Deflectabe medical device

Abstract

A deflectable medical device (1) includes a shape memory alloy wire (15) integrated into a flexible elongated body (11). The shape memory alloy wire (15) is arranged to shorten upon receiving energy from an energy supply (2,4), thereby deflecting the medical device (1). A rod (18) positioned in a lumen (14) of the flexible elongated body (11) and compressed between a fixture (16) in the proximal end (12) of the elongated body (11) and the distal end (13) of the elongated body (11) is responsible for the shape memory alloy wire (15) recovering its initial length upon discontinuation of energy supply.

1 . A deflectable medical device comprising:
 a flexible elongated body comprising a longitudinal axis;   a shape memory alloy wire disposed within the flexible elongated body eccentric to the longitudinal axis, wherein the shape memory alloy wire is configured to shorten in an axial direction in response to receiving energy from an energy supply such that the flexible elongated body is deflected; and   a rod disposed within the flexible elongated body, wherein the rod is configured to provide a force in the axial direction to lengthen the shape memory alloy wire when the energy supply discontinues providing the energy to the shape memory alloy wire.   
     
     
         2 . The device of  claim 1 , wherein the energy supply is connected electrically to the shape memory alloy wire, and wherein the shape memory alloy wire is configured to convert electrical energy provided by the energy supply into heat through electrical resistance. 
     
     
         3 . The device of  claim 1 , wherein the energy supply is connected electrically to a resistor disposed:
 proximate to the shape memory alloy wire; or   coaxial with the shape memory alloy wire; or   as a coating surrounding the shape memory alloy wire; or   as windings of a material around the shape memory alloy wire.   
     
     
         4 . The device of  claim 3 , wherein the resistor heats the shape memory alloy wire when energized with energy from the energy supply. 
     
     
         5 . The device of  claim 1 , wherein the energy supply provides alternating current to a coil surrounding the shape memory alloy wire, and wherein the coil heats the shape memory alloy wire through induction when energized by the alternating current. 
     
     
         6 . The device of  claim 1 , wherein the energy supply is a pump for providing fluid flow proximate to at least a portion of the shape memory alloy wire. 
     
     
         7 . The device of  claim 6 , wherein the fluid flow is hotter than the shape memory alloy wire and provides heat energy to the shape memory alloy wire. 
     
     
         8 . The device of  claim 6 , wherein the fluid flow is cooler than the shape memory alloy wire and removes heat energy from the shape memory alloy wire, such that the shape memory alloy wire is induced to lengthen in the axial direction in response to the fluid flow. 
     
     
         9 . The device of  claim 1 , wherein a control unit controls a quantity of energy received from the energy supply by the shape memory alloy wire. 
     
     
         10 . The device of  claim 1 , further comprising a handgrip on a proximal end of the device. 
     
     
         11 . The device of  claim 1 , wherein the shape memory alloy wire comprises an alloy of Ni—Ti, Cu—Al—Ni, Cu—Zn, or Ni—Ti—Pd. 
     
     
         12 . The device of  claim 1 , wherein the shape memory alloy wire comprises a diameter of between about 50 micrometers and about 200 micrometers. 
     
     
         13 . The device of  claim 1 , wherein the flexible elongated body comprises a polymer. 
     
     
         14 . The device of  claim 13 , wherein the polymer comprises a thermoplastic elastomer. 
     
     
         15 . The device of  claim 14 , wherein the thermoplastic elastomer comprises PEBAX. 
     
     
         16 . The device of  claim 1 , wherein the shape memory alloy wire is incorporated into the flexible elongated body by overmolding. 
     
     
         17 . The device of  claim 1 , wherein the flexible elongated body includes through-holes in a distal portion for dispensing fluid into a surrounding of the distal portion. 
     
     
         18 . The device of  claim 1 , wherein a distal portion of the flexible elongated body further comprises a metallic tip for providing treatment energy to a surrounding of the distal portion.