Surface Mapping Research Articles

Determination of rotation center and diameter of femoral heads using off-the-shelf augmented reality hardware for navigation

In total hip arthroplasty (THA), determining the center of rotation (COR) and diameter of the hip joint (acetabulum and femoral head) is essential to restore patient biomechanics. This study investigates on-the-fly determination of hip COR and size, using off-the-shelf augmented reality (AR) hardware. An AR head-mounted device (HMD) was configured with inside-out infrared tracking enabling the determination of surface coordinates using a handheld stylus. Two investigators examined 10 prosthetic femoral heads and cups, and 10 human femurs. The HMD calculated the diameter and COR through sphere fitting. Results were compared to data obtained from either verified prosthetic geometry or post-hoc CT analysis. Repeated single-observer measurements showed a mean diameter error of 0.63 mm ± 0.48 mm for the prosthetic heads and 0.54 mm ± 0.39 mm for the cups. Inter-observer comparison yielded mean diameter errors of 0.28 mm ± 0.71 mm and 1.82 mm ± 1.42 mm for the heads and cups, respectively. Cadaver testing found a mean COR error of 3.09 mm ± 1.18 mm and a diameter error of 1.10 mm ± 0.90 mm. Intra- and inter-observer reliability averaged below 2 mm. AR-based surface mapping using HMD proved accurate and reliable in determining the diameter of THA components with promise in identifying COR and diameter of osteoarthritic femoral heads.

Geological Mapping of Kaso, Tambaksari, Ciamis, West Java Province Using Lidar Images Interpretation

Abstract Remote sensing nowadays is used to quickly and effectively obtain information about an object, area or phenomenon and can be applied to large areas that are sometimes difficult to reach. Satellites with multispectral imagery are commonly used in geological mapping, but have drawbacks when used in tropical areas such as Indonesia, with dense vegetation, fast sedimentation rates and highly weathered that will cover fresh rocks making it difficult to interpret geological condition through aerial photo. Light Detection And Ranging (LiDAR) images using laser beams to produce elevation data (x,y,z) with high spatial resolution and can penetrate the surface of vegetation are expected to be a solution in areas with dense vegetation that are sometimes difficult to reach. The study was conducted by interpreting the morphometric aspects using Digital Terrain Model (DTM) data processed from LiDAR imagery with a spatial resolution of 1 m/pixel to display the topographical surface in detail. The morphometric aspects used include slope, surface roughness, aspect, hillshade, and stream pattern. Field data validation through surface mapping is carried out to correct the lithology interpretation by comparing the results of LiDAR image interpretation. Field data validation results show that interpretation using LiDAR imagery has good results (79%) through overall accuracy percentage, with the lithology units being sandstones, siltstone, breccias, and andesitic igneous rocks. The lineament interpretation of the DTM data indicates the existence of a geological structure in the form of a normal and strike-slip fault in the study area.

Quantification of Dosimetry Improvement With or Without Patient Surface Guidance

PurposeNon-coplanar beams and arcs are routinely used to improve dosimetry for intracranial cases but their application for extra-cranial cases has been hampered by the risk of collision. This has led to conservative beam selection whose impact on plan dosimetry has not been previously studied. Methods and materialA full-body 3D patient surface was acquired using optical cameras for a single lung patient at the time of CT simulation. Eight SBRT plans were created for the patient, with varying degrees of non-coplanarity and deliverability. The plans included VMAT and IMRT plans ranging from simple, coplanar arcs to multiple non-coplanar arcs and IMRT beams. There was a total of 70 fields created across the 8 plans, of which 21 fields were undeliverable with a 5cm buffer. OAR metrics including R50, Dmax 2 cm from the PTV, lung V20 and chest wall V30 were evaluated. Five expert SBRT dosimetrists from five institutions evaluated field deliverability, with or without the guidance of the clearance map. ResultsIn the dosimetry evaluation, a clear trend in increasing dosimetric compactness and OAR sparing is observed with increasing plan non-coplanarity. R50, Dmax 2cm, lung V20, and chest wall V30 decreased 41%, 39%, 43%, 57%, respectively, from plan 1 (two coplanar partial arcs) to plan 8 (19 non-coplanar IMRT beams). In the observer tests, the expert dosimetrists’ ability to accurately discern beam deliverability due to collision significantly increases with the clearance map. The errors in predicting colliding fields were eliminated using the whole-body surface and clearance map, and the user was able to select fields based on plan quality and patient comfort instead of being overly conservative. ConclusionThe study shows that incorporating a personalized, whole-body clearance map in the treatment planning workflow can facilitate the adoption of non-coplanar beams or arcs that benefit the SBRT plan dosimetry.

QBD approach in HPLC method development and validation of furazolidone

QbD principles for establishment of a HPLC method for Furazolidone with improved robustness and performance. On the basis of the initial prioritization and factor screening studies, the highly influential factors were identified and subsequently optimized for improving the method robustness. The response surface mapping particularly facilitated improved understanding of the factor–response relationship and interactions associated with them. Extensive validation studies further ensured high degree of method robustness with extreme variation in the key variables influencing the method performance. In addition, the method showed improved sensitivity for the Furazolidone much beyond the values reported in the literature.

Multimodal breast cancer risk classifier based on biomaterial impedance analysis

Purpose of the research. Breast cancer is the most common malignant tumor among women in Europe and its early detection plays a leading role in reducing mortality rates. Currently, X-ray mammography is the standard screening method for detecting breast cancer. However, due to the morphological similarities between benign and malignant lesions, many of the positive screening mammograms are false positive (up to 40%). Therefore, automation and intellectualization of this process is an urgent task.Methods. The presented studies examine the problems of finding new, highly sensitive, prompt and non-invasive methods for detecting malignant tumors, based on the use of modern computer and telecommunication technologies, which make it possible not only to identify early manifestations of a pathological focus, but also to monitor the process of the effectiveness of therapy without significant harm to the patient’s health.Results. The presented model of a multi-channel classifier integrates the capabilities of multi-frequency bioimpedance measurements and matrix acquisition of information from the surface of human skin through multi-electrode matrix systems. To do this, based on a matrix of electrodes, 3D mapping of the skin surface in problem areas is carried out. Through multi-frequency scanning, we obtain a three-dimensional bioimpedance image, which is analyzed by a convolutional neural network and/or by a decision maker. The proposed solution allows simultaneous analysis of data by an expert (bioimpedance image) and a convolutional neural network (trained classifier), which leads to a reduction in false positive results.Conclusion. The possibilities of multichannel monitoring open up prospects for constructing impedance multidimensional "portraits" of malignant tumors. To classify “portraits” (diagnostics and preclinical diagnostics), methods and algorithms for image recognition and classification are used.

Surface mapping of gastric motor functions using MRI: a comparative study between humans and rats.

The stomach's ability to store, mix, propel, and empty its content requires highly coordinated motor functions. However, current diagnostic tools cannot simultaneously assess these motor processes. This study aimed to use magnetic resonance imaging (MRI) to map multifaceted gastric motor functions, including accommodation, tonic and peristaltic contractions, and emptying, through a single noninvasive experiment for both humans and rats. Ten humans and 10 Sprague-Dawley rats consumed MRI-visible semisolid meals and underwent MRI scans. We used a surface model to analyze MRI data, capturing the deformation of the stomach wall on ingestion or during digestion. We inferred muscle activity, mapped motor processes, parcellated the stomach into functional regions, and revealed cross-species distinctions. In humans, both the fundus and antrum distended postmeal, followed by sustained tonic contractions to regulate intragastric pressure. Peristaltic contractions initiated from the distal fundus, including three concurrent wavefronts oscillating at 3.3 cycles/min and traveling at 1.7 to 2.9 mm/s. These motor functions facilitated linear gastric emptying with a 61-min half-time. In contrast, rats exhibited peristalsis from the midcorpus, showing two wavefronts oscillating at 5.0 cycles/min and traveling at 0.4 to 0.9 mm/s. For both species, motility features allowed functional parcellation of the stomach along a midcorpus division. This study maps region- and species-specific gastric motor functions. We demonstrate the value of MRI with surface modeling in understanding gastric physiology and its potential to become a new standard for clinical and preclinical investigations of gastric disorders at both individual and group levels.NEW & NOTEWORTHY A novel MRI technique can visualize how the stomach accommodates, mixes, and propels food for digestion in humans and animals alike. Digital models of gastric MRI reveal the functional maps, organization, and distinction of the stomach across individuals and species. This technique holds the unique potential to advance basic and clinical studies of functional gastric disorders.

Complete area-coverage path planner for surface cleaning in hospital settings using mobile dual-arm robot and GBNN with heuristics

Complete area-coverage path planners are essential for robots performing tasks like cleaning, inspection, and surveying. However, they often involve complex calculations, mapping, and determining movement directions, leading to high computational or processing overheads and the risk of deadlocks. This paper proposes an approach for cleaning, i.e., by linear wiping of generic and discontinuous surfaces in hospital settings using inhouse assembled mobile dual-arm (MDA) robotic system. The proposed framework introduces key features: (a) a less resource-intensive approach for MDA positioning and cleaning surface mapping, (b) Modified Glasius Bioinspired Neural Network through use of heuristics (GBNN+H) to optimize surface linear wiping while obstacle avoidance, and traversal across discontinuous surfaces. The advantages of the proposed algorithm are highlighted in simulation with GBNN+H significantly reduces the number of steps and flight time required for complete coverage compared to existing algorithms. The proposed framework is also experimentally demonstrated in a hospital setting, paving the way for improved automation in cleaning and disinfection tasks. Overall, this work presents a generic and versatile, applicable to various surface orientations and complexities.

Modified defect relation for Gauss maps of minimal surfaces with hypersurfaces of projective varieties in the subgeneral position

AbstractIn this paper, we establish some modified defect relations for the Gauss map of a complete minimal surface into a ‐dimension projective subvariety with hypersurfaces of in ‐subgeneral position with respect to . In particular, we give the upper bound for the number if the image intersects each hypersurface a finite number of times and is nondegenerate over , where , that is, the image of is not contained in any hypersurface of degree with . Our results extend and generalize the previous results for the case of the Gauss map and hyperplanes in a projective space. The results and the method of this paper have been applied by some authors to study the unicity problem of the Gauss maps sharing families of hypersurfaces.

A Survey on Network Attack Surface Mapping

Network services are processes running on a system with network exposure. A key activity for any network defender, penetration tester, or red team is network attack surface mapping, the act of detecting and categorizing those services through which a threat actor could attempt malicious activity. Many tools have arisen over the years to probe, identify, and classify these services for information and vulnerabilities. In this article, we survey network attack surface mapping by reviewing several prominent tools and their features and then discussing recent works reflecting unique research using those tools. We conclude by covering several promising directions for future research.

How scanning probe microscopy can be supported by artificial intelligence and quantum computing?

The impact of Artificial Intelligence (AI) is rapidly expanding, revolutionizing both science and society. It is applied to practically all areas of life, science, and technology, including materials science, which continuously requires novel tools for effective materials characterization. One of the widely used techniques is scanning probe microscopy (SPM). SPM has fundamentally changed materials engineering, biology, and chemistry by providing tools for atomic-precision surface mapping. Despite its many advantages, it also has some drawbacks, such as long scanning times or the possibility of damaging soft-surface materials. In this paper, we focus on the potential for supporting SPM-based measurements, with an emphasis on the application of AI-based algorithms, especially Machine Learning-based algorithms, as well as quantum computing (QC). It has been found that AI can be helpful in automating experimental processes in routine operations, algorithmically searching for optimal sample regions, and elucidating structure-property relationships. Thus, it contributes to increasing the efficiency and accuracy of optical nanoscopy scanning probes. Moreover, the combination of AI-based algorithms and QC may have enormous potential to enhance the practical application of SPM. The limitations of the AI-QC-based approach were also discussed. Finally, we outline a research path for improving AI-QC-powered SPM. RESEARCH HIGHLIGHTS: Artificial intelligence and quantum computing as support for scanning probe microscopy. The analysis indicates a research gap in the field of scanning probe microscopy. The research aims to shed light into ai-qc-powered scanning probe microscopy.

Benzothiazole-derived Compound with Antitumor Activıiy: Molecular Structure Determination Using Density Functional Theory (Dft) Method

The Gaussian computational chemistry software package was employed to investigate the molecular structure and energetics of benzothiazole, a compound known for its anti-tumor properties. Density functional theory (DFT) calculations were conducted using the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) method, coupled with the LanL2DZ basis set. Molecular structure optimization was carried out to determine the most stable configurations of the benzothiazole compound. Furthermore, thorough analyses of molecular orbital energies, molecular properties, and molecular electrostatic potential surface maps were performed on the optimized molecular system. Our current research suggests that the compound 2-(4-aminophenyl) benzothiazole, containing benzothiazole, maybe a potential drug candidate for free radical species on cells due to its anti-cancer properties.

Non-contact microwave sensor for FDM 3D printing quality control

ABSTRACT In recent years, 3D printing has undergone a transformational journey – from prototyping technology, limited to laboratories, to a production method used in industry – becoming a powerful tool for creating functional objects. Despite this progress, 3D printing faces ongoing challenges related to defect detection and print quality control. We present an innovative, non-contact, fast and cheap microwave sensor for detecting defects in printed components, related to both mechanical errors and conductivity inhomogeneities. We discuss in detail the methodology of the microwave surface mapping technique and the results obtained for several samples printed with popular filaments. Tests show the ability to detect faults with millimetre precision. The simple design of the entire quality control module allows for easy integration with various types of 3D printers, from popular ones used by hobbyists to professional, highly specialised ones.

Effect of synthetic CT on dose-derived toxicity predictors for MR-only prostate radiotherapy.

Toxicity-driven adaptive radiotherapy (RT) is enhanced by the superior soft tissue contrast of magnetic resonance (MR) imaging compared with conventional computed tomography (CT). However, in an MR-only RT pathway synthetic CTs (sCT) are required for dose calculation. This study evaluates 3 sCT approaches for accurate rectal toxicity prediction in prostate RT. Thirty-six patients had MR (T2-weighted acquisition optimized for anatomical delineation, and T1-Dixon) with same day standard-of-care planning CT for prostate RT. Multiple sCT were created per patient using bulk density (BD), tissue stratification (TS, from T1-Dixon) and deep-learning (DL) artificial intelligence (AI) (from T2-weighted) approaches for dose distribution calculation and creation of rectal dose volume histograms (DVH) and dose surface maps (DSM) to assess grade-2 (G2) rectal bleeding risk. Maximum absolute errors using sCT for DVH-based G2 rectal bleeding risk (risk range 1.6% to 6.1%) were 0.6% (BD), 0.3% (TS) and 0.1% (DL). DSM-derived risk prediction errors followed a similar pattern. DL sCT has voxel-wise density generated from T2-weighted MR and improved accuracy for both risk-prediction methods. DL improves dosimetric and predicted risk calculation accuracy. Both TS and DL methods are clinically suitable for sCT generation in toxicity-guided RT, however, DL offers increased accuracy and offers efficiencies by removing the need for T1-Dixon MR. This study demonstrates novel insights regarding the effect of sCT on predictive toxicity metrics, demonstrating clear accuracy improvement with increased sCT resolution. Accuracy of toxicity calculation in MR-only RT should be assessed for all treatment sites where dose to critical structures will guide adaptive-RT strategies. Patient data were taken from an ethically approved (UK Health Research Authority) clinical trial run at Guy's and St Thomas' NHS Foundation Trust. Study Name: MR-simulation in Radiotherapy for Prostate Cancer. ClinicalTrials.gov Identifier: NCT03238170.

LIBS as diagnostics of analytical chemistry for surface mapping of complex mixed samples simulating debris inside the TEPCO's Fukushima Daiichi Nuclear Power Plant (FDNPS) reactor cores

The Nuclear Energy Agency (NEA) launched the Nuclear Education, Skills and Technology (NEST) Framework to pursue careers in the nuclear field, by exposing researcher working on these topics to international challenging project of real-world issue and by transferring the knowledge and expertise accumulated in the current generation to them through hands-on training.In this framework the 2022 edition of the NEST project offered a training educational period at the Collaborative Laboratories for Advanced Decommissioning (CLADS) located at Tomioka, Futaba District, in the Fukushima prefecture (Japan).Among the research sectors active at CLADS there is the application and development of the LIBS technique as diagnostics of analytical chemistry aiming at characterizing the debris inside the Tokyo Electric Power Company (TEPCO)’s FDNPS reactor cores after the tsunami of March 2011, which destroyed three of the six reactors of the plant. These debris need to be chemically characterized with techniques suitable to be implemented in compact, remote and radiation resistant devices, due to the residual radioactivity of the cores. The present study shows the results in realizing chemical bi-dimensional maps of samples in the form of compressed tablets of mixed oxides, with a complex distribution and concentration of chemicals simulating these debris. The results allowed to create detailed maps of the samples, with spatial resolution down to 0.5 mm and an excellent correspondence between the real spatial distribution of the materials and that reconstructed by LIBS.Moreover, it was found a good correspondence between the nominal concentration of the chemicals and the concentration estimated by using LIBS.This study shows the potentialities of LIBS in the realization of chemical maps on samples of interest for FDNPS, providing multi-elemental images of the samples under analysis.

The impact of choledochal cysts on bile fluid dynamics: A perspective using computational fluid dynamics and surface mapping technique

Choledochal cysts (CCs) are an important risk factor for cholangiocarcinoma, though their etiology remains debated. Given the vital role of bile fluid in digestive processes within the biliary system, examining such mechanisms from the perspective of bile fluid dynamics may offer additional insights for clinical use. This study utilized magnetic resonance imaging (MRI)-based patient-specific scans for detailed reconstruction and further employed the computational fluid dynamic method to assess the physiological functions of each system, including refilling and emptying processes. The impact of bile rheological property was also examined. Key biomechanical parameters—pressure and wall shear stress (WSS)—were displayed on a two-dimensional plane via surface mapping for enhanced visualization and comparative analysis. Outcomes demonstrated a significant reduction in bile flow velocity in CCs patients due to common bile duct's anatomical features and bile's shear-thinning, non-Newtonian nature, with a notable increase in pressure drop observed. In healthy biliary systems, WSS variations were minimal; however, in CCs patients, extreme WSS differences were found, with the highest WSS in the segmental bile duct and the lowest in the dilatation area, presenting a magnitude difference of approximately 1000. CCs one showed WSS levels 100–250 times higher than healthy ones in the common bile duct. Bile rheological properties substantially affect pressure and WSS patterns, particularly WSS, where pathological bile caused a tenfold increase in WSS compared to healthy bile. The findings aimed to enhance the understanding of biliary fluid mechanics in CCs and offer insights into selected fluidic variables for future microfluidic chip experiments.

Evolution of the hydrographic network in the middle Wieprz River Basin (E Poland)

The Wieprz River Valley (Polesie Plain, east Poland) has evolved with regard to its dimensions, position and course since the end of the Neogene, its geological record showing how the Wieprz channel migrated and modified its character. Changes have also been observed in the water balance of the entire middle river basin, related to climate changes in the Pleistocene and Holocene. We provide new maps of the sub-Quaternary surface and trace topographical changes during the Pleistocene. Two separate rivers, the Pre-Bystrzyca and Pre-Wieprz, existed in Preglacial time. During the Narevian Glaciation, a network of subglacial troughs evolved in the area, largely disturbing and overprinting the earlier hydrographic system. Some of the troughs developed in older river valleys. The trough in which the present-day Wieprz gorge near Łęczna is located was most probably formed at that time. During subsequent glaciations and cold periods, sedimentary changes took place in the troughs and valleys – from erosion and removal of the accumulated material to their complete burial by sediments. During the Mazovian Interglacial (MIS 11c), several lakes formed in the study area, recorded by their infills of organic and mineral-organic deposits. During subsequent advances of the Scandinavian ice-sheet, water flow was dammed in towards the north, resulting in the formation of backwaters. Ice-sheet retreat resulted in the flow of proglacial waters towards the south-east, fluvioglacial sediment transport, and then unblocking of flow and subsequent reversal of flow directions to the north and west. During the Odranian Glaciation (MIS 6), catastrophic flow unblocked and shaped the present-day Wieprz gorge.

Effect of a low‐mineralized thermal spring water on skin barrier mechanical properties using atomic force microscopy

AbstractThe mineral content of thermal spring water (TSW) applied to the skin surface can directly influence the skin barrier. Indeed, our previous study showed that Avène TSW (ATSW), a low mineral content thermal spring water, protects the stratum corneum from dehydration compared to a mineral‐rich TSW (MR‐TSW) and maintains skin surface ultrastructure. While many TSWs have been recognized to have beneficial effects on skin, little is known about their localized and specific effects on skin barrier biomechanics at the nanometric scale. The aim of this study was to compare the effects of ATSW with a reference, MR‐TSW, on the biomechanical barrier properties of the skin under homeostasis conditions using atomic force microscopy (AFM). AFM was used to obtain a precise nanomechanical mapping of the skin surface after three applications of both TSW. This provides specific information on the skin topographical profile and elasticity. The topographic profile of skin samples showed a specific compaction of the skin layers after application of MR‐TSW, characterized by an increase of the total number of external skin layers, compared to non‐treated samples. By contrast, ATSW did not modify the skin topographic profile. High‐resolution force/volume acquisitions to capture the elastic modulus showed that it was directly correlated with skin rigidity. The elastic modulus strongly and significantly increased after MR‐TSW application compared to non‐treated skin. By contrast, applications of ATSW did not increase elastic modulus. These data demonstrate that applications of MR‐TSW significantly modified skin barrier properties by increasing skin surface layer compaction and skin rigidity. By contrast, ATSW did not modify the topographical profile of skin explants nor induce mechanical stress at the level of the stratum corneum, indicating it does not disrupt the biophysical properties linked to skin surface integrity.

Quantum chemical computational analysis, electronic transitions, interaction mechanisms analysis by spectroscopic, molecular docking, and molecular dynamic simulation of retinol

Quantum computational simulations based on density functional theory are employed to investigate the molecular structure of Retinol. Both geometrical parameters and electronic transitions for gas and green solvents are calculated. Characteristic frequencies were identified and band assignments were achieved through normal coordinate analysis. The calculated spectra and a comparative study of the vibrational spectra, which included a variety of vibration modes, were compared with the experimental spectra. A compound’s strong reactivity may be indicated by the bandgap, which also indicates the possibility of further charge exchange through the molecule. Determination of relative electrophilicity/nucleophilicity indices of retinol was undertaken through the prediction of condensed Fukui functions, complemented by the generation of molecular electrostatic potential surface maps. This exploration was validated through meticulous correlation with reduced density gradient and isodensity surface plots. The docking analysis of retinol with different proteins was performed to confirm anti-inflammatory activity. To gain comprehensive insights into macromolecule pliability concerning protein–ligand interactions, an effective molecular dynamics simulation was conducted.

Hirshfeld surface analysis, experimental and theoretical evaluation of a new monohydrated organic salt of 2-amino-4‑hydroxy-6-methylpyrimidine (AHMP) and 4-acetamidobenzoic acid (AMBA) for nonlinear optical applications

The organic crystal (AHMP+.AMBA−) of the AHMP and AMBA organic compounds was successfully synthesized and grown by the slow evaporation solution process. The present work focuses on the crystal structure, Hirshfeld surface, spectroscopic and DFT analyses of the title salt. The crystal geometry of AHMP+.AMBA− monohydrated salt was characterized by the single-crystal XRD technique. The synthesized salt crystallizes in the triclinic crystal system and P-1 space group. The identification of the functional groups of the compound has been done by FTIR spectroscopy and DFT/B3LYP-D3/6–311++G(d,p) level of theory. Further, Hirshfeld surface mapping and its associated two-dimensional fingerprint plots predict that the O⋅⋅⋅H and H⋅⋅⋅H interactions are dominant for stabilizing the crystal structure. TG-DTA reveals the crystal is thermally stable up to 168 ºC. The optical studies have been performed by the time-dependent DFT (TD-DFT) and UV–Vis spectroscopic methods. Moreover, the Z-scan experiment has been done to obtain third-order NLO properties. Additionally, the HOMO-LUMO energy gap, MEP maps and theoretical NLO parameters have also been calculated.

Space–time statistics of 2D soliton gas in shallow water studied by stereoscopic surface mapping

Space–time statistics of 2D soliton gas in shallow water studied by stereoscopic surface mapping