Three-dimensional Scanning Research Articles

Observation of biological and emulsion samples by newly developed three-dimensional impedance scanning electron microscopy

Imaging at nanometre-scale resolution is indispensable for many scientific fields such as biology, chemistry, material science and nanotechnology. Scanning electron microscopes (SEM) are widely used as important tools for the nanometre-scale analysis of various samples. However, because of the vacuum inside the SEM, a typical analysis requires fixation of samples, a drying process, and staining with heavy metals. Therefore, there is a need for convenient and minimally invasive methods of observing samples in solution. Recently, we have developed a new type of impedance microscopy, multi-frequency impedance SEM (IP-SEM), which allows nanoscale imaging of various specimens in water with minimal radiation damage. Here, we report a new IP-SEM system equipped with a linear-array terminal, which allows eight tilted images to be observed in a single capture by applying eight frequencies of input signals to each electrode. Furthermore, we developed a three-dimensional (3D) reconstruction method based on the Simulated Annealing (SA) algorithm, which enables us to construct a high-precision 3D model from the 8 tilted images. The method reported here can be easily used for 3D structural analysis of various biological samples, organic materials, and nanoparticles.

Three-dimensional spatial structure and heterogeneity characterization of #5 coal of Shanxi Formation in eastern Ordos basin

Based on macroscopic qualitative observation, microscopic quantitative analysis, low-temperature adsorption, high-pressure mercury intrusion and three-dimensional CT scanning, the spatial structure and heterogeneity of the #5 coal from the eastern Ordos Basin, Shanxi Formation, are quantitatively characterized. The following observation were studied: 1) The main body of the #5 coal was intact structural coal seam, with the density of cleats gradually increasing from north to south. 2) The microscopic composition of the #5 coal is dominated by desmocollinite, which contains small amounts of inertinite and inorganic minerals, with the inorganic component mainly composed of carbonate rocks and a small amount of clay. The carbon content and the content of its inorganic minerals in the #5 coal gradually decrease toward the inner basin, caused by transport distance and depositional environment. 3) At the micrometer scale, no significant pores were observed, and the #5 coal bed is primarily composed of micro-mesopores smaller than 40 nm, with a small number of 50∼100 nm macropores. Simultaneously, micro-fractures in the coal bed were well developed; by using mercury intrusion data of the bimodal feature of the pore throat, indicates the coexistence of micrometer-scale micro-fractures and nanometer-scale mesopores within the coal, with pronounced differences and interconnected complexity. 4) The porosity and permeability of microfractures, as well as the number of microfracture bars and permeability, indicate that the connectivity of coal bed is primarily caused by the microfracture system. By reconstructing the three-dimensional spatial structure of the #5 coal through multiple tests, the heterogeneous characteristics are quantitatively characterized.

Efficacy and Safety of Hyaluronic Acid Combined with Botulinum Toxin Type A in the Treatment of Midcheek Groove: A Prospective Study.

The midcheek groove, a diagonal wrinkle in the infraorbital and infrazygomatic regions, disrupts the entire midface smooth lines and impacts facial aesthetics. Despite current treatments' limited effectiveness, including hyaluronic acid fillers and surgical risks, and the neglect of the medial orbicularis oculi muscle, this study explores the efficacy and safety of combining botulinum toxin type A with sodium hyaluronate injection for midcheek groove treatment, considering anatomical and clinical factors. In this prospective study, healthy participants with midcheek grooves (depth >3 mm) were treated with botulinum toxin type A combined with hyaluronic acid injections. Data were collected at baseline, 4, 12, and 32 weeks as well as 30 min after treatment, and at 1, 3, and 6 months follow-up. Changes in the depth of the midcheek groove were measured using a three-dimensional scanner and assessed using the Patient Satisfaction Assessment Scale. Subgroup analyses were performed to assess the impact of different clinical subtypes on treatment outcomes. Thirty-six volunteers completed this study, and the midcheek groove depth was significantly reduced at 30 min after treatment and at 1, 3, and 6 months of follow-up (p < 0.001). The medial half of the midcheek groove had the best efficacy at 1 month after treatment, while the lateral half responded best at 30 min after treatment. Subgroup analyses showed that clinical subtypes affected treatment efficacy. No complications or severe adverse reactions were observed. Botulinum toxin type A combined with hyaluronic acid injection effectively improved the midcheek groove. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The untapped potential of 3D virtualization using high resolution scanner-based and photogrammetry technologies for bone bank digital modeling

Three-dimensional (3D) scanning technologies could transform medical practices by creating virtual tissue banks. In bone transplantation, new approaches are needed to provide surgeons with accurate tissue measurements while minimizing contamination risks and avoiding repeated freeze-thaw cycles of banked tissues. This study evaluates three prominent non-contact 3D scanning methods—structured light scanning (SLG), laser scanning (LAS), and photogrammetry (PHG)—to support tissue banking operations. We conducted a thorough examination of each technology and the precision of the 3D scanned bones using relevant anatomical specimens under sterile conditions. Cranial caps were scanned as separate inner and outer surfaces, automatically aligned, and merged with post-processing. A colorimetric analysis based on CIEDE2000 was performed, and the results were compared with questionnaires distributed among neurosurgeons. The findings indicate that certain 3D scanning methods were more appropriate for specific bones. Among the technologies, SLG emerged as optimal for tissue banking, offering a superior balance of accuracy, minimal distortion, cost-efficiency, and ease of use. All methods slightly underestimated the volume of the specimens in their virtual models. According to the colorimetric analysis and the questionnaires given to the neurosurgeons, our low-cost PHG system performed better than others in capturing cranial caps, although it exhibited the least dimensional accuracy. In conclusion, this study provides valuable insights for surgeons and tissue bank personnel in selecting the most efficient 3D non-contact scanning technology and optimizing protocols for modernized tissue banking. Future work will advance towards smart healthcare solutions, explore the development of virtual tissue banks.

Full-field Modal Analysis of a Tensegrity Column Using a Three-dimensional Scanning Laser Doppler Vibrometer with a Mirror

Abstract Tensegrity structures become important components of various engineering structures due to their high stiffness, light weight, and deployable capability. Existing studies on their dynamic analyses mainly focus on responses of their nodal points while overlook deformations of their cable and strut members. This study proposes a non-contact approach for experimental modal analysis of a tensegrity structure to identify its three-dimensional (3D) natural frequencies and full-field mode shapes, which include modes with deformations of its cable and strut members. A 3D scanning laser Doppler vibrometer is used with a mirror for extending its field of view to measure full-field vibration of a novel three-strut metal tensegrity column with free boundaries. Tensions and axial stiffnesses of its cable members are determined using natural frequencies of their transverse and longitudinal modes, respectively, to build its theoretical model for dynamic analysis and model validation purposes. Modal assurance criterion (MAC) values between experimental and theoretical mode shapes are used to identify their paired modes. Modal parameters of the first 15 elastic modes of the tensegrity column identified from the experiment, including those of the overall structure and its cable members, can be classified into five mode groups depending on their types. Modes paired between experimental and theoretical results have MAC values larger than 78%. Differences between natural frequencies of paired modes of the tensegrity column are less than 15%. The proposed non-contact 3D vibration measurement approach allows accurate estimation of 3D full-field modal parameters of the tensegrity column.

Safety and efficacy of the amino acid crosslinked hyaluronic acid in the treatment of temple hollowing.

Loss of volume in the temples is an early sign of aging and often gives the impression of a gaunt and emaciated appearance. The authors conduct a clinical study to investigate the safety and effectiveness of the amino acid crosslinked hyaluronic acid (ACHA) for the treatment of temple hollowing. 75 subjects with Temple Hollowing Scale (THS) from 2 to 4 were enrolled and assigned according to the ratio of 2 (ACHA group, n=50): 1 (no treatment control group, n=25). All subjects were assessed at the 12-month follow-up visit using the THS, Global Aesthetic Improvement Scale (GAIS), ultrasound, and three-dimensional scanning. Subjects were instructed to report any adverse events (AEs) within 14 days after the ACHA treatment. An average volume of 4.72±1.13ml was injected into the temples. We received 18 treatment-related AEs reported by 10 subjects. Compared with the control group, THS, GAIS, and soft tissue thickness were significantly improved in the ACHA group at 1 month, 6, and 12 months after injection. Three-dimensional scanning showed that ACHA could maintain a certain volume in the temple 12 months after ACHA injection. ACHA is an effective and safe hyaluronic acid for patients with minimal to severe temple hollowing.

Cracking of silty mudstone subjected to wetting-drying cycles

Cracking affected by wetting-drying cycles is a major cause of shallow failure of soft rock slopes. Knowledge of rock tensile properties and cracking behaviors helps better assess the stability of soft rock slopes. This study aims to examine the cracking behaviors and tensile strength of silty mudstone under wetting-drying cycles. The wetting-drying cycles and Brazilian splitting tests were performed on silty mudstone considering various cycle number and amplitude. The cracking behaviors of wetting-drying cycles were analyzed by digital image correlation, three-dimensional (3D) scanning technology, and scanning electron microscopy. The results reveal a spiral-like pattern of crack ratio escalation in silty mudstone, with a higher crack ratio observed during drying than wetting. Tensile strength and fracture energy correlate negatively with cycle number or amplitude, with cycle number exerting a more pronounced effect. The variance of the maximum principal strain reflects stages of initial deformation, linear deformation, strain localization, and stable deformation. The formation of strain localization zones reveals the physical process of crack propagation. Crack tip opening displacement progresses through stages of slow growth, exponential growth, and linear growth, delineating the process from crack initiation to stable extension. Failure modes of silty mudstone primarily involve tensile and tensile-shear failure, influenced by the geometric parameters of cracks induced by wetting-drying cycles. Fracture surface roughness and fractal dimension increase with cycle number due to mineral dissolution, physical erosion, and nondirectional crack propagation. Hydration-swelling and dehydration-shrinkage of clay minerals, along with absorption-drying cracking, initiate and merge cracks, leading to degradation of the rock mechanical properties. The findings could provide insights for mitigating shallow cracking of soft rock slopes under wetting-drying cycles.

Cocoon microstructures through the lens of topological persistence.

Biological materials display a wide array of functionality, often dictated by complicated microstructures. New geometric and topological strategies allow one to describe the microstructures in a precise and systematic way. This article describes the application of topological persistence and other geometric methods to the microstructural analysis of three-dimensional X-ray micro-computed tomography scans of the Bombyx mori silkworm cocoons. These methods allow conclusions to be drawn about pore space gradients, silk fibre thickness gradients and fibre alignment within the cocoon. The study demonstrates the applicability of these topological and geometric methods to quantify and characterize fibrous materials.

High-speed three-dimensional random access scanning with SPARCLS

High-speed three-dimensional random access scanning with SPARCLS

Assessing the Influence of Hyaluronan Dressing on Wound Healing on Split-Thickness Skin Graft Donor Sites Using a Three-Dimensional Scanner.

Objectives: The topical application of hyaluronic acid after injury may accelerate the wound healing process. We aimed to retrospectively investigate whether the topical application of hyaluronic acid on standardized wounds after split-thickness skin graft removal on the thigh would accelerate wound healing and improve scarring outcomes. Additionally, we aimed to evaluate the usefulness of three-dimensional (3D) scanning to assess scars. Methods: The wound healing process of a hyaluronan group (n = 20) and a control (n = 21) were analyzed and evaluated using 3D scans at 7 and 14 days and 1, 3, and 6 months post-operatively. Scar evaluations by the patients were conducted 6 months post-operatively using the patient and observer scar assessment scale and the Manchester scar scale. Experts evaluated the scars after 6 months using a modified version of both scales. Results: On days 7 and 14, significantly larger areas of the wound surface were closed in the hyaluronan group compared to the control group (p < 0.05). After 1 month, significantly more crusted areas remained in the control group than in the hyaluronan group (p < 0.05). At the 6-month self-assessments, the hyaluronan group evaluated their scars as being significantly better compared to the control group. Conclusions: The topical application of hyaluronic acid in combination with polyurethane foam as a wound dressing after split skin removal accelerated the wound healing rate and positively influenced scar appearance after 6 months. Three-dimensional scanning is useful for evaluating and documenting the wound healing process.

Study on the evolution rules of coal deformation and failure characteristics caused by multiple mining disturbances

During coal mining operations, the coal will be deformed and damaged due to multiple mining disturbances (MMD), often resulting in disasters, like rock burst. To understand the evolution rules of coal deformation under MMD and its final fracture characteristics after impact dynamic load loading, reduce the adverse effects of mining disturbances, and improve disaster prevention and control capabilities, quasi-static uniaxial cyclic loading-unloading (L-U) and dynamic axial compression tests were conducted on large-sized coal-like samples. During the tests, three-dimensional (3D) laser scanning and acoustic emission (AE) monitoring technology were utilized to accurately capture the full-field deformation and AE response data, facilitating a systematic analysis of deformation and fracture characteristics. The results show that: (1) Under the cyclic L-U effect induced by MMD, each loading cycle causes compression deformation with partial recovery during unloading, presenting an overall “wavy” variation trend. (2) The maximum load is the most critical factor affecting the damaged coal deformation, with smaller load resulting in less overall sample deformation. (3) After the impact dynamic loading, the damaged samples suffered large-scale impact splitting failure, with the compressive-shear layer failure mainly occurred inside the holes. (4) Lower loading during cyclic L-U process correlate with reduced damage degree, and smaller debris particles with a higher fractal dimension when impact failure occurs, indicating a more severe impact failure. (5) With multiple cycles of L-U, the cracks inside the sample gradually extend and expand from around the hole to the outside. The greater the load and the number of cycles, the more serious the crack damage will be. (6) In the practical mining process, it is crucial to reinforce roadway interiors while minimizing low-loading cyclic disturbances induced by MMD. The study has obtained the deformation evolution rules and failure characteristics of coal under MMD, providing a theoretical basis for the prevention and control of corresponding engineering disasters.

Deep learning-based image quality assessment for optical coherence tomography macular scans: a multicentre study

AimsTo develop and externally test deep learning (DL) models for assessing the image quality of three-dimensional (3D) macular scans from Cirrus and Spectralis optical coherence tomography devices.MethodsWe retrospectively collected two...

Diagnostic and treatment possibilities in the management of positional plagiocephaly.

Positional plagiocephaly, characterized by an asymmetric skull shape, is the most common craniofacial malformation in infancy. Associated risk factors include apreference for the supine position, first and assisted delivery, multiple pregnancy, prematurity, and congenital muscular torticollis. The diagnosis is established by clinical and anthropometric examinations. In the case of moderate or severe deformity, three-dimensional optical scanning enables adetailed depiction of the deformity and provides asafe and noninvasive tool for follow-up. Treatment mainly includes repositioning of the infant, while orthotic therapy is considered in cases of severe deformity. Cranial orthotic therapy is most effective when started between 4and 7months of age. The total duration of orthotic treatment ranges from 2to 6months. Although the clinical course of positional plagiocephaly is generally benign and the prognosis favorable, its increasing prevalence has prompted the development of novel diagnostic and therapeutic strategies over the past decade.

Tunnel full-space deformation measurement based on improved downsampling and registration approach by point clouds

To fully leverage the volume measurement advantage of three-dimensional laser scanning technology in tunnel deformation monitoring, a full-space deformation analysis is proposed. A Box Improved Moving Average (BIMA) method featured by the adaptive window size downsampling is proposed which aims to achieve varying levels of downsampling in different densities regions. The combination of Maximal Cliques (MAC) and Iterative Closest Point (ICP) is utilized to achieve accurate registration. Point normal information is utilized to determine the correspondence to calculate deformation which shows an average accuracy of 7 % higher than the ICP by a convergence measurement test. The deformation convergence accuracy can go beyond 76 % when the point cloud reserved rate is approximately 10 %. Comparison between the method proposed in this study and the traditional point cloud cross sectional fitting method shows that the discrepancy between these two methods is approximately within 5 mm, with a minimum value of only 0.15 mm.

Synchronous (In)significance: Recording Ukraine’s Cultural Heritage in Real-Time

ABSTRACT Synchronous (In)significance argues for the recognition of a mode of heritage conservation within war-torn Ukraine that is already underway. The paper examines the digital initiative Polycam: Backup Ukraine which allows for everyday users to record, upload and share three-dimensional scans of places, sites and objects that they deem significant within their immediate environment. This evolving contemporary archive is positioned by its founders as a tool for citizen empowerment through the shared availability of the technology and storage of items for heritage capture. The resulting collection provides an unconventional account of the sites, spaces and objects at risk in Ukraine, creating a constellation of high, local, formal and idiosyncratic personal entries. Through this portal, a broad and unsanctioned account of Ukrainian heritage is revealed. This paper draws on the work of Tracy Ireland, Steve Brown and John Schofield which examines the dichotomous relationship of significance and insignificance in the practice of value creation and negotiation of heritage identity. Through this lens it examines how notions of sharing; shared technology, shared ownership and shared access might allow for the creation of a contemporary heritage archive, that interacts with memory, place and things, but does so in ways that “are often not possible in the context of official heritage regimes because of rigid aesthetic paradigms, urban or class conflict, identity politics, or dominant national narratives.” 1 The archive, which draws together digital records of well-regarded heritage sites with unexpected spaces and objects of the personal and the everyday, becomes a means of assessing notions of significance and (in)significance in real-time. This in turn, provides a mechanism for re-evaluating what aspects of the war-torn country are considered worthy of recording and sharing.

Extraction of deterioration and analysis of vegetation impact effects on the south palace wall of Weiyang Palace

Weiyang Palace, the royal palace of the Western Han Dynasty, is a part of the Silk Roads: the Routes Network of Chang’an-Tianshan Corridor on the World Heritage list. The south palace wall of Weiyang Palace is a well-preserved earthen heritage site within the palace, but it is undergoing continuous deterioration due to the influence of vegetation and external environmental factors. This study pioneers the integration of high-resolution three-dimensional LiDAR scanning with multi-source data analysis, including unprecedented on-site botanical surveys, to explore the subtle effects of different vegetation types on the structural integrity of the south palace wall. Through contour line analysis and facade grid analysis, we extracted the deterioration locations of typical sections of the earthen heritage sites. And we classified the overlying vegetation types on the wall using an object-oriented classification algorithm. Our findings reveal a complex interaction between vegetation and earthen structures: paper mulberry exhibits protective qualities against erosion, while Ziziphus jujuba significantly exacerbates structural vulnerabilities. The methodologies applied in this study for extracting deterioration at earthen heritage sites and integrating multi-source spatial data can serve as a technical application model for monitoring and analyzing the driving forces of earthen heritage sites along the entire Silk Road network, thereby better guiding the conservation of earthen heritage sites.

A multicenter bladder cancer MRI dataset and baseline evaluation of federated learning in clinical application

Bladder cancer (BCa), as the most common malignant tumor of the urinary system, has received significant attention in research on the clinical application of artificial intelligence algorithms. Nevertheless, it has been observed that certain investigations use data from various medical facilities to train models for BCa, which may pose a privacy risk. Given this concern, protecting patient privacy during machine learning algorithm training is a crucial aspect that requires substantial attention. One emerging machine learning paradigm that addresses this concern is federated learning (FL). FL enables multiple entities to collaboratively build machine learning models while preserving data privacy and security. In this study, we present a multicenter BCa magnetic resonance imaging (MRI) dataset. The dataset comprises 275 three-dimensional bladder T2-weighted MRI scans collected from four medical centers, and each scan includes diagnostic pathological labels for muscle invasion and pixel-level annotations of tumor contours. Four FL methods are used to assess the baseline of the dataset for both the task of diagnosing muscle-invasive bladder cancer and automatic bladder tumor lesion segmentation.

The MapMe Body Scales: Validity and Reliability of a Biometrically Accurate, Photorealistic Set of Child Body Size Scales.

It is vital to identify children whose weight status means that they may benefit from medical or behavioural support, but adult visual judgements of child weight status are inaccurate, and children are seldom routinely weighed and measured. Consequently, there is a need for validated visual tools for use in training, communication, and interventions relating to child weight. This paper presents validation data for a set of innovative photo-realistic colour body size scales depicting boys and girls aged 4-5 and 10-11. Each age- and gender-specific scale consists of 7 figures based on three-dimensional (3D) scans of 388 children to accurately represent the change in body size caused by changing adiposity. To assess scale validity, 238 adult participants (105 men, 132 women, 1 non-binary individual) undertook two tasks: rating figure adiposity using a visual analogue scale and ranking figures in ascending order of adiposity (OSF Reference: gdp9j). Participants accurately estimated the relative adiposity of each figure, i.e., they were able to tell the difference between figures and correctly rank them by size. This demonstrates scale validity for use in body size tasks. One hundred and fifty-one participants also provided 3-day test-retest data, which demonstrates excellent short-term reliability. Overall, the MapMe child body size scales provide an anthropometrically accurate, valid, reliable, and usable tool for size-related tasks and communication with adults regarding child weight.

3dct Conduit and Oesophageal Metrics, a Valuable Method to Diagnose Post Sleeve Gastrectomy Abnormalities

PurposeReflux after laparoscopic sleeve gastrectomy (LSG) may result from anatomical and functional anomalies in the gastric conduit. Three-dimensional CT scans (3DCT) offer a comprehensive view of gastric anatomy. This study aims to establish specific measurements associated with sleeve abnormalities to standardise the reporting of 3DCT which may help in management of LSG complications.Materials and MethodsThis retrospective study analysed 64 post-LSG patients who underwent gastric 3DCT. Data included clinical demographics, pre-LSG BMI, BMI at 3DCT, and the duration between surgery and examination. Symptomatology prompts the scan and other concurrent investigations. Various 3DCT measurements were taken, including angularis angle (AA), surface area (ASA), conduit length (CL), proximal maximal surface area (PMSA), and distal maximal surface area (DMSA) of the gastric conduit. Patients were categorised based on endoscopy findings and symptomatology. Outcomes post-revisional surgery were assessed and analysed.Results20.3% were male. Pre-LSG BMI and BMI at 3DCT were 45.57 (± 8.3) and 36.3 (± 8.7), respectively. Mean surgery-to-scan period was 6.2 years. 71.8% of patients presented with reflux, regurgitation, or dysphagia, whilst the remainder primarily exhibited weight regain. Patients with endoscopic evidence of stenosis/reflux demonstrated significantly lower gastric volume, ASA, and DMSA (p = 0.002 and p = 0.007, respectively). Oesophageal diameter above the conduit and an ASA to DMSA ratio ≤ 0.5 were negatively associated with AA (p = 0.008 and p = 0.08, respectively). Patients with improved outcomes after revisional bypass and gastrogastrostomy displayed a negative correlation with ASA and positive correlation with the ASA to PMSA ratio (≤ 0.5).Conclusion3DCT measurements have a potential role in defining post-LSG stenosis and predicting outcomes of revisional surgery. Patients with anatomic abnormalities that are shown on CT appear to improve with anatomic correction.Graphical

Therapeutic Effectiveness of a Novel Cranial Remolding Helmet (baby band2) for Positional Plagiocephaly: A Multicenter Clinical Observational Study.

This multicenter study evaluated the efficacy and safety of a novel cranial remolding helmet (baby band2), which is completely custom-made based on the shape of an infant's cranium. The study included 224 full-term infants from moderate to very severe positional plagiocephaly in Japan. Cranial geometry was assessed before and after helmet therapy using a three-dimensional scanner, and changes in the cranial vault asymmetry index (CVAI) were analyzed. The CVAI improved significantly in all patients, with the most significant improvement observed in the most severely affected group [very severe group: -9.1, severe group: -6.6, moderate group: -4.4 (mean values), p < 0.001]. The group that started therapy before the age of 7 months showed greater improvement compared to those who started therapy at the age of 7 months or older; however, both groups demonstrated significant improvement (<7 months group: -6.6, ≥7 months group: -4.4 (mean values), p < 0.001). No significant differences were observed in therapy efficacy between the centers (p = 0.402) and sex (p = 0.131). During the study period, helmet therapy did not lead to head circumference stunting, and the incidence of redness with baby band2 was five patients (2.2%). This study demonstrated that baby band2 is effective and safe for the therapy of positional plagiocephaly.