The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology

We describe the realization of a symmetric integrated channel waveguide Mach-Zehnder sensor which uses the evanescent field to detect small refractive-index changes (¿nmin ¿ 1 × 10¿4) near the guiding-layer surface. This guiding layer consists of ridge structures with a height of 3 nm and a width of 4 ¿m made in Si3N4. This layer has a thickness of 100 nm. The sensor device has been tested with glucose solutions of different bulk refractive indices. Results of a slab-model calculation are in good agreement with obtained experimental results. The feasibility of applying this sensor for immunosensing, detecting directly the binding of antigen to an antibody receptor surface, is shown with antibody-antigen binding experiments

Incidence and clinical significance of cerebral embolism during atrial fibrillation ablation with duty-cycled phased-radiofrequency versus cooled-radiofrequency: a randomized controlled trial

OBJECTIVES The purpose of this study was to randomly compare the incidence of asymptomatic cerebral embolism (ACE) between the second-generation pulmonary vein ablation catheter (PVAC Gold) and the irrigated Thermocool catheter.BACKGROUND Pulmonary vein isolation (PVI) with the PVAC is associated with ACE. The PVAC Gold was designed to avoid this complication.METHODS Patients with paroxysmal atrial fibrillation were randomized 1:1 to PVI with the PVAC Gold or Thermocool catheter. Cerebral magnetic resonance imaging was performed in the days before and after ablation and repeated after 3 months in case of a new lesion. Monitoring for microembolic signals (MES) was performed by using transcranial Doppler ultrasonography. Parameters of coagulation were determined before, during, and after ablation. Neuropsychological tests and questionnaires were applied 10 days before and 3 months after ablation.RESULTS Seventy patients were included in the study (mean age 61 +/- 9 years; 43 male subjects; CHA(2)DS(2)-VASc [congestive heart failure, hypertension, age >= 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score 1.6 +/- 1.2; international normalized ratio 2.7 +/- 0.5; activated clotting time 374 +/- 24 s; p > 0.05 for all parameters). Procedural duration was shorter in the PVAC Gold group (140 +/- 34 vs. 207 +/- 44 min; p < 0.001). Eight (23%; 7 infarcts) patients in the PVAC Gold group exhibited a new ACE, compared with 2 (6%; no infarcts) patients in the Thermocool group (p = 0.042). Median number of MES was higher in the PVAC Gold group (1,111 [interquartile range, 715-2,234] vs. 787 [interquartile range, 532-1,053]; p < 0.001). There were no differences between groups regarding coagulation and neuropsychological outcomes.CONCLUSIONS PVI with the new PVAC Gold was associated with a higher incidence of ACE/cerebral infarcts and number of MES. Both catheters induced a comparable procoagulant state. Because there were no measurable differences in neuropsychological status, the clinical significance of ACE remains unclear. (Cerebral Embolism [CE] in Catheter Ablation of Atrial Fibrillation [AF] [CE-AF]; NCT01361295) (C) 2019 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation

Estimating the Gaze Point of a Student in a Driving Simulator

In this paper we discuss an approach towards passively observing students in a driving simulator. The goal is to enhance the learning experience for students taking lessons in this simulator. To this end, a virtual driving instructor is provided with added information consisting of the gaze behavior of its student. The gaze behavior is defined by estimated head locations and orientations. The learning experience for the student is enhanced by providing added feedback to the student based on his observed behavior