Validation of a fixed tuned planar tripler design optimized for sub-mm wave generation with HBCS devices - Ruf, Marcel; Schür, Jan; Bogdan, N.; Schmidt, Lorenz-Peter; Hartnagel, H. (Proceedings of the European Microwave Association, 2008)
UnivIS-Import:2015-04-16:Pub.2008.tech.IE.LEH.valida

Validation of a Narrowband Signal Processing System for Beam Position Monitoring Purposes in Linear Accelerators - Ruf, Marcel; Trummer, S.; Schmidt, Lorenz-Peter; Setzer, S. (5th German Microwave Conference, 2010)
A new RF frontend for a beam position monitoring system for electron linear accelerators (Linacs) is discussed. The frontend applies a waveguide based input filter section for processing the pulse train, generated by non-interceptive pickups and selection of the desired beam harmonic. Due to increased accuracy, narrowband signal processing was chosen for further signal treatment. Therefore, a two-channel downconverter was designed incorporating two single-balanced diode mixer stages optimized for processing frequencies around 6 GHz, the second beam harmonic in S-Band Linacs. Device characteristics and component validation in a demonstrator with electro-magnetic excitation, simulating beam-induced fields are presented.
lhft_intern.bib::Ruf10

Validation of a Radar Sensor Model under non-ideal Conditions for Testing Automated Driving Systems - Wachtel, Diogo; Schroeder, Sabine; Reway, Fabio; Huber, Werner; Vossiek, Martin (2021 IEEE INTELLIGENT VEHICLES SYMPOSIUM WORKSHOPS (IV WORKSHOPS), 2021)
CRIS-Team WoS Importer:2022-04-29

Validation of Electron Beam Position Monitoring Probes by Comparison of Dose Profile Measurements with Beam Displacement Sensing in the Microwave Range - Ruf, Marcel; Schmidt, Lorenz-Peter; Setzer, S. (Asia-Pacific Microwave Conference, 2011)
The development of a beam position monitoring and control architecture for compact linear accelerators requires novel sensors which fulfill the tight space restrictions given in such systems. This paper presents simulation and experimental data of capacitive pickup probes with high sensitivity capable of sensing beam deflections far below 1 mm and compact enough to be integrated in accelerating structures. The correlation of beam position monitoring output signals with dose profile measurements is presented indicating that the proposed compact sensors together with dedicated BPM hardware allow reliable electron beam trajectory determination.
lhft_intern.bib::Ruf11b

Vector Field Measurements at 150 GHz - Weinzierl, Jochen; Brand, Hans; Schmidt, Lorenz-Peter (Proceedings of the 11th Conference and Exhibition on Microwaves, Radio Communication and Electromagnetic Compatibility MIOP 2001, 2001)
UnivIS-Import:2015-04-16:Pub.2001.tech.IE.LEH.vector

Vector Velocity and Position Measurement Using a 77-GHz Cooperative Radar System - Edstaller, Stefan; Müller, David (IEEE MTT-S International Microwave Symposium Digest, 2019)
We present a 77 GHz cooperative radar system, which uses two standalone FMCW radar sensors for vector velocity and positioning measurements. The system is based on a decentralized signal processing approach, where sampled data from only one sensor is used for full 2-dimensional localization and velocity measurement of a target. The information is also used for direction-of-movement (DOM) estimation. Frequency and phase calibration for the bistatic beat responses is accomplished by using a known reference target and corresponding signal processing algorithms. Measurement results show the applicability of the proposed system for target tracking, localization and 2-dimensional velocity measurements. The average deviation for DOM estimation is better than 1.1 degree and an average velocity error of approximately one percent is achieved.
CRIS-Team Scopus Importer:2019-08-09
Keywords: Millimeter wave radar; multistatic radar; radar measurements; radar signal processing; radar tracking

Vektorielle Feldmesstechnik bei 150 GHz, 300 GHz und 450 GHz - Hofmann, Arnd (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2005)
lhft_intern.bib::Hofmann2005_Phd

Verfahren zur Integration von lokaler Funkortung und Inertialsensorik zur Objektverfolgung innerhalb von Gebäuden - Max, Stephan; Gulden, Peter; Vossiek, Martin (Sensoren und Messsysteme 2008, 2008)
Lokale Funkortungstechniken und Trägheitsnavigationsverfahren besitzen spezifische und in weiten Bereichen disjunkte Vor- und Nachteile. Zur Nutzung und Kombination der Vorteile beider Verfahren wird ein neuer Ansatz zur Kopplung der Systeme (Hybrid Navigation) vorgestellt. Der Ansatz basiert auf einem Beobachter-Konzept, das durch die Verwendung eines indirekten Kalman Filters in einer geschlossenen Regelschleife implementiert wird. Der aus der GPS/INS-Kopplung bekannte Ansatz wird im Folgenden auf die lokale Objektpositionierung transferiert, modifiziert und weiterentwickelt. Abschließende praktische Versuche der realisierten Hybrid-Navigationslösung zeigen deutliche Verbesserungen gegenüber den bisherigen Funkortungssystemen.
UnivIS-Import:2015-04-16:Pub.2008.tech.IE.LEH.verfah

Vergleichende Analyse einer numerischen zeitbereichsbasierten Bitfehlerschätzung in einem vorverstärkten OTDM Empfänger mit experimentellen Ergebnissen - Wietfeld, André; Schubert, C.; Schmauß, Bernhard (Workshop der Fachgruppe 5.3.1, 20.- 21.11., Backnang, 2003)
UnivIS-Import:2015-04-16:Pub.2003.tech.IE.LEH.vergle

Virtual Synthetic Aperture Radar Target Based on a Miniaturized Monostatic Digital Delay Transponder - Stelzig, Michael; Benedikter, Andreas; Horn, Ralf; Jaeger, Marc; Keller, Martin; Scheiber, Rolf; Krieger, Gerhard; Vossiek, Martin (IEEE Microwave and Wireless Components Letters, 2021)
The ice penetrating capability of low-frequency radar systems may offer a unique potential for the detection, localization, and guidance of exploratory ice-penetrating probes for cryospheric applications. As these probes exhibit a comparably small radar cross section (RCS), reliable detection, especially in high clutter surroundings, such as ice sheets, is prevented. As a solution, a miniaturized monostatic digital delay transponder is developed and tested regarding its functionality with an airborne synthetic aperture radar (SAR) sensor.
Keywords: Transponders; Radar; Syntethic aperture radar (SAR); Radar cross-sections (RCS); Delays; Probes; Ice; Pulse compression

Virtuelle Instrumente in der Praxis - Hrobak, Michael; Schramm, Marcus; Schmidt, Lorenz-Peter; Lechner, Armin (Virtuelle Instrumente in der Praxis, 2009)
UnivIS-Import:2015-04-20:Pub.2009.tech.IE.LEH.virtue

Visualization of Magnetic Nanoparticles by Ultrasound Strain Imaging - Huber, Christian; El Aawar, Karim; Ullmann, Ingrid; Lyer, Stefan; Ermert, Helmut (SMSI 2023 Conference – Sensor and Measurement Science International, 2023)
In magnetic drug targeting, superparamagnetic nanoparticles are used as drug carriers. The local accumulation of these particles at the site of the tumor leads to a temporary change in the effective elastic tissue properties in this area. Therefore, mapping this change should allow visualization of the particle distribution. Ultrasound strain imaging is a method to map the local variation of elasticity. This method was tested using a polyvinyl alcohol ultrasound phantom with a magnetic nanoparticle inclusion. It was demonstrated, that this inclusion can be mapped in the proposed wa
Keywords: Ultraschallbildgebung; Ultraschallelastographie; Magnetische Nanopartikel; Magnetic Drug Targeting

Vollständige Integration des virtuellen Tests in den Entwurfsprozess integrierter Schaltungen - Glaser, Daniel; Lu, Ping; Helmreich, Klaus (Tagungsband, 2009)
UnivIS-Import:2015-04-16:Pub.2009.tech.IE.c3scha.vollst

Wall-less Flow Phantoms with 3D printed Soluble Filament for Ultrasonic Experiments - Huber, Christian; Lyer, Stefan; Ermert, Helmut; Heim, Christian; Rupitsch, Stefan J.; Ullmann, Ingrid (Current Directions in Biomedical Engineering, 2023)
Tissue-mimicking materials (TMMs) typically used for ultrasound phantoms include gelatin, agarose and polyvinyl alcohol (PVA). These materials have shown sufficient similarity in ultrasound parameters compared to human tissue. Despite their extensive use for years to generate ultrasound phantoms, no simple and easily reproducible way to generate complex, wall-less ultrasound flow phantoms has been introduced. Commercially available ultrasound flow phantoms are limited to simple flow geometries that do not reflect the complex blood flow in humans. Flow phantoms with complex geometries presented in scientific publications either have walls between TMMs and the flow channel, are limited to one material, or are complicated to produce. In this contribution, we present a method using 3D printing and soluble filament that allows for the reliable and consistent production of complex flow geometries with the typical materials used for ultrasound phantoms and without any walls.
CRIS-Team Scopus Importer:2023-10-20
Keywords: 3D Printing; Flow Experiments; Ultrasound; Ultrasound Phantoms

Water-soluble filament in multifilament approach for ultrasound phantom fabrication - Huber, Christian; Lahmadi, Wahbi; Alballa, Ahmad; Heim, Christian; Rupitsch, Stefan J.; Ermert, Helmut; Ullmann, Ingrid; Lyer, Stefan (Transactions on Additive Manufacturing Meets Medicine, 2024)
Ultrasound phantoms are used in research, equipment testing, calibration, and even in the field of medical training. Despite their importance, commercial ultrasound phantoms are often expensive and may not meet user requirements. While simplistic phantom construction methods exist which use readily available materials, they often lack versatility in both their exterior and interior designs. By using tissue-mimicking materials such as gelatin, agarose, or polyvinyl alcohol mixed with water, simple yet effective ultrasound phantoms can be created through a heating and hardening process. While designing the outer structure of these phantoms can be achieved through the creation of various molds, crafting complex inner structures poses a more difficult task. Additive manufacturing, specifically fused deposition printing with standard 3D printers, presents a promising solution to this challenge. This involves using soluble materials that can be removed after the phantom hardens. In prior research, we successfully demonstrated this methodology using high impact polystyrene and VXL70. Building on this, our current study aims to simplify the process and evaluate non-toxic, water-soluble filaments. Using polyvinyl alcohol filament in combination with high impact polystyrene is a promising approach. These phantoms serve versatile purposes, including the replication of vascular structures or the incorporation of distinct material regions to simulate tumor structures. Through this investigation, we aim to enhance the accessibility and functionality of ultrasound phantoms for diverse research and medical applications.<br

WaterSpy: A High Sensitivity, Portable Photonic Device for Pervasive Water Quality Analysis - Doulamis, Nikolaos; Voulodimos, Athanasios; Doulamis, Anastasios; Bimpas, Matthaios; Angeli, Aikaterini; Bakalos, Nikolaos; Giusti, Alessandro; Philimis, Panayiotis; Varriale, Antonio; Ausili, Alessio; D'Auria, Sabato; Lampropoulos, George; et al. (Sensors, 2019)
In this paper, we present WaterSpy, a project developing an innovative, compact, cost-effective photonic device for pervasive water quality sensing, operating in the mid-IR spectral range. The approach combines the use of advanced Quantum Cascade Lasers (QCLs) employing the Vernier effect, used as light source, with novel, fibre-coupled, fast and sensitive Higher Operation Temperature (HOT) photodetectors, used as sensors. These will be complemented by optimised laser driving and detector electronics, laser modulation and signal conditioning technologies. The paper presents the WaterSpy concept, the requirements elicited, the preliminary architecture design of the device, the use cases in which it will be validated, while highlighting the innovative technologies that contribute to the advancement of the current state of the art.
CRIS-Team WoS Importer:2019-03-01

Welcome from the workshop chair - Vossiek, Martin (European Microwave Week 2013, EuMW 2013 - Conference Proceedings; EuRAD 2013: 10th European Radar Conference, 2013)
CRIS-Team Scopus Importer:2023-03-08

Welcome messages: Welcome from the workshop chair - Vossiek, Martin (European Microwave Week 2013, EuMW 2013 - Conference Proceedings; EuMIC 2013: 8th European Microwave Integrated Circuits Conference, 2013)
CRIS-Team Scopus Importer:2023-03-08

West German Microwave Activity - State of the Art in Satellite Communications - Brand, Hans (MTT006, 1980)
The paper deals with the West German contributions to the growing field of microwave technology with special emphasis on satcom applications. After briefly reviewing the historical development,, the earth stations and some new satellite systems are described in more details. Research and development activities in industry and governmental laboratories conclude the overvie
lhft_intern.bib::thirty_years_LHFT_114

West German University Education in Electrical Engineering - Brand, Hans (1979)
lhft_intern.bib::thirty_years_LHFT_108

Where is the Tag? - Miesen, Robert; Ebelt, Randolf; Kirsch, Fabian; Schäfer, Tobias; Li, Gang; Wang, Haowei; Vossiek, Martin (IEEE Microwave Magazine, 2011)
Radio-frequency identification (RFID) localization developments and trends are reviewed. RFID localization relative to a reader can be broken down into two different tasks: ranging and direction finding. A system with both of these capabilities can provide two-dimensional (2-D) or three-dimensional (3-D) localization and an RFID system with only one of these capabilities can still provide useful functionalities. Standard RFID systems feature only coarse locating capabilities with a granularity given by the dimension of a cell formed by a reader. RFID ranging techniques may be categorized according to three criteria. The first and second are the type of transponder and the fundamental principle behind tag localization. Broadband chipless RFID tags have emerged as very promising candidates for next generation locatable RFID transponder
lhft_intern.bib::Miesen2011c

Whisker-Device-Based Optimisation of Fabrication Process for Planar THz Schottky Diodes - Cojocari, O.; Biber, Stephan; Mottet, B.; Rodriguez-Girones, M.; Schmidt, Lorenz-Peter; Hartnagel, H. (3rd ESA Workshop on Millimetre Wave Technology and Applications, 2003)
UnivIS-Import:2015-04-16:Pub.2003.tech.IE.LEH.whiske

Wideband Imaging Systems in the mm-Wave and THz range for Security and Nondestructive Testing - Nezadal, Martin; Adametz, Julian; Schmidt, Lorenz-Peter (31st URSI General Assembly and Scientific Symposium, 2014)
lhft_intern.bib::NezadalURSI2014

Wireless 3D Localization Concept for Industrial Automation Based on a Bearings Only Extended Kalman Filter - Lipka, Melanie; Sippel, Erik; Hehn, Markus; Adametz, Julian; Vossiek, Martin; Dobrev, Yassen; Gulden, Peter (2018 Asia-Pacific Microwave Conference, 2018)
Modern factories and the fourth industrial revolution demand for solutions to monitor the working area and to support the assembly process. One of the key tasks in this context is the localization and tracking of autonomous robots and vehicles as well as hand driven tools. Promising candidates for flexible, wireless solutions are microwave localization systems, like the 24 GHz frequency modulated continuous wave radar used in this paper. In order to reduce the synchronization effort for the employed secondary radar system, only angle-of-arrival measurements are evaluated for the estimation of 3D position and velocity. Therefore, a novel Extended Kalman Filter is presented in this paper to determine the transponder location solely from bearing measurements and to reduce the influence of measurement outliers. For verification, experimental results from a close-range indoor localization scenario are provided and evaluated with the high-precision reference by a robotic ar
lhft_intern.bib::Lipka2018

Wireless 3D-localization of animals for trait and behavior analysis in indoor and outdoor areas - Millner, Hendrik; Ebelt, Randolf; Vossiek, Martin; Schlender, Kristin; Hoffman, Gundula (IEEE MTT-S International Microwave Workshop on Wireless Sensing, Local Positioning, and RFID, 2009)
This paper describes a system for three dimensional indoor and outdoor localization of animals using a sequential Monte-Carlo-Method. A Kaiman based particle filter is used to improve the measurement quality by incorporating the dynamics of the target object. The positioning method was integrated into a system for animal behavior analysis which provides extensive features to identify habitual residence and movement patterns of the animals. © 2009 IEEE.
UnivIS-Import:2015-04-16:Pub.2009.tech.IE.LEH.wirele
Keywords: Animal localization; Positioning; Real-time location; Sequential Monte Carlo methods

Wireless Chipless Cure Monitoring Sensor for Fibre Reinforced Plastics - Groh, Jannis; Lipka, Melanie; Schür, Jan; Vossiek, Martin (International Microwave Symposium (IMS2017), 2017)

Wireless coherent full-duplex double-sided two-way ranging (CFDDS-TWR) approach with phase tracking based multipath suppression for submillimeter accuracy displacement sensing - Gottinger, Michael; Hoffmann, Marcel; Vossiek, Martin (IEEE MTT-S International Microwave Symposium Digest, 2020)
This paper presents a novel radar technology for precise position measurements (e.g. crane positioning) between two cooperating radar units that is especially suited for use in harsh industrial environments. The concept uses the novel coherent full-duplex double-sided two-way ranging (CFDDS-TWR) FMCW secondary radar concept and combines a beat frequency estimation and a coherent phase tracking even though the two cooperating radar units work incoherently. The novel CFDDS-TWR and phase tracking method allows for an efficient suppression of multipath distortions and enables a displacement measurement with a standard deviation of approx. 13 μm and improves the overall ranging accuracy compared to existing bistatic secondary radar approaches dramatically.
CRIS-Team Scopus Importer:2020-11-06
Keywords: Bistatic radar; Distance measurement; Phase measurement; Synthetic aperture radar; Wireless localization

Wireless Local Positioning Based on Modulated Reflection - Vossiek, Martin (IEEE MTT-S International Microwave Symposium 2008 (IMS 2008), Workshop on Progress in Local and Global Positioning in Europe, 2008)
UnivIS-Import:2015-04-16:Pub.2008.tech.IE.LEH.wirele_7

Wireless Local Positioning Based on Synthetic Apertures - Vossiek, Martin; Parr, Andreas (Microwave Workshops & Exhibition (MWE 2015), 2015)
lhft_intern.bib::Vossiek2015b

Wireless Local Positioning - Vossiek, Martin; Max, Stephan (IEEE Microwave Magazine, 2007)
Local positioning will be one of the most exciting features of the next generation of wireless systems. Completely new concepts and features for wireless data transmission and transponder systems will emerge. Self-organizing sensor networks, ubiquitous computing, location sensitive billing, context dependent information services, tracking and guiding are only some of the numerous possible application areas. This article introduces different concepts of several existing and emerging systems and applications.
UnivIS-Import:2015-03-09:Pub.2007.tech.IE.LEH.wirele

Wireless local positioning - Vossiek, Martin; Wiebking, Leif; Gulden, Peter; Weighardt, J.; Hoffmann, C.; Heide, Patric (IEEE Microwave Magazine, 2003)
Local positioning will be one of the most exciting features of the next generation of wireless systems. Completely new concepts and features for wireless data tansmission and transponder sysems will emerge. This paper introduces different concepts of wireless local-positioning solutions and reviews several existing and emerging systems and applications.
UnivIS-Import:2015-03-09:Pub.2003.tech.IE.LEH.wirele_1

Wireless local positioning - concepts, solutions, applications - Vossiek, Martin; Wiebking, Leif; Gulden, Peter; Weighardt, J.; Hoffmann, C. (IEEE Radio and Wireless Conference, RAWCON 2003, 2003)
Local positioning will be one of the most exciting features of the next generation of wireless systems. Completely new concepts and features for wireless data transmission and transponder systems will emerge. Self-organizing sensor networks, ubiquitous computing, location sensitive billing, context dependent information services, tracking and guiding are only some of the numerous possible application areas. This article introduces different concepts of several existing and emerging systems and application
UnivIS-Import:2015-04-16:Pub.2003.tech.IE.LEH.wirele

Wireless Local Positioning of Freight Carrying Vehicles and Service Robots for Tracking and Autonomous Navigation - Dobrev, Yassen; Vossiek, Martin; Christmann, Mark; Bilous, I; Gulden, Peter (IEEE MTT-S Int. Conf. on Microwaves for Intelligent Mobility (ICMIM 2018), 2018)

Wireless local positioning system for controlled UAV landing in GNSS-denied environment - Pavlenko, Tatiana; Schütz, Martin; Vossiek, Martin; Walter, Thomas; Montenegro, Sergio (2019 IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2019 - Proceedings, 2019)
A novel concept for ad-hoc landing of unmanned aerial vehicles (UAV) in GNSS-denied environment is presented in this paper. In our concept at the beginning of the landing phase the UAV drops several active beacons down to the landing site. It enables the UAV to localize itself via distance and angle information to the deployed beacons. The presented wireless local positioning system is based on 24 GHz secondary radar sensors and allows for accurate and robust 3D-positioning even in harsh weather conditions. The specially designed antennas with large angular coverage assure UAV localization disregarding the beacon's position and orientation. The developed beacon design has small size, low weight and power consumption that perfectly suits the application goal. Measurements of localization and landing scenario using four beacons and the radar unit installed on the drone are shown. The 3D-positioning of the UAV with the RMSE under 36 cm using only a single beacon and 31 cm using four beacons were achieved. These results verify the application of the proposed system as an accurate and redundant UAV landing solution.
CRIS-Team Scopus Importer:2019-11-12
Keywords: Landing; Local positioning system; UAV; Wireless localization

Wireless Local-Positioning Systems for Online Monitoring - Kirsch, Fabian; Miesen, Robert; Vossiek, Martin (IEEE RWW Workshop on Machine-To-Machine (M2M) Communication at IEEE Radio Wireless Week 2013, 20-23 Jan., 2013)
UnivIS-Import:2015-04-16:Pub.2013.tech.IE.LEH.wirele

Wireless Local Positioning with SILO-Based Backscatter Transponders for Autonomous Robot Navigation - Schütz, Martin; Dobrev, Yassen; Carlowitz, Christian; Vossiek, Martin (IEEE MTT-S International Conference on Microwaves for Intelligent Mobility (ICMIM 2018), 2018)
In this paper, we present a concept for wireless local positioning with multiple backscatter transponders based on the switched-injection locked oscillator (SILO). It allows reliable localization and ego-motion estimation of autonomous robots in indoor and outdoor environments. We derive the range-doppler spectrum of the beat signal that is induced by a single transponder in a FMCW radar system. With multiple transponders, a localization network is created that allows multilateral and multiangulation based positioning. For an initial evaluation, we built a miniaturized transponder for the 24 GHz ISM band and proofed the concept with a straightforward measurement, including two transponders, a moving ground robot equipped with a FMCW radar system and a laser tracker referenc
lhft_intern.bib::schuetz18b

Wireless Network-to-Network Localization for Measuring the Spatial Position and Orientation of Vehicles - Ebelt, Randolf; Millner, Hendrik; Vossiek, Martin (IEEE International Conference on Wireless Information Technology and Systems 2010, 2010)
lhft_intern.bib::Ebelt2010a

Wireless Sensor Network Approach for Robust Localization of Mobile Nodes with Minimal Complexity - Fuentes, Michel Juan Carlos; Vossiek, Martin (Elektrotechnik und Informationstechnik, 2008)
Summary: The actual paper introduces a concept for localization of mobile nodes in a wireless sensor network. The realized algorithms are characterized by minimal complexity and high robustness even in networks with scarce resources. The implementation on simple, low-power embedded systems is possible without difficulty. An application of the concept for vehicle tracking illustrates the very good performance of the approach. © 2008 Springer-Verlag.
UnivIS-Import:2015-03-09:Pub.2008.tech.IE.LEH.wirele
Keywords: Parameter estimation; Sequential Monte Carlo Method; Wireless localization

Wireless Sensor Network with 24 GHz Local Positioning Transceiver - Shmakov, Denys; Ebelt, Randolf; Vossiek, Martin (IEEE MTT-S International Microwave Symposium 2012 (IMS 2012), 2012)
This paper reports on an innovative cooperative wireless localization network layout and the design of its network nodes. Each node consists of a 24 GHz FMCW secondary radar for bilateral range measurements between all nodes. Network synchronization and scheduling is based on IEEE 802.15.4 radio units. A novel concept to distributedly pre-synchronize all network nodes with an error of less than 125 ns was implemented and combined with the 24 GHz local positioning radar. With prototypes of the sensor nodes a ranging precision of about 1 cm is demonstrated experimentally. © 2012 IEEE.
UnivIS-Import:2015-04-16:Pub.2012.tech.IE.LEH.wirele
Keywords: FMCW; IEEE 802.15.4; Secondary radar; Sensor network; Time synchronization

Zukunft Ingenieurwissenschaften Zukunft Deutschland - Brand, Hans (2009)
lhft_intern.bib::Brand2009

Zur Berechnung von transversalen Diskontinuitäten in quasiplanarenMillimeterwellenleitern - Schmidt, Lorenz-Peter (Kleinheubacher Berichte 28, Kleinheubacher Tagung 1984 des U.R.S.I. Landesausschusses Deutschland, 1984)
lhft_intern.bib::Schmidt13

Zur Problematik von MMIC-Schaltungsentwuerfen mit Mikrowellen-CAD-Programmenim Frequenzbereich bis 100 GHz - Schmidt, Lorenz-Peter (URSI-Workshop „Felder und Wellen“, 1992)
lhft_intern.bib::Schmidt26

Zur Synthese von Mikrowellen-n-Toren vorgegebener Streumatrix - Brand, Hans (AEU-Archiv für Elektronik und Uberträgungstechnik, 1971)
lhft_intern.bib::thirty_years_LHFT_3

Zweidimensionale Kartierung der retinalen und papillären Mikrozirkulation mittels Scanning-Laser-Doppler-Flowmetrie - Michelson, G; Groh, M; Langhans, M; Schmauß, Bernhard (Klinische Monatsblätter für Augenheilkunde, 1995)
Hintergrund Eine nichtinvasive 2dimensionale Darstellung der retinalen Perfusion ist bisher nicht möglich. Eine klinische quantitative Diagnostik von okulären Durchblutungserkrankungen beruht derzeit auf Untersuchungen der Makrozirkulation. Veränderungen in der Mikrozirkulation, die nicht parallel gehen mit Erkrankungen der größeren Gefäße, können bislang nicht quantitativ nachgewiesen werden. Trotz vorliegender manifester Durchblutungsstörungen in den Kapillaren mit erkennbarem Funktionsausfall kann der makrozirkulatorische Untersuchungsbefund der größeren Gefäße regelrecht sein. Methode Die neu entwickelte Scanning-Laser-Doppler-Flowmetrie stellt eine Kombination eines Laser-Scanning-Sy-stems und einer Detektionseinheit zur Messung der Dopplerverschiebung dar. Das Prinzip dieser Methode beruht auf einer schnellen sequentiellen, punktuellen mehrmaligen Abtastung des zu untersuchenden Gewebes durch einen Laserstrahl mit einem Durchmesser von 10 µm, wobei die Dopplerverschiebung des reflektierten Lichtes gemessen wird. Durch Frequenzanalyse der Intensitäts-Zeit-Kurven eines jeden Gewebepunktes kann die optische Dopplerverschiebung und damit die mittlere Geschwindigkeit von Blutzellen von jedem Gewebepunkt berechnet werden. Mit diesen Zahlenwerten wird ein 2-dimensionales Bild der Durchblutung des untersuchten Gewebes aufgebaut, in dem die Helligkeit des Pixels codiert wird durch die mittlere Dopplerverschiebung. Damit wird eine ortsaufgelöste Abbildung der Durchblutung erzeugt. Durch das konfokale Abbildungsprinzip des Laser-Scanners können nur bestimmte Tiefenschichten abgebildet werden. Die Dicke einer scharf abgebildeten Gewebeschicht beträgt 300 µm. Die Reliabilität und die Validität der Methode wurde bestimmt. Bei 7 Augen wurden 5 Wiederholungsmessungen durchgeführt. Die Blutflußwerte von gleichen Netzhautstellen wurden ausgewertet. Der Reliabilitätskoeffizient ri wurde berechnet durch die Bestimmung der Varianz der biologischen Komponente und der Meßfehlerkomponente. Um festzustellen, ob die „Scanning-Laser-Doppler-Flowmetrie” Blutfluß quantitativ bestimmen kann, wurde ein künstliches Auge mit einem „Netzhautgefäß” hergestellt. Durch dieses System wurde „heparinsiertes” Blut mittels einer genau justierbaren Perfusionspumpe hindurchgepumpt, wobei der Blutfluß bei verschiedenen genau definierten Blutfließgeschwindigkeiten in der Glaskapillare bestimmt worden ist. Beispielhaft werden die Perfusionbilder eines gesunden Auges mit normalen und erhöhten IOP, eines Auges mit fortgeschrittener glaueomatöser Opticusatrophie, eines Auges mit proliferativer diabetischer Retinopathie und eines Auges mit Zentralarterienverschluß dargestellt. Ergebnisse Die Ortsauflösung dieses Systems ist ausreichend, um Kapillaren sichtbar zu machen. Durch das konfokale Abbildungssystem ist die Möglichkeit gegeben, nacheinander Gewebeschichten von 300 µm zu untersuchen und damit eine „Kapillar-Tomographie” durchzuführen. Die Wiederholungsmessungen mit dem Scanning-Laser-Doppler-Flowmeter ergaben folgende Reliabilitäts-Koeffizienten: „Flow” 0.85. ”Volume” 0.83, „Velocity” 0.85. Der Meßfehleranteil beträgt demnach von „Flow” 5%, von „Volume” 2% und von „Velocity” 16%. Es zeigte sich ein linearer Zusammenhang zwischen der eingestellten Fließgeschwindigkeit „V” in der Glaskapillare und dem gemessenen Wert „Flow” (r = 0,97, p < 0,0001). Schlußfolgerung Die entwickelte Methode der „Scanning-Laser-Doppler-Flowmetrie” stellt ein klinisch einsetzbares Gerät dar zur nichtinvasiven Darstellung und Quantifizierung optisch zugänglicher Kapillargebiete. Die punktuelle Bestimmung der Erythrozytenbewegung mittels Laserlicht in vielen Gewebestellen gleichzeitig ermöglicht eine zweidimensionale (ortsaufgelöste) Darstellung der kapillären Perfusion. Durch die hohe Ortsauflösung dieses Systems kommt es zu einer bildhaften Darstellung perfundierter Kapillaren und Gefäße
lhft_intern.bib::thirty_years_LHFT_401

Detection of unsupervised standardized gait tests from real-world inertial sensor data in Parkinson’s disease - Ullrich, Martin; Mücke, Annika; Küderle, Arne; Roth, Nils; Gladow, Till; Gaßner, Heiko; Marxreiter, Franz; Klucken, Jochen; Eskofier, Björn; Kluge, Felix (IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2021)
Gait tests as part of home monitoring study protocols for patients with movement disorders may provide valuable standardized anchor-points for real-world gait analysis using inertial measurement units (IMUs). However, analyzing unsupervised gait tests relies on reliable test annotations by the patients requiring a potentially error-prone interaction with the recording system. To overcome this limitation, this work presents a novel algorithmic pipeline for the automated detection of unsupervised standardized gait tests from continuous real-world IMU data. In a study with twelve Parkinson’s disease patients, we recorded real-world gait data over two weeks using foot-worn IMUs. During continuous daily recordings, the participants performed series of three consecutive 4x10-Meters-Walking-Tests (4x10MWTs) at different walking speeds, besides their usual daily-living activities. The algorithm first detected these gait test series using a gait sequence detection algorithm, a peak enhancement pipeline, and subsequence Dynamic Time Warping and then decomposed them into single 4x10MWTs based on the walking speed. In the evaluation with 419 available gait test series, the detection reached an F1-score of 88.9% and the decomposition an F1-score of 94.0%. A concurrent validity evaluation revealed very good agreement between spatio-temporal gait parameters derived from manually labelled and automatically detected 4x10MWTs. Our algorithm allows to remove the burden of system interaction from the patients and reduces the time for manual data annotation for researchers. The study contributes to an improved automated processing of real-world IMU gait data and enables a simple integration of standardized tests into continuous long-term recordings. This will help to bridge the gap between supervised and unsupervised gait assessment.
Keywords: Machine learning; activity recognition; accelerometer; gyroscope; legged locomotion; protocol; diseases; pipelines; monitoring; hospitals; annotations

Influence of X-Ray Radiation on Historical Paper - Zippert, Patrick; Seuret, Mathias; Maier, Andreas; Hausotte, Tino (11th Conference on Industrial Computed Tomography, 2022)
Historical books are often so fragile that they cannot easily be opened in order to read the contents without damaging them. Current research shows, that industrial X-ray computed tomography (CT) can be used to examine closed historical manuscripts. However, the effect of X-rays on ancient paper has rarely been studied, making it difficult to assess the impact of CT measurements on fragile historical manuscripts in terms of additional destruction. To address this problem, various types of paper were exposed to high levels of X-ray radiation in order to examine them for change in optical properties. The investigations showed increasing yellowing due to the increased radiation energy. However, the severity of the yellowing is strongly dependent on the composition of the paper.<br
Keywords: Historical documents; CT measurement side effects; radiation damage

Resource Allocation for Simultaneous Wireless Information and Power Transfer Systems: A Tutorial Overview - Wei, Zhiqiang; Yu, Xianghao; Ng, Derrick Wing Kwan; Schober, Robert (Proceedings of the IEEE, 2021)
Over the last decade, simultaneous wireless information and power transfer (SWIPT) has become a practical and promising solution for connecting and recharging battery-limited devices due to significant advances in low-power electronics technology and wireless communications techniques. To realize the promised potentials, advanced resource allocation design plays a decisive role in revealing, understanding, and exploiting the intrinsic rate-energy tradeoff capitalizing on the dual use of radio frequency (RF) signals for wireless charging and communication. In this article, we provide a comprehensive tutorial overview of SWIPT from the perspective of resource allocation design. The fundamental concepts, system architectures, and RF energy harvesting (EH) models are introduced. In particular, three commonly adopted EH models, namely, the linear EH model, the nonlinear saturation EH model, and the nonlinear circuit-based EH model, are characterized and discussed. Then, for a typical wireless system setup, we establish a generalized resource allocation design framework that subsumes conventional resource allocation design problems as special cases. Subsequently, we elaborate on relevant tools from optimization theory and exploit them for solving representative resource allocation design problems for SWIPT systems with and without perfect channel state information (CSI) available at the transmitter, respectively. The associated technical challenges and insights are also highlighted. Furthermore, we discuss several promising and exciting future research directions for resource allocation design for SWIPT systems intertwined with cutting-edge communication technologies, such as intelligent reflecting surfaces, unmanned aerial vehicles, mobile edge computing, federated learning, and machine learning.
Keywords: Wireless communication; Resource management; Wireless sensor networks; Integrated circuit modeling; Radio frequency; Systems architecture; RF signals; optimization; resource allocation; simultaneous wireless information and power transfer (SWIPT); wireless pwoer transfer (WPT)