Children formed the familiar heart-shaped logo of pioneering Oxford hospices Helen and Douglas House to mark the 25th anniversary of the charity yesterday.

The event, and an accompanying balloon launch, signalled the start of a year of celebrations for the East Oxford respite care centres.

When Helen House, in Magdalen Road, opened in November 1982, it was the world's first specialist hospice for children.

Sister Frances Domenica, who founded Helen House and then in 2004 Douglas House, which cares for young adults, said it was hard to believe 25 years had passed since Helen House opened.

She said: "It's amazing to look back to very small beginnings, when really there was no blueprint and it was just a very steep learning curve right from the beginning.

"Each family who has come to stay with us has taught us something new, but looking back to the original vision, it's very exciting to see how it hasn't changed.

"Obviously, we have to move with the times and all sorts of things have changed in 25 years, but the original vision, to offer friendship, practical support and professional care to children with life-shortening conditions, hasn't altered."

Since 1982, Helen House has helped hundreds of children and their families and its pioneering vision has led to more than 40 similar centres opening in the UK alone, with further care centres inspired by Helen House as far afield as Germany, Australia and Japan.

Sister Frances said: "For the future we just want to go on doing the same thing, but better.

"The thing which means the most to me is hearing people say they walked through the big red door into the hospice and entered a different world, where they felt safe and cocooned and where people listened to their story.

"The whole thing really is about journeying with them and it's about walking the walk.

"It is hard knowing the people who stay with us are going to die, but in a way the families give us so much and also the team support each other, so you're not doing it alone - nobody takes all the burden."

More than 200 children from five Oxford primary schools - St Aloysius, St Barnabas, SS Mary & John, SS Philip & James and Windmill - gathered at St Edward's School, in Woodstock Road, to create the living representation of the charity's logo.

Hospice patients Charlotte, 12, and Aman, four, then released a heart-shaped container of balloons.

Other events planned to mark the anniversary include a makeover by the Greenfingers Appeal charity of Helen House's garden and a thanksgiving service at Oxford's Christ Church Cathedral.