We began with the view that attaching body sensors to divers was too cumbersome — a problematic approach to monitoring a diver’s underwater condition. After evaluating divers’ needs, we decided to build a system that relied on a fundamental indication of diver condition: continued consistent breathing.

The most obvious indication of continued breathing is the rise and fall of a diver’s chest. Of course, there is no simple way to check the rise and fall of the diver’s chest underwater; but the we found that it was possible to check the use of air from the second-stage pressure regulator, located in the diver’s mouthpiece.

However, placing a sensor in the diver’s mouthpiece is inconvenient for the diver, and since simplicity was one of our prime objectives, we decided that interfacing with the second-stage regulator was not an optimal solution.

Since the second-stage regulator is connected via a single-hose open circuit to the first-stage regulator, the first-stage regulator becomes the ideal one to monitor for proper behavior in order to determine if a diver is breathing without distress.

The best place to monitor the condition of the air in the first-stage intermediate pressure regulator is at the end of the low-pressure inflator hose, where the inflator connects to the first-stage regulator.

How it works. The low-pressure inflator hose receives intermediate-pressure air from the first-stage regulator, as does the hose leading from the first-stage regulator to the second-stage regulator. In other words, the air pressure in those two hoses is identical. With every breath a diver takes the air pressure in both hoses changes from intermediate pressure to ambient pressure.

Placing DiverGuard® on the low-pressure inflator hose provides a relatively simple system for floating the diver, by inflating the buoyancy compensator when necessary. This arrangement prevents the need for additional air-bags that would make a rescue system cumbersome and expensive.

Installing DiverGuard® within the low-pressure inflator hose enables any diver to mount the device independently, without any prior training, simply by opening and closing a cable tie.

DiverGuard™ is protected by a number of pending international patents in the US and other major diving markets throughout the world.