FD-71闪烁辐射仪的三次刻度和比对

本文介绍了FD-71闪烁辐射仪三次刻度和比对的目的、方法和主要结果。实验表明,实验室刻度和现场妻Ⅱ度两种力法是等效的。FD-71具有良好的均匀性,不同的仪器之间,现场测量结果的变异系数一般在5%以内。该仪器具有良好的长期稳定性,在一年之内仍能保持原来的刻度,40台FD-n刻度一年以后,测定结果的变异系数为3.5%,测定均值与高压电离室在3%以内一致。FD-71与高压电离室之间,呈现良好的直线性,其车日关系数约为0.9998。在正常辐射水平下,它与高压电离室的测定结果一般在±10%以内符合。     

Microwave Radiometric Thermometry and its Potential Applicability to Ablative Therapy

Introduction: Current techniques for estimating catheter tip temperature in ablative therapy for cardiac arrhythmias rely on thermocouples or thermistors attached to or embedded in the tip electrode. These methods may reflect the electrode temperature rather than the tissue temperature during electrode cooling so that the highest temperature away from the ablation site may go undetected. A microwave radiometer is capable of detecting microwave radiation as a result of molecular motion. In this study, we evaluated microwave radiometric thermometry as a new technique to monitor temperature away from the electrode tip during ablative therapy utilizing a saline model.Methods and Results: A microwave radiometer antenna and fluoroptic thermometer were inserted in a test tube with circulating room temperature saline kept constant at 23.5°C while the surrounding saline bath was heated from 37°C to 70°C. For every degree rise in the warm saline bath placed either 5mm or 8mm from the radiometer antenna, the radiometer temperature changed 0.26°C and 0.14°C respectively while the fluoroptic temperature probe remained constant at 23.5°C. The radiometer temperature was highly correlated with the warm saline bath temperature (R²=0.997 for warm saline 5mm from the antenna, R²=0.991 for warm saline 8mm from the antenna).Conclusions: Microwave radiometry can estimate distant temperatures by detecting microwave electromagnetic radiation. The sensitivity of the microwave radiometer is also distance-dependent. The microwave radiometer thus serves as a promising instrument for monitoring temperatures at depth away from the catheter-electrode tip in ablative therapy for cardiac arrhythmias.     

Ground-based observations of ultraviolet and total solar radiation in Shenyang, northeast China

Objective This work explores the diurnal variation of Solar ultraviolet radiation (UVR) and total solar radiation (TSR) in northeast China,using daily observations of UVR and TSR in Shenyang.Methods UVR and TSR measurements were carried out from March 1st,2006 to December 31st,2009 in Shenyang,Liaoning province,China (41°51' N,123°27' E).Results Both TSR and UVR showed seasonal variation,reaching the highest levels in summer and the lowest in winter.They showed the greatest fluctuation in summer and autumn....     

Management of phototherapy for neonatal hyperbilirubinemia: Is a new radiometer applicable for all wavelengths and light source types?

Background: To evaluate the clinical effects of phototherapy for neonatal hyperbilirubinemia, it is necessary to measure the rate of cyclobilirubin production, which represents the main photochemical pathway of bilirubin metabolism. Since the Atom Phototherapy Analyzer can be used to calculate the theoretical relative light energy of irradiance as a means of assessing the cyclobilirubin production rate for each wavelength spectrum, the clinical effect of phototherapy can be evaluated regardless of the light source type. Using the Atom Phototherapy Analyzer, the correlation between the irradiance of various light sources with different peak wavelengths and the rate of cyclobilirubin production was investigated in vitro. We also investigated the utility of green LED in vitro. Methods: A bilirubin‐albumin complex solution was prepared, poured into tubes, and irradiated using various light sources. All light sources used were bed‐type phototherapy devices; that is, green and blue LED and green and blue fluorescence tubes. The concentrations of photoisomers were measured after irradiation and compared with the irradiance of the light sources. Results: The irradiance measured by the Atom Phototherapy Analyzer decreased in the following order: blue fluorescence tube > green LED > blue LED > green fluorescence tube. The cyclobilirubin production rates and irradiance values of the light sources were significantly positively correlated (R²= 0.93, P < 0.05). Conclusion: Our data indicate that the Atom Phototherapy Analyzer can be used to objectively evaluate the effects of phototherapy using various light sources. Further, the effects of green LED were similar to those of other light sources in vitro.