bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vascular pattern detection and recognition in endoscopic imaging of the vocal folds
Authors: Boese Axel , Illanes Alfredo , Balakrishnan Sathish , Davaris Nikolaos , Arens Christoph , Friebe Michael 
Published: September 2018

Abstract
At present transoral laryngeal interventions are mainly observed and controlled by an external two dimensional direct microscopic view. This modality provides an overall view on the surgery situs in a straight line of sight. For treatment planning and appropriate documentation, an endoscopic inspection is mandatory prior to surgery. Nowadays a detailed endoscopic work-up of laryngeal lesions can be performed by contact endoscopy in combination with structure enhancement like Narrow Band Imaging. High resolution and magnification of up to 150 times provide detailed visualization of vascular structures and pathological changes of the tissue surface. In these procedures it is difficult however to localize the evaluated areas on large scale scenes like the microscopic view used for surgery. To provide a fast and easy image matching an automated vessel pattern recognition and allocation is presented. Endoscopic images depicting representative vessel structures of the vocal folds are selected out of contact endoscopy video scenes. These images are pre-processed for background homogenization. A Frangi Vessel Segmentation filter and morphological operations are used to extract the vessel structure and match it to the microscopic image. Using this method 4 detailed contact endoscopy images could be allocated in different scenes of the microscope video. This method can be used to simplify treatment planning and to prepare image data for documentation.
Fractal Dimensions of Subviral Particle Movement
Authors: Rausch Andreas , Schanze Thomas 
Published: September 2018

Abstract
The development of new medicines against virus infections like the Marburg virus disease requires an accurate knowledge of the respective pathogens. Conventionally, this process is very time expensive. In cooperation with the Virology of the Philipps-University in Marburg an automatic tracking algorithm for subviral particles in fluorescence image sequences was developed and programmed. To expand the benefit for the pharmaceutical researchers, also the trackevaluations need to be widely automated. In this work, a new parameterizing-method facing the fractal dimensions of spline interpolated subviral particle tracks is presented and tested with simulated and real data. The results reveal a good potential to classify tracks and, thus, types of subviral particles in infected cells.
A Summing Configuration based Low Noise Amplifier for MPI and MPS
Authors: Malhotra Ankit , Buzug Thorsten M. 
Published: September 2018

Abstract
Magnetic particle imaging (MPI) is a novel tomographic imaging modality which uses static and dynamic magnetic fields to measure the magnetic response generated by superparamagnetic iron oxide nanoparticles (SPIONs). For the characterization of the SPIONs magnetic particle spectroscopy (MPS) is used. In the current research, a low noise amplifier (LNA) suitable for MPI and MPS is presented. LNA plays a significant role in the receive chain of MPI and MPS by amplifying the signals from the nanoparticles while keeping the noise induced through its own circuitry minimal. The LNA is based on the summing configuration and fabricated on a printed circuit board (PCB). Moreover, the prototyped LNA is compared with a commercially available pre-amplifier. The input voltage noise of the prototyped LNA with a receiving coil of series resistance of 0.551 mΩ and an inductance of 130 μH is 561 pV/√Hz with a noise figure (NF) of 11.57 dB.
Progress and challenges in the development of novel implant concepts for cardiovascular, ophthalmologic and otolaryngologic applications
Authors: Grabow Niels , Schmitz Klaus-Peter 
Published: September 2018

Abstract
Medical device innovations may contribute to the reconstruction of biological functions, and thereby improve the quality of patients’ lives, as well as extend their life expectancy. The coordinated research project “RESPONSE - Partnership for Innovation in Implant Technology” (BMBF program Twenty20 - Partnership for Innovation, 2014 - 2021) is focusing on the development of novel concepts for implantable medical devices for cardiovascular, ophthalmologic and otorhinolaryngologic applications. The joint research efforts of academia and industry in the RESPONSE consortium address the challenges in implant design, biofunctionalization, process development and production. Particular attention is paid to the process of translation of medical device innovations, cost analysis, as well as health technology assessment.
Electrospinning for polymeric implants in cardiovascular applications
Authors: Kohse Stefanie , Arbeiter Daniela , Reske Thomas , Stiehm Michael , Schmitz Klaus-Peter , Grabow Niels 
Published: September 2018

Abstract
Electrospinning is a method for producing fibrous polymer scaffolds that can be applied in drug delivery systems as well as for polymer-based implants. Biodegradable polymers for the purpose of cardiac tissue engineering are often applied as fibrous scaffolds for morphological mimikry of natural matrices but also drugeluting approaches are very promising. Hydrolytic degradation is one of the key parameters for successful application. The focus of our investigations is on monitoring accelerated in vitro degradation of electrospun nonwoven scaffolds. In the presented study degradation of poly(Llactide) is accelerated by alkaline hydrolysis. The process is characterized by weight loss, loss of molecular mass, surface morphology and thermal behavior of nonwoven samples, showing a fast degradation of the fibrous material within two weeks.
Short Distance Impedance Pneumography
Authors: Klum Michael , Schenck Tianhao , Pielmus Alexandru , Tigges Timo , Orglmeister Reinhold 
Published: September 2018

Abstract
Gold-standards for biosignal acquisition require body-spanning sensor positioning which is contradictory to the high integration of modern wearable medical monitors. In applications where obtrusiveness can decrease accuracy, as in sleep monitoring, compact sensor configurations are not only a matter of convenience. To acquire respiratory signals, most systems rely on nasal cannula pressure sensors or inductance plethysmography. Another well-established method is the impedance pneumography, where we aim to contribute to the field of short distance electrode configurations. Evaluating distances down to 8 cm we report linear correlations above 0.85 with respect to a pneumotachometer reference. We estimate the respiratory rate with an error below 0.2 bpm. Inspiratory and expiratory phase detection is possible with an error below 2.5 %. Using a first order polynomial model we estimated the respiratory flow with a relative error of down to 19 % at 8 cm. We conclude that short distance impedance pneumography is feasible and rough flow and volume estimates are possible using linear models. Further research regarding shorter distances and calibration is of great interest.
Bioimpedance Analysis of L929 and HaCaT Cells in Low Frequency Range
Authors: Teixeira Viviane S. , Kalckhoff Jan-Patrick , Krautschneider Wolfgang , Schroeder Dietmar 
Published: September 2018

Abstract
In this work, Bioimpedance Spectroscopy (BIS) is used to study fluids and cell solutions. A n ew fourelectrode- terminal (4T) chamber using 3D printing and stainless steel corrosion resistant V4A was designed to measure the impedance of live cell solutions at the frequency range 0.1Hz- 1MHz. At f < 1kHz the double layer (DL) that builds at electrode’s surface raises the impedance substantially preventing the observation of the real impedance of the cells. The new 4T design circumvents the DL, is more robust and cheap, and allows for the repeatability of the results. Experiments were performed in vitro with two cell lines, L929 (mouse fibroblasts) and HaCaT (human keratinocytes). Results show that it is possible to distinguish between the two cell types by means of its BIS measurements in the new setup. Also, a low-frequency dispersion (α-dispersion) was observed in HaCaT cells solution, but not in L929. Furthermore, a potentiostat circuit model was developed in LTSpice to simulate the hardware setup and two different circuit models were used to fit cell’s data.
The opportunities of biodynamic lighting in homes for the elderly
Authors: Plischke Herbert , Linek Matthäus , Zauner Johannes 
Published: September 2018

Abstract
Light is an important factor for regulation of circadian, endocrine and metabolic processes in the human body. Through this light has a positive effect on cognition, on the stabilization of circadian rhythms and for general wellbeing. These effects are described as non-visual effects of light. Many dynamic lighting systems are already in use in workplaces and living spaces, aiming to address visual and also non-visual effects. In Europe and US the term “Human Centric Lighting” or abbreviated "HCL” was introduced, as a scientifically agreed concept on how to plan non-visual effects of artificial light in synergy with natural light. Older people, especially with neurological and psychological diseases can especially benefit from this lighting concept. However, in order to achieve the desired non-visual effects, certain conditions should be fulfilled. In Germany the DIN SPEC 67600 is a guideline for the design of biologically effective illumination, with examples for senior- and nursing homes. A goal of this evaluation was to check whether the recommendations of the specification DIN SPEC 67600 in three nursing homes were met and another goal was if effectiveness of the lighting on residents and nursing staff can be determined. Photometric measurements were taken and subjective perceived non-visual effects of light were surveyed using a questionnaire. Results: Although none of the three facilities met all the criteria of the DIN SPEC 67600 guidelines, non-visual lighting effects on residents and nursing staff could be detected. The results also indicate that careful attention should be paid on maintenance of HCL systems. The correct use of HCL solutions in homes for the elderly has opportunities to improve health status if the system is properly designed and maintained. Therefore next to the existing (non-visual) metrics and HCL design guidelines, guidelines for maintaining and regular inspections should be established.
Silicone-based Chip-in-Foil System
Authors: Bleck Lena , Heid Andreas , Metzen Rene von 
Published: September 2018

Abstract
Aiming at devices for bioelectronic medicine, this paper proposes a die embedding process for the fabrication of flexible smart implants. By combining thinned bare dies with a polymeric encapsulation, completely flexible implants can be designed. The dies are encapsulated using a flip-chip process and a backfilling with silicone rubber. A completely even surface without detectable edge between the chip and the surrounding polymer substrate is achieved by gluing the chips face-down onto a polyimide-covered substrate. The backside is coated with silicone rubber and a second carrier substrate is attached. Removing the first substrate subsequent to curing of the silicone leads to chips located under a continuous polyimide layer, enabling the use of microtechnology for further processing steps. A custom-made test chip is proposed that enables the evaluation of the mechanical and chemical stability of the system.
Biomechanics and clinical experience of a 3D biomimicking vascular stent
Authors: Schmidt Wolfram , Wissgott Christian , Brandt-Wunderlich Christoph , Behrens Peter , Schmitz Klaus-Peter , Grabow Niels , Andresen Reimer 
Published: September 2018

Abstract
The presented investigation was designed to assess the biomechanical behavior of a 3D biomimicking self-expanding stent with respect to general technical parameters added by first clinical tests. The test sample was a Veryan Medical Biomimics 3D with 6.0 mm expanded diameter and 80 mm length. The profile of the delivery catheter with mounted stent, the strut thickness, the bending stiffness, the axial stiffness for tension and compression and the length change during expansion were measured. The bending stiffness was 2.73 Nmm², axial stiffness at tension 7.77 N/mm and at compression 97.61 N/mm. The stent shortened during expansion by 11.54 %. Radial force at 5 mm diameter was 2.54 N. Clinical experience provided no stent fractures after 24 months. Duplexsonography showed stent patency without any binary restenosis or intimal hyperplasia.
Histological evaluation of a cochlear implant electrode array with electrically activated shape change for perimodiolar positioning
Authors: Rau Thomas S. , Suzaly N.úha , Pawsey Nick , Hügl Silke , Majdani Lenarz , Majdani Omid 
Published: September 2018

Abstract
For the treatment of deafness or severe hearing loss cochlear implants (CI) are used to stimulate the auditory nerve of the inner ear. In order to produce an electrode array which is both atraumatic and reaches a perimodiolar final position a design featuring shape memory effect was proposed. A Nitinol wire with a diameter of 100 μm was integrated in a state of the art lateral wall electrode array. The wire serves as an actuator after it has been ‘trained’ to adopt the spiral shape of an average human cochlea. Three small diameter platinum-iridium wires (each 20 μm) were crimped to the Nitinol wire in order to produce thermal energy. An insertion test was pursued using a human temporal bone specimen. The prototype electrode array was cooled down by means of immersion in ice water and freeze spray to enable sufficient straightening. Thereafter, insertion into the cochlea through the round window as performed. Insertion was feasible but difficult as premature curling of the electrode occurred during the movement towards the inner ear while passing the middle ear cavity. Therefore, the insertion had to be performed faster than usual. The shape memory actuator was subsequently activated with 450mA current at 5V for 3 seconds. After insertion the specimen was embedded in epoxy resin, microgrinded and all histological slices were assessed for trauma. Perimodiolar position was achieved. No insertion trauma was observed and there were no indications of thermal damage caused by the electrical heating. To the best of our knowledge, this is the first histological evaluation of the insertion trauma caused by an electrically activated shape memory electrode array. These promising results support further research on shape memory CI electrode arrays.
Hemodynamic influence of design parameters of novel venous valve prostheses
Authors: Stiehm Michael , Kohse Stefanie , Schümann Kerstin , Kaule Sebastian , Siewert Stefan , Oldenburg Jan , Keiler Jonas , Grabow Niels , Wree Andreas , Schmitz Klaus-Peter 
Published: September 2018

Abstract
Venous ulcers of the lower limbs are one clinical manifestation of chronic venous insufficiency. Currently, there is no venous valve prosthesis available. This study presents novel venous valve prostheses made of threedimensional electrospun fibrous nonwoven leaflets. The aim of this study was to prove the feasibility of the manufacturing process as well as to investigate design features of the venous valve prostheses from a hemodynamic point of view. An adapted pulse duplicator system (ViVitrolabs, Victoria, BC, CA) was used for characterization of the hydrodynamic performance. For eight different venous valve prototypes flow rate, effective orifice area and regurgitation fraction was investigated in vitro. In particular, tricusp valve designs showed an up to 40% higher effective orifice area as well as 15% higher maximum flowrate compared to bicusp valve designs. However, the regurgitation fraction of the bicusp valve designs is up to 86% lower compared to tricusp valve. Additionally, the hemodynamic performance of the tricuspid valves showed a high sensitivity regarding the leaflet length. Bicuspid valves are less sensitive to changes of design parameters, more sufficient and therefore highly reliable.
Usability Evaluation of a One-Handed Touchbased OR-Table Control
Authors: Krumholz Philipp , Janß Armin , Radermacher Klaus 
Published: September 2018

Abstract
Due to the increasing number and the complexity of devices in the operation room (OR), which are caused by the diversity and variety of proprietary interface designs, the probability for use errors increases. In order to ensure a safe intraoperative workflow in the OR, integrated OR systems with central work stations have been developed. For this, there also exist concepts for handhelds, which offer touchbased graphical user interfaces (GUI). However, those come along with various limitations, e.g. possibility for one-handed interaction, which is influenced i.a. by the size, the design and the working task. Within our investigations, requirements for an enhanced concept have been gathered by taking into account corresponding standards regarding ergonomics, riskmanagement and usability-engineering. According to DIN EN 60601-2-46, machinery directive 2006/42 EG and guideline VDI/VDE 3850, the stipulated user interface has been designed in order to preselect functions on the touchscreen and their subsequent activation by physical buttons. Furthermore, the accessibility of areas of interest has been considered on the touchscreen, to avoid the re-gripping of the handheld. As a first step, the OR-table control for a tablet has been realized with Microsoft Blend, using a 22’ touch monitor. The usability study has been conducted in accordance with DIN EN ISO 9241-11 and IEC 62366. A group of ten surgeons and OR nurses underwent multiple tasks in the framework of a usability test, comparing the developed concept with a common keypad handheld. The study showed comparable results concerning the usability criteria effectiveness and efficiency. However, the concept clearly outperforms the handheld regarding user satisfaction, in particular due to the higher learnability and the easy transfer of daily-used GUI skills. The current approach motivates to develop a functional model of a touch-based handheld for OR-tables as well as with further integrated OR devices and to conduct additional usability studies.
Analysis and Simulation of the Illumination Optics of Rigid Medical Endoscopes
Authors: Gaertner Alexander , Belloni Paola 
Published: September 2018

Abstract
Our work focuses on enhancing the illumination optics of a rigid medical endoscope using optomechanical simulation. We aim on improving the efficiency of the illumination optics to provide more light in the surgeon’s field of view (FOV) and therefore better image quality. We conducted an extensive market analysis and measured several rigid endoscopes and their external light sources in the lighting technology laboratory. Surprisingly, all endoscopes showed a degree of efficiency below 20 %. Our optimization approach is based first on a photometric and colorimetric analysis carried out with an integrating sphere and a goniophotometer. Secondly, the results obtained are implemented in a 3Doptomechanical simulation model developed with the raytracing software LightTools (Synopsis©). In the simulation model both the geometrical components as well as the critical interfaces are examined considering light coupling at boundary surfaces and light transfer within the illumination optics. Moreover, the optimization takes into account spectral power distribution (SPD) and angular light distribution (ALD) of the light provided from the fiberoptic cable connected to an external light source as well as additional interfering factors like gluing, dispersive absorption and total reflection at critical angles.
Clinical Evaluation of Mobile Medical Apps
Authors: Michael Scholtes , Annemarie Behrend , Buedenbender Stephanie , Volker Gross , Keywan Sohrabi 
Published: September 2018

Abstract
Computer applications in medicine are very important. However, there are differences in quality of such software, which periodically led to discussions about safety, regulation, and registration of software applications. Today, the admission procedure of medical products is highly regulated, and this applies also for mobile medical apps. The clinical evaluation is one important aspect of the admission procedure, especially due to the latest regulatory changes of the guideline MedDev 2.7/1 revision 4. The requirements have increased, and uncertainty grows in medical app development companies. The aim of this paper was the development of a process orientated guide, that gives an overview of the needed steps of a clinical evaluation of mobile medical apps and that could help to give a rough estimation about the necessary effort. The guide was developed, based on the relevant literature and legal texts. The clinical evaluation can be conducted in five substeps: “Planning and Scoping”, “Literature Research”, “Literature Assessment”, “Clinical Data Analysis” and “Reporting”. Prospectively, this guide will be evaluated by developers and adjusted, as soon as Medical Device Regulation is legally binding.
Innovative Ventilation Technology for Operating Rooms
Authors: Gruber Sabine , Buhl Sebastian , Bulitta Clemens 
Published: September 2018

Abstract
The purpose of this work was to evaluate the decontamination potential of the Potok system both in an experimental setting in a research Operating Room (OR) with standalone Air Decontamination Units (Potok 150-M-01) and in a clinical setting in a real operating theatre in Moscow. Our experiments showed an impact of the Potok units on the bacterial contamination of the room air according to the Swedish SIS-TS 39:2015 standard. For the initial measurements in our research OR in Weiden this could be shown by a decrease of the bacterial burden at all three different measurement points (OR table, instrumentation tray, periphery). Also the subsequently done measurements in the Moscow hospital verified this decontaminating effectivity of the Potok system. In this case the initial background contamination of the operating theatre was higher than in the research OR in Germany. This bacterial burden could be effectively decreased by the use of the installed Potok based ventilation system.