南方医科大学学报 ›› 2017, Vol. 37 ›› Issue (12): 1637-.

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基于介电特性的人体恶性胃组织支持向量机辅助诊断方法

张洒,厉周,辛学刚   

  • 出版日期:2017-12-20 发布日期:2017-12-20

Support vector machine-assisted diagnosis of human malignant gastric tissues based on dielectric properties

  • Online:2017-12-20 Published:2017-12-20

摘要: 目的基于正常和恶性胃组织介电特性值的差异,运用支持向量机(SVM)对介电特性进行自动鉴别。方法用开端同轴探 头法测量正常和恶性胃组织在42.58~500 MHz频率范围内的介电特性,并对测得的介电特性数据进行Cole-Cole模型拟合。接 收机操作特性(ROC)曲线分析法被用来对各频率点下介电常数、电导率和Cole-Cole拟合参数的鉴别能力进行评估。SVM被 用来对正常和恶性胃组织进行鉴别,鉴别正确率由k折交叉验证进行计算。结果在测量频率范围内,5个低端频率点下介电常 数的ROC曲线下面积达到0.8以上。这5个频率下介电常数的组合作为特征值与SVM结合取得了最高鉴别正确率84.38%, MATLAB运行时间为3.40 s。结论本文提出的基于介电特性的恶性人体胃组织支持向量机辅助诊断方法具有可行性。

Abstract: Objective To achieve differential diagnosis of normal and malignant gastric tissues based on discrepancies in their dielectric properties using support vector machine. Methods The dielectric properties of normal and malignant gastric tissues at the frequency ranging from 42.58 to 500 MHz were measured by coaxial probe method, and the Cole-Cole model was used to fit the measured data. Receiver-operating characteristic (ROC) curve analysis was used to evaluate the discrimination capability with respect to permittivity, conductivity, and Cole-Cole fitting parameters. Support vector machine was used for discriminating normal and malignant gastric tissues, and the discrimination accuracy was calculated using k-fold cross-validation. Results The area under the ROC curve was above 0.8 for permittivity at the 5 frequencies at the lower end of the measured frequency range. The combination of the support vector machine with the permittivity at all these 5 frequencies combined achieved the highest discrimination accuracy of 84.38% with a MATLAB runtime of 3.40 s. Conclusion The support vector machine-assisted diagnosis is feasible for human malignant gastric tissues based on the dielectric properties.