3-D shape measurement endoscope using a single-lens system.
OBJECTIVE
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.


CONCLUSIONS
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.
School 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
Takaaki
T
Takeshita
Minkyu
M
Kim
Yoshikazu
Y
Nakajima
D000465:Algorithms; D000818:Animals; D000886:Anthropometry / Q000295:instrumentation*; D019723:Endoscopes; D004867:Equipment Design; D005240:Feasibility Studies; D007089:Image Enhancement / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D007909:Lenses; D015203:Reproducibility of Results; D013270:Stomach / Q000033:anatomy & histology*; D013552:Swine