Second look Holter ECG in neurorehabilitation.

Background: Many stroke survivors suffer recurrent stroke because paroxysmal atrial fibrillation (AF) was missed and no preventive anticoagulation initiated. This prospective cohort study determined the added diagnostic yield of second-look 24-h electrocardiographic recording (ECG) in a population at high risk for AF: patients who suffered a stroke of such severity that they require inpatient neurorehabilitation.

Methods: We enrolled 508 patients with ischemic stroke admitted to post-acute inpatient neurorehabilitation and determined whether AF was detected during acute care at the referring hospital.

The engineered eyeball, a tunable imaging system using soft-matter micro-optics.

We demonstrate a tunable imaging system based on the functionality of the mammalian eye using soft-matter micro-optical components. Inspired by the structure of the eye, as well as by the means through which nature tunes its optical behavior, we show that the technologies of microsystems engineering and micro-optics may be used to realize a technical imaging system whose biomimetic functionality is entirely distinct from that of conventional optics. The engineered eyeball integrates a deformable elastomeric refractive structure whose shape is mechanically controlled through application of strain using liquid crystal elastomer (LCE) actuators; two forms of tunable iris, one based on optofluidics and the other on LCEs with embedded heaters; a fixed lens arrangement; and a commercial imaging sensor chip.

Iris-like tunable aperture employing liquid-crystal elastomers.

A liquid-crystal elastomer (LCE) iris inspired by the human eye is demonstrated. With integrated polyimide-based platinum heaters, the LCE material is thermally actuated. The radial contraction direction, similar to a mammalian iris, is imprinted to the LCE by a custom-designed magnetic field.

Miniaturized tunable imaging system inspired by the human eye.

We demonstrate the combination of a tunable lens and tunable aperture in a compact imaging system whose structure is inspired by the human eye. The concept is based on innovative optical materials and tuning mechanisms including an optofluidic iris for a tunable aperture and an elastomer lens for focal length tuning. Wavefront and modulation transfer function analysis reveals a high imaging performance of both the individual elements and the complete system.

Tunable solid-body elastomer lenses with electromagnetic actuation.

We present novel biconvex solid-body elastomer (polydimethylsiloxane) lenses, which can be tuned in focal length by using magnetic or mechanical actuation. The focal length change is induced by applying radial elastic strain and is investigated for different initial radii of curvature of the lenses and different actuation designs. In all cases, a linear correlation between induced strain and focal length tuning, in the range of about 10% (approximately 3 mm), is found.