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 stands for Continuous Positive Airway Pressure. CPAP therapy is the most commonly recommended, and the most effective, treatment for obstructive sleep apnea. A CPAP machine provides air at a constant prescribed pressure. The air is delivered to the person through a tube and a CPAP mask.