Thursday, 13 February 2020 17:00

Magnetic Shielding

Talker Dr. Allard Schnabel
Affiliation Physikalisch-Technische Bundesanstalt (PTB)
Berlin, Germany
Date 13.02.2020
Time 17:00 h
Place SR I, Building C, Faculty of Engineering,
Kaiserstr. 2., 24143 Kiel



Environments where the magnetic field is far below the earth magnetic field of 50 µT are a prerequisite for many modern precision experiments. Active magnetic field compensation with coil systems can reduce the external fields by up to two orders of magnitude. Passive magnetic shielding enclosures out of highly permeable material (µr >> 1) can provide volumes of up to 1 m3 with less than 1 nT static magnetic field. In combination with very sensitive magnetic field detectors like SQUIDs and OPMs, numerous basic physics experiments as well as biological studies have been carried out. In the past the driving force for the development of magnetically shielded rooms was brain research due to the spatial and temporal resolution of the neuronal activity. Today the strongest requirements are from basic physics experiments e.g. the search for a finite electric dipole moment of the neutron. These experiments need a homogeneous field of a few µT which should not change by more than 10 fT within 100 s.

Starting from the basic principles of magnetic shielding, commercially available shields will be discussed before the limits of the strongest existing magnetically shielded rooms, like BMSR-2 at PTB, are presented. In praxis, a larger shielding factor is associated with several restrictions which limit the usage of such shields. The demagnetization process (degaussing), necessary to achieve a low static magnetic field inside the shield, will be discussed in detail. It will also be explained why an “equilibration” of the shielding material is needed to obtain a field stable in time when an additional magnetic field is switched on or used inside the chamber.

Monday, 23 September 2019 10:00

Speech Analysis for the Automatic Detection and Monitoring of Parkinson's Disease

Talker Prof. Dr. Juan Rafael Orozco-Arroyave
Affiliation University of Antioquia,
Date 23.09.2019
Time 10:00 h
Place Aquarium, Building D, Faculty of Engineering,
Kaiserstr. 2., 24143 Kiel



Parkinson's diseae (PD) is second most common neurodegenerative disorder worldwide. It affects the control of muscles and limbs in the body and typically has negative impact on the speech production. Other motor activities like handwriting and gait are also affected. This talk will start with a general description of several neurodegenerative disorders including PD, Alzheimer's, and Aphasia. Typical speech disorders suffered by PD patients will be discussed and a methodology to automatically model those symptoms is also introduced. The suitability of such a methodology for the automatic detection and monitoring of PD is also discussed. In the final part of the talk, an extension of the methodology is presented considering other bio signals like handwriting and gait


Short CV

Juan Rafael Orozco-Arroyave was born in Medellín, Colombia in 1981. He is Electronics Engineer from the University of Antioquia (2004). From 2004 to 2009 he was working for a telco company in Medellín, Colombia. In 2011 he finished the MSc. degree in Telecommunications from the Unversidad de Antioquia. In 2015 he finished the PhD in Computer Science in a double degree program between the University of Erlangen (Germany) and the University of Antioquia (Colombia). Currently Juan Rafael Orozco-Arroyave is associate Professor at the University of Antioquia and adjunct researcher at the Pattern Recognition Lab at the University of Erlangen.

Monday, 06 May 2019 16:00

Medical Diagnosis Aided by Automatic Classification: Non-blackbox Approaches for Clinical Voice Assessment

Talker DI Dr.techn. Philipp Aichinger
Affiliation Medical University of Vienna, Dept. of Otorhinolaryngology,
Division of Phoniatrics-Logopedics
Date 06.05.2019
Time 16:00 h
Place Aquarium, Building D, Faculty of Engineering,
Kaiserstr. 2., 24143 Kiel



Voice disorders are socially relevant, because they may lead to significant follow-up costs for health insurances and the economic system, if no adequate treatment is administered timely. Voice quality characterization is pivotal to the clinical care of voice disorders, because it aids the indication, selection, evaluation, and optimization of clinical treatment techniques, including speech therapy by administered by logopedists / speech language pathologists, and phonosurgery, performed by medical doctors specialized on voice disorders.

Current approaches to artificial intelligence, including (Deep) Neural Networks, are not fully accepted by clinical experts, partly due to their black box nature. In particular, explanatory power of these approaches is low. In contrast, we propose to use hand-crafted model based features as input to low-dimensional classification automats. Our features are meant to represent closely the properties of the voice, which are described on the level of voice production, on the level of acoustics, and on the level of perception.

Diplophonia is a particular type of pathological voice qualities, in which two simultaneous pitches are reported by clinical experts to be audible simultaneously. Diplophonia may be a symptom of a vocal dysfunction that needs medical treatment. The inherently subjective definition located on the domain of auditory perception is complemented by our approaches to track two simultaneous fundamental frequencies from high-speed videos of the vocal folds, and from audio signals. Also, first steps with a physiologically grounded hearing model are presented. The hearing model is used to predict from decomposed audio signals of the voice the presence of two simultaneously perceivable pitches.

The figure shows an an endoscopic picture of human vocal folds.


Short biography

Philipp Aichinger is a Research Associate of the Medical University of Vienna (MUV). He is affiliated with the Department of Otorhinolaryngology, Division of Phoniatrics-Logopedics. He graduated interdisciplinary studies in Electrical Engineering/Sound Engineering at the Graz University of Technology (TUG) and the University of Music and Dramatic Arts in Graz (KUG), acquiring expertise both in engineering and in music/perception research. His PhD-thesis "Diplophonic Voice - Definitions, models, and detection" has been supervised by the TUG and the MUV. Philipp is Principal Investigator of a research project FWF KLI722-B30 funded within the Program Clinical Research of the Austrian Science Fund (FWF), entitled “Objective differentiation of dysphonic voice quality types”. He is an organizer of the 2019 Special Session at Interspeech, entitled “Voice quality characterization for clinical voice assessment: Voice production, acoustics, and auditory perception”. He is a member of the IEEE Signal Processing Society, the Audio Engineering Society, and the Acoustical Society of America. He is reviewer for the Journal of the Acoustical Society of America, for the IEEE Transactions on Audio, Speech and Language Processing, for the Journal of Medical and Biological Engineering, for the Journal Biomedical Signal Processing and Control, and for Acta Acustica united with Acustica.

Monday, 29 April 2019 17:00

Die Zukunft in der Diagnostik des sensorischen Nervensystem: welchen Vorteil bringen moderne neurophysiologische Messverfahren?

Talker PD Dr. med. Philipp Hüllemann
Affiliation University Hospital Schleswig-Holstein,
Department of Neurology
Date 29.04.2019
Time 17:00 h
Place Faculty Club, Building C, Faculty of Engineering,
Kaiserstr. 2., 24143 Kiel


Abstract (in German)

Das somatosensorische Nervensystem ist in der Lage verschiedene Empfindungen über unterschiedliche Rezeptoren auf unterschiedlichen Nervenfasern weiterzuleiten, welche im Gehirn dekodiert und interpretiert werden. Entsprechend wird eine Berührung über dick myelinisierte A-Beta-Fasern übermittelt, ein Kaltreiz über dünn myelinisierte Kälte-leitende A-delta-Fasern, Hitzereize über Hitze-sensitive dünn myelinsierte A-delta-Fasern (AMH II), mechanische Reize/-Schmerzreize über mechano-sensitive dünn myelinisierte A-delta-Fasern (AMH I) und Wärmereize über nicht myelinisierte langsam leitende C-fasern. Die zentrale Verarbeitung dieser unterschiedlichen Empfindungen findet in Thalamus, somatosensorischem Kortex, präfrontalem Kortex, cingulärem Kortex, und anderen Teilen des limbischen Systems statt.

In den letzten Jahren wurden unterschiedliche elektrophysiologische Verfahren entwickelt, um jede einzelne Nervenfaserfunktion objektiv zu messen. Einige dieser Verfahren wie beispielsweise die somatosensorisch evozierten Potentiale zur Messung der Berührungsfasern oder die Laser evozierten Potentiale zur Messung der Hitzefasern werden bereits in der klinischen Routinediagnostik angewendet. Andere Verfahren wie beispielsweise die Wärme-, Kälte- oder Pinprick-evozierten Potentiale werden bisher ausschließlich in Forschungslaboren zum Verständnis unterschiedlicher Nervenfaserfunktionen eingesetzt.

Bisher wird in der klinischen Routinediagnostik das sensorische Nervensystem durch Ableitung somatosensorischer Potentiale im EEG gemessen. Dabei werden die Nervenfasern durch Stromimpulse erregt. Das Verfahren zeigt teilweise nicht-reproduzierbare Befunde, zudem können ausschließlich Aussagen über die Integrität der A-beta-Fasern (Berührungsfasern) getroffen werden, welche nur 20% des sensorischen Nervensystems ausmachen. Das schmerzleitende System (A-delta- und C-fasern) kann mit der Routinediagnostik nicht gemessen werden.

Durch neuere technische Entwicklungen können inzwischen alle klinisch relevanten sensorischen Modalitäten wie Vibration, Berührung, Pinprick (spitze Nadelreize), Hitze, Wärme und Kälte durch Stimulus-Synchronisation mit dem EEG in Form evozierter Potentiale abgebildet werden. Somit kann zum einen die Integrität des Hinterstrangsystem und des spinothalamischen Systems, zum anderen die Funktion der dick-, dünn- und unmyelinisierten Nervenfasern objektiv gemessen werden. Das sensorische Profil kann sowohl zur Phänotypisierung für klinische Studien genutzt werden als auch in der klinischen Routine wertvolle diagnostische Hinweise liefern.

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