Evaluation of titanium ultralight manual wheelchairs using ANSI/ RESNA standards.
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Comfortable propulsion and support, light weight, and small dimensions are important features that help preserve upper-limb integrity of manual wheelchair users and improve accessibility. The titanium wheelchair is a product developed in response to these goals, but none of the test results of titanium wheelchairs had been disclosed before this study was performed. We hypothesized that these titanium wheelchairs would be in compliance with American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) standards. We tested 12 ultralight titanium rigid-frame wheelchairs (4 models) using ANSI/RESNA testing procedures and compared the test results with previously tested ultralight and lightweight aluminum wheelchairs. All wheelchairs passed the forward braking effectiveness test, but eight wheelchairs tipped backward before inclining to 7 degrees in the rearward braking effectiveness test. All wheelchairs passed the impact strength tests, but six wheelchairs failed in the static strength tests. Three wheelchairs successfully completed the fatigue tests, but the remaining wheelchairs failed prematurely. This group of titanium wheelchairs had less equivalent cycles and value than the ultralight aluminum wheelchairs that were tested in a previous study. The failure modes revealed important design issues of each model. Our results suggest that manufacturers may need to perform more careful analyses before commercializing new products. (+info)
Energy and public health: the challenge of peak petroleum.
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Petroleum is a unique and essential energy source, used as the principal fuel for transportation, in producing many chemicals, and for numerous other purposes. Global petroleum production is expected to reach a maximum in the near future and to decline thereafter, a phenomenon known as "peak petroleum." This article reviews petroleum geology and uses, describes the phenomenon of peak petroleum, and reviews the scientific literature on the timing of this transition. It then discusses how peak petroleum may affect public health and health care, by reference to four areas: medical supplies and equipment, transportation, energy generation, and food production. Finally, it suggests strategies for anticipating and preparing for peak petroleum, both general public health preparedness strategies and actions specific to the four expected health system impacts. (+info)
Dying to play video games: carbon monoxide poisoning from electrical generators used after hurricane Ike.
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Hemodynamic evaluation of a chronically implanted, electrically powered left ventricular assist system: responses to acute circulatory stress.
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Hemodynamic stress testing was performed in four calves with a chronically implanted left ventricular assist device consisting of a double-valved pump interposed between the left ventricular apex and the descending thoracic aorta. The device was powered either pneumatically (n = 1) or with a transcutaneous energy transmission system (n = 3). Hemodynamic evaluation (cardiac output and right and left ventricular and pulmonary and carotid artery pressures) was carried out at baseline and during all hemodynamically stressed states. Atrial pacing and ventricular pacing to a heart rate of 140 beats/min resulted in no significant change in right or left heart filling pressures or cardiac output. Preload reduction with nitroprusside or transient inferior vena cava balloon occlusion resulted in a marked decrease in left ventricular pressure with preservation of mean arterial pressure. Phenylephrine administration resulted in a marked rise in mean arterial pressure with no change in cardiac output or filling pressure. Induction of ventricular fibrillation resulted in a decrease of mean left ventricular pressure to 11 +/- 8 mm Hg, but mean arterial pressure was maintained at greater than or equal to 50 mm Hg. It is concluded that a multicomponent, implantable, electrically powered assist system is capable of maintaining a normal cardiac output under a wide range of loading conditions and chronotropic states. Although this device is clearly preload dependent, it is capable of maintaining normal systemic pressures during conditions of severe left ventricular dysfunction and circulatory collapse. (+info)
Carbon monoxide exposures after hurricane Ike - Texas, September 2008.
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During power outages after hurricanes, survivors can be at risk for carbon monoxide (CO) poisoning if they use portable generators improperly. On September 13, 2008, Hurricane Ike struck the coast of Texas, leaving approximately 2.3 million households in the southeastern portion of the state without electricity. Six days later, 1.3 million homes were still without electrical power. To assess the impact of storm-related CO exposures and to enhance prevention efforts, CDC analyzed data from five disparate surveillance sources on CO exposures reported during September 13--26 in counties of southeast Texas that were declared disaster areas by the federal government. This report describes the results of that analysis, which indicated that one data source, Texas poison centers, received reports of 54 persons with storm-related CO exposures during the surveillance period. Another data source, the Undersea and Hyperbaric Medical Society (UHMS) hyperbaric oxygen treatment database, reported that 15 persons received hyperbaric oxygen treatment for storm-related CO poisoning. Medical examiners, public health officials, and hospitals in Texas reported that seven persons died from storm-related CO poisoning. Among the data sources, the percentage of reported storm-related CO exposures caused by improper generator use ranged from 82% to 87%. These findings underscore the need for effective prevention messages during storm preparation, warnings, and response periods regarding the correct use of generators and the installation and maintenance of battery-powered CO detectors. (+info)
Technical breakthroughs in the wearable artificial kidney (WAK).
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