The victim was bound upon this wheel, on his knees, with his hands behind his back.
A continuous positive airway pressure (CPAP) machine was initially used mainly by patients for the treatment of sleep apnea at home, but now is in widespread use across intensive care units as a form of ventilation.
CPAP. the most common and most effective treatment for obstructive sleep apnea (OSA) or sleep disordered breathing. The continuous flow of air from a CPAP machine keeps your airway from collapsing during sleep and helps maintain stable oxygen levels as you sleep.