OBJECTIVETo achieve differential diagnosis of normal and malignant gastric tissues based on discrepancies in their dielectric properties using support vector machine.

METHODSThe 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

RESULTSThe 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.

CONCLUSIONThe support vector machine?assisted diagnosis is feasible for human malignant gastric tissues based on the dielectric properties.