Patent application number | Description | Published |
20090099692 | MEDICAL ROBOTIC SYSTEM WITH SLIDING MODE CONTROL - A medical robotic system has a joint coupled to medical device or a slave manipulator or robotic arm adapted to hold and/or move the medical device for performing a medical procedure, and a control system for controlling movement of the joint according to user manipulation of a master manipulator. The control system includes at least one joint controller having a sliding mode control for reducing stick-slip behavior on its controlled joint during fine motions of the joint. The sliding mode control computes a distance to a sliding surface, computes a reaching law gain, and processes the distance and reaching law gain to generate a sliding mode control action that is in absolute value less that a maximum desired feedback control action. The sliding mode control action is then further processed to generate a feedback torque command for the joint motor. | 04-16-2009 |
20090322001 | Spring Counterbalance with Failure Detection - A spring counterbalance mechanism balances a load with a spring. A cable has a protrusion fixed to the cable midway between two ends of the cable. The two free ends of the cable are fixedly coupled to one of the load or the spring, and a cable attachment is coupled to the remaining member. The cable passes through the cable attachment such that the protrusion is captive in the cable attachment and is movable between two stops in the cable attachment. The cable forms two segments each of which couples the spring to the load. The two segments of the cable pass over a pulley. A sensor coupled to the pulley senses rotation of the pulley allowing cable breakage to be detected by the anomalous rotation of the pulley. | 12-31-2009 |
20090324160 | FIXTURE FOR SHAPE-SENSING OPTICAL FIBER IN A KINEMATIC CHAIN - Localized strain is effectively eliminated in a shape sensing optical fiber where the fiber exits a link in a kinematic chain. In one aspect, the fiber is positioned in a channel within a fiber fixture portion of the link, and a surface of a lip of the channel is curved. The curved surface of the lip begins tangent to a wall of the channel and has a maximum radius of curvature that is less than the minimum bend radius that the fiber will experience during shape sensing. In another aspect the fiber is positioned within a shape memory alloy tube that extends from the link. | 12-31-2009 |
20090324161 | FIBER OPTIC SHAPE SENSOR - A shape sensing system to determine the position and orientation of one link with respect to another link in a kinematic chain. An optical fiber is coupled to two or more links in a kinematic chain. A shape sensing segment is defined to start at a proximal link and to end at a distal link, crossing one or more joints. A reference frame is defined at the start of the shape sensing segment. As the joints move, an interrogator senses strain in the shape sensing segment. The sensed strain is used to output a Cartesian position and orientation of the end of the shape sensing segment with respect to the reference frame defined at the start of the shape sensing segment. The pose of the kinematic chain is determined from the Cartesian positions and orientations of one or more shape sensing segments defined for the kinematic chain and from an a priori model and constraints of the kinematic chain. | 12-31-2009 |
20100145521 | ROBOTIC SURGICAL SYSTEM WITH JOINT MOTION CONTROLLER ADAPTED TO REDUCE INSTRUMENT TIP VIBRATIONS - A robotic surgical system has a robot arm holding an instrument for performing a surgical procedure, and a control system for controlling movement of the arm and its instrument according to user manipulation of a master manipulator. The control system includes a filter in its forward path to attenuate master input commands that may cause instrument tip vibrations, and an inverse filter in a feedback path to the master manipulator configured so as to compensate for delay introduced by the forward path filter. To enhance control, master command and slave joint observers are also inserted in the control system to estimate slave joint position, velocity and acceleration commands using received slave joint position commands and torque feedbacks, and estimate actual slave joint positions, velocities and accelerations using sensed slave joint positions and commanded slave joint motor torques. | 06-10-2010 |
20100202727 | FIBER OPTIC SHAPE SENSOR - A shape sensing system to determine the position and orientation of one link with respect to another link in a kinematic chain. An optical fiber is coupled to two or more links in a kinematic chain. A shape sensing segment is defined to start at a proximal link and to end at a distal link, crossing one or more joints. A reference frame is defined at the start of the shape sensing segment. As the joints move, an interrogator senses strain in the shape sensing segment. The sensed strain is used to output a Cartesian position and orientation of the end of the shape sensing segment with respect to the reference frame defined at the start of the shape sensing segment. The pose of the kinematic chain is determined from the Cartesian positions and orientations of one or more shape sensing segments defined for the kinematic chain and from an a priori model and constraints of the kinematic chain. | 08-12-2010 |
20100249506 | METHOD AND SYSTEM FOR ASSISTING AN OPERATOR IN ENDOSCOPIC NAVIGATION - Navigation guidance is provided to an operator of an endoscope by determining a current position and shape of the endoscope relative to a reference frame, generating an endoscope computer model according to the determined position and shape, and displaying the endoscope computer model along with a patient computer model referenced to the reference frame so as to be viewable by the operator while steering the endoscope within the patient. | 09-30-2010 |
20100249507 | METHOD AND SYSTEM FOR PROVIDING VISUAL GUIDANCE TO AN OPERATOR FOR STEERING A TIP OF AN ENDOSCOPIC DEVICE TOWARD ONE OR MORE LANDMARKS IN A PATIENT - Landmark directional guidance is provided to an operator of an endoscopic device by displaying graphical representations of vectors adjacent a current image captured by an image capturing device disposed at a tip of the endoscopic device and being displayed at the time on a display screen, wherein the graphical representations of the vectors point in directions that the endoscope tip is to be steered in order to move towards associated landmarks such as anatomic structures in a patient. | 09-30-2010 |
20100332033 | CONTROL OF MEDICAL ROBOTIC SYSTEM MANIPULATOR ABOUT KINEMATIC SINGULARITIES - A medical robotic system includes an entry guide with articulatable instruments extending out of its distal end, an entry guide manipulator providing controllable four degrees-of-freedom movement of the entry guide relative to a remote center, and a controller configured to manage operation of the entry guide manipulator in response to operator manipulation of one or more input devices. As the entry guide manipulator approaches a yaw/roll singularity, the controller modifies its operation to allow continued movement of the entry guide manipulator without commanding excessive joint velocities while maintaining proper orientation of the entry guide. | 12-30-2010 |
20110009880 | Control System for Reducing Internally Generated Frictional and Inertial Resistance to Manual Positioning of a Surgical Manipulator - A robotic control system is placed in clutch mode so that a slave manipulator holding a surgical instrument is temporarily disengaged from control by a master manipulator in order to allow manual positioning of the surgical instrument at a surgical site within a patient. Control systems implemented in a processor compensate for internally generated frictional and inertial resistance experienced during the positioning, thereby making movement more comfortable to the mover, and stabler from a control standpoint. Each control system drives a joint motor in the slave manipulator with a saturated torque command signal which has been generated to compensate for non-linear viscous forces, coulomb friction, cogging effects, and inertia forces subjected to the joint, using estimated joint angular velocities, accelerations and externally applied torques generated by an observer in the control system from sampled displacement measurements received from a sensor associated with the joint. | 01-13-2011 |
20110044578 | Fixture for Shape-Sensing Optical Fiber in a Kinematic Chain - Localized strain is effectively eliminated in a shape sensing optical fiber where the fiber exits a link in a kinematic chain. In one aspect, the fiber is positioned in a channel within a fiber fixture portion of the link, and a surface of a lip of the channel is curved. The curved surface of the lip begins tangent to a wall of the channel and has a maximum radius of curvature that is less than the minimum bend radius that the fiber will experience during shape sensing. In another aspect, the fiber is positioned within a shape memory alloy tube that extends from the link. | 02-24-2011 |
20110105898 | Real-Time Generation of Three-Dimensional Ultrasound image using a Two-Dimensional Ultrasound Transducer in a Robotic System - Systems and methods for performing robotically-assisted surgical procedures on a patient enable an image display device to provide an operator with auxiliary information related to the surgical procedure, in addition to providing an image of the surgical site itself. The systems and methods allow an operator to selectively access and reference auxiliary information on the image display device during the performance of a surgical procedure. | 05-05-2011 |
20120132009 | FIBER OPTIC SHAPE SENSOR - A shape sensing system to determine the position and orientation of one link with respect to another link in a kinematic chain. An optical fiber is coupled to two or more links in a kinematic chain. A shape sensing segment is defined to start at a proximal link and to end at a distal link, crossing one or more joints. A reference frame is defined at the start of the shape sensing segment. As the joints move, an interrogator senses strain in the shape sensing segment. The sensed strain is used to output a Cartesian position and orientation of the end of the shape sensing segment with respect to the reference frame defined at the start of the shape sensing segment. The pose of the kinematic chain is determined from the Cartesian positions and orientations of one or more shape sensing segments defined for the kinematic chain and from an a priori model and constraints of the kinematic chain. | 05-31-2012 |
20120266442 | FIXTURE FOR SHAPE-SENSING OPTICAL FIBER IN A KINEMATIC CHAIN - A first link and a second link are articulated relative to each other via a joint coupled between the first and second links. A shape-sensing optical fiber is used to sense a position of the first link and the second link relative to each other. The fiber passes through a channel having an opening defining a lip and extending from the first link toward the joint. The lip has a curved surface that begins substantially tangent to a wall of the channel, and during bending of the optical fiber, the optical fiber is positioned tangent to the curved surface of the lip. | 10-25-2012 |