Apparatus and method for image guided insertion and removal of a cannula or needle

Abstract

A means for holding a selected cannula such that the cannula is controllably restricted in motion in all but one line, but still able to slide along the line relatively freely. The motion restricting force may be selectively varied, thereby allowing an unrestricted separation of the cannula and holding/guide device.

1 . An imaging guided device for placing a cannula attached to a magnetically responsive needle at a targeted location, the device comprising: 
 an imaging probe operationally configured with imaging system to present an image;    an attachment connected with the imaging probe, the attachment comprising: 
 a block having at least one magnet to releasably retain the needle by alternating the magnetic force of the magnet applied to the needle,  
   wherein the needle is inserted to and removed from the targeted location as determined in the image at a user adjusted retentive magnetic force, leaving the cannula in place at the targeted location after removal of the needle.    
   
   
       2 . The device of  claim 1 , wherein the magnet comprises at least one removable strip.  
   
   
       3 . The device of  claim 1 , wherein the magnet comprises two removable strips approximately orthogonal to each other.  
   
   
       4 . The device of  claim 3 , wherein the removable strip includes a plurality of magnets having substantially similar magnetic power.  
   
   
       5 . The device of  claim 3 , wherein the removable strip includes a plurality of magnets having substantially different magnetic power.  
   
   
       6 . The device of  claim 5 , wherein the removable strip includes an inner magnetic core and an outer magnetic perimeter.  
   
   
       7 . The device of  claim 1 , wherein the magnet includes a ferrite core having a first gap to engage a moveable magnet bar and a second gap to receive the magnetically responsive needle.  
   
   
       8 . The device of  claim 7 , wherein the moveable magnet bar is slidable within the first gap.  
   
   
       9 . The device of  claim 7 , wherein the moveable magnet bar is translocatable from the first gap.  
   
   
       10 . The device of  claim 7 , wherein the moveable magnet bar is rotatable within the first gap.  
   
   
       11 . The device of  claim 1 , wherein the magnet includes a magnetic core having a first gap to engage a moveable magnet bar and a second gap to receive the magnetically responsive needle.  
   
   
       12 . The device of  claim 11 , wherein the moveable magnet bar is rotatable within the first gap.