Abstract: A user interface system comprises a plurality of linkages connected between a platform and a base. The linkages permit motion of the platform over at least a portion of a spherical surface. A support assembly coupled between the platform and the base comprises a spherical joint having a center of rotation substantially concentric with a center of the spherical surface. The spherical joint constrains motion of the platform to the spherical surface. The system may include a sensor corresponding to each linkage. Each sensor may be coupled to sense a movement of its corresponding linkage in response to motion of the platform over the portion of the spherical surface. A user-manipulable handle may be coupled to the platform so that the user can move the platform.

Abstract: A method is provided for simulating interaction between a tool and an object. The method involves: providing a tool model for simulating the tool in a simulated environment; providing a mesh for simulating the object in the simulated environment, the mesh comprising a plurality of nodes and a plurality of first force functions between pairs of nodes, each first force function being a function of a distance between its corresponding pair of nodes; and deforming the mesh in response to interaction between the tool model and the mesh in the simulated environment. Deforming the mesh may involve: displacing one or more initially displaced nodes; and displacing one or more level-one-connected nodes, displacement of each level-one-connected node dependent on at least one first force function between the level-one-connected node and a corresponding one of the one or more initially displaced nodes.

Abstract: A user interface system comprises a plurality of linkages connected between a platform and abase. The linkages permit motion of the platform over at least a portion of a spherical surface. A support assembly coupled between the platform and the base comprises a spherical joint having a centre of rotation substantially concentric with a centre of the spherical surface. The spherical joint constrains motion of the platform to the spherical surface. The system may include a sensor corresponding to each linkage. Each sensor may be coupled to sense a movement of its corresponding linkage in response to motion of the platform over the portion of the spherical surface. A user-manipulable handle may be coupled to the platform so that the user can move the platform.

Abstract: A method is provided for simulating interaction between a tool and an object. The method involves: providing a tool model for simulating the tool in a simulated environment; providing a mesh for simulating the object in the simulated environment, the mesh comprising a plurality of nodes and a plurality of first force functions between pairs of nodes, each first force function being a function of a distance between its corresponding pair of nodes; and deforming the mesh in response to interaction between the tool model and the mesh in the simulated environment. Deforming the mesh may involve: displacing one or more initially displaced nodes; and displacing one or more level-one-connected nodes, displacement of each level-one-connected node dependent on at least one first force function between the level-one-connected node and a corresponding one of the one or more initially displaced nodes.

Abstract: A method and apparatus for a spherical parallel mechanism are disclosed. The invention involves a platform and at least three kinetic chains. The kinetic chains each comprise a link with one end pivotally coupled to the platform about a first axis and a second end pivotally coupled to an arm about a second axis. The arms in all of the kinetic chains share a common third axis. All of the first, second and third axes for all of the kinetic chains pass through a stationary point in space. Movement of the arms to selected angular positions about the common third axis adjusts an orientation and position of the platform about a spherical surface centered at the stationary point. The parallel mechanism has particular advantages for manipulating implements, such as cameras used in laparoscopic surgery, when the implements are mounted to the mobile platform.

Abstract: A haptic interface for a remote manipulator uses a tunable spring to provide force reflection. The remote manipulator has an operating member coupled to the tunable spring. The operating member is also coupled to a manipulator member. A controller monitors the force with which an operator so moves the operating member and varies a spring constant of the tunable spring to keep the force exerted by the manipulator member on an object at a desired level. The haptic interface allows simultaneous control over the maximum force exerted by the manipulator member as well as the transmission ratio between the operating member and the manipulator member. The remote manipulator may be a surgical grasper, for example. A tunable spring can be smaller and lighter than the high torque actuators used in some prior remote manipulators which provide force feedback.

Abstract: A suturing device is disclosed. The suturing device has particular application in surgery and is readily adaptable for use in laparoscopic surgery. The suturing device has an arcuate needle which is circulated around a circular path. The needle is driven by a drive belt which bears against the rear faces of a pair of closely spaced guides. Idler rollers behind the belt pinch the needle against the guides and slightly deform the drive belt. The needle is firmly gripped between the belt and the guides. The guides and the needle each subtend an angle of about 240.degree.. The motion of the needle is reversible. A surgeon can regulate the motion of the needle by turning a wheel with a fingertip. A pair of tissue gripping jaws are provided to hold tissues in place during suturing. The suturing device may be used to form a knot after a suture has been placed.