Fault-tolerant formation driving mechanism designed for heterogeneous MAVs-UGVs groups

A fault-tolerant method for stabilization and navigation of 3D heterogeneous formations is proposed in this paper. The presented Model Predictive Control (MPC) based approach enables to deploy compact formations of closely cooperating autonomous aerial and ground robots in surveillance scenarios without the necessity of a precise external localization. Instead, the proposed method relies on a top-view visual relative localization provided by the micro aerial vehicles flying above the ground robots and on a simple yet stable visual based navigation using images from an onboard monocular camera. The MPC based schema together with a fault detection and recovery mechanism provide a robust solution applicable in complex environments with static and dynamic obstacles. The core of the proposed leader-follower based formation driving method consists in a representation of the entire 3D formation as a convex hull projected along a desired path that has to be followed by the group. Such an approach provides non-collision solution and respects requirements of the direct visibility between the team members. The uninterrupted visibility is crucial for the employed top-view localization and therefore for the stabilization of the group. The proposed formation driving method and the fault recovery mechanisms are verified by simulations and hardware experiments presented in the paper

Retinal nerve fiber layer measurement in patients with Alzheimer's disease

Retinal nerve fiber layer measurement in patients with Alzheimer's disease The current ophthalmologist's possibilities in diagnostics of Alzheimer's disease Alzheimer disease (AD) is the most common cause of dementia syndrome and mild cognitive impairment. To enroll the disease most securely there are used so called biomarkers using evidence of changed brain metabolism by pozitron emission tomography (PET) and in cerebrospinal fluid or the brain's structure magnetic resonance imaging (MRI). These methods are expensive, organisationally and temporally challenging and burdening for the patients. According to that reasons we are still seeking for alternative attitudes suitable for early diagnosis. The evaluation of thickness of retinal nerve fiber layer (RNFL) which is well accessible to examination through optical aparatus of the eye could be one of the options. The aim of our work was to present current knowledges about Alzheimer's disease targeting relations of Alzheimer's disease and an ophthalmological finding. In the next part of this paper we introduce the retinal nerve fiber layer measurement by optical coherence tomography (OCT) as a potential diagnostics method by screening of patients with Alzheimer's disease and to present our results measured in our cohort of patients. The studied cohort..

Retinal nerve fiber layer measurement in patients with Alzheimer's disease

Retinal nerve fiber layer measurement in patients with Alzheimer's disease The current ophthalmologist's possibilities in diagnostics of Alzheimer's disease Alzheimer disease (AD) is the most common cause of dementia syndrome and mild cognitive impairment. To enroll the disease most securely there are used so called biomarkers using evidence of changed brain metabolism by pozitron emission tomography (PET) and in cerebrospinal fluid or the brain's structure magnetic resonance imaging (MRI). These methods are expensive, organisationally and temporally challenging and burdening for the patients. According to that reasons we are still seeking for alternative attitudes suitable for early diagnosis. The evaluation of thickness of retinal nerve fiber layer (RNFL) which is well accessible to examination through optical aparatus of the eye could be one of the options. The aim of our work was to present current knowledges about Alzheimer's disease targeting relations of Alzheimer's disease and an ophthalmological finding. In the next part of this paper we introduce the retinal nerve fiber layer measurement by optical coherence tomography (OCT) as a potential diagnostics method by screening of patients with Alzheimer's disease and to present our results measured in our cohort of patients. The studied cohort..

Retinal nerve fiber layer measurement in patients with Alzheimer's disease

Retinal nerve fiber layer measurement in patients with Alzheimer's disease The current ophthalmologist's possibilities in diagnostics of Alzheimer's disease Alzheimer disease (AD) is the most common cause of dementia syndrome and mild cognitive impairment. To enroll the disease most securely there are used so called biomarkers using evidence of changed brain metabolism by pozitron emission tomography (PET) and in cerebrospinal fluid or the brain's structure magnetic resonance imaging (MRI). These methods are expensive, organisationally and temporally challenging and burdening for the patients. According to that reasons we are still seeking for alternative attitudes suitable for early diagnosis. The evaluation of thickness of retinal nerve fiber layer (RNFL) which is well accessible to examination through optical aparatus of the eye could be one of the options. The aim of our work was to present current knowledges about Alzheimer's disease targeting relations of Alzheimer's disease and an ophthalmological finding. In the next part of this paper we introduce the retinal nerve fiber layer measurement by optical coherence tomography (OCT) as a potential diagnostics method by screening of patients with Alzheimer's disease and to present our results measured in our cohort of patients. The studied cohort...Souhrn Alzheimerova choroba (ACH) je nejčastější příčinou syndromu demence a mírné kognitivní poruchy (MCI). Nejspolehlivěji je možné diagn ózu ACH zachytit pomocí takzvaných biomarkerů průkazem změny metabolismu mozku pozitronovou emisní tomografií (PET), změnami v mozkomíšním moku nebo struktury mozku magnetickou rezonancí (MRI). Tyto metody jsou finančně nákladné, organizačně a časově náročné a pro pacienta často zatěžující. Z těchto důvodů se hledají alternativní přístupy vhodné pro časnou diagnostiku ACH. Jednou z možností může být zhodnocení tloušťky vrstvy nervových vláken sítnice (RNFL), která je dobře přístupná vyšetření přes optický aparát oka. Cílem naší práce je prezentovat základy současných znalostí o Alzheimerově chorobě se zaměřením na souvislosti ACH s očním nálezem. V další části práce pak představit měření vrstvy nervových vláken sítnice pomocí optické koherenční tomografie (OCT) jako potenciální diagnostickou metodu při screeningu pacientů s ACH a prezentovat výsledky naměřené na našem souboru. Soubor obsahoval 24 pacientů s ACH, respektive 48 změřených očí a 10 pacientů s mírným kognitivním deficitem, respektive 19 změřených očí. Do kontrolního souboru bylo zařazeno 26 osob, respektive 51 změřených očí. Všichni pacienti podstoupili komplexní oční vyšetření včetně vyšetření sítnice v...Oční klinikaDepartment of OphthalmologyLékařská fakulta v Hradci KrálovéFaculty of Medicine in Hradec Králov