Nearly 50 million people are afflicted with epilepsy, worldwide. These patients suffer from unprovoked seizures, where neurons in the cerebral cortex under go uncontrolled, hypersynchronous firing of neurons. 30\% of patients with epilepsy do not respond to drug treatments. For these patients, surgical treatment involving the removal or disconnection of brain matter is one of the only alternatives. Such surgical treatments often rely on long-term monitoring of neuronal activity in the brain using subdurally implanted surface electrodes to locate the epileptic focus, but these clinical methods for mapping neuronal activity suffer from low spatial resolutions and poor noise, which can limit the success of surgical treatments where an error of even 1 mm can be critical. The work described here involves the development of an implantable system for performing optical recordings of intrinsic signal (ORIS) on the surface of the brain. By taking advantage of the unique absorption spectrum of hemoglobin, cerebral blood volume (CBV) can be measured via reflectivity changes in the brain at at specific wavelengths of light. Due to the metabolic demands of the brain, the exaggerated neuronal activity and spiking associated with epileptic seizures can be detected indirectly through changes in CBV. While high resolution ORIS measurements have been recorded using externally mounted CCD sensors, this work presents some of the first developments in producing a fully implantable ORIS sensor. Progress in the development of an implantable ORIS sensor described here includes: an implantable organic light emitting diode (OLED) and organic photodetector (OPD) integrated on a highly flexible parylene-c substrate, an implantable sensor using a microLED array embedded on a flexible polyimide substrate, and the application of quantum dots to microLEDs for optical down-conversion. Successful in vivo detection of seizures is achieved with high signal-to-noise using these methods. Additionally, spatial localization of seizure activity is performed using the microLED array. These developments represent crucial first steps in the development of a full 2D neuronal mapping system using implantable ORIS devices.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 7 uppsatser.

I detta examensarbetesprojekt genomfördes en flygkartering över deponiområdet Stomsjö i Värnamo kommun, mha. en drönare, eller den i detta sammanhang mer använda benämningen UAV (Unmanned Aerial Vehicle). Värnamo kommuns tekniska avdelning var i behov av beräkning av massor vid deponin, ett område på ca 15 hektar samt modellering av densamma. Den låga kostnaden för inköp av UAV och programvara motiverade kommunen att driva egen verksamhet jämfört med att köpa tjänsterna från konsulter. Projektets syfte är att utveckla en effektiv arbetsmetod för kartering i 2D och 3D med UAV samt att dokumentera arbetsgång och hur den geografiska informationen ska kvalitetssäkras och testas. Flygningen är den första och denna rapport ska utgöra ett underlag för kommande flygningar inom kommunen. Insamling av geografisk information utfördes med quadrokoptern DJI Phantom 4 från fyra olika flyghöjder 50, 75, 100 och 120 meter. Fyra 3D-modeller, ortofoton och digitala höjdmodeller (DEM) har tagits fram i programvaran Agisoft. Sammanlagt mättes 6 markstöd in över området samt en kontrollruta (5x5 punkter) på en hårdgjord asfaltsyta. Utifrån kontrollrutan gjordes en jämförelse mellan inmätta GPS-punkters höjdvärden mot rastervärden från respektive höjdmodell. Vid samtliga flygningar erhålls en upplösning (GSD) på mindre än 3 cm/pix i ortofoto. Upplösningen för samtliga höjdmodeller var mindre än 6 cm/pix. Lantmäteriet har under år 2015 genomfört flygfotografering på 2 500 m höjd över området. En jämförelse mellan Lantmäteriets höjddata mot höjddata genererad från UAV-flygfotograferingen gjordes genom en slumpmässig spridning av punkter på hårdgjorda ytor. Resultaten visar att 100 meters flygningen bäst överensstämmer mot Lantmäteriets data. Volym- och areaberäkning gjordes för den södra deponin. Det avgränsade områdets areal är ca 34 300 m2 och volymen 290 000 m3. / In this project the area Stomsjö in Värnamo municipality was mapped using a Unmanned Aerial Vehicle (UAV). Since 1972 Stomsjö landfill is a part of the municipality. The municipality´s technical department needed a calculation and modelling of mass in a landfill, comprising an area of 15hectares. The purpose of the project is to develop an effective mapping method in 2D and 3D with UAV data, and to document the process to ensure geographical information quality. The flight performed in the study constitutes a basis for further upcoming flights within the municipality. The acquisition of geographical data was made at four different altitudes 50, 75, 100 and 120 meters using a DJI Phantom 4 quadcopter. Four 3D models, orthophotos and Digital Elevation Models (DEMs) were created with the software Agisoft PhotoScan. A total of 6 Ground Control Points (GCP) and a control surface on asphalt (5x5 points) were used for evaluation of the models accuracy. A comparison between measured GPS points and raster values from each flight were made on a control surface. The resolution for each generated orthophoto was less than 3 cm/pix. The resolution of the DEMs was less than 6 cm/pix. Lantmäteriet (The Swedish Mapping, Cadastral and Land Registration Authority) conducted aerial photograph acquisition at 2 500 m altitude over the area in 2015. A comparison between altitude data from Lantmäteriet and altitude data from UAV was made through random points generation. The acquisition at 100 meters altitude showed the lowest deviation forms the data derived by Lantmäteriet. Volume and area measurements were performed at the southern part of the landfill. The selected area is about 34 300 m2 in size and the volume amounts to 290 000 m3.

Fringe projection is a commonly used optical technique for measuring the shapes of objects with dimensions of up to about 1 m across. There are however many instances in the aerospace and automotive industries where it would be desirable to extend the benefits of the technique (e.g., high temporal and spatial sampling rates, non-contacting measurements) to much larger measurement volumes. This thesis describes a process that has been developed to allow the creation of a large global measurement volume from two or more independent shape measurement systems. A new 3-D large volume calibration artefact, together with a hexapod positioning stage, have been designed and manufactured to allow calibration of volumes of up to 3 x 1 x 1 m3. The artefact was built from carbon fibre composite tubes, chrome steel spheres, and mild steel end caps with rare earth rod magnets. The major advantage over other commonly used artefacts is the dimensionally stable relationship between features spanning multiple individual measurement volumes, thereby allowing calibration of several scanners within a global coordinate system, even when they have non-overlapping fields of view. The calibration artefact is modular, providing the scalability needed to address still larger measurement volumes and volumes of different geometries. Both it and the translation stage are easy to transport and to assemble on site. The artefact also provides traceabitity for calibration through independent measurements on a mechanical CMM. The dimensions of the assembled artefact have been found to be consistent with those of the individual tube lengths, demonstrating that gravitational distortion corrections are not needed for the artefact size considered here. Deformations due to thermal and hygral effects have also been experimentally quantified. The thesis describes the complete calibration procedure: large volume calibration artefact design, manufacture and testing; initial estimation of the sensor geometry parameters; processing of the calibration data from manually selected regions-of-interest (ROI) of the artefact features; artefact pose estimation; automated control point selection, and finally bundle adjustment. An accuracy of one part in 17 000 of the global measurement volume diagonal was achieved and verified.

No description available.

Previous data have shown that the most prevalent, indirect plasma volume (PV) measurement technique, which utilises changes in haematocrit (Hct) and haemoglobin concentration ([Hb]), underestimates actual PV changes during immersion, when compared to a direct tracer-dilution method. An increase in the F-cell ratio (whole-body haematocrit (Hctw) to large-vessel haematocrit (Hctv) ratio) has been purported as a possible explanation, probably due to hydrostatic and thermally-mediated changes during water immersion. Previous investigators have not quantified the F-cell ratio during immersion. Therefore, this study sought to determine the effect of the F-cell ratio on the indirect method during both, thermoneutral and cold-water immersions. Seven healthy males were tested three times, seated upright in air (control: 21.2°C SD ±1.1), and during thermoneutral (34.5oC SD ±0.2) and cold-water immersion (18.6oC SD ±0.2), immersed to the third intercostal space for 60 min. Measurements during the immersion tests included PV (Evans blue dye column elution, Evans blue dye computer programme, and Hct [Hb]), red cell volume (RCV; sodium radiochromate), cardiac frequency (fc) and rectal temperature (Tre). Plasma volume during the control trial remained stable, and equivalent across the three tests. There was a hydrostatically-induced increase in PV during thermoneutral immersion, when determined by the Evans blue dye method (16.2%). However, the Hct/[Hb] calculation did not adequately reflect this change, and underestimated the relative PV change by 43%. In contrast, PV decreased during cold immersion when determined using the Evans blue dye method by 17.9% and the Hct/[Hb] calculation by 8.0%, respectively, representing a 52% underestimation by the latter method. There was a non-significant decline in RCV during both immersions. Furthermore, an increase (8.6%) and decrease (-14.4%) in blood volume (BV) was observed during thermoneutral and cold-water immersions, respectively. The decline in RCV during thermoneutral immersion attenuated the BV expansion. Despite the disparity between the PV methods, there was no increase in the F-cell ratio during either immersion. In contrast, there was a significant decline in the F-cell ratio during the control: air and thermoneutral immersion, which may indicate that other, undefined variables may impact on the stability of the red cell compartment. The current study is the first to show that the Hct/[Hb] method clearly underestimates PV changes during both thermoneutral and cold-water immersion. Furthermore, RCV was shown, for the first time, to decline during both immersions. However, the changes in the F-cell ratio during this study, did not account for the underestimation of PV change using the Hct/[Hb] method.

The purpose of this study was to investigate sixth grade students&rsquo / conceptual and procedural knowledge and word problem solving skills in the domain of length, area, and volume measurement with respect to gender, previous mathematics achievement, and use of materials. Through the Conceptual Knowledge test (CKT), the Procedural Knowledge Test (PKT), and the Word Problems test (WPT) and the Student Questionnaire, the data were collected from 445 sixth grade students attending public schools located in four different main districts of Ankara. Both descriptive and inferential statistics techniques (MANOVA) were used for the data analysis. The results indicated that the students performed relatively poor in each test. The lowest mean scores were observed in the WPT, then CKT, and PKT respectively. The questions involving length measurement had higher mean scores than area and volume measurement questions in all tests. Additionally, the results highlighted a significant relationship not only between the tests but also between the domains of measurement with a strong and positive correlation. According to the findings, whereas the overall performances of students on the tests significantly differed according to previous mathematics achievement level, gender did not affect the students&rsquo / performance on the tests. Moreover, a wide range of mistakes were found from students&rsquo / written responses to the length, area, and volume questions in the tests. Besides, the results indicated that use of materials in teaching and learning measurement was quite seldom and either low or non-significant relationship between the use of materials and the students&rsquo / performance was observed.

Functional magnetic resonance imaging (fMRI) as it exists, in its many forms and vari- ants, has revolutionized the fields of neurology and psychology by revealing functional differences non-invasively. Although blood oxygenation level dependent (BOLD) fMRI is used interchangeably with fMRI, it measures one single difference in a phys- iological measurement using a set sequence. As such, there are other established changes in the brain that relate to blood movement and capacity that can also be measured using MRI. One measure, exogenous steady state cerebral blood volume, uses a bolus routine contrast agent administered intravenously alongside a pair of high resolution ‘structural-like’ MRI images to provide detailed information within small cortical and subcortical structures. In this thesis I design a semi-automated algorithm to generate maps of steady state exogenous cerebral blood volume magnetic resonance imaging datasets. To do this I developed an algorithm and tested it on existing MRI scanning protocols. A series of automated pre-processing steps are developed and tested, including automated scan flagging for artifacts and requisite vascular segmentation. Then, a methodology is developed to create cerebral blood volume (CBV) region of interest (ROI) masks that can then be applied on an existing database to test known CBV dysfunction in a group of patients at high risk for psychosis. Finally, we develop an experiment to see if template based cerebral blood alterations co-registered with class segmentation maps have any positive predictive value in determining disease state in a well characterized cohort of five age-matched groups in an Alzheimer’s disease neuroimaging study.

The thesis is divided into theoretical and practical part. The theoretical part includes issues associated with runoff and discharge, methods for discharge measurement and measurements of uncertainties. The practical part of the thesis describes a specific process flow measurement in Kopaninský and Jenínský stream. There is a familiarization with the water flow velocity measurement and comparison methods of volume measurement discharge with continuous measurement. The results of the practical part served to refine the rainfall-runoff processes in research catchment areas. Refined values of the flow rate were used as input data for the calculation of the runoff coefficient and for quantifying the losses of nutrients from the catchment areas. Calculation of the runoff coefficient and nutrient losses were compared for the original and the revised equation discharge curve. Volume measurement discharge has shown that the different conditions above measurement weir during continuous monitoring lead to the uncertainties of measurement. That´s why one has to approach to each flowmeasurement individually and consider the situation in a particular installation.

Determination of the extent and state of a limb edema is based on information about its current volume. There are a number of methods for volume measurements. The theoretical part of this semestral thesis discusses the etiology, classification and principles of volume measurements and basic information about ultrasound and stepper motors. The practical part consists of a design of own device for a contactless limb volume measurement with ultrasonic module. It consists of a code for a microcontroller which controles the whole system including the computational operations and a real model of the system.