Deep neural network for fringe pattern filtering and normalization.

We propose a new framework for processing fringe patterns (FPs). Our novel, to the best of our knowledge, approach builds upon the hypothesis that the denoising and normalization of FPs can be learned by a deep neural network if enough pairs of corrupted and ideal FPs are provided. The main contributions of this paper are the following: (1) we propose the use of the U-net neural network architecture for FP normalization tasks; (2) we propose a modification for the distribution of weights in the U-net, called here the V-net model, which is more convenient for reconstruction tasks, and we conduct extensive experimental evidence in which the V-net produces high-quality results for FP filtering and normalization; (3) we also propose two modifications of the V-net scheme, namely, a residual version called ResV-net and a fast operating version of the V-net, to evaluate potential improvements when modifying our proposal. We evaluate the performance of our methods in various scenarios: FPs corrupted with different degrees of noise, and corrupted with different noise distributions. We compare our methodology versus other state-of-the-art methods. The experimental results (on both synthetic and real data) demonstrate the capabilities and potential of this new paradigm for processing interferograms.

Parallel phase shifting radial shear interferometry with complex fringes and unknown phase shift.

We present an interferometric method to analyze transparent samples using complex fringes generated by a parallel phase shifting radial shear interferometer using two coupled interferometers. Parallel interferograms are generated using two interferometers: the first one generates the polarized base pattern, and the second system is used to generate parallel interferograms allowing the adjustment of the x-y positions of the parallel interferograms. To obtain the optical phase map, parallel phase shift is generated by collocating polarizing filters at the output of the system; the polarizers are placed at arbitrary angles since they do not require adjustment because of the phase-recovery algorithm. The optical phase was processed using a two-step algorithm based on a modified Gram-Schmidt orthogonalization method. Such an algorithm has the advantage of not being iterative and is robust to amplitude modulation. The proposed method reduces the number of captures needed in phase-shifting interferometry. We applied the developed system to examine static and dynamics phase objects.

[Isokinetic evaluation of the muscular strength and balance of knee extensor and flexor apparatus of taekwondo athletes]. / Valoración isocinética de la fuerza y balance muscular del aparato extensor y flexor de la rodilla en taekwondoines.

UNLABELLED: Lower limb strength and muscular balance are important attributes in the practice of Taekwondo. OBJECTIVE: To assess through isokinetic dynamometry the muscular strength and balance of knee extensor and flexor apparatus of elite Taekwondo athletes and to compare with recreational-type athletes. METHODS: The maximum torque, the angle of maximum torque, maximum torque work, total work of the series, average power, and flexor and extensor muscle apparatus balance of the knees were obtained. RESULTS: A total of 32 knees were studied. Significantly higher values in peak torque and total work of the series were present in the group of TKD athletes in the extensor muscles, while the maximum torque angle of extensor and flexor muscles was higher in controls. We found a muscular imbalance due to flexor muscle strength deficit in both groups. CONCLUSIONS: Higher levels of muscular strength and an imbalance between the knee flexor and extensor muscle groups characterized the predominant motor gesture of TKD athletes. These results are useful in the design and implementation of training programs, to optimize the value of muscular strength and muscle balance in TKD athletes directed to promote optimal athletic performance and prevent sport-related injuries.

Evidence-based guideline: neuromuscular ultrasound for the diagnosis of carpal tunnel syndrome.

INTRODUCTION: The purpose of this study was to develop an evidence-based guideline for the use of neuromuscular ultrasound in the diagnosis of carpal tunnel syndrome (CTS). METHODS: Two questions were asked: (1) What is the accuracy of median nerve cross-sectional area enlargement as measured with ultrasound for the diagnosis of CTS? (2) What added value, if any, does neuromuscular ultrasound provide over electrodiagnostic studies alone for the diagnosis of CTS? A systematic review was performed, and studies were classified according to American Academy of Neurology criteria for rating articles of diagnostic accuracy (question 1) and for screening articles (question 2). RESULTS: Neuromuscular ultrasound measurement of median nerve cross-sectional area at the wrist is accurate and may be offered as a diagnostic test for CTS (Level A). Neuromuscular ultrasound probably adds value to electrodiagnostic studies when diagnosing CTS and should be considered in screening for structural abnormalities at the wrist in those with CTS (Level B).