Determining anatomical orientations

Abstract

Methods, systems, and apparatus for determining anatomical orientations are described. Data is received that indicates a position of a reference device configured to move with a pelvis of a subject. Data is received that indicates locations corresponding to a reference surface. Data is received that indicates locations on the pelvis. One or more anatomical orientations are determined based on the locations corresponding to the reference surface and the locations on the pelvis. The anatomical orientations are registered to the reference device.

1 .- 15 . (canceled) 
     
     
         16 . An apparatus comprising:
 one or more processing devices; and   one or more data storage devices storing instructions that are operable, when executed by the one or more processing devices, to cause the one or more processing devices to perform operations comprising:
 receiving a pre-operative image of a target bone of a patient, 
 receiving intra-operative data indicating landmark locations on the target bone, 
 receiving data indicating a position of a reference device, 
 determining a first anatomical orientation of the target bone relative to the reference device based on the pre-operative image of the target bone and the intra-operative data indicating landmark locations on the target bone, 
 determining a second anatomical orientation based on at least one of an x-ray image and intra-operative data indicating a reference surface position adjacent to the patient, and 
 determining a position of a tool relative to the target bone based on at least one of the first anatomical orientation and the second anatomical orientation. 
   
     
     
         17 . The apparatus of  claim 16 , wherein the operations further comprise registering the first anatomical orientation and the second anatomical orientation to the reference device. 
     
     
         18 . The apparatus of  claim 16 , wherein the operations further comprise:
 determining a surgical trajectory based on the first anatomical orientation and the second anatomical orientation;   determining a position of the tool relative to the surgical trajectory based on the position of the reference device; and   outputting data indicating the position of the tool relative to the surgical trajectory.   
     
     
         19 . The apparatus of  claim 18 , wherein determining the surgical trajectory based on the first anatomical orientation and the second anatomical orientation comprises determining an orientation at a predetermined inclination angle and a predetermined anteversion angle relative to the first anatomical orientation and the second anatomical orientation. 
     
     
         20 . The apparatus of  claim 16 , wherein the operations further comprise:
 determining a third anatomical orientation of the patient that is orthogonal to the first anatomical orientation and the second anatomical orientation; and   registering the third anatomical orientation to the reference device.   
     
     
         21 . The apparatus of  claim 16 , wherein receiving intra-operative data indicating landmark locations on the target bone comprises receiving data indicating a plurality of locations on the target bone. 
     
     
         22 . The apparatus of  claim 16 , wherein receiving the data indicating the position of the reference device comprises receiving data indicating a position of an electromagnetic field sensor or a fiducial of the reference device. 
     
     
         23 . An apparatus comprising:
 one or more processing devices; and   one or more data storage devices storing instructions that are operable, when executed by the one or more processing devices, to cause the one or more processing devices to perform operations comprising:
 receiving intra-operative data indicating landmark locations on the target bone of a subject, 
 receiving data indicating a position of a reference device attached to the subject, 
 determining a first anatomical orientation of the target bone based on the intra-operative data and the position of the reference device, 
 determining a second anatomical orientation based on at least one of an x-ray image and an intra-operative data indicating a reference surface position adjacent to the subject, and 
 determining a position of a tool relative to the target bone based on at least one of the first anatomical orientation and the second anatomical orientation. 
   
     
     
         24 . The apparatus of  claim 23 , wherein the operations further comprise registering the first anatomical orientation and the second anatomical orientation to the reference device. 
     
     
         25 . The apparatus of  claim 23 , wherein the operations further comprise:
 determining a surgical trajectory based on the first anatomical orientation and the second anatomical orientation;   determining a position of the tool relative to the surgical trajectory based on the position of the reference device; and   outputting data indicating the position of the tool relative to the surgical trajectory.   
     
     
         26 . The apparatus of  claim 25 , wherein determining the surgical trajectory based on the first anatomical orientation and the second anatomical orientation comprises determining an orientation at a predetermined inclination angle and a predetermined anteversion angle relative to the first anatomical orientation and the second anatomical orientation. 
     
     
         27 . The apparatus of  claim 23 , wherein the operations further comprise:
 determining a third anatomical orientation of the subject that is orthogonal to the first anatomical orientation and the second anatomical orientation; and   registering the third anatomical orientation to the reference device.   
     
     
         28 . The apparatus of  claim 23 , wherein receiving intra-operative data indicating landmark locations on the target bone comprises receiving data indicating a plurality of locations on the target bone. 
     
     
         29 . The apparatus of  claim 23 , wherein receiving the data indicating the position of the reference device comprises receiving data indicating a position of an electromagnetic field sensor or a fiducial of the reference device.