5,126 research outputs found

    Towards retrieving force feedback in robotic-assisted surgery: a supervised neuro-recurrent-vision approach

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    Robotic-assisted minimally invasive surgeries have gained a lot of popularity over conventional procedures as they offer many benefits to both surgeons and patients. Nonetheless, they still suffer from some limitations that affect their outcome. One of them is the lack of force feedback which restricts the surgeon's sense of touch and might reduce precision during a procedure. To overcome this limitation, we propose a novel force estimation approach that combines a vision based solution with supervised learning to estimate the applied force and provide the surgeon with a suitable representation of it. The proposed solution starts with extracting the geometry of motion of the heart's surface by minimizing an energy functional to recover its 3D deformable structure. A deep network, based on a LSTM-RNN architecture, is then used to learn the relationship between the extracted visual-geometric information and the applied force, and to find accurate mapping between the two. Our proposed force estimation solution avoids the drawbacks usually associated with force sensing devices, such as biocompatibility and integration issues. We evaluate our approach on phantom and realistic tissues in which we report an average root-mean square error of 0.02 N.Peer ReviewedPostprint (author's final draft

    Roving vehicle motion control Final report

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    Roving vehicle motion control for unmanned planetary and lunar exploratio

    NASA Automated Rendezvous and Capture Review. Executive summary

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    In support of the Cargo Transfer Vehicle (CTV) Definition Studies in FY-92, the Advanced Program Development division of the Office of Space Flight at NASA Headquarters conducted an evaluation and review of the United States capabilities and state-of-the-art in Automated Rendezvous and Capture (AR&C). This review was held in Williamsburg, Virginia on 19-21 Nov. 1991 and included over 120 attendees from U.S. government organizations, industries, and universities. One hundred abstracts were submitted to the organizing committee for consideration. Forty-two were selected for presentation. The review was structured to include five technical sessions. Forty-two papers addressed topics in the five categories below: (1) hardware systems and components; (2) software systems; (3) integrated systems; (4) operations; and (5) supporting infrastructure

    Membrane Spin Up in a Normal Gravity Field: Experiments and Simulations

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    Finite element simulations and experimental observations of the spin up in vacuum of a thin membrane loaded by gravity are presented. The numerical techniques take into account the run time of each simulation and energy convergence; it is shown that accurate results can be obtained quite quickly in a rotating reference frame, and that including stiffness-proportional material damping helps convergence of the integration. It is also found that a very fine finite element mesh around the hub of the membrane is required to obtain consistent results. The experimental setup allows spinning of the membrane in a vacuum box; a measurement technique that uses stereo Digital Image Correlation is presented. A comparison between experiments and simulations using characteristic parameters of the shape of a membrane, i.e. the number of rotational symmetric waves, the average deflection, and the elastic bending strain energy of the membrane, shows good agreement between experiments and simulations
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