Vestibular autonomic reactions in pilots of modified helicopters detected at physical examination

Objective To observe the vestibular autonomic reactions in pilots of modified helicopters detected at physical examination. Methods Electrogastrograms（EGG） of 35 pilots of modified helicopters in normal state were recorded.Coriolis acceleration test was performed in the pilots on electric rotatory chair and stopped when nausea occurred.Then changes in their EGG before and after Coriolis acceleration test were recorded and the degrees of their vestibular autonomic reactions were compared with the reported findings in fighter pilots. Results The average amplitude,average rhythm disturbance,and normal slow wave of EGG for 4min were significantly lower in pilots of helicopters before Coriolis acceleration test than in pilots of fighters after Coriolis acceleration test（259.7μV vs 327.1μV,24.2% vs 28.6%,47.8% vs 38.9%,P＜0.01）.However,no significant difference was found in the average frequency of EGG and in the II° vestibular autonomic reactions between pilots of modified helicopters and fighters before and after Coriolis acceleration test 31.4%（11/35） vs 28.0%（7/25）. Conclusion The average amplitude,average rhythm disturbance,and normal slow wave after Coriolis acceleration test can be used as the indications of vestibular autonomic reactions in pilots of modified helicopters at physical examination.