Method for using a fixator device

Abstract

A method for determining the proper configuration of a fixator or other medical device to correct a given deformity by solving the simultaneous equations representing the kinematic chain for the device. One skilled in the art would appreciate that x-rays, clinical evaluations, or a combination of both may be used to determine the distal and proximal mounting characteristics, including the use of digital x-rays with images from an imaging device to reduce or eliminate the needs for a physician to take measurements. The technique can be expanded to other medical evaluations. Additionally, one skilled in the art would appreciate that the method of the present invention could be written as one or more sets of instructions stored on a computer-readable medium that could be executed by a computer.

1 . A method for characterizing the configuration of a portion of body tissue within a patient, comprising the steps of:
 generating a digital x-ray image comprising a plurality of individual images, wherein the plurality of individual images correspond to a plurality of identifiable shapes associated with an imaging device and with the portion of body tissue;   detecting an edge of each of the plurality of individual images;   identifying outlines from the plurality of individual image edges that correspond to the plurality of identifiable shapes associated with the imaging device;   determining the geometric parameters associated with each of the identified outlines;   characterizing a coordinate system associated with the imaging device based on the determined geometric parameters;   determining one or more anatomical axes associated with the portion of body tissues; and   characterizing the physical configuration of the portion of body tissue based on the one or more anatomical axes and the coordinate system.   
     
     
         2 . The method of  claim 1  wherein the portion of body tissue comprises a first bone fragment and a second bone fragment. 
     
     
         3 . The method of  claim 2  wherein the imaging device is attached to a deformity-correcting fixator and the method is used to align the first bone fragment and the second bone fragment. 
     
     
         4 . The method of  claim 1  wherein the imaging device comprises three balls spatially fixed relative to one another. 
     
     
         5 - 6 . (canceled) 
     
     
         7 . The method of  claim 1  wherein the step of identifying outlines of the first representation comprises using a graphical user interface to identify circular images in the digital file of the x-ray. 
     
     
         8 - 16 . (canceled) 
     
     
         17 . A computer-readable storage device storing a set of computer-executable instructions implementing a method for determining a position of a fixator, the method comprising the steps of:
 a) characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus;   b) determining a first set of fixator characteristics, wherein the first set of characteristics correspond to physical dimensions of the fixator;   c) determining a deformity correction matrix by solving a plurality of simultaneous equations, wherein the equations correspond to kinematic equations;   d) solving for a second set of fixator settings by equating the deformity correction matrix to a deformity correction transform; and   e) reconfiguring the deformity correcting fixator based on the second set of fixator setting.   
     
     
         18 . The computer-readable storage device of  claim 17  wherein the step of characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus further comprises the steps of:
 a) determining an axial rotation for a proximal bone fragment attachment apparatus; 
 b) determining an anterior-posterior rotation for the proximal bone fragment attachment apparatus; 
 c) determining a lateral rotation for the proximal bone fragment attachment apparatus; 
 d) determining a pin offset rotation for the proximal bone fragment attachment apparatus; 
 repeating steps a) through d) for a distal bone fragment attachment apparatus; and 
 determining the bone length. 
 
     
     
         19 . The computer-readable storage device of  claim 17  wherein the step of characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus further comprises the steps of:
 a) generating a digital x-ray image comprising a plurality of individual images, wherein the plurality of individual images correspond to a plurality of identifiable shapes associated with an imaging device and with the portion of body tissue; 
 b) detecting an edge of each of the plurality of individual images; 
 c) identifying outlines from the plurality of individual image edges that correspond to the plurality of identifiable shapes associated with the imaging device; 
 d) determining the geometric parameters associated with each of the identified outlines; 
 e) characterizing a coordinate system associated with the imaging device based on the determined geometric parameters; 
 f) determining one or more anatomical axes associated with portion of body tissue; 
 g) characterizing the physical configuration of the portion of body tissue based on the one or more anatomical axes and the coordinate system; 
 h) repeating steps a) through g) for a second digital x-ray image. 
 
     
     
         20 . A method for characterizing the configuration of a portion of body tissue within a patient, comprising the steps of:
 generating a first two-dimensional digital x-ray image comprising a first plurality of individual images, wherein the first plurality of individual images correspond to a first plurality of identifiable shapes associated with an imaging device and with the portion of body tissue;   generating a second two-dimensional digital x-ray image comprising a second plurality of individual images, wherein the second plurality of individual images correspond to a second plurality of identifiable shapes associated with the imaging device and with the portion of body tissue, the second digital x-ray image showing the imaging device and the portion of body tissue at an angle relative to the first digital x-ray image;   detecting an edge of each of the first plurality of individual images and the second plurality of individual images;   identifying outlines from the first and second pluralities of individual image edges that correspond to the respective first and second pluralities of identifiable shapes associated with the imaging device;   determining the geometric parameters associated with each of the identified outlines;   characterizing a coordinate system associated with the imaging device based on the determined geometric parameters, the step of characterizing a coordinate system comprising determining a three-dimensional coordinate system for the imaging device from the first and second two-dimensional digital x-ray images;   determining one or more anatomical axes associated with the portion of body tissue; and   characterizing the physical configuration of the portion of body tissue based on the one or more anatomical axes and the coordinate system.   
     
     
         21 . The method of  claim 20  wherein the portion of body tissue comprises a first bone fragment and a second bone fragment. 
     
     
         22 . The method of  claim 21  wherein the imaging device is attached to a deformity-correcting fixator and the method is used to align the first bone fragment and the second bone fragment. 
     
     
         23 . The method of  claim 20 , wherein the imaging device comprises three balls, wherein each of the balls are spatially fixed in relationship to one another. 
     
     
         24 . The method of  claim 20 , wherein the step of identifying outlines of the first representation comprises using a graphical user interface to identify circular images in the digital file of the x-ray. 
     
     
         25 . A method for characterizing the configuration of a portion of body tissue within a patient comprising the steps of:
 generating a first two-dimensional digital x-ray image comprising a first plurality of individual images, wherein the first plurality of individual images correspond to a portion of body tissue;   generating a second two-dimensional digital x-ray image comprising a second plurality of individual images, wherein the second plurality of individual images correspond to a portion of body tissue, the second digital x-ray image showing the portion of body tissue at an angle relative to the first digital x-ray image;   superimposing a snapped line in the first two-dimensional x-ray image whose endpoints and alignment roughly correspond to the extremes and orientation of a portion of body tissue;   superimposing a snapped line in the second two-dimensional x-ray image whose endpoints and alignment roughly correspond to the extremes and orientation of a portion of body tissue;   characterizing a plane that both intersects the snapped line in the first two dimensional x-ray image and is normal to the plane of the first two dimensional x-ray image;   characterizing a plane that both intersects the snapped line in the second two dimensional x-ray image and is normal to the plane of the second two dimensional x-ray image;   describing a line that results from the intersection of the above characterized planes whose endpoints correspond to the endpoints of one of the snapped lines;   characterizing a coordinate system such that the origin corresponds to one of the described lines endpoints and one of the axes of the coordinate system is collinear with the described line and the rotation of the remaining axes about the described line are based on a projection of a clinically evaluated rotation of the body tissue about the described line.   
     
     
         26 . The method of  claim 25  wherein the first and second two-dimensional x-ray images are comprised of a plurality of individual images relating to a plurality of distinct body tissues, each of which is characterized individually. 
     
     
         27 . The method of  claim 26  wherein the individually characterized distinct body tissues are related to each other in the common three-dimensional space described in the first and second two-dimensional x-ray images. 
     
     
         28 . The method of  claim 27  wherein the related characterization of distinct body tissues utilizes an augmented transformation matrix containing both position and rotation. 
     
     
         29 . A computer-readable storage device storing a set of computer-executable instructions implementing a method for determining a position of a deformity-correcting fixator, the method comprising the steps of:
 a) characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus, wherein characterizing a mounting condition includes
 generating a first two-dimensional digital x-ray image comprising a first plurality of individual images corresponding to a first plurality of identifiable shapes associated with an imaging device on the deformity-correcting fixator; 
 generating a second two-dimensional digital x-ray image comprising a second plurality of individual images corresponding to a second plurality of identifiable shapes associated with the imaging device on the deformity-correcting fixator, the second digital x-ray image taken at an angle relative to the first digital x-ray image; 
 determining a three-dimensional coordinate system for the imaging device from the first and second two-dimensional digital x-ray images; 
   
       determining the mounting condition of the proximal bone fragment attachment apparatus and the distal bone fragment attachment apparatus based on the determined three-dimensional coordinate system for the imaging device;
 b) determining a first set of fixator characteristics, wherein the first set of characteristics correspond to physical dimensions of the fixator; 
 c) determining a deformity correction matrix by solving a plurality of simultaneous equations, wherein the equations correspond to kinematic equations; 
 d) solving for a second set of fixator settings by equating the deformity correction matrix to a deformity correction transform; and 
 e) reconfiguring the deformity correcting fixator based on the second set of fixator settings. 
 
     
     
         30 . The computer-readable storage device of  claim 29  wherein of computer-executable instructions implementing a method with the step of characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus further comprises the steps of:
 a) determining an axial rotation for a proximal bone fragment attachment apparatus; 
 b) determining an anterior-posterior rotation for the proximal bone fragment attachment apparatus; 
 c) determining a lateral rotation for the proximal bone fragment attachment apparatus; 
 d) determining a pin offset rotation for the proximal bone fragment attachment apparatus; 
 repeating steps a) through d) for a distal bone fragment attachment apparatus; and 
 determining the bone length. 
 
     
     
         31 . The computer-readable storage device of  claim 29  wherein of computer-executable instructions implementing a method with the step of characterizing a mounting condition for a proximal bone fragment attachment apparatus and a distal bone fragment attachment apparatus further comprises the steps of:
 a) detecting an edge of each of the plurality of individual images; 
 b) identifying outlines from the plurality of individual image edges that correspond to the plurality of identifiable shapes associated with the imaging device; 
 c) determining the geometric parameters associated with each of the identified outlines; 
 d) characterizing the three-dimensional coordinate system associated with the imaging device based on the determined geometric parameters; 
 e) determining one or more anatomical axes associated with the portion of body tissue; and 
 f) characterizing the physical configuration of the portion of body tissue based on the one or more anatomical axes and the coordinate system.