Search PubMed⌕ Search

Biomedical subjects

Edward Buckley

Publications and source records attributed to Edward Buckley.

4 recordsLinked to original sources
PubMed2006

Viewing angle enhancement for two- and three-dimensional holographic displays with random superresolution phase masks.

Holographic displays employing binary phase modulation have been demonstrated to be attractive on the grounds of efficiency and miniaturization, and they offer a plausible approach to two-dimensional (2D) and three-dimensional (3D) image projection and display. A novel algorithm--one-step phase retrieval--and corresponding hardware architecture have recently been proposed, providing the performance required for real-time holographic display. However, since viewing angle varies inversely with pixel size, very small display pixels are required to achieve a wide field of view. This is particularly problematic for 3D displays, as the requirement for a large display with small pixels has hitherto necessitated an unachievably large electrical bandwidth. We present a novel approach, utilizing fixed random pixelated quaternary phase masks of greater resolution than the displayed hologram, to dramatically increase the viewing angle for 2D and 3D holographic displays without incurring a bandwidth penalty or significantly degrading image quality. Furthermore, an algorithm is presented to generate holograms accounting for the presence of such a phase mask, so that only one mask is required.

Journal Article↗
PubMed2006

Laser-printer computer-generated holograms exhibiting suppressed higher orders in the replay field.

Conventional computer-generated holograms (CGHs) consist of regularly spaced square pixels, which, when replayed, exhibit many repeated higher orders. Furthermore, such pixellated CGHs are not well suited to printing using a conventional laser printer. In this Letter a novel method is presented that exploits the characteristics of a conventional laser-printing process to generate holograms with replay fields that exhibit markedly suppressed higher orders.

Journal Article↗
PubMed2004

The effect of increases in HMO penetration and changes in payer mix on in-hospital mortality and treatment patterns for acute myocardial infarction.

OBJECTIVE: To determine whether changes in health maintenance organization (HMO) penetration or payer mix affected in-hospital mortality and treatment patterns of patients with acute myocardial infarction (AMI). STUDY DESIGN: Observational study using patient-level logistic regression analysis and hospital and year fixed effects of data from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project Nationwide Inpatient Sample, a geographically diverse sample of 20% of the hospitalized patients in the United States. PATIENTS AND METHODS: Discharges of patients (n = 340,064) with a primary diagnosis of acute myocardial infarction who were treated in general medical or surgical hospitals that contributed at least 2 years of data to the HealthCare Cost and Utilization Project Nationwide Inpatient Sample from 1989 to 1996. In-hospital mortality and rates of cardiac catheterization, angioplasty, or coronary artery bypass grafting for Medicare patients or non-Medicare patients were the main outcome measures. RESULTS: Among Medicare patients, increases in HMO penetration were associated with reduced odds of receiving cardiac catheterization, angioplasty, or coronary artery bypass grafting of 3% to 16%, but were not associated with any change in mortality risk. Increases in the number of HMOs within a metropolitan statistical area, our measure of HMO competition, were associated with small but significant increases in the odds of cardiac catheterization and angioplasty of about 2%. There was no pattern of changes in cardiac procedure rates or in-hospital mortality among non-Medicare patients. CONCLUSION: Increases in HMO penetration reduced cardiac procedure rates by statistically significant but small amounts among Medicare patients with AMI, without affecting mortality rates.

Aged↗