It is more common to perform non-invasive examination during general anaesthesia to ensure effective perioperative patient care. To achieve these results, researchers and clinicians are seeking out different technologies and developing new equipment. One such apparatus is a cerebral oximeter, which is used during cardiac surgery with cardiopulmonary bypass for neuroprotection management for reducing risk of postoperative neurological injury (cerebral stroke, neurocognitive dysfunction, and cerebral haemorrhage). A cerebral oximeter performs non-invasive transcutaneous measurements using near infrared radiation to assess the oxygenation of tissues. The objective of the study was to determine if the angle and thickness of a patient’s skull affects measurements. Intralipid water solution, gelatine, and ink were used to make six phantoms with skull thickness ranging from 6 to 11 mm. All phantoms were bent froma0to20 degrees angle. The cerebral oximeter SOMETICS INVOS 5100C was used to perform regional oximetry measurements. For skull thickness of 11 mm, the rSO2 was 45.8% (SD 0.96); for skull thickness of 10 mm, the rSO2 was 45.25% (SD 2.22); for skull thickness of 9 mm, the rSO2 was 32% (SD 1.63); for skull thickness of 8 mm, the rSO2 was 17% (SD 1.83); for skull thickness of 7 mm, the rSO2 was 15% (SD 0); for skull thickness of 6 mm, the rSO2 was 15% (SD 0). No significant changes were observed regarding the angle of the skull phantom. The thickness of the bone layer of the skull phantom affected the regional oximetry results, whereas the angle of the skull did not affect it.