• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 74
  • 5
  • 1
  • 1
  • Tagged with
  • 81
  • 68
  • 12
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Ultrazvukový anemometr / Ultrasonic anemometer

Hůlka, Jakub January 2015 (has links)
This master’s thesis deals with the construction and realization of an ultrasound anemo- meter. Individual types of anemometers are compared in this thesis, including mechanical, thermo anemometer and ultrasound anemometer. Different construction renderings and measurement principles of ultrasonic anemometers are analyzed. In addition, an experi- mental method of measuring the speed of sound by phase shift between two transmitting frequency is described in the document. This thesis includes the design of an control unit and the realization of a simple prototype of an ultrasonic anemometer. Experimental confirmation of the characteristics of the ultrasound anemometer is the last part of the document.
22

Bezkontaktní měření v procesním inženýrství / Contactless measuring in process engineering

Lavický, Jiří January 2010 (has links)
The objective of my thesis is description of contactless measuring methods, their principle and distribution. There are compiled basic facts about the measurement of laser and ultrasound. In this work is also described non-contact temperature measurement. Part of thesis is non-contact flow measurement on the model.
23

Proudění kapaliny mezi dvěma paralelními deskami, srovnání měření a analytického řešení. / The Fluid Flow Between Two Paralel Plates, the Comparison Between the Measruring and The Analytical Solution.

Kárník, Jan January 2013 (has links)
This master's thesis is focused on measurement of the velocity profiles in liquids using ultrasound. The thesis describes two executed measurements both in the channel with free surface, both in the square shaped pipe. In the introductory part this work deals with clarifying the theoretical fundamentals associated with the measurement method UVP such as the Doppler effect, the speed of sound in the medium or the acoustic impedance of the environment. The next part describes the execution of the velocity profile measurement in the channel with free surface described and there is also the description of the results achieved during this measurement. In the last part the thesis deals with the measurement of the velocity profile in the square shaped pipe. There is also the comparison between the measured velocity profiles and the velocity profiles calculated using the analytical formula. In the conclusion there is the evaluation of achieved results.
24

Design lékařského ultrazvukového přístroje / Design of Medical Ultrasound Diagnostic Machine

Nováková, Monika January 2016 (has links)
The topic of this master’s thesis is design of a medical ultrasound diagnostic machine. The thesis focuses on a new perspective on composition and shaping of the ultrasound machine while respecting technical and ergonomic requirements. The goal of this thesis is addition of an aesthetic value and incorporation of new technologies so the product is able to compete on the current market.
25

Souvislost morfologie svalů břišní stěny s bolestmi zad u elitních hráček florbalu / The relationship between morphology of abdominal wall muscles and back pain in elite floorball players

Kramperová, Adéla January 2021 (has links)
The diploma thesis evaluates the morphology of the abdominal wall muscles focusing on the assessment of lateral symmetry in elite female floorball players and its relationship with the occurrence of back pain in these players. The theoretical part of the thesis includes an overview of the physiological mechanisms of postural stabilization in comparison with deviations in patients with back pain and describes the principles of sonographic examination and its use in physiotherapy. The theoretical part is also focused on the imagining of the abdominal muscles and the summary of specific findings in floorball players and other athletes, with a predominant one-sided load related to the biomechanics of movement in these sports. Methodology: A total of 20 female players of the highest floorball competition in the Czech Republic participated in this research. The linear parameters of the abdominal muscles (m. RA, m. TrA, m. OI and m. OE) and the whole lateral abdominal muscles were measured in players on both sides at rest using sonography. The participants also filled in an electronic questionnaire evaluating back pain. Results: Significant lateral asymmetry of linear parameters of abdominal muscles was demonstrated in the work (p = 0,017; d = 0,52). The relationship between the lateral asymmetry and the...
26

Význam ultrazvukového vyšetření v managementu experimentální transplantace dělohy / The Significance of Ultrasound Examination in the Management of Experimental Uterine transplantation

Matěcha, Jan January 2021 (has links)
The significance of ultrasound examination in the management of experimental uterine transplantation Abstract Uterine transplantation (UTx) represents a new experimental method of treatment of absolute uterine factor infertility (AUFI), which includes inability to conceive and deliver as a result of absence of the uterus. This can be congenital (Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS)) or acquired (after hysterectomy, severe congenital uterine malformations). For a woman affected this way is the uterine transplantation the only way to give birth to a child by herself. This is a very sophisticated and invasive procedure for the treatment of sterility with promising results, but the woman - recipient of the uterus - is burdened by at least three abdominal surgeries (transplantation, Caesarean section, explantation), in vitro fertilization and by the need to use immunosuppressive therapy. The dissertation summarizes current knowledge on this issue from the perspective of a gynecologist-obstetrician, who regularly examined by ultrasound or gynecologically participants in the Czech uterine transplant study in 2016-2019, which was carried out on the basis of a cooperation agreement between two Prague hospitals - IKEM and FN Motol. The set contains data on ten patients with a transplanted uterus, five from...
27

Nové oblasti aplikace ultrazvuku v mikroelektronických technologiích / New Areas of the Ultrasonic Application in Microelectronics Technology

Buršík, Martin January 2014 (has links)
Doctoral thesis deals with the deposition of special thixotropic materials for microelectronic technology. The aim of the work is the development of the new method optimizing the dosing process in order to achieve a print resolution of better than 100 microns. The work includes the development of a special dispensing head (UZD) using the influence of ultrasonic energy. These results demonstrate the possibility of a newly developed method that is able to print thixotropic materials with a resolution of 65 microns. Compared to other methods achieves these results with the commonly used materials for thick film technology with particle size up to 5 microns.
28

Korelacija ultrazvučnih karakteristika ateroskleroze karotidnih arterija i prisustva kardiometaboličkih faktora rizika kod bolesnika sa ishemijskim moždanim udarom / The correlation of ultrasound characteristics of carotid atherosclerosis and the presence of cardiometabolic risk factors in the patients with ischemic stroke

Živanović Željko 04 December 2015 (has links)
<p>UVOD: Ateroskleroza je najče&scaron;ća bolest karotidnih arterija i uzrok je oko 20% svih ishemijskih moždanih udara (IMU). Osim stepena stenoze i određene karakteristike karotidnog plaka označavaju povi&scaron;en rizik za IMU. Ultrazvukom je moguće pouzdano evaluirati aterosklerotske promene na karotidnim arterijama. Iako su faktori rizika (FR) za aterosklerozu istovremeno i FR za IMU, prisustvo identičnih FR kod pacijenata sa IMU, ne znači i prisustvo istog stepena ateroskleroze na karotidnim arterijama. CILJ: Utvrđivanje povezanosti pojedinih ultrazvučnih karakteristika karotidne ateroskleroze, sa prisustvom različitih kardiometaboličkih FR i njihovih biomarkera, kod pacijenata sa IMU. MATERIJAL I METODE: U istraživanje je uključeno 120 pacijenata sa nekardioembolijskim IMU u karotidnom slivu koji su podeljeni u dve grupe; 60 sa lakunarnim i 60 sa nelakunarnim infarktom mozga. Svim pacijentima je određivano prisustvo FR, kao &scaron;to su hipertenzija, dijabetes, hiperlipoproteinemija, pu&scaron;enje, gojaznost, metabolički sindrom, hiperhomocisteinemija i inflamacija. Beležene su vrednosti krvnog pritiska, glikemije, glikoliziranog hemoglobina, parametara lipidskog statusa, apolipoproteina (Apo) A-I i B, lipoproteina a, indeksa telesne mase (BMI), homocisteina, C reaktivnog proteina (CRP). Pomoću karotidnog dupleks ultrazvuka određivane su vrednosti intima-medijalnog zadebljanja (IMT), morfologija plaka, povr&scaron;ina plaka, stepen stenoze. Demografske karakteristike, FR i njihovi biomarkeri, te ultrazvučne karakteristike karotidne ateroskleroze, poređene su između dve grupe pacijenata. Kori&scaron;ćeni su hi-kvadrat test i t-test. Korelacije FR i vrednosti njihovih biomarkera sa različitim karakteristikama karotidnog plaka, određivane su upotrebom Pearsonovog koeficijenta korelacije r i Kramerovog V. Upotrebom regresionih analiza ispitivan je prediktivni značaj određenih FR i njihovih biomarkera u pojavi pojedinih karakteristika karotidnog plaka. REZULTATI: Vi&scaron;e pacijenata sa lakunarnim infarktom je imalo hipertenziju (98.3% naspram 85%; p=0.021). Pacijenti sa lakunarnim infarktom imali su veće vrednosti BMI (27.6 kg/m2 naspram 25.9 kg/m2; p=0.029), dok su pacijenti sa nelakunarnim infarktom imali veće vrednosti CRP (16.4 mg/l naspram 6.8 mg/l; p=0.001). Demografske karakteristike, ostali FR i njihovi biomarkeri, kao i vrednosti karotidnog IMT se nisu značajno razlikovali između dve grupe pacijenata. Pacijenti sa nelakunarnim infarktom su imali veći stepen karotidne stenoze (79.7% naspram 33.2%; p=0,0001), kao i če&scaron;će prisustvo heterogenog plaka (73.3% naspram 35%; p&lt;0,001), hipoehogenog plaka (51.7% naspram 16.7%; p&lt;0.001) i neravnog plaka (81.7% naspram 21.7%; p&lt;0,001). Sa vrednostima IMT značajno (p&lt;0.05) su korelirali životna dob pacijenata (r=0.276), dijabetes (Cramerovo V=0.236), metabolički sindrom (Cramerovo V=0.247), HDL holesterol (r=-0.254), LDL/HDL (r=0.306), ApoA-I (r=-0.386) i ApoB/ApoA-I (r=0.359). Sa prisustvom heterogenog plaka su korelirali metabolički sindrom (Cramerovo V=0.246), ApoB (r=0.213), ApoB/ApoA-I (r=0.207) i povi&scaron;en CRP (Cramerovo V=0.266). Sa neravnom povr&scaron;inom plaka značajno je korelirao povi&scaron;en CRP (Cramerovo V=0.283). Sa stepenom stenoze značajno su korelirali BMI (r=-0.180) i povi&scaron;en CRP (Cramerovo V=0.301). Nezavisni prediktori povi&scaron;enih vrednosti IMT bili su starija životna dob pacijenata (&beta;=0.230; p=0.006), ApoA-I (&beta;=-0.244; p=0.008) i ApoB/ApoA-I (&beta;=0.247; p=0.007). Prediktori prisustva heterogenog plaka bili su mu&scaron;ki pol (p=0.011; OR=3.425), ApoB (p=0.007; OR=8.972), BMI (p=0.0001; OR=0.380), metabolički sindrom (p=0.003; OR=4.555) i povi&scaron;en CRP (p=0.018; OR=2.800). Prediktori prisustva hipoehogenog plaka bili su ApoB (p&lt;0.001; OR=29.2), BMI (p=0.02; OR=0.514), metabolički sindrom (p&lt;0.001; OR=9.224) i povi&scaron;en CRP (p=0.046; OR=2.659). Povi&scaron;en CRP bio je jedini prediktor prisustva neravnog plaka (p=0.002; OR=3.203), kao i prisustva većeg stepene karotidne stenoze (&beta;=0.270; p=0.002). ZAKLJUČAK: Iako je karotidna stenoza znatno zastupljenija među pacijenatima sa nelakunarnim nego lakunarnim nekardioembolijskim IMU, prisustvo kardiometaboličkih FR, njihovih biomarkera i vrednosti IMT se bitno ne razlikuje između ove dve grupe pacijenata. Osim stenoze i prisustvo heterogenog, hipoehogenog i neravnog karotidnog plaka nosi povi&scaron;en rizik za IMU. Među FR i njihovim biomarkerima ApoA-I i ApoB su najbolji prediktori karotidne ateroskleroze. Apolipoprotein B i metabolički sindrom su najjače povezani sa prisustvom heterogenog i hipoehogenog plaka. Povi&scaron;en CRP kod pacijenata sa akutnim IMU može biti znak destabilizacije plaka i ukazivati na prisustvo signifikantne karotidne stenoze.</p> / <p>INTRODUCTION: Atherosclerosis is the most common disease of carotid arteries, causing 20% of all ischemic strokes. Besides the degree of stenosis, certain characteristics of carotid plaques indicate an increased risk for stroke. Carotid ultrasound can reliably evaluate atherosclerotic changes in carotid arteries. Although the risk factors for atherosclerosis are the same as the risk factors for stroke, the presence of identical risk factors in patients with stroke does not necessarily mean the presence of the same degree of carotid atherosclerosis. AIM: To determine correlation of certain characteristics of carotid atherosclerosis detected by ultrasound with the presence of various cardiometabolic risk factors in patients with ischemic stroke. METHODS: The study included 120 patients with noncardioembolic ischemic stroke in the anterior circulation, who were divided into two groups; 60 with lacunar and 60 with nonlacunar brain infarction. The presence of cardiometabolic risk factors, such as hypertension, diabetes, hyperlipoproteinemia, smoking, obesity, metabolic syndrome, hyperhomocysteinemia, and inflammation, was evaluated in all patients. Data regarding blood pressure, glycemia, glycated hemoglobin, lipid status parameters, apolipoprotein (ApoAI and ApoB), lipoprotein a, body mass index (BMI), homocysteine, and C-reactive protein (CRP) were collected. Intima-media thickness (IMT), carotid plaque characteristics (morphology, surface) and the degree of stenosis were determined by carotid duplex ultrasound. Demographic characteristics, risk factors, biomarkers, as well as ultrasound characteristics of carotid atherosclerosis, were compared between patients with lacunar and nonlacunar stroke. Two-sample student t-test and &chi;2 test were used for comparisons. In order to assess the correlation of various risk factors and their biomarkers with different characteristics of carotid plaques, we used the Pearson correlation coefficient r and Cramer&#39;s V. Regression analysis was used to evaluate the association of risk factors and their biomarkers with various carotid atherosclerosis characteristics. RESULTS: More patients with lacunar stroke had hypertension (98.3% vs. 85%; p=0.021). Patients with lacunar stroke had higher BMI values (27.6 kg/m2 vs. 25.9 kg/m2; p=0.029), while patients with nonlacunar stroke had higher CRP values (16.4 mg/l vs. 6.8 mg/l; p=0.001). Demographic characteristics, other risk factors and their biomarkers, as well as carotid IMT were not significantly different between the two groups of patients. Patients with nonlacunar stroke had a higher degree of carotid stenosis (79.7% vs. 33.2%; p=0.0001) and a higher prevalence of heterogeneous plaques (73.3% vs. 35%; p&lt;0.001), hypoechogenic plaques (51.7% vs. 16.7%; p&lt;0.001), and plaques with irregular surface (81.7% vs. 21.7%; p&lt;0,001). IMT was significantly (p&lt;0.05) correlated with the age of patients (r=0.276), diabetes (Cramer&rsquo;s V=0.236), metabolic syndrome (Cramer&rsquo;s V=0.247), HDL cholesterol (r=-0.254), LDL/HDL (r=0.306), ApoA-I (r=-0.386) and ApoB/ApoA-I (r=0.359). The presence of a heterogeneous plaque was correlated with metabolic syndrome (Cramer&rsquo;s V=0.246) ApoB (r=0.213), ApoB/ApoA-I (r=0.207) and elevated CRP (Cramer&rsquo;s V=0.266). A plaque with irregular surface was correlated with elevated CRP (Cramer&rsquo;s V=0.283). The degree of carotid stenosis was correlated with BMI (r=-0.180) and elevated CRP (Cramer&rsquo;s V=0.301). The independent predictors of higher values of IMT were older age (&beta;=0.230; p=0.006), ApoA-I (&beta;=-0.244; p=0.008), and ApoB/ApoA-I (&beta;=0.247; p=0.007). The predictors of the presence of a heterogeneous plaque were male gender (p=0.011; OR=3.425), ApoB (p=0.007; OR=8.972), BMI (p=0.0001; OR=0.380), metabolic syndrome (p=0.003; OR=4.555) and elevated CRP (p=0.018; OR=2.800). The predictors of the presence of a hypoechogenic plaque were ApoB (p&lt;0.001; OR=29.2), BMI (p=0.02; OR=0.514), metabolic syndrome (p&lt;0.001; OR=9.224) and elevated CRP (p=0.046; OR=2.659). Elevated CRP was the only independent predictor of a plaque with irregular surface (p=0.002; OR=3.203) and of a higher degree of carotid stenosis (&beta;=0.270; p=0.002). CONCULSIONS: Although carotid stenosis is significantly more pronounced in patients with nonlacunar than those with lacunar noncardioembolic ischemic stroke, cardiometabolic risk factors, their biomarkers and carotid IMT do not differ significantly between the two groups of patients. In addition to stenosis, a presence of heterogeneous, hypoechogenic and irregular-surface carotid plaques indicates an increased risk for ischemic nonlacunar stroke. Among the cardiometabolic risk factors and their biomarkers, ApoAI and ApoB have the strongest association with carotid atherosclerosis. Apolipoprotein B and metabolic syndrome have the strongest association with a heterogeneous and hypoechogenic carotid plaque. Elevated CRP in patients with acute ischemic stroke may be a sign of carotid plaque destabilization and can indicate a significant carotid stenosis.</p>
29

Cévní zásobení a prokrvení ženské uretry ve vztahu k poruchám kontinence : stanovení vyšetřovacích metod a jejich praktické použití / Vascularity of Female Urethra in Correlation to Urinary Incontinence : Diagnostic Algorithms and Its Clinical Implications

Švabík, Kamil January 2011 (has links)
Introduction: Intrinsic and extrinsic urethral factors play a significant role in urinary continence mechanism in women. Urethral wall structure including inervation, perfusion of submucosal layer etc. is not clinically assessed despite its important role in urethral closure function. The association of incontinence and pelvic floor reconstructive surgery is well known. Every postoperative healing process is associated with factors of ischemia and neovascularisation. According those facts we would expect that the healing and scaring should involve intrinsic urethral mechanism. After reconstructive surgery Implants further increase scaring process. Methods: In our study we included patients with anterior compartment defect. We randomized patients into three interventional arms according the surgical approach and use of implants. Before and 3-5 month after the surgery we performed urodynamic studies and pelvic floor ultrasound examination, including Doppler for urethral perfusion assessment. Another early ultrasound scan was added forth day after surgery. We correlated ultrasound and urodynamic parameters. Results: We randomized 87 patients. We couldn't find any correlation between the morphologic changes and severity of incontinence. Methods for urethral perfusion assessment showed high inaccuracy...
30

Diagnostika a terapie intrauterinních patologií spojených s těhotenstvím. / Diagnosis and therapy of intrauterine pathologies associated with pregnancy.

Švabíková, Lucie January 2015 (has links)
Introduction: Actually 0.7-1 percent of all deliveries can be followed by secondary uterine bleeding. There is a residual trophoblastic tissue diagnosed in most of these cases and it is often managed by repeat intrauterine interventions. These operations are connected with high risk of formation of intrauterine adhesions and their early diagnosis and management can be important for next fertility. Material and methods: There were generally 188 patients included into the study. All patients underwent ultrasound examination in 6 weeks after delivery and ambulant hysteroscopy after next 2 months without anesthesia. Described intrauterine pathologies (residual tissue and adhesions) were managed in one step. Results: In cases with suspect ultrasound finding, the retained trophoblastic tissue was diagnosed by hysteroscopy in 66 percent vs. in 96 percent with sensitivity 85 percent and specificity 85 percent. Patients with intrauterine adhesions had normal ultrasound finding in 74 percent and it did not recognized patients with severe adhesions in 94 percent. Clinical signs had generally 72 percent of patients with diagnosed left residual tissue. Number of severe residual tissue is increasing with delay of instrumental evacuation from delivery (10 vs. 30 percent). When is necessary to repeat the operation...

Page generated in 0.0559 seconds