Method and apparatus for computer aided surgery

Abstract

A number of improvements are provided relating to computer aided surgery. The improvement relates to both the methods used during computer aided surgery and the devices used during such procedures. Some of the improvement relate to controlling the selection of which data to display during a procedure and/or how the data is displayed to aid the surgeon. Other improvements relate to the structure of the tools used during a procedure and how the tools can be controlled automatically to improve the efficiency of the procedure. Still other improvements relate to methods of providing feedback during a procedure to improve either the efficiency or quality, or both, for a procedure.

1 . (canceled) 
     
     
         2 . A free hand navigated surgical saw, comprising:
 a housing, a saw blade extending from the housing and a computer display mounted on the housing wherein the computer display is within the field of view of a user looking at the saw blade while using the free hand navigated surgical saw during a computer aided surgery procedure; and   a wireless communication unit in the free hand navigated surgical saw configured to receive computer readable instructions from a computer assisted surgery system used during the computer aided surgery procedure to change the output of the computer display in response to the computer readable instructions, wherein the computer readable instructions include instructions for altering a view of a representation of a relevant portion of a patient specific virtual model of patient anatomy in the computer display as a result of a detected position and orientation of the free hand surgical saw in relation to the actual patient anatomy represented in the virtual model of the relevant portion of the patient anatomy in the computer display.   
     
     
         3 . The free hand navigated surgical saw of  claim 2  wherein in response to the detected position and orientation of the free hand surgical saw in relation to the actual patient anatomy the orientation of the virtual model of patient anatomy in the computer display changes to a preset view of the virtual model selected from a predefined set of views of the virtual model. 
     
     
         4 . The free hand navigated surgical saw of  claim 3  wherein the predefined set of views of the virtual model are provided from a previously recorded virtual surgery performed using the virtual model of the patient anatomy. 
     
     
         5 . The free hand navigated surgical saw of  claim 2  wherein in response to the detected position and orientation of the free hand surgical saw in relation to the actual patient anatomy the orientation of the virtual model of patient anatomy in the computer display changes to a user defined preset view of the virtual model selected from a previously performed surgical procedure performed using the virtual model. 
     
     
         6 . The free hand navigated surgical saw of  claim 2  wherein in virtual model of the patient anatomy in the computer display changes in response to real time interaction of the free hand surgical saw with the actual patient anatomy. 
     
     
         7 . The free hand navigated surgical saw of  claim 6  wherein a visible indication in the computer display indicates to the user whether the detected position and orientation of the free hand surgical saw corresponds to a previously performed surgical procedure performed using the virtual model. 
     
     
         8 . The free hand navigated surgical saw of  claim 6  wherein the visible indication is a visual representation of the saw blade that is a line when the saw blade is in a proper alignment and an oval when the saw blade is in an improper alignment. 
     
     
         9 . The free hand navigated surgical saw of  claim 6  wherein the visible indication is a color based visual representation indicating whether the position and orientation of the surgical saw corresponds to a position and orientation of the saw in a planned computer aided surgery using the patient specific virtual model. 
     
     
         10 . The free hand navigated surgical saw of  claim 2  wherein the relevant portion of the patient specific virtual model of patient anatomy is a portion of a femur or a tibia or a knee. 
     
     
         11 . The free hand navigated surgical saw of  claim 2  wherein the patient specific virtual model of patient anatomy is annotated in the computer display to indicate portions of the patient that are to be operated on. 
     
     
         12 . The free hand navigated surgical saw of  claim 2  wherein the patient specific virtual model of patient anatomy is annotated in the computer display to indicate boundaries of the tissue to be resected during an actual surgical procedure. 
     
     
         13 . The free hand navigated surgical saw of  claim 2  wherein the patient specific virtual model of patient anatomy is annotated in the computer display to indicate a pre-planned plane along which the patient tissue is to be resected. 
     
     
         14 . The free hand navigated surgical saw of  claim 2  wherein in response to the detected position and orientation of the free hand surgical saw in relation to the actual patient anatomy the orientation of the virtual model of patient anatomy in the computer display changes to a pre-programed view for one of a number of pre-determined cutting plans for a pre-planned TKR procedure.