Positioning Technique Research Articles

Impact of cardiac position, morphology and operative technique on long-term fontan outcomes in heterotaxy.

This study aimed to assess the outcomes of heterotaxy patients undergone the Fontan operation, focusing on morphological features and surgical techniques. Eighty-two consecutive heterotaxy patients who underwent the Fontan operation from 1985 to 2021 were compared to 150 patients with tricuspid atresia (TA) and 144 patients with hypoplastic left heart syndrome (HLHS). The Kaplan-Meier method and Cox proportional hazard model were used to analyze transplant-free survival and predictor of outcomes. The 20-year transplant-free survival rates were comparable between Right Atrial Isomerism (RAI, n = 45) and Left Atrial Isomerism (LAI, n = 37) (RAI vs LAI, 76% [95% confidence interval, 57-87%] vs 68% [47-82%], p = 0.22), although more pulmonary vein interventions at Fontan were needed in RAI. Surgical techniques included extracardiac conduit in 66%, intra-atrial conduit in 9%, lateral tunnel in 18% of the cases. Cardiac position and apicocaval juxtaposition did not influence outcomes, but the inferior vena cava (IVC)-contralateral PA Fontan was associated with 100% survival, while the IVC-ipsilateral PA Fontan at the cardiac apex showed a 67% [34-87%] survival rate at 20 years. In-hospital mortality was higher in heterotaxy (9.8% [5-19%]) compared to TA (1.3% [0.3-5.3%], p < 0.01) and HLHS (2.8% [1.1-7.3%], p = 0.02), with no early death after 2000 in any group. The 20-year transplant-free survival in heterotaxy (72% [59-82%]) was similar to that in HLHS (80% [69-87%], p = 0.11). Various routing techniques can be successfully applied to overcome anatomical challenges in heterotaxy. Despite higher in-hospital mortality, overall survival was similar to HLHS. RAI had comparable survival to LAI with more pulmonary vein interventions at Fontan.

The risk of failure of subcutaneous implantable cardioverter defibrillator therapy: from PRAETORIAN score to clinical practice.

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an alternative to traditional ICDs. The PRAETORIAN score, based on chest radiographs, has been validated to predict the probability of successful S-ICD defibrillation testing by assessing factors like fat thickness between the coil and sternum and generator placement. This study evaluated the correlation between the PRAETORIAN score and clinical characteristics, as well as implantation variables. We retrospectively analyzed data from 1253 patients who had undergone implantation of an S-ICD across 33 centers. The intermuscular positioning of the pulse generator was adopted in all patients. Post-implantation posterior-anterior and lateral chest radiographs were analyzed to calculate the PRAETORIAN score. 95.7% of patients had a PRAETORIAN score <90, indicative of a low risk of conversion failure. Body mass index (BMI) was the only independent predictor of a score ≥90, and all patients with BMI <25kg/m2 (normal weight or underweight) had a score <90. The intermuscular positioning technique resulted in optimal posterior placement of the device in all patients and significant sub-generator fat in only 3% of cases. A shock impedance value >88Ohm enabled to detect a PRAETORIAN score ≥90 with 98% (95% CI 97%-99%) negative predictive value. In contemporary practice, the PRAETORIAN score can be simplified. By adopting an intermuscular approach, two of the three steps of the score-evaluating the adequate posterior positioning of the generator and measuring the sub-generator fat-become superfluous, and impedance may serve as a reliable surrogate of sub-coil fat thickness. Furthermore, our data suggest that for non-obese patients, a favorable PRAETORIAN score is assured, making the score evaluation potentially unnecessary.

Efficacy and safety of conventional biplanar and triangulation method for sacroiliac screw placement in the treatment of unstable posterior pelvic ring fractures: A real-world retrospective cohort study.

The fixation method commonly employed worldwide for treating unstable fractures of the posterior pelvic ring is the percutaneous iliosacral screw technique. However, prolonged operation time and frequent fluoroscopies result in surgical risks. This study aimed to investigate whether a new triangulation method could reduce operative and fluoroscopy times and increase the accuracy of screw placement. This study is a real-world retrospective cohort analysis that examined a patient cohort who underwent percutaneous iliosacral screw fixation between January 1, 2019 and December 31, 2022. Inclusion criteria were patients (1) diagnosed with posterior pelvic ring instability who underwent pelvic fracture closed reduction and percutaneous S1 transverse-penetrating iliosacral screw placement and (2) aged >18 years. Exclusion criteria were: (1) combined proximal femoral fractures, (2) severe soft tissue injury in the surgical area, (3) incomplete imaging data, and (4) declining to provide written informed consent by the patient. The patients were divided into 2 groups according to the screw insertion method: conventional and triangulation methods. Screw placement and fluoroscopy times recorded by the C-arm were compared between the 2 methods. The accuracy of screw placement was evaluated by Smith grading on postoperative CT. Normality tests were conducted to assess the distribution of the quantitative variables and the Chi-square test was used to compare the qualitative variables. The study included a total of 94 patients diagnosed with posterior pelvic ring instability, who underwent percutaneous iliosacral screw placement. The patients were divided into 2 groups: 46 patients treated with the conventional surgical method and 48 patients received the triangulation method. The operation time (61.13±9.69 vs. 35.77±6.27) min and fluoroscopy frequency times (52.15±9.29 vs 24.40±4.04) of the triangulation method were significantly reduced (p<0.001). The use of a triangular positioning technique for the surface positioning of percutaneous iliosacral screws could reduce the operative time and fluoroscopy frequency. And screw placement accuracy using this new method was comparable to that using other conventional methods.

Multi-Global Navigation Satellite System for Earth Observation: Recent Developments and New Progress

The Global Navigation Satellite System (GNSS) has made important progress in Earth observation and applications. With the successful design of the BeiDou Navigation Satellite System (BDS), four global navigation satellite systems are available worldwide, together with Galileo, GLONASS, and GPS. These systems have been widely employed in positioning, navigation, and timing (PNT). Furthermore, GNSS refraction, reflection, and scattering signals can remotely sense the Earth’s surface and atmosphere with powerful implications for environmental remote sensing. In this paper, the recent developments and new application progress of multi-GNSS in Earth observation are presented and reviewed, including the methods of BDS/GNSS for Earth observations, GNSS navigation and positioning performance (e.g., GNSS-PPP and GNSS-NRTK), GNSS ionospheric modelling and space weather monitoring, GNSS meteorology, and GNSS-reflectometry and its applications. For instance, the static Precise Point Positioning (PPP) precision of most MGEX stations was improved by 35.1%, 18.7%, and 8.7% in the east, north, and upward directions, respectively, with PPP ambiguity resolution (AR) based on factor graph optimization. A two-layer ionospheric model was constructed using IGS station data through three-dimensional ionospheric model constraints and TEC accuracy was increased by about 20–27% with the GIM model. Ten-minute water level change with centimeter-level accuracy was estimated with ground-based multiple GNSS-R data based on a weighted iterative least-squares method. Furthermore, a cyclone and its positions were detected by utilizing the GNSS-reflectometry from the space-borne Cyclone GNSS (CYGNSS) mission. Over the years, GNSS has become a dominant technology among Earth observation with powerful applications, not only for conventional positioning, navigation and timing techniques, but also for integrated remote sensing solutions, such as monitoring typhoons, river water level changes, geological geohazard warnings, low-altitude UAV navigation, etc., due to its high performance, low cost, all time and all weather.

Efficacy of Myofascial Release Therapy and Positional Release Therapy in Patients with Upper Trapezius Trigger Points: Study Protocol of a Double-blinded Randomized Clinical Trial.

Myofascial trigger points are incredibly prevalent and are a painful aspect of almost everyone's life at some point. Myofascial trigger point pain can be excruciating and severely impair the quality of life. Therefore, in patients with neck pain caused by upper trapezius trigger, this current clinical trial will demonstrate the effectiveness of myofascial release therapy and positional release therapy in improving the level of pain, neck impairment, pain threshold, and standard of life. A double-blinded randomized clinical trial will be conducted. Fifty-two participants with active myofascial trigger points in the upper trapezius muscle will be recruited based on selection criteria. They will be randomly allocated into group A (conservative treatment + myofascial release technique) or group B (conservative treatment + positional release technique). Both groups will receive the intervention three times a week for 2 weeks. The study will use the Numeric Pain Rating Scale, pressure algometer, Neck Disability Index, and a 36-Item Short-form Questionnaire as outcome measures. This trial will help identify the effectiveness of the positional and myofascial release techniques in active upper trapezius muscle trigger points and their effect on physical parameters. This trial has been prospectively registered at the Clinical Trials Registry-India (CTRI/2023/07/055126) on 12 July 2023.

Clinical efficacy of proximal femoral nail anti-rotation in elderly patients with intertrochanteric fractures with negative medial cortical support: A comparison of lithotomy and scissor position techniques

Background Femoral intertrochanteric fractures are a prevalent type of hip fracture among the elderly population. And proximal femoral nail anti-rotation (PFNA) is the leading surgical technique for managing femoral intertrochanteric fractures in this patient population. Objective This study aimed to evaluate the clinical efficacy of proximal femoral nail anti-rotation (PFNA) in managing intertrochanteric fractures in elderly patients with negative medial cortical support. Additionally, the outcomes associated with two different nail positioning techniques were investigated. Methods Elderly patients with femoral intertrochanteric fractures with negative medial cortical support, treated between January 2017 and January 2021, were included. A retrospective analysis of their clinical data was conducted. Patients were categorized into two groups based on the positioning technique: lithotomy position group (n = 40) and scissor position group (n = 40). Baseline characteristics, perioperative indicators, hidden blood loss, and Harris hip scores were compared. Results The groups exhibited no significant differences in baseline characteristics, incision length, or postoperative tip-apex distance. The scissor position group experienced fewer fluoroscopies, shorter surgical durations, and lower Visual Analogue Scale (VAS) scores for the unaffected limb on postoperative day 1 compared to the lithotomy position group. No significant differences in hidden blood loss were observed between the groups. The Harris hip score for the unaffected side showed no significant differences between the scissor position group on postoperative day 1 and postoperative month 1. However, in the lithotomy position group, the Harris hip score of the unaffected side on postoperative day 1 was significantly lower than that at postoperative month 1. Additionally, the Harris hip score for the unaffected side on postoperative day 1 was substantially higher in the scissor position group compared to the lithotomy position group, although there were no significant differences between the two groups at postoperative month 1. Conclusion PFNA in the scissor position demonstrated advantages over the lithotomy position, including reduced fluoroscopy usage, shorter surgical duration, and less trauma to the unaffected limb. These findings indicate its effectiveness in managing intertrochanteric fractures in elderly patients with negative medial cortical support.

Effect of Mulligan’s Sustained Natural Apophyseal Glide and Positional Release Technique on Pain, Range of Motion and Headache Disability Among Subjects with Cervicogenic Headache.

INTRODUTION: Cervicogenic headaches are unilateral frontotemporal headaches with clinical symptoms similar to migraine. A significant issue for many patients with upper cervical dysfunction is cervicogenic headache, which presents significant challenges for physical therapy management. OBJECTIVES: To determine how well the positional release method and Mulligan’s SNAGs effect on headache disability, pain, and range of movement in cervicogenic headache patients. METHODOLOGY:A purposive sampling strategy was used in a quasi-experimental investigation. Individuals who met the selection criteria and had a clinical diagnosis of cervicogenic headache of were chosen and two groups were formed for cervicogenic headache. Group B received a home exercise program and positional release technique, while Group A received the Mulligan’s SNAG program. OUTCOME MEASURES: Pain, cervical rotation range of motion, headache disability index. RESULTS: A paired "t" test and an independent "t" test were used to evaluate the data at the 5% significance level. The pre- and post-test mean values indicate a decrease in headache severity. The post-test results showed a considerable variation for the outcome variables ofpain, range of motion, and headache impairment between the two groups; nevertheless, the group showed higher gains. CONCLUSION: According to this study, patients with cervicogenic headaches who took Mulligan’s C1-C2 sustained natural apophyseal showed improved pain relief, increased range of motion, and decreased headache disability.

Effect of Tui-Na versus positional release techniques on pregnancy-related low back pain in the third-trimester: A randomized comparative trial.

Researchers are prioritizing the development of an effective treatment approach for third-trimester pregnancy-related low back pain (LBP), a prevalent and costly disorder. Therefore, this study aimed to examine the effects of Tui-Na (TN) versus positional release techniques (PRT) on third trimester pregnancy-related LBP. Fifty pregnant women in their third trimester with low back pain were randomly assigned to 1 of 2 groups for 4 weeks of prescribed treatment (TN or PRT). The primary outcome was LBP intensity. Secondary outcomes included the Oswestry disability index for back disability and the pressure pain threshold of lumbar tender points. Two-way multivariate analysis of variance was used for the data analysis. Multivariate tests indicated statistically significant effects of group (F = 10.062, P < .001, partial η2 = 0.302), time (F = 473.5, P < .001, partial η2 = 0.953), and group-by-time interactions (F = 4.045, P < .001, partial η2 = 0.148). However, the TN group, when compared to the PRT group, revealed a significant decrease in back disability (P < .001, partial η2 = 0.124) and a significant increase in pressure pain threshold at the Rt and Lt points (P = .02 and .001, partial η2 = 0.055, and 0.108, respectively). Within-group comparisons were significant for all measured variables in both the groups (P < .001). Although both TN and PRT are beneficial treatments for third trimester pregnancy-related LBP, TN leads to more beneficial outcomes.

The influence of electrode array design, scalar dislocation and insertion technique on postoperative vertigo in CI surgery - a prospective study.

This study aimed to examine the effect of electrode array design, insertion angle, scalar position, and insertion technique on the occurrence of postoperative subjective vertigo following cochlear implant (CI) surgery using questionnaires in conjunction with objective vestibular functional measurements. We prospectively evaluated subjective vertigo using the Dizziness Handicap Inventory (DHI). Additionally, we performed videonystagmography, video head-impulse tests, and vestibular-evoked myogenic potentials to assess the objective vestibular function preoperatively, at four weeks and 12 months after CI. These results were compared with those of postoperative imaging using digital volume tomography. Postoperative vertigo was observed in 2 out of 62 patients (3%). Cochleostomy (n = 8) did not lead to an increase in postoperative vertigo. Functional diagnostics revealed abnormalities in up to 23% of patients without subjective dizziness. In our patient cohort, neither electrode array dislocation nor increasing insertion depth was associated with an increase in postoperative vertigo. Both postoperative vertigo occurrence and electrode array dislocation rates have significantly decreased due to the optimized atraumatic electrode array design and improved surgical insertion techniques. Neither dislocation nor cochleostomy appeared to induce vertigo but the sample size was too small to draw definitive conclusions.

The Effect of Fusarium Fungal Inoculation, Hole Position, and Induction Technique on Forming Agarwood in Gyrinops versteegii Tree

Gyrinops versteegii, belonging to the Themelaeaceae family, is one of the species producing high-grade agarwood. The induction technique can accelerate the agarwood product. This study inducted the G. versteegii tree with fungal species, a variation of hole position, and an induction technique. The research was done at a domesticated G. versteegii plantation in Sragen and Karanganyar District, Central Java Province. The research material was 18 agarwood trees aged 14 years. Initial inoculation was carried out at a depth of 50 cm from the ground, inoculation holes were made vertically every 50 cm. The distance between inoculation holes was 10 cm horizontally. The depth of the inoculation hole was 1/3 of the tree diameter. The agarwood quality resulted from the inoculated G. versteegii tree characterized by the wood aroma, the discoloration area, wood aroma, and terpenoid content, is significantly affected by the wood position in the stem, the fungal species, and the inoculation technique. The upper stem results in better agarwood than the bottom stem. Using the inoculant of the Fusarium oxysporum can achieve better agarwood than the inoculant of F. solani and mixed F. solani × F. oxysporum. Furthermore, the infusion technique gains a better agarwood result than others.

An Integrated Algorithm Fusing UWB Ranging Positioning and Visual–Inertial Information for Unmanned Vehicles

During the execution of autonomous tasks within sheltered space environments, unmanned vehicles demand highly precise and seamless continuous positioning capabilities. While the existing visual–inertial-based positioning methods can provide accurate poses over short distances, they are prone to error accumulation. Conversely, radio-based positioning techniques could offer absolute position information, yet they encountered difficulties in sheltered space scenarios. Usually, three or more base stations were required for localization. To address these issues, a binocular vision/inertia/ultra-wideband (UWB) combined positioning method based on factor graph optimization was proposed. This approach incorporated UWB ranging and positioning information into the visual–inertia system. Based on a sliding window, the joint nonlinear optimization of multi-source data, including IMU measurements, visual features, as well as UWB ranging and positioning information, was accomplished. Relying on visual inertial odometry, this methodology enabled autonomous positioning without the prerequisite for prior scene knowledge. When UWB base stations were available in the environment, their distance measurements or positioning information could be employed to institute global pose constraints in combination with visual–inertial odometry data. Through the joint optimization of UWB distance or positioning measurements and visual–inertial odometry data, the proposed method precisely ascertained the vehicle’s position and effectively mitigated accumulated errors. The experimental results indicated that the positioning error of the proposed method was reduced by 51.4% compared to the traditional method, thereby fulfilling the requirements for the precise autonomous navigation of unmanned vehicles in sheltered space.

Neural deflection field for sparse-view tomographic background oriented Schlieren

Three-dimensional (3D) density-varying turbulent flows are widely encountered in high-speed aerodynamics, combustion, and heterogeneous mixing processes. Multicamera-based tomographic background-oriented Schlieren (TBOS) has emerged as a powerful technique for revealing 3D flow density structures. However, dozens of cameras are typically required to obtain high-quality reconstructed density fields. Limited by the number of available optical windows and confined space in the harsh experimental environments, TBOS with only sparse views and limited viewing angles often becomes the necessary choice practically, rendering the inverse problem for TBOS reconstruction severely ill-posed and resulting in degraded tomography quality. In this study, we propose a novel TBOS reconstruction method, neural deflection field, utilizing an extremely light-weight deep neural networks to represent the density gradient fields without using any pretrained neural network models. Particularly, state-of-the-art positional encoding techniques and hierarchical sampling strategies are incorporated to capture the density structures of high spatial frequencies. Required background images for TBOS reconstructions are synthesized based on a high-fidelity nonlinear ray-tracing method with the ground truth flows from conducting large eddy simulations on premixed turbulent flames. Owing to these synthesized BOS images, the superiority of the proposed method is quantitatively verified compared to the classical TBOS reconstruction methods, and the specific contributions from the position encoding and the hierarchical sampling strategy are also elucidated.

Development of Advanced Positioning Techniques of UWB/Wi-Fi RTT Ranging for Personal Mobility Applications.

"Smart" devices, such as contemporary smartphones and PDAs (Personal Digital Assistance), play a significant role in our daily live, be it for navigation or location-based services (LBSs). In this paper, the use of Ultra-Wide Band (UWB) and Wireless Fidelity (Wi-Fi) based on RTT (Round-Trip Time) measurements is investigated for pedestrian user localization. For this purpose, several scenarios are designed either using real observation or simulated data. In addition, the localization of user groups within a neighborhood based on collaborative navigation (CP) is investigated and analyzed. An analysis of the performance of these techniques for ranging the positioning estimation using different fusion algorithms is assessed. The methodology applied for CP leverages the hybrid nature of the range measurements obtained by UWB and Wi-Fi RTT systems. The proposed approach stands out due to its originality in two main aspects: (1) it focuses on developing and evaluating suitable models for correcting range errors in RF-based TWR (Two-Way Ranging) technologies, and (2) it emphasizes the development of a robust CP engine for groups of pedestrians. The results obtained demonstrate that a performance improvement with respect to position trueness for UWB and Wi-Fi RTT cases of the order of 74% and 54%, respectively, is achieved due to the integration of these techniques. The proposed localization algorithm based on a P2I/P2P (Peer-to-Infrastructure/Peer-to-Peer) configuration provides a potential improvement in position trueness up to 10% for continuous anchor availability, i.e., UWB known nodes or Wi-Fi access points (APs). Its full potential is evident for short-duration events of complete anchor loss (P2P-only), where an improvement of up to 53% in position trueness is achieved. Overall, the performance metrics estimated based on the extensive evaluation campaigns demonstrate the effectiveness of the proposed methodologies.

ASSESSMENT OF KNOWLEDGE REGARDING KANGAROO MOTHER CARE AMONG NURSES OF A GENERAL HOSPITAL OF LAHORE

Kangaroo Mother Care (KMC) is a proven cost-effective intervention for managing preterm and low-birth-weight infants, particularly in resource-limited settings. Despite its benefits, KMC adoption remains inconsistent in Pakistan. Nurses play a pivotal role in its implementation, but their knowledge and attitudes toward KMC have not been extensively studied. Objective: To assess the knowledge, attitudes, and practices of nurses regarding KMC in a general hospital in Lahore. Methods: A cross-sectional study was conducted with 180 nurses using a structured questionnaire. The questionnaire assessed demographic characteristics, knowledge, attitudes, and practices related to KMC. Data were analyzed using SPSS version 25, employing descriptive and inferential statistics. Results: The study revealed moderate knowledge and confidence levels among nurses regarding KMC. While 43.9% of participants were confident in understanding the principles of KMC, only 41.2% were knowledgeable about proper positioning techniques. Confidence in educating caregivers was higher (48.3%), but only 37.3% strongly believed in KMC’s contribution to neonatal health. Perceived institutional support was deemed adequate by 45.6% of participants, while 37.8% were receptive to further training. Conclusion: Despite moderate awareness, significant gaps in technical knowledge and institutional support hinder the effective implementation of KMC. Targeted educational interventions and policy reforms are needed to enhance nurses' competencies and promote the adoption of KMC in healthcare settings in Pakistan.

Experimental assessment of IMU data processing techniques for a backpack mobile laser scanning system

Abstract. Positioning techniques are fundamental in many automation tasks with several applications. In GNSS-denied environments like in dense forests, other alternatives are required, such as inertial and visual navigation. However, Inertial Measurement Units (IMUs) data, mainly those from microelectromechanical-system (MEMS), are noisy, which affects the orientation estimation. MEMS IMUs have been employed in mobile laser scanning systems due to their compact design and low-cost solutions for short-term navigation. In this paper, we have compared three IMU processing techniques freely available: MAH (Mahony et al., 2009), MAD (Madgwick et al., 2011) and DCM (Hyyti and Visala, 2015). These techniques implemented different approaches to estimate the attitude. They were experimentally assessed with data from a backpack mobile laser scanning system, which is composed of an OS0-128 Ouster LiDAR equipped with an internal IMU. We have used data from a 5-second trajectory segment aiming to evaluate the attitude and position estimation for a local path. The results showed that the DCM algorithm maintained a consistent velocity for 5 seconds, achieving a positional error of 1.4 m, 0.06 m, and 1.05 m along the X-, Y- and Z-axis, respectively. In contrast, MAD and MAH showed a position error over 20 m, 7 m and 3 m along the X-, Y- and Z-axis, respectively, which was affected by the velocity drift.

GNSS reflectometry from low-cost sensors for continuous in situ contemporaneous glacier mass balance and flux divergence

Abstract Recent advances in remote sensing have produced global glacier surface elevation change data. Parsing these elevation change signals into contributions from the climate (i.e. climatic mass balance) and glacier dynamics (i.e. flux divergence) is critical to enhance our process-based understanding of glacier change. In this study, we evaluate three approaches for direct, continuous measurements of the climatic mass balance, flux divergence and elevation change at a site on Gulkana Glacier in Alaska using low-cost global navigation satellite system (GNSS) sensors, GNSS interferometric reflectometry (GNSS-IR), banded ablation stakes with time-lapse cameras and combinations thereof. Cumulative climatic mass balance over the season was 4.85 m and the three approaches were within 0.08 m through early July before the snowpack melted, and within 0.28 m through mid-August. The flux divergence increased from 0.52 ± 0.03 cm d−1 before June 3 to about 0.73 cm d−1 after June 27. We demonstrate a single GNSS system fixed atop an ablation stake can measure contemporaneous climatic mass balance, flux divergence and elevation change based on the antenna's position and GNSS-IR techniques. The ability of these systems to measure glacier mass balance and flux divergence offers unique opportunities for year-round observations on mountain glaciers in the future.

Optically steered time scale generation at OP and NPL and remote comparisons

AbstractIn this paper, we present real-time optically steered time scales generated simultaneously at the Observatoire de Paris (OP) and the National Physical Laboratory (NPL). Throughout one month, experimental UTCx(k) time scales were generated concurrently in the two laboratories alongside the local operational UTC(k) time scales. The UTCx(k) time scales were based on hydrogen masers whose frequencies were calibrated by local optical frequency standards using optical frequency combs, with algorithms being developed for outlier filtering and frequency steering estimations in the two laboratories. The performance of the experimental time scales was assessed through local comparisons against the corresponding UTC(k) time scales, and also through remote comparisons performed both via Coordinated Universal Time (UTC) and by using the GPS Precise Point Positioning (PPP) technique. The two optically steered time scales remained within 4 ns of each other, outperforming the corresponding UTC(k) over the same period. To our knowledge, this is the first reported comparison of two independent “optical time scale” prototypes, and the results demonstrate the capability of optical clocks to produce operational time scales.

Weld seam positioning method for structural reinforcement based on 3D point cloud

Abstract Machine vision technology assists welding robot weld positioning, which can significantly improve welding accuracy and efficiency. This paper delves into a 3D point cloud-based positioning technique specifically tailored for structural reinforcement welds, utilizing the high-precision 3D structured light camera to get 3D point cloud data from the surface of the reinforcement structures, subsequently conducting a comprehensive analysis of the weld’s geometric characteristics. When the weld seam position can be directly collected, the side plate plane and the bottom plate plane of the reinforcement can be divided by the random sample consensus method. The weld points with rich curvature characteristics can be quickly and reliably selected according to the plane constraint. When the weld position cannot be measured directly, the prediction of the weld position is realized by extracting the edge of the upper surface of the reinforcing rib in the depth map and combining the plane normal vector of the base plate and the point laser correction vector. The experimental results show that this method can accurately locate the weld seam with high accuracy in both working scenarios.

Revelation of muscle energy technique and positional release technique in mitigating low back pain, disability, and hyperlordosis in patients with low back pain: A comprehensive review

Background. Low back pain, often known as LBP, is a complicated ailment that has many associated risks, including those related to age, gender, lifestyle, social and psychological background, physical demands of work, social support, pain perception, and much more. Its frequency steadily rises with age and is typically nonspecific or mechanical in nature, with axially abnormal loading that might cause ache in the lower lumbar region. Strain-counter strain (SCS) or positional release technique (PRT) and muscle energy technique (MET) are identified as eligible management for LBP; however, in which way both techniques help to control LBP is to be evaluated. Objectives. To discuss the potential role of MET and PRT in reducing LBP and to find the space between previous and current practice of MET and PRT in correcting the lordosis angle in the lumbar region and disability in LBP patients. Methods. English-language articles were searched online, using the PEDro, PubMed, and Google Scholar databases. Keywords were MET, PRT, LBP, and lumbar lordosis. The articles were published from 2001 to 2022, of which 100 were found to be relevant and 20 to meet the inclusion criteria. They included LBP-related articles with MET and PRT techniques of management, excluding those not related to lumbar lordosis or to those two techniques. Conclusion. Based on the 20 articles reviewed, it was concluded that MET and PRT played a significant role in decreasing participants’ LBP pain, lordosis angle, and functional impairment.

Eye Mapping: Innovative Technique for Precise Iris Positioning in Prosthetic Eye.

The aim of this technique is to institute "Augmented Reality Tool" in the field of maxillofacial prosthesis for an accurate and precise iris positioning in a prosthetic eye. A congenital defect, irreversible damage, a painful blind eye, sympathetic ophthalmia, or the requirement for histological confirmation of a suspected illness can all result in the absence or loss of an eye. In such circumstances, meticulous preoperative, surgical, and prosthetic planning using a multidisciplinary approach is imperative for successful rehabilitation. Augmented reality filter was used to provide precise mapping of facial landmarks and to aid in iris positioning. Smartphone device (S22) was used and artificial intelligence (AI)-generated Instagram application was unfurled and augmented reality (AR) filter was instituted. The filter available in the application made it possible to see and confirm the iris shell's location in three dimensions from various angles. The dimensions thus provided, aided in the correct positioning of the iris in the prosthetic eye. Iris positioning stands as one of the crucial steps in fabricating a patient-specific ocular prosthesis. In the present case report, iris positioning was done using AI has provided an excellent esthetics results and patient compliance was met with satisfaction. Accurate positioning of iris can be done using AR tool which is popular, easily accessible, less technique sensitive, and can be performed with slightest efforts in small clinical set-ups. Relating to patient, it is comfortable, economic, and trouble-free procedure. How to cite this article: Zilpilwar NR, Nimonkar SV, Chitlange P, et al. Eye Mapping: Innovative Technique for Precise Iris Positioning in Prosthetic Eye. J Contemp Dent Pract 2024;25(7):711-714.