Implantable actuator for hearing aid application

Abstract

An electromechanical actuator for an implantable hearing aid device including a mechanical output structure that has a first portion and a second portion, wherein the first portion is a mechanical attachment structure to attach a stapes prosthesis, and wherein the second portion is a wire-like member coupling the mechanical attachment structure to a magnetically permeable armature shaft assembly.

1 .- 33 . (canceled) 
     
     
         34 . An electromechanical actuator for an implantable hearing aid device comprising:
 a hermetic housing of tubular shape closed on one side with a diaphragm and on the other side, with a hermetic feedthrough;   first and second magnets located in said hermetic housing arranged to provide a biasing field in a field region between two substantially opposed pole faces of said first and second magnets;   a magnetically permeable armature located in said biased field region between said opposed pole faces, the location of the magnetically permeable armature defining a first and second working gap between the magnetically permeable armature and respective opposed pole faces of the first and second magnets;   a magnetically permeable armature shaft assembly supporting said magnetically permeable armature, said magnetically permeable armature shaft assembly arranged to allow movement of said magnetically permeable armature between said opposed pole faces in a longitudinal direction defined by the movement of said magnetically permeable armature shaft assembly;   biasing means to provide a biasing force to said magnetically permeable armature shaft assembly to bias said magnetically permeable armature to a predetermined location between said opposed pole faces;   magnetic flux generating means including an electrical signal coil responsive to an input signal delivered by an electrical connection to said hermetic feedthrough to generate a signal flux to modulate the biasing field in said field region thereby providing an unbalanced force to said magnetically permeable armature causing actuation of said magnetically permeable armature shaft assembly;   a mechanical output structure including stimulation means to stimulate the inner ear auditory system responsive to actuation of said magnetically permeable armature shaft assembly; and   a lead electrically connected to outer pins of said hermetic feedthrough and mechanically attached to said titanium housing,   wherein said mechanical output structure has a first portion and a second portion, and wherein the first portion is a mechanical attachment structure to attach a stapes prosthesis, and wherein said second portion is a wire-like member coupling said mechanical attachment structure to said magnetically permeable armature shaft assembly.   
     
     
         35 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 34 , wherein said mechanical attachment structure is of substantially cylindrical shape with an elliptical cross section having a numeric eccentricity ranging from approximately  0  to approximately 0.5. 
     
     
         36 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 34 , wherein said mechanical attachment structure is covered with a silicone layer having a thickness of approximately 0.05 mm to approximately 0.2 mm 
     
     
         37 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 34 , wherein said wire-like member is a straight rod, and further wherein an angle between said mechanical attachment structure and said straight rod is chosen in the range of approximately 80° to approximately 150°. 
     
     
         38 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 37 , wherein said angle between said mechanical attachment structure and said straight rod is in the range from approximately 115° to approximately 125°. 
     
     
         39 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 37 , wherein ball joint means is disposed between said mechanical attachment structure and said straight rod to allow reorientation of said mechanical attachment structure with respect to said straight rod. 
     
     
         40 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 34 , wherein said wire-like member is at least partially bendable during implantation of said implantable hearing aid device. 
     
     
         41 . An electromechanical actuator for an implantable hearing aid device as claimed in  claim 34 , wherein said mechanical attachment structure includes further ball joint means to engage with a stapes prosthesis provided with a ball-shaped head.