Identification of terahertz absorption spectra of medicines using support vector machines

On the base of absorption spectra obtained in the range from 0.2 to 2 THz of six different medicines using terahertz time-domain spectroscopy (THz-TDS) technique, the THz absorption spectra of medicines were identified successfully by support vector machines (SVM). Firstly, absorption spectra of the six different medicines, which were pretreated by normalized unit, were used to train libsvm program. Secondly, absorption spectra of the medicines which were measured on different date, pretreated by normalized unit too, were identified by the libsvm and the identification rate of 100% was achieved. The results indicated that it is feasible to apply SVM on identification of medicines and providing an effective method in the secure inspection and identification for medicines.