Search Results (247)

Early recognition of vascular compromise is essential for reconstructive flap survival. In human surgery, local glucose monitoring is widely used as an objective indicator of perfusion, but its application in veterinary patients is still limited. This report describes postoperative glucose measurement as a simple and minimally invasive method for evaluating flap viability in two dogs. This report describes two prospectively observed clinical cases in which local glucose measurement was applied as an adjunctive monitoring tool during postoperative flap management. Local glucose values were measured with a handheld glucometer at predefined flap and control sites. Serial readings were compared with daily assessments of flap color, temperature, turgor, and wound integrity. A previously suggested threshold of 60–62 mg/dL was used as a reference for potential perfusion compromise. In Case 1, a phalangeal fillet flap showed a brief glucose decline on postoperative days 2–3, followed by normalization and uneventful healing. In Case 2, which underwent advancement flap reconstruction after wound dehiscence, glucose values remained persistently below 60 mg/dL and preceded visible ischemia and distal necrosis. Local glucose monitoring provided rapid and clinically meaningful information about flap perfusion. Transient decreases reflected reversible postoperative congestion, whereas persistent hypoglycemia indicated progressive ischemia. These findings support the use of glucose monitoring as an adjunct in small-animal reconstructive surgery. Full article

Accurate documentation of burn wounds is essential for evaluating treatment outcomes and monitoring healing progression. Traditional two-dimensional (2D) photography remains the clinical standard but lacks depth and volumetric accuracy. Three-dimensional (3D) scanning offers enhanced visualization of wound morphology and tissue vitality, potentially improving objectivity in burn assessment. This study compares two handheld 3D scanning systems—Artec Eva and Revopoint Miraco—in documenting acute and healing burn wounds, using standard clinical photography as the reference. Fifteen patients with second-degree and third-degree burns were prospectively examined at the Burn Unit of AGEL Hospital Košice-Šaca, with five representative cases selected for detailed analysis. For each patient, clinical photographs and paired 3D scans were obtained under standardized conditions and evaluated for color fidelity, wound margin clarity, representation of epithelialisation islands, necrotic tissue, and correlation with clinical findings. Across all cases, Artec Eva demonstrated superior color accuracy, clearer wound delineation, and more realistic visualization of tissue vitality and re-epithelialisation. Revopoint Miraco reliably captured wound shape but produced darker tones and exaggerated surface relief, occasionally distorting depth perception. Overall, both systems successfully identified key healing features; however, Artec Eva provided more clinically accurate and visually consistent results. Three-dimensional scanning represents a valuable adjunct to conventional burn documentation. Full article

Low-cost RGB intraoral cameras are accessible alternatives to intraoral scanners; however, generating panoramic images is challenging due to narrow fields of view, textureless surfaces, and specular highlights. This study proposes a robust stitching framework and identifies optimal acquisition parameters to overcome these limitations. All experiments were conducted exclusively on a mandibular dental phantom model. Geometric consistency was further validated using repeated physical measurements of mandibular arch dimensions as ground-truth references. We employed a deep learning-based approach using SuperPoint and SuperGlue to extract and match features in texture-poor environments, enhanced by a central-reference stitching strategy to minimize cumulative drift errors. To validate the feasibility in a controlled setting, we conducted experiments on dental phantoms varying working distances (1.5–3.0 cm) and overlap ratios. The proposed method detected approximately 19–20 times more valid inliers than SIFT, significantly improving matching stability. Experimental results indicated that a working distance of 2.5 cm offers the optimal balance between stitching success rate and image detail for handheld operation, while a 1/3 overlap ratio yielded superior geometric integrity. This system demonstrates that robust 2D dental mapping is achievable with consumer-grade sensors when combined with advanced deep feature matching and optimized acquisition protocols. Full article

The potential of UAV-based LiDAR (UAV-LiDAR) and handheld LiDAR scanners (HLSs) for forest radiative transfer models (RTMs) was evaluated using a Voxel-Based Point Density Proxy (VPDP) as a diagnostic tool in a Larix kaempferi forest. Structural analysis-computed coverage gap ratio (CGR) revealed distinct behaviors. UAV-LiDARs effectively captured canopy structures (10–45% CGR), whereas HLS provided superior understory coverage, but exhibited a high upper-canopy CGR (>40%). Integrating datasets reduced the CGR to below 10%, demonstrating strong complementarity. Radiative transfer simulations correlated well with Sentinel-2 NIR reflectance, with the UAV-LiDAR ($\mathit{r}$ = 0.73–0.75) outperforming the HLS ($\mathit{r}$ = 0.64–0.69). These results highlight the critical importance of upper-canopy modeling for nadir-viewing sensors. Although integrating HLS data did not improve correlation due to the dominance of upper-canopy signals, structural analysis confirmed that fusion is essential for achieving volumetric completeness. A voxel size range of 50–100 cm was identified as effective for balancing structural detail and radiative stability. These findings provide practical guidelines for selecting and integrating LiDAR platforms in forest monitoring, emphasizing that while aerial sensors suffice for top-of-canopy reflectance, multi-platform fusion is requisite for full 3D structural characterization. Full article

The presented dataset contains spatial models of cones formed from lunar soil simulants. The cones were formed in a laboratory by allowing the soil to fall freely through a funnel. Then, the cones were measured using three methods: a high-precision handheld laser scanner (HLS), photogrammetry, and a low-cost LiDAR system integrated into an iPad Pro. The dataset consists of two groups. The first group contains raw measurement data, and the second group contains the geometry of the cones themselves, excluding their surroundings. This second group was prepared to support the calculation of the cones’ volume. All data are provided in standard 3D file format (.STL). The dataset enables direct comparison of resolution and geometric reconstruction performance across the three techniques and can be reused for benchmarking 3D processing workflows, segmentation algorithms, and shape reconstruction methods. It provides complete geometric information suitable for validating automated extraction procedures for parameters such as cone height, base diameter, and angle of repose, as well as for further research into planetary soil and granular material morphology. Full article

Coastal environments are fragile ecosystems threatened by various factors, both natural and anthropogenic. The preservation and protection of these environments, and in particular, the sand dune systems, which contribute significantly to the defense of the inland from flooding, require continuous monitoring. To this end, high-resolution and high-precision multitemporal data acquired with various techniques can be used, such as, among other things, the global navigation satellite system (GNSS) using the network real-time kinematic (NRTK) approach to acquire 3D points, UAS-based structure-from-motion photogrammetry (SfM), terrestrial laser scanning (TLS), and handheld mobile laser scanning (HMLS)-based light detection and ranging (LiDAR). These techniques were used in this work for the 3D survey of a portion of vegetated sand dunes in the Caleri area (Po River Delta, northern Italy) to assess their applicability in complex environments such as coastal vegetated dune systems. Aerial-based and ground-based acquisitions allowed us to produce point clouds, georeferenced using common ground control points (GCPs), measured both with the GNSS NRTK method and the total station technique. The 3D data were compared to each other to evaluate the accuracy and performance of the different techniques. The results provided good agreement between the different point clouds, as the standard deviations of the differences were lower than 9.3 cm. The GNSS NRTK technique, used with the kinematic approach, allowed for the acquisition of the bare-ground surface but at a cost of lower resolution. On the other hand, the HMLS represented the poorest ability in the penetration of vegetation, providing 3D points with the highest elevation value. UAS-based and TLS-based point clouds provided similar average values, with significant differences only in dense vegetation caused by a very different platform of acquisition and point of view. Full article

Droplet microfluidics enables high-throughput, compartmentalized reactions using minimal reagent volumes, but most implementations rely on precision-fabricated chips and external pumping systems that limit portability and accessibility. Here, we present a handheld vibrational droplet generator that repurposes a consumer electric toothbrush and a modified disposable pipette tip to produce nearly monodisperse water-in-oil droplets without microfluidic channels or syringe pumps. The device is powered by the toothbrush’s built-in motor and controlled by a simple 3D-printed adapter and adjustable counterweight that tune the vibration amplitude transmitted to the pipette tip. By varying the aperture of the pipette tip, droplets with diameters from ~100–300 µm were generated at rates of ~100 droplets s⁻¹. Image analysis revealed narrow size distributions with coefficients of variation below 5% in typical operating conditions. We further demonstrate proof-of-concept applications in digital loop-mediated isothermal amplification (LAMP) and microbiological colony-forming unit (CFU) assays. A commercial feline parvovirus (FPV) kit manufactured by Beyotime Biotechnology Co., Ltd. (Shanghai, China), three template concentrations yielded emulsified reaction droplets that remained stable at 65 °C for 45 min and produced distinct fractions of fluorescent-positive droplets, allowing estimation of template concentration via a Poisson model. In a second set of experiments, the device was used as a droplet-based spreader to dispense diluted Escherichia coli suspensions onto LB agar plates, achieving uniform colony distributions across the plate at different dilution factors. The proposed handheld vibrational generator is inexpensive, easy to assemble from off-the-shelf components, and minimizes dead volume and cross-contamination because only the pipette tip contacts the sample. Although the current prototype still exhibits device-to-device variability and moving droplets in open containers complicate real-time imaging, these results indicate that toothbrush-based vibrational actuation can provide a practical and scalable route toward “lab-in-hand” droplet assays in resource-limited or educational settings. Full article

Background: Accurate assessment of foot morphology is essential in sports medicine, orthopaedics, and footwear design. Manual examination remains common but may lack accuracy and reproducibility. Alternative techniques, such as pedobarography and handheld 3D scanning, may offer more objective and reliable data, given that their reliability and agreement with established methods are confirmed. Methods: Twenty-six healthy adults (age 25.8 ± 4.7 years; BMI 24.1 ± 2.0 kg/m²) were investigated. Foot dimensions were assessed via manual examination, pedobarography, and handheld 3D scanning, each performed in random order by two independent investigators on two separate occasions. Relative and absolute intra-rater reliability were analysed using intraclass correlation coefficients (ICC), the change in the mean of repeated measurements (bias), limits of agreement (LoA), and the typical error (TE). Inter-method agreement was evaluated using Lin’s concordance correlation coefficients (CCC), mean bias, and LoA to assess interchangeability as well as systematic bias. Results: Good-to-excellent relative and absolute intra-rater reliability was found for the distance-related foot dimensions across all methods, except for heel width assessed via pedobarography (small bias but wide LoA and high TE). Relative and absolute reliability of the angular parameters assessed via pedobarography and 3D scanning ranged from poor to excellent. Inter-method agreement between manual examination, pedobarography, and 3D scanning appeared low when considering all three agreement indices (i.e., CCC, mean bias, and LoA). The largest discrepancies were observed for heel width and arch-related measures. Conclusions: All three methods seem reliable for assessing distance-related foot dimensions. However, limited agreement among the three methodological approaches indicates that they cannot be used interchangeably without standardisation. Full article

Accurate and efficient forest inventory methods are crucial for monitoring forest ecosystems, assessing carbon stocks, and supporting sustainable forest management. Traditional field-based techniques, which rely on manual measurements such as diameter at breast height (DBH) and tree height (TH), remain labour-intensive and time-consuming. In this study, we introduce and validate a fully open-source, low-cost terrestrial laser scanning system (LCA-TLS) built from commercially available components and based on the Livox Avia sensor. With a total cost of €2050, the system responds to recent technological developments that have significantly reduced hardware expenses while retaining high data quality. This trend has created new opportunities for broadening access to high-resolution 3D data in ecological research. The performance of the LCA-TLS was assessed under controlled and field conditions and benchmarked against three reference devices: the RIEGL VZ-1000 terrestrial laser scanner, the Stonex X120GO handheld mobile laser scanner, and the iPhone 15 Pro Max structured-light device. The LCA-TLS achieved high accuracy for estimating DBH (RMSE: 1.50 cm) and TH (RMSE: 0.99 m), outperforming the iPhone and yielding results statistically comparable to the Stonex X120GO (DBH RMSE: 1.32 cm; p > 0.05), despite the latter being roughly ten times more expensive. While the RIEGL system produced the most accurate measurements, its cost exceeded that of the LCA-TLS by a factor of about 30. The hardware design, control software, and processing workflow of the LCA-TLS are fully open-source, allowing users worldwide to build, modify, and apply the system with minimal resources. The proposed solution thus represents a practical, cost-effective, and accessible alternative for 3D forest inventory and LiDAR-based ecosystem monitoring. Full article

Accurate measurement of shoulder muscle strength is important for diagnosis, treatment planning, and monitoring recovery. Hand-held dynamometers (HHDs) are widely used in clinical practice but are affected by operator strength, patient positioning, and device stabilization, particularly under high-load conditions. No previous study has directly compared HHD measurements with a reference load cell in a rigid serial configuration or evaluated the effect of different load cell signal processing strategies on the final strength value. The aim of this study was to compare HHD measurements with those obtained from a reference load cell in a rigid serial configuration and to assess how different signal processing strategies applied to load cell data influence the final outcomes. A custom 3D-printed support was developed to align a commercial HHD and a load cell in series, ensuring identical loading conditions. Measurements were performed under two conditions: (i) application of known weights (9.81–98.10 N) and (ii) standardized strength tasks in five healthy volunteers. Agreement between instruments was evaluated using Bland–Altman analysis and Root Mean Square Error (RMSE). In static validation (i.e., experiments applying know weights), the load cell demonstrated stable performance, with standard deviations below 1% of the applied load. HHD variability increased with load, with RMSE rising from 0.55 N at 9.81 N to 5.06 N at 98.10 N. In human testing, the HHD consistently underestimated muscle strength compared with the load cell, with mean differences ranging from −15 N to −19 N, over exerted force ranges of approximately 20–90 N. Overall, the load cell provided stable reference measurements, while the choice of signal processing strategy influenced the results: plateau-phase analysis tended to reduce systematic bias but did not consistently narrow the limits of agreement. Full article

To address the challenges of inefficient Camellia oleifera fruits harvesting in hilly and mountainous regions due to the difficulty of using large machinery, a handheld vibration harvesting device for Camellia oleifera fruits was designed. Based on the vibration-induced detachment process of Camellia oleifera fruits, a single-pendulum dynamic model of the “fruit-branch” system was established and solved to calculate the tangential acceleration required for fruit detachment. The key factors influencing harvesting efficiency were identified as vibration frequency, amplitude, height, and duration. Using ANSYS, modal response and harmonic response analyses were conducted on a 3D model of the Camellia oleifera tree to determine the operational parameters ensuring branch acceleration meets the fruit detachment. Furthermore, a rigid-flexible coupling simulation system integrating the harvesting device and Camellia oleifera tree was developed on the ADAMS. This analysis revealed the variation patterns of branch acceleration with respect to vibration frequency and clamping height, thereby validating the rationality of the dynamic model and the feasibility of the device. Finally, an orthogonal experiment was designed using Design-Expert 13, and multi-objective optimization analysis was performed on the device’s working parameters based on the experimental data. The aforementioned research identified the optimal working parameter combination and actual harvesting performance of the handheld vibration harvesting device: when the vibration frequency is 14 Hz, vibration height is 980 mm, and vibration duration is 13 s, the fruit picking rate reaches 95.22%. The harvesting efficiency of this device is significantly higher than manual picking methods, fully meeting the requirements for efficient Camellia oleifera fruit harvesting. Full article

Newborn immaturity transcends their bodies, immune systems, and communication and perception capabilities, making them vulnerable to the environment. Neonatal jaundice is a common condition, with higher levels of unconjugated bilirubin concentration having neurotoxic effects. Newborns are routinely monitored visually or non-invasively with transcutaneous bilirubinometry (TcB) due to their biological immaturity to conjugate bilirubin. Higher levels of bilirubin are a sign that there is either an unusual rate of red blood cells breaking down or that the liver is not able to eliminate bilirubin through bile into the gastrointestinal tract. Actual devices used in bilirubin screening are hand-held and do not allow operation outside the hospital. Based on these factors, a continuous bilirubin monitoring device for newborns was developed, which enables the evaluation of neonatal jaundice inside or outside the hospital. This non-invasive device operates through a mini-spectrometer in the visible range. It was calibrated with phantoms, and its operation was compared with a gold-standard bilirubinometer through in vitro experiments, exploring the practical range of bilirubin variation in newborns and presenting a clinically acceptable deviation of 1 mg/dL. These experiments showed that the continuous bilirubin monitoring device developed has the potential to be used for remote monitoring of jaundice in newborns. Full article

Forestry is essential for environmental sustainability, biodiversity conservation, carbon sequestration, and renewable resource management. Traditional methods for forest inventory, particularly the manual measurement of diameter at breast height (DBH), are labor-intensive and prone to error. Recent advancements in proximal sensing, including lidar and photogrammetry, have paved the way for more efficient approaches, yet high costs remain a barrier to widespread adoption. This study investigates the potential of close-range photogrammetry (CRP) using low-cost devices, such as smartphones, cameras, and specialized handheld laser scanners (Stonex and LIVOX prototype), to generate 3D point clouds for accurate DBH estimation. We compared these devices by assessing their agreement and efficiency when compared to conventional methods in diverse forest conditions across multiple tree species. Additionally, we analyze factors influencing measurement errors and propose a comprehensive decision-making framework to guide technology selection in forest inventory. The results show that the lowest-cost devices and photogrammetric methods achieved the highest agreement with the conventional (caliper-based) measurements, while mobile applications were the fastest and least expensive but also the least accurate. Photogrammetry provided the most accurate DBH estimates (error ≈ 0.7 cm) but required the highest effort; handheld laser scanners achieved an average accuracy of about 1.5 cm at substantially higher cost, while mobile applications were the fastest and least expensive but also the least accurate (3–3.5 cm error). The outcomes of this research aim to facilitate more accessible, reliable, and sustainable forest management practices. Full article

This study demonstrates the effectiveness of integrating terrestrial laser scanning (TLS) and handheld laser scanning (HLS) for structural diagnostics. The research was conducted on a Small Hydropower Plant (SHP) in Koszalin, Poland. TLS was used to capture the general geometry of the object, while HLS operating in infrared (IR) and blue light modes enabled high-resolution documentation of local damage. Areas of interest were identified using the Surface Variation parameter, and selected zones were scanned with HLS. Both HLS modes delivered consistent results, with differences not exceeding ±0.37 mm. The IR mode proved particularly useful in constrained spaces, allowing for precise measurements without the use of reference markers. Comparative analyses of cross-sections through a major crack confirmed that both HLS modes produce repeatable results with submillimeter accuracy. Integrating TLS and HLS data resolved blind spots inherent to TLS and produced a complete point cloud preserving both global geometry and local detail. The findings confirm the applicability of this hybrid approach in assessing structural damage and highlight its relevance in civil engineering applications. The proposed workflow is effective for documenting inaccessible or complex geometries while optimizing data volume and acquisition time (R1-C10). Full article

Objective: This in vitro study aimed to evaluate and compare the trueness and precision of four extraoral 3D facial scanning systems using a standardized 3D-printed human head model. Methods: A 3D-printed head model with 16 anatomical landmarks and 17 inter-landmark linear distances was fabricated using a high-resolution 3D printer. Caliper measurements were used as reference standards. The model was scanned 15 times by four systems: a handheld scanner (MetiSmile, Shining 3D, Hangzhou, China), a desktop scanner (RAYFace v2.0, Ray Co., Seongnam, Gyeonggi-do, Republic of Korea), and two mobile applications (Heges and Polycam, iPhone 15, Apple Inc., Cupertino, CA, USA). All digital distances were measured in Blender software. To assess intra-observer reliability, all measurements were repeated twice by the same examiner with a 3-week interval between sessions, and intra-class correlation coefficients were calculated using a two-way mixed-effects, single-measurement, absolute-agreement model (ICC 3,1). Trueness, defined as the absolute deviation from the reference caliper values, was compared across scanners using the Kruskal–Wallis test due to its non-normal distribution. Precision, regional trueness and precision values across the four scanners defined as the standard deviation of repeated scans, was analyzed using One-way ANOVA with Tukey post-hoc comparisons for normally distributed datasets (α = 0.05). Distances were measured digitally in Blender software, and trueness (absolute deviation from reference) and precision (standard deviation of repeated scans) were analyzed using the Kruskal–Wallis test and One-way ANOVA with Tukey post hoc comparisons (α = 0.05). Results: The Polycam application demonstrated the highest trueness (0.49 ± 0.32 mm), followed by MetiSmile (0.51 ± 0.36 mm), RAYFace (0.58 ± 0.39 mm), and Heges (0.73 ± 0.42 mm). The MetiSmile scanner showed the highest precision (0.12 ± 0.07 mm), while RAYFace and Polycam exhibited moderate precision (0.28 ± 0.19 mm and 0.15 ± 0.06 mm, respectively). Vertical measurements tended to be more accurate than horizontal ones, and the lower facial region showed smaller deviations; however, these differences were not statistically significant (p > 0.05). Conclusions: MetiSmile achieved the highest precision and Polycam the highest trueness. Although all systems showed mean deviations < 1 mm, only three demonstrated <0.6 mm accuracy (except for Heges scanner). These results suggest that professional and mobile-based scanners can provide clinically acceptable facial data for educational and preliminary digital workflow applications, though further validation under clinical conditions is required. This study provides quantitative evidence on the accuracy and repeatability of commonly available extraoral 3D facial scanning systems under controlled laboratory conditions. The results indicate that both professional-grade and mobile-based scanners can reproduce facial morphology with clinically acceptable deviations, particularly in flat and stable regions such as the forehead and chin. Although only three systems achieved mean trueness below 0.6 mm, all demonstrated errors within 1 mm, sufficient for diagnostic visualization, digital smile design, and preliminary virtual patient modeling. These findings support the safe and cost-effective adoption of extraoral facial scanning in dental education and treatment planning, while emphasizing the need for further validation in real clinical environments where motion, lighting, and soft-tissue variability may affect accuracy. Full article