In 2003, the National Center for Injury Prevention and Control in Atlanta recorded 3,306 unintentional fatal drownings in the United States . Many of the victims were children who drowned in both public and private pools. Regardless of the locale, a common thread ties the tragedies together: pool drownings are preventable. But even with trained lifeguards and aquatic safety awareness, accidents happen.

Contrary to popular belief, drowning is a silent killer. A swimmer in trouble is unlikely to panic and splash about; immobilized by shock, the individual cannot move or breathe, let alone cry for help. The response-time is crucial – a few seconds can make all the difference between recovery and permanent brain damage, between life and death. If lifeguards or other emergency personnel intervene and begin resuscitation within 30 seconds, the victim's chances of recovery are very good, but lifeguards are human -- and that means that they cannot see every swimmer 100 percent of the time. Add heat, noise and light playing with the waves, sometimes trouble remains hidden.

We have smoke detectors in homes. We have surveillance cameras in shopping malls. We have air traffic control systems to keep airplanes from flying into each other. Where are the tools for lifeguards?

Seven years ago a French company was founded on the idea that machine vision technology could help prevent pool drownings; that the right mix of cameras, computers and software could ensure swimmers' safety. Today, Vision IQ/Poseidon develops a computer-aided drowning detection system that helps lifeguards save lives.

The Poseidon System

Although the configuration varies according to the requirements of the pool, each Poseidon system uses the same components: underwater cameras, overhead cameras, PCs, a Matrox Morphis Dual or Quad frame grabber, an LED display panel and a waterproof-touch screen supervision monitor.

Depending on the size of the pool, the Poseidon system may have between 8 and 32 cameras networked to one or more computers. In a typical indoor configuration, overhead cameras will be installed on the ceiling, and if the pool is deeper than nine feet, underwater cameras will be installed on the pool's wall. A Matrox Morphis Dual or Quad frame grabber digitizes the cameras' analog output so the image data can be analyzed. First, the Poseidon software notes if a swimmer's behavior is unusual, and then tracks the individual for several seconds. If the software detects a motionless presence on the bottom of the pool for 10 seconds, an alarm notifies the lifeguards and the LED panel displays the victim's coordinates in the pool. This panel is also equipped with red lights and a siren that are activated when the system detects an incident.