Implantable middle ear transducer having improved frequency response
Apparatus, systems, and methods having or using an improved implantable middle ear transducer for driving an ossicular chain bone to assist in aiding hearing. One embodiment of the present invention is a transducer assembly for converting electrical signals to mechanical vibrations which can be coupled, for example, to the stapes to provide audible frequency vibrations to the cochlea. One transducer assembly includes a pair of fins or gussets coupled to opposite sides of a transducer in the direction of unwanted movement of the transducer. The base of the transducer may be coupled to a base member while the fins have free edges that are near to but not coupled to the base member. Some fins are triangular shaped. The fins may not substantially inhibit vibration in the preferred plane, but can inhibit unwanted vibrations in a plane orthogonal to the preferred direction which can substantially include a plane containing the fins.
1. An implantable transducer assembly for implanting into a middle ear region, the transducer assembly comprising:
an elongate transducer configured to receive an electrical signal and produce a vibration in response to the electrical signal, in which the vibration occurs predominantly in a first plane which includes the transducer longitudinal axis;
the transducer having a length, a free vibrating end, and a fixed region opposite the free end for operable coupling to a bone; and
a pair of fins operably coupled to opposite sides of the transducer, the fins having a thickness dimension,
in which the fins lie in a second plane which is normal to the first plane and in which the second plane includes the transducer longitudinal axis; a base member, in which the transducer fixed region is coupled to the base member, and in which the fins each have a free edge disposed near to but uncoupled to the base member; wherein the transducer is configured to vibrate in the first plane to move the fins in a direction orthogonal to the fin thickness dimension; and
wherein the fins are longitudinally triangular shaped with fin longitudinal axis being parallel to the transducer longitudinal axis.
2. The transducer assembly as in claim 1 , further comprising a protective layer covering the transducer, in which the fins are not directly coupled to the transducer, in which the fins are secured to the protective layer, such that the operable coupling is made through the protective layer.
3. The transducer assembly as in claim 2 , in which the protective layer includes a metallic sheet.
4. The transducer assembly as in claim 3 , in which the metallic sheet is formed of titanium less than 3 mils thick.
5. The transducer assembly as in claim 1 , further comprising a base member, in which the transducer fixed region is coupled to the base member, and in which the fins are not directly coupled to the base member, such that the vibrating in the first plane moves the fins in a direction orthogonal to the fin thickness dimension.
6. The transducer assembly as in claim 1 , in which the fins have a triangular shape but with convex outer edges.
7. The transducer assembly as in claim 1 , in which the fins have a triangular shape but with concave outer edges.
8. The transducer assembly as in claim 1 , in which the fins have rounded outer edges.
9. The transducer assembly as in claim 1 , in which the fins have a length at least 20 percent of the length of the transducer.
10. The transducer assembly as in claim 1 , in which the fins have a length less than 80 percent of the length of the transducer.
11. The transducer assembly as in claim 1 , in which the fins have a length of less than ½ inch.
12. The transducer assembly as in claim 1 , in which the transducer is less than 1 inch long.
13. The transducer assembly as in claim 1 , further comprising a biocompatible bone mount assembly coupled to the transducer fixed region for securing to a bone.
14. The transducer assembly as in claim 1 , in which the transducer is hermitically sealed.
15. A system for treating hearing loss, the system comprising: an implantable transducer assembly for implanting into a middle ear region,
the transducer assembly including: an elongate transducer configured to receive an electrical signal and produce a vibration in response to the electrical signal, in which the vibration occurs predominantly in a first plane which includes the transducer longitudinal axis;
the transducer having a length, a free vibrating end, and a fixed region opposite the free end for operable coupling to a bone; and
a pair of fins operably coupled to the transducer, the fins having a thickness dimension, and in which the fins lie predominantly in a second plane which is normal to the first plane and in which the second plane includes the transducer longitudinal axis; and
an implantable electronic device electrically coupled to the transducer assembly for outputting the electrical signal; a base member, in which the transducer fixed region is coupled to the base member, and in which the fins each have a free edge disposed near to but uncoupled to the base member; wherein the transducer is configured to vibrate in the first plane to move the fins in a direction orthogonal to the fin thickness dimension; and
wherein the fins are longitudinally triangular shaped with fin longitudinal axis being parallel to the transducer longitudinal axis.