Coupling device for a two-part bone-anchored hearing aid apparatus
A coupling device for attaching the external hearing aid part to the skull bone anchored part in a bone conducting hearing aid apparatus. The retaining force in the coupling device is substantially established with a permanent magnet. The bone anchored part and the external hearing aid part include a magnetic part.
1. A coupling device for attaching an external bone conducting hearing aid to a patient, the coupling device comprising:
an anchoring element operative to be anchored in a skull bone of the patient;
a skin penetrating member;
a first magnetic member operatively connected to the skin penetrating member and comprising a magnetic contact surface; and
a second magnetic member operatively connected to the external bone conducting hearing aid and comprising a magnetic contact surface operative to attach to the magnetic contact surface of the first magnetic member and thereby attach the external bone conducting hearing aid to the skin penetrating member.
2. The coupling device according to claim 1 , wherein the anchoring element comprises a screw.
3. The coupling device according to claim 1 , wherein at least one of the first magnetic member and the second magnetic member is a permanent magnet.
4. The coupling device according to claim 1 , wherein one of the first magnetic part and the second magnetic part is a permanent magnet and another of the first magnetic part and the second magnetic part comprises a ferro-magnetic material.
5. The coupling device according to claim 1 , wherein the first magnetic part comprises an annular magnetic part.
6. The coupling device according to claim 1 , wherein the skin penetrating member and connecting screw comprise a single piece.
7. The coupling device according to claim 6 , wherein the first magnetic part is integral with the skin penetrating member and connecting screw.
8. The coupling device according to claim 3 , wherein the permanent magnet is a sintered magnet.
9. The coupling device according to claim 3 , wherein the permanent magnet comprises a non-corrosive surface layer material.
10. The coupling device according to claim 4 , wherein the permanent magnet is a sintered magnet.
11. The coupling device according to claim 4 , wherein the permanent magnet and the ferro-magnetic material both comprise a non-corrosive surface layer material.
12. The coupling device according to claim 1 , wherein the first magnetic part is arranged in the skin penetrating member in such a way that at least a part of the skin penetrating member projects outwards from the magnetic contact surface.
13. The coupling device according to claim 1 , wherein a diameter of the skin penetrating member adjacent to the skull bone is smaller than a diameter of a portion of the skin penetrating member in the vicinity of the external bone conducting hearing aid.
14. The coupling device according to claim 1 , wherein one of the skin penetrating member and the external bone conducting hearing aid comprises a flange operative to prevent the external bone conducting hearing aid from sliding off the skin penetrating member.
15. The coupling device according to claim 1 , wherein the anchoring element comprises a flange operative to limit penetration of the anchoring element in the skull bone.
16. The coupling device according to claim 1 , further comprising:
a connecting screw operatively connecting the skin penetrating member to the anchoring element.
17. The coupling device according to claim 16 , wherein the first magnetic part is integral with the connecting screw.