TY - GEN A1 - Krefting, Dagmar A1 - Zaunseder, Sebastian A1 - Säring, Dennis A1 - Wittenberg, Thomas A1 - Palm, Christoph A1 - Schiecke, Karin A1 - Krenkel, Lars A1 - Hennemuth, Anja A1 - Schnell, Susanne A1 - Spicher, Nicolai T1 - Blutdruck, Hämodynamik und Gefäßzustand: Innovative Erfassung und Bewertung – Schwerpunkt bildbasierte Verfahren T2 - 66. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS), 12. Jahreskongress der Technologie- und Methodenplattform für die vernetzte medizinische Forschung e. V. (TMF), 26. - 30.09.2021, online N2 - Einleitung: Blutdruck gilt als sogenannter Vitalparameter als einer der grundlegenden Indikatoren für den Gesundheitszustand einer Person. Sowohl zu niedriger als auch zu hoher Blutdruck kann lebensbedrohend sein, letzerer ist darüber hinaus ein Risikofaktor insbesondere für Herz-Kreislauferkrankungen, die trotz wichtiger Fortschritte in der Behandlung immer noch die häufigste Todesursache in Deutschland darstellen. Die Hämodynamik, also die raumzeitliche Dynamik des Blutflusses, und der Gefäßzustand sind eng verbunden mit dem Blutdruck und ebenfalls von hoher klinischer Relevanz, u.a. zur Identifikation von Durchblutungsstörungen und ungünstigen Druckverteilungen der Gefäßwand. Innovationen in der Messtechnik als auch in der Datenanalyse bieten heute neue Möglichkeiten der Erfassung und Bewertung von Blutdruck, Hämodynamik und Gefäßzustand [1], [2], [3], [4]. Methodik: In einer gemeinsamen Workshopserie der AG Medizinische Bild- und Signalverarbeitung der GMDS und des Fachausschusses Biosignale der DGBMT werden wir neue Ansätze und Lösungen für Mess- und Analyseverfahren zu Blutdruck und -fluss sowie zum Gefäßzustand vorstellen und diskutieren. Dabei stehen im ersten Workshop auf der GMDS Jahrestagung Bildbasierte Verfahren im Zentrum, während der zweite Workshop auf der DGBMT Jahrestagung den Fokus auf Biosignalbasierten Verfahren legt. Es werden aktuelle Forschungsergebnisse vorgestellt und diskutiert. Es sind jeweils mehrere Vorträge geplant mit ausreichend Zeit zur Diskussion. Folgende Vorträge sind geplant (Arbeitstitel): Sebastian Zaunseder: Videobasierte Erfassung des Blutdrucks Anja Hennemuth: A Visualization Toolkit for the Analysis of Aortic Anatomy and Pressure Distribution Lars Krenkel: Numerische Analyse der Rupturwahrscheinlichkeit zerebraler Aneurysmata Susanne Schnell: Messung des Blutflusses und hämodynamischer Parameter mit 4D flow MRI: Möglichkeiten und Herausforderungen Ergebnisse: Ziel des Workshops ist die Identifikation von innovativen Ansätzen und neuen Methoden zur qualitativen und quantitativen Bestimmung von hämodynamischen Parametern sowie deren kritische Bewertung durch die Community für die Eignung in der klinischen Entscheidungsunterstützung. Diskussion: Der Workshop leistet inhaltlich einen Beitrag zu zentralen Aspekten für die Herz-Kreislauf-Medizin. Er bringt dabei Expertise aus verschiedenen Bereichen zusammen und schlägt die Brücke zwischen Kardiologie, Medizininformatik und Medizintechnik. Schlussfolgerung: Innovative Technologien aus Medizintechnik und Informatik ermöglichen zunehmend einfache und raumzeitlich aufgelöste Erfassung und Bewertung wichtiger Informationen zur Unterstützung von Diagnose und Therapieverfolgung. [1] Zaunseder S, Trumpp A, Wedekind D, Malberg H. Cardiovascular assessment by imaging photoplethysmography - a review. Biomed Tech (Berl). 2018 Oct 25;63(5):617–34. [2] Huellebrand M, Messroghli D, Tautz L, Kuehne T, Hennemuth A. An extensible software platform for interdisciplinary cardiovascular imaging research. Comput Methods Programs Biomed. 2020 Feb;184:105277. [3] Schmitter S, Adriany G, Waks M, Moeller S, Aristova M, Vali A, et al. Bilateral Multiband 4D Flow MRI of the Carotid Arteries at 7T. Magn Reson Med. 2020 Oct;84(4):1947–60. [4] Birkenmaier C, and Krenkel, L. Flow in Artificial Lungs. In: New Results in Numerical and Experimental Fluid Mechanics XIII. Contributions to the 22nd STAB/DGLR Symposium. Springer; 2021. KW - Bildbasierte Verfahren KW - Blutdruck KW - Hämodynamik KW - Blutgefäß KW - Bildgebendes Verfahren Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0183-21gmds0167 ER - TY - JOUR A1 - Lehle, Karla A1 - Philipp, Alois A1 - Krenkel, Lars A1 - Gruber, Michael A1 - Hiller, Karl-Anton A1 - Müller, Thomas A1 - Lubnow, Matthias T1 - Thrombocytopenia During Venovenous Extracorporeal Membrane Oxygenation in Adult Patients With Bacterial, Viral, and COVID-19 Pneumonia JF - ASAIO Journal N2 - Contact of blood with artificial surfaces triggers platelet activation. The aim was to compare platelet kinetics after venovenous extracorporeal membrane oxygenation (V-V ECMO) start and after system exchange in different etiologies of acute lung failure. Platelet counts and coagulation parameters were analyzed from adult patients with long and exchange-free (≥8 days) ECMO runs (n = 330) caused by bacterial (n = 142), viral (n = 76), or coronavirus disease 2019 (COVID-19) (n = 112) pneumonia. A subpopulation requiring a system exchange and with long, exchange-free runs of the second oxygenator (≥7 days) (n = 110) was analyzed analogously. Patients with COVID-19 showed the highest platelet levels before ECMO implantation. Independent of the underlying disease and ECMO type, platelet counts decreased significantly within 24 hours and reached a steady state after 5 days. In the subpopulation, at the day of a system exchange, platelet counts were lower compared with ECMO start, but without differences between underlying diseases. Subsequently, platelets remained unchanged in the bacterial pneumonia group, but increased in the COVID-19 and viral pneumonia groups within 2–4 days, whereas D-dimers decreased and fibrinogen levels increased. Thus, overall platelet counts on V-V ECMO show disease-specific initial dynamics followed by an ongoing consumption by the ECMO device, which is not boosted by new artificial surfaces after a system exchange. Y1 - 2025 U6 - https://doi.org/10.1097/MAT.0000000000002383 SN - 1058-2916 SN - 1538-943X PB - Wolters Kluwer ER - TY - JOUR A1 - Bartsch, Alexander A1 - Eigenberger, Andreas A1 - Felthaus, Oliver A1 - Booth, Brian W. A1 - Krenkel, Lars A1 - Schratzenstaller, Thomas A1 - Prantl, Lukas T1 - Quantification of Cannula Influence on Negative Pressure in Syringe Assisted Liposuction JF - Plastic & Reconstructive Surgery N2 - To make the results of the autologous fat transfer more satisfactory, all parameters of suction, preparation, and reapplication must be well understood. Since syringe-assisted liposuction is frequently used for small-volume procedures, we quantified the influence of the cannula on negative pressure. For these experiments, we used a digital manometer to which a syringe and one of seven different cannulas were connected. Data was collected and analyzed using LabVIEW and Matlab. The volume of our measurement setup was calculated using Boyle-Mariotte's law to ease interpretation, which revealed a volume of 2.82 ± 0.03 mL. We demonstrate that the volume of the measurement setup significantly affects the measurement results. Consequently, we accounted for this factor and calculated the theoretical values accordingly. Statistical analysis shows a significant influence on negative pressure across different cannulas, except for two pairs, which had minimal volume differences. Exemplary, for cannulas with volumes under 1.75 mL, a 2 mL syringe plunger pull was sufficient to create a - 0.5 bar (- 14.8 inHg) negative pressure. The present data indicate that the size of the suction cannula must be considered in syringe-assisted suction to ensure a specific negative pressure is not exceeded. Other research groups have demonstrated that adipocyte vitality and the amount of stromal vascular fraction are reduced by excessively strong negative pressure. Y1 - 2025 U6 - https://doi.org/10.1097/PRS.0000000000012477 SN - 0032-1052 PB - American Society of Plastic Surgeons ER - TY - JOUR A1 - Kranz, Michael A1 - Wagner, Maria Stella A1 - Pointner, Daniel A1 - Haus, Moritz A1 - Lubnow, Matthias A1 - Lehle, Karla A1 - Krenkel, Lars T1 - Polymer embedding of membrane lungs for histological investigations of intra-device clot formation JF - Cardiovascular Medicine N2 - Extracorporeal membrane oxygenation (ECMO) is an invasive but potentially lifesaving treatment option for severe cardiac or respiratory failure. Despite its beneficial effect, coagulation-related complications, mainly due to clot formation, excessive bleeding and the accumulation of deposits in the membrane lung (ML) remain common, causing higher mortality. In this context, the formation of clots and other deposits in the ML is of particular interest. Previous histological examinations of the polymethylpentene fiber mats inside the ML could only be performed in a top view, prohibiting valid quantification and examination of the multi-layered deposits or fiber mat spanning structures. Our objective was the establishment of a polymer embedding to increase the mechanical stability of the deposits and thus enable cross-sectional microtome cutting through the ML hollow-fibers. Clinically used MLs (PLS, Getinge, Rastatt, Germany) were stabilized with a polymer resin (HistoCURE 8100). Specimens were cut out of the embedded MLs and microtome sections with a thickness of 10 µm were performed. In addition to standard histological staining with hematoxylin-eosin (HE) and Pappenheim (May-Grunwald-Giemsa), fluorescence DNA staining for nucleated cells with 4′,6-diamidino-2-phenylindole (DAPI) and SYTOX™ Green as well as immunohistochemical and immunofluorescence staining for the lysosomal enzyme myeloperoxidase (MPO) and von Willebrand factor (vWF) were established. The protocol provides a method for large volume embedding (400 mL). The cellular and extracellular deposits were securely fixed by the polymer scaffold allowing the examination of clots in MLs in native position which was not possible with conventional paraffin embedding. Multi-layered deposits and fiber mat spanning structures are no longer disrupted during specimen extraction and can now be quantified. Staining with HE, Pappenheim, DAPI, SYTOX™ Green, MPO, and vWF was successfully tested with this protocol. This method may be the foundation for new insights into the complex clotting phenomena observed in MLs KW - clot formation KW - ECMO KW - HistoCURE 8100 KW - histology KW - membrane lungs KW - polymer embedding KW - Technovit 8100 Y1 - 2026 U6 - https://doi.org/10.3389/fcvm.2026.1650978 VL - 13 PB - Frontiers CY - Lausanne ER - TY - GEN A1 - Michel, Johanna A1 - Krenkel, Lars T1 - Experimental Investigation of Shear-Induced Generation of Respiratory Aerosol: Simultaneous Measurements of Particle Quantities and Wave Topology T2 - 2nd European Fluid Dynamics Conference (EFDC2), 26-29 August 2025, Dublin, Ireland N2 - Despite the high level of attention on infectious respiratory aerosol during the Covid19 pandemic, little is known about the processes how these particles form inside the respiratory system. Understanding the underlying fluid mechanical processes and their influencing factors would enable the development of drugs to suppress the generation of infectious aerosol. In the proposed work, we focus on the shear-induced mechanism of aerosol generation, which is supposed to occur mostly in the larger airways during coughing. In this process, high air velocities trigger Kelvin-Helmholtz waves in the mucus film, which lines the air vessels. Through a series of instabilities, particles detach from the crest of these waves. In the proposed work, we investigate the process of shear-induced aerosol generation in idealized experiments where we vary the air-flow characteristics and the properties of the mucus fluid. Our central aim here is to deduct an empirical model of the quantity and size distribution of generated particles depending on the mucus rheology and the local shear flow. Further, we observe the wave topology to better understand the coupling between the air flow and the waves. In our experimental setup, we measure the quantity of created particles and the emerging waves simultaneously. To ensure controllable conditions, we simplify the complex flow conditions in the airways. We use a rectangular channel with the bottom wall covered in a mucus mimetic. The mucus mimetic fluid is a synthetic hydrogel developed to recreate the viscoelastic properties and low surface tensions of the mucus. Filtered pressurized air is guided through the channel to trigger shear-induced aerosol generation. After passing the mucus mimetic, the air enters into a collection chamber from where particles are sampled continuously by an aerosol spectrometer. To measure wave topology, we use planar laser induced fluorescence. For this, we stain the mucus mimetic with fluorescent dyes and illuminate a line on the surface of the fluid film with a 532 nm laser. A high-resolution camera captures the resulting fluorescent glow of the mucus mimetic. Figure 1 presents exemplary wave topology results from the experiments, employing varying air flow volume rates, mucus mimetic gel properties, and different configurations of the laser and camera. The resulting wave topologies exhibit significant variation. For the conference, we will conduct parameter studies of the particle quantities and wave topology while varying the mucus mimetic properties and the flow rate of the air. Additionally, we will present grid projection-based techniques to extend the single-line wave measurements and asses the entire surface of the mucus film. Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-88593 ER -