One-shot phase retrieval method for interferometry using a hypercolumns convolutional neural network.

In three dimensional profilometry, phase retrieval technique plays a key role in signal processing stage. Fringe images need to be transformed into phase information to obtain the measurement result. In this paper, a new phase retrieval method based on deep learning technique is proposed for interferometry. Different from conventional multi-step phase shift methods, phase information can be extracted from only a single frame of an interferogram by this method. Here, the phase retrieval task is regarded as a regression problem and a hypercolumns convolutional neural network is constructed to solve it. Firstly, functions and each component of the network model are introduced in details; Then, four different mathematical functions are adopted to generate the training dataset; training and validation strategies are also designed subsequently; Finally, optimization processing is performed to eliminate local data defects in initial results with the help of polynomial fitting. In addition, hardware platform based on point diffraction interferometer is fabricated to support this method. Concluded from the experiment section, the proposed method possesses a desirable performance in terms of phase retrieval, denoising and time efficiency.

Analysis of the effect of postpartum rehabilitation nursing on the management of postpartum depression.

OBJECTIVE: To study the effect of postpartum rehabilitation nursing on the management of postpartum depression. METHODS: A total of 100 primiparas were randomly selected in this study. They were divided into postpartum nursing intervention group (50 cases) and control group (50 cases). The data from prenatal and postpartum women were collected through questionnaires. The Edinburgh postpartum depression scale, social support scale, general self-efficacy scale, and mother's role adaptation questionnaire were distributed to 100 pregnant women. By collecting the results of these questionnaires, the differences between the nursing intervention group and the control group were compared. RESULTS: The results showed that the proportion of postpartum depression in 50 primiparas after postpartum rehabilitation nursing was significantly lower than that of the control group. The physiological and psychological changes of primipara after childbirth would be significant, and would be subject to tremendous pressure from all aspects. CONCLUSIONS: This change and pressure were the main causes of postpartum depression in primipara. Postpartum rehabilitation nursing can effectively alleviate primipara's postpartum depression.

Accurate localization method for subaperture stitching interferometry in aspherical optics metrology.

Aspherical optics have superior performance in many applications. However, precision metrology for an aspherical surface is a key stage in its manufacture. Subaperture stitching interferometry (SSI) is one of the mainstream testing methods for aspherical metrology. In many cases, Annular Stitching Subaperture Interferometry (ASSI) is more suitable for components having rotational symmetry because, compared to SSI, the number of motion directions that need to be adjusted is less. Although motion only along the optical axis is of concern in ASSI, inaccurate localization for subapertures may also occur due to the machining error at the optical center of the optics under test and errors in Cat's eye location, thereby leading to measurement errors. To overcome these problems, an accurate localization method for subaperture stitching is proposed. It is based on the maximum asphericity information between the reference spherical wavefront and the test aspherical surface. First, by using the test aspherical formula and theoretical spherical wavefront, we can calculate the minimum peak-to-valley (PV) value of maximum asphericity. The theoretical location of an optimal reference sphere, which corresponds to this value, can be obtained. Then, we perform a practical test, which starts at the initial zero position, and find an actual minimum PV value near its theoretical location. The difference between the theoretical location and the actual one is the compensation quantity. Finally, we execute ASSI measurement to aspherical optics. The location coordinate of each subaperture is compensated with the acquired quantity. Through the experiments, it can be concluded that the proposed method can improve the measurement accuracy of ASSI in terms of error elimination. The results produced by the new method are more desirable than those of the conventional one.

Hybrid image segmentation method based on anisotropic Gaussian kernels and adjacent graph region merging.

Image segmentation is a key technique in image analysis for object identification. In this paper, a hybrid segmentation method is proposed, which is based on the Anisotropic Gaussian Kernel (ANGK) edge detector and region adjacent graph (RAG) merging algorithm. An anisotropic directional derivative filter is constructed by angled ANGK to detect the edge contour of original images. Based on the gradient magnitude pattern of the edge contour from ANGK processing, watershed transform is adopted to produce initial partition (coarse segmentation result). Finally, combined with the RAG region merging algorithm, the proposed method performs fine segmentation by merging similar fragmented regions (initial partition) iteratively. Additionally, statistic similarity measure and shape cost function in merging cost are also introduced. They provide quantitative criteria for region merging, which have critical influences on the detection result. A series of experiments are conducted to evaluate the performance of this method, and a preferable localization accuracy as well as noise robustness is proved. Compared with conventional edge and region based methods, the proposed one has a superior segmentation effect. Another advantage is that the problem of oversegmentation can be solved effectively.

Precision optical path alignment system for point diffraction interferometer based on image information.

In a point diffraction interferometer, the existence of alignment error between an objective convergent spot and a diffraction pinhole can lead to wavefront error and diffraction intensity reduction. Meanwhile, the contrast of the point diffraction interferograms probably decreases in this procedure. These changes will have significant influence on its inspection precision. A precise alignment system of an optical path for a point diffraction interferometer is proposed in this paper. First, diffraction theory is used to analyze the mathematical relationships of alignment error to diffraction wavefront error and numerical aperture and wavefront error to pinhole size. Then, according to the requirement, the scheme of an optical path alignment system is designed. In this stage, alignment images as well as intensities of a reflected and diffracted beam from the point diffraction plate will be acquired. In addition, an image processing algorithm for measuring alignment error is designed, and a mathematical model between quantities of measurement and control is constructed. Finally, implementation and experiment of this method are also introduced. Misalignment situations, including lateral translation, longitudinal defocus, and tilt error, are well eliminated, and the quality of interferograms is also improved. From the results, it can be concluded that the system is of desirable precision and efficiency.

Effectiveness of advanced nursing care on depression in patients with ovarian cancer: A protocol of systematic review of randomized controlled trial.

BACKGROUND: This systematic review will assess the effectiveness of advanced nursing care (ANC) on depression in patients with ovarian cancer (OC). METHODS: We will identify any relevant randomized controlled trial from Cochrane Library, MEDLINE, Embase, Web of Science, Springer, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure from their inceptions to March 5, 2019. The primary outcome includes depression. The secondary outcomes consist of anxiety, quality of life, and adverse events. Data that meets all the eligibility criteria will be extracted, pooled, and analyzed by using RevMan 5.3 software. Methodological quality for each eligible study will be assessed by using Cochrane risk of bias tool. RESULTS: This study will analyze depression, anxiety, quality of life, and adverse events of ANC on depression in patients with OC. CONCLUSION: The findings of this study will provide the latest evidence for the effectiveness and adverse events of ANC on depression in patients with OC. ETHICS AND DISSEMINATION: No ethic approval is required for this study, because all the data will be extracted from previous published studies. The results of this study will be presented at conference or will be published at a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019126374.

Effects of on-pump versus off-pump coronary artery bypass grafting on myocardial metabolism.

BACKGROUND: On-pump coronary artery bypass grafting (ON-PCABG) and off-pump coronary artery bypass grafting (OF-PCABG) greatly affect myocardial metabolism (MCMB). However, no study has systematically explored and compared the impacts of ON-PCABG and OF-PCABG on MCMB. This study will aim to explore and to compare the effects of ON-PCABG and OF-PCABG on MCMB systematically. METHODS: We will conduct the comprehensive literature search from the following electronic databases from inception to the present: Cochrane Library, EMBASE, MEDILINE, CINAHL, AMED and 4 Chinese databases without language restrictions. This systematic review will only concern randomized controlled trials (RCTs) and case-control studies of ON-PCABG and OF-PCABG on MCMB. The methodological quality of each entered study will be assessed by using Cochrane risk of bias tool. RESULTS: Primary outcomes include myocardial cellular markers, myocardial lactate, oxygen utilization, pyruvate, and intramyocardial concentrations of glucose, urea and lactate. Secondary outcome comprises of glutathione, superoxide dismutase, myeloperoxidase, and oxidative stress and any other complications post surgery. CONCLUSION: This study will provide a high-quality synthesis and will assess and compare the effects of ON-PCABG and OF-PCABG on MCMB based on the current relevant literature evidence. DISSEMINATION AND ETHICS: The results will be submitted to peer-reviewed journals for publication. This study does not require ethic approval, because it only analyzes the data from published literature. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019125381.