AquaSonus Passive-Sonar Pool Alarm

William C. Roberts, Bob Hoenig, and Paula Bailey,, Merrimack, NH

Drowning is the second leading cause of death for children, and most drownings occur in residential swimming pools. The majority of pool alarms are based on water displacement technology. This technology relies on the waves that result from a child falling into the pool reaching the alarm’s trigger mechanism to sound an alarm. This approach results in a product that responds slowly and is prone to false alarm.

The AquaSonus Passive-Sonar System is based on state-of-the-art digital signal processing. The system consists of two separate units that communicate via a wireless RF link. The poolside unit is installed at the edge of the pool and extends into the water. The portion of the unit below the surface of the water contains a hydro phone. It monitors the acoustic sounds that are present in the pool. A microprocessor in the poolside unit digitizes these acoustic signals and analyzes them using software that implements a proprietary digital signal processing algorithm. When the acoustic signature of a child or a pet is detected, an alarm sounds. The poolside unit is battery powered.

“We hope to catch the attention of an organization that recognizes the impact that our technology could have on drowning prevention in residential swimming pools.”

The second unit is a monitor that resides inside the house. When an alarm condition is detected, the poolside unit informs the monitor via the RF link, and an alarm sounds inside the house as well as outside. In addition, the monitor displays the battery condition and overall “health” of the poolside unit via an LED display. The monitor is via a small wallplug power supply, and has battery backup capability in the event of a power failure.

The market for this class of product is large. There are approximately 10.2 million residential in-ground swimming pools worldwide; 5.2 domestic and 5.0 million international. This product is intended for any pool owner who recognizes the inherent hazard associated with pool ownership, and the risk of child drowning.

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Honorable Mentions

BeaconSeal Cargo Security Seal

Bill Forshey, Kalamazoo, MI

Rather than a purely mechanical device like most currently used tamper seals, BeaconSeal uses a microcontroller, electronic circuitry, fiber optics, RFID technology, and custom embedded firmware to add additional levels of security and cargo tracking information.

The BeaconSeal uses an armored optical fiber cable to create a security loop. The device includes a flashing green LED to indicate when the tag is properly sealed. If a break in the security loop is detected, the unit will go into a permanent and irrevocable alarm condition, flashing a red LED pattern continuously. Once activated, the LEDs will flash for approximately the six-month life of the batteries embedded in the unit. The device is designed for one time use and must be removed by the use of cable or bolt cutters.

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An SCBA with Integral Heat Stress Relief

Harold Gier, Niwot, CO

The SuperCritical Air Mobility Pack (SCAMP) provides breathing air and full-body cooling for hazardous materials workers, firefighters, and industry. In addition to providing the air supply, SCAMP solves the problem of heat stress in workers in impermeable suits and/or hot environments. Using ultra-cold (cryogenic) technology, SCAMP has reduced the weight of the breathing air supply while providing cooling at the same time.

The SCAMP supplies a one-hour breathing/cooling apparatus in a package weighing less than 30 pounds. The air is stored in a dewar at -320 ºF. When it leaves the dewar for breathing, it passes though a heat exchanger where it warms up to breathable temperature and simultaneously cools the antifreeze solution circulating around the user’s body in the cooling suit.

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NASA Tech Briefs Magazine

This article first appeared in the November, 2011 issue of NASA Tech Briefs Magazine.

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