Eye Explorer: A robotic endoscope holder for eye surgery.

BACKGROUND: Holding endoscopes by hand when performing eye surgery reduces the dexterity of the surgeon. METHODS: A robotic endoscope holder called "Eye Explorer" is proposed to hold the endoscope and free the surgeon's hand. RESULTS: This device satisfies the engineering and clinical requirements of eye surgery. The force for manual operation is less than 0.5 N. The observable ranges inside the patient's eye considering horizontal and vertical perspectives are 118° and 97°, and the motion of the holder does not interfere with the surgeon's hand and other surgical devices. The self-weight compensation can prevent the endoscope from falling when extra supporting force is released. When comparing the external force exerted on the eye by the Eye Explorer with that in case of manual operation, a decrease of more than 15% can be observed. Moreover, the consumption time of endoscope view adjustment using the Eye Explorer and manual operation does not significantly differ. CONCLUSION: The Eye Explorer allows dual-hand operation, facilitating a successful endoscopic eye surgery.

Pneumatically driven surgical forceps displaying a magnified grasping torque.

BACKGROUND: Sensing the grasping force and displaying the force for the operator are important for safe operation in robot-assisted surgery. Although robotic forceps that senses the force by force sensors or driving torque of electric motors is proposed, the force sensors and the motors have some problems such as increase in weight and difficulty of the sterilization. METHOD: We developed a pneumatically driven robotic forceps that estimates the grasping torque and display the magnified torque for the operator. The robotic forceps has a master device and a slave robot, and they are integrated. In the slave side, the grasping torque is estimated by the pressure change in the pneumatic cylinder. A pneumatic bellows display the torque through a linkage. RESULTS: We confirmed that the slave robot follows the motion of the master, and the grasping torque is estimated in the accuracy of 7 mNm and is magnified and displayed for the operator. CONCLUSIONS: The pneumatically driven robotic forceps has the capability in the estimation of the grasping torque and display of the torque. Regarding future work, the usability and fatigues of the surgeons must be evaluated.

Kinetics and mechanism of selenate and selenite removal in solution by green rust-sulfate.

This work investigated the removal of selenite and selenate from water by green rust (GR) sulfate. Selenite was immobilized by simple adsorption onto GR at pH 8, and by adsorption-reduction at pH 9. Selenate was immobilized by adsorption-reduction to selenite and zero valent selenium (Se0) at both pH 8 and 9. In the process, GR oxidized to a mixture of goethite (FeOOH) and magnetite (Fe3O4). The kinetics of selenite and selenate sorption at the GR-water interface was described through a pseudo-second-order model. X-ray absorption spectroscopy data enabled to elucidate the concentration profiles of Se and Fe species in the solid phase and allowed to distinguish two removal mechanisms, namely adsorption and reduction. Selenite and selenate were reduced by GR through homogeneous solid-phase reaction upon adsorption and by heterogeneous reaction at the solid-liquid interface. The selenite reduced through heterogeneous reduction with GR was adsorbed onto GR but not reduced further. The redox reaction between GR and selenite/selenate was kinetically described through an irreversible second-order bimolecular reaction model based on XAFS concentration profiles. Although the redox reaction became faster at pH 9, simple adsorption was always the fastest removal mechanism.

Silicate Removal in Aluminum Hydroxide Co-Precipitation Process.

The removal mechanisms of silicate using an aluminum hydroxide co-precipitation process was investigated and compared with an adsorption process, in order to establish an effective and validated method for silicate removal from wastewater. Adsorption isotherms, XRD and FT-IR analyses showed that silicate uptake occurred by adsorption to boehmite for initial Si/Al molar ratios smaller than two, but by precipitation of poorly crystalline kaolinite for the ratios larger than two, in both co-precipitation and adsorption processes. Silicate was removed by two steps: (i) an initial rapid uptake in a few seconds; and (ii) a slow uptake over several hours in both processes. The uptake rate in the first step was higher in the co-precipitation process than in adsorption process, presumably due to increased silicate adsorption to boehmite and rapid precipitation of kaolinite. These results suggest that silicate removal using aluminum salts could be effectively achieved if the pH adjustment and aluminum concentration are strictly controlled.