First-in-human continuous 24-hour measurement of intraocular pressure and ocular pulsation using a novel contact lens sensor.

Background/aims: This study assessed the feasibility of a novel contact lens device for intraocular pressure (IOP) and ocular pulse amplitude (OPA) continuous measurements over 24 hours.

Methods: This prospective, open-label, single-centre, non-randomised study included glaucoma and healthy subjects. IOP and OPA values acquired by the pressure-measuring contact lens (PMCL) device in one patient's eye at the beginning of the measurement were compared with tonometry values (Goldman applanation tonometry (GAT) and dynamic contour tonometry (DCT)) in the same eye just before PMCL placement.

A virtual valve for smooth contamination-free flow switching.

We present a channel geometry that allows for clean switching between different inlets of a microchip without any contamination of the inlets or the downstream flow. We drive this virtual valve with a pneumatic pressure setup that minimizes disturbance of the downstream flow during the switching procedure by simultaneous variation of the pressures applied to the different inlets. We assess the efficiency of the setup by spectroscopic measurement of downstream dye concentrations, and demonstrate its practical utility by sequentially constructing multiple layers of alginate hydrogel.