A fiber-optic Raman spectrum sensor system is used for the fast diagnosis of esophageal cancer during clinical endoscopic examination.The system contains a 785nm exciting laser,a Raman fiber-optic probe with 7 large c...A fiber-optic Raman spectrum sensor system is used for the fast diagnosis of esophageal cancer during clinical endoscopic examination.The system contains a 785nm exciting laser,a Raman fiber-optic probe with 7 large core fibers and a focus lens,and a highly sensitive spectrum meter.The Raman spectrum of the tissue could be obtained within 1 second by using such a system. A signal baseline removal and denoising technology is used to improve the signal quality.A novel signal feature extraction method for differentiating the normal and esophageal cancer tissues is proposed,based on the differences in half-height width(HHW)in 1200cm^-1 to 1400cm^-1 frequency band and the ratios of the spectral integral energy between 1600cm^-1-1700cm^-1 and 1500cm^-1- 1600cm^-1 band.It shows a high specificity and effectivity for the diagnosis of esophageal cancer.展开更多
A hybrid phase-sensitive optical time domain reflectometry （φ-OTDR） and Brillouin optical time domain reflectometry （B-OTDR） system which can realize simultaneous measurement of both dynamic vibration and static ...A hybrid phase-sensitive optical time domain reflectometry （φ-OTDR） and Brillouin optical time domain reflectometry （B-OTDR） system which can realize simultaneous measurement of both dynamic vibration and static strain is proposed. Because the Rayleigh scattering light and spontaneous Brilliouin scattering light are naturally frequency-multiplexed, the heterodyne asynchronous demodulation of frequency shift keying （FSK） in optical fiber communications is utilized, and the demodulations of the two scattering signals are synchronized. In addition, the forward Raman amplification is introduced to the system, which not only makes up for the deficiency of spontaneous BriUiouin scattering based distributed fiber sensor, but also has the merit of the single end measurement of B-OTDR. The designed φ/B-OTDR hybrid system has the sensing range of 49km with 10m spatial resolution. The vibration and strain experiments show that this hybrid system has great potential for use in long-distance structural health monitoring.展开更多
In order to enhance the signal-to-noise-ratio of a distributed acoustic sensing system based on phase-sensitive optical time-domain reflectometry （φ-OTDR）, we have proposed a combination of segmented unwrapping alg...In order to enhance the signal-to-noise-ratio of a distributed acoustic sensing system based on phase-sensitive optical time-domain reflectometry （φ-OTDR）, we have proposed a combination of segmented unwrapping algorithm, averaging estimation of phase difference, and infinite impulse response （IIR） filtering method. The enhancement of signal quality is numerically demonstrated. Moreover, we have studied the influence resulted from the light source noise on the φ-OTDR performance. The result has shown that when the linewidth of light source used in the φ-OTDR system is narrower, the performance of the system is better. In a word, such a φ-OTDR system could obtain higher quality demodulated signals when the narrower linewidth light source is chosen and the method of averaging estimation phase difference is used.展开更多
基金multicenter clinical study of endoscopic diagnosis of early esophageal cancer(Grant No.SWH2016ZDCX3007)the State 111 Project(Grant No.B14039)+3 种基金Application of endoscopic minimally invasive technique in diagnosis and treatment of digestive tract injury and disease(Grant No.SWH2016ZDCX2011)Study of effect on fibroblast transdifferentiation and prevention of postoperative esophagus stenosis through regulating the TRADD(Grant No. 81470907)the National Natural Science Foundation of China(NSFC)(Grant Nos.51627806and 51875091)Application of Raman imaging in the diagnosis of gastric cancer(Grant No. cstc2015shmszx 10017).
文摘A fiber-optic Raman spectrum sensor system is used for the fast diagnosis of esophageal cancer during clinical endoscopic examination.The system contains a 785nm exciting laser,a Raman fiber-optic probe with 7 large core fibers and a focus lens,and a highly sensitive spectrum meter.The Raman spectrum of the tissue could be obtained within 1 second by using such a system. A signal baseline removal and denoising technology is used to improve the signal quality.A novel signal feature extraction method for differentiating the normal and esophageal cancer tissues is proposed,based on the differences in half-height width(HHW)in 1200cm^-1 to 1400cm^-1 frequency band and the ratios of the spectral integral energy between 1600cm^-1-1700cm^-1 and 1500cm^-1- 1600cm^-1 band.It shows a high specificity and effectivity for the diagnosis of esophageal cancer.
基金The authors gratefully acknowledge the previous supports provided by the National High Technology Research and Development Program of China （863 Program, Grant No. 2007AA01Z245）, and the supports provided for this research by the Major Program （Grant No. 61290312） and Youth Foundation （Grant No. 61301275） of the National Science Foundation of China （NSFC）, and the Fundamental Research Funds for the Central Universities （Grant No. ZYGX2011 J010）. This work is also supported by Program for Changjiang Scholars and Innovative Research Team inUniversity （PCSIRT, IRTI218）, and the 111 Project （B14039）. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.
基金This work is supported by the National Nature Science Foundation of China （NSFC） under grants （61290312 and 61205048）, the PCSIRT （IRT1218）, and the 111 Project （B14039）.
文摘A hybrid phase-sensitive optical time domain reflectometry （φ-OTDR） and Brillouin optical time domain reflectometry （B-OTDR） system which can realize simultaneous measurement of both dynamic vibration and static strain is proposed. Because the Rayleigh scattering light and spontaneous Brilliouin scattering light are naturally frequency-multiplexed, the heterodyne asynchronous demodulation of frequency shift keying （FSK） in optical fiber communications is utilized, and the demodulations of the two scattering signals are synchronized. In addition, the forward Raman amplification is introduced to the system, which not only makes up for the deficiency of spontaneous BriUiouin scattering based distributed fiber sensor, but also has the merit of the single end measurement of B-OTDR. The designed φ/B-OTDR hybrid system has the sensing range of 49km with 10m spatial resolution. The vibration and strain experiments show that this hybrid system has great potential for use in long-distance structural health monitoring.
文摘In order to enhance the signal-to-noise-ratio of a distributed acoustic sensing system based on phase-sensitive optical time-domain reflectometry （φ-OTDR）, we have proposed a combination of segmented unwrapping algorithm, averaging estimation of phase difference, and infinite impulse response （IIR） filtering method. The enhancement of signal quality is numerically demonstrated. Moreover, we have studied the influence resulted from the light source noise on the φ-OTDR performance. The result has shown that when the linewidth of light source used in the φ-OTDR system is narrower, the performance of the system is better. In a word, such a φ-OTDR system could obtain higher quality demodulated signals when the narrower linewidth light source is chosen and the method of averaging estimation phase difference is used.
基金This work was supported by the National Science Foundation of China （NSFC 61307088） and the Fundamental Research Funds for the Central Universities （ZYGX2012J008）. This work was supported by the National Natural Science Foundation of China （Nos. 61307088, 61205067, and 61505020） and the National Defense Pre-Research Foundation of China （9140A02050413DZ02023）.
