When four-year-old Li Hei-yi was one, she would visit her great-grandfather in a residential home. He'd had a stroke, suffered from diabetes and had had the lower part of one leg amputated. He had outbursts, said Hei-yi's father, social worker Li Koon-kiu, and refused to eat or take his medicine.
But with the child, there was a bond. The one-year-old would interact with her late great-grandfather, oblivious to his ailments, and in between her visits he began to eat again and have a more hopeful outlook.
Both Li and his wife, Vicki Poon Ka-lee, are social workers and they observed how their daughter would roam around the home for the elderly, the residents delighting in watching the little girl.
"You could see the spark in their eyes," says Li, 33, "and how they yearned for some interaction with her."
At the time, Li was working with teenagers through the Young Women's Christian Association, taking the children camping and offering careers advice. Two years ago, he and his wife decided to create a programme for children between the ages of six months and six years to visit homes for the elderly. The programme, called Dr BB, operates across Hong Kong.
Li posts suitable locations on his Facebook page and parents sign up with their children, paying a HK$100 fee, which Li uses to run the project. The families attend a briefing and some of the hundreds of children who have subsequently become involved visit the homes several times.
"At that age, all you have to do is let the children be themselves," Li said. "They are at their most pleasing when you just let them do their own thing. Sadly, adults are unable just to be themselves in such an unguarded way."
The sessions usually last an hour and the interaction between the elderly and the children seems to benefit both sides. "I often give the children stickers, which they love, but it also increases the physical interaction with the kids, as they are encouraged to stick the stickers on them. We also give them rubber bracelets to give to the residents. It makes them feel less isolated when they are with children."
Over the past two years, Li has led more than 70 visits. He's keen to expand this service, as he says there are 300,000 children under the age of six in Hong Kong - plenty of potential visitors.
"Children spend so much time at kindergarten and then school, plus learning music and other extracurricular activities," says Li. "It's important that they interact with others and through that learn social skills and correct morals and values."
Li has received funding from both the Li Ka Shing Foundation and DBS Bank, though that money dries up in November. He's not concerned. "As long as I receive regular, small contributions, I can keep this going," he says.
Having said that, he still needs money to start research into the therapeutic effects of children on elderly people. "There has been a similar study done in Japan and I want to see a study like this in Hong Kong," he says.