@article{FrauenrathHezelRenzetal.2010, author = {Frauenrath, Tobias and Hezel, Fabian and Renz, Wolfgang and de Geyer d'Orth, Thibaut and Dieringer, Matthias and von Knobelsdorf-Brenkenhoff, Florian and Prothmann, Marcel and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {12}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1532-429X}, doi = {10.1186/1532-429X-12-67}, year = {2010}, abstract = {Background To demonstrate the applicability of acoustic cardiac triggering (ACT) for imaging of the heart at ultrahigh magnetic fields (7.0 T) by comparing phonocardiogram, conventional vector electrocardiogram (ECG) and traditional pulse oximetry (POX) triggered 2D CINE acquisitions together with (i) a qualitative image quality analysis, (ii) an assessment of the left ventricular function parameter and (iii) an examination of trigger reliability and trigger detection variance derived from the signal waveforms. Results ECG was susceptible to severe distortions at 7.0 T. POX and ACT provided waveforms free of interferences from electromagnetic fields or from magneto-hydrodynamic effects. Frequent R-wave mis-registration occurred in ECG-triggered acquisitions with a failure rate of up to 30\% resulting in cardiac motion induced artifacts. ACT and POX triggering produced images free of cardiac motion artefacts. ECG showed a severe jitter in the R-wave detection. POX also showed a trigger jitter of approximately Δt = 72 ms which is equivalent to two cardiac phases. ACT showed a jitter of approximately Δt = 5 ms only. ECG waveforms revealed a standard deviation for the cardiac trigger offset larger than that observed for ACT or POX waveforms. Image quality assessment showed that ACT substantially improved image quality as compared to ECG (image quality score at end-diastole: ECG = 1.7 ± 0.5, ACT = 2.4 ± 0.5, p = 0.04) while the comparison between ECG vs. POX gated acquisitions showed no significant differences in image quality (image quality score: ECG = 1.7 ± 0.5, POX = 2.0 ± 0.5, p = 0.34). Conclusions The applicability of acoustic triggering for cardiac CINE imaging at 7.0 T was demonstrated. ACT's trigger reliability and fidelity are superior to that of ECG and POX. ACT promises to be beneficial for cardiovascular magnetic resonance at ultra-high field strengths including 7.0 T.}, language = {en} } @article{MartinFrauenrathOezerdemetal.2011, author = {Martin, Conrad and Frauenrath, Tobias and {\"O}zerdem, Celal and Renz, Wolfgang and Niendorf, Thoralf}, title = {Development and evaluation of a small and mobile Magneto Alert Sensor (MALSE) to support safety requirements for magnetic resonance imaging}, series = {European Radiology}, volume = {21}, journal = {European Radiology}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {1432-1084}, doi = {10.1007/s00330-011-2153-z}, pages = {2187 -- 2192}, year = {2011}, abstract = {Objective The purpose of this study is to (i) design a small and mobile Magnetic field ALert SEnsor (MALSE), (ii) to carefully evaluate its sensors to their consistency of activation/deactivation and sensitivity to magnetic fields, and (iii) to demonstrate the applicability of MALSE in 1.5 T, 3.0 T and 7.0 T MR fringe field environments. Methods MALSE comprises a set of reed sensors, which activate in response to their exposure to a magnetic field. The activation/deactivation of reed sensors was examined by moving them in/out of the fringe field generated by 7TMR. Results The consistency with which individual reed sensors would activate at the same field strength was found to be 100\% for the setup used. All of the reed switches investigated required a substantial drop in ambient magnetic field strength before they deactivated. Conclusions MALSE is a simple concept for alerting MRI staff to a ferromagnetic object being brought into fringe magnetic fields which exceeds MALSEs activation magnetic field. MALSE can easily be attached to ferromagnetic objects within the vicinity of a scanner, thus creating a barrier for hazardous situations induced by ferromagnetic parts which should not enter the vicinity of an MR-system to occur.}, language = {en} } @article{DieringerRenzLindeletal.2011, author = {Dieringer, Matthias A. and Renz, Wolfgang and Lindel, Tomasz D. and Seifert, Frank and Frauenrath, Tobias and von Knobelsdorf-Brenkenhoff, Florian and Waiczies, Helmar and Hoffmann, Werner and Rieger, Jan and Pfeiffer, Harald and Ittermann, Bernd and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Design and application of a four-channel transmit/receive surface coil for functional cardiac imaging at 7T}, series = {Journal of Magnetic Resonance Imaging}, volume = {33}, journal = {Journal of Magnetic Resonance Imaging}, number = {3}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.22451}, pages = {736 -- 741}, year = {2011}, abstract = {Purpose To design and evaluate a four-channel cardiac transceiver coil array for functional cardiac imaging at 7T. Materials and Methods A four-element cardiac transceiver surface coil array was developed with two rectangular loops mounted on an anterior former and two rectangular loops on a posterior former. specific absorption rate (SAR) simulations were performed and a Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-1 calibration method was applied prior to obtain 2D FLASH CINE (mSENSE, R = 2) images from nine healthy volunteers with a spatial resolution of up to 1 × 1 × 2.5 mm3. Results Tuning and matching was found to be better than 10 dB for all subjects. The decoupling (S21) was measured to be >18 dB between neighboring loops, >20 dB for opposite loops, and >30 dB for other loop combinations. SAR values were well within the limits provided by the IEC. Imaging provided clinically acceptable signal homogeneity with an excellent blood-myocardium contrast applying the Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-2 calibration approach. Conclusion A four-channel cardiac transceiver coil array for 7T was built, allowing for cardiac imaging with clinically acceptable signal homogeneity and an excellent blood-myocardium contrast. Minor anatomic structures, such as pericardium, mitral, and tricuspid valves and their apparatus, as well as trabeculae, were accurately delineated.}, language = {en} } @article{SchulteTiggesFoersterNikolovskietal.2022, author = {Schulte-Tigges, Joschua and F{\"o}rster, Marco and Nikolovski, Gjorgji and Reke, Michael and Ferrein, Alexander and Kaszner, Daniel and Matheis, Dominik and Walter, Thomas}, title = {Benchmarking of various LiDAR sensors for use in self-driving vehicles in real-world environments}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {19}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s22197146}, pages = {20 Seiten}, year = {2022}, abstract = {Abstract In this paper, we report on our benchmark results of the LiDAR sensors Livox Horizon, Robosense M1, Blickfeld Cube, Blickfeld Cube Range, Velodyne Velarray H800, and Innoviz Pro. The idea was to test the sensors in different typical scenarios that were defined with real-world use cases in mind, in order to find a sensor that meet the requirements of self-driving vehicles. For this, we defined static and dynamic benchmark scenarios. In the static scenarios, both LiDAR and the detection target do not move during the measurement. In dynamic scenarios, the LiDAR sensor was mounted on the vehicle which was driving toward the detection target. We tested all mentioned LiDAR sensors in both scenarios, show the results regarding the detection accuracy of the targets, and discuss their usefulness for deployment in self-driving cars.}, language = {en} } @article{FrauenrathFuchsDieringeretal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Dieringer, Matthias A. and {\"O}zerdem, Celal and Patel, Nishan and Renz, Wolfgang and Greiser, Andreas and Elgeti, Thomas and Niendorf, Thoralf}, title = {Detailing the use of magnetohydrodynamic effects for synchronization of MRI with the cardiac cycle: A feasibility study}, series = {Journal of Magnetic Resonance Imaging}, volume = {36}, journal = {Journal of Magnetic Resonance Imaging}, number = {2}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.23634}, pages = {364 -- 372}, year = {2012}, abstract = {Purpose: To investigate the feasibility of using magnetohydrodynamic (MHD) effects for synchronization of magnetic resonance imaging (MRI) with the cardiac cycle. Materials and Methods: The MHD effect was scrutinized using a pulsatile flow phantom at B0 = 7.0 T. MHD effects were examined in vivo in healthy volunteers (n = 10) for B0 ranging from 0.05-7.0 T. Noncontrast-enhanced MR angiography (MRA) of the carotids was performed using a gated steady-state free-precession (SSFP) imaging technique in conjunction with electrocardiogram (ECG) and MHD synchronization. Results: The MHD potential correlates with flow velocities derived from phase contrast MRI. MHD voltages depend on the orientation between B0 and the flow of a conductive fluid. An increase in the interelectrode spacing along the flow increases the MHD potential. In vivo measurement of the MHD effect provides peak voltages of 1.5 mV for surface areas close to the common carotid artery at B0 = 7.0 T. Synchronization of MRI with the cardiac cycle using MHD triggering is feasible. MHD triggered MRA of the carotids at 3.0 T showed an overall image quality and richness of anatomic detail, which is comparable to ECG-triggered MRAs. Conclusion: This feasibility study demonstrates the use of MHD effects for synchronization of MR acquisitions with the cardiac cycle. J. Magn. Reson. Imaging 2012;36:364-372. © 2012 Wiley Periodicals, Inc.}, language = {en} } @article{GraesslRenzHezeletal.2013, author = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Dieringer, Matthias A. and Winter, Lukas and {\"O}zerdem, Celal and Rieger, Jan and Kellmann, Peter and Santoro, Davide and Lindel, Tomasz D. and Frauenrath, Tobias and Pfeiffer, Harald and Niendorf, Thoralf}, title = {Modular 32-channel transceiver coil array for cardiac MRI at 7.0T}, series = {Magnetic Resonance in Medicine}, volume = {72}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.24903}, pages = {276 -- 290}, year = {2013}, abstract = {Purpose To design and evaluate a modular transceiver coil array with 32 independent channels for cardiac MRI at 7.0T. Methods The modular coil array comprises eight independent building blocks, each containing four transceiver loop elements. Numerical simulations were used for B1+ field homogenization and radiofrequency (RF) safety validation. RF characteristics were examined in a phantom study. The array's suitability for accelerated high spatial resolution two-dimensional (2D) FLASH CINE imaging of the heart was examined in a volunteer study. Results Transmission field adjustments and RF characteristics were found to be suitable for the volunteer study. The signal-to-noise intrinsic to 7.0T together with the coil performance afforded a spatial resolution of 1.1 × 1.1 × 2.5 mm3 for 2D CINE FLASH MRI, which is by a factor of 6 superior to standardized CINE protocols used in clinical practice at 1.5T. The 32-channel transceiver array supports one-dimensional acceleration factors of up to R = 4 without impairing image quality significantly. Conclusion The modular 32-channel transceiver cardiac array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0T.}, language = {en} } @article{DroopChenRadfordetal.2023, author = {Droop, Philipp and Chen, Shaohuang and Radford, Melissa J. and Paulßen, Elisabeth and Gates, Byron D. and Reilly, Raymond M. and Radchenko, Valery and Hoehr, Cornelia}, title = {Synthesis of 197m/gHg labelled gold nanoparticles for targeted radionuclide therapy}, series = {Radiochimica Acta}, volume = {111}, journal = {Radiochimica Acta}, number = {10}, publisher = {De Gruyter}, address = {Berlin [u.a.]}, issn = {2193-3405}, doi = {10.1515/ract-2023-0144}, pages = {773 -- 779}, year = {2023}, abstract = {Meitner-Auger-electron emitters have a promising potential for targeted radionuclide therapy of cancer because of their short range and the high linear energy transfer of Meitner-Auger-electrons (MAE). One promising MAE candidate is 197m/gHg with its half-life of 23.8 h and 64.1 h, respectively, and high MAE yield. Gold nanoparticles (AuNPs) that are labelled with 197m/gHg could be a helpful tool for radiation treatment of glioblastoma multiforme when infused into the surgical cavity after resection to prevent recurrence. To produce such AuNPs, 197m/gHg was embedded into pristine AuNPs. Two different syntheses were tested starting from irradiated gold containing trace amounts of 197m/gHg. When sodium citrate was used as reducing agent, no 197m/gHg labelled AuNPs were formed, but with tannic acid, 197m/gHg labeled AuNPs were produced. The method was optimized by neutralizing the pH (pH = 7) of the Au/197m/gHg solution, which led to labelled AuNPs with a size of 12.3 ± 2.0 nm as measured by transmission electron microscopy. The labelled AuNPs had a concentration of 50 μg (gold)/mL with an activity of 151 ± 93 kBq/mL (197gHg, time corrected to the end of bombardment).}, language = {en} } @article{Heuermann1999, author = {Heuermann, Holger}, title = {Calibration procedures with series impedances and unknown lines simplify on-wafer measurements}, series = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 47 (1999), H. 1}, journal = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 47 (1999), H. 1}, isbn = {0018-9480}, pages = {1 -- 5}, year = {1999}, language = {en} } @article{HeuermannSchiek1995, author = {Heuermann, Holger and Schiek, B.}, title = {Error corrected impedance measurements with a network analyzer}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 44 (1995), H. 2}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 44 (1995), H. 2}, isbn = {0018-9456}, pages = {295 -- 299}, year = {1995}, language = {en} } @article{WolfSimonSchlick1998, author = {Wolf, Martin R. and Simon, S. and Schlick, Christopher}, title = {Qualitative and Quantitative Analysis of Cooperation / Wolf, M. ; Simon, S. ; Schlick, C.}, series = {Proceedings : May 26 - 29, 1998, Cannes (France) = Actes : 26 - 29 mai 1998 / INRIA, Institut National de Recherche en Informatique et en Automatique, Unit{\´e} de recherche ... F. Darses ..., eds}, journal = {Proceedings : May 26 - 29, 1998, Cannes (France) = Actes : 26 - 29 mai 1998 / INRIA, Institut National de Recherche en Informatique et en Automatique, Unit{\´e} de recherche ... F. Darses ..., eds}, publisher = {-}, address = {Cannes}, pages = {1 -- 5}, year = {1998}, language = {en} } @article{Ritz2002, author = {Ritz, Thomas}, title = {Personalized Information Services: Production and Distribution of these Services employing Mass-Customization}, year = {2002}, language = {en} } @article{WolfFoltzKillichetal.2001, author = {Wolf, Martin R. and Foltz, Christian and Killich, Stephan and Schmidt, Ludger}, title = {Task and Information Modeling for Cooperative Work / Foltz, Christian ; Killich, Stephan ; Wolf, Martin ; Schmidt, Ludger ; Luczak, Holger}, series = {Systems, social and internationalization design aspects of human-computer interaction / ed. by Michael J. Smith, Gavriel Salvendy Vol. 2}, journal = {Systems, social and internationalization design aspects of human-computer interaction / ed. by Michael J. Smith, Gavriel Salvendy Vol. 2}, publisher = {-}, isbn = {0-8058-3608-X}, pages = {172 -- 176}, year = {2001}, language = {en} } @article{HeuermannSadeghfam2004, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Novel balanced inductor for compact differential systems / Sadeghfam, Arash; Heuermann, Holger}, series = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association}, journal = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association}, publisher = {Horizon House Publ.}, address = {London}, isbn = {1-580-53992-0}, pages = {709 -- 712}, year = {2004}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Error Corrected Impedance Measurements with a Network Analyzer}, pages = {125 -- 126}, year = {1994}, language = {en} } @article{NiemuellerFerreinEckeletal.2011, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Eckel, Gerhard and Pirro, David and Podbregar, Patrick and Kellner, Tobias and Rath, Christoph and Steinbauer, Gerald}, title = {Providing Ground-truth Data for the Nao Robot Platform}, series = {RoboCup 2010: Robot Soccer World Cup XIV}, journal = {RoboCup 2010: Robot Soccer World Cup XIV}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-20217-9}, pages = {133 -- 144}, year = {2011}, language = {en} } @article{GrandeMeffertSchoenbergeretal.2012, author = {Grande, Marion and Meffert, Elisabeth and Schoenberger, Eva and Jung, Stefanie and Frauenrath, Tobias and Huber, Walter and Hussmann, Katja and Moormann, Mareike and Heim, Stefan}, title = {From a concept to a word in a syntactically complete sentence: An fMRI study on spontaneous language production in an overt picture description task}, series = {NeuroImage}, volume = {61}, journal = {NeuroImage}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1522-2586}, doi = {10.1016/j.neuroimage.2012.03.087}, pages = {702 -- 714}, year = {2012}, abstract = {Spontaneous language has rarely been subjected to neuroimaging studies. This study therefore introduces a newly developed method for the analysis of linguistic phenomena observed in continuous language production during fMRI. Most neuroimaging studies investigating language have so far focussed on single word or — to a smaller extent — sentence processing, mostly due to methodological considerations. Natural language production, however, is far more than the mere combination of words to larger units. Therefore, the present study aimed at relating brain activation to linguistic phenomena like word-finding difficulties or syntactic completeness in a continuous language fMRI paradigm. A picture description task with special constraints was used to provoke hesitation phenomena and speech errors. The transcribed speech sample was segmented into events of one second and each event was assigned to one category of a complex schema especially developed for this purpose. The main results were: conceptual planning engages bilateral activation of the precuneus. Successful lexical retrieval is accompanied - particularly in comparison to unsolved word-finding difficulties - by the left middle and superior temporal gyrus. Syntactic completeness is reflected in activation of the left inferior frontal gyrus (IFG) (area 44). In sum, the method has proven to be useful for investigating the neural correlates of lexical and syntactic phenomena in an overt picture description task. This opens up new prospects for the analysis of spontaneous language production during fMRI.}, language = {en} } @article{BragardConradvanHoeketal.2011, author = {Bragard, Michael and Conrad, M. and van Hoek, H. and De Doncker, R. W.}, title = {The integrated emitter turn-off thyristor (IETO) : an innovative thyristor-based high power semiconductor device using MOS assisted turn-off}, series = {IEEE transactions on industry applications}, volume = {47}, journal = {IEEE transactions on industry applications}, number = {5}, publisher = {IEEE}, address = {New York}, issn = {0093-9994}, doi = {10.1109/TIA.2011.2161432}, pages = {2175 -- 2182}, year = {2011}, language = {en} } @article{KobFrauenrath2009, author = {Kob, Malte and Frauenrath, Tobias}, title = {A system for parallel measurement of glottis opening and larynx position}, series = {Biomedical Signal Processing and Control}, volume = {4}, journal = {Biomedical Signal Processing and Control}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1746-8108}, doi = {10.1016/j.bspc.2009.03.004}, pages = {221 -- 228}, year = {2009}, abstract = {The simultaneous assessment of glottal dynamics and larynx position can be beneficial for the diagnosis of disordered voice or speech production and swallowing. Up to now, methods either concentrate on assessment of the glottis opening using optical, acoustical or electrical (electroglottography, EGG) methods, or on visualisation of the larynx position using ultrasound, computer tomography or magnetic resonance imaging techniques. The method presented here makes use of a time-multiplex measurement approach of space-resolved transfer impedances through the larynx. The fast sequence of measurements allows a quasi simultaneous assessment of both larynx position and EGG signal using up to 32 transmit-receive signal paths. The system assesses the dynamic opening status of the glottis as well as the vertical and back/forward motion of the larynx. Two electrode-arrays are used for the measurement of the electrical transfer impedance through the neck in different directions. From the acquired data the global and individual conductivity is calculated as well as a 2D point spatial representation of the minimum impedance. The position information is shown together with classical EGG signals allowing a synchronous visual assessment of glottal area and larynx position. A first application to singing voice analysis is presented that indicate a high potential of the method for use as a non-invasive tool in the diagnosis of voice, speech, and swallowing disorders.}, language = {en} } @article{KlingeOttoMuehl2015, author = {Klinge, Uwe and Otto, Jens and M{\"u}hl, Thomas}, title = {High Structural Stability of Textile Implants Prevents Pore Collapse and Preserves Effective Porosity at Strain}, series = {BioMed Research International}, volume = {2015}, journal = {BioMed Research International}, issn = {2314-6133 (Print)}, doi = {10.1155/2015/953209}, pages = {7 pages}, year = {2015}, language = {en} } @article{FrauenrathNiendorfKob2008, author = {Frauenrath, Tobias and Niendorf, Thoralf and Kob, Malte}, title = {Acoustic method for synchronization of Magnetic Resonance Imaging (MRI)}, series = {Acta Acustica}, volume = {94}, journal = {Acta Acustica}, number = {1}, publisher = {Hirzel}, address = {Stuttgart}, issn = {1861-9959}, doi = {10.3813/AAA.918017}, pages = {148 -- 155}, year = {2008}, abstract = {Magnetic Resonance Imaging (MRI) of moving organs requires synchronization with physiological motion or flow, which dictate the viable window for data acquisition. To meet this challenge, this study proposes an acoustic gating device (ACG) that employs acquisition and processing of acoustic signals for synchronization while providing MRI compatibility, immunity to interferences with electro-magnetic and acoustic fields and suitability for MRI at high magnetic field strengths. The applicability and robustness of the acoustic gating approach is examined in a pilot study, where it substitutes conventional ECG-gating for cardiovascular MR. The merits and limitations of the ACG approach are discussed. Implications for MR imaging in the presence of physiological motion are considered including synchronization with other structure- or motion borne sounds.}, language = {en} }