4 research outputs found

    Benefits and pitfalls in the longitudinal assessment of the somatosensory cortex post-stroke using EEG

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    Somatosensory cortex plays an important role in motor planning and execution.After ischemic stroke, both afferent projections to sensory cortices (S1/2) and sensory projections to motor cortices are often affected. Changes in S1 are particularly interesting for our understanding of stroke recovery and rehabilitation strategies. The assessment of sensory impairment after stroke can certainly benefit from affordable and ambulant imaging modalities, like electroencephalography (EEG). Somatosensory evoked potentials (SEPs) recorded with EEG may be used to follow stroke patients longitudinally. In order to detect changes occurring in S1, precise measurements and with high spatial resolution are obligatory. In the present thesis, I first evaluated the capacity of SEPs for tracking longitudinal stroke recovery. Subsequently, I explored the potential benefits and pitfalls of EEG-based monitoring of stroke patients.Biomechatronics & Human-Machine Contro

    Passive WiFi monitoring of the rhythm of the campus

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    Within this research-driven project, passive WiFi monitoring of WiFi enabled devices was used to detect users (students, employees, visitors) of buildings at the campus of Delft University of Technology to gain insight into the Rhythm of the Campus: the occupation, duration of stay and moving pattern at and between the different facilities (faculties, library, auditorium). The research was carried out in request of the University's department of Facility Management and Real Estate (FMRE). In total, 20 WiFi monitors were located at the library, the auditorium and five faculties for one week. Simultaneously, ground truth data was manually collected for two days at the library and the auditorium, using an online questionnaire and a counting application. The retrieved data was classified and filtered, which facilitated data analyses and validation. Resulting from statistical analyses a relation between the number of detected mobile devices and the amount of people inside the buildings was developed. This semi-automated method made it possible to get new insights in building use compared to conventional manual counting methods. For visualisation, an online dashboard was developed as a tool to help the client at the decision making process. The research presented in this paper was carried out as a proof of concept. The results presented in this paper give a concise overview of the extensive possibilities of passive WiFi monitoring for facility managementOTBArchitecture and The Built Environmen

    EEG as an imaging tool: which inverse method can successfully disentangle sources in proximity?

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    The accuracy of EEG source localization depends on the choice of the inverse method, the resolution of the forward model, and the signal to noise ratio (SNR) of the recordings. Since we are interested in disentangling sources in proximity, the goal of our study is to examine the sensitivity of spatial resolution of EEG source reconstruction to a wide variety of factors like reconstruction method, SNR, orientation, inter-dipole distance and depth of the simulated dipoles, etc.We simulated time series to resemble waveforms of somatosensory evoked potentials. Inter-dipole distances and different dipole orientations were investigated as well as the effect of (realistic) noise. We employed both spherical and realistic head models. Source reconstruction was realized using a conventional stationary dipole model, MUSIC, self-consistent MUSIC (SC-MUSIC) algorithm, and e-LORETA. In addition to the above mentioned methods, a new approach is tested building upon the e-LORETA solution: the topography of the maximum of the e-LORETA distribution is projected out of the data before calculating the next e-LORETA inverse solution in a iterative process. The quality of fit (or localization) was defined as the distance between the simulated point- sources and either the estimated point-sources or the activity distributions by means of the Euclidean distance or of the Earth Mover’’s Distance, respectively. As expected, inter-dipole distances played an important role in the ability of every method to disentangle the simulated sources. Overall, SC-MUSIC appeared best suited for disentangling the two simulated sources even at high-noise simulations.Biomechatronics & Human-Machine Contro

    Rhythm of the campus

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    This Geomatics project was carried out in commission of the Municipality of Rotterdam, Geofort Herwijnen and Facility Management of TU Delft. The research project and this report deliver important fundamental information for scientific/academic paper on Wifi trackingGeomaticsArchitecture and The Built EnvironmentGeomatic