Optical sensors for mechanomyography and tissue chromophores

The mechanomyogram (MMG) is a mechanical oscillations observable on the surface of the skin as a muscle contracts. Measurement of the MMG utilizing contact sensors with a weight greater than 6 g has proved to interfere with the measurement. Use of optical displacement sensors without direct contact to the skin would remove this deficiency. A Michelson interferometer, an intensity shift set-up and a configuration able of measuring both MMG and tissue oxygenation dynamics simultaneously were all evaluated in regard to their precision, easy of use and efficacy. The results were analysed using the fast Fourier transform (FFT) and the continuous wavelet transform (CWT) A regular Michelson interferometer proved to be unsuited for measuring oscillations with an amplitude greater than =4. Demodulation of signals exceeding this limit requires cumbersome analysis methods that would not be practically feasible in a clinical set-up. By measuring the light reflected from an oscillating target, a second simpler set-up was able to measure the frequency and amplitude of a tuning fork with high precision. Measurements on biceps bracii was performed but no clear results were found. A set-up combining MMG and tissue chromophores was realised with three optical fibres attached to the skin. The haemoglobin oxygenation dynamics was successfully measured during contraction and relaxation of the biceps brachii but no MMG signal could be deduced. The outcome of this thesis suggest that further research is required to investigate the possibility of designing a set-up able to measure both MMG and haemoglobin oxygenation dynamics with high precision. This would enable a detailed study of muscle dynamics which have not been done before

The Evaluation of Optic Nerves Using 7 Tesla 'Silent' Zero Echo Time Imaging in Patients with Leber's Hereditary Optic Neuropathy with or without Idebenone Treatment

Magnetic Resonance Imaging (MRI) of the Optic Nerve is difficult due to the fine extended nature of the structure, strong local magnetic field distortions induced by anatomy, and large motion artefacts associated with eye movement. To address these problems we used a Zero Echo Time (ZTE) MRI sequence with an Adiabatic SPectral Inversion Recovery (ASPIR) fat suppression pulse which also imbues the images with Magnetisation Transfer contrast. We investigated an application of the sequence for imaging the optic nerve in subjects with Leber's hereditary optic neuropathy (LHON). Of particular note is the sequence's near-silent operation, which can enhance image quality of the optic nerve by reducing the occurrence of involuntary saccades induced during Magnetic Resonance (MR) scanning

Inter-Vendor Reproducibility of Myelin Water Imaging Using a 3D Gradient and Spin Echo Sequence

Myelin water imaging can be achieved using multicomponent T2 relaxation analysis to quantify in vivo measurement of myelin content, termed the myelin water fraction (MWF). Therefore, myelin water imaging can be a valuable tool to better understand the underlying white matter pathology in demyelinating diseases, such as multiple sclerosis. To apply myelin water imaging in multisite studies and clinical applications, it must be acquired in a clinically feasible scan time (less than 15 min) and be reproducible across sites and scanner vendors. Here, we assessed the reproducibility of MWF measurements in regional and global white matter in 10 healthy human brains across two sites with two different 3 T magnetic resonance imaging scanner vendors (Philips and Siemens), using a 32-echo gradient and spin echo (GRASE) sequence. A strong correlation was found between the MWF measurements in the global white matter (Pearson’s r = 0.91; p < 0.001) for all participants across the two sites. The mean intersite MWF coefficient of variation across participants was 2.77% in the global white matter and ranged from 4.47% (splenium of the corpus callosum) to 17.89% (genu of the corpus callosum) in white matter regions of interest. Bland-Altman analysis showed a good agreement in MWF measurements between the two sites with small bias of 0.002. Overall, MWF estimates were in good agreement across the two sites and scanner vendors. Our findings support the use of quantitative multi-echo T2 relaxation metrics, such as the MWF, in multicenter studies and clinical trials to gain deeper understanding about the pathological processes resulting from the underlying disease progression in neurodegenerative diseases

Life cycle cost of maintenance with different levels of automation

At the Swedish Transport Administration two different maintenance strategies are practiced to keep cameras in road tunnels clean. The theory of Life Cycle Cost, LCC, is applied on maintenance depending on its Level of Automation, LoA, and is further developed. In the case of cameras, in Swedish road tunnels the processes demonstrate two different LoA. LCC is used to compare and analyze how the properties between semiautomatic and manual maintenance affect investment costs, operational costs and the cost of preventive and corrective maintenance. Semiautomatic cleaning maintenance of cameras in road tunnels indicate a larger LCC than manual maintenance. This is due to a larger investment cost for machinery, but a similar annual cost for preventive maintenance. The presented properties affecting LCC are placed in a general context. This emphasize the significance of examining costs at high level of detail and comprehend the properties causing the costs

Characterization of myelin water imaging using a gradient and spin echo sequence in human brain and spinal cord

Myelin water imaging is a quantitative magnetic resonance imaging technique that can be used as an in vivo biomarker for myelin in the central nervous system. In 2007, a paradigm shift took place when the standard sequence for myelin water imaging changed from a multi-echo spin echo sequence to a gradient and spin echo (GRASE) sequence. The GRASE sequence has so far only been applied to brain imaging, and reproducibility between different scan vendors has not been assessed. In this study I present the first implementation of myelin water imaging using GRASE in human cervical spinal cord. The reproducibility of myelin water imaging in the spinal cord was found to be high (coefficient of variation = 6.1%, Cronbach’s α = 0.89). A multicenter reproducibility study of myelin water imaging in brain between two scan vendors (Siemens and Philips) was also performed. Results from the two scanners were found to be highly correlated but with a significant offset in myelin water fraction of 4.3%. Together, these two studies provide strong evidence of the reproducibility of myelin water imaging. It is an important step forward in the development of bringing myelin water imaging to the mainstream.Science, Faculty ofPhysics and Astronomy, Department ofGraduat

När magin försvinner : En studie om artificiell intelligens betydelse för företag

I denna uppsats undersöks fenomenet artificiell intelligens och vilken funktion den i dagsläget fyller för företag. Uppsatsens första del består av en förstudie där begreppet artificiell intelligens (AI) reds ut. Förstudien skapar en bättre förståelse för AI - vilken kombineras med teori kring teknikimplementering hos företag för att skapa en analysmodell, som i uppsatsens andra del appliceras på fallföretaget Zecobyte. De slutsatser som slutligen nås är att Zecobyte arbetar med AI-teknologi, men att tekniken egentligen inte skiljer sig något särskilt från någon annan typ av IT-teknologi. De utvecklar innovativa produkter, vilka utnyttjar Big Data fenomenet, med olika kundnyttor vilka även de inte skiljer sig markant från de kundnyttor som genereras från annan IT-teknologi. Vi konstaterar även att det finns mycket potential hos AI och avslutar med att öppna upp för fortsatta studier inom området

När magin försvinner : En studie om artificiell intelligens betydelse för företag

I denna uppsats undersöks fenomenet artificiell intelligens och vilken funktion den i dagsläget fyller för företag. Uppsatsens första del består av en förstudie där begreppet artificiell intelligens (AI) reds ut. Förstudien skapar en bättre förståelse för AI - vilken kombineras med teori kring teknikimplementering hos företag för att skapa en analysmodell, som i uppsatsens andra del appliceras på fallföretaget Zecobyte. De slutsatser som slutligen nås är att Zecobyte arbetar med AI-teknologi, men att tekniken egentligen inte skiljer sig något särskilt från någon annan typ av IT-teknologi. De utvecklar innovativa produkter, vilka utnyttjar Big Data fenomenet, med olika kundnyttor vilka även de inte skiljer sig markant från de kundnyttor som genereras från annan IT-teknologi. Vi konstaterar även att det finns mycket potential hos AI och avslutar med att öppna upp för fortsatta studier inom området

När magin försvinner : En studie om artificiell intelligens betydelse för företag

I denna uppsats undersöks fenomenet artificiell intelligens och vilken funktion den i dagsläget fyller för företag. Uppsatsens första del består av en förstudie där begreppet artificiell intelligens (AI) reds ut. Förstudien skapar en bättre förståelse för AI - vilken kombineras med teori kring teknikimplementering hos företag för att skapa en analysmodell, som i uppsatsens andra del appliceras på fallföretaget Zecobyte. De slutsatser som slutligen nås är att Zecobyte arbetar med AI-teknologi, men att tekniken egentligen inte skiljer sig något särskilt från någon annan typ av IT-teknologi. De utvecklar innovativa produkter, vilka utnyttjar Big Data fenomenet, med olika kundnyttor vilka även de inte skiljer sig markant från de kundnyttor som genereras från annan IT-teknologi. Vi konstaterar även att det finns mycket potential hos AI och avslutar med att öppna upp för fortsatta studier inom området