Kazunori Yokoyama

Surgical Skill Evaluation by Force Data for Endoscopic Sinus Surgery Training System

In most surgical training systems, task completion time and error ratio are common metrics of surgical skill. To avoid applying unnecessary and injurious force to the tissue, surgeons must know for themselves how much force they are exerting as they handle surgical tools. Our goal is to develop an endoscopic sinus surgery (ESS) training system that quantitatively evaluates the trainees surgical skills. In this paper, we present an ESS training system with force sensors for surgical skill evaluation. Our experiment revealed that the integral of the force data can also be one of the useful metrics of surgical skill.

Photopolymer for recording transmission and reflection volume phase holograms

Recently, a number of photopolymers for recording volume phase hologram have been proposed. We have developed the novel photopolymerizable materials for recording the transmission and reflection volume holograms. These hologram recording materials are composed of lower-refractive index binding polymers, higher-refractive index monomers, plasticizers, photoinitiators, and photosensitive dyes. In this paper, the experimental result for the holograms using these materials would be presented. These materials can record both transmission and reflection volume holograms with high sensitivity, high diffraction efficiency, high resolution, and high heat resistance. These holograms were self-developing and white light was sufficient for fixing. After recording holograms, no treating to fix such as heat processing or postexposure of UV were needed. The optical and thermal properties of obtained hologram are written as follow. The diffraction efficiencies were over 90 percent. Transmittance was about 90 percent. Sensitivities were less than 10 mJ/cm2 from UV light to Ar ion laser. And these holograms have the heat resistance over 100 degrees C. The mechanisms of refractive index modulation in photopolymerization of the materials are also discussed.