In the craniofacial surgery image-slices obtained from tomographies are used for planning and simulation of surgical interventions. Using these image-slices three-dimensional geometric models can be reconstructed, rep...
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ISBN:
(纸本)1586030140
In the craniofacial surgery image-slices obtained from tomographies are used for planning and simulation of surgical interventions. Using these image-slices three-dimensional geometric models can be reconstructed, representing bones and soft tissue. However, for planning complex surgical interventions simulation methods are needed additionally to the pure visualisation. Exemplary, planning a Frontal Orbital Advancement (FOA) operation the cutting trajectories, their depth and orientation in each point, the drill hole, the position, orientation and deformation of bones, etc. are the point of interest. Especially for intraoperative execution supported by navigation systems or robots. In order to be able to plan such complex interventions with the help of computers, geometrical and haptical models must be generated from the image-slices. On the one hand these models represent the anatomical structures exactly, on the other hand they are needed for the simulation of the different activities, which have to be performed during the surgical intervention like drilling, milling, deforming, positioning, etc. Beside the geometrical and haptical models methods for interactions must be supplied to the physician for an accurate and intuitive planning of the surgical intervention. We developed such an operation planning system which is already used in clinical practise in Heidelberg.
Grasping of unmodelled objects in unstructured scenes is a significant task in numerous robot applications. In order to reach short cycle times, grasp planning must make the best of the image information acquired all ...
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Grasping of unmodelled objects in unstructured scenes is a significant task in numerous robot applications. In order to reach short cycle times, grasp planning must make the best of the image information acquired all at once, which comprises more or less visual occlusions and thus unknown regions. For time reasons, it is not acceptable to inspect in further steps all unknown regions by means of local sensing before grasp planning. We present a grasp planning system, which determines explicitly the fractions of grasp operations in known and unknown regions. Using that crucial information, a planning system may not request a tool change, but prefer a grasping operation with the mounted gripper, which moves mostly in known and free regions. Then, only a small part has to be executed slowly using local sensing with, for examples, proximity or force torque sensors.
A new algorithm for segmenting and tracking deformable (shape-changing) linear (thin and long with negligible diameter) objects in video images is presented. The core of algorithm is to detect the two boundary curves ...
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ISBN:
(纸本)0769507506
A new algorithm for segmenting and tracking deformable (shape-changing) linear (thin and long with negligible diameter) objects in video images is presented. The core of algorithm is to detect the two boundary curves of a deformable linear object within adaptive tracking windows. The boundaries are found by analyzing the gray value gradients within the tracking windows. The algorithm allows moderate changes in the image brightness by introducing tolerance parameters to the algorithm. It also provides a robust tracking of the shape- and width-changing object by using a fuzzy estimation of the object's membership function at the tracked points. The result describes the shape of the object and is used to define features for shape change detection.
A new algorithm for segmenting and tracking deformable (shape-changing) linear (thin and long with negligible diameter) objects in video images is presented. The core of the algorithm is to detect the two boundary cur...
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ISBN:
(纸本)0780362977
A new algorithm for segmenting and tracking deformable (shape-changing) linear (thin and long with negligible diameter) objects in video images is presented. The core of the algorithm is to detect the two boundary curves of a deformable linear object within adaptive tracking windows. The boundaries are found by analyzing the gray value gradients within the tracking windows, The algorithm provides a robust tracking of the shape- and width-changing object by using a fuzzy estimation of the object's membership function at the tracked points. The result of the segmentation is a list of base describing the shape of the object. This list is used to define features for shape change detection. For the feature analysis, we propose an algorithm which works well for several classes of feature curves. Experiments on robotic applications using both algorithms show promising results.
This paper presents intelligent object distribution architecture to maximize the performance and intelligence of a distributed surgical robotics system and its preliminary implementation in an MR-guided surgical robot...
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We seek to build CIS research systems within a flexible, open architecture. In this paper, we outline our solutions to the problems of system design, construction, and integration in this environment: building distrib...
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A new approach to automatically generate polyhedral convex cones from contact graphs for identification of assembly process states is presented. The state of contact between subassemblies is changing as operation proc...
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A new approach to automatically generate polyhedral convex cones from contact graphs for identification of assembly process states is presented. The state of contact between subassemblies is changing as operation proceeds in manipulative tasks such as part-mating. Measured contact forces and the resulting torques provide information about the contact geometry which is used to guide the assembly operation. In this paper, we present a method to calculate contact graphs for polyhedral subassemblies. The nodes of the contact graph represent contact formations of the subassemblies and the arcs represent neighborhoods of contact formations. This information is used to generate polyhedral convex cones for each contact formation considering friction. These polyhedral convex cones describe static equilibrium for each contact formation and are used to identify the contact state by measuring forces and torques during a part-mating.
Presents a new operation planning system which enables a surgeon to plan and perform complex robot-supported surgical interventions. The system has been evaluated in the Clinic for Cranio-Maxillo-Facial Surgery at the...
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Presents a new operation planning system which enables a surgeon to plan and perform complex robot-supported surgical interventions. The system has been evaluated in the Clinic for Cranio-Maxillo-Facial Surgery at the University of Heidelberg. In contrast to commercial systems, our goal was that the system should consider the complete surgical intervention and not just a single procedure of it. A second goal was that the system should enable the management of complex operations, independent of which way the intervention is intra-operatively performed (without technical support, with passive navigation support or with active support by robots). Our system supports the surgeon during pre-operative planning as well as during the intra-operative execution phase. Therefore, we developed a model of the course of operation by which the management of surgical interventions is made possible. The focus of this paper is on this course model. First, we introduce instruction graphs and describe the structure of each activity, observing its attributes and their context. Additionally, various surgical scopes are presented which enable the surgeon to select one view among different ones in the individual operation procedures, in accordance with medical and technical knowledge as well as in accordance with different degrees of abstraction. Finally, we demonstrate the realisation of the introduced course model in our operation planning system and present first results in clinical practice.
In this paper, we present a system for performing a complex surgical intervention using virtual reality (VR) technology. With the aid of the system, the intervention can be planned and simulated exactly before perform...
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This paper presents an approach to sensor-based obstacle modeling in a configuration space for manipulator motion planning in unknown environments. In order to achieve this objective, an efficient algorithm is used to...
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