Adjustable implant and method of use

1. A system comprising:

an adjustable implant configured for implantation internally within a subject, the adjustable implant comprising a permanent magnet configured for rotation about an axis of rotation, the permanent magnet operatively coupled to a drive transmission configured to alter a dimension of the adjustable implant;

an external adjustment device configured for placement on or adjacent to the skin of the subject comprising at least one magnet configured for rotation, the external adjustment device further comprising a motor configured to rotate the at least one magnet and an optical encoder comprising a light source and a light receiver configured to monitor the position of a surface mechanically coupled to the motor, whereby rotation of the at least one magnet of the external adjustment device effectuates rotational movement of the permanent magnet of the adjustable implant and alters the dimension of the adjustable implant; and

drive control circuitry configured to receive an input signal from the optical encoder corresponding to the angular position of the at least one magnet and drive the motor of the external adjustment device to achieve a target dimension of the adjustable implant.

2. The system of claim 1 , wherein the target dimension comprises a numerical endpoint dimension of the adjustable implant.

3. The system of claim 1 , wherein the target dimension comprises a numerical incremental increase or decrease in the dimension of the adjustable implant.

4. The system of claim 1 , wherein the drive transmission comprises a lead screw operatively coupled to the permanent magnet of the adjustable implant and a nut moveable along a length of the lead screw.

5. The system of claim 4 , wherein the nut is operatively coupled to an actuating member.

6. The system of claim 1 , further comprising a feedback device operatively coupled to the permanent magnet of the adjustable implant, the feedback device configured to generate a signal upon rotational movement of the permanent magnet of the adjustable implant.

7. The system of claim 6 , wherein the external adjustment device comprises a sensor configured to detect the signal generated from the feedback device.

8. The system of claim 6 , wherein the signal is one of an acoustic signal, a magnetic signal, or a light signal.

9. The system of claim 1 , wherein the at least one magnet of the external adjustment device comprises a first permanent magnet and a second permanent magnet.

10. The system of claim 9 , wherein the external adjustment device comprises a housing having a recessed portion located substantially between the first permanent magnet and the second permanent magnet of the external adjustment device.

11. The system of claim 9 , wherein the locations of the first and second permanent magnets of the external adjustment device relative to the permanent magnet of the adjustable implant remain substantially the same through an adjustment procedure.

12. The system of claim 1 , wherein the external adjustment device is configured to effectuate rotational movement of the permanent magnet of the adjustable implant through clothing worn by the subject.

13. The system of claim 1 , wherein the drive control circuitry is configured to control at least one of the speed and rotational direction of the motor.

14. The system of claim 1 , wherein the drive control circuitry is operatively coupled to an input device configured to input a numerical target dimension.

15. The system of claim 14 , wherein the input device comprises a keypad.

16. The system of claim 1 , wherein the drive control circuitry is operatively coupled to a display.

17. The system of claim 1 , wherein the drive control circuitry is incorporated into the external adjustment device.

18. The system of claim 1 , the external adjustment device further comprising a sensor configured to detect the current draw of the motor during adjustment of the adjustable implant.

19. The system of claim 1 , further comprising a slip clutch interposed between the motor and the at least one magnet of the external adjustment device.

20. The system of claim 1 , further comprising an implantable storage device configured to store patient information data.

21. The system of claim 20 , wherein the implantable storage device comprises a RFID storage element.

22. The system of claim 20 , wherein patient information data comprises data corresponding to a current state of the adjustable implant and wherein the drive control circuitry is configured to read the stored current state.

23. The system of claim 20 , wherein the drive control circuitry is configured to write to the implantable storage device with patient information data.

24. The system of claim 23 , wherein the written data comprises an updated status of the adjustable implant after an adjustment.

25. The system of claim 1 , wherein the at least one magnet of the external adjustment device comprises a plurality of magnets.

26. The system of claim 1 , further comprising a back iron configured to modify the magnetic coupling between the permanent magnet and the at least one magnet of the external adjustment device.

27. The system of claim 26 , wherein the back iron is formed from one of steel or stainless steel.

28. The system of claim 1 , wherein rotational movement of the permanent magnet of the adjustable implant comprises rotational movement through less than 360° .

29. The system of claim 1 , wherein rotational movement of the at least one magnet of the external adjustment device comprises rotational movement through less than 360° .

30. A method of adjusting an implant device configured for implantation internally within a subject, the implant device comprising a permanent magnet configured for rotation about an axis of rotation, the permanent magnet operatively coupled to a drive transmission configured to alter a dimension of the adjustable implant, the method comprising:

inputting numerical drive instructions into drive control circuitry of a programmable external adjustment device comprising a motor, at least one permanent magnet configured for rotational movement in response to actuation of the motor, and an encoder configured to monitor the rotational movement of the at least one permanent magnet of the external adjustment device; and

adjusting the implant device in accordance with the instructions stored in the drive control circuitry of the external adjustment device, wherein the drive control circuitry is configured to receive an input signal from the encoder corresponding to the angular position of the at least one permanent magnet of the external adjustment device.

31. The method of claim 30 , wherein the at least one permanent magnet comprises two permanent magnets.

32. The method of claim 31 , wherein the two permanent magnets apply an additive torque to the permanent magnet of the adjustable implant.

33. The method of claim 30 , wherein the drive instructions comprise a numerical endpoint dimension of the adjustable implant.

34. The method of claim 30 , wherein the drive instructions comprise a numerical incremental increase or decrease in the dimension of the adjustable implant.

35. The method of claim 30 , further comprising updating the drive control circuitry with a current state of the adjustable implant.

36. The method of claim 35 , wherein the current state of the adjustable implant is manually input to the drive control circuitry.

37. The method of claim 35 , wherein the current state of the adjustable implant is retrieved automatically by the drive control circuitry.

38. The method of claim 37 , wherein data corresponding to the current state of the adjustable implant is contained within an implantable storage device located internally within the subject.

39. The method of claim 38 , wherein the implantable storage device comprises a RFID storage device.

40. The method of claim 38 , wherein after adjustment of the adjustable implant, an updated state of the adjustable implant is transmitted to and stored in the implantable storage device.

41. The method of claim 30 , further comprising sensing the degree of movement of the permanent magnet of the adjustable implant with a sensor in the external adjustment device.

42. The method of claim 41 , wherein the degree of movement of the permanent magnet of the adjustable implant comprises the number of full or partial rotations of the permanent magnet of the adjustable implant and said degree of movement is stored in the external adjustment device.

43. The method of claim 41 , wherein the sensor is configured to receive the signal corresponding to the degree of movement of the permanent magnet of the adjustable implant and wherein the signal is one of an acoustic signal, a magnetic signal, or a light signal.

44. The method of claim 30 , further comprising measuring the current draw of the motor of the external adjustment device and stopping the motor when said measured current draw exceeds a pre-determined threshold.

45. The method of claim 30 , further comprising adjusting the magnetic field between the at least one permanent magnet of the external adjustment device and the permanent magnet of the adjustable implant device with a back iron.

46. The method of claim 30 , wherein rotational movement of the permanent magnet of the adjustable implant comprises rotational movement through less than 360° .

47. The system of claim 30 , wherein rotational movement of the at least one permanent magnet of the external adjustment device comprises rotational movement through less than 360° .