TY - CHAP A1 - Thieme, Dorothea A1 - Linnemann, Birgit ED - Heese, Carl ED - Schütz, Sandra ED - Obergrießer, Stefanie T1 - Nachhaltigkeit und Effektivität von Kompressionsmaßnahmen in Prävention des Postthrombotischen Syndroms T2 - Die Nachhaltigkeitsziele der UN im Spiegel der Wissenschaft : Beispiele aus der Sozial- und Gesundheitsforschung N2 - Etwa 20–50 % der Patientinnen und Patienten mit akuter tiefer Beinvenenthrombose entwickeln in den ersten 5 Jahren postthrombotische Komplikationen, die durch Schwellung, Schmerzen und eingeschränkter Lebensqualität zu Frühberentungen führen können. Eine frühzeitig eingeleitete Therapie mit Antikoagulanzien fördert die Rekanalisation thrombosierter Venen in der Frühphase und verhindert Rezidivthrombosen im Verlauf. Der Nutzen der Kompressionstherapie wird immer wieder diskutiert. Ziel des Reviews ist, Nachhaltigkeit und Effektivität zum Einsatz von Kompressionsmaßnahmen in Prävention des Postthrombotischen Syndroms darzustellen. Die Literaturrecherche ergibt 4375 Treffer, 130 Studien und Fachartikel werden eingeschlossen. Zwei randomisierte kontrollierte Studien (RCTs) zeigen eine klare Empfehlung für Kompressionsmaßnahmen und Mobilisation in der Akutphase einer tiefen Beinvenenthrombose. zwei RCTs bewerten die präventive Wirkung von Kompressionsstrümpfen und zeigen, dass sich die Rate postthrombotischer Komplikationen um etwa 50 % reduzieren lässt (p < 0,001; p < 0,001 und HR 0,49 (95 %-KI, 0,29–0,84; p = 0,011)). Zwei RCTs können beim Vergleich von Kompressions- versus Placebostrümpfen keine signifikante Besserung postthrombotischer Beschwerden nachweisen (HR 1,13, 95 %-KI 0,73–1,76; p = 0,58), beide Publikationen sind kritisch zu hinterfragen. Ein RCT stellt dar, dass die Höhe der Kompressionsstrümpfe keine signifikanten postthrombotischen Auswirkungen zeigen (p = 0,017) und zwei RCTs belegen, dass eine individualisierte Therapie mit Kompressionsstrümpfen der Standardtherapiedauer von 24 Monaten nicht unterlegen ist. Voraussetzung für die Effektivität ist die korrekte Applikation. KW - Effektivität KW - Kompressionsbehandlung KW - Nachhaltigkeit KW - Postthrombotisches Syndrom KW - Prävention Y1 - 2025 SN - 978-3-658-43333-8 U6 - https://doi.org/10.1007/978-3-658-43334-5_16 SN - 2731-8834 SP - 271 EP - 299 PB - Springer VS CY - Wiesbaden ER - TY - GEN A1 - Weber, Karsten T1 - Transparenz aus praktischer und regulatorischer Perspektive: Ein Beitrag zur Technikfolgenabschätzung der KI? Y1 - 2023 ER - TY - GEN A1 - Weber, Karsten T1 - Verantwortung als Leitprinzip der Arbeit der Gemeinsamen Ethikkommission der Hochschulen Bayerns (GEHBa) Y1 - 2023 ER - TY - GEN A1 - Weber, Karsten T1 - Driverless vehicles and software dependency: sustainability, security, and safety are at stake Y1 - 2023 ER - TY - GEN A1 - Weber, Karsten T1 - KI und Sterben Just-in-Time BT - Wenn das Unwägbare voraussehbar und das Unvermeidliche beeinflussbar wird Y1 - 2023 ER - TY - GEN A1 - Weber, Karsten T1 - „Ist da jemand?“ – Die Geschichte des Versuchs denkende Maschinen zu bauen Y1 - 2023 ER - TY - GEN A1 - Weber, Karsten T1 - Social challenges that (might) come from AI Y1 - 2023 ER - TY - JOUR A1 - Weiherer, Maximilian A1 - Eigenberger, Andreas A1 - Egger, Bernhard A1 - Brébant, Vanessa A1 - Prantl, Lukas A1 - Palm, Christoph T1 - Learning the shape of female breasts: an open-access 3D statistical shape model of the female breast built from 110 breast scans JF - The Visual Computer N2 - We present the Regensburg Breast Shape Model (RBSM)—a 3D statistical shape model of the female breast built from 110 breast scans acquired in a standing position, and the first publicly available. Together with the model, a fully automated, pairwise surface registration pipeline used to establish dense correspondence among 3D breast scans is introduced. Our method is computationally efficient and requires only four landmarks to guide the registration process. A major challenge when modeling female breasts from surface-only 3D breast scans is the non-separability of breast and thorax. In order to weaken the strong coupling between breast and surrounding areas, we propose to minimize the variance outside the breast region as much as possible. To achieve this goal, a novel concept called breast probability masks (BPMs) is introduced. A BPM assigns probabilities to each point of a 3D breast scan, telling how likely it is that a particular point belongs to the breast area. During registration, we use BPMs to align the template to the target as accurately as possible inside the breast region and only roughly outside. This simple yet effective strategy significantly reduces the unwanted variance outside the breast region, leading to better statistical shape models in which breast shapes are quite well decoupled from the thorax. The RBSM is thus able to produce a variety of different breast shapes as independently as possible from the shape of the thorax. Our systematic experimental evaluation reveals a generalization ability of 0.17 mm and a specificity of 2.8 mm. To underline the expressiveness of the proposed model, we finally demonstrate in two showcase applications how the RBSM can be used for surgical outcome simulation and the prediction of a missing breast from the remaining one. Our model is available at https://www.rbsm.re-mic.de/. KW - Statistical shape model KW - Non-rigid surface registration KW - Breast imaging KW - Surgical outcome simulation KW - Breast reconstruction surgery Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-30506 N1 - Corresponding author: Christoph Palm N1 - Zugehörige arXiv-Publikation: https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/2023 VL - 39 IS - 4 SP - 1597 EP - 1616 PB - Springer Nature ER - TY - JOUR A1 - Brébant, Vanessa A1 - Weiherer, Maximilian A1 - Noisser, Vivien A1 - Seitz, Stephan A1 - Prantl, Lukas A1 - Eigenberger, Andreas T1 - Implants Versus Lipograft: Analysis of Long-Term Results Following Congenital Breast Asymmetry Correction JF - Aesthetic Plastic Surgery N2 - Aims Congenital breast asymmetry represents a particular challenge to the classic techniques of plastic surgery given the young age of patients at presentation. This study reviews and compares the long-term results of traditional breast augmentation using silicone implants and the more innovative technique of lipografting. Methods To achieve this, we not only captured subjective parameters such as satisfaction with outcome and symmetry, but also objective parameters including breast vol-ume and anthropometric measurements. The objective examination was performed manually and by using the Vectra H2 photogrammetry scanning system. Results Differences between patients undergoing either implant augmentation or lipograft were revealed not to be significant with respect to patient satisfaction with surgical outcome (p= 0.55) and symmetry (p= 0.69). Furthermore, a breast symmetry of 93 % was reported in both groups. Likewise, no statistically significant volume difference between the left and right breasts was observed in both groups (p\0.41). However, lipograft patients needed on average 2.9 procedures to achieve the desired result, compared with 1.3 for implant augmentation. In contrast, patients treated with implant augmentation may require anumber of implant changes during their lifetime. Conclusion Both methods may be considered for patients presenting with congenital breast asymmetry. KW - Congenital Breast Asymmetry KW - 3D volumetry KW - Autologous fat injections KW - Three-dimensional imaging KW - Lipograft Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-32404 N1 - Corresponding author der OTH Regensburg: Vanessa Brébant VL - 46 SP - 2228 EP - 2236 PB - Springer Nature ER - TY - JOUR A1 - Maier, Johannes A1 - Weiherer, Maximilian A1 - Huber, Michaela A1 - Palm, Christoph T1 - Imitating human soft tissue on basis of a dual-material 3D print using a support-filled metamaterial to provide bimanual haptic for a hand surgery training system JF - Quantitative Imaging in Medicine and Surgery N2 - Background: Currently, it is common practice to use three-dimensional (3D) printers not only for rapid prototyping in the industry, but also in the medical area to create medical applications for training inexperienced surgeons. In a clinical training simulator for minimally invasive bone drilling to fix hand fractures with Kirschner-wires (K-wires), a 3D-printed hand phantom must not only be geometrically but also haptically correct. Due to a limited view during an operation, surgeons need to perfectly localize underlying risk structures only by feeling of specific bony protrusions of the human hand. Methods: The goal of this experiment is to imitate human soft tissue with its haptic and elasticity for a realistic hand phantom fabrication, using only a dual-material 3D printer and support-material-filled metamaterial between skin and bone. We present our workflow to generate lattice structures between hard bone and soft skin with iterative cube edge (CE) or cube face (CF) unit cells. Cuboid and finger shaped sample prints with and without inner hard bone in different lattice thickness are constructed and 3D printed. Results: The most elastic available rubber-like material is too firm to imitate soft tissue. By reducing the amount of rubber in the inner volume through support material (SUP), objects become significantly softer. Without metamaterial, after disintegration, the SUP can be shifted through the volume and thus the body loses its original shape. Although the CE design increases the elasticity, it cannot restore the fabric form. In contrast to CE, the CF design increases not only the elasticity but also guarantees a local limitation of the SUP. Therefore, the body retains its shape and internal bones remain in its intended place. Various unit cell sizes, lattice thickening and skin thickness regulate the rubber material and SUP ratio. Test prints with higher SUP and lower rubber material percentage appear softer and vice versa. This was confirmed by an expert surgeon evaluation. Subjects adjudged pure rubber-like material as too firm and samples only filled with SUP or lattice structure in CE design as not suitable for imitating tissue. 3D-printed finger samples in CF design were rated as realistic compared to the haptic of human tissue with a good palpable bone structure. Conclusions: We developed a new dual-material 3D print technique to imitate soft tissue of the human hand with its haptic properties. Blowy SUP is trapped within a lattice structure to soften rubber-like 3D print material, which makes it possible to reproduce a realistic replica of human hand soft tissue. KW - Dual-material 3D printing KW - Hand surgery training KW - Metamaterial KW - Support material KW - Tissue-imitating hand phantom KW - Handchirurgie KW - 3D-Druck KW - Biomaterial KW - Lernprogramm Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-979 N1 - Corresponding author: Christoph Palm VL - 9 IS - 1 SP - 30 EP - 42 PB - AME Publishing Company ER - TY - JOUR A1 - Maier, Johannes A1 - Weiherer, Maximilian A1 - Huber, Michaela A1 - Palm, Christoph T1 - Optically tracked and 3D printed haptic phantom hand for surgical training system JF - Quantitative Imaging in Medicine and Surgery N2 - Background: For surgical fixation of bone fractures of the human hand, so-called Kirschner-wires (K-wires) are drilled through bone fragments. Due to the minimally invasive drilling procedures without a view of risk structures like vessels and nerves, a thorough training of young surgeons is necessary. For the development of a virtual reality (VR) based training system, a three-dimensional (3D) printed phantom hand is required. To ensure an intuitive operation, this phantom hand has to be realistic in both, its position relative to the driller as well as in its haptic features. The softest 3D printing material available on the market, however, is too hard to imitate human soft tissue. Therefore, a support-material (SUP) filled metamaterial is used to soften the raw material. Realistic haptic features are important to palpate protrusions of the bone to determine the drilling starting point and angle. An optical real-time tracking is used to transfer position and rotation to the training system. Methods: A metamaterial already developed in previous work is further improved by use of a new unit cell. Thus, the amount of SUP within the volume can be increased and the tissue is softened further. In addition, the human anatomy is transferred to the entire hand model. A subcutaneous fat layer and penetration of air through pores into the volume simulate shiftability of skin layers. For optical tracking, a rotationally symmetrical marker attached to the phantom hand with corresponding reference marker is developed. In order to ensure trouble-free position transmission, various types of marker point applications are tested. Results: Several cuboid and forearm sample prints lead to a final 30 centimeter long hand model. The whole haptic phantom could be printed faultless within about 17 hours. The metamaterial consisting of the new unit cell results in an increased SUP share of 4.32%. Validated by an expert surgeon study, this allows in combination with a displacement of the uppermost skin layer a good palpability of the bones. Tracking of the hand marker in dodecahedron design works trouble-free in conjunction with a reference marker attached to the worktop of the training system. Conclusions: In this work, an optically tracked and haptically correct phantom hand was developed using dual-material 3D printing, which can be easily integrated into a surgical training system. KW - Handchirurgie KW - 3D-Druck KW - Lernprogramm KW - Zielverfolgung KW - HaptiVisT KW - Dual-material 3D printing KW - hand surgery training KW - metamaterial KW - tissue imitating phantom hand Y1 - 2020 U6 - https://doi.org/10.21037/qims.2019.12.03 N1 - Corresponding author: Christoph Palm VL - 10 IS - 02 SP - 340 EP - 455 PB - AME Publishing Company CY - Hong Kong, China ER - TY - JOUR A1 - Noisser, Vivien A1 - Eigenberger, Andreas A1 - Weiherer, Maximilian A1 - Seitz, Stephan A1 - Prantl, Lukas A1 - Brébant, Vanessa T1 - Surgery of congenital breast asymmetry - which objective parameter influences the subjective satisfaction with long-term results JF - Archives of Gynecology and Obstetrics N2 - Purpose Congenital breast asymmetry is a serious gynecological malformation for affected patients. The condition hits young women in puberty and is associated with socio-esthetic handicap, depression, and psychosexual problems. Surgical treatment is usually early in the patient's lifetime, so a long-term sustainable solution is important. Although postoperative outcome has been evaluated in several studies before, this study is the first to analyze which objective parameters have the greatest influence on subjective satisfaction with long-term results. Methods Thirty-four patients diagnosed with congenital breast asymmetry that underwent either lipofilling or implant therapy between the years of 2008 to 2019 were examined. On average, our collective comprised patients seven years after surgery. Data were mainly gathered through manual measurements, patient-reported outcome measures (Breast Q™), and breast volumetry based on 3D scans (Vectra® H2, Canfield Scientific). Results Among all analyzed parameters, only areolar diameter correlated significantly negatively with the subjective outcome satisfaction of the patient. Regarding the subjective assessment of postoperative satisfaction with similarity of the breasts, again the mean areolar diameter, but also the difference in areolar diameter and breast volume between the right and left breasts correlated significantly negatively. Conclusion Areolar diameter was revealed as being a significant factor influencing subjective long-term satisfaction in breast asymmetry patients. Moreover, 3D volumetry proves to be an effective tool to substantiate subjective patient assessments. Our findings may lead to further improvements to surgical planning and will be expanded in further studies. KW - Congenital breast asymmetry KW - Poland syndrome KW - Lipofilling KW - Silicone implant KW - 3D volumetry Y1 - 2021 U6 - https://doi.org/10.1007/s00404-021-06218-0 PB - Springer Nature ER - TY - CHAP A1 - Franz, Daniela A1 - Dreher, Maria A1 - Prinzen, Martin A1 - Teßmann, Matthias A1 - Palm, Christoph A1 - Katzky, Uwe A1 - Perret, Jerome A1 - Hofer, Mathias A1 - Wittenberg, Thomas T1 - CT-basiertes virtuelles Fräsen am Felsenbein BT - Bild- und haptischen Wiederholfrequenzen bei unterschiedlichen Rendering Methoden T2 - Bildverarbeitung für die Medizin 2018; Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 11. bis 13. März 2018 in Erlangen N2 - Im Rahmen der Entwicklung eines haptisch-visuellen Trainingssystems für das Fräsen am Felsenbein werden ein Haptikarm und ein autostereoskopischer 3D-Monitor genutzt, um Chirurgen die virtuelle Manipulation von knöchernen Strukturen im Kontext eines sog. Serious Game zu ermöglichen. Unter anderem sollen Assistenzärzte im Rahmen ihrer Ausbildung das Fräsen am Felsenbein für das chirurgische Einsetzen eines Cochlea-Implantats üben können. Die Visualisierung des virtuellen Fräsens muss dafür in Echtzeit und möglichst realistisch modelliert, implementiert und evaluiert werden. Wir verwenden verschiedene Raycasting Methoden mit linearer und Nearest Neighbor Interpolation und vergleichen die visuelle Qualität und die Bildwiederholfrequenzen der Methoden. Alle verglichenen Verfahren sind sind echtzeitfähig, unterscheiden sich aber in ihrer visuellen Qualität. KW - Felsenbein KW - Fräsen KW - Virtualisierung KW - Computertomographie KW - Computerassistierte Chirurgie Y1 - 2018 SN - 978-3-662-56537-7 U6 - https://doi.org/10.1007/978-3-662-56537-7_51 SP - 176 EP - 181 PB - Springer CY - Berlin ER - TY - CHAP A1 - Maier, Johannes A1 - Huber, Michaela A1 - Katzky, Uwe A1 - Perret, Jerome A1 - Wittenberg, Thomas A1 - Palm, Christoph T1 - Force-Feedback-assisted Bone Drilling Simulation Based on CT Data T2 - Bildverarbeitung für die Medizin 2018; Algorithmen - Systeme - Anwendungen; Proceedings des Workshops vom 11. bis 13. März 2018 in Erlangen N2 - In order to fix a fracture using minimally invasive surgery approaches, surgeons are drilling complex and tiny bones with a 2 dimensional X-ray as single imaging modality in the operating room. Our novel haptic force-feedback and visual assisted training system will potentially help hand surgeons to learn the drilling procedure in a realistic visual environment. Within the simulation, the collision detection as well as the interaction between virtual drill, bone voxels and surfaces are important. In this work, the chai3d collision detection and force calculation algorithms are combined with a physics engine to simulate the bone drilling process. The chosen Bullet-Physics-Engine provides a stable simulation of rigid bodies, if the collision model of the drill and the tool holder is generated as a compound shape. Three haptic points are added to the K-wire tip for removing single voxels from the bone. For the drilling process three modes are proposed to emulate the different phases of drilling in restricting the movement of a haptic device. KW - Handchirurgie KW - Osteosynthese KW - Simulation KW - Lernprogramm Y1 - 2018 U6 - https://doi.org/10.1007/978-3-662-56537-7_78 SP - 291 EP - 296 PB - Springer CY - Berlin ER - TY - CHAP A1 - Eixelberger, Thomas A1 - Wittenberg, Thomas A1 - Perret, Jerome A1 - Katzky, Uwe A1 - Simon, Martina A1 - Schmitt-Rüth, Stephanie A1 - Hofer, Mathias A1 - Sorge, M. A1 - Jacob, R. A1 - Engel, Felix B. A1 - Gostian, A. A1 - Palm, Christoph A1 - Franz, Daniela T1 - A haptic model for virtual petrosal bone milling T2 - 17. Jahrestagung der Deutschen Gesellschaft für Computer- und Roboterassistierte Chirurgie (CURAC2018), Tagungsband, 2018, Leipzig, 13.-15. September N2 - Virtual training of bone milling requires realtime and realistic haptics of the interaction between the ”virtual mill” and a ”virtual bone”. We propose an exponential abrasion model between a virtual one and the mill bit and combine it with a coarse representation of the virtual bone and the mill shaft for collision detection using the Bullet Physics Engine. We compare our exponential abrasion model to a widely used linear abrasion model and evaluate it quantitatively and qualitatively. The evaluation results show, that we can provide virtual milling in real-time, with an abrasion behavior similar to that proposed in the literature and with a realistic feeling of five different surgeons. KW - Osteosynthese KW - Simulation KW - Lernprogramm Y1 - 2018 UR - https://www.curac.org/images/advportfoliopro/images/CURAC2018/CURAC 2018 Tagungsband.pdf VL - 17 SP - 214 EP - 219 ER -