Terahertz Spectral Characteristics Research Of Gastric Carcinoma

Terahertz Time-domain Spectroscopy(THz-TDS)technology is a new coherent detection technology,which attracted widespread attention in the field of biomedicine recent years.Terahertz wave’s energy is low,using terahertz wave to detect biological tissue won’t cause ionization damage.In addition,the characteristic spectrum of many biological macromolecules’ vibration level locates in the terahertz frequency range,thus biological tissue can be studied by terahertz spectroscopy technology at the molecular level.The current world’s cancer incidence keep increasing year by year,and gastric cancer is one of the three major cancer whose mortality rate ranks among the top.With the constantly understanding of cancer,human come to realize that the prevention and early detection is one of the best ways to treat cancer.In order to achieve accurate and rapid diagnosis of the gastric cancer,we use Terahertz Time-domain Spectroscopy technology analyzing spectral characteristics of the gastric cancer tissues and normal tissues and studying terahertz wave’s disparate impact which caused by cancerous.All of these are in order to verify the feasibility of Terahertz Time-domain Spectroscopy technology used in the diagnosis of gastric cancer and explore a simple,high sensitive method for the diagnosis of gastric cancer.The main work of this paper are summarized as follows:Firstly,it described the nature of the terahertz wave,the generation and detection methods and Terahertz Time-domain Spectroscopy system.Combined with relevant biomedical theory,it gave a briefly resolution of terahertz technology used for cancer detection’s mechanism.Secondly,it collected stomach’s cancer tissues and normal tissues,prepared slices which were frozen dried for terahertz spectroscopy analysis,then used Terahertz Time-domain Spectroscopy system to obtain the spectral data of the samples.The study found: gastric cancer and normal tissues’ spectrum of the same patient and normal tissues’ spectrum between different patients both have lager difference,but the gastric tissues’ absorption spectrum of different patients havesame characteristics.That is both in the 0.5-0.8THz and 1.4-1.7THz will appear an absorption peak.In addition,it discussed the absorption peak appears in the spectrum combined with biological tissue’s cancer pathology knowledge and it maybe caused by elevated levels of bound water,glutamic acid and tryptophan in gastric carcinoma.Lastly,in order to achieve the accurate diagnosis of gastric cancer,it studied the determination method of gastric cancer tissues and normal tissues based on Regularized Extreme Learning Machine.Principal Component Analysis was used to reduce the terahertz absorption spectra data’s dimension and Regularized Extreme Learning Machine was used to classify the samples.Experimental result shows that proposed method has higher accuracy compared with traditional Linear Discriminant Analysis and Support Vector Machine,it can recognize gastric cancer tissues and normal tissues well.Studies have shown that gastric detection methods based on Terahertz Time-domain Spectroscopy technology can distinguish normal and cancerous tissues well,it has good prospects in the detection of gastric carcinoma.