The respiratory polygraph looks for specific markers and oxygen levels in the patient’s blood during sleep. This exam is useful for confirming an obstructive sleep apnoea diagnosis. Unlike polysomnography, this test is carried out at home. The patient wears two belts (one around the chest and one around the lap) to record respiratory movements, a sensor at the base of their neck to record snoring and breathing sounds, an oximeter to measure blood oxygen levels, and a nasal cannula to monitor air flow. For more informations on polygraphy equipment, click here.