bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Deep Correlation Features to define the Meta Style of Cell Images for Classification
Authors: Grützmacher Simon , Kemkemer Ralf , Curio Cristóbal 
Published: September 2019

Abstract
Digital light microscopy techniques are among the most widely used methods in cell biology and medical research. Despite that, the automated classification of objects such as cells or specific parts of tissues in images is difficult. We present an approach to classify confluent cell layers in microscopy images by learned deep correlation features using deep neural networks. These deep correlation features are generated through the use of gram-based correlation features and are input to a neural network for learning the correlation between them. In this work we wanted to prove if a representation of cell data based on this is suitable for its classification as has been done for artworks with respect to their artistic period. The method generates images that contain recognizable characteristics of a specific cell type, for example, the average size and the ordered pattern.
3d print of heart rhythm model with cryoballoon catheter ablation of pulmonary vein
Authors: Wehsener Sandra , Heinke Matthias , Müssig Robin , Hörth Johannes , Junk Stefan , Schrock Steffen 
Published: September 2019

Abstract
The visualization of heart rhythm disturbance and atrial fibrillation therapy allows the optimization of new cardiac catheter ablations. With the simulation software CST (Computer Simulation Technology, Darmstadt) electromagnetic and thermal simulations can be carried out to analyze and optimize different heart rhythm disturbance and cardiac catheters for pulmonary vein isolation. Another form of visualization is provided by haptic, three-dimensional print models. These models can be produced using an additive manufacturing method, such as a 3d printer. The aim of the study was to produce a 3d print of the Offenburg heart rhythm model with a representation of an atrial fibrillation ablation procedure to improve the visualization of simulation of cardiac catheter ablation. The basis of 3d printing was the Offenburg heart rhythm model and the associated simulation of cryoablation of the pulmonary vein. The thermal simulation shows the pulmonary vein isolation of the left inferior pulmonary vein with the cryoballoon catheter Arctic Front AdvanceTM from Medtronic. After running through the simulation, the thermal propagation during the procedure was shown in the form of different colors. The three-dimensional print models were constructed on the base of the described simulation in a CAD program. Four different 3d printers are available for this purpose in a rapid prototyping laboratory at the University of Applied Science Offenburg. Two different printing processes were used and a final print model with additional representation of the esophagus and internal esophagus catheter was also prepared for printing. With the help of the thermal simulation results and the subsequent evaluation, it was possible to draw a conclusion about the propagation of the cold emanating from the catheter in the myocardium and the surrounding tissue. It was measured that just 3 mm from the balloon surface into the myocardium the temperature dropped to 25 °C. The simulation model was printed using two 3d printing methods. Both methods, as well as the different printing materials offer different advantages and disadvantages. All relevant parts, especially the balloon catheter and the conduction, are realistically represented. Only the thermal propagation in the form of different colors is not shown on this model. Three-dimensional heart rhythm models as well as virtual simulations allow very clear visualization of complex cardiac rhythm therapy and atrial fibrillation treatment methods. The printed models can be used for optimization and demonstration of cryoballoon catheter ablation in patients with atrial fibrillation.
Assessment of 4D Ultrasound Systems for Image-guided Radiation Therapy – Image Quality, Framerates and CT Artifacts
Authors: Ipsen Svenja , Bruder Ralf , García-Vázquez Verónica , Schweikard Achim , Ernst Floris 
Published: September 2019

Abstract
4D ultrasound (4D US) is gaining relevance as a tracking method in radiation therapy (RT) with modern matrix array probes offering new possibilities for real-time target detection. However, for clinical implementation of USguided RT, image quality, volumetric framerate and artifacts caused by the probe’s presence during planning and / or setup computed tomography (CT) must be quantified. We compared three diagnostic 4D US systems with matrix array probes using a commercial wire phantom to measure spatial resolution as well as a calibration and a torso phantom to assess different image quality metrics. CT artifacts were quantified in the torso phantom by calculating the total variation and percentage of affected voxels between a reference CT scan and CT scans with probes in place. We found that state-of-the-art 4D US systems with small probes can fit inside the CT bore and cause fewer metal artifacts than larger probes. US image quality varies between systems and is task-dependent. Volume sizes and framerates are much higher than the commercial guidance solution for US-guided RT, warranting further investigation regarding clinical performance for image guidance.
Development of a modular Decubitus Prophylaxis System: DekuProSys
Authors: Gallinger Simon , Jankowski Natalie , Bister Milena , Korge Sandra , Trachterna Astrid , Hildebrand Stefan , Oruc Tamer , Niewöhner Jörg , Heitman Urte , Downes Robert , Kraft Marc 
Published: September 2019

Abstract
Pressure ulcers (decubiti) are one of the most frequent side effects in the palliative care setting. Terminally ill and dying people have multiple comorbidities resulting in a high risk to develop pressure ulcers. These skin lesions are caused by pressure, friction and shearing forces in combination with several risk factors (e.g. moisture, tissue condition). People of all ages with reduced activity can suffer from decubitus ulcers. In palliative care, the treatment of symptoms to ensure the highest possible quality of life is of primary importance. Ethical controversies and difficult decision-making often lead to uncertainties and burdens for caregivers, patients and relatives. In the DekuProSys project, a decubitus prophylaxis system for inpatient and outpatient palliative care of people of all ages is being developed. The system will assist caregivers in patient care in multiple ways. It will capture and report risk factors for decubitus, assist at decision making and documentation. Furthermore, it will provide care information and instruction if needed. Aiming for an innovative and useful solution, the project follows a user-centered and interdisciplinary approach.
Controlled biodegradation of metallic biomaterials by plasma polymer coatings using hexamethyldisiloxane and allylamine monomers
Authors: Teske Michael , Wulf Katharina , Fink Joschka , Brietzke Andreas , Arbeiter Daniela , Eickner Thomas , Senz Volkmar , Grabow Niels , Illner Sabine 
Published: September 2019

Abstract
Plasma enhanced chemical vapor deposition is a promising process for the generation of tailor-made polymer coatings on medical devices in order to improve their implant/ host interaction. The ultra-thin coatings can fulfil a variety of purposes, depending on the monomers used, the process conditions and the location of the coated implants in the human body. In addition, even complex geometries can be coated easily and without the application of solvents. Particularly hydrophilic and hydrophobic plasma polymer coatings can improve biocompatibility, especially in blood contact. Furthermore, the selection of the monomers used enables the generation of specific functional groups for further surface immobilization of drugs, such as proteins, by chemical crosslinking. The release of toxic residues from polymeric implants, such as monomers, additives or degraded components, can also be avoided. The aim of our investigation was the generation of plasma polymer films, their characterization and application as coatings for biodegradable metallic biomaterials in order to retard the degradation process. Metallic biomaterials, in various forms are frequently used in orthopaedics, dentistry, cardiovascular and neurosurgical equipment, because of their tensile strength, fracture toughness, fatigue strength and electrical conductivity. Plasma polymerization was performed using the monomers hexamethyldisiloxane and allylamine. The resulting plasma polymers were analysed in an accelerated degradation test. Both plasma polymers appear to be promising, while polyHMDSO appears to degrade over time and polyallylamine indicates to be stable.
Safety evaluation of resveratrol as an active compound for drug-eluting cardiovascular implants
Authors: Khaimov Valeria , Reske Thomas , Matschegewski Claudia , Grabow Niels , Eickner Thomas 
Published: September 2019

Abstract
Resveratrol is a member of stilbenoids with promising anti-atherosclerotic properties. This hallmark makes it an extremely interesting candidate for local drug delivery to damaged tissue adjacent to the implant in order to reduce implant-related complications. For the regulatory approval drug-eluting medical devices have to be thoroughly tested for safety, efficacy and interactions with the surrounding tissue, including tests for sensitization among others. Studies for sensitization help to estimate the risk for an allergic reaction upon prolonged exposure to a chemical compound. Due to increased social and regulatory demand for replacement of animal experiments by in vitro approaches a number of reliable predictive non-animal tests have been developed. Here, we assessed the skin sensitization potential of resveratrol by the direct peptide reactivity assay (DPRA), one of the first non-animal tests adopted by the OECD.
Kinematics of the Lumbo–Pelvic Complex under Different Loading Conditions
Authors: Weidling Martin , Voigt Christian , Wendler Toni , Heilemann Martin , Werner Michael , Jarvers Jan-Sven , Heyde Christoph-E. 
Published: September 2019

Abstract
The lumbo-pelvic complex is a highly complex structural system. The current investigation aims to identify the kinematics between interacting bone segments under different loading conditions. A specimen of the lumbo-pelvic complex was obtained from a human body donor and tested in a self-developed test rig. The experimental setup was designed to imitate extension, flexion, right and left lateral bending and axial rotation to the left and to the right, respectively. The vertebra L3 was firmly embedded and load was introduced via hip joints. Using a digital image correlation (DIC) system, the 3D motions of 15 markers at different landmarks were measured for each loadcase under cyclic loading. For each loadcase, the kinematics were analyzed in terms of three-dimensional relative movements between L3 and the sacrum. The usefulness of the experimental technique was demonstrated. It may serve for further biomechanical investigations of relative motion of sacroiliac and vertebral joints and deformation of bony structures.
Quantitative Imaging of the Iron-Oxide Nanoparticle- Concentration for Magnetic Drug Targeting Employing Inverse Magnetomotive Ultrasound
Authors: Fink Michael , Lyer Stefan , Alexiou Christoph , Rupitsch Stefan J. , Ermert Helmut 
Published: September 2019

Abstract
Magnetomotive Ultrasound is an imaging technique that is capable to detect tissue, which is perfused by magnetic nanoparticles. However, this modality is restricted to qualitative imaging only. Therefore, we present an extended Magnetomotive Ultrasound algorithm, which allows the quantitative determination of the spatial distribution of magnetic nanoparticle density in tissue. The algorithm is based on an iterative adjustment of simulated data to measurements. Experiments with tissue-mimicking phantoms reveal that the presented method leads to the spatial particle concentration in the correct order of magnitude.
Probabilistic Estimation of Human Interaction Needs in Context of a Robotic Assistance in Geriatrics
Authors: Philipp Patrick , Bommersheim Marie , Robert Sebastian , Beyerer Jürgen 
Published: September 2019

Abstract
The key purpose of assistance robots is to help people coping with work-related or everyday tasks. To ensure an intuitive and effective support by an assistance robot, its expectation conform behavior is essential. In particular, when using assistance robots in geriatrics to assist elderly patients, special attention to the human-robot interaction should be paid. In order to help elderly patients maintain their independence and abilities as much as possible, the robot should only intervene when its support is needed. Therefore, the continuous estimation of the patient’s need for interaction is of particular importance. For enabling suitable models to estimate this need, we elaborate the use of Bayesian Networks. The analysis of our results seems promising, yielding a robust and practical approach.
Universal LIMS based platform for the automated processing of cell-based assays
Authors: Schmieder Florian , Polk Christoph , Gottlöber Felix , Schöps Patrick , Sonntag Frank , Deuse Ronny , Jede Aline , Petzold Thomas 
Published: September 2019

Abstract
Nowadays, cell-based assays are an elementary tool for diagnostics, animal-free substance testing and basic research. Depending on the application, the spectrum ranges from simple static cell cultures in microtiter plates to dynamic co-cultures in complex micro physiological systems (organ-on-a-chip). Depending on the complexity of the assay, numerous working steps have to be performed and the data from different analysis systems have to be processed, combined and documented. A universal platform has been developed for the automated handling of cell-based assays, which combines a laboratory information management system (LIMS) with a laboratory execution system (LES), a universal laboratory automation platform and established laboratory equipment. The LIMS handles the administration of all laboratory-relevant information, the planning, control and monitoring of laboratory processes, as well as the direct and qualified processing of raw data. Using a kidney-on-achip system as an example, the realization of complex cellbased assays for the animal-free characterization of the toxicity of different antibiotics will be demonstrated. In the kidney-on-a-chip system the artificial proximal tubular barrier was formed by seeding human immortalized proximal tubule cells (RPTEC) and human blood outgrowth endothelial cells (BOEC) on ThinCert™ membranes. Transepithelial electrical resistance (TEER) was measured daily to evaluate the barrier function of the cellular layers. Fluid handling and TEER measurements were performed using a laboratory automation platform that communicates directly with the LIMS. The LES supports laboratory assistants in executing the manual handling steps of the experiments.
Identification of factors influencing insertion characteristics of cochlear implant electrode carriers
Authors: Hügl Silke , Aldag Nina , Lenarz Thomas , Rau Thomas S. , Becker Alexander , Glasmacher Birgit 
Published: September 2019

Abstract
Insertion studies in artificial cochlea models (aCM) are used for the analysis of insertion characteristics of different cochlear implant electrode carrier (EC) designs by measuring insertion forces. These forces are summed forces due to the measuring position which is directly underneath the aCM. The current hypothesis is that they include dynamic friction forces during the insertion process and the forces needed to bend an initially straight EC into the curved form of the aCM. For the purposes of the present study, straight EC substitutes with a constant diameter of 0.7 mm and 20.5 mm intracochlear length were fabricated out of silicone in two versions with different stiffness by varying the number of embedded wires. The EC substitutes were inserted into three different models made of polytetrafluoroethylene (PTFE), each model showing only one constant radius. Three different insertion speeds were used (0.11 / 0.4 / 1.6 mm/s) with an automated insertion test bench. For each parameter combination (curvature, speed, stiffness) twelve insertions were conducted. Measurements included six full insertions and six paused insertions. Paused insertions include a ten second paused time interval without further insertion movement each five millimetres. Measurements showed that dynamic and static components of the measured summed forces can be identified. Dynamic force components increase with increased insertion speeds and also with increased stiffness of the EC substitutes. Both force components decrease with larger radius of the PTFE model. After the insertion, the EC substitutes showed a curved shape, which indicates a plastic deformation of the embedded wires due to the insertion into the curved models. The results can be used for further research on an analytical model to predict the insertions forces of a specific combination of selected parameters as insertion speed and type of EC, combined with given factors such as cochlear geometry.
Characterization of a measurement setup for the thermomechanical characterization of curved shape memory alloy actuators
Authors: Suzaly Nuha , Keller Marie Christina , Hügl Silke , Lenarz Thomas , Rau Thomas S. , Karsten Elvira 
Published: September 2019

Abstract
The bend and free recovery (BFR) test according to ASTM F2082 is a standard method to determine the transition temperatures of Nitinol shape memory alloys (SMAs). Unfortunately, this standard method is limited to SMA wires which are straight in its trained shape. Thus, the standard BFR test is not suitable for thermomechanical characterization of curved Nitinol SMA wires which should serve as actuators in cochlear implants in future. We developed a modified BFR measurement setup to determine the active austenite finish (AF) temperature of these very thin wires (Ø100 μm). The active AF temperature specifies the completion of the shape recovery upon heating. A parametric study of the measurement setup was carried out to investigate the influence of the heating rate on the observed active AF temperature and to verify the repeatability of the measurement setup. First, the curved wire was straightened in a cold water bath before inserting it into a water bath that is gradually heated from 5 °C to 45 °C. The shape change of the previously straightened wire was then recorded throughout the experiment using a digital microscope. Five different heating rates were employed: 0.25 K/min, 0.33 K/min, 0.5 K/min, 1 K/min as well as an unregulated maximum heating rate achievable of approximately 1.5 K/min. Furthermore, an investigation on the test-retest reliability was performed with three wires by repeating the experiment ten times with each wire. The results of this study revealed no influence of the heating rate on the thermomechanical response of the wires. Based on data from this study, a regulated heating rate of 1 K/min is suggested for future investigations, as this reduces the duration of the measurement from four hours to less than an hour. The values obtained from each wire through the test-retest reliability investigation showed a standard deviation of 1.9 K, 1.1 K and 2.1 K respectively. Our developed measurement setup demonstrates appropriate repeatability of the measurements.
Numerical investigation of stent designs for wireless access to integrated sensors
Authors: Großmann Swen , Ott Robert , Kosub Richard , Schmitz Klaus-Peter , Siewert Stefan , Schmidt Wolfram , Grabow Niels 
Published: September 2019

Abstract
In recent years, a progressive interest in the implementation of wireless access to cardiovascular implants has been established. This manifests in new devices, such as arterial pressure sensors, or additional functionalities added to established implants like stents. However, common stent designs, possessing highly optimized mechanical properties, often consist of cylindrically arranged struts with connections in-between which can be considered as short-circuited inductive coils. As a consequence, the small inductance raises the resonance frequency, which may decrease the in vivo performance of the wireless connection between the stent and the external readout device. Thus, new designs were developed to overcome this limitation, for example by avoiding the short-circuit due to a helical arrangement of the struts. Within this work we compare the performance of a common stent design and a helical design by means of numerical simulations. We are using two designs which only differ in the arrangement of the struts. The electromagnetic and mechanical properties are investigated using a finitedifference time-domain algorithm and finite element method, respectively. We will show that a common stent design exhibits resonance frequencies in the gigahertz regime, much higher than the frequencies of comparable helical designs. Furthermore, we compare the mechanical performance of the two designs and reveal individual distinctions in the radial stiffness, bending stiffness, and the von Mises stress.
Development of an experimental setup for the in vitro investigation of mitral valve repair devices
Authors: Ott Robert , Kaule Sebastian , Großmann Swen , Pfensig Sylvia , Stiehm Michael , Schmitz Klaus-Peter , Siewert Stefan , Öner Alper , Grabow Niels 
Published: September 2019

Abstract
Mitral regurgitation (MR) occurs with a prevalence of approximately 10 % in patients aged 75 years or older and therefore is one of the most frequent indications for heart valve surgery. During the last decade surgical mitral valve repair (MVR) procedures emerged as the gold standard for the treatment of clinically relevant MR. However, for surgically inoperable or high-risk patients transcatheter-based MVR devices present a valuable treatment option. Within the current study, we developed an experimental setup to investigate the hydrodynamic performance of transcatheterbased MVR devices in vitro. The bicuspid mitral valve (MV) model employed in the experimental setup features a D-shaped MV annulus with d1 = 26.30 mm, d2= 30.05 mm and chordae tendineae with a length of l1= 25 mm attached to two papillary muscle structures. Pressure gradient - volumetric flow rate (Δp-Q) relations were investigated for steady state backward flow with transvalvular pressure gradients ranging from 0.75 mmHg ≤ Δp ≤ 103.13 mmHg. Deionized water at 37 °C with a dynamic viscosity of 1.002 mPa∙s and a density of 998 kg/m3 was used. A test-chamber consisting of a press-fit MV holder and cylindrical in- and outflow tracts were developed. Different designs for the exchangeable press-fit MV holder were manufactured using additive manufacturing technologies providing an optimal fitting for variable MV sizes and pathologies. In- and outflow tracts featuring a diameter of d = 50 mm and a height of h = 60 mm were made from transparent polymethylmethacrylate to allow for easy optical access during measurements. The experimentally investigated Δp-Q relation yields a quadratic correlation for the open MV and a linear correlation for the closed MV. A transvalvular closing pressure of (4.94 ± 0.04) mmHg was measured for the MV model.