Adjustable implant system
View Patent ↗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;
an internal magnet within the tubular body member, the internal magnet configured to rotate in response to a rotating external magnetic field;
a first lead screw coupled to a first end of the internal magnet by a first drive cable, wherein rotation of the internal magnet rotates the first drive cable which communicates said rotation to the first lead screw; 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 changing a dimension of the ring shape.
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 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.
6. The system of claim 5 , 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.
7. 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.
8. The system of claim 7 , 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.