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Cardiac resynchronization therapy with atrioventricular and interventricular pacing delay optimized biventricular pacing is an established therapy for heart failure patients with sinus rhythm and reduced left ventricular ejection fraction. The aim of the study was to evaluate atrioventricular and interventricular pacing delay optimization in cardiac resynchroniza-tion therapy by transthoracic impedance cardiography in biventricular pacing with different left ventricular electrode po-sition. In biventricular pacing heart failure patients with lateral, posterolateral and anterolateral left ventricular electrode position, the mean optimal atrioventricular sening delay was 108.6 ± 20.3 ms and the mean optimal interventricular pac-ing delay -12.3 ± 25.9 ms. Transthoracic impedance cardiography may be a useful technique to optimize atrioventricular and interventricular pacing delay in biventricular pacing with different left ventricular electrode position.
Cardiac resynchronization therapy is an established therapy for heart failure patients with sinus rhythm, reduced left ventricular ejection fraction and prolongation of QRS duration. The aim of the study was to evaluate ventricular desynchronization with electrical interventricular delay (IVD) to left ventricular delay (LVD) ratio in atrial fibrillation heart failure patients. IVD and LVD were measured by transesophageal posterior left ventricular ECG recording. In atrial fibrillation heart failure patients with prolonged QRS duration, the mean IVD-to-LVD-ratio was 0.84 +/- 0.42 with a range from 0.17 to 2.2 IVD-to-LVD-ratio. IVD-to-LVD-ratio correlated with QRS duration. IVD-to-LVD-ratio may be a useful parameter to evaluate electrical ventricular desynchronization in atrial fibrillation heart failure patients.
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.
Smoothie: a solution for device and content independent applications including 3D imaging as content
(2014)
Network landscape of recent time contains many different network technologies, a wide range of end-devices with a large scale of capabilities and power, and an immense quantity of information represented in different data formats. Research on 3D imaging, virtual reality and holographic techniques will result in new user interfaces (UI) for mobile devices and will increase their diversity and variety. A lot of effort is being made in order to establish open, scalable and seamless integration of various technologies and content presentation for different devices including those that are mobile, considering the individual situation of the end user. Till today the research is going on in different parts of the world but the task is not completed yet. The goal of this research work is to find a way to solve the above stated problems by investigating system architectures to provide unconstrained, continuous and personalized access to the content and interactive applications everywhere and at anytime with different devices. As a Solution of the problem considered, a new architecture named “Smoothie” is proposed.
The improvements in the hardware and software of communication devices have allowed running Virtual Reality (VR) and Augmented Reality (AR) applications on those. Nowadays, it is possible to overlay synthetic information on real images, or even to play 3D on-line games on smart phones or some other mobile devices. Hence the use of 3D data for business and specially for education purposes is ubiquitous. Due to always available at hand and always ready to use properties of mobile phones, those are considered as most potential communication devices. The total numbers of mobile phone users are increasing all over the world every day and that makes mobile phones the most suitable device to reach a huge number of end clients either for education or for business purposes. There are different standards, protocols and specifications to establish the communication among different communication devices but there is no initiative taken so far to make it sure that the send data through this communication process will be understood and used by the destination device. Since all the devices are not able to deal with all kind of 3D data formats and it is also not realistic to have different version of the same data to make it compatible with the destination device, it is necessary to have a prevalent solution. The proposed architecture in this paper describes a device and purpose independent 3D data visibility any time anywhere to the right person in suitable format. There is no solution without limitation. The architecture is implemented in a prototype to make an experimental validation of the architecture which also shows the difference between theory and practice.
E-Tutoren-Ausbildung: Lernerfahrungen reflektieren – Lehrhandlungskompetenzen dialogisch aufbauen
(2014)
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.
The Internet of Things (IoT), ubiquitous computing and ubiquitous connectivity, Cyber Physical Systems (CPS), ambient intelligence, Machine-to-Machine communication (M2M) or Car-to-Car (C2C)-communication, smart metering, smart grid, telematics, telecare, telehealth – there are many buzzwords around current developments related to the Internet.
This contribution gives an overview on such IoT-applications, as they are already used today to improve the availability of information, increase efficiency, push system limits and extend the value chain. At a closer look, the economic and technical development can be separated into different phases. It is interesting that we are currently at the threshold to a new phase, with decentralized and cooperative communication and control nodes as cornerstones. Thus, embedded systems and their connectivity are in the middle of the scene.
This recent development is described along with some example projects from the author’s team which are used in industrial automation, energy supply and distribution (home automation and smart metering), traffic engineering (cooperative driver assistance systems), and in telehealth and telecare.
Transcatheter aortiv valve implantation is a new safe strategy treatment for patients with symptomatic severe aortic stenosis and high operative risk. The aim of the study was to compare the pre-and post- muiscatheter aortiv valve implantation procedures to determine the atrioventricuktr conduction time as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortiv valve implantation. The transcatheter aortiv valve implantation patients were divided into groups without pacemaker and with dual or single chamber pacemEtker with diffent atrioventrieular conduction time disturbance before and after transcatheter aortiv valve implantation. In heart failure, patients without permanent pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was prolonged after transcatheter aortiv valve implantation. In patients with permanent dual chamber pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was normalised with dual chaniber atrioventrieuku pacing mode. Atrioventricular conduction time may be a useful parameter to evaluate the risk of post-procedural atrioventricular conduction block and permanent pacemaker therapy in transcatheter north, valve implantation patients.
Die zunehmende Anzahl von Transistoren mit immer kleineren Strukturgrößen führt zu einer zunehmenden Leistungsaufnahme in modernen Prozessoren. Das gilt insbesondere für High-End Prozessoren, die mit einer hohen Taktfrequenz betrieben werden. Die aufgenommene Leistung wird in Wärme umgewandelt, die in einer Temperaturerhöhung der Prozessoren resultiert. Hohe Betriebstemperaturen verursachen u.a. eine verringerte Rechenleistung, eine kürzere Lebensdauer des Prozessors und höhere Leckströme. Aus diesen Gründen wird aktives, dynamisches thermisches Management immer wichtiger. Dieser Beitrag stellt eine Erweiterung zu dem Standard- Linux-Scheduler in der Kernel-Version 3.0 für eingebettete Systeme vor: einen PID-Regler, der unter Angabe einer Solltemperatur eine dynamische Frequenz- und Spannungsskalierung durchführt. Die Experimente auf dem Freescale LMX6 Quadcore-Prozessor zeigen, dass der PID-Regler die Betriebstemperatur des Prozessors an die Solltemperatur regeln kann. Er ist die Grundlage für eine in Zukunft zu entwickelnde prädiktive Regelung.
MPC-Workshop Februar 2014
(2014)
MPC-Workshop Juli 2014
(2014)
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.
This paper describes the magmaOffenburg 3D simulation team trying to qualify for RoboCup 2013. While last year’s TDP focused on different ways how robot behavior can be defined in the magmaOffenburg framework this year we focus on how we statistically evaluate new features on distributed systems. We also show some results gained through such analysis.
In the brain-cell microenvironment, diffusion plays an important role: apart from delivering glucose and oxygen from the vascular system to brain cells, it also moves informational substances between cells. The brain is an extremely complex structure of interwoven, intercommunicating cells, but recent theoretical and experimental works showed that the classical laws of diffusion, cast in the framework of porous media theory, can deliver an accurate quantitative description of the way molecules are transported through this tissue. The mathematical modeling and the numerical simulations are successfully applied in the investigation of diffusion processes in tissues, replacing the costly laboratory investigations. Nevertheless, modeling must rely on highly accurate information regarding the main parameters (tortuosity, volume fraction) which characterize the tissue, obtained by structural and functional imaging. The usual techniques to measure the diffusion mechanism in brain tissue are the radiotracer method, the real time iontophoretic method and integrative optical imaging using fluorescence microscopy. A promising technique for obtaining the values for characteristic parameters of the transport equation is the direct optical investigation using optical fibers. The analysis of these parameters also reveals how the local geometry of the brain changes with time or under pathological conditions. This paper presents a set of computations concerning the mass transport inside the brain tissue, for different types of cells. By measuring the time evolution of the concentration profile of an injected substance and using suitable fitting procedures, the main parameters characterizing the tissue can be determined. This type of analysis could be an important tool in understanding the functional mechanisms of effective drug delivery in complex structures such as the brain tissue. It also offers possibilities to realize optical imaging methods for in vitro and in vivo measurements using optical fibers. The model also may help in radiotracer biomarker models for the understanding of the mechanism of action of new chemical entities.
A highly scalable IEEE802.11p communication and localization subsystem for autonomous urban driving
(2013)
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. It has found its place in hardware and firmware implementations and is currently tested in various field tests. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed for the support of highly autonomous driving. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. It mainly concentrates on the detection of pedestrians and other vulnerable road users (VRU), but also supports pre crash safety applications. Thus it is mainly targeted for the support of traffic safety applications in intra-urban scenarios. This contribution describes the Ko-TAG part of the overall initiative, which develops a subsystem to improve the real-time characteristics of IEEE802.11p needed for precise time of flight real-time localization. In doing this, it still fits into the regulatory schemes. It discusses the approach for definition and verification of the protocol design, while maintaining the close coexistence with existing IEEE802.11p subsystems. System simulations were performed and hardware was implemented. Test results are shown in the last part of the paper.
A Localization System Using Inertial Measurement Units from Wireless Commercial Handheld Devices
(2013)
This paper describes a newly developed technology for the calculation of trajectories of mobile objects, which is based on commercially available sensors being integrated into modern mobile phones and other gadgets. First, a step counting technique was implemented. Second, a novel step length estimator is proposed. These two algorithms utilize the data from accelerometer sensor only. Third, the heading information was obtained using a gyroscope with complementary filter in quaternion form. The combined algorithm was implemented on a low-power ARM processor to provide the trajectory points relative to an initial point. The proposed technique was tested by 10 subjects, in different shoes with different paces. The dependence of the performance of the technology on the attaching point of the mobile device is weak. The proposed algorithms have better balance and estimation accuracy and depend in less degree on the variety in physical parameters of people in comparison with the existing techniques. In experiments inertial measurement units were mounted in different places, i.e. in the hand, in trousers or in T-shirt pockets. The return position error did not exceed 5% of the total travelled distance for all performed tests.
The communication technologies for automatic meter reading (smart metering) and for energy production and distribution networks (smart grid) have the potential to be one of the first really highly scaled machine-to-machine-M2M-applications. During the last years, two very promising developments around the wireless part of the smart grid communication were initialized, which possibly could have an impact on the network architectures and the markets far beyond Germany and far beyond energy automation. Besides the specification of the OMS Group of a security extension to the Wireless M-Bus protocol (EN13757-4), the German Federal Office for Information Security (Bundesamt für Sicherheit in der Informationstechnik, BSI) has designed a Protection Profile (PP) and a Technical Directive (TR) for the communication unit of an intelligent measurement system (Smart Meter Gateway), which were released in March 2013. This design uses state of the art technologies and prescribes their implementation in real-life systems. At first, the proposed paper will present the most important characteristics of this architecture. It will then give an insight into the implementation of the OMS security protocols, which imply the usage of a mutually authenticated SSL protocol also in the Local Metrological Network. This is achieved with the help of an additional Authentication and Fragmentation Layer (AFL). This secure communication will be terminated in a BSI conformant secure smart meter gateway, which is developed in a different project and described in the second step. Finally, the contribution will discuss the integration of such a metering network into an overall telecommunication network and PKI infrastructure.
Efficient, low-cost, secure and reliable communication solutions are a major stepping stone for smart metering and smart grid applications. This especially holds true for the so called primary communication or local metrological network (LMN) between a local meter or actuator and a data collector or gateway, where the highest requirements with regard to cost, bandwidth, and energy efficiency have to be taken into consideration. Multiple developments and field tests are going on in this field, however, energy autarkic devices are hardly found, yet. This contribution describes the development of an automatic water meter reading (AWMR) technology based on Wireless M-Bus to provide water utility companies with an automatic remote water meter reading solution. It addresses the special needs of home utilities by providing a remote metering solution independent from the electricity infrastructure, both in terms of data communication and in terms of power supply. For this project, a cost efficient integrated energy harvesting system powered by the available water flow was developed, to enable operation independently of the mains grid, and eliminate the need for battery replacement for near-zero maintenance costs.
The combination of fossil-derived fuels with ethanol and methanol has acquired relevance and attention in several countries in recent years. This trend is strongly affected by market prices, constant geopolitical events, new sustainability policies, new laws and regulations, etc. Besides bio-fuels these materials also include different additives as anti-shock agents and as octane enhancer. Some of the chemical compounds in these additives may have harmful properties for both environment and public health (besides the inherent properties, like volatility). We present detailed Raman spectral information from toluene (C7H8) and ethanol (C2H6O) contained in samples of ElO gasoline-ethanol blends. The spectral information has been extracted by using a robust, high resolution Fourier-Transform Raman spectrometer (FT-Raman) prototype. This spectral information has been also compared with Raman spectra from pure additives and with standard Raman lines in order to validate its accuracy in frequency. The spectral information is presented in the range of 0 cm-1 to 3500 cm-1 with a resolution of 1.66cm-1. This allows resolving tight adjacent Raman lines like the ones observed around 1003cm-1 and 1030cm-1 (characteristic lines of toluene). The Raman spectra obtained show a reduced frequency deviation when compared to standard Raman spectra from different calibration materials. The FT-Raman spectrometer prototype used for the analysis consist basically of a Michelson interferometer and a self-designed photon counter cooled down on a Peltier element arrangement. The light coupling is achieved with conventional62.5/125μm multi-mode fibers. This FT-Raman setup is able to extract high resolution and frequency precise Raman spectra from the additives in the fuels analyzed. The proposed prototype has no additional complex hardware components or costly software modules. The mechanical and thermal disturbances affecting the FT-Raman system are mathematically compensated by accurately extracting the optical path information of the Michelson interferometer. This is accomplished by generating an additional interference pattern with a λ = 632.8 nm Helium-Neon laser (HeNe laser). It enables the FT-Raman system to perform reliable and clean spectral measurements from the materials under observation.
Efficient, low-cost, secure and reliable communication solutions are a major stepping stone for smart metering and smart grid applications. This especially holds true for the so called primary communication or local metrological network (LMN) between a local meter or actuator and a data collector or gateway, where the highest requirements with regard to cost, bandwidth, and energy efficiency have to be taken into consideration. Multiple developments and field tests are going on in this field, however, energy autarkic devices are hardly found, yet.
Ranging errors are inevitable in all local positioning systems, including those based on Time-of-Flight (ToF) technique. Results of experiments show that the major cause for these errors is a signal degradation from multipath propagation. This effect is especially critical in case of Non-Light-of-Sight (NLOS) conditions. This paper describes causes that affects ranging errors for nanoLOC™-TOF-technology and presents estimations for the probability density functions of such errors under different NLOS conditions. The provided estimations allow the improvement of the accuracy of the localization through the subsequent mitigation of the ranging errors from the measurements. Additionally, it is proposed to increase the number of cases of NLOS-conditions for the improvement of the accuracy.
Automatic Meter Reading (AMR) is a major enabler for the upcoming smart grid. Potentially, it will be one of the first really large-scale M2M-communication solutions for sensor applications.
To date, the definition of the standardized communication stacks for Local Metrological Network (LMN) in AMR is still ongoing. This holds true both for ZigBee Smart Energy Profile and for Wireless M-Bus according to EN 13757. During this process, there is the necessity for flexible, albeit optimized solutions, which support the different existing and upcoming versions of the communication protocols. In the case of Wireless M-Bus, the major contender for European and possibly Asian installations, this is valid not only for the different operation modes (C-, N-, P-, Q-, R-, S-, and T-modes), which work in different frequencies (i.e. 868 MHz, 433 MHz, and 169 MHz) but also for the application layer, where additional bodies, like EN137575, Open Metering System (OMS) Group, or national bodies follow their approaches.
This contribution describes requirements, design techniques and experiences from the development of highly efficient Wireless M-Bus protocol stacks with support of good flexibility and portability between microcontroller platforms and RF-transceivers. The presented approach is not limited to the use of modern software engineering design processes, as such, but also includes essential additional features like testing or simulation, as well as tools for commissioning and monitoring.
Android is an operating system which was developed for use in smart mobile phones and is the current leader in this market. A lot of efforts are being spent to make Android available to the embedded world, as well. Many embedded systems do not have a local GUI and are therefore called headless devices. This paper presents the results of an analysis of the general suitability of Anroid in headless embedded systems and ponders the advantages and disadvantages. It focuses on the hardware related issues, i.e. to what extent Android supports hardware peripherals normally used in embedded systems.
In this paper we propose a motion framework forbipedal robots that decouples motion definitions from stabilizingthe robot. This simplifies motion definitions yet allows dynamicmotion adaptations. Two applications, walking and stopping onone leg, demonstrate the power of the framework. We show thatour framework is able to perform walking and stopping on one legeven under extreme conditions and improves walking benchmarkssignificantly in the RoboCup 3D soccer simulation domain.
Autonomous humanoid robots need high torque actuators to be able to walk and run. One problem in this context is the heat generated. In this paper we propose to use water evaporation to improve cooling of the motors. Simulations based on thermodynamic calculations as well as measurements on real actuators show that, under the assumption of the load of a soccer game, cooling can be considerably improved with relatively small amounts of water.
The formation of secondary phases in the porous electrodes is a severe mechanism affecting the lifetime of solid oxide fuel cells (SOFC). It can occur via various chemical mechanisms and it has a significant influence on cell performance due to pore clogging and deactivation of active surfaces and triple-phase boundary (TPB). We present a modeling and simulation study of nickel oxide formation (reoxidation) and carbon formation (coking) within the SOFC anode. We use a 2D continuum model based on a multi-phase framework [Neidhardt et al., J. Electrochem. Soc., 159, 9 (2012)] that allows the introduction of arbitrary solid phases (here: Ni, YSZ, NiO, Carbon) plus gas phase. Reactions between the bulk phases are modeled via interface-adsorbed species and are described by an elementary kinetic approach. Published experimental data are used for parameterization and validation. Simulations allow the prediction of cell performance under critical operation conditions, like (i) a non-fuel operation test, where NiO formation is taking place (Figure 1a), or (ii) an open circuit voltage (OCV) stability test under hydrocarbon atmosphere, where solid carbon is formed (Figure 1b). Results are applied for enhanced interpretation of experimental data and for prediction of safe operation conditions.
The communication between objects, i.e. between cars (car-2-car, C2C), between cars and infrastructure (car-2-infrastructure, C2I) and between cars and vulnerable road users (car-2-VRU, C2VRU) is a major stepping stone towards traffic applications to enable efficient and safe traffic flow. However, these applications pose very high requirements to the communication protocols, which go beyond the capabilities of an available standardized solution.
This contribution shows how iterative design processes can help to fulfill these requirements, while re-using a maximum of elements from one level to the next and thus avoiding unrealistic overhead. In especially, the added value of simulation and emulation in this iterative process is elaborated.
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. It has found its place in hardware and firmware implementations and is currently tested in various field tests. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed and its benefit for traffic safety applications is evaluated. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. It mainly concentrates on the detection of pedestrians and other vulnerable road users (VRU), but also supports pre crash safety applications. The Ko-TAG proposal enriches the current IEEE802.11p real-time characteristics needed for precise time-of-flight real-time localization. This contribution describes the development of a subsystem, which extends the functionality of IEEE802.11p and fits into the regulatory schemes. It discusses the approach for definition and verification of the protocol design, while maintaining the close coexistence with existing IEEE802.11p subsystems. System simulations were performed and hardware was implemented. The next step will be field measurements to verify the simulation results.
In the dual membrane fuel cell (DM-Cell), protons formed at the anode and oxygen ions formed at the cathode migrate through their respective dense electrolytes to react and form water in a porous composite layer called dual membrane (DM). The DM-Cell concept was experimentally proven (as detailed in Part I of this paper). To describe the electrochemical processes occurring in this novel fuel cell, a mathematical model has been developed which focuses on the DM as the characteristic feature of the DM-Cell. In the model, the porous composite DM is treated as a continuum medium characterized by effective macro-homogeneous properties. To simulate the polarization behavior of the DM-Cell, the potential distribution in the DM is related to the flux of protons and oxygen ions in the conducting phases by introducing kinetic and transport equations into charge balances. Since water pressure may affect the overall formation rate, water mass balances across the DM and transport equations are also considered. The satisfactory comparison with available experimental results suggests that the model provides sound indications on the effects of key design parameters and operating conditions on cell behavior and performance.
Das Ausmaß der elektrischen ventrikulären Desynchronisation bei reduzierter linksventrikulärer Funktion ist von Bedeutung für den Erfolg der Resynchronisationstherapie der Herzinsuffizienz mit biventrikulärer Stimulation. Das Ziel der Untersuchung besteht in der nichtinvasiven Messung der elektrischen inter-ventrikulären Desynchronisation mit und ohne ischämische Herzerkrankung bei kardialen Resynchronisationstherapie Respondern. Bei Patienten mit 25,3 ± 7,3 % reduzierter linksventrikulärer Ejektionsfraktion und 166,9 ± 38,5 ms QRS-Dauer wurde das transösophageale linksventrikuläre EKG abgeleitet. Die QRS-Dauer korrelierte mit dem interventrikulären und links-ventrikulären Delay bei Resynchronisationstherapie Respondern mit nicht-ischämischer Herzerkrankung.
Transösophageales interventrikuläres Delay bei Vorhofflimmern und kardialer Resynchronisation
(2013)
Die transösophageale linksventrikuläre Elektrokardiographie ermöglicht die Evaluierung der elektrischen ventrikulären Desynchronisation im Rahmen der kardialen Resynchronisationstherapie der Herzinsuffizienz. Das Ziel der Untersuchung besteht in der präoperativen Abschätzung des transösophagealen interventrikulären Delays bei Vorhofflimmern und kardialer Resynchronisationstherapie. Bei Patienten mit Vorhofflimmern, Herzinsuffizienz New York Heart Association Klasse 3,0 ± 0,2 und QRS-Dauer 159,6 ± 23,9 ms wurde das fokusierte transösophageale linksventrikuläre EKG abgeleitet. Die kardiale Resynchronisationstherapie Responder QRS-Dauer korrelierte mit dem transösophagealen interventrikulären Delay bei Vorhofflimmern.
Special implant connection module was developed to combine full features of two commercial heart rhythm simulators, ARSI-4 and Intersim II, into a master-slave teaching system. Seven workstations were equipped with the Carelink and Homemonitoring remote patient monitoring systems. This combination enables in-vitro training of physicians, nurses and students in pace-maker and defibrillator measurements during implantation and individual programming in the follow-up. Thus, extended sets of arrhythmias and electrode problems can be used to simulate problems and their solutions in a wide range of the clinical routine.
The design of control systems of concentrator photovoltaic power plants will be more challenging in the future. Reasons are cost pressure, the increasing size of power plants, and new applications for operation, monitoring and maintenance required by grid operators, manufacturers and plant operators. Concepts and products for fixed-mounted photovoltaic can only partly be adapted since control systems for concentrator photovoltaic are considerable more complex due to the required high accurate sun-tracking. In order to assure reliable operation during a lifetime of more than 20 years, robustness of the control system is one crucial design criteria. This work considers common engineering technics for robustness, safety and security. Potential failures of the control system are identified and their effects are analyzed. Different attack scenarios are investigated. Outcomes are design criteria that encounter both: failures of system components and malicious attacks on the control system of future concentrator photovoltaic power plants. Such design criteria are a transparent state management through all system layers, self-tests and update capabilities for security concerns. The findings enable future research to develop a more robust and secure control system for concentrator photovoltaics when implementing new functionalities in the next generation.
The communication system of a large-scale concentrator photovoltaic power plant is very challenging. Manufacturers are building power plants having thousands of sun tracking systems equipped with communication and distributed over a wide area. Research is necessary to build a scalable communication system enabling modern control strategies. This poster abstract describes the ongoing work on the development of a simulation model of such power plants in OMNeT++. The model uses the INET Framework to build a communication network based on Ethernet. First results and problems of timing and data transmission experiments are outlined. The model enables research on new communication and control approaches to improve functionality and efficiency of power plants based on concentrator photovoltaic technology.
Decrease of non-responder rate is the main chal-lenge in cardiac resynchronization therapy. The problem could be solved, partly, in the follow-up by consequent indi-vidualization of hemodynamic pacing parameters. The eso-phageal electrogram feature of the Biotronik ICS 3000 programmer was used in the follow-up of 20 heart failure patients carrying implants for cardiac resynchronization therapy. Adverse hemodynamic programming of the sensed and paced AV delay could be easily observed and replaced by the individual optimal duration in 3 patients (15%) VDD and DDD operation.This result proves the value of esophageal electrogram recording CRT follow-up.
Network landscape of recent time contains many different network technologies, a wide range of end-devices with a large scale of capabilities and power, and an immense quantity of information and data represented in different formats. Research on 3D imaging, virtual reality and holographic techniques will result in new user interfaces (UI) for mobile devices, will increase their diversity and variety. In this paper software architecture has been proposed to establish device and content format independent communication including 3D imaging and virtual reality data as content. As experimental validation the concept is implemented in collaborative Language Learning Game (LLG), which is a learning tool for language acquisition.
The paper proposes a system architecture for charging infrastructure that serves the requirements of future fleets of shared-use electric vehicles in urban scenarios. The focus of the development is on the interfaces to central stakeholders such as mobility service providers, distribution network operators and utilities. The main concept of the proposed system is the adherence to a stringent resource-oriented design approach, following the design principles of the Representational State Transfer (REST) architectural software style for distributed systems. This design approach is used from the cloud-based services down to the implementation of the charging infrastructure's control algorithms. Focusing on the resources of the various entities simplifies the implementation of their interactions, compared to the explicit declaration of services that are available. The system design ensures that the charging infrastructure is open to all users and generates a benefit beyond basic charging operations. Integration in emerging smart markets is done via open web-based interfaces. These allow for the generation of an added value of concrete services for shared-use electric mobility. A link to the field of grid operation is proposed using the ISO/IEC 61850 telecontrol standard. The smart meter capabilities of the charging stations can be used to gain additional information on the current state of the distribution grid. As an exemplary service a load management service for a fleet of shared-use electric vehicles is going to be implemented.
MPC-Workshop Februar 2013
(2013)
MPC-Workshop Juli 2013
(2013)
Die immer weitreichenderen Anwendungen des Smart Metering und des Smart Grid stellen immer höhere Anforderungen an Kommunikationstechnologien, die die Zielkonflikte aus Echtzeitfähige, Stabilität, Kosten und Energieeffizienz möglichst anwendungsoptimiert und auf einem immer höheren Niveau lösen. Insbesondere im Bereich der so genannten Primärkommunikation zwischen einem Sensor- oder Aktorknoten und einem Datensammler mit Gatewayfunktionalität konnten in den vergangenen Jahren wesentliche Fortschritte erzielt werden. Zu nennen sind hierbei insbesondere die Aktivitäten der ZigBee Alliance rund um den offenen Spezifikationsprozess des ZigBee Smart Energy Profiles (SEP) und der OMS-Gruppe beim ZVEI, die auf dem Wireless M-Bus nach EN13757-4 aufbauen, der sich seinerseits lebhaft und zielgerichtet weiter entwickelt. Der Beitrag diskutiert die vorhandenen Einschränkungen und die verfügbaren Lösungsansätze. Er illustriert diese anhand einiger öffentlich geförderter Projekte, an denen das Team des Autors beteiligt ist.
The following paper presents the results of a feasibility study about Bluetooth Low Energy (BLE) based wireless sensors. The development of industrial wireless sensors leads to important demands for the wireless technologies like a low energy consumption and a resource saving simple protocol stack. Bluetooth Low Energy (BLE) is a rather new wireless standard which will completely fulfill these fundamental requirements. A self-designed BLE sensor system has been used to explore the common applicability of BLE for wireless sensor systems. The evaluation results of various analyses with the BLE sensor system are now presented in this paper.
This paper describes the magmaOffenburg 3D simulation team trying to qualify for RoboCup 2012. While last year’s TDP focused on the tool set created for 3D simulation and the support for heterogeneous robot models, this year we focus on the different ways how robot behavior can be defined in the magmaOffenburg framework and how those behaviors can be improved by learning.
Experiences with a telecare platform integration of ZigBee sensors into a middleware platform
(2012)
Responder-rate in cardiac resynchronization therapy (CRT) of patients in sinus rhythm (SR) or atrial fibrillation (AF) mainly depends on accurat selection, optimal position of the left ventricular electrode and individualization of hemodynamical parameters of the implanted biventricular pacing system during follow-up. High resolution esophageal left heart electrocardiography offers a quick and semi-invasive approach to the electrical activity of left atrium and left ventricle. It was used in 62 heart failure patients in sinus rhythm and 11 in atrial fibrillation after implantation of CRT systems to compare the semi-invasive interventricular conduction delay (IVCDE) with QRS width. In all of the patients, guideline decision for CRT was linked with IVCDE of about 40ms and up. From logical point of view, IVCDE provides the minimal target interval for the left ventricular electrode placement in order to exclude non-responders. Esophageal measurement of interatrial conduction intervals in VDD and DDD pacing was utilized to individualize the AV delay and to exclude adverse hemodynamic effects.
Capture threshold (CT) for transesophageal left atrial (LA) pacing (TLAP) and transesophageal left ventricular (LV) pacing (TLVP) with conventional cylindrical electrodes (CE) are higher than TLAP feeling threshold (FT). Purpose of the study was to evaluate focused TLAP CT and FT for supraventricular tachycardia (SVT) initiation and focused TLVP CT for cardiac resynchronisation therapy (CRT) simulation.
Methods: SVT initiation in patients (P) with palpitations (n=49, age 47 ± 17 years) was analysed during spontaneous rhythm and during focused bipolar TLAP with atrial constant current stimulus output, distal CE and three or seven 6 mm hemispherical electrodes (HE) (TO, Osypka AG, Rheinfelden, Germany). CRT simulation in heart failure P (n=75, age 62 ± 11 years) was evaluated by focused bipolar TLAP and/or TLVP with ventricular constant voltage stimulus output and different pacing mode.
Results: Focused electrical pacing field between CE and HE (n=28) allowed low threshold TLAP with 8.0 ± 2.6 mA CT at 9.9 ms stimulus duration (SD) which was lower than 9.2 ± 4.5 mA FT at 9.9 ms SD. Focused electrical pacing field between HE and HE (n=21) allowed low threshold TLAP with 8.1 ± 2.2 mA CT at 9.9 ms SD which was lower than 9.8 ± 5.0 mA FT at 9.9 ms SD. SVT initiation by programmed AAI TLAP was possible in 23 P and not possible in 26 P. CRT simulation was evaluated with TLAP and TLVP with VAT, D00 and V00 pacing mode and 95.5 ± 10.9 V TLVP CT at 4.0 ms SD.
Conclusions: Programmed focused AAI TLAP allowed initiation of SVT with very low CT and high FT and focused electrical pacing field between CE-HE and HE-HE.CRT simulation with focused TLAP and/or TLVP with VAT, D00 and V00 pacing mode may be a useful technique to detect responders to CRT.
Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy in approximately two-thirds of symptomatic heart failure (HF) patients (P) with left bundle branch block (LBBB). The aim of this study was to evaluate left atrial (LA) conduction delay (LACD) and left ventricular (LV) conduction delay (LVCD) using pre-implantational transesophageal electrocardiography (ECG) in sinus rhythm (SR) CRT responder (R) and non-responder (NR).
Methods: SR HF P (n=52, age 63.6±10.4 years; 6 females, 46 males) with New York Heart Association (NYHA) class 3.0±0.2, 24.4±7.1 % LV ejection fraction and 171.2±37.6 ms QRS duration (QRSD) were measured by bipolar filtered transesophageal LA and LV ECG recording with hemispherical electrodes (HE) TO catheter (Osypka AG, Rheinfelden, Germany). LACD was measured between onset of P-wave in the surface ECG and onset of LA deflection in the LA ECG. LVCD was measured between onset of QRS in the surface ECG and onset of LV deflection in the LV ECG.
Results: There were 78.8 % SR CRT R (n=41) with 171.2±36.9 ms QRSD, 73.3±25.7 ms LACD, 80.0±24.0 ms LVCD and 2.3±0.5 QRSD-LVCD-ratio. SR CRT R QRSD correlated with LACD (r=0.688, P<0.001) and LVCD (r=0.699, P<0.001). There were 21.2 % SR CRT NR (n=11) with 153.4±22.4 ms QRSD (P=0.133), 69.8±24.8 ms LACD (n=6, P=0.767), 54.2±31.0 ms LVCD (P<0.0046) and 3.9±2.5 QRSD-LVCD-ratio (P<0.001). SR CRT NR QRSD not corre-lated with IACD (r=-0.218, P=0.678) and IVCD (r=0.042, P=0.903). During a 22.8±21.3 month CRT follow-up, the CRT R NYHA class improved from 3.1±0.3 to 1.9±0.3 (P<0.001). In CRT NR, NYHA class not improved (2.9±0.4 to 2.9±0.2, P=1) during 11.2±9.8 months BV pacing.
Conclusions: Transesophageal LA and LV ECG with HE can be utilized to analyse LACD and LVCD in HF P. Pre-implantational LVCD and QRSD-LVCD-ratio may be additional useful parameters to improve P selection for SR CRT.
Machine-to-machine communication is continuously extending to new application fields. Especially smart metering has the potential to become the first really large-scale M2M application. Although in the future distributed meter devices will be mainly connected via dedicated primary communication protocols, like ZigBee, Wireless
M-Bus or alike, a major percentage of all meters will be connected via point to point communication using GPRS or UMTS platforms. Thus, such meter devices have to be extremely cost and energy efficient, especially if the devices are battery based and powered several years by a single battery. This paper presents the development of an automated measurement unit for power and time, thus energy characteristics can be recorded. The measurement unit includes a hardware platform for the device
under test (DUT) and a database based software environment for a smooth execution and analysis of the measurements.
The research project Ko-TAG [2], as part of the research initiative Ko-FAS [1], funded by the German Ministry of Economics and Technologies (BMWi), deals with the development of a wireless cooperative sensor system that shall pro-vide a benefit to current driver assistance systems (DAS) and traffic safety applications (TSA). The system’s primary function is the localization of vulnerable road users (VRU) e.g. pedestrians and powered two-wheelers, using communication signals, but can also serve as pre-crash (surround) safety system among vehicles. The main difference of this project, compared to previous ones that dealt with this topic, e.g. the AMULETT project, is an underlying FPGA based Hardware-Software co-design. The platform drives a real-time capable communication protocol that enables highly scalable network topologies fulfilling the hard real-time requirements of the single localization processes. Additionally it allows the exchange of further data (e.g. sensor data) to support the accident pre-diction process and the channel arbitration, and thus supports true cooperative sensing. This paper gives an overview of the project’s current system design as well as of the implementations of the key HDL entities supporting the software parts of the communication protocol. Furthermore, an approach for the dynamic reconfiguration of the devices is described, which provides several topology setups using a single PCB design.
Currently, QRS width and bundle branch block morphology are used as electrocardiographic guideline criterias to selectheart failure (HF) patients with interventricular desynchronization in sinus rhythm (SR) for cardiac resynchronisationtherapy (CRT). Nevertheless, up to 30% of these patients do not benefit from implantation of CRT systems. Esophagealleft ventricular electrogram (LVE) enables semi-invasive measurement of interventricular conduction delays (IVCD)even in patients with atrial fibrillation (AF). To routinely apply this method, a programmer based semi-invasiveautomatic quantification of IVCD should to be developed. Our aims were todefine interventricular conduction delaysby analyzing fractionated left ventricular (LV) deflections in the esophageal left ventricular electrogram of HF patientsin SR or AF.
In 66 HF patients (49 male,17 female, age 65 ± 10 years) a 5F TOslim electrode (Osypka AG, Germany) was perorallyapplied. Using BARD EP Lab, cardiac desynchronization was quantified as interval IVCD between onset of QRS insurface ECG and the investigator-determined onset of the left ventricular deflection in LVE. IVCD was compared withthe intervals between QRS onset and the first maximum (IVCDm1) and between QRS onset and the second maximum(IVCDm2) of the LV complex.
QRS of 173 ± 26 ms was linked with empirical IVCD of 75 ± 25 ms, at mean. First and second LV maximum could beascertained beyond doubt in all patients. Significant correlations of the p<0,01 level were found between IVCD and theIVCDm1 of 96 ± 28 ms as well as between IVCD and the IVCDm2 of 147 ± 31 ms, at mean. To standardize automatic measurement of interventricular conduction delays with respect to patients with fractionatedLV complexes, the first maximum of the LV deflection should be utilized to qualify the IVCD of HF patients with sinusrhythm and atrial fibrillation.
About 20% of those heart failure patients receiving cardiac resynchronization therapy (CRT) are in atrial fibrillation (AF). Current guidelines apply for patients in sinus rhythm only. Recent studies have shown again, that successful resynchronization is closely linked to a pre-existent ventricular desynchronization. In those studies, the interventricular conduction delay (IVCD) was determined prior to device implantation by ultrasound in patients with sinus rhythm (SR)only. In patients with AF this method ́s use is limited.
To implement left-heart electrogram (LHE) into standard programmers and to simplify IVCD measurement in heart failure patients with AF, LHE was recorded in 11 AF patients with heart failure by Biotronik ICS3000 programmer via a15Hz Butterworth high-pass filter. Therefore, TOslim esophageal electrode (Dr. Osypka GmbH, Rheinfelden, Germany) was perorally applied and fixed in position of maximal left ventricular defection. IVCD was measured between onset of QRS in surface ECG and left ventricular defection (LV) in LHE. In addition, intra-left ventricular conduction delay (ILVCD) was measured as duration of LV in LHE.
In all of the 11 AF patients, desynchronization was quantifiable by LHE. Mean QRS of 162 ± 27ms (120-206ms) was linked with IVCD of 62ms ± 27ms (37-98ms) and ILVCD of 110 ± 20ms (80-144ms), at mean. Correlation between IVCD and QRS was 0.39 (n. s.) with IVCD/QRS ratio of 0.38 ± 0.11 (0.22-0.81).
A 15Hz high-pass filtered LHE feature of the Biotronik ICS3000 programmer is feasible to quantify ventricular dyssynchrony in heart failure patients with AF in order to clearly indicate implantation of CRT systems. As relations between QRS duration, IVCD and ILVCD considerably differ interindividually, the predictive values of IVCD, ILVCD and IVCD/QRS ratio for individual CRT response or non-response shall be identified in follow-up studies.
ECG simulators, available on the market, imitate the electric activity of the heart in a simplified manner. Thus, they are suitable for education purposes but not really for testing algorithms to recognize complex arrhythmias needed for pacemakers and implantable defibrillators. Especially certain discrimination between various morphologies of atrial and ventricular fibrillation needs simulators providing native electrograms of different patients’ heart rhythm events. This explains the necessity to develop an ECG simulator providing high-resolution native intracardiac and surface electrograms of in-vivo rhythm events. In this paper we demonstrate an approach for an ECG simulator based on a consumer multichannel soundcard and a corresponding software application for a laptop computer. This Live-ECG Simulator is able to handle invasive electrogram recordings from electrophysiological studies and send the data to a modified external soundcard for subsequent digital to analog conversion. The hardware is completed with an electronic circuit providing level adjustment to adapt the output amplitude to the input conditions of several cardiac implants.
Cardiac resynchronization therapy with biventricular pacing is an established therapy for heart failure patients with electrical left ventricular desynchronization. The aim of this study was to evaluate left atrial conduction delay, intra left atrial conduction delay, left ventricular conduction delay and intra left ventricular conduction delay in heart failure patients using novel signal averaging transesophageal left heart ECG software.
Methods: 8 heart failure patients with dilated cardiomyopathy (DCM), age 68 ± 9 years, New York Heart Association (NYHA) class 2.9 ± 0.2, 24.8 ± 6.7 % left ventricular ejection fraction, 188.8 ± 15.5 ms QRS duration and 8 heart failure patients with ischaemic cardiomyopathy (ICM), age 67 ± 8 years, NYHA class 2.9 ± 0.3, 32.5 ± 7.4 % left ventricular ejection fraction and 167.6 ± 19.4 ms QRS duration were analysed with transesophageal and transthoracic ECG by Bard LabDuo EP system and novel National Intruments LabView signal averaging ECG software.
Results: The electrical left atrial conduction delay was 71.3 ± 17.6 ms in ICM versus 72.3 ± 12.4 ms in DCM, intra left atrial conduction delay 66.8 ± 8.6 ms in ICM versus 63.4 ± 10.9 ms in DCM and left cardiac AV delay 180.5 ± 32.6 ms in ICM versus 152.4 ± 30.4 ms in DCM. The electrical left ventricular conduction delay was 40.9 ± 7.5 ms in ICM versus 42.6 ± 17 ms in DCM and intra left ventricular conduction delay 105.6 ± 19.3 ms in ICM versus 128.3 ± 24.1 ms in DCM.
Conclusions: Left heart signal averaging ECG can be utilized to analyse left atrial conduction delay, intra left atrial conduction delay, left ventricular conduction delay and intra left ventricular conduction delay to improve patient selection for cardiac resynchronization therapy.
Cardiac resynchronization therapy (CRT) with biventricular pacing is an established therapy for heart failure (HF) patients (P) with ventricular desynchronization and reduced left ventricular (LV) ejection fraction. The aim of this study was to evaluate electrical right atrial (RA), left atrial (LA), right ventricular (RV) and LV conduction delay with novel telemetric signal averaging electrocardiography (SAECG) in implantable cardioverter defibrillator (ICD) P to better select P for CRT and to improve hemodynamics in cardiac pacing.
Methods: ICD-P (n=8, age 70.8 ± 9.0 years; 2 females, 6 males) with VVI-ICD (n=4), DDD-ICD (n=3) and CRT-ICD (n=1) (Medtronic, Inc., Minneapolis, MN, USA) were analysed with telemetric ECG recording by Medronic programmer 2090, ECG cable 2090AB, PCSU1000 oscilloscope with Pc-Lab2000 software (Velleman®) and novel National Intruments LabView SAECG software.
Results: Electrical RA conduction delay (RACD) was measured between onset and offset of RA deflection in the RAECG. Interatrial conduction delay (IACD) was measured between onset of RA deflection and onset of far-field LA deflection in the RAECG. Interventricular conduction delay (IVCD) was measured between onset of RV deflection in the RVECG and onset of LV deflection in the LVECG. Telemetric SAECG recording was possible in all ICD-P with a mean of 11.7 ± 4.4 SAECG heart beats, 97.6 ± 33.7 ms QRS duration, 81.5 ± 44.6 ms RACD, 62.8 ± 28.4 ms RV conduction delay, 143.7 ± 71.4 ms right cardiac AV delay, 41.5 ms LA conduction delay, 101.6 ms LV conduction delay, 176.8 ms left cardiac AV delay, 53.6 ms IACD and 93 ms IVCD.
Conclusions: Determination of RA, LA, RV and LV conduction delay, IACD, IVCD, right and left cardiac AV delay by telemetric SAECG recording using LabView SAECG technique may be useful parameters of atrial and ventricular desynchronization to improve P selection for CRT and hemodynamics in cardiac pacing.
New frontiers of supraventricular tachycardia and atrial flutter evaluation and catheter ablation
(2012)
Radiofrequency catheter ablation (RFCA) has revolutionized treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. Although developed in the 1980s and widely applied in the 1990s, the technique is still in development. Transesophageal atrial pacing (TAP) can used for initiation and termination of supraventricular tachycardia (SVT).
Methods: The paroxysmal SVT include a wide spectrum of disorders including, in descending order of frequency, atrial flutter, atrioventricular (AV) nodal reentry, Wolff-Parkinson-White syndrome, and atrial tachycardia. While not life-threatening in most cases, they may cause important symptoms, such as palpitations, chest discomfort, breathlessness, anxiety, and syncope, which significantly impair quality of life. Medical therapy has variable efficacy, and most patients are not rendered free of symptoms. Research over the past several decades has revealed fundamental mechanisms involved in the initiation and maintenance of all of these arrhythmias. Knowledge of mechanisms has in turn led to highly effective surgical and catheter-based treatments. The supraventricular arrhythmias and their treatment are described in this report. SVT initiation was analysed with programmed TAP in 49 patients with palpitations (age 47 ± 17 years, 24 females, 25 males).
Results: In comparison to antiarrhythmic drug therapy the radiofrequency catheter ablation in patients suffering from atrial flutter, atrioventricular nodal reentry, atrioventricular reentry and atrial tachycardia is the better choice in most cases. TAP SVT initiation was possible in 23 patients before RFCA. Atrial cycle length of SVT was 320 ± 59 ms. We initiated AV nodal reentrant tachycardia (AVNRT, n=15), atrial tachycardia (AT, n=6) and AV reentrant tachycardia with Kent pathway conduction (AVRT, n=2) before RFCA.
Conclusions: Radiofrequency catheter ablation is a successful and safe method to cure most patients with paroxysmal supraventricular tachycardias. TAP allowed initiation and termination of SVT especially in outpatients.
In this paper, a complete passive transponder device has been discussed which is meant to monitor leakage in silicone breast implants. The passive tag operates in the HF frequency range of 13.56MHz using RFID ISO 15693 standard. The complete system consists of the transponder, reader and a PC. This paper focusses on the development of such a state of the art passive RFID transponder to monitor the wellness of the silicone breast implants periodically in order to detect leakage in the same. Keyword: RFID (Radio frequency identification device), EM (Electromagnetic) field, Passive Transponder, Silicone breast implants.
Remote measurement of the physiology, so-called biotelemetry, is a key technology in the modern veterinary medicine. The usage of wireless implants has less impact on the behavior of animals than manual measurement methods and cause less disturbance than wired devices. But, common biotelemetry still uses proprietary communication and power concepts focused on small systems with one animal. Therefore, the University of Applied Sciences Offenburg is developing a low-cost RFID system called muTrans1, which is able to measure ECG, pressure, temperature, oxygen saturation and activity. The muTrans uses an own RFID sensor transponder and standardized commercial components and combines them to a scalable RFID system able to build-up RFID sensor networks with a nearly unlimited size.
During the last ten years the development of wireless sensing applications has become more and more attractive. A major reason for this trend is the large quantity of available wireless technologies. The progressing demand on wireless technologies is mainly driven through development from the industrial wireless sensors market. Especially requirements like low energy consumption, a resource saving simple protocol stack and short timing delays between different states of the wireless transceivers are very important for wireless sensors. Bluetooth Low Energy (BLE) is a rather new wireless standard in addition to the traditional Bluetooth standard (Basis rate and enhanced data rate, BR/EDR) [1]. The BLE will completely fulfill these fundamental requirements. First BLE transceiver chips and modules are available and have been tested and implemented in products. In this paper the performance analysis results of a BLE sensor system which is based on the TI transceiver CC2540F [5] will be presented. The results can be taken for further important investigations like lifetime calculations or BLE simulation models.
In the field of smart metering it can be observed that standardized protocol, like Wireless M-Bus or ZigBee, enjoy a rapidly increasing popularity. For the protocol implementations, however, up to now, mostly legacy engineering processes and technologies are used, and modern approaches such as model driven design processes or open software platform are disregarded. Therefore, within the WiMBex project, it shall be demonstrated that it is possible to develop a commercial class Wireless M-Bus implementation following state-of-the art design process and using TinyOS as an open source platform. This contribution describes the overall approach of the project, as well as the state and the first experiences of the current work in progress.
This paper analyzes the applicability of existing communication technology on the Smart Grid. In particular it evaluates how networks, e.g. Peer-to-Peer (P2P) and decentralized Virtual Private Network (VPN) can help set up an agent-based system. It is expected that applications on Smart Grid devices will become more powerful and be able to operate without a central control instance. We analyze which requirements agents and Smart Grid devices place on communication systems and validate promising approaches. The main focus is to create a logical overlay network that provides direct communication between network nodes. We provide a comparison of different approaches of P2P networks and mesh-VPNs. Finally the advantages of mesh-VPN for agent-based systems are worked out.
Since cabling is very complex and often causes reliability problems in aircrafts new approaches which base on wireless technologies are highly desired. In this paper an innovative communication system is proposed that uses the essential elements of the airframe for data transfer. The communication is based on the wireless standard for Digital Video Broadcasting (DVB) and enables high data rates, which are required for the in-flight entertainment system as an example of use.
Today's network landscape consists of many different network technologies, a wide range of end-devices with a large scale of capabilities and power, and an immense quantity of information and data represented in different formats. Research on 3D imaging, virtual reality and holographic techniques will result in new user interfaces (UI) for mobile devices and will increase their diversity and variety. In this paper software architecture has been proposed to establish device and content format independent communication, implemented in Language Learning Game (LLG).
MPC-Workshop Februar 2012
(2012)
Multi-phase management is crucial for performance and durability of electrochemical cells such as batteries and fuel cells. In this paper we present a generic framework for describing the two-dimensional spatiotemporal evolution of gaseous, liquid and solid phases, as well as their interdependence with interfacial (electro-)chemistry and microstructure in a continuum description. The modeling domain consists of up to seven layers (current collectors, channels, electrodes, separator/membrane), each of which can consist of an arbitrary number of bulk phases (gas, liquid, solid) and connecting interfaces (two-phase or multi-phase boundaries). Bulk and interfacial chemistry is described using global or elementary kinetic reactions. Multi-phase management is coupled to chemistry and to mass and charge transport within bulk phases. The functionality and flexibility of this framework is demonstrated using four application areas in the context of post-lithium-ion batteries and fuel cells, that is, lithium-sulfur (Li-S) cells, lithium-oxygen (Li-O) cells, solid oxide fuel cells (SOFC) and polymer electrolyte membrane fuel cells (PEFC). The results are compared to models available in literature and properties of the generic framework are discussed.
MPC-Workshop Juli 2012
(2012)
This paper describes the magmaOffenburg 3D simulation team trying to qualify for RoboCup 2011. While last year’s TDP focused on the tool set created for 3D simulation in this year we describe the further improvement in this tools as well as some new features we implemented focusing on heterogeneous robot models which seem to be used in RoboCup 2012.
An additional tool was written to simply generate situation-dependent strategies. Furthermore some tools, described last year, are now integrated in one single GUI to easy things up.
Introduction: Patient selection for cardiac resynchronization therapy (CRT) requires quantification of left ventricular conduction delay (LVCD). After implantation of biventricular pacing systems, individual AV delay (AVD) programming is essential to ensure hemodynamic response. To exclude adverse effects, AVD should exceed individual implant-related interatrial conduction times (IACT). As result of a pilot study, we proposed the development of a programmer-based transoesophageal left heart electrogram (LHE) recording to simplify both, LVCD and IACT measurement. This feature was implemented into the Biotronik ICS3000 programmer simultaneously with 3-channel surface ECG.
Methods: A 5F oesophageal electrode was perorally applied in 44 heart failure CRT-D patients (34m, 10f, 65±8 yrs., QRS=162±21ms). In position of maximum left ventricular deflection, oesophageal LVCD was measured between onsets of QRS in surface ECG and oesophageal left ventricular deflection. Then, in position of maximum left atrial deflection (LA), IACT in VDD operation (As-LA) was calculated by difference between programmed AV delay and the measured interval from onset of left atrial deflection to ventricular stimulus in the oesophageal electrogram. IACT in DDD operation (Ap-LA) was measured between atrial stimulus and LA..
Results: LVCD of the CRT patients was characterized by a minimum of 47ms with mean of 69±23ms. As-LA and Ap-LA were found to be 41±23ms and 125±25ms, resp., at mean. In 7 patients (15,9%), IACT measurement in DDD operation uncovered adverse AVD if left in factory settings. In this cases, Ap-LA exceeded the factory AVD. In 6 patients (13,6%), IACT in VDD operation was less than or equal 10ms indicating the need for short AVD.
Conclusion: Response to CRT requires distinct LVCD and AVD optimization. The ICS3000 oesophageal LHE feature can be utilized to measure LVCD in order to justify selection for CRT. IACT measurement simplifies AV delay optimization in patients with CRT systems irrespective of their make and model.
Introduction: To simplify AV delay (AVD) optimization in cardiac resynchronization therapy (CRT), we reported that the hemodynamically optimal AVD for VDD and DDD mode CRT pacing can be approximated by individually measuring implant-related interatrial conduction intervals (IACT) in oesophageal electrogram (LAE) and adding about 50ms. The programmer-based St Jude QuickOpt algorithm is utilizing this finding. By automatically measuring IACT in VDD operation, it predicts the sensed AVD by adding either 30ms or 60ms. Paced AVD is strictly 50ms longer than sensed AVD. As consequence of those variations, several studies identified distinct inaccuracies of QuickOpt. Therefore, we aimed to seek for better approaches to automate AVD optimization.
Methods: In a study of 35 heart failure patients (27m, 8f, age: 67±8y) with Insync III Marquis CRT-D systems we recorded telemetric electrograms between left ventricular electrode and superior vena cava shock coil (LVtip/SVC = LVCE) simultaneously with LAE. By LVCE we measured intervals As-Pe in VDD and Ap-Pe in DDD operation between right atrial sense-event (As) or atrial stimulus (Ap), resp., and end of the atrial activity (Pe). As-Pe and Ap-Pe were compared with As-LA an Ap-LA in LAE, respectively.
Results: End of the left atrial activity in LVCE could clearly be recognized in 35/35 patients in VDD and 29/35 patients in DDD operation. We found mean intervals As-LA of 40.2±24.5ms and Ap-LA of 124.3±20.6ms. As-Pe was 94.8±24.1ms and Ap-Pe was 181.1±17.8ms. Analyzing the sums of As-LA + 50ms with duration of As-Pe and Ap-LA + 50ms with duration of Ap-Pe, the differences were 4.7±9.2ms and 4.2±8.6ms, resp., only. Thus, hemodynamically optimal timing of the ventricular stimulus can be triggered by automatically detecting Pe in LVCE.
Conclusion: Based on minimal deviations between LAE and LVCE approach, we proposed companies to utilize the LVCE in order to automate individual AVD optimization in CRT pacing.
In-vivo and in-vitro comparison of implant-based CRT optimization - What provide new algorithms?
(2011)
Introduction: In cardiac resynchronization therapy (CRT), individual AV delay (AVD) optimization can effectively increase hemodynamics and reduce non-responder rate. Accurate, automatic and easily comprehensible algorithms for the follow-up are desirable. QuickOpt is the first attempt of a semi-automatic intracardiac electrogram (IEGM) based AVD algorithm. We aimed to compare its accuracy and usefulness by in-vitro and in-vivo studies.
Methods: Using the programmable ARSI-4 four-chamber heart rhythm and IEGM simulator (HKP, Germany), the QuickOpt feature of an Epic HF system (St. Jude, USA) was tested in-vitro by simulated atrial IEGM amplitudes between 0.3 and 3.5mV during both, manual and automatic atrial sensing between 0.2 and 1.0mV. Subsequently, in 21 heart failure patients with implanted biventricular defibrillators, QuickOpt was performed in-vivo. Results of the algorithm for VDD and DDD stimulation were compared with echo AV delay optimization.
Results: In-vitro simulations demonstrated a QuickOpt measuring accuracy of ± 8ms. Depending on atrial IEGM amplitude, the algorithm proposed optimal AVD between 90 and 150ms for VDD and between 140 and 200ms for DDD operation, respectively. In-vivo, QuickOpt difference between individual AVD in DDD and VDD mode was either 50ms (20pts) or 40ms (1pt). QuickOpt and echo AVD differed by 41 ± 25ms (7 – 90ms) in VDD and by 18 ± 24ms (17-50ms) in DDD operation. Individual echo AVD difference between both modes was 73 ± 20ms (30-100ms).
Conclusion: The study demonstrates the value of in-vitro studies. It predicted QuickOpt deficiencies regarding IEGM amplitude dependent AVD proposals constrained to fixed individual differences between DDD and VDD mode. Consequently, in-vivo, the algorithm provided AVD of predominantly longer duration than echo in both modes. Accepting echo individualization as gold standard, QuickOpt should not be used alone to optimize AVD in CRT patients.
Existing approaches solving multi-vehicle pickup and delivery problems with soft time windows typically use common benchmark sets to verify their performance. However, there is a gap from these benchmark sets to real world problems with respect to instance size and problem complexity. In this paper we show that a combination of existing approaches together with improved heuristics is able to deal with the instance sizes and complexity of real world problems. The cost savings potential of the heuristics is compared to human dispatching plans generated from the data of a European carrier.
Significance of new electrocardiographic parameters to improve cardiac resynchronization therapy
(2011)
Introduction: Oesophageal left heart electrogram (LHE) is a valuable tool providing electrocardiographic parameters for cardiac resynchronization therapy (CRT). It can be utilized to measure left ventricular (LVCD) and intra-leftventricular conduction delays (ILVCD) in heart failure patients to justify implantation of CRT systems. In the follow-up, LHE enables measurement of implant-related interatrial conduction times (IACT) which are the key intervals defining the hemodynamically optimal AV delay (AVD).
Methods: By TOSlim oesophageal electrode and Rostockfilter (Osypka AG, Rheinfelden, Germany), LHE was recorded in 39 heart failure patients (10f, 29m, 65±8yrs., QRS=163±21ms) after implantation of CRT systems according to guidelines. In position of maximal left ventricular deflection, LVCD and ILVCD were measured and compared with QRS width. In position of maximal left atrial deflection (LA), IACT was determined in VDD and DDD operation as interval As-LA and Ap-LA between atrial sense event (As) or stimulus (Ap), resp., and onset of LA. AVD was individualized using SAV =As-LA + 50ms for VDD and PAV=Ap-LA + 50ms for DDD operation.
Results: The CRT patients were characterized by minimal transoesophageal LVCD of 40ms but 73±20ms, at mean, ILVCD of 90±24ms and QRS/LVCD ratio of 2.4±0.6. The measured As-LA of 39±24ms and Ap-LA of 124±26ms resulted into SAV of 89±24ms and PAV of 174±26ms. In case of empirical AVD programming using 120ms for SAV and 180ms for PAV, the LHE revealed inverse sequences of LA and Vp in 4 patients (10%) during VDD and 13 patients (33%) in DDD pacing. In these patients, Vp preceded LA as IACT exceeded the programmed AVD.
Conclusion: Guideline indication of CRT systems is associated with LVCD of 40ms or more. Therefore, individual LVCD offers the minimal target interval that should be reached during left ventricular electrode placement to increase responder rate. Postoperatively, AV delay optimization respecting implant-related IACTs excludes adverse hemodynamic effects.
Electrical velocimetry to optimize VV delay in biventricular VVIR and DDD pacing for heart failure
(2011)
Introduction: VV delay (VVD) is the only parameter to hemodynamically optimize cardiac resynchronization therapy (CRT) for patients with atrial fibrillation (AF). Electrical velocimetry (EV) has been established to monitor thoracic electrical conductivity and to calculate hemodynamic surrogate parameters. We compared the response of this method to hemodynamic parameter changes between CRT patients with sinus rhythm (SR) and patients with AF.
Methods: VVD was individualized in 17 CRT patients in SR (12m, 5f, 67.0±7.2yrs.) after echo AV delay optimization and in 11 CRT patients in AF (10m, 1f, 69.8±9.6yrs.) using the Aesculon Cardiovascular Monitor (Osypka Medical, Berlin, Germany). Serial 30s EV recordings were accomplished, decreasing the VVD stepwise by 10ms from +60ms to -60ms between right and left ventricular stimulus. Optimal VVD was determined by the maximum of at least two of the three averaged parameters stroke volume (SV), cardiac output (CO) and cardiac index (CI). The response of SV, CO and CI was tested comparing their values in optimal VVD and suboptimal VVD. Suboptimal VVD was defined by optimal VVD±20ms.
Results: In all 28 patients in SR and AF, EV recordings resulted in optimal VVD. Between suboptimal and optimal mean VVD of 18.6±30.8ms between left and right ventricular stimulus, SV increased by 7.2±6.8%, CO by 7.8±7.2% and CI by 10.0±13.3% (all p<0.02). In the SR group with VVD of 18.8± 29.6ms, SV increased by 4.6±2.9%, CO by 5.0±2.9% and CI by 4.9±2.9% (all p<0.02). In the AF group with VVD of 18.2±4.0ms, SV increased by 10.4±8.9%, CO by 11.3±9.5% and CI by 16.4±18.2% (all p<0.02). Significant differences were not found between optimal VVD in SR and AF patients.
Conclusion: EV is a feasible serial method to individualize VVD in DDD and VVIR pacing for heart failure. Its response to hemodynamic changes demonstrates the value of EV for VVD fine-tuning.
Introduction: Cardiac resynchronization therapy (CRT) with left ventricular (LV) pacing is an established therapy for heart failure (HF) patients (P) with ventricular desynchronisation and reduced LV ejection fraction (EF). The aim of this study was to test the utilization of the transesophageal approach to measure arterial pulse pressure (PP) during LV pacing and electrical interventricular conduction delay (IVCD), to better select patients for CRT.
Methods: 32 HF patients (age 64 ± 10 years; 5 females, 27 males) with New York Heart Association (NYHA) class 2.8 ± 0.6, 27 ± 11 % LV EF and 155 ± 35 ms QRS duration were analysed with semi-invasive left cardiac pacing and electrocardiography. Esophageal TO8 Osypka catheter of 10.5 F diameter was perorally applied to the esophagus and placed in the position of maximum left atrial (LA) deflection and maximum LV deflection to measure PP with VAT or D00 pacing modes.
Results: Temporary transesophageal LV pacing was possible with VAT mode (n=16) and D00 mode (n=16) in all patients. In 15 Δ-PP-responders, PP was higher during LV pacing on than LV pacing off (78.3 ± 26.6 versus 65.9 ± 23.7 mmHg, P < 0.001) and NYHA class improved from 3.1 ± 0.35 to 2.1 ± 0.35 (P < 0.001) during 29 ± 26 month biventricular (BV) pacing follow-up (6 Medtronic and 9 Boston BV pacing devices). In 17 Δ-PP-non-responders, PP was not higher during LV pacing on than LV pacing off (61.5 ± 23.9 versus 60.9 ± 23.5 mmHg, P = 0.066). IVCD was significant longer in Δ-PP-responders than in Δ-PP-non-responders (87 ± 33 ms versus 37± 29 ms, P < 0.001).
Conclusion: Semi-invasive transesophageale LA and LV pacing with D00 and VAT mode and LV electrogram recording may be useful techniques to predict CRT improvement.
Home Care Applications and Ambient Assisted Living become increasingly attractive. This is caused as well by market pull, as the number of elderly people grows monotonously, as well as by technology push, as technological advances and attractive products pave the way to economically advantageous offerings. However, in real-life applications, a significant number of challenges remain. Those include seamless communication between products from different supplier, due to the lack of sufficiently standardized solutions, energy budgets, and scalability of solutions. This paper presents the experience from the InCASA project (Integrated Network for Completely Assisted Senior Citizen's Autonomy), where architectures for heterogeneous physical and logical communication flows are examined.