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Introduction: Despite lots of developments in the last years, radiofrequency ablation of rhythm diseases is a safe but still complex procedure that requires special experience and expertise of the physicians and biomedical engineers. Thus, there is a need of special trainings to become familiar with the different equipment and to explain several effects that can be observed during clinical routine.
Methods: The Offenburg University of Applied Sciences offers a biomedical engineering study path specialized in the fields of cardiology, electrophysiology and cardiac electronic implants. It`s Peter Osypka Institute for Pacing and Ablation provides teaching following the slogan “Learning by watching, touching and adjusting”. It conducts lots of trainings for students as well as young physicians interested in electrophysiology and radiofrequency ablation.
Results: In-vitro trainings will be provided using the Osypka HAT 200 and HAT300s, Stockert EPshuttle and SmartAblate system as well as the Boston EPT-1000XP and Maestro 3000 and the Radionics RFG-3E cardiac radio frequency ablation generators. All of them require different handling as well as special accessories like catheter connection cables or boxes and back plates. The participants will be trained in the setup of temperature, power and cut-off impedance dependent on different ablation catheters. Furthermore troubleshooting in hard- and software is part of the program. Performing procedures in pork or animal protein and using physiological saline solution to simulate the blood flow, they can study the influence of contact force and impedance on lesion geometry etc. and to avoid adverse effects like “plops”. Lots of catheter types are available: 4mm tip, 8mm standard and gold tip, open and closed irrigated tip ablation catheters of different companies. The experiments will be completed by measuring the lesion size dependent on the used catheter type and ablation settings.
Conclusion: In-vitro training in radiofrequency ablation is a challenge for biomedical engineering students and young physicians.
Active safety systems for advanced driver assistance systems act within a complex, dynamic traffic environment featuring various sensor systems which detect the vehicles’ surroundings and interior. This paper describes the recent progress towards a performance evaluation of car-to-car communication (C2C) for active safety systems - in particular for crash constellation prediction. The methodology introduced in this work is designed to evaluate the impact of different sensors on the accuracy of a crash constellation prediction algorithm. The benefit of C2C communication (viewed as a virtual sensor) within a sensor data fusion architecture for pre-crash collision prediction is explored. Therefore, a simulation environment for accident scenarios analysis reproducing real-world sensor behaviour, is designed and implemented. Performance evaluation results show that C2C increases confidence in the estimated position of the oncoming vehicle. With C2C enhancement the given accuracy in time-to-collision (TTC) estimation is achievable about 110 ms earlier for moderate velocities at TTC range of [0.5s..0.2s]. The uncertainty in the vehicle position prediction at the time of collision can be reduced about half by integrating C2C communication into the sensor data fusion.
Die bisherigen Forschungen [1] im Bereich der Entlastungen von den örtlichen Spannungskonzentrationen in den Sicherungsringnuten beschränken sich auf glatte Vollwellen. Über die Abschwächung der Kerbwirkung von Sicherungsringnuten bei Zahn- und Keilwellen lagen bisher keine systematischen Untersuchungen und keine ausreichend gesicherten Ergebnisse vor. Deshalb wurden Untersuchungen zur Ermittlung der entlastenden Wirkung der Spannungsformzahlen von SR-Nuten bei Zahnwellen durchgeführt. Diese erfolgen mittels der Finite-Elemente-Methode (FEM) für die Belastungsarten Zug/Druck, Biegung und Torsion. Eine Formzahlreduktion von ca. 35% in der SR-Nut konnte bei Biegung und Zug/Druck realisiert werden. Bei Torsion beträgt diese ca. 30 % nach der NSH bzw. 12% nach der GEH gegenüber der originalen Kerbgeometrie ohne Entlastungsnuten. Die gewonnenen Ergebnisse erweitern die qualitativen und quantitativen Erkenntnisse über die Entlastung von der mehrfachen Kerbwirkung.
Der hier vorliegende Beitrag beschreibt erste Untersuchungsergebnisse mit der Finite-Elemente-Methode (FEM) zur Kerbspannungsanalyse an Durchdringungskerben bei Getriebewellen. Es handelt sich dabei um eine Umlaufnut sowie einen Wellenabsatz mit jeweils überlagerter Querbohrung. In beiden Fällen wird die Bohrung im Bereich der maximalen Spannungskonzentration der Umlaufnut bzw. des Wellenabsatzes angebracht. Entsprechende Formzahldiagramme werden angegeben und neue Näherungsgleichungen für eine genauere Formzahlberechnung je nach Belastungsart Torsion, Biegung und Zug/Druck aufgestellt. Die neu gewonnenen FEM-Ergebnisse erweitern die qualitativen und quantitativen Erkenntnisse über die in der Literatur vorhandenen Berechnungsverfahren und werden als Grundlage für weitere Untersuchungen zu dem bislang wenig erforschten Thema „räumliche Durchdringungskerbwirkung“ und deren Entlastung verwendet.
Die scharfkantig eingestochenen Sicherungsringnuten (SR-Nut) in Profilwellen (Zahn- und Keilwellen) bewirken höhere Kerbwirkung. Diese ergibt sich infolge der Überlagerung zwischen SR-Nutradius und Zahnfussradius speziell bei Torsionsbeanspruchung unter Beachtung der Einflüsse der Zähnezahl z, des Bezugsdurchmessers dB und des Moduls m. Eine Möglichkeit zur Minderung dieser Kerbwirkung besteht in der absichtlichen Anbringung von umlaufenden Zusatzkerben, symmetrisch vor und hinter der nach DIN 471 genormte Hauptkerbe. Die vorliegende Arbeit soll einen weiteren Beitrag zu dem noch wenig erforschten Thema "Entlastungsnuten an Profilwellen" bringen. Der Beitrag beschreibt die numerischen Ergebnisse einer ersten Untersuchung, die bei der Entlastung von SR-Nuten auf Zahnwellen bei Zug/Druck, Biegung und Torsion entstehen. Die Ermittlung der entlastenden Wirkung erfolgt mittels der Finite-Elemente-Methode (FEM). Die Untersuchung der Kerbformzahlen und ihrer Verringerung in Abhängigkeit von den geometrischen Parametern der Zahnwelle der SR-Nut und der Entlastungkerbe sowie die daraus optimierten Ergebnisse stellen dabei das zentrale Thema dar. Die Ergebnisse werden als Diagramme und Gestaltungshinweise angegeben. Die Untersuchungen zeigen, dass sich mithilfe von Entlastungskerben mit den optimalen Geometrieverhältnissen Spannungsformzahlreduktionen bis zu ca 35% bei Zug/Druck oder Biegung bzw. ca 30% bei Torsion ermöglichen lassen. Die erzielte Entlastungswirkung ist vom Kerbtiefenverhältnis, von der Form und Lage der Entlastungsnut, vom Bundlängenverhaltnis, vom Kerbabstand zwischen Nutradius und Zahnfussradius sowie von der Belastungsart abhängig.
This paper presents the competence-, business- and research-orientated education approach Fit4PracSis (= Fit for Practice and Sciences). Fit4PracSis is designed for freshman students in interdisciplinary engineering degree programs. It is an education concept, which is establishing a relationship to the future profession and scientific work during the introductory study phase. The freshman students will be early trained in important skills, which are necessary for the successful achievement of the final degree and the future business and research activities.
Meeting the requirements of smart grids local, decentralized subnets will offer additional potentials to stabilize and compensate the utility grid mainly on the low voltage level. In a quite complex configuration these decentralized energy systems are combined power, heat and cooling power distributions. According to the regional and local availability of renewable energy sources advanced energy management concepts should consider climatic conditions as well as the state of the interacting utility grid and consumption profiles. The approach uses demonstrational setups to develop a forecast based energy management for trigeneration subnets by taking into account the running conditions of local electrical and thermal energy conversion units. This should lead to the best coverage of the demand and supporting/stabilizing the utility grid at the same time. For the first of three demonstrational projects the priorities of the subnet are given with the maximization of the CHP operation to substitute a major part of the heating and cooling power delivered by electric heaters or compression chillers.
A former remote area power supply was converted to a smart cogeneration subnet with combined heat and power to develop and validate a forecast based energy management at the University of Applied Sciences in Offenburg/Germany. Locally processed weather forecasts and forecasted demand profiles are integrated to allow a precise reaction to changes of fluctuating power sources, changes in scheduled demand profiles and to improve the energy efficiency of the supply. The management of the electrical and thermal storages is influenced by the forecasted energy contributions and the forecasted demand. Further approaches should improve the accuracy of forecasting algorithms and integrate parameter models gained of a detailed monitoring to realize predictive controllers.
Although short range wireless communication explicitly targets local and very regional applications, range continues to be an extremely important issue. The range directly depends on the so called link budget, which can be increased by the choice of modulation and coding schemes. Especially, the recent transceiver generation comes with extensive and flexible support for Software Defined Radio (SDR). The SX127x family from Semtech Corp. is a member of this device class and promises significant benefits for range, robust performance, and battery lifetime compared to competing technologies. This contribution gives a short overview into the technologies to support Long Range (LoRa ™), describes the outdoor setup at the Laboratory Embedded Systems and Communication Electronics of Offenburg University of Applied Sciences, shows detailed measurement results and discusses the strengths and weaknesses of this technology.
Logging information is more precious as it contains the execution of a system; it is produced by millions of events from simple application logins to random system errors. Most of the security related problems in the cloud ecosystem like intruder attacks, data loss, and denial of service, etc. could be avoided if Cloud Service Provider (CSP) or Cloud User (CU) analyses the logging information. In this paper we introduced few challenges, which are place of monitoring, security, and ownership of the logging information between CSP and CU.
Also we proposed a logging architecture to analyze the behaviour of the cloud ecosystem, to avoid data breaches and other security related issues at the CSP space. So that we believe our proposed architecture can provide maximum trust between CU and CSP.
Since direct current high energy shock fulguration was initially performed in the mid 1980s, ablation of cardiac arrhythmias has come to widespread use. Today the most frequently used energy source for catheter ablation is radio frequency (RF). It was the German engineer Peter Osypka who made available the HAT 100 as the first simple commercial RF ablator.
Nevertheless, in the first years of ablation, physicians were effectively working in the dark. Until today with an increasing understanding of arrhythmia mechanisms, both at the atrial and ventricular levels, this curative technology has made tremendous progress. Now, due to crucial improvement of RF ablation generators, temperature and contact force sensor catheters in combination with non-flouroscopic electroanatomical mapping technologies, computerized temperature and impedance controlled radiofrequency catheter ablation can be used to cure all types of arrhythmias including atrial and ventricular fibrillation. For the latter, cooled ablation by saline solution irrigated catheters has been developed to a widely used standard method. This procedure resulting in pulmonary vein isolation requires transseptal puncture and is technically demanding. Nevertheless, it has shown to be more effective than antiarrhythmic drug therapy.
While earliest RF ablations were performed with non-steerable catheters, today are used steerable sensor catheters without or with external and internal cooling and tips of 4mm or 8mm length. Further innovations like integration of mapping and cardiac imaging give exact information of the number of pulmonary veins and branching patterns and help to correlate electrical signals with anatomical structures.
The magnetic navigation significantly improved the success rates and safety of catheter ablation. Thus, in most cases RF catheter ablation has developed in the treatment of supraventricular arrhythmias from an alternative approach to drug therapy into the first therapeutic choice providing low complication rates.
In future, robotic navigation will further simplify procedures and reduce radiation exposure of this curative approach.
Non-responder rate in cardiac resynchronization therapy (CRT) could be partly decreased by individualized parameter optimization excluding adverse hemodynamic timing. In heart failure patients with sinus rhythm, an atrial kick enables the completion of atrial contraction and may significantly enhance the ventricular filling. Compared to that, exclusion of atrial kick is a sign of suboptimal atrioventricular timing. However, the recognition of atrial kick by echocardiography will be negatively affected in patients requiring a very short or long AV delays.
Data is ever increasing in the computing world. Due to advancement of cloud technology the dynamics of volumes of data and its capacity has increased within a short period of time and will keep increasing further. Providing transparency, privacy, and security to the cloud users is becoming more and more challenging along with the volume of data and use of cloud services. We propose a new approach to address the above mentioned challenge by recording the user events in the cloud ecosystem into log files and applying MAR principle namely 1) Monitoring 2) Analyzing and 3) Reporting.