Integrating eye rotation and contrast sensitivity into image quality evaluation of virtual reality head-mounted displays.

Visual perception on virtual reality head-mounted displays (VR HMDs) involves human vision in the imaging pipeline. Image quality evaluation of VR HMDs may need to be expanded from optical bench testing by incorporating human visual perception. In this study, we implement a 5-degree-of-freedom (5DoF) experimental setup that simulates the human eye geometry and rotation mechanism.

Evaluation of monocular and binocular contrast perception on virtual reality head-mounted displays.

Purpose: Visualization of medical images on a virtual reality (VR) head-mounted display (HMD) requires binocular fusion of a stereoscopic pair of graphical views. However, current image quality assessment on VR HMDs for medical applications has been primarily limited to time-consuming monocular optical bench measurement on a single eyepiece.

Approach: As an alternative to optical bench measurement to quantify the image quality on VR HMDs, we developed a WebXR test platform to perform contrast perceptual experiments that can be used for binocular image quality assessment.

A comparison of cup-to-disc ratio estimates by fundus biomicroscopy and stereoscopic optic disc photography in the Tema Eye Survey.

PurposeTo determine if there are systematic differences in cup-to-disc ratio (CDR) grading using fundus biomicroscopy compared to stereoscopic disc photograph reading.MethodsThe vertical cup-to-disc ratio (VCDR) and horizontal cup-to-disc ratio (HCDR) of 2200 eyes (testing set) were graded by glaucoma subspecialists through fundus biomicroscopy and by a reading center using stereoscopic disc photos. For validation, the glaucoma experts also estimated VCDR and HCDR using stereoscopic disc photos in a subset of 505 eyes that they had assessed biomicroscopically.

Quantitative determination of 17 beta-estradiol and progesterone in cellular fractions of term placentae of normal and hypertensive patients.

During pregnancy the placenta is both the source and target for the actions of steroid hormones. In fact, an intact feto-placental unit is capable of elaborating increasing levels of a wide variety of steroid hormones and many other substances. The falling levels of steroid hormones, like estrogens and progesterone in serum and urine have been reported during pregnancy induced hypertension and/or preeclampsia.

Characterization of 1,2-benzo-8-(2-aminoethyl)-3-phenoxazone.

The compound 1,2-benzo-8-(2-aminoethyl)-3-phenoxazone (1) is synthesized by reacting tyramine with 1-nitroso-2-naphthol in the presence of nitric acid. During the reaction, tyramine and 1-nitroso-2-naphthol undergo condensation, ring closure, and subsequent oxidation steps to form 1. Compound 1 is characterized by one- and two-dimensional NMR spectroscopy and mass spectrometry.