bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer activities for cardiovascular, ophthalmologic and otolaryngologic medical device innovations
Authors: Grabow Niels , Senz Volkmar , Schmitz Klaus-Peter 
Published: February 2021

Abstract
The consortium RESPONSE is a cooperation of partners from science and industry within the BMBFProgram “Twenty20 - Partnership for Innovation”, 2014- 2021. Current efforts are being made towards the transfer of new products, technologies and processes in the field of medical devices. Here, RESPONSE is focusing on novel concepts of implantable medical devices for cardiovascular, ophthalmologic and otolaryngologic application. Platform technology approaches, such as drug delivery systems for responsive functionalized implants or smart implant technologies, are being used to enable new applications.
Wearable Pressure Sensing for Vojta Therapy Guidance
Authors: Steffen Büchner , Christian Gibas , Rainer Brück , Nina Nemcová , Wolfram Müller , Katrin Schürholz 
Published: February 2021

Abstract
The authors propose a glove with pressure sensitive fingertips and muscle tension detection of the thumb to aid in the physiotherapy of infants, children and adults according to Vojta. The therapy has to be carried out at home by the parents of children with cerebral palsy, or other movement disturbances up to 4 times per day. Often, parents struggle to carry out the practices because of insecurities regarding the therapy’s proper application. The presented glove is tailored towards the specific needs of Vojta therapy, e.g. flexibility and small sensor size, and can help parents gather objective data on their therapy application at home. It has been tested in multiple therapy sessions on adult probands and seems to be a suitable tool to support parents and therapists in training alike. Additionally, the results of the accompanied therapy sessions provide arguments against what the critics have often cited about the painfulness of the therapy.
Sensitivity analysis of a computer model of neonatal oxygen transport
Authors: Huttova Veronika , Rafl Jakub , Bachman Thomas E. , Kudrna Petr , Rozanek Martin , Möller Knut 
Published: February 2021

Abstract
Computer models of neonatal oxygenation could serve as a tool for a comprehensive comparison of closed-loop automated oxygen control systems. The behaviour of such models depends, besides the input data of the inspired fraction of oxygen and the premature infant's breath pattern, on internal parameters of the model. The aim of this study was to perform a sensitivity analysis of a computer model of neonatal oxygen transport to clarify the influence of its internal physiological parameters on the output signal of peripheral oxygen saturation (SpO2). We performed a multi-parameter sensitivity analysis using Monte Carlo simulations for randomly generated values of eight internal parameters. The influence on the model output SpO2 signal was evaluated using five characteristics of the output signal. The relations between the parameters and the output characteristics were displayed using scatter plots and analysed by linear correlation, standardized regression, and partial correlation. The main result of the study is that in our model the oxygen consumption in the tissue and the cardiac output have the greatest influence on the SpO2 drop and minimal SpO2 value during simulated desaturation. The rate of development of desaturation and its duration are most affected by the diffusion resistance of the alveolar-capillary membrane. The results of the sensitivity analysis will help to optimize the performance of the computer model of neonatal oxygen transport.
A rule-based expert system for real-time feedback-control in deep brain stimulation
Authors: Bremm Rene Peter , Koch Klaus Peter , Krüger Rejko , Hertel Frank , Gonçalves Jorge 
Published: February 2021

Abstract
Programming in deep brain stimulation (DBS) is often a labour-intensive process. Although automatic closed-loop stimulation has recently been receiving considerable attention, it is still far from clinical settings. Testing in-loop stimulation in a clinical setting is extremely challenging due to manual programming and the lack of synchronisation between stimulation and monitoring devices. In this work, we present a simple rulebased expert system to test feedback-controlled DBS in a clinical setting. The new application operates in closed-loop with the physician as acting person and real-time feedback from an accelerometer. Patients with movement disorders such as in essential tremor announce an individually acceptable level of tremor as a boundary condition for control. As a proof-of-concept, the expert system provides continuous recommendations of stimulation parameters and guides the physician to increase or decrease DBS amplitude by capturing tremor acceleration power on the patients’ forearms. The introduced application considers the technical and practical aspects in a clinical setting. Data obtained from test subjects provide insight into tremor dynamics. We demonstrate the clinical applicability of the rule-based control system for future research focusing on tremor dynamics and inloop stimulation. Finally, a telemetry streaming system could provide the interface for the application of automatic tremor control without the physician as acting person.
Efficient Body Registration Using Single-View Range Imaging and Generic Shape Templates
Authors: Çallar Tolga-Can , Rueckert Elmar , Böttger Sven 
Published: February 2021

Abstract
Computer-aided medical systems, e.g. in the fields of medical robotics or image-based assistance, are continuously investigated to overcome human limitations concerning perception, memory or dexterity. A common requirement of such systems is the availability of a digital model describing the patient’s position and morphology during a procedure. Operational complexity and technical limitations of established 3D imaging methods leave clinical settings in need of a method for the fast acquisition of a three-dimensional body surface representation. For this purpose, we propose an unsupervised and efficient body registration pipeline based on the markerless elastic registration and completion of single-view stereo range images of the body surface with statistical parametric body shape templates. Initial results show a promising representative quality of the models generated through the registration process with submillimetric fitting accuracy and realistic surface morphology, indicating the general feasibility of our approach as an instant body registration method for automated medical and biometric applications.
Cross-sectional analysis of tubular polymer semi-finished products using ultrasound in comparison with other measuring methods
Authors: Sahmel Olga , Siewert Stefan , Schmidt Wolfram , Schmitz Klaus-Peter , Grabow Niels 
Published: February 2021

Abstract
In the sector of biomedical engineering and implant technology, high-precision geometry is often decisive for successful end product functionalization. Especially in the production of tubular polymer semi-finished products, e.g. for stent fabrication, it is important to assure the desired parameters, such as inner and outer diameter and wall thickness. Within the current study we analyzed semifinished products for manufacturing of polymeric stents using three different methods. Biodegradable poly-L-lactide (PLLA) tubes were examined by means of micro computed tomography, ultrasonic scanning and scanning electron microscopy. The final evaluation presents clear advantages of the ultrasonic measuring method for the measurement of outer and inner diameter and wall thickness.
Investigations of flow alteration of commissural misalignment of TAVR using Particle Image Velocimetry
Authors: Borowski Finja , Oldenburg Jan , Pfensig Sylvia , Kaule Sebastian , Siewert Stefan , Schmitz Klaus-Peter , Stiehm Michael 
Published: February 2021

Abstract
Due to the raising number of TAVR implantations (transcatheter aortic valve replacement), tests for durability and prevention of associated diseases are becoming increasingly important. Not only the anatomy but also the positioning of the TAVR is decisive for its clinical performance. A misalignment in the circumferential direction can influence the flow in the sinus and thus inhibit the blood supply of the coronary arteries and influence the thrombosis potential. Therefore, the modification of the flow field is investigated in this study. For the characterization of the flow fields the measuring method of digital particle image velocimetry is used. A hydraulic circulation model is used to generate physiological flow and pressure conditions. Additionally, an aortic root model with Sinus Valsalvae, which represents the implantation environment, was developed. A prototype of a TAVR was implanted aligned to the commissure lines of the native valve leaflets on the one hand, and misaligned by 60 degree to the commissure of the native valves on the other hand. By determining the velocity vector fields, it could be shown that implantation of the TAVR with a commissureal misalignment influences the flow around the leaflets. A comparison of the flow fields shows that different recirculation areas occur. This is also indicated by a comparison of the mean velocities in the sinus and the observed shear rates. The influence of the altered flow field on the thrombosis and hemolysis potential should be investigated in future studies.
Degradable dual co-electrospun polyester based nonwovens for guided tissue regeneration
Authors: Oschatz Stefan , Reske Thomas , Schmitz Klaus-Peter , Illner Sabine , Markhoff Jana , Eickner Thomas , Grabow Niels 
Published: February 2021

Abstract
In this study, initial experiments are presented regarding the suitability of polyester based nonwoven composite materials for guided tissue regeneration based on degradation. The in vitro degradation of poly(lactic-coglycolic acid)/polydioxanone and polycaprolactone/ polydioxanone mats has been performed under accelerated condition in alkaline glycine buffer at 50 °C for 21 days. The degradation of the materials has been characterized regarding total mass loss and macroscopic morphological changes, as well as determination of the molecular weight degradation via GPC experiments.
Immobilizing hydrolytic active Papain on biodegradable PLLA for biofilm inhibition in cardiovascular applications
Authors: Teske Michael , Kießlich Tina , Fischer Julia , Bahl Hubert , Wulf Katharina , Eickner Thomas , Grabow Niels , Illner Sabine 
Published: February 2021

Abstract
The use of biomaterials in medicine is becoming increasingly important. One of the main concerns is the foreign body associated infection caused by direct microbial contamination or clinical infections. The bacterial biofilm formation on biomaterials depends on their surface properties. Therefore, several anti-adhesive surface modifications were developed. Nevertheless, the demand for antimicrobial agents that prevent bacterial colonisation is still largely unmet. The immobilization of active antimicrobial agents, such as antibacterial peptides or enzymes, offers a potential approach to achieve long-lasting effectiveness. In this investigation, the hydrolytic enzyme papain with its published antibacterial activity was covalently immobilized on the well-established biodegradable biomaterial poly-L-lactic acid (PLLA). For the characterization of the enzymes on the PLLA surfaces, the protein content and enzyme activity were determined. A biofilm assay was performed to test the effect of the papain-modified PLLA samples on the biofilm-forming bacterial strain Clostridioides difficile, one of the most frequently occurring human nosocomial pathogens. The investigated hydrolytic enzyme papain could be immobilized by coupling via the crosslinker EDC to the PLLA surface. Detection was performed by determination of the amount of protein and the reduced biofilm growth after 24 h and 72 h compared to the reference.
PEGDA drug delivery scaffolds prepared with UV curing process
Authors: Rekowska Natalia , Konasch Jan , Riess Alexander , Mau Robert , Eickner Thomas , Seitz Hermann , Grabow Niels , Teske Michael 
Published: February 2021

Abstract
Individually tailored drug delivery systems (DDSs) are considered one of the most promising therapeutic tools for the creation of safe and effective treatments. DDSs as a novel approach should be beneficial in curing systemic as well as local ailments, where a high topical concentration of the drug and a reduction of side effects are desirable. It could also be favorable for patients requiring customized treatments, showing atypical profiles of drug metabolism. Development of particular drug delivery devices require the selection of a suitable scaffold material, which should exhibit proper mechanical and biological properties, but also enable adjustment of the drug release according to a specific need. Thus, it is extremely important to expand the knowledge concerning potential DDS components. Poly(ethylene glycol) diacrylate (PEGDA) according to its properties can be easily used as a DDS resin and shaped into a desired structure with the employment of techniques based on photopolymerization, including some novel 3D printing techniques. As a continuation of our previous works, in this paper drug release studies from conventionally prepared PEGDA scaffolds are presented. We have shown that in PEGDA materials, the release profile of the low molecular weight model drug acetylsalicylic acid can be altered by water content. PEGDA as a delivery material should be further investigated to specify its potential as a comonomer and a matrix for pharmaceutical agents.
Recognition of tenogenic differentiation using convolutional neural network
Authors: Dursun Gözde , Balkrishna Tandale Saurabh , Eschweiler Jörg , Tohidnezhad Mersedeh , Markert Bernd , Stoffel Marcus 
Published: February 2021

Abstract
Methodologies to assess stem cell differentiation in the culturing state are needed for regenerative medicine and tissue engineering techniques. In recent years, convolutional neural networks (CNNs), a class of deep neural networks, have made impressive advancements in image-based classification, recognition and detection tasks. CNNs have been introduced as a non-invasive cell characterization method by learning features directly from image data of unlabeled cells. Furthermore, this approach serves as a rapid and inexpensive methodology with high performance compared to traditional techniques that require complex laboratory procedures including antibody staining and gene expression analysis. Here, we studied the potential of the CNNs approach to recognize stem cell differentiation based on cell morphology utilizing phasecontrast microscopy images.We have examined the differentiation potential of bone marrow mesenchymal stem cells (BMSCs) into tenocytes, with the treatment of bone morphogenetic protein-12 (BMP-12). After treatment, the phase-contrast images of cells were obtained directly from cell culture flasks to train CNN and the differentiated phenotype of stem cells was characterized by immunostaining. CNN was able to classify the cells into three groups including non-stem cells (chondrocytes), stem cells (BMSCs) and differentiated stem cells (tenocytes) based on their morphology with 92.2 % accuracy. The presented study revealed that CNN performed faster and non-invasive cell classification task compared to traditional methodologies.
Smart 4D-printed implants and instruments
Authors: Wild Michael de , Dany Sebastian , John Christoph , Schuler Felix 
Published: February 2021

Abstract
Selective laser melting (SLM) was used to manufacture smart programmed structures with customized properties made of biocompatible NiTi shape-memory alloy. A series of helixes was produced with systematically varied SLM process parameters Laser Exposure Time and Laser Power in order to specifically change the thermo-mechanical material properties of the 3D-structures. This innovation opens up the possibility to adjust the NiTi phase transformation temperature during the manufacturing process. This controllable property determines which of the two crystallographic phases martensite or austenite is present at a certain operating temperature and allows the mechanical properties to be adjusted: martensitic devices are soft and pseudo-plastic due to the shape-memory effect, whereas austenitic structures are pseudo-elastic. In a further step, the SLM process parameters were locally varied within 4Dprinted twin-helixes. As a result, the phases, respectively the mechanical properties of a single component were adjusted at different locations. The ratio of elastic to plastic deformation and the spring constant of the helix can be locally controlled. This allows, for example, the spatio-temporal programming of 3D-printed surgical instruments or implants that are stimuliresponsive.
Measurement of respiratory rate with inertial measurement units
Authors: Beck Simon , Laufer Bernhard , Krueger-Ziolek Sabine , Moeller Knut 
Published: February 2021

Abstract
Demographic changes and increasing air pollution entail that monitoring of respiratory parameters is in the focus of research. In this study, two customary inertial measurement units (IMUs) are used to measure the breathing rate by using quaternions. One IMU was located ventral, and one was located dorsal on the thorax with a belt. The relative angle between the quaternion of each IMU was calculated and compared to the respiratory frequency obtained by a spirometer, which was used as a reference. A frequency analysis of both signals showed that the obtained respiratory rates vary slightly (less than 0.2/min) between the two systems. The introduced belt can analyse the respiratory rate and can be used for surveillance tasks in clinical settings.
Raman Spectroscopy to Characterize Bladder Tissue for Multidimensional Diagnostics of Cancer in Urology
Authors: Krafft C. , Guo S. , Bocklitz T. , Popp J. , Bronsert P. , Miernik A. 
Published: February 2021

Abstract
Fiber optic Raman spectroscopy offers labelfree identification of cancer in the bladder under in vivo conditions. However, state-of-the-art Raman technology does not enable to scan the entire bladder wall. Our multidimensional approach within the project Uro-MDD combines panoramic 3D-image reconstruction of white light cystoscopy and fluorescence lifetime imaging to define regions of interest for Raman-assisted diagnostics. First Raman results are presented from human control and cancer bladder specimens that demonstrated how to obtain specific molecular information. Such Raman images can be used in a clinical setting to determine cancer margins and the resection status. Fiber probes are under development to translate the technique to in vivo screening.
Simulating a Ground Truth for Transit Time Analysis of Indicator Dilution Curves
Authors: Reiß Michael , Naber Ady , Nahm Werner 
Published: February 2021

Abstract
Transit times of a bolus through an organ can provide valuable information for researchers, technicians and clinicians. Therefore, an indicator is injected and the temporal propagation is monitored at two distinct locations. The transit time extracted from two indicator dilution curves can be used to calculate for example blood flow and thus provide the surgeon with important diagnostic information. However, the performance of methods to determine the transit time Δt cannot be assessed quantitatively due to the lack of a sufficient and trustworthy ground truth derived from in vivo measurements. Therefore, we propose a method to obtain an in silico generated dataset of differently subsampled indicator dilution curves with a ground truth of the transit time. This method allows variations on shape, sampling rate and noise while being accurate and easily configurable. COMSOL Multiphysics is used to simulate a laminar flow through a pipe containing blood analogue. The indicator is modelled as a rectangular function of concentration in a segment of the pipe. Afterwards, a flow is applied and the rectangular function will be diluted. Shape varying dilution curves are obtained by discrete-time measurement of the average dye concentration over different cross-sectional areas of the pipe. One dataset is obtained by duplicating one curve followed by subsampling, delaying and applying noise. Multiple indicator dilution curves were simulated, which are qualitatively matching in vivo measurements. The curves temporal resolution, delay and noise level can be chosen according to the requirements of the field of research. Various datasets, each containing two corresponding dilution curves with an existing ground truth transit time, are now available. With additional knowledge or assumptions regarding the detection-specific transfer function, realistic signal characteristics can be simulated. The accuracy of methods for the assessment of Δt can now be quantitatively compared and their sensitivity to noise evaluated.
Measurement of the retinal irradiation exposure during diaphanoscopic illumination
Authors: Sieber Nicole , Kölbl Phillip , Lingenfelder Christian , Stucke-Straub Kathrin , Kupferschmid Sebastian , Hessling Martin 
Published: February 2021

Abstract
For the visualisation of the intraocular space it is essential to illuminate the inside of the eye. One illumination approach is diaphanoscopy, in which the light of an extraocular source is transmitted through the tissue layers of the eyewall. The transmission properties of these tissues and their irradiation load depend on applied diaphanoscope contact pressure. However, excessive illumination can lead to irreversible photochemical and thermal damage to the retina. In diaphanoscopic illumination, the retina is particularly at risk due to its proximity to the light source. Therefore, the photochemical and thermal retinal hazards, resulting from direct transmitted light through the eyewall, are determined for different applied pressures of the diaphanoscope on the eye (15, 65 and 115 kPa). The study is performed on porcine eyes with different pigmentation. So, the difference in intraocular irradiance, photochemical and thermal hazards, as well as the maximal exposure time is also examined for different pigmentations. For less pigmented eyes the irradiance inside the eye, the photochemical and the thermal hazard are higher than for higher pigmented eyes. The values also become significantly higher for increasing applied pressure with the diaphanoscope but do not exceed given limits in the standard DIN EN ISO 15004-2: 2014.
Developing an Intuitive and Feasible Setup for In-room Control During MRI-guided Interventions
Authors: Reich C. Martin , Unger Michael , Melzer Leon , Jochimsen Thies , Sattler Bernhard , Sabri Osama , Melzer Andreas 
Published: February 2021

Abstract
Magnetic resonance image (MRI)-guidance for minimally invasive interventions instead of CT-guidance is a promising technique to reduce radiation exposure for both patients and clinicians. Technical challenges have to be managed in order to meet safety regulations while enabling inroom system control and communication. Using nonproprietary software and hardware, several gradations for a setup for interventional MRI were elaborated. Eventually, a quickly and easily installable setup was established for technical support during MRI-guided interventions in the PET/MRI suite at the Department of Nuclear Medicine at University Hospital Leipzig. It is adaptable for most MRI suites.