Qi Qihar University

Longjiang, China

Qi Qihar University

Longjiang, China
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Liu X.,Johns Hopkins University | Ramella-Roman J.C.,Catholic University of America | Huang Y.,Johns Hopkins University | Guo Y.,Johns Hopkins University | And 2 more authors.
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2013

In this study, we propose a generic speckle simulation for optical coherence tomography (OCT) signal, by convolving the point-spread function (PSF) of the OCT system with the numerically synthesized random sample field. We validate our model and use the simulation method to study the statistical properties of cross-correlation coefficients between A-scans, which have been recently applied in transverse motion analysis by our group. The results of simulation show that oversampling is essential for accurate motion tracking; exponential decay of OCT signal leads to an underestimate of motion that can be corrected; lateral heterogeneity of sample leads to an overestimate of motion for a few pixels corresponding to the structural boundary. © 2012 Optical Society of America.

Wei L.,Qi Qihar University | Guo Y.,Qi Qihar University | Guo Y.,Johns Hopkins University
Optical Engineering | Year: 2013

Based on the principle of laser-linear array charge-coupled device (CCD) detection technology, a high accuracy nontouch on-line system for monitoring roller wear is brought forward. The principle and composition of the laser-linear array CCD detection system and the operation process were expatiated. Aiming at the errors of the roller's axes shifting during the detection process, compensating steps were adopted from the vertical and the parallel direction to the detection surface. This effectively enhanced the accuracy of the detection system. Experiments proved that the accuracy of the system could reach the demand of the practical production process. It provides a new method for high speed, accuracy, and automatic on-line monitoring of roller wear. r shapegear array CCD detection. A simulation-software program is also compiled based on this principle. By using this program, the I/O signals's data for this system is gained and the detection curves can be drawn automatically. © The Authors.

Guo Y.,Qi Qihar University | Guo Y.,Johns Hopkins University | Wang Y.,Yanshan University | Jin M.,Qi Qihar University
Optik | Year: 2014

By studying the output characteristics of random type optical fiber displacement sensor and semicircular type optical fiber displacement sensor, a sensor of new structure was designed. Using the ratio of the two output signals as the output of the whole system, the measurement range was enlarged, the linearity was improved, and the errors of reflective and absorbent changing in target surface are automatically compensated. Meantime, an optical fiber sensor model of correcting static error and linearizing the output curve based on BP artificial neural network was set up. The intrinsic errors such as fluctuations in the light, circuit excursion, the intensity losses in the fiber lines and the additional losses in the receiving fiber caused by bends were eliminated. By discussing in theory and experiment, the error of nonlinear is 2.9%, the measurement range reaches to 3.0 mm and the relative accuracy is 2%. This kind of sensor offers such advantages as no electromagnetic interference, simple construction, high sensitivity, good accuracy and stability. © 2013 Elsevier GmbH.

Guo Y.,Qi Qihar University | Guo Y.,Johns Hopkins University | Wang Y.,Yanshan University | Liu X.,Johns Hopkins University
Optics and Lasers in Engineering | Year: 2014

According to the characteristics and the demand of the detection accuracy, an optical detection scheme for monitoring roller condition was proposed and experimentally demonstrated. By analyzing the principle and setting up the mathematical model, a real-time optical detection system is presented in this paper. Moreover error compensation methods of the optical detection part, installation and movement of the detection device, and eccentricity, roundness and rotary movement of the working roller have been adopted in order to ensure the detection process in atrocious condition and to examine roller's shape precisely in real-time. A series of experiments were performed to verify the validity and practical applicability of the detection system. It provides a new method for high speed, accurate and automatic real-time detection for roller condition. © 2013 Elsevier Ltd. All rights reserved.

Guo Y.,Qi Qihar University | Guo Y.,Johns Hopkins University | Wei L.S.,Qi Qihar University | Liu X.,Johns Hopkins University
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2013

OCT is playing an important role in interventional operations and some other therapies recent years. In many interventional operations the temperature of the tissue is also one of the main factors that will influence the operation result. Therefore monitoring the temperature of the operational tissue real time is critical for the operation and therapy. In this paper an endoscopic OCT probe for interventional operation with real time temperature monitoring function is presented. It consists of a micro OCT probe and a fluorescence thermometer. These two parts are installed in a base with a transparent shell of 3.0mm diameter and share one light source. Principles and structures of each part and the whole system are stated in detail. The experimental results indicate that the interventional operations OCT system can be used for rotated scanning imaging to obtain more tissue information and at the same time the temperature of the operational tissue can be monitored precisely. © 2013 Copyright SPIE.

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