Made available in DSpace on 2015-12-06T23:47:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2007 / Visando definir a influência do gênero na evolução do remodelamento miocárdico e da disfunção ventricular pós-Infarto do Miocárdio (IM) em ratos, 21 machos (peso corpóreo: x ± sd: 244 ± 45 g) e 24 fêmeas (peso corpóreo: 200 ± 12 g) que tiveram o ramo interventricular anterior da coronária ocluído cirurgicamente foram submetidos a exame Doppler ecocardiográfico (DE) uma e seis semanas após indução do IM. Os animais foram agrupados segundo o gênero e o tamanho do IM em: 1) IMM F1 (n = 12): fêmeas portadoras de IM considerados moderados, por terem dimensão compreendida entre 20 e 39% do perímetro do ventrículo esquerdo (VE), analisadas na primeira semana que se seguiu à oclusão coronária; 2) IMM F6: os mesmos animais de IMM F1 analisados na sexta semana que se seguiu à oclusão coronária; 3) IMG F1 (n = 12): fêmeas portadoras de IM considerados grandes, por terem dimensão igual ou superior a 40 % do VE, analisadas na primeira semana que se seguiu à oclusão coronária; 4) IMG F6: os mesmos animais de IMG F1 analisados na sexta semana que se seguiu à oclusão coronária; 5) IMM M1 (n = 9): machos portadores de IM moderados analisados na primeira semana que se seguiu à oclusão coronária; 6) IMM M6: os mesmos animais de IMM M1 analisados na sexta semana que se seguiu à oclusão coronária; 7) IMG M1 (n = 12): machos portadores de IM grandes analisados na primeira semana que se seguiu à oclusão coronária; 8) IMG M6: os mesmos animais de IMG M1 analisados na sexta semana que se seguiu à oclusão coronária. Foram também analisados ratos normais, tomados como controle: CF1 (n = 7): ratas analisadas após uma semana de terem sido incluídas no protocolo; CF6: os mesmos animais de CF1 analisados na sexta semana; CM1 (n = 8): ratos analisados após uma semana de terem sido incluídos no protocolo; CM6: os mesmos animais de CM1 analisados na sexta semana. O tamanho do IM foi definido durante exame Doppler ecocardiográfico, em associação com as seguintes variáveis: 1) diâmetro do átrio esquerdo; 2) diâmetros transversos diastólico e sistólico do VE; 3) áreas transversas diastólicas e sistólicas do VE; 4) fração de encurtamento da área transversa (FEAT) do VE; 5) onda E; 6) onda A e 7) razão E/A. Foram avaliados, também, peso corpóreo no início e no final do protocolo e a freqüência cardíaca nos momentos de realização do DE. As variáveis dimensionais (diâmetros e áreas) tiveram seus valores expressos nas suas grandezas dimensionais habituais (cm e cm2 ) e normalizados para o peso corpóreo (cm/g e cm2 /g). Os resultados evidenciaram que: 1) o IM não afetou o ganho de peso dos animais; 2) não houve modificações expressivas da freqüência cardíaca; 3) diferentemente do que ocorreu com os dados considerados em suas grandezas absolutas – que guardaram progressão coerente com o desenvolvimento da fisiopatologia que se segue ao IM – com freqüência, a correção dos dados dimensionais pelo peso corpóreo resultou em informações que dificilmente se conciliavam com a evolução lógica das variáveis; 4) o IM condicionou aumento da dimensão das cavidades e comprometimento da ejeção ventricular e do esvaziamento atrial; 5) as variáveis do exame DE sofreram modificações proporcionais ao tamanho do IM e ao tempo que se seguiu à oclusão coronária, isto é, como regra, infartos grandes tiveram alterações mais acentuadas do que IM moderados e nas avaliações concretizadas na sexta semana as variáveis atingiram nível de anormalidade mais acentuado do que na primeira semana após oclusão coronária; 6) não foram encontradas diferenças consistentes entre os dados obtidos em machos e fêmeas que permitissem caracterizar comportamento peculiar dependente de gênero, durante o período de acompanhamento previsto no protocolo. / To define the influence of the gender on the myocardial remodeling evolution and on the ventricular dysfunction after myocardial infarction (MI) in rats, 21 males (body weight: x ± sd: 244 ± 45 g) and 24 females (body weight: 200 ± 12 g) that had the anterior intraventricular coronary branch surgically occluded were submitted to echocardiographic Doppler Examination (DE) one and six weeks after the induction of the MI. The animals were grouped according to gender and length of the MI in: 1) MMI F1 (n = 12): females with moderate MI, that is to say, MI between 20 and 39% of the perimeter of the left ventricle (LV), analyzed in the first week after the coronary occlusion; 2) MMI F6: the same animals as in MMI F1 analyzed in the sixth week after the coronary occlusion; 3) MIL F1 (n = 12): females with MI considered large (equal to or larger than 40% of the LV) analyzed in the first week after the coronary occlusion; 4) MIL F6: the same animals as in IMG F1 analyzed in the sixth week following the coronary occlusion; 5) MMI M1 (n = 9): males with moderate MI analyzed in the first week following the coronary occlusion; 6) MMI M6: the same animals as in MMI M1 analyzed in the sixth week following the coronary occlusion; 7) MIL M1 (n =12): males with large MI analyzed in the first week following the coronary occlusion; 8) MIL M6: the same animals as in MIL M1 analyzed in the sixth week following the coronary occlusion. Normal rats, used as control, were also analyzed: CF1 (n = 7) females analyzed one week after they were included in the protocol; CF6: the same animals as in CF1 analyzed in the sixth week; CM1 (n = 8): male rats analyzed one week after they were included in the protocol; CM6: the same animals as in CM1 analyzed in the sixth week. The size of the MI was defined during echocardiographyc Doppler examination in association to the following variables: 1) left atrium diameter; 2) LV diastolic and systolic transverse diameters; 3) LV diastolic and systolic transverse areas; 4) fractional area change (FAC) of the LV; 5) E wave; 6) A wave and 7) E/A ratio. Body weight at the beginning and at the end of the protocol, and the heart rate in the moments of DE examination were also evaluated. The dimensional variables (diameters and areas) were expressed in the usual dimensional values (cm and cm2 ) and normalized for the body weight (cm/g and cm2 /g). The results showed that: 1) the MI did not affect the gain of weight of the animals; 2) there was no expressive changes in the heart rate; 3) differently of what occurred with the data considered as absolute values – which keep coherent progression with the development of the pathophysiology that followed the MI – the correction of dimensional data by the body weight, frequently, resulted in information which difficultly conciliated with the logical evolution of the variables; 4) the MI increased the cavities dimension and impaired ventricular ejection and atrial emptying; 5) the variables of the DE examination changed proportionally to the MI size and to the time which followed the coronary occlusion. Indeed, as a rule, large MI had alterations more pronounced than the moderate and in the sixth week the variables reached level of abnormality more pronounced to that saw at the first week after coronary occlusion; 6) there were no consistent differences in the data obtained in males and females that could characterize a peculiar behavior dependent on the gender, during the accompanying period of the protocol. / BV UNIFESP: Teses e dissertações

Resumo não disponível

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Saúde Animal, 2016. / Submitted by Camila Duarte (camiladias@bce.unb.br) on 2016-09-16T16:29:19Z No. of bitstreams: 1 2016_LarissaCaixetaVieira.pdf: 848532 bytes, checksum: a5a344e3d5ea751babe0e717f29e1128 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-11-08T11:46:34Z (GMT) No. of bitstreams: 1 2016_LarissaCaixetaVieira.pdf: 848532 bytes, checksum: a5a344e3d5ea751babe0e717f29e1128 (MD5) / Made available in DSpace on 2016-11-08T11:46:34Z (GMT). No. of bitstreams: 1 2016_LarissaCaixetaVieira.pdf: 848532 bytes, checksum: a5a344e3d5ea751babe0e717f29e1128 (MD5) / A utilização dos protocolos de imagens ultrassonográficas Doppler, possibilita de forma não invasiva e de baixo custo, mapear circulações periféricas mediante correlações estabelecidas entre traçados espectrais e hemodinâmicas vasculares. Esse trabalho teve como objetivo detectar os parâmetros das artérias digitais palmares laterais dos membros torácicos de equinos Puro Sangue Árabe correlacionando provas de enduro à períodos de descanso impostos aos animais. No presente trabalho foi possível concluir que os aspectos vasculares Doppler relacionados ao teor de exercício, descanso, à idade, ao peso e ao tamanho dos animais, se mantiveram constantes nos 24 animais utilizados. Acredita-se que a ultrassonografia Doppler possa auxiliar satisfatoriamente na obtenção de parâmetros normais e consequentemente na detecção de afecções podais frente à elevada especificidade e sensibilidade do método. Entretanto, as variações Doppler inerentes, ao operador/equipamento, ao ambiente e ao próprio animal devem ser de forma prévia e sistematicamente avaliadas com intuito de aprimorar ao máximo a sensibilidade e especificidade da técnica. __________________________________________________________________________________________________ ABSTRACT / The use of Doppler ultrasound images protocols, enables non-invasively and low cost, mapping peripheral circulations by correlations established between spectral and vascular hemodynamic tracings. This study aimed to detect the parameters of the digital arteries palmar side of the forelimbs of horses Purebred Arabian correlating evidence enduro to rest periods 2 imposed on animals. In this study it was concluded that the vascular Doppler aspects related to the exercise content, rest, age, weight, and size of the animals remained constant in the 24 animals used. It is believed that Doppler ultrasound can aid in obtaining satisfactorily normal way and consequently the detection of feet forward diseases with high specificity and sensitivity of the method. However, the Doppler variations inherent to the operator / equipment, the environment and animal itself should be of prior form and systematically evaluated in order to improve the maximum sensitivity and specificity of the technique.

Resumo não disponível

M.Ing. (Electrical And Electronic Engineering) / A brief introduction to laser Doppler anemometry is given. Signal processing techniques for LOA are discussed with specific reference to the salient advantages and disadvantages of each. The abovementioned discussion motivates the use of adaptive filters as parametric spectral estimators for frequency ext~action from Doppler signals. Two adaptive algorithms ie. 'the least mean sqaures' (LMS) and the 'recursive least sqaures' (RLS), are discussed. Results of a real-time application of the LMS algorithm, as implemented on the TMS320-10, as well as the results from a full study of the Kalman algorithm are shown and discussed. The implementation of a digital signal processor to make the application of parametric spectral estimation to LOA viable is discussed under the following headings: analogue module; mathematical processor; communications module; storage an~ display unit. The system is based qn a eight bit converter with conversion rates ranging from the lower audio range to 20MHz. It has a versatile trigger system to facilitate easy capture of Doppler data. Captured data is stored in an onboard FIFO register and is available to the mathematical processing unit for spectral analysis. '/ The mathematical processing unit is a sixteen bit, multi-processor environment specifically implemented for parametric spectral estimation. The system comprises three TMS320-10 signal processors which are connected by means of a high speed parallel communications channel. Processed data is available to a display and storage system via a high speed interface card that interfaces the sixteen bit signal processor environment to the eight bit environment of the display device.

For a synthetic aperture radar (SAR) system, the Doppler centroid is the azimuth Doppler frequency received from a point scatterer centered in the azimuth antenna pattern. This parameter is required by the SAR processor in order to properly focus SAR images. Since the azimuth Doppler spectrum is weighted by the azimuth antenna pattern, the Doppler centroid can be determined by locating the peak of the Doppler spectrum. This measurement, however, is ambiguous because the azimuth Doppler spectrum is aliased by the radar pulse repetition frequency (PRF). To resolve the ambiguity, the antenna beam angle, which determines the Doppler centroid, is measured; the accuracy of this measurement must be high enough to determine the Doppler centroid to within ±PRF/2. For some SAR systems, such as the future Radarsat system, the beam angle measurement must be very accurate; this can be technically infeasible or too costly to implement. This thesis examines an alternative approach to resolving the Doppler centroid ambiguity which does not require accurate beam angle measurement In most SAR processors, several partial azimuth aperture "looks" are processed, rather than a single long aperture, in order to yield a final SAR image with reduced speckle noise. If the Doppler centroid is in error by an integer number of PRFs, then the SAR looks will be defocussed and misregistered in range. The degree of misregistration depends on with which Doppler centroid ambiguity the data is processed. The new method for Doppler centroid ambiguity estimation measures the range displacement of SAR looks using a cross-correlation of looks in the range direction. The theoretical background and details of the new method are discussed. The effects of differing terrain types, wave motion, and errors in the azimuth frequency modulation (FM) rate are addressed. The feasibility of the approach is demonstrated by testing the cross-correlation algorithm on available Seasat data processed with simulated Doppler centroid ambiguity errors. The Seasat analysis is extrapolated to the Radarsat system with favourable results. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Orientador: Maria Aparecida Brenelli Vitali / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-23T23:03:37Z (GMT). No. of bitstreams: 1 AranhaNetto_Abimael_D.pdf: 3767312 bytes, checksum: 673571c251ef3a09f6ab2343a5f16c6f (MD5) Previous issue date: 1998 / Resumo: Resumo: A poli citem ia e hiperviscosidade são morbidades de grande relevância no período neonatal, determinando manifestações clínicas e comprometimento neurológico em grande número de recém-nascidos. Os fatores envolvidos no desencadeamento das alterações neurológicas ainda não foram suficientemente esclarecidos, propiciando controvérsias sobre a oportunidade e eficácia do seu tratamento, principalmente em crianças assintomáticas. Recentemente tem sido investigada a influência do fluxo sangüíneo cerebral na sua fisiopatogenia, embora não existam resultados conclusivos, visto que a quantificação do fluxo cerebral em recém-nascidos é bastante complexa, por incorporar múltiplos elementos decorrentes da adaptação fisiológica propiciado pelo nascimento. Utilizando a ultra-sonografia Doppler, o objetivo do presente estudo foi avaliar a velocidade de fluxo sangüíneo cerebral em recém-nascidos policitêmicos assintomáticos e normocitêmicos e analisar a influência de algumas variáveis perinatais na hemodinâmica cerebral. Estudaram-se prospectivamente 42 recém-nascidos a termo atendidos no Serviço de Neonatologia do CAISM-UNICAMP, sendo 25 normocitêmicos e 17 policitêmicos. Com 1, 2, 12 e 24 horas de vida, foram realizadas mensurações da velocidade de fluxo cerebral através de ultra-sonografia Doppler em artéria cerebral anterior e calculados a resistência vascular periférica, a "hindrance" vascular e o transporte de células vermelhas. No mesmo período foram medidos hematócrito, viscosidade e pC02 venosos. Através de monitorização não invasiva também foram determinadas a pressão arterial e freqüência cardíaca. Os resultados demonstraram que as medidas ae velocidade de fluxo cerebral foram significativamente mais baixas nos recém-nascidos policitêmicos, exceto o índice de resistência de Pourcelot, que não mostrou diferenciação entre os grupos. A resistência vascular cerebral foi aumentada nos policitêmicos, sem modificação relativa da geometria vascular, porém o transporte de células vermelhas não apresentou diferença significativa entre os grupos. Os valores de velocimetria Doppler aumentaram significativamente entre a 23 e 243 horas de vida, acompanhados por diminuição paralela da resistência periférica. Estas variações coincidiram com as modificações do hematócrito e da viscosidade sangüínea, que apresentaram diminuição significativa no mesmo período. A análise de regressão simples mostrou que os valores de viscosidade sangüínea foram inversamente relacionados ao fluxo em todos os tempos analisados. Os resultados da análise múltipla demonstraram resultados diferentes para cada tempo de vida, embora a relação adequação peso/idade e a presença/ausência de policitemia tenham permanecido como as variáveis mais constantes como preditoras da velocidade de fluxo no período estudado, com os valores de viscosidade sendo incorporados ao modelo de predição somente a partir da 128 hora de vida. Concluiu-se que no primeiro dia de vida houve uma variação significativa da velocidade de fluxo e da resistência vascular cerebral, tendo as medidas ultra-sonográficas de velocidade, exceto o I.R., apresentada diferenciação significativa entre recém-nascidos policitêmicos e normocitêmicos, embora o transporte de células vermelhas não tenha sido diferente entre eles. A predição de velocidade de fluxo cerebral seguiu um modelo complexo, sendo influenciado de maneira importante pela adequação peso/idade, pela presença/ausência de policitemia neonatal e tendo a variação da viscosidade sangüínea apresentado expressão apenas a partir da 128 horas de vida / Abstract: Abstract: Polycytemia and hyperviscosity are morbidity of high relevance during the neonatal period, leading to clinical events and neurological problems in a great number of newborns. The involved triggering effects on these alterations are not yet well clarified leading to controversies about the opportunity and efficacy of its treatment. Recent studies have investigated the influence of cerebral blood flow in, but until now the results are not conclusive due to the complexity in dealing with multiple elements arising from the delivery physiological adaptation. The objective of this study was to evaluate the cerebral blood flow, using Doppler ultrasound, in normocytemic and asymptomatic polycytemic newborns and to analyze the influence of some neonatal variables in the brain hemodynamics. Forty-two term newborn delivered at the Neonatology Service of CAISM-UNICAMP where investigated, being twenty five normocytemic and seventeen polycytemic. The cerebral blood flow velocity was measured in the anterior cerebral artery at 1,2, 12 and 24 hours of life and from these measurements the vascular cerebral resistance, the vascular "hindrance" and the red cells transport were calculated. At the above mentioned time schedule were collected venous blood samples and measured hematocrit values, viscosity and pC02. U sing non-invasive techniques were also evaluated the mean blood pressure and the cardiac frequency. There was no difference of weight and gestational age between the groups and the blood flow velocities were significantly lower in the polycytemic newborn group, except for the resistance index that did not show difference between the groups. In the group of polycytemics the mean blood pressure and the vascular cerebral resistance were increased without relative modification in the vascular geometry, while the red cells transport did not present significant difference. The blood flow velocity increased significantly from the 2nd until the 24th hours of life for the two groups followed by the parallel decrease of the peripheral resistance. These changes matched with variations in hematocrit and blood viscosity that presented significant decrease. As a conclusion, there is a time significant variation of the blood flow velocity and the cerebral vascular resistance in first day of life and that these values present significant difference between the normo and polycytemic newborns, but the prediction of flow follows a complex model, with important influence from the adequate weight/gestational age and having the variation of blood viscosity influence only after the 12th hour of life / Doutorado / Doutor em Pediatria

Introdução: O Doppler tecidual (DT) surgiu como uma técnica ecocardiográfica para registro das velocidades do miocárdio e evoluiu para a determinação da deformação miocárdica regional com medida do strain rate (SR) e strain longitudinal e radial unidimensionais. Nosso objetivo foi determinar padrões de normalidade em neonatos e analisar seqüencialmente esses índices em períodos de alta e baixa resistência vascular pulmonar. Casuística e Método: Selecionaram-se 55 crianças com idade média de 20,14 ± 14,0 horas, constituindo o Grupo I (G I). Um segundo exame foi realizado em 30 crianças que retornaram após 31,9 ± 2,9 dias de vida, constituindo o Grupo II (G II). As velocidades do DT pulsado foram obtidas em cortes transversais (R) e longitudinais (L) do ventrículo esquerdo (VE) em posições apical 4 e 2 câmaras e no VD (paredes livre e inferior). Foram medidas velocidades sistólicas (onda Sm), diastólica inicial (Em), diastólica final (Am) de pico e a relação Em/Am. Pelo menos três ciclos cardíacos consecutivos com taxa de quadros/s superior a 300 foram digitalmente obtidos nos cortes mencionados e analisados posteriormente utilizando programa específico para medida das curvas de SR/strain e seus componentes sistólico, diastólico inicial e final. Resultados: As velocidades demonstraram gradiente bem definido com redução progressiva na direção base-ápice do coração. As velocidades do VD foram superiores às do VE quando comparadas com as medidas nas paredes septal (S), anterior (A) e lateral (L). No GI verificamos diferença significativa entre as medidas do SR/strain sistólicos do segmento basal da parede S em relação à apical (-1,90 ± 0,61, - 25,90 ± 4,90 vs -1,66 ± 0,25, - 24,23 ± 3,08), p=0,04 e p=0,02 e do segmento médio em relação ao apical (p=0,01 e 0,02). A avaliação regional do VD demonstrou strain sistólico maior no segmento médio em relação ao basal (-33,20 ± 6,34 vs -28,38 ± 4,90, p=0,00) e em relação ao segmento apical (-33,20 ± 6,34 vs -31,95 ± 5,06, p=0,021). Os valores absolutos de SR/strain e todos os seus componentes foram maiores na direção R quando comparados com a L (SR sistólico 2,99 ± 0,78 s-1 vs (-)1,90 ± 0,60 s-1 strain sistólico 49,72% ± 12,86% vs (-) 25,86% ± 4,83 p=0,00). Quando comparamos os GI e GII verificamos redução do strain sistólico do VE na direção R e L nas paredes S, L e A em todos os segmentos. O SR sistólico reduziu apenas na porção basal da parede L (-1,91 ± 0,46 s-1 vs - 1,71 ± 0,33 s-1, p=0,02). O VD apresentou no GII aumento significativo do strain sistólico e diastólico inicial em todos os segmentos e paredes. O SR sistólico também apresentou aumento dos valores nos segmentos basal e médio de sua parede livre e na parede inferior. A correlação entre a onda Sm e SR/strain sistólicos não foi significativa. Conclusão: Os índices regionais de deformação miocárdica constituem técnica clínica reproduzível em neonatos e podem monitorar alterações seqüenciais fisiológicas da circulação neonatal precoce e tardia. São mais robustos que as velocidades na quantificação da função regional. / Background: Color Doppler myocardial imaging (CDMI) has emerged as an echocardiographic technique for determining myocardial velocities and has been further developed to allow the determination of one-dimension regional longitudinal and radial strain rate (SR)and strain. Our goal was to determine normal values in neonates and sequentially analyse these indices in periods of high and low pulmonary vascular resistance. Study population and methods: Fifty-five term newborns with mean age of 20.14 ± 14.0 hours were selected to be part of Group I (GI). A second echo study was performed on 30 children that had returned with 31.9 ± 2.9 days after birth, being Group II (GII). Pulsed wave Doppler tissue velocities (PWDTV) were obtained in short axis (R) and longitudinal (L) axis of the left ventricle (LV) in apical 4 and 2 chamber view and in 4 and 2 chamber of the right ventricle (RV), including RV free lateral and inferior walls. Peak systolic (Sm), peak early diastolic (Em) and peak late diastolic (Am) motion velocities and Em/Am ratio were measured. At least three consecutive cardiac cycles with frame rate more than 300 fps were stored in digital format from the mentioned views for offline analysis by using dedicated software for measuring peak systolic and peak early and late diastolic SR/strain. Results: PWTDV have shown a well-defined gradient with progressive peak reduction from base to apex. RV velocities were higher than those of the LV whem compared to septal (S), anterior (A) and lateral (L) walls. In GI there was a significant difference between systolic SR/strain measurement of basal S segment in relation to apical (-1.90 ± 0.61, -25.90 ± 4.90 vs -1.66 ± 0.25, - 24.23 ± 3.08), p=0.04 e p=0.02 and from the mid in relation to the apical segment (p=0.01 e 0.02). Regional RV longitudinal function showed that systolic strain recorded from the mid segment was significantly higher than that recorded from the basal segment (-33.20 ± 6.34 vs -28.38 ± 4.90, p=0.00) and that from the apical segment (-33.20 ± 6.34 vs ?31.95 ± 5.06, p=0.021). The absolute and all components of SR/strain were significantly higher in R direction when compared to the L ones (systolic SR 2.99 ± 0.78 s-1 vs (-)1.90 ± 0.60 s-1 systolic strain 49.72% ± 12.86% vs (-)25.86% ± 4.83 p=0.00). When comparing data from GI and GII, we noticed reduction of LV systolic strain in the second group for both R and L, in all segments of S, L and A walls. Systolic SR showed reduction of the values in GII only in the basal segment of the L wall (-1.91 ± 0.46 s-1 vs ?1.71 ± 0.33s-1, p=0.02). Regional RV function showed systolic and early diastolic strain significantly higher in all segments of wall in GII. Systolic SR also showed higher values in the basal and mid segments of RV free lateral and inferior wall in GII when comparing to GI. The correlation between peak systolic velocity Sm and peak systolic SR/strain was not significant. Conclusion: Regional myocardial deformation indices are reproducible clinical techniques in neonates and can monitor physiological sequential circulatory changes of the early and late neonatal period. They are more robust than velocities in the quantification of the regional myocardial function.

This thesis proposes a system architecture for a high-data rate mobile Local Multipoint Distribution Service (LMDS) Network. Its goal is to provide a workable "strawman" design that can serve as a basis for further research. The architecture is designed to offer broadband services to train commuters via LMDS. The thesis provides a broad overview of system aspects, such as Doppler shift, modulation selection, and error correction coding. These parameters and others are important in providing a robust design. This thesis discusses a set of criteria that seek the best approach in terms of economical feasibility, throughput capabilities, design complexity, data routing, and robustness in serving multiple mobile units simultaneously. These criteria are examined through link budget analysis, layout designs, and throughput efficiency. System throughput specifications are calculated for services, such as web browsing, email, ftp, and voice services to 100 train commuters. The information rate was 134.4 Mbps. The information rate plus overhead, which includes routing, bit and framing synchronization, and error correction coding, was approximately 201.51 Mbps. Using Carson's rule, the total required bandwidth for downstream transmissions was approximately 263 MHz. This throughput requirement was a criterion in selecting the appropriate system architecture. Three approaches were evaluated: LMDS Infostations, Tower Sites, and Infostations/Tower Sites. Infostations are low-powered wireless cells designed to offer individual pockets of high bandwidth connectivity for broadband services. Tower Sites use switched antenna beams to offer continuous services to train commuters. The hybrid solution, Infostations/Tower Sites, offers continuous services with increased power requirements and increased base stations separation when compared to the Infostation approach. Link budgets were examined for the Infostations and Tower Site approach. The initial required power for the Infostation was 1 mW. A 42.4 dB Eb/No link margin was computed using the Friis equation. The initial required power for the Tower Site approach was 500 mW. A 10.2 dB Eb/No link margin was computed with this approach. Tradeoffs with the non-fixed parameters were made to vary the link margins. An economically feasible number of required units were also determined. Approximately 3,000 low-powered Infostations would be needed to offer continuous service. Only 93 Tower Sites would be required and 4*93 Tower Site/Infostation units would be needed to supply continuous, seamless services over a 230-miles coverage area. The LMDS Tower Site was chosen to be the most suitable approach because of its robustness in meeting the pre-defined criteria. / Master of Science

No description available.