bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated control of the laser welding process of heart valve scaffolds
Authors: Weber Moritz , Hoheisel Anna L. , Glasmacher Birgit
Published: December 2016

Using the electrospinning process the geometry of a heart valve is not replicable by just one manufacturing process. To produce heart valve scaffolds the heart valve leaflets and the vessel have to be produced in separated spinning processes. For the final product of a heart valve they have to be mated afterwards. In this work an already existing three-axes laser was enhanced to laser weld those scaffolds. The automation control software is based on the robot operating system (ROS). The mechatronically control is done by an Arduino Mega. A graphical user interface (GUI) is written with Python and Kivy.
Determination of the membrane hydraulic permeability of MSCs
Authors: Lopez Jennifer Contreras , Lauterböck Lothar , Glasmacher Birgit
Published: December 2016

A successful cryopreservation is based on knowledge of the optimal cooling rate. So far, this is often determined by way of complex parameter studies. Alternatively, the identification of cell specific characteristics, such as osmotic behaviour, membrane hydraulic permeability and activation energy could be used to calculate the optimal cooling rate. These parameters should be determined for supra-zero and sub-zero temperatures. In this study cryomicroscopy was used. Mesenchymal stromal cells (MSCs) from bone marrow were analysed. The determined membrane hydraulic permeability for sub-zero temperatures is significantly lower than that for supra-zero temperatures. On the contrary the activation energy is significantly higher in the presence of ice. The addition of a cryoprotective agent (CPA) such as dimethyl sulfoxid (DMSO) shows an additional influence on the characteristics of the membrane of the cell. The optimal cooling rate was determined with these parameters. For cryopreservation without DMSO the optimal cooling rate was found to be 12.82 K/min. If the MSCs were frozen with 5% (v/v) DMSO the optimal cooling rate is 16.25 K/min.
Medication process in Styrian hospitals
Authors: Hahnkamper Patrick , Baumgartner Christian , Schröttner Jörg
Published: December 2016

The aim of this work was to analyse the medication process and the potential for errors during the process steps. For this purpose, a literature review was conducted and a questionnaire was developed to compare the results from the literature with the current medication process in Styrian hospitals. The questionnaire was divided into four different parts with a total of 29 questions. For the survey all 37 Styrian hospitals were contacted whereas 11 filled out the questionnaire. The survey showed that there is no standardized medication process defined and that the rate of medication errors is generally underestimated. In addition, technical solutions may help to reduce errors but are expected to be hardly used in clinical practice.
Control tower to surgical theater
Authors: Buccioli Matteo , Traldi Leo
Published: December 2016

The main social priority is to reduce public debt and to streamline national health service (NHS) costs. Consequently, health managers need to acquire operating methods within their managerial structures so that all available resources are better planned in terms of effectiveness and efficiency, without compromising patient safety. In order to identify the information categories needed to know the whole surgical process is necessary to divide these in two main categories, supply and demand. Demand Information Group (DIG) contains the information that identify patients and its needs in terms of care. Instead Supply Information Group (SIG) contains information about hospital resources in order to cover the supply. The surgical process analyzed in terms such as industrial production process has the goal of produce the “health product for the patient” and its central part is performed in the operating room by a surgical team. This does not mean that the precedent and subsequent phases of the operating room have minor importance, in fact to obtain a high quality “health product” and reduce to a minimum the clinical risks related to the patient it is necessary that each phase of the process is carried out in the right way. The implementation of a Control Tower Approach allows for the management of productive process, able to guide hospital managers to identify the best strategies and to improve the risk management of patient safety in response to the guidelines of the World Health Organization.
Development of a skull phantom for the assessment of implant X-ray visibility
Authors: Hoffmann Thomas , Klink Fabian , Boese Axel , Fischer Karin , Beuing Oliver , Rose Georg
Published: December 2016

The paper presents the development and test of a skull phantom, which can be used for the assessment of the radiographic visibility of neurovascular implants. State of the art methods are based on specimens of the human skull. These are highly individual and not suitable for comparison of different radiographic data sets. The development process of the skull phantom is described from data generation to image processing, design and manufacturing using 3D printing. An experimental setup is recommended to generate reproducible data sets for implant visibility assessment with bone mimicking structures of the phantom. The model is evaluated by qualitative comparison with equivalent data sets of the original human skull model. The results show, that contrast characteristics of the phantom and the human skull model are similar. X-ray attenuation of the human bone is higher than the polymeric phantom material. The introduced phantom allows the determination of X-ray attenuation characteristics of different neurovascular implants for medical approval and testing processes.
Improvement of a subviral particle tracker by the use of a LAP-Kalman-algorithm
Authors: Rausch Andreas , Müller Dennis , Schanze Thomas
Published: December 2016

Automated detection and tracking of subviral particles is a promising method to obtain insights in complicated virus-cell interactions. This paper describes the implementation of a linear assignment problem solver and a Kalman-filter in an existing particle tracking algorithm. Two different simulated image sequences are used for the evaluation of the algorithms. Tracking and detection results of the new implemented solver are compared to the results of the original algorithm. The improved algorithm is able to improve the results by closing gaps in the particle tracks.
EyeGuidance – a computer controlled system to guide eye movements
Authors: Köhler Bernd , Bretthauer Georg , Guthoff Rudolf F. , Reichert Klaus-Martin , Sieber Ingo , Stachs Oliver , Toso Lorenzo , Allgeier Stephan
Published: December 2016

The densely innervated human cornea is the only superficial tissue of the human body in which nerve fibres are accessible in vivo by corneal confocal microscopy (CCM). Morphological parameters of the corneal sub-basal nerve plexus (SNP) derived from CCM images can potentially serve as a sensitive biomarker for early diagnosis of various neurodegenerative diseases. The evaluation of a single image with a typical field of view of 0.16 mm2 is insufficient for robust morphometric assessment. Mosaicking approaches have therefore been proposed to examine the SNP on a larger scale. Here we present a highly automated technique that significantly facilitates the generation of mosaic images of the SNP and is suitable for clinical tests.
US/MRI fusion with new optical tracking and marker approach for interventional procedures inside the MRI suite
Authors: Nagaraj Yeshaswini , Menze Bjoern , Friebe Michael
Published: December 2016

Interventional MRI in closed bore high-field systems is a challenge due to limited space and the need of dedicated MRI compatible equipment and tools. A possible solution could be to perform an ultrasound procedure for guidance of the therapy tools outside the bore, but still on the MRI patient bed. That could track and subsequently combine the superior images of MRI with the real-time features of ultrasound. Conventional optical tracking systems suffer from line of sight issues and electromagnetic tracking does not perform well in the presence of magnetic fields. Hence, to overcome these issues a new optical tracking system called inside-out tracking is used. In this approach, the camera is directly attached to the US probe and the markers are placed onto the patient to achieve the location information of the US slice. The evaluation of our novel system of framed fusion markers can easily be adapted to various imaging modalities without losing image registration. To confirm this evaluation, phantom studies with MRI and US imaging were carried out using a point-registration algorithm along with a similarity measure for fusion. In the inside-out system approach, image registration was found to yield an accuracy of upto 4 mm, depending on the imaging modality and the employed marker arrangement and with that provides an accuracy that cannot be easily achieved by combining pre-operative MRI with live ultrasound.
3D segmentation of thyroid ultrasound images using active contours
Authors: Poudel Prabal , Hansen Christian , Sprung Julian , Friebe Michael
Published: December 2016

In this paper, we propose a method to segment the thyroid from a set of 2D ultrasound images. We extended an active contour model in 2D to generate a 3D segmented thyroid volume. First, a preprocessing step is carried out to suppress the noise present in US data. Second, an active contour is used to segment the thyroid in each of the 2D images. Finally, all the segmented thyroid images are passed to a 3D reconstruction algorithm to obtain a 3D model of the thyroid. We obtained an average segmentation accuracy of 86.7% in six datasets with a total of 703 images.
Classification of indirect immunofluorescence images using thresholded local binary count features
Authors: Singh Susaiyah Allmin Pradhap , Pathan Suhail Parvaze , Swaminathan Ramakrishnan
Published: December 2016

Computer aided classification of HEp-2 cell based indirect immunofluorescence (IIF) images is a recommended procedure for standardising autoimmune disease diagnostics. In this work a novel feature, the thresholded local binary count (TLBC) has been proposed to classify IIF images into one among six classes. The TLBC is rotational invariant and is insensitive to pixel quantization noise. It characterizes the local binary gray scale pixel information in an image. The proposed feature along with global features such as area, entropy, illumination level and mean intensity, when classified using a support vector machine gave an accuracy of 86%. This feature could help in improving the diagnostics of autoimmune diseases which is highly clinically significant.
Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV) experimentation
Authors: Hütter Larissa , Geoghegan Patrick H. , Docherty Paul D. , Lazarjan Milad S. , Clucas Donald , Jermy Mark
Published: December 2016

Compliant phantoms of the human aortic arch can mimic patient specific cardiovascular dysfunctions in vitro. Hence, phantoms may enable elucidation of haemodynamic disturbances caused by aortic dysfunction. This paper describes the fabrication of a thin-walled silicone phantom of the human ascending aorta and brachiocephalic artery. The model geometry was determined via a meta-analysis and modelled in SolidWorks before 3D printing. The solid model surface was smoothed and scanned with a 3D scanner. An offset outer mould was milled from Ebalta S-Model board. The final phantom indicated that ABS was a suitable material for the internal model, the Ebalta S-Model board yielded a rough external surface. Co-location of the moulds during silicone pour was insufficient to enable consistent wall thickness. The resulting phantom was free of air bubbles but did not have the desired wall thickness consistency.
Effect of the number of electrodes on the reconstructed lung shape in electrical impedance tomography
Authors: Schullcke Benjamin , Krueger-Ziolek Sabine , Gong Bo , Moeller Knut
Published: December 2016

Electrical impedance tomography (EIT) is used to monitor the regional distribution of ventilation in a transversal plane of the thorax. In this manuscript we evaluate the impact of different quantities of electrodes used for current injection and voltage measurement on the reconstructed shape of the lungs. Results indicate that the shape of reconstructed impedance changes in the body depends on the number of electrodes. In this manuscript, we demonstrate that a higher number of electrodes do not necessarily increase the image quality. For the used stimulation pattern, utilizing neighboring electrodes for current injection and voltage measurement, we conclude that the shape of the lungs is best reconstructed if 16 electrodes are used.
Computer assisted assessment of progressing osteoradionecrosis of the jaw for clinical diagnosis and treatment
Authors: Kober Cornelia , Kjeller Göran , Sader Robert , Zeilhofer Hans-Florian , Berg Britt-Isabelle
Published: December 2016

Osteoradionecrosis (ORN) is a serious side effect of oncologic radiation therapy. Often, surgical removal of the affected skeletal tissue is indicated. In cranio-maxillofacial surgery, partial or total resection of the upper or lower jaw implies a severe impairment of the patient‘s quality of life. Up to now, clear display of ORN is still a challenge. This part of the project is dedicated to medical visualization of progressing ORN for clinical diagnosis. Currently, clinical diagnosis of ORN is mostly based on computer tomography (CT). With regard to its high advantages as e.g. reduced radiation dose, we additionally evaluate cone beam computer tomography (CBCT). After registration on a suitable reference and refined image processing and segmentation, all patient’s CT-/CBCT-data are subjected to various rendering techniques configured for the respective purpose, namely visualization of destructive and/or sclerotic skeletal alterations, consideration of cortical or trabecular bone, and analysis based on CT or CBCT. Recent achievements within the project were demonstrated with special focus on evaluation of both, CT and CBCT as well as on close cooperation with the clinical setting.
Evaluation of open-source software for the lung segmentation
Authors: Alnaser Aseel , Gong Bo , Moeller Knut
Published: December 2016

In this study we evaluated open-source software for lung segmentation. Several parameters which emphasize on functionality, usability, image quality and 3D export are considered for this evaluation. Based on these parameters, a scoring system is generated. Our preliminary evaluation results indicated that the Pulmonary toolkit obtains the best overall performance according to the scoring system. However, the ranking of software shows a certain variation among different criteria. The selection of software should regard the focus and the specific interest of the user.
Radiopacity assessment of neurovascular implants
Authors: Hoffmann Thomas , Gugel Sebastian , Beuing Oliver , Rose Georg
Published: December 2016

An experimental method for radiopacity evaluation of neurovascular implants is presented. State of the art methods are described for cardiovasular implants. To extend the methods to neurovascular devices, imaging parameters were determined from clinical radiography data sets and protocols. To reduce background noise, a thresholding method is introduced. This method is evaluated on a setup with four different laser cut and braided stents. The results are compared to current evaluation methods without filtering. It is shown that unfiltered methods underestimate the radiopacity by 0.89 mm ± 0.21 mm (aluminum equivalent). The introduced method is highly repeatable and uses modern clinical imaging technology. Thus an image evaluation under realisitc conditions is possible. Slightly visible vascular devices and implants can be compared with high accuracy.
Rapid prototyping of replica knee implants for in vitro testing
Authors: Verjans Mark , Asseln Malte , Radermacher Klaus
Published: December 2016

The understanding of the complex biomechanics of the knee is a key for an optimal implant design. To easily investigate the influence of prosthetic designs on knee biomechanics a rapid prototyping workflow for knee implants has been developed and evaluated. Therefore, different manufacturing technologies and post-treatment methods have been examined and overall seven different replica knee implants were manufactured. For evaluation, the manufacturing properties such as surface accuracy and roughness were determined and kinematic behaviour was investigated in a novel knee testing rig. It was carried out that PolyJet-Modelling with a sanded surface resulted in changed kinematic patterns compared to a usual CoCr-UHMWPE implant. However, fused deposition modelling using ABS and subsequent surface smoothening with acetone vapor showed the lowest roughness of the manufactured implants and only minor kinematic differences. For this reason this method constitutes a promising approach towards an optimal implant design for improved patient-satisfaction and long lifetime of the implant. Finally the workflow is not only limited to the knee.
Protecting ultra- and hyperhydrophilic implant surfaces in dry state from loss of wettability
Authors: Lüers Steffen , Laub Markus , Jennissen Herbert P.
Published: December 2016

Ultrahydrophilic titanium miniplates with sandblasted and acid etched (SLA) surfaces were protected from loss of hydrophilicity by an exsiccation layer of salt and stored in a dry state. Various salts in different concentrations were tested in respect to their conservation capacity and optical appearance. Potassium phosphate buffer in a specified composition appeared to be optimal. This optimal system was applied in a long time storage experiment showing no loss of hydrophilicity over years. It was also transferred with success to hyperhydrophilic dental implants.
Plasma treatment on novel carbon fiber reinforced PEEK cages to enhance bioactivity
Authors: Banghard Michael , Freudigmann Christian , Silmy Kamel , Stett Alfred , Bucher Volker
Published: December 2016

Carbon fiber reinforced polyetheretherketone (CFR-PEEK) has similar mechanical properties to human bone and is considered as the best alternative material to substitute titanium for spine cage implants. To compensate its poor osteogenic properties and limited bioinertness, CFR-PEEK was coated with a thin film of titanium. In the study, we investigated the biological response in vitro of titanium coated CFR-PEEK with different vacuum plasma pretreatments. The so modified surface revealed first hints for a good cell response by excellent cell adhesion and morphology of human osteoblast – like cells MG 63 (ATXX:’CRL-1427). Thus, the findings show that surface roughness of CFR-PEEK material has a profound effect on the biological activity via vacuum plasma treatment.
Wear of a total intervertebral disc prosthesis
Authors: Micheler Carina , Krampe Erhard , Foehr Peter , Haerst Miriam , Burgkart Rainer
Published: December 2016

In this study we characterized the wear behavior of a tribological system with material combinations of the total intervertebral disc prosthesis InDisc (Institute of Medical and Polymer Engineering) – consisting of two laser sintered titanium alloy plates with an elastomer inbetween. For the tests a translatory oscillation test bench was used which simulates the kinematic and the physiological environment of the lumbar spine. In the interface between the elastomer (Silopren LSR 2670) and the laser sintered titanium alloy (Ti6Al4V) abrasion cords out of silicone rubber with a maximal area of 500 × 700 μm2 were generated as well as individual particles with a size of 10 × 20 to 40 × 50 μm2. In the second prosthesis interface of Ti6Al4V and bone, bone particles with an area of 0.5 × 0.5 to 1 × 1 μm2 were detected. The wear particles and the amount of wear volume influence the biological response of a total intervertebral disc prosthesis in the body.
Digital health and digital biomarkers – enabling value chains on health data
Authors: Meister Sven , Deiters Wolfgang , Becker Stefan
Published: December 2016

Smart Devices, IoT and Co. are changing healthcare. The possibilities for pervasive sensing and analysis are fast increasing and new therapy concepts as well as business models are arising, related to the term “Digital Health”. The paper will give a brief overview on the history and ask, whether Digital Health is more than Telemedicine 4.0. Furthermore, we will ask for the prospective currency to participate in new preventive offer. Data is the new oil – Digital Biomarkers enable new value chains on health data and allow for the personalization of healthcare. We will present ongoing work of Fraunhofer ISST on a Digital Biomarker called beHealthy Health Score.
Usability in the lifecycle of medical software development
Authors: Trauzettel Franziska , Minge Michael
Published: December 2016

A close cooperation with users is necessary to ensure that interactive systems are robust, easy to use and accepted. Therefore, in medical technology, standards for usability are of fundamental importance. We investigated with the presented study how the concept of usability is currently understood and implemented in medical software companies. Interviews were conducted with 21 employees of German enterprises. Furthermore we extended an already existing quantitative online survey where 53 companies (including 24 from the health industry sector) participated in. Results show that the importance of usability is recognized by most of the respondents. Moreover, a wide variety of methods and approaches is known and implemented for exploring user needs and evaluating system prototypes. However, it was observed that human-centered design activities mainly focus on functionality, risk prevention and accessibility. Hedonic user needs and subjective perceptions (“user experience”) still play a minor role. Based on the results, practical requirements are derived and a “best case” for methodological approach is introduced.
Device development guided by user satisfaction survey on auricular vagus nerve stimulation
Authors: Kampusch Stefan , Kaniusas Eugenijus , Thürk Florian , Felten Dorian , Hofmann Ibolya , Széles Jozsef C.
Published: December 2016

Development of wearable point-of-care medical devices faces many challenges. Besides technological and clinical issues, demands on robustness, miniaturization, and user interface design are of paramount importance. However, a systematic assessment of these non-functional but essential requirements is often impossible within the first product cycle. Later, surveys on user satisfaction with existing devices and user demands can offer significant input for device re-development and improvement. In this paper, we present a survey on satisfaction with and demands for a wearable medical device for percutaneous auricular vagus nerve stimulation (pVNS). We analyzed 36 responses from patients treated with pVNS and five responses from experienced physicians in order to devise a future concept of pVNS. Main shortcomings of a current pVNS device were identified to be lacking water resistance and mechanical robustness, both impairing daily activities. Painful sensation during pVNS application, unwanted side effects like skin irritations and strongly varying perception of the stimulation were reported. Results urge for more patient self-governance and an (automatic) adjustment of the stimulation to the current physiological state of the patient. Attained results support a strategic approach for future developments of pVNS towards personalized health care.
Empirical assessment of the time course of innovation in biomedical engineering: first results of a comparative approach
Authors: Farkas Robert , Puiu Andrei Alexandru , Hamadeh Nader , Bukowski Mark , Schmitz-Rode Thomas
Published: December 2016

The pathway from the flash of a technological invention until its use as a medical device in every day care is tedious and burdensome. But the often postulated acceleration has to balance the speed of innovation and the indispensable product safety by an improved understanding of the innovation cycle. While several studies investigated the time course of pharmaceutical innovation, a comparable empirical analysis of medical devices is lacking. Thus we evaluated the time between the patent priority date and the corresponding receipt of the CE mark as a function of a medical device risk class in 61 cases. The statistical analysis yielded a time increment (trend) from medical devices in risk category I (median = 5.8 years) compared to risk category III (median = 10.4 years), which is close to literature reported values for drug development (9–12 years). The difference between products in risk classes I and II did not reach significance. To investigate the underlying facts, a text-mining approach especially to resolve the ambiguity of, e.g. patents, CE Marks etc. is suggested for increasing the sample size.
Assessment of nasal resistance using computational fluid dynamics
Authors: Osman Jan , Großmann Friederike , Brosien Kay , Kertzscher Ulrich , Goubergrits Leonid , Hildebrandt Thomas
Published: December 2016

Anterior rhinomanometry is the current gold standard for the objective assessment of nasal breathing by determining the nasal resistance. However, computational fluid dynamics would allow spatially and temporally well- resolved investigation of additional flow parameters. In this study, measured values of nasal resistance are compared with measured values. An unclear discrepancy between the two methods was found, suggesting further investigation.
Inspiratory and expiratory elastance in a non-linear autoregressive model of pulmonary mechanics
Authors: Langdon Ruby , Docherty Paul D. , Möller Knut
Published: December 2016

For patients with acute respiratory distress syndrome (ARDS), the use of mathematical models to determine patient-specific ventilator settings can reduce ventilator induced lung injury and improve patient outcomes. A non-linear autoregressive model of pulmonary mechanics was used to identify inspiratory and expiratory pressure-dependent elastance (Ei
and Ee
) as independent variables. The analysis was implemented on 19 data sets of recruitment manoeuvres (RMs) that were performed on 10 mechanically ventilated patients. At pressures p = 15–20 cmH2O the agreement between Ei
and Ee
was low. However, Ei
was a well-matched predictor of Ee
for p = 25–40 cmH2O, with R2 ≥ 0.78, and there was no significant bias in the difference between Ei
and Ee
. Since many other models cannot uniquely identify Ei
and Ee
, the outcome may provide further insight into the characteristics of ARDS lungs in sedated patients.
Principle study on the signal connection at transabdominal fetal pulse oximetry
Authors: Böttrich Marcel , Laqua Daniel , Husar Peter
Published: December 2016

Transabdominal fetal pulse oximetry is an approach to measure oxygen saturation of the unborn child non-invasively. The principle of pulse oximetry is applied to the abdomen of a pregnant woman, such that the measured signal includes both, the maternal and the fetal pulse curve. One of the major challenges is to extract the shape of the fetal pulse curve from the mixed signal for computation of the oxygen saturation. In this paper we analyze the principle kind of connection of the fetal and maternal pulse curves in the measured signal. A time varying finite element model is used to rebuild the basic measurement environment, including a bulk tissue and two independently pulsing arteries to model the fetal and maternal blood circuit. The distribution of the light fluence rate in the model is computed by applying diffusion equation. From the detectors we extracted the time dependent fluence rate and analyzed the signal regarding its components. The frequency spectra of the signals show peaks at the fetal and maternal basic frequencies. Additional signal components are visible in the spectra, indicating multiplicative coupling of the fetal and maternal pulse curves. We conclude that the underlying signal model of algorithms for robust extraction of the shape of the fetal pulse curve, have to consider additive and multiplicative signal coupling.
Evaluating different approaches to identify a three parameter gas exchange model
Authors: Kretschmer Jörn , Docherty Paul D. , Riedlinger Axel , Möller Knut
Published: December 2016

Mathematical models can be employed to simulate a patient’s individual physiology and can therefore be used to predict reactions to changes in the therapy. To be clinically useful, those models need to be identifiable from data available at the bedside. Gradient based methods to identify the values of the model parameters that represent the recorded data highly depend on the initial estimates. The proposed work implements a previously developed method to overcome those dependencies to identify a three parameter model of gas exchange. The proposed hierarchical method uses models of lower order related to the three parameter model to calculate valid initial estimates for the parameter identification. The presented approach was evaluated using 12 synthetic patients and compared to a traditional direct approach as well as a global search method. Results show that the direct approach is highly dependent on how well the initial estimates are selected, while the hierarchical approach was able to find correct parameter values in all tested patients.
Effects of fibrosis on the extracellular potential based on 3D reconstructions from histological sections of heart tissue
Authors: Rottmann Markus , Zürn Jannik , Arslan Ufuk , Klingel Karin , Dössel Olaf
Published: December 2016

Atrial fibrillation is the most common arrhythmia. However, the mechanisms of AF are not completely understood. It is known that fractionated signals are measured in AF but the etiology of fractionated signals is still not clear. The central question is to evaluate the effects of segmented fibrotic areas in histological tissue sections on the extracellular potential in a simulation study. We calculated the transmembrane voltages and extracellular potentials from the excitation wave front around a 3D fibrotic area from mouse hearts that were reconstructed from histological tissue sections. Extracellular potentials resulted in fragmented signals and differed strongly by stimulations from different directions. The transmural angle of the excitation waves had a significantly influence on the signal morphologies. We suggest for future clinical systems to implement the possibility for substrate mapping by stimulations from different directions in sinus rhythm.
From imaging to hemodynamics – how reconstruction kernels influence the blood flow predictions in intracranial aneurysms
Authors: Glaßer Sylvia , Berg Philipp , Voß Samuel , Serowy Steffen , Janiga Gabor , Preim Bernhard , Beuing Oliver
Published: December 2016

Computational fluid dynamics (CFD) is increasingly used by biomedical engineering groups to understand and predict the blood flow within intracranial aneurysms and support the physician during therapy planning. However, due to various simplifications, its acceptance remains limited within the medical community. To quantify the influence of the reconstruction kernels employed for reconstructing 3D images from rotational angiography data, different kernels are applied to four datasets with patient-specific intracranial aneurysms. Sharp, normal and smooth reconstructions were evaluated. Differences of the resulting 24 segmentations and the impact on the hemodynamic predictions are quantified to provide insights into the expected error ranges. A comparison of the segmentations yields strong differences regarding vessel branches and diameters. Further, sharp kernels lead to smaller ostium areas than smooth ones. Analyses of hemodynamic predictions reveal a clear time and space dependency, while mean velocity deviations range from 3.9 to 8%. The results reveal a strong influence of reconstruction kernels on geometrical aneurysm models and the subsequent hemodynamic parameters. Thus, patient-specific blood flow predictions require a carefully selected reconstruction kernel and appropriate recommendations need to be formulated.
Flow optimised design of a novel point-of-care diagnostic device for the detection of disease specific biomarkers
Authors: Dethloff Manuel , Dangers Marc , Wilmes Boris , Seitz Hermann
Published: December 2016

For the development of a novel, user-friendly and low cost point-of-care diagnostic device for the detection of disease specific biomarkers a flow optimised design of the test system is investigated. For this, computational fluid dynamics and rapid prototyping methods are used. The result is a functional design, which can be used for further experimental investigations.
Improved FPGA controlled artificial vascular system for plethysmographic measurements
Authors: Laqua Daniel , Brieskorn Carina , Koch Jan Hannes , Rothmayer Markus , Zeiske Steve , Böttrich Marcel , Husar Peter
Published: December 2016

The fetal oxygen saturation is an important parameter to determine the health status of a fetus, which is until now mostly acquired invasively. The transabdominal, fetal pulse oximetry is a promising approach to measure this non-invasively and continuously. The fetal pulse curve has to be extracted from the mixed signal of mother and fetus to determine its oxygen saturation. For this purpose efficient algorithms are necessary, which have to be evaluated under constant and reproducable test conditions. This paper presents the improved version of a phantom which can generate artificial pulse waves in a synthetic tissue phantom. The tissue phantom consists of several layers that mimic the different optical properties of the fetal and maternal tissue layers. Additionally an artificial vascular system and a dome, which mimics the bending of the belly of a pregnant woman, are incorporated. To obtain data on the pulse waves, several measurement methods are included, to help understand the behavior of the signals gained from the pulse waves. Besides pressure sensors and a transmissive method we integrated a capacitive approach, that makes use of the so called “Pin Oscillator” method. Apart from the enhancements in the tissue phantom and the measurements, we also improved the used blood substitute, which reproduces the different absorption characteristics of fetal and maternal blood. The results show that the phantom can generate pulse waves similar to the natural ones. Furthermore, the phantom represents a reference that can be used to evaluate the algorithms for transabdominal, fetal pulse oximetry.
Control scheme selection in human-machine- interfaces by analysis of activity signals
Authors: Doneit Wolfgang , Mikut Ralf , Liebetanz David , Rupp Rüdiger , Reischl Markus
Published: December 2016

Human-Machine Interfaces in rehabilitation engineering often use activity signals. Examples are electrical wheelchairs or prostheses controlled by means of muscle contractions. Activity signals are user-dependent and often reflect neurological weaknesses. Thus, not all users are able to operate the same control scheme in a robust manner. To avoid under- and overstraining, the interface ideally uses a control scheme which reflects the user’s control ability best. Therefore, we explored typical phenomena of activation signals. We derive criteria to quantify the user’s performance and abilities and present a routine which automatically selects and adapts one of three control schemes being best suited.
Event-based sampling for reducing communication load in realtime human motion analysis by wireless inertial sensor networks
Authors: Laidig Daniel , Trimpe Sebastian , Seel Thomas
Published: December 2016

We examine the usefulness of event-based sampling approaches for reducing communication in inertial-sensor-based analysis of human motion. To this end we consider realtime measurement of the knee joint angle during walking, employing a recently developed sensor fusion algorithm. We simulate the effects of different event-based sampling methods on a large set of experimental data with ground truth obtained from an external motion capture system. This results in a reduced wireless communication load at the cost of a slightly increased error in the calculated angles. The proposed methods are compared in terms of best balance of these two aspects. We show that the transmitted data can be reduced by 66% while maintaining the same level of accuracy.
Automatic pairing of inertial sensors to lower limb segments – a plug-and-play approach
Authors: Graurock David , Schauer Thomas , Seel Thomas
Published: December 2016

Inertial sensor networks enable realtime gait analysis for a multitude of applications. The usability of inertial measurement units (IMUs), however, is limited by several restrictions, e.g. a fixed and known sensor placement. To enhance the usability of inertial sensor networks in every-day live, we propose a method that automatically determines which sensor is attached to which segment of the lower limbs. The presented method exhibits a low computational workload, and it uses only the raw IMU data of 3 s of walking. Analyzing data from over 500 trials with healthy subjects and Parkinson’s patients yields a correct-pairing success rate of 99.8% after 3 s and 100% after 5 s.
Contactless respiratory monitoring system for magnetic resonance imaging applications using a laser range sensor
Authors: Krug Johannes W. , Odenbach Robert , Boese Axel , Friebe Michael
Published: December 2016

During a magnetic resonance imaging (MRI) exam, a respiratory signal can be required for different purposes, e.g. for patient monitoring, motion compensation or for research studies such as in functional MRI. In addition, respiratory information can be used as a biofeedback for the patient in order to control breath holds or shallow breathing. To reduce patient preparation time or distortions of the MR imaging system, we propose the use of a contactless approach for gathering information about the respiratory activity. An experimental setup based on a commercially available laser range sensor was used to detect respiratory induced motion of the chest or abdomen. This setup was tested using a motion phantom and different human subjects in an MRI scanner. A nasal airflow sensor served as a reference. For both, the phantom as well as the different human subjects, the motion frequency was precisely measured. These results show that a low cost, contactless, laser-based approach can be used to obtain information about the respiratory motion during an MRI exam.
Development of a low-cost senor based aid for visually impaired people
Authors: Loepthien Nora , Jehnichen Tanja , Hauser Josephine , Schullcke Benjamin , Möller Knut
Published: December 2016

The aim of the project is the development of an aid for blind or visually impaired people, considering economic aspects as well as easy adaptability to various daily situations. Distance sensors were attached to a walking frame (rollator) to detect the distance to obstacles. The information from the sensors is transmitted to the user via tactile feedback. This is realized with a number of vibration motors which were located at the upper belly area of the subject. To test the functionality of the aid to the blind, a testing track with obstacles has been passed through by a number of volunteers. While passing the track five times the needed time to pass through, as well as the number of collisions, were noticed. The results showed a decline in the average time needed to pass though the testing track. This indicates a learning process of the operator to interpret the signals given by the tactile feedback.
Patient assistive system for the shoulder joint
Authors: Scheuner Erika , Fabech Jonas , Textor Dominik , Kuster Roman , Heinlein Bernd
Published: December 2016

The mobility of the upper extremity is essential for everyday activities and for independent living. Shoulder disorders affect the range of motion, therefore a patient assistive system (PAS) for the shoulder joint can be used to compensate the restrictions. The developed PAS supports up to 120° of flexion and abduction. The portable dynamic orthotic consists of two levers and is attached to a hip belt. The upper arm of the patient is connected to the device using a brace. The prototype is driven by one motor and controlled by surface electromyography (EMG). The functionality of the system was successfully verified by tests with healthy subjects. For further development, a study with shoulder patients will be performed and health professionals will evaluate the PAS.
Automatic depth scanning system for 3D infrared thermography
Authors: Unger Michael , Franke Adrian , Chalopin Claire
Published: December 2016

Infrared thermography can be used as a pre-, intra- and post-operative imaging technique during medical treatment of patients. Modern infrared thermal cameras are capable of acquiring images with a high sensitivity of 10 mK and beyond. They provide a planar image of an examined 3D object in which this high sensitivity is only reached within a plane perpendicular to the camera axis and defined by the focus of the lens. Out of focus planes are blurred and temperature values are inaccurate. A new 3D infrared thermography system is built by combining a thermal camera with a depth camera. Multiple images at varying focal planes are acquired with the infrared camera using a motorized system. The sharp regions of individual images are projected onto the 3D object’s surface obtained by the depth camera. The system evaluation showed that deviation between measured temperature values and a ground truth is reduced with our system.
Patient-specific hip prostheses designed by surgeons
Authors: Coigny Florian , Todor Adi , Rotaru Horatiu , Schumacher Ralf , Schkommodau Erik
Published: December 2016

Patient-specific bone and joint replacement implants lead to better functional and aesthetic results than conventional methods [1], [2], [3]. But extracting 3D shape information from CT Data and designing individual implants is demanding and requires multiple surgeon-to-engineer interactions. For manufacturing purposes, Additive Manufacturing offers various advantages, especially for low volume manufacturing parts, such as patient specific implants. To ease these new approaches and to avoid surgeon-to-engineer interactions a new design software approach is needed which offers highly automated and user friendly planning steps.
Syntactic variation and diachrony. The case of the Dutch dative alternation
Authors: Geleyn Tim
Published: December 2016

In Dutch, as in several other languages, many ditransitive verbs alternate between a construction with two unmarked NP objects coding the recipient and the theme (the
How to identify moral language in presidential speeches: A comparison between a social-psychological and a cognitive-linguistic approach to corpus analysis
Authors: Renardel de Lavalette Kiki Y. , Steen Gerard , Burgers Christian
Published: December 2016

Lakoff (2002 [1996],Moral politics. How liberals and conservative think. Chicago: The University of Chicago Press) presents the Theory of Moral Politics (TMR), as based in the roles of metaphor in moral thinking in American Politics. Two distinct methods of data analysis, one social-psychological and one cognitive-linguistic, have been employed to empirically test Lakoff’s assertions on moral reasoning, but have yielded different results. We applied both methods to the same corpus of speeches to determine whether they would yield similar results and could thus be considered to be equally appropriate ways of testing the presence of moral language. We show that the method affects what sort of conclusion can be drawn from research. Consequently, when testing TMR, we recommend that the corpus-linguistic method used is critically evaluated.
Limeating Inc
Authors: Rossolatos George
Published: December 2016

Competitive and speed eating by now constitute a mainstay in contemporary food culture. This paper outlines an emergent consumptive trend that radiates through Furious Pete’s, a popular professional speed eater, postcolonial omnivorous ethos that is tagged ‘limeating’, denoting eating to the limit or eating the limit. By drawing on the key distinction between drives and desire, I argue that the cultural phenomenon of limeating eludes and at the same time buttresses consumptive desire, while inviting the limeater’s audience to a regressive path to unbound orality, coupled with an indiscriminate will-to-introjection. Furious Pete is shown to be instituting a new hamburger standard that, contrary to the established Big Mac Index, does not concern the relative pricing of Big Macs across cultures, but the annihilation of differentially valorized gastronomic offerings in the face of cannibalistic drives.
The Anthropo-Semiotics of the Chinese Funeral Striptease
Authors: Mosquera Alexander
Published: December 2016

Although ritual funeral dances have been present throughout the history of some human societies, it is noteworthy that in some rural areas of countries such as China the funeral striptease as a cultural tradition has been established. The general goal of this work is to understand the presence of the striptease as a component part of funeral rituals in Chinese rural culture. To this end, the works of Finol on anthropo-semiotics (2011), of Lotman on the semiotics of culture (1996, 1998, 1999, 2000), of Peirce on triadic semiotics (1987), of Van Gennep on rites of passage (1984, 2008), and Del Fresno’s concept of Netnography (2011) were used to analyze this phenomenon from an epistemological introspective-experiential approach (Padrón Guillén 2001, 2003). The study concludes with three main findings: the funeral striptease serves as a mask used by humans to hide the fear of death, to give an aesthetic role to death, and to express the underlying nakedness of a person faced with the binomial life/death.
Discursive Heterogeneity in Chinese Literature
Authors: Gándara Lelia , Sartori María Florencia
Published: December 2016

In this paper we explore the marks of discursive heterogeneity in literary works produced in situations of language and culture contact. We analyze novels written by contemporary Chinese authors who live outside the People’s Republic of China and produce their work in English and French: Qiu Xiaolong (裘小龙) and Dai Sijie (戴思杰), respectively. We address marks of heteroglossia and discursive heterogeneity and explore the construction of the narrator and the narratee in their novels. In order to validate our analysis, we compare these authors with a Chinese writer who lives and produces his work in China: Mo Yan’s on his French and Spanish translated novels. Taking into account the discursive strategies deployed and the polyphonic marks, we demonstrate that Qiu and Dai construct Chinese narrators and Western narratees, while Mo Yan constructs Chinese narrators and narratees. In our analysis we apply notions of polyphony from Bakhtin and Ducrot, rhetoric concepts from Olbrecht-Tyteca and Per elman, the notion of discursive heterogeneity by Authier, and the discursive ethos analysis proposed by Maingueneau.
Marczewski–Burstin Representations vs. Bernstein and Dense Subsets
Authors: Nowik Andrzej
Published: December 2016

We find values of superposition of Marczewski-Burstin operation and operation of finding Bernstein sets. Several counterexamples of Marczewski-Burstin systems are given.
Painlevé Equation PII and Strongly Normal Extensions
Authors: Miri Sofiane El-Hadi
Published: December 2016

The aim of this paper is to show that if F is a differential field and y is a PII transcendent such that tr.deg.F 〈y〉 = 2, then every constant in F〈y〉 is in F. We also show that in this case, F〈y〉 is not contained in any strongly normal extension.
More on Ostrowski Type Inequalities for some S-Convex Functions in the Second Sense
Authors: Liu Zeng
Published: December 2016

Some Ostrowski type inequalities for functions whose second derivatives in absolute value at certain powers are s-convex in the second sense are established. Two mistakes in a recently published paper are pointed out and corrected.