Abstract: Apparatus for monitoring a pose of a tool relative to an object includes plural range sensors arranged on a support. The range sensors may be provided by plural ultrasound transducers. The support is integrated with or coupled to: the tool. The tool may comprise a guide configured to constrain another tool to be moved along an axis defined by the guide. The transducers output signals that encode plural measured distances between points having known locations relative to the support and points on a surface of the object. A data processing system is configured to: process the signals to obtain the plural measured distances; and process the measured distances to generate an estimated pose of the support relative to the object. A user feedback interface is operative to communicate to a user information about a current pose of the tool relative to the object. The apparatus has example application in surgery including drilling holes for pedicle screws.

Abstract: An apparatus and method for tracking the position of one or more connected rigid bodies using markers attached to the rigid bodies by flexible connectors. Systems based on this method are comprised of flexible connectors, a position tracking system and a data processing algorithm to determine the positions and orientations of the rigid bodies. Variations in the methods of attachment of the flexible connectors, the means by which flexibility in the connector is produced, and in the layout of the markers are presented.

Abstract: A hinge structure composed of a supporting hinge and aligning hinge. The supporting hinge is composed of a first and second part one of which has a first bearing with a spherical bearing portion the other a cooperating seat and preferably a cylindrical bearing surface opening therefrom. The first bearing cooperates with seat and the cylindrical bearing surface to support and prevent relative lateral movement of the first part while permitting rotational movement. The aligning hinge is formed of a second bearing having spherical bearing surface portion and a second hinge portion with a cylindrical bearing portion adapted to receive the second bearing in mating relation to permit rotation around the spherical axis of its spherical portion while preventing lateral movement.

Abstract: An operating stage is formed by a rigid ring and is provided with a resilient wedge forming helically wound spring that forms a plurality of resilient pressure applying, suture gripping wedging clamps around the stage and positioned adjacent to the bottom outside corner of the stage.