An All-solid Rechargeable Battery for a Fully Internal Cochlear Implant

Sensorineural hearing lossSNHLaffectsmillion people in the United Statesand overmillion people worldwideleading to a significantly lowered quality of life and a large economic burdenFor those with severe to profound SNHLa cochlear implant is currently the only available route for restoring `adequateandaposfunctionalityOnlyimplants had been done worldwide tilland aboutdevices are being sold annuallyThis large discrepancy between those that can benefit and those that actually get the implant is driven partly by their costavailability and the lack of trained surgeons and facilitiesHoweverthere are critical limitations in the current devices which contribute significantly to very low adoptionaThe external microphone does not localize sound from the auricle and ear canalintroducing unnatural cuesbThe cumbersomehighly visible unit attached to the skull outside the mastoid boneconnected by a cable to the sound processor and rechargeable battery placed behind the earsmakes the disability very obviousand creates an unacceptable social stigma for many patientscausing them to refuse this optioncThe device must be taken off during showering or swimmingalthough a few water resistant versions are now availableand during sleepingincreasing the likelihood of damagemisplacementor the ability to communicate in these situationsdHaving an external magnet can lead to skin breakdown and implant extrusioneThe large footprint and placement leaves open the risk for device migration requiring revision surgeryA fully internal cochlear implantFICIwould address this large unmet medical needThe lack of a self contained power supply is a key roadblock preventing realization of all FICIsBased upon our extensive experience with fabricating lithium ion batteryLIBelectrodesand our synthesis of several novel solid polymer electrolytes specifically targeted for LIBswe hypothesize that an all solid LIB with a LiFePOcathodea Li Ti Oanode and a lithium salt dopedpolyethylene oxide solid electrolytewill meet all of the electrochemicalsafety and footprint requirements for this applicationAt AudianceIncwe have the engineeringelectrochemical and medical expertizeas well as the facilities to fabricate this batterycharacterize its performance and iterate on processing strategies and component loadings until it meets or exceeds all of the metrics required for a FICIThe all solid LIB will remove one of the most critical roadblocks for the development of a FICIand thus open up an option for many patients around the world with severe to profound SNHLThe battery design strategy could also be used for other implants that have similar stringent performance metrics Narrative Severe to profound sensorineural hearing loss affects millions of people worldwideleading to a significantly lowered quality of life and a large economic burdenWhile current cochlear implants are a very successful prosthetic for this populationit has limitationsand a fully internal cochlear implantFICIthat provides the most natural aural cues and complete invisibility is an important optionIn this workwe will develop a battery that meets the performance criteriathe footprint and the durability required for this implantthus removing one of the most critical roadblocks in the path towards a FICI