For those who have never heard the sound
of another human being's voice, a cochlear implant can be a miracle.
Cochlear implants provide the sense of sound to those who are deaf due
to damage of the cochlea, a spiral-shaped bone in the inner ear
that contains the receptor organ for hearing.
It really is a lifetime device.
It's not like some implants where they're in for five years
or ten years or you really only put them when you get
to your 60's or your 70's.
People use these at very young ages.
Angelique Johnson is the CEO of MEMStim ,
a medical device start-up
that is innovating how cochlear implants are manufactured.
A cochlear implant consists of two parts -
the visible external microphone made up of a sound processor
and transmitter and the internal receiver and electrode array
which connects directly to the patient's nervous system.
The electrode array consists of bundles of metal wires that make
up the electrical circuit of the device.
In order to implant the arrays, surgeons must directly insert them
into the patients' spiral-shaped cochlea.
For the brain to recognize and translate a sound,
hair fibers within the cochlea must produce electrical currents
which stimulate the auditory nerve.
What you can do with a cochlear implant is you replace the electrical
information from the hair cells with electrical circuitry.
So you have electrodes that now stimulate, right,
pathways that lead to the auditory nerve.
But despite some advances,
the microscopic circuitry
in the electrode arrays is still manufactured by hand,
a complex and time-consuming process that makes the devices expensive
and inaccessible for many patients.
The cochlear electrode array itself,
there's a limitation in the manufacturing processes that can allow us
to innovate that and that's really what we're trying to address.
Johnson believed that if she could improve the manufacturing process,
then she could lower the cost of production,
allowing more people in need of implants the ability to afford them.
While working on her PhD at the University of Michigan,
Johnson created MEMStim to commercialize her idea
to improve cochlear implant manufacturing
and received funding the National Science Foundation
to foster her business plan and obtain customer feedback.
Johnson's initial idea was to add additional electrodes,
vision sensors and other performance enhancements to the array,
but ended up going down a different path after receiving feedback.
If you can't make the technology safe for human use, right,
and durable enough for surgical use,
then none of those performance enhancements will ever make it
to the patient and so what we did is we took a step back
and focused more on the manufacturing process.
She realized she had to automate the micro-fabrication
of the tiny electrode arrays,
so she turned to a machine-driven process
that would eliminate the need for costly hand-made manufacturing.
Johnson now operates MEMStimat the University of Louisville
where she demonstrates her micro-fabrication process.
In a controlled manufacturing environment called a cleanroom,
he begins with basic siliconwafers,
which will be used to form the electrode arrays
that will stimulate the auditory nerve.
Im going to take this silicone, which is medical grade silicone
and Im going to spin it onto this silicon wafer.
We just use it like a saucer so we can build our devices on it
and just take it from tool to tool.
Using machines to add or etch away layers of silicone ,
Johnson can create different designs and features
on the electrode arrays, a process that has never been done before
to produce these types of devices.
This is one wafer that has, you can see the little dots
on it are the electrodes and these are the bond paths back here
so this is one type of design.
The prototypes of the arrays are then sent to a practicing surgeon
at Ohio State University to test the devices in human cadavers,
a necessary first step before use in living people.
MEMStim is one of the first companies
to manufacture a cochlear implant electrode array
to this extent using micro-fabrication.
In 2012 and 2015, Johnson was granted patents from the U.S. Patent
and Trademark Office for her electrode arrays
and automated micro-fabrication process.
Johnson's next step is to secure approval from the U.S. Food
and Drug Administration so that one day
in the not too distant future doctors will be able
to implant her technology in humans.
Being able to do things to really improve the technology is really
kind of a motivator, you know,
for me to just improve the quality of life for patients.
Her company's goal is to sell these electrode arrays directly
to cochlear implant manufacturers, but Johnson's personal mission is
to help give people the sense of sound and a better quality of life,
the innovation process at its best.