Method and apparatus for reconstructing bone surfaces during surgery

Abstract

There is provided a method for intraoperatively presenting an approximate model of an anatomical structure by collecting a cloud of small surfaces. The cloud of small surfaces is gathered with a registration pointer having an adapted tip capable of making contact with the surface of an anatomical structure and registering the normal at the point of contact.

1 . A method for intraoperatively presenting a representation of an anatomical structure, the anatomical structure being a bone, the method comprising:
 acquiring input data by applying a tool directly in contact against locations on said bone and tracking the tool;   processing said input data into a representation of said bone without using an image of the anatomical structure taken preoperatively or intra-operatively; and   displaying said representation without any image of the anatomical structure taken preoperatively or intra-operatively, and with orientation data of a tracked surgical tool on an output device.   
   
   
       2 . A method as claimed in  claim 1 , wherein said processing comprises processing said input data into a cloud of locations forming a mosaic and representing a portion of said anatomical structure. 
   
   
       3 . A method as claimed in  claim 1 , wherein said processing comprises smoothing over a surface represented by said input data to display a smoothed surface of a portion of said anatomical structure. 
   
   
       4 . A method as claimed in  claim 3 , wherein said processing comprises providing on said smoothed surface said plurality of locations where said input data was acquired. 
   
   
       5 . A method as claimed in  claim 4 , comprising repeating said acquiring input data after said displaying to adjust said model of said anatomical structure. 
   
   
       6 . A method as claimed in  claim 1 , wherein said processing comprises reconstructing a three-dimensional model using said input data to display a three-dimensional model of a portion of said anatomical structure. 
   
   
       7 . A method as claimed in  claim 1 , wherein said processing comprises reconstructing a three-dimensional model using said input data and a known model of said anatomical structure to display a three-dimensional model of said anatomical structure. 
   
   
       8 . A method as claimed in  claim 1 , wherein said processing comprises selecting a known model from a known model database comprising a plurality of known models of varying sizes and shapes and performing an algorithm to determine a best-fit match of said input data onto said known model. 
   
   
       9 . A method as claimed in  claim 8 , wherein said processing comprises providing on said known model said best-fit match such that said best-fit match is displayed on said output device. 
   
   
       10 . A method as claimed in  claim 2 , wherein said processing comprises attaching a portion of a known model of said anatomical structure to said mosaic representing a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed. 
   
   
       11 . A method as claimed in  claim 3 , wherein said processing comprises attaching a portion of a known model of said anatomical structure to said smoothed surface of a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed. 
   
   
       12 . A method as claimed in  claim 6 , wherein said processing comprises attaching a portion of a known model of said anatomical structure to said three-dimensional model of a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed. 
   
   
       13 . A method as claimed in  claim 1 , wherein said acquiring input data comprises determining a normal to each of said plurality of locations. 
   
   
       14 . A method as claimed in  claim 1 , wherein processing said input data into a representation comprises processing a representation of axes of the anatomical structure. 
   
   
       15 . A method as claimed in  claim 1 , wherein processing said input data into a representation comprises processing a representation from the normal of locations on the bone. 
   
   
       16 . A method as claimed in  claim 1 , wherein processing said input data into a representation comprises processing said input data into an approximate model of the anatomical structure. 
   
   
       17 . A method as claimed in  claim 1 , wherein displaying said representation with a tracked surgical tool comprises displaying said representation with a cutting block.