Phase-change and shape-change materials

Abstract

An implant includes a shape-memory material having a transformation temperature. The implantable element is configured to be implanted, and to perform a first therapeutic function when the shape-memory material is in a first shape. An energy applicator is configured to change the shape-memory material from the first shape to a second shape by raising a temperature of the shape-memory material to the transformation temperature by radiating energy to the implant from outside the body. The implant is configured to perform a second therapeutic function while the shape-memory material is in the second shape, the second therapeutic function being qualitatively different from the first therapeutic function. Other embodiments are also described.

1 - 66 . (canceled) 
     
     
         67 . Apparatus for use with a portion of a body of a subject, comprising:
 an implantable element, comprising a shape-memory material having a transformation temperature, the implantable element configured to be implanted in the portion, and to perform a first therapeutic function with respect to the portion when the shape-memory material is in a first shape, and while the implantable element is implanted in the portion; and   an energy applicator, configured to be disposed outside the body, and to change the shape-memory material from the first shape to a second shape, by raising a temperature of the shape-memory material to the transformation temperature, by radiating energy to the implantable element from outside the body,   the implantable element being configured to perform a second therapeutic function with respect to the portion when the shape-memory material is in the second shape and while the implantable element is implanted in the portion, the second therapeutic function being qualitatively different from the first therapeutic function.   
     
     
         68 . The apparatus according to  claim 67 , wherein the implantable element is shaped as a cylindrical stent when the shape-memory material is in the first shape. 
     
     
         69 . The apparatus according to  claim 68 , wherein the implantable element is shaped as a venturi tube when the shape-memory material is in the second shape. 
     
     
         70 . A method for use with a portion of a body of a subject, comprising:
 implanting an implantable element in the portion such that the implantable element performs a first therapeutic function with respect to the portion the implantable element including a shape-memory material that has a transformation temperature, the shape-memory material being in a first shape during the performing of the first therapeutic function; and   causing the implantable element to perform a second therapeutic function with respect to the portion by   changing the shape-memory material from the first shape to a   second shape by raising a temperature of the shape-memory material to the transformation temperature by radiating energy to the implantable element from outside the body while the implantable element is implanted in the portion and when the shape-memory material is in the second shape, the second therapeutic function being qualitatively different from the first therapeutic function.   
     
     
         71 . The method according to  claim 70 , wherein:
 the first therapeutic function is opening a blood vessel of the subject,   the implantable element is shaped as a cylindrical stent when the shape-memory material is in the first shape thereof, and   implanting the implantable element in the portion comprises implanting the implantable element in the portion such that the implantable element (i) is shaped as a cylindrical stent, and (ii) opens the blood vessel.   
     
     
         72 . The method according to  claim 71 , wherein:
 the second therapeutic function is increasing blood pressure in a portion of the blood vessel that is upstream of the implantable element,   the implantable element is shaped as a venturi tube when the shape-memory material is in the second shape thereof, and   causing the implantable element to perform the second therapeutic function comprises causing the implantable element to increase the blood pressure in the portion of the blood vessel by shaping the implantable element as a venturi tube.   
     
     
         73 - 80 . (canceled) 
     
     
         81 . The apparatus according to  claim 67 , wherein the implantable element is configured to be implanted inside a blood vessel of the subject, and, when the shape-memory material is in the second shape, is configured to cause a new blood vessel to generate that circumvents a region of the blood vessel within which the implantable element is implanted, by causing a controlled narrowing of a wall of the blood vessel at the region. 
     
     
         82 . The apparatus according to  claim 67 , wherein the implantable element is configured to be implanted in a cerebral artery of the subject, and wherein:
 while the implantable element is implanted within the cerebral artery and is in the first shape, the implantable element is configured to widen the cerebral artery; and   while the implantable element is implanted within the cerebral artery and is in the second shape, the implantable element is configured to increase intercellular gaps of a blood brain barrier of the subject.   
     
     
         83 . The apparatus according to  claim 67 , wherein the energy applicator comprises an RF generator that is configured to change the shape-memory material from the first shape to a second shape by raising the temperature of the shape-memory material to the transformation temperature, by radiating RF energy to the implantable element from outside the body. 
     
     
         84 . The apparatus according to  claim 67 , wherein the energy applicator comprises an ultrasound transducer that is configured to change the shape-memory material from the first shape to a second shape by raising the temperature of the shape-memory material to the transformation temperature, by radiating ultrasound energy to the implantable element from outside the body. 
     
     
         85 . The apparatus according to  claim 67 , wherein the energy applicator comprises a magnetic field generator that is configured to change the shape-memory material from the first shape to a second shape by raising the temperature of the shape-memory material to the transformation temperature, by radiating magnetic energy to the implantable element from outside the body. 
     
     
         86 . The method according to  claim 70 , wherein radiating energy to the implantable element from outside the body comprises radiating RF energy to the implantable element from outside the body. 
     
     
         87 . The method according to  claim 70 , wherein radiating energy to the implantable element from outside the body comprises radiating ultrasound energy to the implantable element from outside the body. 
     
     
         88 . The method according to  claim 70 , wherein radiating energy to the implantable element from outside the body comprises radiating magnetic energy to the implantable element from outside the body. 
     
     
         89 . The method according to  claim 70 , wherein:
 implanting the implantable element in the portion comprises implanting the implantable element inside a blood vessel of the subject, and   causing the implantable element to perform the second therapeutic function comprises causing the implantable element to cause a new blood vessel to generate that circumvents a region of the blood vessel within which the implantable element is implanted.   
     
     
         90 . The method according to  claim 70 , wherein:
 implanting the implantable element in the portion such that the implantable element performs the first therapeutic function comprises implanting the implantable element inside a cerebral artery of the subject such that the implantable element widens the cerebral artery; and   causing the implantable element to perform the second therapeutic function comprises causing the implantable element to increase intercellular gaps of a blood brain barrier of the subject