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Laser photocoagulation is a standard interventional tool in vitreoretinal surgery. Commonly applied treatments such as grid photocoagulation and panretinal photocoagulation involve the application of hundreds of dot-like laser burns to the retina. In order to enhance the accuracy and reduce the tedium of this procedure, we are developing a robot-assisted technique for retinal laser photocoagulation...
Active physiological tremor compensation instruments have been under research and development recently. The sensing unit of the instruments provides information on three degrees-of-freedom (DOF) motion of the instrument tip using accelerations provided by accelerometers placed inside the instruments. A complete vector of angular acceleration of the instrument needs to be known to obtain information...
This paper demonstrates tremor compensation for human subjects using an active handheld micromanipulator. This instrument uses optical and inertial sensing to detect its own motion, estimates tremor using linear filtering, and a flexure-based manipulator to actuate the tip. Compensation results while tracing a line with the tool are presented for both novice users and a trained surgeon. Learning effects...
Development of a handheld microsurgical manipulator that incorporates active cancellation of the hand tremor of the user is ongoing. Thus far, experiments with the instrument have involved mechanical tools or end-effectors. In considering the possibility of laser procedures with the instrument, it is conceivable that a laser version of the instrument could be developed with no moving parts, using...
This paper presents the design and initial experimental results of a flexure-based parallel manipulator that is actuated by three piezoelectric stacks. The manipulator is for an active handheld tremor canceling device for microsurgery. By using flexures to approximate pin and ball joints, errors due to friction, backlash, and imperfect assemblies have been eliminated. The results show that the manipulator...
A method is presented for data-driven calibration of the magnetometer in an active handheld microsurgical instrument in the presence of a surgical microscope. The instrument is designed to provide tremor compensation during vitreoretinal microsurgery. An adaptive-network-based fuzzy inference system is used to generate a calibration based on data points collected at random locations throughout the...
This paper presents the development of an inverse kinematic model for a flexure-based micromanipulator using a feedforward neural network. The manipulator is part of an active handheld instrument designed to cancel hand tremor during microsurgery. The manipulator is actuated using three piezoelectric stacks. Preliminary results yield a mean squared error of 5% of the total stack range of motion, and...
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