Planar Reconstruction Research Articles

Planar Reconstruction of Regular Surfaces’ Three-Dimensional Morphology and Tribology Application

The three-dimensional morphology of frictional sub-surfaces holds significant importance for studying tribological issues. However, the uniformity of the horizontal datum in 3D scanning is limited for curved surfaces, resulting in the inability to obtain accurate contour characterization parameters from the scanning results. This study aims to address this issue by constructing regular surface equations and normalizing the 3D profiler scanning results. By fitting the data, a “plane” surface representative of the surface features is obtained, and the paper demonstrates this approach on the surface morphology of different worn parts in the frictional area of spherical bearings located in the specific environment of the Three Gorges gate. The results indicate that the obtained “plane” effectively reconstructs the three-dimensional morphology map of the regular surface. Moreover, this reconstructed plane not only clearly illustrates the surface characteristics but also provides the foundation for analyzing the wear mechanism.

Prepectoral Direct-to-Implant versus Staged Tissue Expander Breast Reconstruction: A Comparison of Complications.

Direct-to-implant (DTI) reconstruction has multiple advantages over a staged tissue expander (TE) approach. However, its use may be limited by concerns of increased complications. This study is the largest series to date comparing postoperative outcomes for DTI versus TE reconstruction in the prepectoral plane. The authors retrospectively reviewed 348 patients who underwent 536 total immediate, prepectoral implant-based breast reconstructions between January of 2018 and December of 2021. The authors compared the presence of risk factors and the rate of six separate complications between patients who underwent DTI versus TE reconstruction up to 1 year after surgery. Of 348 patients, 147 (42%) and 201 (58%) underwent TE and DTI reconstruction ( P = 0.1813), respectively. The overall infection rate was 16.4% ( n = 57). DTI patients had a significantly greater incidence of wounds ( P < 0.0001), including minor ( P < 0.0011) and major wounds ( P < 0.0053). Significantly greater mastectomy resection weights were found for DTI patients who experienced any complication ( P < 0.0076), postoperative wounds ( P < 0.0001), and major wounds specifically ( P < 0.0035). Compared with medium-thickness acellular dermal matrix (ADM), extra thick ADM was associated with significantly increased rates of infection ( P < 0.0408) and wounds ( P < 0.0001). Prepectoral DTI reconstruction in patients with adequate flap perfusion may have complication rates comparable to staged TE reconstruction, apart from a higher incidence of postoperative wounds. Greater mastectomy resection weights and thickness of ADM may specifically contribute to infection and wound-healing complications. Prepectoral DTI reconstruction is encouraged in the patients with adequate flap perfusion and moderate to low mastectomy resection weights who desire comparable or smaller implant volumes. Therapeutic, III.

A Clinical Approach to Semiautomated Three-Dimensional Fetal Brain Biometry-Comparing the Strengths and Weaknesses of Two Diagnostic Tools: 5DCNS+TM and SonoCNSTM.

(1) Objective: We aimed to evaluate the accuracy and efficacy of AI-assisted biometric measurements of the fetal central nervous system (CNS) by comparing two semiautomatic postprocessing tools. We further aimed to discuss the additional value of semiautomatically generated sagittal and coronal planes of the CNS. (2) Methods: Three-dimensional (3D) volumes were analyzed with two semiautomatic software tools, 5DCNS+™ and SonoCNS™. The application of 5DCNS+™ results in nine planes (axial, coronal and sagittal) displayed in a single template; SonoCNS™ depicts three axial cutting sections. The tools were compared regarding automatic biometric measurement accuracy. (3) Results: A total of 129 fetuses were included for final analysis. Our data indicate that, in terms of the biometric quantification of head circumference (HC), biparietal diameter (BPD), transcerebellar diameter (TCD) and cisterna magna (CM), the accuracy of SonoCNS™ was higher with respect to the manual measurement of an experienced examiner compared to 5DCNS+™, whereas it was the other way around regarding the diameter of the posterior horn of the lateral ventricle (Vp). The inclusion of four orthogonal coronal views in 5DCNS+™ gives valuable information regarding spatial arrangements, particularly of midline structures. (4) Conclusions: Both tools were able to ease assessment of the intracranial anatomy, highlighting the additional value of automated algorithms in clinical use. SonoCNS™ showed a superior accuracy of plane reconstruction and biometry, but volume reconstruction using 5DCNS+™ provided more detailed information, which is needed for an entire neurosonogram as suggested by international guidelines.

Reconstruction of transient acoustic field using sparse real-time near-field acoustic holography

A sparse real-time near-field acoustic holography method is proposed to precisely and stably reconstruct a transient sound field. By a time-domain impulse response function, a time domain convolution equation between the pressure time-wavenumber spectra on the hologram and reconstruction planes is first established. Then, a smoothed ℓ0-norm optimization algorithm is applied to solve the serious ill-conditioned problem of the inverse process to get the pressure time-wavenumber spectrum of the reconstruction plane. The key part of solving this problem is to approximate replace the discontinuous ℓ0-norm by using a suitable continuous Gaussian function family, and a steepest ascent algorithm is introduced to minimize the continuous function for obtaining the optimal solution. Finally, the pressure time-wavenumber spectra of the reconstruction plane for all wavenumbers at all times are solved, and the corresponding time-dependent pressures are gained by the two-dimensional space inverse Fourier transform. A numerical simulation is conducted to observe the reconstruction capacity of the proposed method. The simulation effect prove that the proposed method can accurately reconstruct the transient sound field, and its reconstruction results are compared to those of the real-time near-field acoustic holography (RTNAH) with Tikhonov regularization and YALL1 modal for verifying the superiority of the proposed method. The YALL1 module utilizes an alternating direction algorithm for solving the ℓ1 minimization problems. Several parameters including the noise, position of the holograph plane and two initialization values are discussed in the simulation. The comparison and discussion results show that the reconstruction effect of the proposed method is much better than those of RTNAH with Tikhonov regularization and YALL1 modal under different parameter configurations. An experiment with a percussive steel plate is implemented for further validating the effectivity of the proposed method.

Adductor canal block techniques do not lead to involvement of sciatic nerve branches: a radiological cadaveric study

IntroductionLow and high volume mid-thigh (ie, distal femoral triangle) and distal adductor canal block approaches are frequently applied for knee surgical procedures. Although these techniques aim to contain the injectate...

Occupancy Planes for Single-View RGB-D Human Reconstruction

Single-view RGB-D human reconstruction with implicit functions is often formulated as per-point classification. Specifically, a set of 3D locations within the view-frustum of the camera are first projected independently onto the image and a corresponding feature is subsequently extracted for each 3D location. The feature of each 3D location is then used to classify independently whether the corresponding 3D point is inside or outside the observed object. This procedure leads to sub-optimal results because correlations between predictions for neighboring locations are only taken into account implicitly via the extracted features. For more accurate results we propose the occupancy planes (OPlanes) representation, which enables to formulate single-view RGB-D human reconstruction as occupancy prediction on planes which slice through the camera's view frustum. Such a representation provides more flexibility than voxel grids and enables to better leverage correlations than per-point classification. On the challenging S3D data we observe a simple classifier based on the OPlanes representation to yield compelling results, especially in difficult situations with partial occlusions due to other objects and partial visibility, which haven't been addressed by prior work.

HbA1c Reduction by Imeglimin (Twymeeg) In Diabetic Patient with Pancreatic Atrophy on Curved Planar Reconstruction (CPR)

HbA1c Reduction by Imeglimin (Twymeeg) In Diabetic Patient with Pancreatic Atrophy on Curved Planar Reconstruction (CPR)

Fast Numerical Reconstruction of Integral Imaging Based on a Determined Interval Mapping

In this paper, a fast numerical reconstruction of the integral imaging based on a determined interval mapping is proposed. To reduce the computation time, the proposed method employs the determined interval mapping instead of the use of magnification. In the numerical reconstruction procedure, the acquired elemental image array (EIA) from the 3D object is displayed. The flipped elemental image (EI)s are numerically formed by the virtual pinhole array. Then, the determined interval depending on the reconstruction plane is calculated and applied to each flipped EI. These flipped EIs are shifted to match the determined interval at the reconstruction plane and superimposed together. After this superimposed image is divided by the number of the superposition, the position error between the location of the shifted EI and the pixel position of the reconstruction plane is corrected by interpolation. As a result, the refocused image depending on the reconstruction plane can be reconstructed rapidly. From the experimental result, we confirmed that the proposed method largely decreased the computation time compared with the conventional method. In addition, we verified that the quality of the reconstruction by the proposed method is higher than the conventional method by the use of the structural similarity index method.

Obscured tree branches segmentation and 3D reconstruction using deep learning and geometrical constraints

The shortage of agricultural labourers worldwide has left many groups unharvested and wasted, which motivates researchers worldwide to research fruit harvesting robots extensively. One of the major problems in fruit harvesting is to selectively avoid hard obstacles such as tree branches so that more optimal picking positions can be found and more fruits throughout the tree can be harvested. However, tree branches are often obscured in unstructured natural orchards and thus necessary branch reconstruction and recovery are required. The current branch reconstruction and recovery methods for harvesting robots focus on planar reconstruction with few occlusions while the existing 3D tree modelling methods are not optimised for harvesting purposes that require low computational cost and high localisation accuracy. This work presented a novel framework that reconstructs and recovers 3D obscured branches from planar images and depth maps captured by an RGB-D camera. The framework comprises three parts: branch segmentation using Unet++, branch reconstruction using Point2Skeleton and branch recovery using a novel obscured branch recovery (OBR) algorithm. Branch segmentation using Unet++ with InceptionV3 encoder shows the best overall result with IoU and F1-score of 0.6249 and 0.7692 respectively. OBR recovery algorithm achieves average reconstruction accuracy of 0.72. The mean error of the reconstructed total surface and obscured surface using OBR is 18.68 mm and 38.11 mm with a standard deviation of 14.3 mm and 32.64 mm. The result shows that this framework can effectively reconstruct spatial information of visible and obscured branches from a single view image which can potentially be utilised in harvesting robots.

A Decade of Nipple-Sparing Mastectomy: Lessons Learned in 3035 Immediate Implant-Based Breast Reconstructions.

Nipple-sparing mastectomy is commonly performed for breast cancer treatment or prevention. The authors present one of the largest breast reconstruction series in the literature. A single-institution retrospective review was conducted from 2007 to 2019. The authors' query identified 3035 implant-based breast reconstructions after nipple-sparing mastectomy, including 2043 direct-to-implant and 992 tissue expander-to-implant reconstructions. The overall major complication rate was 9.15%, and the nipple necrosis rate was 1.20%. Therapeutic mastectomy was associated with higher overall complications and explantations compared with prophylactic mastectomy ( P < 0.01). In comparisons of unilateral and bilateral procedures, bilateral mastectomy had an increased risk for complications (OR, 1.46; 95% CI, 0.997 to 2.145; P = 0.05). Tissue-expander reconstructions had higher rates of nipple necrosis (1.9% versus 0.88%; P = 0.015), infection (4.2% versus 2.8%; P = 0.04), and explantation (5.1% versus 3.5%; P = 0.04) compared with direct-to-implant reconstruction. When assessing plane of reconstruction, the authors found similar rates of complications between subpectoral dual-plane and prepectoral reconstruction. There was no difference in complications between reconstruction with acellular dermal matrix or mesh compared with total or partial muscle coverage without acellular dermal matrix/mesh (OR, 0.749; 95% CI, 0.404 to 1.391; P = 0.361). Multivariable regression analysis revealed preoperative radiotherapy (OR, 2.465; 95% CI, 1.579 to 3.848; P < 0.001), smoking (OR, 2.53; 95% CI, 1.581 to 4.054; P < 0.001), and a periareolar incision (OR, 3.657; 95% CI, 2.276 to 5.875; P < 0.001) to be the strongest predictors of complications and nipple necrosis ( P < 0.05). Nipple-sparing mastectomy and immediate breast reconstruction has a low rate of complications. In this series, radiation therapy, smoking, and incision choice predicted overall complications and nipple necrosis, whereas direct-to-implant reconstruction and acellular dermal matrix or mesh did not increase risk. Therapeutic, III.

The Impact of Prior Breast Augmentation on Breast Reconstruction after Mastectomy

Background: The risk of women developing breast cancer after augmentation mammaplasty may be lower than the general population, with minimal current literature on breast reconstruction in this population. We sought to evaluate the impact of previous augmentation on postmastectomy breast reconstruction. Methods: Retrospective review of patients who underwent mastectomies from 2017 to 2021 at our institution was performed. Analysis included frequencies and percentages, descriptive statistics, chi-square analysis, and Fisher exact test. Results: Four hundred seventy patients were included, with average body mass index of 29.1 kg/m2, 96% identifying as White, and an average age at diagnosis of 59.3 years. Twenty (4.2%) patients had a prior breast augmentation. Reconstruction was performed in 80% of the previously augmented patients compared to 49.9% of nonaugmented patients (P = 0.01). Reconstruction was alloplastic in 100% of augmented and 88.7% of nonaugmented patients (P = 0.15). All reconstructed augmented patients underwent immediate reconstruction compared with 90.5% of nonaugmented patients (P = 0.37), and two-stage reconstruction was most common (75.0% versus 63.5%; P = 0.42). Of the previously augmented patients, 87.5% increased implant volume, 75% underwent same implant plane reconstruction, and 68.75% underwent same implant-type reconstruction as their augmentation. Conclusions: Previously augmented patients were more likely to undergo reconstruction after mastectomy at our institution. All reconstructed augmented patients underwent alloplastic reconstruction, with most performed immediately in staged fashion. Most patients favored silicone implants and maintained the same implant type and plane of reconstruction, with increased implant volume. Larger studies are required to further investigate these trends.

An iteratively reweighted time-domain acoustic method for reconstructing the transient acoustic field

An improved iterative reweighted least-squares based on real-time near-field acoustic hologram method (RTNAH) is proposed to reconstruct the transient acoustic field. First, time-domain convolution relation formula between the pressure time-wavenumber spectra on the hologram and reconstruction planes is first established by an impulse response function, and the corresponding matrix equation is obtained. Then, for solving the pressure spectra on the reconstruction plane, an improved iterative reweighted least-squares algorithm is applied for solving the minimization problem of the sum of 2-norm residual and 2-norm weighted solution under the weighted and sparse representation framework. By controlling the iteratively updated weighting matrix, the sparsity of the solution is promoted. Finally, the pressure spectra of the reconstruction plane are estimated, and the corresponding time-varying pressures are acquired by the two-dimensional inverse Fourier transform. A numerical simulation is conducted to observe the reconstruction capacity of the proposed method. The simulation results demonstrate that the proposed method can reconstruct the transient acoustic field in time-space domains very well. Meanwhile, several vital parameters are discussed, and the superiorities of the proposed method are testified by comparing to RTNAH with Tikhonov regularization and YALL1 model. An experiment is implemented for further validating the effectivity of the proposed method.

Pointing of the Hexagonal Pixel Shape Telescope without NSB Using Star Reconstruction in the Cherenkov photodetection Plane

In this article, we investigate, without the presence of Night Sky Background(NSB), the best pointing method which is independent of any deformation of the structure or mechanical effects. The method is direct and on real time, we will used the presence of stars in the photodetection plane during observation, to reconstruct the direction of the telescope. We will first present the method used to reconstruct the pointing direction in real time and then evaluate the impact of the different systematics on the pointing accuracy.

Reconstruction of helmholtz plane to stabilize zinc metal anode/electrolyte interface

Dendrites proliferation and parasitic side reactions on zinc metal anodes (ZMAs) severely weaken the energy efficiencies of aqueous zinc metal batteries (AZMBs). Herein, an effective Helmholtz plane (HP) reconstruction mechanism on ZMAs in ZnSO4 electrolyte activated by zinc pyrrolidone carboxylate (PCA-Zn) additive is proposed. Systematical experiments together with numerical simulations identified that the dissociated PCA− anions featuring bis-zincophilic-terminal preferentially adhere to the ZMAs surface with carboxyls serving as anchors to replace H2O and SO42−, reshaping an H2O/SO42−-repellent HP to restrain water-triggered side reactions. Meanwhile, the other free zincophilic carbonyl terminals of PCA− anions endow the restructured HP with spatial confinement effect on Zn2+, effectively suppressing their rampant in-plane diffusion and homogenizing ions flux during Zn deposition. Moreover, the HP exhibits a self-repair behavior against unexpected electrode surface damage upon cycling. Benefiting from the multifunctional HP that enables more stable ZMAs/electrolyte interphasial chemistry, an excellent Zn||Zn symmetric electroplating/stripping cyclic durability exceeding 300 h under a depth of discharge up to 40% (20 mA cm−2/20 mAh cm−2) is achieved, accounting for significantly boosted rechargeability (89.7% capacity holding ratio after 5000 cycles) of the carbon-cloth@polyaniline||ZMA full AZMBs compared to that without PCA-Zn additive (malfunction after only 960 cycles).

Understanding substrate-driven growth mechanism of copper silicide nanoforms and their applications

The growth mechanism of various nanoforms of copper/copper silicide on Si substrates with different orientations is reported here. The triangular, square and rectangular copper/copper silicide nanostructures are deposited on silicon substrates with (111), (100) and (110) orientations respectively, by thermal evaporation of metallic copper at different substrate temperatures. Investigations confirm that the nanostructures consist of a pure copper layer on top of a copper silicide layer. The morphology and growth behaviour studies confirmed for the first time that the formation of well-defined structures and shapes are governed by the Si substrate orientation and the surface reconstruction of the Si planes. The copper silicide nanostructures are used in field emission applications and also serve as a template for the growth of carbon nano-fibre.

Reconstruction of incomplete X-ray diffraction pole figures of oligocrystalline materials using deep learning

X-ray diffraction crystallography allows non-destructive examination of crystal structures. Furthermore, it has low requirements regarding surface preparation, especially compared to electron backscatter diffraction. However, up to now, X-ray diffraction has been highly time-consuming in standard laboratory conditions since intensities on multiple lattice planes have to be recorded by rotating and tilting. Furthermore, examining oligocrystalline materials is challenging due to the limited number of diffraction spots. Moreover, commonly used evaluation methods for crystallographic orientation analysis need multiple lattice planes for a reliable pole figure reconstruction. In this article, we propose a deep-learning-based method for oligocrystalline specimens, i.e., specimens with up to three grains of arbitrary crystal orientations. Our approach allows faster experimentation due to accurate reconstructions of pole figure regions, which we did not probe experimentally. In contrast to other methods, the pole figure is reconstructed based on only a single incomplete pole figure. To speed up the development of our proposed method and for usage in other machine learning algorithms, we introduce a GPU-based simulation for data generation. Furthermore, we present a pole widths standardization technique using a custom deep learning architecture that makes algorithms more robust against influences from the experiment setup and material.

Numerical simulation of the three-sleeper asynchronous tamping operation of ballast bed based on the virtual unit module and polyhedral ballast model

Reasonable asynchronous tamping operation plays an important role in improving and maintaining the performance of the ballast bed. In studies conducted so far, constant velocity or angular velocity was applied to simulate the movement of tamping picks. This is in total contrast to the actual situation. For better simulation of three-sleeper asynchronous tamping operation, an innovative method of “plane reconstruction and space fusion” for rapid construction of polyhedral ballast particles was first proposed. The asynchronous squeezing of tamping picks was attained with the help of the coaxial rotation method for different bodies and a virtual unit module was developed. Then, a new relative velocity friction model was utilized to analyze the contact force inside the ballast bed. Finally, the coupling model of three-sleeper asynchronous tamping machine-ballasted track was established and verified. The results showed that the penetration stage has the greatest impact on the compactness of ballast at the bottom of the sleeper. The void ratio is relatively small, the elasticity and settlement of the ballast bed after tamping are minimum when the track lifting amount is 30 mm and the squeezing force is 7.8kN, and the tamping effect is the optimal.

Accuracy of Caudocranial Canine Femoral Radiographs Compared to Computed Tomography Multiplanar Reconstructions for Measurement of Anatomic Lateral Distal Femoral Angle.

This study aimed to compare the accuracy of sternal recumbency caudocranially obtained radiographs of canine femora to computed tomographic (CT) frontal plane reconstructions of the same femora for assessing anatomic distal lateral femoral angles (aLDFA). Multicentre, retrospective study utilizing 81 matched radiographic and CT studies of clinical patients undergoing assessment for various issues were reviewed. Anatomic lateral distal femoral angles were measured, and accuracy assessed with descriptive statistics and Bland-Altman plot analysis, with CT considered the reference standard. Sensitivity and specificity of a cut-off for measured aLDFA (102 degrees) were determined to assess radiography as a screening tool for significant deformity. Radiographs on average overestimated aLDFA by 1.8 degrees compared to CT. Bland-Altman analysis identified a 15.4 degrees 95% limit of agreement range and a tendency for greater overestimation at higher average measured value. Radiographic measurement of aLDFA of 102 degrees or less had a 90% sensitivity, 71.83% specificity, and 98.08% negative predictive value for the CT measurement being less than 102 degrees. Accuracy of aLDFA measurement by caudocranial radiographs does not demonstrate sufficient accuracy when compared to CT frontal plane reconstructions with unpredictable differences. Radiographic assessment is a useful screening tool to exclude animals with a true aLDFA of greater than 102 degrees with a high degree of certainty.

Data-driven determination of low-frequency dipole noise mechanisms in stalled airfoils

An aeroacoustic investigation of planar time-resolved particle image velocimetry (PIV) measurements in the streamwise surface-normal plane of a NACA 0012 airfoil in static stall is presented at chord-based Reynolds number textrm{Re}_c=7.1times 10^4. Instantaneous planar pressure reconstructions are obtained using a Poisson solver and the dipole noise emanating from the surface is extrapolated via Curle’s acoustic analogy. To correlate structure in the velocity field to the generation of noise, a data-driven framework utilising the proper orthogonal decomposition (POD) and the spectral Linear Stochastic Estimation (sLSE) is employed. The flow structures responsible for noise are found to concentrate in proximity to the trailing edge. In addition, a conditional analysis for the extreme noise events reveals that downwash and upwash events in proximity to the trailing edge, coupled with slow and fast-moving fluid at the incipient shear layer, are correlated to local maxima and minima in the acoustic fluctuations, respectively.Graphical abstract

Immediate Combined Hand Reconstruction in a Patient with Complex Tissue Defect and Total Finger Amputation

Clinical evaluation of bones, tendons, joints, vessels, nerves and muscles at the patient's first presentation plays a critical role in determining the reconstruction plan of injured hand. In crush injury, skeletal stabilization forms the foundation for the entire reconstruction plane. In the basic approach, debridement of devitalized tissues, bone fracture stabilization, neurovascular repair, graft and flap coverage of critical tissues are applied respectively. In certain circumstances ectopic replantation can be an option in severely crushed injuries. Here in, we present the combined immediate reconstruction process of a patient applied with soft tissue defect in the hyposthenia region of the left hand, bony defect of the 4th and 5th metacarpals and total amputation of the 5th finger