bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Roughness-Dependent Corrosion: Implications for Cochlear Implant Reliability
Authors: Blank Tatiana , Behrens Sabine , Klose Christian , Jürgen Maier Hans 
Published: December 2024

Abstract
The corrosion behavior of platinum electrodes in cochlear implant (CI) systems is a critical factor affecting their long-term functionality. This study investigated the influence of the surface roughness of the platinum electrodes on their corrosion behavior. The results of in vitro experiments indicate that higher surface roughness tends to accelerate corrosion by providing numerous initiation sites. Although the electrochemical measurements of platinum electrodes with different surface roughnesses showed only slight differences in terms of shifts in potentials and higher corrosion current densities, data from the literature suggests an enhanced charge capacity with rougher surfaces. These findings contribute to an understanding of the failure mechanisms of CIs and can ultimately help to improve the design and durability of CI systems.
Hydrophobic Surface Coatings for the Functionalization of Stimulation Electrodes
Authors: Bode Tom , Drexler Jan , Müller Marc , Paasche Gerrit , Glasmacher Birgit 
Published: December 2024

Abstract
This study examines hydrophobic surface coatings for stimulation electrodes to mitigate foreign body reactions and encapsulation. Electrospinning of polydimethylsiloxane (PDMS) resin is explored to create fiber structures for electrode coatings. PDMS resin is succesfully processed into fiber mats. Electrospun PDMS fiber structures showed an increased water contact angle (124 °/125 °) in comparison to a cast flat film (102 °). To further increase hydrophobicity, the fabrication process of Slippery Liquid-Infused Porous Surface (SLIPS) systems with a polyurethane substrate and different natural lubricants is assessed with promising results in an increase in water contact angles up to 11°. The findings suggest the potential of these surface coatings to enhance the performance and safety of stimulation electrodes.
Placement and Orientation of an Accelerometer Sensor Attached to the Human Incus in Hearing Implants
Authors: Burovikhin Dmitrii , Kitsopoulos Panagiota , Lauxmann Michael , Grosh Karl 
Published: December 2024

Abstract
In this study a method for determining the best placement and optimal orientation of the implantable piezoelectric accelerometer attached to the short process of the incus is developed. The accelerometer is intended to be used as a replacement for an external microphone to enable totally implantable cochlea implants or as part of a totally implantable hearing aid. The best location is determined to be near the incudomalleolar joint. The optimal orientation of the sensor at the determined location is obtained using two criteria - maximum voltage sum and minimum loudness level sum. The method described in the paper can be used to further optimize the design and the performance of the accelerometer.
Muscle twitch thresholds depending on the direction of current stimulation
Authors: Dölker Eva-Maria , Haueisen Jens 
Published: December 2024

Abstract
Acoustic or visual warning signals for workers in hazardous situations might fail under loud and/or lowvisibility work situations. A warning system that uses electrocutaneous stimulation can overcome this problem. This study aimed to compare vertical, diagonal, and horizontal current stimulation directions at the upper arm to select the one with the lowest amount of muscle twitching. Fourteen electrodes were attached in two rows to the upper right arm of 15 participants. The stimulation was conducted with bi-phasic rectangular pulses of 150 μs and amplitudes of up to 25 mA. Muscle twitch thresholds have been determined and a circumferential stimulation signal was presented as warning pattern for the three current stimulation directions and evaluated regarding alertness, discomfort, and urgency. For single stimulation pulses, muscle twitches occurred slightly less often at the horizontal stimulation direction compared to the other two and muscle twitch thresholds showed no systematic differences. For the warning patterns, no considerable differences were found regarding the evaluation of alertness, discomfort, and urgency and no differences were found for muscle twitching. In conclusion, all orientations seem suitable for warning pattern presentation and none of the directions has a clear advantage in reducing muscle twitch.
An Educational App for the Selection of Blood Glucose Meters: A Cross-Sectional Study
Authors: Doniec Rafał , Krzepina Tymoteusz , Siecinski Szymon , Tausif Irshad Muhammad , Grzegorzek Marcin 
Published: December 2024

Abstract
In this cross-sectional study, we examined the abundance of blood glucose meter (BGM) models in the Polish and German medical device markets and their technical specifications. Information from a medical equipment wholesaler’s database was gathered for comparison of BGMs from five manufacturers: Roche Diabetes Care, LifeScan Inc, Abbott, Ascensia Diabetes Care, and Genexo, and for model Glucomaxx BT TaiDoc Technology Corporation. Key parameters such as blood sample size, measurement time, memory capacity, and measurement range were considered. An application was developed to aid in BGM selection for people with type 1 or type 2 diabetes. The results showed a high correlation with laboratory measurements and similarity in key functionalities between the models. The application, tested on 30 individuals aged 18 to 79 years, demonstrated stability, speed, and a user-friendly interface, facilitating efficient data processing and generating recommendations.
Proof of Concept for measuring vital signs using UWB transceivers
Authors: Egemann Noel , Kitzig Andreas , Naroska Edwin 
Published: December 2024

Abstract
This paper shows the possibility of using Ultrawideband (UWB) DW3000 transceivers for noninvasive vital sign monitoring via a transversal propagation method. The transceivers can provide a cheaper, more flexible, and easierto- apply measurement of vital signs than traditional electrocardiogram (ECG) devices. This will not substitute the common medical use but instead can make vital sign monitoring more accessible in other scenarios. Potential applications beyond clinical settings, like measuring the vital signs of a car driver, can be achieved. The primary focus of this study is the possibility of utilizing inexpensive UWB transceivers for ballistocardiography (BCG) measurements. The vital signs are measured on a small focus group to verify the results on a larger spectrum. A photoplethysmogram (PPG) device is used for reference measurement. The results show a great accuracy of 3 breaths per minute for respiration rate measurement. The heartbeat measurement shows an error mostly within 3 bpm due to the resolution of the proposed setup. Methods for further verification of the results, together with increasing the accuracy and resolution of the setup are proposed.
Noise reduction in non-invasive brain-computer interfaces for robot control
Authors: Glaessner Janine , Meyer Dagmar , Schilling Meinhard 
Published: December 2024

Abstract
To employ a brain-computer interface to control an assistance robot could help disabled people to achieve a minimum degree of autonomy and reduce their dependence on caregivers for simple tasks. In this project, we use a textile, capacitive brain computer interface (BCI) to control an assistant robot. Our BCI is based on Steady State Visual Evoked Potentials (SSVEP), which are a response of the brain to a periodic visual stimulus at a fixed frequency. Since the brain signals are in the microvolt range, the noise reduction of external disturbances has a high relevance. Here, we demonstrate a correlation method for detecting and eliminating phase shifts between different measurements for averaging. This method allows measurements in unshielded environment of two microvolts (uV) with an averaging factor of 100 in our non-invasive BCI set-up.
Analysis of muscle fatigue using entropybased measures from the recurrence pattern of surface electromyography signals
Authors: Hiremath Deepa S. , Sundar Banerjee Shib , Karthick P. A. , Swaminathan Ramakrishnan 
Published: December 2024

Abstract
Neuromuscular fatigue can be monitored using complexity domain analysis of surface electromyography (sEMG) signals. This study provides a technique to detect fatigue induced change in signal complexity using the entropic measurements of its recurrence pattern. For this purpose, fifteen participants have been recruited to perform isometric fatiguing exercise and signals are acquired from the biceps brachii muscle of the dominant hands. Thresholded recurrence plot is constructed from the non-fatigue and fatigue segments of the signal. Bidimensional dispersion entropy (DispEn2D) is calculated to quantify the textural change in the resulting recurrence plot. The results show that the present approach can distinguish between non-fatigue and fatigue states. Decrease in the DispEn2D values in the fatigue state shows there is an increase in periodic component of sEMG signal during fatiguing contraction.
Potential of magnetic shape memory alloys in medical applications
Authors: Hutter Marco , Mayer Juliane , Schäfer Max B. , Pott Peter P. , Gundelsweiler Bernd 
Published: December 2024

Abstract
Systems based on smart materials have become an increasing research focus in recent years, as their properties provide opportunity for higher functional integration, improved energy efficiency and completely new functionalities. Magnetic shape memory alloys (MSM) provide a promising option here. However, they have received limited attention in the field of medical engineering. This paper therefore aims to provide an introduction into the (magneto-mechanical) properties of MSM and to give an overview of existing applicationsoriented research, both in general and in medical engineering. In the reviewed literature, NiMnGa has been used in several prototypes of micro pumps for intracranial drug delivery and lab-on-a-chip systems. FePd, another MSM alloy, has aroused interest in research into temporary implants.
Evaluation of the Usage of Graph Database in a Nutrition App for Determining Potential Nutrient Inhibition
Authors: Jhonson Reynald , Fischer Patrick , Sohrabi Keywan , Groß Volker , Scholtes Michael 
Published: December 2024

Abstract
In recent years, the popularity of veganism has surged, prompting a growing interest in its health implications. While vegan diets offer numerous benefits, they also pose challenges due to potential deficiencies in essential nutrients and the presence of anti-nutrients in plant-based foods. This paper addresses the need for a comprehensive understanding of nutrient interactions, particularly those involving antinutrients, by creating a Knowledge Graph. Utilizing Natural Language Processing techniques, essential nutritional entities were extracted from unstructured texts, and a custom Named Entity Recognition model was implemented. These data were then used to construct a Knowledge Graph using Neo4j, a leading graph database. Despite the potential of the developed Knowledge Graph to visualize nutrient interactions, limitations persist due to the scarcity of available data on antinutrient interactions. Nonetheless, the Knowledge Graph provides a promising avenue for exploring and understanding the complexities of nutrient interactions, facilitating future research and informing dietary choices.
Assessment of Driver Stress using Multimodal wereable Signals and Self-Attention Networks
Authors: Pavan Kaveti , Ganapathy Nagarajan 
Published: December 2024

Abstract
Assessment of driver stress, crucial for road safety, can greatly benefit from the analysis of multimodal physiological signals. However, fusing such heterogeneous data poses significant challenges, particularly in intermediate fusion where noise can also be fused. In this study, we address this challenge by exploring a 1D convolutional neural network (CNN) with self-attention mechanisms on multimodal data. Electrocardiogram (ECG) signals (256 Hz) and respiration (RESP) signals (128 Hz) were obtained from ten subjects using textile electrodes while driving in different scenarios, namely normal driving and phone usage (calling). The obtained multimodal data is preprocessed and then applied to a self-attention mechanism (SAM) CNN (SAMcNN) to identify driver stress. Experiments are validated using Leave-one-outsubject cross validation. The proposed approach is capable of classifying driver stress. It is observed that shorter segments yield an accuracy of 64.16% compared to longer segment lengths. Thus, exploring self-attention mechanisms for multimodal signals using wearable shirts facilitates non-intrusive monitoring in real-world driving scenarios.
Influences on rPPG-Based Spatial Blood Perfusion Maps
Authors: Kobel Svenja Nicola , Wuerich Carolin , Ernst Anna Lotta , Fusshoeller Eva , Grueter Jan Niclas , Haendler Jakob , Wiede Christian , Seidl Karsten 
Published: December 2024

Abstract
Recent studies show the feasibility of using local remote photoplethysmography (rPPG) for non-contact blood perfusion assessment by creating spatial pulsatile blood perfusion maps. While global rPPG has been widely studied for its robustness, e.g. for non-contact measurement of heart rate, local analyses pose greater challenges in terms of noise suppression and thus reliability. In this paper, the effect of temperature and illumination changes on signal-to-noise ratio (SNR) perfusion maps is analysed. The results show the importance of consistent temperature and controlled illumination for improving SNR and ensuring reliable blood perfusion measurements using rPPG. This emphasises the need for standardised external conditions for accurate interpretation of the results and medical applicability.
In vitro biostability testing of stent cover materials
Authors: Koper Daniela , Reske Thomas , Siewert Stefan , Schmitz Klaus-Peter , Kaule Sebastian 
Published: December 2024

Abstract
Cast polyurethane films made of an aliphatic polycarbonate-based thermoplastic polyurethane (Carbothane PC) and poly(ether urethane) (Pellethane) were manufactured and their biostability under a static strain rate was investigated in vitroin comparison to unloaded samples. The PU films were stretched to an elongation of 300% and exposed to hydrogen peroxide/cobalt chloride (H2O2/CoCl2) solution for specific periods of time (up to 63 days). Unstrained PU samples were treated in the same way for comparison. The samples were observed for surface degradation via scanning electron microscopy and the bulk erosion by measuring the weight difference. The surface roughness greatly increased in strained Pellethane with scanning electron microscopy (SEM) evidence of deep cracks and holes or ragged and stretched fractures perpendicular to the direction of stress. Carbothane showed a lower degradation compared with Pellethane under mechanical constraint.
Automatic Alignment of Three-Bracket Setup for Orthodontic Measurements
Authors: Leinthaler Ida , Gierling Hanna , Jäger Rudolf , Lapatki Bernd , Mayer Judith , Schmidt Falko , Peuscher Heiko 
Published: December 2024

Abstract
Orthodontic tooth movement is related to application of forces and moments to individual teeth. Experimental testing of orthodontic wires helps clinicians to exert adequately dimensioned therapeutic loads. In this work, an existing experimental setup to analyze the force delivery of orthodontic wires is augmented with an algorithm that automatically finds a neutral position in which the wire transmits as little force and torque as possible; to this end, the drives of the setup are traversed to an optimal position based on measurements. The algorithm is first tested with the help of a simulation-based software-in-the-loop framework and then implemented on the real setup. Experimental results show massive time savings compared to manual alignment.
Finite element modeling of a piezoelectric actuator coupled to the cochlear round window
Authors: Liu Houguang , Kou Yinxin , Wang Jie , Lenarz Thomas , Maier Hannes 
Published: December 2024

Abstract
Round window (RW) stimulation is an application of active middle ear implants. However, its clinical outcomes show a substantial degree of variability due to the mismatch of the diameter of the actuator and the RW membrane, and the surgically challenging for placing the actuator. To address this problem, we developed a new piezoelectric actuator for RW stimulation. Firstly, we specifically designed the actuator’s mechanical structure for the RW stimulation. Then, we constructed a finite element (FE) model of the piezoelectric actuator coupled with the human ear’s RW membrane. Using this coupled FE model, we studied the influence of the actuator’s supporting stiffness and the number of piezoelectric stack layers on the stimulated stapes velocity. Finally, we fabricated the piezoelectric actuator and tested its output on human cadaver temporal bones. The results show that the developed piezoelectric actuator has the advantages of a wide operating frequency range and controlled preload on the RW membrane.
Completely defined cell culture medium for advanced alveolar models
Authors: Nellinger Svenja , Heine Simon , Steeb Lothar , Kluger Petra J. 
Published: December 2024

Abstract
In vitro alveolar models are an important tool study respiratory physiology, investigate lung diseases, develop and test new therapies, and simulate inhalation exposure to environmental pollutants or therapeutic agents. A defined cell culture medium is essential for maintaining consistent and reliable in vitro models. In this study a defined cell culture medium for advanced alveolar models based on epithelial A549 cell line and endothelial EaHy926 cell line is developed. Cellular survival was proven by quantification of LDH release. It was shown that co-culture of the cells enhances cellular survival compared to the endothelial monoculture. The formation of a homogeneous monolayer on laminin coated membranes was confirmed by actin staining. Further, the expression of cell type specific proteins (endothelial: CD31, VE-cadherin; epithelial: ZO1 and E-cadherin) was shown. Overall, we demonstrated a completely defined cell culture medium that can be used for the setup of an advanced in vitro alveolar model for biomedical application like drug development or breath gas analysis.
Development of an in vitro three-layered skin wound healing model for pre-clinical testing
Authors: Nowakowski Sophia , Schmidt Freia F. , Kluger Petra J. 
Published: December 2024

Abstract
Skin wound healing involves many cell types in a stepwise process of tissue regeneration. Reepithelialization is an essential characteristic of successful healing. In tissue engineering, mimicking the complex process of injury repair in vitro is challenging and requires the development of advanced skin models. In this study, a simple and reproducible method for wounding three-layered skin models on membranes with different pore sizes (0.4, 1, 3 μm) was established. The model allows the investigation of reepithelialization processes in a more complex environment. Hemalaun-eosin (HE) and 3-[4,5-dimethylthiazole-2-yl]-2,5- diphenyltetrazolium bromide (MTT) staining proved sufficient removal of the epidermis directly after wounding. An increasing pore size of the culture membrane delayed the reepithelialization time. Transepithelial electrical resistance (TEER) measurements provided non-invasive monitoring of reepithelialization, showing increasing values 4 days after wounding for the skin models on 0.4 and 1 μm membranes but not for those on 3 μm membranes. Cytokine quantification of interleukin (IL)-6 and IL-8 complemented the TEER results with increasing levels directly after wounding for all skin models. This skin wounding model could be used to simulate different wounding scenarios and test wound matrix materials. Furthermore, it could be adapted by adding immune cells to resemble the in vivo setup more closely.
Speech-Controlled Robot Enabling Cognitive Training and Stimulation in Dementia Prevention for Severely Disabled People
Authors: Schewior Jonas , Grefen Roman , Verde Rodolfo , Ergardt Alina , Zhao Ying , Kullmann Walter H. 
Published: December 2024

Abstract
The current German medical S3-guideline on dementia recommends the use of cognitive training and stimulation, e.g. through shared games, for mild cognitive impairment and mild dementia. The use of cobots, which allow direct human-robot collaboration, enables people with paralyzed upper limbs to actively participate in social activities. This research presents a novel approach through the development of a voice-controlled board game specifically tailored to the inclusion needs of people with severe disabilities. The human voice commands recorded via USB microphones are digitally filtered. Speech recognition of the control commands is performed using a Convolutional Neural Network (CNN) based on the VGG- 16 architecture. The robot´s activity is controlled utilizing the ROS 2 robot operating system. A portable table-based complete system with a 3D-printed Tic-Tac-Toe playing field and robot assistant for severely disabled paralyzed people has been developed. The robot control system employs a pick-and-place mechanism, seamlessly integrating with speech recognition to enhance gameplay interaction. The CNN model achieves an impressive accuracy rate of 97%, ensuring reliable speech recognition performance throughout gameplay. The targeted integration of robotic technologies and artificial intelligence opens new avenues in the prevention of mental illness, care support and inclusion of older and disabled people.
Predicting MDS-UPDRS-III score changes using mobile device biomarkers
Authors: Semkiv Khrystyna , Schreiner Simon J. , Blaser Gian E. , Baumann Christian R. , Karlen Walter 
Published: December 2024

Abstract
Digital biomarkers derived from mobile sensors could enable more frequent and objective monitoring of motor disorder symptoms. In this study, we examined the sensitivity of five tablet-based tests in predicting changes in the MDS-UPDRS-III scores following controlled Levodopa administration, utilizing regression models trained on data from 28 patients. Our experiments revealed that the best-performing single-test models exhibited an inverse prediction in 5 patients. A combined model incorporating two tests reduced misclassification to three patients. Further stratification of patients into symptom-specific groups, based on the presence of medication-induced tremor changes, and training two subgroup-specific models led to only one subject being misclassified. These results underscore the potential of mobile device biomarkers for prediction of symptom changes in Parkinson’s disease patients and the need for individualization.
Development of a model system for in vitro simulated application testing of neurovascular stent systems
Authors: Siewert Stefan , Brandt-Wunderlich Christoph , Streckenbach Felix , Paetow Hagen , Schmidt Wolfram , Stiehm Michael , Langner Sönke , Cantré Daniel , Weber Marc-André , Schmitz Klaus-Peter 
Published: December 2024

Abstract
In vitro test setups for simulated application testing are necessary for physician training as well as for development and benchmarking of various devices in interventional neuroradiology. Within the current study, we implemented a test setup for in vitro simulated application testing. Trackability in the distal catheter area, which was positioned inside a complex 3D vascular model was analyzed for two neurovascular stent systems (Neuroform EZ 4.0x20 mm and Enterprise VRD 4.5x14 mm) combined with different microcatheters (Excelsior XT-27 Flex, PX Slim Delivery Microcatheter and Prowler Select Plus Infusion Catheter). The described test setup allows for a diffentiation of neurovascular stent systems with regard to the trackability force as a major procedure related indicator for device handling. Therefore, the simulated application system presented within the current work represents an indispensable tool for safely and efficiently developing and evaluating new technologies for interventional neuroradiology prior to clinical implementation.