bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer Aided Detection of Polyps in Whitelight- Colonoscopy Images using Deep Neural Networks
Authors: Wittenberg Thomas , Zobel Pascal , Rathke Magnus , Mühldorfer Steffen 
Published: September 2019

Abstract
Early detection of polyps is one central goal of colonoscopic screening programs. To support gastroenterologists during this examination process, deep convolutional neural network can be applied for computer-assisted detection of neoplastic lesions. In this work, a Mask R-CNN architecture was applied. For training and testing, three independent colonoscopy data sets were used, including 2484 HD labelled images with polyps from our clinic, as well as two public image data sets from the MICCAI 2015 polyp detection challenge, consisting of 612 SD and 194 HD labelled images with polyps. After training the deep neural network, best results for the three test data sets were achieved in the range of recall = 0.92, precision = 0.86, F1 = 0.89 (data set A), rec = 0.86, prec = 0.80, F1 = 0.82 (data set B) and rec = 0.83, prec = 0.74, F1 = 0.79 (data set C).
Development and manufacturing of a custom made implant regarding the new European Medical Device Regulation
Authors: Schonhoff Mareike , Heinze Astrid , Carrillo Juliette , Lopinski Annika , Großkreutz Damian , Hanusek Stefan 
Published: September 2019

Abstract
New technologies are great opportunities for personalized medicine. Custom made implants can be very helpful for patients with severe bone defects or in case of bone tumor. Through the European Union it is regulated how many possibilities and restrictions all medical devices have. Because of critical vulnerabilities a new European Medical Device Regulation (MDR) was published in May 2017 and it will enter into force in May 2020. For the manufacturers of customized products it will change the documentation of the manufacturing and tracking of serious incidents. Patients with a pelvis defect of Paprosky IIb and higher can benefit from a custom made pelvis implant, because all planning steps according to biomechanic and bone contact to the implant can be designed and proofed during a reconstruction process. With regular modular implant systems, it probably can be a trial and error procedure during the surgery according to biomechanic and a stable position of the implant. Based on the 3D-Reconstruction of CT-Scans of a patient with a Paprosky 2b pelvis defect, a personalized acetabulum implant was designed. To maintain as much bone as possible, the implant was shaped to the remaining pelvic bone stock. Additive manufacturing gives the opportunity to produce custom made single items even in a quality that ful-fills the requirements of the MDR. Modern Selective Laser Melting (SLM) and Electron Beam melting (EBM) Systems are able to produce Titanium or CoCr parts in the ISO standards for Implants (ISO 5832 ff). In this study the process chain, starting from the reconstruction, to the design and the production of a custom made acetabulum cup was run through on an exemplary CTData of one patient. With this example, it was shown that it is possible, to establish a process, that is able to address surgical needs for patients that benefit from those techniques.
A Piezoelectric Flexural Plate Wave (FPW) Bio-MEMS Sensor with Improved Molecular Mass Detection for Point-of-Care Diagnostics
Authors: Walk Christian , Wiemann Matthias , Görtz Michael , Weidenmüller Jens , Jupe Andreas , Seidl Karsten 
Published: September 2019

Abstract
A piezoelectric FPW-sensor has been developed for a point of care device in this work. The Bio- MEMS FPW-sensor consists of an electrode configuration termed as an interdigital transducer (IDT) placed on a membrane. An input IDT excites and an output IDT detects the propagating acoustic waves through a PZT layer. Design optimizations and fabrication improvements of the FPW-sensor led to significantly reduced attenuation of the wave signal and the damping of the propagating waves between the IDTs. The working principle of mass loading is shown using different low-viscous liquids. A densitydependent sensitivity of -0.39 MHz/g/cm³ was evaluated. After the membrane was functionalized, the Bio-MEMS FPW-sensor was used to measure a specific chemokine in complex solution. By design improvements, the resolution was significantly increased from 0.7 Hz/nM to 14 Hz/nM.
Automated detection of bone splinters in DEXA phantoms using deep neural networks
Authors: Rüger Steffen , Firsching Markus , Lucic Julija , Ennen Alexander , Uhlmann Norman , Wittenberg Thomas 
Published: September 2019

Abstract
Dual energy radiographic imaging is a method to provide material information and can be used to differentiate between various tissue types. Dual energy X-ray absorption (DEXA) can be applied for breast density, osteoporosis or bone fracture analysis. To support radiologists with the assessment of DEXA images, machine learning can be applied. Specifically, deep convolutional neural networks (DCNNs) can be used for medical image analysis. In this work a DCNN is proposed and evaluated for automated detection of bone splinters in DEXA phantom images. The image data consists of 47 phantoms with (35) and without (12) bone splinters. Material decomposition and energy weighting results in additional image channels. Various DCNN architectures and parameters were explored. A classification rate in regions with 90 % and without 99 % bone splinters was achieved.
Catheter pose-dependent virtual angioscopy images visualized on augmented reality glasses
Authors: Haxthausen Felix von , Jäckle Sonja , Strehlow Jan , Ernst Floris , García-Vázquez Verónica 
Published: September 2019

Abstract
Fluoroscopy and digital subtraction angiography provide guidance in endovascular aortic repair (EVAR) but introduce radiation exposure and require the administration of contrast agent. To overcome these disadvantages, previous studies proposed to display the pose of an electromagnetically (EM) tracked catheter tip within a three-dimensional virtual aorta on augmented reality (AR) glasses. For further guidance, we propose to create virtual angioscopy images based on the catheter tip pose within the aorta and to display them on HoloLens. The aorta was segmented from the computed tomography (CT) data using MeVisLab software. A landmarkbased registration allowed the calculation of the pose of the EM sensor in the CT coordinate system. The sensor pose was sent to MeVisLab running on a computer and a virtual angioscopy image was created at runtime based on the segmented aorta. When requested by HoloLens, the last encoded image was sent from MeVisLab to the AR glasses via Wi-Fi using a remote procedure call (gRPC), and then decoded and displayed on HoloLens. For evaluation purposes, the latency of transmitting and displaying the images was measured using two different lossy compression formats (namely JPEG and DXT1). A mean latency of 82 ms was measured for the JPEG format. On the other hand, using the DXT1 format, the mean latency was reduced by 87 %. This study proved the feasibility of creating pose-dependent virtual angioscopy images and displaying them on HoloLens. Additionally, the results showed that the DXT1 format outperformed the JPEG format regarding latency. The virtual angioscopy may add valuable additional information for guidance in radiation-sparing EVAR procedure approaches.
Application of 3R principles in small animal GLP testing of biomaterials
Authors: Kischkel Sabine , Brietzke Andreas , Schmidt Wolfram , Eickner Thomas , Grabow Niels , Matschegewski Claudia 
Published: September 2019

Abstract
On the protection of animals used for scientific purposes, the EU Parliament adopted Directive 2010/63/EU. The essential factor is the 3R principle: Replacement, Reduction and Refinement. In 2013, the third amendment to the German Animal Welfare Act was revised and adapted to the European Directive. The majority of animals in science are used in basic research, as well as in translational and applied research. In medical research, animal experimentation is conducted to clarify previously unknown life processes and basic biological relationships, in order to improve diagnostics and treatment of human diseases. Before an animal experiment can be performed, it must be reported to and approved by the responsible authorities. The planned research project must be justified scientifically, and it must be demonstrated that the personnel and spatial/ technical prerequisites are in place to successfully complete the project. If all conditions are met, the approval can be granted, but may be subject to conditions. The guiding principle of essentiality also affects the procedure of the experiments: The number of animals used and the pain, suffering and damage caused to these animals must be limited to what is absolutely necessary. In this context, the 3R principle has to be applied. To obtain reliable results, it is essential that the laboratory animals are in normal physiological conditions and free of pain and fear. Scientific interest and animal welfare are therefore not in opposition, but rather mutually dependent. In our GLP (Good Laboratory Practice) laboratory we test new drug release systems for different biomedical applications in rabbits after careful selection of the animal model. Stress during animal experiments must be avoided as far as possible. Providing pain-killers and ensuring the best possible husbandry and care conditions are crucial for the animal’s wellbeing and absence of pain and anxiety. In the present work we report our different experience in a GLPcertified biomaterial test laboratory.
Electrical Dipole Source Localization using Hybrid Least Squares Method in combination with ICA
Authors: Samann Fars , Rausch Andreas , Schanze Thomas 
Published: September 2019

Abstract
In biomedical engineering, dipole source localization is commonly used to identify brain activities from scalp recorded potentials, which is known as inverse problem of electroencephalography (EEG) source localization. However, this problem is fundamental in biomedical engineering, medicine and neuroscience. The EEG inverse problem is non-linear, in addition, it is ill-posed and the solver can be unstable, i.e. the solution is non-unique and it is highly sensitive to small changes of the measured signal (noise). For solving the EEG inverse problem iterative methods, like Levenberg-Marquardt algorithm, are usually considered. However, these techniques require good initial values and many electrodes N, since a large redundancy supports the finding of the right solution. Therefore, in this paper, a hybrid method of linear and non-linear modelling and least squares approach are proposed to overcome of these problems: the solutions calculated by means of a linear approximation of EEG inverse problems serve as initial values for solving the original non-linear model. In addition, independent component analysis (ICA) is combined with the proposed hybrid least squares method to separate different dipole sources from multiple EEG signals. The performance of the hybrid least squares method with and without ICA is measured in term of root mean square error. The simulation results show that the proposed method can estimate the location of dipole source with acceptable accuracy under high noise condition and small N comparing with linear least squares method considering larger N. Finally, it should be mentioned that the proposed method promises advantages in finding solutions of the EEG inverse problem effectively.
Multiscale Parameter Estimation (msPE) of QRS complexes distorted by magnetohydrodynamic effects at 7 Tesla
Authors: Spicher Nicolai , Kukuk Markus , Maderwald Stefan , Ladd Mark E. 
Published: September 2019

Abstract
During ultra-high-field magnetic resonance imaging, the acquisition of electrocardiography is impeded by artifacts. This poses a challenge in examinations where the QRS complex is used as a trigger for activating image acquisition. In this work, we customize a framework for multiscale parameter estimation for processing electrocardiography signals acquired inside and outside an ultra-high-field scanner bore: The parameters of a QRS complex modeled by a Gaussian function were estimated using scale-dependent algebraic expressions for 600 heartbeats from three subjects. Sensitivity ≥ 94% and accuracy ≤ 5ms in each experiment indicate feasibility of this approach, and, additionally, run time is within the acceptable range for triggering latency in the majority of cases. Hence, we see a real-time implementation as an avenue for future work.
Local blood flow analysis and visualization from RGB-video sequences
Authors: Kossack Benjamin , Wisotzky Eric L. , Hilsmann Anna , Eisert Peter , Hänsch Ronny 
Published: September 2019

Abstract
The extraction of heart rate and other vital parameters from video recordings of a person has attracted much attention over the last years. In this paper, we examine time differences between distinct spatial regions using remote photoplethysmography (rPPG) in order to extract the blood flow path through human skin tissue in the neck and face. We can show that the visualization of the blood flow path corresponds to the physiologically defined path.
Foetal heart rate assessment by empirical mode decomposition and spectral analysis
Authors: Fuentealba Patricio , Illanes Alfredo , Ortmeier Frank 
Published: September 2019

Abstract
This paper focuses on studying the time-variant dynamics involved in the foetal heart rate (FHR) response resulting from the autonomic nervous system modulation. It provides a comprehensive analysis of such dynamics by relating the spectral information involved in the FHR signal with foetal physiological characteristics. This approach is based on two signal processing methods: the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and time-varying autoregressive (TV-AR) modelling. First, the CEEMDAN allows to decompose the signal into intrinsic mode functions (IMFs). Then, the TV-AR modelling allows to analyse their spectral dynamics. Results reveal that the IMFs can involve significant spectral information (p -value < 0.05) that can help to assess the foetal condition.
Generation of an azide-modified extracellular matrix by adipose-derived stem cells using metabolic glycoengineering
Authors: Nellinger Svenja , Keller Silke , Southan Alexander , Wittmann Valentin , Volz Ann-Cathrin , Kluger Petra J. 
Published: September 2019

Abstract
Natural extracellular matrix (ECM) represents an ideal biomaterial for tissue engineering and regenerative medicine approaches. For further functionalization, there is a need for specific addressable functional groups within this biomaterial. Metabolic glycoengineering (MGE) provides a technique to incorporate modified monosaccharide derivatives into the ECM during their assembly, which was shown by us earlier for the production of a modified fibroblast-derived dermal ECM. In this study, adipose-derived stem cells (ASCs) were treated with the azide-modified monosaccharide derivate 1,3,4,6-tetra-O-acetyl-N-azidoacetylgalactosamine (Ac4GalNAz). Toxicity and viability assays after 24 h and 72 h incubation revealed high biocompatibility of Ac4GalNAz in contact with ASCs. The successful incorporation of the functional azide groups into the glycocalyx and the ECM of the ASCs was proven by conjugation with a fluorescent dye via a copper-catalyzed click reaction. Thus, Ac4GalNAz in combination with ASCs was confirmed to achieve an azidemodified ECM as a multifunctional biomaterial for further applications.
A Hybrid Mock Circulation for Control Algorithms of Ventricular Assist Devices
Authors: Salesch Tobias , Gesenhues Jonas , Abel Dirk 
Published: September 2019

Abstract
This paper deals with the design, simulation and control of a new lightweight hybrid Mock-Loop (MCL) concept. The proof of concept is evaluated by two simulation approaches. First, the design parameters are chosen by an optimal control problem. Second, a cascading controller structure is evaluated in a simulation. Both show that with a suitable range of the design parameter the new lightweight concept can be used as a MCL. To validate these findings, further investigations with the MCL under realistic test conditions are required.
Protective role of vitamin E to reduce oxidative degradation of soft implantable polyurethanes: In vitro study
Authors: Kutuzova Larysa , Molentor Olga , Wu Feng , Song Wenyao , Kandelbauer Andreas , Lorenz Günter 
Published: September 2019

Abstract
Vitamin E (VitE) additives are important in treating osteoarthritis inclusive cartilage regeneration due to their antioxidant and anti-inflammatory properties. The present research study focuses on the ability of biological antioxidant VitE (alpha-tocopherol isoform) to reduce or minimize oxidative degradation of soft implantable polyurethane (PU) elastomers after extended periods of time (5 months) in vitro. The effect of the oxidation storage media on the morphology of the segmented PUs was evaluated by mechanical softening, crystallization and melting behavior of both soft and hard segments (SS, HS) using dynamic mechanical analysis (DMA). Bulk mechanical properties of the potential implant materials during ageing were predicted from comprehensive mechanical testing of the biomaterials under tension and compression cyclic loads. 5-months in vitro data suggest that the prepared siloxane-poly(carbonate-urethane) formulations have sufficient resistance against degradation to be suitable materials for chondral long-term bio-stable implants. Most importantly, the positive effect of incorporating VitE (0.5 or 1.0% w/w) as bio-antioxidant and lubricant on the bio-stability was observed for all PU-types. VitE-additives protected the surface layer from erosion and cracking during chemical oxidation in vitro as well as from thermal oxidation during extrusion re-processing.
Support function of self-expanding nitinol stents – Are radial resistive force and crush resistance comparable?
Authors: Brandt-Wunderlich Christoph , Schmidt Wolfram , Grabow Niels , Stiehm Michael , Siewert Stefan , Andresen Reimer , Schmitz Klaus-Peter 
Published: September 2019

Abstract
The main task of any vascular stent is the mechanical support of the re-opened vessel. This support function may be quantified by the compressive properties of the stent in radial outer loading conditions. Different test methods are standardized and are accepted to provide relevant data. Six commercially available self-expanding stents were investigated with regard to their forcedeformation behavior during radial as well as elliptical deformation. The measured radial resistive force and crush resistance were not qualitatively congruent for all stents. As a conclusion both test methods should be considered when describing the compressive properties of self-expanding stents.
Extrusion as a manufacturing process for polymer micro-tubes for various bio-medical applications
Authors: Sahmel Olga , Siewert Stefan , Schmitz Klaus-Peter , Arbeiter Daniela , Grabow Niels , Kreiner Christine Friederike , Guthoff Rudolf 
Published: September 2019

Abstract
In various biomedical applications extrusion represents a common manufacturing process for polymeric semi-finished products. Extrusion allows the processing of a wide range of biomaterials, as well as different cross-sectional geometries. The present work focuses on the development of an extrusion process for polymer micro-tubes used for medical devices manufacturing, e.g. microstents for minimally invasive glaucoma therapy. Semi-finished products were manufactured by means of extrusion and dip-coating. Morphology was investigated using biaxial laser measurement and scanning electron microscopy (SEM). For the analysis of mechanical and thermal properties of the specimens uniaxial tensile testing and differential scanning calorimetry (DSC) were performed. While dip-coated micro-tubes reveal a smooth and homogeneous surface, SEM micrographs of extruded micro-tubes exhibit some longitudinal grooves. Mechanical properties of extruded and dip-coated micro-tubes are comparable, so that the presented extrusion process can be regarded suitable for the manufacturing of polymer microtubes in a sub-millimeter scale. A future improvement of nozzle design will allow for a smooth surface of extruded semi-finished products.
Technical Support of Wound Healing Processes: Project Status
Authors: Dawn Parente Jacquelyn , Möller Knut , Hensler Sabine , Kühlbach Claudia , Mueller Margareta M. , Belloni Paola , Chase J. Geoffrey 
Published: September 2019

Abstract
The optimized wound healing (OWID) project provides technical support of wound healing processes. Advanced biophysical treatment therapies using light (photobiomodulation), negative pressure wound therapy (NPWT), and electrical stimulation show biological effects. Specifically, a biphasic dose-response curve is observed where lower doses activate cells, while above a threshold, higher doses are inhibitory. However, no standard protocols and no multi-modal treatment studies determine specific therapy needs. The OWID project aims to develop a multi-modal treatment device and modelbased therapy for individualized wound healing. This work presents the OWID project status. Currently, a photobiomodulation prototype delivers red, green, and blue light ‘medicine’ at prescribed therapeutic ‘doses’. The calculation of incident light necessarily considers transmission properties of the intervening cell culture plate. Negative pressure wound therapy (NPWT) and electrical impedance tomography (EIT) hardware are being adapted for use in vitro. Development of mathematical models of wound healing and therapy control are supported by treatment experiment outcome measures conducted in a wounded 3D tissue model. Parameter sensitivity analysis conducted on an existing mathematical model of reepithelialization results in changing parameter values influencing cellular movement rates. Thus, the model is robust to fit model parameters to observed reepithelialization rates under treatment conditions impacting cellular activation, inhibition, and untreated controls. Developed image analysis techniques have not captured changes in wound area after photobiomodulation treatment experiments. Alternatively, EIT will be tested for wound area analysis. Additionally, live dyes will be introduced to non-invasively visualize the reepithelialization front on a smaller, cellular scale. Finally, an overall therapeutic feedback control model uses model reference adaptive control to incorporate the intrinsic biological reepithelialization mechanism, treatment loops, and treatment controller modulation at a wound state. Currently, the OWID project conducts photobiomodulation treatment experiments in vitro and has developed mathematical models. Future work includes the incorporation of multi-modal wound healing treatment experiments.