Deviation Angle Research Articles

A leading error compensation method for weld seam tracking based on dual-sensing and dual-wavelength

Purpose Leading error in line laser weld seam tracking significantly affects tracking accuracy. This paper aims to propose an accurate and reliable compensation method without increasing system complexity for weld seam tracking to improve tracking precision. Design/methodology/approach Based on the line laser seam tracking method, the seam image is simultaneously captured to obtain the angle offset of the seam relative to the sensor direction, which is then combined with the leading distance to calculate the leading error. The two sensing methods use different wavelengths and are captured simultaneously by a color industrial camera. The images of the two different wavelengths can be separated by extracting the RGB components, and the compensated tracking results are obtained after image processing. Findings The results of static positioning experiment indicate that the average absolute error in weld seam positioning is reduced to 0.099 mm after compensation. The real-time tracking experiments demonstrate that the proposed method preserves tracking accuracy even with changes in the sensor’s angle of deviation during welding, with the average absolute error being 0.248 mm. This method effectively enhances the precision of line laser weld seam tracking when the sensor exhibits a deviation relative to the welding direction. Originality/value By using the dual-sensing and dual-wavelength method for leading error compensation, the method effectively addresses the leading error issue while maintaining the advantages of the line laser seam tracking method.

The association between the circadian misalignment of serum cortisol acrophase and sleep end time with chemotherapy-induced peripheral neuropathy

ABSTRACT Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of chemotherapy. The objective of this prospective observational study was to examine the association between circadian misalignment (CM), as measured by phase angle difference (PAD) of biological and behavioral rhythms and CIPN. The PAD of cortisol acrophase and actigraphy-based sleep end time in breast cancer patients was measured and categorized into low PAD (n = 11) and high PAD (n = 12) groups based on median value. CIPN was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-CIPN20 (CIPN20). The assessment of CM revealed that the sleep end time of the low PAD group was more delayed in relation to cortisol acrophase compared to the high PAD group. The low PAD group demonstrated significantly higher CIPN20 global and sensory scale scores compared to the high-PAD group at one month post-chemotherapy, with an estimated group difference of 17.63 ± 4.75 and 27.07 ± 6.70 (p = 0.001 and p < 0.001, respectively). The present findings indicate that the low PAD group, which exhibited a relatively delayed behavioral rhythm with respect to its biological rhythm, displayed an increased susceptibility to CIPN. Further large-sample research is necessary to attain a comprehensive understanding of the mechanisms through which CM affects CIPN.

Application of Voltage Optimization Strategy for Rotary Power Flow Controllers in Loop Closing of Distribution Networks

To mitigate voltage limit issues in the operation of a novel electromagnetic voltage regulation device, this paper presents a flexible loop-closing control strategy with voltage optimization. The approach uses a two-stage path optimization: in the first stage, the voltage phase at the loop-closing point is adjusted to ensure smooth operation, while in the second stage, the voltage magnitude is optimized to prevent voltage limits and achieve seamless regulation. By integrating phase angle difference calculations with coordinated rotation angle control, the simulation results show that this strategy reduces loop-closing current by approximately 95.87% compared to direct loop closing, decreases voltage fluctuations by around 50.0% compared to traditional methods, and shortens operation time by 40.14%. This approach significantly enhances system stability and response speed, effectively addressing the issue of excessive loop-closing current caused by voltage deviations at distribution network tie switches.

Virtual reality head-mounted display game for intermittent exotropia in a randomized controlled trial

To evaluate the effects of orthoptic training using a virtual reality (VR) head-mounted display game in patients with intermittent exotropia (IXT), a prospective, randomized, double-blind study was performed in 62 patients ≥ 13 years with IXT of ≥ 8 prism diopters (∆) and with a near ≥ distance angle, i.e., basic type and convergence insufficiency-type IXT. Patients were randomly assigned to a video-game group that induced convergence (exercise group) and a placebo-game group not inducing convergence (control group), and completed the program 15 min/day for 4 weeks. Subjective symptom scores, angle of exodeviation, near point of convergence, stereoacuity, fusional control scores using the Newcastle Control Score (NCS) and the Office Control Score (OCS) were noted. Outcome measures were assessed after 4 weeks, and re-evaluated after a washout period of 4 weeks. After using the VR game for 4 weeks, the near angle of exodeviation significantly decreased from 29.6 ± 9.5∆ to 25.3 ± 9.0∆ in the exercise group (p < 0.001), which was still maintained after 4 weeks of discontinuation (p = 0.008). There were no significant differences in the near angle of exodeviation in the control group at either the 4- or 8-week visits (p = 0.075, 0.093, respectively). The fusional control scores of the NCS and OCS significantly improved at the 4-week (p = 0.001, 0.003, respectively) and 8-week visits (p = 0.004, < 0.001, respectively) only in the exercise group. In conclusion, orthoptic training using a VR game improved the near angle of exodeviation and fusional control scores in IXT.

Noise-immune zeroing neural dynamics for dynamic signal source localization system and robotic applications in the presence of noise

Time angle of arrival (AoA) and time difference of arrival (TDOA) are two widely used methods for solving dynamic signal source localization (DSSL) problems, where the position of a moving target is determined by measuring the angle and time difference of the signal's arrival, respectively. In robotic manipulator applications, accurate and real-time joint information is crucial for tasks such as trajectory tracking and visual servoing. However, signal propagation and acquisition are susceptible to noise interference, which poses challenges for real-time systems. To address this issue, a noise-immune zeroing neural dynamics (NIZND) model is proposed. The NIZND model is a brain-inspired algorithm that incorporates an integral term and an activation function into the traditional zeroing neural dynamics (ZND) model, designed to effectively mitigate noise interference during localization tasks. Theoretical analysis confirms that the proposed NIZND model exhibits global convergence and high precision under noisy conditions. Simulation experiments demonstrate the robustness and effectiveness of the NIZND model in comparison to traditional DSSL-solving schemes and in a trajectory tracking scheme for robotic manipulators. The NIZND model offers a promising solution to the challenge of accurate localization in noisy environments, ensuring both high precision and effective noise suppression. The experimental results highlight its superiority in real-time applications where noise interference is prevalent.

Cephalometric Parameters as Predictive Factors for Orthognathic Surgery in Unilateral Cleft Lip and Palate Patients: A Systematic Review and Meta-Analysis.

To identify cephalometric parameters that could predict future need for orthognathic surgery (OGS) in patients with unilateral cleft lip and palate (UCLP). Final search was conducted on July 7, 2024, across PubMed, Scopus, Embase, Web of Science, Cochrane, Ovid Medline, EBSCO, and LILACS, without any language and publication time restriction. Studies comparing surgical versus nonsurgical UCLP patients were included. Two independent reviewers screened studies, and those included were evaluated using Quality in Prognostic Studies (QUIPS) tool. Random-effects meta-analysis of various sagittal and vertical cephalometric parameters (SNA, SNB, ANB, mandibular plane angle [MPA], and lower anterior face height [%LFH]) was performed. Ten studies were included in systematic review and 5 in meta-analysis. Quality in Prognostic Studies tool assessment indicated moderate risk in 6 studies, with 2 demonstrating high and low risks of bias. Meta-analysis revealed that in the 5- to 8-year age group, significant differences were observed in SNA and ANB angles between surgical and nonsurgical groups, with mean differences of 2.25° (95% confidence interval [CI] = 1.12, 3.39) and 3° (95% CI = 1.86, 4.15), respectively. In 9- to 14-year age group, significant differences were found in all 3 sagittal parameters: SNA angle difference of 2.65° (95% CI = 1.44, 3.86), SNB angle difference of 3.23° (95% CI = −4.69, −1.77), and ANB angle difference of 5.54° (95% CI = 3.66, 7.42). Vertical parameters (MPA and %LFH) were not statistically significant between groups in any age group. Cephalometric parameters could be a valuable predictive factor for determining the future need for OGS in patients with UCLP. ANB angle has been shown to be a significant predictor for distinguishing between surgical and nonsurgical patients.

Numerical analyses of a mid-IR metasurface spectral beam combiner with high efficiency and low phase distortion

Mid-infrared lasers have been widely used in chem/bio-sensing, medical diagnostics, environmental monitoring, and defense. These applications frequently require broad spectral coverage, high brightness, and compact size. Spectral beam combining (SBC) technology has been proven to be efficient in scaling laser power and broadening spectral range. Although the blazing grating has been successfully applied as the SBC component in mid and far infrared, its performance is limited by strong dispersion and polarization dependence. In this paper, we proposed a spectral beam combiner based on the dual-band anomalous reflective metasurface. The combiner had ultra-high, polarization-independent anomalous reflectivity in two spectral bands (4.0 μm and 4.6 μm). In both bands, the bandwidth with over 95% reflectivity was 100 nm. These properties made both the dense SBC and two-band SBC possible. Moreover, the impacts of the input laser properties on the combining efficiency and beam quality were thoroughly studied. The metasurface beam combiner exhibited high tolerance to the incident angle deviation and input laser spectral linewidth. Even when the laser has a broad linewidth of 70 nm incident on the beam combiner with a large angle deviation of 10°, the beam combiner still showed a higher than 90% efficiency and good reflective beam quality M2&lt;1.5. In addition, in the dense SBC situation, when 7 individual lasers with a central wavelength interval of 25 nm were combined the beam propagation parameter M2 was better than 1.5. We believe that the metasurface spectral beam combiner was an effective alternative to the commercial diffractive gratings and was capable of combining multiple beams from broadband laser sources.

A redundant steering-by-wire system and multi-axle cooperative steering control algorithm for super autonomous rapid transit

In view of the safety problems of the single-channel hydraulic steering system which widely used in the multi-axle cooperative steering system of super autonomous rapid transit (SRT), a multi-axle cooperative steering system based on redundant steering-by-wire is developed. Firstly, the real-time task and system status judgment are placed in the master station of the steering controller for processing, fully ensuring the real-time performance of the task. At the same time, the slave station is set to synchronously process the task and judge the status. The two channels of the steering system work simultaneously, and when one channel fails, the other channel can take over the system in real time. This redundancy strategy ensures the safety of the vehicle. Secondly, a multi-axle cooperative steering control algorithm for SRT is proposed. The steering control system consists of a feedforward and an additional feedback control. The feedforward control is subdivided into three steps. In a first step the angle of axle 2 is calculated with dynamic model of first module and the driven path is estimated. This path is used in a second step to calculate the desired kinematics and finally the desired kinematics are transformed into the desired lateral forces by means of the inverse vehicle model. An additional nonlinear feedback controller stabilizes the tracking behavior on vehicle status level. By establishing the kinematics model of SRT and adopting the PID control of yaw angle deviation, the control error of the vehicle is dynamically compensated, and the control accuracy and robustness of the SRT multi-axle cooperative control algorithm are ensured. The steering system has been applied to the three-module &amp; six-axle SRT, with the functions of steering-by-wire and track following, and can achieve the minimum turning radius of 15 m, and its good control accuracy and stability are verified by experiments.

Feather Evolution Following Flight Loss In Crown Group Birds: Relaxed Selection And Developmental Constraints.

Feathers are complex structures exhibiting structural/functional disparity across species and plumage. Flight was lost in >30 extant lineages from ~79.58 Ma-15 Ka. Effects of flight loss on senses, neuroanatomy, and skeletomusculature are known. To study how flightlessness affects feathers, we measured 11 feather metrics across the plumage of 30 flightless taxa and their phylogenetically closest volant taxa, with broader sampling of primaries across all orders of crown birds. Our sample includes 27 independent flight losses, representing nearly half of extant flightless species. Feather asymmetry measured by barb angle differences between trailing and leading vanes decreases in flightless lineages, most prominently in flight feathers and weakest in contour feathers. Greatest changes in feather anatomy occur in older flightless lineages (penguins, ratites). Comparative methods show some microscopic feather traits are not dramatically modified after flightlessness compared to body mass increase and relative wing and tail fan reduction, but changes toward greater symmetry are stronger. Relaxing selection for flight does not rapidly modify feather flight adaptations, apart from asymmetry. Feathers of recently flightless lineages resemble their volant relatives. Developmental constraints and relaxed selection for novel feather morphologies may explain some observed changes. Macroscopic changes to flight apparati (skeletomusculature, airfoil size) are more evident in recently flightless taxa and could more reliably detect flightlessness in fossils, with increased feather symmetry as a potential microscopic signal. We observed apical modification in later stages of feather development (asymmetric displacement of barb loci), while morphologies arising during early developmental stages are only altered after millions of years of flightlessness.

Abstract TMP77: Robotic-Guided Implantation of 3D-Printed Hydrogel Scaffolds to Enhance Axonal Regeneration and Functional Recovery After Stroke: A Novel Minimally Invasive Surgical Approach

Ischemic strokes often disrupt white matter (WM) microstructure, particularly affecting the corticospinal tract (CST) in the internal capsule (IC), leading to significant motor deficits. While evidence shows that axon sprouting occurs post-stroke, it often follows erratic paths, limiting functional recovery. Recent advances in 3D-printed hydrogel scaffolds have shown promise in guiding axon regeneration in spinal cord injury models. We hypothesize that implanting these scaffolds at white matter sites affected by stroke, aligned with CST fibers, will enhance functional axonal regeneration and motor recovery. Our aim is to develop and validate a precise and clinically applicable scaffold delivery system for future human studies. We have developed a novel, minimally invasive stereotaxic method for the precise deployment of 1.3 mm diameter scaffolds within the IC of non-human primates (NHPs). Our approach utilizes a clinically available stereotactic robot (ROSA, ZimmerBiomet) combined with a linear cannula system (AlphaOmega) to plan scaffold placement. Then, we attempted to deploy scaffolds devices into thermally coagulated lesions in NHPs (n=2) and simulated lesions within hydrogel phantoms (n=2). Post-implant MRI, co-registered with high-resolution diffusion tensor imaging were applied to check for scaffold placement accuracy (n=4). We further complement the scaffold placement method by using a novel neurosurgical microrobot (Robeauté) designed for navigation along 3D nonlinear curves, with accuracy confirmed by CBCT imaging in phantom tests. Our implantation methods accurately placed scaffolds in the intended locations and orientations, aligning with CST fibers in both phantom models and NHP brains. The deviation angle between the scaffold and CST fibers was 17.83° (SD 6.71°, n=3). The scaffolds were precisely positioned within the IC, validating our approach. Our robot-guided method accurately steered them to their intended position, demonstrating minimal errors in targeted white matter regions. The methods described are poised for clinical translation, potentially extending the applicability of scaffold technology for improving motor function post-stroke. We are preparing NHPs for behavioral and upper limb motor assessments to evaluate the impact of scaffold implantation on axon regeneration, recovery, and performance. This research aims to enhance our understanding of ischemic stroke and develop innovative therapies to restore motor function in patients.

Sex-specific anatomical variation of circle of Willis arteries.

Anatomical variations in the circle of Willis (CoW) arteries are common and can affect hemodynamic stress, thereby influencing the risk of cerebrovascular pathology. Previous studies have suggested sex differences in CoW anatomy, but findings vary due to limited study population size and different measurement methods. This study aims to investigate sex differences in artery diameters, anatomical variants and bifurcation angles of the CoW using a large population cohort and semi-automatic measurements. Sex-specific CoW anatomical variations were assessed using Magnetic Resonance Angiography (MRA) scans of 1,052 individuals without intracranial vascular abnormalities. Diameters and bifurcation angles of large CoW arteries (>1.2 mm) were measured with a semi-automatic tool. Diameters of smaller anterior communicating artery (Acom) and posterior communicating arteries (Pcoms) and the anatomical variants of the CoW were determined manually. Generalized Linear Models (GLMs) and logistic regression models with adjustments for covariates were used to compare anatomical variations between sexes. Men exhibited larger diameters in all semi-automatically measured CoW arteries. A complete anterior CoW was more prevalent in men than women, while there was no difference for the posterior CoW. Aplasia/hypoplasia of the Acom was more prevalent in women. Aplasia/hypoplasia of one Pcom was more common in women, while aplasia/hypoplasia of both Pcoms was more common in men. No sex differences were found in CoW bifurcation angles and in the occurrence of fetal-type posterior cerebral arteries. This study identified significant CoW differences in artery diameters and anatomical variants between sexes, while bifurcation angles between arteries were comparable. Future research should investigate the association between these sex-specific CoW variations and cerebrovascular pathology.

Kinematic analysis of upper limb fractures: Insights for rehabilitation strategies.

Upper limb fractures significantly alter movement, impacting function and recovery. Three-dimensional motion analysis allows precise assessment of these changes. Sixty patients were divided into four groups: shoulder, elbow, wrist fractures, and controls. Functional assessment was performed using the DASH questionnaire, followed by three-dimensional kinematic analysis with eight Oqus 300 cameras and 14 reflective markers on the thorax, scapula, humerus, forearm, and hand. The Acromion Marker Cluster method was used for accurate scapular tracking. Tasks analyzed included hand on shoulder, hand on back, and hand on neck. All measured variables are expressed in degrees. The analysis focused on the differences in maximum joint angles for each degree of freedom across the tasks. These differences were assessed using MANOVA, followed by ANOVAs and Tukey's post hoc test when applicable. Significant kinematic differences were observed between the fracture groups and the control group across all tasks. Shoulder fracture patients exhibited the greatest reductions in humeral flexion and abduction. Elbow fracture patients showed the most restricted elbow flexion. Wrist fracture patients presented significantly reduced radial/ulnar deviation. These movement impairments were observed across all tasks, with the most pronounced limitations seen in the hand-to-shoulder task. Effect sizes (η2) indicated clinically meaningful impacts, particularly for shoulder and wrist movements. This study reveals distinct kinematic alterations following upper limb osteosynthesis, emphasizing the need for individualized rehabilitation strategies addressing these specific movement impairments to optimize recovery.

Motion Capture-based 3-Dimensional Measurement of Range of Motion in Patients Undergoing Cervical Laminoplasty.

A prospective study. To measure 3-dimensional cervical range of motion (ROM) by noninvasive optical tracking-based motion-capture technology in patients undergoing laminoplasty, and to elucidate the postoperative effects of laminoplasty on cervical mobility. Cervical laminoplasty is a motion-sparing decompression surgery for degenerative cervical myelopathy. Unlike cervical laminectomy and fusion, the true postoperative impact of laminoplasty on neck motion has not been well studied. Participants comprised 25 patients undergoing double-door cervical laminoplasty for degenerative cervical myelopathy in a single center. Maximum flexion/extension, left/right rotation, and left/right side bending were recorded using the motion-capture device preoperatively and 3 months postoperatively. ROMs in 3 orthogonal axes were calculated. Preoperative differences in C2-7 Cobb angles on lateral flexion/extension x-rays were also measured as the radiologic ROM to assess reliability. Preoperative and 1-year postoperative Japanese Orthopaedic Association score, Neck Disability Index [NDI], and Euro-QOL were recorded, and correlations with ROMs were assessed. Preoperative mean (±SD) ROMs for flexion/extension, rotation, and side bending were 90±17, 107±16, and 53±17 degrees, respectively. Although radiologic sagittal ROM measurement showed a smaller range than motion capture, averaging 36±13 degrees, a moderate to strong correlation between radiologic and motion capture values was observed (R=0.57, P =0.003). Preoperative NDI showed a negative correlation with coronal ROM (rho=-0.547, P =0.02). Postoperative ROM showed a significant reduction in rotation (95±16 degrees, P =0.002) but not in flexion/extension or side bending. Three-dimensional motion-capture analysis allowed reliable measurement of cervical ROM. Rotational ROM was significantly reduced after laminoplasty, showing that cervical kinematics are still significantly altered.

Radiographic Horizontal Conjugate Gaze Deviation: Clinical Correlates.

The potential diagnostic value of radiographic, horizontal, conjugate gaze deviation (Rad h-CGD) was first recognized in 2003 by Simon et al. Thereafter, interest grew related to its potential use as a marker of different neurologic and vestibular disorders. Over the past 20 years, we have identified clinical correlates of Rad h-CGD including those caused by supratentorial and infratentorial lesions. We propose clinicians and radiologists will better diagnose and manage patients by knowing the different diagnostic possibilities for Rad h-CGD. We report different clinical correlates of Rad h-CGD relevant for localizing and lateralizing lesions. We measured the angle of deviation and correlated it with the clinical findings and underlying mechanisms. We then reviewed important data from the previous literature relevant to the localization of each lesion and combined it with our experience into the design of a practical algorithm to interpret Rad h-CGD. Using Rad h-CGD provides useful information about the diagnosis and localization and may reveal subtle ocular findings not clear on physical examination. However, Rad h-CGD alone cannot distinguish between supratentorial and infratentorial lesions, and therefore, the clinical context is critical. Moreover, although Rad h-CGD occurs with strokes due to large vessel occlusion, it could also be seen with an acute vestibular syndrome, secondary to a peripheral vestibular neuritis. Other possibilities include ischemic events in the cerebellum, brainstem, and labyrinth.

Full-Arch Digital Implant Impression Trueness: An in Vivo Study.

To evaluate the trueness of maxillary and mandibular full-arch implant digital impressions with and without additional reference objects. Seventeen maxillary and 6 mandibular arches with four implants were randomly divided into a group with additional reference objects (wRO group, n = 12) and without them (woRO group, n = 11) and scanned with an intraoral scanner (IOS). For each jaw, the control model (CM) data was obtained to evaluate the deviations in the scan body positions in the wRO and woRO groups. CM and IOS data sets were imported into metrology software for distance and angle measurements between scan body pairs 1-2, 1-3, and 1-4. Unsigned values of distance and angle data differences between CM and IOS groups were used for further analysis. The highest statistically significant (p < 0.05) differences between distance and angulation measurements of the maxilla and mandible were observed in the 1-4 scan body pair group (136 ± 95 μm, 0.95° ± 0.79°; 362 ± 233 μm, 2.22° ± 2.11°, respectively). Distance deviations of the mandible were higher in all scan body pair groups. The woRO group had higher distance and angulation unsigned trueness values than in the wRO group, especially in the 1-4 scan body pair (224 ± 183 μm, 1.77° ± 1.76°;169 ± 162 μm, and 0.83° ± 0.57°, respectively). IOS for the full-arch cases had statistically and clinically significant distance and angle deviations. Higher deviations were observed in the single mandibular scan body pair. The tendency of diminished distance and angular deviations with the utilization of the additional reference objects was observed, though these differences were not statistically significant.

Are Vestibular Function or Visuospatial Perception Affected in Individuals with Idiopathic Scoliosis?

Purpose: It was aimed to investigate relationship between characteristics of the curve and balance, vestibular dysfunction, visuospatial perception, navigation performance, and quality of life in idiopathic scoliosis. Material and Methods: 33 participants with idiopathic scoliosis were included. Radiography, ScolioDetector application, unipedal stance test, Utenberger test (displacement and rotation), Visuospatial Memory Test, triangle completion task, and Scoliosis Research Society-22 evaluation parameters were. Results: According to the type of curve, a significant difference was found only in the unipedal stance test with the right eyes closed and in the rotation with the eyes open (p0.05), except for the duration of standing on one foot with eyes open on the right soft ground (p=0.009); There was a significant difference in displacement and eyes-open rotation angle (p

Replication of Coupled Movements of the Wrist: A Cadaveric Study of Total Wrist Arthroplasty.

The purpose of this study was to determine how well the active range of motion and the forces required to achieve motions are maintained following cadaveric implantation of the ball-and-socket style total wrist arthroplasty (TWA). An active wrist motion simulator was used to produce flexion, extension, radioulnar deviation, dart-thrower's motion, and circumduction in 14 fresh-frozen cadaveric wrists before and after TWA. Identical tendon displacements were applied to five major wrist flexors and extensors to control motion presurgery and postsurgery. Motion trials were recorded using biplanar video fluoroscopy and digitally reconstructed with 6 degrees of freedom using x-ray reconstruction of moving morphology. Wrist angles were subsequently measured with respect to an anatomically based radial coordinate system. Forces applied to the five actuated tendons were recorded by the simulator throughout all motion trials. Maximum wrist angles, dart-thrower's motion plane orientation, circumduction ellipse parameters, and peak tendon forces in pre-TWA and post-TWA conditions were compared. There were no significant differences in maximal flexion, extension, radial, or ulnar deviation angles when comparing preoperative anatomic wrists with the same wrist following implantation of the TWA. Orientation of dart-thrower's motion planes and circumduction ellipses with respect to the sagittal plane increased after cadaveric surgery, whereas the area of the circumduction ellipses remained similar. Tendon forces were similar in anatomic and TWA wrists apart from flexor forces, which decreased in flexion in TWA wrists. In our cadaveric setup, the TWA was able to recreate functional motion patterns without significantly increased tendon forces. The results of this study support the assertion that a ball-and-socket style TWA can provide a postoperative range of motion adequate to perform activities of daily living.

Automated strabismus detection and classification using deep learning analysis of facial images

Strabismus, or eye misalignment, is a common condition affecting individuals of all ages. Early detection and accurate classification are essential for proper treatment and avoiding long-term complications. This research presents a new deep-learning-based approach for automatically identifying and classifying strabismus from facial images. The proposed methodology leverages Convolutional Neural Networks (CNNs) to achieve high accuracy in both binary (strabismus vs. normal) and multi-class (eight-class deviation angle for esotropia and exotropia) classification tasks. The dataset for binary classification consisted of 4,257 facial images, including 1,599 normal cases and 2,658 strabismus cases, while the multi-class classification involved 480 strabismic and 142 non-strabismic images. These images were labeled based on ophthalmologist measurements using the Alternate Prism Cover Test (APCT) or the Modified Krimsky Test (MK). Five-fold cross-validation was employed, and performance was evaluated using sensitivity, accuracy, F1-score, and recall metrics. The proposed deep learning model achieved an accuracy of 86.38% for binary classification and 92.7% for multi-class classification. These results demonstrate the potential of our approach to assist healthcare professionals in early strabismus detection and treatment planning, ultimately improving patient outcomes.

Design of Tool Shape and Evaluation of Deformation Behavior by Digital Image Correlation Method in V-Bending of Sheet Metal Using Plastic Tools Manufactured by 3D Printer

In the V-bending of sheet metals using a pair of plastic punch and die manufactured by a 3D printer, the effects of two different dimensions designed with the same tool geometry on the deformation behaviors of the punch, die, and sheet were evaluated. The deformation behavior and strain distribution of the punch, die, and sheet were analyzed using a digital image correlation method. Sheets from pure aluminum to ultra-high-strength steel were bent using the two tools with different spans; one was designed on the assumption of tool steel material, and the other was designed on the assumption of plastic material. In both tools, the large compressive strain appeared around the center of the punch tip and on the corners of the die. The tools with a long span for the plastic material gave a lower bending force and small deformation of the plastic tools. The angle difference between a bent sheet at the bottom dead center and a tool was smaller for the tools with the long span, although the springback in the bent sheet appeared. It was found that the design method on the assumption of the plastic material is effective for the V-bending plastic tools.

Aesthetic Perception to Different Facial Profiles—An Evaluation Based on Age, Sex, Educational Status, and Study Area

Objectives This study aimed to determine the aesthetic preferences of profile silhouettes according to various soft tissue analyses commonly used in orthodontic practice. Methods For this observational study, lateral photographs were taken of two patients. Nasolabial and mentolabial angles were digitally altered in 20° increments, obtaining four photographic series, and a survey was carried out, recruiting 330 participants to evaluate their preferences according to these categories: very attractive, somewhat attractive, little attractive, and unattractive. The relationship between variables was evaluated using the chi-square test ( χ2) and Cohen’s d ( d) for effect size. Results Significant correlations were obtained between variables ( p &lt; .001; p &lt; .05). Female participants, those 23-33 years old, graduates, and those from Health Sciences obtained a higher prevalence when choosing the most balanced facial profile. Differences in the nasolabial angle were more detected. Conclusion There was a tendency to prefer profiles with a more open nasolabial angle and a flatter mentolabial sulcus in women. The variables that proved to have the most influence were educational status and age.