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No description available.

The development of pulsed type radar signals is examined, with a brief review of matched filtering. Gated RF, linear and non-linear FM pulse-compression (chirp) and matched filtering of radar signals is reviewed in depth. Emphasis is given to identifying the desirable characteristics of each method. A new method of non-linear FM pulse-compression is introduced; it utilizes the Eigen Function (a form of the raised-cosine family) of functions) as its modulating term. Its properties are then compared to those of the linear and non-linear systems reviewed in the preceding sections. Design considerations for implementation on a surface acoustic wave device are presented.

Given the current obesity epidemic in tandem with the aging US population, it is imperative to identify methods for reducing cardiovascular disease (CVD) risk that will be efficacious for both sexes. Arterial stiffness (AS) is an independent risk factor for a first cardiovascular event that increases with advancing age and obesity. Previous studies have found that modest weight loss (WL) of 5 to 10 percent successfully reduces AS and other risk factors for CVD. However, it remains unclear whether WL via caloric restriction reduces AS similarly among sexes. We tested the hypothesis that WL via caloric restriction would reduce AS more in men than women because men accumulate more abdominal visceral fat (VF) and lose more with WL compared with women of similar age and adiposity. To test our hypothesis AS was assessed from measurements of pulse wave velocity and ultrasonography of the carotid artery (Ã -SI). Total body and VF were measured using dual energy x-ray absorptiometry and computed tomography scans, respectively. Subjects underwent a 12-week WL intervention. No baseline differences in AS were observed between sexes. However, men were heavier and demonstrated higher levels of VF while women were fatter and had higher levels of abdominal subcutaneous fat. Contrary to our hypothesis both sexes experienced similar decreases in AS with WL despite greater reductions in VF in men. Our findings suggest that VF loss is not the primary mechanism mediating reductions in AS with WL. Future studies are needed to determine the mechanisms of arterial destiffening with WL. / Master of Science

Arterial pulse pressure is critically important to a number of diseases such as isolated systolic hypertension, coronary artery disease and heart failure. Determining the cause of increased pulse pressure has been hampered for two reasons. First, pulse pressure results from contraction of the heart and the load formed by the complex arterial tree. Pressure pulses travel from the heart to the peripheral arteries. As they reach a bifurcation or change in arterial wall properties, some of the pulses get reflected and propagate retrograde towards the heart. Second, two different modeling approaches (0-D and 1-D) describe the arterial system. The Windkessel model ascribed changes in pulse pressure to changes in total arterial compliance (Ctot) and total arterial resistance, whereas the transmission model ascribed them to changes in the magnitude, timing and sites of reflection. Our investigation has addressed both these limitations by finding that a complex arterial system degenerates into a simple 2-element Windkessel model when wavelength of the propagated pulse increases. This theoretical development has yielded three practical results. First, isolated systolic hypertension can be viewed as a manifestation of a system that has degenerated into a Windkessel, and thus increased pulse pressure is due to decreased Ctot. Second, the well-discussed Augmentation Index does not truly describe augmentation of pulse pressure by pulse reflection. Third, the simple 2-element Windkessel can be used to characterize the interaction among heart, arterial system and axial-flow left ventricular assist device analytically. The fact that arterial systems degenerate into Windkessels explains why it becomes much easier to estimate total arterial compliance in hypertension?total arterial compliance is the dominant determinant of pulsatile pressure.

Arterial pulse pressure is critically important to a number of diseases such as isolated systolic hypertension, coronary artery disease and heart failure. Determining the cause of increased pulse pressure has been hampered for two reasons. First, pulse pressure results from contraction of the heart and the load formed by the complex arterial tree. Pressure pulses travel from the heart to the peripheral arteries. As they reach a bifurcation or change in arterial wall properties, some of the pulses get reflected and propagate retrograde towards the heart. Second, two different modeling approaches (0-D and 1-D) describe the arterial system. The Windkessel model ascribed changes in pulse pressure to changes in total arterial compliance (Ctot) and total arterial resistance, whereas the transmission model ascribed them to changes in the magnitude, timing and sites of reflection. Our investigation has addressed both these limitations by finding that a complex arterial system degenerates into a simple 2-element Windkessel model when wavelength of the propagated pulse increases. This theoretical development has yielded three practical results. First, isolated systolic hypertension can be viewed as a manifestation of a system that has degenerated into a Windkessel, and thus increased pulse pressure is due to decreased Ctot. Second, the well-discussed Augmentation Index does not truly describe augmentation of pulse pressure by pulse reflection. Third, the simple 2-element Windkessel can be used to characterize the interaction among heart, arterial system and axial-flow left ventricular assist device analytically. The fact that arterial systems degenerate into Windkessels explains why it becomes much easier to estimate total arterial compliance in hypertension?total arterial compliance is the dominant determinant of pulsatile pressure.

Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. Frank Gross, Florida State University, FAMU-FSU College of Engineering, Dept. of Electrical and Computer Engineering. Title and description from dissertation home page (viewed Oct. 3, 2003). Includes bibliographical references.

Thesis (M.S.P.H.)--University of Michgian, 1939.

Thesis (M.S.P.H.)--University of Michgian, 1939.

BACKGROUND: Electroconvulsive therapy (ECT) is an effective intervention for major depressive disorder, especially for subsets of depression that resist more common therapies. However, ECT use is limited by its significant risk for adverse cognitive side effects. Shortening the pulse width of the current used has been demonstrated to lower this risk; however, the shorter pulse may not sufficiently elicit therapeutic effects. A systematic review was performed to determine if UBP ECT is as efficacious as BP ECT, and therefore would be a valid treatment for managing depression. METHODS: We conducted a literature search of MedLine/PubMed, Embase, Cochrane CENTRAL, and Google Scholars databases in October 2017 with the terms “depression”, “major depressive disorder”, “electroconvulsive therapy”, “ECT”, “brief”, “ultrabrief”, and “sine wave”. Studies were selected using inclusion criteria and exclusion criteria. Effects sizes were calculated from formalized mood rating pre-ECT and post-ECT, response rates and remission rates. Heterogeneity and reporting bias of the articles were also assessed. Data were analyzed using meta-analysis tools provided by the Erasmus Research Institute of Management. RESULTS: Data from 9 studies resulted in a pooled Cohen’s d = 0.16 (CI = -0.08 to 0.43, p = 0.149). The effect size alone favors BP ECT over UBP ECT in improving mood as per MADRS/HRSD ratings, but if given p > 0.05, results were non-significant. BP ECT was determined to be more efficacious then UBP ECT in terms of both achieving response and achieving remission, with a pooled ORresponse = 0.72 (CI – 0.49 to 1.05, p = 0.027) and pooled ORremission = 0.65 (CI = 0.42 to 0.98, p = 0.011). CONCLUSION: The choice to use BP ECT or UBP ECT is a balance between the burden of side effects and efficacy. These data suggest that patients with a lower risk of developing cognitive side effect and/or need urgent intervention receive BP ECT. Conversely, patients with a higher risk of developing adverse cognitive side effects and/or are not in need of urgent intervention may benefit UBP ECT. Additional studies are recommended to confirm these findings and clarify the optimal use of these two modalities of ECT.