bluuebunny/crossref_metadata_2025 huggingface dataset:
Double-Blind Multicenter Randomized Clinical Trial Comparing Glucagon vs Placebo in the Resolution of Alimentary Esophageal Impaction
Authors: de Benito Sanz Marina , Tejedor-Tejada Javier , Mangas-Sanjuan Carolina , Santa Eva de la , Cebrian Irene , Talegón Raquel , Sánchez-Ocaña Ramón , Pérez-Pariente José M. , Pérez-Miranda Manuel , García-Alonso Francisco Javier ,   on behalf of the GLUCAGON study group
Published: September 2023

INTRODUCTION:

The aim of this study was to compare the effectiveness of glucagon vs placebo in resolving esophageal foreign body impaction (EFBI), as well as the length of the procedure and adverse events.

METHODS:

This was a multicenter, randomized, double-blind trial involving consecutive patients diagnosed with alimentary EFBI. Participants were randomized to receive either 1 mg of intravenous glucagon or placebo. All patients underwent upper endoscopy, and adverse events were assessed through a protocolized telephonic interview 7 days later.

RESULTS:

The study included 72 subjects in the glucagon group and 68 in the placebo group. The foreign body was not identified in 23.6% of subjects in the glucagon group and 20.6% of subjects in the placebo group (difference 3%, 95% confidence interval −10.7% to 16.8%, P = 0.67). The median time required to remove the foreign body was similar in both groups 4 minutes (range 2–10) in the glucagon group and 3.5 minutes (range 2–7) in the placebo group (difference 0.5 minutes, 95% confidence interval −1.3 to 2.3; P = 0.59). The most common adverse event reported in both groups was mild pharyngeal pain.

DISCUSSION:

Glucagon is no more effective than placebo in resolving EFBI or shortening the time required to remove the foreign body (EUDRA-CT number 2019-004920-40).
Interseccionalidad
Authors: Di Renzo Gabriela María
Published: September 2023

La interseccionalidad es actualmente un campo importante de estudio y se ha convertido en una de las contribuciones más importantes del feminismo. El concepto fue formalizado por Kimberlé Crenshaw como cruce de caminos para significar las diversas formas en las que la raza y el género interactúan para dar forma a las múltiples dimensiones de la experiencia laboral de las mujeres negras. La categoría cobra relevancia en el ámbito jurídico, pero pronto se expande a otras ciencias, especialmente en el ámbito de las disciplinas sociales y en un contexto de habla inglesa. Como enfoque orientado a la justicia, la interseccionalidad realiza importantes aportes a la ética teológica, entre otros: promover un razonamiento moral que asuma un sujeto constituido por múltiples ejes de desigualdades, concientizar acerca de la necesidad de analizar las propias posiciones de poder o de privilegio y considerar las voces y las experiencias de los que están activamente involucrados.
Icono y sentido
Authors: García Sánchez Rafael
Published: September 2023

En el presente artículo trataremos de definir el icono en contraste con la obra de arte en el sentido más moderno del término. A lo largo del texto daremos cuenta de la densidad teológica y de la originalidad que el icono posee, de su peculiar penetración en el sentido de lo real, así como de la relación ontológica que mantiene con el modelo que epifánicamente representa. Al mismo tiempo pretendemos aglutinar las constantes metodológicas y formales que el iconógrafo muestra en su hacer, muchas de las cuales, aunque parcialmente conocidas y analizadas, se hallan dispersas en la bibliografía más especializada.
Biohacking Social: una estrategia pedagógica para el fortalecimiento de la educación y el fomento de la alfabetización científica en Medellín, Colombia
Authors: Cardona-Echeverry Andrés , Posada-Ferez Alejandra , Zapata-Martínez Juan-Felipe
Published: September 2023

Es innegable el impacto que la educación de calidad y el acceso a la información tienen en el desarrollo sostenible de las sociedades. Una estrategia enfocada a mejorar la calidad de la educación y la democratización de la ciencia es lo que podría denominarse biohacking social. En este trabajo se propone un modelo de escuelas de creación que integra actores sociales con nuevas tecnologías para solucionar problemas como el que se considera en este trabajo: las falencias en la infraestructura de los laboratorios de primaria y secundaria en países como Colombia. Las iniciativas de software libre y ‘hazlo tú mismo’ proveen alternativas sostenibles y replicables para abordar problemas como la falta de equipos de laboratorio, en aras de garantizar un ambiente educativo de calidad. Adicionalmente, se relaciona la experiencia obtenida interviniendo  comunidades de la ciudad de Medellín a través espacios de divulgación y alfabetización científica como mecanismos de democratización de la ciencia. Las intervenciones a diferentes comunidades demuestran la importancia que tiene acercar la ciencia a la cotidianidad, así como su relevancia para promover la apropiación social del conocimiento.
Effect of Convalescent Plasma Therapy on Mortality and Viral Load in Severely Ill Patients with COVID-19
Authors: Moravec Jan , Müller Martin , Turek Petr , Moravec Michal , Nejtek Tomáš , Zazula Roman
Published: September 2023

The use of convalescent plasma (CP) appeared to be a promising, easily available and safe way of treatment of severe COVID-19 at the onset of the pandemic in early 2020. Conducted in 2020 and 2021, our study of 52 severely to critically ill COVID-19 patients who received CP plasma as a treatment and of 97 controls found no difference in 30-day or 90-day mortality rates. A significant viral load drop in most patients (4.7 log10 [p<0.001] copies/ml) was observed following CP administration. Retrospective analysis of selected inflammatory markers and immunoglobulins showed higher C-reactive protein levels among the study group, and their decrease on Day 7.
The Role of Demographic and Clinical Characteristics in Distinguishing Testicular Torsion from Torsion of the Appendix Testis: A Single-center Retrospective Study
Authors: Zvizdic Zlatan , Aganovic Amila , Milisic Emir , Jonuzi Asmir , Zvizdic Denisa , Vranic Semir
Published: September 2023

The acute scrotum (AS) in the pediatric population is a medical emergency. AS is usually caused by testicular torsion (TT) and torsion of the appendix testis (TAT). The current study explored which demographic and clinical characteristics can help distinguish between TT and TAT. We analyzed all children ≤16 years who underwent surgical exploration for AS. The patients were divided into Group 1/TT and Group 2/TAT. Ninety patients were included in the study (24 with TT and 66 with TAT). The peak incidence of TT was significantly higher than in the TAT group (p<0.001). Scrotal pain was more prevalent in the TAT group (p=0.02), whereas systemic signs (nausea/vomiting and abdominal pain) affected more frequently the TT patients (p=0.003 and p<0.001, respectively). The duration of symptoms was significantly longer in the TAT group (p<0.001). The duration of symptoms in the TT cohort significantly impacted the testicular salvage (p=0.008). Color Doppler ultrasound (CDUS) findings of absent/decreased testicular blood flow in the affected testis strongly favored the diagnosis of TT (p<0.001). The older age, shorter duration of symptoms, systemic signs, and CDUS findings can help distinguish between the two most common acute scrotum causes.
Successful Treatment of Detachment of the Incision after Al-Ghorab Procedure: A Case Report and Review of Literature
Authors: Ergül Rifat Burak , Ramazanoğlu Mehmet Akif , Sambel Murat , Akşit Sinan , Dursun Murat , Kadıoğlu Ateş
Published: September 2023

Al-Ghorab procedure is known as open distal shunt for the treatment of ischemic priapism. In the literature, no information in terms of complications is available in three of fourteen studies. In the remaining eleven studies, complications occurred in five studies only. Here we present a case report describing successful treatment of detachment of the incision after Al-Ghorab procedure.
Twórcy polskiej historii oświaty i wychowania w latach 1945–2021. Kraków 30.03.2022 – 31.03.2022 r. – sprawozdanie z konferencji
Authors: Łapot Mirosław
Published: September 2023

Twórcy polskiej historii oświaty i wychowania w latach 1945–2021. Kraków 30.03.2022 – 31.03.2022 r. – sprawozdanie z konferencji
Myśl pedagogiczna Aleksandra Grozy. Wokół cyklu Elementarzy
Authors: Gruntkowska Dominika
Published: September 2023

Aleksander Groza was the author of a series of three alphabet books: The greater alphabet book, The lesser alphabet book and The little alphabet book. This series was created in the Ukraine in 1860. Aleksander Groza was, first of all, a writer and poet, a representative of the so-called “Ukrainian school” in Polish literature, a nobleman and a representative of the middle-class gentry. The aim of the article is to characterize the alphabet books both in terms of structure and content. I will be interested in the values that Aleksander Groza intended to foster in his students, as well as how his ideas presented themselves against the epoch.
Kollokationen in schriftlichen Textproduktionen. Eine empirische Untersuchung bei ungarischen DaF–Lernern
Authors: Pintye-Lukács Erzsébet
Published: September 2023

The goal of this paper is to test productive collocational competence of German as a foreign language students at the University of Debrecen. The test aims to analyze compensational strategies that are used by students in their texts. In the first part of this paper we take a look at the terms collocation and collocational competence and the second part aims to show the results of the written test.
Zwischen Bildungsmisere und Bildungsreform(en): Reflexionen angehender Fremdsprachenlehrkräfte über moderne Bildungssysteme und Zukunftsperspektiven des institutionellen Fremdsprachenlernens
Authors: Durbaba Olivera
Published: September 2023

This paper presents a small-scale empirical study which included 21 senior-year students of German as a major who took a course on the methodology of teaching German as a foreign language in the spring semesters 2020 and 2021, at the Faculty of Philology at the University of Belgrade (Serbia). The students were encouraged to read several articles by the Austrian educational philosopher Konrad Paul Liessmann and to record their reflections on the possible effects of the commercialization of purpose-oriented knowledge. The articles in question are based on Liessmann’s so-called “Theory of Uneducation”. The students’ tasks were analyzed and discussed, with the focus on their statements regarding the following aspects: a) possible challenges, opportunities and dangers of unavoidable digitization and mechanization in everyday life and at school, and b) the changing roles and tasks in the educational context. All this more or less aims at application-oriented knowledge management. The participants supported Liessmann’s thesis that education is losing value through commercial exploitation, accumulation of TV quiz knowledge and extensive testing and examining. However, his skepticism with regard to digitization in the school system and his plea for more traditional canons of school subjects were mostly met with disapproval by the participants.
Nauczyciele języków obcych: Iluzje – fakty – badania
Authors: Komorowska Hanna
Published: September 2023

The article aims to analyze meanings underlying the popular concepts of a good teacher, efficient teacher, novice, expert and experienced non-expert from a diachronic perspective. Criteria used across developmental stages of second language acquisition/ foreign language teaching in the process of teacher accreditation are examined, as well as social contexts influencing teacher evaluation. Reasons for teachers’ dissatisfaction with European school systems are presented, as well as coping strategies employed by frustrated teachers. New challenges springing from economic, social and cultural student diversity are also discussed. Implications are sought for pre- and in-service teacher education.
Rola szkolnego opiekuna praktyk w świetle analizy rozmów pohospitacyjnych z przyszłymi nauczycielami języka francuskiego
Authors: Szymankiewicz Krystyna
Published: September 2023

The practicum is an important part of the training of prospective foreign language teachers. The reflections proposed in this article deal with the assumptions of mentoring when confronted with its practical implementation, with a particular focus on learning through mentoring dialogues. The text provides an overview of the main models of mentoring in order to show the complexity of the tasks faced by the mentor teacher. Characteristics of the mentoring dialogue are also presented. This theoretical base is referred to in the study, which consisted of a qualitative analysis of mentoring dialogues and comments made afterwards by prospective teachers of French as a foreign language. The aim of the study was to identify the supervisory style, dialogue activity and mentoring roles performed by the mentor teachers. The analysis was also intended to show what kind of mentoring behavior is expected by the pre-service students. The findings show that the majority of mentor teachers dominate the conversation and prefer a directive supervisory style, which seems to meet the trainees’ expectations and needs. The pre-service students emphasize the importance of mentoring dialogues as a learning opportunity, and appreciate constructive criticism, positive reinforcement and concrete guidance on how to teach. The implication of the findings is discussed at the end.
Pandemia, globalne Południe i przyszłość polityki emancypacyjnej
Authors: Barszczewski Jakub
Published: September 2023

Celem artykułu jest krytyczna analiza konsekwencji pandemii COVID-19 na globalnym Południu oraz debaty, jaka wyłoniła się wśród peryferyjnych intelektualistów (lub piszących z perspektywy podporządkowanych) wokół (ekonomicznej i dyskursywnej) marginalizacji społeczeństw niezachodnich. Przedmiotem analizy są teksty opublikowane od momentu rozpoczęcia pandemi w 2020 roku, które skonfrontowane zostały z teoretyczną refleksją, jaka wyłoniła się w ostatnich kilkunastu latach. Artykuł przedstawia oddziaływanie strukturalnych uwarunkowań peryferii na przebieg pandemii oraz problemy specyficzne tych społeczności. Debata na temat pandemii wskazuje na rosnące upodmiotowienie wiedzy tworzonej na globalnym Południu i potrzebę dialogu między zachodnią myślą krytyczną i peryferyjną pod kątem bardziej nowatorskich ontologii życia społecznego.
Cyber / techno / nauka. Narracje na temat stechnicyzowanej kultury w kontekście przedostatniej edycji festiwalu Permutacje
Authors: Bromboszcz Roman
Published: September 2023

Tekst kontekstualizuje realizacje artystyczne zaprezentowane w trakcie przedostatniej edycji Festiwalu Permutacje, który odbył się w Galerii CKiS “Wieża Ciśnień” w czerwcu 2021 w Polsce. Użytymi narzędziami w analizie są narracje naukowe takie, jak artykuły i monografie na temat cyberkultury, technokultury i STS’u. Artykuł stawia pytania o to, czy są one przydatne w interpretacji dzieł zebranych na wystawie, jakie miejsce pozostawiają dla fantastyki naukowej, co je różni, a w czym są wspólne w kontekście stechnicyzowanej kultury współczesnej.
Dynamic fluctuations in foreign language enjoyment during cognitively simple and complex interactive speaking tasks
Authors: Chen Tzu-Hua
Published: September 2023

Despite evidence on the interaction between cognitive individual differences (IDs) and task complexity, our knowledge of how affective IDs, such as foreign language enjoyment (FLE), interact with task complexity and other factors is limited. Since tasks and activities were found by Dewaele and MacIntyre (2014) to be most relevant to FLE, and since task complexity might interact with learners’ perceptions of task difficulty, it is important to investigate how task complexity impacts FLE changes. Informed by the complex dynamic systems theory, this study employed a mixed-methods multiple case study design to study patterns and causes of high and low FLE arousals. The participants were four pairs of Taiwanese high-intermediate EFL university students who were engaged in simple or complex storytelling tasks with speech acts of refusals. The speakers’ interactions were triangulated with an individual learner’s rating of FLE on a per-second scale and stimulated recalls. Results revealed idiosyncratic patterns of FLE fluctuations of peer interlocutors and a high degree of overlap in sources of low and high FLE in both groups. Speakers reported high FLE as a result of interesting storylines inherent in task design and created by peers, the use of picture prompts, peer collaboration, and task performance. Performance problems, failure to retrieve appropriate vocabulary, task design, and lack of ideas led to low FLE arousals. The findings suggest that task complexity combined with other task-induced, social, and individual factors to affect the fluctuations of FLE. Implications for task design and oral communication instruction to promote FLE are discussed.
Individual differences in computer-assisted language learning research
Authors: Li Banban
Published: September 2023

In the era of rapid technological expansion, the integration of various technologies into the process of second and foreign language (L2) learning and teaching has become pervasive, making computer-assisted language learning (CALL) a well-established field (Golonka et al., 2014). There is now a consensus that individual differences (IDs) significantly influence the process and product of L2 learning (Pawlak, 2020). With a plethora of technology-based options and functionalities, CALL provides learners with a high degree of autonomy (Pawlak et al., 2016), making it an environment that is ripe for capitalizing on learners’ individuality (p. 17). However, despite their critical role, IDs have not garnered the attention they genuinely merit in this context (Pawlak, 2022). To address this issue, Mirosław Pawlak and Mariusz Kruk put together the volume Individual Differences in Computer-Assisted Language Learning Research, providing timely and insightful guidelines for the exploration of IDs in CALL and the broader realm of second language acquisition (SLA) research.
Influence of the skull bone and brain tissue on the sound field in transcranial extracorporeal shock wave therapy: an ex vivo study
Authors: Reinhardt Nina , Schmitz Christoph , Milz Stefan , de la Fuente Matías
Published: September 2023

Objectives

Focused ultrasound is mainly known for focal ablation and localized hyperthermia of tissue. During the last decade new treatment options were developed for neurological indications based on blood-brain-barrier opening or neuromodulation. Recently, the transcranial application of shock waves has been a subject of research. However, the mechanisms of action are not yet understood. Hence, it is necessary to know the energy that reaches the brain during the treatment and the focusing characteristics within the tissue.

Methods

The sound field of a therapeutic extracorporeal shock wave transducer was investigated after passing human skull bone (n=5) or skull bone with brain tissue (n=2) in this ex vivo study. The maximum and minimum pressure distribution and the focal pressure curves were measured at different intensity levels and penetration depths, and compared to measurements in water.

Results

Mean peak negative pressures of up to −4.97 MPa were reached behind the brain tissue. The positive peak pressure was attenuated by between 20.85 and 25.38 dB/cm by the skull bone. Additional damping by the brain tissue corresponded to between 0.29 and 0.83 dB/cm. Compared to the measurements in water, the pulse intensity integral in the focal spot was reduced by 84 % by the skull bone and by additional 2 % due to the brain tissue, resulting in a total damping of up to 86 %. The focal position was shifted up to 8 mm, whereas the basic shape of the pressure curves was preserved.

Conclusions

Positive effects may be stimulated by transcranial shock wave therapy but damage cannot be excluded.
Quantification of carbon black tattoo ink hydrophobicity pre- and post-sonication
Authors: Bruin Jordaan Jean de , Postema Michiel , Carlson Craig S. , Nixon Ken J.
Published: September 2023

Despite growing academic interest for dermal inking in contemporary society, the reason why skin tattoos remain visible for life has predominantly been studied from a biological perspective. In preliminary physics studies of ink it has been presumed that the hydrophobicity of its main constituent prevents further dilution of pigment dispersion and therefore may be a contributing factor to aforementioned lifelongevity. According to these early studies, ultrasound might change the hydrophobicity of microparticles. The purpose of this study was to confirm or refute the presence of hydrophobic components in carbon black tattoo ink and to relate sonication to such presence. Cuvettes with n-octanol, distilled water, and a droplet of unsonicated or sonicated carbon black ink were shaken, allowed to settle and subsequently photographed. The sonicated ink had been subjected to ultrasound during 5 min at a centre frequency of 1 MHz, a pulse-repetition frequency of 1 kHz, and a 10% duty cycle. The greyscale values in both parts of the cuvettes were averaged. The resulting ratio of light intensities was an indicator for the ink hydrophobicity. The intensity partition coefficient of carbon black ink was measured to be greater than 103 before sonication and less than 103 after sonication. Carbon black tattoo ink was found to be very hydrophobic. However, sonication was found to make the dispersion less hydrophobic. Influencing the hydrophobicity of tattoo ink might change the permanence of a skin tattoo.
High-speed optical observations of asymmetric pulsations of microbubbles released from tablet matrix
Authors: Anderton Nicole , Carlson Craig S. , Xinyue Hu , Otake Naoyuki , Sorjonen Joona , Kudo Nobuki , Ketolainen Jarkko , Postema Michiel
Published: September 2023

Microbubbles with a negligible shell are of utmost importance in the study of harmonic ultrasound contrast agents. The purpose of this study was to collect and quantify experimental pulsation footage of gas microbubbles released from tablet matrix under sonication. Radii were measured as a function of time of 50 microbubbles that had been released from tablet matrix and were subjected to 3-cycle pulses of 1-MHz ultrasound with a 0.3-MPa peak-negative pressure. The size distribution was measured, as well as pre- and postsonication radii. The experimental footage showed proof of asymmetric buckling, but also of excursion-only behaviour. The former phenomenon has been attributed to a surplus of material accumulated on the microbubble-liquid interfaces, whilst the latter phenomenon has been associated with the presence of incompressible material inside the microbubbles. The postsonication resting radii of 41 microbubbles had become less compared to the corresponding pre-sonication radii. The opposite effect was observed with eight microbubbles in the same size range. This feasibility study confirmed that the gas microbubbles released from tablet matrix may pulsate asymmetrically. Thus, they might be suitable tracers for harmonic imaging.
PH-triggered drug release of ciprofloxacin from layer-by-layer coatings on titanium
Authors: Rieks Desiree , Kampmann Andreas , Gellrich Nils-Claudius , Ehlert Nina
Published: September 2023

Implant-associated infections are still a major issue in implant surgery. Biofilms tend to form on implant surfaces, like titanium, and can hardly be reached by the immune system. Additionally, systemic treatments with antibiotics often fail and cause severe side effects for the patient. Direct delivery of the antibiotic from the implant surface to the surrounding tissue is one approach to solve this problem. To realize this, the application of pH-sensitive coatings on implant surfaces, which release their cargo only if an infection arises, is a promising option. This can be triggered by the decrease of the pH value occurring in infected tissue. For such pH-sensitive systems with integrated drug loading capacity layer-by-layer coatings with weak polyelectrolytes can be used. Here, we present a coating applied on titanium substrates by dip-coating. As negatively charged polyelectrolyte polyacrylic acid, as positively charged poly(allylamine hydrochloride) is used. As an effective drug, the antibiotic ciprofloxacin is incorporated into the coating and the release profiles are recorded.
Sonic cracking of calcium carbonate-encapsulated microbubbles observed at moderate acoustic amplitudes
Authors: Poortinga Albert T. , Postema Michiel , Carlson Craig S. , Anderton Nicole , Yamasaku Momoka , Otake Naoyuki , Kudo Nobuki
Published: September 2023

Theranostic agents are materials that act both as tracers during diagnostic imaging and as vehicles carrying and releasing therapeutics during treatment. Ultrasoundtriggered theranostic agents comprise shell-encapsulated microbubbles that pulsate during low-amplitude ultrasonic imaging and release their payload upon higher-amplitude sonication whilst simultaneously assisting in the permeation of target tissue. High-amplitude release may be undesirable due to unwanted side effects related to inertial cavitation. However, low-amplitude release from microbubbles typically requires thin encapsulating shells, which in turn may be permanently disrupted under diagnostic imaging conditions. The purpose of this study was to investigate the suitability for theranostic applications of a novel microbubble agent with thick shells composed of calcium carbonate. Hydrophobised calcium carbonate-encapsulated microbubbles of radii between 1.0 μm and 11 μm were subjected to short ultrasound pulses of 1-MHz ultrasound at acoustic amplitudes of 0.5MPa or less, which corresponds to low mechanical indices. During sonication, high-speed video footage was recorded at a frame rate of ten million frames per second. We observed pulsations but no gas release at a 0.1-MPa amplitude and intra-encapsulation fragmentation during sonication at a 0.3-MPa amplitude. At 0.5-MPa amplitude sonication, release was observed from more than 70% of the microbubbles in the field of view. This finding indicates that the microbubbles were stable scatterers during 0.1-MPa sonication, but instable vehicles during 0.5-MPa sonication. The pressures used in this study to observe release were too low to allow for unwanted inertial cavitation. In conclusion, therefore, the microbubbles studied were a promising theranostic agent whose contents could be released at moderate acoustic amplitudes.
Feasibility study for a possible therapy of bacterial keratitis by UVB irradiation
Authors: Fischer Simone , Fehler Nicole , Hessling Martin
Published: September 2023

Bacterial keratitis is a widespread disease in which bacteria have infected the cornea. This can lead to blindness and should be treated immediately after diagnosis. However, antibiotics do not reach pathogens inside the cornea. Therefore, it is investigated whether UVB irradiation might be a feasible therapy that reaches and inactivates bacteria even deep inside the cornea. Thus, the cornea transmission of porcine eyes was measured to reveal a high UVB penetration. As Escherichia coli (E. coli) is one of the relevant pathogens, E. coli suspensions were irradiated by a 311 nm UVB lamp, to explore the antimicrobial impact of the UVB radiation. Finally, as a worst-case scenario, it was investigated whether E. coli behind the cornea was also inactivated. A cornea transmission of 36.4 ± 5.9 % was observed at 311 nm and an irradiation dosage of 1.9 J/cm2 was found for a three log reduction of E. coli in suspension. The reduction of E. coli by 311 nm irradiation even behind the cornea could be confirmed. Therefore, by this approach, it should be possible to reach bacteria even deep inside the cornea by means of UVB irradiation as a fast keratitis therapy.
Deep Learning by Domain Transfer for Early Tumor Detection in the Urinary Bladder
Authors: Eixelberger Thomas , Maisch Philip , Kruck Stephan , Belle Sebastian , Kriegmair Maximilian , Bolenz Christian , Wittenberg Thomas
Published: September 2023

Background: Bladder cancer (BCa) is the second most common genitourinary malignancy and has a mortality of 165,000 deaths p.a. The diagnosis of BCa is mostly carried out using cystoscopy - the visual examination of the urinary bladder with an endoscope. White light cystoscopy is currently considered as gold standard for the diagnosis. Nevertheless, especially flat, small or weakly textured lesions, are very difficult to detect and diagnose. Objective: With the advent of deep learning and already commercially available systems for the detection of adenomas in colonoscopy, it is investigated how such a system - for colonoscopy - performs if retrained and tested with cystoscopy images. Methods: A deep neural network with a YOLOv7-tiny architecture was pre-trained on 35,699 colonoscopy images (partially from Mannheim), yielding a precision = 0.92, sensitivity = 0.90, F1 = 0.91 on public colonoscopy data collections. Results: Testing this adenomadetection network with cystoscopy images from three sources (Ulm, Erlangen, Pforzheim), F1 scores in the range of 0.67 to 0.74 could be achieved. The network was then retrained with 12,066 cystoscopy images (from Mannheim), yielding improved F1 scores in the range of 0.78 to 0.85. Conclusion: It could be shown that a deep learning network for adenoma detection in colonoscopy is ad-hoc able to detect approximately 75% of the lesions in the urinary bladder in cystoscopy images, suggesting that these lesions have a similar appearance. After retraining the network with additional cystoscopy data, the performance for urinary lesion detection could be improved, indicating that a domain-shift with adequate additional data is feasible.
A practical example of an integrated interoperable neuromonitoring system based on IEEE 11073 SDC and HL7
Authors: Weßbecher Lea , Berger Johann , Neumann Juliane , Lente Kornelius , Krüger Thilo B.
Published: September 2023

Purpose: With the ongoing work on the Health Level Seven (HL7) standards and the IEEE 11073 Serviceoriented Device Connectivity (SDC) family, the demand for open integration of medical devices in the operating room (OR) has become clear. Nevertheless, there are very few interoperable medical devices available to date. This work describes a practical example of connecting an intraoperative neuromonitoring (IONM) device with a radiofrequency (RF) surgical device based on SDC and with the hospital information system (HIS) based on HL7. Methods: Before starting the surgery, patient-related data must be entered into the neuromonitoring system. To minimize manual input, we integrated an automized patient data query based on HL7, which completes all other necessary data provided by the HIS after entering the patient identification number. During the surgery, while mapping neural structures in the situs using IONM, the parallel operation of RF devices for coagulation generates artifacts in the neuromonitoring signals, which makes a reliable interpretation of the IONM signals impossible. Therefore, we developed an IEEE 11073 SDC interface for the neuromonitoring device and implemented an SDC-based OR control panel. While placing the hand probe for mapping neural structures in the situs, the OR control panel suppresses the coagulation of the electrosurgical instrument and only reenables it, after the mapping has been terminated. After the surgery, the generated IONM report can be uploaded into the HIS using HL7. Therewith it is assigned automatically to the previously selected patient. Result: With the SDC- and HL7-enabled neuromonitoring system, we showed a practical use case of interoperable medical devices to optimize surgical workflow.
Method for CAD/CAM-based production of patient-specific anatomical bone surrogates from polyurethane rigid foams of different densities for various clinical applications
Authors: Sembdner Philipp , Blaurock Karl , Paetzold-Byhain Kristin
Published: September 2023

Physical models of bony areas are used in the medical environment for training, patient information or for various examinations. These are idealized average models which, however, do not reflect the individuality of a respective patient. Furthermore, the mechanical properties of the bony structure with cortical bone and cancellous bone are not considered in most models. A few manufacturers, such as SawBone, offer models and material blocks that approximate the properties of the bone. However, these are not patientspecific either. This paper presents a proposal for a method to create patient-specific physical bone models with CAD/CAM technologies that approximate shape and mechanical properties. The models are made of two different rigid polyurethane foams for cortical bone and cancellous bone. The methodical development includes the elaboration of a framework starting from the patient's CT data, through design derivation, to fabrication. Furthermore, a possible process for fabrication in the form of a demonstrator and its application in sawing tests will be demonstrated.
Model-based Tracking of Magnetic Sensor Gloves in Real Time
Authors: Boueke Moritz , Hoffmann Johannes , Schmidt Tobias , Bald Christin , Bergholz Robert , Schmidt Gerhard
Published: September 2023

While mechanical tracking is commonly seen in robot-assisted surgery, contactless gesture control leads to a more intuitive approach. Magnetic localization systems might be able to provide an untethered access to the necessary hand movement data. A model-based system exploiting a priori knowledge to improve the accuracy and robustness can be beneficial in this context. We present a proof of concept, in which the index finger of a digital twin of a hand is tracked with three simulated sensors. Based on the physiological composition, the finger is modeled as a kinematic chain with rotational degrees of freedom between the segments according to the corresponding finger joints. We applied an extended Kalman filter using this description to enhance position and rotation estimates for the sensors on the finger segments. We achieved mean absolute errors < 1 cm for the positions and < 10 for the local rotations with first simulations of a bending motion.
A Concept for Myocardial Current Density Estimation with Magnetoelectric Sensors
Authors: Engelhardt Erik , Elzenheimer Eric , Hoffman Johannes , Schmidt Tobias , Zaman Adrian , Frey Norbert , Schmidt Gerhard
Published: September 2023

In this paper we present a novel noninvasive approach to estimate current densities in the heart from magnetocardiography. The proposed algorithm uses nested optimization to model current densities in equally-sized voxels of myocardial tissue. First-order Thiran all-pass filters are used to describe the propagation between voxels.We demonstrate feasibility of the algorithm for a noise-free single-layer simulation. However, challenges remain, such as addressing measurement noise and optimizing propagation velocity. Overall, this approach has the potential to complement or replace invasive catheter-based electrophysiological studies for localization of arrhythmogenic tissue.
Combined Method for Segmentation of Multiple Needles in 3D Liver CT
Authors: Moravová Adéla , Bale Reto , Harders Matthias
Published: September 2023

Radiofrequency ablation is a minimally invasive technique for treating liver or kidney tumors, where precisely inserted ablation probes destroy the tumor tissue with induced heat around their tips. Automatic segmentation of needles from the abdominal computed tomography (CT) scans enables large-scale procedure evaluation and creates a baseline ground truth for automated planning approaches. Our method for needle segmentation enables the detection of multiple needles from unlabeled CT scans by sequential combination of two approaches, a classical method and a neural network. The former method detects intensity-prominent needles in 3D. The latter focuses on the detection of needles with lower intensity, that remained undetected by the classical method. A well-known encoder-decoder approach on axial slices of the CT scan gives a segmentation mask for the needles prominent in slices. To train the network, we create a synthetic dataset, adding needles to clean abdominal CT slices. Our network trained on a small synthetic dataset is able to generalize to clinical CT scans. The performance of the combined method is evaluated on ten anonymous patients from the Medical University of Innsbruck each with up to 18 needles inserted in the liver without any template.
Muscle stimulation for peripheral venous oxygen saturation estimation using photoplethysmography: a proof-of-concept
Authors: Badiola Idoia , Lyu Chenglin , Ferchland Arne , Comes Fabian , Blazek Vladimir , Leonhardt Steffen , Lueken Markus
Published: September 2023

The body’s ability to balance oxygen supply and demand can be compromised in conditions such as shock, sepsis, and heart failure. Thus, measuring venous oxygen saturation (SvO2) simultaneously with the well-established peripheral arterial oxygen saturation can help in the clinical management of these conditions. Some authors have suggested a non-invasive SvO2 estimation method that acquires venous blood volume variations generated through the calf muscle pump using photoplethysmography (PPG): the Venous Muscle Pump Test (VMPT). However, the technique presents significant variability in the rhythm and speed of the foot dorsal flexions needed for the VMPT and cannot be performed on unconscious subjects and those with reduced mobility. This study proposes using functional electrical stimulation (FES) to stimulate the calf muscle and generate rhythmic and reproducible muscle contractions. A human proof-of-concept study was conducted with three healthy young male participants. The PPG signals achieved through the VMPT with conventionally active and FES-induced movements were compared. We found that FES-induced movement produced reproducible venous blood volume variations comparable to the ones induced by the active movement. However, it also leads to lower venous refilling time and lower muscle power. Although further individualized tuning of the stimulation parameters is needed to achieve more conclusive results, FES-induced movement proves to be a promising alternative to the conventional VMPT technique to measure venous oxygen saturation and assess venous insufficiency in specific clinical situations.
Conception And Implementation of an virtual Reality application for the evaluation of different types of commercially available haptic gloves
Authors: Schmücker Vanessa , Grensing Florian , Jakob Rebekka , Gießer Christian , Brück Rainer , Eiler Tanja
Published: September 2023

Immersion and presence are important aspects of virtual reality (VR). Efforts are therefore being made to enhance these effects in order to increase the impact of VR and its transferability to reality. This is particularly important in research areas such as medical education and psychology. The development of haptic gloves has therefore increased significantly in recent years. These are immersive input devices designed to make virtual objects tangible. However, the research field is still very new and there is insufficient research on their handling and effect. For this reason, an application was developed to compare different haptic data gloves with different haptic technologies. A glove with vibrotactile feedback (Manus Prime X Haptic VR) and a glove with additional force feedback (SenseGlove) were used and compared in multiple tasks. These include finger tracking and gesture recognition, as well as hand tracking and the behaviour of gloves when grasping objects with and without haptics. The aim is to determine how well the haptics could be integrated and which is more accepted by the test subjects. For this purpose, a questionnaire has been designed to evaluate the effect of the haptic gloves on users. It aims to get a first impression of the tactile gloves available on the market and to advance research in the area.
Limitations of Pacemaker Spike Detection in Capacitive ECGs via Deep Learning
Authors: Rohr Maurice , Huang Zhaolan , Umutcan Uguz Durmus , Dettori Rosalia , Napp Andreas , Walter Marian , Leonhardt Steffen , Hoog Antink Christoph
Published: September 2023

Pacemaker spike detection is an important step in monitoring paced patients. Capacitive ECG facilitates unobtrusive monitoring of subjects during daily routines such as driving. Robust algorithms are required to deal with low signal quality and artifacts, e.g. by employing fusion of multiple signal channels. Due to the low signal-to-noise ratio of the measurement, there are limitations to detection accuracy compared to conventional ECG monitors. Especially low voltage stimulations such as bipolar pacemaker spikes are hard to detect. We present a convolutional network approach to improve on recent signal processing algorithms.We show a realistic evaluation of its performance using leave-one-subject-out cross validation (LOOCV), its dependence on the size of the receptive field, and an estimation of an upper performance bound.
Multi-Height Extraction of Clinical Parameters Improves Classification of Craniosynostosis
Authors: Becker Anna Maria , Schaufelberger Matthias , Kühle Reinald Peter , Freudlsperger Christian , Nahm Werner
Published: September 2023

Introduction: 3D surface scan-based diagnosis of craniosynostosis is a promising radiation-free alternative to traditional diagnosis using computed tomography. The cranial index (CI) and the cranial vault asymmetry index (CVAI) are well-established clinical parameters that are widely used. However, they also have the benefit of being easily adaptable for automatic diagnosis without the need of extensive preprocessing. Methods: We propose a multi-height-based classification approach that uses CI and CVAI in different height layers and compare it to the initial approach using only one layer. We use ten-fold cross-validation and test seven different classifiers. The dataset of 504 patients consists of three types of craniosynostosis and a control group consisting of healthy and non-synostotic subjects. Results: The multi-height-based approach improved classification for all classifiers. The k-nearest neighbors classifier scored best with a mean accuracy of 89% and a mean F1-score of 0.75. Conclusion: Taking height into account is beneficial for the classification. Based on accepted and widely used clinical parameters, this might be a step towards an easy-to-understand and transparent classification approach for both physicians and patients.
Determination of the water content of an ex vivo porcine liver
Authors: Busch Christoph , Rupitsch Stefan J. , Moeller Knut
Published: September 2023

When modeling High-Frequency (HF) surgical applications the choice of the right dielectric tissue parameters is a key factor for success. The water content of biological tissue is of particular importance since the dielectric tissue properties highly depend on it. Therefore, we investigate a simple and fast method for the determination of relative tissue water content using small samples of an ex vivo porcine liver. To identify the water content, we utilized a desiccation and weighing experiment. It is assumed that the weight loss can be directly attributed to the loss of water in the case of desiccation. Based on the ratio between the initial and dry weight of a sample, the relative water content can be determined. The drying procedure lasted 28 hours, with 16 small samples taken from an ex vivo porcine liver. At the end of the drying procedure, a relative tissue water content of 69.6 % ± 1.1 % was observed. Using a curve fit to the measured data, it can be assumed that approximately 99.3 % of the tissue water content had evaporated by the end of the drying process. With the drying and weighing method used, we were able to determine the water content of the ex vivo porcine liver relatively easily. However, our results also suggest that optimizations of the applied method should be considered for future measurements. Especially, if a faster determination of the water content is required, which in a broader sense should afterward serve for the validation of a simulation model.
Proof-of-Concept: Conceptual design and realisation of an educational augmented reality (AR) application for anaesthesia induction
Authors: Maleszka Leonie , Breuer-Kaiser Andreas , Schäfer Marcel , Lehn Karsten , Felderhoff Thomas
Published: September 2023

Increasing patient safety during operations is an inevitable topic in anaesthesiology. The cockpit strategy presented by Vogelsang et al. addresses this issue with elements such as closed loop communication and the use of checklists. In this paper, the use of checklists is taken up further. An AR application is presented that augments checklists for anaesthesia induction into the user’s field of view. The application is to be implemented in teaching and help prospective physicians to internalise the workflows in anaesthesiology more quickly and sustainably. A working prototype has been created and loaded onto the HoloLens 2. The prototype is being assessed and evaluated by an anaesthetist. The feedback will be included into the following development steps. The application will be further adapted to the needs and requirements of the users. In order to evaluate the usability and the user experience, students and medical professionals should test and evaluate the application repeatedly.
Generation and validation of a PREP sample response
Authors: Rölle Annika , Felderhoff Thomas , Enax-Krumova Elena , Eitner Lynn , Höffken Oliver , Maier Christoph , Simal Özgül Özüm
Published: September 2023

PREP are typical signal courses in the EEG, which are used to investigate the influence of neuropathologies or, for example, post-traumatic headaches on pain processing. The medically meaningful peaks are detected manually for further analysis. To develop a more time-efficient method, an automatic, latency-independent way of detection was created using the cross-correlation function, which generates a sample response for each data set. The comparison of automatic and manual methods shows advantages and disadvantages of both methods, but no significant deviation of the automatic method can be found.
Towards non-invasive Wilson’s disease progression monitoring based on corneal copper content
Authors: Mayer Juliane , Narr Julia , Pott Peter P.
Published: September 2023

Patients suffering from Wilson’s disease accumulate copper in their body. Copper load may become visible as Kayser-Fleischer (KF) rings - colorful copper-sulfur granules in the base of the cornea. Reoccurrence of KF rings in patients under anti-copper medication may be a sign for ineffective treatment. This work proposes a hand-held sensing system based on infrared reflectivity measurement of the cornea as a potential method for regular at-home progression monitoring. The intensity of the LEDs used is safe for operation on the human eye. As proof of concept, reflectivity was measured when placing the sensor onto samples of white paper that had copper tape of different sizes centered within the sensitive area. Further, reflectivity was determined for different solutions of copper sulfate in saline that were poured into adapter bowels fitting the sensor head, with Cu2+ concentrations of the samples deducted from literature. While the prototype system can be used to differentiate between two copper strips of 6 and 12 mm2 or larger, a different measuring principle would be needed to also determine the concentration of copper sulfate solutions. Since these two in-vitro models cannot fully represent the complex in-vivo molecular conditions of patients’ corneas, additional measurements on patients’ eyes are necessary to evaluate the potential of the proposed sensing system.