The bracelets constantly emit low-frequency radio signals that can be tracked within a mile, even in areas that Global Positioning System and other tracking devices fail. The program has allowed 903 bracelet wearers to be successfully found—all within 30 minutes.

"With GPS, if a person were to wander and go undercover or go inside a building, we'd have false readings," said Sgt. George Schifano, the program's coordinator for both the county and state. "This has a 100 percent success rate."

Schifano said the bracelets, which are about the size of a wristwatch, cost about $263 each and $25 per month for staffing and battery-replacement costs. But the program is entirely volunteer-run and funded by donations.

Gene Saunders, CEO of the nonprofit Project Lifesaver International, said the program started about six years ago when he worked for the police force in Chesapeake, Va. Saunders was part of a team responsible for search-and-rescue operations.

"We were starting to get more and more Alzheimer's patients," he said. "And honestly, we were not doing a great job of getting them back—some we didn't find until days later, and they were deceased. Some we found after it was too late to prevent injury."

So after some research, his team decided to try the transmitter system and received a grant from a local hospital to start a 15-month pilot program.

"The first rescue we ever did was a minute and a half," Saunders said. "For some reason, word started spreading and phone calls started coming in from all over."

Now, the program is active in 35 states. Locally, only a handful of people have been outfitted with transmitters, but Schifano said he has a list of more who will be receiving them in the following weeks.

In Willow Glen, Schifano has visited Willow Glen Villa to provide information about Project Lifesaver. The assisted-living facility has more than 30 residents who have Alzheimer's disease. And while the facility already has an audible alert that sounds each time a door opens, Schifano said that the program's bracelets are just another way to be sure of each patient's safety.

He isn't sure if the facility will decide to implement the bracelets. He said, however, that the brackets would be provided free of charge to any resident. Those who choose to use the bracelet would then be required to pay $25 per month for a new battery.

He plans to visit other Willow Glen locations to provide more people with information about the bracelet, but no firm dates for visits have been set.

Schifano said that in addition to caregivers of older adults, parents of children with autism, Down syndrome or similar disorders would benefit from the program. But he jokingly cautioned that the bracelets are not intended to do detective work for suspicious parents and spouses.

"It's not designed for tracking kids and husbands and wives," he said. "There has to be kind of a medical nexus to it."

For more information about Project Lifesaver or to make a donation, contact Sgt. George Schifano at 408.808.4768.

Staff Writer Amy Wicks contributed to the story.