Thesis (Ph. D.)--Michigan State University. Dept. of Electrical Engineering, 2008. / Title from PDF t.p. (viewed on July 2, 2009) Includes bibliographical references (p. 147-155). Also issued in print.

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Robert Butera; Committee Member: Pamela Bhatti; Committee Member: Todd McDevitt

Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vii, 118 p. : ill. Includes abstract. Includes bibliographical references.

Typescript. / Digitized by Kansas Correctional Industries

Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Includes bibliographical references. / M.S.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 105-112).

The purpose of this study was to examine the effects of hydration status on the prediction of body composition using BIA, NIR, and DEXA. Twenty healthy males and females ages 18 to 28 were recruited for this study. The subjects were dehydrated in the climate control chamber and engaged in physical exercise, until they lost approximately 1%, 2%, and 3% of their pre-exercise body weight. Percent body fat (%BF), body weight, and urinalysis measures were taken initially on day 1, on day 4 at euhydration, following 1%, 2%, and 3% dehydration, and upon rehydration during day 5. The results indicated that there were significant decreases for %BFBIA and %BFNIR between euhydration and 1%, 2%, and 3% dehydration. %BFDExA did not significantly change.There were also significant differences in the response to dehydration between each technique. Proper hydration should be ensured before %BF is estimated with BIA and NIR. / School of Physical Education

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on September 16, 2009). Thesis advisor: Dr. Steve Ball. Includes bibliographical references.

The purpose of this investigation was to determine the effect of premenstrual edema (water retention) on measurements of percent body fat (%BF) in ovulating women during the menstrual cycle utilizing bioelectrical impedance. Specifically, this study was designed to investigate the difference between bioelectrical impedance measurements of %BF recorded during day 1 of menses, day 7, day -1 midcycle, midcycle, day 21, and days -3, -2, and -1 premenses. Determinations of impedance were made in 26 regularly menstruating women aged 20.23±0.74 yr using an electrical impedance analyzer with a four-electrode arrangement that induces a painless signal ( 800 !microamps at 50 kHz) into the body. Internal consistency reliability estimates made approximately 5 min apart during each test day ranged from R = .96-.99 for the impedance measurements of %BF, and the stability reliability correlation coefficients ever the eight observation days ranged from r = .92-.97 for the impedance measurements of %BF. The reliability analyses indicated that %BF esitimated from bioelectrical impedance was measured reliably. Specific days of the menstrual cycle did not significantly affect impedance measurements of %BF. Analysis of variance with repeated measures also indicated that day during the menstrual cycle did not significantly affect weight (Wt), %BF, resistance (Re), or total body water (TBW) measurements. However, urine osmolality (Osm) and basal body temperature (BBT) were significantly affected across days of the menstrual cycle (p < .01). A dramatic decline in Osm was noted at midcycle followed by a rise which peaked at day -3 premenses. After day -3 premenses, Osm rapidly declined at menses. The dramatic decline in Osm at midcycle may reflect changes in urine concentration due to actions of elevated estrogen associated with ovulation. BBT dropped prior to midcycle and then began to rise until day -3 of the next menses and then it dropped slightly. The drop prior -co midcycle may be also reflected by changes in the hormonal concentration of estrogen. The biphasic BBT response was considered to be presumptive evidence that ovulation had occurred. A 2 x 2 factorial analysis of variance with repeated measures demonstrated that there was a significant interaction between cycle length and activity level on measurements of Wt, %BF, and BBT (p < .05). As light activity subjects with average cycle lengths became moderately active, their %BF decreased from 26.51±0.63% to 21.11±0.50% followed by a dramatic increase to 29.40±0.62% as they became highly active. On the otherhand, as light activity subjects with above average cycle lengths became more and more active, their %BF dropped drastically from 35.11±1.44% to 18.72±0. 75%. The data support the hypothesis that bioelectrical impedance measurements of %BF recorded during the normal menstrual cycle are not significantly different. However, a larger population is required to validate the applicability of these results. / M.S.

The objective of the proposed research is to design an experimental setup to assess the ability of impedance measurements to characterize mouse embryonic stem cell (ESC) and embryoid body (EB) growth and differentiation. Existing quality assurance measurements used to stage the growth and differentiation of embryoid bodies are labor intensive and most often destructive to the cells, thus present methods are typically valid for a single time point. Bioimpedance measurements are non-invasive and non-destructive, presenting an alternative approach to this challenge. These measurements can be done continuously for real-time measurements on the changes in embryoid body growth and differentiation. A system capable of making bioimpedance measurements of ESC and EB suspensions was designed along with a biocompatible test device to hold the cells and Ag-AgCl electrodes. The system uses a lock-in amplifier to record the magnitude and phase changes of the ESC and EB suspensions when a 1 Vpp signal sweeping frequencies from 100 Hz to 100 kHz is applied. The system performance was validated with a test case of 1 mL of 0.1 M KCl. Then experiments with cell culture media, ESCs, and EBs were performed, with varying concentrations of cells and EBs. Experimental results for single ESC suspensions showed promise in detecting a difference in cell concentration between 2 million and 4 million cells in 0.5 mL of media. Results for four day old EBs were ambiguous, and we conclude that a different experimental set up is required due to EB settling during experimentation.