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.

What is claimed is: 
     
         1 . A hand held surgical tool comprising:
 a housing having a distal end and a proximal end;   a shaft having a distal end adapted to engage tissue at a pre-determined surgical site, the shaft disposed within and moveable relative to an interior portion of the housing;   an actuator coupled to the shaft and configured to provide controllable movement of the shaft relative to the distal end of the housing;   one or more elements coupled to an exterior portion of the housing for use in detecting a position and orientation of the surgical tool; and   a processor attached to or coupled to the housing, the processor in communication with the actuator and having instructions to control the operation of the actuator for controllable movement of the shaft in response to a signal received from a surgical computer.   
     
     
         2 . The tool of  claim 1 , wherein the signals received by the processor to operate the actuator are based on a surgical plan for a patient anatomy within the pre-determined surgical site and a position and orientation of the surgical tool relative to the patient anatomy within the pre-determined surgical site, the position and orientation obtained using the one or more elements. 
     
     
         3 . The tool of  claim 2 , wherein the surgical computer is configured to correlate the position and orientation of the surgical tool to the surgical plan for the patient anatomy within the pre-determined surgical site. 
     
     
         4 . The tool of  claim 2 , wherein when the distal end of the shaft is engaged with tissue a portion of the patient anatomy in the pre-selected surgical site is marked. 
     
     
         5 . The tool of  claim 4 , wherein the patient anatomy is a bone. 
     
     
         6 . The tool of  claim 5 , wherein the mark comprises a visible mark. 
     
     
         7 . The tool of  claim 1 , wherein the one or more elements for detecting the position and orientation of the surgical tool are part of a reference frame. 
     
     
         8 . The tool of  claim 1 , wherein the one or more elements for detecting the position and orientation of the surgical tool include a plurality of position markers. 
     
     
         9 . A surgical system comprising the tool of  claim 1 , further comprising an optical tracking system configured to optically track the one or more elements to detect the position and orientation of the surgical tool. 
     
     
         10 . The surgical system of  claim 9 , wherein the optical tracking system is configured to communicate the position and orientation of the surgical tool to the surgical computer. 
     
     
         11 . A surgical system comprising the tool of  claim 2 , further comprising a monitor configured to display the movement of the hand held surgical tool in real time. 
     
     
         12 . The surgical system of  claim 11 , wherein the monitor is further configured to display a portion of the surgical plan for the patient anatomy within the pre-determined surgical site. 
     
     
         13 . The surgical system of  claim 12 , wherein the patient anatomy is a portion of a femur or a tibia or a knee. 
     
     
         14 . The tool of  claim 1 , wherein the processor communicates with the surgical computer through a wired connection. 
     
     
         15 . The tool of  claim 1 , wherein the processor communicates with the surgical computer through a wireless connection. 
     
     
         16 . The tool of  claim 1 , wherein the actuator is an electromechanical actuator. 
     
     
         17 . The tool of  claim 1 , wherein the range of the actuator movement is configured to extend the distal end of the shaft past the distal end of the housing. 
     
     
         18 . The tool of  claim 2 , wherein the surgical plan includes a plan for a total knee replacement surgery. 
     
     
         19 . The surgical tool of  claim 1 , wherein the hand held surgical tool includes a surface for manually grasping the device. 
     
     
         20 . A surgical system comprising:
 a surgical computer;   a hand held surgical tool comprising:
 a housing having a distal end and a proximal end; 
 a shaft having a distal end adapted to engage tissue at a pre-determined surgical site, the shaft disposed within and moveable relative to an interior portion of the housing; 
 an actuator coupled to the shaft and configured to provide controllable movement of the shaft relative to the distal end of the housing; 
 one or more elements coupled to an exterior portion of the housing for use in detecting a position and orientation of the surgical tool; and 
 a processor attached to or coupled to the housing, the processor in communication with the actuator and having instructions to control the operation of the actuator for controllable movement of the shaft in response to a signal received from a surgical computer; and 
 a monitor for displaying the position of the hand held surgical tool. 
   
     
     
         21 . The surgical system of  claim 20 , further comprising an optical tracking system configured to optically track the one or more elements for detecting the position and orientation of the surgical tool. 
     
     
         22 . A method for marking a patient, the method comprising:
 creating a three dimensional representation of a portion of the patient to which a bone or tissue cutting procedure is to be performed;   identifying an area of the three dimensional representation corresponding to a portion of bone or tissue for which the procedure is to be performed;   tracking a guided surgical tool to determine a position and orientation of the tool relative to the portion of bone or tissue;   marking a portion of the bone or tissue with a tissue engaging portion at a distal most end of a shaft extending from the guided surgical tool; and   operating an actuator coupled to a housing of the guided surgical tool in response to an indication that the tissue engaging portion of the distal most end of the shaft is in an undesired position, the operating step providing relative movement between the shaft and the housing to prevent engagement of the distal most end of the shaft with the bone or tissue.   
     
     
         23 . The method of  claim 22 , wherein the surgical tool is a freehand surgical tool. 
     
     
         24 . The method of  claim 22 , wherein marking includes modifying a surface of the portion of the bone or tissue. 
     
     
         25 . The method of  claim 22 , further comprising comparing the three dimensional representation of the portion of the patient to the position and orientation of the tool using a surgical computer. 
     
     
         26 . The method of  claim 22 , wherein tracking the surgical tool includes using an optical tracking system to track a reference frame on the surgical tool. 
     
     
         27 . The method of  claim 22 , further comprising guiding the surgical tool to mark the portion of bone or tissue with an outline corresponding to a shape of a preselected prosthesis. 
     
     
         28 . The method of  claim 27 , wherein the prosthesis is a femoral implant. 
     
     
         29 . The method of  claim 21 , further comprising guiding the surgical tool to mark the portion of bone or tissue with lines corresponding to cut planes for a total knee replacement procedure. 
     
     
         30 . The method of  claim 29 , further comprising preselecting the lines corresponding to cut planes based on the three dimensional representation of the portion of the patient and a configuration of a preselected prosthesis.