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Application of computer-assisted navigation in treating congenital maxillomandibular syngnathia:A case report
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作者 Li-Qin Lin Shan-Shan Bai Min Wei 《World Journal of Clinical Cases》 SCIE 2019年第5期650-655,共6页
BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing... BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing, and breathing as well as temporomandibular joint ankylosis. The main goal of the surgery is to release the ankylosis, establish functioning mandible, and prevent re-fusion.However, surgical procedures for this disease are rarely reported.CASE SUMMARY Here, we report a 7-mo-old girl with bilateral maxillomandibular syngnathia. The patient presented with difficulty in feeding, breathing, sounding, and swallowing and had developmental dysplasia. For treatment, we performed bone isolation by computer-assisted navigation and used silicone to fix the wound surface to prevent refusion of bone. To our knowledge, this is the only syngnathia case in the literature treated using computer-assisted navigation. With the guidance of precise navigation, we were able to minimize operation time by at least one hour,the patient's blood vessels, nerves, and tooth germs were well protected, and excessive bleeding was avoided. After six weeks, the patient showed improvement in mouth opening and no major issues of feeding.CONCLUSION Application of computer-assisted navigation can significantly improve accuracy,effectiveness, and surgical safety in correcting congenital maxillomandibular syngnathia. 展开更多
关键词 CRANIOFACIAL ABNORMALITIES MANDIBULAR diseases MAXILLA computer-assisted navigation Case report
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Lumbar spine superior-level facet joint violations: percutaneous versus open pedicle screw insertion using intraoperative 3-dimensional computer-assisted navigation 被引量:12
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作者 Tian Wei Xu Yunfeng +7 位作者 Liu Bo Liu Yajun He Da Yuan Qiang Lang Zhao Lyu Yanwei Han Xiaoguang Jin Peihao 《Chinese Medical Journal》 SCIE CAS CSCD 2014年第22期3852-3856,共5页
Background Percutaneous pedicle screw use has a high rate of cranial facet joint violations (FVs) because of the facet joint being indirectly visualized.Computer-assisted navigation shows the anatomic structures cle... Background Percutaneous pedicle screw use has a high rate of cranial facet joint violations (FVs) because of the facet joint being indirectly visualized.Computer-assisted navigation shows the anatomic structures clearly,and may help to lower the rate of FVs during pedicle screw insertion.This study used computed tomography (CT) to evaluate and compare the incidence of FVs between percutaneous and open surgeries employing computer-assisted navigation for the implantation of pedicle screw instrumentation during lumbar fusions.Methods A prospective study,including 142 patients having lumbar and lumbosacral fusion,was conducted between January 2013 and April 2014.All patients had bilateral posterior pedicle screw-rod instrumentation (top-loading screws) implanted by the same group of surgeons; intraoperative 3-dimensional computer navigation was used during the procedures.All patients underwent CT examinations within 6 months postoperation.The CT scans were independently reviewed by three reviewers blinded to the technique used.Results The cohort comprised 68 percutaneous and 74 open cases (136 and 148 superior-level pedicle screw placements,respectively).Overall,superior-level FVs occurred in 20 patients (20/142,14.1%),involving 27 top screws (27/284,9.5%).The percutaneous technique (7.4% of patients,3.7% of top screws) had a significantly lower violation rate than the open procedure (20.3% of patients,14.9% of top screws).The open group also had significantly more serious violations than did the percutaneous group.Both groups had a higher violation rate when the cranial fixation involved the L5.A 1-level open procedure had a higher violation rate than did the 2-and 3-level surgeries.Conclusions With computer-assisted navigation,the placement of top-loading percutaneous screws carries a lower risk of adjacent-FVs than does the open technique; when FVs occur,they tend to be less serious.Performing a single-level open lumbar fusion,or the fusion of the L5-S1 segment,requires caution to avoid cranial adjacent FVs. 展开更多
关键词 facet joint pedicle screw PERCUTANEOUS computer-assisted navigation lumbar spine
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Computer-assisted navigation systems for insertion of cannulated screws in femoral neck fractures: a comparison of bi-planar robot navigation with optoelectronic navigation in a Synbone hip model trial 被引量:17
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作者 WANG Jun-qiang ZHAO Chun-peng SU Yong-gang ZHOU Li HU Lei WANG Tian-miao WANG Man-yi 《Chinese Medical Journal》 SCIE CAS CSCD 2011年第23期3906-3911,共6页
Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement. Currently there is little information available regarding accuracy and efficiency of the different navigated proce... Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement. Currently there is little information available regarding accuracy and efficiency of the different navigated procedures. The aim of this study was to compare two fluoroscopic navigation tracking technologies, a novel bi-planar robot navigation and standardized optoelectronic navigation, versus standard freehand fluoroscopic insertion in a Synbone hip model. Methods Eighteen fixed Synbone hip models were divided into 3 groups. C-arm navigated cannulated screws (AO-ASIF, diameter 7.3 mm) were inserted using freehand targeting (control group). A novel bi-planar robot system (TINAV, GD2000) and an optoelectronic system (Stryker OTS Navigation System) were used for the navigated procedures (robot group and optoelectronic group). Accuracy was measured using radiographic evaluation including the measurement of screw parallelism and decentralization, and joint penetration. To evaluate the efficiency, the number of guidewire passes, operative time and fluoroscopic images taken were noted. Results The two computer-assisted systems provided significantly improved accuracy compared to the freehand technique. Each of the parameters, including guidewire passes and number of fluoroscopy images, was significantly lower when using the computer-assisted systems than for freehand-unguided insertion (P 〈0.05), but operative time was significantly shorter when using freehand-unguided insertion than for the computer-assisted systems (P 〈0.05). Accuracy, operative time and number of fluoroscopy images taken were similar among the two navigated groups (P 〉0.05), but guidewire passes in the robot group were significantly less than in the optoelectronic group (P 〈0.05). Conclusions Both bi-planar robot navigation and optoelectronic navigation were similarly accurate and have the potential to improve accuracy and reduce radiation for freehand fluoroscopic targeting for insertion of cannulated screws in femoral neck fractures. Guidewire passes in the robot group were significantly less than in the optoelectronic group. However, both navigated procedures were associated with time-consuming registration and hi.qh rates of failed matching procedures. 展开更多
关键词 femoral neck computer-assisted navigation screw fixation
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Learning curve of computer-assisted navigation system in spine surgery 被引量:8
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作者 BAI Yu-shu ZHANG Ye +5 位作者 CHEN Zi-qiang WANG Chuan-feng ZHAO Ying-chuan SHI Zhi-cai LI Ming LIU Ka Po Gabriel 《Chinese Medical Journal》 SCIE CAS CSCD 2010年第21期2989-2994,共6页
Background Spine surgery using computer-assisted navigation (CAN) has been proven to result in low screw misplacement rates, low incidence of radiation exposure and excellent operative field viewing versus the conve... Background Spine surgery using computer-assisted navigation (CAN) has been proven to result in low screw misplacement rates, low incidence of radiation exposure and excellent operative field viewing versus the conventional intraoperative image intensifier (CⅢ). However, as we know, few previous studies have described the learning curve of CAN in spine surgery.Methods We performed two consecutive case cohort studies on pedicel screw accuracy and operative time of two spine surgeons with different experience backgrounds, A and B, in one institution during the same period. Lumbar pedicel screw cortical perforation rate and operative time of the same kind of operation using CAN were analyzed and compared using CⅢ for the two surgeons at initial, 6 months and 12 months of CAN usage.Results CAN spine surgery had an overall lower cortical perforation rate and less mean operative time compared with CⅢ for both surgeon A and B cohorts when total cases of four years were included. It missed being statistically significant,with 3.3% versus 4.7% (P=0.191) and 125.7 versus 132.3 minutes (P=0.428) for surgeon A and 3.6% versus 6.4%(P=0.058), and 183.2 versus 213.2 minutes (P=0.070) for surgeon B. in an attempt to demonstrate the learning curve,the cases after 6 months of the CAN system in each surgeon's cohort were compared. The perforation rate decreased by 2.4% (P=0.039) and 4.3% (P=0.003) and the operative time was reduced by 31.8 minutes (P=0.002) and 14.4 minutes (P=0.026) for the CAN groups of surgeons A and B, respectively. When only the cases performed after 12 months using the CAN system were considered, the perforation rate decreased by 3.9% (P=0.006) and 5.6% (P 〈0.001) and the operative time was reduced by 20.9 minutes (P 〈0.001) and 40.3 minutes (P 〈0.001) for the CAN groups of surgeon A and B, respectively.Conclusions In the long run, CAN spine surgery decreased the lumbar screw cortical perforation rate and operative time. The learning curve showed a sharp drop after 6 months of using CAN that plateaued after 12 months; which was demonstrated by both perforation rate and operative time data. Careful analysis of the data showed CAN is especially useful for less experienced surgeon to reduce perforation rate and intraoperative time, although further comparative studies are anticipated. 展开更多
关键词 computer-assisted navigation learning curve degenerative scoliosis spine surgery
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Pedicle screw placement in the thoracic spine: a randomized comparison study of computer-assisted navigation and conventional techniques 被引量:17
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作者 武汉 高中礼 +3 位作者 王金成 李英普 夏鹏 姜睿 《Chinese Journal of Traumatology》 CAS 2010年第4期201-205,共5页
Objective: To evaluate the accuracy of computer-assisted pedicle screw installation and its clinical benefit as compared with conventional pedicle screw installation techniques. Methods: Total 176 thoracic pedicle s... Objective: To evaluate the accuracy of computer-assisted pedicle screw installation and its clinical benefit as compared with conventional pedicle screw installation techniques. Methods: Total 176 thoracic pedicle screws placed in 42 thoracic fracture patients were involved in the study randomly, 20 patients under conventional fluoroscopic control (84 screws) and 22 patients had screw insertion under three dimensional (3D) computer-assisted navigation (92 screws). The 2 groups were compared for accuracy of screw placement, time for screw insertion by postoperative thincut CT scans and statistical analysis by χ^2 test. The cortical perforations were then graded by 2-mm increments: Grade Ⅰ (good, no cortical perforation), Grade Ⅱ (screw outside the pedicle 〈2 mm), Grade Ⅲ (screw outside the pedicle 〉2 mm). Results: In computer assisted group, 88 (95.65%) were Grade Ⅰ (good), 4 (4.35%) were Grade Ⅱ (〈2mm), no Grade Ⅲ (〉2 mm) violations. In conventional group, there were 14 cortical violations (16.67%), 70 (83.33%) were Grade Ⅰ (good), Ⅱ (13.1%) were Grade Ⅱ (〈2 mm), and 3 (3,57%) were Grade Ⅲ (〉2 mm) violations (P〈0.001). The number (19.57%) of upper thoracic pedicle screws ( T1-T4 ) inserted under 3D computer-assisted navigation was significantly higher than that (3.57%) by conventional fluoroscopic control (P〈0.001). Average screw insertion time in conventional group was (4.56 ±1.03) min and (2.54 ± 0.63) min in computer assisted group (P〈0.001). In the conventional group, one patient had pleura injury and one had a minor dura violation. Conclusions: This study provides further evidence that 3D computer-assisted navigation placement ofpedicle screws can increase accuracy, reduce surgical time, and be performed safely and effectively at all levels of the thoracic spine, particularly upper thoracic spine. 展开更多
关键词 Surgery computer-assisted Bone screws Spinal fractures
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Clinical application of improved 2D computer-assisted fluoroscopic navigation through simulating a 3D vertebrae image to guide pedicle screw internal fixation
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作者 刘恩志 《外科研究与新技术》 2011年第2期94-94,共1页
Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixa... Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixation,distraction 展开更多
关键词 Clinical application of improved 2D computer-assisted fluoroscopic navigation through simulating a 3D vertebrae image to guide pedicle screw internal fixation
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基于Navigation的移动应用屏幕导航设计方法
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作者 李维勇 嵇雪 《三门峡职业技术学院学报》 2025年第4期133-138,共6页
移动应用的导航设计是提升用户体验的重要因素之一。随着Android平台Navigation组件的引入,导航设计变得更加方便和高效。介绍了基于Navigation的移动应用屏幕导航设计方法,包括Navigation组件的基础使用、高级特性和UI/UX设计中的应用... 移动应用的导航设计是提升用户体验的重要因素之一。随着Android平台Navigation组件的引入,导航设计变得更加方便和高效。介绍了基于Navigation的移动应用屏幕导航设计方法,包括Navigation组件的基础使用、高级特性和UI/UX设计中的应用原则。在设计流程中,将用户需求、应用场景和平台标准作为设计依据,使用Sketch、Adobe XD等工具完成原型设计,再通过用户测试和迭代完善设计。 展开更多
关键词 navigation组件 移动应用 屏幕导航设计 UI/UX设计 设计流程
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Research on Offensive-Defensive Technology System and Key Technologies of Navigation Warfare 被引量:1
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作者 WANG Jian FU Jing +2 位作者 LONG Ke CHANG Xinuo LIU Jiaxing 《Aerospace China》 2025年第1期9-13,共5页
As the core information infrastructure of modern information warfare,the offensive and defensive confrontations of satellite navigation systems have given rise to navigation warfare,which focuses on seizing control of... As the core information infrastructure of modern information warfare,the offensive and defensive confrontations of satellite navigation systems have given rise to navigation warfare,which focuses on seizing control of navigation resources.Based on the space segment,control segment,and user segment of satellite navigation systems,this paper systematically constructs an offensive-defensive technology system for navigation warfare,and deeply analyzes core measures such as signal enhancement and suppression,autonomous navigation and link jamming,anti-jamming reception,and integrated navigation.It extracts key technologies including adaptive nulling antennas,joint filtering,and multi-dimensional combined jamming,and discusses the technical effectiveness of these technologies by incorporating relevant cases.The advantages of navigation warfare stem from multi-segment coordination and technological inte-gration.In the future,the development directions of navigation warfare will focus on three aspects:enhancing satellite capabilities,tackling core technical challenges,and building a multi-dimensional system. 展开更多
关键词 navigation warfare satellite navigation offensive-defensive technology ANTI-JAMMING integrated navigation
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Development and Application of the Portable Electromagnetic Navigation for Neurosurgery 被引量:1
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作者 Sheng-kun Lang Zhi-chao Gan +5 位作者 Qun Wang Xing-hua Xu Fang-ye Li Jia-shu Zhang Cai Meng Xiao-lei Chen 《Current Medical Science》 2025年第3期562-573,共12页
Background and Objective Electromagnetic navigation technology has demonstrated significant potential in enhancing the accuracy and safety of neurosurgical procedures.However,traditional electromagnetic navigation sys... Background and Objective Electromagnetic navigation technology has demonstrated significant potential in enhancing the accuracy and safety of neurosurgical procedures.However,traditional electromagnetic navigation systems face challenges such as high equipment costs,complex operation,bulky size,and insufficient anti-interference performance.To address these limitations,our study developed and validated a novel portable electromagnetic neuronavigation system designed to improve the precision,accessibility,and clinical applicability of electromagnetic navigation technology in cranial surgery.Methods The software and hardware architecture of a portable neural magnetic navigation system was designed.The key technologies of the system were analysed,including electromagnetic positioning algorithms,miniaturized sensor design,optimization of electromagnetic positioning and navigation algorithms,anti-interference signal processing methods,and fast three-dimensional reconstruction algorithms.A prototype was developed,and its accuracy was tested.Finally,a preliminary clinical application evaluation was conducted.Results This study successfully developed a comprehensive portable electromagnetic neuronavigation system capable of achieving preoperative planning,intraoperative real-time positioning and navigation,and postoperative evaluation of navigation outcomes.Through rigorous collaborative testing of the system’s software and hardware,the accuracy of electromagnetic neuronavigation has been validated to meet clinical requirements.Conclusions This study developed a portable neuroelectromagnetic navigation system and validated its effectiveness and safety through rigorous model testing and preliminary clinical applications.The system is characterized by its compact size,high precision,excellent portability,and user-friendly operation,making it highly valuable for promoting navigation technology and advancing the precision and minimally invasive nature of neurosurgical procedures. 展开更多
关键词 Electromagnetic navigation PORTABLE Cranial surgery
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Improving the Position Accuracy and Computational Efficiency of UAV Terrain Aided Navigation Using a Two-Stage Hybrid Fuzzy Particle Filtering Method
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作者 Sofia Yousuf Muhammad Bilal Kadri 《Computers, Materials & Continua》 SCIE EI 2025年第1期1193-1210,共18页
Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively r... Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively researched for both aerial and underwater navigation applications.However,many TAN systems that rely on recursive Unmanned Aerial Vehicle(UAV)position estimation methods,such as Extended Kalman Filters(EKF),often face challenges with divergence and instability,particularly in highly non-linear systems.To address these issues,this paper proposes and investigates a hybrid two-stage TAN positioning system for UAVs that utilizes Particle Filter.To enhance the system’s robustness against uncertainties caused by noise and to estimate additional system states,a Fuzzy Particle Filter(FPF)is employed in the first stage.This approach introduces a novel terrain composite feature that enables a fuzzy expert system to analyze terrain non-linearities and dynamically adjust the number of particles in real-time.This design allows the UAV to be efficiently localized in GPS-denied environments while also reducing the computational complexity of the particle filter in real-time applications.In the second stage,an Error State Kalman Filter(ESKF)is implemented to estimate the UAV’s altitude.The ESKF is chosen over the conventional EKF method because it is more suitable for non-linear systems.Simulation results demonstrate that the proposed fuzzy-based terrain composite method achieves high positional accuracy while reducing computational time and memory usage. 展开更多
关键词 Sensor fusion fuzzy logic particle filter composite feature terrain aided navigation
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Alignment-optimised coaxial visible-NIR-II dual-channel surgical navigation system and its clinical application in blood-supply assessment
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作者 ZHANG Yu-Huang LIU Xiao-Long +3 位作者 SUN Si-Ying FAN Xiao-Xiao LIN Hui QIAN Jun 《红外与毫米波学报》 北大核心 2025年第5期663-670,共8页
Fluorescence imaging in the second near-infrared window(NIR-II,900-1880 nm)offers high signalto-background ratio(SBR),enhanced definition,and superior tissue penetration,making it ideal for real-time surgical navigati... Fluorescence imaging in the second near-infrared window(NIR-II,900-1880 nm)offers high signalto-background ratio(SBR),enhanced definition,and superior tissue penetration,making it ideal for real-time surgical navigation.However,with single-channel imaging,surgeons must frequently switch between the surgi⁃cal field and the NIR-II images on the monitor.To address this,a coaxial dual-channel imaging system that com⁃bines visible light and 1100 nm longpass(1100LP)fluorescence was developed.The system features a custom⁃ized coaxial dual-channel lens with optimized distortion,achieving precise alignment with an error of less than±0.15 mm.Additionally,the shared focusing mechanism simplifies operation.Using FDA-approved indocya⁃nine green(ICG),the system was successfully applied in dual-channel guided rat lymph node excision,and blood supply assessment of reconstructed human flap.This approach enhances surgical precision,improves opera⁃tional efficiency,and provides a valuable reference for further clinical translation of NIR-II fluorescence imaging. 展开更多
关键词 NIR-II DUAL-CHANNEL fluorescence imaging surgical navigation COAXIAL
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Prediction Method of Polar Navigation Window Period Based on Risk Evaluation
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作者 JIANG Jia−qi SHI Gui−jie WANG De−yu 《船舶力学》 北大核心 2025年第6期986-999,共14页
With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation wind... With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction. 展开更多
关键词 window period risk evaluation polar navigation risk index
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A Review on Modeling Environmental Loading Effects and Their Contributions to Nonlinear Variations of Global Navigation Satellite System Coordinate Time Series 被引量:1
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作者 Zhao Li Weiping Jiang +3 位作者 Tonie van Dam Xiaowei Zou Qusen Chen Hua Chen 《Engineering》 2025年第4期26-37,共12页
Nonlinear variations in the coordinate time series of global navigation satellite system(GNSS) reference stations are strongly correlated with surface displacements caused by environmental loading effects,including at... Nonlinear variations in the coordinate time series of global navigation satellite system(GNSS) reference stations are strongly correlated with surface displacements caused by environmental loading effects,including atmospheric, hydrological, and nontidal ocean loading. Continuous improvements in the accuracy of surface mass loading products, performance of Earth models, and precise data-processing technologies have significantly advanced research on the effects of environmental loading on nonlinear variations in GNSS coordinate time series. However, owing to theoretical limitations, the lack of high spatiotemporal resolution surface mass observations, and the coupling of GNSS technology-related systematic errors, environmental loading and nonlinear GNSS reference station displacements remain inconsistent. The applicability and capability of these loading products across different regions also require further evaluation. This paper outlines methods for modeling environmental loading, surface mass loading products, and service organizations. In addition, it summarizes recent advances in applying environmental loading to address nonlinear variations in global and regional GNSS coordinate time series. Moreover, the scientific questions of existing studies are summarized, and insights into future research directions are provided. The complex nonlinear motion of reference stations is a major factor limiting the accuracy of the current terrestrial reference frame. Further refining the environmental load modeling method, establishing a surface mass distribution model with high spatiotemporal resolution and reliability, exploring other environmental load factors such as ice sheet and artificial mass-change effects, and developing an optimal data-processing model and strategy for reprocessing global reference station data consistently could contribute to the development of a millimeter-level nonlinear motion model for GNSS reference stations with actual physical significance and provide theoretical support for establishing a terrestrial reference frame with 1 mm accuracy by 2050. 展开更多
关键词 Environmental loading Global navigation satellite system Nonlinear variations Time series analysis Surface mass distribution Green’s function Spherical harmonic function
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Comment on autonomous celestial navigation technology for spacecraft
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作者 Haonan YANG Xiaolin NING 《Chinese Journal of Aeronautics》 2025年第7期288-290,共3页
1. Introduction Celestial navigation is a kind of navigation with a long history.With the increasing demand for intelligent autonomy and antielectromagnetic interference in spacecraft, celestial navigation has become ... 1. Introduction Celestial navigation is a kind of navigation with a long history.With the increasing demand for intelligent autonomy and antielectromagnetic interference in spacecraft, celestial navigation has become one of the current research hotspots in spacecraft autonomous navigation. Spacecraft face complex electromagnetic interference in orbit. The time-varying, non-Gaussian interference from internal devices and external environment can lead to measurement distortion. 展开更多
关键词 celestial navigation spacecraft autonomous navigation autonomous navigation electromagnetic interference measurement distortion intelligent autonomy SPACECRAFT antielectromagnetic interference
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Multi-type feature fusion visual navigation for asteroid landing
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作者 Wenbo XIU Shengying ZHU Yanjie LIU 《Chinese Journal of Aeronautics》 2025年第7期529-544,共16页
In order to address the challenges encountered in visual navigation for asteroid landing using traditional point features,such as significant recognition and extraction errors,low computational efficiency,and limited ... In order to address the challenges encountered in visual navigation for asteroid landing using traditional point features,such as significant recognition and extraction errors,low computational efficiency,and limited navigation accuracy,a novel approach for multi-type fusion visual navigation is proposed.This method aims to overcome the limitations of single-type features and enhance navigation accuracy.Analytical criteria for selecting multi-type features are introduced,which simultaneously improve computational efficiency and system navigation accuracy.Concerning pose estimation,both absolute and relative pose estimation methods based on multi-type feature fusion are proposed,and multi-type feature normalization is established,which significantly improves system navigation accuracy and lays the groundwork for flexible application of joint absolute-relative estimation.The feasibility and effectiveness of the proposed method are validated through simulation experiments through 4769 Castalia. 展开更多
关键词 Pose estimation Multi-type feature fusion Feature selection Landmark selection NORMALIZATION Absolute navigation Relative navigation Visual navigation
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Design and Ground Verification for Vision-Based Relative Navigation Systems of Microsatellites
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作者 DU Ronghua LIAO Wenhe ZHANG Xiang 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第1期37-55,共19页
This paper presents the design and ground verification for vision-based relative navigation systems of microsatellites,which offers a comprehensive hardware design solution and a robust experimental verification metho... This paper presents the design and ground verification for vision-based relative navigation systems of microsatellites,which offers a comprehensive hardware design solution and a robust experimental verification methodology for practical implementation of vision-based navigation technology on the microsatellite platform.Firstly,a low power consumption,light weight,and high performance vision-based relative navigation optical sensor is designed.Subsequently,a set of ground verification system is designed for the hardware-in-the-loop testing of the vision-based relative navigation systems.Finally,the designed vision-based relative navigation optical sensor and the proposed angles-only navigation algorithms are tested on the ground verification system.The results verify that the optical simulator after geometrical calibration can meet the requirements of the hardware-in-the-loop testing of vision-based relative navigation systems.Based on experimental results,the relative position accuracy of the angles-only navigation filter at terminal time is increased by 25.5%,and the relative speed accuracy is increased by 31.3% compared with those of optical simulator before geometrical calibration. 展开更多
关键词 microsatellites vision-based relative navigation optical simulator ground verification angles-only navigation
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Diagnostic value of artificial intelligence computer-assisted diagnosis (computer assisted-diagnosis eye function) for colorectal polyps
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作者 Hendra Asputra Hasan Maulahela +4 位作者 Achmad Fauzi Cleopas M Rumende Amanda Pitarini Nina Kemala Sari Hamzah Shatri 《Artificial Intelligence in Gastroenterology》 2025年第3期1-9,共9页
BACKGROUND The gold standard for colorectal polyp screening is currently colonoscopy,but the miss rate is still high and the adenoma detection rate and polyp detection rate are still low.The risk factors include the p... BACKGROUND The gold standard for colorectal polyp screening is currently colonoscopy,but the miss rate is still high and the adenoma detection rate and polyp detection rate are still low.The risk factors include the patient,operators,and the tools used.The use of artificial intelligence(AI)in colonoscopy has gained popularity by assisting endoscopists in the detection and characterization of polyps.AIM To evaluate the diagnostic performance of AI-assisted colonoscopy[computer assisted diagnosis(CAD)eye function]for colorectal polyp characterization.METHODS This study used a cross-sectional design conducted at the Gastrointestinal Endoscopy Center of Dr.Cipto Mangunkusumo Hospital in January-May 2024 on adult patients with suspected colorectal polyps.RESULTS A total of 60 patients with 100 polyps were involved in this study.Based on the results of the examination,it was found that the AI CAD eye function examination had a sensitivity of 79.17%,specificity of 75.00%,positive predictive value(PPV)of 89.06%,negative predictive value(NPV)of 58.33%,and accuracy of 78.00%.In polyps with diminutive size,sensitivity was 86.27%,specificity was 60.00%,PPV was 95.65%,NPV was 30.00%,and accuracy was 83.93%.Meanwhile,in polyps with non-diminutive size,sensitivity was 61.90%,specificity was 78.26%,PPV was 72.22%,NPV was 69.23%,and accuracy was 70.45%.In polyps on the left side of the colon,sensitivity was 78.85%,specificity was 81.25%,PPV was 93.18%,NPV was 54.17%,and accuracy was 79.41%.Meanwhile,in rightsided polyps the sensitivity was 80.00%,specificity was 66.67%,PPV was 80.00%,NPV was 66.67%,and accuracy was 75.00%.In sessile polyps the sensitivity was 81.54%,specificity was 50.00%,PPV was 91.38%,NPV was 29.41%,and accuracy was 77.33%.Meanwhile,in non-sessile polyps,the sensitivity was 57.14%,specificity was 88.89%,PPV was 66.67%,NPV was 84.21%,and accuracy was 80.00%.CONCLUSION AI CAD eye function examination had a high sensitivity value in diminutive,sessile polyps and right-sided polyps and a high specificity in non-diminutive,non-sessile polyps and left-sided polyps. 展开更多
关键词 Artificial intelligence computer-assisted diagnosis eye function Colorectal polyps Inflammatory bowel disease Artificial intelligence assisted
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Enhanced deep reinforcement learning for integrated navigation in multi-UAV systems
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作者 Zhengyang CAO Gang CHEN 《Chinese Journal of Aeronautics》 2025年第8期119-138,共20页
In multiple Unmanned Aerial Vehicles(UAV)systems,achieving efficient navigation is essential for executing complex tasks and enhancing autonomy.Traditional navigation methods depend on predefined control strategies an... In multiple Unmanned Aerial Vehicles(UAV)systems,achieving efficient navigation is essential for executing complex tasks and enhancing autonomy.Traditional navigation methods depend on predefined control strategies and trajectory planning and often perform poorly in complex environments.To improve the UAV-environment interaction efficiency,this study proposes a multi-UAV integrated navigation algorithm based on Deep Reinforcement Learning(DRL).This algorithm integrates the Inertial Navigation System(INS),Global Navigation Satellite System(GNSS),and Visual Navigation System(VNS)for comprehensive information fusion.Specifically,an improved multi-UAV integrated navigation algorithm called Information Fusion with MultiAgent Deep Deterministic Policy Gradient(IF-MADDPG)was developed.This algorithm enables UAVs to learn collaboratively and optimize their flight trajectories in real time.Through simulations and experiments,test scenarios in GNSS-denied environments were constructed to evaluate the effectiveness of the algorithm.The experimental results demonstrate that the IF-MADDPG algorithm significantly enhances the collaborative navigation capabilities of multiple UAVs in formation maintenance and GNSS-denied environments.Additionally,it has advantages in terms of mission completion time.This study provides a novel approach for efficient collaboration in multi-UAV systems,which significantly improves the robustness and adaptability of navigation systems. 展开更多
关键词 Multi-UAV system Reinforcement learning Integrated navigation MADDPG Information fusion
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Clinical Application of Imaging Navigation Technology in the Treatment of Pulmonary Tuberculosis
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作者 Yanju Su Peng Wang +3 位作者 Hui Jiang Dianhai Zhong Qiuye Ma Mingjun Huang 《Journal of Clinical and Nursing Research》 2025年第4期370-376,共7页
Objective:To observe the guiding role of image navigation technology in the treatment of patients with tuberculosis.Methods:A total of 188 patients with multidrug-resistant tuberculosis(MDR-TB)and rifampin-resistant t... Objective:To observe the guiding role of image navigation technology in the treatment of patients with tuberculosis.Methods:A total of 188 patients with multidrug-resistant tuberculosis(MDR-TB)and rifampin-resistant tuberculosis(RR-TB)who were hospitalized in the hospital from September 2023 to September 2024 were included.After random equal division,94 patients were included in the control group and received systemic anti-tuberculosis chemotherapy;94 patients were included in the treatment group.Based on systemic anti-tuberculosis treatment,digital subtraction angiography(DSA)technology was used to inject targeted drugs into the bronchial lumen through bronchoscopy to complete anti-tuberculosis treatment.The changes in sputum bacteria and imaging were observed in the two groups.Results:The sputum negative conversion rate in the treatment group was significantly higher than that in the control group(86.2%;70.2%)(u=2.74,P<0.01).The absorption rate of CT imaging lesions(significant absorption)was significantly higher than that of the control group(83.0%;50%)(u=2.45,P<0.05).The closure rate of chest CT cavities was significantly higher than that of the control group(74.2%;39.1%)(u=2.20,P<0.05).During the treatment process,the improvement of clinical symptoms was significantly higher than that of the control group,and the difference was statistically significant.There was no statistically significant difference in the incidence of adverse reactions between the two groups(x^(2)=0.434,P>0.05).Conclusion:Based on DSA,targeted drug infusion within the bronchoscope can significantly improve the efficacy of the disease,with mild adverse reactions that patients can tolerate.It is worthy of promotion and application. 展开更多
关键词 Image navigation DSA BRONCHOSCOPY Targeted infusion therapy MDR-TB RR-TB
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Semi-Autonomous Navigation Based on Local Semantic Map for Mobile Robot
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作者 ZHAO Yanfei XIAO Peng +1 位作者 WANG Jingchuan GUO Rui 《Journal of Shanghai Jiaotong university(Science)》 2025年第1期27-33,共7页
Mobile robots represented by smart wheelchairs can assist elderly people with mobility difficulties.This paper proposes a multi-mode semi-autonomous navigation system based on a local semantic map for mobile robots,wh... Mobile robots represented by smart wheelchairs can assist elderly people with mobility difficulties.This paper proposes a multi-mode semi-autonomous navigation system based on a local semantic map for mobile robots,which can assist users to implement accurate navigation(e.g.,docking)in the environment without prior maps.In order to overcome the problem of repeated oscillations during the docking of traditional local path planning algorithms,this paper adopts a mode-switching method and uses feedback control to perform docking when approaching semantic goals.At last,comparative experiments were carried out in the real environment.Results show that our method is superior in terms of safety,comfort and docking accuracy. 展开更多
关键词 semi-autonomous navigation mobile robot semantic map voice interaction
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