Patent ID: 8632544

Claim:
An internal osteodistraction device, including two fixing points ( 7 , 8 ) for attachment to a bone in a way that enables increasing the distance between the fixing points in a controlled manner, a magnetostrictive element ( 1 ) capable of producing a reciprocating mechanical motion in a changing magnetic field, and unidirectional movement permitting elements, wherein when the magnetostrictive element is only subjected to compressive or tensile forces, the magnetostrictive element is adapted to push a member ( 2 ), where said member engages said unidirectional movement permitting elements, allowing for increasing a distance between the fixing points, and as the magnetostrictive element is in process of returning to its original length, a second member ( 3 ) engages said unidirectional movement permitting elements and allows the magnetostrictive element to resume its original length in such a way that the distance between the fixing points of the distraction device does not change substantially or that the distance between the fixing points retracts to a lesser extent than what was the increase of the distance therebetween as a result of the pushing action, wherein the magnetostrictive element acts on the members that engage the unidirectional movement permitting elements, and the members and unidirectional movement permitting elements are located only between the magnetostrictive element and one of the two fixing points.