Hearing implant

• US 20090043149A1
• Filed: 01/13/2006
• Published: 02/12/2009
• Est. Priority Date: 01/13/2005
• Status: Active Grant

• Current Assignee: MED-EL Elektromedizinische Gerate GmbH (MED-EL Corporation)
• Original Assignee: Sentient Medical Ltd.
• Inventors: Abel, Eric William
• Granted Patent: US 8,864,645 B2
• Time in Patent Office: Days
• US Class Current: 600/25
• CPC Class Codes: A61F 2002/183 Ear parts
• CPC Class Codes: H04R 17/02 Microphones
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window

Abstract

The present invention concerns an actuator for an implantable hearing aid for implantation into the human middle ear. The actuator comprises a substantially elongate piezoelectric component (34, 36) having first and second operating end faces (41, 43), said end faces extending substantially at right angles to the longitudinal axis of the piezoelectric component. Also there is provided a frame component comprising at least one flextensional amplifier element (32), the flextensional amplifier element being integral with and connecting first and second frame end portions (42, 44), the first and second frame end portions also extending substantially at right angles to longitudinal axis of the piezoelectric component when fitted thereto, whereby the first and second end portions are in contact with the piezoelectric component end faces.

Claims

1. An actuator for a hearing aid for implantation into the human middle ear, the actuator comprising:

a substantially elongate piezoelectric component having first and second operating end faces, said end faces extending substantially at right angles to the longitudinal axis of the piezoelectric component; and

a frame component comprising at least one flextensional amplifier element, the flextensional amplifier element being integral with and connecting first and second frame end portions, the first and second frame end portions also extending substantially at right angles to the longitudinal axis of the piezoelectric component when fitted thereto, whereby the first and second end portions are in contact with the piezoelectric component first and second operating end faces.

2. An actuator according to claim 1, wherein said piezoelectric component operates in d33 expanding mode.

3. An actuator according to claim 1, wherein said piezoelectric component operates in d31 contracting mode.

4. An actuator according to any one of claims 1 to 3, wherein said frame component comprises a duality of flextensional amplifier elements each integral with said first and said second end portions of said frame component.

5. An actuator according to any one of claims 1 to 4, wherein said one or more flextensional amplifier elements have a substantially arcuate form with curvature directed towards said piezoelectric component.

6. An actuator according to any one of claims 1 to 4, wherein said one or more flextensional amplifier elements have a substantially arcuate form with curvature directed away from said piezoelectric component.

7. An actuator according to any one of claims 1 to 6, wherein said piezoelectric component comprises one or more stacks of piezoelectric elements.

8. An actuator according to claims 1 to 7, wherein a base support having support and mounting means for attachment means for attaching and securing said actuator to said bones of said ossicular chain is provided fixedly mounted upon one or more of said at least one flextensional amplifier elements of said frame component.

9. An actuator according to claims 1 to 8, wherein said piezoelectric component comprises an array of stacks of said piezoelectric elements and said stacks are disposed apart from one from another by the provision of a base support, having support and mounting means for attachment means for attaching and securing said actuator to said bones of said ossicular chain.

10. An actuator according to claim 9, wherein a duality of said base supports is provided, fixedly mounted respectively upon each of a duality of said flextensional amplifiers of said frame component.

11. An actuator according to claims 1 to 10, wherein said integral first and second end portions of said frame component have substantially the same thickness as the wall thicknesses of said flextensional amplifiers.

12. The actuator according to claims 1 to 10, wherein said integral first and second end portions of said frame component have substantially greater thickness than the wall thicknesses of said flextensional amplifiers.

13. An actuator according to claims 1 to 12, wherein said integral first and second end portions of said frame component each is provided with a recess so sized and shaped as to constitute receival and securing means for said first and second operating ends of said piezoelectric components;

14. An actuator according to claims 1 to 12, wherein said integral first and second end portions of said frame component is each provided with fold down tabs, whereby the folding down of said fold down tabs constitutes means for creating receival and securing means for said first and second operating ends of said piezoelectric components.

15. An actuator according to claims 1 to 14, wherein said integral first and second end portions of said frame component each are secured to said first and second operating ends of said piezoelectric components by securing means in the form of suitable adhesive means.

16. An actuator according to claims 1 to 15, wherein said actuator is powered by a suitable photodetector device.

17. An actuator according to claims 1 to 15, wherein said actuator is powered by a suitable telemetry device.

18. An actuator according to claims 1 to 15, wherein said actuator is powered by a suitable battery.

19. An actuator according to claims 1 to 15, wherein said actuator is powered by a suitable induction coil.

20. An actuator according to claims 1 to 15, wherein said actuator is powered by a storage device such as a capacitor.

21. An actuator according to claims 1 to 20, wherein said actuator is coupled by attachment coupling means to at least one of said bones of said ossicular chain.

22. An actuator according to claim 21, wherein said attachment coupling means are in the form of crimpable clips;

23. An actuator according to claim 21, wherein said attachment coupling means are in the form of spring clips.

24. An actuator according to any one of claims 21 to 23, wherein said attachment coupling means are disposed about the incudostapedial joint.

25. An actuator according to claims 21 to 24, wherein said attachment coupling means are made from titanium or titanium alloy.

26. An actuator according to claims 21 to 24, wherein said attachment coupling means are made from a shape memory alloy making use of the shape memory property.

27. An actuator according to claims 21 to 24, wherein said actuator is coupled by attachment coupling means made from a shape memory alloy making use of the superelastic property.

28. An actuator according to claims 1 to 27, wherein said actuator is provided with housing means to isolate one or more of its components from the local environment.

29. An actuator according to claim 28, wherein said housing means is in the form of an enclosure or membrane.

30. An actuator according to claim 28 or 29, wherein said housing means is made of plastics.

31. An actuator according to claims 1 to 27, wherein said actuator is provided with coating means to isolate one or more of its components from the local environment.

32. An actuator according to claims 1 to 27, wherein said actuator is provided with covering means to isolate one or more of its components from the local environment.

33. An actuator according to claims 1 to 32, wherein in use, the stapes is movable relative to the incus by the operation of said actuator making use of the flexibility of the incudostapedial joint.

37. A method for surgically implanting an actuator according to any of claims 1 to 34, the method comprising inserting the actuator into the middle ear via the ear canal and incised and folded back eardrum.

34. An actuator for a hearing aid for implantation into the human middle ear for amplifying sound vibration comprising:

a piezoelectric component comprising a piezoelectric element or stack of said elements or an array of said stacks of said elements, the or each piezoelectric component having first and second operating ends; and

a frame component comprising at least one flextensional amplifier element, said frame component further having first and second end portions integral with and disposed substantially at right angles to the main axis of said flextensional amplifier element or amplifier elements, such that said first and second end portions of said frame component provide close receival and fitting means for said first and second operating ends of said piezoelectric component, said flextensional amplifier element or amplifier elements operating with displacement substantially orthogonal with respect to the operating direction of said piezoelectric component; and

the assembly created thereby constituting an actuator surgically implantable into the middle ear through the ear canal and via the incised and folded back tympanum;

whereby

said actuator may be secured with securing means to one or more bones of the human ossicular chain without the removal or destruction of any part of any said bone.

36. A method according to claim 34, wherein the assembled actuator is surgically implantable into the middle ear through the ear canal and via the incised and folded back tympanum.

35. A method of forming an actuator for a hearing aid for implantation into the human middle ear, the method comprising the steps:

providing a substantially elongate piezoelectric component having first and second operating end faces, said end faces extending substantially at right angles to the longitudinal axis of the piezoelectric component;

providing a frame component comprising at least one flextensional amplifier element, the flextensional amplifier element being integral with and connecting first and second frame end portions, the first and second frame end portions also extending substantially at right angles to longitudinal axis of the piezoelectric component when fitted thereto, whereby the first and second end portions are in contact with the piezoelectric component first and second operating end faces; and

assembling the piezoelectric component and the frame component.