Bernard Stoneham signed up for the Mindme GPS locating device after his wife Gill, who has dementia, got disorientated near their home in Fishbourne, Chichester.
He says the device alerted him when his wife got lost while she was walking the couple's dog and without it "I wouldn’t have known where to look for her."
Mr Stoneham said: "If Gill gets into difficulty, she can speak to the staff through the device. They can then contact me or other nominated persons with her position.
"All I can say is how grateful I am to have had the use of this piece of hi-tech wizardry and what a difference it makes at this difficult time in our lives."
More top news
Ukip leader Paul Nuttall has announced that he will be standing for the seat of Boston and Skegness in the forthcoming General Election.
Beckie Finch and Adam Ryan met on the dating show but the groom had to track down his future missus after filming as he didn't pick her.
The Prime Minister was reportedly coming under pressure from Tory MPs in the south to cancel HS2.