Abstract:
A computer-assisted surgery system comprises instruments adapted to be used to perform tasks related to surgery. A reference device is in a fixed relation to a bone. A rotating magnet creates a magnetic field plane, the rotating magnet being connected to one of the instrument and the reference device. A magnetometer on the other of the instrument and the reference device produces signals as a function of at least its orientation relative to the magnetic field plane. A processing unit tracks said orientation of the instrument relative to the bone using said signals from the magnetometer subjected to the magnetic field plane.
Abstract:
A method for assisting in positioning the acetabular cup comprises orienting a cup positioning instrument with a cup thereon in an initial reference orientation relative to an acetabulum of a pelvis with the cup forming a joint with the acetabulum, the cup positioning instrument comprising an inertial sensor unit with pre-planned orientation data for a desired cup orientation based on at least one landmark of the pelvis, The cup positioning instrument is rotated to a desired abduction angle as guided by an interface of the cup positioning instrument, based on movements relative to at least one landmark. The cup positioning instrument is rotated to a desired anteversion angle as guided by the interface of the cup positioning instrument, based on movements relative to the at least one landmark. Upon reaching the desired cup orientation as indicated by the interface, the cup is impacted into the acetabulum.
Abstract:
A method for assisting in positioning the acetabular cup comprises orienting a cup positioning instrument with a cup thereon in an initial reference orientation relative to an acetabulum of a pelvis with the cup forming a joint with the acetabulum, the cup positioning instrument comprising an inertial sensor unit with pre-planned orientation data for a desired cup orientation based on at least one landmark of the pelvis, The cup positioning instrument is rotated to a desired abduction angle as guided by an interface of the cup positioning instrument, based on movements relative to at least one landmark. The cup positioning instrument is rotated to a desired anteversion angle as guided by the interface of the cup positioning instrument, based on movements relative to the at least one landmark. Upon reaching the desired cup orientation as indicated by the interface, the cup is impacted into the acetabulum.
Abstract:
A computer-assisted surgery system for obtaining a distance between at least two fixed points relative to a bone comprises a first accelerometer unit located at a first fixed location on the bone, and producing first acceleration data during a movement of the bone. A second accelerometer unit is located at a second fixed location on the bone, and simultaneously producing second acceleration data during the movement. A gyroscope unit is fixed to the bone and simultaneously producing angular rates of change of said movement. A processor unit obtains the acceleration data and the angular rates of change for calculating the distance between the first fixed position and the second fixed position on the bone using a distance value of a distance vector between the accelerometer units. An interface outputs the distance between the first fixed position and the second fixed position relative to the bone. A method for calculating a distance between at least two points on a bone is provided.
Abstract:
A computer-assisted surgery (CAS) system for navigating a surface of an anatomical feature in a coordinate system comprises an apparatus for obtaining points of a surface of an anatomical feature including a base adapted to be secured to the anatomical feature, a spherical joint supported by the base, the spherical joint having a ball member rotatable in at least two rotational degrees of freedom relative to the base and having a center of rotation fixed relative to the base, a distance-measurement device connected to the ball member such that a distance-measurement axis of the distance-measurement device passes through said center of rotation of the ball member. An inertial sensor unit produces signals representative of the orientation of the distance-measurement device. A CAS processor receives the signal from the at least one inertial sensor unit and outputs orientation data relating at least an object relative to the surface of the anatomical feature using the model of the surface in the coordinate system and the signals from the at least one inertial sensor unit.
Abstract:
The disclosed device for verifying a hip-knee-ankle angle includes a mounting base having a planar abutting surface adapted for direct abutting against a resected surface on a distal femur, and a first inertial sensor in communication with a computer assisted surgery (CAS) system to determine an orientation of the mounting base and to digitize a mechanical axis of the femur. A visual alignment guide element is pivotably mounted to the mounting base such that the angular position of the visual alignment guide element is adjustable so as to be visually aligned with a mechanical axis of a tibia. A difference between orientations of the mounting base and the visual alignment guide is calculated by the computer assisted surgery system to determine the hip-knee-ankle angle.
Abstract:
A hip resurfacing CAS system for guiding an operator in altering a femoral head in computer-assisted surgery for subsequent implanting of a femoral head implant, comprises a trackable reference on the femur. A registration tool is trackable. A bone-altering tool is associated with a resurfacing of the femoral head. A tracking apparatus tracks the tools. A resurfacing processing unit is connected to the tracking apparatus so as to receive tracking data for the tools. The resurfacing processing unit has a position/orientation calculator to calculate from the tracking data a position and orientation of the trackable reference to track the femoral frame of reference, and of the registration tool and the bone-altering tool. A model generator receives position and orientation data of the registration tool to produce a model of the femoral head and neck with respect to the femoral frame of reference. A resurfacing evaluator determines an evaluated bone resurfacing alteration as a function of a position and/or orientation of the bone-altering tool with respect to the bone model of the femoral head and neck, and a tool geometry model, at least prior to resurfacing being performed.
Abstract:
A computer-assisted surgery system for guiding alterations to a bone, comprises a trackable member secured to the bone. The trackable member has a first inertial sensor unit producing orientation-based data. A positioning block is secured to the bone, and is adjustable once the positioning block is secured to the bone to be used to guide tools in altering the bone. The positioning block has a second inertial sensor unit producing orientation-based data. A processing system providing an orientation reference associating the bone to the trackable member comprises a signal interpreter for determining an orientation of the trackable member and of the positioning block. A parameter calculator calculates alteration parameters related to an actual orientation of the positioning block with respect to the bone.
Abstract:
A glenosphere-implant positioning device comprises a coupling body having a first portion adapted to contact a spherical portion of a glenosphere implant, and a second portion adapted to contact an underside portion of the glenosphere implant, such that the coupling body is configured to be releasably coupled to a glenosphere implant in a known manner. A guide is connected to the coupling body and is configured to be slidingly engaged to a guide pin representative of a desired implanting orientation of the glenosphere implant or to a periphery of an implanted baseplate. A method for installing a glenosphere implant on an implanted baseplate is also provided.
Abstract:
A tool for digitizing a mechanical axis of a tibia using a computer-assisted surgery system is described. The tool includes upper and lower mounting ends interconnected by an alignment rod extending therebetween. The upper mounting end is releasably fastenable to an upper reference point on a tibial plateau and the lower mounting end includes a self-centering malleoli engaging mechanism having opposed caliper arms displaceable in a common plane relative to each other for clamping engagement with the medial and lateral malleoli of the ankle. At least one trackable member is mounted to the alignment rod of the tool and is in communication with the computer assisted surgery system for providing at least orientation information of the alignment rod. The mechanical axis of the tibia is parallel to the alignment rod and extends between the upper and lower reference points when the tool is mounted on the tibia.