November 10, 2010 — To keep soldiers in the battlefield healthy, the U.S. Army is exploring new ways to detect harmful bacteria in water.
Current techniques for analyzing water in the field can take as long as 24 hours to complete, according to …
High-power ultrasound, currently used for cell disruption, particle size reduction, welding and vaporization, has been shown to be 99.99 percent effective in killing bacterial spores after only 30 seconds of non-contact exposure in experiments. In the experiments, bacterial spores contained in a paper envelope, were placed slightly (3mm) above the active area of a specially equipped source of inaudible, high frequency (70 to 200 kHz) sound waves and hit for 30 seconds. There was no contact medium, such as water or gel, between the ultrasound source and the spores as is typically used in low-power, medical diagnostic ultrasound. The experiments mark the first time that Non-Contact Ultrasound (NCU) has been shown to inactivate bacterial spores.
Researchers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., have demonstrated a prototype device that automatically and continuously monitors the air for the presence of bacterial spores. The result is a novel alarm capability reminiscent of smoke detectors. Current methods for detecting bacterial spores, such as anthrax, require a trained operator. The large number of trained monitors required, with associated costs, limits widespread implementation of these methods.