Accurate gaze direction measurements with free head movement for strabismus angle estimation.

We present the Delft Assessment Instrument for Strabismus in Young children (DAISY) a device designed to measure angles of strabismus in young children fast and accurately. DAISY allows for unrestrained head movements by the mean of a triple camera vision system that simultaneously estimates the head rotation and the eye pose. The device combines two different methods to record bilateral eye position: corneal reflections (Purkinje images) and pupillary images.

Single-sided and small-scaled grasping of delicate tissues: effectiveness of indirect heat-induced attachment and detachment.

Introduction: Indirect heat-induced attachment and detachment (iHIAD) is a promising concept for gripping delicate tissues in microsurgery. However, the optimal settings of iHIAD are unknown. This study evaluates the effects of the instrument heating properties and initial contact force on the adhesion force, detachment success and thermal damage.

An observational study to quantify manual adjustments of the inspired oxygen fraction in extremely low birth weight infants.

Aim: To quantify manual fraction of inspired oxygen (FiO(2)) adjustments performed by caregivers in extremely low birth weight (ELBW; ≤1000 g) infants, in relation to oxygen saturation (SpO(2)) and bedside care.

Methods: In a single-centre study, FiO(2) , SpO(2) and alarm limits of ELBW infants were collected for 3 days continuously, while caregivers were filmed. A descriptive analysis, focused on manual FiO(2) adjustments, was performed.

Human error in strabismus surgery: quantification with a sensitivity analysis.

Background: Reoperations are frequently necessary in strabismus surgery. The goal of this study was to analyze human-error related factors that introduce variability in the results of strabismus surgery in a systematic fashion.

Methods: We identified the primary factors that influence the outcome of strabismus surgery.

Threshold amplitude and frequency for ocular tissue release from a vibrating instrument: an experimental study.

Purpose: During retinal pigment epithelium (RPE) and choroid graft translocation in the treatment of patients with exudative age-related macular degeneration, the adhesion of the graft to the translocation instrument complicated its submacular release. Vibration of the instrument improved the release of the graft. This study was conducted to validate the effectiveness of the principle of vibration and to determine the threshold amplitude and frequency required for development of an optimized instrument.

Elasticity, viscosity, and deformation of orbital fat.

Purpose: For development of a finite element analysis model of orbital mechanics, it was necessary to determine the material properties of orbital fat and its degree of deformation in eye rotation.

Methods: Elasticity and viscosity of orbital fat of eight orbits of four calves and two orbits of one rhesus monkey were measured with a parallel-plate rheometer. The degree of deformation of orbital fat was studied in two human subjects by magnetic resonance imaging (MRI) through the optic nerve in seven (first subject) or fourteen positions of gaze from left to right.

A finite-element analysis model of orbital biomechanics.

To reach a better understanding of the suspension of the eye in the orbit, an orbital mechanics model based upon finite-element analysis (FEA) has been developed. The FEA model developed contains few prior assumptions or constraints (e.g.