bluuebunny/crossref_metadata_2025 huggingface dataset:
Immersive virtual reality versus webcam in an online language
course
Authors: Herrera Borja
Published: December 2021

This paper investigates the differences between Immersive Virtual
Reality (IVR) and the webcam (WBC) in the context of a Spanish
distance-learning course. Two specific objectives were set: (1) to determine
the existence of a relationship of dependence between the device used and
the oral interaction, and (2) to analyse the existence of a dependency
relationship between the device utilised and the perception of copresence.
To that end, online courses and semi-structured interviews were conducted.
Regarding the first objective, there is a higher chance of speaking
exchanges between student-tutor and tutor-student when using WBC. As for the
second objective, we did not have sufficient feedback to determine whether
the perception of copresence varies depending on the two profiles. However,
the analysis indicates that non-verbal communication was essential for IVR
volunteers to experience copresence. The conclusions suggest that the IVR
could be more appropriate than WBC for socio-constructivist and
communicative teaching pedagogies2.
Students’ perceptions of digital storytelling in primarily asynchronous
EFL classes at a Japanese university
Authors: Kasami Naoko
Published: December 2021

This study aims to analyse the initial use of Digital Storytelling (DS)
in primarily asynchronous classes in order to yield results and
recommendations for future courses. All participants were students in
elective English courses at a Japanese university in Spring, 2020. Due to
COVID-19, the courses were redesigned and conducted remotely with the use of
pre-recorded materials. Data were collected through a post-questionnaire.
This short paper reports what was found from the data by analysing the
questionnaire with CALL evaluation criteria developed by Jamieson, Chapelle,
and Preiss (2005). From the post-questionnaire, it was revealed that the DS
assignment was perceived positively to some extent in remote learning
settings. However, it also highlighted the need for further in-depth
technical and language support and interactive learning
opportunities.
Capturing potential learning sequences in intercultural interactions
through telecollaboration
Authors: Madden Oneil , Nelson Trishana , Barnett-Passard Rona
Published: December 2021

Telecollaboration allows for students to develop foreign/second language
competences linguistically, culturally, and interculturally. The use of
platforms, such as WhatsApp and Zoom, is now more frequently exploited in
foreign language education to ensure that a wider cross section of students,
including Jamaicans, can develop global competences. This paper reports on
Phase 4 of ClerKing, a six-week Franco-Jamaican telecollaborative project,
which occurred between Applied Foreign Languages (AFL) students of English
from University Clermont Auvergne (UCA), France, and students of various
disciplines taking French courses in the Department of Modern Languages and
Literatures at the University of the West Indies (UWI), Mona, Jamaica.
Telecollaboration consisted in 45 participants of mixed ages and genders
discussing different intercultural topics in groups. Using the exploratory
approach, we seek to identify moments of Potential Learning Sequences (PLS).
Preliminary findings show that PLS could be made apparent through vocabulary
and syntax development, culture-specific knowledge, and negotiation of
meaning.
Facilitating L2 listening through automatic detection of speech and
lexical difficulties
Authors: Mirzaei Maryam Sadat , Meshgi Kourosh
Published: December 2021

This paper focuses on Partial and Synchronized Caption (PSC) as a tool
to train L2 listening and introduces new features to facilitate
speech-related difficulties. PSC is an intelligent caption that extensively
processes the audio and transcript to detect and present difficult words or
phrases for L2 learners. With the new features, learners can benefit from
repetition and slowdowns of particular audio segments that are automatically
labeled difficult. When encountering high speech rates, the system slows
down the audio to the standard rate of speech. For disfluencies in speech
(e.g. breached boundaries), the system generates the caption and repeats
that video segment. In our experiments, intermediate L2 learners of English
watched videos with different captions and functionalities, provided
feedback on new PSC features, and took a series of tests. Smart repetition
and slowdown components received positive learner feedback and led to
significant improvement in L2 listening recognition.
Face issues in second language teaching via videoconferencing: the role of the smile as a co-verbal semiotic resource
Authors: Pétillat Agnès , Foucher Anne-Laure , Wigham Ciara R.
Published: December 2021

Synchronous online language teaching involves the simultaneous employment of a range of techno-semio-pedagogical competences (Guichon, 2012). Indeed, given their flexibility and versatility, digital tools and the Internet can render teacher-student interactions dynamic. Among the necessary professional skills and strategies for online synchronous teaching, this paper focuses on the specific dimensions of affective competences and the social need to maintain a climate of comfort during one-to-one online tutoring interactions. We focus on a particular social phenomenon that is strongly linked to emotions – facework (Goffman, 1967). Applied to computer assisted language learning, we analyse how this social practice unfolds in an interactional environment where the perception of the other is mediated by a videoconferencing platform. We noted four different types of facework triggering situations: lexical breakdowns, private anecdote tellings, overlaps, and interruption of learner reflection time. Our multimodal analysis of facework reveals the frequent use of the smile as a mimicry semiotic resource and highlights the phenomenon of interactional synchrony.
Klasyfikacja słownictwa z zakresu pola WYPOSAŻENIE I WYSTRÓJ WNĘTRZ
Authors: Zagłoba Katarzyna
Published: December 2021

Artykuł przedstawia podział słownictwa z zakresu pola semantyczno-tematycznego WYPOSAŻENIE I WYSTRÓJ WNĘTRZ. We wstępie autorka odnosi się do klasyfikacji innych badaczy (Andrzeja Markowskiego, Barbary Batko-Tokarz, a także Anny Piotrowicz i Małgorzaty Witaszek-Samborskiej), a następnie prezentuje własną propozycję podziału na podpola. Poszczególne podpola zobrazowane są przykładowymi leksemami zgromadzonymi na terenie powiatu poddębickiego.
Gwarowa etykieta językowa i religia
Authors: Sikora Kazimierz
Published: December 2021

W artykule podjęto próbę przedstawienia zależności pomiędzy licznie obecnymi w gwarze modlitewnymi formułami codziennej etykiety a tradycyjną chłopską religijnością i osadzonymi w niej: modelem wiejskiej grzeczności oraz systemem wartości i norm obyczajowych. Jak dowodzą analizy wybranych formuł grzecznościowych (quasi-religijnego powitania, pożegnania, powitania przy pracy i jedzeniu posiłków), mają one początek w kulturowym mechanizmie religijnej aksjologizacji rozmaitych sfer życia, skryptów, gestów kultury, oraz w sakralizacji pracy na roli i wszystkich obszarów związanej z nią aktywności człowieka. Należą one jednocześnie do kultury „dobrego słowa”, traktującej życzenie jako realny dar, zapewniający odbiorcy, z pomocą Boga, pomyślność, zdrowie i szczęście we wszelkich okolicznościach życia prywatnego i społecznego (nie wyłączając jedzenia i spożywania alkoholu). Artykuł reprezentuje antropologiczno-kulturowy nurt badań w dialektologii.
An Ultra-Fast Digitally Reconstructed Radiograph (DRR) Implementation of the Siddon-Jacobs Algorithm using Parallel Computing: Runtime Improvement of an Intensity-Based 2D/3D Registration
Authors: Alvarez-Gomez Julio C. , Jimenez Palavicini Gerardo , Roth Hubert , Wahrburg Jürgen
Published: December 2021

A key component of an intensity-based 2D/3D registration is the digitally reconstructed radiograph (DRR) module, which creates 2D projections from pre-operative 3D data, e.g., CT and MRI scans. On average, an intensity-based 2D/3D registration requires ten iterations and the rendering of twelve DRR images per iteration. In a typical DRR implementation, the rendering time is about two seconds, and the registration runtime is four minutes. We present an implementation of the Siddon-Jacobs algorithm that uses a novel pixel-step approach to determine the pixel location of the rendering plane. In addition, we calculate the intensity of each pixel in the rendering plane using a parallel computing approach. The DRR rendering time is reduced to 10ms on average so that the registration runtime can be achieved in an average of 4.8 seconds.
Investigating dry electro-chemical polishing of titanium structures
Authors: Simeunovic Sven , Jung Christiane , Mory Dominik , Seiler Daniel , Wild Michael de
Published: December 2021

With the introduction of novel automated polishing methods, more attention has recently been paid to postprocessing methods of metallic implants. One such method is the polishing process known as DryLyte®. The most significant difference to previous electropolishing methods is the use of solid organic polymer particles activated with sulfonic acid acting as the electrolyte. The solid particle electrolyte raises new question in terms of polishing results for small features as well as overall polishing quality of metallic surfaces. The aim of this study was to determine the quality of the polishing process for titanium rods with different initial surface roughness and with tapped holes in three different orientations (0°, 45°, 90°) by subjecting them to the DryLyte® polishing process for 30 min. In addition, the influence of the process parameters voltage and the anodic time T2 during the treatment on the resulting surface quality and the polishing efficiency was determined. In conclusion, the dry electrochemical finishing process has shown great smoothing capabilities for titanium even with small, tapped holes. The Ra values were lowered significantly throughout all titanium samples after 30 min polishing time.
Development of a virtual reality simulation for exposure based addiction therapy
Authors: Rick Faust Moritz Mourice , Hanshans Christian , Bröll Lukas M. , Maisch Bettina
Published: December 2021

After the success of virtual reality (VR) applications in supporting exposure-based and psychoeducational cognitive behavioural therapy for various mental illnesses, the technology is also gaining traction in addiction medicine. This paper will describe the concept behind a custom-developed VR simulation for this application with a particular emphasis on alcohol-related addictive disorders. Using Unreal Engine 4, an exposure simulation and a scenario for learning and applying coping strategies were developed for the Oculus Quest. Because of the common association of supermarkets with the procurement of alcohol among addicts, a small shop was implemented as initial scenario. Since the feeling of presence is an important parameter in the quality assessment of a simulation, the degree of immersion was evaluated in initial practical tests after development. In surveys with ten healthy testers, the majority showed a feeling of immersion. Cybersickness and unrealistic collision physics were identified as disruptive factors to the extent of immersion. This work provides the basis for a novel concept for addiction therapy which focusses on a fusion of playful psychoeducation, adjustable exposure, and the internalization of coping strategies with the help of multisensory biofeedback as well as the documentation of the objective physiological measurements for assessment of therapy success. The aim is to best possible address the specific requirements for clinical and home use in terms of self-containment, immersion, and ease of use. To evaluate and exploit the scientific potential of this concept scientific studies and technical improvements to both simulation and hardware are required.
Forecasting the Future of Healthcare Democratization
Authors: Barbazzeni Beatrice , Fritzsche Holger , Friebe Michael
Published: December 2021

Health longevity, cost reduction, prevention-based healthcare, personalized medicine, predictive diagnostic, transformed care delivery, de-aging, healthy lifestyle trends, and implementation of intelligent technologies should lead to a more democratized (availability for everyone on this planet) healthcare provision. Forecasting the future of healthcare and health policy certainly is imperfect but nevertheless a precious scientific approach that can lead to novel innovative approaches. In the last decade, the healthcare system faced several challenges, including the significant increase of care costs, demographic changes towards the older population, inability to prevent and overcome pandemics, increased chronic and non-communicable diseases, or resistance to adopting emerging technologies. The need to shift the focus from sickness to health becomes a critical mission. We developed a lecture titled "Healthtech Innovation Design" for graduate students from medicine, biomedical engineering, neuroscience and software engineering. The lecture's goal is to teach innovation methodologies, exponential technologies and methods to achieve healthcare democratization. A critical component is to promote initiatives with global teams focused on the future of health. The educational and initiative programs were impactful in growing interest toward innovation, focusing on disruption and healthcare democratization. Participants awareness towards the main issues and challenges was raised. Interdisciplinary participation was qualitatively processed to generate a holistic vision toward innovation. Through embracing digitalization to a patient-centric approach, affordable care services, and the expansion of precision medicine, the entire healthcare organization and management will likely undergo a worldwide change. Notably, digital technologies, the leverage of artificial intelligence and empathy would satisfy unmet clinical needs. With a future-oriented statement, the forecast of healthcare becomes more imaginable, in which democratization will allow the affordability of services in different countries and economic status.
Assuring Quality of Scaffolds in Musculoskeletal Tissue Engineering
Authors: Becker Alexander , Fricke Dierk , Roth Bernhard , Glasmacher Birgit
Published: December 2021

In order to achieve the high quality required in medical products, reliable characterization methods and quality management systems are necessary. In the field of musculoskeletal Tissue Engineering (mTE), electrospinning is utilized to manufacture fibre scaffolds as implant material. Depending on the application, in this case the regeneration of tendon-bone junctions, properties like the degree of fibre orientation, homogeneity of fibre throughout the scaffold and reaction to external mechanical load are of particular importance. Currently, destructive methods, like scanning electron microscopy (SEM), are widely used to determine these properties. In addition to the destruction of the samples, these methods often only allow the investigation of very small sections. In this study, we present two new methods for the fast, non-destructive and contactless characterization of electrospun fibre scaffolds for mTE. These methods are based on Transillumination Imaging (TI) and Mueller Matrix Polarimetry (MMP), utilizing low-power laser sources or LED light sources, respectively, to determine the relative homogeneity (TI) and the degree of fibre orientation (MMP) in electrospun fibre scaffolds.
Haptic User Interface of a Cable-Driven Input Device to Control the End Effector of a Surgical Telemanipulation System
Authors: Schäfer Max B. , Al-Abboodi Bha A. , Pott Peter P.
Published: December 2021

In robotic telemanipulation for minimally-invasive surgery, lack of haptic sensation and non-congruent movement of input device and manipulator are major drawbacks. Input devices based on cable-driven parallel mechanisms have the potential to be a stiff alternative to input devices based on rigid parallel or serial kinematics by offering low inertia and a scalable workspace. In this paper, the haptic user interface of a cable-driven input device and its technical specifications are presented and assessed. The haptic user interface allows to intuitively control the gripping movement of the manipulator’s end effector by providing a two-finger precision grasp. By design, the interface allows to command input angles between 0° and 45°. Furthermore, interaction forces from the manipulator’s end effector can be displayed to the user’s twofinger grasp in a range from 0 N to 6 N with a frequency bandwidth of 17 Hz.
Concept for parallel placement of flexible needles for Irreversible Electroporation
Authors: Arif Hanbal , Liehr Uwe Bernd , Wendler Johann Jakob , Friebe Michael , Boese Axel
Published: December 2021

Irreversible Electroporation (IRE) is a non-thermal tumor ablation treatment applicable for prostate cancer. IRE uses ultra-short but strong electrical pulses to destroy cancer cells nonthermally [1]. Clinically available IRE therapy requires two or more needle electrodes placed around the target tissue to apply the electric fields. A pre-requirement to achieve successful and effective ablation is an accurate and parallel needle placement to cover the tumor zone. Differences in tissue density, organ surface curvature as well as organ and patient motion in combination with long and highly flexible needle electrodes causes’ difficulties to achieve the desired target accuracy during needle placement process. We propose a concept of a shooting mechanism in combination with a grid template support to improve the parallel needle placement process for prostate cancer treatment. Instead of conventionally inserting the needle in the body by hand, it can be placed with high speed using a shooting device setup, that works similar like a biopsy gun.
State-of-the-Art: Biodesign based Innovation Ecosystems in Europe
Authors: Fritzsche Holger , Mahbub Elaha , Boese Axel , Friebe Michael
Published: December 2021

Today's healthcare challenges with unmet clinical needs, high regulation and certification standards, and increasing costs demand faster innovation and technical translation. To address this challenge, Stanford released a fellowship called Biodesign, where need-based healthcare innovation is taught with the approach identify, invent and implement. Since then, different European institutions have adopted the Biodesign innovation approach and organized within the Biomedical Engineering- Innovation, Design, and Entrepreneurship Alliance (BMEidea EU). The generation of successful healthcare innovation isn't only based on participating in an Innovation teaching program. It is much more a matter of having the right innovation ecosystem with an open creative mindset, experts, the respective stakeholders, and access to essential resources within reach (close to clinic). Through a qualitative survey, seven Biodesign based teaching programs in the EU were examined. The study from an academic perspective contains information covering Resources, Activities, Academic Performance, and Transfer Performance. The demand for new healthcare innovations, and especially innovation training programs that address challenges, developed collaboratively with the respective stakeholders, is increasing. Additionally, there is a growing expectation that innovation needs to reach the market quickly and be implemented accordingly. A Healthcare Innovation Ecosystem, where different entities function as a productive unit with a shared vision and committed to application-driven research and technology transfer, will increase innovation's success and adaptation.
Minimum irradiance required to inhibit microbial growth to prevent ventilatorassociated pneumonia by an endotracheal tube equipped with blue LEDs
Authors: Sicks Ben , Stock Christina , Peter Sarah , Meurle Tobias , Hoenes Katharina , Spellerberg Barbara , Hessling Martin
Published: December 2021

Artificial respiration is saving lives especially in the COVID-19 pandemic, but it also carries the risk to cause ventilator-associated pneumonia (VAP). VAP is one of the most common and severe nosocomial infections, often leading to death and adding a major economic burden to the healthcare system. To prevent a proliferation of microbial pathogens that cause VAP, an endotracheal tube (ETT) equipped with blue LEDs (LED-ETT) was developed. This blue wavelength exhibits antimicrobial properties but may also harm human tracheal cells at higher irradiances. Therefore, the aim of this study was to find the minimal required irradiance for microbial reduction of 1 log level in 24 h by applying LED-ETTs. A LED-ETT with 48 blue LEDs (450 nm) was fixed in a glass tube, which served as a trachea model. The investigation was carried out with irradiations of 4.2, 6.6 and 13.4 mW/cm² at 37 °C for 24 h. The experiments were performed with Acinetobacter kookii as a surrogate of Acinetobacter baumannii, which is classified as critical by the WHO. Samples of A. kookii suspensions were taken every 4 h during irradiation from the trachea model. Bacteria concentrations were quantified by determining colony forming units (CFU)/ml. A homogeneous irradiance of only 4.2 mW/cm² generated by the blue LEDs, at a LED forward current of 3.125 mA, is sufficient to achieve a 1 log reduction of A. kookii within 24 h. The total irradiation dose within this period was 360 J/cm2. Human cells survive this dose without cellular damage. Previous studies revealed that the pathogen A. baumannii is even more sensitive to blue light than A. kookii. Therefore, blue LED-ETTs are expected to reduce A. baumannii without harming human tracheal cells.
Flow profile generation for a left ventricular assist device using iterative learning control
Authors: Borchers Patrick , Walter Marian , Leonhardt Steffen , Telyshev Dmitry , Pugovkin Alexander
Published: December 2021

Nowadays, rotary blood pumps for the treatment of end-stage heart failure patients are usually fixed-speed controlled. Therefore, without sufficient heart activity, patients may reveal reduced blood flow pulsatility. However, there is evidence that pulsatile flow reduces adverse events. Furthermore, optimized pump flow profiles could be used to achieve certain control objectives. Therefore, a pump flow model is identified and subsequently used to design a control system with an iterative learning controller to generate desired pump flow patterns. Either a flow sensor is required for direct measurement or the flow can be estimated from pressure sensor readings using the proposed pump flow model. For comparison, a PID controller with disturbance feedforward control is also designed. Furthermore, the robustness against respiratory sinus arrhythmia is analyzed.
Customised micro-electrode array (MEA) test setup featuring a silicone-casted overlay with two chambers for separated cell seedings
Authors: Mau Robert , Kussauer Sophie , Matzmohr Uta , David Robert , Seitz Hermann
Published: December 2021

Micro-electrode array (MEA) systems are noninvasive platforms for the investigation of electrophysiological properties of cell layers, such as spontaneously active cardiomyocytes. An MEA chip is composed of two-dimensional grids of dot-like electrodes embedded into glass. Here we present a test setup featuring a customised two-chamber silicone overlay. The overlay is designed to be placed on an MEA with two separate electrode fields and enables the seeding of two distinct cell sub-types on the MEA for synchronised drug testing applications while giving the possibility of analysing intersubtype-specific cellular interactions. The overlay has a full size of 10 x 10 x 5 mm (width x length x height), each chamber has a size of 2.5 x 6 x 5 mm (V = 75 mm³). The chambers are separated by a wall with a thickness of 0.3 mm. The overlay was manufactured via silicone-casting, utilising a 3D printed model. The model is 3D printed via high accurate digital light processing (DLP). In addition, a DLP 3D printed cover optimises the attachment of the overlay on an MEA. A proofof- principle of the utilisation of the overlay is demonstrated.
Characterization of loading profiles via handrails and harness during body weight supported treadmill training
Authors: Schmidt Katharina , Hochmann David
Published: December 2021

Body weight supported treadmill training is used for patients who are severely limited in their movements. During walking therapy handrails and harnesses ensure the patient’s stability and safety. Although, locomotion training is a common rehabilitation technique, data of forces applied to handrails or overhead lifts are limited. Therefore, the primary objective of this study was to measure the vertical reaction force during treadmill therapy. An additional purpose was the characterization of the loading profiles by defining suitable parameters. To measure the patient’s needs for support during treadmill training, the handrails were instrumented with strain gauges and a force sensor was placed between the harness and the ceiling lift. In order to provide gait phase detection, an inertial sensor was attached to each foot. The results confirm that the combined measuring systems are appropriate to record the total vertical weight relief. Although all patients show different loading profiles, a recurring pattern can be recognized for each patient, which allows the derivation of various parameters to characterize the single profiles. The additional information of the measurements can help the supervising physiotherapist to better understand the specific level of support the patient needs. A subsequent response and the providing of corresponding instructions by the therapist can lead to an even more individualized therapy.
Finite Element Modelling of a Hearing Contact Lens Coupled to the Middle Ear
Authors: Burovikhin Dmitrii , Lauxmann Michael , Dalhoff Ernst
Published: December 2021

Hearing contact lens (HCL) is a new type of hearing aid devices. One of its main components is a piezoelectric actuator (PEA). In order to evaluate and maximize the HCL’s performance, a model of the HCL coupled to the middle ear was developed using finite element (FE) approach. To validate the model, vibrational measurements on the HCL and temporal bones were performed using a Laser-Doppler-Vibrometer (LDV). The model was validated step by step starting with HCL only. Then a silicone cap was fitted onto the HCL to provide an interface between the HCL and the tympanic membrane. The HCL was placed on the tympanic membrane and additional measurements were performed to validate the coupled model. The model was used to evaluate the sensitivity of geometrical and material parameters with respect to performance measures of the HCL. Moreover, deeper insight was gained into the feedback behavior, which causes whistling sounds, and the contact between the HCL and tympanic membrane.
Influence of surface material and reprocessing on the durability of antimicrobial surfaces
Authors: Buhl Sebastian , Stich Alexander , Vogt Jeannine , Brückner Ralph , Bulitta Clemens
Published: December 2021

The risk of infection from contaminated surfaces has already been shown in several publications. Due to the increased demand for optimized infection control measures during the Corona pandemic, antimicrobial surface technologies have gained more an interest. Apart from many proofs of efficacy, there are only a few studies dealing with the durability of these surface coatings with regard to the material and the reprocessing measures. This work did therefore examine the impact of different materials and surface textures, as well as different detergents and disinfectants, on the durability of antimicrobial surface technologies. Differently structured materials (glass, wood, plastics, metal) and wallpaper bonded to plasterboard were coated with an TiO2Ag based antimicrobial coating (HECOSOL GmbH, Bamberg). These test samples are then used to perform abrasion tests with various cleaning and disinfecting agents and cloth systems (microfiber cloth, cotton cloth, foam cloth). The majority of the test samples in our experimental setup showed at least significant activity. According to our results, both the selection of cleaning and disinfection methods including wiping systems and the surface material have a major impact on the durability of antimicrobial coatings. In order to be able to come to conclusions about the long-term activity of these surface technologies, the effectiveness should be tested not only during the development phase, but also in the finished product and again after several reprocessing cycles in use.
Technical light-field setup for 3D imaging of the human nerve head validated with an eye model
Authors: Schramm Stefan , Dietzel Alexander , Blum Maren-Christina , Link Dietmar , Klee Sascha
Published: December 2021

With the new technology of 3D light field (LF) imaging, fundus photography can be expanded to provide depth information. This increases the diagnostic possibilities and additionally improves image quality by digitally refocusing. To provide depth information in the human optic nerve head such as in glaucoma diagnostics, a mydriatic fundus camera was upgraded with an LF imager. The aim of the study presented here was the validation of the technical setup and resulting depth estimations with an appropriate eye model. The technical setup consisted of a mydriatic fundus camera (FF450, Carl Zeiss Meditec AG, Jena, Germany) and an LF imager (R12, Raytrix GmbH, Kiel, Germany). The field of view was set to 30°. The eye model (24.65 mm total length) consisted of a two-lens optical system and interchangeable fundus models with papilla excavations from 0.2 to 1 mm in steps of 0.2 mm. They were coated with red acrylic lacquer and vessels were drawn with a thin brush. 15 images were taken for each papilla depth illuminated with green light (wavelength 520 nm ± 20 nm). Papilla depth was measured from the papilla ground to the surrounding flat region. All 15 measurements for each papilla depth were averaged and compared to the printed depth. It was possible to perform 3D fundus imaging in an eye model by means of a novel LF-based optical setup. All LF images could be digitally refocused subsequently. Depth estimation in the eye model was successfully performed over a 30° field of view. The measured virtual depth and the printed model papilla depth is linear correlated. The presented LF setup allowed high-quality 3D one-shot imaging and depth estimation of the optic nerve head in an eye model.
The Online “Expert-Panel” – Review of a Novel Web-seminar Format
Authors: Mattis Patricia , Habenstein Birgit , Wittenberg Thomas
Published: December 2021

Since 2021, the Fraunhofer Institutes ITEM and IIS and the German Society for Biomedical Engineering (VDE DGBMT) have launched a new online seminary. This sustainable format, referred to as "Expert Panel", stimulates scientific interaction by introducing research topics and innovations within sixty minutes. The panel with three experts from different fields presents and discusses perspectives from science, clinical practice, and the industry. The first season of the "Expert Panel" offered comprehensive insights on the latest developments and innovations within "New Interventional Methods for Tomorrow's Hearing". Each topic was presented by a triad of experts from science, clinical practice, as well as the industry. The sessions comprised life-demonstration of planning tools for surgical interventions, the presentation of patient-individual intervention techniques and novel audiological systems for Cochlea Implant (CI) fitting and many more inspiring technologies. Each “Expert Panel” concluded with a moderated Q&A final. The sessions provided condensed updates and unique insights from applied research and had a lively attendance of up to more than 120 participants from the fields of research, clinic, and industry. This kind of format does not only drive interpersonal and interdisciplinary knowledge transfer - especially in times of home office - it also enables establishing a community of network partners, who meet at the “Expert Panel” on a regular basis. In addition, education credits have been offered to the medical community, thus creating additional benefit for the participants.
Towards computer aided diagnosis of infective endocarditis in whole-slide images of heart valve tissue using FISH
Authors: Bruns Volker , Franz Daniela , Kuritcyn Petr , Wiesmann Veit , Rathke Magnus , Wittenberg Thomas , Wießner Alexandra , Kursawe Laura , Moter Annette , Kikhney Judith , Münzenmayer Christian
Published: December 2021

Infective endocarditis (IE) is an infection of the endocardium, and the heart valves associated with high morbidity and mortality. Fluorescence in situ Hybridization (FISH) is a molecular imaging technique used for diagnosis of IE based on histological heart valve tissue sections. FISH allows detection and identification of microorganisms and gives information about their quantity and spatial distribution. This information is important to guide appropriate antibiotic treatment. However, as manual FISH image analysis is time- and costexpensive, an automated image analysis pipeline (consisting of tissue segmentation, bacteria detection, and spot detection modules) is proposed to assist locating potential regions with microorganisms. The proposed approach was evaluated in a study, where five observers manually assessed a set of 171 fields-of-view (FoVs) captured in 400-fold magnification from 10 randomly chosen WSI for the presence of microorganisms, morphologically detected by the nucleic acid stain DAPI. The task of the observers was to mark the presented image using a 2-class score (‘positive/questionable’ or ‘negative’). The human assessment was compared to the results suggested by the algorithm. The proposed algorithm locates and ranks potential regions with microorganisms in heart valve sections so that experts can validate them in higher power FoVs for the presence of bacteria and identify their species. The automated system for preselecting and recommending adequate FoVs is thus a starting point to support experts and save human resources. It is now ready to be further developed for the detection of bacteria by FISH.
Changes of Physiological parameters of the patient during laparoscopic gynaecology
Authors: Jalal Nour Aldeen , Alshirbaji Tamer Abdulbaki , Docherty Paul D. , Neumuth Thomas , Laufer Bernhard , Moeller Knut
Published: December 2021

Analysing and fusing data from the medical devices of different disciplines (anaesthesiology and surgery) inside the operating rooms may promote awareness during surgical procedures. In this work, the changes of physiological parameters of patients undergoing laparoscopic gynaecology procedures were analysed. The statistical relationship between the intra-abdominal pressure and airway peak pressure was evaluated. Patients ventilated with pressure-controlled ventilation (PCV) and intermittent mandatory ventilation (IMV) were included. The results demonstrated that increasing the intra-abdominal pressure (IAP) resulted in increasing the airway peak pressure and decreasing the lung compliance. The Pearson correlation coefficient between the IAP and the airway peak pressure was 0.910 in PCV-patients and 0.952 in IMV-patients when changes of the ventilation settings were considered. Additionally, major hemodynamic changes included alterations in the mean blood pressure (MBP), where the MBP increased after insufflating the abdomen and decreased after abdomen deflation.
Development and Implementation of an OpenSource IoT Platform, Network and Data Warehouse for Privacy-Compliant Applications in Research and Industry
Authors: Stadler Sebastian , Borrero Eduardo Romero , Zauner Johannes , Hanshans Christian
Published: December 2021

In the scientific field, data acquisition using commercial or self-developed sensors is a necessity for many research activities. Data security and data privacy are important requirements in all types of IoT applications, especially in the medical context. IoTree42 is a powerful, OpenSource platform that closes the gap between cost-efficiency, the ease of use and digital sovereignty. The flexible and user-friendly design makes the platform ideal for the originally conceived research context. Nevertheless, it can be used for smaller budget-oriented setups and industrial applications with thousands of sensors and actuators likewise. The platform was developed with security in mind by minimizing interfaces and the use of stable software components and transport protocols. IoTree42 utilizes lightweight OpenSource software cast into a flexible backend, allowing the deployment not only on full-fledged servers but also on single board computers like the Raspberry Pi. Data is transmitted with low overhead via MQTT, a robust protocol optimized for machine to machine communication. The transmission technology between all components is freely selectable. Besides data acquisition, IoTree42 enables control of actuators and automation through interfaces with visual programming tools. This allows for remote interventions without requiring prior programming experience. The incoming data can conveniently be visualized in dashboards or easily be exported for further analysis. The network consists of a central server and satellites (gateways) arranged in a star topology. Sensors and actuators connect to the gateway. The initial setup of the server and the gateways is automated, well documented, and can be done within minutes. Thanks to the increasing usage and the contribution of the community, the pool of code examples for sensors is growing and lowers the entry hurdle for users without programming background. IoTree42 is a fast-growing, multi-user, hardware and cloud agnostic, easy to deploy, privacy compliant and competitive solution compared to commercial IoT alternatives.
Comparison of Characteristics of Poly(Nisopropylacrylamide) in Bulk Hydrogel and Ball-milled Microgel Forms
Authors: Huling Jennifer , Illner Sabine , Grabow Niels , Teske Michael
Published: December 2021

Poly(N-isopropylacrylamide) hydrogels are a popular temperature sensitive biomaterial. Bulk hydrogels can be quickly and easily processed into microgels using a ball mill. However, there is no information on whether the mechanical milling process affects critical PNIPAM characteristics. In this work, we compare swelling and thermo-responsive properties for a series of PNIPAM gels in bulk and microgel forms.
Generalised Image Processing Method for Quantitative Analysis of Nucleus, Cell and Focal Adhesion Clusters
Authors: Nair Rajasree Padmakumari Hemachandran , Menon Rohit , Kemkemer Ralf
Published: December 2021

Focal adhesion clusters (FAC) are dynamic and complex structures that help cells to sense physicochemical properties of their environment. Research in biomaterials, cell adhesion or cell migration often involves the visualization of FAC by fluorescence staining and microscopy, which necessitates quantitative analysis of FAC and other cell features in microscopy images using image processing. Fluorescence microscopy images of human umbilical vein endothelial cells (HUVEC) obtained at 63x magnification were quantitatively analysed using ImageJ software. A generalised algorithm for selective segmentation and morphological analysis of FAC, nucleus and cell morphology is implemented. Further, a method for discrimination of FAC near the nucleus and around the periphery is implemented using masks. Our algorithm is able to effectively quantify different morphological characteristics of cell components and shows a high sensitivity and specificity while providing a modular software implementation.
Comparison of temperature mapping methods for experimental validation of numerical heat transfer analysis of biomaterials and medical devices
Authors: Pfensig Sylvia , Tautorat Carsten , Grossmann Swen , Grabow Niels , Schmitz Klaus-Peter , Siewert Stefan
Published: December 2021

Titanium represents an important biomaterial for implantable medical devices. During medical device manufacturing by means of welding, implant structures are partially exposed to high temperatures. Additionally, active implants such as pacemakers can heat up during operation. Therefore, numerical studies of heat propagation within titanium structures represent an essential tool to assess functionality and safety of medical devices. The current study focusses on the development of a method for experimental validation of numerical heat transfer analysis of biomaterials such as titanium. Numerical heat transfer analysis was performed using the software Abaqus. A finite-element model was established including material properties such as density, thermal conductivity und specific heat capacity. Temperature distribution among a locally applied thermal load was calculated. Furthermore, effects such as convection were considered. For validation, an experimental setup was implemented according to the numerical calculation using a local heating tool. Heat propagation in the sample was determined, respectively. Radiation-based heat determination was performed using an infrared thermographic camera aligned parallel to the sample surface. Contact-based heat determination was performed using thermocouples fixed to the surface at defined distances from the point of local heat input. For evaluation of numerical and experimental results, temperature- time curves were compared for five distinct measuring points, respectively. While infrared thermography offers the advantage of non-contact measurements, difficulties may arise from the definition of correct emissivity and challenging sample surface characteristics, such as metallic reflectance and surface texture. The thermocouple-based temperature measurement shows a high sensitivity to local temperature changes, but it is not always suitable due to the influence on the sample by thermocouple fixation. Infrared thermography and thermocouple based temperature measurements represent suitable procedures for experimental validation of numerical heat transfer analysis of titanium. An individual decision for the most suitable method must be made considering the specific sample and its further application.
Automation of online particle measurement during the simulated use of catheters and stent systems
Authors: Wiese Inga , Kurzhals Anja , Rhinow Grit , Tautorat Carsten , Kamke Frank , Brandt-Wunderlich Christoph , Schmitz Klaus-Peter , Grabow Niels , Schmidt Wolfram
Published: December 2021

The assessment of the coating integrity of cardiovascular implants such as catheters and stent systems is of crucial importance for device approval. Released particles may represent a potential health risk for the patients. Thus, an analysis of the particles released at simulated in-vivo conditions depending on their size and number is required by international standards (ISO, ASTM) as well as national authorities. In this study, an automated test bench for online particle measurement is presented. For software controlled automation, sensor data transmission and solenoid valves were implemented. A user interface was created for setting test parameters and data recording. The setup was validated by investigating standard particles as well as those released during the simulated application of non-industrial coated balloons. The measurement data were compared with results generated using the previous manual test routine. The results show an improvement in the reproducibility of the measurements, which can be attributed to the simplified handling for the user.
Differentiation of Mild Cognitive Impairment Conditions in MR Images using Fractional order Jacobi Fourier Moment Features
Authors: Dadsena Ravi , Sadhukhan Deboleena , Swaminathan Ramakrishnan
Published: December 2021

Mild Cognitive Impairment (MCI) is the asymptomatic, preclinical transitional stage among aging and Alzheimer’s Disease (AD). Detection of MCI can ensure the timely intervention required to manage the disease’s severity. Morphological alterations of Lateral Ventricle (LV) is considered as a significant biomarker for disease diagnosis. This research aims to analyze the shape alterations of the LV region using Fractional Order Jacobi Fourier Moment (FOJFM) features, which are categorized by their generic nature and capabilities to perform time-frequency analysis. T1-weighted transaxial view brain MR images (HC = 92 and MCI = 63) are obtained from publicly available Open Access Series of Imaging Studies (OASIS) database. The LV region is delineated using Weighted Level Set (WLS) segmentation method and results are compared to Ground Truth (GT) images. FOJFM features are employed to characterize the morphometry of LV region. From this segmented region, 200 features are computed by varying the value of order and fractional parameters. Random Forest (RF) and Support Vector Machine (SVM) classifiers are used to differentiate Healthy Control (HC) and MCI subjects. Results show that WLSE is able to delineate the LV structure. The segmented region shows good correlation with the GT area. FOJFM features are observed to be statistically significant in discriminating HC and MCI subjects with p<0.05. For MCI subjects, the feature values show higher variation as compared with HC brain, which might be due to the surface expansion of ventricular area during disease progression. SVM and RF classifiers show high performance F-measure values of 93.14% and 86.24%, respectively, for differentiating MCI conditions. The proposed moment based FOJFM features are able to capture the morphological changes of LV region related to MCI condition. Hence the proposed pipeline of work can be useful for the automated and early diagnosis of diseased conditions
Development and validation of a test facility for pivotal characterization of glaucoma drainage devices
Authors: Siewert Stefan , Guthoff Rudolf , Kamke Frank , Grossmann Swen , Stiehm Michael , Schmidt Wolfram , Stahnke Thomas , Grabow Niels , Schmitz Klaus-Peter
Published: December 2021

Implant devices for micro invasive glaucoma surgery (MIGS) are gaining increasing acceptance in clinical ophthalmic use. The implant requirements are defined in international standards, such as ANSI Z80.27-2014 and the 2015 Guidance for Industry and Food and Drug Administration Staff “Premarket Studies of Implantable Minimally Invasive Glaucoma Surgical (MIGS) Devices”. The exact fluid-mechanical characterization represents a crucial part of the development and approval of innovative implant devices for MIGS. The current work describes the development and preliminary validation of a versatile test facility for pivotal characterization of glaucoma drainage devices. The test setup enables a pressurization of test specimens by means of two water columns. For measurement of pressure and volume flow, a pressure transducer and a total of three liquid flow meters were implemented into the test setup. Validation was conducted by experimental pressureflow characterization of standardized tubes and a comparison to theoretical results according to Hagen Poiseuille's law for stationary laminar flow of a Newtonian fluid in a tube with a circular cross section. Ultrapure water at (35 ± 2) °C was used for the analyses. The developed test setup potentially enables pressure-flow characterization of test specimens in a wide flow range of 0 μl min-1 ≤ Q ≤ 5.000 μl min-1. The preliminary test facility validation showed a good agreement of measured and theoretical volume flow characteristics as a function of the pressure difference, in the currently investigated flow range of Q < 80 μl min-1. The developed test facility is suitable for pivotal in vitro characterization of glaucoma drainage devices. Future investigations will focus on the final validation of the whole flow range and on the use of the test facility for fluid-mechanical characterization of self-developed prototypes of glaucoma microstents as well as commercially available glaucoma drainage devices.