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Published on: July 5, 2016
3-D shape measurement endoscope using a single-lens system
Takaaki Takeshita1, Minkyu Kim, Yoshikazu Nakajima
1School of Engineering, The University of Tokyo, Intelligent Modeling Laboratory Room # 602, Yayoi 2-11-16, Bunkyo, Tokyo, 113-8656, Japan. takeshita@image.t.u-tokyo.ac.jp
Purpose:
A three-dimensional (3-D) shape measurement endoscopic technique is proposed to provide depth information, which is lacking in current endoscopes, in addition to the conventional surface texture information. The integration of surface texture and 3-D shapes offers effective analytical data and can be used to detect unusual tissues. We constructed a prototype endoscope to validate our method.
Methods:
A 3-D measurement endoscope using shape from focus is proposed in this paper. It employs a focusing part to measure both texture and 3-D shapes of objects. Image focusing is achieved with a single-lens system.
Results:
A prototype was made in consideration of proper endoscope sizes. We validated the method by experimenting on artificial objects and a biological object with the prototype. First, the accuracy was evaluated using artificial objects. The RMS errors were 0.87 mm for a plate and 0.64 mm for a cylinder. Next, inner wall of pig stomach was measured in vitro to evaluate the feasibility of the proposed method.
Conclusion:
The proposed method was efficient for 3-D measurement with endoscopes in the experiments and is suitable for downsizing because it is a single-lens system.
