Objective: To develop a three-dimensional pre-surgical planner and an intraoperative guidance system for high tibial osteotomy. The parameters that describe the placement and orientation of the osteotomy resection pla...
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Objective: To develop a three-dimensional pre-surgical planner and an intraoperative guidance system for high tibial osteotomy. The parameters that describe the placement and orientation of the osteotomy resection planes were to be transmitted to an accompanying guidance system that allowed the surgeon to reproducibly perform the planned procedureMaterials and Methods: The planning system and guidance system were coded using OpenGL on UNIX workstations. In vitro tests were performed to compare the reproducibility of the computer-enhanced technique to that of the traditional technique, and an in vivo pilot study was initiatedResults: In vim, the computer-enhanced technique produced a significant reduction, by one half, in both the maximum error of correction and the standard deviation of the correction error. Preliminary in vivo results on six patients suggest that similar error diminution will occur during regular clinical application of the techniqueConclusions: Both studies showed that the computer system is simple to use. The work suggests that three-dimensional planning and performance of high tibial osteotomy is essential for accurate correction of the alignment of the lower limb.
Objective: The objective was to develop a fixation-based three-dimensional presurgical planner and an intraoperative guidance system for distal radius osteotomy. Fixation-based surgery is a technique premised on using...
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This paper discusses a survey of users of contaminated-land information and guidance. The survey was designed to assist in the understanding of user needs in the context of the developing risk-based approach to decisi...
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Objective: To develop a three-dimensional pre-surgical planner and an intraoperative guidance system for high tibial osteotomy. The parameters that describe the placement and orientation of the osteotomy resection pla...
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In this paper a local trajectory planner is described and applied. This planner works in three dimensional environment populated with static and passive movable obstacles. The main contribution of this paper is a prop...
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In this paper a local trajectory planner is described and applied. This planner works in three dimensional environment populated with static and passive movable obstacles. The main contribution of this paper is a proposal of a new method of autonomous navigation. Novelty of this approach relies on splitting the motion planning problem into two stages: a decision mode and a trace mode. In the decision mode, vehicle selects its current direction of motion on the basis of the current value of a performance index. In the trace mode vehicle traces boundary and edges of obstacles using its on-board sensors. Depending on vehicle's environment, the two modes follow one another many times. Another new idea is a negative velocity feedback. The feedback stabilizes velocity of the vehicle around a value considered safe in a given environment. The planner, although autonomous, may be adjusted by higher order system (strategic behavior) by changing its parameters. It is not computationally intensive and therefore can be used in real-time applications.
During enterprise knowledge development in any organisation, developers and stakeholders an faced with situations that require them to make decisions in order to reach their intentions. To help the decision-making pro...
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During enterprise knowledge development in any organisation, developers and stakeholders an faced with situations that require them to make decisions in order to reach their intentions. To help the decision-making process, guidance is required. Enterprise Knowledge Development (EKD) is a method offering a guided knowledge development process. The guidance provided by the EKD method is based on a decision-making pattern promoting a situation and intention oriented view of enterprise knowledge development processes. The pattern is iteratively repeated through the EKD process using different types of guiding knowledge. Consequently, the EKD process is systematically guided. The presentation of the decision-making pattern is the purpose of this paper. (C) 2000 Elsevier Science B.V. All rights reserved.
Inertial navigation technology is used widely for the guidance of aircraft, ships and land vehicles, as well as in an increasing number of civil applications such as robotics, surveying underground well bores and the ...
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Inertial navigation technology is used widely for the guidance of aircraft, ships and land vehicles, as well as in an increasing number of civil applications such as robotics, surveying underground well bores and the control of drilling operations. This article describes the techniques and the sensors used in modern systems and outlines a number of applications in which inertial system technology is being used today.
The IAEA launched a fire safety programme in 1993 to assist Member States in improving fire safety both in new and existing nuclear power plants (NPPs). Under this programme, the IAEA has published a number of guidanc...
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The IAEA launched a fire safety programme in 1993 to assist Member States in improving fire safety both in new and existing nuclear power plants (NPPs). Under this programme, the IAEA has published a number of guidance and practical documents related to fire safety in NPPs. Ar the request of Member States, fire safety review missions and training courses have also been conducted. In order to improve the reliability of pre safety assessment and promote advanced techniques in this area, the IAEA has established a data collection and reporting system which includes Sire relevant incidents. The IAEA has also organized various technical meetings on five safety for information exchange. IAEA activities on fire safety at NPPs will be continued However, it is expected that, after the IAEA guidance documents have been completed, ficture efforts will focus on assistance in the application this guidance, i.e. on safety review services and training courses.
PURPOSE: To test the hypothesis that real-time magnetic resonance (MR) imaging-guided passive catheter tracking is feasible with use of dilute gadolinium (Gd) filled catheters, to determine the optimal Gd concentratio...
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PURPOSE: To test the hypothesis that real-time magnetic resonance (MR) imaging-guided passive catheter tracking is feasible with use of dilute gadolinium (Gd) filled catheters, to determine the optimal Gd concentration required for tracking, and to measure catheter tip tracking accuracy. MATERIALS AND METHODS: The authors tested a seal-time, T1-weighted, two-dimensional, spoiled gradient-recalled echo MR imaging sequence suitable for tracking catheters, In a yogurt phantom, the authors placed 5-F catheters filled with 2%-12% Gd solutions. MR imaging was performed with and without use of a projection dephaser that suppressed background signal, The authors measured signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and enhancement ratio to determine the optimal Cd concentration for catheter depiction, Catheter tip tracking accuracy was measured in an acrylic phantom with use of linear regression analysis, with goodness of fit assessed statistically with the F test. RESULTS: Peak catheter SNR, CNR, and enhancement ratios were obtained with 4%-6% Gd concentrations. Tip tracking accuracy was determined to be +/- 0.41 mm (R-2 = 0.99;P < .0001). MR imaging reconstructions were displayed up to 3.1 frames/sec. CONCLUSIONS: Accurate MR imaging-guided passive catheter tracking was feasible in real-time with use of dilute Gd-filed catheters, This technique may have application in MR imaging-guided endovascular procedures.
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