Dual sensing saves toddlers’ lives
A number of electronic alarm systems have been developed to detect child-sized objects falling into ponds and pools
Dual sensing saves toddlers’ lives
Problem: , but none we are aware of until now seem to be of much use. Either they cannot guarantee to detect such an event, or more likely, they detect spurious events and cry ‘wolf’, negating their usefulness.
Solution: Robin Hatherell, managing director of Xltronix, has developed the Hydrosure, an alarm system that uses not just one sensor but two.
The device floats in the water and combines a hydrophone in the bottom part and a motion sensor in the top part. Only if the shock wave detected by the hydrophone has a pattern associated with a child falling into the water is the motion sensor enabled.
The device is powered by a nickel metal hydride battery rechargeable via a solar cell mounted on top of the device.
Application: The device can detect a child weighing 6kg or more falling in at distances up to 4m. The basic unit costing £150 initiates a sounder while a more sophisticated unit, costing £220, initiates a sounder and also transmits an alarm radio signal up to 100m.
Hatherell says he adapted the idea from a vibration intruder alarm that he has also developed. This, too, has two sensor systems combined in the same sort of way to avoid generating false alarms. Incidentally, the Hydrosure recently won the Welsh Development Agency Innovation Challenge Award 2002. TSHydrosure
