National Repository of Grey Literature 6 records found  Search took 0.00 seconds. 
Automated diagnosis of sleep disorders using wearable devices
Sigmund, Jan ; Mekyska, Jiří (referee) ; Mikulec, Marek (advisor)
Sleep disorders induce many negative repercussions. Furthermore, research about their connection to cognitive health is increasing in numbers. This thesis concerns detection of poor sleep quality via raw actigraphy data. Existing method for assessing sleep was selected, it’s performance was validated against polysomnography on 27 patients. Used algorithm defines sleep as the absence of change in arm angle. Resulting 81 % sensitivity, 62 % specificity and 78 % accuracy is different from the outcome in the pilot study. Two approaches, to determine sleep quality were used. Both are based on comparing sleep features – first, with National Sleep Foundation recommendations and second, with control group without sleep disorders (7 persons). The goal was to pinpoint the remaining 19 patients with diagnosis. The recommendation for SOL, WASO, NA>5 and SE had higher sensitivity (75 %), lower specificity (71 %) and identical accuracy (74 %). These approaches were then also tested on 7-day actigraphy, consisting of 27 subjects, that are presumed to have prodromal dementia with Lewy bodies. Same principle was applied to try to predict LBD and thereby address the link between sleep quality and neurodegeneration. This resulted in 86 % sensitivity, 38 % specificity and 63 % accuracy. With regard to achieving solid sensitivity in all cases and good accuracy this could be used to indicate sleep quality.
Research of the new augmentation methods for online handwriting
Sigmund, Jan ; Burget, Radim (referee) ; Zvončák, Vojtěch (advisor)
Graphomotor difficulties of school-aged children are characterised by problems in handwriting and drawing and can lead to developmental dysgraphia. Timely clinical diagnosis is critical to provide preventive care. In practice however, it is not feasible on day-to-day basis due to the need for expert staff and the prevalence of difficulties up to 30\%. Machine learning models can serve as an accessible objective tool for evaluating graphomotor functioning. In most cases there is not enough data collected, which results in poor classification performance. Therefore, this thesis focuses on data augmentation of online handwriting. Generating artificial samples is based on recombination of intrinsic mode functions, obtained by empirical mode decomposition. IMFs of health controls, numbering 72, and with graphomotor difficulties, 94 children in total, are calculated. The decomposition is performed specifically on X and Y coordinate time series. IMFs of the same indices of different subjects are randomly interchanged, thus producing a new signal. Then, the graphomotor features of the original and artificial time series are extracted. Only the spatial ones related to the coordinates are selected. Finally, the correlations of the features of the two databases will be analyzed and compared.
Automated diagnosis of sleep disorders using wearable devices
Sigmund, Jan ; Mekyska, Jiří (referee) ; Mikulec, Marek (advisor)
Sleep disorders induce many negative repercussions. Furthermore, research about their connection to cognitive health is increasing in numbers. This thesis concerns detection of poor sleep quality via raw actigraphy data. Existing method for assessing sleep was selected, it’s performance was validated against polysomnography on 27 patients. Used algorithm defines sleep as the absence of change in arm angle. Resulting 81 % sensitivity, 62 % specificity and 78 % accuracy is different from the outcome in the pilot study. Two approaches, to determine sleep quality were used. Both are based on comparing sleep features – first, with National Sleep Foundation recommendations and second, with control group without sleep disorders (7 persons). The goal was to pinpoint the remaining 19 patients with diagnosis. The recommendation for SOL, WASO, NA>5 and SE had higher sensitivity (75 %), lower specificity (71 %) and identical accuracy (74 %). These approaches were then also tested on 7-day actigraphy, consisting of 27 subjects, that are presumed to have prodromal dementia with Lewy bodies. Same principle was applied to try to predict LBD and thereby address the link between sleep quality and neurodegeneration. This resulted in 86 % sensitivity, 38 % specificity and 63 % accuracy. With regard to achieving solid sensitivity in all cases and good accuracy this could be used to indicate sleep quality.
Návrh konstrukce barové židle s vyšší houževnatostí
Sigmund, Jan
The main aim of this diploma thesis is the design and implementation of innovative construction of selected bentwood barstool. This innovation has been focused on selected connections in the construction while increasing their toughness. Findings and knowledge in the field of eco-design, design of seating furniture, adhesion and material properties technology were used for elaboration of the draft. In the practical part, innovative design barstool has been designed and constructed on the basis of related expertise, underlying bachelor thesis and results of performed tests. Construction has been subjected to non-standardized tests for compressive strength and strain energy absorption.

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