Systems and methods for adjusting an annuloplasty ring with an integrated magnetic drive

Abstract

Systems and methods treat a heart valve using a magnetically adjustable annuloplasty ring attached to or near a cardiac valve annulus. A changing magnetic field may be used to selectively increase or decrease a circumference of, or otherwise modify the shape of, the implanted annuloplasty ring. The adjustable annuloplasty ring includes a tubular body member, one or more adjustable members, and an internal magnet within the tubular body member. The tubular body member and the one or more adjustable members form a ring shape. The internal magnet is configured to rotate in response to a rotating external magnetic field. The internal magnet is coupled to the one or more adjustable members to change a dimension of the ring shape as the internal magnet rotates. A system for treating a heart valve may include an external adjustment device having one or more external magnets to generate the rotating external magnetic field.

1 . A system for treating a heart valve, the system comprising:
 an adjustable annuloplasty ring configured to be attached to or near a cardiac valve annulus, the adjustable annuloplasty ring comprising:
 a tubular body member; 
 one or more adjustable members, the tubular body member and the one or more adjustable members forming a ring shape; and 
 an internal magnet within the tubular body member, the internal magnet configured to rotate in response to a rotating external magnetic field; 
 wherein the internal magnet is coupled to the one or more adjustable members to change a dimension of the ring shape as the internal magnet rotates. 
   
     
     
         2 . The system of  claim 1 , wherein the internal magnet comprises a cylindrical magnet having magnetic poles divided along a plane running the length of the cylinder. 
     
     
         3 . The system of  claim 2 , wherein the internal magnet is a permanent magnet. 
     
     
         4 . The system of  claim 1 , wherein the adjustable annuloplasty ring further comprises a magnet housing attached to the internal magnet, the magnet housing rotating with the rotation of the internal magnet, the magnet housing coupling the internal magnet to the one or more adjustable members. 
     
     
         5 . The system of  claim 1 , wherein the adjustable annuloplasty ring further comprises:
 a first lead screw coupled to a first end of the internal magnet, wherein the first lead screw rotates with the rotating internal magnet; and   a drive nut coupled to the one or more adjustable members, wherein threads of the drive nut engage threads of the first lead screw, and wherein rotation of the first lead screw advances the first lead screw through the drive nut to pull or push the one or more adjustable members to change the dimension of the ring shape.   
     
     
         6 . The system of  claim 5 , wherein the one or more adjustable members comprise a wire. 
     
     
         7 . The system of  claim 6 , wherein the wire comprises nitinol. 
     
     
         8 . The system of  claim 5 , wherein the adjustable annuloplasty ring further comprises a first drive cable to couple a first end of the internal magnet to the first lead screw. 
     
     
         9 . The system of  claim 8 , wherein the adjustable annuloplasty ring further comprises:
 a first fixed arm coupled to a first end of the tubular body member; and   a second fixed arm coupled to a second end of the tubular body member;   wherein the one or more adjustable members comprise a first swivel arm hinged to the first fixed arm at a first pivot point, and wherein rotation of the first lead screw results in the first swivel arm rotating around the first pivot point.   
     
     
         10 . The system of  claim 9 , wherein the one or more adjustable members further comprise a second swivel arm having a first end hinged to the second fixed arm at a second pivot point, and the second swivel arm having a second end hinged to the first drive nut at a third pivot point, wherein rotation of the first lead screw results in the second swivel arm rotating around the second pivot point and the drive nut rotating around the third pivot point. 
     
     
         11 . The system of  claim 9 , wherein the one or more adjustable members further comprise:
 a second swivel arm having a first end hinged to the second fixed arm at a second pivot point;   a second lead screw; and   a second drive cable to couple a second end of the internal magnet to the second lead screw;   wherein rotation of the internal magnet results in rotation of the second lead screw;   wherein the drive nut includes a first set of threads to engage the threads of the first lead screw and a second set of threads to engage the threads of the second lead screw;   and wherein rotation of the second lead screw results in the second swivel arm rotating around the second pivot point.   
     
     
         12 . The system of  claim 1 , wherein the internal magnet includes a hollow opening therein for coupling the internal magnet to the one or more adjustable members. 
     
     
         13 . The system of  claim 12 , wherein at least a portion of the hollow opening is threaded, and wherein the adjustable annuloplasty ring further comprises a lead screw interfacing with the threads of the hollow opening to draw the lead screw into or out of the hollow opening as the internal magnet rotates. 
     
     
         14 . The system of  claim 13 , wherein the lead screw comprises a flexible wire comprising threads cut or formed in a first end of the flexible wire, wherein the first end of the flexible wire is coupled to a first end of the internal magnet. 
     
     
         15 . The system of  claim 14 , wherein the flexible wire further comprises threads cut or formed in a second end of the flexible wire, wherein the second end of the flexible wire is coupled to a second end of the internal magnet. 
     
     
         16 . The system of  claim 13 , wherein the adjustable annuloplasty ring further comprises:
 a drive cable having a first end coupled to the lead screw;   wherein the adjustable annuloplasty ring further comprises:
 a first fixed arm coupled to a first end of the tubular body member; and 
 a second fixed arm coupled to a second end of the tubular body member; 
   wherein the one or more adjustable members comprise:
 a first swivel arm hinged to the first fixed arm at a first pivot point; 
 a second swivel arm having a first end hinged to the second fixed arm at a second pivot point; and 
 a push rod having a first end coupled to a second end of the drive cable within a passage way in the second swivel arm, the push rod having a second end hinged to a second end of the first fixed arm at a third pivot point. 
   
     
     
         17 . The system of  claim 12 , wherein the adjustable annuloplasty ring further comprises:
 a drive cable having a first end coupled within the hollow opening in the internal magnet, wherein rotation of the internal magnet results in rotation of the drive cable; and   a lead screw coupled to a second end of the drive cable, wherein rotation of the drive cable results in rotation of the lead screw;   wherein the adjustable annuloplasty ring further comprises:
 a first fixed arm coupled to a first end of the tubular body member; and 
 a second fixed arm coupled to a second end of the tubular body member; 
   wherein the one or more adjustable members comprise:
 a first swivel arm hinged to the first fixed arm at a first pivot point; 
 a second swivel arm having a first end hinged to the second fixed arm at a second pivot point, wherein a second end of the second fixed arm comprises a drive nut that interfaces the lead screw. 
   
     
     
         18 . The system of  claim 17 , wherein the first swivel arm comprises a jewel bearing coupled to the lead screw. 
     
     
         19 . The system of  claim 1 , wherein the adjustable annuloplasty ring is sized and configured to be placed into a heart through a catheter or trocar. 
     
     
         20 . The system of  claim 19 , wherein the size of the adjustable annuloplasty ring in any direction is less than approximately 10 mm when inserted into the catheter or trocar and greater than approximately 20 mm when attached to or near the cardiac valve annulus. 
     
     
         21 . The system of  claim 19 , wherein the one or more adjustable members comprise a superelastic wire extending from a first end of the tubular body to a second end of the tubular body to form the ring shape, wherein the superelastic wire is configured to be compressed to allow the adjustable annuloplasty ring to be inserted through the catheter or trocar, and wherein the superelastic wire is configured to be pushed into or out of the tubular body in response to the rotation of the internal magnet. 
     
     
         22 . The system of  claim 19 , wherein the one or more adjustable members comprise:
 a wire comprising a first end coupled to a first end of the tubular body member, wherein the wire is configured to be pushed into or out of tubular body in response to the rotation of the internal magnet; and   a latch to selectively connect and disconnect a second end of the wire to a second end of the tubular body member,   wherein the latch includes a disconnected state to allow the adjustable annuloplasty ring to be inserted into the catheter or trocar, and   wherein the latch includes a connected state to form the ring shape when the adjustable annuloplasty ring is attached to or near the cardiac valve annulus.   
     
     
         23 . The system of  claim 22 , wherein the latch is selected from a group comprising a socket and a lock pin latch, a ramp and pawl latch, a knuckle style latch, a screw and nut latch, and a T-bar style latch. 
     
     
         24 . The system of  claim 22 , wherein the adjustable annuloplasty ring further comprises a swivel arm comprising a first end hinged to a second end of the tubular body at a pivot point, and wherein the latch connects and disconnects the second end of the wire to a second end of the swivel arm. 
     
     
         25 . The system of  claim 19 , wherein the one or more adjustable members comprise:
 a first arm comprising a first end coupled to a first end of the tubular member, the first arm configured to be pulled into or out of the tubular member in response to the rotation of the internal magnet;   a second arm comprising a first end coupled to a second end of the first arm and a second end coupled to a second end of the tubular member;   a folding hinge to connect the second arm to the first arm, the folding hinge allowing the ring shape to be folded during insertion of the adjustable annuloplasty device through the catheter or trocar;   a locking sleeve configured to slide along the first arm and the second arm to lock the folding hinge in an extended position for attachment of the adjustable annuloplasty ring to or near the cardiac valve annulus.   
     
     
         26 . The system of  claim 1 , wherein the adjustable annuloplasty ring further comprises:
 a gear coupled to the internal magnet; and   a rack in mechanical communication with the gear and the one or more adjustable members,   wherein, in response to the rotating internal magnet, the gear rotates to slide the rack so as to push the one or more adjustable members into or out of the tubular body member.   
     
     
         27 . The system of  claim 26 , wherein the one or more adjustable members comprise a wire having a first end coupled to a first end of the tubular member and a second end configured to slide into and out of the second end of the tubular member. 
     
     
         28 . The system of  claim 27 , wherein the rack is cut or formed in the second end of the wire. 
     
     
         29 . The system of  claim 1 , further comprising:
 an external adjustment device comprising one or more external magnets configured to generate the rotating external magnetic field.   
     
     
         30 . The system of  claim 29 , wherein the one or more external magnets comprise a permanent magnet. 
     
     
         31 . The system of  claim 29 , wherein the one or more external magnets comprise an electromagnet. 
     
     
         32 . The system of  claim 29 , wherein the one or more external magnets comprise at least one cylindrical magnet having magnetic poles divided along a plane running the length of the cylinder. 
     
     
         33 . The system of  claim 32 , wherein the internal magnet comprises a cylindrical magnet having magnetic poles divided along a plane running the length of the cylinder, and wherein rotating the one or more external magnets in a first direction results in a rotation of the internal magnet in a second direction. 
     
     
         34 . The system of  claim 29 , wherein the external adjustment device further comprises:
 a controller; and   a first stepper motor in communication with the controller, the first stepper motor coupled to at least a first subset of the one or more external magnets;   wherein the controller is configured to control the rotation of the first stepper motor.   
     
     
         35 . The system of  claim 34 , wherein the external adjustment device further comprises:
 a second stepper motor in communication with the controller, the second stepper motor coupled to at least a second subset of the one or more external magnets;   wherein the controller is configured to control the rotation of the second stepper motor.   
     
     
         36 . The system of  claim 34 , wherein the one or more external magnets comprise four cylindrical magnets in a non-aligned, Halbach configuration. 
     
     
         37 . The system of  claim 29 , wherein the one or more external magnets comprise two C-shaped electromagnets arranged to generate respective magnetic fields that are perpendicular to one another. 
     
     
         38 . The system of  claim 1 , further comprising a magnetic adjustment device comprising:
 a catheter system configured to be inserted into a heart chamber; and   an activation magnet configured to be inserted through the catheter system into the heart chamber,   wherein the catheter system is configured to rotate the magnet within the heart chamber to generate the rotating external magnetic field.   
     
     
         39 . The system of  claim 1 , further comprising a magnetic brake configured for implantation within a patient in an area outside of the patient's heart,
 wherein, in the absence of the rotating external magnetic field, the magnetic brake is configured to prevent the internal magnet from rotating, and   wherein, in the presence of the rotating external magnetic field, the magnetic brake is configured to allow the internal magnet to rotate.   
     
     
         40 . A method for treating a heart valve, the method comprising:
 providing an adjustable annuloplasty ring comprising:
 a tubular body member; 
 one or more adjustable members, the tubular body member and the one or more adjustable members forming a ring shape; and 
 an internal magnet within the tubular body member, the internal magnet configured to rotate in response to a rotating external magnetic field; 
 wherein the internal magnet is coupled to the one or more adjustable members to change a dimension of the ring shape as the internal magnet rotates; and 
   implanting the annuloplasty ring on or near a patient's cardiac valve annulus.   
     
     
         41 . The method of  claim 40 , further comprising:
 after implantation, applying the rotating external magnetic field to reshape the annuloplasty ring.   
     
     
         42 . The method of  claim 41 , wherein applying the rotating external magnetic field after implantation comprises:
 allow the patient to substantially recover from the implantation before applying the external magnetic field.   
     
     
         43 . The method of  claim 41 , wherein applying the rotating external magnetic field after implantation comprises:
 applying the external magnetic field during open heart surgery.   
     
     
         44 . The method of  claim 40 , wherein applying the rotating magnetic field comprises:
 arranging an array of cylindrical magnets in a non-aligned, Halbach configuration;   placing the patient in a central area of the magnet array; and   rotating the plurality of cylindrical magnets at a desired frequency.   
     
     
         45 . The method of  claim 40 , wherein applying the rotating magnetic field comprises:
 percutaneously delivering one or more activation magnets to a heart chamber; and   rotating the one or more activation magnets at a desired frequency.   
     
     
         46 . The method of  claim 40 , further comprising:
 providing an implantable magnetic brake; and   implanting the magnetic brake near the patient's heart,   wherein, in the absence of the rotating external magnetic field, the magnetic brake prevents the internal magnet from rotating, and   wherein, in the presence of the rotating external magnetic field, the magnetic brake allows the internal magnet to rotate.   
     
     
         47 . A system for treating a heart valve, the system comprising:
 an adjustable annuloplasty ring comprising:
 means for attaching the adjustable annuloplasty ring to or near a cardiac valve annulus, the adjustable annuloplasty ring comprising: 
 means for forming a ring shape; and 
 means for changing a dimension of the ring shape in response to a rotating external magnetic field. 
   
     
     
         48 . The system of  claim 47 , further comprising means for applying the rotating external magnetic field to a patient to reshape the annuloplasty ring. 
     
     
         49 . The system of  claim 47 , further comprising:
 means for, in the absence of the rotating external magnetic field, disabling the means for changing the dimension of the ring shape.