Abstract: A pelvic digitizer device has a body defined by a shaft having a tooling end and a handle end with a handle for being manipulated. A visual guide is oriented in a reference plane of the digitizer device. A cup is connected to the tooling end and adapted to be received in an acetabulum of a patient. An inertial sensor unit is connected to the body, the inertial sensor unit having a preset orientation aligned with the reference plane.

Abstract: A method tracks a tool with respect to a bone in computer-assisted surgery. A reference tracker with a MEMS unit is secured to the bone. The tracker outputs data relating to its orientation. A tool provided with a MEMS unit and secured to the bone is preset with an initial orientation. The tool outputs tracking data related to orientation of the tool once initialized. A trackable frame of reference relating the bone to the orientation of the tracker is created. The MEMS unit of the tool is initialized. A relation between the initial orientation of the tool and the orientation of the tracker at initialization of the MEMS unit of the tool is recorded. Orientational data of the tool relative to the frame of reference of the bone calculated using the relation is displayed. A computer-assisted surgery system for tracking a tool with respect to a bone after an initialization of a MEMS unit is also described.

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 system for tracking a femoral frame of reference in computer-assisted surgery comprises a sensor unit. The sensor unit is adapted to be secured to the femur. The sensor unit comprises accelerometer and gyroscope sensors that produce orientation data. A processing unit receives gyroscope and accelerometer data. The processing unit comprises a gyroscope-data calculator to provide calculated acceleration data resulting from movements of the femur, an accelerometer-data calculator to calculate measured acceleration data resulting from movements of the femur, and an acceleration comparator to relate an orientation of the sensor unit to the femur to define a femoral frame of reference. The femoral frame of reference is defined from the comparison between the calculated and the measured acceleration data. A sensor orientation interface provides orientation data for the femur from a tracking of the femoral frame of reference. A method for tracking a femoral frame of reference is also provided.

Abstract: A system for tracking a femoral frame of reference in computer-assisted surgery comprises a sensor unit. The sensor unit is adapted to be secured to the femur. The sensor unit comprises accelerometer and gyroscope sensors that produce orientation data. A processing unit receives gyroscope and accelerometer data. The processing unit comprises a gyroscope-data calculator to provide calculated acceleration data resulting from movements of the femur, an accelerometer-data calculator to calculate measured acceleration data resulting from movements of the femur, and an acceleration comparator to relate an orientation of the sensor unit to the femur to define a femoral frame of reference. The femoral frame of reference is defined from the comparison between the calculated and the measured acceleration data. A sensor orientation interface provides orientation data for the femur from a tracking of the femoral frame of reference. A method for tracking a femoral frame of reference is also 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.

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 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: An impactor for positioning and inserting an acetabular cup into an acetabulum of a pelvis during hip arthroplasty is described. The impactor includes a guide element mounted to an elongated body and including first and second openings aligned with each other to define an axial passage. The first and second openings and the axial passage receive a guide pin therethrough that is pinned in a fixed position to the pelvis. The guide element provides a mechanical orientation guide which restricts an angular orientation of the impactor relative to the guide pin when the guide pin is pinned in the fixed position relative to the pelvis and received through the first and second openings of the guide element. Centering the openings of the guide element relative to the guide pin in the fixed position accordingly achieves a desired orientation of the impactor within a predetermined angular tolerance.

Abstract: A computer-assisted surgery (CAS) system for tracking an orientation of a pelvis comprises at least one instrument, the instrument having an acetabulum abutment end adapted to be received in an acetabulum, a rim abutment adapted to be abutted against a rim of the acetabulum, and an indicator representative of a physical orientation of the instrument. An inertial sensor unit is connected to the at least one instrument, the inertial sensor unit producing readings representative of its orientation.

Abstract: A computer-assisted surgery system for outputting at least one of a leg length discrepancy and an offset between a preoperative leg condition and a post-implant rejointing leg condition comprises instruments. An inertial sensor unit is connected to one of the instrument, the inertial sensor unit producing readings representative of its orientation.

Abstract: A computer-assisted surgery (CAS) system comprises a cup implanting device including a shaft having a tooling end and a handle end with a handle for being manipulated, the shaft having a longitudinal axis, the tooling end adapted to support a cup for being received in an acetabulum of a patient, and a rotation indicator having a visual guide representative of a device plane, wherein the device plane is in a known position and orientation relative to a center of the cup on the tooling end.

Abstract: A computer-assisted surgery system comprises a calibrating instrument adapted to be applied to a pelvis in a known manner, and a surgical instrument. A computer-assisted processor unit operating a surgical assistance procedure and comprises at least one portable inertial sensor unit configured to be connected to the at least one calibrating instrument and the at least one surgical instrument, the portable inertial sensor unit outputting readings representative of its orientation. A geometrical relation data module provides a geometrical relation data between the orientation of the portable inertial sensor unit, of the calibrating instrument and of the surgical instrument.

Abstract: A tracking system is provided for tracking an objects. A first and a second trackable member each have an inertial sensor unit producing at least orientation-based data. A processing unit receives the orientation-based data from the trackable members. The processing unit has an orientation calculator calculating an orientation of the second trackable member with respect to the first trackable member from the orientation-based data of both said trackable members, whereby the processing unit calculates an orientation of the objects. A method is also provided.

Abstract: A tracking system is provided for tracking objects. A first and a second trackable member each have an inertial sensor unit producing at least orientation-based data. A processing unit receives the orientation-based data from the trackable members. The processing unit has an orientation calculator calculating an orientation of the second trackable member with respect to the first trackable member from the orientation-based data of the trackable members, whereby the processing unit calculates an orientation of the objects. A method for tracking objects is also provided.

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 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 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 digitizer device comprises an elongated body and legs connected to the elongated body. At least one joint is between the legs and the elongated body such that free ends of the legs are displaceable relative to one another. An inertial sensor unit is connected to the elongated body, the inertial sensor unit having a preset orientation aligned with the elongated body. A table reference device comprises a body adapted to be fixed to an operating table. An inertial sensor unit is with a preset orientation related to the operating table.