Mri compatible medical devices

Abstract

A medical device for conducting electrical signal comprises an elongate member and a plurality of cables. Each cable may have three concentric layers: a first layer with an inner conductor, a second layer with an inner insulator, and a third layer with an outer conductor. The inner insulator electrically isolates the outer conductor from the inner conductor.

1 .- 20 . (canceled) 
     
     
         21 . A medical device for conducting an electrical signal, the medical device comprising:
 an elongate member with a proximal end and a distal end;   a first lumen disposed within and extending along a portion of the elongate member;   a cable extending through the first lumen; and   a second lumen disposed within the elongate member and configured to introduce other medical devices inside the elongate member.   
     
     
         22 . The medical device of  claim 21 , wherein the second lumen is located at a radial center of the elongate member. 
     
     
         23 . The medical device of  claim 21 , wherein the second lumen is located off-center in the elongate member. 
     
     
         24 . The medical device of  claim 21 , wherein the other medical devices comprise stylets. 
     
     
         25 . The medical device of  claim 24 , wherein the stylets are configured to help with maneuvering and placement of the medical device. 
     
     
         26 . The medical device of  claim 21 , further comprising additional lumens disposed within and extending along a portion of the elongate member. 
     
     
         27 . The medical device of  claim 26 , further comprising additional cables, each cable extending through one of the additional lumens. 
     
     
         28 . The medical device of  claim 26 , wherein the first lumen and the additional lumens are disposed in a circle surrounding the second lumen. 
     
     
         29 . The medical device of  claim 21 , wherein the cable comprises three concentric layers including:
 a first layer comprising an inner conductor,   a second layer comprising an inner insulator, and   a third layer comprising an outer conductor, wherein the second layer is configured to substantially electrically isolate the first layer from the third layer.   
     
     
         30 . The medical device of  claim 21 , further comprising an electrical contact disposed at the proximal end of the elongate member and an electrode disposed at the distal end of the elongate member, wherein the cable is electrically coupled to the electrical contact and the electrode. 
     
     
         31 . A medical device for conducting an electrical signal, the medical device comprising:
 an elongate member with a proximal end and a distal end;   a first set of lumens disposed within and extending along a portion of the elongate member, each lumen of the first set of lumens creating a channel for a cable; and   a second lumen disposed within the elongate member and configured to introduce other medical devices inside the elongate member.   
     
     
         32 . The medical device of  claim 31 , wherein the first set of lumens comprises eight lumens. 
     
     
         33 . The medical device of  claim 31 , wherein the first set of lumens forms a circle surrounding the second lumen. 
     
     
         34 . The medical device of  claim 31 , wherein the second lumen is located at a radial center of the elongate member. 
     
     
         35 . The medical device of  claim 31 , further comprising a plurality of cables, each cable extending through one lumen of the first set of lumens. 
     
     
         36 . A medical device for conducting an electrical signal, the medical device comprising:
 an elongate member with a proximal end and a distal end;   an electrical contact disposed at the proximal end;   an electrode disposed at the distal end;   a cable extending along a portion of the elongate member, the cable electrically coupled to the electrical contact and the electrode; and   a lumen disposed within the elongate member and configured to introduce other medical devices inside the elongate member.   
     
     
         37 . The medical device of  claim 36 , wherein the other medical devices comprise stylets. 
     
     
         38 . The medical device of  claim 36 , wherein the lumen is located at a radial center of the elongate member. 
     
     
         39 . The medical device of  claim 36 , wherein the cable comprises three concentric layers including:
 a first layer comprising an inner conductor,   a second layer comprising an inner insulator, and   a third layer comprising an outer conductor, wherein the second layer is configured to substantially electrically isolate the first layer from the third layer.   
     
     
         40 . The medical device of  claim 39 , wherein the outer conductor of the cable is configured to reduce electromagnetic interference of an external source of electromagnetic energy on the inner conductor of the cable.