ABSTRACT
We experimentally demonstrate a simple and novel technique to simultaneously insert a liquid into the core of a hollow-core photonic crystal fiber (PCF) and a different liquid into its cladding. The result is a liquid-core, liquid-cladding waveguide in which the two liquids can be selected to yield specific guidance characteristics. As an example, we tuned the core-cladding index difference by proper choice of the inserted liquids to obtain control over the number of guided modes. Single-mode guidance was achieved for a particular choice of liquids. We also experimentally and theoretically investigated the nature of light confinement and observed the transition from photonic bandgap to total internal reflection guidance both with the core-cladding index contrast and with the PCF length.
ABSTRACT
In vertebroplasty, physician relies on both sight and feel to properly place the bone needle through various tissue types and densities, and to help monitor the injection of PMMA or cement into the vertebra. Incorrect injecting and reflux of the PMMA into areas where it should not go can result in detrimental clinical complication. This paper focuses on the human-computer interaction for simulating PMMA injection in our virtual spine workstation. Fluoroscopic images are generated from the CT patient volume data and simulated volumetric flow using a time varying 4D volume rendering algorithm. The user's finger movement is captured by a data glove. Immersion CyberGrasp is used to provide the variable resistance felt during injection by constraining the user's thumb. Based on our preliminary experiments with our interfacing system comprising simulated fluoroscopic imaging and haptic interaction, we found that the former has a larger impact on the user's control during injection.
