Is it permissible, in Sharia, for a doctor to insert a breathing tube into a dead person whose return to life is not hoped for, for the purpose of training?

A person's death is legally determined in two cases: complete and irreversible cessation of their heart and breathing, or complete and irreversible failure of all brain functions and brain decomposition. If a person is determined to be dead, it is not permissible to harm them by inserting a breathing tube for training purposes, due to the sanctity of the deceased, as Allah Almighty says: (And We have certainly honored the children of Adam), and the Prophet, peace and blessings be upon him, said: "Breaking the bone of a dead person is like breaking it when he is alive." However, if their death has not been determined, there is no harm in inserting a breathing tube for their benefit.