The Development Of The Portable Raman Gastroscope Probe And The Application Evaluation In Diagnosis Of Gastric Mucosal Disease

Research Background:Gastric cancer is one of the most common malignant tumors,which morbidity and mortality are high.Out of the 183 countries in the world,the incidence of gastric cancer in China was in the fifth place,and the death rate was in 6th place.Our country is facing with a severe disease burden.Gastric cancer can occur at any age and the incidence increases significantly with age.The prognosis of gastric cancer is closely related to the staging stage,and early diagnosis is very important for early treatment of gastric cancer.At present,gastroscope,ultrasound gastroscope,CT,hematological tumor markers are widely used in clinic.The definitive diagnosis of gastrie cancer depends on pathological results,which is closely related to the doctor’s experience.Besides,there are risks of bleeding and perforation.To establish real-time,nondestructive,objective,accurate diagnostic techniques and methods based on gastroscope has extremely important significance and clinical application potential.Normal gastric mucosa has a typical Raman peaks.When the cell had become cancerous,it will show different Raman peaks.We can accurately identify normal tissue and tumor tissue with the help of chemometrics.Raman spectroscopy has been used in the diagnosis of gastric cancer for more than a decade.The results of previous studies confirmed that the Raman spectrum can identify gastric cancer from different method,laying a foundation for the application of Raman spectroscopy to clinical application.but past research methods couldn’t meet the needs of clinical application for in order to be able to in vivo observation,real-time access to different Raman spectra changes in gastric mucosa tissue diagnosis,this research explored and developed the portable Raman endoscopy system.Objective:The application of Raman spectroscopy to the detection of clinical gastric cancer can realize the early,noninvasive and rapid diagnosis of gastric cancer.At present,there are no reports on the design and development of portable Raman gastric cancer detection system in China.The purpose of our study is to build a portable Raman gastric cancer detection system,and to evaluate its value in the diagnosis of gastrie cancer and to lay the foundation for the research and development of Raman gastroscope in the future.Methods:Firstly,we chose 785nm semiconductor laser emitter,conduction fiber,optical fiber probe and micro spectrometer to build the portable Raman gastric cancer detection system.Secondly,the Raman spectra of normal gastric tissues and gastric cancer tissues were collected by the portable Raman gastric cancer detection system and Laser Micro-Raman Spectrometer.After preprocessing the spectrum,we can find the difference between normal tissue and gastric cancer.Based on pathological diagnosis results,we evaluate the diagnostic efficacy of portable Raman spectroscopy by accuracy,sensitivity and specificity.Result:Based on extensive literature review and Monte Carlo simulation we have developed the portable Raman gastroscope probe independently,and it can obtain the raman spectra of gastric mucosa tissues quickly in vitro.The portable Raman gastroscope probe can obtain the raman spectra of normal gastric tissues and gastric cancer,just like Laser Micro-Raman Spectrometer,and their raman spectroscopy showed significant difference.After the preprocess of smoothing,baseline elimination and normalization,combined with stoichiometry,these spectroscopic data were analysed by the way of Principle Component Analyses.Both the portable Raman endoscopy and microscopic Raman spectroscopy provided significant difference between the Raman spectrum of gastric cancer tissue and normal tissue.The accuracy,sensitiveness and specificity of portable Raman endoscopy were respectively 82.1%、91.07%、87.5%.Conclusion:The portable Raman gastric detection can obtain abundant spectral data of gastric mucosa tissues.Raman spectrum combined with stoichiometry can provide an effective way in the diagnosis of gastric cancer.The portable Raman gastric cancer detection system can distinguish gastric cancer tissue from normal tissue effectively but the device could not be examined in vivo by gastroscope,and have great potential applications.We will continue to shrink the device and combine it with gastroscope to realize non-invasive detection in vivo and in situ.The thesis has established the theory and the practice foundation for developing Raman gastroscope applied to clinical practice.