Magnetically navigable and/or controllable device for removing material from body lumens and cavities

Abstract

A magnetically navigable atherectomy device includes a cutting head, a flexible drive shaft having a proximal and a distal end, with the cutting device on the distal end, and a magnet associated with the cutting head, the magnet of sufficient size to allow the cutting head to be oriented by an externally applied magnetic field. The magnet may be a portion of the cutting head made from a magnetically permeable or permanent magnetic material, a portion of the drive shaft made from a magnetically permeable or permanent magnetic material; a separate magnet between the cutting head and the drive shaft, a portion a magnet on a sheath covering the drive shaft. Alternatively a guide wire can provided with a magnetic material on its distal end. Through the application of a magnetic field and/or a magnetic gradient, the artherectomy device can be guided to the location of the atheromatous material in the body. Once at the site of atheromatous material, through the application of a magnetic field or magnetic gradient, the device can be manipulated into proximity to the atheromatous material to remove the material.

1 . A device for removing material from the surface of body lumens and cavities, the device comprising: 
 a cutting head; and    a magnet associated with the cutting head, the magnet of sufficient size to allow the cutting head to be oriented by an externally applied magnetic field.    
   
   
       2 . The device according to  claim 1  wherein the magnet comprises a portion of the cutting head made from a magnetically permeable or permanent magnetic material.  
   
   
       3 . The device according to  claim 1  further comprising a flexible drive shaft having a proximal and a distal end, with the cutting device on the distal end, and wherein the magnet comprises a portion of the flexible drive shaft being made of a magnetically permeable or permanent magnetic material.  
   
   
       4 . The device according to  claim 1  wherein the magnet is a magnetically permeable or permanent magnetic material disposed between the cutting head and the flexible drive shaft.  
   
   
       5 . The device according to  claim 1  further comprising a sheath, over the drive shaft, and wherein the magnet is on the distal end of the sheath.  
   
   
       6 . The device according to  claim 1  further comprising a generally axially extending passage through the cutting head and the drive shaft for accommodating a guide wire.  
   
   
       7 . A method of removing material from the surface of a body lumen or cavity, the method comprising: 
 introducing a guide wire having magnetic material at its distal end into the body lumen or cavity, and navigating the guide wire to the site of the material to be removed by successively applying a magnetic field to orient the distal end of the guide wire and advancing the guide wire in the lumen or cavity to the site of the material to be removed;    advancing a tool having a cutting head for removing the material, along the guide wire to the site of the material, and    operating the cutting head to remove the material from the walls of the blood vessel.    
   
   
       8 . The method according to  claim 7  wherein the step of advancing the guide wire comprises applying a magnetic field gradient to the distal end of the guide wire to apply a motive force to move the distal end of the guide wire.  
   
   
       9 . The method according to  claim 7  wherein the step of operating the cutting head to remove the material comprises advancing the tool over the guide wire into close proximity with the magnetic material, and applying a magnetic field to the magnetic material to orient the cutting head of the tool.  
   
   
       10 . The method according to  claim 7  wherein the step of operating the cutting head to remove the material comprises advancing the tool over the guide wire into close proximity with the magnetic material, and applying a magnetic gradient to the magnetic material to move the cutting head toward the material in the lumen or cavity.  
   
   
       11 . The method according to  claim 7  wherein the step of operating the cutting head to remove the material comprises advancing the tool over the guide wire into close proximity with the magnetic material, and applying a magnetic field to orient the cutting head and a magnetic gradient to move the cutting head toward the material in the lumen or cavity.  
   
   
       12 . A method of removing material from the surface of a body lumen or cavity, the method comprising: 
 introducing a guide wire having magnetic material at its distal end into the body lumen or cavity, and navigating the guide wire to the site of the material to be removed;    advancing a tool having a cutting head for removing the material, along the guide wire to the site of the material and into close proximity with the magnetic material; and    operating the cutting head to remove the material from the walls of the lumen or cavity by applying at least a magnetic field to orient the cutting head or a magnetic gradient to move the cutting head within the lumen or cavity.    
   
   
       13 . The method according to  claim 12  wherein the step of operating the cutting head to remove the material comprises applying a magnetic field to the magnetic material to orient the cutting head of the tool toward the material in the lumen or cavity.  
   
   
       14 . The method according to  claim 12  wherein the step of operating the cutting head to remove the material comprises applying a magnetic gradient to the magnetic material to move the cutting head toward the material in the lumen or cavity.  
   
   
       15 . The method according to  claim 12  wherein the step of operating the cutting head to remove the material comprises applying both a magnetic field to orient the cutting head and a magnetic gradient to move the cutting head toward the material in the lumen or cavity.  
   
   
       16 . A method of removing material from the walls of a body lumen or cavity, comprising: 
 introducing a tool having a cutting head on its distal end and a magnet associated with the cutting head into the lumen or cavity, and navigating the tool to the site of the material to be removed by successively applying a magnetic field to orient the distal end of tool and advancing the tool in the lumen or cavity to the site of the material to be removed; and    operating the cutting head to remove the material from the surface of the lumen or cavity.    
   
   
       17 . The method according to  claim 16  wherein the step of advancing the tool comprises applying a magnetic field gradient to the distal end of the tool to apply a motive force to move the distal end of the tool.  
   
   
       18 . The method according to  claim 16  wherein the step of operating the cutting head to remove the material comprises applying a magnetic field to the magnet associated with the cutting head to orient the cutting head of the tool.  
   
   
       19 . The method according to  claim 16  wherein the step of operating the cutting head to remove the material comprises applying a magnetic field gradient to the magnetic material associated with the cutting head to move the cutting head within the lumen or cavity.  
   
   
       20 . The method according to  claim 16  wherein the magnet associated with the cutting head is at least a part of the cutting head made of a magnetic material.  
   
   
       21 . A method of removing material from the walls of a body lumen or cavity, comprising: 
 introducing a tool having a cutting head on its distal end and a magnet associated with the cutting head into the lumen or cavity, and navigating the tool to the site of the material to be removed;    operating the cutting head to remove the material from the surface of the lumen or cavity by applying at least a magnetic field to orient the cutting head or a magnetic gradient to move the cutting head within the lumen or cavity.    
   
   
       22 . The method according to  claim 23  wherein the step of operating the cutting head to remove the material comprises applying a magnetic field to the magnet associated with the cutting head to orient the cutting head of the tool.  
   
   
       23 . The method according to  claim 23  wherein the step of operating the cutting head to remove the material comprises applying a magnetic gradient to the magnetic material associated with the cutting head to move the cutting head within the lumen or cavity.  
   
   
       24 . The method according to  claim 23  wherein the step of operating the cutting head to remove the material comprises applying both a magnetic field to orient the cutting head and a magnetic gradient to move the cutting head toward the material in the lumen or cavity.  
   
   
       25 . The method according to  claim 21  further comprising the step of applying a continuously changing magnetic field to precess the cutting head within the lumen or cavity.  
   
   
       26 . The method according to  claim 25  wherein the step of applying a continuously changing magnetic field is done with a computer controlled magnet.  
   
   
       27 . The method according to  claim 21  further comprising the step of applying a continuously changing magnetic gradient to move the cutting head within the lumen or cavity.