CHICAGO, USA (AP) - The parents of an eight-year-old boy who has had severe brain damage for years have sued a Chicago hospital, alleging that doctors pronounced their son dead, keeping him off his ventilator for hours, even though relatives continued to insist that the boy's eyes and body were still moving.

The lawsuit filed this week by Sheena Lane and Pink Dorsey on behalf of their son, Jaylen Dorsey, accuses Mercy Hospital and Medical Center of negligence in the February incident and alleges that nearly five hours passed before staff agreed to perform a cardiac ultrasound, which showed Jaylen Dorsey's heart was beating.

"You didn't have to be a doctor to see that the heart was pumping blood," the boy's father, Pink Dorsey, said at a news conference Friday.

The hospital denies the lawsuit's allegations and said in a written statement that Jaylen arrived at the hospital after suffering full cardiac arrest for 25 minutes and doctors treated him for "an extended period of time" before declaring him dead.

"Despite extensive resuscitative efforts, Jaylen did not immediately regain a pulse and no heart activity was noted for several hours," the hospital said. "... While this is a very rare occurrence, extensive resuscitation efforts, medication and young age can result in a patient's heart function returning spontaneously. We hope for continued strength for Jaylen."

At Friday's news conference, the couple said Jaylen has had severe brain damage since age two and that his disabilities have kept him bedridden and on a ventilator. His father said that before going to the hospital, Jaylen would smile at family members and could hear them, but that he no longer does. He also said they would see Jaylen smile again "in heaven."

Their lawyers said that because of the ongoing lawsuit, they would not be releasing details about the boy's disabilities and condition.

According to the couple, Jaylen was taken to Mercy Hospital and pronounced dead on February 18 after his mother found him unresponsive.

They say Jaylen's eyes continued to flick open, but that they were told that the lingering effects of medicine were causing that to happen.

"We're not doctors, so we just went along with what they told us," Dorsey said.

So family members began to plan a funeral for the boy.

But when other relatives arrived at the hospital, they gasped when they saw Jaylen's eyes opening, the boy's father said.

The lawsuit says the family had to demand that medical staff conduct more tests and that a cardiac ultrasound finally showed the boy's heart was beating.

His parents are seeking US$200,000 in damages. The lawsuit says they suffered hours of "severe emotional distress."

The boy's parents also worry that the hours he was off his respirator while at the hospital may have worsened his condition.