Piezoelectric film transducer

• US 20040181117A1
• Filed: 04/13/2001
• Published: 09/16/2004
• Est. Priority Date: 08/07/1996
• Status: Abandoned Application

• Current Assignee: St Croix Medical Incorporated
• Original Assignee: St Croix Medical Incorporated
• Inventors: Bushek, Donald J., Brillhart, Bruce A., Kroll, Kai, Adams, Theodore P.
• Application Number:
  US09/834,332
• Publication Number:
  US 20040181117A1
• Time in Patent Office: Days
• US Class Current: 600/25
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: H04R 1/46 Special adaptations for use as contact microphones, e.g. on musical instrument, on stethoscope throat mountings H04R1/14
• CPC Class Codes: H04R 17/025 using a piezoelectric polymer
• 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

A method and apparatus transduces between mechanical and electrical signals within a middle ear to improve hearing. An electromechanical transducer film, preferably polyvinylidene fluoride (PVDF), is carried by a mount secured to the middle ear. The film is constrained by the mount, or by the mount and an auditory element. The invention includes substantially straight, bow-shaped, hoop-shaped, and bi-element transducer film embodiments. The film transduces between mechanical vibrations of an auditory element, such as the malleus or stapes, and electrical signals for use with an electronics unit of a partial middle ear implantable (P-MEI) or total middle ear implantable (T-MEI) hearing aid.

Claims

1. An at least partially implantable hearing assistance system, comprising:

a vibrator including a mount, adapted to be secured to a middle ear and a piezoelectric transducer film, carried by the mount, proportioned to be mechanically coupled to the middle ear and to vibrate the auditory element in response to an electrical input signal;

an electronics unit, electrically coupled for providing the electrical input signal to the vibrator; and

a programmer, adapted for communicative coupling to the electronics unit.

2. The system of claim 1, in which the film is secured at a plurality of constraint points.

3. The system of claim 2, in which the film is secured to transform longitudinal variations in a physical dimension of the film into vibrations of the auditory element.

4. The system of claim 2, in which the film has a hoop shape.

5. The system of claim 2, in which the film has a substantially straight length.

6. The system of claim 2, in which the film has a bow shape.

7. The system of claim 2, further comprising first and second arms, each extending radially outward from the mount and mechanically coupled to the film.

8. The system of claim 2, in which the film comprises polyvinylidene fluoride.

9. The system of claim 2, in which the piezoelectric transducer film is mechanically coupled to the mount at first and second constraint points, and having between the first and second constraint points at least one driving point on the film coupled to an auditory element at the driving point such that a variation in a film length between the first and second constraint points is transformed into an approximately orthogonal variation in position of the driving point for vibrating the auditory element.

10. The system of claim 2, in which the film is a bi-element transducer film.

11. An at least partially implantable hearing assistance system, comprising:

an electromechanical sensor, including a mount adapted to be secured to a middle ear, and a piezoelectric transducer film carried by the mount, in which the film is proportioned for mechanically coupling to an auditory element in the middle ear, and the film is adapted for receiving vibrations from the auditory element and producing a resulting output voltage in response to the vibrations;

an electronics unit, electrically coupled for providing the electrical input signal to the vibrator; and

a programmer, adapted for communicative coupling to the electronics unit.

12. The system of claim 11, in which the resulting output voltage is produced across a thickness of the film and provided to an electronics unit.

13. The system of claim 11, in which the film is secured at a plurality of constraint points.

14. The system of claim 11, in which the film is secured to transform vibrations of the auditory element into longitudinal dimensional variations of the film.

15. The system of claim 11, in which the film has a hoop shape.

16. The sensor of claim 11, in which the film has a substantially straight length.

17. The sensor of claim 11, in which the film has a bow shape.

18. The sensor of claim 11, further comprising first and second arms, each extending radially outward from the mount and mechanically coupled to the film.

19. The sensor of claim 11, in which the film comprises polyvinylidene fluoride.

20. The sensor of claim 11, in which the film is coupled at a vibrated point to an auditory element within the middle ear, and mechanically coupled to the mount at first and second constraint points such that vibrations received from the auditory element at the vibrated point produce a variation in a longitudinal direction of the film which in turn produces a resulting output voltage.

21. The sensor of claim 20, in which the resulting output voltage is produced across a thickness of the film and provided to an electronics unit.

22. The sensor of claim 11, in which the film is a bi-element transducer film.