Method for confirming registration of tracked bones
A process for confirming registration of bones involved in a joint replacement procedure is provided that includes a three dimensional (3-D) models of the bones being generated. The bones are tracked with a tracking device attached to each of the bones to allow 6-degrees of freedom (DOF) tracking during the joint replacement procedure. The 3-D models to the bones are registered and the bones having the tracking device are moved. A corresponding motion in the 3-D models with the moving of the bones is then observed. The registration of the 3-D models to the bone when the observations of the 3-D models move in correspondence with the actual bones is then confirmed or an alarm when an algorithm detects the 3-D bone models move unexpectedly during the movement of the bones. A system for confirming registration of bones involved in the joint replacement procedure is also provided.
1. A process for confirming registration of bones involved in a joint replacement procedure, said process comprising:
generating a three dimensional (3-D) models of the bones involved in the joint replacement procedure;
tracking the bones with a tracking device attached to each of the bones involved in the joint replacement procedure to allow 6-degrees of freedom (DOF) tracking during the joint replacement procedure;
registering the 3-D models to the bones involved in the joint replacement procedure;
moving the bones having the tracking device;
observing a corresponding motion in the the 3-D models with said moving of the bones involved in the joint replacement procedure; and
confirming the registration of the 3-D models to the bones involved in the joint replacement procedure when the observations of the 3-D models move in correspondence with the bones involved in the joint replacement procedure or providing an alarm when an algorithm detects the 3-D bone models move unexpectedly during the movement of the bones involved in the joint replacement procedure.
2. The process of claim 1 wherein the 3-D models are virtual and said observing is on a video display.
3. The process of claim 1 wherein the registration is confirmed to a computer-assisted surgical system using an input mechanism in communication with the computer-assisted surgical system.
4. The process of claim 1 further comprising re-registering the 3-D models to the bones involved in the joint replacement procedure if the observations of the 3-D bone models collide.
5. The process of claim 1 further comprising re-registering the 3-D models to the bones involved in the joint replacement procedure if the observations of the 3-D models rotate outside of a known anatomical region.
6. The process of claim 5 wherein the bones involved in the joint replacement procedure are a femur and an acetabulum and the 3-D models are re-registered when the observations of the femur 3-D model rotates outside the center of the acetabulum 3-D model.
7. The process of claim 1 further comprising re-registering the 3-D models if the observations of a first 3-D bone model is separated from a second 3-D bone model beyond a specified threshold distance.
8. The process of claim 7 wherein the specified threshold distance is an expected cartilage thickness on an end of one or more bones involved in the joint replacement procedure.
9. The process of claim 1 further comprising simulating operation of the bones involved in the joint replacement procedure as a joint to yield an optimal configuration and displaying the optimal configuration on the corresponding motion in the 3-D models.
10. The process of claim 1 wherein the said alarm is present providing an alarm when an algorithm detects the 3-D bone models move unexpectedly during the movement of the bones involved in the joint replacement procedure.
11. The process of claim 10 wherein the unexpected movements of the 3-D bone models is a movement beyond a specified threshold distance between the 3-D bone models.
12. The process of claim 11 wherein the specified threshold distance is a distance greater than an expected cartilage thickness.
13. The process of claim 10 wherein the bones involved in the joint replacement procedure are a femoral head and an acetabulum and the unexpected movements of the 3-D bone models is a rotation of the femoral head 3-D model outside of the center of the acetabulum 3-D model.