by Ng Chung-sang. / Parallel title in Chinese characters. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaf 101.

Made available in DSpace on 2016-01-26T12:51:24Z (GMT). No. of bitstreams: 1 martagabriel_dissert.pdf: 5511768 bytes, checksum: 5fac42af6982c753eff37d2c54f3fd17 (MD5) Previous issue date: 2010-04-07 / Transcranial Doppler sonography is the technique more designate to detect intracranial hemorrhage (ICH) and periventricular leukomalacia (PVL) among preterm. This technique evidence the most important cerebral arteries, mainly arteries the circle of Willis, obtaining blood flow arteries resistance index (RI), becoming upset in cranial hemorrhage and hypoxic-ischemic injuries. Objectives: 1. Investigate the clinical application of Doppler sonography in detection of cerebral lesions in very low birth weight neonates. 2. Evaluate the prognosis considering severity and death according to the presence of changes in cerebral arteries detected by Doppler in these neonates. Casuistics and Methods: A total of 50 preterm infants with gestational age varying between 29 and 32 weeks (30.8  1.5 weeks) and birth weigh 550 to 1.500g (1.179  288g) were submitted to four transcranial Doppler sonography during the intervals between 1st to 5th day of life, 10th to 17th, 18th to 30th, and 30th to 44th days of life. The preterm was submitted to the anterior and transtemporal fontanelle technique with asepsis care of equipment and operator. Results: Cerebral lesions in 16 (32%) preterm, 11 (22%) cases of intracranial hemorrhage, 4 (8%) of periventricular leukomalacia, and 1(2%) of cerebral toxoplasmosis were detected. The study with Doppler demonstrated that the value of RI varied according to the time of performing exam. The mean value of RI in the anterior, middle, and posterior cerebral arteries of preterm with intracranial hemorrhage (n = 11) increased of the first to third exam. There was a statistically significant difference among mean values of RI of the anterior and posterior cerebral arteries (p = 0.001 and p = 0.043, respectively) of preterm without cerebral lesions and with ICH only the first exam. Conclusions: The transcranial Doppler sonography in very low birth weigth neonates is useful in detection of cerebral lesions as intracranial hemorrhage, periventricular leukomalacia, and cerebral toxoplasmosis. Changes of RI of the anterior, middle, and posterior cerebral arteries detected by Doppler, although nonpredictor of death, are related with severity of the clinical presentation in these neonates. / O ultrassom craniano (USC) com Doppler é o exame mais indicado paradetectar hemorragias intracranianas (HIC) e leucomalácia peri-ventricular (LPV) em prematuros. A técnica com Doppler demonstra os mais importantes ramos da vasculatura cerebral, notadamente as artérias principais do Polígono de Willis, determinando índice de resistência (IR) do fluxo sangüíneo nessas artérias, que pode estar alterado em sangramentos cranianos e eventos hipóxico/isquêmicos. Objetivos: 1. Investigar a aplicação clínica da ultra-sonografia craniana com Doppler na detecção de alterações cerebrais em crianças prematuras de muito baixo peso. 2. Avaliar o prognóstico, considerando gravidade e óbito, de acordo com presença de alterações em artérias cerebrais detectadas por Doppler nesses prematuros. Casuística e Método: Foram estudadas prospectivamente 50 crianças prematuras, com a idade gestacional variando entre 29 e 32 semanas (30,8  1,5 semanas) e peso ao nascimento de 550 a 1.500 g (1.179  288g). Todas foram submetidas a quatro exames de USC com Doppler, sendo o primeiro entre o 1º e 5º dia de vida, o segundo entre 10º e 17º, o terceiro entre 18º e 30º e o quarto entre 30º e 44º dia de vida. Os pacientes foram submetidos à técnica transfontanela anterior e transtemporal, com todos os cuidados em assepsia do aparelho e operador. Resultados: Foram detectadas alterações cerebrais em 16 (32%) crianças, sendo 11 (22%) casos de HIC, 4 (8%) de LPV e 1 (2%) de toxoplasmose cerebral. O estudo com Doppler apresentou valores do índice de resistência (IR), que variaram dependendo da época da realização dos exames. O valor médio do IR nas artérias cerebrais anterior, média e posterior das crianças com HIC (n = 11) aumentou do primeiro ao terceiro exame. Houve diferença estatisticamente significante entre valores médios de IR das artérias cerebrais anterior e posterior (p=0,001 e p=0,043, respectivamente) de crianças sem alterações cerebrais e com HIC apenas no primeiro exame. Conclusões - A ultrassonografia craniana com Doppler em RN prematuras de muito baixo peso é de grande valia na detecção de alterações cerebrais como hemorragia intracraniana, leucomalácia periventricular e toxoplasmose cerebral. Alterações no IR das artérias cerebrais anterior, média e posterior detectadas pelo Doppler, embora não preditoras de morte, estão relacionadas com a gravidade do quadro clínico em crianças prematuras de muito baixo peso.

Orientador: Luiz Carlos Marques / Banca: Lindsay Unno Gimenez / Banca: Cezinande Meira / Banca: Gilson Hélio Toniollo / Banca: Lúcia Helena Rodrigues / Resumo: O Brasil possui o maior rebanho bovino comercial do mundo e chegou a 212,8 milhões de cabeças em 2011. Foram comercializadas 12,3 milhões de doses de sêmen bovino em 2012. O efetivo de fêmeas bovinas em idade reprodutiva é 61,4 milhões e a utilização de duas doses de sêmen por vaca estima-se que 10% do rebanho nacional está sendo inseminado. A fertilidade é uma importante característica nos sistemas produtivos e o macho de grande importância. Utilizando a termografia infravermelha (TIV) e ultrassonografia Doppler a termorregulação e o fluxo sanguíneo foram avaliados em touros. Dois grupos de seis touros foram avaliados por um ano e os dados obtidos da termografia - temperatura global do plexo (TGP), temperatura global do escroto (TGE), temperatura do plexo esquerdo (TPE), temperatura do plexo direito (TPD), temperatura do escroto esquerdo (TEE), temperatura do escroto direito (TED) e da ultrassonografia Doppler - velocidade sistólica máxima (VSM), velocidade diastólica final (VDF), índice de pulsatilidade (IP), índice de resistência (IR) e a temperatura ambiental (TA) foram correlacionados com os espermogramas. Foram observadas correlações positivas e negativas entre as variáveis da TIV e US Doppler com as variáveis dos espermogramas e conclui-se que a TIV permite a observação de alterações precoces da temperatura do plexo e escroto; a US Doppler demonstrou correlações entre a VDF, IR e IP com qualidade do sêmen; de acordo com este estudo touros com qualidade de sêmen superior apresentaram menor impedância vascular das artérias testiculares / Abstract: Brazil has the largest commercial cattle herd in the world and reached 212,8 million head in 2011. 12,3 million doses of bovine semen were sold in 2012. Effective from cows of reproductive age is 61,4 million and the use of two doses of semen per cow is estimated that 10 % of the national herd is being inseminated. Fertility is an important feature in production systems and the bull has great importance. Using infrared thermography (IRT) and Doppler ultrasonography thermoregulation and blood flow were evaluated in bulls. Two groups of six bulls were evaluated for a year and the data of thermography - global temperature plexus (GTP), global temperature of the scrotum (GTE), temperature of the left plexus (TLP), temperature of the right plexus (TRP), temperature the left scrotum (TLE), temperature of the right scrotum (TRE) and Doppler ultrasonography - peak systolic velocity (PSV ), end diastolic velocity (EDV), pulsatility index (PI), resistance index (RI) and room temperature (RT) were correlated with semen analyzes. Positive and negative correlations were found between the variables of IRT and US Doppler variables of semen analyzes and concludes that IRT allows observation of early changes of the plexus and scrotal temperature; Doppler US demonstrated correlations between EDV, RI and IP with semen quality; according to this study bulls with superior quality of semen showed lower vascular impedance of the testicular arteries / Doutor

Made available in DSpace on 2014-06-11T19:31:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-27Bitstream added on 2014-06-13T20:01:22Z : No. of bitstreams: 1 inoue_rm_dr_botfm.pdf: 589090 bytes, checksum: ea16d419cf739717f9304922ab4c9de5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cirrose hepática é definida como um processo difuso de fibrose intersticial associada à formação de nódulos regenerativos e à modificação na fígado, a repercussão da cirrose hepática é sistêmica. Assim, na fase avançada da doença são descritas alterações cerebrais como a encefalopatia hepática, renais ..• como a síndrome hepato-renal, pulmonares como a síndrome porto-pulmonar e cardíacas como a cardiomiopatia cirrótica. Os objetivos do trabalho são caracterizar as alterações hemodinâmicas e cardíacas de pacientes com cirrose hepática e verificar se houve evidência de cardiomiopatia própria da cirrose hepática. Foram estudados 66 pacientes portadores de cirrose hepática (CH), sendo 54 (82 %) homens e 12 (18 %) mulheres. O grupo controle (CONT) foi constituído de 32 indivíduos sadios, sendo 21 (66 %) homens e 11 (34 %) mulheres. Os indivíduos foram submetidos a exames clínicos e cardíacos por meio de doppler-ecocardiograma. As variáveis estudadas foram analisadas pelo teste ANOVA de duas vias considerando-se os fatores sexo (Masc e Fem) e grupo (CH e CONT) seguido pelo teste de comparações múltiplas de Tukey ao nível de significância de 0,05. As médias e desvios padrões das idades (anos) foram: CH Masc = 49 ± 10; CH Fem = 47 ± 14; CONT Masc = 52 ± 9; CONT Fem = 53 ± 8. Não foram observadas diferenças estatisticamente significantes entre os grupos, quanto a idade. As variáveis... / Cirrhosis is a liver disease characterized by diffuse interstitial fibrosis associated with, regenerative nodules and with intra-hepatic circulation changes. Although the primary damage occurs in the liver, cirrhosis is associated with systemic repercussions. For instance, in the advanced stages of the disease, it has been are described hepatic encephalopatphy syndrome, renal failure such as that accompany the hepato-renal syndrome, pulmonary hypertension observed in portopulmonary syndrome and cardiac alterations. The presence of a specific cardiomyopathy related to the cirrhosis is a matter of controversy. The present study was undertaken to evaluete the cardiac and hemodynamic alterations in patientes suffering from hepatic cirrhosis to analyse the evidence of cirrhotic cardiomyopathy... (Complete abstract click electronic access below)

Tese de mestrado integrado. Engenharia Civil - Hidráulica. Faculdade de Engenharia. Universidade do Porto. 2012

<p>Ultralyd er i dag et standardverktøy innen hjertediagnostikk. Analyse av ventrikkelfunksjon gjøres subjektivt ved å se på gråskala ultralydopptak av hjertet. Dette gjør dokumentasjon og opplæring vanskelig. Det er derfor ønskelig med kvantitative mål på ventrikkelfunksjon. Kvantitative metoder kan benytte høy tidsoppløsning og dermed også registrere flere detaljer.</p><p>To teknikker for kvantitativ ventrikkelanalyse er vevs-Doppler og speckle tracking (mønsterfølging). Ved bruk av disse teknikkene er det viktig å sikre kvaliteten av resultatene samtidig som analyseprosessen kan gjennomføres så effektivt som mulig. I denne avhandlingen presenteres flere metoder for å sikre kvalitet og øke effektivitet ved kvantitativ ventrikkelanalyse som alle er relatert til bruk av høy tidsoppløsning.</p><p>For å kunne gjøre effektiv ventrikkelanalyse behøves analyseverktøy. Et slikt verktøy som fungerer med både vevs-Doppler og speckle tracking presenteres i denne avhandlingen. Dette verktøyet har gjort flere store kliniske studier mulig. Ved analyse av hendelsene som skjer innen en hjertesykel er det viktig å dele opp hjertesykelen i ulike faser. Venstre ventrikkels tømmingsfase avsluttes ved at aortaklaffen lukkes, og denne hendelsen må derfor bestemmes før kvantitative parametre i slutten av tømmingsfasen og i overgangen til fyllingsfasen kan bestemmes. I denne avhandlingen vurderes og testes ulike kandidater for bestemmelse av lukkingen. To gunstige kandidater i hastighetskurver fra basale deler av ventrikkelen ble funnet: andre nullkryssing etter tømming og høyeste positive akselerasjon etter tømming før fylling. Et eget bidrag viser at den siste av disse kan bestemmes automatisk. For å oppnå høy tidsoppløsning kreves høy datarate. En populær metode for å øke datarate er flere parallelle mottaksstråler for hver sendestråle. I vanlig gråtoneavbilding av hjertet er det imidlertid observert at dette medfører uønskede linjelignende strukturer i bildet. I denne avhandlingen vises det at årsaken til dette er at de parallelle strålene deformeres når de passerer strukturene mellom hjertet og proben. Avhandlingen inneholder også et bidrag som viser hvordan bruk av parallelle mottakstråler kan medføre at vevs-Doppler kurver blir hentet fra et annet sted i hjertet enn det intensjonen var. Samlet er avhandlingen et bidrag til fortsatt utvikling og forbedring av kvantitative ultralydmetoder innen hjertediagnostikk.</p>

The hydrodynamics of an agitated tank have been studied byphase-Doppler anemometry. The focus is on the impeller anddischarge region of a 45o pitched blade turbine (PBT). Thestudy includes agitation of pure water as well as of a dilutesuspension of process particles. A three-dimensionalphase-Doppler anemometer is used to measure local,instantaneous, three-dimensional velocities of the fluid and ofthe suspended particles. A shaft encoding technique is used toresolve the turbulent fluctuations from the periodic velocityfluctuation due to the impeller blades, and to provide moredetailed information about the variations relative to theimpeller blade. Velocity bias is corrected for by the total3-dimensional velocity. The mean flow field, the fluctuating velocities, and thecomplete Reynolds stress tensor, are reported for the liquidphase flow. The periodic fluctuations in the flow that aregenerated by the impeller blades are eliminated in theexamination of the turbulence. The anisotropy of the turbulenceis assessed by the invariants of the anisotropy tensor. Thetrailing vortex structure is demonstrated to be associated withhigh kinetic energy and strong anisotropy of the turbulence.The vortex is still observable 130-140 degrees behind theblade. It gradually moves down from the impeller blade but thelocation in radial direction remains essentially unchanged. Theinfluence of the periodic fluctuations is examined and it isshown that the turbulence appears more isotropic when theperiodic fluctuations are not eliminated. The solid particle concentration is low below the impellerand is high above the impeller tip. The particles diverge fromthe liquid flow mean direction, especially below the agitatorclose to the tip where the strongest turbulence is found.Periodic fluctuations in the particle concentration relate tothe variations found in the angle-resolved mean velocity andfluctuating velocity. The ratio of the maximum to the minimumconcentration is about 2.0 in the present study. The baffles influence on the conditions in the impellerregion, and this influence can be observed on the fluid meanvelocity field, the angle-resolved velocities, the kineticenergy, and on the behavior of larger process particles. In theimpeller region the highest kinetic energies are about 15%higher upstream of the baffle than at the middle plane betweenthe baffles. The highest energy level in the middle plane isactually the lowest value and is therefore not representativewhen rotation symmetry is assumed. Local energy dissipation rates have been investigated, andthe integration of the local energy dissipation rates overdifferent control volumes has been compared with macroscopicenergy balance calculations. The discrepancy is significant.Different reasons have been analyzed and recommendations forfurther investigation are given. I n the outflow region there is a significant variation alsoin the direction of the instantaneous velocity, which may leadto direction bias in the case of non-spherical measurementvolume. In order to account for this direction bias, amathematical model is developed to estimate the projected areaof the measurement volume in LDA or PDA. It is shown that theprojected area variation can lead to a significant directionbias in determination of time averaged values and localparticle concentration in a highly turbulent stirred tank flow.This bias is however negligible for an orthogonal optical setup, as is used in the present study. <b>Keywords:</b>Hydrodynamics, phase-Doppler anemometer,suspension, pitched-blade turbine, anisotropy, turbulence,Reynolds stresses, trailing vortex, kinetic energy, stirredtank

Ultralyd er i dag et standardverktøy innen hjertediagnostikk. Analyse av ventrikkelfunksjon gjøres subjektivt ved å se på gråskala ultralydopptak av hjertet. Dette gjør dokumentasjon og opplæring vanskelig. Det er derfor ønskelig med kvantitative mål på ventrikkelfunksjon. Kvantitative metoder kan benytte høy tidsoppløsning og dermed også registrere flere detaljer. To teknikker for kvantitativ ventrikkelanalyse er vevs-Doppler og speckle tracking (mønsterfølging). Ved bruk av disse teknikkene er det viktig å sikre kvaliteten av resultatene samtidig som analyseprosessen kan gjennomføres så effektivt som mulig. I denne avhandlingen presenteres flere metoder for å sikre kvalitet og øke effektivitet ved kvantitativ ventrikkelanalyse som alle er relatert til bruk av høy tidsoppløsning. For å kunne gjøre effektiv ventrikkelanalyse behøves analyseverktøy. Et slikt verktøy som fungerer med både vevs-Doppler og speckle tracking presenteres i denne avhandlingen. Dette verktøyet har gjort flere store kliniske studier mulig. Ved analyse av hendelsene som skjer innen en hjertesykel er det viktig å dele opp hjertesykelen i ulike faser. Venstre ventrikkels tømmingsfase avsluttes ved at aortaklaffen lukkes, og denne hendelsen må derfor bestemmes før kvantitative parametre i slutten av tømmingsfasen og i overgangen til fyllingsfasen kan bestemmes. I denne avhandlingen vurderes og testes ulike kandidater for bestemmelse av lukkingen. To gunstige kandidater i hastighetskurver fra basale deler av ventrikkelen ble funnet: andre nullkryssing etter tømming og høyeste positive akselerasjon etter tømming før fylling. Et eget bidrag viser at den siste av disse kan bestemmes automatisk. For å oppnå høy tidsoppløsning kreves høy datarate. En populær metode for å øke datarate er flere parallelle mottaksstråler for hver sendestråle. I vanlig gråtoneavbilding av hjertet er det imidlertid observert at dette medfører uønskede linjelignende strukturer i bildet. I denne avhandlingen vises det at årsaken til dette er at de parallelle strålene deformeres når de passerer strukturene mellom hjertet og proben. Avhandlingen inneholder også et bidrag som viser hvordan bruk av parallelle mottakstråler kan medføre at vevs-Doppler kurver blir hentet fra et annet sted i hjertet enn det intensjonen var. Samlet er avhandlingen et bidrag til fortsatt utvikling og forbedring av kvantitative ultralydmetoder innen hjertediagnostikk.

The use of transcranial Doppler (TCD) ultrasound for the assessment of cerebral blood flow velocity (CBFV) provides an indication of cerebral blood flow assuming the diameter of the insonated vessel remains constant. Studies using TCD have traditionally described cerebrovascular hemodynamics with respect to CBFV and cerebrovascular resistance (CVRi); however, a more complete assessment of the cerebral circulation can be gleaned from the analysis of within beat characteristic of the TCD velocity waveform for the determination of cerebrovascular tone. Therefore, the general purpose of the presented studies was to assess CBFV responses and within beat characteristic for the description of cerebrovascular hemodynamics after long duration spaceflight, with sustained orthostasis, in response to changes in the partial pressure of end tidal carbon dioxide (PETCO2), and with NG stimulation. After long duration spaceflight, cerebrovascular autoregulation was found to be impaired along with a reduction in cerebrovascular CO2 reactivity (Study 1). Additionally, critical closing pressure (CrCP) was found to be increased suggesting potential remodelling of the cerebrovasculature contributing to an increase in cerebrovascular tone (Study 2). With sustained orthostasis, CBFV was found to progressively decrease and to be related to reductions in PETCO2 and increases in CrCP suggesting the contribution of changes in cerebrovascular tone leading to the development of syncope (Study 4). The CBFV reduction with the progression towards syncope was also associated with changes in waveform morphology such that the dicrotic notch point was less than the end diastolic value (Study 3). Mathematical modelling (RCKL) was used to further assess changes in cerebrovascular hemodynamics for physiological interpretation of changes in CBFV waveform morphology and found that the amplitude of the dicrotic notch and the calculation of the augmentation index were both significantly related to vascular compliance before and after stimulation with NG (Study 5). The use of quantitative assessments of common carotid artery (CCA) blood flow as an indicator of cerebral blood flow suggested the dilation of the middle cerebral artery (MCA) with NG (Study 5 and 6) and changes in MCA diameter with acute alterations in PETCO2 (Study 6). CCA and MCA velocity wave morphology were assessed showing that with changes in PETCO2, changes in CBFV velocity wave were not reflected in the CCA trace (Study 7). In addition, further assessment of the CBFV velocity trace and the calculation of CrCP and the augmentation index suggested that with changes in PETCO2 cerebrovascular compliance and cerebrovascular tension, both thought to be components of cerebrovascular tone, change independently (Study 7). Combined, the results of the presented studies suggest that changes in cerebrovascular hemodynamics can be determined from alterations in the CBFV velocity waveform morphology. However, further work is required to determine how these variations relate to specific components of cerebrovascular tone, including alterations in cerebrovascular compliance and vascular tension, and how these variables change with acute and chronic alterations in cerebrovascular hemodynamics.

Individuals with severe physical impairments have a reduced ability to communicate through movement and speech. We investigated transcranial Doppler ultrasound as a potential measurement modality for a novel brain-computer interface. It was hypothesized that cognitive activity would result in detectable changes in cerebral blood flow velocity within the middle cerebral arteries. Nine able-bodied participants alternated between rest and two different mental activities - silent word generation and mental rotation. Two analyses were performed to assess the feasibility and practicality of a TCD-based brain-computer interface. Both mental activities were independently differentiated from rest with high accuracy. Intuitive time-domain features were sufficient for classification. Data transmission rate was quadrupled by differentiating all three classes simultaneously using shorter state durations. Transcranial Doppler ultrasound can be used to automatically detect cognitive activity and may be useful as the basis of a brain-computer interface.