基于拟合法和谱减法的牙釉质电子顺磁共振波谱处理方法对比研究  

Study on the comparison of processing method of EPR spectrum of tooth enamel based on the fitting process method and spectral subtraction method

作　　者：林军平 刘玉连[1] 焦玲[1] 阮书州 苏锴骏 董伟 王海云 张文艺[1] LIN Jun-ping;LIU Yu-lian;JIAO Ling(Institute of Radiation Medicine,Chinese Academy of Medical Sciences and Peking Union Medical College,Tianjin 300192,China)

机构地区：[1]中国医学科学院北京协和医学院放射医学研究所,天津300192

出　　处：《中国医学装备》2022年第4期54-59,共6页China Medical Equipment

基　　金：天津市科技计划(20JCQNJC00330)“用于核应急中子剂量检测的级联GEM组织等效正比计数器研究”;核探测与核电子学国家重点实验室资助项目(SKLPDE-KF-202106)“核应急中基于GEM的低放气率微腔TEPC研制”。

摘　　要：目的:建立拟合法和谱减法的牙釉质电子顺磁共振(EPR)波谱处理方法,分析对比两种方法处理羊牙釉质EPR波谱的结果。方法:收集自由放养的2~5岁山羊牙齿,根据年龄分为2岁组、3岁组和5岁组,采用物理化学结合的方法获取3组年龄不同的山羊牙釉质样品,测量牙釉质样品的EPR波谱。利用基于矩阵模型的拟合法和谱减法处理EPR波谱,获取辐射诱导信号(RIS)的强度,对RIS强度及其对应的照射剂量进行线性回归分析,并利用曲线方程估算样品受照剂量。比较两种方法的剂量估算下限,以及估算结果的准确度和精确度。结果:拟合法和谱减法的剂量估算下限分别为0.06 Gy和0.1 Gy。当照射剂量<0.1 Gy时用拟合法处理;谱减法和拟合法的百分误差期望值分别为22.04%和18.19%,拟合法的准确度高于谱减法;精确度范围分别为0.095~0.217、0.088~0.214,拟合法的精确度高于谱减法。结论:拟合法与谱减法相比,波谱处理过程更加简化,可提高EPR波谱处理的速度和可靠性,并可提高剂量估算的准确度、精确度。拟合法可降低剂量估算下限,并可在低剂量区提供较为准确的估算结果。Objective:To establish the processing methods of electron paramagnetic resonance(EPR)spectrum of teeth enamel based on the fitting process method and spectral subtraction method,and analyze and compare the results of the EPR spectrum of two kinds of methods in processing teeth enamel.Methods:Teeth of goats aged 2-5years old that were feeding as free method were selected,and they were divided into 2 years old group,3 years old group and 5years old group according to the ages of goats.The combined method of physics and chemistry was adopted to obtain teeth enamel samples of goats of 3 groups with different ages,and the EPR spectrums of these teeth enamel samples were measured.The fitting method and spectral subtraction method based on matrix model were used to process EPR spectrum,so as to obtain the intensity of adiation-induced signal(RIS).The RIS intensity and the corresponding radiation dose were used to analyze linear regression,and then the curve equation was used to estimate exposure dose of sample.The lower limit of dose estimation,and the accuracy and precision of estimation results of the two kinds of methods were compared.Results:The lower limits of dose estimation of fitting method and spectral subtraction method were 0.06 Gy and 0.1 Gy,respectively.The fitting method should be used when the radiation dose was less than 0.1 Gy.The expectation value of percentage error of spectral subtraction method and fitting method was 22.05%and 17.33%,respectively,which meant the accuracy of fitting method was higher than that of spectral subtraction method.And the ranges of precisions of them were 0.095-0.217 and 0.088~0.214,respectively,which meant the precision of fitting method was higher.Conclusion:Compared with the spectral subtraction method,the processing procedure of the spectrum of fitting method is more simplified,which can improve the velocity and reliability of processing EPR spectrum,and can increase the accuracy and precision of dose estimation.In addition,the fitting method can reduce lower limit of d

关 键 词：电子顺磁共振(EPR) 牙釉质 波谱拟合 剂量估算 

分 类 号：R445.2[医药卫生—影像医学与核医学]