bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological test methods for stents: cellular responses to microstructured biomaterials
Authors: Klußmann-Fricke Bastian-Jesper , Stahnke Thomas , Siewert Stefan , Reske Thomas , Bohne Eric , Schmitz Klaus-Peter , Khaimov Valeria 
Published: September 2022

Abstract
One of the greatest challenges in the development of novel implants is to find materials that optimally interact with the tissue and support the function of the implant over a long period of time. Especially considering the fact that biomaterials are used in multiple applications in modern implants, a better understanding of the physiology of the tissue in contact with the material becomes more and more important. To better understand the cellular responses to biomaterials, it is furthermore necessary that the models used reflect the physiological conditions at the implant site. However, in most cases, immortalized cell lines instead of tissue-specific primary cells are used to study the biocompatibility of implant materials. When interpreting these results, it is important to consider that cell lines differ significantly from primary cells found in their native environment. In this study, we examined the morphological differences between a cell line and primary cells upon contact with various implant structures resembling implant prototypes. Using a mouse fibroblast cell line in comparison with primary porcine fibroblasts, we discuss the results with respect to the use of cell lines for biocompatibility testing of biomaterials. Our results suggest that to better estimate meaningful results regarding the compatibility of implant structures, key control experiments should always be performed with specific primary cells.
Biomechanical Characterization of Human Corneal Lenticules
Authors: Nambiar Malavika , Liechti Layko , Studer Harald , Sinha Roy Abhijit , Seiler Theo G. , Büchler Philippe 
Published: September 2022

Abstract
In surgical refractive interventions over-correction or under-correction still occur in 10-15 % of cases. Improved outcomes could be achieved by incorporating patient-specific corneal biomechanics into surgical planning. As a first step, this study mechanically characterizes and numerically simulates corneal lenticules harvested during a refractive intervention called Corneal Lenticule Extraction for Advanced Refractive Correction (CLEAR). These human corneal lenticules were mechanically tested in uniaxial extension in nasal-temporal and 45 deg orientations. An HGO material model that accounts for the unique collagen arrangement of the human cornea was developed and used to identify the material parameters using a finite element model of the experimental setup. The material parameters that best represent the experimental force/displacement were obtained by parameter estimation using Bayesian optimization. The uniaxial experiments performed on 3 patients did not show distinctive differences in orientation. The estimated material parameters fit well with the experimental data, representing a promising material model. In the future, Brillouin measurements will be performed on the CLEAR patients before lenticule extraction so that material parameters can be estimated in vivo, providing the surgeon with a patient specific-surgical planning tool.
Radial compliance of porcine coronary arteries ex vivo under pulsatile flow – perspectives for stent biomechanics
Authors: Brandt-Wunderlich Christoph , Kosche Florence , Schmidt Wolfram , Grabow Niels , Stiehm Michael , Schmitz Klaus-Peter , Siewert Stefan 
Published: September 2022

Abstract
Besides visual assessment of the intra-vascular appearance, intravascular optical coherence tomography (IVOCT) enables precise diameter measurements within the coronary arteries. The current study presents an upgraded test setup allowing the investigation of the elastic properties of porcine coronary arteries ex vivounder pulsatile flow conditions. IV-OCT imaging was performed within the left circumflex artery of a porcine heart applying a normotensive and a hypertensive pressure regime at different pulse rates. Radial compliance was derived from the luminal diameter as well as intra-arterial pressure measurements. Test results show a significant reduction of radial compliance under pulsatile conditions, when compared to reference measurements under steady flow. The mean radial compliance decreased with increasing pulse rate, which can be attributed to the viscoelastic properties of the arterial wall.
Hemoglobin ratio as a forgotten parameter for automatic feedback control systems in preterm neonates
Authors: Tejkl Leos , Kudrna Petr , Rafl Jakub 
Published: September 2022

Abstract
This paper deals with the analysis of the relationship between fetal hemoglobin (HbF) and adult hemoglobin (HbA) in preterm infants as a function of the gestational week and newborn weight based on the available literature. The role of other parameters on the shift and shape of the OHDC curve is also discussed. The function could be useful when dynamic development of OHDC in a neonate occurs in emergencies such as blood transfusions. The main idea is to incorporate the dynamic evolution of the hemoglobin conversion as a mathematical function into existing models of oxygenation in preterm neonates or into automatic feedback control algorithms of oxygenation. This could help further individualize and optimize the oxygenation settings of preterm neonates.
KTeXpand – a novel microfluidic device for advanced cell based cross matching
Authors: Schneider Daniel , Behrens Stephan , Philipp Jürgen , Eitler Jiri , Stumpf Julian , Tonn Torsten , Sonntag Frank , Hugo Christian , Schmieder Florian 
Published: September 2022

Abstract
Antibody-mediated rejection after kidney transplantation is a major limitation for long-term survival of donated kidneys within the recipient allograft. With the existing HLA cross-matching test only complement activating donor specific antibodies are evaluated. Other measurements are more sensitive, but cannot assert the clinical relevance of the donor specific antibodies. Thus, novel methods that address the more complex nature of cellular interactions with serum components are needed to improve antibody-mediated rejection prediction. Recent studies suggest, that the interaction of natural killer cells of the recipient with endothelial cells of the donor is of major interest. Here we present a microfluidic cell culture device and a corresponding assay to test for the relevance of natural killer cell activated antibody-mediated rejection in vitro. Therefore, a protocol to co-cultivate both cell types and track natural killer cell activated killing within a fluorescence-based assay was established. To automate this approach, the prototype of a well plate sized microfluidic device was developed, that enables staining of the two cell types and repeatable and timedependent co-cultivation of the cells with serum. This automated approach enables further evaluation of the clinical relevance of the established assay paving the way to additional information on HLA cross-matching that helps to quickly estimate the probability of Antibody-mediated rejection and the clinical relevance of donor specific antibodies.
Development of an EMG-based Elbow- Exoskeleton with Twisted String Actuation
Authors: Weymann Sylvia , Pretty Chris G. , Pott Peter P. 
Published: September 2022

Abstract
This paper presents an exoskeleton for upper extremity rehabilitation of stroke patients. In order to make rehabilitation widely available, the goal is an inexpensive, portable, and easy-to-use therapy for paralysis of the arm. The exoskeleton is actuated by twisted string actuators (TSA). To reduce the length of the TSA a motor with hollow shaft was chosen, as this allows the string to run through the motor. The control of the exoskeleton is designed for predefined elbow flexion exercises. The start of the movement is triggered by a threshold value in the sEMG of the m. biceps brachii. To evaluate the controller, the exoskeleton performed a flexion movement (5° to 115°) in 2 s and then an extension back to 5° in the same time after a 1 s wait. To simulate different force requirements, additional weights up to 1500 g were attached. During both, the flexion and extension movement, that angle tracking error was sufficiently small and the steady state error was zero. The angular velocity of the elbow joint showed pronounced oscillations with increasing weights. The results show that TSAs can be used to actuate elbow exoskeletons. Thus lightweight, ergonomic, simple and small rehabilitation devices can now be built on this basis. The elasticity of the system must be considered in future work. sEMG must be further implemented to control more sophisticated functions of the rehabilitation device.
Femtosecond laser manufacturing technology for microstents as innovative medical devices to treat open-angle glaucoma
Authors: Siewert Stefan , Bohne Eric , Grossmann Swen , Schmidt Wolfram , Grabow Niels , Stahnke Thomas , Guthoff Rudolf , Stiehm Michael , Schmitz Klaus-Peter 
Published: September 2022

Abstract
The increasing trend of minimally invasive therapy methods for widespread diseases in the cardiovascular system, in the field of ophthalmology, ear, nose, and throat medicine, or gynecology, leads to an extensive demand for innovative microdevice manufacturing technologies. Femtosecond (fs)-laser technology offers a wide range of applications in the field of cutting, milling, and surface structuring on the micro- and nanometer scale. Ophthalmic devices for glaucoma therapy have dimensions in the submillimeter range. Irrespective of this, there are high demands on the safety and efficacy of these implants. Within the current study, fs-laser-based manufacturing technologies for functional elements of a novel microstent for glaucoma therapy were developed, considering potential industrial scalability. We successfully developed a mounting mechanism for quick and reproducible manufacturing of a micromechanical valve mechanism for safe regulation of intraocular pressure. Furthermore, we successfully developed a fs-laser-based process for manufacturing grooves as part of a fixation mechanism for a stable device positioning inside the eye. The results show that fs-laser manufacturing represents a promising technology for manufacturers of medical microdevices, such as ophthalmic microstents.
Design considerations and applications of a biomedical test bench development kit
Authors: Tautorat Carsten , Kamke Frank , Lebahn Kerstin , Grabow Niels , Schmidt Wolfram 
Published: September 2022

Abstract
Applications and requirements for biomedical test benches are often quite different, but there is always a need to monitor and usually to control processes. Commercially available development systems can be used to build simple laboratory setups up to industrial systems but are limited with respect to high costs and information for required validation. A test bench development kit is presented which ensures high compatibility for prospective developments, adaptations and embedding of sensors and actuators. The development kit is based on a printed circuit board built around the singleboard computer Raspberry PI. Supporting circuitry for power control, logics and special functions are implemented. Several types of peripheral devices can be connected via two serial bus standards (I2C, or RS-485). Current applications demonstrate the achieved level of automation and process control.
Neonatal seizure detection algorithms: The effect of channel count
Authors: Borovac Ana , Runarsson Thomas Philip , Thorvardsson Gardar , Gudmundsson Steinn 
Published: September 2022

Abstract
The number of electrodes used to acquire neonatal EEG signals varies between institutions. Therefore, tools for automatic EEG analysis, such as neonatal seizure detection algorithms, need to be able to handle different electrode montages in order to find widespread use. The aim of this study was to analyse the effect of montage on neonatal seizure detector performance. A full 18-channel montage was compared to reduced 3- and 8-channel montages using a convolutional neural network for seizure detection. Sensitivity decreased by 10 - 18 % for the reduced montages while specificity was mostly unaffected. Electrode artefacts and artefacts associated with biological rhythms caused incorrect classification of nonseizure activity in some cases, but these artefacts were filtered out in the 3-channel montage. Other types of artefacts had little effect. Reduced montages result in some reduction in classifier accuracy, but the performance may still be acceptable. Recording artefacts had a limited effect on detection accuracy.
Experiences of intercultural teaching activities in the field of eHealth
Authors: Nemec Iris , Malásková Michaela , Pavão João , Pereira Luis , Frohner Matthias 
Published: September 2022

Abstract
The funded research Project HealthCONNECT implements measure to promote the term eHealth in teaching and means to ease the exchange of lecturers and students to perceive different views of this topic. This report introduces the activities that have been implemented, stresses challenges that were observed and derives suggestions how to establish a co-operation between different institutes of higher education. This includes the mutual participation and inclusion of lecturers in teaching and evaluation activities; spanning from assessing students’ projects till chairing master examinations. The co-operative organization and hosting of eHealth Summer Schools is another mean to share knowledge in the domain of eHealth with students and colleagues abroad. Such activities require a stable co-operation between the involved institutions that only can be build upon a trustworthy relationship between the lecturers as they are paving the way.
Microstent for minimally invasive treatment of Fallopian tube occlusions – porcine implantation ex vivo
Authors: Dierke Ariane , Klußmann-Fricke Bastian-Jesper , Rosam Paula , Brandt-Wunderlich Christoph , Knorre Luise , Stiehm Michael , Bock Andrea , Grabow Niels , Wree Andreas , Zygmunt Marek , Schmitz Klaus-Peter , Siewert Stefan 
Published: September 2022

Abstract
Involuntary female infertility represents a sensitive issue, which is frequently caused by an impaired patency of the Fallopian tube. Current treatment options, such as in vitro fertilisation (IVF) or tubal reconstruction, are related to high costs or surgical risks. Therefore, a need for an alternative highly safe and effective minimally invasive therapy option is assumed. The current work presents a proof-of-concept for a novel microstent in combination with a delivery system for treatment of proximal Fallopian tube occlusions. For this purpose, a microstent prototype was implanted into a porcine Fallopian tube ex vivo using the presented delivery system. The results of the procedure were analyzed using a micro-computed tomography (μ-CT). Based on the μ-CT imaging, critical parameters of the microstent, such as radial patency, were assessed. The microstent implantation leads to an increased opening area of the Fallopian tube. Additionally, the microstent does not impair the anatomical shape of the tube epithelium and adapts well to the anatomical path. In further studies, the functionality of the Fallopian tube will be examined after microstent implantation in vivo.
Neural Network Classification of Surgical Tools in Gynecological Videos
Authors: Abdulbaki Alshirbaji Tamer , Aldeen Jalal Nour , Docherty Paul D. , Neumuth Thomas , Moeller Knut 
Published: September 2022

Abstract
Automated surgical tool classification will improve the workflow of surgery. Previous research tackled this task mainly in cholecystectomy procedures due to availability of a relatively large and labelled set (Cholec80 dataset). However, the complexity of the procedure type has an impact on the robustness of the deep learning approaches. Therefore, the classification capability of CNNs on data of more complex procedures with many surgical tools was investigated. In this work, laparoscopic videos of 14 gynaecological procedures were recorded and labelled for surgical tool presence. Then, the DenseNet-121 model was trained to identify surgical tools according to functionality. Experimental results imply high classification performance for some surgical tools. The mean average precision over all the tools was 67%. This study is an initial benchmark for detecting surgical tools in realistic settings.
Computation of flow through TAVI device by means of physics informed neural networks
Authors: Oldenburg Jan , Borowski Finja , Schmitz Klaus-Peter , Stiehm Michael 
Published: September 2022

Abstract
Cardiovascular diseases are among the most common diseases with high mortality, including aortic valve stenosis and insufficiency. Minimally invasive implantation of transcatheter aortic valve prosthesis (TAVI) has become the standard procedure for patients with increased risk for open surgery. It is commonly accepted that the long-term outcome of aortic valve replacement depends on hemodynamic performance. This motivates the analysis of the velocity field in the vicinity of the TAVI. Computational fluid dynamics (CFD) methods have been established in the past, but show limitations in terms of computational effort when rapid design optimization or patient-specific decision making in real time is required. In this study we show the usage of PINNs for predicting fluid flow through a TAVI device. We also show a method of enforcing boundary conditions for this specific problem. Due to the physics involved in the training process, this principle does in theory not require additional training data. To validate the method, we performed CFD simulations that solved the Navier-Stokes equations be means of finite volume methods. Besides the good estimation of the main flow components, discrepancies between CFD and PINN results are present. Nevertheless, the flow structures have certain similarities in the coarse spatial localization of the vortex patterns occurring in flow around the TAVI device.
Development of a test rig for the diagnosis of arthritic knee joint defects in the case of lower extremity amputees in orthopaedic technology
Authors: Subke Jörg , Stelz Joshua , Schneider Benedict , Schwalbe Hans-Joachim , Wolf Udo 
Published: September 2022

Abstract
If the alignment of a leg prosthesis is inadequate there will be the danger of arthritic defects occurring in the preserved knee joint. Acoustic-kinetic joint analysis in orthopaedic technology allows monitoring of the knee joint of an amputee after the alignment of a leg prosthesis and to recognize early joint defects resulting in adaptation of the alignment of the prothesis. A test rig was developed which includes acoustic emission analysis of the knee, video-based gait analysis, ground reaction force measurement and the measurement of the holding forces of the hands. During the examination a subject must do 3 one-legged knee bends during 10 sec with the preserved leg. To support the subject two grab handles were fixed with force sensors to a frame. A series of 6 measurements were recorded with breaks of 2 min. The recorded forces of the leg show a double hump pattern during the knee bend. The rising edge of the flexion phase was not uniform. The forces show no conclusive uniform pattern. The fitness of the probands acts as an indicator for the pattern of the force signals. The signals of the measurements show the necessity of the support for both hands to execute a one-legged knee bend. The understanding of the 3 measured forces is important for the arthritic diagnosis of the knee joint.
On model-based hyperspectral imaging
Authors: Papke Kai , Hornberger Christoph 
Published: September 2022

Abstract
Several contributions are presented to aid the analysis of hyperspectral images by utilizing appropriate optical models. The algorithms are described by means of the perfusion of human skin and a corresponding two-layer tissue model. The particular role of the mean photon path length within the medium is discussed and two approaches to solve the inverse problem, i.e., the derivision of perfusion parameters from given spectra, are outlined.
Intelligent Garment based ECG Monitoring with AI support for Elderly
Authors: Linti Carsten , Blocher Sandra , Downes Robert , Bandte Martina 
Published: September 2022

Abstract
Smart underwear was designed to meet the demands of elderly people be monitored in outpatient environments. Especially the demands of women have been addressed, who have heart failure but who still want to live in their home. The smart bra comprises textile electrodes and an ECG event recorder. The recorder transmits the data to the doctor only if artificial intelligence (AI) has discovered critical events in ECG signals. An implemented convolutional neural network, which uses the wavelet transformation of the ECG as input and to determine an interference index for this ECG signal is implemented. The smart bra can be part of new remote monitoring services such as e-consultation or as a new home-based follow-up to ensure seamless patient care after hospital or rehabilitation stays. Healthcare personnel has better access to the patient´s digital ECG data without direct consultation, independently of where the patient lives and the patient can feel safer.
How Does Subsidiary Autonomy Influence Performance in the Emerging Economy: Different Moderating Effects of Subsidiary Entrepreneurship
Authors: Tsai Chengan 
Published: September 2022

Abstract
Previous research has confirmed the overall positive relationship between subsidiary autonomy and performance. However, given the lack of consensus regarding the effect of subsidiary autonomy on performance, contingency is required to understand complex linkages and possible causality in both developed and emerging economies. This study adopts the agency theory and entrepreneurship to address the interplay among subsidiary autonomy, entrepreneurship, and performance in the emerging economy of China. The empirical results indicate that renewal entrepreneurship has a positive moderating effect and venturing entrepreneurship has an inverted U-shaped moderating effect on the positive relationship between subsidiary autonomy and performance. This study extends the research context and contributes to the literature on agency theory and entrepreneurship in the multinational corporation.
Homogeneous four-manifolds with half-harmonic Weyl curvature tensor
Authors: Calviño-Louzao Esteban , Ferreiro-Subrido María , Garcia-Rio Eduardo , Vázquez-Lorenzo Ramon 
Published: September 2022

Abstract
We show that a four-dimensional homogeneous manifold with half-harmonic Weyl curvature tensor is symmetric or homothetic either to the only nonsymmetric anti-self-dual homogeneous manifold or to the 3-symmetric space.
GRENZEN VON ETHIKCODIZES
Authors: Weber Karsten 
Published: September 2022

Abstract
Technology penetrates into all areas of our everyday and individual life and changes it in a considerable speed. This applies particularly to developments of information and communication technology since this technology shows its effects not only at our workplaces but transforms and sometimes determines the social behavior of people. Unfortunately, development and use of technology certainly doesn't go hand into hand with the acceptance of responsibility for consequences of effects of developing and using technology. Instead, the opposite behavior is quite common. If this process of the rejection of responsibility shall be stopped, the sensibility of developers and users of technology for consequences of their own behavior have to be aroused and strengthened. In the following text at first I will describe some reasons to formulate ethical guidelines. After this, with the example of the ethical guidelines of the German Gesellschaft für Informatik e. V. (GI), I will discuss, whether such ethical guidelines are ethical in the strict sense of the word and whether they actually can be a contribution to accomplish the striven aim of assignment of responsibility for the results of developing and using technolog