Browsing by Author "Rapley, Bruce Ian"
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- ItemThe design and testing of a magnetic biostimulator : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy, Massey University, Palmerston North(Massey University, 1994) Rapley, Bruce IanA commercial pulsed electromagnetic field therapy unit, typical of those used in current medical practice, is evaluated. The principle of operation is determined, and the magnetic field output quantified. The unit is trialed on a human subject to verify the manufacturer's claims regarding the physiological responses of both vasoconstriction and vasodilation. The results do not confirm the manufacturer's claims. A programmable magnetic biostimulator is designed and tested. This approach is unique, featuring a transconductance amplifier to drive the stimulation coil. Significant increases in performance are obtained in comparison to standard voltage feedback amplifiers, particularly with rapid rise-time waveforms, such as square waves. The magnetic biostimulator is trialed in a clinical setting on four experimental subjects to determine the claimed vasodilation response of pulsed magnetic fields. Two subjects are normal, healthy individuals, and two have been diagnosed as having Primary Raynaud's Disease, a disorder of peripheral circulation. Various responses are recorded and discussed in the text. The magnetic biostimulator is trialed in a laboratory situation in order to determine the effect of magnetic fields on the cytogenetics of the broad bean, Viciafaba. No significant differences in the number of chromosome or chromatid breaks are recorded between the control and test groups. Significant differences at the 95% probability level between the control and test groups are recorded, however, for various stages of the cell cycle. This finding may imply that various forms of exogenous magnetic fields may affect the cellular mechanisms involved in mitosis. The clinical and laboratory trials verify the effectiveness and practicality of the chosen design. In reviewing the performance of the magnetic biostimulator, suggestions for future implementations are discussed.
- ItemSound in the military environment : detection, measurement and perception : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy, Massey University, Palmerston North campus, Institute of Food, Nutrition and Human Health. EMBARGOED until further notice.(Massey University, 2013) Rapley, Bruce IanThe sound environment in which we work and its effects on us has been the subject of considerable research over the last century. With the advances in technology and electronic engineering, increasingly sophisticated laboratory equipment has been developed that has been able to be applied to the biological sciences. Accordingly much progress has been made in understanding hearing in both man and animals. Although there is significant new information currently available, much of it has not yet filtered into the health and safety workplace management system. The continued reliance on the A-frequency weighting is one example where scientific progress has outstripped current management practice. This research sought to determine and measure the acoustic spectrum in various working scenarios within the New Zealand military, particularly in land transport that may amount to long periods for some soldiers. In addition the research included a pilot study of the effects of these sound environments on military personnel with respect to hearing and cognition. The research included a number of novel techniques including binaural manikins developed to quantify the sound within military vehicles, from a human perspective, utilising the latest SAM (Spectro-Acoustic Meter) technology. In addition, a water filled manikin (“Aquaman”) was constructed with internal sensors to determine the effects of external sound and vibration as transmitted into the human body. Comparison of spectra and energy levels facilitated modelling of the total sound absorbed by a human body. The research showed that in the military vehicles examined, the sound environment is neither homogeneous nor symmetrical and likely contributed to the hearing and cognition effects observed. As the research had to fit in with the New Zealand Army’s daily operations only a small number of participants was available at any one time. Further research with a larger population is necessary to qualify and quantify the initial results obtained from the pilot study.