Objective:To evaluate the clinical performance of radiation treatment equipment inspection status of the medical and health institutions in Nanjing. Methods: Twenty-two 60Coy teletherapy machine and 12 Teclast subsidiary medical accelerator were detacted from January 2012 to December 2012 in Nanjing. Results: The performance qualified rate of 60Coy teletherapy machine is higher. In other standards, the 60Coy teletherapy machines have different degrees of failures. The performance test results of electronic medical accelerator is good, the majority of medical electronic accelerator performance can comply with the relevant national standards. Conclusion: Regular checks on the performance of radiation treatment equipment and on time check can ensure clinical efficacy and safety of patients treated with radiotherapy treatment.

A revolving drum, about 40cm in diameter, with vertical stripes on its surface, was used in examination. The drum was held 50cm in front of the eyes of aircrew receiving examination. The horizontal optokinetic nystagmus was elicited by vertical black stripes moving horizontally. The examinee was instructed to gaze straight ahead at the black stripes, without deliberate fixation. The drum speed was kept constant at 20?, 40?,60?,80?,100?,120?/s. The velocity of the slow component of nystagmus, its frequency, amplitude and symmetry were recorded when the reaction reached its peak.The slow component velocity and the frequency were increased with the drum speed, but the amplitude was decreased with the drum speed. The wave forms of optokinetic nystagmus were usually of five types.