Neural fingerprinting on MEG time series using MiniRocket

Neural fingerprinting is the identification of individuals in a cohort based on neuroimaging recordings of brain activity. In magneto- and electroencephalography (M/EEG), it is common practice to use second-order statistical measures, such as correlation or connectivity matrices, when neural fingerprinting is performed. These measures or features typically require coupling between signal channels and often ignore the individual temporal dynamics. In this study, we show that, following recent advances in multivariate time series classification, such as the development of the RandOm Convolutional KErnel Transformation (ROCKET) classifier, it is possible to perform classification directly on short time segments from MEG resting-state recordings with remarkably high classification accuracies. In a cohort of 124 subjects, it was possible to assign windows of time series of 1 s in duration to the correct subject with above 99% accuracy. The achieved accuracies are vastly superior to those of previous methods while simultaneously requiring considerably shorter time segments

Электропривод приёмного устройства линии производства гибких нагревательных элементов

Целью работы является разработка и исследование системы векторного управления асинхронным двигателем с короткозамкнутым ротором для приёмного устройства линии производства гибких нагревательных элементов с инвертором с синусоидальной ШИМ с предмодуляцией третьей гармоникой, а также исследование свойств и выявление достоинств и недостатков различных способов управления автономных инверторов напряжения по принципу широтно-импульсной модуляции.The aim of the work is to develop and analyze the system of vector control of induction motor with squirrel-cage rotor for take-up machine of the cable production line with the voltage source inverter with third harmonic injection sinusoidal PWM, as well as to analyze the properties and identify the advantages and disadvantages of various methods of control of voltage source inverter on the principle of pulse width modulation

Towards Ultra-High Resolution Fibre Tract Mapping of the Human Brain – Registration of Polarised Light Images and Reorientation of Fibre Vectors

Polarised light imaging (PLI) utilises the birefringence of the myelin sheaths in order to visualise the orientation of nerve fibres in microtome sections of adult human post-mortem brains at ultra-high spatial resolution. The preparation of post-mortem brains for PLI involves fixation, freezing and cutting into 100-μm-thick sections. Hence, geometrical distortions of histological sections are inevitable and have to be removed for 3D reconstruction and subsequent fibre tracking. We here present a processing pipeline for 3D reconstruction of these sections using PLI derived multimodal images of post-mortem brains. Blockface images of the brains were obtained during cutting; they serve as reference data for alignment and elimination of distortion artefacts. In addition to the spatial image transformation, fibre orientation vectors were reoriented using the transformation fields, which consider both affine and subsequent non-linear registration. The application of this registration and reorientation approach results in a smooth fibre vector field, which reflects brain morphology. PLI combined with 3D reconstruction and fibre tracking is a powerful tool for human brain mapping. It can also serve as an independent method for evaluating in vivo fibre tractography

Localisation and time courses of CMV generators from MFT analysis of average MEG signals

The research presented here is divided into two parts. The first part addresses questions relating to the localisation capability of magnetoencephalography (MEG), with emphasise on testing the accuracy of typical MEG systems before any source reconstruction is applied. The second and main part is concerned with localisation and time courses of neuronal generators contributing to both the slow and fast neuromagnedc field changes associated with the contingent negative variation (CNV) in the normal human brain. We use multi-channel and full head MEG systems to study the magnetic counterpart of the CNV, the contingent magnetic variation (CMV). MEG analysis of such near DC-like signals requires advanced source reconstruction that is able to identify widely distributed as well as focal sources which often fire simultaneously from cortical as well as from deeper brain structures. We use magnetic field tomography (MFT) to extract time courses of regional brain activity. Results are presented from a multi-subject CMV study performed using the BTi MAGNES II system (Experiment 1) and a single subject experiment, using the CTF whole cortex system (Experiment 2). From Experiment 1 we identified four different CMV generators (auditory cortex, sensorimotor cortex, inferior prefrontal cortex, posterior inferior parietal area) and observed priming of the auditory cortex as part of the early CMV complex and the priming of the sensorimotor cortex as part of the late CMV complex. These results were confirmed by Experiment 2, where the full head coverage also revealed two additional areas, the supplementary motor area and the posterior cingulate cortex, which were dramatically reduced when identical runs were repeated. The SMA activity has been notoriously difficult to identify non-invasively from electrophysiological data, especially from MEG, so our success in identifying them clearly and showing how they change with repetition can he considered as the highlight of our project

Identifikation der Stimulus bezogenen intrinsischen Moden von MEG-Signalen

This work presents a combination of the “Empirical Mode Decomposition” (EMD) and the response identification via “Cross Trial Phase Statistics” (CTPS) for single trial analysis of MEG data. The algorithm is demonstrated on recon-structed current source signals from an MEG experiment with acoustically triggered finger movements. Using CTPS, the intrinsic modes of these signals can be classified according to their relevance and their temporal relation with respect to the stimulation