The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform

Umamaheswar Duvvuri - One of the best experts on this subject based on the ideXlab platform.

  • Output control of da Vinci surgical system's surgical graspers.
    The Journal of surgical research, 2013
    Co-Authors: Paul J. Johnson, David E. Schmidt, Umamaheswar Duvvuri
    Abstract:

    The number of robot-assisted surgeries performed with the da Vinci surgical system has increased significantly over the past decade. The articulating movements of the robotic surgical grasper are controlled by grip controls at the master console. The user interface has been implicated as one contributing factor in surgical grasping errors. The goal of our study was to characterize and evaluate the user interface of the da Vinci surgical system in controlling surgical graspers. An angular manipulator with force sensors was used to increment the grip control angle as grasper Output angles were measured. Input force at the grip control was simultaneously measured throughout the range of motion. Pressure film was used to assess the maximum grasping force achievable with the endoscopic grasping tool. The da Vinci robot's grip control angular input has a nonproportional relationship with the grasper Instrument Output. The grip control mechanism presents an intrinsic resistant force to the surgeon's fingertips and provides no haptic feedback. The da Vinci Maryland graspers are capable of applying up to 5.1 MPa of local pressure. The angular and force input at the grip control of the da Vinci robot's surgical graspers is nonproportional to the grasper Instrument's Output. Understanding the true relationship of the grip control input to grasper Instrument Output may help surgeons understand how to better control the surgical graspers and promote fewer grasping errors. Copyright © 2014 Elsevier Inc. All rights reserved.

Paul J. Johnson - One of the best experts on this subject based on the ideXlab platform.

  • Output control of da Vinci surgical system's surgical graspers.
    The Journal of surgical research, 2013
    Co-Authors: Paul J. Johnson, David E. Schmidt, Umamaheswar Duvvuri
    Abstract:

    The number of robot-assisted surgeries performed with the da Vinci surgical system has increased significantly over the past decade. The articulating movements of the robotic surgical grasper are controlled by grip controls at the master console. The user interface has been implicated as one contributing factor in surgical grasping errors. The goal of our study was to characterize and evaluate the user interface of the da Vinci surgical system in controlling surgical graspers. An angular manipulator with force sensors was used to increment the grip control angle as grasper Output angles were measured. Input force at the grip control was simultaneously measured throughout the range of motion. Pressure film was used to assess the maximum grasping force achievable with the endoscopic grasping tool. The da Vinci robot's grip control angular input has a nonproportional relationship with the grasper Instrument Output. The grip control mechanism presents an intrinsic resistant force to the surgeon's fingertips and provides no haptic feedback. The da Vinci Maryland graspers are capable of applying up to 5.1 MPa of local pressure. The angular and force input at the grip control of the da Vinci robot's surgical graspers is nonproportional to the grasper Instrument's Output. Understanding the true relationship of the grip control input to grasper Instrument Output may help surgeons understand how to better control the surgical graspers and promote fewer grasping errors. Copyright © 2014 Elsevier Inc. All rights reserved.

David E. Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • Output control of da Vinci surgical system's surgical graspers.
    The Journal of surgical research, 2013
    Co-Authors: Paul J. Johnson, David E. Schmidt, Umamaheswar Duvvuri
    Abstract:

    The number of robot-assisted surgeries performed with the da Vinci surgical system has increased significantly over the past decade. The articulating movements of the robotic surgical grasper are controlled by grip controls at the master console. The user interface has been implicated as one contributing factor in surgical grasping errors. The goal of our study was to characterize and evaluate the user interface of the da Vinci surgical system in controlling surgical graspers. An angular manipulator with force sensors was used to increment the grip control angle as grasper Output angles were measured. Input force at the grip control was simultaneously measured throughout the range of motion. Pressure film was used to assess the maximum grasping force achievable with the endoscopic grasping tool. The da Vinci robot's grip control angular input has a nonproportional relationship with the grasper Instrument Output. The grip control mechanism presents an intrinsic resistant force to the surgeon's fingertips and provides no haptic feedback. The da Vinci Maryland graspers are capable of applying up to 5.1 MPa of local pressure. The angular and force input at the grip control of the da Vinci robot's surgical graspers is nonproportional to the grasper Instrument's Output. Understanding the true relationship of the grip control input to grasper Instrument Output may help surgeons understand how to better control the surgical graspers and promote fewer grasping errors. Copyright © 2014 Elsevier Inc. All rights reserved.

S.a. Counter - One of the best experts on this subject based on the ideXlab platform.

  • Auditory brainstem and cortical responses following extensive transcranial magnetic stimulation.
    Journal of the neurological sciences, 1994
    Co-Authors: S.a. Counter
    Abstract:

    The long term effects of transcranial electromagnetic stimulation (TEMS) on auditory brainstem and cortical evoked responses and on neuroanatomical structures in the auditory tract were investigated over a 12 month period in rabbits exposed to 1000 stimuli at 100% maximum stimulation level (2.0 tesla Instrument Output) with a clinical magnetic coil positioned over the cranium. (1) The tone and click audiograms of the pre and post TEMS-exposed plugged ears were normal and did not differ significantly, suggesting that the protected cochlea is unaffected by TEMS. (2) The mean absolute and interwave latencies of auditory brainstem evoked responses (ABR) and the peak amplitudes of the vertex positive waves P1, P3, and P4 in the exposed rabbits were within normal limits, and comparable those of the normal, pre-exposed animals. Wave P5 in the exposed animals was more variable and significantly different from the normal data in mean latency and amplitude. (3) The mean latencies and amplitudes of the post exposed cortical (late) auditory evoked responses (CAER) were not significantly different from the non-exposed ears. Light microscopic examination of sections of the cochlear nucleus and inferior colliculus, possible sources of waves P2 and P5, respectively, of the ABR, showed no EMS-related changes in cellular organization or histological damage. In conclusion, no deleterious effects of TEMS were observed on the protected ear or the peripheral and central auditory system of rabbits after extensive exposure to long term, high intensity, low frequency time-varying magnetic field stimulation with a clinical Instrument.

Raytheon Stx Corp. - One of the best experts on this subject based on the ideXlab platform.

  • Nimbus/TOMS Science Data Operations Support
    2019
    Co-Authors: Nasa, Raytheon Stx Corp.
    Abstract:

    Projected goals include the following: (1) Participate in and provide analysis of laboratory and in-flight calibration of LTV sensors used for space observations of backscattered LTV radiation; (2) Provide support to the TOMS Science Operations Center, including generating Instrument command lists and analysis of TOMS health and safety data; (3) Develop and maintain software and algorithms designed to capture and process raw spacecraft and Instrument data, convert the Instrument Output into measured radiance and irradiances, and produce scientifically valid products; (4) Process the TOMS data into Level 1, Level 2, and Level 3 data products; (5) Provide analysis of the science data products in support of NASA GSFC Code 916's research.