, Marianne and Samrykit, Markus and Hess, Michael and Fuerst, David and Schrempf, Andreas},
  Journal = {{Conf Proc IEEE Eng Med Biol Soc}},
  Year = {2015},
  Url = {https://doi.org/10.1109/EMBC.2015.7319540},
  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.}
  }

2014

• M. Hollensteiner, D. Fuerst, and A. Schrempf, “Artificial muscles for a novel simulator in minimally invasive spine surgery.,” Conf Proc IEEE Eng Med Biol Soc, pp. 506-509, 2014.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Hollensteiner2014a,
  Title = {Artificial muscles for a novel simulator in minimally invasive spine surgery.},
  Author = {Hollensteiner, Marianne and Fuerst, David and Schrempf, Andreas},
  Journal = {{Conf Proc IEEE Eng Med Biol Soc}},
  Year = {2014},
  Pages = {506-509},
  Url = {https://doi.org/10.1109/EMBC.2014.6943639},
  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.}
  }

• D. Fuerst, M. Hollensteiner, and A. Schrempf, “A novel augmented reality simulator for minimally invasive spine surgery,” Proceedings of the 2014 summer simulation multiconference, p. {28:1–28:5}, 2014.
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Fuerst2014a,
  Title = {A Novel Augmented Reality Simulator for Minimally Invasive Spine Surgery},
  Author = {Fuerst, David and Hollensteiner, Marianne and Schrempf, Andreas},
  Year = {2014},
  Pages = {{28:1--28:5}},
  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.},
  Journal = {Proceedings of the 2014 Summer Simulation Multiconference},
  Publisher = {Society for Computer Simulation International},
  Url = {http://dl.acm.org/citation.cfm?id=2685617.2685645}
  }

• D. Fuerst, M. Hollensteiner, and A. Schrempf, “Neuartiger Simulator fuer die minimal-invasive Wirbelsaeulenchirurgie,” 9. Jahrestagung der Deutschen Wirbelsaeulengesellschaft, 2014.
  [BibTeX]

  @Article{Fuerst2014b,
  Title = {{Neuartiger Simulator fuer die minimal-invasive Wirbelsaeulenchirurgie}},
  Author = {David Fuerst and Marianne Hollensteiner and Andreas Schrempf},
  Journal = {{9. Jahrestagung der Deutschen Wirbelsaeulengesellschaft}},
  Year = {2014},
  Abstract = {}
  }

2013

• M. Hollensteiner, D. Fuerst, and A. Schrempf, “Artificial vertebrae for a novel simulator in minimally invasive spine surgery.,” Biomed Tech (Berl), 2013. doi:10.1515/bmt-2013-4409
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Hollensteiner2013a,
  Title = {Artificial Vertebrae for a Novel Simulator in Minimally Invasive Spine Surgery.},
  Author = {Hollensteiner, Marianne and Fuerst, David and Schrempf, Andreas},
  Journal = {{Biomed Tech (Berl)}},
  Year = {2013},
  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.},
  Doi = {10.1515/bmt-2013-4409},
  Url = {http://dx.doi.org/10.1515/bmt-2013-4409}
  }

2012

• D. Fuerst and A. Schrempf, “Patientsim – development of an augmented reality simulator for surgical training of vertebroplasty and kyphoplasty.,” BioMed 2012, Innsbruck Austria, 2012. doi:10.2316/P.2012.764-078
  [BibTeX] [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.

  @Article{Fuerst2012b,
  Title = {PatientSIM - Development of an augmented reality simulator for surgical training of vertebroplasty and kyphoplasty.},
  Author = {Fuerst, David and Schrempf, Andreas},
  Journal = {{BioMed 2012, Innsbruck Austria}},
  Year = {2012},
  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.},
  Doi = {10.2316/P.2012.764-078}
  }

• D. Fuerst, D. Stephan, P. Augat, and A. Schrempf, “Foam phantom development for artificial vertebrae used for surgical training.,” Conf Proc IEEE Eng Med Biol Soc, vol. 2012, p. 5773–5776, 2012. doi:10.1109/EMBC.2012.6347306
  [BibTeX] [Abstract] [Download PDF]
  

  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.

  @Article{Fuerst2012a,
  Title = {Foam phantom development for artificial vertebrae used for surgical training.},
  Author = {Fuerst, David and Stephan, Daniel and Augat, Peter and Schrempf, Andreas},
  Journal = {{Conf Proc IEEE Eng Med Biol Soc}},
  Year = {2012},
  Pages = {5773--5776},
  Volume = {2012},
  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.},
  Doi = {10.1109/EMBC.2012.6347306},
  Url = {http://dx.doi.org/10.1109/EMBC.2012.6347306}
  }