Wavefront reconstruction of discontinuous phase objects from optical deflectometry.

One of the challenges of phase measuring deflectometry is to retrieve the wavefront from objects that present discontinuities or non-differentiable gradient fields. Here, we propose the integration of such gradient fields based on an L p-norm minimization problem. The solution of this problem results in a nonlinear partial differential equation, which can be solved with a fast and well-known numerical method and does not depend on external parameters. Numerical reconstructions on both synthetic and experimental data are presented that demonstrate the capability of the proposed method.

Two-dimensional phase unwrapping based on Fourier transforms and the Yukawa potential spectrum.

The two-dimensional phase unwrapping problem (PHUP) has been solved with discrete Fourier transforms (FTs) and many other techniques traditionally. Nevertheless, a formal way of solving the continuous Poisson equation for the PHUP, with the use of continuous FT and based on distribution theory, has not been reported yet, to our knowledge. The well-known specific solution of this equation is given in general by a convolution of a continuous Laplacian estimate with a particular Green function, whose FT does not exist mathematically. However, an alternative Green function called the Yukawa potential, with a guaranteed Fourier spectrum, can be considered for solving an approximated Poisson equation, inducing a standard procedure of a FT-based unwrapping algorithm. Thus, the general steps for this approach are described in this work by considering some reconstructions with synthetic and real data.

Direct phase unwrapping method based on a local third-order polynomial fit.

When recovering smooth phases by phase unwrapping algorithms, many noniterative algorithms are available. However, normally those algorithms offer approximations of the current phase that cannot be accurate enough. This is because the majority of them are based on global approaches instead of local ones. Although smooth estimations are not often expected in phase reconstructions for real applications, a smooth initial guess could be useful for robust iterative techniques. Therefore, based on the most recent local polynomial approaches, we propose a simple least-squares fitting of the partial derivatives of the phase, normally estimated from the wrapped operator, by considering local polynomial models of the phase up to the third order. Synthetic and real data of wrapped phases are considered in our work.

A comparative analysis of costs of single and dual rapid HIV and syphilis diagnostics: results from a randomised controlled trial in Colombia.

BACKGROUND: HIV and congenital syphilis are major public health burdens contributing to substantial perinatal morbidity and mortality globally. Although studies have reported on the costs and cost-effectiveness of rapid diagnostic tests (RDTs) for syphilis screening within antenatal care in a number of resource-constrained settings, empirical evidence on country-specific cost and estimates of single RDTs compared with dual RDTs for HIV and syphilis are limited. METHODS: A cluster randomised controlled study design was used to compare the incremental costs of two testing algorithms: (1) single RDTs for HIV and syphilis and (2) dual RDTs for HIV and syphilis, in 12 health facilities in Bogota and Cali, Colombia. The costs of single HIV and syphilis RDTs and dual HIV and syphilis RDTs were collected from each of the health facilities. The economic costs per woman tested for HIV and syphilis and costs per woman treated for syphilis defined as the total costs required to test and treat one woman for syphilis were estimated. RESULTS: A total of 2214 women were tested in the study facilities. Cost per pregnant woman tested and cost per woman treated for syphilis were US$10.26 and US$607.99, respectively in the single RDT arm. For the dual RDTs, the cost per pregnant woman tested for HIV and syphilis and cost per woman treated for syphilis were US$15.89 and US$1859.26, respectively. Overall costs per woman tested for HIV and syphilis and cost per woman treated for syphilis were lower in Cali compared with Bogota across both intervention arms. Staff costs accounted for the largest proportion of costs while treatment costs comprised <1% of the preventive programme. CONCLUSIONS: Findings show lower average costs for single RDTs compared with dual RDTs with costs sensitive to personnel costs and the scale of output at the health facilities. TRIAL REGISTRATION NUMBER: NCT02454816; results.

PANLAR Consensus Recommendations for the Management in Osteoarthritis of Hand, Hip, and Knee.

OBJECTIVE: The objective of this consensus is to update the recommendations for the treatment of hand, hip, and knee osteoarthritis (OA) by agreeing on key propositions relating to the management of hand, hip, and knee OA, by identifying and critically appraising research evidence for the effectiveness of the treatments and by generating recommendations based on a combination of the available evidence and expert opinion of 18 countries of America. METHODS: Recommendations were developed by a group of 48 specialists of rheumatologists, members of other medical disciplines (orthopedics and physiatrists), and three patients, one for each location of OA. A systematic review of existing articles, meta-analyses, and guidelines for the management of hand, hip, and knee OA published between 2008 and January 2014 was undertaken. The scores for Level of Evidence and Grade of Recommendation were proposed and fully consented within the committee based on The American Heart Association Evidence-Based Scoring System. The level of agreement was established through a variation of Delphi technique. RESULTS: Both "strong" and "conditional" recommendations are given for management of hand, hip, and knee OA and nonpharmacological, pharmacological, and surgical modalities of treatment are presented according to the different levels of agreement. CONCLUSIONS: These recommendations are based on the consensus of clinical experts from a wide range of disciplines taking available evidence into account while balancing the benefits and risks of nonpharmacological, pharmacological, and surgical treatment modalities, and incorporating their preferences and values. Different backgrounds in terms of patient education or drug availability in different countries were not evaluated but will be important.

Color-fringe pattern profilometry using a generalized phase-shifting algorithm.

In order to overcome the limitations of the sequential phase-shifting fringe pattern profilometry for dynamic measurements, a color-channel-based approach is presented. The proposed technique consists of projecting and acquiring a colored image formed by three sinusoidal phase-shifted patterns. Therefore, by using the conventional three-step phase-shifting algorithm, only one color image is required for phase retrieval each time. However, the use of colored fringe patterns leads to a major problem, the color crosstalk, which introduces phase errors when conventional phase-shifting algorithms with fixed phase-shift values are utilized to retrieve the phase. To overcome the crosstalk issue, we propose the use of a generalized phase-shifting algorithm with arbitrary phase-shift values. The simulations and experimental results show that the proposed algorithm can significantly reduce the influence of the color crosstalk.

Total variation regularization cost function for demodulating phase discontinuities.

We introduce a method based on the minimization of a total variation regularization cost function for computing discontinuous phase maps from fringe patterns. The performance of the method is demonstrated by numerical experiments with both synthetic and real data.

Comparison of the clinical expression of patients with ankylosing spondylitis from Europe and Latin America.

OBJECTIVE: To compare the clinical, demographic, and serologic characteristics and the treatment of patients diagnosed with ankylosing spondylitis (AS) from Europe (EU) and Latin America (LA). METHODS: We included 3439 patients from national registries: the Spanish Registry of Spondyloarthritis (REGISPONSER), the Belgian registry (ASPECT), and the Latin American Registry of Spondyloarthropathies (RESPONDIA). We selected patients with diagnosis of AS who met the modified New York classification criteria. Demographic, clinical, disease activity, functional, and metrological measurement data were recorded. Current treatment was recorded. The population was classified into 2 groups: patients with disease duration < 10 years and those with disease duration ≥ 10 years. A descriptive and comparative analysis of variables of both groups was carried out. RESULTS: There were 2356 patients in EU group and 1083 in LA group. Prevalence of HLA-B27 was 71% in LA group and 83% in EU group (p < 0.001). We found a greater frequency of peripheral arthritis and enthesitis (p < 0.001) in the LA population; prevalence of arthritis was 57% in LA and 42% in EU, and for enthesitis, 54% and 38%. Except for treatment with anti-tumor necrosis factor (anti-TNF), the use of nonsteroidal antiinflammatory drugs (NSAID), corticosteroids, and disease-modifying antirheumatic drugs (DMARD), and the association of anti-TNF and methotrexate use showed a significant difference (p < 0.001) in the 2 populations. CONCLUSION: The principal differences in the clinical manifestations of patients with AS from EU and LA were the greater frequency of peripheral arthritis and enthesitis in LA group, the higher percentage of HLA-B27 in EU group, and the form of treatment, with a greater use of NSAID, steroids, and DMARD in the LA group.

GPU based real-time quadrature transform method for 3-D surface measurement and visualization.

In this article, we propose a massively parallel, real-time algorithm for the estimation of the dynamic phase map of a vibrating object. The algorithm implements a Fourier-based quadrature transform and temporal phase unwrapping technique. CUDA, a graphic processing unit programming architecture was used to implement the algorithm. It was tested on a fringe pattern sequence using three devices with different capabilities, achieving a processing rate greater than 1600 frames per second (fps).

Epidemiology of spondyloarthropathies in Central America.

The authors reviewed retrospectively a cohort of 233 spondyloarthropathy patients observed in 2 centers in Guatemala City, Guatemala, and in hospitals in San Salvador, El Salvador, and San José, Costa Rica. Guatemalan patients were either from the clinic of Guatemalan Association against Rheumatic Diseases (n = 105) or from the private clinic of AGK (n = 78). El Salvador patients (n = 17) were from Hospital Instituto Salvadoreño del Seguro Social, and Costa Rican patients (n = 33) were from Hospital Calderón Guardia, San José, Costa Rica. Except for the Costa Rican data, which were published in 2007, the patients' medical records were analyzed using standardized questionnaires. Prevalence of spondyloarthropathy was slightly higher in females than males (57% versus 43%, respectively). The median age was 47.5 years. Most of our patients were diagnosed with reactive arthritis or undifferentiated arthritis (47% and 33%, respectively); 10% of patients had ankylosing spondylitis and 9% psoriatic arthritis.

Dynamic 3-D shape measurement method based on quadrature transform.

In this work, it is presented a combination of temporal phase unwrapping technique and Fourier-based quadrature transform to obtain the dynamic phase map from a vibrating object. The proposed combination results on a very simple algorithm which allows an accurate and versatile 3D reconstruction of the object under analysis.

Fast phase recovery from a single closed-fringe pattern.

A new framework for phase recovery from a single fringe pattern with closed fringes is proposed. Our algorithm constructs an unwrapped phase from previously computed phases with a simple open-fringe-analysis algorithm, twice applied for analyzing horizontal and vertical oriented fringes, respectively. That reduces the closed-fringe-analysis problem to that of choosing the better phase between the two oriented computed phases and then of estimating the local sign. By propagating the phase sign [and a tilewise constant (DC) term] by regions [here named tiles] instead of a pixelwise phase propagation, our analysis of closed-fringe patterns becomes more robust and faster. Additionally, we propose a multigrid refinement for improving the final computed phase.

Fast half-quadratic regularized phase tracking for nonnormalized fringe patterns.

Although one of the simplest and powerful approaches for the demodulation of a single fringe pattern with closed fringes is the regularized phase-tracking (RPT) technique, this technique has two important drawbacks: its sensibility at the fringe-pattern modulation and the time employed in the estimation. We present modifications to the RPT technique that consist of the inclusion of a rough estimate of the fringe-pattern modulation and the linearization of the fringe-pattern model that allows the minimization of the cost function through stable numerical linear techniques. With these changes, the demodulation of nonnormalized fringe patterns is made with a significant reduction in the processing time, preserving the demodulation accuracy of the original RPT method.

A risk assessment tool (OsteoRisk) for identifying Latin American women with osteoporosis.

OBJECTIVE: To develop a simple and easy-to-use tool for identifying osteoporotic women (femoral neck bone mineral density [BMD] T-scoresor=50 in Latin America who had femoral neck BMD measurements. MEASUREMENTS AND MAIN RESULTS: A risk index was developed from 1,547 patients based on least square regression using age, weight, history of fractures, and other variables as predictors for BMD T-score. The final model was simplified by reducing the number of predictors; sensitivity and specificity were evaluated before and after reducing the number of predictors to assess performance of the index. The final model included age, weight, country, estrogen use, and history of fractures as significant predictors for T-score. The resulting scoring index achieved 91% sensitivity and 47% specificity. Simplifying the index by using only age and weight yielded similar performance (sensitivity, 92%; specificity, 45%). Three risk categories were identified based on OsteoRisk, the index using only age and body weight: high-risk patients (index <=-2; 65.6% were osteoporotic), moderate-risk patients (-2< index <=1; 26.7% were osteoporotic), and low-risk patients (index>1; 8% were osteoporotic). Similar results were seen in a validation sample of 279 women in Brazil. CONCLUSION: Age and weight alone performed well for predicting the risk of osteoporosis among postmenopausal women. The OsteoRisk is an easy-to-use tool that effectively targets the vast majority of osteoporotic patients in Latin America for evaluation with BMD.

Systematic perturbation calculation of integrals with applications to physics.

In this paper we generalize and improve a method for calculating the period of a classical oscillator and other integrals of physical interest, which was recently developed by some of the authors. We derive analytical expressions that prove to be more accurate than those commonly found in the literature, and test the convergence of the series produced by the approach.

Improvement of the regularized phase tracking technique for the processing of nonnormalized fringe patterns.

One of the powerful approaches to demodulate a single fringe pattern is the regularized phase tracking (RPT) technique. Here, a new improvement in the RPT technique is presented. This new improvement consists in the addition of one term that models the fringe-pattern modulation. With this new term, the RPT technique can be used for the demodulation of nonnormalized fringe patterns. The performance of the improved RPT technique is shown on examples of various fringe patterns.

Validación del protocolo para el estudio de la hemorragia uterina anormal con ecografía endovaginal y medio de contraste (sonohisterografía) / Protocol validation for the abnormal uterine hemorrhage with endovaginal ultrasonography and contrast media (sonohysterography)

La evaluación del sangrado uterino anormal especialmente en los postreproductivos, convencionalmente se hace recurriendo a las biopsias y aspiraciones endometriales ciegas en el consultorio, o al curetaje uterino bajo anestesia general. Dichos procedimientos, además de ser invasivos, han mostrado ser poco sensibles y específicos en la detección y el tratamiento de la patología focal del endometrio (pólipos, leiomiomas submucosos), y además pueden resultar costosos. Con el advenimiento de la histeroscopia, se han obviado muchas de las dificultades atribuidas a la biopsia ciega y el curetaje uterino, pero aquella, ademas de requerir un entrenamiento específico y un equipo costoso, requiere de anestesia local o general, en ocasiones dilatación del cervix y en muchas instancias arroja resultados negativos. De otro lado, la histeroscopia sólo permite evaluar el canal cervical y la cavidad endometrial, sin poder visualizar la pared miometrial, los anexos y otras estructuras pélvicas, lo cual desvirtúa su uso en una gran proporción de pacientes como investigación inicial rutinaria en el sangrado uterino anormal.

Quadratic cost functional for wave-front reconstruction.

A quadratic cost functional for reconstruction of a high-resolution wave front from a coarse wave front is presented. The functional uses as data the position and the direction of the coarse wave front that had previously been computed with a ray-tracing method. This functional uses an optical relationship between the ray information and the wave front's shape to reconstruct a high-density wave front. The performance of the proposed functional is illustrated by reconstruction of complicated wave fronts for which this functional has an accuracy that is superior to that of conventional interpolation methods.

Correlación clínico-electromiográfica en el síndrome del túnel carpal

Se escogieron al azar 24 pacientes (48 manos) con síntomas y signos del Síndrome del Túnel Carpal (STC). Fueron valorados clínicamente por 2 reumatólogos y luego por un electromiografista. El objetivo del estudio fue comparar el diagnóstico clínico con los hallazgos electromiográficos. El dolor (Sensibilidad: 0,88), el Hormigueo (Sensibilidad: 0,91) y el adormecimiento (sensibilidad: 0,92), así como el despertar nocturno a causa de los mismos (95 por ciento de los pacientes) y los signos de Tinel (Sensibilidad; 0,57) y Phalen (Sensibilidad: 0,84) fueron los elementos clínicos de más valor. Se concluye que el diagnóstico clínico es valioso en esta entidad y que sólo los casos seleccionados deben someterse a estudios electromiográficos