METHOD AND SYSTEM FOR TRACKING TOOLS IN COMPUTER-ASSISTED SURGERY

Abstract

A system for tracking a bone-altering tool in computer-assisted surgery, comprising a first trackable reference secured to a first bone, with a first frame of reference being associated with the first trackable reference. A bone-altering tool is securable to the first bone in a secured configuration. Sensors track the trackable reference for position and orientation. A position/orientation calculator is connected to the sensor device to calculate a position and orientation of the first frame of reference. An alteration parameter calculator is associated with the position/orientation calculator to determine a position and orientation of the bone-altering tool in the secured configuration as a function of the position and orientation of the first frame of reference and of the secured configuration. A method for tracking tools using the tracking of a bone is provided.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof and in which:

FIG. 1 is a block diagram of an alteration parameter calculator system constructed in accordance with a preferred embodiment of the present invention;

FIG. 2 is a flowchart of a method for calculating alteration parameters in accordance with another preferred embodiment of the present invention;

FIG. 3 is an exploded view of a rasp and bone-altering tool used with the system of FIG. 1; and

FIG. 4 is an assembly view of the rasp and bone-altering tool of FIG. 3.

Claims

1. A system for tracking a bone-altering tool in computer-assisted surgery, comprising: a first trackable reference secured to a first bone, with a first frame of reference being associated with the first trackable reference;a bone-altering tool securable to the first bone in a secured configuration;sensors to track at least the first trackable reference for position and orientation;a position/orientation calculator connected to the sensor device to calculate a position and orientation of the first frame of reference; andan alteration parameter calculator associated with the position/orientation calculator to determine a position and orientation of the bone-altering tool in said secured configuration as a function of the position and orientation of the first frame of reference and of said secured configuration.

2. The system according to claim 1, further comprising a second trackable reference secured to a second bone, with a second frame of reference being associated with the second trackable reference, the alteration parameter calculator calculating at least one parameter associated with alterations to the second bone by the bone-altering tool in the secured configuration as a function of the position and orientation of the bone-altering tool and of the second frame of reference.

3. The system according to claim 2, further comprising a calibration tool to digitize a model of the second bone with respect to the second frame of reference, with said at least one parameter being alterations to the second bone calculated by the alteration parameter calculator from the model of the second bone.

4. The system according to claim 1, wherein the secured configuration is represented by position and orientation data associated with an interface between the bone and the bone-altering tool, and with a virtual model of the bone-altering tool.

5. The system according to claim 4, wherein the virtual model of the bone-altering tool is known preoperatively.

6. The system according to claim 4, further comprising a calibration tool to digitize said position and orientation data associated with said interface between the bone and the bone-altering tool.

7. The system according to claim 1, further comprising a calibration tool to digitize said position and orientation data pertaining to said secured configuration of the bone-altering tool with respect to the first frame of reference.

8. The system according to claim 2, wherein the first bone is a resected femur having a broach implanted therein, the bone-altering tool being a reamer securable to the broach in the secured configuration, the second bone being a pelvis and the at least one parameter being a surface of an acetabulum of the pelvis being altered by the reamer.

9. The system according to claim 1, wherein the first bone has an implant, and the bone-altering tool is secured to the implant of the first bone in said secured configuration.

10. A method for tracking a tool secured to a bone/bone implant in computer-assisted surgery, comprising the steps of: tracking a first trackable reference secured to a first bone/bone implant for position and orientation;obtaining an interface relation of the tool secured to the first bone/bone implant;obtaining a model of the tool; andcalculating at least a position of the tool secured to the first bone/bone implant as a function of the tracking of the first trackable reference, of the interface relation and of the model of the tool.

11. The method according to claim 10, further comprising a step of tracking a second trackable reference secured to a second bone while tracking said first trackable reference, and a step of calculating an alteration performed on the second bone as a function of said position and an orientation of the tool, said tracking of the second trackable reference, and a model of the second bone.

12. The method according to claim 11, further comprising a step of digitizing a surface of the second bone to obtain the model of the second bone.

13. The method according to claim 10, wherein the step of obtaining the interface relation is performed by digitizing a surface of the first bone/bone implant with respect to the first trackable reference.

14. The method according to claim 10, wherein the step of obtaining the model of the tool involves retrieving the model created preoperatively.

15. The method according to claim 11, wherein the step of tracking the first trackable reference has the first trackable reference on a femur, the step of obtaining the interface relation involves a reamer secured to an implant in the femur, the step of tracking the second trackable reference has the second trackable reference on a pelvis, and the step of calculating an alteration involves calculating alterations to a surface of an acetabulum of the pelvis.