Patent ID: 7116794

Claim:
A hearing aid anchoring fixture for anchoring a direct bone conduction hearing aid to a skull bone, comprising: a threaded portion having a cutting edge, the cutting edge having a cavity defined therein, the cavity being adjacent to the cutting edge and having a volume V c ; the threaded portion having a maximum outer diameter d 1 and an inner diameter d 2 ; a thread having a thread depth d t being half of a difference between the maximum outer diameter d 1 of the threaded portion and the inner diameter d 2 of the thread, where d t is between 10% and 20% of the maximum outer diameter of the threaded portion, the threaded portion having a surface layer, the surface layer having a thickness greater than 100 nanometers; and a flange disposed at one end portion of the hearing aid anchoring fixture, the flange having a surface facing the threaded portion, the surface having a groove defined therein, the hearing aid fixture having a thread pitch t p , in an interval 0.5 mm≦t p ≦0.8 mm.