RESUMEN
Objective To propose specific suggestions for exemption management of X-ray devices applying for exemption management. Methods The weight analysis of influence of shielding thickness and tube voltage on the radiation dose leakage of low-energy X-ray devices was carried out through test analysis, and the radiation status of 50 X-ray devices applied for end-user exemption in Shenzhen, China was investigated. Results There was no significant correlation between the ambient dose equivalent rate and the tube voltage and tube current of the X-ray device. The ambient dose equivalent rate of 50 X-ray devices was 0.16-1.20 μSv/h. Among them, 8 X-ray devices had radiation dose leakage, that is, the ambient dose equivalent rate was greater than 0.36 μSv/h; the ambient dose equivalent rate of one X-ray device was 1.2 μSv/h, exceeding exemption management requirements. Conclusion Applications for exemption management and filing of X-ray devices should be treated differently, and their own shielding effect and inherent safety have a greater impact on radiation safety, which should be focused on.
RESUMEN
The purpose of this study was prospectively to research the relationship between EEG power spectrum and anesthesia depth. Twenty-four patients,aged 20 to 50 years , ASA grade ,scheduled for selected surgical operations, were randomly divided into two groups:enflurane and isoflurane groups. Anesthesia was induced by thiopental 5 mg/kg and atracurium 6-7 mg/kg intravenously and maintained by inhalation anesthetics. After intubation patients were ventilated mechanically to maintain the level of PETCO2 between 4. 27 and 4. 93 kpa. NIBP,HR,SpO2 , ECG and EEG were recorded during anesthesia. According to TOF stimulation test intravenous atracurium 10-15 mg was given intermittently to maintain the ratio of T4/T1 less than 25%. Two channels EEG monitor was applied with the filtration range from 0 to 30 Hz Anesthesia level, adjusted at 0. 5,0. 8, 1. 0, 1. 3, 1. 5, 1. 3, 1. 0, 0.8 or 0. 5 MAC in sequence ,was maintained for 10 to 15 minutes before SEF (spectral edge frequency)and MPF (median power frequency) were recorded. NIBP decreased and HR increased with the inhaled agent concentration (IAC) level rising. The lowest BPs were 13. 1 /9. 33 kPa and 12. 9/8. 1kpa in both groups. There were negative remarkable correlations between either SEF or MPF and IAC in both groups (=- 0. 94 and -0. 82,P