A beam-splitter-type 3-D endoscope for front view and front-diagonal view images

作者：Kamiuchi Hiroki^*; Masamune Ken; Kuwana Kenta; Dohi Takeyoshi; Kim Keri; Yamashita Hiromasa; Chiba Toshio

来源：International Journal of Computer Assisted Radiology and Surgery, 2013, 8(1): 111-120.

DOI：10.1007/s11548-012-0678-5

• 3-D endoscope
• Field-of-view
• Beam splitter
• Polarization plate
• Minimally invasive surgery

In endoscopic surgery, surgeons must manipulate an endoscope inside the body cavity to observe a large field-of-view while estimating the distance between surgical instruments and the affected area by reference to the size or motion of the surgical instruments in 2-D endoscopic images on a monitor. Therefore, there is a risk of the endoscope or surgical instruments physically damaging body tissues. To overcome this problem, we developed a 7- mm 3-D endoscope that can switch between providing front and front-diagonal view 3-D images by simply rotating its sleeves.
This 3-D endoscope consists of a conventional 3-D endoscope and an outer and inner sleeve with a beam splitter and polarization plates. The beam splitter was used for visualizing both the front and front-diagonal view and was set at 25A degrees to the outer sleeve's distal end in order to eliminate a blind spot common to both views. Polarization plates were used to avoid overlap of the two views. We measured signal-to-noise ratio (SNR), sharpness, chromatic aberration (CA), and viewing angle of this 3-D endoscope and evaluated its feasibility in vivo.
Compared to the conventional 3-D endoscope, SNR and sharpness of this 3-D endoscope decreased by 20 and 7 %, respectively. No significant difference was found in CA. The viewing angle for both the front and front-diagonal views was about 50A degrees. In the in vivo experiment, this 3-D endoscope can provide clear 3-D images of both views by simply rotating its inner sleeve.
The developed 3-D endoscope can provide the front and front-diagonal view by simply rotating the inner sleeve, therefore the risk of damage to fragile body tissues can be significantly decreased.

• 出版日期2013-1