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.
See also: CPAP (continuous positive airway pressure) Sleep Apnea machine. Nasal Continuous Positive Airway Pressure (CPAP) delivers air into your airway through a specially designed nasal mask or pillows. The flow of air creates enough pressure when you inhale to keep your airway open. CPAP is considered the most effective nonsurgical treatment for snoring and sleep apnea. See patients taking CPAP w/humidifier.