His father Christopher Barnes denies manslaughter.
Paramedics rushed Harry Barnes from his home in Midhurst to St Richard’s Hospital in Chichester on June 24, 2017, but he tragically died the following day at Southampton University Hospital.
Doctors found that tiny Harry had suffered fractures to his spine and brain damage.
Barnes, of Barlavington Way, Midhurst, is charged with manslaughter and causing grievous bodily harm.
Barnes, a heating engineer, denies the offences and his trial began today.
He had been alone with baby Harry when he collapsed, Lewes Crown Court heard this morning.
Prosecutor Jennifer Knight said: “Sometime before 12.37pm on 24th June 2017, 10 week old Harry Barnes collapsed.
“His heart stopped beating and he stopped breathing.
“He never regained consciousness and he died the next day when life support was withdrawn.”
Examinations revealed that Harry had suffered a number of injuries, the court heard.
These included a thin film of blood found underneath one of the membranes that surround the spine and the brain.
Ms Knight said this type of injury is caused ‘by a very particular kind of movement that is caused by shaking of a baby or by shaking and impact’.
Harry also suffered brain damage caused by a ‘prolonged period of insufficient oxygen supply to the brain’ and was also found to have bleeding in his retinas, bleeding around his optic nerves and fractures to his spine, the court heard.
In a statement to police, Barnes said that he had never done anything that could have caused Harry’s injuries.
He said he knew the proper way to hold his son and was always very careful, the court heard.
The prosecutor said: “The medical evidence revealed that Harry Barnes’ injuries had been caused during at least two episodes of injury, one around the time of his collapse and another several days earlier.
“It is the crown’s case that this defendant Christopher Barnes, Harry Barnes’ father, who was alone with him at the time of his collapse is responsible for his death and also for the injuries that had been caused to him.”
The trial continues.