bluuebunny/crossref_metadata_2025_split huggingface dataset:
An automatic systolic peak detector of blood pressure waveforms using 4th order cumulants
Authors: Schmidt Marcus , Schumann Andy , Bär Karl-Jürgen , Rose Georg 
Published: December 2016

Abstract
The arterial blood pressure (ABP) holds a lot of information about the cardiovascular system. To analyse the ABP signal, at first the pulse wave has to be detected correctly. Due to influences, e.g. of noise, an accurate beat detection is a challenging task. In this work, a novel real-time ABP detector based on higher-order statistics is presented. The method uses the 4th order cumulants for ABP-peak detection. To evaluate this detector, the Fantasia database freely available at physionet was used. In this database, 142,936 systolic peaks were available to check the efficiency of the beat detector. A sensitivity of 99.91% and a positive predictive value of 99.50% were achieved with the novel method.
In-vitro experiments to characterize ventricular electromechanics
Authors: Arnold Robert , Prassl Anton J. , Hofer Ernst , Plank Gernot 
Published: December 2016

Abstract
Computer simulation turns out to be beneficial when clinical data lack spatio-temporal resolution or parameters cannot be measured at all. To derive trustworthy results, these in-silico models have to thoroughly parameterized and validated. In this work we present data from a simplified in-vitro setup for characterizing ventricular electromechanics. Right ventricular papillary muscles from New Zealand rabbits were isolated and stretched from slack length to lmax
, i.e. the muscle length at maximum active force development. Active stress development showed an almost linear increase for moderate strain (90–100% of lmax
) and a significant decrease for larger strain (100–105% of lmax
). Passive strain development showed a nonlinear increase. Conduction velocity CV showed an increase of ≈10% between low and moderate strain and no significant decrease beyond. Fitting active active stress-strain relationship using a 5th-order polynomial yielded adequate results for moderate and high strain values, whereas fitting using a logistic function yielded more reasonable results for low strain values. Passive stress-strain relationship was satisfactorily fitted using an exponential function.
Detection of microsleep events in a car driving simulation study using electrocardiographic features
Authors: Lenis Gustavo , Reichensperger Patrick , Sommer David , Heinze Christian , Golz Martin , Dössel Olaf 
Published: December 2016

Abstract
Microsleep events (MSE) are short intrusions of sleep under the demand of sustained attention. They can impose a major threat to safety while driving a car and are considered one of the most significant causes of traffic accidents. Driver’s fatigue and MSE account for up to 20% of all car crashes in Europe and at least 100,000 accidents in the US every year. Unfortunately, there is not a standardized test developed to quantify the degree of vigilance of a driver. To account for this problem, different approaches based on biosignal analysis have been studied in the past. In this paper, we investigate an electrocardiographic-based detection of MSE using morphological and rhythmical features. 14 records from a car driving simulation study with a high incidence of MSE were analyzed and the behavior of the ECG features before and after an MSE in relation to reference baseline values (without drowsiness) were investigated. The results show that MSE cannot be detected (or predicted) using only the ECG. However, in the presence of MSE, the rhythmical and morphological features were observed to be significantly different than the ones calculated for the reference signal without sleepiness. In particular, when MSE were present, the heart rate diminished while the heart rate variability increased. Time distances between P wave and R peak, and R peak and T wave and their dispersion increased also. This demonstrates a noticeable change of the autonomous regulation of the heart. In future, the ECG parameter could be used as a surrogate measure of fatigue.
Automation of a test bench for accessing the bendability of electrospun vascular grafts
Authors: Bensch Martin , Müller Marc , Bode Michael , Glasmacher Birgit 
Published: December 2016

Abstract
One of the greatest challenges in cardiovascular tissue engineering is to develop vascular grafts with properties similar to autologous vessels. A promising approach is the fabrication of scaffolds from biodegradable polymers by electrospinning. Unstructured vascular subs possess a weak dimensional stability resulting in lumen collapse when subjected to bending stress. In order to examine different structured grafts, a standardised test method is required. A manual test method, designed in a former study, was adopted in terms of standardisation and automation. Therefore, a control system was programmed to regulate the required electronics. The electronic circuit was then developed and put into service. To fix samples into the test bench a new sample holder and a new collector for electrospinning were designed. Subsequently, a validation showed the new systems’ improved functionality compared to the former test bench. The samples were manufactured with the new collector. They could be fixed to the sample holder with high repeatability. The demand for vascular grafts with biological and mechanical properties similar to autologous vessels requires a standardised test method to examine bendability. The new test system enables the scaffolds to be examined regarding bendability with low personal expense and a simultaneously high degree of reproducibility. In addition, the new collector geometry can be easily adapted to higher or lower inner diameters. Hence, a new sample geometry was developed within this work.
Influence of storage conditions on the release of growth factors in platelet-rich blood derivatives
Authors: Düregger Katharina , Peng Anqi , Eblenkamp Markus 
Published: December 2016

Abstract
Thrombocytes can be concentrated in blood derivatives and used as autologous transplants e.g. for wound treatment due to the release of growth factors such as platelet derived growth factor (PDGF). Conditions for processing and storage of these platelet-rich blood derivatives influence the release of PDGF from the platelet-bound α-granules into the plasma. In this study Platelet rich plasma (PRP) and Platelet concentrate (PC) were produced with a fully automated centrifugation system. Storage of PRP and PC for 1 h up to 4 months at temperatures between −20°C and +37°C was applied with the aim of evaluating the influence on the amount of released PDGF. Storage at −20°C resulted in the highest release of PDGF in PRP and a time dependency was determined: prolonged storage up to 1 month in PRP and 10 days in PC increased the release of PDGF. Regardless of the storage conditions, the release of PDGF per platelet was higher in PC than in PRP.
Cryopreservation of cells using defined serum-free cryoprotective agents
Authors: Volbers Jan-Cedric , Lauterböck Lothar , Hofmann Nicola , Glasmacher Birgit 
Published: December 2016

Abstract
For regenerative purposes, there is a high demand for viable and active cells. A big issue is to have enough viable cells available at any given time. One solution is cryopreservation. In this context, DMSO is used as cryoprotective agent (CPA) along with fetal bovine serum for nutrient supply and stress shielding effects. To use these cells for human clinical studies, it is important to eliminate the serum to prevent foreign immune reactions and virus transmittance and DMSO for its toxic effect. In this study a serum free cryopreservation solution and protocol has been established. The combination of methylcellulose and poloxamer 188 provide the basis for the new CPA. Other additves are α-tocopherol, ectoine, prolin and ascorbic acid. The CPAs were examined with 3T3-cells and multipotent stromal cells from the common marmoset monkey (Callithrix jacchus). The cells were preserved with various CPA concentrations, incubation times and different cooling rates. To enable a higher throughput of encouraging conditions a fluorescence microscopy analysis was used. The use of methylcellulose, poloxamer 188 and α-tocopherol enables the reduction of DMSO [up to 2.5% (v/v)] and the elimination of serum without viability losses compared to control.
New bioreactor vessel for tissue engineering of human nasal septal chondrocytes
Authors: Princz Sascha , Wenzel Ulla , Schwarz Silke , Rotter Nicole , Hessling Martin 
Published: December 2016

AbstractCultivation of human nasal septal chondrocytes in a self-established automated bioreactor system with a new designed reactor glass vessel and the results of a computational fluid dynamics model are presented. The first results show the effect of a homogeneous fluidic condition of the continuous medium flow and the resulting stresses on the scaffolds’ surface and their influence on the migration of the cells into the scaffold matrix under these conditions. For this purpose computational models, generated with the computational fluid dynamics software STAR-CCM+, and the results of alcian blue staining for newly synthesized sulphated glycosaminoglycans have been compared during cultivation in the new and a first version of the glass reactor vessel with inhomogeneous fluidic conditions, with the same automated bioreactor system and under similar cultivation conditions.
Climate retainment in carbon dioxide incubators
Authors: Schuh Matthias B. , Kirsch Michael , Dillmann David , Breuer Franziska , Eblenkamp Markus 
Published: December 2016

Abstract
Ensuring optimal climate conditions during cultivation is essential for successful and reproducible cell culture based investigation. Being the gold standard, carbon dioxide incubators fulfill this demand in various geometries and sizes to suit diverse cultivation applications. A door opening results in a climate breakdown followed by a restoration period during which optimal conditions cannot be guaranteed. The following paper investigates the influence of incubator door design to optimize climate retainment during the above mentioned event.
Multiple factors influencing OR ventilation system effectiveness
Authors: Buhl Sebastian , Eschenbecher Nicole , Hentschel Sabine , Bulitta Clemens 
Published: December 2016

Abstract
The issue of surgical site infections has become more critical during the last years. The number of airborne microbes depends on the number released by the staff in the room or supplied from neighbouring rooms. In order to minimize the risk of nosocomial infections during surgical procedures technical developments like ventilation systems were introduced in the operating room (OR). In this study several factors like clothing and types of ventilation systems have been investigated and their impact on the effectiveness for reducing microbial burden in the OR has been assessed. In case of OR-gowns we found a benefit for a disposable Swedish clothing concept regarding microbiological contamination in comparison with the German standard multiuse clothing. Moreover our study shows that there is comparable effectiveness of a fairly novel temperature controlled airflow ventilation system (TAF) compared to standard low turbulent uni-directional airflow (TAV).
Evaluation of an app-based stress protocol
Authors: Noeh Claudius , Fonseca Carlos , Mollenhauer Johannes , Hofmann Simon , Steinbrecher Llisa , Haller Andreas , Scholtes Michael , Schudt Florian , Sohrabi Keywan , Gross Volker 
Published: December 2016

Abstract
Stress is a major influence on the quality of life in our fast-moving society. This paper describes a standardized and contemporary protocol that is capable of inducing moderate psychological stress in a laboratory setting. Furthermore, it evaluates its effects on physiological biomarkers. The protocol called “THM-Stresstest” mainly consists of a rest period (30 min), an app-based stress test under the surveillance of an audience (4 min) and a regeneration period (32 min). We investigated 12 subjects to evaluate the developed protocol. We could show significant changes in heart rate variability, electromyography, electro dermal activity and salivary cortisol and α-amylase. From this data we conclude that the THM-Stresstest can serve as a psychobiological tool for provoking responses in the cardiovascular-, the endocrine and exocrine system as well as the sympathetic part of the central nervous system.
Investigation of the pressure gradient of embolic protection devices
Authors: Kurzhals Anja , Matthies Jörn-Bo , Andresen Reimer , Grabow Niels , Schmitz Klaus-Peter , Schmidt Wolfram 
Published: December 2016

Abstract
To avoid debris coming to the cerebral vessels during carotid artery stenting, embolic protection devices (EPD) are placed in front of the lesion. To evaluate their influence on the antegrade blood flow a test setup with a silicone tube simulating the internal carotid artery is realized. The pressure gradient of five different EPD was measured while particles were brought into the circuit and were caught by the systems. Additionally the microscopic structure of the systems was observed to correlate the morphology and the pressure gradient. The FiberNet device had the lowest pressure gradient. It was the only system that consists of fibers contrary to the systems RX Accunet, Angioguard RX, FilterWireEZ and EmboshieldNAV that contain porous membranes.
Computer assistance in femoral derotation osteotomy: a bottom-up approach
Authors: Auer Christoph , Kallus Sebastian , Geisbüsch Andreas , Dreher Thomas , Dickhaus Hartmut 
Published: December 2016

Abstract
Severe gait abnormalities in patients with cerebral palsy are often treated by correction osteotomy. The established procedure of femoral derotation osteotomy (FDO) has proven effective to realign femur anteversion. Nevertheless, studies have revealed that therapy outcome is subject to substantial inter-patient variability and systematic loss of correction. Our previous work suggests that practical limitations in FDO may significantly contribute to this effect. In this work, we propose a novel computer assisted measurement system to support FDO with objective measurement (desired accuracy: ∼ ± 3°) and continuous monitoring of derotation. A prototype system based on the clinically emerging electromagnetic tracking technology is demonstrated which incorporates technical and operational considerations to enable continuous measurement in OR conditions while preserving the conventional workflow without disruptions. In phantom studies, the achieved measurement accuracy (standard error

≅
±
1.6

)

∘

$\cong\pm 1.6{}^{\circ})$

proved high potential and may hugely benefit the quality of surgical execution. Currently, the prototype system is assessed under OR conditions in an in-vivo study with CP patients. Early experience shows high appreciation among surgeons and good potential for future application.
Resectoscope with an easy to use twist mechanism for improved handling
Authors: Fritzsche Holger , Boese Axel , Schostak Martin , Friebe Michael 
Published: December 2016

Abstract
One of the oldest methods used in minimally invasive surgeries is the transurethral resection. This is an operation technique in which diseased tissue from the bladder or the prostate is removed using a resectoscope through the urethra [Schostak M, Blana A, Hrsg. Alternative operative Therapien in der Uroonkologie. Berlin, Heidelberg, Springer Berlin Heidelberg; 2016]. A resectoscope has a channel for the view of the surgeon, a liquid supply, a working channel and a hand piece which could rotate up to 360 degrees. A RF- electrode on the tip of the resectoscope is used to cut out pathological growths. For diseased tissue which is located in the bladder on the ventral side, a rotation of the resectoscope up to 180 degrees is necessary. This means on the one side tiring of the hands, wrist pain and a change of the position of the operating surgeon. On the other side a reorganization of the connected tubes and cables is necessary. To avoid these problems and integrate additional features a standard resectoscope was adapted with an easy to use twist mechanism. After discussion with experienced urological surgeons a complete new design of the resectoscope with a twist mechanism in combination with a gyro sensor and a reference display was realized.
In vitro simulation of distribution processes following intramuscular injection
Authors: Probst Mareike , Schmidt Martin , Weitschies Werner , Seidlitz Anne 
Published: December 2016

Abstract
There is an urgent need for in vitro dissolution test setups for intramuscularly applied dosage forms. Especially biorelevant methods are needed to predict the in vivo behavior of newly developed dosage forms in a realistic way. There is a lack of knowledge regarding critical in vivo parameters influencing the release and absorption behavior of an intramuscularly applied drug. In the presented work the focus was set on the simulation of blood perfusion and muscle tissue. A solid agarose gel, being incorporated in an open-pored foam, was used to mimic the gel phase of muscle tissue and implemented in a flow through cell. An aqueous solution of fluorescein sodium was injected. Compared to recently obtained in vivo results the distribution of the model substance was very slow. Furthermore an agarose gel of lower viscosity an open-pored foam and phosphate buffer saline pH 7.4 were implemented in a multi-channel-ceramic membrane serving as a holder for the muscle imitating material. Blood simulating release medium was perfused through the ceramic membrane including filling materials. Transport of the dissolved fluorescein sodium was, in case of the gel, not only determined by diffusion but also by convective transport processes. The more realistic the muscle simulating materials were constituted the less reproducible results were obtained with the designed test setups.
Adjusting inkjet printhead parameters to deposit drugs into micro-sized reservoirs
Authors: Mau Robert , Oldorf Paul , Peters Rigo , Seitz Hermann 
Published: December 2016

Abstract
Drug delivery systems (DDS) ensure that therapeutically effective drug concentrations are delivered locally to the target site. For that reason, it is common to coat implants with a degradable polymer which contains drugs. However, the use of polymers as a drug carrier has been associated with adverse side effects. For that reason, several technologies have been developed to design polymer-free DDS. In literature it has been shown that micro-sized reservoirs can be applied as drug reservoirs. Inkjet techniques are capable of depositing drugs into these reservoirs. In this study, two different geometries of micro-sized reservoirs have been laden with a drug (ASA) using a drop-on-demand inkjet printhead. Correlations between the characteristics of the drug solution, the operating parameters of the printhead and the geometric parameters of the reservoir are shown. It is indicated that wettability of the surface play a key role for drug deposition into micro-sized reservoirs.
A flexible standalone system with integrated sensor feedback for multi-pad electrode FES of the hand
Authors: Loitz Jan C. , Reinert Aljoscha , Neumann Ann-Kristin , Quandt Fanny , Schroeder Dietmar , Krautschneider Wolfgang H. 
Published: December 2016

Abstract
Functional electrical stimulation aims to help patients suffering from stroke or spinal cord injury to supplement lost motor function. Effective functional electrical stimulation requires precise placement of the stimulation electrode. Finding the correct placement, however, can be difficult and time consuming. Another common problem with functional electrical stimulation is early occurrence of muscle fatigue upon repetitive stimulation, limiting treatment efficiency. Both, precise electrode placement as well as the reduction of muscle fatigue can be achieved using multi-pad electrodes. Here we present a new standalone device for multi-pad functional electrical stimulation. The device is easy to use and designed to help patients recovering from stroke to train and perform opening of the hand.
Smart control for functional electrical stimulation with optimal pulse intensity
Authors: Reinert Aljoscha , Loitz Jan C. , Quandt Fanny , Schroeder Dietmar , Krautschneider Wolfgang H. 
Published: December 2016

Abstract
Transcutaneous electrical stimulation is a common treatment option for patients suffering from spinal cord injury or stroke. Two major difficulties arise when employing electrical stimulation in patients: Accurate stimulation electrode placement and configuration of optimal stimulation parameters. Optimizing the stimulation parameters has the advantage to reduce muscle fatigue after repetitive stimulation. Here we present a newly developed system which is able to automatically find the optimal individual stimulation intensity by varying the pulse length. The effectiveness is measured with flex sensors. By adapting the stimulation parameters, the effect of muscle fatigue can be compensated, allowing for a more stable movement upon stimulation over time.
Tactile display on the remaining hand for unilateral hand amputees
Authors: Li Tao , Huang Huaiqi , Antfolk Christian , Justiz Jörn , Koch Volker M. 
Published: December 2016

Abstract
Human rely profoundly on tactile feedback from fingertips to interact with the environment, whereas most hand prostheses used in clinics provide no tactile feedback. In this study we demonstrate the feasibility to use a tactile display glove that can be worn by a unilateral hand amputee on the remaining healthy hand to display tactile feedback from a hand prosthesis. The main benefit is that users could easily distinguish the feedback for each finger, even without training. The claimed advantage is supported by preliminary tests with healthy subjects. This approach may lead to the development of effective and affordable tactile display devices that provide tactile feedback for individual fingertip of hand prostheses.
Effects of sustained electrical stimulation on spasticity assessed by the pendulum test
Authors: Vargas Luna José L. , Guðfinnsdóttir Halla K. , Magnúsdóttir Gígja , Guðmundsdóttir Vilborg , Krenn Matthias , Mayr Winfried , Ludvigsdóttir Guðbjörg K. , Helgason Thordur 
Published: December 2016

Abstract
Neuromodulation using electrical stimulation is able to enhance motor control of individuals suffering an upper motor neuron disorder. This work examined the effect of sustained electrical stimulation to modify spasticity in the leg muscles. We applied transcutaneous spinal cord stimulation with a pulse rate of 50 Hz for 30 min. The subjects were assessed before and after the intervention using in a pendulum test setup. The motion of the free swinging leg was acquired through video tracking and goniometer measurements. The quantification was done through the R2n index which shows consistency identifying the spasticity levels. In all incomplete SCI subjects having severe spasticity, the results show that electrical stimulation is effective to modify the increased muscle tone.