3. 5 days after the initial surgery, and following the protocol in place for these procedures, the tunnelization and battery placement will take place. This is done under general anaesthesia. During anaesthetic induction, the patient is exposed to incremental doses of propofol. Different plasmatic concentrations will be targeted using the mathematical model in the target controlled infusion (TCI) pump. These recordings will be called "propofol at a 0.5, 1, 1.5, 2, 2.5 μg/mL".