bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antifibrotic Drug Delivery for Glaucoma Treatment – Determination of Josamycin in vivo
Authors: Eickner Thomas , Huling Jennifer , Oschatz Stefan , Lange Helge , Peil Anita , Undre Nasrullah , Stachs Oliver , Stahnke Thomas , Grabow Niels , Jünemann Anselm , Fuellen Georg 
Published: December 2024

Abstract
Antifibrotic treatment during glaucoma surgery leads to an improved outcome for patients. Drug delivery systems for placement under the subconjuctiva after surgery made of cyclodextrins and crosslinked with Epichlorohydin were loaded with Josamycin and tested in vivo. After subconjunctival application in three New Zealand White rabbits, blood samples were taken by the means of Mitra devices at defined time points. Determination of blood levels of Josamycin was performed using liquid chromatography mass spectrometry. Detection of Josamycin was achieved during 48 h suggesting a sustained release over the course of this study.
Initial biological evaluation of nanofiber and microwire biomaterials
Authors: Götz Andreas , Markhoff Jana , Senz Volkmar , Grabow Niels , Illner Sabine , Teske Michael 
Published: December 2024

Abstract
Due to the direct long-term contact with living tissue, the biocompatibility of implants is particularly demanding. In this context, biointegration of implants highly depends on cell colonialization on the surface or in the gap between implant and tissue, as well as cell ingrowth in porous implant structures. Fibrous material is predestined based on two variable parameters, fiber thickness and pore size. Various applications in implant coating, stenting, wound treatment, bone surgery, or cardiovascular field are possible. Coating with cell-friendly material can significantly improve the biocompatibility of the underlying material. In this study, the biocompatibility of medical device samples made of microwire and nanofiber substrates was compared according to ISO 10993-5. In particular, a metal tissue of microwire (stainless steel, 316L) and polymeric nanofiber nonwoven poly-L-lactic acid (PLLA) as well as titanium (Ti) sputtered variants thereof (316L-Ti, PLLA-Ti) were tested in vitro. In order to evaluate their environmental compatibility and their effects on L929 cell line (murine fibroblasts) evaluation was performed via direct contact with 30,000 cells per 48-well in non-adherent plates for 48 h and 96 h. The metabolic activity of cells was determined via CellQuanti-Blue assay, morphological analysis were done using fluorescence staining phalloidin and DAPI. Briefly outlined, microwires were colonized immediately, whereas initially spherical cells settled on nanofiber substrates and later coalesced forming a common cell cluster. The results show independency of structure, ultrathin titanium coating improves cell viability. The findings indicate that the idea of making a surface appealing to cells has potential. It can therefore be assumed that physical vapor deposition (PVD) sputtering of Ti on implant surfaces is a suitable approach to maintain or improve their biocompatibility, regardless of the surface structure of the implants.
FRAME – A FRAMEwork for Objectively Measuring Fear Based on Physiological and Psychological Data
Authors: Grensing Florian , Schmücker Vanessa , Hildebrand Anne Sophie , Klucken Tim , Maleshkova Maria 
Published: December 2024

Abstract
Psychological trials, such as behavioural avoidance tests (BAT), are a fundamental part of the phobia therapeutic process. In order to link physiological reactions with specific points in time during psychological trials, it is necessary to integrate observation data with data collected automatically by sensors, such as wearable devices. To this end, this paper introduces FRAME - a framework for combining real-world events occurring during psychological trials with physiological data collected by wearables. FRAME consists of three parts, an Observation App, a data integration module and a Virtual Reality (VR) App. The Observation App captures events and their exact time of occurrence. The integration module links the observations with the respective physiological data, allowing an in-depth analysis of physiological reactions. The VR App provides a virtual scenario based on the BAT in vivo, thus enabling a BAT in virtuo. The practical applicability of FRAME is tested within a study comparing behavioural avoidance tests in vivo and in virtuo, assessing 25 patients with arachnophobia wearing an Empatica E4.
LIPSS on polymeric implant surfaces - a fabrication study
Authors: Grossmann Swen , Tetzlaff Lucas , Grabow Niels , Schmitz Klaus-Peter , Siewert Stefan 
Published: December 2024

Abstract
Laser-induced periodic surface structures (LIPSS) offer the potential to engineer cell adhesion, cell orientation, and cell density on implant surfaces through periodic structures on the nanometer and micrometer scale. Due to their straightforward fabrication on metal surfaces, they provide an essential tool for optimizing implants according to their intended use. However, these types of structures can only be produced on a limited amount of polymers. Within this study, methods of implementing LIPSS on polymer films are investigated using manufacturing processes established in biomedical engineering. For this purpose, a polymer possessing USP class VI certification and ISO 10993 proven biocompatibility is used. The presented processes are easy to implement and can contribute significantly to the implementation of surface active structures like LIPSS on medical devices and commercial implants.
Bone replacement material with optimized structure, manufactured using additive printing technology
Authors: Hergenröder Anna , Scherrieble Andreas , Linti Carsten , Gresser Götz T. 
Published: December 2024

Abstract
Additive manufacturing with Arburg Plastic Freeforming (APF), an extrusion-based additive manufacturing process, was used to produce biomimetic bone scaffolds for assistance of osteosynthesis made of poly-caprolactone (PCL) with channel structures for the ingrowth of blood vessels. The specific creation of defined channel structures is very important to support the ingrowth of blood vessels, which significantly supports the regeneration of natural tissue. The tibia model used was divided into the corticalis and the spongiosa to be able to compare the realization of the different requirements of the two natural structures with the printed structures separately. Microtome cuts of the manufactured bone scaffolds with channels were prepared for characterization with light microscopy. Compression tests were carried out on a tensile testing machine. It was found that the channels in the tibial cortex led to a slightly higher stiffness compared to those without channels due to the frame outlines. Overall, however, the stiffness of the Polycaprolactone (PCL) scaffolds was significantly lower than that of natural bone. In the spongiosa scaffolds, the stiffness with channels was lower than that without channels, but still within the physiological range, as was the model without channels. The porosity was within the required range for both scaffold types.
Estimation of Venous Oxygen Saturation Through Non-Invasive Optical Sensing at the Jugular Veins
Authors: Hill Jordan F. , Campbell Jake , Chase J. Geoffrey , Pretty Christopher G. 
Published: December 2024

Abstract
Non-invasive, real-time venous oxygen saturation (SvO2) measurements provide the potential to improve health outcomes in transfusions, ventilator care, and in the intensive care unit. Current methods use catheters which are invasive, expensive, and pose potential high-risk, with only discrete measurements from a jugular vein obtained. This research designed, developed, and tested a proof-of-concept optical sensor similar to a pulse oximeter for non-invasive, continuous SvO2 monitoring at the external jugular vein (EJV). Testing on three subjects met the aim of correctly identifying the EJV waveform and provided an SvO2 estimation within the usual healthy range of 60-90%. SvO2 estimates from the EJV pulse of 71.1%, 72.2%, and 70.4% and breathing pulse of 74.7%, 75.3%, and 74.1%, all fall within range, with trials capturing clear EJV waveforms from the single-point sensor. Further research is necessary to calibrate and validate the device against gold-standard blood gas analysers. However, the initial results prove the sensor’s reliability and potential in detecting and estimating SvO2 non-invasively, which has the potential to benefit patients across a wide range of clinical settings.
Early-detection of pre-eclampsia: Concept and design of a portable prototype
Authors: Janzen Swantje , Wagner Jessica , Pott Peter P. 
Published: December 2024

Abstract
Pre-eclampsia is one of the most common causes of maternal and perinatal death worldwide. It is a hypertensive pregnancy disease with reduced perfusion of numerous organs. The main symptoms of the disease include elevated blood pressure, proteinuria and the associated subcutaneous fluid retention in the fingers, hands and face of the pregnant woman. In this paper a concept of a portable prototype for early-detection of preeclampsia is presented. The assembled sensor systems enable portable monitoring of the main symptoms to detect changes at an early stage. The sensor system for determining blood pressure is based on photoplethysmography. The sensor system for detecting subcutaneous fluid retention uses the absorption bands of the fluid when illuminated with near-infrared light. For the validation experiments, finger models made of silicone with different fluid retention levels were produced. The results show a correlation between the measured transmitted light intensity and the fluid retention. The results represent a possibility for the portable measurement of important vital parameters in connection with preeclampsia.
Release Rates of Prednisolone-21-Hydrogen- Succinate from 3D-Printed Silicone as Material for Patient-Individualized Drug Releasing Implants
Authors: Knabel Martina , Dräger Gerald , Lenarz Thomas , Scheper Verena 
Published: December 2024

Abstract
For treating idiopathic sudden sensorineural hearing loss, prednisolone is commonly used. However, systemic or middle ear injections often lead to insufficient drug delivery to the inner ear, causing ineffective treatment and systemic side effects. An implant inserted into the middle ear and delivering the drug directly to the inner ear offers a promising solution, providing controlled, long-term drug release with potentially better efficacy and fewer side effects. Individualized implants made of prednisolone-containing silicone can optimize inner ear treatment by fitting the patient's middle ear anatomy. To gauge the properties of prednisolone-21- hydrogen succinate containing silicone, samples with different geometries and drug concentrations have been 3D-printed. The shore hardness of samples with three different drug concentrations was assessed. Three different shapes with four different drug concentrations were incubated in artificial perilymph for up to 56 days to evaluate the release rates. The resulting eluates were analyzed via Ultra high precision liquid chromatography coupled with a time-of-flight micro-mass spectrometer. Samples were softer when a higher drug concentration was used. A high burst release of prednisolone after one hour was measured. Afterward, the release rates decreased and reached a relatively constant rate after ten days and stayed there for at least another 46 days. The release rates were multiple times higher when the samples had a higher surface-to-volume ratio. The softer the sample, the higher the release rate, unproportional to the concentration increase.
Evaluation of a semi-automated robotic system for percutaneous interventions: Phantom-based assessment of accuracy
Authors: Lutz Raffael , Wörnle Christian David , Kuntz Lukas , Winter Fabius , Rathmann Nils , Stallkamp Jan , Siegfarth Marius 
Published: December 2024

Abstract
Robotic systems have the potential to improve the accuracy and efficiency of percutaneous interventions. However, their widespread adoption is hindered by challenges such as high costs and usability deficiencies. To address these challenges, we designed a novel semi-automated robotic system that combines manual and robotic degrees of freedom for needle guidance. Since the initial presentation of the system, we have implemented hardware and software improvements. The objective of this study is to evaluate the accuracy of the system. To achieve this, experiments were conducted that involved the entire process from CT scanning to lesion targeting with a needle, using a phantom that replicated abdominal lesions of varying sizes. A total of 36 needle insertions were performed, and a control scan was conducted each time to evaluate the needle tip position. The results demonstrate promising accuracy, with a mean Euclidean error of 5.8 ± 1.7 mm. Qualitative analysis showed that lesion targeting was successful across different sizes, with a total success rate of 27 out of 36 attempts. Although our prototype shows promising accuracy, there is still room for improvement compared to existing systems. Future efforts will prioritize enhancing accuracy, exploring usability aspects, and validating the system's performance with medical professionals.
Native and cell-derived extracellular matrix exhibit disparate immunogenic and immunomodulatory effects
Authors: Nellinger Svenja , Kluger Petra J. 
Published: December 2024

Abstract
The extracellular matrix (ECM) represents the natural environment of the cells and consists of various fibrous and non-fibrous proteins. It can be generated by decellularization of native tissue (dECM) or by isolation from cultured cells in vitro (cdECM). In the present study the immunomodulatory effect of dECM from native adipose tissue and cdECM from adipose derived stem cells (cdECM) on monocytes and ASCs encapsulated in gellan gum-ECM hybrid hydrogels was investigated. The monocyte activation test revealed a higher secretion of IL6 and TNFα in monocytes incubated with dECM compared to cdECM. Encapsulated ASCs in gellan gum-ECM-hybrid hydrogels exhibit different cytokine profiles (IL8, IL6, MCP-1, TNFα) when cultured with dECM or cdECM or gellan gum alone. The demonstrated differences in cellular behavior in the present of the two different types of ECM should be considered when using them as a biomaterial for in vitro as well as in vivo applications.
Fantastic squeaks and where to find them: producing and analysing audible acoustics from leipäjuusto
Authors: Nurkkala Elina , Carlson Craig S. , Hopia Anu , Postema Michiel 
Published: December 2024

Abstract
Chewing not only converts food chunks to digestible proportions, it also conveys audible acoustics resulting in a perception on the type and condition of the food being eaten. As biomedical engineers, we may want to reproduce the same eating experience for those who cannot chew or for those who have allergic reactions to some foods. But to understand this psychoacoustic phenomenon better, it is crucial to understand what produces the sound of specific foods. The purpose of this paper is to present a straightforward methodology to produce audible acoustics from a notoriously loud Finnish delicacy and analyse the sound produced. One hundred samples of leipajuusto and one hundred samples of Gouda cheese for controls were subjected to shear between a bamboo board and a wetted blade. All leipajuusto samples and none of the Gouda cheese samples produced audible squeaks. A 0.1-s delay between blade displacement and sound production was observed. We attribute this delay to the buildup to release. The frequency spectra from pushing and pulling movements were observed to have only negligible differences. This indicated that the internal structure between events did not change. Therefore, the hypothesis that a disruptive event underlies the squeaking process is less plausible.
Generation of Shape Models of Calcified TAVR populations for Solid Mechanics Simulations by means of Deep Learning
Authors: Oldenburg Jan , Borowski Finja , Supp Laura , Öner Alper , Schmitz Klaus-Peter , Stiehm Michael 
Published: December 2024

Abstract
Minimally invasive transcatheter aortic valve replacement (TAVR) procedure has become the preferred procedure for patients with aortic valve stenosis or insufficiency with high risk for conventional open surgery. The favorable clinical outcomes of high-risk patients led to an expansion of the cohort including intermediate and low-risk patients. A critical aspect of advancing TAVR procedures lies in preoperative planning, integrating patient-specific in-silico deployment simulation and post-deployment fluid mechanics assessments. This study introduces a novel approach to calcified TAVR patient shape modeling, addressing this problems. The model integrates an extended mesh generated by DeepCarve, encompassing the aortic arch, and a novel deep learning-based volumetric shape model of calcifications. The key innovation lies in the utilization of a conditional Convolutional Variational Autoencoder (cCVAE) to generate realistic calcification patterns, demonstrating promising preliminary results in matching actual cohort data. Future investigations should focus on data collection from diverse medical centers to validate and refine the proposed methodology. This study showcases significant progress in generating synthetic TAVR patient geometries, incorporating detailed anatomical structures such as the aortic root, valve, and arch, along with volumetric calcification patterns. These findings represent a crucial step towards enabling real-time preoperative TAVR planning, inclusive of patient- specific in-silico deployment simulation and comprehensive fluid mechanics assessments.
Detecting Ineffective Efforts during Expiration for Neonates with Attention RNNs
Authors: Oprea Camelia , Stegemann Lara , Olivier Lena Sophie , Buglowski Mateusz , Becker Sabine , Orlikowsky Thorsten , Kowalewski Stefan , Schoberer Mark , Stollenwerk André 
Published: December 2024

Abstract
Patient-ventilator asynchronies occur during mechanical ventilation when there is a mismatch between the patient’s needs and the ventilator’s settings. Ineffective Efforts during Expiration (IEE) is such an asynchrony, which if undetected can cause patient stress and prolong the ventilation duration. Current approaches to detect IEEs only target adult patients and are not directly applicable to newborns. This work explores the use of Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM) models to detect IEEs in neonates. An attention mechanism is employed to additionally offer a visual explanation for the network’s classification. All of the tested attention RNN architectures yield an accuracy of over 90%, with LSTMs performing slightly better than simple RNNs. A user study is conducted to evaluate the usability of the employed explainability method. The results show that the used visualizations are intuitive to understand, however the network’s attention itself can be misleading in certain cases.
Radar-based elderly fall detection using SPWVD and ResNet Network
Authors: P. J. Swarubini , Ganapathy Nagarajan 
Published: December 2024

Abstract
Falls in the elderly population present substantial health risks, often resulting in morbidity and a decline in quality of life. Conventional fall detection methods, including wearable devices and cameras, are hindered by issues such as variable lighting conditions and privacy considerations. Radarbased fall detection has emerged as a promising alternative, providing an unobtrusive method. This study aims to classify fall detection using Smoothed Pseudo Wigner-Ville distribution (SPWVD) images and ResNet-50 model. For this, an online publicly available radar database comprising 15 subjects is utilized. Radar signals is processed into SPWVD timefrequency representation images for analysis. The SPWVD images is fed into the ResNet-50 model. Experiments are performed and performance is evaluated using 10- fold cross validation. The proposed approach is able to distinguish elderly fall. Using ResNet-50 model, the approach yields a maximum average classification f-measure, area under curve score, precision and, sensitivity of 67.15%, 52.31%, 50.55% and, 99.88%, respectively. Hence, the proposed framework holds promise for accurately and efficiently detecting falls among the elderly population within their private environments.
Reducing artifacts in electrically evoked auditory potentials (eAEP)
Authors: Polterauer Daniel , Neuling Maike , Mandruzzato Giacomo , Polak Marek , Müller Joachim , Hempel John-Martin 
Published: December 2024

Abstract
Introduction: In auditory evoked potentials (= AEP), auditory brainstem response (= ABR) is the gold standard for objective analysis of the auditory pathway using acoustical stimulators like headphones during hearing screening and patient assessment. Where no response can be recorded, electrical stimulation can be used in pre-, intra-, or postoperative scenarios to confirm the excitability of the auditory nerve (= eAEP). In eAEP, the recording of brainstem response (= eABR) is mostly the method of choice. Sometimes in eABR, the stimulation artifact can not only harden but even prevent the detection of the response waveforms. Methods: Many factors can influence the stimulation artifact when recording an eAEP. Neurological recording systems are recommended as well as some approved AEP systems traditionally used in ENT for amplification to avoid large stimulation artifacts in the response waveforms, but able to recover in <1 ms from saturation. High stimulation rates (~90 Hz) can lead to overlapping of the response waveforms with the following stimulation artifact. In preoperative eAEP, stimulation artifacts are often high due to extra-cochlear stimulation. In intra- and postoperative eAEP, the artifact is lower and mostly similar across patients. Results: The recommended recording systems show low stimulation artifacts in almost any case for intra- and postoperative eABR. In contrast, later responses, like electrically evoked auditory middle-latency response (= eAMLR) and electrically evoked auditory late response (= eALR), are less affected by artifacts. Conclusion: The stimulation artifact can be a problematic factor. Depending on the EP system, intra- and postoperative eABR can be challenging when trying to record the response waves. Where possible, clinicians should think about eAMLR or eALR for results with less stimulation artifact. Finally, the most important factor remains using a recording system that can handle the stimulation artifact. We do not recommend recording devices with high artifacts for preoperative eABR. For intra- and postoperative eABR, the recommended systems can prevent challenging recording.
Manufacturing of porous polymer films as a basis for the novel cardiovascular implant devices
Authors: Reske Thomas , Koper Daniela , Kaule Sebastian , Merryweather Bradley , Khaimov Valeria , Grabow Niels , Schmitz Klaus-Peter , Siewert Stefan 
Published: December 2024

Abstract
For applications in the cardiovascular field, the production of tailored biomaterials such as those required for insulations or patches is a key technology. In this work we were able to manufacture thermoplastic silicone polycarbonate elastomer scaffolds with a porous external surface. The samples were produced using the dip coating process. Pores were created using the salt leaching technique. The complete removal of the salt was verified by Raman microscopy. The absence of solvents was demonstrated by biocompatibility tests using an endothelial cell line. The potential functionality of the system was thus demonstrated. The next step will focus on promoting the adhesion of suitable cells for specific applications.