Its inventor says a system tested in Ohio two weeks ago could be a help after mine cave-ins like the one in Utah.

Former Navy submarine technician Russell Breeding says the underground system he developed uses sensors that can track miners within three meters of their location.

The recent test occurred at Ohio's Century Mine. It's owned by Murray Energy, the Cleveland company that also operates the Utah mine where six workers are trapped.

With Breeding's invention, miners would wear battery-powered transmitters that emit signals which could be picked up by a computer.

He got the idea after West Virginia's Sago Mine disaster in 2006, in which 13 miners were trapped for nearly two days. Only one survived.

Breeding also had a personal motivation: He grew up near mines in New Philadelphia, Ohio. Breeding now lives in Virginia Beach, Virginia.