Abstract: A pelvic digitizer device comprises a body comprising: 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 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 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 computer-assisted surgery system for planning/guiding alterations to a bone in surgery, comprises a trackable member adapted to be secured to the bone. The trackable member has a first inertial sensor unit producing orientation-based data for at least two degrees of freedom in orientation of the trackable member A positioning block is adapted to be secured to the bone, with at least an orientation of the positioning block being adjustable once the positioning block is secured to the bone to reach a selected orientation at which the positioning block is used to guide tools in altering the bone. The positioning block has a second inertial sensor unit producing orientation-based data for at least two degrees of freedom in orientation of the positioning block. 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 from the orientation-based data.

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 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 system for planning/guiding alterations to a bone in surgery, comprises a trackable member adapted to be secured to the bone. The trackable member has a first inertial sensor unit producing orientation-based data for at least two degrees of freedom in orientation of the trackable member A positioning block is adapted to be secured to the bone, with at least an orientation of the positioning block being adjustable once the positioning block is secured to the bone to reach a selected orientation at which the positioning block is used to guide tools in altering the bone. The positioning block has a second inertial sensor unit producing orientation-based data for at least two degrees of freedom in orientation of the positioning block. 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 from the orientation-based data.

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.