Navigation of medical instrument

Abstract

The subject invention pertains to a device for inserting medical instruments into the human body. In a specific embodiment, the subject device can be made from a material which is invisible under Magnetic Resonance Imaging (MRI). The subject device can incorporate three or more MRI compatible marks. The imaging of these three or more markers can allow the determination of the orientation of the device. A virtual image of the device can then be shown in an MRI image.

1 . An apparatus for inserting an instrument into a human body, comprising: 
 an element configured to be fixedly positioned relative to a part of the human body, wherein at least a portion of the element is invisible under magnetic resonance imaging;    an instrument insertion channel movably connected to the element, wherein at least a portion of the instrument insertion channel is invisible under magnetic resonance imaging;    a means for determining the relative position of the instrument insertion channel with respect to the element such that once the position of the element is known, the position of the instrument insertion channel is known, or that once the position of the instrument insertion channel is known, the position of the element is known; and    at least three positioning markers, wherein the at least three positioning markers are each fixedly positioned relative to the element, fixedly positioned relative to the instrument insertion channel, or fixedly positioned relative to an instrument.    
   
   
       2 . The apparatus according to  claim 1 , wherein the element is configured to be fixedly positioned relative to a human head.  
   
   
       3 . The apparatus according to  claim 1 , wherein the at least three positioning markers are visible under magnetic resonance imaging.  
   
   
       4 . The apparatus according to  claim 3 , wherein under magnetic resonance imaging, the at least three positioning markers allow determination of the orientation of the element and determination of the orientation of the instrument insertion channel.  
   
   
       5 . The apparatus according to  claim 3 , wherein the at least three positioning markers can be distinguished from one another by magnetic resonance imaging.  
   
   
       6 . The apparatus according to  claim 5 , wherein the at least three positioning markers comprise coils.  
   
   
       7 . The apparatus according to  claim 5 , wherein at least one of the at least three positioning markers comprises a volume filled with a material positively or negatively identifiable under magnetic resonance imaging.  
   
   
       8 . The apparatus according to  claim 3 , further comprising a means for showing a virtual image of the instrument insertion channel in a magnetic resonance image.  
   
   
       9 . The apparatus according to  claim 1 , wherein the at least three positioning markers comprise optically active or optically reflecting positioning markers.  
   
   
       10 . The apparatus according to  claim 1 , wherein the at least three positioning markers are fixedly positioned relative to the element, wherein the position of the element can be determined by monitoring the at least three positioning markers fixedly positioned with respect to the element such that the position of the instrument insertion channel can be determined via the means for determining the relative position of the instrument insertion channel with respect to the element.  
   
   
       11 . The apparatus according to  claim 10 , wherein one of the at least three positioning markers comprises a titanium screw.  
   
   
       12 . The apparatus according to  claim 10 , wherein at least one of the at least three positioning markers are within the element.  
   
   
       13 . The apparatus according to  claim 1 , wherein the at least three positioning markers are fixedly positioned relative to the instrument insertion channel, 
 wherein the position of the instrument insertion channel can be determined by monitoring the at least three positioning markers such that the position of the element can be determined via the means for determining the relative position of the instrument insertion channel with respect to the element.    
   
   
       14 . The apparatus according to  claim 1 , wherein the at least three positioning markers comprise six positioning markers, wherein three of the six positioning markers are fixedly positioned relative to the element and three of the six positioning markers are fixedly positioned relative to the instrument insertion channel.  
   
   
       15 . The apparatus according to  claim 14 , wherein the three of the six positioning markers fixedly positioned relative to the element are distinguishable from the three of the six positioning markers fixedly positioned relative to the instrument insertion channel.  
   
   
       16 . The apparatus according to  claim 15 , wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to different wavelengths.  
   
   
       17 . The apparatus according to  claim 15 , wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to a different codification.  
   
   
       18 . The apparatus according to  claim 15 , wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to different geometrically designed reflectors.  
   
   
       19 . The apparatus according to  claim 1 , wherein two of the at least three positioning markers are fixedly positioned relative to the element, and 
 wherein one of the at least three positioning markers is fixedly positioned relative to the instrument insertion channel.    
   
   
       20 . The apparatus according to  claim 19 , wherein at least one of the two of the at least three positioning markers fixedly positioned relative to the element comprises a titanium screw.  
   
   
       21 . The apparatus according to  claim 1 , wherein the at least three positioning markers comprise: 
 a first positioning marker fixedly positioned relative to the instrument insertion channel,    a second positioning marker fixedly positioned relative to the element, and    a third positioning marker fixedly positioned relative to a distal end of the instrument.    
   
   
       22 . The apparatus according to  claim 1 , wherein the means for determining the relative position of the instrument insertion channel with respect to the element comprises: 
 a means for measuring an azimuth angle that the instrument insertion channel makes with respect to an axis parallel to a plane of the element, and    a means for measuring a zenith angle that the instrument insertion channel makes with respect to the plane of the element.    
   
   
       23 . The apparatus according to  claim 22 , wherein the means for measuring the azimuth angle comprises a scaling on a top piece attached to the element, and 
 wherein the means for measuring the zenith angle comprises a scaling on the element.    
   
   
       24 . The apparatus according to  claim 1 , further comprising: 
 a means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body.    
   
   
       25 . The apparatus according to  claim 24 , wherein the means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body comprises: 
 a tilting means, wherein the tilting means comprises: 
 a first movable lamina having a first opening, and  
 a second movable lamina having a second opening,  
   wherein the first movable lamina is positioned relative to the element configured to be fixedly positioned relative to a human skull and the second movable lamina is positioned relative to the first movable lamina such that the instrument insertion channel extends through the first opening of the first movable lamina and the second opening of the second movable lamina,    wherein the first opening is shaped such that the first movable lamina allows the instrument insertion channel to tilt in a first plane, wherein the second opening is shaped such that the second movable lamina allows the instrument insertion channel to tilt in a second plane orthogonal to the first plane.    
   
   
       26 . The apparatus according to  claim 25 , further comprising a means for actuating a tilting motion.  
   
   
       27 . The apparatus according to  claim 24 , wherein the means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body comprises: 
 a worm wheel movable attached to the instrument insertion channel, wherein the worm wheel provides a tilting motion and a rotating motion.    
   
   
       28 . The apparatus according to  claim 27 , further comprising a means for actuating the tilting motion and the rotating motion.  
   
   
       29 . The apparatus according to  claim 1 , further comprising: 
 a stabilization channel removably positioned within the instrument insertion channel such that upon inserting an instrument into the instrument insertion channel, the instrument is inserted through the stabilization channel.    
   
   
       30 . The apparatus according to  claim 29 , further comprising: 
 a mounting for shifting in an axial direction with respect to the instrument insertion channel, wherein the stabilization channel extends through the mounting.    
   
   
       31 . The apparatus according to  claim 30 , further comprising a means for actuating movement of the mounting in the axial direction.  
   
   
       32 . A method for inserting an instrument into a human body, comprising: 
 positioning an apparatus at a location relative to a part of a human body, wherein the apparatus comprises: 
 i) an element configured to be fixedly positioned relative to the part of a human body,  
 ii) an instrument insertion channel, and  
 iii) at least three positioning markers at a location relative to the part of a human body, wherein the at least three positioning markers are each fixedly positioned relative to the element, fixedly positioned relative to the instrument insertion channel, or fixedly positioned relative to an instrument,  
   wherein positioning the apparatus at a location relative to a part of a human body comprises: 
 positioning the element with relative to the part of a human body, and  
 positioning the instrument insertion channel with respect to the element; and  
   determining the orientation of the apparatus with respect to the part of a human body, wherein determining the orientation of the apparatus with respect to the part of a human body comprises: 
 monitoring the at least three positioning markers, and  
 determining the relative position of the instrument insertion channel with respect to the element.  
   
   
   
       33 . The method according to  claim 32 , wherein the element comprises a self-cutting thread, wherein fixedly attaching the element to the part of a human body comprises screwing the element into a human skull.  
   
   
       34 . The method according to  claim 32 , wherein monitoring the at least three positioning markers comprises imaging the at least three positioning markers with a magnetic resonance imaging system.  
   
   
       35 . The method according to  claim 32 , wherein monitoring the at least three positioning markers comprises imaging the at least three positioning markers with a respective camera system.  
   
   
       36 . The method according to  claim 32 , wherein determining the relative position of the instrument insertion channel with respect to the element comprises: 
 monitoring a means for measuring an azimuth angle that the instrument insertion channel makes with respect to an axis parallel to a plane of the element, and    monitoring a means for measuring a zenith angle that the instrument insertion channel makes with respect to the plane of the element.    
   
   
       37 . The method according to  claim 36 , further comprising indicating the azimuth angle and the zenith angle in an MR image.  
   
   
       38 . The method according to  claim 37 , further comprising adjusting the orientation of the MR image to the orientation of the apparatus with respect to the part of a human body.  
   
   
       39 . The method according to  claim 37 , further comprising adjusting the position of the instrument insertion channel with respect to the orientation of the MR image.  
   
   
       40 . The method according to  claim 32 , further comprising creating a virtual image of the apparatus in a MR image.  
   
   
       41 . The method according to  claim 32 , wherein determining the orientation of the apparatus with respect to the part of a human body determines the orientation of an instrument inserted through the instrument insertion channel.