Implantable sound sensor for hearing prostheses

Abstract

A sound sensor implantable in a recipient of a hearing device. The sound sensor comprises a biocompatible housing comprising a cavity having an opening at a first end of the housing and a membrane attached to the housing so as to hermetically seal the opening, wherein the membrane vibrates in response to vibration of at least one of a structure of the recipient's ear and fluid within one of the recipient's body cavities. The sound sensor also comprises a vibrational sensor disposed in the housing configured to detect vibrations of the membrane, and configured to generate signals representative of the detected vibrations; and a transmitter configured to provide the generated signals to one or more other components implanted in the recipient.

What is claimed is: 
     
         1 . A sound sensor, comprising:
 a housing including a cavity having an opening at a first end of the housing;   a membrane attached to the housing so as to hermetically seal the opening, the membrane being configured to vibrate in response to vibration within the recipient;   an internal sensor, disposed in the housing, the sensor being configured to detect a physical phenomenon resulting from movement of the membrane, wherein   the sound sensor is implantable,   the sound sensor is configured to output signals representative of the detected physical phenomenon, and   the sound sensor is a tube microphone.   
     
     
         2 . The sound sensor of  claim 1 , wherein:
 the internal sensor is spaced away from the membrane.   
     
     
         3 . The sound sensor of  claim 1 , wherein:
 the surface of the membrane exposed to the internal environment of the housing located inboard from the housing is free from contact with any structure of the sound sensor.   
     
     
         4 . The sound sensor of  claim 1 , wherein:
 the physical phenomenon is a change in an environment within the housing resulting from vibrations of the membrane at sound frequencies.   
     
     
         5 . The sound sensor of  claim 1 , further comprising:
 a transmitter disposed inside the housing and configured to provide signals generated by the internal sensor to a component outside the housing.   
     
     
         6 . The sound sensor of  claim 1 , wherein:
 the cavity contains a fluid medium;   the fluid medium transfers vibrations from the membrane to the internal sensor; and   the physical phenomenon is vibrations of the membrane.   
     
     
         7 . The sound sensor of  claim 1 , wherein:
 the internal sensor is a microphone; and   a defined gas layer is positioned between a sensing element of the microphone and the membrane.   
     
     
         8 . The sound sensor of  claim 1 , wherein:
 the membrane is only in contact with walls of the housing.   
     
     
         9 . A method, comprising:
 capturing vibrations located in a middle or inner ear cavity of a recipient with an implanted sensor implanted in the recipient; and   transducing the vibrations into an electrical output signal, wherein   the captured vibrations generate motion of a membrane of the implanted sensor, and   the vibrations that are captured are vibrations that are conducted through fluid in the body to the membrane, the fluid being in direct contact with the membrane.   
     
     
         10 . The method of  claim 9 , wherein:
 the portion of the membrane that is exposed to the environment within the body in contact with only the fluid through which the vibrations travel.   
     
     
         11 . The method of  claim 9 , wherein:
 the implanted sensor is located in an artificial canal in a skull of the recipient.   
     
     
         12 . The method of  claim 9 , wherein:
 the implanted sensor is located in a cochlea of the recipient.   
     
     
         13 . The method of  claim 9 , further comprising:
 transferring vibrations from the membrane to a transducer inside the implanted sensor via conduction of the transferred vibrations through fluid in the implanted sensor.   
     
     
         14 . The method of  claim 9 , wherein:
 the only structure of the implanted sensor that is in contact with the membrane is the housing and/or a component that attaches the membrane to the housing.   
     
     
         15 . A sound sensor implantable in a recipient of a hearing device, the sound sensor comprising:
 a biocompatible housing comprising a cavity having an opening at a first end of the housing;   a membrane attached to the housing so as to hermetically seal the opening, the membrane being configured to vibrate in response to vibration within the recipient;   a vibrational sensor, disposed in the housing, the vibrational sensor being configured to:
 detect vibrations of the membrane; and 
 generate signals representative of the detected vibrations; and 
   a transmitter disposed inside the biocompatible housing and configured to provide the generated signals to one or more other components implanted in the recipient.   
     
     
         16 . The sound sensor of  claim 15 , wherein:
 the sound sensor is configured to couple the housing to a stationary bony structure of the recipient.   
     
     
         17 . The sound sensor of  claim 15 , wherein:
 the sound sensor is a tube microphone.   
     
     
         18 . The sound sensor of  claim 15 , wherein:
 the aspect ratio of the sensor is less than or equal to approximately 0.4.   
     
     
         19 . The sound sensor of  claim 15 , wherein:
 the membrane is circular and has a diameter that is less than or equal to approximately 9 mm.   
     
     
         20 . The sound sensor of  claim 15 , further comprising:
 a suspension of fluid within the housing, wherein the vibrational sensor is coupled to the housing via the fluid suspension.   
     
     
         21 . An implantable hearing prosthesis, comprising:
 the sound sensor of  claim 15 ;   an implantable sound processor; and   an implantable stimulator unit configured to generate stimulation signals for delivery to the recipient, wherein   the one or more other components implanted in the recipient is at least one of the implantable sound processor or the implantable stimulator unit.   
     
     
         22 . The sound sensor of  claim 15 , wherein:
 the implantable sound sensor is configured such that the housing is stationary when the membrane vibrates.   
     
     
         23 . The sound sensor of  claim 15 , wherein:
 the sound sensor is configured such that the membrane is completely free to move in both directions along a longitudinal axis of the sound sensor with resistance corresponding to an amount at least about equal to that which results from tension of the membrane and pressure inside the sound sensor.   
     
     
         24 . A method, comprising:
 drilling a canal having an opening in a middle ear cavity of a recipient;   inserting an implantable transducer into the canal; and   securing the implantable transducer in the canal.   
     
     
         25 . The method of  claim 24 , wherein:
 the action of drilling the canal includes drilling from the outside of the recipient's head to a middle ear cavity of the recipient.   
     
     
         26 . The method of  claim 24 , wherein:
 the action of inserting the implantable transducer into the canal includes inserting a sound sensor having an aspect ratio of less than or equal to 0.75.   
     
     
         27 . The method of  claim 24 , further comprising:
 implanting into the recipient a device configured to stimulate tissue of the recipient, wherein   the implantable transducer is a sound sensor.   
     
     
         28 . The method of  claim 27 , wherein:
 at least subsequent to the action of implanting the device configured to stimulate tissue, the device configured to stimulate tissue is in signal communication directly or indirectly with the sound sensor.   
     
     
         29 . The method of  claim 24 , further comprising:
 Executing a myringotomy to create a passage through a tympanic membrane.   
     
     
         30 . The method of  claim 24 , wherein:
 the implantable transducer is a sound sensor including a membrane configured to vibrate when exposed to sound; and   no tissue of the recipient is connected to the membrane.   
     
     
         31 . The method of  claim 24 , wherein:
 the implantable transducer is a sound sensor including a membrane configured to vibrate when exposed to sound; and   tissue of the recipient is connected to the membrane.