No abstract

The development, fabrication, and testing of a compact multiplexed system of electrosprays are presented with the dual goal of increasing by orders of magnitude the liquid flow rate to be dispersed and of retaining the quasimonodispersity of the generated droplets. The system was microfabricated as an array of nozzles etched in silicon, with a density of 250 sources/cm 2 . Although the operation of a single electrospray is rather forgiving with respect to the electrode geometry, successful performance of the multiplexed system is critically dependent on a careful selection of the electrode configuration, which in the present work entails an extractor electrode mounted at a distance from the spray sources that is comparable to the distance between sources (on the order of 0.5 mm). The electrode has the dual function of limiting electric field cross-talk between neighboring sources and minimizing space charge feedback from the spray cloud. Measurements of current and droplet size as a function of flow rate and of droplet size distribution using ethanol demonstrated that the system may be optimized to produce uniform droplets simultaneously from all parallelized electrosprays, each one operating as an isolated spray in the quasimonodisperse cone-jet mode. Ease of operation and uniformity in size from spray to spray require strategies to increase the pressure drop in the liquid flow path and/or to uniformize the electric field at the spray sources.

Background/Aims: Augmented reality (AR) technology solves the problem of view switching in traditional image-guided neurosurgery systems by integrating computer-generated objects into the actual scene. However, the state-of-the-art AR solution using head-mounted displays has not been widely accepted in clinical applications because it causes some inconvenience for the surgeon during surgery. Methods: In this paper, we present a Tablet-AR system that transmits navigation information to a movable tablet PC via a wireless local area network and overlays this information on the tablet screen, which simultaneously displays the actual scene captured by its back-facing camera. With this system, the surgeon can directly observe the intracranial anatomical structure of the patient with the overlaid virtual projection images to guide the surgery. Results: The alignment errors in the skull specimen study and clinical experiment were 4.6 pixels (approx. 1.6 mm) and 6 pixels (approx. 2.1 mm), respectively. The system was also used for navigation in 2 actual clinical cases of neurosurgery, which demonstrated its feasibility in a clinical application. Conclusions: The easy-to-use Tablet-AR system presented in this study is accurate and feasible in clinical applications and has the potential to become a routine device in AR neuronavigation.

No abstract

No abstract