Adjustable registration frame

Abstract

A system for determining the position and orientation of a medical device relative to an image space during image-guided medical procedures. The system comprises a flexible pad mounted on the subject such that a part covers the region of interest. The pad incorporates detectable registration members. Prior to the procedure, the device is coupled to the pad, which is then rigidized, so that there is no movement of the registration members relative to each other and relative to the device. The fixed relation-ship between the device and the registration members is determined from initial images, for example using detectable markers attached to the device, enabling the pose of the device relative to the image space of images of the region of interest to be determined later, even if the device is remote from the region of interest. This minimizes exposure of the subject and medical staff to radiation.

1 . A method for determining the real-time position and orientation of an automated medical device relative to an image space during an image-guided procedure, using a mounting apparatus configured for mounting on a body of a subject and for coupling the automated medical device thereto, at least one registration frame comprising at least one semi-flexible strip coupled to the mounting apparatus, and a processor, the method comprising:
 (a) obtaining one or more initial images of the mounting apparatus and the automated medical device coupled thereto;   (b) calculating the position and orientation of the automated medical device relative to the image space in the one or more initial images;   (c) detecting the at least one semi-flexible strip in the one or more initial images;   (d) identifying which of the at least one semi-flexible strip is included in a scan of the one or more initial images;   (e) calculating the position and orientation of the at least one semi-flexible strip relative to the image space in the one or more initial images;   (f) determining the position and orientation of the at least one semi-flexible strip relative to the automated medical device based on the calculated positions and orientations of the automated medical device and of the at least one semi-flexible strip relative to the image space in the one or more initial images;   (g) obtaining one or more real-time images of a region of interest, the one or more real-time images including a portion of the at least one registration frame;   (h) detecting the at least one semi-flexible strip of the portion of the at least one registration frame in the one or more real-time images;   (i) determining the real-time position and orientation of the at least one semi-flexible strip relative to the image space in the one or more real-time images, wherein determining which semi-flexible elements are included in the scan may be based on an highest correlation found between calculated position and orientation of the at least one semi-flexible strip relative to the image space in the one or more real time images and calculated position and orientation of the at least one semi-flexible strip relative to the image space in the one or more initial images; and   (j) determining the real-time position and orientation of the automated medical device relative to the image space in the one or more real-time images based on the real-time position and orientation of the at least one semi-flexible strip of the at least one registration frame relative to the image space of said one or more real time images and the position and orientation of the at least one at least one semi-flexible strip of the at least one registration frame relative to the automated medical device determined based on the one or more initial images.   
     
     
         2 . The method of  claim 1 , comprising, upon identifying which of the at least one semi-flexible strip is included in a scan of the one or more initial images, calculating initial values of one or more predetermined geometric parameters for the at least one registration member. 
     
     
         3 . The method of  claim 1 , comprising, identifying which of the at least one semi-flexible strip is included in the scan of the one or more initial images, identifying initial values of one or more predetermined material parameters for the at least one registration member. 
     
     
         4 . The method of  claim 2 , comprising, upon detecting the at least one semi-flexible strip of the portion of the at least one registration frame in the one or more real-time images, calculating real-time values of the one or more predetermined geometric parameters for the at least one semi-flexible strip of the portion of the registration frame. 
     
     
         5 . The method of  claim 2 , comprising, upon detecting the at least one semi-flexible strip of the portion of the at least one registration frame in the one or more real-time images, calculating real-time values of the one or more predetermined material parameters for the at least one semi-flexible strip of the portion of the at least one registration frame. 
     
     
         6 . The method of  claim 4 , comprising comparing the real-time values of the one or more predetermined geometric parameters to the initial values of the one or more predetermined geometric parameters and identifying the at least one semi-flexible strip of the portion of the at least one registration frame based on the highest correlation found between real-time values and initial values. 
     
     
         7 . The method of  claim 2 , wherein the predetermined geometric parameters comprise one or more of: angle, distance, length, shape, plane, relative position and coordinate system. 
     
     
         8 . The method of  claim 1 , comprising detecting in the one or more initial images, one or more registration markers attached to the automated medical device. 
     
     
         9 . The method of  claim 1 , wherein the registration frame configured to be coupled to the mounting apparatus either as an integral part of the mounting apparatus or removably coupled thereto. 
     
     
         10 . A method for determining the real-time position and orientation of an automated medical device relative to an image space during an image-guided procedure, the method comprising:
 providing a system comprising:
 a mounting apparatus configured for mounting on a body of a subject and for coupling the automated medical device thereto; 
 at least one registration frame configured as at least one semi-flexible element and coupled to the mounting apparatus, such that during the image-guided procedure, there is substantially no relative movement between the at least one semi-flexible element and the automated medical device coupled to the mounting apparatus; and 
 at least one processor; 
   obtaining one or more real-time images of a region of interest in the body of the subject, the one or more real-time images including a portion of the at least one registration frame having the at least one semi-flexible strip;   detecting the at least one semi-flexible strip of the at least one registration frame in the one or more obtained real-time images;   determining the real-time position and orientation of the of the at least one semi-flexible strip relative to the image space; and   determining the real-time position and orientation of the automated medical device relative to the image space based on the determined real-time position and orientation of the portion of the at least one semi-flexible strip relative to the image space and a predetermined relationship between the automated medical device and the at least one semi-flexible strip of the at least one registration frame.   
     
     
         11 . The method of  claim 10 , wherein the step of determining the real-time position and orientation of the at least one semi-flexible strip relative to the image space comprises finding for each of the at least one semi flexible strip a plane which contains the at least on semi flexible strip, and calculating an angle between every two planes. 
     
     
         12 . The method of  claim 11 , wherein the step of determining the real-time position and orientation of the at least one semi flexible strip relative to the image space comprises:
 calculating for every two planes a line where the two plants intersection is found;   calculating the minimal distance between the two intersection lines, the minimal distance points and the position and orientation of the intersection lines' coordinate system of the coordinate system of the image space; and   calculating the real-time position and orientation of the intersection lines' coordinate system relative to the image space.   
     
     
         13 . The method of  claim 10 , further comprising determining the predetermined relationship between the automated medical device and the at least one at least one semi-flexible element using one or more initial images. 
     
     
         14 . A system for determining the real-time position and orientation of an automated medical device relative to an image space during image-guided procedures, the system comprising:
 a mounting apparatus configured for mounting on a body of a subject and for coupling the automated medical device thereto;   at least one registration frame coupled to the mounting apparatus; and   a processor configured to:
 detect a portion of the at least one registration frame in one or more real-time images obtained from an imaging system; 
 determine the real-time position and orientation of the portion of the at least one registration frame relative to the image space; and 
 determine the real-time position and orientation of the automated medical device relative to the image space based on the determined real-time position and orientation of the portion of the at least one registration frame relative to the image space and a predetermined relationship between the automated medical device and the at least one registration frame. 
   
     
     
         15 . The system of  claim 14 , wherein the processor is configured to determine the predetermined relationship between the automated medical device and the at least one registration frame using one or more initial images obtained from the imaging system. 
     
     
         16 . The system of  claim 14 , wherein the at least one registration member comprises at least one semi-flexible element. 
     
     
         17 . The system of  claim 14 , further comprising one or more registration markers attached to the automated medical device, and wherein the processor is configured to detect the one or more registration markers in one or more images obtained from the imaging system.