Visual Measurements Research Articles

Brief online suicide risk assessment of adults does not affect state mood, even in the context of elevated suicidality self-stigma, suicidal ideation and psychological distress.

The current study aimed to assess whether online suicide risk assessment affects state mood and is the first to examine if suicide-related self-stigma or coping related to suicidal ideation are predictors of mood change. The Australian participants (N = 661, Mage = 34.9, SD = 12.3, 57.1% female), recruited through a crowd-sourcing platform, completed a visual analogue mood measure before and after the Suicidal Ideation Attributes Scale (SIDAS), an assessment tool. Followed by a modified version of the Internalised Stigma Scale, the Brief COPE and DASS-21. State mood did not change from pre- to post-suicide risk assessment in the overall sample, t(662) = -.16, p = .868, d = -.01. Contrary to hypotheses, neither self-stigma nor coping were related to mood change following exposure to the SIDAS. The multiple regression model was not significant, F(9,643) = 1.16, p = .31., nor was any single predictor including gender, current Suicide risk β = -.04, t = -.80 or psychological distress β = -.09, t = -1.76, p = .08. These findings suggest that online exposure to a suicide risk tool is unlikely to be iatrogenic in relation to state mood, even in the context of elevated self-stigma, suicidal ideation and psychological distress.

Radial polarisation patterns identify macular damage: a machine learning approach

ABSTRACT Clinical relevance Identifying polarisation-modulated patterns may be an effective method for both detecting and monitoring macular damage. Background The aim of this work is to determine the effectiveness of polarisation-modulated patterns in identifying macular damage and foveolar involvement using a methodology that involved feature selection, Naïve Bayes supervised machine learning, cross validation, and use of an interpretable nomogram. Methods A cross-sectional study involving 520 eyes was undertaken, encompassing both normal and abnormal cases, including those with age-related macular disease, diabetic retinopathy or epiretinal membrane. Macular damage and foveolar integrity were assessed using optical coherence tomography. Various polarisation-modulated geometrical and optotype patterns were employed, along with traditional methods for visual function measurement, to complete perceptual detection and identification measures. Other variables assessed included age, sex, eye (right, left) and ocular media (normal, pseudophakic, cataract). Redundant variables were removed using a Fast Correlation-Based Filter. The area under the receiver operating characteristic curve and Matthews correlation coefficient were calculated, following 5-fold stratified cross validation, for Naïve Bayes models describing the relationship between the selected predictors of macular damage and foveolar involvement. Results Only radially structured polarisation-modulated patterns and age emerged as predictors of macular damage and foveolar involvement. All other variables, including traditional logMAR measures of visual acuity, were identified as redundant. Naïve Bayes, utilising the Fast Correlation-Based Filter selected features, provided a good prediction for macular damage and foveolar involvement, with an area under the receiver operating curve exceeding 0.7. Additionally, Matthews correlation coefficient showed a medium size effect for both conditions. Conclusions Radially structured polarisation-modulated geometric patterns outperform polarisation-modulated optotypes and standard logMAR acuity measures in predicting macular damage, regardless of foveolar involvement.

Endpoints and Design for Clinical Trials in USH2A-Related Retinal Degeneration: Results and Recommendations From the RUSH2A Natural History Study.

To evaluate functional and structural assessments as endpoints for clinical trials for USH2A-related retinal degeneration. People with biallelic disease-causing variants in USH2A, visual acuity ≥ 20/80, and visual field ≥ 10° diameter were enrolled in a 4-year, natural history study. Participants underwent static perimetry, microperimetry, visual acuity, fullfield stimulus testing (FST), and optical coherence tomography annually. Rates of change estimated from mixed-effects linear models and percentages of eyes with changes exceeding the coefficient of repeatability (CoR) or thresholds conforming with U.S. Food and Drug Administration (FDA) guidelines were evaluated. Rates of change were generally more sensitive to change than proportions of eyes exceeding a threshold such as the CoR. Baseline ellipsoid zone area ≥ 3mm2 was necessary to detect change. Mean sensitivity and volumetric hill of vision measures on static perimetry had similar properties and were the most sensitive to changes of the continuous measures. The highest 4-year proportions of eyes exceeding the CoR were from FST testing (47%) and microperimetry (32%). Specification of loci as functional transition points (FTPs) resulted in 45% (static perimetry) and 46% (microperimetry) at 4years, meeting FDA guidelines for progression. Rate of change of mean sensitivity on static perimetry was a sensitive perimetric continuous measure. Percentages of within-eye change were largest with FST testing and microperimetry. FTPs appear to be particularly sensitive to change. These results affect clinical trial design for USH2A-related retinal degeneration. Analyses of natural history data from the Rate of Progression in USH2A-Related Retinal Degeneration (RUSH2A) study can inform eligibility criteria and endpoints for clinical trials.

A Calculation Method of Bearing Balls Rotational Vectors Based on Binocular Vision Three-Dimensional Coordinates Measurement

The rotational speed vectors of the bearing balls affect their service life and running performance. Observing the actual rotational speed of the ball is a prerequisite for revealing its true motion law and conducting sliding behavior simulation analysis. To address the need for accuracy and real-time measurement of spin angular velocity, which is also under high-frequency and high-speed ball motion conditions, a new measurement method of ball rotation vectors based on a binocular vision system is proposed. Firstly, marker points are laid on the balls, and their three-dimensional (3D) coordinates in the camera coordinate system are calculated in real time using the triangulation principle. Secondly, based on the 3D coordinates before and after the movement of the marker point and the trajectory of the ball, the mathematical model of the spin motion of the ball was established. Finally, based on the ball spin motion model, the three-dimensional vision measurement technology was first applied to the measurement of the bearing ball rotation vector through formula derivation, achieving the analysis of bearing ball rolling and sliding characteristics. Experimental results demonstrate that the visual measurement system with the frame rate of 100 FPS (frames per second) yields a measurement error within ±0.2% over a speed range from 5 to 50 RPM (revolutions per minute), and the maximum measurement errors of spin angular velocity and linear velocity are 0.25°/s and 0.028 mm/s, respectively. The experimental results show that this method has good accuracy and stability in measuring the rotation vector of the ball, providing a reference for bearing balls' rotational speed monitoring and the analysis of the sliding behavior of bearing balls.

Accurate reconstruction of turbine blade point cloud and multiple point cloud registration based on structured light

In recent years, the industry has increasingly adopted vision-guided laser processing techniques to machine cooling holes in turbine blades, placing higher demands on the accuracy of visual measurement. Therefore, to meet the need for high-precision measurement of the three-dimensional shape of turbine blades in the context of laser processing of film cooling holes, this paper proposes a structured light-based method for precise reconstruction of turbine blade point clouds and multi-point cloud registration. Specifically, to improve the accuracy of point cloud reconstruction, an improved phase matching and reconstruction method based on epipolar constraints is proposed. To enhance the accuracy and stability of multi-point cloud registration, a weighted iterative closest point (ICP) method combined with a mark point registration strategy is proposed, optimizing the stability of the ICP algorithm and achieving high-quality multiple point cloud stitching. Experimental results validate the effectiveness and accuracy of the proposed method.

Pose Estimation of a Cobot Implemented on a Small AI-Powered Computing System and a Stereo Camera for Precision Evaluation.

The precision of robotic manipulators in the industrial or medical field is very important, especially when it comes to repetitive or exhaustive tasks. Geometric deformations are the most common in this field. For this reason, new robotic vision techniques have been proposed, including 3D methods that made it possible to determine the geometric distances between the parts of a robotic manipulator. The aim of this work is to measure the angular position of a robotic arm with six degrees of freedom. For this purpose, a stereo camera and a convolutional neural network algorithm are used to reduce the degradation of precision caused by geometric errors. This method is not intended to replace encoders, but to enhance accuracy by compensating for degradation through an intelligent visual measurement system. The camera is tested and the accuracy is about one millimeter. The implementation of this method leads to better results than traditional and simple neural network methods.

Development of an intelligent geographic information system for mountain roads monitoring: Ground data collection and analysis

This study examines the development of an intelligent geographic information system for mountain road monitoring. To make well-informed and timely management decisions in the planning, construction, and maintenance of mountain roads, and to anticipate potential critical situations and their effects on road conditions, it is imperative to employ modern methodologies. This study involves data collection from a specific section of a mountain road situated near Almaty, Kazakhstan. We gathered data on the road section through visual assessment, measurements of the coefficient of adhesion, and the acquisition of material samples from the structural layers of the roadbed. Based on the visual assessment and surface adhesion measurements, it became evident that the deformation of the studied road section, which includes a network of cracks and "non-standard" transverse cracks, is attributed to mountain mass shifts and water flows from slopes. Laboratory analysis of the collected samples revealed that excessive water saturation could result in cracks during freeze-thaw cycles, while a low resistance coefficient would lead to softening during humid conditions. An Intelligent Geographic Information System (IGIS) will incorporate the collected data alongside open remote sensing and weather data. The objective is to utilize this integrated system in the future for forecasting road conditions and maintenance requirements for similar roads in mountainous regions of the area. The measurements are carried out according to the state standards. That makes the system useful for government management purposes.

Comparison of ultrasound guided erector spinae plane block and fascia iliaca block for postoperative analgesia in hemiarthroplasty: a double-blind randomized trial

Background & Objective: Peripheral nerve blocks are one of the peri-operative analgesic options that abolish surgical stress response, reduce the use of opioids, and control postoperative pain. During the previous few decades regional anesthesia and analgesia techniques have been widely used, especially with the enhanced safety and precision in these procedures with the use of ultrasound. We compared the efficacy of Erector Spinae Plane Block (ESPB) with Fascia Iliaca Block (FIB) for postoperative pain in hemiarthroplasty surgery. Methodology: This randomized double-blind trial included sixty-eight cases scheduled for hemiarthroplasty under spinal anesthesia. Patients were randomly divided into two equal groups: Group ES received ESPB, and Group FI received FIB. Blocks were performed preoperatively using 15 mL bupivacaine 0.25%- and 15 mL lidocaine 2%. Postoperatively, pain was assessed with Visual Analogue Scale (VAS) at 1 h, 2 h, 6 h, 12 h and 24 h. Results: The mean time to first dose and the amount of morphine used in the first 24 hours were comparable between Group ES and Group FI. Visual analogue scale measurements at rest and movement showed insignificant differences between both groups at 1 h, 2 h, 6 h, 12 h and 24 h. Quadriceps motor impairment revealed significant reduction in Group ES compared to Group FI (11.76 vs 44.12%, P = 0.006). Conclusions: In hemiarthroplasty, the analgesic profile of erector spinae plane block was comparable with fascia iliaca block with superiority of the former in preserving the quadriceps motor power. Keywords: Ultrasound, Erector Spinae Plane Block, Fascia Iliaca Block, Analgesia, Hemiarthroplasty Citation: Ahmed MB, Mohammed MM, Amin SMM, Belata MM. Comparison of ultrasound guided erector spinae plane block and fascia iliaca block for postoperative analgesia in hemiarthroplasty: a double-blind randomized trial. Anaesth. pain intensive care 2024;28(5):791−797; DOI: 10.35975/apic.v28i5.2562 Received: April 29, 2024; Reviewed: August 19, 2024; Accepted: August 25, 2024

Orbits of Binary Stars: from Visual Measures to Speckle Interferometry

Knowledge of the orbits of visual binary stars has always been one of the fundamentals of astronomy. Based historically on the visual measures, nowadays the orbits rely more (or exclusively) on the accurate speckle data. This prompts reconsideration of the methods of orbit calculation, undertaken here and illustrated by 20 examples, from accurate to drastically revised and tentative orbits. Good understanding and critical assessment of the input data is a key requirement, especially concerning visual measures. Combination of visual and speckle data is still needed for long-period binaries, but the relative weights must match their respective errors. When the orbit can be fully constrained only by accurate speckle data, the old measures should be ignored. Orbits can be classified into three grades: (A) fully constrained, (B) semiconstrained, and (C) preliminary or tentative. Typical use cases of visual orbits are listed. Accurate parallaxes from Gaia, together with the orbits, will greatly expand the data on stellar masses. Continued speckle monitoring will be an essential complement to Gaia, but the vast amount of new pairs will restrict future work on orbits to the most interesting or relevant objects.

Vision impairment in school students: Results of a school-based study in Qatar

Background: Pediatric vision impairment (VI) has profound implications for a child's development, intellectual skills, and quality of life. The aim of this study was to assess the prevalence of VI among primary and preparatory school students in Qatar. Methods: A school-based cross-sectional study was conducted among students in grades 1, 3, 5, 7, and 9 in Qatar. School nurses conducted visual acuity (VA) measurement using a Snellen chart placed 6 meters away, with an E symbol, in which the 6/6 line is the standard for normal vision. Each student's information was recorded in their electronic health records (government schools, GSs) or in Excel sheets (private schools, PSs). Results: Three hundred and thirty schools participated in this survey, with 99,379 students divided into 45,670 from GSs and 53,709 from PSs. The prevalence of abnormal VA among students was 10.4% in GSs and 12.6% in PSs. There was no significant association between VI and gender or nationality, although VI was higher in grades 5, 7, and 9 but not statistically significant. Furthermore, the proportion of visually impaired students diagnosed with refractive errors and wearing glasses or contact lenses during vision measurement was 14.7% in GSs and 27% in PSs. Conclusion: The study provides comprehensive and baseline data on VI among the school children of Qatar. The vision screening helped in the early detection of VI in one-tenth of the affected students. However, urgent interventions are needed to enhance screening strategies for future studies on the causes of VI.

Validation of a French Version of the Visual Function and Corneal Health Status Instrument and Correlation With Vision and Glare Measurements in Fuchs Endothelial Corneal Dystrophy.

To validate a French version of the Visual Function and Corneal Health Status (V-FUCHS) instrument in Fuchs endothelial corneal dystrophy (FECD) and to correlate questionnaire scores with objective measurements of best-corrected visual acuity (BCVA) and intraocular straylight. The original V-FUCHS 15-item instrument was designed to assess VA and glare in patients with FECD. It was translated from English to French and back translated to English by independent translators. The questionnaire was administered on 2 occasions (4 weeks apart), and BCVA, modified Krachmer grade, and straylight were measured. Construct validity, internal consistency, test-retest reliability, and predictive validity were assessed. A total of 159 subjects, aged 41 to 86 years, were prospectively recruited from July 2019 to October 2020 and classified into 6 groups: mild, moderate, or advanced FECD; unilateral or bilateral Descemet membrane endothelial keratoplasty for FECD; and healthy controls (n = 35). Construct validity was confirmed by item response theory model. Cronbach alpha demonstrated excellent internal consistency (VA: 0.91, glare: 0.88), and intraclass correlations showed good test-retest reliability (VA: 0.75 and glare: 0.82). Significant correlations were observed between both VA and glare factors and the modified Krachmer grade, BCVA, and straylight. The proposed French version of the V-FUCHS instrument provides a valid and reliable tool for the assessment of visual disability in patients with FECD. This questionnaire bridges the gap between self-reported FECD symptoms and objective clinical measurements, which may prove useful to optimize the timing of surgery and to assess postoperative improvement in symptoms.

Investigation on intermittent flow characteristics in horizontal pipe by visualization measurement method

Accurate measurement and prediction of the intermittent flow characteristics in horizontal pipes is important for constructing multiphase flow models and ensuring pipe flow safety. In this paper, a quantitative image post-processing technique for intermittent flow characteristics based on gray histogram image similarity is proposed, which can realize the measurement of slug frequency. In addition, the technique also has the ability to classify a large number of images, and can quickly find the elongated bubble head, liquid film area and liquid slug area of intermittent flow. On the basis of this technique, combined with image post-processing methods such as gas–liquid interface feature analysis, a set of intermittent flow image processing technique with perfect route is formed. Based on this post-processing technique, the similarity image oscillation trajectories of plug flow and slug flow are obtained. There are differences in the similarity image oscillation trajectories of the two intermittent sub-flow patterns, and the similarity image of the plug flow has an obvious platform period and trailing rising line, which can be used as a basis for the classification of the two intermittent sub-flow patterns. A correlation for predicting the slug frequency of intermittent sub-flow patterns is developed. The accuracy of this slug frequency prediction correlation can be improved by about 10 % compared to not dividing the sub-flow patterns. When the mixture Froude number Frm is less than 5.0, the radial position of the elongated bubble head decreases linearly as the Frm increases. When the Frm is greater than 5.0, the elongated bubble head oscillates near the middle of the pipe. Prediction correlations for the radial position of the elongated bubble head and the slug velocity are established separately, and the maximum error is ± 10 %. The modified mixed Froude number is proposed, and based on this, a new prediction model for the transition from plug flow to slug flow is established.

A Novel Procedure for Treating Radial Keratotomy (RK) Induced Corneal Irregularity Utilizing Treatment of Epithelial Compensation of Higher-Order Aberrations and Topographic Guided Ablation-The CREATE Protocol.

To present the outcomes of a retrospective study of treatment of radial keratotomy-induced corneal irregularity with topographic guided ablation and a trans-epithelial approach based on epithelial compensation. Sixty eyes of 31 patients were treated for radial keratotomy-induced corneal irregularity utilizing a customized trans-epithelial topographic guided ablation photorefractive keratectomy (PRK) for treatment of corneal higher-order aberrations and lower-order astigmatism. Three-month results were analyzed via measurement of vision, refraction, residual higher-order aberrations (HOAs), residual lower-order and higher-order aberrations, as well as for loss or gains of lines of best corrected visual acuity. Higher-order aberrations (HOA) were reduced by 69%, with an 80% reduction of higher-order aberrations grouped with lower-order aberrations (Grouped). Most (95%) of eyes achieved 20/40 vision or better, 50% of eyes gained 1-9 lines of best corrected vision, and no eyes had loss of best corrected vision. Use of the CREATE protocol to treat RK-induced corneal irregularity resulted in a significant decrease in HOA, as well as a significant improvement in corrected distance visual acuity.

Adaptive positioning of large-scale aircraft components using a simplified image-based visual servoing via online measurement of ball-head center

In digital alignment systems, ensuring fast and accurate alignment between the ball head on large aircraft components and the ball socket of the positioner is the key to aircraft assembly efficiency and quality. Image-based visual servoing is one of the most advanced techniques with high efficiency and positioning accuracy, but it does not account for measuring the ball-head position. Moreover, variable target positions, similar feature interference, and poor lighting conditions pose great challenges to the fast and robust visual measurement of ball-head position. Hence, an online visual measurement method is introduced to measure the absolute position of the ball head in real time. An adaptive region of interest extraction algorithm and an improved edge following method are introduced to extract the elliptical contour from the ball-head image, and ellipse detection is achieved through a simple triplet selection algorithm. A geometric model based on the perspective projection of the sphere is established for estimating the ball-head center. Then, the simplified image-based visual servoing method is developed by constantizing the image Jacobian matrix. Next, an adaptive positioning method of large-scale aircraft components with multiple ball heads is proposed from a holistic perspective. Finally, experiments show that the final positioning accuracy of each ball head in the X/Y plane is less than ± 0.05 mm, with an efficiency almost ten times that of the conventional method. After adaptive adjustment, the position and angle errors of the simulated component are reduced within 0.6 mm and 0.3°, respectively.

Experimental study on pressure drop and ice blockage characteristics of ice slurry flow in big-diameter pipes

Ice slurry utilization in district cooling brings about attractive reduction in both the storage volume and transportation power of the cold thermal energy. However, the ice slurry flow characteristics, particularly in big-diameter pipes, remains unclear, hindering the application of ice slurry in large-scale district cooling systems. This paper prepared the ice slurry from pure water without any additives to experimentally study its flow characteristics in big-diameter pipes, including DN50, DN80, DN100 and DN190 pipes. The normalized pressure drops and friction factors have been obtained at various velocities and ice fractions. Generally, the pressure drop characteristics did not conform to the Blasius correlation which could predict the single-phase flow until the Reynolds number exceeded a certain threshold, known as the transition Reynolds number. The transition Reynolds numbers were in the range of 3.91 × 104-6.77 × 104 depending on the ice volume fractions ranging from 5% to 21% in the present study. Some visualization measures have been employed to help to observe the flow pattern and confirm the occurrence of ice blockage which was found nowhere but in the branches and expansion. The ice blockage occurred intermittently in the branches, whereas it was irreversible in the expansion. The critical velocity at which the ice blockage began to occur was quantitatively determined, which increased with increasing the ice volume fraction. This study provides a guide for evaluating the pump power and transportation safety of the ice slurry flow in big-diameter pipes.

Enhancing efficiency and quality control: The impact of Digital Twins in drinking water networks.

This paper showcases the successful development and implementation of two Digital Twin prototypes within the Lab Digital Twins project, designed to enhance the efficiency and quality control of Aigües de Barcelona's drinking water network. The first prototype focuses on asset management, using (near) real-time data and statistical models, and achieving a 70% success rate in predicting pump station failures 137 days in advance. The second prototype addresses water quality monitoring, leveraging machine learning to accurately forecast trihalomethane levels at key points in the distribution system, and enabling proactive water quality management strategies, ensuring compliance with stringent safety standards and safeguarding public health. The paper details the methodology of both prototypes, highlighting their potential to revolutionize water network management. PRACTITIONER POINTS: Digital representation of assets and processes in the drinking water treatment network Early fault detection in assets, and predictions of trihalomethane formation in the drinking water distribution network Reduction on monitoring time and incident response for target assets by means of Digital Twins Improvement in visualization, prediction, and proactive measures for asset management and water quality control Contribution to the growing knowledge on Digital Twins and their potential to revolutionize water network operations.

Clinical validation of a cross-platform digital visual acuity measurement system

Clinical validation of a cross-platform digital visual acuity measurement system

RD-VIO: Robust Visual-Inertial Odometry for Mobile Augmented Reality in Dynamic Environments.

It is typically challenging for visual or visual-inertial odometry systems to handle the problems of dynamic scenes and pure rotation. In this work, we design a novel visual-inertial odometry (VIO) system called RD-VIO to handle both of these two problems. First, we propose an IMU-PARSAC algorithm which can robustly detect and match keypoints in a two-stage process. In the first state, landmarks are matched with new keypoints using visual and IMU measurements. We collect statistical information from the matching and then guide the intra-keypoint matching in the second stage. Second, to handle the problem of pure rotation, we detect the motion type and adapt the deferred-triangulation technique during the data-association process. We make the pure-rotational frames into the special subframes. When solving the visual-inertial bundle adjustment, they provide additional constraints to the pure-rotational motion. We evaluate the proposed VIO system on public datasets and online comparison. Experiments show the proposed RD-VIO has obvious advantages over other methods in dynamic environments.

Influence of Rarefaction Degree and Aft-Body Geometry on Supersonic Flows

During atmospheric entry, super-/hypersonic vehicles cross distinct atmospheric layers characterized by large density variations and thus experience different flow regimes ranging from free molecular, transition, slip, to continuous regimes. Due to the distinct modeling strategy between these regimes and complex physical phenomena appearing near the vehicles (boundary-layer/shock interaction, base-flow recirculation, etc.), assessing their aerodynamic properties may be difficult. The present work focuses on supersonic flows around sharp-base geometries in both continuous and slip-flow regimes and aims at highlighting the influence of both rarefaction degree and base geometry on the vehicles’ aerodynamic features. For this purpose, three axisymmetric cone-cylinder geometries with right-angled, rounded, or flared rear parts are considered. Flow visualization, pressure, and drag measurements are carried out at Mach number Ma=4 and Knudsen numbers ranging from Kn=4×10−4 to 1×10−2 in the supersonic rarefied MARHy wind tunnel. The experimental data are compared with numerical results of simulations performed with a continuous-flow Navier–Stokes (NS) solver and two rarefied flows codes: a discrete-ordinate Bhatnagar–Gross–Krook (K) solver and a direct simulation Monte Carlo (SPARTA) solver. While the NS solver overestimates frictional drag as Kn rises, the rarefied K and SPARTA results show satisfactory agreement with experimental data. The latter numerical results highlight the main effects of rarefaction: as Kn increases, shocks become more diffuse, skin friction strengthens (leading to a significant increase in drag coefficients), and the extent of the base-recirculation decreases. Regarding the aft-body geometry, its influence on the base recirculation vanishes with increasing Kn.

A flexible camera calibration method for pose vision measurement system of roadheader

Cameras used for visual measurement in underground roadway construction sites are difficult to calibrate. Therefore, this study proposed an on-site camera calibration method that does not require manual intervention. First, the virtual point and line features on the plane target are constructed using pole-polar constraints. Second, a homography model based on point-and-line features is established. Finally, a combined objective function based on the dynamic weight coefficient is proposed to optimise the calibration results further. Relevant simulations and experiments showed that the maximum internal parameter error obtained using the proposed method was 0.463 %, and the maximum position estimation error of the roadheader was 30 mm. In addition, the results show that this method is superior to other methods in terms of calibration accuracy and robustness, solving the difficulty of camera calibration in underground roadway construction sites and guaranteeing high-precision pose vision measurement.