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.
Continuous positive airway pressure (CPAP) therapy is a common treatment for obstructive sleep apnea. It includes a small machine that supplies a constant and steady air pressure, a hose, and a mask or nose piece. Common problems with CPAP include a leaky mask, trouble falling asleep, and a dry mouth or nose.