Since 2016 the University Department of Neurology, under the leadership of Professor Dr. Hans-Jochen Heinze and technical direction of Professor Dr. Ing. H. Hinrichs, has been represented in Zenit II with the new Elekta Neuromag® TRIUX magnetoencephalograph. The machine has 102 magnetometer and 204 planar gradiometer sensors and is able to simultaneously record 64 EEG channels.
Magnetoencephalography is used to measure magnetic fields that are caused by neuronal activity in the human brain. The magnitude of the usable signals ranges between 10-12 and 10-15 tesla. The magnetic fields that prevail in the surrounding area, such as a car at a distance of 50m at 10-8 to 10-9 tesla, environmental interferences at 10-6 to 10-8 tesla or the earth’s magnetic field at approx. 10-4 tesla, are prevented from reaching the measuring equipment by a shielded room.
The test subject takes up a seated position inside the chamber. The head is located in a cryogenic vessel. Here, there are superconductive measuring sensors in liquid helium 248 known as Superconducting Quantum Interface Devices (SQUIDS).
The test subject is presented with visual, auditory or tactile stimuli. The magnetic fields triggered by the neuronal activity are detected by the SQUIDs, digitized electronically and recorded by computer.
The data is run through special tools to create an image of the measured magnetic fields. The results are representations such as the isocontour map shown.
Fig. 1: Isocontour map of a magnetic field distribution
The positions of some SQUIDs are shown schematically in this diagram. This 2-dimensional representation shows the magnetic field distributions for a given point in time.
In order to incorporate the structural factors of a test subject, MRI data can also be included and the brain activity depicted in color.
Fig. 2: Structural MRI with dipoles
Fig. 3: Current density distribution
The magnetoencephalograph is used cognitively for basic neuroscientific research as well as looking at clinical and scientific problems by the following departments:
- Department of Neurology at the University of Magdeburg, Professor Dr. med. Hans-Jochen Heinze
- Behavioral Neurology (IfN), Professor Dr. med. Hans-Jochen Heinze
- Clinical Research Group, Professor Dr. med. Emrah Düzel
- Cognitive Neurophysiology, Professor Dr. med. Jens-Max Hopf
- Experimental Neurology, Professor Dr. med. Ariel Schoenfeld
and by the working groups in the University Department of Neurology:
- Memory and Consciousness, Dr. Alan Richardson-Klavehn
Multimodal Integration, Dr. rer. nat. Tömme Noesselt