Long Term Efficacy of a Supraciliary Micro-stent Combined with Cataract Surgery in the Treatment of Glaucoma

Purpose: The purpose of this study is to evaluate the long-term efficacy of supraciliary micro-stent implantation in combination with phacoemulsification in the treatment of mild-moderate primary open angle glaucoma (POAG). Methods: Retrospective data of patients previously enrolled in the “Study of an Implantable Device for Lowering Intraocular Pressure in Glaucoma Patients Undergoing Cataract Surgery” (COMPASS trial), in which patients with mild-moderate POAG had undergone either cataract surgery alone or cataract surgery combined with implantation of a supraciliary micro-stent, were collected. Eligible patients had since exited the trial and had 5-8 years of postoperative data available. The primary outcome measure was the proportion of eyes with a “complete success” defined as an IOP ≤ 18 mmHg on no glaucoma medications and not having undergone any secondary surgical procedures for IOP control. Thirty-three eyes were in the treatment group and 12 eyes were in the control group. Device safety was also reviewed. Results: Significantly more eyes in the treatment group achieved a “complete success” (61%) versus those eyes in the control group (17%) (p\u3c0.05). When controlling for patient age, sex, preoperative visual field, preoperative IOP, and preoperative anti-glaucoma medication usage, eyes in the treatment groups were 9 times more likely to meet the primary outcome measure versus control group (p=0.004). Mean postoperative IOP was 17.7 ± 4.8 in the control group versus 15.0 ± 4.4 in the treatment group (p=0.08), while mean medication usage was 0.9 ± 0.7 in the control group versus 0.4 ± 0.7 in the treatment group (p=0.01). Average follow up was 6.38 years. No device related adverse events, such as corneal decompensation occurred. Conclusion: Implantation of a supraciliary micro-stent combined with cataract surgery in eyes with mild-moderate POAG demonstrates better long term IOP control than those eyes undergoing cataract surgery alone

Design and optimization of three-dimensional scanning laser range finder

The purpose of this project is to develop a technique for minimizing the number of iterations needed to determine the XY&Z position for a laser rangefinding system. Using a Charged Coupled Device (CCD) camera to view a robotic work area a user can select an object on a monitor. A LASER is used to project a beam into the work area and the camera in conjunction with image processing software and hardware is used to locate the LASER spot. The purpose of the research in this paper is to devise techniques to minimize the number of points needed to determine XY&Z location without sacrificing accuracy. The techniques developed to reduce the number of iterations worked very well. They were extensively tested in the laboratory to determine the number of iterations needed for a solution and the accuracy of that solution. However, the error for calculating the XYZ position was adversely affected by system errors. These system errors were comprised of the errors associated with positioning motors and with the camera modeling. Changing the configuration could minimize these errors and dramatically improve the accuracy. (Abstract shortened by UMI.)

Multi-Valley Physics of Two-Dimensional Electron Systemson Hydrogen-Terminated Silicon (111) Surfaces

Recent work on two dimensional electron systems (2DES) has focused increasingly on understanding the way the presence of additional degrees of freedom (e.g. spin, valleys, subbands, and multiple charge layers) affect transport as such effects may be critical to the development of nanoscale and quantum devices and may lead to the discovery of new physics . In particular, conduction band valley degeneracy opens up a rich parameter space for observing and controlling 2DES behavior. Among such systems, electrons on the (111) surface of silicon are especially notable because effective mass theory predicts the conduction band to be sixfold degenerate, for a total degeneracy (spin ×valley) of 12 in the absence of a magnetic field B. Previous investigations of Si(111) transport using Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) observed a valley degeneracy gv of 2 except in certain specially prepared samples with low mobility. We have developed a novel device architecture for investigating transport on a H-Si(111)-vacuum interface free from the complications created by intrinsic disorder at Si-SiO2 interfaces. The resulting devices display very high mobilities (up to 110,000 cm2/Vs at 70 mK, more than twice as large as the best silicon MOSFETs), enabling us to probe valley-dependent transport to a much greater degree than previously possible. In particular, we observed detailed Integer Quantum Hall structure with hints of Fractional states as well. These devices display clear evidence of six occupied valleys, including strongly “metallic” temperature dependence expected for large gv. Some devices show strong sixfold degeneracy while others display a partial lifting of the degeneracy, resulting in unequal distribution of electrons among the six valleys. This symmetry breaking results in anisotropic transport at low B fields, but other observed anisotropies remain unexplained. Finally, we apply this unusual valley structure to show how corrections to the low-B magnetoresistance and Hall effect can provide information about valley-valley interactions. We propose a model of valley drag, similar to Coulomb drag in bilayer systems, and find good agreement with our experimental data, though a small residual drag in the T→0 limit remains unexplained

Advanced automation in space shuttle mission control

The Real Time Data System (RTDS) Project was undertaken in 1987 to introduce new concepts and technologies for advanced automation into the Mission Control Center environment at NASA's Johnson Space Center. The project's emphasis is on producing advanced near-operational prototype systems that are developed using a rapid, interactive method and are used by flight controllers during actual Shuttle missions. In most cases the prototype applications have been of such quality and utility that they have been converted to production status. A key ingredient has been an integrated team of software engineers and flight controllers working together to quickly evolve the demonstration systems