Weighted spline based integration for reconstruction of freeform wavefront.

In the present work, a spline-based integration technique for the reconstruction of a freeform wavefront from the slope data has been implemented. The slope data of a freeform surface contain noise due to their machining process and that introduces reconstruction error. We have proposed a weighted cubic spline based least square integration method (WCSLI) for the faithful reconstruction of a wavefront from noisy slope data. In the proposed method, the measured slope data are fitted into a piecewise polynomial. The fitted coefficients are determined by using a smoothing cubic spline fitting method. The smoothing parameter locally assigns relative weight to the fitted slope data. The fitted slope data are then integrated using the standard least squares technique to reconstruct the freeform wavefront. Simulation studies show the improved result using the proposed technique as compared to the existing cubic spline-based integration (CSLI) and the Southwell methods. The proposed reconstruction method has been experimentally implemented to a subaperture stitching-based measurement of a freeform wavefront using a scanning Shack-Hartmann sensor. The boundary artifacts are minimal in WCSLI which improves the subaperture stitching accuracy and demonstrates an improved Shack-Hartmann sensor for freeform metrology application.

[Frequency of physical symptoms in anxiety-depressive disorders: cross-sectional study in a population of 202 psychiatric consultants]. / La fréquence des symptômes physiques dans les troubles anxio-dépressifs: étude transversale chez une population de 202 consultants psychiatriques.

INTRODUCTION: physical symptoms associated with anxiety-depressive disorders have been the subject of several studies for several decades given their frequencies and their consequences. The aim of our study was to specify the frequency of the major physical symptoms of anxiety disorders such as panic disorder (PD), generalized anxiety disorder (GAD), phobic disorder (PhD) and depressive disorder (major depressive episode (MDD) in the framework of a depressive disorder). METHODS: we conducted a cross-sectional descriptive study on a sample of 202 consultants in a department of psychiatry. RESULTS: the average age of patients was 42 years (19-70 years), with a slight female predominance (118; 58%). Anxiety-depressive disorders included MDD (113;56%), PD (61;30.2%), GAD (55; 27.2%) and PhD (30;14.9%). Patients with 2 to 5 and more than 5 symptoms accounted for 15.9% and 39.6% respectively (depressive disorders), and 9.5% and 62.9% (anxiety disorders). The most reported symptoms were cardiopulmonary symptoms (75%), general symptoms (73.8%) and neurological symptoms (65.8%). CONCLUSION: physical symptoms associated with anxiety-depressive disorders are variable and often occur together. They can affect prognosis, making these psychiatric disorders difficult to treat. Early screening, paying particular attention to these physical symptoms, helps prevent these complications.

Subaperture stitching for measurement of freeform wavefront.

A method based on subaperture stitching for measurement of a freeform wavefront is proposed and applied to wavefronts calculated from the slope data acquired using a scanning Shack Hartmann sensor (SHS). The entire wavefront is divided into a number of subapertures with overlapping zones. Each subaperture is measured using the SHS, which is scanned over the entire wavefront. The slope values and thus the phase values of separately measured subapertures cannot be connected directly due to various misalignment errors during the scanning process. The errors lying in the vertical plane, i.e., piston, tilt, and power, are minimized by fitting them in the overlapping zone. The radial and rotational misalignment errors are minimized during registration in the global frame by using active numerical alignment before the stitching process. A mathematical model for a stitching algorithm is developed. Simulation studies are presented based on the mathematical model. The proposed mathematical model is experimentally verified on freeform surfaces of a cubic phase profile.