Reliable and Fault-Resilient Schemes for Efficient Radix-4 Complex Division

Complex division is commonly used in various applications in signal processing and control theory including astronomy and nonlinear RF measurements. Nevertheless, unless reliability and assurance are embedded into the architectures of such structures, the suboptimal (and thus erroneous) results could undermine the objectives of such applications. As such, in this thesis, we present schemes to provide complex number division architectures based on (Sweeney, Robertson, and Tocher) SRT-division with fault diagnosis mechanisms. Different fault resilient architectures are proposed in this thesis which can be tailored based on the eventual objectives of the designs in terms of area and time requirements, among which we pinpoint carefully the schemes based on recomputing with shifted operands (RESO) to be able to detect both natural and malicious faults and with proper modification achieve high throughputs. The design also implements a minimized look up table approach which favors in error detection based designs and provides high fault coverage with relatively-low overhead. Additionally, to benchmark the effectiveness of the proposed schemes, extensive fault diagnosis assessments are performed for the proposed designs through fault simulations and FPGA implementations; the design is implemented on Xilinx Spartan-VI and Xilinx Virtex-VI FPGA families

Secondary Intraocular Lens

Secondary intraocular lens (IOL) implantation has evolved over the past few decades. Several new techniques, lens options, and materials now exist. Careful patient selection is important to determine the optimal secondary IOL technique. Intraocular lens placement in the capsular bag is the most ideal followed by sulcus placement. However, the best option when no capsular support exists in an aphakic patient remains unclear. Surgeons should be aware of contraindications for each technique; however, there are several situations where anterior chamber intraocular lens (ACIOL), scleral-fixated intraocular lens (SFIOL), and iris fixation can all be used. In those cases, surgeon familiarity and comfort with the secondary IOL technique can determine the type of surgery performed

Reliable Radix-4 Complex Division for Fault-Sensitive Applications

Complex division is commonly used in various applications in signal processing and control theory including astronomy and nonlinear RF measurements. Nevertheless, unless reliability and assurance are embedded into the architectures of such structures, the sub-optimal (and thus erroneous) results could undermine the objectives of such applications. As such, in this paper, we present schemes to provide complex number division architectures based on Sweeney, Robertson, and Tocher-division with error detection mechanisms. Different error detection architectures are proposed in this paper which can be tailored based on the eventual objectives of the designs in terms of area and time requirements, among which we pinpoint carefully the schemes based on recomputing with shifted operands to be able to detect faults based on recomputations for different operands in addition to the unified parity (simplified detecting code) and hardware redundancy approach. The design also implements a minimized look up table approach which favors in error detection based designs and provides high fault coverage with relatively-low overhead. Additionally, to benchmark the effectiveness of the proposed schemes, extensive error detection assessments are performed for the proposed designs through fault simulations and field-programmable gate array (FPGA) implementations; the design is implemented on Xilinx Spartan-6 and Xilinx Virtex-6 FPGA families

SPONTANEOUS LAMELLAR MACULAR HOLES CLOSURE

PurposeTo report two cases of spontaneous closure of lamellar macular holes with epiretinal proliferation (ERP).MethodsObservational cases report.ResultsTwo patients affected with lamellar macular hole showed progressive and spontaneous closure of the hole associated with ERP development. At presentation, both patients presented with irregular foveal contour, and foveal cavitation with apparent loss of retinal tissue. In both cases, ERP, also called "lamellar hole-associated epiretinal proliferation", was present and increased in size over time. This proliferation progressively developed across the hole with apparent restoration of the foveal contour and preservation of visual acuity.ConclusionThis report describes two cases of lamellar macular hole in which ERP increased over time, resulting in lamellar macular hole closure. Such observations may suggest a spontaneous healing process driven by glial cell proliferation

SPONTANEOUS LAMELLAR MACULAR HOLES CLOSURE.

PurposeTo report two cases of spontaneous closure of lamellar macular holes with epiretinal proliferation (ERP).MethodsObservational cases report.ResultsTwo patients affected with lamellar macular hole showed progressive and spontaneous closure of the hole associated with ERP development. At presentation, both patients presented with irregular foveal contour, and foveal cavitation with apparent loss of retinal tissue. In both cases, ERP, also called "lamellar hole-associated epiretinal proliferation", was present and increased in size over time. This proliferation progressively developed across the hole with apparent restoration of the foveal contour and preservation of visual acuity.ConclusionThis report describes two cases of lamellar macular hole in which ERP increased over time, resulting in lamellar macular hole closure. Such observations may suggest a spontaneous healing process driven by glial cell proliferation

Metabolomics Analysis of Human Vitreous in Diabetic Retinopathy and Rhegmatogenous Retinal Detachment

The vitreous humor is a highly aqueous eye fluid interfacing with the retina and lens and providing shape. Its molecular composition provides a readout for the eye’s physiological status. Changes in cellular metabolism underlie vitreoretinal pathologies, but despite routine surgical collection of vitreous, only limited reports of metabolism in the vitreous of human patients have been described. Vitreous samples from patients with rhegmatogenous retinal detachment (<i>n</i> = 25) and proliferative diabetic retinopathy (<i>n</i> = 9) were profiled along with control human vitreous samples (<i>n</i> = 8) by untargeted mass-spectrometry-based metabolomics. Profound changes were observed in diabetic retinopathy vitreous, including altered glucose metabolism and activation of the pentose phosphate pathway, which provides reducing equivalents to counter oxidative stress. In addition, purine metabolism was altered in diabetic retinopathy, with decreased xanthine and elevated levels of related purines (inosine, hypoxanthine, urate, allantoate) generated in oxidant-producing reactions. In contrast, the vitreous metabolite profiles of retinal detachment patients were similar to controls. In total, our results suggest a rewiring of vitreous metabolism in diabetic retinopathy that underlies disease features such as oxidative stress and furthermore illustrates how the vitreous metabolic profile may be impacted by disease

Metabolomics Analysis of Human Vitreous in Diabetic Retinopathy and Rhegmatogenous Retinal Detachment

The vitreous humor is a highly aqueous eye fluid interfacing with the retina and lens and providing shape. Its molecular composition provides a readout for the eye’s physiological status. Changes in cellular metabolism underlie vitreoretinal pathologies, but despite routine surgical collection of vitreous, only limited reports of metabolism in the vitreous of human patients have been described. Vitreous samples from patients with rhegmatogenous retinal detachment (<i>n</i> = 25) and proliferative diabetic retinopathy (<i>n</i> = 9) were profiled along with control human vitreous samples (<i>n</i> = 8) by untargeted mass-spectrometry-based metabolomics. Profound changes were observed in diabetic retinopathy vitreous, including altered glucose metabolism and activation of the pentose phosphate pathway, which provides reducing equivalents to counter oxidative stress. In addition, purine metabolism was altered in diabetic retinopathy, with decreased xanthine and elevated levels of related purines (inosine, hypoxanthine, urate, allantoate) generated in oxidant-producing reactions. In contrast, the vitreous metabolite profiles of retinal detachment patients were similar to controls. In total, our results suggest a rewiring of vitreous metabolism in diabetic retinopathy that underlies disease features such as oxidative stress and furthermore illustrates how the vitreous metabolic profile may be impacted by disease