Torqueable and Deflectable Medical Device Shaft

Abstract

A medical device shaft for connection with a handle and for insertion within a body includes an elongated, deflectable shaft having a proximal shaft portion, an intermediate shaft portion, and a distal shaft portion. The elongated, deflectable shaft includes a transition in stiffness from the proximal shaft portion to the distal shaft portion. In a preferred implementation, the shaft includes a plurality of slits that extend perpendicular to a longitudinal axis of the shaft. Varying at least one of the number of slits, the location of slits, the frequency of slits, the orientation of the slits, the size of the slits, and the depth of the slits varies the transition of stiffness.

1 . A medical device, comprising:
 an elongated, deflectable shaft having a proximal shaft portion, an intermediate shaft portion, and a distal shaft portion, the proximal portion and intermediate portions comprising a tubing and the distal shaft portion comprising a braided member;   a plurality of slits defined in the elongated shaft;   a handle disposed adjacent to a proximal end of the elongated shaft; and   one or more steering wires having a first end attached to the handle and a second end attached adjacent to the distal shaft portion of the elongated shaft;   wherein the elongated shaft becomes progressively more flexible from the proximal shaft portion to the distal shaft portion.   
     
     
         2 . The medical device of  claim 1 , further comprising a steering knob attached to the handle. 
     
     
         3 . The medical device of  claim 2 , wherein the one or more steering wires are attached to the steering knob. 
     
     
         4 . The medical device of  claim 3 , wherein rotation of the steering knob causes deflection and bending of the distal shaft portion. 
     
     
         5 . The medical device of  claim 1 , wherein the braided member comprises counter-wound double wires. 
     
     
         6 . The medical device of  claim 1 , wherein the tubing is a nickel-titanium alloy tube. 
     
     
         7 . The medical device of  claim 1 , wherein the braided member provides torqueability, bendability, and prevents the distal shaft portion from collapsing. 
     
     
         8 . The medical device of  claim 1 , further comprising a first polymer layer disposed over the proximal shaft portion and the intermediate shaft portion. 
     
     
         9 . The medical device of  claim 8 , wherein at least a portion of the braided member is disposed over and contacting the first polymer layer. 
     
     
         10 . The medical device of  claim 9 , further comprising a second polymer layer disposed over the elongate shaft and the braided member. 
     
     
         11 . A medical device, comprising:
 an elongate member including a proximal portion, an intermediate portion, and a distal portion extending distally from the intermediate portion to a distal end of the device, the proximal portion and intermediate portions comprising a generally tubular member and the distal portion comprising a braided member;   a plurality of slits defined in the proximal and intermediate portions of the elongate member;   a handle disposed adjacent to a proximal end of the elongate member;   a steering knob attached to the handle; and   one or more steering wires having a first end attached to the steering knob and a second end attached adjacent to the distal portion of the elongate member;   wherein at least one of the number of slits, the location of slits, the frequency of slits, the orientation of the slits, the size of the slits and the depth of the slits are varied to vary the stiffness of the proximal and intermediate portions of the elongate member.   
     
     
         12 . The medical device of  claim 11 , wherein the medical device has a transition in stiffness from the proximal portion to the distal portion. 
     
     
         13 . The medical device of  claim 11 , wherein the number of slits per unit length is greater near the intermediate portion of the elongate member than near the proximal portion of the elongate member. 
     
     
         14 . The medical device of  claim 11 , wherein the slits in the elongate member have a depth and slits on the elongate member near the intermediate portion are deeper than the slits on the elongate member near the proximal portion. 
     
     
         15 . The medical device of  claim 11 , wherein the elongate member has a longitudinal axis and wherein the slits are arranged generally perpendicular to the longitudinal axis. 
     
     
         16 . The medical device of  claim 11 , wherein the distal portion is deflectable.