WASHINGTON — Tom Dougherty jokes that he takes "get-lost walks." To his wife, Cleo, it’s a constant fear: When will his Alzheimer’s get bad enough that she has to end his 4-mile daily strolls?

The Irvine, Calif., woman is about to watch her husband’s neighborhood meandering via computer while she works. The Alzheimer’s Association is adapting technology developed for monitoring prisoners to let caregivers track where their loved ones drive or walk — and alert them if they go beyond the virtual fences each family can set.