Segmentation of carbon nanocones in TEM images using generalized Hough transform

Bakalářská práce se zabývá problematikou automatické detekce karbonových nanostruktur v TEM obrazech pomocí zobecněné Houghovy transformace. Je zde popsána teorie Houghovy transformace obrazu za účelem detekce analyticky popsatelných i obecných struktur. Dle charakteristiky TEM obrazů karbonových nanostruktur jsou vytvořeny syntetické testovací obrazy, které jsou předzpracovány kombinací morfologických operací a prahování s globálním prahem. Je navržen algoritmus Houghovy transformace, který detekuje nanokužely v umělých obrazech. Úspěšnost a přesnost detekce je testována v závislosti na parametrech použitých při vytváření umělých obrazů nebo úrovni předzpracování.Bachelor thesis deals with automatic detection of carbon nanostructures in TEM images using generalized Hough transform. There is described the theory of Hough transform in order to detect analytic as well as general structures in images. According to the characteristics of carbon nanostructures TEM images synthetic test images, that are preprocessed by morphological operations and thresholding with global threshold, are created. Hough transform algorithm that detects nanocones in synthetic images of carbon nanocone structures is created. Success and accuracy of detection is tested changing the parameters of artificial images or level of preprocessing.

Brain connectivity estimation

Epileptické onemocnění mozku je spojeno se změnou aktivity neuronových center. Analýza konektivity mozku se zabývá statistickou závislostí aktivity neuronových center. Předchozí studie ukazují na změnu konektivity mozkové tkáně v okolí epileptického ložiska. Příčiny změn v konektivitě a její charakteristika v interiktálních záznamech však není zcela známa. V této práci jsou analyzována data z intrakraniálních EEG elektrod, umístěných uvnitř a v bezprostředním okolí epileptického ložiska. Změna konektivity v epileptickém ložisku a jeho okolí byla sledována pomocí metody nelineární korelace. Byl detekován pokles konektivity v epileptickém ložisku během delta spánku na frekvencích nad 80 Hz. Dále byl zjištěn pokles konektivity na rozhraní epileptického ložiska a zdravé tkáně. Pozorované jevy byly navíc zvýrazněny během spánku. Zároveň bylo zjištěno, že konektivita na rozhraní epileptického ložiska projevuje nelineární charakter. Z výsledků tedy vyplývá, že fyziologické procesy během spánku ovlivňují konektivitu v blízkosti epileptického ložiska a redukce konektivity v jeho okolí může souviset s nelinearní závislostí aktivit neuronů uvnitř a vně něj. Práce potvrzuje hypotézy předchozích studií a odkrývá nové skute čnosti o konektivitě epileptického ložiska z pohledu nelineárních dějů. Navazující studium těchto poznatků může vést k přesnější lokalizaci epileptického ložiska a k lepšímu pochopení procesů, které způsobují epileptické záchvaty.Epileptic disease is connected with change in activity of neuronal clusters. Brain connectivity analysis deals with statistic interdependencies between different neuronal centres. Earlier studies show that changes in connectivity can be seen near primary epileptic site. What is changing connectivity and its characteristic in interictal recordings are yet to be fully known. In this thesis are analyzed data from intracranial EEG electrodes, positioned in and neighboring areas of epileptic site. Changes in connectivity of epileptic site and its surroundings are observed by nonlinear correlation method. Decrease in connectivity of epileptic site during slow wave sleep was detected on frequencies above 80 Hz. Reduced connectivity was measured on the border of epileptic zone and normal tissue. Observed features are accentuated during sleep. It was also found out that connectivity at the border of epileptic zone apears to have nonlinear property. The results show that physiological processes during sleep are influencing connectivity near epileptic site and decrease in connectivity may be related to nonlinear dependence of neuronal activity at the border of epileptic zone. This study confirms hypothesis of the earlier studies and reveals new facts about connectivity of epileptic site from the perspective of nonlinear processes. Consequent study based on this findings might lead to more precise delineation of epileptic site and to better understanding of processes, which are causing epileptic fits.

Epilepsy Personal Assistant Device-A Mobile Platform for Brain State, Dense Behavioral and Physiology Tracking and Controlling Adaptive Stimulation

Epilepsy is one of the most common neurological disorders, and it affects almost 1% of the population worldwide. Many people living with epilepsy continue to have seizures despite anti-epileptic medication therapy, surgical treatments, and neuromodulation therapy. The unpredictability of seizures is one of the most disabling aspects of epilepsy. Furthermore, epilepsy is associated with sleep, cognitive, and psychiatric comorbidities, which significantly impact the quality of life. Seizure predictions could potentially be used to adjust neuromodulation therapy to prevent the onset of a seizure and empower patients to avoid sensitive activities during high-risk periods. Long-term objective data is needed to provide a clearer view of brain electrical activity and an objective measure of the efficacy of therapeutic measures for optimal epilepsy care. While neuromodulation devices offer the potential for acquiring long-term data, available devices provide very little information regarding brain activity and therapy effectiveness. Also, seizure diaries kept by patients or caregivers are subjective and have been shown to be unreliable, in particular for patients with memory-impairing seizures. This paper describes the design, architecture, and development of the Mayo Epilepsy Personal Assistant Device (EPAD). The EPAD has bi-directional connectivity to the implanted investigational Medtronic Summit RC+S-TM device to implement intracranial EEG and physiological monitoring, processing, and control of the overall system and wearable devices streaming physiological time-series signals. In order to mitigate risk and comply with regulatory requirements, we developed a Quality Management System (QMS) to define the development process of the EPAD system, including Risk Analysis, Verification, Validation, and protocol mitigations. Extensive verification and validation testing were performed on thirteen canines and benchtop systems. The system is now under a first-in-human trial as part of the US FDA Investigational Device Exemption given in 2018 to study modulated responsive and predictive stimulation using the Mayo EPAD system and investigational Medtronic Summit RC+S-TM in ten patients with non-resectable dominant or bilateral mesial temporal lobe epilepsy. The EPAD system coupled with an implanted device capable of EEG telemetry represents a next-generation solution to optimizing neuromodulation therapy

Thalamic deep brain stimulation modulates cycles of seizure risk in epilepsy

Chronic brain recordings suggest that seizure risk is not uniform, but rather varies systematically relative to daily (circadian) and multiday (multidien) cycles. Here, one human and seven dogs with naturally occurring epilepsy had continuous intracranial EEG (median 298 days) using novel implantable sensing and stimulation devices. Two pet dogs and the human subject received concurrent thalamic deep brain stimulation (DBS) over multiple months. All subjects had circadian and multiday cycles in the rate of interictal epileptiform spikes (IES). There was seizure phase locking to circadian and multiday IES cycles in five and seven out of eight subjects, respectively. Thalamic DBS modified circadian (all 3 subjects) and multiday (analysis limited to the human participant) IES cycles. DBS modified seizure clustering and circadian phase locking in the human subject. Multiscale cycles in brain excitability and seizure risk are features of human and canine epilepsy and are modifiable by thalamic DBS

Measurement of HGB beer colloidal ageing and tannoid content development using complex turbidimetric analysis.

Measurements of HGB beers were carried out in concentrated and blended samples to analyse the chill haze and tannoid content development during the thermal forced ageing process. The measurements were performed by the method of complex turbidimetric analysis (CTA), based on a single instrumentation for beer chill haze determination in commercial bottles and polyvinylpyrrolidone/tannoid content titration of beer samples in usual reaction tubes. For illustration of the efficiency of the CTA method, the initial values of saturated ammonium sulphate precipitation limits (SASPL) and sensitive protein (SP) levels were determined, too. The CTA method confirmed enhanced colloidal stability of the blended HGB final product due to lower content of the high molecular weight haze active proteotannic complexes. An almost linear correlation between the chill haze and tannoid content development during beer ageing process, starting from some concentration threshold level after a certain lag time was revealed.The correlation between the tannoid content of HGB beer in blended and non blended state was found also linear. The CTA method can be effectively used for the evaluation and prediction of the HGB beer colloidal ageing process and diagnostics of the causes of production inhomogeneity.Measurements of HGB beers were carried out in concentrated and blended samples to analyse the chill haze and tannoid content development during the thermal forced ageing process. The measurements were performed by the method of complex turbidimetric analysis (CTA), based on a single instrumentation for beer chill haze determination in commercial bottles and polyvinylpyrrolidone/tannoid content titration of beer samples in usual reaction tubes. For illustration of the efficiency of the CTA method, the initial values of saturated ammonium sulphate precipitation limits (SASPL) and sensitive protein (SP) levels were determined, too. The CTA method confirmed enhanced colloidal stability of the blended HGB final product due to lower content of the high molecular weight haze active proteotannic complexes. An almost linear correlation between the chill haze and tannoid content development during beer ageing process, starting from some concentration threshold level after a certain lag time was revealed.The correlation between the tannoid content of HGB beer in blended and non blended state was found also linear. The CTA method can be effectively used for the evaluation and prediction of the HGB beer colloidal ageing process and diagnostics of the causes of production inhomogeneity