The parents of an 8-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 by Sheena Lane and Pink Dorsey on behalf of their son, Jaylen Dorsey, accuses Mercy Hospital and Medical Centre 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 on Friday.

The hospital denies the lawsuit’s allegations, and said 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.

At the news conference, the couple said Jaylen has had severe brain damage since age 2 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.”

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.