ENERGY HARVESTING COCHLEAR IMPLANT

• US 20140303688A1
• Filed: 12/02/2011
• Published: 10/09/2014
• Est. Priority Date: 11/02/2011
• Status: Active Grant

• Current Assignee: Haluk Kulah, Levent Beker, Nebil Goksu
• Original Assignee: Haluk Kulah, Levent Beker, Nebil Goksu
• Inventors: Kulah, Haluk, Goksu, Nebil, Beker, Levent
• Granted Patent: US 9,630,007 B2
• Time in Patent Office: Days
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/3785 generated by biological activity or substance, e.g. body movement
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• 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
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

The invention is related to a totally implantable cochlear implant having a transducer which is a piezoelectric vibration energy harvester to be mounted on the ossicular chain or the tympanic membrane to detect the frequency of oscillations and generate the required voltage to stimulate the relevant auditory nerves. The invention enables patients'"'"' continuous access to sound, since it eliminates the outside components of conventional cochlear implants. The invention also eliminates the problem of battery need, since the transducer generates voltage required to stimulate auditory nerves from the vibrations of ossicular chain. The transducer is fabricated using Microelectromechanical Systems (MEMS) fabrication techniques. The invention incorporates of two main parts, a transducer acting both as a frequency detector and an energy harvester, and electrodes to stimulate the auditory nerve inside the cochlea.

Claims

1. A method for converting acoustic waves to voltage outputs which is used to stimulate auditory nerves in a cochlear implant,

wherein the cochlear implant comprises a transducer and a cochlear electrode connecting the transducer to the auditory nerve wherein the transducer comprising:

at least one base attached onto a vibrating element of a auditory system that vibrates under the influence of the incoming acoustic waves,

an army of cantilever beams each with one free end and one fixed end attached to the base, and each having a predetermined natural frequency,

a piezoelectric piece bonded to each of the cantilever beams and

at least one harvester electrode associated with every cantilever beam to harvest voltages produced by the piezoelectric pieces and connected to the cochlear electrode to transmit and the voltage to the cochlear electrode;

the method for converting acoustic waves to voltage outputs comprising the steps of

exposing the cantilever beams to vibrations produced on the vibrating element of the auditory system under the influence of the incoming acoustic waves and

generating the voltage outputs due to piezoelectricity, at the piezoelectric pieces associated with every vibrating cantilever beam,

wherein each of the piezoelectric pieces are bonded on the surface of the cantilever beam and near the fixed end so that the piezoelectric pieces experience the maximum possible stresses,

wherein the voltage outputs, generated by the piezoelectric pieces associated with each cantilever beam vibrating near its natural frequency, are higher than a threshold voltage value which is the threshold voltage value required to stimulate the auditory nerve,

and in that the predetermined natural frequencies of the cantilever beams correspond to the frequencies that a patient is unable to perceive.

2. The method of claim 1 wherein at least one of the cantilever beams incorporates a tip mass for the predetermination of the natural frequency.

3. The method of claim 1 wherein the transducer comprises multiple bases having the cantilever beams of different natural frequencies, bonded on top of each other forming layers.

4. The method of claim 1 wherein the number of the cantilever beams ranges from Ito 30.

5. The method of claim 1 wherein the transducer further comprises a biocompatible coating.

6. The method of claim 1 wherein each voltage output corresponds to a particular frequency band of the incoming acoustic waves.